• Korea journal of population studies
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• v.29 no.1
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• pp.269-292
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• 2006

The current environmental problem is global, and threatens the very existence of human beings. Many factors have been argued as the causes of environmental problem. The examples include anthroponcentric human perspective on nature, increase in the knowledge on nature, development of technology, economic growth and unequal distribution, and population increase, etc. The scholars who argues population increase have focused on over-population. However, the estimation of optimum population size has not been attempted in terms of environmental carrying capacity. In such a context, this paper aims at estimating optimum population size in South Korea in terms of environmental carrying capacity. The estimation was done from two approaches. One was based on the state of environment, the other was based on 'the desirable state of environment' Koreans expect. The former is termed an objective approach, while the latter is termed an approach based on social consensus. About 47.5 millions were estimated from the former approach, and 48.5 millions from the latter approach. However, optimum population size increase by 50.5 millions if government increase environmental budget to 2.00% among total budget. As such, different optimum population size is estimated according to the values of variables. The most significant variable determining optimum population size is environmental budget, and followed by supply of clean energy. The estimated optimum population size was based on the time-series data from 1993 to 2002. Therefore, time-series data collected from other years will result in different estimation model, and then different optimum population size will be estimated.

• Journal of the Korean Chemical Society
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• v.53 no.4
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• pp.445-452
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• 2009

In this study, the influences of the context of discrepant events on the conceptual change process using cognitive conflict strategy were investigated in terms of students' cognitive and motivational variables such as cognitive conflict, situational interest, attention, effort, conceptual understanding. A preconception test was administered to 536 seventh graders. A test of response to a discrepant event and a situational interest questionnaire were then administered. The context of discrepant events, either scientific or everyday, was randomly presented to the subjects. After learning the concept of density, the tests of attention, effort, and conceptual understanding were administered. The reponses of 194 students who had been found to possess the target misconception were analyzed. The results revealed that the scientific-context discrepant event induced higher cognitive conflict than everyday-context one. The context of discrepant events, however, did not show significant correlations with situational interest, attention, effort, and/or conceptual understanding. The result of path analysis indicated that the context of discrepant events both directly influenced cognitive conflict and indirectly influenced conceptual understanding via cognitive conflict.

• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.25-43
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• 1996

정보시스템이 효과적이기 위해서는 정보가 도출되는 자료의 무결성이 우선 전제되어야 한다. 특히 오늘날과 같이 사회가 다양한 활동들을 지원하기 위해 컴퓨터를 이용한 정보시스템에 점점 더 의존해감에 따라 정보시스템에서 사용되는 자료의 질을 적절한 수준으로 유지 및 관리해야 할 필요성이 더욱 절실히 대두되게 되었다. 그럼에도 불구하고 여전히 관리자들은 효과적인 의사결정 및 활동을 위해 필요한 최신의 정확한 자료들을 제공 받지 못하고 있으며 [Nesbit 1985], 정보시스템이 기대 이하의 성능을 나타내는 가장 단순하고 일반적인 원인은 정보시스템에 입력된 자료가 부정확하거나 불완전하기 때문인 것으로 나타나고 있다 [Ballou and Pazer 1989]. 낮은 질의 자료는 즉각적인 경제적 손실뿐만 아니라 보다 많은 간접적이고 경제적으로 측정하기 어려운 손실들을 초래한다. 그리고 아무리 잘 관리되는 시스템에도 시간이 흐름에 따라 여러가지 원인에 의해 저장된 자료에 오류가 발생하게 된다. 자료의 질을 적절한 수준으로 유지하기 위해서는 이와 같은 오류는 주기적으로 발견 및 수정되어야 한다. 이와 같은 작업을 데이타베이스 감사라고 한다. 본 논문에서는 데이타베이스에 저장된 자료의 질을 주기적으로 향상시키기 위한 최적 데이타베이스 감사시점을 일반적인 비용모형을 통해 결정하는 과정을 제시하고, 그와 관련된 사항들에 대해 논의하였다. 데이타베이스는 오류 발생률도 다르고 오류의 결과도 상당히 다른 여러개의 자료군들로 구성되어 있다고 가정하였다. 그리고 각 자료군에서의 오류 누적과정은 확정적이 아닌 확률적인 과정으로 모형화하고, 단순한 오류의 발생뿐만 아니라 오류의 크기도 확률적으로 변하는 상황을 모형에 반영하여 보다 현실성있게 모형화하였다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.920-924
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• 2009

유비쿼터스 환경에서 끊임없이 동적으로 변하는 환경에서 수많은 상황데이터가 발생하고 상황정보로 추상화하는 과정이 필수적이다. 본 논문에서는 미리 정의된 코드 값들과 측정된 센싱 값들이 연속으로 구성되기 때문에 이를 분리해내고 해석하는 과정이 매우 임의적이고, 가변적이어서 연산을 반복적으로 수행하는 것은 시스템의 오류를 발생하게 하는 문제점이 있다. 본 시스템은 raw 데이터 형식의 USN 데이터를 초기 수집 이후 여러 프로세스들이 추상화된 데이터를 다룰 수 있도록 함으로써 데이터 처리에서 발생할 수 있는 오류를 제거하고자 데이터 추상화를 위한 상황인식 프레임워크를 개발하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.50-58
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• 2012

