• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.574-577
• /
• 2009

본 논문은 외판원 문제(TSP: Traveling Salesman Problem)를 이용하여 로봇중심의 FMC(Flexible Manufacturing Cell)에서 반송 로봇의 작업순서를 설계하는 방법을 제시하였다. 이를 위해, 먼저 다수의 설비와 반송 로봇으로 구성된 대표적인 로봇 중심의 FMC를 가상으로 설계한 후, 실험계획법을 이용하여 다양한 조건에서의 주요 반응변수들의 인과관계를 규명하였다. 실험결과, 처리량, 반송로봇의가동률, 그리고 Buffer의 평균 대기 작업물의 수가 주요 반응변수들로 선정되었으며, 이를 기반으로 순서기반 조합최적화 문제인 TSP로 로봇 작업순서를 설계하였다. 제안한 방법과 기존의 방법을 비교하기 위해서 시뮬레이션을 수행 한 결과 제안된 TSP 방법이 기존의 방법 보다 반송 로봇의 교착 (Deadlock) 상태를 방지하여 처리량 등 주요 반응변수들 모두를 향상 시키는 결과를 가져왔다. 더불어,이 방법은 본 연구에서 제시한 FMC 뿐 아니라 반도체나 LCD(Liquid Crystal Display) 생산 공정과 같이 반송 로봇에 의해 구성되어 있는 장치 산업분야에 적용가능하다는 측면에서 큰 효과가 기대된다.

• Culinary science and hospitality research
• /
• v.22 no.5
• /
• pp.82-94
• /
• 2016

This study on CRM oftKorean restaurant guests to test the emotional response and behavioral intention. Three kinds of variables(service quality, information quality, system quality) from Korean restaurant guests were set to test the CRM. Results of the multiple regression analysis revealed a positive significant relationship with respect to quality of service, quality information, and quality system with all customer emtional reaction. Second, the results also found that the three independent variables of quality of service (${\beta}=.104$, P<.01), information quality (${\beta}=.215$, P<.001), and system quality (${\beta}=.682$, P<001) had a significant positive effect on the dependent variable for customer behavior (+). Third, CRM quality of service, quality information, and quality of the restaurant system are shown to influence the behavior and it also showed that both the part-mediated effects.

• The Korean Journal of Applied Statistics
• /
• v.3 no.2
• /
• pp.27-37
• /
• 1990

We consider the statistical control problem for the mixture model in which one can choose the values of independent variables that produce the values of the dependent variables as close to the target values as possible. The theory suggested for the problem is reviewed and an extended model with respect to the assumption of variance and the number of dependent variables is suggested. A Basyesian treatment is studied for the above problem with example as an illustration.

• The Korean Journal of Applied Statistics
• /
• v.30 no.5
• /
• pp.793-808
• /
• 2017

We compare various variable screening methods on multiclass classification problems when the data is ultrahigh-dimensional. Two different approaches were considered: (1) pairwise extension from binary classification via one versus one or one versus rest comparisons and (2) direct classification of multiclass responses. We conducted extensive simulation studies under different conditions: heavy tailed explanatory variables, correlated signal and noise variables, correlated joint distributions but uncorrelated marginals, and unbalanced response variables. We then analyzed real data to examine the performance of the methods. The results showed that model-free methods perform better for multiclass classification problems as well as binary ones.

• Communications for Statistical Applications and Methods
• /
• v.17 no.1
• /
• pp.127-140
• /
• 2010

In interim analysis, group sequential tests are widely used for the ethical, scientific, and economic reasons. In this paper, we propose the group sequential tests using both type I and type II error spending rate functions when the response variable is discrete, especially binomial distribution, in the interim analysis. In addition, we propose new error spending rate function which covers the formerly proposed. Our method has good property that is flexible, fast and easily applicable. A numerical simulations are carried out to evaluate our method and it shows good performance.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1997.11a
• /
• pp.331-336
• /
• 1997

