Improving the evaluation of software development methodology adoption and its impact on enterprise performance Abstract. Although the literature studying software development methodologies (SDMs) lists several significant positive effects of the deployment of SDMs, investments into SDMs by the enterprises remain relatively limited. Strategic investments decisions, such as SDMs investments, are mostly taken with the goal of improving enterprise performance. In this paper a model for evaluation of the adoption of SDMs that focuses on the abovementioned SDMs impact on enterprise performance is proposed. The model was empirically tested in four case studies in software development small and medium enterprises (SMEs) in Slovenia. The case studies confirmed that the use of the proposed model enabled SMEs to improve SDMs related investment and adoption decisions and enabled SMEs to invest their limited resources in the most productive and competitive way. The case study experience with the proposed model suggests that its use would also bring similar benefits to larger software development enterprises. A SDM can be defined as a collection of procedures, techniques, tools, and documentation aids which will help the system developers in their efforts to implement a new information system [4] . In the past decades various formal SDMs emerged that were based on different underlying philosophies and were developed in both academic and commercial environments. The main motive for their creation was to provide efficient software development procedures that would produce better software for computer supported information systems at an acceptable cost. However, many enterprises dealing with software development do not use formal SDMs and rely mainly on ad hoc development procedures. Fitzgerald [21] , for instance reports that 60 per cent of enterprises do not use any SDM and that only 14 per cent use a formalised commercial SDM. Different reasons for this situation have been identified [33, 44, 59] and considerable efforts have been invested into improvement of SDM adoption in software development enterprises [20, 51, 52] . Most of these efforts considered SDM adoption as an IT decision that technicians should decide upon and often neglected the role of business management. Moreover, the assumption that SDM adoption is an IT decision is frequently encouraged by the rest of the enterprise [4] . However, application of SDM typically involves a considerable investment in time, effort and money. Therefore, it is argued that business managers in general should participate more actively in such decisions [4] . To increase business manager's involvement in SDM investments it is important to better understand the impact of SDM on enterprise performance. However, knowing only the potential impact of a SDM procedure on enterprise performance does not enable managers to enact proper SDM related improvement actions. They also need to understand the level of adoption of a specific SDM procedure, since only sufficiently adopted SDM procedures deliver actual enterprise performance benefits. Therefore only the combined understanding of adoption of SDM procedures and their impact on enterprise performance can form the appropriate basis for managers' investment decisions concerning SDM in the enterprises. In order to significantly improve the managerial organising vision of what for, how and how much should SDM be used the following research questions need to be posed:. 1. How can the evaluation of SDM procedure adoption and impact on enterprise performance be modelled? (RQ1) 2. Can such model identify SDM procedures with important enterprise performance benefits? (RQ2) 3. Can such model provide nontrivial information about SDM procedures that was previously unknown to managers responsible for SDM management? (RQ3) 4. Can such model improve SDM related investment and adoption decisions?. To answer these questions the paper starts with the review of the relevant literature in section 2. Based on this review a model is proposed that evaluates the adoption of SDM procedures and their influences on enterprise performance in section 3. Next, in section 4, the paper addresses all the methodological issues that had to be resolved before the conceptual model could be empirically tested. Finally, in section 5, the results of the multiple case study are presented and the paper concludes with a discussion about the technological and managerial implications of the results. The research methodology is based on embedded multiple case design with replicability analysis as defined by Yin [60] . Adoption of SDM procedures and their impact on enterprise performance in different software development contexts that are common in SMEs in Slovenia were studied. SDMs were studied on level of their procedures as stated in the literature review. The study had to take into account that adoption of a SDM is a long-term process with impacts which can be observed only over longer time periods. Thus it focused on perceptions of primary characteristics of SDM procedures (adoption levels, economic impact) of key employees that have a good understanding of their SDM. Researchers in the field of IT innovation adoption often use perceived characteristics instead of directly measuring primary characteristics. According to Downs and Mohr [18] the findings of many studies, which have examined the primary characteristics of innovations, have been inconsistent, as primary attributes are intrinsic to an innovation independent of their perception by potential adopters. The behaviour of individuals, however, is predicated by how they perceive these primary attributes. Since different adopters might perceive primary characteristics in different ways, their eventual behaviours might differ. Similar approach was used also in other SDM studies [29, 51] . The proposed model was used in four different cases: a software development enterprise dealing with development of web-based applications (case A), two different software development enterprises that produce their own pre-packaged business solutions software (cases B and C), and an enterprise producing financial software (case D). The basis for the evaluation of SDM procedure adoption (FrqUse and FrqOpp) and their impact on enterprise performance (Goal, Cost and Prod) were questionnaires that were used in each single case. They included the 2 dimensions of SDM adoption and the 3 dimensions of enterprise performance and were filled out partially by technical managers and partially by SDM users of the studied enterprises. The questions about FrqUse (how often is a SDM procedure actually used in a case of a given opportunity) and FrqOpp (how often opportunities for use of SDM procedure arise) were evaluated with 7-point ordinal scales (never=1, very seldom=2, seldom=3, sometimes=4, often=5, very often=6, always=7). The questions about SDM procedure impact on enterprise performance were also close-ended questions, however they used a seven-point Likert scale between 7 (strongly agree that a specific SDM procedures affects a specific dimension of enterprise performance) and 1 (strongly disagree that a specific SDM procedures affects a specific dimension of enterprise performance), where 0 meant neither agreement or disagreement with the statement.. The results are presented on a scatter chart comprising FrqUse as a vertical dimension and FrqOpp as a horizontal dimension. To help direct management efforts in improvement of individual SDM procedures four quadrants were formed in the scatter chart by using the medians of FrqUse and FrqOpp. Medians were used instead of means of scale because of the positive perception bias encountered during case studies which is discussed in detail in section 6. The four quadrants follow the logic suggested by Vavpotic and Bajec [51] : the first quadrant contains inefficient and unadopted SDM procedures, the second quadrant contains inefficient but adopted procedures, the third quadrant contains unadopted but efficient procedures and the fourth quarter contains adopted and efficient procedures. Efficient SDM procedures are those that have a lot of opportunities for use during the software development process (FrqOpp higher than median) while adopted SDM procedures are those that are actually used in the software development process (FrqUse higher than median).. For procedures in the first quadrant managers should investigate whether it makes sense to continue investing in them. An example of such procedure could be a procedure that is less appropriate for the needs of an organisation and has never been popular between SDM users. A possible course of action would be to discard such SDM procedures (e.g. an old procedure for system design based on structured methods in an enterprise that now uses object oriented development environment). For procedures in the second quadrant managers need to focus on creating more opportunities for their use as these procedures are already well used when an opportunity for their use arises. For instance, these can be SDM procedures that had a lot of opportunities for use in the past and are still accepted by SDM users, but are technically less appropriate for development of new systems. A recommended course of action to improve such procedure might be to replace accepted procedures with technically more appropriate procedures that do not require of SDM users to drastically change the way they work (e.g. procedures that use Enterprise generation language [39] might be introduced instead of procedures that employ Java to replace procedures based on an old programming language that developers are familiar with). The third quadrant shows procedures that have a lot of opportunities for use but are not used. An example could be a new procedure that is very suitable for development of new systems but are not yet accepted by SDM users. In such case managers should try to improve acceptance of such SDM procedures by additionally training and educating SDM users (e.g. procedures for test automation might be introduced, but not accepted by testers that are accustomed to manual test procedures therefore the testers should be additionally trained in the field of test automation). The fourth quadrant shows procedures that have a lot of opportunities for use and are well used by SDM users. Such procedures should be monitored so that when they fall from the fourth quadrant management can deploy an appropriate course of action (e.g. procedure for data modelling that is technically efficient and also accepted by SDM users should be monitored to detect technological advances that could make this procedure obsolete).. Although the suggested separation of SDM procedures into the four quadrants enables managers to select a general course of action [51] it does not help them to understand the value of individual SDM procedures for the enterprise which would in our opinion significantly improve managerial SDM related investment and adoption decisions (RQ4). For this reason each SDM procedure is presented by a point in one of the four quadrants of the scatter chart that is additionally described by its average evaluated impact on cost (marked as C), goal (marked as G) and product (marked as P).. Finally, the results of the evaluation and possible courses of action are discussed with the evaluation participants. In this way the evaluation participants are involved not only in the collection of facts, but also in the coconstruction and interpretation of the case narrative [10] .. The four cases are described in the following subsections. The cross-case discussion is included in the last subsection.