The objective of this study is to develop the theoretical model of the telecommunication system service availability from the user perspective. We assume non-homogeneous Poisson process for the call arrival process and continuous time Markov chain for the system state. The proposed model effectively describes the user model of the user-perceived service reliability by including the time-varying call arrival rate. We also include the operational failure state where the user cannot receive any service even though the system is functioning.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.5
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• pp.1023-1031
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• 1994

The closed forms of consistent mass matrix with rotational inertia matrix are developed for free vibration analysis in space sutructures containing linearly tapered members with cross section of thin-walled I-sections. The exact displacement functions are used for formulating mass matrices. The very small slopes of the tapered member are used in usual practice, such that the series expansion forms of these are also developed to avoid numerical failure in vibration analysis. Significant improvements of accuracy and efficiency of free vibation analysis are achieved by using the mass matrices developed in this study. Frequencies of free vibation of tapered members are compared with solutions based upon stepped representation of beam element in the ANSYS. The mass matrices presented in this study can be used for the free vibration analysis of tapered and prismatic members.

• Journal of Educational Research in Mathematics
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• v.20 no.4
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• pp.493-509
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• 2010

Researchers have suggested that educators have to focus their attention on variability and reasoning about variation as means of developing students' statistical thinking in school mathematics. This paper investigated knowledge for the teaching of variability and reasoning about variation; what are sources of variability, how to cope with variability, what are types of variability, how to recognize variability, and the relationship between statistical problem solving and variability. The results involve: discussion on the sources of variability and how to cope with variability promotes students' awareness of different types of variability and students' motivation in the following steps in the statistical activity; emphasis on reasoning about variation in teaching representation of data accords with objectives of statistics education; reexamination of curriculum for statistics education is needed, which has a content-oriented arrangement.

• Management & Information Systems Review
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• v.30 no.1
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• pp.39-69
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• 2011

This study is conducted to clarify when a person faces an ethical dilemma in business situation, what affects on individual ethical decision-making(from ethical judgments to behavioral intention, nonethical behaviors) in the organizational context. especially, the present study examined the direct and indirect effects of love of money, individuals' perceptions of work climate, perceptions of organizational justice on their ethical judgments and behavioral intentions regarding an ethical dilemma. The subjects of the research were Pusan National University business school enrolled students(n=160). The research was substantiated through statistical analysis of credibility and validity, correlation, variance, and moderated regression analysis. The results indicated that, although perceived ethical climate dimensions did not have a direct effect on behavioral intentions, but had a direct effect on nonethical behaviors. Climates perceived as egoistic were significant moderating effects. and love of money had a direct effect on behavioral intention. Perceptions of organizational justice had a direct effect on behavioral intentions. Especially, interactional justice had a strong influence on ethical behavioral intentions than distributive justice and procedural justice. In depth discussion implications, limitations, and future research directions were supplied.

• Journal of Families and Better Life
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• v.12 no.2
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• pp.41-49
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• 1994

본 연구의 노인의 주거이동행동이 가족생활 주기의 다른 단계의 가구들과는 다른 행태를 나타내고 있으며 이에 대한 연구는 노인들의 생활을 이해하는데 중요한 연구주제가 될 수 있음을 소개하고자 시도되었다. 이를 위하여 노인들의 주거이동 유형과 주거이동을 결 정하고 목적지를 선택하는 의사결정의 과정에 관하여 살펴보고 노인이 이동후 받게 되는 부정적인 영향들과 이러한 부정적인 결과들을 최소화 시킬수 있는 중재변인들을 제시하였다. 이러한 이론적 관점들을 토대로 하여 앞으로 우리나라에서 이루어져야 할 노인의 주거이동 연구의 방향을 제시하였다.

• 주택과사람들
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• s.155
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• pp.20-21
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• 2003

오는 7월부터 ''도시 및 주거환경 정비법''이 시행되면 공동주택 시장은 크게 변할 것으로예상된다. 이 법은 그 동안 개발지상주의가 팽배해 있던 공동주택 시장을 성장관리 체제로 전환해 관리하겠다는 의도에서 출발했다. 이 법이 시행되면 향후 재건축사업은 도시계획 차원에서 관리가 가능해지고, 그 동안 수많은 사업추진 과정에서 나타난 비리와 잡음이 차단되는 등 운영관리 측면에서 긍정적인 변화를 기대할 수 있게 된다. 하지만 이러한 내부적인 변화에도 불구하고 도시 및 주거환경 정비법의 도입은 공동주택 시장에 여러 가지 문제점을 노출할 우려가 높다.