• 정보처리학회논문지B
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• 제15B권6호
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• pp.585-594
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• 2008

모바일 단말기를 사용하여 모바일 웹 서비스를 제공하는 과정에서 고려해야 할 사항은 끊김없는 서비스와 품질 보장형 서비스 이다. HMIIPv6는 끊김으로 인해 발생되는 패킷 손실과 지연 현상을 개선하기 위하여 MAP을 둔다. 하지만 MN을 위하여 패킷을 수신하고 전달하기 때문에 부하가 집중된다. 이는 보다 빨리 처리해야 할 실시간 데이터를 빨리 처리하지 못하는 결과는 낳는다. 뿐만 아니라 품질 보장 서비스를 위해서는 적응적 모바일 서비스 방법이 필요하다. 하지만 이 방법은 다양한 단말기의 하드웨어적인 차이점으로 인한 컨텐츠의 서비스 응답시간비용이 필요하다. 따라서 본 논문에서는 끊김없는 서비스를 위하여 MAP에 큐를 두어 실시간 데이타 처리 성능을 향상시켰다. 또한 응답시간비용을 줄이기 위하여 컨텐츠의 구성요소를 이용하여 컨텐츠를 재사용할 수 있는 캐시를 갖는 모바일 웹서비스 방법을 제안한다. 수식 분석과 시뮬레이션 결과, 제안방법인MAP에 큐를 두는 방식과 모바일 노드의 이동성을 고려한 캐시 방법이 다른 다양한 시스템 조건에서 우수함을 알수 있었다.

• 조명전기설비학회논문지
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• 제21권2호
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• pp.64-70
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• 2007

전기배선에서 전압강하의 발생을 피할 수는 없다. 전기배선에서 발생되는 전압강하는 열 손실을 의미한다. 이 열은 절연체의 특성을 변화시키게 되고 이로 인하여 절연성능을 저하시키게 되며 나아가 누전, 감전, 정전 및 화재 등의 사고를 일으키는 원인이 되기도 한다. 그러므로 전기배선의 설계시에 전압강하에 대한 최적화 설계는 안전성, 경제성을 결정하는 중요한 요소가 된다. 본 연구에서는 저압의 전기설비인 가로등, 빌딩, 지하철역사 등 공공의 안전확보가 최우선 요구되는 다중 분산부하계통에서의 전압강하가 전기배선에 미치는 영향을 분석하고, 안전성 및 경제성 제고를 위한 전압강하 최적화 방안 및 설계 프로그램 개발을 하였다.

• 한국정보통신학회논문지
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• 제19권9호
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• pp.1991-1998
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• 2015

본 논문은 하이브리드 발룬을 갖는 계산가능 다이폴안테나가 접지판 위에 수평 및 수직으로 놓여 있을 경우의 안테나 인자 특성을 모멘트법으로 검토하고 있다. 안테나 인자의 표현식은 전력부정합손실의 개념을 적용하여 도출한 식을 사용하였으며, 안테나 인자의 계산에서 나타나는 안테나의 입력 임피던스 및 유효길이는 모멘트법을 적용하여 계산하고 있다. 그 결과, 접지판 위에서의 안테나 인자 특성은 안테나의 편파상태에 따라 달라지며 자유공간 안테나 인자와는 최대 ± 0.14 dB 의 차이가 발생함을 알 수 있었다. 또한, 수평편파인 경우의 안테나 인자 변동폭이 수직편파인 경우보다 0.2 dB 정도 더 크다는 것도 확인할 수 있었다.

• 한국축산식품학회지
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• 제30권2호
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• pp.216-222
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• 2010

This study was carried out to determine the effects of olive oil prepared tomato powder (OPTP) used as lycopene source on fresh pork patties. OPTP was not added (0%; C), or was added at 0.25% (T1), 0.5% (T2), 0.75% (T3) and 1.0% (T4) in a basic pork patty formula and patties were stored for 7 days at $5^{\circ}C$. pH values of T3 and T4 were lower (p<0.05) than those of control until storage day 3. However, pH values of treated samples were dramatically increased (p<0.05) after 7 d of storage. Cooking loss values of treatments were lower (p<0.05) than those of control at day 1 of storage. Thiobarbituric acid reacting substances values were lower (p<0.05) in all treatments than in untreated samples during storage. All treated samples had lower values (p<0.05) for lightness ($L^*$) but significantly higher values (p<0.05) for redness ($a^*$) and yellowness ($b^*$) than the untreated samples during storage. Total plate counts of T4 were lower (p<0.05) than others during storage. In sensory evaluation, the scores of color, aroma and overall acceptability in T3 and T4 scored higher (p<0.05) than those of control at days 1 and 3 of storage, however, statistical significance was not found (p>0.05) among the samples after 7 days of storage. In conclusion, tomato powder-treated groups were significantly higher in redness ($a^*$) and yellowness ($b^*$), and lipid oxidation was inhibited, as compared with control during storage. Therefore, as a natural additive, tomato powder could be used to extend the self-life of meat products, providing the consumer with food containing natural additives, which might be seen more healthful than those of synthetic origin.

