Predicting preferences of university students for prepaid vs post paid cell phone service plans

Information and communication technologies have recently become widely used, especially among the younger population. In this study, the factors affecting the preference of undergraduate students for prepaid or postpaid cell phone service plans were analyzed and a multi-layer perceptron type feed forward neural network model was developed to predict the preferences. Using the responses to the questionnaire administered to a group of undergraduate students in Istanbul University, the factors determining the preference for service plan were determined with χ2 test for independence. A classification model based on multi-layer perceptron type neural networks was developed. The classification accuracy of this model was compared to linear regression, LDA, QDA, Naive Bayes and decision tree approaches and shown to be superior.     

A comparative content analysis of face-to-face vs. asynchronous group decision making

A field experiment was conducted to analyze the process and contents of group discussions. Groups solved a case study either orally or through an asynchronous computer-mediated communication system. Findings show that asynchronous groups had broader discussions and submitted more complete reports than their face-to-face counterparts. However, there was no difference in the ability to transfer information from the discussion to the report; under both conditions, about 15% of the issues mentioned in the discussion were omitted from the final report. In terms of coordination, face-to-face teams covered the case study questions sequentially, while asynchronous groups were more focused on solving their general disagreements.     

网络空间安全本科量子信息教学实践

量子信息是量子物理和信息技术交叉融合产生的新兴学科。近年来，量子信息技术得到了迅速发展，并开始衍生相关产业。与此相对，量子信息从业人员严重缺乏，工程技术人员对量子信息技术的理解不够深入、实操能力不足，这些已成为限制该技术发展和应用的严重瓶颈。人才的匮乏源于教育的缺失。当前，我国的量子信息和新工科蓬勃发展，已具备将量子信息相关课程渗透到工科专业本科阶段的基本条件。在新工科教学思想的指导下，中国科学技术大学面向网络空间安全专业的本科生开设了量子信息相关的导论课程。课程基于我校在量子信息方面的研究和基础，与网络空间安全专业的核心需求和特色结合，在教学目标、课程结构和内容、授课方法和实践手段等方面进行了完整而创新的设计，并取得了较好的教学效果。该课程的教学思路和实践方法为网络空间安全学科的量子信息教学提供了有价值的参考。     

Developing multi-dimensional evaluation criteria for English learning websites with university students and professors

Many English learning websites have been developed worldwide, but little research has been conducted concerning the development of comprehensive evaluation criteria. The main purpose of this study is thus to construct a multi-dimensional set of criteria to help learners and teachers evaluate the quality of English learning websites. These evaluation guidelines are based on web usability, learning materials, functionality of assisting language learning, technology integration, and learner preferences. In order to achieve this goal, the researchers used a rigorous four-phase procedure and utilized both qualitative and quantitative research methods with university students and professors in Design-based Research to construct and refine the evaluation criteria in 2008–2009. Fifty-eight evaluation criteria were refined and finalized. In addition, to cope with the difficulties in applying the derived criteria and explaining what the results indicate, this study presents a practical application by evaluating an English learning website.     

An empirical study of FORTRAN programs

A sample of programs, written in FORTRAN by a wide variety of people for a wide variety of applications, was chosen ‘at random’ in an attempt to discover quantitatively ‘what programmers really do’. Statistical results of this survey are presented here, together with some of their apparent implications for future work in compiler design. The principal conclusion which may be drawn is the importance of a program ‘profile’, namely a table of frequency counts which record how often each statement is performed in a typical run; there are strong indications that profile-keeping should become a standard practice in all computer systems, for casual users as well as system programmers. This paper is the report of a three month study undertaken by the author and about a dozen students and representatives of the software industry during the summer of 1970. It is hoped that a reader who studies this report will obtain a fairly clear conception of how FORTRAN is being used, and what compilers can do about it.     

