• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.3
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• pp.69-78
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• 2012

Reduction of power consumption has been a major issue and an interesting challenge to maximize the lifetime of wireless sensor networks. We investigate the practical meaning of N-policy in queues as a power saving technique in a WSN. We consider the N-policy of a finite M/M/1 queue. We formulate the optimization problem of power consumption considering the packet loss probability. We analyze the trade-off between power consumption and the packet loss probability and demonstrate the operational characteristics of N-policy as a power saving technique in a WSN with various numerical examples.

• Lingua Humanitatis
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• v.5
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• pp.293-310
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• 2003

This study starts with a remark on the frequent usage of the term 'generation culture' in the explanations of cultural change. The term 'generation culture' itself does have neither a clear meaning nor any academic consensus for its operational definition yet. Depending on intuitions or common senses, in most cases, of everyday lift experience, the tends to designate the co-existence of different cultural layers as composing subsystems of a little broader Korean cultural trend. I tried here to analyze different positions and perspectives in the employment of this term, sometimes with strategic intentions of each social groups. Economic or political positions, for example, are intertwined with the quest of identification concerning 'we' and 'other' grouping dynamics in the Age of Globalization, which accelerates the speed of cultural re-territorialization. And the role of consumption activity as a kind of cultural indication has gained more weight in that process. This analysis will remind us, also, of the post-modem society's assumption about the space-and-time in transition, and its fluctuation.

• Journal of Mechanical Science and Technology
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• v.19 no.8
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• pp.1554-1567
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• 2005

When multiple robotics systems with several sub-chains grasp a common object, the inherent force redundancy provides a chance of utilizing internal loading. Analysis of grasping space based internal loading is proposed in this work since this method facilitates understanding the physical meaning of internal loadings in some applications, as compared to usual operational space based approach. Investigation of the internal loading for a triple manipulator has been few as ,compared to a dual manipulator. In this paper, types of the internal loading for dual and triple manipulator systems are investigated by using the reduced row echelon method to analyze the null space of those systems. No internal loading condition is derived and several load distribution schemes are compared through simulation. Furthermore, it is shown that the proposed scheme based on grasping space is applicable to analysis of special cases such as three-fingered and three-legged robots having a point contact with the grasped object or ground.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.195-211
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• 2023

For the commercialization For the commercialization of autonomous vehicles (AV), the operational design domain (ODD) of automated driving systems (ADS) is to be clearly defined. A common language and consistent format must be prepared so that AV-related stakeholders can understand ODD at the same level. Therefore, overseas countries are presenting a standardized ODD framework and developing scenarios that can evaluate ADS-specific functions based on ODD. However, ODD includes conditions reflecting the characteristics of each country, such as road environment, weather environment, and traffic environment. Thus, it is necessary to clearly understand the meaning of the items defined overseas and to harmonize them to reflect the specific domestic conditions. Therefore, in this study, domestic optimization of the ODD classification system was performed by analyzing the domestic driving environment based on international standards. The driving environment of currently operating self-driving car test districts (Sangam, Seoul, and Gwangju) was investigated using the developed domestic ODD items. Then, based on the results obtained, the ranges of the ODDs in each test district were determined and compared.

• School Mathematics
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• v.10 no.4
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• pp.537-555
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• 2008

The study aims to analyze elementary school students' understanding of the concept of equality sign in contexts, to reflect the types of contexts for equality sign which mathematics textbook series for $1{\sim}4$ grades on natural numbers and its operation provide, and to invetigate the effects of teaching methods of the concept of equality sign suggested in this research. In order to achieve these purposes, the origin, concept, and contexts of equality sign were theoretically reviewed and organized. Also the error types in using equality sign were reflected. Modelling, discussing truth or falsity of equations, identifying relations between numbers and their operation, conjecturing basic properties of numbers and their operations, experiencing diverse contexts for equality sign, and creating contexts for equality sign are set up as teaching methods for better understanding the concept of equality sign. The conclusions are as follows. Firstly, elementary school students' under-standing of the concept of equality sign varied by context and was generally far from satisfactory. In particular, they had difficulties in understanding the concept of the equal sign in contexts with operations on both sides. The most frequently witnessed error was to recognize equality sign as a result of operations. Secondly, student' lack of understanding of the concept of equality sign came from the fact that elementary textbooks failed to provide diverse contexts for equality sign. According to the textbook analysis, contexts with operations on the left side of the equal sign in the form of $a{\pm}b=c$ were provided excessively, with the other contexts hardly seen. Thirdly, teaching methods provided in the study were found to be effective for enhancing understanding the concept of equality sign. In other words, these methods enabled students to focus on relational understanding of concept of equality sign rather than operational one.

