A new environment for education? The computer in the home

This paper derives from an interdisciplinary research project which is studying the engagement of young people with different aspects of techno-popular culture. The focus is on the young person and the significance of digital technologies in their lives as a whole. Drawing on cultural studies research we are investigating the ways in which the contexts for computer use are structured by the different discourses present within the family, and the ways in which these discourses may provide a framing context for children’s interactions with digital technology. Drawing on socio-cultural research we take the view that learning is learning to do something with a cultural or cognitive tool. Our analysis of data from case studies of 16 families shows that the context of home computer use amongst young people is far from a simple and uniform phenomenon and is structured by the different discourses present within the family. What young people learn through interaction with computers is thus as much framed by the context of use as by the affordance of the technology.     

The power manipulability – A new homogeneous performance index of robot manipulators

Jacobian-based performance indices such as the manipulability ellipsoid, the condition number and the minimum singular value, have been very helpful tools both for mechanical manipulator design and for determining suitable manipulator postures to execute a given task. For a manipulator having complex degrees of freedom (translations and rotations), Jacobian matrix becomes non-homogeneous, i.e. it contains elements with different physical units; therefore, the evaluation of its determinant, eigenvalues or singular values needs the combination of quantities of different nature, which is physically inconsistent and moreover it corresponds to a noncommensurable system. In this paper, a new performance index of robot manipulators is proposed. It is fully homogeneous and it constitutes a physically consistent system whether the manipulator contains joints of different natures, or the task space combines both translation and rotation motion. The development is concerned with the study of power within the mechanism. Given that the power has the same physical units in translation and rotation, it can be used as a homogeneous or natural performance index of manipulators by examining the behaviour of its basic components namely, force and speed, at different kinematics configurations. Furthermore, the new concept of vectorial power is introduced, followed by to the quadrivector of apparent power, and leading to the final homogeneous performance index of the power manipulability (PM). This new approach matches perfectly with mechanisms having joints of different natures, as well as with a task space combining both translation and rotation.     

A contribution to the real-time simulation of coupled finite element models of machine tools – A numerical comparison

In this paper the real-time simulation of finite element (FE) models of machine tools on a multi-processor architecture is presented. The simulation model is based on several FE component models that are connected by non-linear couplings. These couplings allow relative motions of the components in a wide range. The coupled linear FE models are decomposed at the non-linear coupling nodes and each component is solved locally. The linear structure of the components can be used for efficient simulation methods and the components can be distributed to several processors for a parallel computation. Methods that differ in numerical accuracy and stability, computational effort and real-time capacity will be presented. By means of a complex example, it will be illustrated that a parallel, stable computation can be realized time-deterministically.     

Collusive attacks to “circle-type” multi-party quantum key agreement protocols

We find that existing multi-party quantum key agreement (MQKA) protocols designed for fairness of the key are, in fact, unfair. Our analysis shows that these protocols are sensitive to collusive attacks; that is, dishonest participants can collaborate in predetermining the key without being detected. In fact, the transmission structures of the quantum particles in those unfair MQKA protocols, three of which have already been analyzed, have much in common. We call these unfair MQKA protocols circle-type MQKA protocols. Likewise, the transmission structures of the quantum particles in MQKA protocols that can resist collusive attacks are also similar. We call such protocols complete-graph-type MQKA protocols. A MQKA protocol also exists that can resist the above attacks but is still not fair, and we call it the tree-type MQKA protocol. We first point out a common, easily missed loophole that severely compromises the fairness of present circle-type MQKA protocols. Then we show that two dishonest participants at special positions can totally predetermine the key generated by circle-type MQKA protocols. We anticipate that our observations will contribute to secure and fair MQKA protocols, especially circle-type protocols.     

玩转“牛排” The new iPad完全攻略

苹果在今年3月7日正式发布了第三代iPad产品,这款产品被命名为The new iPad(以下简称"新iPad")。它拥有一块1536×2048的巨型视网膜屏,并配备了一个采用背光成像技术的后置500万像素iSight摄像头。它还配备了一颗A5X四核处理器,同时内存容量也首次提升到了1GB。那么,新iPad在这一系列的升级之后,给我们带来了什么新的体验与用途呢?     

