ppxscal/embedding_network huggingface dataset:
Makumba: the role of the technology for the sustainability of amateur programming practice and community
Authors: Cristian Bogdan, Rudolf Mayer
Venue: Proceedings of the fourth international conference on Communities and technologies (2009)

We address the issue of sustainability of practice, which we regard as crucial for the sustainability of the community at large. In the absence of material reward, sustaining a specialized activity such as programming is not trivial especially when members move often in and out of the community. Our case is the group of voluntary, amateur student programmers from a European-wide student organization. We present this setting as an Amateur Community and as a Community of Practice, and show how such framing helps in understanding sustainability of practice. Although being totally voluntary and managing a large intranet, the group has been thriving for six years. To explain such high practice sustainability we examine the role of the technology framework used by the group during this time. We then propose a more general framework for understanding practice sustainability in the context of amateur communities of practice.
Error-resilient scalable compression based on distributed video coding
Authors: Mourad Ouaret, Frédéric Dufaux, Touradj Ebrahimi
Venue: Image Communication (2009)

Distributed Video Coding (DVC) is a new paradigm for video compression based on the information theoretical results of Slepian-Wolf (SW) and Wyner-Ziv (WZ). In this work, a performance analysis of image and video coding schemes based on DVC is presented, addressing temporal, quality and spatial scalability. More specifically, conventional coding is used to obtain a base layer while WZ coding generates the enhancement layers. At the decoder, the base layer is used to construct Side Information (SI) for the DVC decoding process. Initially, we show that the scalable DVC approach is codec-independent, which means that it is independent from the method used to encode the base layer. Moreover, the influence of the base layer quality on the overall performance of the schemes is studied. Finally, evaluation of the proposed schemes is performed in both cases, with and without transmission errors. The simulation results show that scalable DVC has a lower compression efficiency than conventional scalable coding (i.e. scalable video coding and JPEG2000 for video and image, respectively) in error-free conditions. On the other hand, the DVC-based schemes show better error resilience as they outperform conventional scalable coding in error-prone conditions. More specifically, the Rate Distortion (RD) performance of the proposed schemes for image coding is compared with respect to Reed Solomon (RS) protected JPEG2000. While the latter exhibits a cliff effect as its performance dramatically decreases after a certain error rate, the performance of the DVC-based schemes decreases in a steady way with error rate increase.
Using Background Knowledge and Context Knowledge in Ontology Mapping
Authors: Hassan Fatemi, Mohsen Sayyadi, Hassan Abolhassani
Venue: Proceeding of the 2008 conference on Formal Ontologies Meet Industry (2008)

Recent evaluations of mapping systems show that lack of background knowledge, most often domain specific knowledge, is one of the key problems of mapping systems these days. In fact, at present, most state of the art systems, for the tasks of mapping large ontologies, perform not with such high values of recall (~ 30%), because they mainly rely on label and structure based similarity measures. Disregarding context knowledge in ontology mapping is another drawback that almost all current approaches suffer from. In this paper we use the semantic web as background knowledge and introduce a novel approach for capturing context knowledge from the ontology for improving mapping results. We have successfully tested our approach with the public test cases of the Ontology Alignment Evaluation Initiative 2005 and achieved promising results.
A fuzzy cognitive map approach for analysis of electronic consumer products in terms of usability among different age groups
Authors: Gulcin Yucel, Ayse Elvan Bayraktaroglu, Murat Engin Unal
Venue: International Journal of Mobile Learning and Organisation (2009)

As a result of widespread use of mobile devices, the role of electronic consumer products (ECPs) in education (mobile learning) is getting important day by day. As ECPs are made up of both hardware and software, both aspects should be considered when evaluating their usability. In this paper, a methodology is proposed to explore the importance of usability dimensions of ECPs among old, middle-aged and young people using FCM. In the case study, mobile phones were chosen as the target product. According to the findings, learnability and efficiency are the most important factors for all age groups. Screen size is found to be the third most important factor for the old user groups. Moreover, the number and function of the button sizes come are found to be important factors for young users.
Proactivity, Autonomy & Social Networking: Transitional Environments for the Japanese Educational Context
Authors: Deborah C. Turk, John W. Brine
Venue: Proceeding of the 2006 conference on Learning by Effective Utilization of Technologies: Facilitating Intercultural Understanding (2006)

