Evaluation of a CAL package for modelling

This paper describes some work done in evaluating a computer package called MODL, for development of mathematical models. The package is described briefly with an example of typical graphical output and the inputs required (i.e. lines typed) to produce such a model. After a study of student use of the package, attention is focused on the way a lecturer used it.Simulation programs have been in use in the classroom for some time. MODL compares with these pre-written simulations as an individual trek through the Himalayas would relate to a pre-planned package tour through India. In one the tourist is taken through selected experiences, mostly on a well beaten path. In the other he is entirely free to direct his own affairs, which implies almost no limit to what can be seen and done, though there may be traps for the unwary.MODL may well open doors for teachers, and even the students, who wish to experiment with models in their own discipline, without waiting for programmers and mathematicians to develop simulations. Some teachers could be waiting for the opportunity to exercise their creativity, providing it proves feasible for them to build models with the package. Modelling, as distinct from using a model, is such a new, though potentially important area, that we must not prejudge it.     

Evaluation of student learning in CAL

Computer Assisted Learning, using self-teaching packages in a simulation mode, is a relatively new and interesting medium of teaching. Within the context of the project Computers in the Undergraduate Science Curriculum, part of the aim of the evaluation has been to assess the contribution this kind of CAL can make to the enhancement of student learning. The evaluation techniques used are described, together with some conclusions about the nature of the learning that CAL can provide.     

The design and development of CAL materials in undergraduate science

This paper describes the work of the project Computers in the Undergraduate Science Curriculum (CUSC) which is supported by the National Development Programme in Computer Assisted Learning, based in the U.K. The development procedure used by the project is described, and the preliminary evaluation findings are outlined. In particular, it is possible to establish a few basic principles for the design of this kind of simulation, semi-structured CAL package.

Evaluation has always been an important feature of the project and here provides an account of some of the learning gains identified so far.     

CAL software design for transferability

The successful transfer of CAL software is often thwarted by differences between the computer system on which the software was developed and that on which it is required to be implemented. Facilities which CAL programs may exploit are usually those most vulnerable to change between different computer systems.Drawing upon experience gained in the design, programming, and subsequent transfer of CAL programs in engineering, examples are given of features which may cause problems during implementation and alternatives or improvements are suggested. FORTRAN and GINO-F are proposed as machine and device independent standards, for implementation language and graphics subroutine library, respectively.Good programming practices are described with a view to obtaining readable and easily maintained programs of a sound quality. Importance is placed on modularity in design as the key to writing transportable programs. The idea that every module should conceal some design decisions from all other modules is described with reference to modules that have proved to be particularly useful or advisable. This technique enables a design to be produced in which machine dependencies and difficult design decisions may be confined to a handful of routines. This makes the program more adaptable and gives the teacher and programmer greater freedom to change the implementation, allowing the program to move to any computer system where similar functions can be implemented.     

Statistical consensus methods for improving predictive geomorphology maps

A variety of predictive models is currently used to map the spatial distribution of earth surface processes and landforms. In this study, we tested statistical consensus methods in order to improve the predictive accuracy of geomorphological models. The distributions of 12 geomorphological formations were recorded at a resolution of 25 ha in a sub-arctic landscape in northern Finland. Nine environmental variables were used to predict probabilities of occurrence of the formations using eight state-of-the-art modelling techniques. The probability values of the models were combined using four different consensus methods. The accuracy of the models was calculated using spatially independent test data by the area under the curve (AUC) of a receiver-operating characteristic (ROC) plot. The mean AUC values of the geomorphological models varied between 0.711 and 0.755 based on single-model techniques, whereas the corresponding values based on consensus methods ranged from 0.752 to 0.782. The weighted average consensus method had the highest predictive performance of all methods. It improved the accuracy of 11 predictions out of 12. The results of this study suggest that the consensus methods have clear advantages over single-model predictions. The simplicity of the consensus methods makes it straightforward to implement them in predictive modelling studies in geomorphology.     

