Freund 이변량 지수분포의 매개변수 추정과정 검토

박철순,유철상,Park, Cheol-Soon,Yoo, Chul-Sang 한국수자원학회 2012 한국수자원학회논문집 Vol.45 No.2

본 연구에서는 연최대치 독립 호우사상의 결정에 사용되는 Freund 이변량 지수분포의 매개변수 추정과정을 구체적으로 검토하였다. 먼저, 모멘트법을 이용하는 경우를 구체적으로 검토하고, 그 결과를 최우도법을 적용한 결과와 비교하였다. 두 방법을 1961~2010년 서울지점의 시강우 자료에 적용하여 연최대치 독립 호우사상을 선정하고, 그 결과를 비교 검토하였다. 이러한 과정을 통해 얻은 결과는 다음과 같다. 첫째, 매개변수 추정방법으로 모멘트법을 적용하는 경우에는 두변량의 평균과 분산뿐만 아니라 상관계수도 고려해 주어야 하는 것으로 나타났다. 둘째, 최우도법은 두변량의 평균에 대한 재현성이 우수하고, 모멘트법은 분산의 경년변동을 잘 나타내는 것으로 나타났다. 셋째, 모멘트법과 최우도법을 통해 선정한 연최대치 독립 호우사상들은 대체로 유사한 것으로 나타났다. 다르게 선정된 호우사상은 최우도법의 경우에는 총 강우량이 큰 것, 모멘트법의 경우에는 강우강도가 큰 것으로 나타났다. This study reviewed the parameter estimation procedure of the Freund bivariate exponential distribution for the decision of the annual maximum rainfall event. The method of moments was reviewed first, whose results were compared with those from the method of maximum likelihood. Both methods were applied to the hourly rainfall data of the Seoul rain gauge station measured from 1961 to 2010 to select the annual maximum rainfall events, which were also compared each other. The results derived are as follows. First, when applying the method of moments for the parameter estimation, it was found necessary to consider the correlation coefficient between the two variables as well as the mean and variance. Second, the method of maximum likelihood was better to reproduce the mean, but the method of moments was better to reproduce the annual variation of the variance. Third, The annual maximum rainfall events derived were very similar in both cases. Among differently selected annual maximum rainfall events, those with the higher rainfall amount were selected by the method of maximum likelihood, but those with the higher rainfall intensity by the method of moments.

독립 호우사상에 대한 이변량 강우빈도해석 및 강우-유출해석

박철순,유철상,전창현,Park, Cheol-Soon,Yoo, Chul-Sang,Jun, Chang-Hyun 한국수자원학회 2012 한국수자원학회논문집 Vol.45 No.7

본 연구에서는 독립 호우사상을 이용하여 이변량 빈도해석 및 유출해석을 수행하고, 이를 기존 단변량 빈도해석 결과와 비교 평가하였다. 본 연구는 규모가 다른 중랑천, 청계천, 우이천유역 등 세 유역에 대해 수행되었다. 유출모형으로 Clark 모형을 이용하였고, 유효우량은 SCS 방법을 적용하여 계산하였다. 강우의 시간분포 모형으로 교호블록 방법 및 Huff 방법을 적용하여 그 결과가 비교될 수 있도록 하였다. 그 결과를 정리하면 다음과 같다. (1) 연최대치 독립 호우사상계열의 이변량 빈도해석 결과, 지속기간이 짧은 경우에는 단변량 빈도해석 결과와의 차이가 매우 크나 지속기간이 길어짊에 따라서 그 차이가 현저히 줄어드는 것으로 나타났다. 아울러 지속기간이 짧은 경우, 단변량 빈도해석 결과가 이변량 빈도해석 결과보다 더욱 크게 나타났으나 특정 지속기간 이상부터 그 결과가 역전되는 것으로 나타났다. (2) 교호블록 시간분포 방법을 적용하는 경우가 Huff 방법을 적용한 경우보다 더욱 큰 첨두유출량을 발생시키는 것으로 나타났다. 아울러 교호블록 방법을 적용하는 경우에는 강우 지속기간의 증가에 따라서 첨두유출량이 점차 증가하는 것으로 나타났으나, 강우 지속기간이 대략 24시간 정도 되었을 때 그 값이 거의 수렴하는 것으로 나타났다. (3) 중랑천 유역에 대해 Huff 방법을 적용하여 유출해석을 수행한 결과에서는 이변량 설계강우를 적용한 경우가 단변량 설계강우를 적용한 경우보다 더욱 큰 홍수량을 발생시키는 것으로 나타났다. 반면에 청계천 및 우이천 유역의 경우에는 이변량 설계강우를 적용한 경우보다 단변량 설계강우를 적용한 경우의 홍수량이 다소 큰 것으로 나타났다. 그러나 교호블록 방법을 적용한 경우에서는 모든 유역에 대해 이변량 설계강우를 적용한 경우가 단변량 설계강우를 적용한 경우보다 큰 홍수량을 발생시키는 것으로 나타났다. In this study, the bivariate frequency analysis of the independent annual rainfall event series was done to be used for the runoff analysis, whose results were also compared with those from the conventional univariate frequency analysis. This study was applied to three differently-sized basins such as the Joongryang Stream, Chunggye Stream, and Ooyi Stream. The Clark model was used as the runoff model, and the SCS method was applied for the calculation of the effective rainfall. The alternating block method and the Huff method were considered to be compared for the temporal distribution of rainfall event. Summarizing the results are as follows. (1) The difference between the univariate and bivariate frequency analysis results were large when the rainfall duration was short, but significantly decreased as the rainfall duration increased. The univariate frequency analysis results were bigger when the rainfall duration was short, but smaller in opposite case. (2) The peak flow derived by applying the alternating block method was bigger than that by the Huff method. Also, the peak flow when applying the alternating block method increased as the rainfall duration increased, but converged smoothly around the rainfall duration of 24 hours. (3) For the Joongryang Stream, when applying the Huff method, the peak flow derived for the bivariate frequency analysis was bigger than that for the univariate case, but for the other two basins, the results were opposite. When applying the alternating block method, the results were consistent for all three basins that the peak flow derived by applying the bivariate frequency analysis was bigger than those by the univariate frequency analysis.

