ppxscal/embedding_network huggingface dataset:
Exploring exploring a word processor
Authors: John M. Carroll, Robert L. Mack, Clayton H. Lewis, Nancy L. Grischkowsky, Scott R. Robertson
Venue: Human-computer interaction (1985)

Studies of people learning to use contemporary word-processing equipment suggest that effective learning is often "active," proceeding by self-initiated problem solving. The instructional manuals that accompany current word-processing systems often penalize and impede active learning. A set of instructional materials was constructed for a commercial word processor, specifically designed to support and encourage an active learning orientation. These "guided exploration" (GE) materials are modular, task oriented, procedurally incomplete, and address error recognition and recovery. Learners using the GE materials spent substantially less time yet still performed better on a transfer of learning posttest than learners using commercially developed self-study materials. Qualitative analysis of aspects of the learning protocols of participants suggested that active learning mechanisms may underlie this advantage.
A new concise representation of frequent itemsets using generators and a positive border
Authors: Guimei Liu, Jinyan Li, Limsoon Wong
Venue: Knowledge and Information Systems (2008)

A complete set of frequent itemsets can get undesirably large due to redundancy when the minimum support threshold is low or when the database is dense. Several concise representations have been previously proposed to eliminate the redundancy. Generator based representations rely on a negative border to make the representation lossless. However, the number of itemsets on a negative border sometimes even exceeds the total number of frequent itemsets. In this paper, we propose to use a positive border together with frequent generators to form a lossless representation. A positive border is usually orders of magnitude smaller than its corresponding negative border. A set of frequent generators plus its positive border is always no larger than the corresponding complete set of frequent itemsets, thus it is a true concise representation. The generalized form of this representation is also proposed. We develop an efficient algorithm, called GrGrowth, to mine generators and positive borders as well as their generalizations. The GrGrowth algorithm uses the depth-first-search strategy to explore the search space, which is much more efficient than the breadth-first-search strategy adopted by most of the existing generator mining algorithms. Our experiment results show that the GrGrowth algorithm is significantly faster than level-wise algorithms for mining generator based representations, and is comparable to the state-of-the-art algorithms for mining frequent closed itemsets.
Self-equilibrium control on a dynamic bicycle ride
Authors: Chieh-Tsung Chi
Venue: WSEAS Transactions on Systems and Control (2007)

It is very important for a biker to ride comfortably and safely around everywhere. Through analyzing the stability characteristic of a bicycle when it was driven on each sloping road, the position of the center of gravity (COG) was commonly one of the key influencing factors. Therefore, this study presented a simple approach to measure the inclination degree of sloping road and fed to the system controller for changing the COG position. Moreover, the front-to-back adaptive equilibrium control of a bicycle ride was controlled by means of a hysteresis algorithm, and built in a control unit. The COG position of a whole bicycle system allowed to be changed by either manual or automatic mode which was completely dependent upon biker decision. For convenience, an experimental prototype had first been established in the laboratory. Later, several experiments, such as the feasibility and flexibility concerning system control structure were related to a bicycle were performed on the prototype. Simulation and experimental results showed that the dynamic equilibrium of a bicycle when it was driven on each sloping road could be controlled by using the posture control approach proposed in this paper. In addition, the increasing cost concerning additional facilities was cheap and easily retrofitted into the existing bicycles.
Game theoretic approach to location sharing with privacy in a community-based mobile safety application
Authors: Hua Liu, Bhaskar Krishnamachari, Murali Annavaram
Venue: Proceedings of the 11th international symposium on Modeling, analysis and simulation of wireless and mobile systems (2008)