CAL 97

This paper argues the case for wider recognition of the role of co/inter-authorship in the performing arts with specific reference to the work of shinkansen, a unit for performance media production. It further proposes that interactions between new technologies and the performing arts have acted as a catalyst for the understanding and appreciation of collaborative processes and exchange in the arts.     

Cumulative latency-of-response recording for evaluating CAL

Extrinsic evaluation of the educational contribution of computers is made complex, both by the relative novelty of CAL, on the one hand, and the Piagetian claims for LOGO on the other. Cumulative latency-of-response (CLARE) recording is proposed as an intrinsic technique which, by combining elements from both computational and behavioral traditions, provides, not only an effective evaluation tool but also a means of exploring the process of learning itself.     

Implementation techniques for interactive CAL programs

A model-independent study is made of interactive CAL programs that deal with the specific area of the modelling of systems, and the programming techniques that affect their educational value are discussed. An environment having the objective of maximizing the impact of interactive CAL is described and developed.     

Investigating CAL?

Can CAL facilitate discussions and problem solving? Surveys of classroom activities during mathematics lessons in British secondary schools present a rather gloomy picture. Disproportionately large amounts of time are devoted to teacher explanations, and to pupil exercises. Activities such as discussions, practical work, problem solving and investigations happen so rarely that they are collectively referred to as “missing activities”. Can CAL help? Tutorial CAL, of course, reinforces the exposition-imitation mode of teaching. Other kinds of CAL exist, though.An observational study watched 170 mathematics lessons in which the microcomputer was used as a teaching aid. Teachers chose freely from a collection of over 90 programs. The most popular programs, in terms of how often thet were chosen, and how their usefulness was rated by the observers, were investigative in style. This paper describes the lessons which were based on the four most popular programs used (JANE, SUBGAME, EUREKA and VECTOR). Each one facilitated some of the “missing activities”. The role of the microcomputer as an agent of change in teaching style towards more open methods is described and discussed.     

On methods for improving performance of PI-type fuzzy logiccontrollers

To improve limitations of fuzzy PI controller especially when applied to high order systems, we propose two types of fuzzy logic controllers that take out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional fuzzy PI controllers. The structures of the proposed controller were motivated by the problems of fuzzy PI controllers that they generally give inevitable overshoot when one tries to reduce rise time of response especially when a system of order higher than one is under consideration. Since the undesirable characteristics of the fuzzy PI controller are caused by integrating operation of the controller, even though the integrator itself is introduced to to overcome steady state error in response, we propose two fuzzy controllers that fuzzily clear out integrated quantities according to situation. The first controller determines the fuzzy resetting rate by situations described fuzzily by error and error rate, and the second one by error and control input. The two structures both give reduced rise time as well as small overshoot     

Conceptualising work activity for CAL systems design

Abstract  As computing technology has increasingly become relevant to people's everyday lives, emphasis is being placed on ensuring Computer Assisted Learning (CAL) tools support users in ways that are meaningful to them. This requirement has highlighted the need to understand the complex and often dynamic social and cultural organisation of collaborating individuals in context. Here, the aim is to conceptualise the natural flow and evolution of work practices so as to inform the design of these systems. This paper reports on empirical findings of an investigation into the design requirements for a CAL system for supporting knowledge sharing activities in an organisation.     

Research needs in CAL

Abstract The demise of MEP, and the arrival of MeSU as its successor, naturally provoke thoughts about the directions that future research and development for IT in education should take. This paper explores current research styles, and argues that the problems of developing and disseminating CAL appropriate to the production of desirable educational outcomes in class are unlikely to be solved by current approaches. Successful innovation requires more than enthusiastic teachers, careful laboratory studies, and a collection of regional information offices. There are urgent research needs for more studies of CAL in representative classrooms, and for studies of the implications of the socio-administrative structure of schools on the accessibility of computing resources. On a larger scale, work is needed that links CAL to major on-going curriculum development programmes, such as new GCSE curricula.     