O O O O O O O O O O O O B I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


An integrated visualization environment for the virtual observatory: current status and future directions Visual exploration and discovery applications are invaluable tools to provide prompt and intuitive insights into the intrinsic data characteristics of modern astronomy and astrophysics datasets. Due to the massively large and highly complex datasets, various technical challenges are involved to reach e.g. interactivity, integration, navigation and collaboration. This paper describes a number of approaches to address these challenges, and focuses on the current status of VisIVO (Visualization Interface for the Virtual Observatory) concentrating on the provided tools ranging from a desktop application to a science gateway and a mobile application. We emphasize the latest developments made in the context of past and current international European funded projects and highlight planned future developments towards further integration within the framework of the Virtual Observatory. Modern astronomy and astrophysics produce massively large data volumes (in the order of petabytes) coming from observations or simulation codes executed on high performance supercomputers. Such data volumes pose significant challenges for storage, access and data analysis, leading to the development of a fourth data intensive science paradigm (Hey et al., 2009 ) (also known as eScience). A critical aspect in understanding, interpreting, and verifying the outcome of automated analysis and data mining processes is the visualisation of the scientific results. Data visualization is a fundamental, enabling technology for knowledge discovery, and an important research field that covers a number of different topics such as: optical and radio imaging (Nita et al., 2011) , simulation results (Labadens et al., 2012) , multi-dimensional exploration of catalogues (Beaumont et al., 2013) and public outreach visuals (Kent, 2013) .. Visual exploration of big data sets poses some critical challenges that must drive the development of a new generation of graphical software tools, specifically:. Interactivity The majority of existing astronomical analysis and processing solutions lack the ability to deal with data sets exceeding the local machine's memory capacity while visual exploration and discovery in complex, multi-dimensional datasets is more effective through real-time interaction although sizes may not fit the available memory (Jin et al., 2010) ;. Integration Most of the data analysis systems are implemented as a set of separate independent tasks that can interact and exchange information via stored files only. This will be a significant factor which delays or even prohibits day-to-day data analysis tasks over big data sizes. Visualization tools should be ideally fully integrated within the scientists' toolkit for seamless usage, abstracting from technical details freeing scientists to concentrate in doing science (e.g. see Goodman (2009) Nowadays astronomy and astrophysics produce massively large data volumes coming from observations or simulation codes executed on high performance supercomputers. Data visualization is a fundamental, enabling technology for knowledge discovery, involving a number of technical challenges, e.g. allowing real-time interaction although data sizes may not fit the available memory; providing tools that are fully integrated within the scientists' toolkit, sophisticated navigation in ubiquitous environments and finally collaborative mechanisms.. We have described a number of approaches towards addressing these challenges, focusing on the latest technological advances within VisIVO which is unique integrated ecosystem for visualisation providing comprehensive services for collaborative portals and mobile applications for visualization and data exploration.. We gave an overview on the developments of the VisIVO ecosystem within a number of national and international European funded projects and presented scientific cases on particle tracking visualization to identify high atomic number materials, comparing on line visualizations of large scale cosmological simula-32 http://www.canfar.phys.uvic.ca/canfar tions, and disseminating results for public outreach.. We presented the planned developments within the context of the Virtual Observatory framework to provide an integrated visual analytics ecosystem for big data analysis and visualization. Finally, we outlined future developments in terms of a new generation layered conceptual design, underpinning the overall ecosystem and also in making use of emerging technologies and infrastructures, such as exploitation of GPUs/coprocessors and cloud computing.