지식 네트워크에서 지식 전파 행위자 모형

박철순(Chul soon Park) 한국생산관리학회 2014 한국생산관리학회지 Vol.25 No.4

본 연구는 지식 네트워크에서 지식이 전파되는 행태를 행위자 기반 모형으로 모형화하였다. 이를 위해 선행 연구를 통해 지식 전파에 영향을 주는 요인들을 네트워크 속성, 기업 속성, 지식 속성으로 분류하였으며 이를 포괄하는 변수들을 도입한 모형을 제시하였다. 방대한 모의실험으로 얻은 데이터를 바탕으로 하여 지식의 암묵성을 중심으로 지식 전파에 영향을 미치는 요인들을 분석하였다. 그 결과 지식의 암묵성이 클수록 지식 네트워크의 전반적인 지식수준은 낮아졌으며 기업 간 지식 격차는 커짐을 확인했다. 내부 혁신 역량, 흡수 역량과 같이 기업 속성에 속하는 변수들은 지식 전파에 긍정적인 영향을 끼쳤는데, 이 관계를 지식의 암묵성이 조절함을 밝혔다. 즉, 내부 혁신 역량 또는 흡수 역량이 큰 기업일수록 지식수준이 높아지는데 암묵성이 큰 지식일수록 그 효과가 더 증가함을 확인한 것이다. This paper presents an agent-based model for knowledge diffusion on knowledge network. Based on literature review regarding knowledge network, the factors that affects the behavior of knowledge diffusion are classified as three categories: network-related, firm-related, and knowledge-related factors. The model adopts all three categories as driver of knowledge diffusion including the depreciation rate of knowledge (network-related), internal innovation capacity, absorptive capacity, learning capacity, degree centrality (thus far, firm-related), and tacitness of transferred knowledge (knowledge-related). This paper analyzes the effect of knowledge tacitness on knowledge diffusion based on large simulation runs. It shows that as the tacitness increases, the mean of knowledge level decreases, whereas the coefficient of variation among network members increases. Also, we find that the firm-related variables such as internal innovation capacity and absorptive capacity have a significantly positive effect on firm's knowledge level. We further find that the tacitness of transferred knowledge moderates the relationship between the firm-related variables and knowledge diffusion. It means that the positive effect of a firm's absorptive capacity (or internal innovation capacity) on its knowledge level increases as the tacitness of knowledge increases.

비즈니스 프로세스 로직 표현을 지원하는 RFID 미들웨어 개발

박철순(Chul-Soon Park),배성문(Sung-Moon Bae),고로(Gao Lu) 한국산업경영시스템학회 2008 한국산업경영시스템학회지 Vol.31 No.3

  Because of different hardware specifications, there are no unified protocol commands to use with various kinds of RFID readers. The current commercial RFID middlewares do not satisfy the various requirements from users to support business process logic representation. The EPCglobal, which is leading organization for the RFID research, suggested a RFID middleware architecture which is called ALE(Application Level Events) standard. However, their architecture also does not provide the application level’s interfaces. Therefore, a new RFID middleware architecture is required to provide basic RFID functions, conform to ALE’s specification and, additionally, support application level’s business logic representation.<BR>  This paper proposes a ALE-based RFID middleware architecture which provides business process logic representation. At first, the basic RFID control functionalities are identified. Secondly, the business process logic requirements in RFID applications are identified and classified into six categories. Third, the Middelware architecture is implemented with Java and XML technology so that it can easily extended to support the various RFID hardware’s protocols. Finally, an example RFID prototype system is developed to show the proposed architecture’s feasibility and validate it. The proposed middleware is expected to be used in various application areas since it is using XML technology for easy adaptation and it also conforms to ALE interface which is standard specification.

