• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.226-227
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• 2015

This research is to measure and analyze the thermal performance of the apartment structure and to evaluate and establish standards of thermal insulation defect in order to make the basic data necessary for determining the degree of the thermal performance degradation and for repairing and reinforcing the exterior wall of the existing apartment. The following conclusions could be derived thorough the investigation of outer wall temperature distribution and the insulation assesment experiments using a model of specimens for the apartment houses' outer walls. It was confirmed that for the thermal performance through the insulating material thicknesses 5cm, 8cm in walls, the thermal insulation thickened by 3cm, from 5cm to 8cm, but that the actual temperature difference reached only about 1 ~ 2℃. This implies that the thermal performance improvement using the thermal insulation in walls is not significant and that it is difficult to insulate the thermal bridge area.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.162-171
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• 2017

Unmanned military vehicles (UMVs) are most commonly characterized as dealing with dull, dirty, and dangerous tasks with automation. Although most of the UMVs are designed to a high degree of autonomy, the human operator will still intervene in the robot's operation, and teleoperate them to achieve his or her mission. Thus, operator capacity, together with robot autonomy and user interface, is one of the most important design factors in the research and development of the UMVs. Further, communication may affect the operator task performance. In this paper, we analyze the operator performance and the communication effects on the operator performance by using the extended Petri nets, called OTSim nets. The OTSim nets was designed by the authors, being extended using pure Petri nets.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.73-78
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• 2003

In order to improve the safety performance oi construction projects, effective and corporative safety management program between head office and job site must be implemented. And its performance must be measured and analyzed for the identification of the problems in the safety management area. This study proposes a previous evaluation model of safety performance for the large construction firm in order to enhance their safety level. The fundamental data for proposed model is based on the past research(Son 2002), which is structured of evaluation criteria. weighted factor. statistical evaluation formula. The model would help the firm management in identifying the weak areas of safety performance in terms of the degree performing certain safety tasks. It is expected that the model could contribute to achieving the "zero accident" level.ot; level.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.90-94
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• 2004

Among various modern control theories, PID control has been well used for several decades. PID algorithms needs son tuning methods are used for selecting PID parameters. But in some cases various kinds of performance indices are used instead of well-known tuning rules, and so variable type of performance index must be tested so that controllers, output characteristics and disturbance rejection property meets some specifications. In this paper, linear conbinational type of performance using error signal, time, control input and robustness is used to the PID control of air conditioning system. By the 2 DOF PID parmeters minimizing perfromacne index, controllers, output characteristics and robustness properties are analyzed. Simulations are done with MATLAB m file and mdl files.

• ETRI Journal
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• v.44 no.1
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• pp.105-116
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• 2022

In this study, a novel group-indexed orthogonal frequency division multiplexing index modulation (OFDM-IM) scheme is proposed to achieve a tradeoff between spectral efficiency (SE) and bit-error-rate (BER) performance. In the proposed scheme, the total subcarriers in a group are divided into subgroups, and additional bits are transmitted by subgroup indexing, unlike the conventional OFDM-IM scheme, which uses index bits to select active subcarriers. With the proposed scheme, the additional degree of freedom provided by the number of active subgroups selected provides a tradeoff between spectral efficiency and BER performance. Decoding is performed in steps to reduce computional complexity in the decoder design. Simulaton results show that the number of active subgroups selected influences the proposed scheme's performance in terms of energy efficiency, spectral efficiency, and BER performance.

• Management & Information Systems Review
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• v.29 no.4
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• pp.333-357
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• 2010

Purposes of this paper are to investigate whether managers' compensation is sticky as accounting performance(ROA) vary or not and explore further what factors influence the managers' compensation stickiness. To empirically study the stickiness of managers' compensation, we used the financial data from manufacturing firms lised in the Korea Stock Exchange(1,000 firm-year data for 4 years). The results are as follows : First, managers' compensation is sticky with respect to change in accounting performance. That is, the increase in managers' compensation as accounting performance increases is greater than the decrease in managers' compensation in respect to equivalent decrease in accounting performance. Second, the degree of managers' compensation stickiness increases when managers have influence and contribution to firm value. Specifically, the degree of stickiness is positively associated with investment opportunity set, intangible assets' value, uncertainty of firms' operating environment, complexity of organizational hierarchy. But firms' size reversely impacts on the degree of managers' compensation stickiness.