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Challenges and Directions in Formalizing the Semantics of Modeling Languages Developing software from models is a growing practice and there exist many model-based tools (e.g., editors, interpreters, debuggers, and simulators) for supporting model-driven engineering. Even though these tools facilitate the automation of software engineering tasks and activities, such tools are typically engineered manually. However, many of these tools have a common semantic foundation centered around an underlying modeling language, which would make it possible to automate their development if the modeling language specification were formalized. Even though there has been much work in formalizing programming languages, with many successful tools constructed using such formalisms, there has been little work in formalizing modeling languages for the purpose of automation. This paper discusses possible semantics-based approaches for the formalization of modeling languages and describes how this formalism may be used to automate the construction of modeling tools. With increasing frequency, scientists and engineers in diverse areas of focus, as well as end-users with specific domain expertise, are requiring computational processes to allow them to complete some task (e.g., avionics engineers who seek input on a modeled design from verification tools, or geneticists who need to describe computational queries to process a gene expression). A challenge emerges from the lack of knowledge of such users in terms of expressing their computational desire (i.e., such users typically are not familiar with programming languages). Model-driven engineering (MDE) is an approach that provides higher levels of abstraction to allow such users to focus on the problem, rather than the specific solution or manner of realizing that solution through lower level technology platforms [46] [52] . However, the potential impact of modeling is reduced due to the imprecise nature in which modeling languages are defined [26] . The large majority of modeling languages are defined in an ad hoc manner that lacks precision and a common reference definition for understanding the meaning of language concepts. In current practice, the meaning of a modeling language is often contained only in a model translator (we will use the term model interpreter in this paper to refer to such translators) that converts a model representation into some other form (e.g., source code). The current situation in MDE is not unlike the early period of computing when the definition of a programming language was delegated to "what the compiler says it means." Such an approach not only promotes misunderstanding of the meaning of a modeling language, but also limits opportunities for automating the generation of various language tools (much like the adoption of grammars provided a reference point for compiler and other tool generation for a programming language). The advantages of formal specification of programming language semantics are well-known. First, the meaning of a program is precisely and unambiguously defined; second, it offers a unique possibility for automatic generation of language-based tools (e.g., [27] ). Unfortunately, formal specifications, syntax and semantics, of modeling languages have not been developed to this level yet. Although the syntax of modeling languages is commonly specified by metamodels, an appropriate and standard formalism for specifying the (behavioral) semantics of modeling languages does not yet exist. Hence, there is no automatic generation of model interpreters, debuggers, simulators and verification tools.. In this paper, we describe challenges and directions in formalizing the semantics of modeling languages. The ideas developed in this paper were derived from the Workshop on Formalization of Modeling Languages held in conjunction with the European Conference on Object-Oriented Programming (ECOOP) in Maribor, Slovenia, on June 21, 2010. The paper is organized as follows. Section 2 motivates the need for semantics in modeling languages and reviews existing work in this area. In Section 3, we describe an approach based on state machine models. Section 4 describes a metamodel-based approach to semantics. In Sections 5 and 6, we discuss our experiences with semantics-based modeling tools for verification. Finally, we conclude in Section 7. DSMLs allow end-users and domain experts to specify the core essence of a problem using visual abstractions that are close to the problem space of a specific domain. A key research challenge in the adoption of such modeling languages concerns the manner in which the semantics of each DSML is specified. Typically, the behavioral semantics of a DSML is described within individual hard-coded model interpreters. Such a representation of the semantics is not specified in a manner that is ameliorable to formal analysis and generation of model-based tools. As such, the utility of a DSML is hampered due to the lack of a single representation that formally denotes the semantics of the language. This paper has described several research projects that investigate and develop a formal, yet widely usable, means to specify DSML semantics. Our future work is automatic generation of model interpreters, simulators, debuggers and verifiers from such semantic specifications, which would have significant impact on the current practice of model-driven engineering in terms of automating many tasks that are currently done ad hoc in a manual hand-crafted manner.

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The application of statistical reliability theory in the context of Intelligent Environments: a tutorial review Abstract Intelligent Environments often require the integration of multi-modal sensing and actuating technologies with high performance real-time computation, including artificial intelligence systems for analysis, learning patterns and reasoning. Such systems may be complex, and involve multiple components. However, in order to make them affordable, Intelligent Environments sometimes require many of their individual components to be low-cost. Nevertheless, in many applications-including safety-critical systems, and systems monitoring the health and well-being of vulnerable individuals, it is essential that these Intelligent Environment systems are reliable, which the issue of affordability must not compromise. If such environments are to find real application and deployment in these types of domain, it is necessary to be able to obtain accurate predictions of how probable any potential failure of the system is in any given timeframe, and of statistical parameters regarding the expected time to the first, or between successive, failures. Such quantities must be kept within what are deemed to be acceptable tolerances if the Intelligent Environment is to be suitable for applications in these critical areas, without requiring excessively high levels of human monitoring and/or intervention. In this paper, an introductory overview of statistical reliability theory is presented. The applicability of this to the context of Intelligent Environments-particularly those involving safety critical or other sensitive issues-is discussed, along with how such reliability modelling can be used to influence the design, implementation and application of an Intelligent Environment. The theme of "Intelligent Environments" (IEs) or "Smart Environments" has been much researched over the last 10-20 years [1, 33] , and the paradigm combines multimodal sensing and proactive assistive technology with machine learning and AI, often leading to complex multicomponent systems. It has found prototype applications in many domains-for example, ambient assisted living [2, 3, 15] , dialogue systems [4] , environmental monitoring [5] , smart homes [6] , offices [7] , transport systems [8] , and even smart cities [9] . The theme of this new journal is "Reliable Intelligent Environments". However, with the exception of a few studies which have focused-in on the reliability of some individual aspects [8, 10] and a number of empirical [11] or simulation [12, 13] studies, very little attention appears to have been given to investigating the reliability of such IEs. Such reliability could be essential in safety-critical applications, where the well-being of people [2, 3, 14, 15] , animals and/or the natural environment [5] could be at risk in cases of the system failing. Although a distributed system may sometimes display "graceful degradation" when a small number of its components fail, for example through self-reconfiguration or self-healing [1] , models of how likely failures of components are, and how serious these are for the performance of the entire system, will still be highly valuable. Some authors have questioned whether a statistically-based risk analysis is appropriate for safety-critical systems: Can any system which has even the smallest risk of failure be acceptable as a "safety-critical" system? However, in reality, there is no such thing as a completely risk free, or absolutely reliable, system. Indeed, safety and reliability are somewhat related concepts-"reliability" indicates an assessment of probability of a system failing, whereas "safety" relates to assessing the consequences of such a failure, and mitigating against them [34] . A system-even a so-called "safetycritical" one-could be regarded as "safe for purpose" if the expected time before it fails greatly exceeds its expected total duration of use, or if the consequences of such a failure are not at all serious. A much more detailed discussion of reliability theory in the context of safety-critical and similar systems can be found in [35] [36] [37] . The primary aim of this paper is to raise awareness of this type of approach.. In this paper, I give a review of the well-established field of statistical reliability theory, and indicate how it could be relevant to the reliability of IEs. This is only intended as a brief introduction to the field, and the reader is referred to existing texts for a more comprehensive coverage of the theory. Although the theory, and its discussion here, will primarily be discussed in the context of hardware reliability, it can also be applied to software and network failures, and indeed part of