• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.211-214
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• 2001

This paper introduces a ZC-ZVS PWM(Pulse-Width -Modulation) boost converter. The IGBT(main switch) of the proposed converter is always switched at ZCS and soft switching of MOSFET(auxiliary switch) as well. Therefore, the proposed converter minimized the turn on/turn off switching losses of switches and reduced conduction losses by using IGBT switch. Moreover, using paralleled IGBT-MOSFET switch overcame the switching frequency limitation. Therefore high power density system can be realized. As mentioned above, the characteristics are verified through experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1222-1224
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• 2005

AC loss is an important factor in the development of superconducting tapes and superconducting power applications. In this paper, magnetization loss in YBCO coated conductor have been measured and compared with Brandt equation. Measurements of magnetization loss were performed under various angles of external magnetic field to consider the anisotropic characteristics of YBCO coated conductors. The results show that measured values of magnetization loss agreed well with the calculated value by using Brandt equation, especially at large degrees of incidence angle. The magnetization losses were strongly influenced by the direction of external magnet field as were expected.

• 한국동물위생학회지
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• 제44권2호
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• pp.61-71
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• 2021

Caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis has been a predominant disease among small ruminants on farms, causing significant losses for farm producer in the larger part of goat rearing nations across the world, for over a century. However, the control measures have not been very effective due to the chronic and usually subclinical nature of the infection. This has caused significant financial losses due to chronic ill-thrift, carcass condemnation, decreased meat yields and low reproduction as well as animal welfare. The current status of caseous lymphadenitis, with updated reseach information to the etiology, pathogenesis, clinical signs, identification, prevalence, prevention and vaccination are delineated in the review.

• 대한지역사회영양학회지
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• 제17권3호
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• pp.341-352
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• 2012

It is well established that excessive sodium intake is related to a higher incidence of chronic diseases such as hypertension, stroke, coronary heart disease, cardiovascular disease and gastric cancer. Although the upper limit of the current sodium intake guideline by WHO is set at 2,000 mg/day for adults, sodium intake of Koreans is well over 4,700 mg/capita/day implying an urgent need to develop and implement sodium intake reduction policy at the national level. This study investigated the cost-effectiveness of the sodium intake reduction policy, for the first time, in Korea. Analyses were performed using most recent and representative data on national health insurance statistics, healthcare utilization, employment information, disease morbidity/mortality, etc. The socioeconomic benefits of the policy, resulting from reduced morbidity of those relevant diseases, included lower medical expenditures, transportation costs, caregiver cost for inpatients and income losses. The socioeconomic benefits from diminished mortality included reductions in earning losses and welfare losses caused by early deaths. It is estimated that the amount of total benefits of reducing sodium intake from 4.7 g to 3.0 g is 12.6 trillion Korean Won; and the size of its cost is 149 billion Won. Assuming that the effect of sodium intake reduction would become gradually evident over a 5-year period, the implied rate of average return to the sodium reduction policy is 7,790% for the following 25 years, suggesting a very high cost-effectiveness. Accordingly, development and implementation of a mid-to-long term plan for a consistent sodium intake reduction policy is extremely beneficial and well warranted.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.119-124
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• 2001

A general procedure to implement the sensitivity analysis of PSC flexural members is proposed based on the analytical calculation of the gradients of stresses and strains with respect to the 21 design variables in a closed format. The formulation covers the long term losses including concrete creep, shrinkage, and PS steel relaxation as well as load effects. The derived formulation is applied to the rectangular section PSC beam with prestressing and nonprestressing steels for the sensitivity analysis. The analytically calculated sensitivity results are compared with those numerically calculated.

• 한국세라믹학회지
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• 제18권4호
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• pp.247-256
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• 1981

Silica bricks had been in arc-furnace roofs of various sizes and steelmaking practices. The resulting materials were examined with reference to mineral and chemical changes. Silica bricks develope definite zones while in service. These zones represent a concentration gradient through the brick that results from the thermal gradient across the brick and from the furnace atmosphere. There are major brick losses by spalling as well as by melting of the hot-face surface in an iron-oxide rich liquid.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.477-480
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• 2003

Packet losses in the Internet can dramatically degrade quality of multimedia streams. Forward Error Correction (FEC) is one of the best methods that can protect data from packet erasures by means of sending additional redundant information. Proposed control algorithm provides the possibility of receiving real-time multimedia streams of given quality wifth minimal traffic overhead. The traffic optimization is reached by adjusting packet size as well as block code parameters. Calculations and simulation results show that for non-bursty network conditions traffic optimization can lead to more than 50% bandwidth reduction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.142-149
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• 2000

It is required that the indoor-noise level of KHST (Korean high speed train) should be lower than 66 ㏈(A) at 350 km/h. In this study, the indoor-noise level of KHST has been predicted to determine the maximum allowable sound power levels of major noise sources. It is found that the indoor-noise requirement for KHST can be met by increasing the transmission losses of the floor and side-wall structures as well as by lowering the sound power levels of two major noise sources including the motor fans.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.32.2-32.2
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• 2009

We examine cyclotron resonant interactions of radiation belt electrons with VLF chorus, plasmaspheric ELF hiss and electromagnetic ion cyclotron (EMIC) waves. Bounce-averaged diffusion rates depend on wave mode, equatorial pitch-angle, electron energy and L-shell. As well, diffusion rates can be sensitive to the latitudinal distributions of particle density and wave power. For different configurations of the plasmasphere, we calculate electron precipitation loss timescales due to combined scattering by VLF chorus, ELF hiss and EMIC waves.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.3-6
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• 2003

In this work the AC loss measurement setup based on an iron core background magnet, not used in a conventional one, has been successfully developed, To prove its validity, a round-robin test for the same Bi-2223 tape sample among three institutes has been done. The results show that test data from the developed setup well agree with losses measured at different institutes.