• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.47-59
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• 2009

Due to the application-specific nature of wireless sensor networks, the sensitivity to such a requirement as data reporting latency may vary depending on the type of applications, thus requiring application-specific algorithm and protocol design paradigms which help us to maximize energy conservation and thus the network lifetime. In this paper, we propose a novel delay-adaptive sensor scheduling scheme for energy-saving data gathering which is based on a two phase clustering (TPC). The ultimate goal is to extend the network lifetime by providing sensors with high adaptability to the application-dependent and time-varying delay requirements. The TPC requests sensors to construct two types of links: direct and relay links. The direct links are used for control and forwarding time critical sensed data. On the other hand, the relay links are used only for data forwarding based on the user delay constraints, thus allowing the sensors to opportunistically use the most energy-saving links and forming a multi-hop path. Simulation results demonstrate that cluster-based delay-adaptive data gathering strategy (CD-DGS) saves a significant amount of energy for dense sensor networks by adapting to the user delay constraints.

• Journal of The Korean Association For Science Education
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• v.15 no.2
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• pp.173-184
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• 1995

The purpose of this study was to analyse the problems of 'Science Inquiry Experiment Contest(SIEC)' which was one of 8 programs of 'The 2nd Student Science Inquiry Olympic Meet(SSIOM)'. The results and conclusions of this study were as follows: 1. It needs to reconsider the role of practical work within science experiment because practical work skills form one of the mainstays in current science. But the assessment of students' laboratory skills in the contest was made little account of. It is necessary to remind of what it means to be 'good at science'. There are two aspects: knowing and doing. Both are important and, in certain respects, quite distinct. Doing science is more of a craft activity, relying more on craft skill and tacit knowledge than on the conscious application of explicit knowledge. Doing science is also divided into two aspects, 'process' and 'skill' by many science educators. 2. The report's and checklist's assessment items were overlapped. Therefore it was suggested that the checklist assessment items were set limit to the students' acts which can't be found in reports. It is important to identify those activities which produce a permanent assessable product, and those which do not. Skills connected with recording and reporting are likely to produce permanent evidence which can be evaluated after the experiment. Those connected with manipulative skills involving processes are more ephemeral and need to be assessed as they occur. The division of student's experimental skills will contribute to the accurate assess of student's scientific inquiry experimental ability. 3. There was a wide difference among the scores of one participant recorded by three evaluators. This means that there was no concrete discussion among the evaluators before the contest. Despite the items of the checklists were set by preparers of the contest experiments, the concrete discussions before the contest were necessary because students' experimental acts were very diverse. There is a variety of scientific skills. So it is necessary to assess the performance of individual students in a range of skills. But the most of the difficulties in the assessment of skills arise from the interaction between measurement and the use. To overcome the difficulties, not only must the mark needed for each skill be recorded, something which all examination groups obviously need, but also a description of the work that the student did when the skill was assessed must also be given, and not all groups need this. Fuller details must also be available for the purposes of moderation. This is a requirement for all students that there must be provision for samples of any end-product or other tangible form of evidence of candidates' work to be submitted for inspection. This is rather important if one is to be as fair as possible to students because, not only can this work be made available to moderators if necessary, but also it can be used to help in arriving at common standards among several evaluators, and in ensuring consistent standards from one evaluator over the assessment period. This need arises because there are problems associated with assessing different students on the same skill in different activities. 4. Most of the students' reports were assessed intuitively by the evaluators despite the assessment items were established concretely by preparers of the experiment. This result means that the evaluators were new to grasp the essence of the established assessment items of the experiment report and that the students' assessment scores were short of objectivity. Lastly, there are suggestions from the results and the conclusions. The students' experimental acts which were difficult to observe because they occur in a flash and which can be easily imitated should be excluded from the assessment items. Evaluators are likely to miss the time to observe the acts, and the students who are assessed later have more opportunity to practise the skill which is being assessed. It is necessary to be aware of these problems and try to reduce their influence or remove them. The skills and processes analysis has made a very useful checklist for scientific inquiry experiment assessment. But in itself it is of little value. It must be seen alongside the other vital attributes needed in the making of a good scientist, the affective aspects of commitment and confidence, the personal insights which come both through formal and informal learning, and the tacit knowledge that comes through experience, both structured and acquired in play. These four aspects must be continually interacting, in a flexible and individualistic way, throughout the scientific education of students. An increasing ability to be good at science, to be good at doing investigational practical work, will be gained through continually, successively, but often unpredictably, developing more experience, developing more insights, developing more skills, and producing more confidence and commitment.

• The Journal of Korean Philosophical History
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• no.43
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• pp.231-266
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• 2014

The main contents of Baopuzi inner chapters becomes the basis for the claim "to be achieved Xian the way people can be" named and Shenxian theory that is deployed in the center of the universe body theory with a focus on Xuan and YI and Tao and a problem of "demonstration of Shenxian exist", or ancient science that describes the Chinese alchemy and Taoism spell in other words, inner chapters are writing and how to get prescription way of Shenxian, of medicine to become a predecessors, elephant of some of the changes in the ghost apparition, the longevity, how to avoid the epidemic out of the evil. Inner chapters are presented a regimen thought, the rationale for its mystical religion and philosophy of Monasticism ship on the basis of the theory Shenxian so. Baopuzi Inner chapters is presented in detail how to reach a comprehensive and realistic Shenxian long life in prison without the pre-Qin dynasty Taoism and Qinhan dynasty and times across the Weijin dynasty Shenxian ideas. And is presented in a typical Waidan and Neidan Taoism exercise this system and that in Taoism (Regimen) Thought the important position. Thought of Regimen is very important right information Inner chapters which constitutes the establishment of an important theoretical basis Shenxian Taoism of Gehong this research right in that you can see at a glance the thought of Regimen of Inner chapters is the desperate need for this requirement. It aims to illuminate the entire look of Regimen ever appeared immediately in Inner chapters this paper. After the analysis of the body Tao theory, The theory of the body and the spirit, The theory of Xingming, The theory of Shenxian theoretical foundations of thought appeared in Inner chapters Based on this, the first one conducted regulating the qi flowing in the channels method, Daoyin method, Pranayama, Closed breath, I saw one at the specifics of regimen method such, art of controlling and swallowing breath from the mouth, Convinced, Tuna breathing, Sishenshouyi method, Jinehuandan method, Fangzhongshu. And reporting features found Inner chaptersfinally saw the spirit of Regimen weigh its value.