• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.19-27
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• 2016

Maritime transport is now regarded as one of the main contributors to global climate change by virtue of its $CO_2$ emissions. Meanwhile, slow steaming, i.e., slower ship speed, has become a common practice in the maritime industry so as to lower $CO_2$ emissions and reduce bunker fuel consumption. The practice raised various operational decision issues in terms of shipping companies: how much ship speed is, how much to bunker the fuel, and at which port to bunker. In this context, this study addresses an operation problem in a shipping companies, which is the problem of determining the ship speed, bunkering ports, and bunkering amount at the ports over a given ship route to minimize the bunker fuel and ship time costs as well as the carbon tax which is a regulatory measure aiming at reducing $CO_2$ emissions. The ship time cost is included in the problem because slow steaming increases transit times, which implies increased in-transit inventory costs in terms of shippers. We formulate the problem as a nonlinear lot-sizing model and suggest a Lagrangian heuristic to solve the problem. The performance of the heuristic algorithm is evaluated using the data obtained from reliable sources. Although the problem is an operational problem, the heuristic algorithm is used to address various strategic issues facing shipping companies, including the effects of bunker prices, carbon taxes, and ship time costs on the ship speed, bunkering amount and number of bunkering ports. For this, we conduct sensitivity analyses of these factors and finally discuss study findings.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.20 no.2
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• pp.76-81
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• 2009

Ovjectives: As the attention devoted to children's mental health increases, medical costs and burdens mount as well. In the present study, we evaluated the association between socioeconomic status(SES) and major child psychiatric symptoms. Methods: The subjects of this study were children of recruited from a mental health screening program in the Seoul Sungbuk mental health center over the course of 3 months. To establish the SES of each child, we collected data about each child's medical insurance, years of parental education, household income, family structure and housing. 149 children & parents completed questionnaires including the Childhood Depression Inventory(CDI) and the Korean Attention Deficit Hyperactivity Disorder Rating Scale(K-ARS). Results: The mean K-ARS-P score was $12.1{\pm}11.1$ and the suspected prevalence of ADHD was 20.8%(n=31). The mean cm score was $12.9{\pm}7.9$, and the prevalence of suspected depression was 16.8%(25). Depressive symptoms and ADHD symptoms were both more severe than those observed in a previous epidemiologic study in Korea. Depressive symptoms were more closely associated with family SES status. Conclusion: SES status is one of the most important risk factors in the development of major child psychiatric symptoms. In our study we found that depressive symptoms in particular were most tightly associated with psychosocial factors. Evaluation of the risk factors, early screening and intervention for low SES children would be valuable mental health management tactics to implement in a community mental health system.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.713-716
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• 2013

Social and behavioral scientists have proposed that a person's belief system crucially influences his or her behaviour, and therefore may affect outcomes of pain management. The purpose of this study was to explore the relationship between analgesic beliefs, analgesic adherence and pain experience amongst Taiwanese cancer outpatients. The cross-sectional study included 92 oncology outpatients in two teaching hospitals in the Taipei area of Taiwan. The research instruments included the Pain Opioid Analgesic Beliefs Scale-Cancer (POABS-CA), opioid adherence, and the Brief Pain Inventory-Chinese (BPI-Chinese). Beliefs about pain and opioids demonstrated a significant relationship with patients' opioid adherence (r = -0.30, p < 0.01). The more negative beliefs regarding opioids and pain the patient had, the worse their adherence to around the clock (ATC) analgesic regimen. However, there was no significant correlation between opioid belief and pain experience. As well, there were no significant relationships between adherence to opioid regimen and any of the measures of pain experience. The study highlights the potential importance of a patient's pain and opioid beliefs in adherence to pain medication.

