Mahalanobis Taguchi System을 이용한 자동차 브레이크 성능 만족도를 고려한 설계조건 선정에 관한 연구

홍정의(Jung-Eui Hong),권홍규(Hong-Kyu Kwon) 한국산업경영시스템학회 2007 한국산업경영시스템학회지 Vol.30 No.1

  Mahalanobis Taguchi-System (MTS) is a pattern information technology, which has been used in different diagnostic applications to make quantitative decisions by constructing a multivariate system using data analytic methods without any assumption regarding statistical distribution. MTS performs Taguchi’s fractional factorial design based on the Mahalanobis distance as a performance metric. In this work, MTS used for analyzing automotive brake feeling system, which measured as a brake feel index (BFI) from 9 attributes. The automobile which has a good BFI score treated as a normal group for constructing Mahalanobis space. The results of this research show that two attributes (Pre load & Max deceleration) have a minus gain value and can be removed from further analysis. The difference of MD value between using all 9 attributes and just using significant attribute compared.

The effects of F anion doping on the electrochemical properties in Li₄Ti<SUB>5</SUB>O<SUB>12</SUB> as anode materials for lithium ion batteries

Jung-Eui Hong(홍정의),Su-Jeong Park(박수정),Kwang-Sun Ryu(류광선) 한국전지학회 2021 한국전지학회지 Vol.1 No.2

Li₄Ti5O12 및 불소로 치환된 Li₄Ti5O12-xFx(x=0.1 및 0.2)를 합성하고 전기화학적 특성을 확인했다. 입방 구조 격자상수는 F 도핑의 양이 증가함에 따라 증가했으며 F 이온의 치환은 Ti<SUP>3+</SUP>/Ti<SUP>4+</SUP>의 혼합 이온의 발생으로 인해 LTO의 전기 전도도를 향상시켰으나 F 도핑이 증가할수록 LTO의 전기화학적 성능에 부정적인 영향을 미친다. We have expected that F doping in spinel LTO will improve the electrochemical performance along with electronic conductivity. The pristine Li₄Ti5O12 and fluorine anion substituted Li₄Ti5O12-xFx (x=0.1 and 0.2) powders are synthesized by sol-gel method and verified physical and electrochemical properties. The cubic lattice parameters increases with increasing the amount of F doping. The substitution of F ion is possible to improve the electronic conductivity of LTO because of the generation of mixed valence state of Ti<SUP>3+</SUP>/Ti<SUP>4+</SUP>. However, the more amount of F doping increase, the gap between the anodic peak and cathodic peak more increase because of inductive effect of F doping. In addition, the F doping is having a negative influence on the electrochemical performance of spinel LTO. Therefore, the electronic conductivity improved, on the contrary, the electrochemical performance turns for the worse with the doping of fluorine content.

전기로를 이용한 제강공정의 최적 스크랩 배합 비율 선정에 대한 연구

홍정의 ( Jung Eui Hong ) 대한설비관리학회 2012 대한설비관리학회지 Vol.17 No.4

In steel production, an electric arc furnace (EAF) is most commonly used to melt raw material in order to produce liquid steel. Scrap is the main raw material which differs in regard to the content of iron and of some chemical elements. The price of scrap depends on these attributes. In order to obtain the desired quality and quantity, each melting bath unit of steel has either its own material constraints or the constraints for electric arc furnace such as the capacity of EAF. In addition, the availability and transportation of scrap are also restricted because they need space. This research is to create an optimization model which minimizes the cost of raw material The running speed of the model is reasonably guaranteed by properly designing the combinatorial structure with branch and bound rules. Simulation results show significant improvement compared to the : the cost of scrap steel is reduced by 2 to 6% and the time of charging buckets is 2 to 10 minutes faster.

