• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.1003-1009
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• 2000

Four young swamp buffalo cows of similar age ranging in body weight (W) between 280 to 380 kg and trained for doing physical exercise were used in two consecutive experiments, each using a latin square design, to determine energy expenditure for draught. The experiments consisted of field trials using 4 levels of work load, i.e. no work as control and loads amounting 450 to 500 Newton (N) continuous traction for respectively 1, 2 and 3 h daily for 14 consecutive days for experiment 1, and no work, traction loads equaling 5, 10 and 15% of W for 3 h daily for 14 days for experiment 2. Heart rate during rest and exercise was monitored using PE-3000 HR monitor. Cows were fed only king grass (Penisetum purpuroides) ad libitum and were subjected to balance trials. Body composition was estimated in vivo by the body density method and daily energy expenditure (EE) was calculated from ME minus RE. RE was calculated from the changes in body-protein and -fat measured before and immediately after the 14 d experimental period assuming an energy equivalent of 39.32 MJ/kg fat and 20.07 MJ/kg protein. $E_{exercise}$ ($EE_{work}\;-\;EE_{resting}$), which was the energy spent for doing the traction during 1, 2 and 3 h was 7.13, 15.45 and 19.90 MJ, respectively. $EE_{work}$ for the 1 h treatment group was 39.75 MJ/d equivalent to 1.30 times $EE_{resting}$. The values for the 2 and 3 h treatment groups were 1.75 and 1.86 times resting energy requirement, respectively. Absolute efficiency of work in all exercise trials of experiment 2 was around 27.28%. The increases of daily $E_{exercise}$ values were correlated to elevation of heart rate (HR) according to the equation $E_{exercise}=(0.270HR^{0.363}\;-\;1)$ MJ, while draught force related to heart rate according to the equation DF (N)=6.66 HR - 361.62. Blood glucose and triglyceride levels were gradually elevated with time during the course of exercise. Mean values of blood glucose were 91.7, 115.0 and 116.2 mg/dl for cows after 1, 2 and 3 h pulling loads at 15% W respectively as compared to 88.2 mg/dl prior to work. In the same order and treatment, mean blood triglyceride concentrations were 13.5, 13.3 and 14.8 mg/dl, and 11.5 mg/dl for control. For blood lactate, the values were 1.68, 1.63 and 1.66 mM, and 0.80 mM for control. Glucose was used as the major source of energy during the initial phase of exercise, but for prolonged work, fat will replace carbohydrate as the main substrate. Accumulation of lactate persisted for some time at the end of the exercise trials.

• 한국산림과학회지
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• 제97권3호
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• pp.266-273
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• 2008

소나무, 상수리나무 묘목의 생장 및 영양상태에 미치는 토양산성화의 영향을 조사하고 묘목의 생장과 토양용액 중의 (Ca+Mg+K)/Al 몰비와의 관계를 검토하였다. 인위적으로 산성화 시킨 산림토양에서 생육한 소나무, 상수리나무 묘목의 생장저해에는 토양용액 중의 pH 저하와 이에 따른 토양용액으로의 Al 용출 및 묘목의 지하부에 있어서 Al 농도의 증가에 따른 지상부의 Ca 등의 식물 필수원소의 감소 등이 관여하고 있음을 시사하였다. 토양산성화에 따른 묘목의 생장저하 수준은 토양의 Al 농도뿐만 아니라 Al과 Ca, Mg 및 K과의 무기영양소 균형도에 의해 결정되며, 두 수종 모두 토양용액 중의 (Ca+Mg+K)/Al 몰비가 6.0 이하가 되면 건물생장이 현저하게 저하하고 그 비가 0.8인 경우 건물생장이 대조구 값에 비하여 소나무 묘목에서 약 60%, 상수리나무 묘목에서 약 50% 저하하였다. 앞으로, 산성우 등의 산성강하물에 의한 토양산성화가 수목의 생장 및 영양상태에 미치는 영향을 평가할 경우, 토양용액 중의 (Ca+Mg+K)/Al 몰비는 삼림생태계 피해예측에 대한 산성강하물의 한계부하량의 평가에 있어 중요한 지표가 될 수 있다고 판단된다.

