OpenRaiser/Intern-Atlas huggingface dataset:
Speaking Plant Approach for Automatic Fertigation System in Greenhouse
Venue: arXiv cs.OH 2013
Year: 2013

Nowadays, many vegetables are grown insidegreenhouses in which environment is controlled and nutrition can be supplied through water supply using electrical pump, namely fertigation. Dosage of nutrition in water for many vegetable plants are also known so that by controllingwater supply all the needsfor the plants to grow are available. Furthermore, water supply can be controlled using electrical pump which is activated according to theplants conditionin relation with water supply. In order to supply water and nutrition in the right amount and time, plants condition can be observed using a CCD camera attached to image processing facilitiesto develop a speaking plant approach. In this study, plants development during their growing periodare observedusing image processing. Three populationsof tomato plants, with less, enough, and exceeded nutrition in water,are captured using a CCD camera every three days, and the images were analyzed using a developed computer program for the heightof plants. The results showed that the development of the plants can be monitored using this method. After that, the responseof plant growth in the same condition was monitored, and the responsewas used as input for the fertigation system to turn electrical pump automatically on and off, so the fertigation system could maintain the growth of the plants.
Improving the management of cost and scope in software projects using agile practices
Venue: arXiv cs.SE 2013
Year: 2013

While organizations want to develop software products with reduced cost and flexible scope, stories about the applicability of agile practices to improve project development and performance in the software industry are scarce and focused on specific methodologies such as Scrum and XP. Given these facts, this paper aims to investigate, through practitioners' perceptions of value, which agile practices are being used to improve two performance criteria for software projects-cost and scope. Using a multivariate statistical technique known as Exploratory Factor Analysis (EFA), the results suggest that the use of agile practices can be represented in factors which describe different applications in software development process to improve cost and scope. Also, we conclude that some agile practices should be used together in order to get better efficiency on cost and scope in four development aspects: improving (a) team abilities, (b)management of requirements, (c) quality of the code developed, and (d) delivery of software on-budget and on-time.
Computing as compression: the SP theory of intelligence
Venue: arXiv cs.AI 2013
Year: 2013

This paper provides an overview of the SP theory of intelligence and its central idea that artificial intelligence, mainstream computing, and much of human perception and cognition, may be understood as information compression. The background and origins of the SP theory are described, and the main elements of the theory, including the key concept of multiple alignment, borrowed from bioinformatics but with important differences. Associated with the SP theory is the idea that redundancy in information may be understood as repetition of patterns, that compression of information may be achieved via the matching and unification (merging) of patterns, and that computing and information compression are both fundamentally probabilistic. It appears that the SP system is Turing-equivalent in the sense that anything that may be computed with a Turing machine may, in principle, also be computed with an SP machine. One of the main strengths of the SP theory and the multiple alignment concept is in modelling concepts and phenomena in artificial intelligence. Within that area, the SP theory provides a simple but versatile means of representing different kinds of knowledge, it can model both the parsing and production of natural language, with potential for the understanding and translation of natural languages, it has strengths in pattern recognition, with potential in computer vision, it can model several kinds of reasoning, and it has capabilities in planning, problem solving, and unsupervised learning. The paper includes two examples showing how alternative parsings of an ambiguous sentence may be modelled as multiple alignments, and another example showing how the concept of multiple alignment may be applied in medical diagnosis.
Socially stable matchings in the Hospitals / Residents problem
Venue: arXiv cs.GT 2013
Year: 2013

In the Hospitals/Residents (HR) problem, agents are partitioned into hospitals and residents. Each agent wishes to be matched to an agent in the other set and has a strict preference over these potential matches. A matching is stable if there are no blocking pairs, i.e., no pair of agents that prefer each other to their assigned matches. Such a situation is undesirable as it could lead to a deviation in which the blocking pair form a private arrangement outside the matching. This however assumes that the blocking pair have social ties or communication channels to facilitate the deviation. Relaxing the stability definition to take account of the potential lack of social ties between agents can yield larger stable matchings. In this paper, we define the Hospitals/Residents problem under Social Stability (HRSS) which takes into account social ties between agents by introducing a social network graph to the HR problem. Edges in the social network graph correspond to resident-hospital pairs in the HR instance that know one another. Pairs that do not have corresponding edges in the social network graph can belong to a matching M but they can never block M. Relative to a relaxed stability definition for HRSS, called social stability, we show that socially stable matchings can have different sizes and the problem of finding a maximum socially stable matching is NP-hard, though approximable within 3/2. Furthermore we give polynomial time algorithms for three special cases of the problem.
Structural Tractability of Counting of Solutions to Conjunctive Queries
Venue: arXiv cs.LO 2013
Year: 2013

