• 한국산학기술학회논문지
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• 제20권9호
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• pp.551-557
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• 2019

생산 공정에서 발생하는 비정상적인 이상 (fault)의 진단 (diagnosis)은 고품질의 제품을 생산함에 있어 필수적이라 할 수 있다. 회분식 공정 (batch process)과 같이 부가가치가 큰 반도체나 의약품 등의 첨단 제품을 생산하는 공정에서는 더욱 실시간 진단의 역할이 커지고 있다. 본 연구에서는 회분식 공정으로부터 얻은 측정 데이터와 비선형 분류(nonlinear classification)에 기초한 실시간 이상 진단 체계에 있어서 변수선택과 미래값 추정 기법이 진단 성능에 미치는 영향을 평가한다. 공정 변수 중 진단에 필수적이며 기여도가 높은 변수만을 선택하여 진단 모델 (diagnosis model)을 구성함으로써 진단 성능의 향상을 기대할 수 있다. 본 연구에서는 여러 변수선택 (variable selection) 기법들의 진단 성능을 비교 평가한다. 또한, 현재 진행 중인 회분식 조업 데이터는 종료되기 이전에는 진단에 필요한 전체 데이터를 얻을 수 없으므로 현재 시점에서 측정되지 못한 미래 측정값 (future observations)이 추정되어야 한다. 미래값 추정방법들의 선택이 변수선택과 분류기반 진단 관점에서 진단 성능에 어떻게 영향을 주는지 평가한다. 폴리염화비닐 회분식 공정에 대한 사례 연구를 수행하여 최적의 변수선택과 미래값 추정방법을 도출하였다. 변수선택 방법에 따라 최대 21.9%와 13.3%의 성능 향상을 보였으며 미래값 추정방법에 따라서는 최대 25.8%와 15.2% 향상됨을 알 수 있었다.

• 한국건축시공학회지
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• 제10권4호
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• pp.95-103
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• 2010

본 연구는 지붕방수공법 선정에 계층분석기법을 적용하여 의사 결정하는 과정을 제안하는 것이 목적이다. 지붕방수공법에 대한 경험에 대하여 본 연구에서 설계 전문가, 시공 전문가, 그리고 유지관리 전문가 그룹에 설문조사를 실시하였다. 설문조사의 첫 번째 계층은 성능, 경제적, 그리고 유리관리 측면으로 구성하였고, 설문의 두 번째 계층은 13개 항목으로 구성하여 Expert Choice를 이용하여 순위를 계산하였다. 설문 분석결과 각 전문가들은 다른 선택을 하였는데, 모든 분야의 전문가는 방수성능 측면을 가장 중요시 하는 것으로 나타났다.

• ETRI Journal
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• 제30권1호
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• pp.89-100
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• 2008

We consider the feature recombination technique in a multiband approach to speaker identification and verification. To overcome the ineffectiveness of conventional feature recombination in broadband noisy environments, we propose a new subband feature recombination which uses subband likelihoods and a subband reliable-feature selection technique with an adaptive noise model. In the decision step of speaker recognition, a few very low unreliable feature likelihood scores can cause a speaker recognition system to make an incorrect decision. To overcome this problem, reliable-feature selection adjusts the likelihood scores of an unreliable feature by comparison with those of an adaptive noise model, which is estimated by the maximum a posteriori adaptation technique using noise features directly obtained from noisy test speech. To evaluate the effectiveness of the proposed methods in noisy environments, we use the TIMIT database and the NTIMIT database, which is the corresponding telephone version of TIMIT database. The proposed subband feature recombination with subband reliable-feature selection achieves better performance than the conventional feature recombination system with reliable-feature selection.

• 대한산업공학회지
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• 제32권1호
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• pp.18-28
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• 2006

Some issues which should be considered in an R&D project selection problem are as follows: First, quantitative analysis on the efficiencies of R&D projects is required to guarantee objective validity in the evaluation of the projects. For this reason, the methodology for selecting R&D projects should be based on mathematical models that perform quantitative analysis. Second, in general there are ordinal factors like Likert-scale in the data for evaluating R&D projects. Previous researches, however, couldn't suggest explicit methods incorporating these ordinal factors into models. Third, for the R&D project selection problems with limited resources like budget, it is necessary to decide the perfect ranking of the all projects. This paper develops a mathematical model that can be applicable to the problems of selecting R&D projects with the previous features. In this paper, we improve the original DEA model for evaluating efficiency to incorporate ordinal factors and suggest a new model which can decide the perfect ranking of all projects by merging the improved DEA model and AHP method. Furthermore a web-based R&D project selection system using the DEA/AHP model suggested in this paper is developed and illustrated.

