• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.237-242
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• 2019

Spark variance technique is melded the jagged spill-over-sonance status of the glitter-differentiation knowledge level (GDKL) on the spark knowledge gestalt. The knowledge level condition by the spark knowledge gestalt system is comprised with the spill-over-sonance system. As to search a spot of the glitter situation, we are obtained of the spark value with black-red dot by the spill-over upper structure. The concept of knowledge level is comprised the reference of glitter-differentiation level for variance signal by the spark sonance gestalt. Further presenting a jagged variance of the GDKL of the maximum in terms of the spill-over-sonance gestalt, and spark spot sonance that was the a spark value of the far variance of the Spa-kg-FA-${\rho}_{MAXN}$ with $17.68{\pm}2.22units$, that was the a spark value of the convenient variance of the Spa-kg-CO-${\rho}_{MAXN}$ with $7.55{\pm}0.59units$, that was the a spark value of the flank variance of the Spa-kg-FL-${\rho}_{MAX}$ with $2.70{\pm}0.48units$, that was the a spark value of the vicinage variance of the Spa-kg-VI-${\rho}_{MAX}$ with $0.48{\pm}0.05units$. The spill-over sonance will be to appraisal at the jagged ability of the spill-over-sonance gestalt with black-red dot by the spark knowledge level on the GDKL that is presented the glitter-differentiation gestalt by the knowledge level system. Spill-over knowledge system will be possible to restrain of a gestalt by the special signal and to employ a spark data of spill-over sonance level.

• 한국전자파학회논문지
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• 제17권9호
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• pp.829-835
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• 2006

본 논문에서는 초고출력용 X-band 카세그레인 반사판 안테나 시스템에서 반사판의 표면 형상을 변형시켜 spill-over가 효과적으로 감소하는 현상에 대하여 이론적인 고찰을 수행하였다. 이러한 구조는 이중의 쌍곡면 부 반사판을 적용함으로써 주 반사판의 크기를 확장하지 않고 급전 혼 안테나에서 방사된 전파 패턴의 확장각을 증가시켜 spill-over특성이 감소되도록 설계하였다. 결과적으로 본 논문에서 제안된 카세그레인 반사판 안테나가 기존의 설계 방법에 의한 반사판 안테나에 비해 약 9 %의 효율 향상과 10 dB의 부엽 레벨 감소가 구현됨을 이론적으로 확인하였다.

• 디지털융복합연구
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• 제6권2호
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• pp.97-105
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• 2008

This paper tries to measure the spill-over effect of the production and investment of telecommunication service industry (hereafter telecommunication industry), using the most recent data of 2003 input-output tables. The results are summarized as follows. First, the industries which have the biggest spill-over effect from the production of telecommunication industry is miscellaneous business service (including the sale commission of telecommunication service), other engineering services (including royalty), and business consumption. Second, the production of telecommunication industry induces more value-added, and less production, less import, and less employment than related industries such as radio and television equipment, communications and broadcasting equipment, and computer and peripheral equipment. Third, while the investment of telecommunication service amounts to 15% of its production, the effect of the investment on production, value-added, consumption, and employment reaches 70% of that of its production. The policy implication of this paper is that the telecommunication industry contributes to overall economy mainly through its investment.

• 한국해양공학회지
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• 제19권4호
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• pp.35-41
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• 2005

There has been increasing offshore oil exploration, drilling, and production activities, as well as a huge amount of petroleum being transported by tankers and pipelines through the ocean and costal environment. Assessment must be made of the potential risk of damage resulting from the exploration, development and transportation activities. This is achieved through predictive impact evaluations of the fate of hypothetical or real oil spills. VVhen an oil spill occurs, planning and execution of cleanup measures also require the capability to forecast the short-term and long-term behavior of the spilled oil. A great amount of effort has been spent by government agencies, oil industries, and researchers over the past decade to develop more realistic models for oil spills. Numerous oil spill models have been developed and applied, most of which attempt to predict the oil spill fate and behavior. For an actual contingency planning, the oil fate and behavior model should be combined with an oil spill incident model, an environmental impact and risk model and a contingency planning model. The purpose of this review study is to give an overview of existing oil spill models that deal with the physical, chemical, biological, and socia-economical aspects of the incident, fate, and environmental impact of oil spills. After reviewing the existing models, future research needs are suggested. In the study, available oil spill models are separated into oil spill incident, oil spill fate and behavior, environmental impact and risk, and contingency planning models. The processes of the oil spill fate and behavior are reviewed in detail and the characteristics of existing oil spill fate and behavior models are examined and classified so that an ideal model may be identified. Finally, future research needs are discussed.