• Journal of The Korean Association For Science Education
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• v.17 no.1
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• pp.75-83
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• 1997

The purpose of this study was to determine the strategies that middle school students used in solving problems concerning density and solubility. These were compared in the aspects of problem contexts for 42 students of varying logical reasoning ability, spatial ability, and learning approach. A coding scheme used consists of five categories: reading & organization, production, errors, evaluation, and strategy. Students' protocols were analyzed after intercoder agreement had been established to be .95. The results were as follows: 1. Students had more difficulties in reading and organizing the problems in everyday contexts than in scientific contexts. Students at the concrete-operational stage and / or surface approach were more likely to have difficulties in reading and organizing the problems than those at the formal-operational stage and / or deep approach. 2. Students tended to split up the solubility problems into sub-problems and to solve the density problem in everyday contexts in random manner. These were significantly correlated with the test scores concerning logical reasoning ability, spatial ability, and learning approach at the .1 level of significance. 3. Major errors in solving the density problems were to disregard the given information or generated and to use inappropriate information. Many errors in solving the solubility problems were found to be executive errors. The strategy to use the information given appropriately was positively related to students' logical reasoning ability, spatial ability, and learning approach. 4. More evaluation strategies were found in everyday contexts. Their strategies to grasp the meaning of answers and to check the math were significantly related to students' logical reasoning ability. 5. Students used the random trial-and-error strategy more than the systematic strategy and the systematic trial-and-error strategy, especially in everyday contexts. The strategies used by the students were significantly related to students' logical reasoning ability, spatial ability, and learning approach.

• Journal of Families and Better Life
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• v.22 no.1
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• pp.103-114
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• 2004

This study was performed by the literature review on housing of the aged in Korea with social constructionism perspective. This kind of research may be utilized as a theoretical framework for performance of any systems of housing for the aged. In terms of structural context, the value of conventional custom of filial piety thoughts and duty for family are being collapsed, which nay be suitable to the change of society, should be considered for positive acceptance of changes in ideology. In terms of institutional context, a method to grope for housing for the aged should be established through amicable cooperation between organizations of legalization concerned. In terms of organizational context, there is no organization that exclusively concern housing for the aged until now, thus, development of concrete manual is required for jobs of service in current department of policy for the aged. In terms of operational context, the service may include the understanding of characteristics of the aged and design of housing may also change the service of administration, and as cooperation in the local community care systems may change the service to the aged in the field. Connection of these services and operation of these organizations nay be required in the field to manage housing. Finally in terms of intersubjective context, as the form and method of housing management service is important, with understanding of the social meaning and importance on the role of manager.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.375-382
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• 2011

There is no system to obtain the basic data and proceed data and user input interface is complex, thus there are some limitation to utilize the oil spill prediction model. It is difficult to build the scientific response strategy in order to respond oil spill accident rapidly because it is impossible to operate the oil spill prediction model any time. In this study, the optimum operational system for oil spil prediction model has been developed considering the present system. External real time data has been linked because of impossibility of building all basic data and minimum database has been build in this study. Through this data system, real time oil spill prediction model can be utilized. And the user interface has been designed to reduce the error of the interface between user and model and the output interface has been proposed to analyze the result of modeling at multidimensional aspect. While the system for oil spill prediction model as the result of this study has some uncertainties because of depending on external data, the thing that we can predict oil spill using operate the model rapidly as soon as the accident occurred can be meaning in the response field.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.47-58
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• 2012

This study selects political and military decision factors of Participatory Government's Wartime Operational Control(OPCON) Transition and analyzes, both quantitatively and qualitatively, the effects and relations between those factors. Previous research utilizing the Analytic Hierarchy Process(AHP) selected their decision factors based on academic data and field experience, requiring more objective analysis of the factors. For this study, we conducted a survey among security subject matter experts(SME) both online and offline. The results show that OPCON transition's decision factors were to 'recover military sovereignty', 'set the conditions for peaceful reunification' and 'improve ROK image through enhancing national power' which differs little from the previous AHP method studies. It also showed that 'recover military sovereignty' and 'set the conditions for peaceful reunification' had no relationship to each other and that the key factor that decided the OPCON Transition was actually 'recover military sovereignty' which represents the interest of the liberal party in ROK. This study finds its meaning by analyzing the decision factors of Participartory Government's OPCON Transition thorugh Delphi and DEMATEL method.

• Journal of Korean Academy of Nursing
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• v.19 no.1
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• pp.92-98
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• 1989

Concept analysis is a formal linguistic exercise to determine certain defining attributes. The basic purpose of concept analysis is to clarify ambiguous concepts in a theory, and to propose a precise operational definition which reflects its theoretical base (Walker, 1983, 27~28). In later life, elderly people are faced with various psychological problems such as depression, and lowered self-esteem for these psychological problems of the elderly. Reminiscence has been studied as an effective therapeutic measure by gerontologists and psychologists. It is considered to have potential as an effective nursing intervention with geriatric clients. The purpose of this paper was to explore the feasibility of adopting reminiscence as a nursing intervention through analysis of the concept. The concept can be defined as follows : Reminiscence is thinking and talking about one's past with or without a specific purpose. It is a composite mental process which involves psychological, emotional, and social interactional aspects. The defining attributes of reminiscence are : 1. Thinking about past experiences which are meaningful to oneself. 2. It includes the emotional aspect of past experiences. 3. It occurs with or without specific purposes. 4. It is communicated to others by means of language and the subject has the feeling of being heard. In regard to the consequences of reminiscence, it is expected to contribute to psychological adaptation by providing a sense of self-fulfillment and self-achievement, promoting the discovery of the meaning of life, decreasing depression, and overcoming guilt feelings and conflict about one's past. However, if the past is regarded as a total failure, it may be harmful to the psychological well-being of the subject.