• Journal of Environmental Science International
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• v.29 no.9
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• pp.885-905
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• 2020

This study described the characteristics of the upstream migration of salmon (Chum salmon, Oncorhynchus keta) along Yeon-gok Stream in the eastern coastal region of Korea from October 24 to November 9, 2018 using radio tag and data storage tag loggers for the detection of the locations of tagged salmon and measurement of water temperature. Tracking experiments were conducted and classified into four types (case 1 to case 4) depending on the release time and the number of salmon tracked. Experiments from case 1 to case 3 were classified depending on the number of salmon tracked into cases in which a single tagged salmon was tracked (case 1), a pair of tagged salmon was tracked (case 2), and salmon were tracked by different sex ratios (case 3). Experiments from cases 1 to 3 were conducted between 10 AM and 1 PM, and case 4 was conducted after 3:30 PM. Salmon moved and spawned in the downstream region of the Yeon-gok, where water temperature is higher than in other rivers and salmon return in Canada, Russia, Japan, and the U.S.A. Most of the radio-tagged salmon swam in deep and shaded areas during the day but actively moved upstream close to sunset, regardless of the release time. Females showed relatively more active movements than males during upstream migration.

• Journal of the Korean Institute of Telematics and Electronics
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• v.5 no.3
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• pp.9-24
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• 1968

This report is concerned with the optimum design of hyper-aprupt p-n junctiea silion diode and fabriction of this diode usable for electrical tuning application. Impurity profile in the junction was assumed to clean exponential function. With this assunntion, an optimum criterion for designing standard AM radio tuning capacitor was derived. In the diffusion process, after aluminum and antimony as impurties were deposited in vacuum on a P-type silicon wafer, the diffusion was followed by loading the wafer into the high temperature furnace.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1403-1406
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• 2003

This paper presents a user preference description for graphics contents that is developed in the process of the MPEG-21 DIA(Digital Item Adaptation) standard. The description scheme in this paper is proposed by the authors and adopted in the current AM (Adaptation Model) document of the MPEG-21 DIA. The goal of MPEG-21 standard is providing a multimedia framework that Provides augmented and transparent use of digital contents across various networks and terminals fur the life cycle of digital contents. DI (Digital Item) is a standardized basic unit of digital contents for transaction in the scope of MPEG-21. DIA contains both media resources and metadata including rights information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.852-859
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• 2006

This paper suggests a developing approach of EHF TWTA for satellite communications. In order to improve RF performance and gain, we design and realize an EHF TWTA using a linearizer and drive amplifiers. Through the embodiment and experiment of 80 W EHF TWTA, this method satisfies the design specifications. Therefore, this approach is very useful and can be used to develop the similar equipments.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.344-347
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• 2013

본 고에서는 AM과 FM라디오의 디지털방송 전환을 위하여 현재 사용 중인 방송대역에서의 IN-BAND 방식 외에도 VHF 하위대역 혹은 VHF상위대역을 사용하는 OUT-Of-BAND 방식에 대해 각 전송방식의 장단점을 분석하였다. 그러나 현재 디지털라디오뿐만 아니라 TV도 UHDTV 도입을 위해 VHF상위대역 주파수 사용을 원하고 있어 DMB와 라디오와 TV의 차세대방송 주파수 요구가 상호 충돌이 예상된다. 그러므로 본 고에서는 FM의 디지털라디오 전환방법으로 VHF하위대역(TV채널 5번과 6번)에서의 OUT-Of-BAND 방법에 의한 DRM+ 전송방식 적용을 제안하고 있다, 중파라디오의 디지털방송도 동일 계열 DRM 기술 적용으로 수신기를 값싸게 제조하고 빠르게 보급함으로써 디지털라디오의 활성화 방안을 제시하고 있다.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.449-453
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• 2003

In this paper, we evaluate the performance of zone-based registration, distance-based registration and distance-based registration considering call arrival. We propose the mobility model, which can be used to analyze the performance of three registration schemes. Numerical results show that zone-based registration needs less number of registration than distance-based registration. On the other hand, the registration load of the distance-based registration is equally distributed to all cells in a location area. However, the registration load of the distance-based registration considering call arrival is similar to that of zone-based registration and equally distributed to all cells in a location am Therefore, the proposed scheme can be effectively used restricted radio resources.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.210-215
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• 2001

The pole antenna of vehicles for AM/FM radio broadcasting receptions has many probems, such as damageable mechanical system and noise etc. It is considered that noise is composed of the structural vibration noise and the air flow induced aerodynamic noise. Also we find out that the setting process of a printed on-glass automobile antenna has many difficulties. Recently, the above mentioned problems can be reduced by employing enhanced wiper antenna which utilizes the windshied wiper arm. The new system is a passive antenna. In this study, experiments for the characteristics of a wiper antenna by measuring the SWR, radiation pattern and received powe have been carried out. The experimental results show that the efficiency of the wiper antenna has better performance than any other antenna.