• The Journal of Information Systems
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• v.12 no.2
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• pp.57-72
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• 2003

The purpose of this paper is to propose the modeling of multiagent based SCM and implement the prototype in the Internet environment. SCM process follows the supply chain operations reference (SCOR) model which has been suggested by Supply Chain Counsil. SCOR model has been positioned to become the industry standard for describing and improving operational process in SCM. Five basic processes, plan, source, matte, deliver and return are defined in the SCOR model, through which a company establishes its supply chain competitive objectives. A supply chain is a world wide network of suppliers, factories, warehouses, distribution centers and retailers through which raw materials are acquired, transformed or manufactured and delivered to customers by autonomous or semiautonomous process. With the pressure from the higher standard of customer compliance, a frequent model change, product complexity and globalization, the combination of supply chain process with an advanced infrastructure in terms of multiagent systems have been highly required. Since SCM is fundamentally concerned with coherence among multiple decision makers, a multiagent framework based on explicit communication between constituent agents such as suppliers, manufacturers, and distributors is a natural choice. Multiagent framework is defined to perform different activities within a supply chain. Dynamic and changing functions of supply chain can be dealt with multi-agent by cooperating with other agents. In the areas of inventory management, remote diagnostics, communications with field workers, order fulfillment including tracking and monitoring, stock visibility, real-time shop floor data collection, asset tracking and warehousing, customer-centric supply chain can be applied and implemented utilizing multiagent. In this paper, for the order processing event between the buyer and seller relationship, multiagent were defined corresponding to the SCOR process. A prototype system was developed and implemented on the actual TCP/IP environment for the purchase order processing event. The implementation result assures that multiagent based SCM enhances the speed, visibility, proactiveness and responsiveness of activities in the supply chain.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.1 s.1
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• pp.117-125
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• 1993

GSIS is a system that contains spatially referenced data that can be analyzed and converted to information for a specific set of purpose, or application. The key feature of a GSIS is the analysis of data to produce new information. The current emphasis in the transportation is to implement GSIS in conjunction with real time systems Requirements for a transportation GSIS are very different from the traditional GSIS software that has been designed for environmental and natural resource applications. A transportation GSIS may need to include the ability for franc volume, forecasting, pavement management A regional transportation planning model is actually a set of models that are used to inventory and then forecast a region's population, employment, income, housing and the demand of automobile and transit in a region. The data such as adminstration bound, m of landuse, road networks, location of schools, offices with populations are used in this paper. Many of these data are used for analyzing of traffic volume, traffic demand, time of mad construction using GSIS.

• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.83-93
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• 2020

Bivariate measure of risk and error(BMORE) plot is originally designed to depict bivariate output data and related statistics obtained from a stochastic simulation such as sample mean, median, outliers, and a boundary of a certain percentile of simulation data. When compared to the static numbers, the plot has a big advantage in visualization that enables scholars and practitioners to understand the potential variability and risk in the simulation data. In this study, beyond just the construction of the plot to depict the variability of a certain system, we add a chance constraint to the plot and apply it for decision making such as checking the feasibility of systems, comparing performances of the systems on statistical background, and also analyzing the sensitivity of the problem parameters. In order to demonstrate an application of the plot, we employ an inventory management problem as an example. However, the techniques and algorithms suggested in this paper can be applied to any other problems comparing systems on bivariate performance measures with simulation/experiment results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.611-616
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• 2018

RFID-based Smart cabinets can make a recognition error owing to the electromagnetic wave interference. This paper proposes and implements a smart cabinet system for inventory management using RFID, especially which can be applied to biological laboratories. We calculate the optimal value of partition distance for the higher recognition rate between RFID tags and the reader, and the optimal partition thickness for electromagnetic wave absorption to achieve the higher recognition rate, in which two kinds of the partitions have been tested, a pure steel partition with various thickness and a thin steel partition attached with electromagnetic waves absorber. The experimental results show that the most recommended partition structure for the smart cabinets is one with the partition distance of 30cm and the partition thickness of 1mm attached with the electromagnetic wave absorption tapes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.568-574
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• 2015