A new generation of community-based social networking mobile applications is emerging. In these applications, there is often a fundamental tension between users' desire for preserving the privacy of their own data and their need for fine-grained information about others. Our work is motivated by a community-based mobile application called Aegis, a personal safety enhancement service based on sharing location information with trusted nearby friends. We model the privacy-participation tradeoffs in this application using a game theoretic formulation. Users in this game are assumed to be self-interested. They prefer to obtain more fine-grained knowledge from others while limiting their own privacy leak (i.e. their own contributions to the game) as much as possible. We design a tit-for-tat mechanism to give user incentives to contribute to the application. We investigate the convergence of two best response dynamics to achieve a non-trivial Nash equilibrium for this game. Further, we propose an algorithm that yields a Pareto optimal Nash equilibrium. We show that this algorithm guarantees polynomial time convergence and can be executed in a distributed manner.
Expert system based adaptive dynamic matrix control for ball mill grinding circuit
Authors: Xi-song Chen, Shi-hua Li, Jun-yong Zhai, Qi Li
Venue: Expert Systems with Applications: An International Journal (2009)

Ball mill grinding circuit is a multiple-input multiple-output (MIMO) system characterized with couplings and nonlinearities. Stable control of grinding circuit is usually interrupted by great disturbances, such as ore hardness and feed particle size, etc. Conventional model predictive control usually cannot capture the nonlinearities caused by the disturbances in real practice. Multiple models based adaptive dynamic matrix control (ADMC) is proposed for the control of ball mill grinding circuit. The novelty of the strategy lies in that intelligent expert system is developed to identify the current ore hardness and then select a proper model for ADMC. Compared with the various nonlinear DMC strategies, the approach can synthesize and analyze as many variables and status as possible to adequately and reliably identify the process conditions, and it does not introduce additional computational complexity, which makes it readily available to the industrial practitioner. Simulation results and industrial applications demonstrate the effectiveness and practicality of this control strategy.
Removing backward go-to statements from Ada programs: possibilities and problems
Authors: Ward D. Maurer
Venue: Proceedings of the 2008 ACM annual international conference on SIGAda annual international conference (2008)

We here apply a recent mathematical result to the design of a process for removing backward go-to statements from Ada programs. Such statements are often used by programmers whose only reasons to use Ada are contractual. The mathematical result involves directed graphs, such as the flow graphs of programs, and the first step in our algorithm involves constructing the flow graph of an Ada program. In the second step, this flow graph is rearranged according to our mathematical result, which specifies a linear order for every flow graph, together with a structure for it, of loops within loops, in which no loops overlap. In the third step, a new Ada program is produced from the rearranged flow graph. A problem arises here, within the syntax of Ada, which does not allow branching into a sequence of statements. We show how this problem must be addressed, even though addressing it can involve removing existing structure from the Ada program which we are processing.
Peaks Detection in X-Ray Diffraction Profiles Using Grid Computing
Authors: Enrique Morales-Ramos, Miguel A. Vega-Rodríguez, Antonio Gómez-Iglesias, Miguel Cárdenas-Montes, Juan A. Gómez-Pulido, Florentino Sánchez-Bajo
Venue: Proceedings of the OTM 2008 Confederated International Conferences, CoopIS, DOA, GADA, IS, and ODBASE 2008. Part I on On the Move to Meaningful Internet Systems: (2008)

X-Ray scattering techniques pose some problems for automatic peaks detection on diffraction profiles that can be interesting from a computational point of view. In this way, finding out the measure in which a model fits to an a priori known profile is an optimization problem needing the definition of a figure of merit, whose calculation involves a hard computing effort. A sequential algorithm exploring all the existing possibilities in the solution space of this problem surely would be discarded due to its cost in terms of execution time. Running this algorithm on a grid computing infrastructure helps to reduce a lot this effort and allows to show real results and to offer conclusions about the application of this recent distributed computing paradigm to scientific matters.
New Mechanisms for Mixing Time- and Behaviour-Dependent Tactics in Negotiation Strategies
Authors: Jan Richter, Ryszard Kowalczyk
Venue: Proceedings of the 2008 IEEE/WIC/ACM International Conference on Web Intelligence and Intelligent Agent Technology - Volume 02 (2008)