In this paper, we describe the theoretical framework for a transitional educational environment for the Japanese context. Building on a previously developed LMS structure for a Technical Reading course, this new course aims to focus on fostering conditions for greater self-reflection, peer feedback, intertextuality, accountability and student control. It uses a combination of LMS (Moodle) features and the blogging capability of a social networking environment (Elgg). This paper will report on its preliminary findings on the student use of the Elgg blogging feature and the Moodle workshop module.
Exploiting Varying Resource Requirements in Wavelet-based Applications in Dynamic Execution Environments
Authors: Bert Geelen, Vissarion Ferentinos, Francky Catthoor, Spyridon Toulatos, Gauthier Lafruit, Thanos Stouraitis, Rudy Lauwereins, Diederik Verkest
Venue: Journal of Signal Processing Systems (2009)

In the context of future dynamic applications, systems will exhibit unpredictably varying platform resource requirements. To deal with this, they will not only need to be programmable in terms of instruction set processors, but also at least partial reconfigurability will be required. In this context, it is important for applications to optimally exploit the memory hierarchy under varying memory availability. This article presents a mapping strategy for wavelet-based applications: depending on the encountered conditions, it switches to different memory optimized instantations or localizations, permitting up to 51% energy gains in memory accesses. Systematic and parameterized mapping guidelines indicate which localization should be selected when, for varying algorithmic wavelet parameters. The results have been formalized and generalized to be applicable to more general wavelet-based applications.
Influence of environmental temperature on the dynamic properties of a die attached MEMS device
Authors: Jing Song, Qing-An Huang, Ming Li, Jie-Ying Tang
Venue: Microsystem Technologies (2009)

Die attach is one of the major processes that may induce unwanted stresses and deformations into micro-electro-mechanical systems (MEMS). The thermo-elastic coupling between the die and package may affect the performance of MEMS under various temperature loads, causing unreasonable effects of the output signal, such as zero offset, temperature coefficient of offset (TCO), nonlinearity, ununiformity and hysteresis, etc. A complete characterization of these effects is critical for a more reliable design. This work presents experimental studies of the temperature effects on the dynamic properties of MEMS. Microbridges and strain gauges with different dimensions were used as test structures. They were surface-micromachined on test chips and the chips were die attached on organic laminate substrates using epoxy bonding as well as tape adhering. The material and dimension of the substrate were specially defined to amplify the magnitude of the coupled deformation for the convenience of investigation. Modal frequencies of the microbridges under a set of controlled environmental temperature before and after die attach were measured using a laser Doppler vibrometer system. The average initial residual strain was also measured from the strain gauges to help analyze the dynamic behavior. Nonlinear TCO of the frequencies were observed to be as large as 2,500&#x2013;5,000&#x00a0;ppm for the epoxy-bonded samples, in contrast with much smaller values for the tape-adhered and unpackaged ones. The frequencies recovered to their original values beyond the curing temperature of the epoxy. A distributed feature was also observed in frequencies of the microbridges with the same length but at different locations of the chip with a maximum relative difference of 20%. The process of thermal cycling and wire bonding was also applied to the samples and caused tender shifts of the frequencies. The experiments reveal major factors that are related to the temperature effects of die attached MEMS and the results are useful for improving the reliability of a package&#x2013;device co-design.
Web based Collaborative Environment for Engineering Graphics Education
Authors: Lianguan Shen, Mujun Li, Xiaodong Wang, Wei Zhao, J. J. Zheng
Venue: Proceeding of the 2006 conference on Learning by Effective Utilization of Technologies: Facilitating Intercultural Understanding (2006)

A web based interactive environment specially for Engineering Graphics education is proposed, which provides a virtual collaborative education platform for geographically distributed teachers and students. The system of B/S (browser/server) mode, different from general netmeeting program, can make a vectorgraph of DWG format show on clients' browsers online synchronously. And then the graphics can be discussed by modifying the objects or putting designed marks on it, as if on a sheet of blueprint. The updated objects by a user can show on the others' browsers immediately. The users can also talk and listen to each other to express their own opinions. In the system the users are organized in different groups according to respective interested topics. In a group there is a controller and the control power can be transferred among the members. The system serves as a bridge between students and teachers for their extracurricular activities. With the tool the student can give his/her haze on browser and ask for help or choose their desired teacher to give some advice, while the teacher can correct student's schoolwork on their own browser. When the schoolwork is checked and corrected, no suspicion of its version is needed to have, the original drawing remains intact and the subsequent external marks are saved in different file respectively. Once the teacher wants to disabuse and give his instructions to one or some students he should only declare or inform them to come to the website at same time and no necessary to come to classroom. Now it has integrated together with a self developed Web based Engineering Graphics courseware and a praxis system into a complete web based engineering education system.
Ambiance: A Mobile Agent Platform for End-User Programmable Ambient Systems
Authors: Reza Razavi, Kirill Mechitov, Gul Agha, Jean-François Perrot
Venue: Proceeding of the 2007 conference on Advances in Ambient Intelligence (2007)

