• IE interfaces
• /
• v.12 no.1
• /
• pp.10-18
• /
• 1999

Job shop manufacturing environments are using the concept of cellular manufacturing systems(CMS) which has several advantages in reducing production lead times, setup times, work-in-process, etc. Utilizing the similarities between cell-machine, part-machine, and the shape/size of parts, CMS can group machines and parts resulting in improved efficiency of this system. However, when grouping machines and parts in machine cells, there inevitably occurs exceptional elements(EEs), which can not operate in the same machine cell. Minimizing these EEs in CMS is a critical point that improving production efficiency. Constraints in machine duplication cost, machining process technology, machining capability, and factory space limitations are main problems that prevent achiving the goal of maintaining an ideal CMS environment. This paper presents an algorithm that minimizes EEs under the constraints of machine duplication cost and factory space limitation. Developing exceptional operation similarity(EOS) by cell-machine incidence matrix and part-machine incidence matrix, it brings the machine cells that operate the parts or not. A mathematical model to minimize machine duplication is developed by EOS, followed by a heuristic algorithm in order to reflect dynamic situation resulting from minimizing exceptional elements process and the mathematical model. A numerical example is provided to illustrate the algorithm.

• Iberoamérica
• /
• v.12 no.1
• /
• pp.407-439
• /
• 2010

Growth of researches addressing cross-culture in international business is exponential. This article reviews the extant researches around the national culture and describes the various conceptualization of culture through discussion of some of popular models of national culture. This article presented some of the most important issues in international business surrounding globalization, especially convergence and divergence of cultures and cultural changes. Global rapid changes in international business environment request the reconsideration of the assumption of cultural stability and the simple view of culture, which tends to examine the static influence of a few cultural factors in isolation form other cultural factors and contextual elements. This paper identifies a valid cultural grouping and proposes the following typology of the possible methodologies in international business; Ethnological description, Use of proxies, Direct values inference, and Indirect values inference. Rather than selecting a single methodology, it appears to be more appropriate to use multi-method in the cross-cultural international business research. It has been shown that cultural change is intertwined with socioeconomic-institutional variables, and that these variables may also add to determine culture contemporarily. This paper also explained the dynamics of culture as multi-level, multi-layer constructs. According to this model, we may understand how the dynamic nature of culture conveys the top-down-bottom-up processes where one cultural level affects changes in other level of culture.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.4
• /
• pp.63-73
• /
• 2023

This study explores modern portfolio theory by integrating the Black-Litterman portfolio with time-series clustering, specificially emphasizing K-shape clustering methodology. K-shape clustering enables grouping time-series data effectively, enhancing the ability to plan and manage investments in stock markets when combined with the Black-Litterman portfolio. Based on the patterns of stock markets, the objective is to understand the relationship between past market data and planning future investment strategies through backtesting. Additionally, by examining diverse learning and investment periods, it is identified optimal strategies to boost portfolio returns while efficiently managing associated risks. For comparative analysis, traditional Markowitz portfolio is also assessed in conjunction with clustering techniques utilizing K-Means and K-Means with Dynamic Time Warping. It is suggested that the combination of K-shape and the Black-Litterman model significantly enhances portfolio optimization in the stock market, providing valuable insights for making stable portfolio investment decisions. The achieved sharpe ratio of 0.722 indicates a significantly higher performance when compared to other benchmarks, underlining the effectiveness of the K-shape and Black-Litterman integration in portfolio optimization.

• Journal of Internet Computing and Services
• /
• v.6 no.6
• /
• pp.85-97
• /
• 2005

In this paper, we construct the traffic information database by using the acquired data from the traffic information devices installed in road network, and, by referring to this database, propose the intersection simulation system which can dynamically manage the real-time traffic flow for each section of road from the intersections, This system consists of hierarchical 3 parts, The lower layer is the physical layer where the traffic information is acquired on an actual road. The traffic flow control framework exists in the middle layer. The framework supports the grouping of intersection, the collection of real-time traffic flow information, and the remote monitoring and control by using the traffic information of the lower layer, This layer is designed by extending the distributed object group framework we developed. In upper layer, the intersection simulator applications controlling the traffic flow by grouping the intersections exist. The components of the intersection application in our system are composed of the implementing objects based on the Time-triggered Message-triggered Object(TMO) scheme, The intersection simulation system considers the each intersection on road as an application group, and can apply the control models of dynamic traffic flow by the road's status. At this time, we use the real-time traffic information collected through inter-communication among intersections. For constructing this system, we defined the system architecture and the interaction of components on the traffic flow control framework which supports the TMO scheme and the TMO Support Middleware(TMOSM), and designed the application simulator and the user interface to the monitoring and the controlling of traffic flow.

• Journal of Internet Computing and Services
• /
• v.9 no.5
• /
• pp.85-97
• /
• 2008

Recently, service-oriented systems have been issued by their properties of reducing software development time and effort by reusing functional service units. The reusability of services can effectively promote through loose coupling between services and loose coupling between services depends on component-based system. That is, the component-based system is designed by grouping the tightly coupled classes of the object-oriented system and the service-oriented system is designed by the component-based system. Therefore, to design the component-based system and service-oriented system efficiently, a metric to measure the coupling between classes accurately needs. In this paper, we propose a coupling metric between classes applying a structural property, a dynamic property, and the normalized value by 0-1. We prove the theoretical soundness of the proposed metric by the axioms of briand et al, and suggest the accuracy and practicality through a case study. We suggest the evaluation results of the proposed metric through a comparison with the conventional metrics.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.6
• /
• pp.23-35
• /
• 2009

This study proposes a methodology for estimating representative section travel times using individual vehicle travel information under the ubiquitous transportation environment (UTE). A novel approach is to substantialize a concept of dynamic node-links in processing trajectory data. Also, grouping vehicles was conducted to obtain more reliable travel times representing characteristics of individual vehicle travels. Since the UTE allows us to obtain higher accuracy of vehicle positions, travel times for each lane can be estimated based on the proposed methodology. Evaluation results show that less than 10% of mean absolute percentage error was achievable with 20% of probe vehicle rate. It is expected that outcome of this study is useful for providing more accurate and reliable traffic information services.