CPLD를 이용한 5상 스텝모터의 마이크로스텝 구동 성능향상에 관한 연구

박철순(Chul-soon Park),지대영(Dea-young JI),안호균(Ho-Kyun Ahn),박승규(Seung-kyu Park) 전력전자학회 1999 전력전자학술대회 논문집 Vol.- No.-

This paper presents the design and implementation of a microstep control IC using complex programmable logic device(CPLD). The microstep driving method is used for high performance motion control, low vibration and low noise in motor control system. The improvement of the electrical and mechanical driving characteristic of a step motor is achieved by applying microstep driver.

공급사슬 통합과 기업 성과의 관계

박철순(Chul Soon Park) 한국경영학회 2012 經營學硏究 Vol.41 No.6

While the supply chain management literature is piled regarding the benefits of supply chain integration on performance, the structure of detailed dimensions and the impact of such integration dimensions on firm performance remains largely an unexplored area of research. Based on the literature review regarding supply chain integration and strategic theories including resourcebased view, relational view, and extended resource-based view, this study categorize the supply chain integration as three dimensions: internal integration, supplier integration, and customer integration. We hypothesize that the internal integration is an antecedent of the other integration dimensions. Further we hypothesize that while there may be no direct benefit of internal integration on performance, the internal integration might support supplier integration and customer integration in the supply chain, which in turn might impact firm performance. Finally, we hypothesize that there is moderating effect of firm size on the relationship between supply chain integration and firm performance. In other words, the significance of paths among the supply chain integration and firm performance can be differed according to the firm size. To examine our hypotheses, we collected data of 193 firms from 22 manufacturing industries. In order to assess the validity and reliability of constructs, we examined composite reliability, average variance extracted, and Cronbach`s alpha for every constructs. The results showed that all constructs are reliable and valid. To test the research hypotheses, a structural model is provided and tested whether the structural path coefficients were significant. To confirm the fitness of our structural model, we compared it with the other alternative models. Based on the goodness of fit and parsimonious indices, we confirmed that our model is the best fit among others. In order to test the moderating effect of firm size, we categorized the data based on the firm size into two groups: a larger firm and a smaller firm group. Finally, we used a structural equations modeling program, AMOS 18.0, to analyze the significance of difference of hypothesized paths between the two groups. Based on the analysis, we empirically showed that supply chain integration is composed of three dimensions as suggested: internal integration, supplier integration, and customer integration. Our analyses also showed that there was no direct benefit of internal integration on firm performance; however the internal integration supported customer integration and supplier integration, which in turn increased the firm performance. Further, there is moderating effect of firm size on the relationship between supplier integration and firm performance as well as customer integration and firm performance. In a larger firm group, a coefficient of a path from customer integration to performance was significant while that from supplier integration to performance was not. Conversely, in a smaller firm group, a coefficient of a path from supplier integration to performance was significant while that from customer integration to performance was not. It showed that there is a significant difference in the relationship between supply integration and firm performance according to the firm size. Practical and academic contribution of this study can be stated as follows. First, we confirmed that supply chain integration was composed of three discriminate constructs: internal integration, supplier integration, customer integration. Second, since the internal integration is a precedence of the other two dimensions, a manager should focus on the internal integration at first and then turn his or her efforts on the external integration practices. Finally, we revealed that there was a difference of relationship between supply chain integration and firm performance according to firm size. This result contribute to operations management consistency research and provides theory-driven and e

공급자참여와 고객참여 및 학습,훈련이 품질성과와 기업성과에 미치는 영향

박철순 ( Chul Soon Park ) 한국품질경영학회 2012 품질경영학회지 Vol.40 No.1

This study investigates the impact of supplier involvement, customer involvement, and employee training on product quality and organizational performance. Based on literature review, this study develops hypotheses and tests them by employing a structural equations model. Using survey data of 193 firms from 22 manufacturing industries, this study empirically shows that the activities for supply chain quality management (SCQM) enhance the quality and organizational performance. Specifically, quality leadership is revealed to be an antecedent of other SCQM activities. The most contributable finding is, while the supplier involvement and employee training directly enhance the organizational performance, customer involvement indirectly improves it via quality performance.