This paper studies three different mixing mechanisms for creating negotiation strategies out of single tactics. It shows that a mechanism introduced by Faratin et al [5] can result in a non-monotonic behaviour in a negotiation strategy in some scenarios where the time- and behavior- dependent tactics are mixed. In single issue negotiations this behaviour seems irrational and the paper proposes an additional simple constraint to solve that problem. Moreover two new mixing mechanisms are introduced and discussed: one based on individual negotiation threads of all imitative tactics and one based on single concessions. Results of an experiment demonstrate that the two new methods gain on average higher utilities than the constrained original method but at the same time can increase the risk to fail negotiation in some scenarios.
Minimizing spatial and time reservation with Collision-Aware DCF in mobile ad hoc networks
Authors: Lubo Song, Chansu Yu
Venue: Ad Hoc Networks (2009)

Carrier sensing is widely adopted in wireless communication to protect data transfers from collisions. For example, distributed coordination function (DCF) in IEEE 802.11 standard renders a node to defer its communication if it senses the medium busy. For the duration of deferment, each frame carries, in its MAC header, a 16-bit number in microseconds during which any overhearing node must defer. However, even if the carrier signal is detected, both ongoing and a new communication can be simultaneously successful depending on their relative positions in the network or equivalently, their mutual interference level. Supporting multiple concurrent communications is important in multihop ad hoc networks in order to maximize the network performance. However, it is largely ignored in DCF of the 802.11 standards because it is primarily targeted at single-hop wireless LANs. In addition, in DCF, the time duration information mentioned above is not delivered to all potential interferers, particularly those in the distance. This paper proposes Collision-Aware DCF (CAD) that efficiently utilizes the available channel resource along with the spatial as well as time dimension. First, each node makes its deferment decision adaptively based on the feedback from the communication counterpart and the status of the medium rather than on a simple, fixed carrier sense threshold as DCF. Second, CAD embeds the spatial and time reservation requirements in the PHY header, which is transmitted at the lowest data rate, so that a larger group of neighbors become aware of the ongoing communication and thus avoid collisions. Extensive experiments based on ns-2 network simulator show that CAD consistently outperforms DCF regardless of node mobility, traffic intensity, and channel randomness. For practicality, this paper discusses the implementation of CAD based on the DCF specification.
From minimal signed circuits to the dynamics of Boolean regulatory networks
Authors: Elisabeth Remy, Paul Ruet
Venue: Bioinformatics (2008)

It is acknowledged that the presence of positive or negative circuits in regulatory networks such as genetic networks is linked to the emergence of significant dynamical properties such as multistability (involved in differentiation) and periodic oscillations (involved in homeostasis). Rules proposed by the biologist R. Thomas assert that these circuits are necessary for such dynamical properties. These rules have been studied by several authors. Their obvious interest is that they relate the rather simple information contained in the structure of the network (signed circuits) to its much more complex dynamical behaviour. We prove in this article a nontrivial converse of these rules, namely that certain positive or negative circuits in a regulatory graph are actually sufficient for the observation of a restricted form of the corresponding dynamical property, differentiation or homeostasis. More precisely, the crucial property that we require is that the circuit be globally minimal. We then apply these results to the vertebrate immune system, and show that the two minimal functional positive circuits of the model indeed behave as modules which combine to explain the presence of the three stable states corresponding to the Th0, Th1 and Th2 cells. Contact: ruet@iml.univ-mrs.fr Supplementary information: Supplementary data are available at Bioinformatics online.
A class of parallel tiled linear algebra algorithms for multicore architectures
Authors: Alfredo Buttari, Julien Langou, Jakub Kurzak, Jack Dongarra
Venue: Parallel Computing (2009)

