• 대한전기학회논문지:전력기술부문A
• /
• 제50권1호
• /
• pp.28-37
• /
• 2001

This paper presents an efficient algorithm for the loss minimization of distribution system by automatic sectionalizing switch operation in large scale distribution systems. Simulated annealing is particularly well suited for large combinational optimization problem, but the use of this algorithm is also responsible for an excessive computation time requirement. Tabu search attempts to determine a better solution in the manner of a greatest-descent algorithm, but it can not give any guarantee for the convergence property. The hybrid algorithm of two methods with two tabu lists and the proposed perturbation mechanism is applied to improve the computation time and convergence property Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.

• 한국산업융합학회 논문집
• /
• 제21권1호
• /
• pp.29-36
• /
• 2018

Low pressure casting process for unidirectional carbon fiber reinforced aluminum (UD-CF/Al) composites which is an infiltration route of molten Al into porous UD-CF preform has been a cost-effective way to obtain metal matrix composites (MMCs) but, easy to cause non-uniform fiber distribution as CF clustering. Such clustered CFs have been a problem to decrease the density and thermal conductivity (TC) of composites, due to the existence of pores in the clustered area. To obtain high thermal performance composites for heat-sink application, the relationship between fiber distribution and porosity has to be clearly investigated. In this study, the CF distribution was evaluated with quantification approach by using two-dimensional spatial distribution method as local number 2-dimension (LN2D) analysis. Note that the CFs distribution in composites sensitively changed by sizes of Cu bridging particles between the CFs added in the UD-CF preform fabrication stage, and influenced on only $LN2D_{var}$ values.

• 대한수학회보
• /
• 제55권3호
• /
• pp.679-698
• /
• 2018

In this paper, with optimal normalized constants, the asymptotic expansions of the distribution and density of the normalized maxima from generalized Maxwell distribution are derived. For the distributional expansion, it shows that the convergence rate of the normalized maxima to the Gumbel extreme value distribution is proportional to 1/ log n. For the density expansion, on the one hand, the main result is applied to establish the convergence rate of the density of extreme to its limit. On the other hand, the main result is applied to obtain the asymptotic expansion of the moment of maximum.

• 한국구조물진단유지관리공학회 논문집
• /
• 제13권2호통권54호
• /
• pp.231-242
• /
• 2009

통계적 구조물 손상진단에서 기저분포는 구조물에 손상이 없을 때 획득된 동적 응답 특성이 이루는 통계 분포이다. 일반적으로 구조물에 손상이 발생했을 때 손상에 민감한 구조물의 동적 응답 특성은 기저분포의 꼬리 부근에 주로 나타나게 된다. 최근 연구자들은 기저분포의 꼬리 부분을 정확하게 모사하기 위해 극치분포에 주목하고 있으나, 구조물 손상진단의 관점에서 극치분포의 이론적 이해에 대한 연구는 거의 이루어지지 않았다. 이 연구에서는 신뢰성 있는 통계적 구조물 손상진단을 위해 필요한 극치분포의 점근적 수렴성을 매개변수 추정법을 이용하여 규명한다. 특히, 극치 추출에 필요한 표본크기와 극치분포의 점근적 수렴성의 관계를 정량적으로 보인다. 또한, 극치분포 추정에서 표본크기와 통계적 구조물 손상진단에서 발생하는 손상오류경보 빈도에 대한 관계를 정량적으로 규명한다. 차량 이동하중을 받는 2경간 트러스 교량에서 수치해석 기법을 통해 모사된 가속도 데이터를 이용하여 제안된 기법의 타당성을 검증한다.

