• The Korean Journal of Applied Statistics
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• v.23 no.1
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• pp.167-178
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• 2010

The orthogonality is an important property in the experimental designs. We usually use supersaturated designs in case of large factors and small runs. These supersaturated designs do not satisfy the orthogonality. Hence, we need the means for the evaluation of the degree of the orthogonality of given supersaturated designs. We usually use the numerical measures as the means for evaluating the degree of the orthogonality of given supersaturated designs. We can use the graphical methods for evaluating the degree of the orthogonality of given supersaturated designs.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.178-179
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• 2010

본 논문은 MIMO 시스템에서 Comb 방식의 파일럿 구조를 이용한 채널 추정에 관해서 논의한다. 기존의 채널 추정은 시간영역에서 정해진 구간의 평균 이용하여 계산량이 아주 작은 방법을 사용한다. 본 논문은 각각의 안테나에 존재하는 파일럿에 직교코드를 넣어 기존의 알고리듬 보다 긴 채널 추정을 가능하게 하였다. 제안된 알고리듬은 컴퓨터 시뮬레이션을 통해 기존 방식보다 긴 채널을 추정함을 알 수 있다.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.175-178
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• 1991

The drive system of servo motor is requested to have robustness of disturbance and parameter variation. However, the dynamics of PMSM drive change significantly by forced disturbance and parameter variation. Moreover, the state error caused by them should be suppressed completely and rapidly. In this paper, the vector-control system of PMSM using dual adaptive control loop is investigated. In the proposed system, linear adaptive control loop rapidly recovers the state error caused by both disturbance and parameter variation. In the dual adaptive control loop, the inner loop reduces the system sensitivity of parameter variation and disturbance, and the outer loop suppresses the state error caused by them completely. The proposed servo system is verified through a computer simulations and experimental results.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.2
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• pp.81-85
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• 2016

It is recognized that safety is a key point of technical competency. Its adoption is widely spread in development of products and it is essentially necessary in aerospace industry because airborne system and equipment are used complex high-technology and implemented systematic performance using software. This study reviews system safety assessment, development assurance level, airborne software, RTCA DO-178 process, and considerations & pitfalls in software development.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.177-178
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• 2008

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.178-186
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• 2010

Business models of e-commerce which have been successfully applied in a developed society do not always guarantee success in other environments where the degree of IT availability differs. This is due to the difference of culture, systems and technological basis among the countries. This study aimed to compare e-commerce system acceptance in countries with different environments and to identify the determining factors for the acceptance of e-commerce. The result shows that, in order to make e-commerce easily accepted in countries with different IT environments, factors such as trust, reputation and usefulness should be addressed more sincerely in the business strategy.

• Journal of Korean Biological Nursing Science
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• v.13 no.2
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• pp.174-178
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• 2011

Purpose: The purpose of this study was to find factors influencing needlestick and sharp injuries (NSI). Methods: This study was a descriptive research for current situation of NSI, recognition and implementation for standard precaution, and factors influencing NSI exposures. The subjects were 450 nursing students of 2 universities in Seoul and Kyunggi-do. The data were collected from June to November, 2008. The gathered data were analyzed by descriptive statistics and regression analysis. Results: The 33.8% of 450 nursing students experienced NSI during 2 weeks clinical training. NSI events were more common among third-year students than second-year students. The most common causative device causing needlestick injuries was blood glucose lancet as 12.4%. Frequencies influencing NSI were students' year and experience of needlestick injuries. Conclusion: The results suggest development of education guidelines for nursing students and implementation of continual systematic education and training in clinic to control blood-borne infections efficiently.

• Journal of the Korean Statistical Society
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• v.23 no.1
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• pp.167-178
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• 1994

To estimate coefficient matrix in autoregressive model, usually ordinary least squares estimator or unconditional maximum likelihood estimator is used. It is unknown that for univariate AR(p) model, unconditional maximum likelihood estimator gives better power property that ordinary least squares estimator in testing for unit root with mean estimated. When autoregressive model contains multiple unit roots and unconditional likelihood function is used to estimate coefficient matrix, the seperation of nonstationary part and stationary part of the eigen-values in the estimated coefficient matrix in the limit is developed. This asymptotic property may give an idea to test for multiple unit roots.

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.175-178
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• 2002

A number of controlled selection methods, which have some advantages for practical surveys in considering controls beyond stratification, have developed throughout the last half-century. With respect to the optimization of sampling plan, it is obvious that we may use optimal controlled selection in preference to satisfactory controlled selection. However, there are currently certain restrictions on the employment of optimal controlled selection. We present further research to improve an algorithm for optimal controlled selection and to develop standard software.

• Journal of fish pathology
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• v.20 no.2
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• pp.169-178
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• 2007