전산 실험 모형을 적용한 자동차 흡기계의 소음 저감에 대한 최적 설계

류제선(Ryu, Je-Seon),진정언(Jin, Jung-Un),차경준(Cha, Kyung-Joon),오재응(Oh, Jae-Eung),심현진(Sim, Hyoun-Jin) 한국소음진동공학회 2005 한국소음진동공학회 논문집 Vol.15 No.10

We propose an optimal design to improve the capacity by reducing the noise of the intake system. The length and radius of each component of the current Intake system are selected as control factors. We accept the output from computer simulator with orthogonal arrays. Then, the Kriging estimates are computed. From this, we exploit the optimal design of the intake system by adapting simulated annealing. From the results of this optimal design, we conclude that Kriging method with the orthogonal arrays is the efficient method for Design and Analysis of Computer Experiments and we propose the useful results for the low noise intake system.

Use of the estimated critical values adapting a regression equation for the approximate entropy test

차경준,류제선,Cha, Kyung-Joon,Ryu, Je-Seon 한국데이터정보과학회 2002 한국데이터정보과학회지 Vol.13 No.2

The statistical testing methods have been widely recognized to determine the plain and cipher texts. In fact, the randomness for a sequence from an encryption algorithm is necessary to guarantee security and reliance of cipher algorithm. Thus, the statistical randomness tests are used to discover cipher text. In this paper, we would provide the critical value for an approximate entropy test by estimating the nonlinear regression equation when the number of sequence and the level of significance are given. Thus, we can discern plan and cipher text for real problem with given number of sequence and the level of significance. Also, we confirm the fitness of the estimated critical values from the rate of success for plain or cipher text.

Use of the estimated critical Values adapting regression equation for the approximate entropy test

차경준(Kyung Joon Cha),류제선(Je Seon Ryu) 한국데이터정보과학회 2002 한국데이터정보과학회지 Vol.13 No.2

The statistical testing methods have been widely recognized to determine the plain and cipher texts. In fact, the randomness for a sequence from an encryption algorithm is necessary to guarantee security and reliance of cipher algorithm. Thus, the statistical randomness tests are used to discover cipher text. In this paper, we would provide the critical value for an approximate entropy test by estimating the nonlinear regression equation when the number of sequence and the level of significance are given. Thus, we can discern plan and cipher text for real problem with given number of sequence and the level of significance. Also, we confirm the fitness of the estimated critical values from the rate of success for plain or cipher text.

The Optimal Design of Low Noise of the Engine Cooling Fan using Kriging Method

Hyoun-Jin Sim(심현진),Sung-Hyoun Kim(김성현),Je-Seon Ryu(류제선),Kyung-Joon Cha(차경준),Jung-Yoon Lee(이정윤),Jae-Eung Oh(오재응) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the Optimal Design for Noise Reduction of the Engine Cooling Fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.

태아심박동 제 변수를 이용한 임신주수 추정알고리즘의 개발

차경준(Kyung Joon Cha),박영선(Young Sun Park),류제선(Je Seon Ryu),윤상순(Sang Soon Yoon),황정혜(Jung Jung Hae),정성로(Sung Ro Chung),문형(Hyung Moon),박문일(Moon Il Park) 대한산부인과학회 2001 Obstetrics & Gynecology Science Vol.44 No.11

N/A Objective : The objective of this study is to estimate gestational age by using FHR parameters after linear and nonlinear analysis of FHR data. Linear spectral decomposition has a limit to describe and analyze the nonlinear and complex physiological nature. Random processing and chaotic analysis assist to quantify some patterned energies, interaction of the physiological system in body system, which the constancy is preserved, and complexity of physical cardiovascular system. But there are no great development of new device which notify fetal age. Methods : From March 1995 to December 2000, 2,548 cases who received NST during antenatal visit were included in this study. Among these cases, 1000 cases were sampled randomly. We divided this cases into a study and a control group, 500 cases for model building set and the other 500 cases for validation set. Each FHR parameters such as baseline FHR, variability (AMP, MMR), acceleration & deceleration (15 bpm- 15 seconds), loss of signal, the number of fetal movement were analysed by using our own computerized HYFM-I, II software system. The linear and non-linear analysis of FHR were done after extracting approximate entropy (ApEn) value. Finally, we performed regression analysis and extract an equation for estimation of gestational weeks using bootstrap method. Results : We extract a following equation using above study method: Log(GA)=5.870-0.051(Sloss*)-0.065(Mean FHR*)+0.049(Mean FHR*)2-0.058(FM*)+0.048(AMP*)2+0.121(A1515*)-0.031(A1515*)2+0.036(ApEn*)2 Conclusions : Accurate dating of pregnancy, namely gestational week is very important for antenatal diagnosis in the field of perinatal medicine. This study will propose scientific research results which are useful for studying normal and morbid generating physiological fetal condition. We extract an appropriate equation for estimation of gestational weeks only using FHR parameters. We hope to compare our result with other authors` results in the near future.