• 정보처리학회논문지D
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• 제10D권7호
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• pp.1067-1076
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• 2003

데이터베이스 공유 시스템(Database Sharing System: DSS)은 고성능 트랜잭션 처리를 위해 제안된 시스템이다. DSS에서 고속의 통신망으로 연결된 노드들은 별도의 메모리와 운영체제를 가지며, 데이터베이스를 저장하고 있는 디스크는 모든 노드에 의해 공유된다. 그리고 빈번한 디스크 액세스를 피하기 위해 각 노드는 자신의 메모리 버퍼에 최근에 액세스한 페이지들을 캐싱한다. 본 논문에서는 DSS를 구성하고 있는 각 노드의 부하를 효과적으로 분산한 수 있는 동적 트랜잭션 분배 알고리즘을 제안한다. 제안한 알고리즘은 각 노드에 할당된 주사본 권한을 이용함으로써 노드별 참조 지역성을 지원하고, 그 결과 캐쉬 이용률을 증가하여 디스크 액세스 수를 최소화한다. 뿐만 아니라, 노드의 현재 부하를 고려하여 트랜잭션 분배 정책을 결정함으로써 특정 노드에 트랜잭션이 집중되는 것을 피한다. 제안된 알고리즘의 성능평가를 위해 시뮬레이션 실험을 수행하였으며, 실험결과 제안된 알고리즘이 기존 알고리즘들보다 트랜잭션 처리율에서 높은 성능을 보였다. 특히 트랜잭션 부하량이 높은 경우와 편중된 데이터 참조를 보이는 경우에 좋은 성능을 보였다.

• 한국시스템다이내믹스연구
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• 제2권2호
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• pp.25-40
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• 2001

This paper describes the forecast of power plant construction in a competitive korean electricity market. In Korea, KEPCO (Korea Electric Power Corporation, fully controlled by government) was responsible for from the production of the electricity to the sale of electricity to customer. However, the generation part is separated from KEPCO and six generation companies were established for whole sale competition from April 1st, 2001. The generation companies consist of five fossil power companies and one nuclear power company in Korea at present time. Fossil power companies are scheduled to be sold to private companies including foreign investors. Nuclear power company is owned and controlled by government. The competition in generation market will start from 2003. ISO (Independence System Operator will purchase the electricity from the power exchange market. The market price is determined by the SMP(System Marginal Price) which is decided by the balance between demand and supply of electricity in power exchange market. Under this uncertain circumstance, the energy policy planners such as government are interested to the construction of the power plant in the future. These interests are accelerated due to the recent shortage of electricity supply in California. In the competitive market, investors are no longer interested in the investment for the capital intensive, long lead time generating technologies such as nuclear and coal plants. Large unclear and coal plants were no longer the top choices. Instead, investors in the competitive market are interested in smaller, more efficient, cheaper, cleaner technologies such as CCGT(Combined Cycle Gas Turbine). Electricity is treated as commodity in the competitive market. The investors behavior in the commodity market shows that the new investment decision is made when the market price exceeds the sum of capital cost and variable cost of the new facility and the existing facility utilization depends on the marginal cost of the facility. This investors behavior can be applied to the new investments for the power plant. Under these postulations, there is the potential for power plant construction to appear in waves causing alternating periods of over and under supply of electricity like commodity production or real estate production. A computer model was developed to sturdy the possibility that construction will appear in waves of boom and bust in Korean electricity market. This model was constructed using System Dynamics method pioneered by Forrester(MIT, 1961) and explained in recent text by Sternman (Business Dynamics, MIT, 2000) and the recent work by Andrew Ford(Energy Policy, 1999). This model was designed based on the Energy Policy results(Ford, 1999) with parameters for loads and resources in Korea. This Korea Market Model was developed and tested in a small scale project to demonstrate the usefulness of the System Dynamics approach. Korea electricity market is isolated and not allowed to import electricity from outsides. In this model, the base load such as unclear and large coal power plant are assumed to be user specified investment and only CCGT is selected for new investment by investors in the market. This model may be used to learn if government investment in new unclear plants could compensate for the unstable actions of private developers. This model can be used to test the policy focused on the role of unclear investments over time. This model also can be used to test whether the future power plant construction can meet the government targets for the mix of generating resources and to test whether to maintain stable price in the spot market.

• 한국수산과학회지
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• 제25권3호
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• pp.176-180
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• 1992

어류를 고밀도 순환여과식으로 양식하는 담수양어장에서 암모니아를 제거하기 위하여 고정 생물막 질산화 반응으로 처리하는 잠수여상 장치를 사용할 때 최대의 양식밀도와 최적의 운전조건을 파악 할 목적으로 수리학적 부하율에 따른 암모니아 제거효율 실험을 실시한 결과는 다음과 같다. 유입수의 암모니아 농도가 약 10mg/l(9.43-13.66mg/l)일 때 암모니아 제거율은 각각의 수리학적 부하가 0.028, 0.037, 0.056 및 $0.111m^3/m^2\;\cdot\;day$로 증가함에 따라서 76.24, 62.88, 39.09 및 $9.20\%$로 감소하였다. 이상의 실험 자료를 어류사육조내 암모니아 농도의 물질수지식으로 적용시킨 결과, 어류 사육조의 암모니아 농도를 10mg/l이하로 유지시키고자 할 경우, 양식 가능한 최대 양식밀도는 암모니아 생성량을 기준으로 1.52mg/min이었으며 이 조건에서 잠수여상 반응조의 최적의 수리학적 부하율은 $0.047m^3/m^2\;\cdot\;day$로 운전되어야 한다.