the following section will discuss the issue of software reliability and defects. Although the applicability of reliability theory to software systems is less well-known than its relevance to physical and hardware systems, software reliability has been modelled statistically since the early 1970s [38] . The reader is referred to [39, 40] , and the comprehensive review paper by Lyu [38] , for examples of this.. The remainder of this paper is organized as follows: the next section provides a review of related literature, discussing some issues of reliability in hardware and software systems, followed by a section illustrating how a systems modelling approach to viewing a complex system such as an Intelligent Environment can lead to a perspective which allows the statistical or probabilistic modelling of its reliability. Section 4 will first introduce some important terminology (Sect. 4.1), followed by an introduction (in Sect. 4.2), to various probabilistic models of reliability. Section 5 discusses how these concepts can be applied to models of Intelligent Environments, with examples, and the paper ends with my conclusions in Sect. 6. This paper has presented some of the issues relating to the reliability of complex systems, such as Intelligent Environments, and highlighted how important it is to gain a better theoretical understanding of, and to be able to model and predict, the reliability of such systems. The basic concepts of statistical reliability theory, along with examples illustrating how these may be applicable to the context of Intelligent Environments, have been presented. Although this article can only hope to give a very brief introduction to this highly important topic, suggestions for further reading to give more in-depth knowledge of the field have been given. As noted above, relatively little work appears to have been carried out on applying reliability theory to the context of Intelligent Environments. However, there have been some studies which have applied some concepts from this approach to empirical studies of reliability in intelligent systems. Suh et al. [8] address the problem of possible component failure within an intelligent transportation system by adding redundancy to the system through the replication of critical objects, enhancing fault tolerance by avoiding the existence of "simple points of failure" within the system. They compute the "availability" of such a system for fulfilling its purpose as the ratio of its mean time to failure [MTTF, also known as the mean time between failures (MTBF)] to the sum of its MTTF and its mean time to repair (MTTR, i.e. the mean time required to repair the system after a failure). They noted the importance of Brewer's CAP conjecture (or CAP theorem) [16, 17] , namely that any distributed system can at best simultaneously provide two, but not three, out of consistency (all nodes of the system can access the same data at the same time), availability (failures of individual components do not prevent the operation of remaining components) and partition (fault) tolerance (loss of an arbitrary amount of shared information does not prevent the system from operating). Poledna et al. [10] investigated the predictability of the quality of service in real-time systems with replicated components and flexible scheduling schemes.. Augusto and McCullagh [14] discuss safety considerations, and the implications of not taking these sufficiently into account, in the development of Intelligent Environments, but do not explicitly apply reliability theory to their study. Zhang et al. [11] consider the reliability of location detection in IEs, noting sensor failure, range, location and interference as possible sources of problems. However, again, they do not actually employ any analysis based on reliability theory.. Rather more theoretical work has been carried out on modelling the reliability (or lack of it) of complex software systems. It has been noted that the complexity of the software required to govern IEs can develop complex, unexpected interactions which can lead to instability in the behavior of the system [1, 18] . Lipow [19] and Gaffney [20] undertook pioneering work to estimate the number of faults present in a large piece of program code, and this was generalized to predicting and controlling the prevalence and effects of software defects by Compton and Withrow [21] . These studies have been extensively extended by Hatton [22] [23] [24] who carried out empirical studies on 123 software packages (55 written in Fortran and 68 in C) covering over 40 different application domains, and also produced a highly general model of the distribution of software defects in terms of the size of the software components, using principles from statistical physics. Although formal methods for "program proving", such as the Z specification method [25] [26] [27] can be used to verify the reliability of simple software systems, this is not normally practical for highly complex systems. Similarly, although conventional software engineering practice quite correctly advocates clear specification of requirements, careful design and implementation and rigorous testing [1, 28, 29] , for highly complex systems, possibly involving many thousands of lines of program code, with many conditional or decision statements and highly numerous potential paths through the code, testing to allow for all possible situations which might occur during the entire lifes-pan of the system being used in application becomes totally impracticable [23] . Hatton [30] has noted that, at best, software systems tend to exhibit approximately one fault per 10,000 lines of code, measured over the working lifetime of the program, but at worst the fault rate may be up to 100 times this-namely one fault per 100 lines of code! Furthermore, even code written in "standardised" forms of programming languages may contain ambiguities-the ISO specification for C lists no fewer than 119 constructions of uncertain definition [23] ! Hatton also notes that different types of software defects have widely varying probabilities of resulting in failure, and are ranked by severity according to these probabilities, over the working lifespan of the software system of interest [23] .. Bearing in mind the above discussions, and the intrinsic complexity of the hardware and software systems, and their interactions, required to construct and maintain a typical IE, plus the previously highlighted need for safety in and reliability of IEs, emphasizes the necessity for better theoretical understanding and modelling of reliability of IE components and their interdependencies. This motivates the rationale for the remainder of this paper.

O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Demosaicing using optimal recovery Abstract-Color images in single-chip digital cameras are obtained by interpolating mosaiced color samples. These samples are encoded in a single-chip charge-coupled device by sampling the light after it passes through a color filter array (CFA) that contains different color filters (i.e., red, green, and blue) placed in some pattern. The resulting sparsely sampled images of the three-color planes are interpolated to obtain the complete color image. Interpolation usually introduces color artifacts due to the phase-shifted, aliased signals introduced by the sparse sampling of the CFAs. This paper introduces a nonlinear interpolation scheme based on edge information that produces high-quality visual results. The new method is especially good at reconstructing the image around edges, a place where the visual human system is most sensitive. This paper developed a novel demosaicing algorithm using optimal recovery interpolation [2] . Through examples and PSNR values, it demonstrated that the new method performs especially well in regions of strong edges, where most other algorithms fail and where the human visual system seems most sensitive to errors. The new method is compared against three other algorithms: linear, weighted gradient of [6] and the alternating projections algorithm of [4] . The input images used for this test are Kodak Photo CD images of 384 256 pixels. The full color images are down-sampled as in Fig. 1 (with the same top-left pattern) to obtain the Bayer array mosaiced images. The mosaiced images are then interpolated back to full color images. Results are reported using sample color images, PSNR 2 values and in some cases the error norm is reported in the S-CIELab metric [30] , [31] . The demosaiced results presented in this paper can be viewed and downloaded online from [24] . 2 PSNR is calculated as 10 First, we test the four demosaicing algorithms on the lighthouse, sails, window, and statue images. The color image results of [6] were obtained directly from the author's web page in a lossless PPM format and the algorithm of [4] was obtained directly from the author. The cropped results are displayed in Figs. 8-11 . In order to better discriminate, the color artifacts the cropped images are enlarged 4 4 times using pixel replication. In Fig. 8 , the bluish color artifacts in the fence are removed best using the optimal recovery algorithm. The cropped version of the sails image is shown in Fig. 9 . The color artifacts in linear and weighted gradient are very obvious. In all four images, there is a noticeable zippering color artifact (i.e., noticeable color differences in neighboring pixels). The artifact is most pronounced around the numbers and at the boundary between the yellow and blue colors. In the four images, the zippering effect is least pronounced in the optimal recovery result. Fig. 10 depicts a cropped version of the window image. The color differences are harder to notice, but looking at the four results, the optimal recovery image again seems to have the smallest zippering artifact. Finally, Fig. 11 depicts the cropped version of the statue image. While the artifacts between the first two and the last two images are easier to notice, the difference between the alternating projection algorithm and optimal recovery are much more difficult to observe.. Our next evaluation is based on comparisons of PSNRs. algorithm performs better. The fifth row of Table I shows the PSNR values when using only one pass in interpolating the green channel. Notice that, in most cases, using one pass gives