• 한국통신학회논문지
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• 제26권6B호
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• pp.867-873
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• 2001

최근 들어 초고속통신에 많이 이용되는 ADSL의 경우 케이블(bundle)안에 ISDN이나 HDSL이 제공되는 경우, 대역이 부분적으로 중첩되거나 불완전한 대역 필터링 때문에 그에 따른 spill-over 혼선 잡음의 영향을 받게 된다. 본 논문에서는 유선 선로에서 ISDN과 HDSL에 의한 ADSL의 성능 저하를 분석하였다. 그 결과, 이들에 의한 spill-over 혼선잡음은 ADSL의 성능에 많은 저하를 가져오며, 특히 HDSL의 경우 심각한 혼선잡음을 일으킴을 확인하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.981-984
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• 2006

Oil pollution of the ocean is a major environmental problem, especially in its coastal zones. Synthetic aperture radar (SAR) flown on satellites, such as ERS-2 and Envisat, has been proved to be a useful tool in oil spill monitoring due to its wide coverage, day and night, and all-weather capability. The total 120 SAR images containing oil spill over the East China Sea were collected and analyzed, ranging in date from July 23, 2002 to November 11, 2005. After preprocessed, SAR images were segmented by adaptive threshold method. The oil spill images were incorporated into GIS after distinguished from look-like phenomena, finally we presented the oil spills distribution map for the East China Sea. The wide-swath and quick-looks SAR imagery for mapping of oil spill distribution over large marine areas were proved to be useful when full resolution data are not available. After the temporal and spatial distribution of the oil spills were analyzed, we found that most of oil spills were distributed along the main ship routes, which means the illegal discharge by ships, and the occurrence of oil spill detected on SAR images acquired during morning and summer is much higher than during evening and winter.

• 한국정보전자통신기술학회논문지
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• 제6권3호
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• pp.152-155
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• 2013

본 논문은 위성방송 수신용 소형 파라볼라 안테나의 높이를 보다 낮추기 위하여 반사면의 상하 부분을 부분적으로 절단하였을 때 나타나는 spill-over 의 증가로 인한 성능지수의 저하를 분석하였다. 또한 안테나를 고도각 0도부터 60도까지 트래킹하는 경우에 측엽과 후엽이 받는 대지면 열잡음의 증가로 인한 잡음온도의 영향을 고려하고, LNA 의 잡음지수로 인한 총 잡음온도의 증가 영향을 고려하여 성능지수 값을 시뮬레이션하여 그 결과를 분석하였다. 분석 결과, 원형 파라볼라의 반사면 상하부분을 35% 절단하였을 때, 잡음온도는 약 15K 정도 증가하였으며, G/T 비는 2.5dB 정도 저하하였다.

• 한국통신학회논문지
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• 제32권11A호
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• pp.1213-1218
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• 2007

본 연구에서는 일본 TV 방송 신호의 월경실태를 파악하기 위하여 부산에 측정 시스템을 구성하고, 그 신호들을 APD 곡선으로 분석하였다. 부산에서 2006년 2월부터 10월까지 약 9개월 일본 방송신호에 대해서 측정하였다. 측정된 영상의 질은 최고영상이 2.5 레벨이고, 음질은 최대음질이 3 레벨이다. 일본 방송신호에 대한 분석결과 부산에서 일본 방송을 관찰할 수 있었으며, 특히 36과 38번 채널에 대해서는 계절에 따른 APD 곡선을 그려 분석하였다.

• 한국해안·해양공학회논문집
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• 제23권3호
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• pp.193-204
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• 2011

역동적인 파랑에 노출되는 경우 다양한 failure mode를 쉽게 드러내는 Oil boom의 성능을 개선하기 위해 가장 정교한 파랑모형인 spatially filtered Navier-Stokes 식을 LES (Large Eddy Simulation), 잔차응력에 대한 LDS (Lagrangian Dynamic Smagorinsky 모형), SPH (Smoothed Particle Hydrodynamics) 기법을 활용하여 해석하는 새로운 수치모형이 제언되었다. 이어 부유식 Oil Boom의 누유특성을 규명하기 위해 oil spill, progressive wave, oil boom의 상호작용을 oil boom이 계류삭에 고정되어있는 경우와 oil boom의 excursion이 허용된 경우에 대해 각각 수치모의 하였다. 모의결과 oil boom의 skirt 길이가 수심의 30% 이상이고 excursion이 허용된 경우 oil spill의 차폐 기능은 극대화되는 것으로 밝혀졌다. 이와 더불어 y = 1~2 m 사이에 오일막과 해수의 경계층에서 생성된 와류가 저면으로 확산되면서 시계방향과 반 시계방향의 와류가 엇갈리게 생성되는 coherent eddies가 관측되어 수리실험을 통해 그 존재가 알려진 Kelvin-Helmholz파의 성장과정과 계면으로부터의 일탈과정이 수치모의된 것으로 판단된다.

• 한국해양공학회지
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• 제32권6호
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• pp.474-484
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• 2018

In this study, a new numerical modeling system was proposed to predict oil spills, which increasingly occur at sea as a result of abnormal weather conditions such as global warming. The hydrodynamic conditions such as the flow velocity needed to calculate oil dispersion were estimated using a three dimensional hydrodynamic model based on the Navier-Stokes equation, which considered all of the physical variations in the vertical direction. This improved the accuracy compared to those estimated by the conventional shallow water equation. The advection-diffusion model for the spilled oil was combined with the hydrodynamic model to predict the movement and fate of the oil. The effects of absorption, weathering, and wind were also considered in the calculation process. The combined model developed in this study was then applied to various test cases to identify the characteristics of oil dispersion over time. It is expected that the developed model will help to establish initial response and disaster prevention plans in the event of a nearshore oil spill.