• 대한교통학회지
• /
• 제23권2호
• /
• pp.143-150
• /
• 2005

통행분포의 예측과정에서 장래 O-D표는 행의 합 및 열의 합이 통행발생 예측단계에서 예측된 존의 유출 통행량 및 유입 통행량에 근접해야 한다는 제약조건을 만족시키기 위하여 수렴계산을 하게 된다. 기존 수렴계산 방법들은 통행분포 예측모형에 의해 예측된 존간 통행분포량이 수렴계산과정에서 상당히 달라질 수 있고, 그 결과로, 예측된 존간 통행분포패터의 변형을 가져올 수 있다. 본 논문에서는 이와 같은 문제점을 해결하고자, 새로운 수렴계산방법을 개발하였다. 기존 수렴계산 방법들이 O-D표의 행의 합과 유출 통행량, 그리고 열의 합과 유입통행량을 근접시키기 위하여 비율로써 행과 열을 순차적으로 반복하면서 수렴계산을 행하는 것과 달리, 개발된 방법은 총 통행량을 기준으로 유출통행량, 유입통행량과의 차를 가중평균으로써 최소화시키는 수렴계산 특성을 갖는다. 개발된 수렴계산 방법을 38개 존의 실제 O-D표를 이용하여 현재까지 가장 많이 사용되어온 프레타법 및 퍼니스법과 비교, 검증하였으며, 검증결과 개발된 방법은 제약조건을 충족시킴과 동시에 통행분포 예측모형으로부터 예측된 존간 통행분포량과의 차가 다른 방법에 비해 최소화 되어 유용한 거승로 증명되었다.

• Journal of Korea Trade
• /
• 제25권3호
• /
• pp.153-168
• /
• 2021

Purpose - In this study, we aim to explore new distribution strategies for sustainable growth in the era of the 4th industrial revolution, focusing on SMEs (small and medium-sized enterprises) in Korea, and suggest ways to upgrade the government's official distribution channel to the next level. Design/methodology - First of all, this paper explored the prior research, the current status of sales support for SMEs, and the changes in the distribution industry due to COVID-19 pandemic. Based on Moon (2016)'s ABCD strategic model - Agility, Benchmarking, Convergence, and Dedication, the study then derived directions in which official distribution channels should move and the new distribution strategy for Korean SMEs to secure competitive advantage. Findings - First, in terms of 'Agility', in order to upgrade official distribution channels, which are currently at some competitive disadvantages compared to private distribution companies, we must quickly introduce technologies for the 4th industrial revolution, such as AI, Big Data, etc., and establish precise strategies to strengthen the capabilities of SMEs. Second, in terms of 'Benchmarking', the use of "Chamelezones" has been increasing to enhance the competitiveness of offline stores in line with recent ontact trends. Therefore, official distribution channels should also benchmark such cases, strengthening their competitiveness by utilizing offline spaces more efficiently and effectively. Third, in terms of 'Convergence', in line with the rapidly changing trend of the times, official distribution channels should also promote active partnerships with media commerce, e-commerce and ICT platforms, as well as cooperation with private retailers, and focus on creating synergy effects through them. Finally, from the perspective of 'Dedication', digitalization should be promoted step by step, finding the sector that can accelerate digital among the value chains of official distribution channels, and continuing to discuss how to digitize it realistically. Originality/value - Based on this analysis, we have presented strategies and implications for innovating official distribution channels for SMEs, which will contribute to enhancing the competitive advantage of official distribution channels in the post COVID-19 pandemic era.

• 대한수학회보
• /
• 제58권6호
• /
• pp.1419-1443
• /
• 2021

The asymmetric Laplace distribution arises as a limiting distribution of geometric summations of independent and identically distributed random variables with finite second moments. The main purpose of this paper is to study the weak limit theorems for geometric summations of independent (not necessarily identically distributed) random variables together with convergence rates to asymmetric Laplace distributions. Using Trotter-operator method, the orders of approximations of the distributions of geometric summations by the asymmetric Laplace distributions are established in term of the "large-𝒪" and "small-o" approximation estimates. The obtained results are extensions of some known ones.