better PSNR values, but using two passes improves the lighthouse results by 0.55 dB. The last row of Table I shows the results when optimal recovery is applied to the differences of red to green and blue to green. The results are slightly worse than the weighted gradient algorithm. This seems surprising at first. However, interpolating the red and blue channels uses training vectors that are coarser (i.e., the location of the samples in the training vectors are more distant from each other), and, therefore, there is more error in estimating the proper local quadratic class, which is particularly bad for textured regions. On the positive side, using optimal recovery on the difference image is not recommended since the computational time almost triples. To further test the difference between the two algorithms, optimal recovery is compared against alternating projection on a much larger data set containing image classes of: birds, faces, flowers, nature, patterns, structures, and textures. Due to space limitations, the TIF results from these tests and original images are available only online [24] . Looking strictly at PSNR values, the image database seems to be very evenly divided into images for which optimal recovery gives better values and images for which alternating projections gives better values. A subset of these PSNR values are listed in Tables II-IV . In this case, PSNR values do not provide a convincing argument for the superiority of one algorithm over the other. Here, a subjective assessment seems to be more valuable. Looking at the images presented in Figs. 8-11 and online [24] , the results suggest that in textured regions the alternating projections algorithm performs best, while in regions of well-defined edges, optimal recovery produces better results. The intuition behind these results is that optimal recovery's strength is reconstructing well defined (i.e., longer) edges. In regions of long edges, the training data is more representative of the local edge and the algorithm determines a quadratic signal class that better represents the edge behavior. In textured regions, where edges tend to be shorter and in different directions, the local training set is not as representative of the local data and the algorithm introduces more errors. The lighthouse and sails images contain such long edges: the fence and the mast. On the other hand, images window and statue have large texture regions with poorly defined edges.. In evaluating image quality, we also compared the different methods using S-CIELab metrics 3 [30] , [31] . The results are shown in Table V . In this case, the alternating projection algorithm consistently gives a smaller (better) value for the metric when evaluated over the entire image. To demonstrate the visual impression that optimal recovery is better in regions with edges, we evaluated the S-CIELab metric on selected regions of the image. For each image, there are two types of patches being considered: a textured patch and a strong edge patch, as in Fig. 12 . The S-CIELab results are shown in Table VI . It is now clear that in regions with strong edges, where the human eye is most sensitive, optimal recovery performs well, while in textured regions, where vision is not as sensitive, its performance deteriorates.. From our subjective results, the most objectionable artifacts seem to be artifacts in regions of strong edges and not artifacts in textured regions. This seems to indicate that optimal recovery is the preferred algorithm from a visually subjective point of view. As suggested by one of the reviewers, an alternative approach would be to consider a hybrid algorithm where optimal recovery demosaicing is applied around edges, while a different demosaicing algorithm is applied in textured regions. This can be an area of future research.

B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O O O O O O O O O


A re-conceptualization of the interpretive flexibility of information technologies: redressing the balance between the social and the technical Interpretive flexibility -the capacity of a specific technology to sustain divergent opinionshas long been recognised as playing an important role in explaining how technical artefacts are socially constructed. What is less clear is how a system's technical characteristics might limit its ability to be interpreted flexibly. This gap in the literature has largely arisen because recent contributions to this debate have tended to be rather one-sided, focussing almost solely upon the role of the human agent in shaping the technical artefact, and in so doing either downplaying or ignoring the artefact's shaping potential. The broad aim of this study was to reappraise the nature and role of interpretive flexibility but giving as much consideration to how an information system's technical characteristics might limit its ability to be interpreted flexibly, as we do to its potential for social construction. In this paper we use the results of two in-depth case studies, in order to propose a re-conceptualisation of the role of interpretive flexibility. In short, this model helps explain how the initial interpretations of stakeholders are significantly influenced by the scope and adaptability of the system's functionality. Stakeholder interpretations will then, in turn, influence how the system's functionality is appropriated and exploited by users, to allow divergent interpretations to be realised and sustained. The modern organisation is one arena in which the dictum 'there is nothing constant but change' is particularly pertinent. A key driver of this unrelenting change is the application of information technologies and systems. Information technology (IT) is now a ubiquitous and increasingly critical part of the fabric of the modern organisation, supporting its day-to-day operations and all aspects of the decision-making process, as well as its strategic positioning. It is therefore perhaps not surprising that information technologies and systems have already had a marked impact on the ways in which work is organised, allocated and ultimately accomplished (Marcus & Robey, 1988; Clegg et al, 1997; Doherty & King, 1998; Daniels & White, 2005) . For example, Davidson & Chiasson (2005) demonstrate how staff in a hospital had to adjust clinical practices to accommodate the use of an electronic medical records systems. Moreover, Doherty & King (2001) suggest that the introduction of technology may have significant affects upon the overall design of an organization, in terms of its culture and structure. At the other end of the spectrum, information technologies have also been demonstrated to have a marked influence on the behaviour and motivation of individual members of staff (Zuboff, 1988) .. Whether it be at the macro or the micro level (Poulymenakou & Holmes, 1996) , there is now almost universal agreement, within the literature, that the introduction of IT is associated with significant organisational change. However, there are very differing accounts concerning the nature of the relationship. As DeSanctis & Poole (1994: 123) note the literature has become polarised, with commentators either viewing IT as the 'causal agent of change' or 'an opportunity for change'. Contributions that view IT as a causal agent of change can be broadly classified as technically deterministic, whilst those that view IT as an opportunity for change reflect a more social constructivist perspective. However, Orlikowski (1992) argues that these competing views of IT present a false dichotomy and that IT should be conceived as a fundamental 'duality': IT is both shaped through the actions of human agents and the technology will also influence the actions and behaviour of users. Indeed, there has been a growing consensus that information technology is both shaping of, and shaped, by its working environment (Rose & Jones, 2004) . The social constructivist side of this equation is supported by the wide variety of evidence that the application of identical technologies, in similar organisational contexts can result in very different organisational impacts (e.g. Barley, 1986 , Sahay & Robey, 1995 . What is less clear is how the technical characteristics of an information system might constrain the ways in which it can be interpreted (Kallinikos, 2004a; Rose & Jones, 2004) , and in so doing, how the technology might exert a shaping influence on its host organisation. Interpretive flexibility -which can be defined as 'the capacity of a specific technology to sustain divergent opinions' 260) -is one important yet arguably under-researched, concept that might help to explain both how different realities can be shaped from the implementation of the same technology and how its technical characteristics might moderate the extent to which it can be socially shaped. The broad aim of the research, presented in this paper, was therefore to develop new insights into the nature and role of interpretive flexibility, by exploring the development, implementation and use of a standard software package in the UK's network of NHS operated Community Trusts 1 .. Another enduring theme within the information systems' literature relates to the potential of information technologies and systems to either facilitate empowerment or reinforce control (Bloomfield, 1995; Zuboff, 1988 ). On the one hand, information systems can be viewed as an ideal tool for the monitoring and regulation of employee performance (Torkzadeh & Doll, 1999) and are therefore typically associated with the 'the desire to realise and maintain 1 Following a reorganisation of UK's National Health Service that began in April 1999 many of the responsibilities held by Community Care Trusts (such as, developing primary and community health services and commissioning hospital care for their local populations) passed to new Primary Care Trusts (PCT). Consequently, many Community Trusts have either ceased to exist or their roles have been greatly reduced with many staff that previously worked for the Care Trusts now being employed by the new PCTs. A review of the NHS's latest IT strategy [D of H, 2002] suggests that the issues discussed in this paper with regard to Community Trusts are likely to be just as relevant for the recently created Primary Care Trusts.. control' (Bloomfield & McLean, 2003; 55) . On the other hand, there