• Journal of Korean Academy of Nursing
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• v.26 no.2
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• pp.359-371
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• 1996

This study has been done for the purpose of testing the effect of health education on the performance of health promoting behavior in college students, and identifying the factors affecting health promoting behaviors. A Nonequivalent control group posttest research design was used. Two hundred thirty college students at K College in T city were studied. Of them, 114 who attended a systematic health education session for three hours a week during one semester were the experimental group. And 116 college students who were chosen of matched sampling of grade, class and sex were the control group. This study was conducted from March 1 to July 2, 1995. The instruments used for this study included a survey of general characteristics, perceived health status, self-esteem, health promoting behavior and health locus of control. Analysis of data was done by use of mean, 1-test, Pearson correlation coefficient and multiple regression. The results of this study are summarized as follows : 1) The average item score for the health promoting behavior was low at 2.52. In the sub-categories, the highest degree of performance was ‘harmonious relationships’, following ‘sanitary life’, ‘self-esteem’, ‘rest and sleep’, and ‘emotional support’ and the lowest degree was ‘professional health management’. 2) Hypothesis 1 that the college students who get health education will have a higher degree of health promoting behavior than the college students who do not get health education was accepted. There was a statistically significant difference between the average of the experimentalgroup, 2.60, and the average of the control group, 2.45.（t＝11.30, p＝0.0009）. 3) Hypothesis 2 that the college students who get health education will have a higher score of perceived health status than college students who do not get the health education was rejected. （t＝1.13, p＝0.289） 4) Performance of health promoting behavior was positively correlated with self-esteem and grade and negatively correlated with perceived health status. 5) The most important factor affecting performance of health promoting behavior was self-esteem. The following suggestions are made based on the above results : 1) Replication of the research is needed to confirm effects of health education. 2) More effective health education programs need to be developed through by modification of teaching methods and content analysis of health education. 3) Other factors affecting health promoting behavior should be identified. 4) Nursing colleges or departments of nursing should make an effort to develop and carry out various health education programs for the health promotion of all college students.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.217-224
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• 2024

This paper proposes an efficient dimension reduction method (DRM) that considers the nonlinearity of the performance functions in reliability-based design optimization (RBDO). The dimension reduction method evaluates the reliability more accurately than the first-order reliability method (FORM) using integration quadrature points and weights. However, its efficiency is hindered as the number of quadrature points increases owing to the need for an additional evaluation of the performance function. In this study, we assessed the nonlinearity of the performance function in RBDO and proposed criteria for determining the number of quadrature points based on the degree of nonlinearity. This approach suggests adjusting the number of quadrature points during each iteration of the RBDO process while maintaining the accuracy of theDRM while improving the computational efficiency. The nonlinearity of the performance function was evaluated using the angle between the vectors used in the maximum probable target point (MPTP) search. Numerical tests were conducted to determine the appropriate number of quadrature points according to the degree of nonlinearity. Through a 2D numerical example, it is confirmed that the proposed method improves the efficiency while maintaining the accuracy of the dimension reduction method or Monte Carlo Simulation (MCS).