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.159-169
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• 2019

Objective: Models for genomic selection assume that the reference population is an unselected population. However, in practice, genotyped individuals, such as progeny-tested bulls, are highly selected, and the reference population is created after preselection. In dairy cattle, the intensity of selection is higher in males than in females, suggesting that cows can be added to the reference population with less bias and loss of accuracy. The objective is to develop formulas applied to any genomic prediction studies or practice with preselected animals as reference population. Methods: We developed formulas for calculating the reliability and bias of genomically enhanced breeding values (GEBV) in the reference population where individuals are preselected on estimated breeding values. Based on the formulas presented, deterministic simulation was conducted by varying heritability, preselection percentage, and the reference population size. Results: The number of bulls equal to a cow regarding the reliability of GEBV was expressed through a simple formula for the reference population consisting of preselected animals. The bull population was vastly superior to the cow population regarding the reliability of GEBV for low-heritability traits. However, the superiority of reliability from the bull reference population over the cow population decreased as heritability increased. Bias was greater for bulls than cows. Bias and reduction in reliability of GEBV due to preselection was alleviated by expanding reference population. Conclusion: Cows are easier in expanding reference population size compared with bulls and alleviate bias and reduction in reliability of GEBV of bulls which are highly preselected than cows by expanding the cow reference population.

• 한국구조물진단유지관리공학회 논문집
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• 제23권1호
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• pp.154-162
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• 2019

세계적으로 지진과 같은 자연재해로 인한 대규모 피해가 증가하고 있다. 다양한 연구를 통하여 건물에 대한 내진성능은 확보되었으나, 비구조요소의 내진성능 확보 미흡으로 인하여 인명 피해 및 경제적 손실이 발생하고 있다. 비구조요소는 구조물에 설치되는 위치가 다양하고, 구조물의 위치에 따라 발생하는 진동특성이 다르므로 구조물의 위치별 응답스펙트럼이 필요하다. 또한 구조물의 형식과 구조물이 설치되는 위치에 따라 구조물에 발생하는 응답스펙트럼이 다르게 발생한다. 따라서 응답스펙트럼의 선정이 중요하므로 비구조요소에 작용하는 응답스펙트럼을 도출할 수 있는 명확한 방법이 필요하다. 본 논문에서는 응답스펙트럼을 도출하는 방법을 제안하였으며, 제안한 방법으로 국내에서 발생 가능한 지반응답스펙트럼과 구조시스템을 선정하여 구조해석을 수행하였다. 또한, 간단한 수식으로 응답스펙트럼을 도출하는 방법을 제안함으로서, 비구조요소의 내진시험에 필요한 응답스펙트럼을 생성할 수 있도록 하였다.

• 한국재료학회지
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• 제29권8호
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• pp.469-476
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• 2019

A lead-free bulk ceramic having a chemical formula $Ba_{0.8}Ca_{0.2}(Ti_{0.8}Zr_{0.1}Ce_{0.1})O_3$ (further termed as BCTZCO) is synthesized using mixed oxide route. The structural, dielectric, impedance, and conductivity properties, as well as the modulus of the synthesized sample are discussed in the present work. Analysis of X-ray diffraction data obtained at room temperature reveals the existence of some impurity phases. The natural surface morphology shows close packing of grains with few voids. Attempts have been made to study the (a) effect of microstructures containing grains, grain boundaries, and electrodes on impedance and capacitive characteristics, (b) relationship between properties and crystal structure, and (c) nature of the relaxation mechanism of the prepared samples. The relationship between the structure and physical properties is established. The frequency and temperature dependence of the dielectric properties reveal that this complex system has a high dielectric constant and low tangent loss. An analysis of impedance and related parameters illuminates the contributions of grains. The activation energy is determined for only the high temperature region in the temperature dependent AC conductivity graph. Deviation from the Debye behavior is seen in the Nyquist plot at different temperatures. The relaxation mechanism and the electrical transport properties in the sample are investigated with the help of various spectroscopic (i.e., dielectric, modulus, and impedance) techniques. This lead free sample will serve as a base for device engineering.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.396-408
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• 2019

