• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.581-585
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• 1998

This paper presents the new current sharing control method of a 12-pulse phase-controlled rectifier(PCR) for a UPS. The control circuit of the 12-Pulse PCR with a parallel operating rectifier system is proposed to balance input currents and to reduce the harmonics of input current. The PCR is used widely in the industrial world, since its cost is much lower than that of the PWM converter and the composition of control circuits is simple. This system is developed and tested for a 3-phase 400KVA UPS system and the experimental results in this application are included.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.129-130
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• 2010

For the high power demand and N+1 redundancy, this paper presents the digital load share (LS) controller design and the implementation of paralleled phase-shifted full-bridge converters (PSFBC) used in distributed power systems. By adopting the digital control strategy, separately used ICs for PSFBC and LS control functions in analog systems can be merged into a cost-effective digital controller. To compensate and stabilize both PSFBC and LS loops with the direct digital design approaches, small-signal model of the system is derived in discrete-time domain. The steady-state and dynamic load sharing performances are also investigated. Experimental results from two 1.2 kW paralleled PSFBC modules are shown to verify the proposed work.

• 유통과학연구
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• 제14권9호
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• pp.47-64
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• 2016

Purpose - This study reviews the past studies that have researched Vendor Managed Inventory (VMI) as a well-known supply chain collaboration program. The main goals of this study are to figure out how VMI brings significant benefits to the supply chain system and suggest additional areas that future studies would address to discover the true nature of VMI. Research design, data, methodology - This study conducts literature reviews on numerous studies that have researched VMI. The past studies are classified in terms of several main issues that have been commonly addressed by many researchers. This study also identifies three key collaborative features of VMI, which possibly explain why VMI improves the supply chain performance. Results - This study finds out that most past studies focused on a limited research issues about VMI. Many researchers have considered integrated decision making and information sharing to be key features that enables VMI to improve the supply chain performance. Conclusions - Based on the findings from the literature review, this study suggests that future studies on VMI take account of new research issues and pay attention to cost payment that researchers have rarely addressed.

• ETRI Journal
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• 제32권1호
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• pp.1-10
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• 2010

In this paper, we present a fast Fourier transform (FFT) processor with four parallel data paths for multiband orthogonal frequency-division multiplexing ultra-wideband systems. The proposed 128-point FFT processor employs both a modified radix-$2^4$ algorithm and a radix-$2^3$ algorithm to significantly reduce the numbers of complex constant multipliers and complex booth multipliers. It also employs substructure-sharing multiplication units instead of constant multipliers to efficiently conduct multiplication operations with only addition and shift operations. The proposed FFT processor is implemented and tested using 0.18 ${\mu}m$ CMOS technology with a supply voltage of 1.8 V. The hardware- efficient 128-point FFT processor with four data streams can support a data processing rate of up to 1 Gsample/s while consuming 112 mW. The implementation results show that the proposed 128-point mixed-radix FFT architecture significantly reduces the hardware cost and power consumption in comparison to existing 128-point FFT architectures.

• Industrial Engineering and Management Systems
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• 제9권1호
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• pp.1-9
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• 2010

Increasing product variety based on product family and product platform provides a company with a competitive advantage over its competitors. As products become more complex, short-life cycled and customized, the design efforts require more knowledge-intensive, collaborative and coordinating efforts for information sharing. By sharing knowledge, information, component and process across different families of products, the product realization process will be more efficient, cost-effective and quick-responsive. Formal Concept Analysis (FCA) is used for analyzing data and forming semantic structures that are formal abstractions of concepts of human thoughts. A Web Ontology Language (OWL) is designed for applications that need to process the content of information instead of simply presenting information to humans. OWL also captures the evolution of different components of the product family. The purpose of this paper is to develop product variety modeling to increase the usefulness of common platform. In constructing and analyzing product ontology, FCA is adopted for conceptual knowledge processing. For the selected product family, product variety Ontology is constructed and implemented using prot$\'{e}$g$\'{e}$-2000.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권1호
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• pp.51-58
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• 2011

Extensible processors provide an efficient mechanism to boost the performance of the whole system without losing much flexibility. However, due to the intense demand of low cost and power consumption, customizing an embedded system has been more difficult than ever. In this paper, we present a framework for custom instruction generation considering both area constraints and resource sharing. We also present how we can speed up the process through pruning and library-based design space exploration.

• Journal of Information Processing Systems
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• 제19권4호
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• pp.513-526
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• 2023

Supply chain coordination plays a critical role in improving the enterprise performance and the competitive advantage of fresh e-commerce. This study explores the coordination problem of a two-echelon fresh produce e-commerce supply chain comprising a fresh e-commerce enterprise and a fresh supplier in a novel framework. In this framework, the fresh e-commerce sells fresh produce and provides promotion effort; meanwhile, the fresh supplier deliveries fresh produce and provides freshness-keeping effort. Specifically, the optimal decisions under centralized and decentralized decision-making are compared, and it is found that centralized decision-making is more profitable. Based on this work, we created a cost-sharing and revenue-sharing combination contract. This study demonstrates that this contract effectively coordinates the supply chain and makes both parties achieve Pareto optimization when the parameters meet certain conditions. Finally, the feasibility and validity of the contract are presented through a numerical example.