AHP를 활용한 온라인 게임의 사용성 평가요인에 관한 연구

홍정의(Hong, Jung-Eui) 한국상품학회 2021 商品學硏究 Vol.39 No.3

본 연구의 목적은 양질의 온라인 게임 이용 가능성을 선정하기 위한 평가 기준을 수립하고 평가 요소에 대한 정량적 척도를 이용한 평가 모델을 제시하는 것이다. 본 연구는 온라인 게임의 사용성에 관한 연구로 한정되었으며, 공간적 범위는 한국에 거주하며 온라인 게임을 사용한 경험이 있는 20 ~ 30 대 사용자로 제한하였다. 설문 조사를 기반으로 AHP (Analytical Hierarchy Process) 기법을 사용하여 고객 피드백을 반영하기 위해 AHP 분석 프로그램 인 Expert Choice11.5가 사용하였다. 온라인 게임사용에 영향을 미치는 요소 (사회적 응집력, 도전적 재미, 감각적 재미 및 상호 작용)를 살펴보고 이러한 요소가 고객의 온라인 게임 사용성에 얼마나 영향을 미치는지 우선순위를 분석하였다. 또한 중대성 비교에 앞서 응답자의 응답의 일관성을 파악하기 위해 의사 결정 과정에서 발생할 수 있는 오류를 파악하기 위해 그룹 간 일관성 비율 (CR)을 비교분석하였다. 본 연구를 통해 온라인 게임에 대한 서비스 품질 평가 모델을 제시하고, 온라인 게임 서비스의 지속적인 품질관리를 위한 기본 정보를 제공하고 향후 다양한 서비스를 제공 할 수 있는 기회를 제공할 수 있을 것으로 판단된다. The purpose of this study is establish evaluation criteria to select the availablitiy of good quality online game and to present an evaluation model that uses quantitative scales for evaluation factors. This study was limited to those related to the usability of online games, and the spatial scope was limited to users in their 20s and 30s who live in Korea and have experience using online games. Based on the survey, Expert Choice11.5, an AHP analysis program, was used to reflect customer feedback using the Analytical Hierarchy Process (AHP) technique.We look at the factors that affect online game usage (social cohesion, challenging fun, sensory fun, and interactivity) and analyze the priorities of howmany these factors affect customers online game usability. In addition, the consistency ratio (CR) between groups was checked to identify possible errors in the decision-making process in order to identify the consistency of respondents responses prior to the materiality comparison. Through this study, the service quality evaluation model is presented for the online game, and the opportunity to provide basic information for continuous qualitymanagement of the online game service and providing various services in the futurewill be given.

Mahalanobis Taguchi System을 이용한 척추질환 환자의 진단에 관한 연구

홍정의(Jung Eui Hong) 한국산업경영시스템학회 2012 한국산업경영시스템학회지 Vol.35 No.4

The Mahalanobis-Taguchi System is a diagnosis and predictive method for analyzing patterns in multivariate cases. The goal of this study is diagnosis of the spondylolisthesis from biomedical data that is derived from the shape and orientation of the pelvis and lumbar spine. The data set has six attributes including pelvic incidence, pelvic tilt, lumbar lordosis angle, sacral slope, pelvic radius and grade of spondylolisthesis and two class including normal and abnormal. From University of California at Irvine machine learning repository, 100 normal and 150 spondylolisthesis patient’s data were used for this study. Mahalanobis Taguchi System (MTS) application process and the diagnosis results were described in this paper.

다중회귀분석과 Mahalanobis Distance 이상치 탐색방법을 이용한 고강도 콘크리트 강도 예측 모델 개발에 관한 연구

홍정의 ( Jung Eui Hong ) 대한설비관리학회 2011 대한설비관리학회지 Vol.16 No.2

High-performance concrete(HPC) is a new terminology used in concrete construction industry. Several studies have shown that concrete strength development is determined not only by the water-to-cement ratio but also influenced by the contents of other concrete ingredients. HPC is a highly complex material, so it is very difficult task to modeling its behavior. This research aimed to predict the compressive strength of HPC with multiple linear regression analysis. Mahalanobis Distance(MD) outlier detection method used for the purpose of detecting outlier and increase prediction ability of regression analysis. The detailed procedure of calculating Mahalanobis Distance (MD) is described. The effects of outlier compared with before and after at the multiple linear regression.