The tubes which are applied in jacket platforms as the supporting structure might be collided by supply vessels. Such kind of impact will lead to plastic deformation on tube members. As a result, the ultimate strength of tubes will decrease compared to that of intact ones. In order to make a decision on whether to repair or replace the members, it is crucial to know the residual strength of the tubes. After being damaged by lateral impact, the simply supported tubes will definitely loss a certain extent of load carrying capacity under uniform axial compression. Therefore, in this paper, the relationship between the residual ultimate strength of the damaged circular tube by collision and the energy dissipation due to lateral impact is investigated. The influences of several parameters, such as the length, diameter and thickness of the tube and the impact energy, on the reduction of ultimate strength are investigated. A series of numerical simulations are performed using nonlinear FEA software LS-DYNA. Based on simulation results, a non-dimensional parameter is introduced to represent the degree of damage of various size of tubes after collision impact. By applying this non-dimensional parameter, a simplified formula has been derived to describe the relationship between axial compressive residual ultimate and lateral impact energy and tube parameters. Finally, by comparing with the allowable compressive stress proposed in API rules (RP2A-WSD A P I, 2000), the critical damage of tube due to collision impact to be repaired is proposed.

• The Plant Pathology Journal
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• 제37권3호
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• pp.215-231
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• 2021

Brown leaf spot disease caused by Nigrospora guilinensis on Phellodendron chinense occurs in a large area in Dayi County, Chengdu City, Sichuan Province, China each year. This outbreak has severely reduced the production of Chinese medicinal plants P. chinense and caused substantial economic losses. The bacterial isolate JKB05 was isolated from the healthy leaves of P. chinense, exhibited antagonistic effects against N. guilinensis and was identified as Bacillus megaterium. The following fermentation medium and conditions improved the inhibitory effect of B. megaterium JKB05 on N. guilinensis: 2% glucose, 0.1% soybean powder, 0.1% KCl, and 0.05% MgSO₄; initial concentration 6 × 10⁶ cfu/ml, and a 42-h optimal fermentation time. A composite of 0.1% nano-SiO₂ JKB05 improved the thermal stability, acid-base stability and ultraviolet resistance by 16%, 12%, and 38.9%, respectively, and nano-SiO₂ was added to the fermentation process. The best formula for the wettable powder was 35% kaolin, 4% polyethylene glycol, 8% Tween, and 2% humic acid. The following quality test results for the wettable powder were obtained: wetting time 87.0 s, suspension rate 80.33%, frequency of microbial contamination 0.08%, pH 7.2, fineness 95.8%, drying loss 1.47%, and storage stability ≥83.5%. A pot experiment revealed that the ability of JKB05 to prevent fungal infections on P. chinense increased considerably and achieved levels of control as high as 94%. The use of nanomaterials significantly improved the ability of biocontrol bacteria to control this disease.

• 한국터널지하공간학회 논문집
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• 제12권3호
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• pp.223-237
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• 2010

본 연구에서는 화재에 의한 콘크리트의 단면손실과 역학적 특성을 저하하는 주요 요인 가운데 온도증가율, 즉 초기가열구배를 변화시키면서 모의화재실험을 수행하였다. 그리고 수행된 모의화재실험에서 관찰된 단면손실을 모사하기 위하여 요소제거모델을 활용한 유한요소해석법에 의해 열전달해석을 수행하였다. 이때 모의화재실험결과와 수치해석결과가 가장 일치하는 대류열전달계수를 반복적인 해석과정을 통해 도출하였다 이상의 과정으로부터 얻어진 초기가열구배에 따른 대류열전달계수의 변화를 조사한 결과, 각 초기가열구배별 대류열전달계수의 변화는 분수함수 형태로 근사시킬 수 있었다. 최종적으로 모의화재실험으로부터 도출된 초기가열구배별 대류열전달계수의 변화 결과를 내삽하여 다양한 초기가열구배에 따른 화재경과시간별 대류열전달계수의 변화를 추정할 수 있는 수식을 함께 제시하였다.