• Asian-Australasian Journal of Animal Sciences
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• 제26권5호
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• pp.711-715
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• 2013

To investigate the effect of restricted grazing time on behavior of Tan sheep on desert steppe, forty 4-months old male Tan sheep with an original body weight (BW) of $15.62{\pm}0.33$ kg were randomly allocated to 4 grazing groups which corresponded to 4 different restricted grazing time treatments of 2 h/d (G2), 4 h/d (G4), 8 h/d (G8) and 12 h/d (G12) access to pasture. The restricted grazing times had a significant impact on intake time, resting time, ruminating time, bite rate and movement. As the grazing time decreased, the proportion of time spent on intake, bite rate and grazing velocity significantly (p<0.05) increased, but resting and ruminating time clearly (p<0.05) decreased. The grazing months mainly depicted effect on intake time and grazing velocity. In conclusion, by varying their foraging behavior, Tan sheep could improve grazing efficiency to adapt well to the time-limited grazing circumstance.

• 한국항공우주학회지
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• 제40권4호
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• pp.285-291
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• 2012

본 논문에서는 간섭계 레이더 고도계를 활용한 지형참조항법의 성능을 분석하고자 한다. 간섭계 레이더 고도계는 항체의 주변 지형의 고도 중 가장 높은 값을 측정값으로 취함으로써 항법의 정확성을 향상시키고 있다. 이에 본 연구에서는 간섭계 레이더 고도계의 적용에 따른 새로운 측정 모델을 제시하고 이에 따른 지형참조항법 시스템을 구축하려 한다. 또한 필터에 따른 지형참조항법의 성능 분석을 위하여 확장형 칼만 필터, 무향 칼만 필터, 파티클 필터를 적용하며 여러 환경의 변화에 따른 지형참조항법의 성능을 도출고자 한다.

• Elastomers and Composites
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• 제34권1호
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• pp.11-19
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• 1999

카본블랙 첨가량, 촉진제에 대한 황 함량비에 따른 가황고무의 점탄성 특성을 반발탄성, 저장 및 손실 모듈러스, tan ${\delta}$를 통하여 고찰하였다. 반발탄성은 촉진제에 대한 황 함량비가 낮을수록, 배합고무중 카본-블랙의 체적분율이 낮을수록 높게 나타났다. 저장 모듈러스는 카본블랙 첨가량과 변형이 증가할수록 감소하였으나, 가황시스템과는 무관하게 나타났다. 특히 카본블랙 첨가량이 낮은 수준 ($40{\sim}50phr$)에서는 변형이 3% 이상에서, 첨가량이 높은 수준(60phr 이상)에서는 변형이 6% 이상에서 일정한 저장 모듈러스를 보이고 있어 입자간에 형성되는 망상구조는 6% 이상의 변형에서 파괴됨을 알 수 있다. 손실 모듈러스는 카본블랙 첨가량이 낮은 수준에서는 별다른 영향이 없으나, 높은 수준에서는 1% 변형에서 최대값을 보인 후 완만히 감소하였다. Tan ${\delta}$는 가황시스템에 대한 의존성은 약하나 카본블랙 첨가량 및 변형이 증가함에 따라 증가하였으나, 카본블랙 첨가량에 관계없이 2% 변형에서 최대값을 나타내었다.

• 한국축산식품학회지
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• 제42권4호
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• pp.580-592
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• 2022

The aim of the present study was to evaluate the effectiveness of Lycium barbarum polysaccharide (LBP) on lipid oxidation and protein degradation in Tan sheep meatballs during the frozen period. The meatballs were treated with LBP at 0.01%, 0.02%, and 0.03% and stored at -18±1℃ for 0, 3, 6, 9, and 12 weeks. The effects of LBP treatment were investigated using the contents of total volatile basic nitrogen (TVB-N), texture profile (TP), thiobarbituric acid reactive substances (TBARS), colour, and pH values, compared with 0.02% butylated hydroxytoluene treatment and the blank control. The results showed that LBP treatment significantly decreased TBARS content compared with the control, which confirmed LBP to be a highly effective component in preventing lipid oxidation of Tan sheep meatballs during frozen storage, and protein degradation in Tan sheep meatballs had a significant inhibition effect because of TVB-N value reduction. In addition, the colour, TP and pH values of meatballs treated with LBP were improved dramatically. To further determine the quality changes of the blank control and all treated groups during storage, the comprehensive score evaluation equation based on principal component analysis was obtained: Y=0.51632Y₁+0.29589Y₂ (cumulative contribution rate=81.221%), and the 0.02% LBP-treated group had a higher comprehensive score than the other groups, and the quality of LBP-treated meatballs was better as well. In summary, LBP may reduce or inhibit lipid oxidation and protein degradation, and enhance overall quality and shelf-life in prepared meat products.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1561-1563
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• 2004

