• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.957-966
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• 1996

An attempt was made to measure the availability of waste heat, released from the cooling system of a small engine, which can be utilized for grain drying. An engine powered flat-bed rough rice dryer was constructed and the performance of the dryer with available engine-waste heat was analyzed for 10 , 20, 30 and 40 cm rough rice bulk depths with a constant dryer base area of 0.81$m^2$/min. The waste heat was sufficient to increase the drying air temperature 7 to 12$^{\circ}C$ at an air flow rate of 8.8 to 5.7㎥/min, while the average ambient temperature and relative humidity were 24$^{\circ}C$ and 70%. The minimum energy requirement was 3.26 MJ/kg of water removed in drying a 40 cm deep grain bed in 14h. A forty to fifty centimeter deep grained seems to be optimum in order to avoid over-drying in the top layers. On the basis of minimum energy requirement (3.26 MJ/kg ) , an estimation was made that the waste heat harvest from an engine of a power range of 1 to 10.5PS can dry about 0.1 to 1 metric on of rough rice from 23% to 15% m.c. (w.b) in 12 h at an average ambient temperature and relative humidity of $25^{\circ}C$ and 80%, respectively. The engine-waste heated grain dryer can be used in the rural areas of non industrialized countries where electricity is not available.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.37-47
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• 1984

Using the soil bin systems, this study was carried out to analyze the effects of the angular and tilling speed of the rotary shaft with the edge curves which were $30^{\circ}$ and $40^{\circ}$, and the edged blade which were single and double, on the torque requirement of rotary tillage. In the analyses, we developed the mathematical models for the torque requirments of rotary tillage, and analyzed the optimum conditions of each variable for the minimum tillage torque requriements. The results of the study were summarized as follows. 1. The required tilling torque by one rotary blade has the minimum value when the tilling speed of the rotary blade was low, and the revolution of the rotary blade was fast, in general. 2. The torque requirements of single edged blade was decreased to about 81% in comparing with that of double edged blade of which the edge curved angle was $40^{\circ}$ and the tilling speed was 29.40 cm/sec. But, for the mean values, the maximum torque requirements were decreased to 45%, and the mean torque requirements were decreased to 35%. 3. For the edge curved angle, the torque requirements of ${\theta}=40^{\circ}$ were 48% more than that of ${\theta}=30^{\circ}$ in the maximum tilling torque in case that the rotary blade were double edged blade. but, there was not a difference when the rotary blades were single edged blade. The mean tilling torques of ${\theta}=40^{\circ}$ were 6% more when the rotary blade was double edged blade, and were 11% less at single edged blade, than that of ${\theta}=30^{\circ}$. 4. In order to reduce the torque requirements for tilling, the optimum revolutions of the rotary shaft were analyzed as that 204-240 rpm for the double edged blade and 280-320 rpm for the single edged blade.

• 한국중재학회지:중재연구
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• 제22권2호
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• pp.103-124
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• 2012

Because the Korea-U.S. Free Trade Agreement (Korea-U.S. FTA) and the North American Free Trade Agreement (NAFTA) have an overlapping contracting party, the United States, their provisions have much in common. The investment chapters of these agreements, especially, show many similarities, and thanks to these similarities, it is likely that the Korea-U.S. FTA arbitration tribunal for investor-state disputes regarding the environment will put great weight on the NAFTA tribunals' interpretations of those similar provisions. Since the NAFTA tribunals have already handled many environment-related arbitration cases, their interpretations will help heighten the predictability of environment-related Korea-U.S. FTA arbitration cases. This paper analyzes the environment-related NAFTA cases in which the tribunal has issued an award, which are the Metalclad case, S.D. Myers case, Waste Management case, Methanex case, Glamis Gold case, and Chemtura case. According to this analysis, the most controversial NAFTA provisions have been Article 1102 (national treatment), Article 1105 (minimum treatment standard, fair and equitable treatment), and Article 1110 (expropriation). The NAFTA tribunals applied the requirement of these articles in a strict manner, reducing the possibility of finding a violation. After the aforementioned analysis, this paper proceeds to compare the national treatment, minimum treatment standard (fair and equitable treatment), and expropriation provisions of the Korea-U.S. FTA and NAFTA and to predict the impact that the environment-related awards under NAFTA can have on environment-related Korea-U.S. FTA cases. It is expected that the NAFTA interpretations of the national treatment and minimum treatment provisions are likely be used as they are, but not the interpretations of expropriation, because of the differences in the expropriation provisions of the two agreements.

