• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.3
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• pp.40-47
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• 1997

안테나의 특성은 셀룰러 시스템의 서비스 품질에 직접적으로 영향을 미치는 요소가 되며, 특히 섹터화로 인한 용량의 증가를 기할 수 있는 CDMA 시스템의 경우에는 매우 중요한 의미를 갖는다. 본 논문의 지향성 안테나를 이용하여 전력 제어된 CDMA 셀을 섹터화할 경우 얻을 수 있는 용량의 이득을 논의한다. 용량의 측면에서 이상적인 안테나 패턴과 비교할 때 실제 안테나 패턴의 역방향 링크 용량 효율을 해석적으로 구한다. 셀룰러 CDMA 시스템의 용량은 동일한 주파수 대역을 사용할 수 있는 최대 통신 채널의 수이므로 용량 효율은 결국 주파수 스펙트럼 이용 효율을 의미한다. 측정된 반사판 섹터 안테나 패턴을 대상으로 분석한 결과를 제시하고 패턴 특성과 섹터 셀의 배치 구조에 따라 용량 효율이 86~97%로 변화함을 보인다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.173-175
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• 2011

적극적인 관제 및 책임 관제구역 도입의 필요성과 안전항행을 위한 정보제공 및 업무 효율성 증진 방안 강구로 현재 섹터 관제를 시행하고 있으며 선박의 충돌사고 예방 및 해양환경보호에 큰 역할을 하고 있는 것이 사실이다. 하지만 일반적 형태와 상이한 부산항의 관제섹터 변경구역에서의 현 문제점과 합리적인 VHF채널 운영방안을 제시한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.211-216
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• 2009

Chattering phenomenon is still a large drawback of VSS. To overcome this problem, various approaches have been reported. A new notion of sliding sector has been proposed recently. In this paper, fuzzy control with time-varying boundary layer using the sliding sector theory with continued input function in the sector is proposed. This paper analyzes the stability, using Lyapunov function on the sliding sector. Computer simulation for inverted pendulum results in elimination of the chattering phenomenon.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.3
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• pp.168-173
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• 2007

Chattering phenomenon is still a large drawback of VSS. To overcome this problem, various approaches have been reported. A new notion of sliding sector has been proposed recently. In this paper, new methods of the nonlinear system control using the sliding sector theory with continued input function in the sector is proposed. This paper analyzes the stability, using Lyapunov function on the sliding sector. computer simulation for inverted pendulum results in elimination of the chattering phenomenon.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.3
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• pp.1-17
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• 2020

The Fourth Sector has been attracting attention as a means to solve the various problems plaguing modern society; it emerged to overcome the Third Sector's issues such as excessive reliance on the government and service model isomorphism, represented by social economy enterprises (Meadows, 1972; Howaldt & Schwarz, 2010). Social venture companies have been mentioned as key agents of the Fourth Sector (Gyeonggi Research Institute, 2018). However, the academic and policy concepts related to social ventures continue to be vague. Therefore, this study aims to clarify the concept of social ventures as part of the Fourth Sector, and research development strategies for the vitalization of the social venture ecosystem in an effort to encourage inclusive growth of society. To achieve these goals, it establishes the concept of social ventures differentiated from the Third Sector, based on previous studies, and presents the importance of an intermediate support organization for the ecosystem's vitalization. Furthermore, to propose strategies for said vitalization, the study derives detailed forms of social venture intermediate support organizations, and provides suggestions regarding their importance and roles through social innovation levels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.263-268
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• 2016

A rapid increase of data amount, used in ship-to-ship transmission of safety and logistics information, ships in the inland sea have trouble transmitting real-time information transmission due to an increase in traffic load caused by data transmitted by land station and offshore ships. In this study, therefore, communication is carried out by adaptively controlling the detailed beam width based on the distribution of offshore ships in land station durable in marine environment. Then after the adaptive sector system enabling real-time communication support between ships concentrated in an inland sea and land station is applied, the performance verification is conducted based on the respective Call Blocking Rates of an omnidirectional antenna, fisted sector system, and adaptive sector system. The performance verification result shows that adaptive sector system has better performance than the fixed sector system as the density of ship, q value, increases, and that the smaller the beam width is, the better performance of adaptive sector system will be.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.693-697
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• 2008

Generally, the rate of reuse should be increased within the certain area for efficient operation of radio resources in a CDMA mobile communication system, and then signal interference between the sane radio channels should be minimized. for this reason, this study conducted a simulation of cell secterization methods(3 and 4 sectors) as a practical and immediately applicable method to the field to minimize signal interference, to construct an economical network, and to increase the efficiency of frequency use. Also, by analyzing RSSi, $E_c/I_o$, $E_b/N_t$ and 3-way handoff which were simulation results, their possibility of use was identified.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.818-826
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• 2011

This paper proposes a novel FTL (Flash Translation Layer) algorithm employing sector-level mapping technique based on locality to reduce the number of erase operations in flash memory accesses. Sector-level mapping technique shows higher performance than other mapping techniques, even if it requires a large mapping table. The proposed algorithm reduces the size of mapping table by employing dynamic table update, processes sequential writes by exploiting sequential locality and extracts hot sector in random writes. Experimental results show that the number of erase operations has been reduced by 75.4%, 65.8%, and 10.3% respectively when compared with well-known BAST, FAST and sector mapping algorithms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.115-118
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• 2000

본 논문에서는 4 개의 다이폴 소자로 구성한 4 섹터 지향성 절환 원형 배열 다이폴 안테나의 기본 특성을 검토하고 있다. 안테나의 방사 지향성이 순차적으로 4 섹터 절환이 가능하도록 하기 위해 급전 및 무급전 소자를 적절히 이용하고 있으며, 무급전 소자의 유도 전류에 의한 원형 배열 안테나의 특성 개선을 위해 급전 소자를 제외한 나머지 소자들을 단락 또는 개방시켜 방사 지향성 및 이득 특성 등을 계산하고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.317-319
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• 1999

공간 데이터베이스에서 공간 데이터간의 근접성을 알아보아야 할 필요가 많이 발생한다. 이를 위해, 본 연구에서는 방향 관계와 거리 관계가 혼합된 형태의 질의에서 공간적으로 가까운 객체를 순서적으로 추출해내는 방법을 제안한다. 점진적 거리 조인 알고리즘을 근간으로 섹터 기반 모델을 적용하여 객체들을 순서적으로 추출할 수 있도록 한다. 섹터의 분류와 섹터들간 정렬 순서에 따라 추출된 값을 필요에 따라 제한조건의 조절이 가능하다는 장점이 있다. 또한, 점진적 거리조인 알고리즘에 있어서의 데이터 크기에 따른 성능 저하 문제도 어느 정도 해결할 수 있음을 기술하고 있다.