is growing literature that information technologies -through the provision of appropriate information to the desk-tops of employees -might also enable more autonomous ways of working (Psoinos et al, 2000) . Consequently, we intend to explore how the interpretive flexibility of very similar information systems might either facilitate empowerment or reinforce a control orientation. It was envisaged that by comparing and contrasting these extreme and opposing outcomes, it would be possible to gain a deeper and richer understanding of the nature and role of interpretive flexibility.. The remainder of this paper has been organised into five distinct sections. In the second section, the literature on interpretive flexibility is critically reviewed, before we provide an overview of, and a justification for, the research methods used, in the third section. The fourth, and most substantive section reports on the impact and implications of the introduction of new information systems at two Community Care Trusts. In the final two sections, we interpret the implications of our findings in the context of the literature. Research into the role of information systems, within the organisational context, is an ambitious undertaking, and therefore contains a number of inherent limitations. For example, the adoption of the case study format reduced the number of organisations that could realistically participate and there is also the potential for some bias with respect to the way in which these cases, and the interviewees, were ultimately chosen. Consequently, whilst the study provides many interesting and novel insights, these limitations do highlight the need for follow-up studies to be conducted that adopt different methods, and target different populations and respondents, to investigate the wider currency of the results. Of particular importance, in terms of follow-up research, will be longitudinal studies. As was noted earlier, the interpretations of stakeholders are highly unlikely to remain constant over the operational life of an information system. It is highly probable that an information system will be reinterpreted, in light of changing organisational circumstances, which may necessitate appropriating the system's functional flexibility in different ways, or even seeking to have its functional boundaries redefined. The on-going, recursive nature of the relationship, between a system's material characteristics and the subjective interpretations of its stakeholders, underscores the need for more longitudinal studies to explore how well our theoretical model reflects organisational realities, in the longer term. Moreover, it is envisaged that such studies might help to shed light on the transmutation points between deterministic and nondeterministic interaction of man and machine. To provide deeper and richer insights into the role and nature of interpretive flexibility by explicitly exploring how the technical characteristics of a specific information system might constrain or facilitate its ability to be interpreted flexibly. The study has provided fresh evidence to support Barley's (1986) finding that identical software applications, implemented in very similar organisational contexts, can result in very different organisational impacts. More specifically, the study reiterates findings that near identical information systems, when applied in very similar organisational contexts, can be used to either facilitate empowerment or to impose a control orientation. However, this paper's most important contribution relates to its primary focus on the nature and role of interpretive flexibility. It has been possible to use the evidence from the case studies to derive a new conceptualisation of interpretive flexibility, which explicitly recognises the important shaping role of technology. This resultant model, as summarised in figure 1, and described in the remainder of the section, is intended to demonstrate how the material characteristics of the technology influence what it means to users, which will in turn influence how the technology's functionality is appropriated to reinforce the interpretation, when used.

O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B O B I O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


The development of synthetic biology: a patent analysis In the past decades, synthetic biology has gained interest regarding research and development efforts within the biotechnology domain. However, it is unclear to what extent synthetic biology has matured already into being commercially exploitable. By means of a patent analysis, this study shows that there is an increasing trend regarding synthetic biology related patent applications. The majority of retrieved patents relates to innovations facilitating the realisation of synthetic biology through improved understanding of biological systems. In addition, there is increased activity concerning the development of synthetic biology based applications. When looking at potential application areas, the majority of synthetic biology patents seems most relevant for the medical, energy and industrial sector. Furthermore, the analysis shows that most activity has been carried out by the USA, with Japan and a number of European countries considerably trailing behind. In addition, both universities and companies are major patent applicant actor types. The results presented here form a starting point for follow-up studies concerning the identification of drivers explaining the observed patent application trends in synthetic biology. Within life sciences, the concept of synthetic biology has gained interest over the past decade due to its believed potential to improve biotechnology-based translational applications (Burbelo et al. 2010) . Its transformation from a philosophical construct towards a real discipline has led to awareness among stakeholders in a position to influence or become affected by synthetic biology's diffusion into society. However, in spite of its expansion over the past decade, a lack of specific market-based studies limits the potential to properly assess synthetic biology's progress regarding R&D and market penetration attempts.. A number of science and technology indicators can be applied to asses technological progress, including patent statistics (Hinze and Schmoch 2004) . Patent indicators can be used for a number of reasons (ibid.). First of all, patent indicators can be considered early signals for future commercial applications. Due to the general underlying costly and time-consuming nature of patent application, patent statistics indicate a certain amount of optimism or expectation concerning described features within patents showing economic potential (Basberg 1987) . Secondly, patent analysis can be valuable in analysing technology development in relation to competition between sectors or countries (Liu and Shyu 1997) . Thirdly, based on assessments of current technology trends, patent analyses can be used in planning technology oriented national strategies Electronic supplementary material The online version of this article (doi:10.1007/s11693-013-9121-7) contains supplementary material, which is available to authorized users. (Abraham and Moitra 2001) . Finally, patent analysis data can be used in modelling practices concerning market development of emerging technologies (Ashton and Sen 1988) .. Innovation research based on patent analyses seems to indicate that emerging technologies generate specific patterns. Traditionally, patent development within specific sectors was believed to follow an S-shaped pattern (Liu and Shyu 1997) . A more recent study, based on analyses of over 40 different science-based emerging technologies, expanded this pattern by identifying the following phases (Schmoch 2007): 1 1. An initial start of mainly experimentation and knowledge gain 2. Increased development of R&D once commercial exploitability has been reached 3. Disillusionment of industry as a result of being noncompetitive compared to alternative technologies on industrial scale 4. Regained interest of industry, as a result of being competitive compared to alternative technologies on industrial scale 5. Decreasing patent applications as a result of field saturation of the technology Regarding this model, analysing patent trends of synthetic biology could provide valuable information in what developmental phase synthetic biology could be placed. Furthermore, a patent analysis provides an opportunity to perform cross-country comparisons regarding patent filing dynamics. In addition, a patent analysis could assist in the identification of actors and organisations active in synthetic biology. Finally, the analysis of synthetic biology patents could provide more detailed knowledge concerning the nature, presence and temporal development of translational synthetic biology patent applications.. The contribution of this paper is twofold. First, a methodological approach is presented for analysing patenting activities in synthetic biology. One of the difficulties in performing patent analyses for emerging technologies relates to their unspecific classification within the international patent classification (IPC). Due to potential 'groupoverlapping' nature of emerging technology patent content, such patents are in general classified under multiple existing groups. Therefore, patent content analysis is required to identify emerging technology patents within the IPC. This paper presents a methodology, based on both the IPC and patent content, which can be applied to extract patent applications related to synthetic biology. The second contribution of this paper is the identification of patent application trends within synthetic biology. Based on the applied patent analysis approach, the retrieved patent collection has been used to perform several analyses with respect to cross-country comparisons, actor identification and sector relevant patenting dynamics. This patent analysis contains the following steps:. • Step 1: Setting technology independent search criteria Patents can be filed on both national and international level. Search criteria are set to define in which patent office patents will be searched for. In addition, the timeframe is set to limit the years of patent applications that will be included in the final patent search.