• 한국통신학회논문지
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• 제38C권3호
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• pp.247-253
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• 2013

본 논문에서는 선박 통합 게이트웨이를 이용하여 선박 내 기기를 하나의 네트워크로 연결하는 선박 네트워크(Ship Area Network)에 대하여 네트워크의 구조를 분석하고 모든 기기의 연결을 담당하는 선박 통합 게이트웨이의 망요소적 역할 및 필요 최소 성능에 대해 분석한다. 이를 위하여 선박 내 네트워크에 대한 참조망 구조 및 종단간 연결에 대해 분석하고 트래픽 모델 및 선박 네트워크의 요구사항을 분석하였다. 그리고 이를 바탕으로 선박 통합 네트워크 구조를 반영하는 네트워크 시뮬레이터를 설계하였다. 망요소에 대한 성능 평가 결과, 제안한 네트워크에서 통합 게이트웨이가 스위치로서 동작하고 약 30,000 packets/s 이상의 성능을 보유하였을 때, 선박 네트워크가 선박 내부의 트래픽을 안정적으로 전송하였음을 확인할 수 있었다.

• Journal of Communications and Networks
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• 제8권2호
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• pp.169-174
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• 2006

In this paper, the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage (FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of international mobile telecommunication (IMT)-2000 and systems beyond IMT-2000. The calculated spectrum requirement in the maximum spectral efficiency case is reduced by approximately 40% compared to a minimum spectral efficiency case. The effect of the distribution ratio on the required spectrum is smaller than the effect of the spectral efficiency. As the flexible spectrum usage margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}$ = 0.5 is 801.63 MHz, while the required spectrum for ${\rho}$ = 1.0 is 6295.4 MHz. This is equivalent to an increase of 785.32 %.

• 한국압력기기공학회 논문집
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• 제11권2호
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• pp.20-24
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• 2015

During refueling Outage, In-service inspections(ISIs) for the Nuclear Power Plant components are mandatory requirement in accordance with ASME Code Sec. XI. Especially, in current ultrasonic testing is one of the most important NDT techniques that are used for volumetric examination methods for nuclear power plant components, and accurate sizing of flaw indication by UT is essential to assure the integrity of the components. However, ASME code specifies minimum requirement for vessel examination procedure, and so far many different flaw sizing approaches have been tried to apply. Through the Round Robin Test(RRT), the accuracy of ultrasonic flaw sizing using DAC techniques was measured with the mock-ups simulating typical pressure vessel welds. These mock-ups contain artificially introduced flaws of known size and location. This paper shows experimental comparison data on the accuracy of techniques using such as 6dB drop, 50%DAC, 20%DAC and 20%DAC with beam spread correction, and also shows that diverse DAC techniques can be effectively applied to the assessment of the flaw sizing for pressure vessel welds in the stage of welding and fabrication.

• 한국구조물진단유지관리공학회 논문집
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• 제11권2호
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• pp.109-116
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• 2007

본 논문의 목적은 경량기포모르터를 충전한 스틸스터드와 복합스터드 내력벽체의 내화성능을 KS규준에 따라 평가하는데 있다. 주거용과 상업용 건물의 최소 내화 요구시간은 2시간이다. 시험 결과로부터 스틸 스터드와 복합스터드에 경량기포 모르터를 충전한 두 시험체 모두 2시간 내화 성능을 만족하는 것으로 나타났다. 또한 복합스터드 패널 시험체의 경우 내화 성능면에서 스틸 스터드 패널 시험체 보다 우수하다는 것을 정량적 평가하였다.