In this paper we explore the problem of counting solutions to conjunctive queries. We consider a parameter called the \emph{quantified star size} of a formula $φ$ which measures how the free variables are spread in $φ$. We show that for conjunctive queries that admit nice decomposition properties (such as being of bounded treewidth or generalized hypertree width) bounded quantified star size exactly characterizes the classes of queries for which counting the number of solutions is tractable. This also allows us to fully characterize the conjunctive queries for which counting the solutions is tractable in the case of bounded arity. To illustrate the applicability of our results, we also show that computing the quantified star size of a formula is possible in time $n^{O(k)}$ for queries of generalized hypertree width $k$. Furthermore, quantified star size is even fixed parameter tractable parameterized by some other width measures, while it is $\W{1}$-hard for generalized hypertree width and thus unlikely to be fixed parameter tractable. We finally show how to compute an approximation of quantified star size in polynomial time where the approximation ratio depends on the width of the input.
Capacity Bounds and Sum Rate Capacities of a CLass of Discrete Memoryless Interference Channels
Venue: arXiv cs.IT 2013
Year: 2013

This paper studies the capacity of a class of discrete memoryless interference channels where interference is defined analogous to that of Gaussian interference channel with one-sided weak interference. The sum-rate capacity of this class of channels is determined. As with the Gaussian case, the sum-rate capacity is achieved by letting the transceiver pair subject to interference communicate at a rate such that its message can be decoded at the unintended receiver using single user detection. It is also established that this class of discrete memoryless interference channels is equivalent in capacity region to certain degraded interference channels. This allows the construction of capacity outer-bounds using the capacity regions of associated degraded broadcast channels. The same technique is then used to determine the sum-rate capacity of discrete memoryless interference channels with mixed interference as defined in the paper. The obtained capacity bounds and sum-rate capacities are used to resolve the capacities of several new discrete memoryless interference channels.
The separation problem for regular languages by piecewise testable languages
Venue: arXiv cs.FL 2013
Year: 2013

Separation is a classical problem in mathematics and computer science. It asks whether, given two sets belonging to some class, it is possible to separate them by another set of a smaller class. We present and discuss the separation problem for regular languages. We then give a direct polynomial time algorithm to check whether two given regular languages are separable by a piecewise testable language, that is, whether a $BΣ1(<)$ sentence can witness that the languages are indeed disjoint. The proof is a reformulation and a refinement of an algebraic argument already given by Almeida and the second author.
On Influence, Stable Behavior, and the Most Influential Individuals in Networks: A Game-Theoretic Approach
Venue: arXiv cs.GT 2013
Year: 2013

We introduce a new approach to the study of influence in strategic settings where the action of an individual depends on that of others in a network-structured way. We propose \emph{influence games} as a \emph{game-theoretic} model of the behavior of a large but finite networked population. Influence games allow \emph{both} positive and negative \emph{influence factors}, permitting reversals in behavioral choices. We embrace \emph{pure-strategy Nash equilibrium (PSNE)}, an important solution concept in non-cooperative game theory, to formally define the \emph{stable outcomes} of an influence game and to predict potential outcomes without explicitly considering intricate dynamics. We address an important problem in network influence, the identification of the \emph{most influential individuals}, and approach it algorithmically using PSNE computation. \emph{Computationally}, we provide (a) complexity characterizations of various problems on influence games; (b) efficient algorithms for several special cases and heuristics for hard cases; and (c) approximation algorithms, with provable guarantees, for the problem of identifying the most influential individuals. \emph{Experimentally}, we evaluate our approach using both synthetic influence games as well as several real-world settings of general interest, each corresponding to a separate branch of the U.S. Government. \emph{Mathematically,} we connect influence games to important game-theoretic models: \emph{potential and polymatrix games}.
A Robust Zero-point Attraction LMS Algorithm on Near Sparse System Identification
Venue: arXiv cs.IT 2013
Year: 2013

The newly proposed $l_1$ norm constraint zero-point attraction Least Mean Square algorithm (ZA-LMS) demonstrates excellent performance on exact sparse system identification. However, ZA-LMS has less advantage against standard LMS when the system is near sparse. Thus, in this paper, firstly the near sparse system modeling by Generalized Gaussian Distribution is recommended, where the sparsity is defined accordingly. Secondly, two modifications to the ZA-LMS algorithm have been made. The $l_1$ norm penalty is replaced by a partial $l_1$ norm in the cost function, enhancing robustness without increasing the computational complexity. Moreover, the zero-point attraction item is weighted by the magnitude of estimation error which adjusts the zero-point attraction force dynamically. By combining the two improvements, Dynamic Windowing ZA-LMS (DWZA-LMS) algorithm is further proposed, which shows better performance on near sparse system identification. In addition, the mean square performance of DWZA-LMS algorithm is analyzed. Finally, computer simulations demonstrate the effectiveness of the proposed algorithm and verify the result of theoretical analysis.
Proposition d'une technique de gestion de projet dans les startups
Venue: arXiv cs.OH 2013
Year: 2013