Electrochemical Performance of Li₄Ti₅O<SUB>12</SUB> Modified by Carbon on Surface as an Anode of Lithium Ion Batteries

Jung-Eui Hong(홍정의),Kyu-Sik Kim(김규식),Han-Jin Jeon(전한진),Kwang-Sun Ryu(류광선) 한국전지학회 2021 한국전지학회지 Vol.1 No.1

스피넬구조를 가진 Li₄Ti₅O12 (LTO) 물질은 이론용량 175 mAh/g을 가지며 리튬이온의 삽입과 탈리의 뛰어난 가역성을 가진다. 또한 충전 및 방전 동안 용량 변화가 적다는 장점이 있다. 그러나 LTO는 전기전도성이 낮다는 단점이 있어 광범위하고 실용적인 적용에서는 제한적이라는 단점이 있다. 탄소코팅은 일반적으로 쉬우며, 효과적이며 그 결과도 전해액과의 표면에서의 전기전도성을 개선시킬 수 있다. 또한 전기적 성능의 향상도 가능하다. 여기서 LTO 표면에 malic산(C₄H₆O₅)을 이용하여 표면을 개질하여 리튬이온전지에서 음극에 사용 가능한 LTO의 성능개선을 위한 연구를 실시하였다. 본 연구에서는 1 wt%의 malic산으로 표면을 개질한 LTO가 가장 우수한 용량과 성능 유지를 하는 것을 알 수 있었다. Li₄Ti₅O12 (LTO) material with spinel structure has a theoretical capacity of 175 mAh/g and has excellent reversibility of insertion and desorption of lithium ions. In addition, there is an advantage that there is little change in capacity during charging and discharging. However, LTO has a disadvantage in that it has low electrical conductivity and is therefore limited in a wide range of practical applications. Carbon coating is generally easy and effective, and the result can also improve the electrical conductivity at the surface with the electrolyte. In addition, it is possible to improve the electrical performance. Here, the LTO surface was modified using malic acid (C₄H₆O₅) to improve the performance of LTO, which can be used as a negative electrode in a lithium ion battery. In this study, it was found that the surface-modified LTO with 1 wt% malic acid maintained the best capacity and performance.

서포트 벡터 머신을 이용한 질병의 진단에 관한 연구

홍정의 ( Jung Eui Hong ) 대한설비관리학회 2014 대한설비관리학회지 Vol.19 No.2

Support Vector Machines (SVM) are supervised learning algorithms that analyze data and recognize patterns and used for classification and regression analysis. Specially, SVM is an linear classifier to perform in such a way as to minimize the generalization error. In this study, SVM apply to diagnosis breast cancer. Breast cancer test data have 9 test parameters 2 class and 683 patients. Randomly select some patients as a train data for SVM train and predict the other patient data. The diagnosis results are compared with both different train data size and different training parameters.

신경망이론을 이용한 어인자의 수준사이를 고려한 최적조건 선정에 관한 연구

홍정의(Jung Eui Hong) 한국품질경영학회 2002 품질경영학회지 Vol.30 No.2

Defining the relationship between the quality of injection molded parts and the process condition is very complicate because of lots of factor are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation even though restricted application. In this research, Neural Network applied for finding optimal processing condition. The percent of volumetric shrinkage compared on each case and show neural network can be successfully applied selecting optimum condition not only within factor level but also between factor level.

Mahalanobis Taguchi System을 이용한 파킨슨병 환자의 음성분석을 통한 진단에 관한 연구

홍정의(Jung-eui Hong) 한국산업경영시스템학회 2009 한국산업경영시스템학회 학술대회 Vol.2009 No.추계

Human voice is very sensitively reacts to human's minute physical condition. Therefore, voice disorders effects patients profoundly especially in the case of Parkinson's disease. Acoustic tools such as MDVP, can potentially measure various voice function objectively. Many different approaches have been applied for analyzing the voice disorders for diagnosis of Parkinson's disease. With the voice data of suspected Parkinson's patients from UCI machine learning repository which have 23 Parkinson's disease data and 8 healthy data, Mahalanobis Taguchi System(MTS) applied for diagnosis of Parkinson's disease. The correct diagnosis performance is compared to previous research results.