In this paper, we researched the dielectric properties and voltage dependence on slice XLPE sheet from 22[kV] and 154[kV] power cable. We studied effects for impurities and water for semiconductor shield through a dielectric properties experiment to estimate performance of insulating materials in power cable. Capacitance and tan${\delta}$ of 22[kV], 154[kV] were 53/43[pF] and $7.4{\times}10^{-4},\;2.1510^{-4}$. In these results, the trend was increased with the increase of temperature. The tan${\delta}$ of XLPF/ semiconductor layer was increased as compared with that of XLPE. Dielectric properties reliability of tan${\delta}$ was small.

• 한국환경과학회지
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• 제8권2호
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• pp.177-182
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• 1999

Nitrifier consortium entrapped in Ca-alginate bead were packed into aerated packed bed bioreactor and non aerated packed bed bioreactor and the performances of two bioreactors were evaluated for the removal of ammonia nitrogen from synthetic aquaculture water. Total ammonia nitrogen(TAN) removal rate was decrease in aerated packed bed bioreactor below 0.3hr of hydraulic residence time(HRT), but increased in non aerated packed bed bioreactor until 0.5hr of HRT. At HRT of 0.05hr, TAN removal rate of non aerated packed bed bioreactor was about 335g TAN/㎥/day and the optimum ratio of packing height and inside diameter of reactor (H/D) was 4. The performance of two bioreactors indicated that non aerated packed bed bioreactor was better than aerated packed bed bioreactor in ammonia removal from synthetic aquaculture water.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.521-522
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• 2011

국내 원자력발전소에 설치되어 있는 고압케이블은 장기 운전에 따라 열화진단 및 유지보수의 필요성이 증대되고 있다. 본 논문에서는 고압케이블의 열화진단에 많이 이용되고 있는 VLF Tan${\delta}$ 기술에 대해 소개하고 원자력발전소에 설치되어 있는 4.16kV급 고압케이블의 건전성을 확인하기 위하여 원자력발전소 계획예방정비 기간 중 VLF Tan${\delta}$ 측정 장비를 사용하여 고압 케이블의 열화진단을 수행한 결과를 기술하였다.

• 한국안전학회지
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• 제9권1호
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• pp.48-55
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• 1994

In this paper, It is studied that the variation of the dielectric absorption of the specimen according to the change with $^{60}$ Co-${\gamma}$ ray irradiation dose of the influence of temperature and applied voltage. In order to investigate the effect of irradiated oriented polypropylene film, we have observed dielectric properties within the temporature range of 30~130 ($^{\circ}C$) and voltage range of 100~250 (V). As for the dependency of temperature by tan $\delta$, the $\alpha$ peak which appears at high temperature increases accordingly to the increment of irradiation dose which is contributed by the crystal region and moves towards the high temperature. The $\beta$ peak which appears the orientation by dipoles and molecular motions in the amorphous region at low temperature. For the dependency of voltage by tan $\delta$ at low temperature, the peak of the tan $\delta$ shifts accordingly to the increment of irradiation dose towards the high temperature region.

• 한국균학회지
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• 제45권4호
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• pp.377-380
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• 2017

In 2015, a new leaf spot disease was observed on strawberry seedlings in Wanju, Korea. Tanned brown spots appeared on the leaves of the infected plants, and often coalesced to form larger necrotic areas, resulting in the death of foliage. An isolate was obtained in pure culture. On the basis of morphological characteristics and molecular analysis of internal transcribed spacer rDNA sequence, the causal agent was identified as Pilidium concavum. Pathogenicity tests revealed the isolate was pathogenic to the leaves and fruits of strawberry. To the best of our knowledge, this is the first report of P. concavum causing tan-brown leaf spot on strawberry in Korea.

• 한국전기전자재료학회논문지
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• 제21권10호
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• pp.896-900
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• 2008

A measurement method of the dielectric constant of materials whose standard sample is not prepared easily is proposed. The unprepared sample of the material is placed in a cavity, and the resonant frequency is measured. A commercial software simulates the same sample and the cavity leading to find the correct dielectric constant. The measured samples include a ceramic, a forced glass, and a powdered enamel. The measured dielectric constant of a ceramic, a forced glass, and a powdered enamel are 11-j0.0033(${\epsilon}_{\gamma}=11,\;tan{\delta}=0.0003$), 4.15-j0.053(${\epsilon}_{\gamma}=4.15,\;tan{\delta}=0.0128$), and 3.9-j0.042(${\epsilon}_{\gamma}=3.9,\;tan{\delta}=0.0108$) respectively.