This project is part of the development of mobile CRM. It aims to develop a management application client named NOMALYS. This application allows the commercial and business leaders to see their CRM Mobile. We have focused in this project on the techniques of projects management, this study allowed to classify different techniques for managing software projects and proposed the most closely technique that match the needs of the studied company.
The Multidimensional Study of Viral Campaigns as Branching Processes
Venue: arXiv cs.SI 2013
Year: 2013

Viral campaigns on the Internet may follow variety of models, depending on the content, incentives, personal attitudes of sender and recipient to the content and other factors. Due to the fact that the knowledge of the campaign specifics is essential for the campaign managers, researchers are constantly evaluating models and real-world data. The goal of this article is to present the new knowledge obtained from studying two viral campaigns that took place in a virtual world which followed the branching process. The results show that it is possible to reduce the time needed to estimate the model parameters of the campaign and, moreover, some important aspects of time-generations relationship are presented.
Quantum and Concept Combination, Entangled Measurements and Prototype Theory
Venue: arXiv cs.AI 2013
Year: 2013

We analyze the meaning of the violation of the marginal probability law for situations of correlation measurements where entanglement is identified. We show that for quantum theory applied to the cognitive realm such a violation does not lead to the type of problems commonly believed to occur in situations of quantum theory applied to the physical realm. We briefly situate our quantum approach for modeling concepts and their combinations with respect to the notions of 'extension' and 'intension' in theories of meaning, and in existing concept theories.
Least-Squares FIR Models of Low-Resolution MR data for Efficient Phase-Error Compensation with Simultaneous Artefact Removal
Venue: arXiv cs.CV 2013
Year: 2013

Signal space models in both phase-encode, and frequency-encode directions are presented for extrapolation of 2D partial kspace. Using the boxcar representation of low-resolution spatial data, and a geometrical representation of signal space vectors in both positive and negative phase-encode directions, a robust predictor is constructed using a series of signal space projections. Compared to some of the existing phase-correction methods that require acquisition of a pre-determined set of fractional kspace lines, the proposed predictor is found to be more efficient, due to its capability of exhibiting an equivalent degree of performance using only half the number of fractional lines. Robust filtering of noisy data is achieved using a second signal space model in the frequency-encode direction, bypassing the requirement of a prior highpass filtering operation. The signal space is constructed from Fourier Transformed samples of each row in the low-resolution image. A set of FIR filters are estimated by fitting a least squares model to this signal space. Partial kspace extrapolation using the FIR filters is shown to result in artifact-free reconstruction, particularly in respect of Gibbs ringing and streaking type artifacts.
Simulations and Bisimulations For Coalgebraic Modal Logics
Venue: arXiv cs.LO 2013
Year: 2013

We define a notion of Lambda-simulation for coalgebraic modal logics, parametric on the choice Lambda of predicate liftings for a functor T. We show this notion is adequate in several ways: i) it preserves truth of positive formulas, ii) for Lambda a separating set of monotone predicate liftings, the associated notion of Lambda-bisimulation corresponds to T-behavioural equivalence (moreover Lambda-n-bisimulations correspond to T-n-behavioural equivalence), and iii) in fact, for Lambda-separating and T preserving weak pullbacks, difunctional Lambda-bisimulations are T-bisimulations. In essence, we arrive at a modular notion of equivalence that, when used with a separating set of monotone predicate liftings, coincides with T-behavioural equivalence regardless of whether T preserves weak pullbacks (unlike the notion of T-bisimilarity).
Artifact Lifecycle Discovery
Venue: arXiv cs.SE 2013
Year: 2013

Artifact-centric modeling is a promising approach for modeling business processes based on the so-called business artifacts - key entities driving the company's operations and whose lifecycles define the overall business process. While artifact-centric modeling shows significant advantages, the overwhelming majority of existing process mining methods cannot be applied (directly) as they are tailored to discover monolithic process models. This paper addresses the problem by proposing a chain of methods that can be applied to discover artifact lifecycle models in Guard-Stage-Milestone notation. We decompose the problem in such a way that a wide range of existing (non-artifact-centric) process discovery and analysis methods can be reused in a flexible manner. The methods presented in this paper are implemented as software plug-ins for ProM, a generic open-source framework and architecture for implementing process mining tools.
Making Systems More Robust with Flexible RPC Lookup
Venue: arXiv cs.DC 2013
Year: 2013