• Journal of Animal Science and Technology
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• 제62권5호
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• pp.628-637
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• 2020

In poultry diets, a requirement of crude protein is one of the most important factors in poultry productivity. Besides, the Pekin duck requirement of crude protein is still not clear. This experiment was conducted to determine the crude protein requirement of Pekin duck on diet formulation by investigation of growth performance, carcass trait, and analysis of blood parameter for a hatch to 21-day (d) of age. A total of 432 male White Pekin ducks were randomly allocated to six levels of crude protein (i.e., 15%, 17%, 19%, 21%, 23%, and 25%) to give six replicate pens per treatment with 12 ducklings per each pen. Body weight and feed intake were measured weekly by calculating feed conversion ratio and protein intake. Two ducklings each pen was euthanized via cervical dislocation for analysis of carcass trait and plasma blood on 21-d of age. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. The level of crude protein requirements of Pekin ducks for 21 days after the hatch was estimated to be 20.63% and 23.25% diet for maximum daily gain, and minimum feed conversion ratio, respectively.

• 시스템엔지니어링학술지
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• 제6권1호
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• pp.1-13
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• 2010

KC-100 is a 4 seats, single piston engine, civil aircraft whose type certificate is applied for KAS 23 (FAR 23) for the first time in Korea. Its system safety assessment and analysis have been conducted to meet the minimum safety requirement in KAS 23 and to verify the safety of equipment, system, and installation in accordance with the requirement of ${\S}$23.1309 and the guidelines in FAA AC 23.1309-1D and SAE ARP 4761. This safety assessment begins with the FHA (Functional Hazard Assessment) at aircraft and system level in preliminary design phase, and all of the safety assessment and analysis reports including the preliminary version of SSA (System Safety Assessment) have been prepared during detail design phase. The revised version of these safety reports will be approved by Airworthiness Authority through the ground and flight test phases. In this paper, the safety assessment requirement in ${\S}$23.1309, safety assessment guideline in AC 23.1309-1D, and safety assessment and analysis methods in ARP 4761 will be explained based on the application example for KC-100 development. The experience and knowledge of this system safety assessment for civil aircraft can be applied to commuter aircraft of FAR 23 class or large transport airplane of FAR 25 class.

• 한국농림기상학회지
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• 제15권1호
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• pp.50-58
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• 2013

일 최고기온 및 최저기온에 의해 구동되는 개화생리모형에 근거하여 개나리, 진달래, 벚꽃의 온도시간을 추정하고 이를 이용하여 기후변화에 따른 미래 봄꽃 개화일의 지리적 분포를 한반도 전 지역을 대상으로 파악하고자 하였다. RCP8.5 기반의 한반도 전역 12.5km 해상도 일별 기온전망자료를 이용하여 미래 3개 평년(2011-2040, 2041-2070, 2071-2100)의 개화일을 예측하고 이를 기준평년(1971-2000)의 실측 분포와 비교하였다. 봄꽃 3종 모두 지속적으로 개화시기가 앞당겨지고 기준평년에는 개화 불가능지역으로 분류되는 양강도와 개마고원까지 미래에는 개화가 가능해질 것으로 전망된다. 가까운 미래인 2011-2040 평년에는 봄꽃 3종 모두 지역에 따라 최소 3~5일에서 최대 10~11일까지 개화시기가 단축될 것으로 예상된다. 중간 미래인 2041-2100 기간에는 최소 9~11일부터 최대 23~24일까지 개화시기가 단축되고, 먼 미래인 2071-2100 평년이 되면 개나리와 진달래는 최소 17~19일에서 최대 36~38일까지 평균 25일이 줄어들며, 벚꽃개화는 평균 26일이 단축될 것으로 전망된다. 개화일 단축일수는 내륙 산간지대보다 해안도서 및 평야지대에서 커지는 경향이다.