본 연구에서 산업재해 사례를 연구 대상으로 재해 발생의 여러 가지 요인들의 관련을 검토하고자 통계적 기법을 이용한 재해요인별 상관분석, 또는 영향의 정도 파악, 재해 요인의 통제에 따른 기타 재해요인에 대한 영향 분석을 시도하는 통계학적 분석 방법을 이용한 재해 발생의 중요요인을 분석하고자 첫째, 산업재해 통계 자료의 내용을 분석하여 재해 관련 변수들을 파악하는데 불안전 행동 및 불안전상태에 의한 재해 형태와 기타 변수들 간의 정성적 상관분석을 통한 상관계수를 고찰, 둘째, 명목척도인 범주형 변수 상호 간의 관련 여부를 파악하기 위해 카이제곱(chi-square)검정을 행하여 입원 일수를 종속 변수로 하는 기타 변수들의 독립성 여부와 변수 상호간 연관이 있다고 판단될 때 각 변수의 연관의 정도 비교, 셋째, 어떤 변수 상호간 일정한 관계를 가질 때 변수의 범주별로 반응변수(종속변수)에 미치는 영향을 회귀식 형태로 파악하고 비교하기 위하여 로짓(logit)모형을 적용하였다. (중략)

• The Korean Journal of Applied Statistics
• /
• v.23 no.5
• /
• pp.857-870
• /
• 2010

This study was conducted to investigate the relationship between the socio-demographic factors and the Korean consumers palatability evaluation grades with Hanwoo sensory evaluation data from 2006 to 2008 by National Institute of Animal Science. The dichotomy logistic regression model and the multinomial logistic regression model are fitted with the independent variables such as the consumer living location, age, gender occupation, monthly income, beef cut and the the palatability grade as the categorical dependent variable and tenderness, 리avor and juiciness as the continuous dependent variable. Stepwise variable selection procedure is incorporated to find the final model and odds ratios are calculated to nd the associations between categories.

• The Korean Journal of Applied Statistics
• /
• v.20 no.1
• /
• pp.195-204
• /
• 2007

In order to represent multiple regression data, an alternative graphical method, called as SSR Plot, is proposed by using geometrical description methods. This plot uses the relation that the sum of sqaures for regression (SSR) of two explanatory variables is known as the sum of the SSR of one variable and the increase in the SSR due to the addition of other variable to the model that already contains a variable. This half circle shaped SSR plot contains vectors corresponding explanatory variables. We might conclude that some explanatory variables corresponding to vectors which locate near the horisontal axis do affect the response variable. Also, for the regression model with two explanatory variables, a magnitude of the angle between two vectors can be identified for suppression.

• Journal of the Korean Data and Information Science Society
• /
• v.25 no.2
• /
• pp.403-410
• /
• 2014

Binary logistic regression analysis is a statistical technique that explains binary response variable by quantitative or qualitative explanatory variables. In the binary logistic regression model, the probability that the response variable equals, say 1, one of the binary values is to be explained as a transformation of linear combination of explanatory variables. This is one of big barriers that non-statisticians have to overcome in order to understand the model. In this study, an educational tool is developed that explains the need of the binary logistic regression analysis using Excel VBA. More precisely, this tool explains the problems related to modeling the probability of the response variable equal to 1 as a linear combination of explanatory variables and then shows how these problems can be solved through some transformations of the linear combination.

• Proceedings of the KIEE Conference
• /
• 2003.10b
• /
• pp.21-23
• /
• 2003

본 연구에서는 반응표면기법을 이용하여 5상, 10/8 스위치드 리럭턴스 모터의 최적설계를 수행하였다. 반응표면 기법은 여러 개의 독립적인 설계변수가 출력 함수에 복합적인 작용을 하고 있을 때, 설계변수의 변화에 대한 출력함수의 변화를 추정하는 통계적인 분석방법이다. 여기서는, 모터 형상을 결정하는 모든 기하학적인 치수들을 변수로 선택하였고, D-Optimal 기법을 이용하여 실험 점들을 선택하였다. 각각의 실험점들에 대해서 FEM 해석을 수행하였고, 평균토크와 권선면적을 만족하는 최소부피의 모터를 설계하였다. 반응표면 모델을 이용하여 최적설계를 수행하였고, 각도와 전류에 따른 토크 프로파일과 인덕턴스 프로파일을 얻었다. 이를 바탕으로 동적 거동을 예상해 보았다. 반응표면기법을 이용한 최적설계에서는 global optimum을 보장할 수 있으며, 최적설계에 소요되는 시간을 줄일 수 있다.