개선된 고상 합성법을 통한 LiNi 0.5 Mn 1.5 O 4 양극재 연구

박철순(Chul-Soon Park),조성규(Seong-Gyu Cho) 한국산업기술융합학회(구. 산업기술교육훈련학회) 2024 산업기술연구논문지 (JITR) Vol.29 No.1

이 논문에서는 다양한 원료 NiO, Ni 2 O 3 , MnO 2 , Mn 3 O 4 를 사용하여 LiNi 0.5 Mn 1.5 O 4 를 비드밀 혼합 공정을 사용하여균일한 혼합을 통해 불순물을 줄이고 스프레이 드라이 공정을 사용 균일한 2차 입자 모양과 분포를 얻은 개선된 고상 합성법으로 합성했다. 율속 특성에 최적화된 원료를 선택하고 개선된 공정을 적용하여 얻어진 LiNi 0.5 Mn 1.5 O 4 는 XRD 및 SEM을 통해 1차 입자와 2차 입자가 성공적으로 합성되는 것을 확인하였다. 이 결과는 개선된 고상 합성법 으로 합성된 LiNi 0.5 Mn 1.5 O 4 는 생산 비용을 낮춰 상업적 가치를 향상시키며, 리튬이온이차전지에 적용되어 높은 에너지 밀도와 고전압을 얻는 연구 목표가 달성되었으며, LiNi 0.5 Mn 1.5 O 4 가 효율적인 에너지 저장 솔루션으로 활용 될 수있음을 제시하였다. In this study, LiNi 0.5 Mn 1.5 O 4 was synthesized from various raw materials, including NiO, Ni 2 O 3 , MnO 2 , and Mn 3 O 4 . An improved solid-phase synthesis method was then used to reduce impurities through uniform mixing via bead milling and to achieve a consistent secondary particle shape and distribution through spray drying. The LiNi 0.5 Mn 1.5 O 4 was obtained by selecting materials optimized for rate capability and by applying an improved synthesis process. X-ray diffraction and scanning electron microscopy analyses confirmed that LiNi 0.5 Mn 1.5 O 4 successfully synthesized primary and secondary particles. This result showed that LiNi 0.5 Mn 1.5 O 4 , when subjected to an improved solid-phase synthesis, reduces production costs ,enhances its commercial value, and can be applied to lithium-ion secondary batteries to achieve high energy density and high voltage. In short, LiNi 0.5 Mn 1.5 O 4 can be used as an efficient energy storage material.

포장용 다단상자의 RFID 인식률 예측에 관한 연구

박철순 ( Chul Soon Park ),전진환 ( Jin Hwan Jeon ),정종윤 ( Jong Yun Jung ),김지관 ( Jie Kwna Kim ) 대한설비관리학회 2012 대한설비관리학회지 Vol.17 No.2

Although RFID technology has been widely applied in the industrial fields, especially in logistics, it was restrictively implemented mainly because of detection problem, especially in environments of metals, farm products or liquids. We cannot overlook this problem because the RFID tag may be attached to the packages that contain materials which may influence the detection. Therefore, we need a way to predict the reading rate of RFID on various conditions and adequately cope with detectability problems. The purpose of this paper is to develop the prediction model for the RFID reading rate on various conditions. At first, we selected a list of test materials from expert interview and literature survey, and performed experimental design using orthogonal array table to investigate influence by materials. Second, we built prediction models using neural networks and support vector machine (SVM) with data from experiment. Finally, we compared the developed prediction models and selected the SVM model as the best prediction model. The SVM model gives us predicted reading rates of high accuracy under the conditions of various contents and environmental factors.

비즈니스 규칙 기반의 3자 물류 운영 지원

박철순(Chul soon Park),방양희(Yang hee Bang),성홍석(Hong suk Sung) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.2

The business process of global third party logistics company is defined as a network of logistics activities which involves the products that are manufactured in the developing countries, such as Vietnam, China and so on, and delivered to North or South American countries via intermediate stopover sites. The third party logistics company usually uses proprietary logistics information system to support the related logistics activities. However, each consignor sometimes may require different business process based on the customer type or characteristics of their products. Therefore, the third party logistics company need to modify their business process to reflect customer’s requirements, resulting in the modification of logistic information systems and additional costs. Therefore, a flexible mechanism is required to efficiently support the various types of requirements by the owners of the products. In this paper, first, we figured out various business rules related to third party global logistics activities. Second, we grouped the identified business rules into business processes, objects, relations, dependency, policy, representations, execution, and resources and further into precondition, postcondition, and invariant based on checking point in time. Furthermore, the categorized rules are classified into inter-activity and intra-activity rules based on the execution range. Third, we proposed a rule syntax to describe the defined rules into scripts which are understood by user and information system together. When each activity is executed, the rule manager checks whether there are rules related with the activity execution. Finally, we developed a prototype rule management system to show the feasibility of our proposed methodology and to validate it with an example.