Modern distributed systems use names everywhere. Lockservices such as Chubby and ZooKeeper provide an effective mechanism for mapping from application names to server instances, but proper usage of them requires a large amount of error-prone boiler-plate code. Application programmers often try to write wrappers to abstract away this logic, but it turns out there is a more general and easier way of handling the issue. We show that by extending the existing name resolution capabilities of RPC libraries, we can remove the need for such annoying boiler-plate code while at the same time making our services more robust.
Energy Cooperation in Energy Harvesting Communications
Venue: arXiv cs.IT 2013
Year: 2013

In energy harvesting communications, users transmit messages using energy harvested from nature during the course of communication. With an optimum transmit policy, the performance of the system depends only on the energy arrival profiles. In this paper, we introduce the concept of energy cooperation, where a user wirelessly transmits a portion of its energy to another energy harvesting user. This enables shaping and optimization of the energy arrivals at the energy-receiving node, and improves the overall system performance, despite the loss incurred in energy transfer. We consider several basic multi-user network structures with energy harvesting and wireless energy transfer capabilities: relay channel, two-way channel and multiple access channel. We determine energy management policies that maximize the system throughput within a given duration using a Lagrangian formulation and the resulting KKT optimality conditions. We develop a two-dimensional directional water-filling algorithm which optimally controls the flow of harvested energy in two dimensions: in time (from past to future) and among users (from energy-transferring to energy-receiving) and show that a generalized version of this algorithm achieves the boundary of the capacity region of the two-way channel.
A legal perspective of E-business and E-marketing for small and medium enterprises
Venue: arXiv cs.CY 2013
Year: 2013

Electronic businesses are witnessing enormous growth as more and more people are switching to online platforms. The widespread use of Internet has opened new channels to operate trade for many businesses. Also electronic marketing has become a proven channel of passing on the word to the customers. Legal and ethical issues quickly become an area of concern. In this research recommendations are made to harmonize IT and Internet Laws. A novel approach is proposed to promote legal risk management culture in organizations. It begins with revising current state of regulations surrounding eBusinesses and electronic marketing. The proposed approach offers risk management by considering risk mitigation strategy, educating people and use of information technology. Monitoring compliance requirements are met by reviewing the latest changes in regulations and rewarding the employees who ensures the successful implementation of the strategy.
Principles of Security: Human, Cyber, and Biological
Venue: arXiv cs.CR 2013
Year: 2013

Cybersecurity attacks are a major and increasing burden to economic and social systems globally. Here we analyze the principles of security in different domains and demonstrate an architectural flaw in current cybersecurity. Cybersecurity is inherently weak because it is missing the ability to defend the overall system instead of individual computers. The current architecture enables all nodes in the computer network to communicate transparently with one another, so security would require protecting every computer in the network from all possible attacks. In contrast, other systems depend on system-wide protections. In providing conventional security, police patrol neighborhoods and the military secures borders, rather than defending each individual household. Likewise, in biology, the immune system provides security against viruses and bacteria using primarily action at the skin, membranes, and blood, rather than requiring each cell to defend itself. We propose applying these same principles to address the cybersecurity challenge. This will require: (a) Enabling pervasive distribution of self-propagating securityware and creating a developer community for such securityware, and (b) Modifying the protocols of internet routers to accommodate adaptive security software that would regulate internet traffic. The analysis of the immune system architecture provides many other principles that should be applied to cybersecurity. Among these principles is a careful interplay of detection and action that includes evolutionary improvement. However, achieving significant security gains by applying these principles depends strongly on remedying the underlying architectural limitations.
Guaranteed Performance Leader-follower Control for Multi-agent Systems with Linear IQC-Constrained Coupling
Venue: arXiv cs.SY 2013
Year: 2013

This paper considers the leader-follower control problem for a linear multi-agent system with undirected topology and linear coupling subject to integral quadratic constraints (IQCs). A consensus-type control protocol is proposed based on each agent's states relative its neighbors. In addition a selected set of agents uses for control their states relative the leader. Using a coordinate transformation, the consensus analysis of the multi-agent system is recast as a decentralized robust control problem for an auxiliary interconnected large scale system. Based on this interconnected large scale system, sufficient conditions are obtained which guarantee that the system tracks the leader. These conditions guarantee a suboptimal bound on the system tracking performance. The effectiveness of the proposed method is demonstrated using a simulation example.
Robust blind methods using $\ell_p$ quasi norms
Venue: arXiv cs.IT 2013
Year: 2013

It was shown in a previous work that some blind methods can be made robust to channel order overmodeling by using the $\ell_1$ or $\ell_p$ quasi-norms. However, no theoretical argument has been provided to support this statement. In this work, we study the robustness of subspace blind based methods using $\ell_1$ or $\ell_p$ quasi-norms. For the $\ell_1$ norm, we provide the sufficient and necessary condition that the channel should satisfy in order to ensure its identifiability in the noise-less case. We then study its frequency of occurrence, and deduce the effect of channel parameters on the robustness of blind subspace methods using $\ell_1$ norms.