We are interested in situations where multiple uncoordinated non-professional programmer end-users want to exploit the Ambient Intelligence (AmI) infrastructure on their own, without calling in embedded systems programmers, in order to support their daily activities. Our goal is allowing them to achieve this objective through on-the-fly creation and execution of high-level programs that we call uQueries (for user-defined or ubiquitous queries). The key challenge then is to support the cost-effective and stepwise development of uQuery engines --systems for end-user programming and execution of uQueries. We present a meta-level architecture that addresses this issue by leveraging Artificial Intelligence methods that make possible the separation of uQuery representation and reasoning concerns from those of their effective execution through model-to-code transformation. We show that (1) interconnections between ambient devices may be dynamically specified as control flows between high-level descriptions of their primitive functionality, (2) specifications may be elaborated by concurrent, uncoordinated end-users through a Web interface, and (3) they may be automatically distributed and concurrently executed on ambient devices as a system of mobile agents. We have created a prototype of this architecture, the Ambiance Platform, which has allowed experimental validation of the approach using an application scenario proposed in the state-of-the-art of relevant research areas. This experience led us to identify important issues to be explored, including dynamic and seamless integration of sensor and actuator nodes into the system. Furthermore, opportunities exist for significant performance and resource use optimization, for instance by integrating learning mechanisms into uQuery specification, transformation and execution.
Data Quality Tags and Decision-making: Improving the Design and Validity of Experimental Studies
Authors: Rosanne Price, Graeme Shanks
Venue: Proceeding of the 2008 conference on Collaborative Decision Making: Perspectives and Challenges (2008)

Providing decision-makers with information about the quality of the data they are using has been empirically shown to impact both decision outcomes and the decision-making process. However, little attention has been paid to the usability and relevance of the data quality tags and the experimental materials used in studies to date. In this paper, we highlight the potential impact of these issues on experimental validity and propose the use of interaction design techniques to address this problem. We describe current work that applies these techniques, including contextual inquiry and participatory design, to improve the design and validity of planned data quality tagging experiments. The benefits of this approach are illustrated by showing how the outcomes of a series of contextual inquiry interviews have influenced the design of the experimental materials. We argue that interaction design techniques should be used more widely for experimental design.
An asymptotic hybrid difference scheme for singularly perturbed third and fourth order ordinary differential equations with discontinuous source term
Authors: V. Shanthi, N. Ramanujam
Venue: Neural, Parallel Scientific Computations (2008)

We consider Singularly perturbed Boundary-Value Problems (BVPs) for third and fourth order Ordinary Differential Equations (ODEs) with a discontinuous source term and a small positive parameter multiplying the highest derivative. Because of the type of Boundary Conditions (BCs) imposed on these equations these problems can be transformed into weakly coupled systems. In this system, the first equations does not have the small parameter but the second contains it. In this paper a computational method named as "An asymptotic hybrid finite difference scheme" for solving these systems is presented. In this method we first find an zero order asymptotic approximation to the solution and then the system is decoupled by replacing the first component of the solution by this approximation in the second equation. Then the second equation is independently solved by a hybrid finite difference method. Numerical experiments support our theoretical results.
Frequent itemset mining on graphics processors
Authors: Wenbin Fang, Mian Lu, Xiangye Xiao, Bingsheng He, Qiong Luo
Venue: Proceedings of the Fifth International Workshop on Data Management on New Hardware (2009)

We present two efficient Apriori implementations of Frequent Itemset Mining (FIM) that utilize new-generation graphics processing units (GPUs). Our implementations take advantage of the GPU's massively multi-threaded SIMD (Single Instruction, Multiple Data) architecture. Both implementations employ a bitmap data structure to exploit the GPU's SIMD parallelism and to accelerate the frequency counting operation. One implementation runs entirely on the GPU and eliminates intermediate data transfer between the GPU memory and the CPU memory. The other implementation employs both the GPU and the CPU for processing. It represents itemsets in a trie, and uses the CPU for trie traversing and incremental maintenance. Our preliminary results show that both implementations achieve a speedup of up to two orders of magnitude over optimized CPU Apriori implementations on a PC with an NVIDIA GTX 280 GPU and a quad-core CPU.
Integrating Off-line and On-line Schedulers
Authors: Riccardo Rasconi, Nicola Policella, Amedeo Cesta
Venue: Proceeding of the 2006 conference on ECAI 2006: 17th European Conference on Artificial Intelligence August 29 -- September 1, 2006, Riva del Garda, Italy (2006)