• Journal of Digital Contents Society
• /
• v.13 no.3
• /
• pp.385-392
• /
• 2012

The definition of the product market in a supplier's point of view can cause various problems in the market activities of companies because specific situations are excluded and the consideration for discontinuity is lacking by identifying segmented markets with processes, raw materials, the similarity of product functions and so forth. Furthermore, as this definition is static and general, it is difficult to express and predict the dynamic market changes. Meanwhile, customer-oriented market segment can be obtained by grouping substitutable products and related customers in the situation pursuing specific benefits. This definition of the product market enables us to find threats and opportunities emerging in markets and promotes effective performance assessments and resource allocation. The purpose of this paper is suggesting a framework to select data mining techniques proper for the customer data characteristics to identify customer oriented product market.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.192-192
• /
• 1999

SIMS(Secondary Ion Mass Spectrometry)는 다른 표면 분석장비와 비교하여^g , pp m,^g , pp b 단위의 미량분석이 가능한 장비로서, 특히 depth Profiling을 위한 dynamic SIMS는 Mass Spectrometer의 종류에 따라 Quadrupole SIMS (Q-SIMS)와, Magnetic Sector SIMS (M-SIMS)로 분류된다. 한편, Q-SIMS와 달리 M-SIMS의 경우, Transmission을 높여 주기 위해 Sample Holder에 수 keV의 bias를 걸어 주는데, 이로 인하여 분석 원소에 대한 Sensitivity가 향상되어 지는 반면, RSF의 변화와 같은 분석상의 Artifact가 발생하게 된다. 일반적으로 Q-SIMS의 경우에는 RSF의 RSD(Relative Standard Deviation)가 1%이내에서 보고되고 있지만 M-SIMS에 있어서는 이러한 Deviation이 M-SIMS보다 크게 나타난다. 이 차이는 주로 Sample Holder와 Immersion Lens 사이에 형성되는 Magnetic Field의 왜곡과 Spectrometer의 문제로부터 발생한다. 본 논문에서는 Sample Holder의 종류 및 holder so window 위치에 따라 RSF의 차이를 측정하고 그 data를 RS/1 통계 Package를 이용하여 계량적으로 검증하였으며, 그 차이의 원인과 대책을 제시하고자 한다. 실험에 사용된 Sample은 Si(100) p-type Wafer에 Boron을 이온 주입하여 제작하였다. 이온 주입 장비는 Varian E-500HP이며, 5.0E13 ions/cm2의 dose양을 80keV의 Energy로 각각 7도와 22도의 Tilt와 Twist Angle로 이온 주입을 하였다. SIMS분석에 사용된 Sample Holder는 각각 3 Hole, 9 Hole Type HOlder이며, 분석은 Cameca IMS-6f를 사용하여 B에 대한 Matrix Peak으로 28Si++를 얻었다. 실험 결과 3 Hole Type Sample Holder의 경우 RSF의 RSD는 5.84%, 9Hle Type Sample Holder의 경우는 14.3%로 나타났으나 분석 Window의 위치에 따르는 Grouping을 실시한 결과, 3 Hole Type Sample Holder의 경우 1.2%, 9Hole Type Sample Holder의 경우 9.8%로 RSF의 변화가 감소하였다. 이러한 Deviation은 Sample Holder를 Mount시킬 때 세 개의 Screw를 이용하여 Immersion Lens와의 평형을 잡아주기 때문에 발생하며, 이 Munting을 정확히 해줌으로써 RSF의 변화를 줄일 수 있으나, 실제로 완벽한 Mounting이 불가능하기 때문에 RSF를 일정하게 하기 위해서는 Sample Holder so Window의 취치를 일정하게 설정한 후 분석을 실시해야 한다고 판단된다.

• Journal of Digital Contents Society
• /
• v.7 no.1
• /
• pp.25-33
• /
• 2006

As becoming the age of ubiquitous, there are many discussion and publication for standards to express platform profile. These various platform profiles have some problems. The solve these problems, we propose and develop a new posting mechanism which improve the performance of contents adaptation engine by simplifying platform profile and processing various type of platform profiles; we introduce the way to integrate different profiles to solve nut to recognize the profile which is used by different adaptation system and simplify platform profile by grouping the similar attributes of platform profiles. Proposed system can processing different profiles and also the system overhead to processing a profile and creating a dynamic profile has reduced. As a result overall performance of content adaptation system has increased.

• Journal of Digital Convergence
• /
• v.13 no.7
• /
• pp.169-175
• /
• 2015

An effective way to understand the dynamic and time series that follows the passage of time, as valuation is to establish a model to analyze the phenomena of the system. Model of the decision process is efficient clustering information of the total mass of the time series data of the relevant population been collected in a particular number of sub-groups than to look at all a time to an understand of the overall data through each community-specific model determination. In this study, a sub-grouping of the group and the first of the two process model of each cluster by determining, in the following in sub-population characterized by a fusion with heuristic Bayesian clustering techniques proposed a process which can reduce calculation time and cost was confirmed by experiments using actual effectiveness valuation.