As multicore systems continue to gain ground in the high performance computing world, linear algebra algorithms have to be reformulated or new algorithms have to be developed in order to take advantage of the architectural features on these new processors. Fine grain parallelism becomes a major requirement and introduces the necessity of loose synchronization in the parallel execution of an operation. This paper presents algorithms for the Cholesky, LU and QR factorization where the operations can be represented as a sequence of small tasks that operate on square blocks of data. These tasks can be dynamically scheduled for execution based on the dependencies among them and on the availability of computational resources. This may result in out of order execution of tasks which will completely hide the presence of intrinsically sequential tasks in the factorization. Performance comparisons are presented with LAPACK algorithms where parallelism can only be exploited at the level of the BLAS operations and vendor implementations.
Profiler and compiler assisted adaptive I/O prefetching for shared storage caches
Authors: Seung Woo Son, Sai Prashanth Muralidhara, Ozcan Ozturk, Mahmut Kandemir, Ibrahim Kolcu, Mustafa Karakoy
Venue: Proceedings of the 17th international conference on Parallel architectures and compilation techniques (2008)

I/O prefetching has been employed in the past as one of the mechanisms to hide large disk latencies. However, I/O prefetching in parallel applications is problematic when multiple CPUs share the same set of disks due to the possibility that prefetches from different CPUs can interact on shared memory caches in the I/O nodes in complex and unpredictable ways. In this paper, we (i) quantify the impact of compiler-directed I/O prefetching - developed originally in the context of sequential execution - on shared caches at I/O nodes. The experimental data collected shows that while I/O prefetching brings benefits, its effectiveness reduces significantly as the number of CPUs is increased; (ii) identify inter-CPU misses due to harmful prefetches as one of the main sources for this reduction in performance with the increased number of CPUs; and (iii) propose and experimentally evaluate a profiler and compiler assisted adaptive I/O prefetching scheme targeting shared storage caches. The proposed scheme obtains inter-thread data sharing information using profiling and, based on the captured data sharing patterns, divides the threads into clusters and assigns a separate (customized) I/O prefetcher thread for each cluster. In our approach, the compiler generates the I/O prefetching threads automatically. We implemented this new I/O prefetching scheme using a compiler and the PVFS file system running on Linux, and the empirical data collected clearly underline the importance of adapting I/O prefetching based on program phases. Specifically, our proposed scheme improves performance, on average, by 19.9%, 11.9% and 10.3% over the cases without I/O prefetching, with independent I/O prefetching (each CPU is performing compiler-directed I/O prefetching independently), and with one CPU prefetching (one CPU is reserved for prefetching on behalf of others), respectively, when 8 CPUs are used.
Discretized Fractional Calculus with a Series of Chebyshev Polynomial
Authors: Tsuyako Miyakoda
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2009)

In this paper, we tried to evaluate the fractional derivatives by using the Chebyshev series expansion. We discuss the indefinite quadrature rule to estimate the fractional derivatives of Riemann-Liouville type.
Sampled tracking for linear delayed plants using piecewise functioning controller
Authors: Wang Haoping, Vasseur Christian, Chamroo Afzal, Koncar Vladan
Venue: WSEAS Transactions on Systems and Control (2007)

This article presents a control method to realize tracking of linear plants that deliver a delayed and sampled state. To do so, we make use of a class of piecewise functioning controller (PFC): bi-sampled controller. The use of this type of controller allows sampled tracking with a delay twice as much as that on the state's output. Thus, we propose an optimal mathematical approach of the dynamics of our controller. We then give an adaptation of this mathematical approach, using only the delayed and sampled state. Computer simulation results are given so as to enhance the theoretical aspect of our method.
LIDF: Layered intrusion detection framework for ad-hoc networks
Authors: Nikos Komninos, Christos Douligeris
Venue: Ad Hoc Networks (2009)