• 한국도서관정보학회지
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• 제11권
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• pp.69-99
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• 1984

A dramatic development in the new technology of copying materials has presented us with massive problems on reconciling the conflicts between copyright owners and potential users of copyrighted materials. The adaptation to this changing condition led some countries to revise their copyright laws such as in the U. S. in 1976 and in Korea in 1984 for merging with the international or universal copyright conventions in the future. Copyright defined as exclusive rights given to copyright owners aims to secure a fair return for an author's creative labor and to stimulate artistic creativity for the general public good. The exclusive rights on copyrightable matters, generally for reproduction, preparation of derivative works, public distribution, public performance, and public display, are limited by fair use for scholarship and criticism and by library reproduction for its preservation and interlibrary loan. These limitations on the exclusive rights are concerned with all aspects of library services and cause a great burden on librarian's daily duty to provide balance between the rights of creators and the needs of library patrons. The fair use as one of the limitations on it has been coupled with enormous growth of a new technology and extended from xerography to online database systems. The implementation of the fair use and library reprography in Korean law to the local practices is examined on the basis of the new American copyright act of 1976. Under the draft revision of Korean law, librarians will face many potential problems as summarized below. 1. Because the new provision of 'life time plus 50 years' will tie up substantial bodies of material longer than the old law, until that date librarians would need permissions from the owners and should pay attention to the author's death date. 2. Because the copyright can be sold, distributed, given to the heirs, donated, as a whole or a part, librarians should chase down the heirs and other second owners. In case of a derivative work, this is a real problem. 3. Since a work has its protection from the moment of its creation, the coverage of copyrightable matter would be extended to the published or the unpublished works and librarian's work load would be heavier. Without copyright registration, no one can be certain that a work is in the public domain. Therefore, librarians will need to check with an authority. 4. For implementation of limitations on exclusive rights, fair use and library reproduction for interlibrary loan, there can be no substantial aggregate use and there can be no systematic distribution of multicopies. Therefore, librarians should not substitute reproductions for subscriptions or purchases. 5. For the interlibrary loan by photocopying, librarians should understand the procedure of royalty payment. 6. Compulsory licenses should be understood by librarians. 7. Because the draft revision of Korean law is a reciprocal treaty, librarians should take care of other countries' copyright law to protect foreign authors from Korean law. In order to solve the above problems, some suggestions are presented below. 1. That copyright clearinghouse or central agency as a centralized royalty payment mechanism be established. 2. That the Korean Library Association establish a committee on copyright. 3. That the Korean Library Association propose guidelines for each occasion, e.g. for interlibrary loan, books and periodicals and music, etc. 4. That the Korean government establish a copyright office or an official organization for copyright control other than the copyright committee already organized by the government. 5. That the Korean Library Association establish educational programs on copyright for librarians through seminars or articles written in its magazines. 6. That individual libraries provide librarian's copyright kits. 7. That school libraries distribute subject bibliographies on copyright law to teachers. However, librarians should keep in mind that limitations on exclusive rights are not for an exemption from library reprography but as a convenient access to library resources.

• Journal of Biosystems Engineering
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• 제3권2호
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• pp.35-61
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• 1978

동력경운깅가 일반 경사지에서 견인주행하는 경우 견인주행성능과 주행특성을 구명하기 위하여 토양의 종류 및 상태는 일정하게 하고 지면의 기하학적 조건과 견인주행속도 및 견인하중을 변수로 하여 외부동력전달계의 시점인 좌우차륜과 토양간에 발생하는 차륜구동력 및 굴름정항과 Engine에서 구동륜까지 내부전달계를 통하여 전달된 동력의 이론치와 실험치와의 부합여부를 검정하고 부가적으로 동력경운기가 경사지기계화의 동력기로써의 가능성여부와 문제점을 찾으려한다.

• Journal of Biosystems Engineering
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• 제3권2호
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• pp.34-34
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• 1978

동력경운깅가 일반 경사지에서 견인주행하는 경우 견인주행성능과 주행특성을 구명하기 위하여 토양의 종류 및 상태는 일정하게 하고 지면의 기하학적 조건과 견인주행속도 및 견인하중을 변수로 하여 외부동력전달계의 시점인 좌우차륜과 토양간에 발생하는 차륜구동력 및 굴름정항과 Engine에서 구동륜까지 내부전달계를 통하여 전달된 동력의 이론치와 실험치와의 부합여부를 검정하고 부가적으로 동력경운기가 경사지기계화의 동력기로써의 가능성여부와 문제점을 찾으려한다.