The new ipad “屏”什么火？

上月，当互联网发布2012年最新的中国平板电脑市场分析月报时．我们惊奇地发现，因乔老爷的死而备受世人关注的The new ipad （以下简称“iPad3）．如今只剩下了—“关注”二宇。……为什么堪称乔布斯遗作的神器．会论为大家“眼中的好东西“，而无法吸引更多人去疯狂购买呢？     

A quantitative multimodal discourse analysis of teaching and learning in a web-conferencing environment – The efficacy of student-centred learning designs

This paper presents a quantitative approach to multimodal discourse analysis for analyzing online collaborative learning. The coding framework draws together the fields of systemic functional linguistics and Activity Theory to analyze interactions between collaborative-, content- and technology-related discourse. The approach is used to examine how the task subject matter, the activity design, and the choice of interface affected interaction and collaboration for a computing course conducted in a web-conferencing environment. The analysis revealed the critical impact of activity design on the amount and type of discourse that transpired. Student-centred designs resulted in over six times more student discourse as compared to teacher-centred designs and created a learning environment where students took greater ownership over the tasks and contributed more to the content-based discussion. The paper also incorporates a rationale for the approach to coding and a reflection on its efficacy for discourse analysis in technology-based learning environments.     

“Virtual laboratory environment” (VLE): a software environment oriented agent and object for modeling and simulation of complex systems

Our research relates to multi-agent and oriented object modeling and simulation of the complex systems. Our research interest itself more particularly with system where the spatial and temporal component make a great part of system to model (for example, ecosystems or systems of production). Within the framework of this article, we will be interested in the flexible production systems.The simulation of complex systems requires generally the integration and the coupling of heterogeneous models (multi-agent, mathematical, and so on). This heterogeneity is a consequence of the diversity of the disciplines and abilities of designers. The approach that we develop consists in the development of “virtual laboratories ”. Our platform “virtual laboratory environment” (VLE) enables us to specify, simulate and analyze spatial complex systems. VLE is based on the concepts of reactive agents, objects and spatial and temporal multi-scale systems.     

The effects of joint angle variability and different driving load scenarios on maximum muscle activity – A driving posture simulation study

To date, no studies have been conducted on the main and interaction effects of joint angles on maximum muscle activity in different driving load scenarios. To investigate the influence of joint angle variability on the muscular system, this study calculated maximum muscle activity during three static driving load scenarios through the use of musculoskeletal inverse dynamic simulation. Six joint angles in sagittal plane were varied with reference to reported driving posture angles in the literature. A digital manikin with a height of 180 cm and weight of 70 kg was used with simple muscles and a minimum fatigue criterion for muscle activation optimization. Three static driving load scenarios were simulated: sitting with no external forces except gravity, steering, and pedaling operation. Prediction models were developed for each driving load scenario using Least Squares Support Vector Machine. Finally, the Pareto optimization method was applied for multi-objective optimization combining the three developed models.The results indicate that the developed models can be used for the prediction of simulated maximum muscle activity. The six joint angles explain a higher percentage of maximum muscle activity variance in the steering and pedaling operation scenarios compared to the sitting scenario. The six joint angles differ in their main and interaction effects on maximum muscle activity depending on the driving load scenario. The optimum joint angle values of the driving posture depend on the driving load scenarios. The different driving postures based on minimum maximum muscle activity are presented for the three driving load scenarios.Relevance to industryThe results of this study can be utilized in establishing driving posture simulation models to improve vehicle interiors during the early development stage. Furthermore, the results of this study can provide base data for the development of a tool for real driving posture evaluation of maximum muscle activity.     

A response to “Genetic programming and emergence”

Banzhaf (Genet Program Evol Mach, 2013) raises some interesting points about emergence in the context of genetic programming. However, his central tenet, that genetic programming is an example of top-down emergence, is invalidated by the fact that the evolutionary framework and the system being evolved are two separate structures. Rather, genetic programming is an instance of one emergent system designing a second one. Biological evolution provides a better example of what could be considered top-down emergence.     