As ad-hoc networks have different characteristics from a wired network, the intrusion detection techniques used for wired networks are no longer sufficient and effective when adapted directly to a wireless ad-hoc network. In this article, first the security challenges in intrusion detection for ad-hoc networks are identified and the related work for anomaly detection is discussed. We then propose a layered intrusion detection framework, which consists of collection, detection and alert modules that are handled by local agents. The collection, detection and alert modules are uniquely enabled with the main operations of ad-hoc networking, which are found at the OSI link and network layers. The proposed modules are based on interpolating polynomials and linear threshold schemes. An experimental evaluation of these modules shows their efficiency for several attack scenarios, such as route logic compromise, traffic patterns distortion and denial of service attacks.
Routing optimization heuristics algorithms for urban solid waste transportation management
Authors: Nikolaos V. Karadimas, Nikolaos Doukas, Maria Kolokathi, Gerasimoula Defteraiou
Venue: WSEAS Transactions on Computers (2008)

During the last decade, metaheuristics have become increasingly popular for effectively confronting difficult combinatorial optimization problems. In the present paper, two individual meatheuristic algorithmic solutions, the ArcGIS Network Analyst and the Ant Colony System (ACS) algorithm, are introduced, implemented and discussed for the identification of optimal routes in the case of Municipal Solid Waste (MSW) collection. Both proposed applications are based on a geo-referenced spatial database supported by a Geographic Information System (GIS). GIS are increasingly becoming a central element for coordinating, planning and managing transportation systems, and so in collaboration with combinatorial optimization techniques they can be used to improve aspects of transit planning in urban regions. Here, the GIS takes into account all the required parameters for the MSW collection (i.e. positions of waste bins, road network and the related traffic, truck capacities, etc) and its desktop users are able to model realistic network conditions and scenarios. In this case, the simulation consists of scenarios of visiting varied waste collection spots in the Municipality of Athens (MoA). The user, in both applications, is able to define or modify all the required dynamic factors for the creation of an initial scenario, and by modifying these particular parameters, alternative scenarios can be generated. Finally, the optimal solution is estimated by each routing optimization algorithm, followed by a comparison between these two algorithmic approaches on the newly designed collection routes. Furthermore, the proposed interactive design of both approaches has potential application in many other environmental planning and management problems.
Experience with usability evaluation of e-learning systems
Authors: Andrina Grani&#x0107;
Venue: Universal Access in the Information Society (2008)

Progress in the field of e-learning has been slow, with related problems mainly associated with the poor design of e-learning systems. Moreover, because of a depreciated importance of usability, usability studies are not very frequent. This paper reports the experience with the usability assessment of intelligent learning and teaching systems which are based on TEx-Sys model and are intended to enhance the process of knowledge acquisition in daily classroom settings. The applied scenario-based usability evaluation, as a combination of behaviour and opinion based measurements, enabled to quantify usability in terms of users&#x2019; (teachers&#x2019; and students&#x2019;) performance and satisfaction. According to the achieved results, the main directions for interface redesign are offered. The acquired experience indicates that useful usability assessments with a significant identification of interface limitations can be performed quite easily and quickly. On the other hand, it raised a series of questions which, in order to be clarified, require further comprehensive research, the more so if the employment of universal design within e-learning context is considered.
Investigation of evolutionary optimization methods of TSK fuzzy model for real estate appraisal
Authors: Dariusz Król, Tadeusz Lasota, Bogdan Trawiński, Krzysztof Trawiński
Venue: International Journal of Hybrid Intelligent Systems (2008)

Takagi-Sugeno-Kang fuzzy model to assist with real estate appraisals is described and optimized using evolutionary algorithms. Two approaches were compared in the paper. The first one consisted in learning the rule base and the second one in combining learning the rule base and tuning the membership functions in one process. Moreover two model variants with three and five triangular and trapezoidal membership functions describing each input variable were tested. Several TSK fuzzy models comprising different number of input variables were evaluated using the MATLAB. The evolutionary algorithms were based on Pittsburgh approach with the real coded chromosomes of constant length comprising whole rule base or both the rule base and all parameters of all membership functions. The experiments were conducted using training and testing sets prepared on the basis of actual 150 sales transactions made in one of Polish cities and located in a residential section. The results obtained were not decisive and further research in this area is needed.