• KIEAE Journal
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• 제16권2호
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• pp.79-85
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• 2016

Purpose: It is difficult to calculate frame U-value because of the two reason. First is selection of air properties in cavity. Second is calculation method in window frame. For this reason, it is important to decide cavity properties in window frame. However, international standards offered different method(ISO 15099, ISO 10077) and air properties was changed according to the two methods. The aim of this study was to suggest method for deriving accurate frame U-value using international standard methods and CFD simulation. Method: First, this study conducted analysis calculation method of ISO 15099 and ISO 10077. And, CFD simulation conducted based on same condition. Finally, ISO calculation and CFD simulation results were verified through comparison with real experiment results. Result: The results show that effective conductivity of ISO 15099 was the highest value. ISO 10077 and CFD result followed. The convergent values of ISO 10077 was the highest. ISO 15099 and CFD followed. ISO calculation reflecting CFD simulation results will reduce error with experimental results.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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• pp.240-243
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• 2004

"전자무역플랫폼(e-trade Platform)"은 최신의 정보기술을 활용하여 무역업체가 시장조사에서 계약, 상역, 외환, 통관, 물류, 결제까지 모든 무역업무프로세스를 단절 없이(Seamless) 처리할 수 있는 단일창구(Single Window)를 제공하며, 무역업체의 정보화 수준에 따라 다양한 서비스 및 인프라에 대한 연계방식(Interface)을 제공함으로써 대기업뿐만 아니라 중소기업도 무역관련 유관기관 및 정부, 나아가서는 글로벌 연계까지 가능케 하는 전자무역서비스와 이를 연계하여 통합된 환경을 제공하는 전자무역인프라 (전자무역문서 보관소, 전자무역 중계시스템, 전자무역 표준저장소)를 총칭한다.

• 무역상무연구
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• 제44권
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• pp.213-238
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• 2009

This thesis examines the problems faced in the clearance procedures of Korea's e-customs system for which improvements are necessary, and suggests various ways of overcoming those problems. Practical implications regarding the advancement of Korea's e-customs system are as follows. First, the substructure of the e-customs clearance system, which is the basis for the establishment of a global single window, should be developed into a more modern and advanced system. Second, additional improvements in the law are required to render the broad array of Internet-based export and import documents legally binding. Third, customized services should be provided in order to improve the operating efficiency of the e-customs clearance system. Fourth, the reputation of Korea's e-customs clearance system should be raised via the strengthening of a cooperative system between concerned parties, including exporters and importers. This innovative approach to systematic improvements will come about when we can simplify current customs clearance procedures and establish a fairer customs inspection administration regime. Additionally, when we review the methods intrinsic to our customs system, we must emphasize the urgency of proper completion of related systems and arrangements in the trade business and similar fields.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.200-205
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• 2012

In the high oil price age, intensification of energy efficiency promotion in the building sector is required. Windows are dominating in large percent of whole building loads, and are regarding as the primary target of energy efficiency. In this study, in order to reduce heat loss of buildings, we investigate the thermal performance properties of Temperable Low-e glazing coated Ag membrane that has high electrical conductivity. The Temperable Low-e glazing windows has high insulation and shading properties, and it has strength that can supply various product which consumers want. In order to evaluate thermal performance of temperable windows, we install single low-e windows and double low-e windows in the experimental chamber and analysis the comparison heating energy consumption between single and double Low-e glazing windows. performance evaluation was conducted.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.727-729
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• 2002

In this paper, we proposed quad variable rates ADPCM coding method and its implementation on C6000 DSP, which is modified from the standard ADPCM of ITU G.726 for speech quality improvement considering the environmental noise Four coding rates, 16Kbps, 24Kbps, 32Kbps and 40Kbps are used for speech window samples and the rate decision threshold is decided by the environmental noise level. The object of the proposed method is to reduce the coding rate while retaining the speech quality and the speech quality is considerably close to 40Kbps single rate coder with the coding rate close to 16Kbps single rate coder under the environmental noise. The environmental noise level affects the coding rate and the noise level is calculated per every speech window samples. At high noise level, more samples are coded at higher rates to enhance the quality, but at low noise level, only the big speech signals are coded at higher rates and more speech samples are coded at lower coding rates to reduce the coding rates. The influence of the noise on tile speech signal is considerably high for small signals and the small signal has the higher ZCR (zero crossing rate). The method is simulated in PC and to be implemented on C6000 floating point DSP board in real time operations.