The design and implementation of a holistic training model for language teacher education in a cyber face-to-face learning environment

This study reports a qualitative investigation that examines the design and implementation of a holistic teacher training model in a cyber face-to-face language learning context. To this end, this study first proposes an e-training model called the Practice, Reflection and Collaboration (PRC) model, and discusses the rationale and theoretical framework underpinning each key component of the model. This is followed by the discussion of how the model was implemented in a 12-week e-teacher training program with the participation of trainee teachers and real distance students. This analysis focuses on how each component of the proposed model worked in our case, and what mechanisms were employed to nurture the trainees’ professional and personal development to become competent and confident e-teachers.     

Informing aggression–prevention efforts by comparing perpetrators of brief vs. extended cyber aggression

As debate continues over the definition of cyberbullying, an important endeavor is identifying aggression–prevention efforts likely to impact reasons for cyberbullying and the broader phenomenon of cyber aggression. No empirical research has examined whether there are useful prevention-related distinctions between perpetrators of cyberbullying vs. perpetrators of brief cyber aggression. Using an online survey, this study explored perpetrators’ beliefs, emotions, and behaviors related to 72 brief vs. 128 extended episodes of cyber aggression. The most pronounced difference was that more extended-episode perpetrators reported having been hurt by something that happened in cyberspace. One pronounced similarity was that if there had been a news story about the perpetrator doing it, 79% or more of both groups said they would not have felt proud; whereas 63% or more said they would have felt ashamed. Among both groups, 76% or more did not agree with the assertion that there should be no offline consequence for online behavior. The findings support prevention efforts intended to do the following: encourage respect and empathy, facilitate adaptive communication and decision-making skills, promote socially appropriate ways of coping with anger and conflict, and increase knowledge and application of relevant rules and laws.     

An empirical study of Java bytecode programs

We present a study of the static structure of real Java bytecode programs. A total of 1132 Java jar‐files were collected from the Internet and analyzed. In addition to simple counts (number of methods per class, number of bytecode instructions per method, etc.), structural metrics such as the complexity of control‐flow and inheritance graphs were computed. We believe this study will be valuable in the design of future programming languages and virtual machine instruction sets, as well as in the efficient implementation of compilers and other language processors. Copyright © 2006 John Wiley & Sons, Ltd.     

Applied relaxation: an experimental analogue study of therapist vs. computer administration

This experimental analog component study compared two ways of administrating relaxation, either via a computer or by a therapist. The second phase of applied relaxation was used, which is called “release-only relaxation”. Sixty participants from a student population were randomized to one of three groups: computer-administered relaxation, therapist-administered relaxation, or a control group in which participants surfed on the Internet. Outcome was measures using psychophysiological responses and self-report. Objective psychophysiological data and results on the subjective visual analogue scale suggest that there was no difference between the two forms of administration. Both experimental groups became significantly more relaxed than the control group that surfed on the Internet. Practical applications and future directions are discussed.     

Configuration vs. adaptation for business process variant maintenance: An empirical study

Many approaches for process variant management employ a reference model for deriving a target variant either using configuration or adaptation mechanisms. What is missing at this stage is empirical insight into their relative strengths and weaknesses. Our paper addresses this gap. We selected C-YAWL and vBPMN for a comparative, empirical user study. Both approaches center on a reference process, but provide different types of configuration and adaptation mechanisms as well as modularization support. Along with this aspect, we investigate the effect of model complexity and professional level on human process variant modeling performance. Given unlimited processing time, we could not show that complexity or the participant's professional level significantly impacts the task success rate or user contentment. Yet, an effect of model complexity can be noted on the execution speed for typical variant maintenance tasks like the insertion and deletion of process steps. For each of the performance measures of success rate, user contentment and execution speed, vBPMN performs significantly better than C-YAWL. We argue that this is due to vBPMN's advanced modularization support in terms of pattern-based process adaptations to construct process variants. These insights are valuable for advancing existing modeling approaches and selecting between them.     

An innovative approach of risk planning for space programs.