O O O B I O B I O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Space partitioning strategies for indoor WLAN positioning with cascade-connected ANN structures Position information in indoor environments can be procured using diverse approaches. Due to the ubiquitous presence of WLAN networks, positioning techniques in these environments are the scope of intense research. This paper explores two strategies for space partitioning when utilizing cascadeconnected Artificial Neural Networks (ANNs) structures for indoor WLAN positioning. A set of cascadeconnected ANN structures with different space partitioning strategies are compared mutually and to the single ANN structure. The benefits of using cascade-connected ANNs structures are shown and discussed in terms of the size of the environment, number of subspaces and partitioning strategy. The optimal cascade-connected ANN structures with space partitioning show up to 50% decrease in median error and up to 12% decrease in the average error with respect to the single ANN model. Finally, the single ANN and the optimal cascade-connected ANN model are compared against other well-known positioning techniques.

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Peripheral Circadian Oscillators Circadian rhythms are ~24-hour cycles of physiology and behavior that are synchronized to environmental cycles, such as the light-dark cycle. During the 20th century, most research focused on establishing the fundamental properties of circadian rhythms and discovering circadian pacemakers that were believed to reside in the nervous system of animals. During this time, studies that suggested the existence of circadian oscillators in peripheral organs in mammals were largely dismissed. The discovery of a single-locus circadian pacemaker in the nervous system of several animals affirmed the single-oscillator model of the circadian system. However, the discovery of the genes that constituted the molecular timekeeping system provided the tools for demonstrating the existence of bona fide circadian oscillators in nearly every peripheral tissue in animals, including rodents, in the late 1990s and early 2000s. These studies led to our current understanding that the circadian system in animals is a hierarchical multi-oscillatory network, composed of master pacemaker(s) in the brain and oscillators in peripheral organs. Further studies showed that altering the temporal relationship between these oscillators by simulating jet-lag and metabolic challenges in rodents caused adverse physiological outcomes. Herein we review the studies that led to our current understanding of the function and pathology of the hierarchical multi-oscillator circadian system. Circadian rhythms, which are 24-hour cycles of behavior and physiology (e.g. sleep/wake and core body temperature cycles), are ubiquitous and observed in most organisms. Before the 1960s, scientists established the three fundamental properties of circadian rhythms. First, the circadian rhythm must be self-sustained and free-run with a period of ~24 hours (i.e. the 24h rhythm persists in constant conditions). Second, the circadian rhythm should entrain to (be synchronized by) environmental cycles, such as the light-dark cycle. Third, the circadian rhythm should maintain a ~24h period across a physiological range of temperatures (i.e. it is temperature-compensated). After these formal properties were established, the next goal was to discover the locus of the self-sustained circadian oscillator.. During the 1960s and 1970s, scientists searched for the location of the circadian pacemaker in multicellular organisms. At this time, it was believed that a pacemaker(s) located in the brain or in a neuroendocrine gland drives overt circadian rhythms in behavior and physiology. The approaches used were to lesion, transplant, and culture candidate pacemaker tissues. For an organ to qualify as the circadian pacemaker, it had to adhere to the fundamental circadian properties. Lesioning should abolish the overt circadian rhythms and transplantation of that tissue should restore the circadian rhythms. Moreover, the tissue must express a circadian rhythm in vitro in constant conditions. Using these methods, the locus of the circadian pacemaker was identified in the central nervous system of several animals-the optic lobe in cockroaches (lesion [1] , transplant [2] , in vitro [3] ), the pineal gland in house sparrows (lesion [4] , transplant [5, 6] ) and the suprachiasmatic nucleus (SCN †) of the hypothalamus in rodents (lesion [7, 8] , in vivo isolation [9] , transplant [10] [11] [12] [13] , in vitro [14] [15] [16] ). It was later shown that the pacemakers in non-mammalian vertebrate species are distributed in a circadian axis and include the retina, SCN, and pineal gland. The dominant pacemaker in the axis varies in each species [17] [18] [19] .. Although the single-pacemaker model of the circadian system was the prevailing view in the 20 th century, scientists were also making discoveries suggesting that circadian oscillators could be located in peripheral tissues. This hierarchical multi-oscillator view of the circadian system was not widely accepted. More than 40 years after the initial discoveries that implicated peripheral tissues as circadian clocks, it is now dogma in the field of chronobiology that the circadian system is a hierarchical multi-oscillator network of circadian clocks. Herein we review the studies that led to our current understanding of the hierarchical multi-oscillator circadian system.