This work pursues an empirical study on the mutual interactions among a set of off-line and on-line constraint-based scheduling approaches. We devise a set of closed loop execution management algorithms, and compare their behavior within an experimental framework which allows to directly assess the consequences of each chosen strategy combination against the injection of a number of disturbing events, through simulated schedule executions.
Energy-robustness tradeoff in cellular network power control
Authors: Chee Wei Tan, Daniel P. Palomar, Mung Chiang
Venue: IEEE/ACM Transactions on Networking (TON) (2009)

In the seminal paper by Foschini and Miljanic in 1993, a distributed power control algorithm was developed to meet SIR targets with minimal powers in cellular network uplinks. Since the SIR on an active link may dip below the SIR target during the transient after a new user enters the cell, Bambos et al. proposed an active link protection algorithm to provide robustness, at the expense of higher energy consumption. This paper examines the tradeoff between energy and robustness. An optimization problem is formulated where robustness is captured in the constraint and the price of robustness penalized in the objective function. A distributed algorithm is developed to solve this problem. Local convergence and optimality of equilibrium are proved for the algorithm. The objective function modulates the tradeoff between energy and robustness, and between energy and speed of admission, as illustrated through a series of numerical experiments. A parameterized family of objective functions is constructed to control the transient and equilibrium properties of robust distributed power control.
Efficient symbolic execution of strings for validating web applications
Authors: D. Shannon, I. Ghosh, S. Rajan, S. Khurshid
Venue: Proceedings of the 2nd International Workshop on Defects in Large Software Systems: Held in conjunction with the ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA 2009) (2009)

Symbolic execution is a popular technique used in formal verification of software and hardware systems. In this paper we examine three different ways of performing symbolic execution for the purpose of formal model checking, on web application software implemented with the Java programming language. We evaluate the different techniques on real industrial applications and compare them on issues of performance, implementation ease, and ease-of-use. There are some special characteristics of web applications like extensive use of string inputs that need to be tackled before traditional symbolic execution techniques become feasible. We provide details of how we have solved those issues.
Designing with Video: Focusing the user-centred design process, 1st edition
Authors: Salu Ylirisku, Jacob Buur
Venue:  (2007)

Digital video for user-centred co-design is an emerging field of design, gaining increasing interest in both industry and academia. It merges the traditions of design ethnography, participatory design, interaction analysis, scenario-based design, and usability studies into an integrated approach, which values the designers capacity to study and change the world creatively. Designing with Video: Focusing the User-centred Design Process covers the whole user-centred design project. The book illustrates in detail how digital video can be utilised throughout a design process, from the early user studies, through making sense of the video content and envisioning the future with video scenarios, to provoking change with video artefacts. A must-read for those wishing to create more value through insightful design, the text builds upon a wealth of real, first-hand case studies both in academic and industrial contexts, and is complemented by video excerpts. Teachers, students and professionals in design will all benefit from this approach for developing new ways of enhancing their design processes.
Resource Discovery in Computational Grids: State-of-the-art and Current Challenges
Authors: Aisha Naseer, Lampros Stergioulas
Venue: Proceeding of the 2005 conference on Self-Organization and Autonomic Informatics (I) (2005)

The emerging Grid technologies hold out the promise of a global information channel that is far more powerful and uniquely distinct from the existing internet framework. This paper aims to provide a state of the art of work addressing the need of resource discovery in computational Grids. The various resource discovery models, techniques and approaches are discussed along with their pros & cons, and recommendations are made with respect to practical implementation and directions of future research in Grid resource discovery.
How to Generate Reader Interest in What You Write
Authors: Philip Yaffe
Venue: Ubiquity (2009)

Who has not discovered to their dismay that no one wants to read their most carefully crafted, meritorious, compelling, and passionate writings? Think of all the proposals you have written that no one is interested in. Or the web pages, the blog posts, or the company brochures. Chances are, your failures are linked to an inability to connect with what your readers would be interested in reading. Our intrepid writer about writing, Phil Yaffe, offers some valuable insight into how to get people to read your stuff. He says you need to adopt the "expository writing challenge": that no one is interested in what you are inclined to write, therefore you must discover what they want to read. Only then you can get started, and only then you can succeed. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player