From “Onto-GeoNoesis” to “Onto-Genesis”: The Design of Geographic Ontologies

An important issue in geographic ontological research is the ability to design new ontologies. In this context, we first explore the desiderata of domain ontologies in terms of their constituting elements: i.e., the lexicon, concepts, relations, and axioms. Furthermore, we touch upon several characteristics of geographic concepts, which have puzzled geographic information scientists, and present critical topics of geographic ontological research. Based on the previous aspects of the problem, and guided by prior work of analyzing existent geographic ontologies, we have identified their qualities and deficiencies with regard to completeness and adequacy. This meta-ontological approach has guided us in presenting herein, a framework for generating robust geographic ontologies, which will comply with the semantics of the concepts of the specific domain.     

A game-theoretic model of TV show “The Voice”

This paper proposes a game-theoretic model of the two-player best-choice problem with incomplete information. The players (experts) choose between objects by observing their quality in the form of two components forming a sequence of random variables (x_i, y_i), i = 1,..., n. By assumption, the first quality component x_i is known to the players and the second one y_i is hidden. A player accepts or declines an object based on the first quality component only. A player with the maximal sum of the components becomes the winner in the game. The optimal strategies are derived in the cases of independent and correlated quality components.     

A Review of “A Librarian's Guide to an Uncertain Job Market”

SUMMARY

The reference collections of most research libraries contain a readily identifiable collection of standard paper sources used in locating tests and test-related materials for education and psychology. Yet currently there is no electronic equivalent, no set of Internet resources that has been identified as constituting an online literature on tests and measurements. This study attempts to investigate what resources are now available on the Internet for tests and measurements, and identifies the most useful ones. In order to keep the study manageable, the emphasis is on resources for psychological testing, with some educational psychology materials included as well. Whenever possible, evaluative summaries of these resources have been included.     

A “lifegame” approach to surface modeling and rendering

Conway's Lifegame is a trivial and wellknown application of a more general theory called the theory of cellular automata. Complex systems modeling may be based on the theory of cellular automata, originated by John von Neumann. Our approach is to define simple components that we call analog automata. An analog automaton is a finite state automaton where the state is defined in terms of real numbers representing physical quantities such a position, velocity, mass or color. Deterministic state transition function are applied to these automata using information from the state of neighboring automata. In our case, successive generations in the evolution of these cellular automata are mapped onto polygonal meshes in order to build and texture arbitrary surfaces.     

The “presence of others” in a virtual environment: different collaborative modalities with hybrid resources

The purpose of this study is to see in which forms and under which conditions social presence turns into collaboration. Eight couples were asked to find some objects in a virtual environment in which collaboration was allowed but not mandatory. The qualitative analysis of the video recordings shows that all participants resorted to collaboration in forms that were justified by the requirements of the task, the environmental affordances and the different expertise.

Reprint of “Virtual cut-through: A new computer communication switching technique”

In this paper a new switching technique called virtual cut-through is proposed and its performance is analyzed. This switching system is very similar to message switching, with the difference that when a message arrives in an intermediate node and its selected outgoing channel is free (just after the reception of the header), then, in contrast to message switching, the message is sent out to the adjacent node towards its destination before it is received completely at the node; only if the message is blocked due to a busy output channel is a message buffered in an intermediate node. Therefore, the delay due to unnecessary buffering in front of an idle channel is avoided. We analyze and compare the performance of this new switching technique with that of message switching with respect to three measures: network delay, traffic gain and buffer storage requirement. Our analysis shows that cut-through switching is superior (and at worst identical) to message switching with respect to the above three performance measures.

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A Review of “The Library: An Illustrated History”

Abstract

This paper describes one library's experience of using the Internet in its delivery of service to users. It describes the scope and methods of usage of the Internet via ALISplus, the Library's universal information access workstation at California State University, Fresno. It discusses the results of user surveys which were administered during the 1992/93 and 1993/94 academic years at the Library to assess the users' general response to the newly implemented ALISplus, with a focus on the accessibility of the Internet resources. ALISplus has provided access to the Library's GEAC/ADVANCE OPAC, CD-ROM databases, as well as other resources available through the Internet since the Summer 1993. The collective efforts which went into the process of developing the University's World Wide Web home page, under the leadership of the Library, are also described.