Recently RFID not only is widely utilized in various fields such as inventory management, merchandize logistics, etc., but also, has evolved as an important component of the Internet of Things (IoT). According to increasing the utilization field of RIFD, studies for security and privacy for RFID system have been made diverse. Among them, the ownership transfer protocols for RFID tags have also been proposed in connection with the purchase of products embedded with RFID tag. Recently, Kapoor and Piramuthu proposed a RFID ownership transfer protocol to solve the problems of security weakness of the previous RFID ownership transfer protocols. In this paper, we show that Kapoor-Piramuthu's protocol also has security problems and provide a new protocol to resolve them. Security analysis of newly proposed protocol shows the security concerns are resolved.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.633-633
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• 2015

재해의 발생 빈도 증가와 불규칙성, 대형화 추세에 따른 SOC 시설물 피해가 증가함에 따라 유관 기관의 재난/재해 정보 수집은 지속적으로 이루어지고 있다. 그러나 각 기관별로 자료가 분산 관리됨에 따라 선제적 재해대응 체계는 갖추어지지 못하고 있는 실정이다. 이에, 예방적 유지관리체계 구현을 위한 분산정보 공유형 재해대응 인벤토리를 구축하고자 한다. 본 인벤토리는 3차원 공간정보를 기반으로 분산 관리되고 있는 재난/재해 관련 정보를 수집하고 이렇게 수집된 데이터들의 통합적 관리를 위해 데이터 표준화를 거쳐 선제적 재해 대응의 원천 데이터로 활용될 수 있다. 본 연구에서는 인벤토리 관리/연계 모듈의 설계 방안을 마련하고자 국내외 인벤토리 관련 시스템 현황조사를 진행하고 관리 및 연계 대상 데이터의 항목을 선정하고 내용을 분류하였다. 또한, 시스템 요구사항을 수집하고 정의하고 관리/연계 모듈의 세부기능 정의를 하였다. 뿐만아니라, 프로토타입 개발을 위해 서비스 제공 형태와 데이터 제공 방식을 결정하였다. 본 연구에서 개발하고 있는 프로토타입은 Web Service 기반의 REST 방식으로 데이터를 제공할 것이며, 3차원 공간 정보를 기반으로 하고 있다. 본 연구에서는 프로토타입 개발을 위해 기본 주재도를 제작하고 연구 지역의 시설물 정보를 구축하였다. 분산정보 공유형 재해대응 인벤토리 시스템은 분산 관리되고 있는 재난/재해 정보들을 자료 송/수신 모듈을 통하여 수집하고 데이터 필터링 모듈에서 수집된 자료의 표준화와 품질측정을 진행하여 데이터의 신뢰도를 향상 시킬 것이다. 또한, 데이터 관리 모듈을 이용하여 공간정보 데이터를 검증하고 최적화 관리를 할 수 있도록 하며, 시스템 관리 모듈에서 유관기관에서 유입되는 자료들을 관리하고자 한다. 이렇게 구축된 인벤토리 시스템은 선제적 재해대응 의사결정의 원천 데이터를 제공하고 SOC 시설물의 유지관리에 활용될 수 있을 것으로 판단된다.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.59-71
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• 2019

The distribution logistics center has its own inventory, so designing an efficient storage area is very important. The purpose of this study is to present the optimal storage area calculation method for distribution logistics center considering the use of standard pallet unit load, and the results of this study are as follows. First, standard rack modules for storing T-11 and T-12 type pallet, which is generally used in Korea, were defined. Second, a variety of pallet transport equipments were investigated and analyzed to define the standard transport equipment's work passageway by type. Finally, it has great implications in terms of suggesting measures to minimize unused space that may occur during placement of pallet rack modules within storage space, as well as the easy and optimal calculation of the storage area for the distribution logistics center. Future research require a study on the layout of the entire distribution logistics center, which reflects the latest logistics technologies, such as standard rack modules for Mini-Load and GTP picking system.