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VE-LLI-VO: Vessel Enhancement Using Local Line Integrals and Variational Optimization Abstract-Vessel enhancement is a primary preprocessing step for vessel segmentation and visualization of vasculatures. In this paper, a new vessel enhancement technique is proposed in order to produce accurate vesselness measures and vessel direction estimations that are less subject to local intensity abnormalities. The proposed method is called vessel enhancement using local line integrals and variational optimization . First, vessel enhancement using local line integrals is introduced in which a vessel model is embedded by regarding a vessel segment as a straight line based upon the second order information of the local line integrals. Useful quantities similar to the eigenvalues and eigenvectors of the Hessian matrix are produced. Moreover, based upon the local line integrals, junctions can be detected and handled effectively. This can help deal with the bifurcation suppression problem which exists in the Hessian-based enhancement methods. Then a more generic curve model is embedded to model vessels and a variational optimization framework is introduced to generate optimized vesselness measures. Experiments have been conducted on both synthetic images and retinal images. It is experimentally demonstrated that produces improved performance as compared with the widely used techniques in terms of both vesselness measurement and vessel direction estimation. O PTIC FUNDUS photography technique is a widely used procedure for the diagnosis of retinopathies. The inspection of vasculatures in the retinal images not only plays an important role in diagnosing ophthalmic diseases, e.g., retinal artery occlusion, glaucoma, but also helps reveal nonophthalmic diseases, such as hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. However, the current optic fundus photographs often present remarkable noise, inadequate intensity contrast and intensity variations. These effects make the analysis of the retinal images difficult. To improve the retinal image quality, vessel enhancement, which is primarily used as a preprocessing step for vessel segmentation and visualization, has been studied intensively by different research groups in the past decades.. Vessel enhancement methods often take an image as input and for each point, a vesselness measure is calculated based upon local image features. Among all the vessel enhancement methods, the Hessian-based methods have been used widely because of the fact that its core component, the Hessian matrix, offers elegant geometrical interpretations and is able to retrieve useful vascular information from the images. In this work, the Hessian-based methods refer to those techniques that exploit the eigenvalues and/or the eigenvectors of the Hessian matrix during the vessel enhancement procedure. To the best of our knowledge, Koller et al. [1] were the first research group to propose the use of information extracted from the Hessian matrix in the context of vessel enhancement. Their method uses the eigenvectors of the Hessian matrix for vessel direction estimation and applies a matching filter along the vessel direction to detect vessel presence. Krissian et al. [2] later refined this matching filter. While only the eigenvectors of the Hessian matrix are used in [1] and [2] , other works [3] - [6] take the eigenvalues into consideration. In these works, the eigenvalues are combined to distinguish curve-linear structures from the image background region. Among the previous methods, a method proposed by Frangi et al. [4] is one of the most commonly used vessel enhancement methods in practice. It utilizes all the eigenvalues and has an intuitive geometric interpretation.. While the Hessian-based methods are widely used in different areas of image processing [7] - [11] , its drawback is obvious due to the fact that the Hessian matrix is based upon second derivatives, which are local measures. Therefore, without a relatively global view of the vasculatures, the Hessian-based methods only offer local shape descriptions. It, hence, suffers from over sensitivity to local intensity abnormalities, which can be viewed as deviations of intensity structures from the targeted ones, e.g., 1) noise which gives false positive responses; 2) uneven responses inside a vessel; and 3) suppressed bifurcations. This property deteriorates the effect of visualization, and also adversely affects the quality of the subsequent segmentation methods, especially for variational segmentation frameworks such as [12] in which the contour evolution can get stuck at local optimum.. In all the previous works, a vesselness measure reflects the possibility that a point belongs to a vessel. Each image point is therefore viewed as an individual and only information inside the local region of this point is used to compute the vesselness responses. It does not take into account the geometrical property of the particular vessel segment to which a point belongs. Not only should a more robust vesselness measure reflect whether a point belongs to a vessel segment, but also reveal whether the vessel segment is a strong one or not. As will be described in this paper, a new view on vesselness measure should shift its focus from a point to the vessel segment in which the point resides, and make the measure less sensitive to local intensity abnormalities. To that attempt, vessel enhancement using local line integrals and variational optimization is proposed in this paper. In the first step, vessel enhancement using local line integrals is introduced. It models a vessel segment as a straight line and exploits the second order information of the local line integrals in order to capture potentially existing line structures with less sensitivity to local intensity abnormalities. Useful quantities similar to the eigenvalues and eigenvectors of the Hessian matrix are produced in a multiscale fashion and then combined to generate a vesselness measure. With the new vesselness measure, it is relatively easy to detect junction points in the images. With an adaptive length for line integrals, junction regions can be detected and enhanced. By using this straight line vessel model, is able to take more information into consideration and can give better vessel direction estimations and vesselness responses, as will be demonstrated in the experiments.. To further improve the quality of the vesselness measures, a variational optimization framework is proposed to extend to form the method. A more generic curve model is used to model vessel segments to capture vessels with various shapes, in contrast to the straight line model used in the previous . calculates an optimized vesselness measure based upon the features of the possible vessel segment (more specifically, the centerline of the vessel segment) to which a point belongs. can produce smooth vesselness responses along vessels and give good performance in background suppression. The new method has been tested on both synthetic and retinal images. Detailed quantitative and qualitative comparisons will be presented in Section VI. This paper is organized as follows. In Section II, three Hessian-based vessel enhancement methods are briefly introduced and compared. Section III gives a full account of . In order that the later experiments are fair, optimal parameters are searched (see Section IV) based upon the analysis of enhancement results. The idea of is elaborated in Section V. The underlying principle of is described with illustrations. In Section VI, is tested on synthetic images and two publicly available databases of the retinal images. Qualitative and quantitative results obtained by using different methods are presented and discussed. This paper is concluded in Section VII. Contributions of this work can be summarized as follows. In this paper, limitations of the Hessian-based vessel enhancement methods have been discussed, which stem from the fact that the Hessian matrix is a local measure sensitive to local intensity structures. A new view on the vesselness measure has been proposed. A more robust vesselness measure should not only reflect whether a point belongs to a vessel segment, but also whether the vessel segment is a strong one or not. The new view on the vesselness measure shifts focus from a point to the vessel segment to which the point belongs.. Vessel enhancement using local line integrals is first proposed in this paper. A vessel model is embedded as the prior knowledge by regarding a vessel segment as a straight line and using the second order information of the local line integrals.. is less sensitive to local intensity abnormalities. Therefore, it can produce more accurate vesselness measures and vessel direction estimations. Useful quantities similar to the eigenvalues and eigenvectors of the Hessian matrix are produced by . These quantities can be exploited in any existing Hessian-based vesselness measure methods. With the local line integrals, junction regions can be detected and handled effectively with smaller line integral length. This can give better enhancement results than the existing Hessian-based methods which will suppress these junction regions. A variational optimization framework is further proposed to improve quality of vesselness measures. It is used as an extension on to form .. can produce smooth vesselness responses along vessels, give good performance in background suppression, and reduce the narrowing effect of some Hessian-based methods. utilizes a more generic curve model instead of straight line segments used in . Therefore, it can locate vessels with large curvatures, which is a limitation for .

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