• 한국게임학회 논문지
• /
• 제6권2호
• /
• pp.33-44
• /
• 2006

본 논문은 디지털 기술의 발전에 따른 문화콘텐츠 유통의 발전, 특히 게임산업의 유통체계를 살펴보고 있다. 컨버젼스 기술의 발전에 따라, 문화콘텐츠 유통에 있어서 핵심적인 가치의 중심은 플랫폼에서 콘텐츠로 옮겨가고 있는데, 이와 관련하여 특히 게임산업의 유통구조에서는 3가지 유형(오프라인, 온라인, 모바일 게임)이 나타난다고 알려지고 있다. 본 논문에서는 심층인터뷰 등을 통한 사례조사를 통해 앞으로 통합적인 모델로 발전할 것으로 검증하고 있다. 결론적으로 본 논문은 이러한 변화에 맞추어 앞으로 문화콘텐츠산업의 장기적인 발전을 위해 유통구조의 개선, 기업과 퍼블리셔 등 관계자들의 갈등해소, 국제화 등을 위한 다각적 정책지원이 더욱 필요함을 제안하고 있다.

• 한국산업융합학회 논문집
• /
• 제9권3호
• /
• pp.207-214
• /
• 2006

In this paper, the stability of SA(Spectral Acceleration) fragility curves is studied for the two sets of elastic modulus of concrete. In doing that, general purpose structural analysis program and generally used probability density function are used. The results of structural analysis are represented by Bernoulli distribution which says damage or no damage. By the use of Maximum Likelihood Method, two parameters of lognormal distribution - median and standard deviation - are found. With them, the fragility curves are constructed.

• 유통과학연구
• /
• 제13권1호
• /
• pp.27-33
• /
• 2015

Purpose - The ICT market in the EU is lagging behind that of the US; however, algorithm and software development within the EU have grown steadily, and they involve focusing on the creative cultural convergence conceptualized as part of Horizon 2020 and connecting neighboring markets in the EE and the Mediterranean region. It is essential to study the requirements to market the EU's creative ICT development in emerging industrial countries after examining its applicability in these countries. Research design, data, and methodology - This study deals with data pertaining to the EU's creative industry and competitive edge. The global cultural expansion of the EU facilitates a new concept involving not only low-cost IT products to enhance local cultural artifacts through R&D and the construction of efficient infrastructure services, but also information exchange with a realistic commercialization of the technology that can be applied for creative cultural localization. In the European industry, research on algorithms has been applied for the benefit of consumers. We investigated how the process is conducted in the EU. Results - Europe needs to adjust its economic structure to the local culture as part of IT distribution convergence. The convergence has been converted into a production algorithm with IT in the form of low-cost production. This is because there is an attempt to improve the quality of transport infrastructure, workforce availability, and the distribution of the distance to the local industries and consumers, using IT algorithms. Integrated into the manufacturing industry, based on the ICT infrastructure and solutions, smart localized regional clusters are formed with the help of grafting. Europe has own strategy to increase the number of hub-and-spoke cities. Europe is now becoming integrated, with an EPC system for regional cooperation rather than national competition in ICT technology. Europe has also been recognized in this study as changing the step-by-step paradigm for global competitiveness through new creative culture industries. Conclusions - As a result, there are several ways of converging with others through EU R&D intensity; therefore, the EU can be seen as successfully increasing marginal value, which is useful in developing a special industrial cluster or local cultural cities that create converged development by connecting people and objects with IT. In fact, when compared to the US, Europe has a strong culture and the car industries have a tendency to overshadow the IT industries with integration of services in IT distribution. Considering the rapid environmental changes, the convergence of IT services is likely to take place in Europe, similar to the pharmaceutical industry and the automotive industry. This requires a focus on human resources and automated systems management. The trend is to move away from low-wage industries, switched to key personnel centers of the local university-industry. EU emphasizes the creation of IT market demand in Europe involving local cultural convergence for marketing as the second step to strengthen the economic hub-and-spoke areas.