• Journal of Intelligence and Information Systems
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• v.18 no.3
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• pp.35-51
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• 2012

Cloud computing is internet-based computing where computing resources are offered over the Internet as scalable and on-demand services. In particular, in case a number of various cloud services emerge in accordance with development of internet and mobile technology, to select and provide services with which service users satisfy is one of the important issues. Most of previous works show the limitation in the degree of user satisfaction because they are based on so called concept similarity in relation to user requirements or are lack of versatility of user preferences. This paper presents cloud service selection reasoning which can be applied to the general cloud service environments including a variety of computing resource services, not limited to web services. In relation to the service environments, there are two kinds of services: atomic service and composite service. An atomic service consists of service attributes which represent the characteristics of service such as functionality, performance, or specification. A composite service can be created by composition of atomic services and other composite services. Therefore, a composite service inherits attributes of component services. On the other hand, the main participants in providing with cloud services are service users, service suppliers, and service operators. Service suppliers can register services autonomously or in accordance with the strategic collaboration with service operators. Service users submit request queries including service name and requirements to the service management system. The service management system consists of a query processor for processing user queries, a registration manager for service registration, and a selection engine for service selection reasoning. In order to enhance the degree of user satisfaction, our reasoning stands on basis of the degree of conformance to user requirements of service attributes in terms of functionality, performance, and specification of service attributes, instead of concept similarity as in ontology-based reasoning. For this we introduce so called a service attribute graph (SAG) which is generated by considering the inclusion relationship among instances of a service attribute from several perspectives like functionality, performance, and specification. Hence, SAG is a directed graph which shows the inclusion relationships among attribute instances. Since the degree of conformance is very close to the inclusion relationship, we can say the acceptability of services depends on the closeness of inclusion relationship among corresponding attribute instances. That is, the high closeness implies the high acceptability because the degree of closeness reflects the degree of conformance among attributes instances. The degree of closeness is proportional to the path length between two vertex in SAG. The shorter path length means more close inclusion relationship than longer path length, which implies the higher degree of conformance. In addition to acceptability, in this paper, other user preferences such as priority for attributes and mandatary options are reflected for the variety of user requirements. Furthermore, to consider various types of attribute like character, number, and boolean also helps to support the variety of user requirements. Finally, according to service value to price cloud services are rated and recommended to users. One of the significances of this paper is the first try to present a graph-based selection reasoning unlike other works, while considering various user preferences in relation with service attributes.

• Journal of the Korean Home Economics Association
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• v.27 no.3
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• pp.39-51
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• 1989

In this study, 419 students of the 6th grade in three schools in Masan were surveyed. The students having less than 24 items among 48 protein-rich foods easily obtained were considered as unbalanced-diet students. Their general circumstances, character, status of growth and development and school performance were compared with those of balanced-diet students. The results were following. 1. The actual condition of unbalanced diets of protein-rich food 1) Female showed high degree of unbalanced diet in meat food while male in shell-food. Both sexes liked processed food stuffs such as ham, sausage and boiled fish paste but not salted. Both of them disliked beans. 2) The reason for unbalanced diet, they answered, was bad taste and smell of some foods. The reason, their mothers amswered, was they fed their children some particualr foods. 3) The attitudes of the mothers against unbalanced diets were coaxing their children to eat some foods for they are good for health or forcing their children to eat some foods. The most effective method on the children was coaxing and the next was changing cuisines. 2. The general circumstances of the students. 1) 168 students (male: 85, female:83) among 419 students who were studied were unbalanced-diet students and the extent of unbalanced diet was similar in both sexes. 2) The rate of unbalanced-diet students was higher among the students who were the first child in the family, had a small family or were fed milk or mixed milk. 3) The school career of unbalanced-diet student's mothers was higher and the rate of unbalanced-diet students was higher among the students who have rich families or career mothers. 3. The status of physical condition 1) The height and weight of unbalanced-diet students were lower than those of the standard of Korean children. The status of balanced-diet students were better than that of the standard. 4. Degree of school performance 1) The school records of unbalanced-diet students was 81.4 points in average, which was 1.3 points lower than the average of city students and that of balanced-diet students was 2.8 points higher than average. There was a significant gap between the two groups. 5. The relation between unbalanced diet and character 1) Compared balanced-diet students, unbalanced-diet students showed high degree of nervousness and coldheartedness and low degree of self-reliance and self-possession. There was a significant gap between the two groups and it showed that unbalanced diets affected the formation of character.