• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.237-251
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• 2012

Recently, the direct terrestrial broadcasting reception has been reduced rapidly and not been improved even in digital broadcast environment. The distribution plan of 700MHz frequency band(Ch.52~69) will make the problem worse because the spectrum might be allocated to mobile communication use. In this paper, we investigated the efficient frequency usage for DTV signal reception improvement and next generation broadcasting. The frequency amount required for reception improvement and for next generation broadcasting service is presented. We estimated the beneficial effect when the spectrum(108MHz Frequency Width) is used for SFN transmission technology, UHDTV and Full-HD 3DTV.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.401-411
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• 2009

Commercial sports facilities dissatisfy and have the problem in facility management and social institution when we compare with advanced nation. To develop commercial sports facilities, government must improve facility management ability and increase social institutional support. First, to improve facility management ability, government must make effort for instructor's treatment better, employment extension, strengthening of management and marketing ability, improvement of service quality and consumer satisfaction, facility's modernization. Second, to extend social institutional support, government have to make effort for cultivation and disposition of specialized human power, deregulation and institution improvement of sports facility, support extension of taxes and finance, establishing information network of sports facility. Finally, the main body of commercial sports facilities have to make progressive effort for improving facility management ability, and government have to make excellent social environment developing commercial sports facilities.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.113-118
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• 2017

As interest in mobile devices and networks has increased recently, voice over internet protocol (VoIP) service, which is a technology for transmitting voice data using an existing internet protocol (IP) network, has rapidly spread, Cheap voice call service has become possible. As the digital broadcasting service becomes popular, hybrid fiber coaxial (HFC) network technology, which uses broadband cable network through fusion of broadcasting and communication, utilizes existing communication system and network equipment to provide various new services such as interactive broadcasting service. Therefore, if UGS-AD is applied to VoCM and RTPS is applied to MTA in order to guarantee the quality of voice data in actual HFC Internet service network, it is possible to smoothly perform voice data transmission in narrow upstream band which is a problem in actual commercial HFC network We also proposed a method to improve VoIP service by improving QoS of voice data in HFC Internet service network.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.555-561
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• 2015

The construction industry is a labor-oriented and quality, cost, and schedule performance is effected by technicians. However, the construction industry have faced a labor shortage problem. Therefore, technician graying and no new workers inflow cause labor shortage and decline of worker's skill level. The utilization of foreign technicians instead of domestic technicians has been increased in the construction industry. This paper performed questionnaire survey for 43 managers on 14 project fields to determine the current status and problems of construction technicians and to propose a improvement plan. As a result, most foreign technicians are carpenters and iron workers, but the skill levels are generally lower than domestics. The major problems for foreign technicians are communication and non-skilled. Then, labor productivity and accident rates of foreign technicians are higher than domestics. This paper proposes that skill training programs, language lessons, and multi-cultural programs are effective to improve foreign workers' problems.

• Proceedings of the Korean Professional Engineer Association Conference
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• 1996.12a
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• pp.76-102
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• 1996