• 대한치과기공학회지
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• 제37권4호
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• pp.285-293
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• 2015

Purpose: The following study analyzes the mediating effects of professionalism on the relationship between major selection conviction and career decision level of dental technology students. It is to be used as basic data for improvement of the students' career decision level and an effective way to train professionals of the colleges. Methods: The survey was conducted on dental technology students. The collected data was analyzed by the statistical program SPSS 18.0. The results were analyzed by reliability, frequency, multiple-way ANOVA, correlation, multiple regression. To test for significance on each item, p<0.05 has been decided as a standard. Results: The analysis shows that the students' age and clinical practice experience bring a significant difference in major selection conviction, career decision level and professionalism. Professionalism has been found to bring significance mediating effects in relation to major selection conviction and career decision level. Conclusion: To improve the quality and pride as a professional as well as satisfaction with major selection can be expected to raise the standard of the students' career decision level.

• 한국도서관정보학회지
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• 제37권2호
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• pp.47-72
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• 2006

권장도서목록은 ‘좋은 책’을 안내하여 책의 선택을 돕는 역할을 한다. 현재 다양한 기관에서 발행되는 권장도서 목록은 도서관 및 교육현장에서 어린이 및 청소년용 독서자료 선택을 위한 선정도구로 많이 활용되고 있다. 이러한 현실을 고려해서 이 연구에서는 어린이 및 청소년도서용 권장도서목록의 생산현황을 살펴보고, 이들 전장도서목록이 선정도구로 적합한지를 평가하였다. 이후 권장도서목록이 선정도구로 기능하기 위해서, 어떻게 개발되는 것이 좋은지 그 개발방안을 제안하였다.

• 대한치과기공학회지
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• 제33권4호
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• pp.427-440
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• 2011

Purpose: The following research analyzes the causes of major selection and career decision of students studying dental technology. It is to be used as basic data for the management of career improvement program. Methods: The survey has been processed to 490 college students studying Dental Technology in D-college. Questionnaire consists of major selection confidence sheet (14 items) and career decision confidence sheet (18 items) and was scored with 5-points per question. The collected data was analyzed by the statistical program: SAS V8 for Windows. To test for significance on each item, p < 0.05 has been decided as a standard. Results: The analysis of result about the level of confidence on major selection has valid difference by genders, serving military service or not, experience of studying one more year to enter the college or not, making career decision and grade. The analysis of result about career decision has valid difference by gender, serving military service, career decision, day and night course, age and native place. Conclusion: We develop the career advice program and manage it effectively, the confidence on the major selection and pride about its faculty will be high to dental technology students.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.99-105
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• 2012

Recently, there are many user selection algorithms in multi user multiple-input multiple-output (MU-MIMO) systems. One of well-known user selection methods is Semi orthogonal user selection (SUS). It is an algorithm maximizing channel capacity. However, it is applicable only when user's antenna is one. We propose a generalized user selection algorithm regardless of the number of user's antennas. In the proposed scheme, Base station (Bs) selects the first user who has the highest determinant of channel and generates a user group that correlation with first user's channel is less than allowance of correlation. Then, each determinant of channels made up of first user's channel and a user's channel in the generated group is calculated and BS selects the next user who has the highest determinant of that. BS selects following users by repeating above procedure. In this paper, we get better performance because of selecting users who have the highest determinant of channel as well as allowance of correlation optimally calculated through matrix operations.

• 한국ITS학회 논문지
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• 제14권1호
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• pp.68-76
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• 2015

본 논문에서는 원형 배열 안테나를 장착한 차량이 이동하면서 메쉬 네트워크 환경을 구성할 때 다중 노드 빔 형성을 위한 안테나 선택 방식과 전력 제어 알고리즘을 제안한다. 제안한 안테나 선택 방법은 안테나의 방사 이득을 고려하여 빔 형성을 위한 안테나를 선택하고, 두 개 이상의 노드가 인접할 경우 배열 이득을 최대화하기 위해 안테나를 중복으로 선택한다. 제안한 전력 제어 알고리즘은 중복 안테나 선택 시 SIR이 최대가 되도록 각 안테나의 전력을 제어한다. 전산모의 실험을 통하여 제안한 알고리즘을 적용하여 기존의 방식과 비교하여 두 노드가 $15^{\circ}$로 인접했을 때 최대 2.5 dB의 SIR 향상을 보인다.

• 보건의료산업학회지
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• 제13권2호
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• pp.39-54
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• 2019

Objectives: This study was performed to investigate selection factors for specialized hospital and to find out the impact of hospital selection factors on satisfaction, revisiting invention and recommendations. Methods: A survey was performed with 398 inpatients of 4 specialized joint hospital in Busan. Data were collected from August to October 2016 with questionnaires and analyzed using SPSS 24.0. Results: First, inpatients know that it was a specialized hospital were highly satisfied and willing to revisit and recommend. Second, in hospital satisfaction, influence size was shown in order of specialty factors, service quality factors, physical factors, and accessibility factors. Third, the intention to revisit hospitals was higher in the awareness of a specialized hospital and high satisfied inpatients, and recommendation intend were affected by the higher revisitation intention, the high satisfaction level, and the high professionality level. Conclusions: All the hospital selection 4 factors for joint specialized hospitals affects satisfaction level which is linked to revisit and recommend. Specialized Hospitals will have to strengthen qualitative management of hospital selection factors to enhance patient satisfaction.