• 해양환경안전학회지
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• 제21권3호
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• pp.259-265
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• 2015

It is clearly understood that e-navigation is beneficial to prevent collision and grounding of ships. The purpose of this study is to define and present a future ship operation system under the e-navigation environment in order to provide clear direction for the design of Korean e-navigation system. The future ship operation system consists of shipboard navigational system, shore supporting system and maritime communication system. To achieve the objectives of this study, the ship operation system was discussed separately into SOLAS ships and non-SOLAS ships in this study. In SOLAS ships, mariners become a system manager, choosing system presets, interpreting system output, and monitoring vessel response. In small ships and fishing vessels, mariners may enjoy their navigation by using the automatic tracking of ship's position on the portable electronic chart display. The improved bridge design, integrated and harmonized navigational system and single window reporting will reduce significantly the administrative and physical workload of mariners. Mariners can concentrate their attention more on navigational duty under the e-navigation environment. To build an effective Korean e-navigation system, the essential navigational functions and e-navigation services for small ships and fishing vessels must be identified and developed taking into account user needs.

• 전기전자학회논문지
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• 제21권3호
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• pp.284-287
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• 2017

본 연구에서는 3차원 소자 시뮬레이션을 통하여 단일 게이트 피드백 전계효과 트랜지스터의 전기적 특성과 채널 길이에 따른 메모리 윈도우 특성 변화를 확인하였다. 소자의 채널 길이는 50 nm에서 100 nm까지 변화시켜가며 시뮬레이션을 수행하였다. 시뮬레이션 결과 0에 가까운 문턱전압이하 기울기(< 1 mV/dec)와 ${\sim}1.27{\times}10^{10}$의 $I_{on}/I_{off}$ 비율을 얻었다. 또한 메모리 윈도우를 확인한 결과 채널 길이 50 nm의 소자는 0.31 V의 메모리 윈도우가 생성되었으나 채널 길이 100 nm의 소자는 메모리 윈도우가 생성되지 않았다.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.776-780
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• 2017

To avoid imaging artifacts and interpretation mistakes, an improvement of the uniformity in gamma camera systems is a very important point. We can expect excellent uniformity using cadmium zinc telluride (CZT) photon counting detector (PCD) because of the direct conversion of the gamma rays energy into electrons. In addition, the uniformity performance such as integral uniformity (IU), differential uniformity (DU), scatter fraction (SF), and contrast-to-noise ratio (CNR) varies according to the energy window setting. In this study, we compared a PCD and conventional scintillation detector with respect to the energy windows (5%, 10%, 15%, and 20%) using a $^{99m}Tc$ gamma source with a Geant4 Application for Tomography Emission simulation tool. The gamma camera systems used in this work are a CZT PCD and NaI(Tl) conventional scintillation detector with a 1-mm thickness. According to the results, although the IU and DU results were improved with the energy window, the SF and CNR results deteriorated with the energy window. In particular, the uniformity for the PCD was higher than that of the conventional scintillation detector in all cases. In conclusion, our results demonstrated that the uniformity of the CZT PCD was higher than that of the conventional scintillation detector.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.687-691
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• 2007

It is important to increase the sound proof performance of building for reducing the influence of aircraft noise on the bais of actual survey of existed buildings. The purpose of this study is to propose the basic data for designing sound insulation of residential house. In this study, field measurement of aircraft noise Interior and outside noise level difference were carried out for 7 days in 2 residential houses. As the result, aircraft noise levels showed to be Leq $71.8{\sim}74.5$dB(A), WECPNL $82.2{\sim}83.4$ and indoor noise level were NC-55 ${\sim}63$ over acceptable NC-30 in 2 measured houses. Noise reduction effect showed to be $15.8{\sim}23.1$dB(A) in measured houses, and houses with double window were preferable to those with single window in sound proof performance. The outside sound pressure level for residential house was a little different according to the type of source. In measuring by using aircraft noise it was effected by angle and distance from measuring point, to aircraft, window area, and sound absorption of room, and so on.

• 한국전자파학회논문지
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• 제18권11호
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• pp.1318-1326
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• 2007

본 논문에서는 waffle-iron 도파관 여파기의 실용적인 설계 방법을 기술하였다. 설계 과정은 두 단계로 이루어진다. 첫 단계로는 waffle-iron 구조의 단일 window에 대해 EM S/W tool를 이용하여 S-파라미터를 구하고, ABCD 파라미터로 변환하여 K-인버터를 계산하고, 두 번째 단계는 분포 정수 원형 여파기와 일치되게 window의 크기를 최적화한다. 설계 방법을 검증하기 위해 위성통신용 Ka 대역 여파기를 설계하고 제작하였다. 측정 결과는 계산 결과와 비교하여 양호하게 일치하였다.