북한은 전력부족난과 전기품질의 저하로 인하여 주요 생산기업에 지장을 주고 있으며, 노후 발전소의 성능저하도 함께 진행되고 있는 것으로 추정된다. 이에 대한 적절한 대책이 없는 한 그 상황은 더욱 악화될 전망이다. 한반도 에너지 개발기구(KEDO)가 추진하고 있는 경수로 원자력 발전기가 6～7년 후에 준공된다고 해도 이처럼 불안정한 전력계통에 병입되어 원활한 운전이 가능할런지 기대하기 곤란하다. 이러한 실정에서 \circled1 전력부족으로 주파수가 저하될 때 우선 순위가 낮은 부하를 제한하는 자동 부하제한 방식을 포함한 자동 주파수 제어 계통개선 \circled2 기존발전소 성능과 이용을 향상을 위한 재가동(Repowering) 등의 리 엔지니어링 \circled3 가스터빈 복합화력과 열병합발전(Co-generation) 등과 같이 건설기간이 짧고 비용이 적게 들며 송전 설비 건설도 불필요한 분산형 전원의 건설 \circled4 수력발전소와 조력발전소의 건설 \circled5 양수발전 등 전력에너지 저장설비의 개발 \circled6 송전전압격상과 배전방식개선 및 종합전력정보시스템 구축 \circled7 남ㆍ북한 전력계통 내지는 동북아시아 전력계통을 연계하는 평화망사업(Peace Network Project)등의 추진이 경수로 사업에 선행되어야 한다. 특히 러시아, 중국, 한국, 일본의 발전 에너지원 분포와 년간 부하곡선을 고려할 때 동북아시아 전력계통의 연계는 관련국 상호간에 에너지 환경과 경제적 측면에서 상당한 이득과 안정성을 강화해 줄 것이며, 기술발전과 평화공존에 크게 기여 할 것이다. 이를 위하여 관련국의 전력계통연계 전문가들이 참여하는 남\ulcorner북한전력 계통연계연합회(Co-Pia ; Co-rea Power Systems Interconnection Association)와 동북아지역전력 계통연합회(Near Pia=North-Eastern Asia Region Power Systems Interconnection Association)의 구성을 제안하는 바이다. 주요용어(Key Words): 자동주파수 제어(AFC), 리엔지니어링(Re-Engineering), 분산형 전원(Dispersed Generation System), 전력저장(Power Storage), 부하조절기(Load Conditioner), 수요관리(DSM) 연계(Interconnection), 인터시스템(Intersystem), 통합자원계획(IRP), 안전성 강화(Security Enhancement), 전력시장개방(Electricity Free Maket), 통일비용(Unification Expense, Unification Cost), 남ㆍ북한전력계통연계연합회(Co-Pia), 동북아지역전력 계통연계연합회(Nea,-Pia).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.681-684
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• 2015

Power amplifier is an essential component for transmitting signals to a remote receiver in wireless communication systems. Power amplifier is a non-linear device in general, and the nonlinear distortion becomes severer as the output power increases. The nonlinearity results in spectral regrowth, which leads to adjacent channel interference, and decreases the transmit signal quality. To linearize power amplifiers, many techniques have been developed so far. Among the techniques, digital pre-distortion is known as the most cost and performance effective technique. However, the linearization performance falls down abruptly when the power amplifier operates in its saturation region. This is because of the severe nonlinearity. To relieve this problem, this paper proposes a new adaptive predistortion technique. The proposed technique controls the adaptive algorithm based on the power amplifier input level. Specifically, for small signals, the adaptive predistortion algorithm works normally. On the contrary, for large signals, the adaptive algorithm stops until small signals occur again. By doing this, wrong coefficient update by severe nonlinearity can be avoided. Computer simulation results show that the proposed method can improve the linearization performance compared with the conventional digital predistortion algorithms.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.04a
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• pp.79-79
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• 2001