크리깅 모형을 이용한 컴퓨터 실험의 설계와 분석

차경준,류제선,최항석 漢陽大學校 自然科學硏究所 2001 自然科學論文集 Vol.21 No.-

최근 많은 과학적 현상에서 서로 다른 위치에 있는 자료들이 공간적인 상호 작용에 의해 영향을 받는 복잡한 컴퓨터 모델링이 연구되고 있다. 그러한 연구들은 주로 공간적 변인에 의해 영향을 받는 자료에 대하여 상호 연관성을 고려한 함수식에 대한 예측모형에 초점을 두고 있다. 본 연구에서는 컴퓨터 실험에서의 메타모델로서 크리깅 방법을 제시하고, 컴퓨터 모델링을 통하여 생성된 자료를 가지고 크리깅 방법의 정확성과 효율성을 검증하였다. In many fields of design of experiments, the complicate computer modeling, which is influenced by inter-action of various data, has been studied. These studies are focused on prediction models for the functions considering the inter-correlated points influenced by spatial variation. In this paper, we describe the definition, the prediction function and the algorithm of kriging method and examine the accuracy of kriging by using validation method.

디자인혁신에 있어서 유사성 판단에 관한 연구 : 의자, 시계, Facade를 중심으로 concentrated on the identity of chair, clock, Facade

한정완,차경준,오희권,류제선 한국디자인과학학회 1999 디자인과학연구 Vol.2 No.-

신제품이 개발 출시되어 크게 성장 할 수 있다는 것은 그것을 채택, 수용해 줄 수 있는 혁신층과 조기수용자 층의 소비자 구조를 가지고 있어야만 한다. 신제품 수용자의 조기 확보는 신제품 개발에 소요된 비용은 조기에 보충할 수 있고, 많은 고객을 확보하여 매출의 증대가 용이하고, 마케팅비용의 감소를 가져올 수 있으며. 시장에서 리더십을 가짐으로써 효과적 시장 진입이 되기도 한다. 이와 같이 신제품의 수용과 확산의 연구에서 혁신성이 차지하는 중요도가 매우 높기 때문에 많은 관심을 끌어 온 것이 사실이다. 그러나 이러한 혁신과 수용성 연구의 중요성에 비추어 혁신성에 대한 발견 사실의 모호성과 함께 관련변수에 관한 끊임없는 논의가 지속되어 왔고, 동시에 혁신성 연구가 지금까지 취하여 왔던 방향과 주제에 관련해서도 많은 비판이 이루어져 온 것도 사실이다. 이러한 관점에서 본 연구에서는 아직 논리적으로나 실체적으로 방법론이 확립되어 있지 않은 디자인 혁신의 개념을 새롭게 정립하고 그 특징과 요소를 분석하고 객관적인 기준으로 변한 할 수 있는 지표를 찾는다. 또한 디자인 혁신에 있어서 유사성 판단에 관한 실험을 통해 제품 집단의 유형과 기준을 명확히 파악하고 각 샘플의 공간 해석과 함께 시자극적 특성을 정량적으로 평가하는 실험적 이론으로 사용하고자 한다. 이는 디자인에 있어서의 혁신을 인지하고 각 제품 속에 속한 샘플들을 특징별로 지각하는 보다 과학적인 디자인 접근방법에 관해 새로운 방향을 모색할 수 있도록 하였다. If a new product Is devised and to be sold, it Should possess the group of people who are inclined to change and accept the product, and the group of consumers who can buy them. If you occupy the consumers to buy the products earlier, you car make up with the expenditure that you have spent to devise and make products, facilitate the raise of the sales, decrease the marketing expenditure, and have effective access to the market by going ahead of others. Like this the Innovation has great influence in the accepting and spreading of the products. However in spite of these Innovation and acceptance, there have kept the ceaseless disputes about finding the Innovation and related function, at the same time the study of innovation has been criticized about the direction and the theme we have taken until now. From this point of view, the methodology has not been established In the area of logic and its reality, and this study tries to set up the concepts and analyze the characteristic and the elements and find the standard to change those characteristics and elements in to objective standard. In addition, through the judgment of the similarity In the design innovation, it tries to identify clearly the types and the standard of the set of the products, Interpret the space of each sample, and use it as the experimental theory to evaluate the visual characteristics, Thus it can perceive innovation of the design. perceive the characteristics of the samples in each products, and find the new direction in the more scientific access to design.