提高计算机网络可靠性的方法研究

为研究提高计算机网络可靠性的方法,研究建设高可靠计算机网络的途径,满足国民经济和社会生活对高可靠计算机网络的需要,在简要介绍计算机网络发展现状的基础上,从工程实践角度总结出计算机网络的可靠性设计原则,并通过某单位计算机网络的硬件设计实例,提出了完整的网络系统硬件可靠性设计方案.通过结合莱研究所计算机网络的软件设计实例,提出了一套网络系统的软件可靠性设计方法.该可靠性设计技术对提高计算机网络的可靠性设计水平具有参考价值.     

A comparison of two training methods for improving warning symbol comprehension

This study compared the effectiveness of two different types of training in improving comprehension of warning symbols by younger (aged 20-35 years) and older adults (aged 50-70 years). The verbal label training paired the symbol with a label describing its meaning while the accident scenario training further expanded on the nature of the hazard, the required/prohibited actions, as well as the possible consequences of failing to comply. Contrary to prior research (e.g., [Lesch, M.F., 2003. Comprehension and memory for warning symbols: age-related differences and impact of training. J. Safety Res. 34, 495-505]), there was no difference in comprehension for younger and older adults prior to training, with both groups only obtaining about 40% correct responses. Both types of training improved performance on a subsequent comprehension test. However, the accident scenario training produced a higher percentage of correct responses, greater confidence in those responses, as well as a longer-lasting reduction of reaction times. In order to further improve symbol design, as well as training to address comprehension difficulties, future research should more closely examine symbol characteristics that influence comprehension.     

Student opinion of tutorial CAL

A tutorial CAL program was written to replace a human teacher in a mastery learning experience, using the authoring language “STAF2” running on a DEC VAX 11/780 computer. Students had full access to the program, which was informal in nature, flexible and capable of recognizing most if not all inputs made to it in response to the questions it posed. The topic of the mastery experience was that of batch growth of bacteria. A previous paper reported upon the students' cognitively assessed performance in a formative evaluation. The students were also asked to complete an evaluation questionnaire about the use of the program as a replacement for a human tutor. Analysis of the responses showed that use of the program met with greater than expected approval, though only as long as a detailed printed handout was provided to support it. Examination of the questionnaire responses also showed that females had more difficulty than males in answering the program questions, though they preferred it as a means of tuition more than males. Since there were no sigrificant differences between males and females in terms of the assessment test, the greater difficulty could not be ascribed to differences in ability. Partial correlation analysis of the questionnaire variables showed that the students felt much less need of human assistance and responded well to the informal style of the program, correctly judging it to be closely related to that of the lecturer who wrote it. The program also stimulated the formation of small tutorial groups to use it. These findings auger well for the future use of programmed tutorials, provided they are not used to excess or in circumstances that are not appropriate to the medium.     

Freeman四方向链码压缩率提高的方法研究

文中通过大量的实验,在研究现有的基于Freeman方向链码的方法的基础上,对提高Freeman四方向链码压缩率的方法进行了深入的研究.从改变码值含义定义并对码值进行Huffman编码,进而对出现频率最高的码值进行计算编码等不同角度,进行大量的实验、比较与分析.提出了一个Freeman四方向链码新方法:计算编码不等长相对四方向Freeman链码——AVRF4.实验结果表明,其链码压缩率比Freeman八方向链码提高了26％,而比原始Freeman四方向链码提高了15％.     

提高振弦式传感器测量精度的方法研究

振弦式传感器是水利工程和结构监测中应用较为广泛的设备之一.针对振弦式传感器输出信号微弱、放大检测中容易受到干扰而造成的测量精度下降问题,通过一个大坝高边坡安全监测工程应用实例的研究,从硬件的合理设计和软件的数据处理两方面详细分析和有效解决了振弦式传感器测量过程中的干扰问题,大大提高了振弦式传感器的测量精度.     

Using CAD programs in CAL

Practical experience has shown that CAD programs can provide an invaluable aid in the learning process when integrated into the syllabus in lecture and laboratory periods. It is suggested that this is CAL and should be a major area of future development of CAL in engineering education.