• 한국산업보건학회지
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• 제31권4호
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• pp.353-366
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• 2021

Objectives: An appropriate level of cost support is being proposed to maximize the participation rate. In addition, as the amount of support is highly concentrated at the level of the limit under the current level of supports, the level of cost support is low when the actual level of cost of measuring the working environment exceeds the limit. This paper describes the adjustment of an appropriate cost support rate. Methods: First, this paper analyzes the current cost support status using data from the KOSHA. Second, an alternative for adjusting the cost support rate is presented in consideration of the incentive aspect. Third, we present simulation results for the average cost support rate, the impact of each alternative on finance, and more. Fourth, the most desirable adjustment method is presented after comparing and analyzing the results of various alternatives. Results: In this paper, we present a new scale model. This model is a mixture of flat-rate, fixed rate, and subside cap. It is expected that the new model will not only facilitate participation in businesses with low measurement costs, but also have the effect of controlling measurement costs for institutions that incur greater costs. It is also expected that setting a cap will have the effect of considering government finances and inducing excessively costly institutions to reduce costs. Thus, the new model is likely to be superior to others. If the fourth plan is applied to new businesses and the fifth plan is applied to sustainable businesses, the average cost support rates will be 87.68 percent and 65.18 percent, respectively, and the needed finances will be 2.5 billion won, 18.8 billion won, and 21.3 billion won in total. Conclusions: It seems most desirable to introduce a new model that combines flat-rate, fixed-rate, and subsidy cap systems and achieve an appropriate cost support rate through this model.

• 한국산학기술학회논문지
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• 제20권8호
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• pp.594-603
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• 2019

대형항공사(Network Carrier)와 저원가항공사(Low Cost Carrier)의 양분화된 영업환경에서 승객의 서비스에 대한 다양한 요구와 항공사의 수입보존을 위해 대 내외적으로 무한 경쟁에 직면하고 있다. 이러한 환경 속에서 기업의 성과를 위해 21세기 지식정보화 사회를 맞이하여 기업들의 새로운 지식을 창출하고 활용하기 위한 노력은 기업의 장기적 생존을 결정하는 핵심적인 경쟁우위 도구로 간주되어 왔다. 따라서 본 연구에서는 항공사 구성원의 조직문화유형, 지식공유 활동, 조직업무 효과성 사이의 총체적인 관점에서 어떠한 인과관계를 밝히고자 한다. 본 연구의 대상은 K와 A항공사에 사전협조를 구하여 종사자를 대상으로 자료 수집을 실시하였다. 연구 대상자는 K와 A항공사에 재직 중인 종사자를 대상으로 2019년 5월 1일부터 2019년 5월 17일까지 실시한 설문조사 450명의 자료를 분석에 사용하였다. 자료 분석을 위해 SPSS Statistics 22.0과 AMOS 22.0 통계프로그램을 사용하였으며, 분석결과는 다음과 같다. 첫째, 항공사 구성원의 조직문화 유형이 지식공유에 미치는 영향을 살펴보면, 창의혁신문화, 관계집단문화, 위계지향문화 모두 지식공유에 유의한 정의 영향을 미치는 것으로 나타났다. 둘째, 항공사 구성원의 지식공유는 조직업무 효과성에 유의한 정의 영향을 미치는 것으로 나타났다. 셋째, 조직문화 중, 창의혁신문화, 관계집단문화, 위계지향문화 모두 조직업무 효과성에 유의한 정의 영향을 미치는 것으로 나타났다. 넷째, 조직문화와 조직업무 효과성의 관계에서 지식공유는 매개효과가 있는 것으로 나타났다. 본 연구의 결과를 통해 향후 항공업계의 조직업무효과성 향상을 위해서는 지식공유의 역할을 제시하고, 지식공유를 위한 조직문화 형성의 틀 마련의 중요성을 제공해 주었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.111-114
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• 2017

지속적인 디지털 콘텐츠의 이용 증가와 고품질화에 따라 인터넷 상의 대용량 데이터 스토리지 서비스 필요성도 증가하고 있다. 이를 위해 널리 사용되는 웹하드 서비스는 다수의 이용자들에게 웹을 통해 데이터를 저장, 관리, 공유 할 수 있는 편리한 기능을 제공하지만, 대용량의 저장 공간 사용에 대한 고비용 문제와 일부 이용자들이 중요한 데이터를 인터넷 상에 보관하기를 기피하는 현상을 해결할 필요가 있다. 반면, 외장 하드디스크와 같은 휴대형 스토리지 디바이스는 PC 등 연결된 호스트에서만 사용이 가능하므로 다른 이용자들과 데이터를 공유하기 위한 관리 및 보안 기능이 추가적으로 요구된다. 본 논문에서는 이러한 기존 방식들의 장점을 결합한 웹 기반의 데이터 스토리지 시스템을 제안한다. 제안되는 시스템은 외장 하드 디스크와 같은 디바이스를 필요에 따라 서버에 연결했을 때 웹을 통해 쉽게 원격에서 데이터를 관리, 공유할 수 있는 기능을 제공한다.