• Proceedings of the KIPE Conference
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• 1998.10a
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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.

• Proceedings of the KIPE Conference
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• 2010.07a
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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.

• Journal of Distribution Science
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• v.14 no.9
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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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• v.32 no.1
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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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• v.9 no.1
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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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• v.11 no.1
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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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• v.19 no.4
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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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.594-603
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• 2019

This purpose of this study is for an Airline company to discover and utilize new knowledge because knowledge and information are considered core tools for achieving high performance and competitive advantage, and achieving high performance and competitive advantage will surely determine the long-term survival of airline companies. Therefore, this study aims to reveal the causal relationships among different types of organizational culture, the knowledge sharing activities and the effectiveness of organizational work by airline members from a holistic viewpoint. The results of analysis are as follows. First, when examining the effects of the organizational culture types of airline members on knowledge sharing, a creative innovation culture, a relational group culture and a hierarchical orientation culture all showed positive effects on knowledge sharing. Second, the knowledge sharing by airline members showed a significant positive effect on the effectiveness of organizational work. Third, the creative innovation culture, the relational group culture and the hierarchical orientation culture all showed positive effects on the effectiveness of organizational work. Fourth, knowledge sharing did not have a mediating effect on the relationship between organizational culture and the effectiveness of organizational work.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.111-114
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• 2017

As digital contents are widely used and require increasingly high quality, the data storage services over Internet also become more and more important. One of popular services, web-hard, provides lots of users with web-based functions for data storage, management and sharing but such storage utilization requires quite high cost compared to using portable storage devices. Moreover, some users may avoid putting their important data into open Internet area. On the other hand, portable storage devices are cheaper but can be used only when they are physically connected to host devices such as PC. Also additional management and security functions should be equipped to support data sharing among users. In this paper, we propose a web-based data storage system combining those advantages of aforementioned two approaches. The proposed system immediately provides web-based services for data management and sharing when a portable device such as SDD is connected to the server.