백판지는 포장용기로 사용되기 때문에 인쇄적성 이외에 다양한 후가공적성이 요구 된다. V Varnish Coating도 이러한 후가공적성 중의 하나로서 국내 인쇄소에서는 기계 코팅으로 불리 우며, 목적은 표면에 고분자수지 피막을 입힘으로써 인쇄물의 광택을 높여서 상품가치를 높이고 수운침투와 같은 외부환경의 변화로부터 상품을 안전하게 보관하기 위함이다. arnish C Coating은 인쇄기의 마지막 Unit에서 인쇄와 동일한 방식으로 진행되는데, 코팅액의 배합은 인쇄소와 인쇄물에 따라 상이하다. 본 연구는 Varnish Coating(OI하 기계코팅) 광택향상을 통 한 품질개선 목적으로 수행되었다. 기계 코팅의 특 성 을 파 악 하 기 위 해 서 Gas Chromatography / Mass Spectrometer와 FT -IR Sp e ectrometer를 사용하여 성문운석을 실시해본 결과 코팅액으로 사용되는 광택바니스는 아크 랄과 페놀수지를 툴루엔 계열의 용매에 녹인 용액이고, 흐$\mid$석제로 쓰이는 인쇄바니스는 스티 렌수지를 동일한 용매에 녹인 용액으로 조사되었다. 기계코팅광택 저하현상의 원인파악을 위해서 도공층의 공극구조를 Mercury Porosimeter를 이용하여 파악한 결과 기공의 부피가 상 대적으로 크게 나타났다. 위의 결과를 토대로 기계코팅광택 저하는 코팅액이 과도한 기공부피를 갖는 도공층 내부 로 대부분 홉수되고 표면에 적은 양만이 잔류하기 때문으로 판단하고 해결방안은 도공층의 기공부피를 줄이는 쪽으로 정하였다. Mayor Coater와 QC를 이용하여 Coating Color Formula t tion 번경실힘을 진행하여 도공지 물성을 분석하였다. 그 결과 Double Coating의 Top Color에 서 강력한 상호작용을 하는 Protein과 콜레이를 감량 하고 경질탄산칼숨을 배제하여 기공의 부피를 줄인 경우 기계코팅광택 향상효과가 두드러지게 나타났다. 이러한 Lab 실험을 바탕으로 결정된 Color Formulation에 대한 현장실험을 진행하였고 Lab 평가 및 실인쇄 평가 결과 원하는 수준의 기계코팅광택 향상을 얻을 수 있었다. 몇 차례의 현장실험과 Long-Run Test한 제품들에 대한 물성을 문석한 결과 기계코팅굉택은 인쇄 광택과 같은 경향을 나타냈으며 실협실적으로 간단하게 측정되는 물성 중에서 Air Permeability와 강한 음의 상관관계롤 보였다.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.6
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• pp.95-105
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• 2017

The Purpose of This Study is to Develop a Checklist Model of Evaluation Diagnosis to Increase the Competitiveness of SMEs in Local Governments. The Evaluation Diagnostic Check Sheet Development Procedure Proceeded in the Order of Preliminary Investigation (Major Company Survey, Analysis of Characteristics of the Industry, Selection of Core Functions, etc.), Research and Development (Development of Core Function Check Sheet, Development of Core Function Improvement Tools). The Evaluation Model is divided into Five Categories (Vision and Strategy System, Quality Assurance and Product Safety, Field Management Level, Statistical Process Control, Improvement Activities), and 1) Recognition, 2) System, 3) Operation, 4) Review and Supplement. This Evaluation Model is expected to Contribute to the Selection of the Mainstream SMEs among the Companies Scattered within the Local Autonomous Entities, thereby Enhancing the Competitiveness of SMEs.

• Journal of the Korean Society for information Management
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• v.28 no.3
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• pp.65-82
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• 2011

Statement of responsibility in bibliographical records plays a key role in clarifying intellectual responsibility of the work, and it also plays a role in making up access points. However, cataloging rules for the statement of responsibility mostly deal with the distinction between the principal role and minor roles. This becomes a problem because the responsibility type itself is more important than the order of the types. For this reason, in this paper I will explore improvements of the description methods of statement of responsibility by organizing the role indicators. Namely, using the role indicators more effectively than the current description methods do, we can collocate the dispersed statements of responsibilities. The role indicators can also be used for an author facet in information retrieval and can provide additional information for authority control.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.23-28
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• 2017

For manufacturing industry to achieve efficient manufacturing process, improving a company's productivity and reducing cost is a required task of the current manufacturing companies. For design of efficient manufacturing process and improvement of productivity, efficient manufacturing process method is studied through removal of unnecessary elements analyzing motions and using test-bed linkage system based on virtual reality. When building process line after verifying optimization through virtual process arrangement simulation in advance, it is available to save additional cost for process modification or supplement to result in practical effects of improving a company's manufacturing competition. Reducing design period, improving equipment, making automation, realizing ergonomics, and improving process through this study, it will be available to achieve improvement of productivity, enhancement of quality, cost reduction as well as employees' satisfaction for safety and health.