According to the current rule-based risk management approach at the National Aeronautics and Space Administration (NASA), the effort is directed to contain all identified risks of a program. The identification of hazards and mitigation effort proceeds along with the development of the system hardware, till all the tradable resources for a program is exhausted. In this process, no conscious effort is made to evaluate risks and associated cost, and the final design is likely to have undesirable residual risks. This approach also results in allocating a significant amount of resources to gain only marginal mitigation of hazard and leave some undesirable hazards in the system due to the budget limitation. The approach in the proposed knowledge-based risk planning system makes a conscious attempt to trade risk with other resources, e.g., schedule, cost, reliability, performance, and others in a judicious and cost-effective way. A knowledge of the feasible option sets requiring high incremental cost for a marginal gain in hazard reduction helps the management to make decision for residual risk that falls within an acceptable range for an option set.     

An experimental study of adaptive control for evolutionary algorithms

In this paper, we investigate how adaptive operator selection techniques are able to efficiently manage the balance between exploration and exploitation in an evolutionary algorithm, when solving combinatorial optimization problems. We introduce new high level reactive search strategies based on a generic algorithm's controller that is able to schedule the basic variation operators of the evolutionary algorithm, according to the observed state of the search. Our experiments on SAT instances show that reactive search strategies improve the performance of the solving algorithm.     

Evaluation of a mobile learning organiser for university students

This paper describes a 10-month trial of a mobile learning organiser, developed for use by university students. Implemented on a wireless-enabled Pocket PC hand-held computer, the organiser makes use of existing mobile applications as well as tools designed specifically for students to manage their learning. The trial set out to identify the most-used tools for such a learning device and their patterns and problems of usage. The primary uses of the organiser were communication, time-management and access to content. No single application took precedence. The results from an analysis of questionnaire surveys and focus groups indicate that there was a demand for institutional support of mobile learning, in particular to provide course content and timetabling information. Wireless connectivity was crucial to the usefulness of the organiser. Usability issues relating to the hardware and software had considerable impact on the students' usage and satisfaction with the system.     

An experimental study of scheduling algorithms for many-task applications

The Journal of Supercomputing - The paper studies the performance of algorithms for scheduling of many-task applications in distributed computing systems. Two important classes of such applications...     

An experimental study of some algorithms for unsupervised learning

Three well-known algorithms for unsupervised learning using a decision-directed approach are the random labeling of patterns according to the estimated a posteriori probabilities, the classification according to the estimated a posteriori probabilities, and the iterative solution of the maximum likelihood equations. The convergence properties of these algorithms are studied by using a sample of about 10 000 handwritten numerals. It turns out that the iterative solution of the maximum likelihood equations has the best properties among the three approaches. However, even this one fails to yield satisfactory results if the number of unknown parameters becomes large, as is usually the case in realistic problems of pattern recognition.     

On the performance of COBOL programs in large vs. mini computers

The comparative performance characteristics of COBOL programs in a small versus large computer systems are investigated. The vehicle consists of a set of synthetic benchmark COBOL programs, each measuring a particular aspect of COBOL computations, data manipulation, and input/output is made on both a large scale computer (IBM 370/158) and a minicomputer (Texas Instruments TI980). Results of a number of such experiments are presented and comparisons made between results obtained from the two systems.     

Comparative study of netbooks and tablet PCs for fostering face-to-face collaborative learning

With the recent appearance of netbooks and low-cost tablet PCs, a study was undertaken to explore their potential in the classroom and determine which of the two device types is more suitable in this setting. A collaborative learning activity based on these devices was implemented in 5 sessions of a graduate engineering course of 20 students, most of whom were aged 22-25 and enrolled in undergraduate computer science and information technology engineering programs. Student behavior attributes indicating oral and gesture-based communication were observed and evaluated. Our findings indicate that in the context in which this study was undertaken, tablet PCs strengthen collective discourse capabilities and facilitate a richer and more natural body language. The students preferred tablet PCs to netbooks and also indicated greater self-confidence in expressing their ideas with the tablet’s digital ink and paper technology than with the netbooks’ traditional vertical screen and keyboard arrangement.     

An experimental study of energy dips for speech and music

Speech signals generally have many intervals with low energy “energy dips”. For music signals, energy dips are not always remarkable. We studied stochastic features of energy dips for speech and music signals. A certain difference was found between the signals in the length of energy dips. Also, the number of energy dips in a time window and their distribution were investigated. From this distribution, a threshold number of energy dips was estimated which provided a scheme for the discrimination of speech from music.