• Journal of Advanced Marine Engineering and Technology
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• 제29권4호
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• pp.436-442
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• 2005

Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices. In this paper, characteristics on oscillating heat pipe according to operating conditions (environment temperature, charging ratio of working fluid, inclination) based on experimental study was investigated From the experimental results $25^{\circ}C$(environment temperature) R-141b (working fluid) $40\%$ (charging ratio) was best performace at others of inclination angle and the top heating mode of OCHP performed $80\%$ efficiency of the bottom heating mode.

• 약학회지
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• 제24권2호
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• pp.135-141
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• 1980

The crystal and molecular structure of 2-methyl-3-(N-trimethyl ammonium)phenol iodide, $C_{10}H_{16}NOI, was determined by X-ray diffraction method. The compound crystallizes in the orthorhombic space group $P_{na2}_{1}$ with a=13.327(3), b=12.496(3), C=7.227(2)A and Z=4. A total of 489 independent observed reflections were collected by the automated Four-circle diffractometer and was solved by heavy atom method and refined by anisotropic block-diagonal least-squares method to the R value of 0.04. The benzene ring is slightly distorted from regular hexagon. The I atom and 2-methyl-3-(N-trimethyl ammonium)phenol group is held together by van der Waals forces in the crystal. Intermolecular hydrogen bond is of the type O-H....I with the length 3.35.angs.. Apart from the hydrogen bonding system the molecules are held together by van der Waals forces in the crystal.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권2호
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• pp.73-81
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• 2003

The performance of heat exchanger using oscillating heat pipe (OHP) for low temperature waste heat recovery was evaluated. OHP used in this study was made from low finned copper tubes connected by many turns to become the closed loop of serpentine structure. The OHP heat exchanger was formed into shell and tube type. R-22 and R-141b were used as the working fluids of OHP with a fill ratio of 40 vol.%. Water was used as the working fluid of shell side. As the experimental parameters, the inlet temperature difference between heating and cooling water and the mass velocity of water were changed. The mass velocity of water was changed from 30 kg/$m^2$s to 92 kg/$m^2$s. The experimental results showed that the heat recovery rate linearly increased as the mass velocity and the inlet temperature difference of water increased. Finally, the performance of OHP heat exchanger was evaluated by $\varepsilon$-NTU method. It was found that the effectiveness would be 80% if NTU were about 1.5.

• 한국토양비료학회지
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• 제49권6호
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• pp.743-750
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• 2016

Recently, usage of UAV (Unmanned Aerial Vehicle) has increased in agricultural part. This study was conducted to classify onion and garlic using supervised classification of a fixed-wing UAV (Model : Ebee) images for evaluation of possibility about estimation of onion and garlic cultivation area using UAV images. Aerial images were obtained 11~12 times from study sites in Changryeng-gun and Hapcheon-gun during farming season from 2015 to 2016. The result for accuracy in onion and garlic image classification by R-G-B and R-G-NIR images showed highest Kappa coefficients for the maximum likelihood method. The result for accuracy in onion and garlic classification showed high Kappa coefficients of 0.75~0.97 from DOY 105 to DOY 141, implying that UAV images could be used to estimate onion and garlic cultivation area.

• 설비공학논문집
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• 제13권5호
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• pp.368-376
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• 2001

Performance of heat exchanger was evaluated to heat exchanger using oscillating heat pipe for waste heat recovery of low temperature. Oscillating heat pipe used in this study was formed to the closed loop of serpentine shapes using copper tubes. Heat exchanger was formed to shell and tube type and composed of low finned tube. R-22 and R-141b were used to the working fluids of tube side and their charging ratio was 40%. And, water was used to the working fluid of shell side. As the experimental parameters, the inlet temperature difference of heating and cooling part of secondary fluid and the mass velocity of secondary fluid were used. The mass velocity of secondary fluid was changed from 90 kg/$m^2s\; to\;190 kg/m^2$s from the experimental results, heat recovery rate was linearly increased to the increment of the mass velocity of secondary fluid and the inlet temperature difference of secondary fluid. Finally, the performance of heat exchanger was evaluated by using $\varepsilon$-NTU method. It was found that NTU was about 1.5 when effectiveness was decided to 80%.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.141-151
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• 2002

The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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• pp.138-141
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• 2002

The channel of the superconducting Flux Flow Transistor has been fabricated with plasma etching method using ICP. The ICP conditions were 700 W of ICP power, 150 W of rf chuck power, 5 mTorr of the pressure in chamber and 1:1 of Ar : $Cl_2$, respectively. The channel etched by plasma gas showed superconducting characteristics of over 77 K and superior surface morphology. The critical current of SFFT was altered by varying the external applied current. As the external applied current increased from 0 to 12 mA, the critical current decreased from 28 to 22 mA. Then the obtained $r_m$ values were smaller than $0.1\Omega$ at a bias current of 40 mA. The current gain was about 0.5. Output resistance was below $0.2\Omega$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1034-1038
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• 1995

The purpose of this study is to research and develop $TiS_2$ composite cathode for lithium polymer battery(LPB). $TiS_2$ electrode represent a class of insertion positive electrode used in Li secondary batteries. In this study, we investigated preparation of $TiS_2$ composite cathode and AC impedance response of $TiS_2$ composite/SPE/Li cells as a function of state of charge(SOC) and cycling. The resistance of B type cell using $TiS_2PEO_8LiClO_4PC_5EC_5$ composite cathode was lower than that of A type cell using $TiS_2PEO$ composite cathode. The cell resistance of B type cell is high for the first few percent discharge, decreases for midium discharge and then increases again toward the end of discharge. We believe the magnitude of the cell resistance is dominated by passivation layer impedance and small cathode resistance. AC impedance results indicate that the cell internal resistance increase with cycling, and this is attributed to change of passivation layer impedance with cycling. The passivation layer resistance($R_f$) of B type cell decreases for the 2nd cycling and then increases again with cycling. Redox coulombic efficiency of B type cell was about 141% at 1st cycle and 100% at 12th cycle. Also, $TiS_2$ specific capacity was 115 mAh/g at 12 cycle.

• Journal of Animal Science and Technology
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• 제45권5호
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• pp.689-694
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• 2003

출산기술연구소 대관령지소에서 출생한 한우 암소로부터 시간적인 간격을 두고 조사된 체중측정 기록에 대해 비선형의 성장곡선 모형을 적용하여 한우 암소의 개체별 성장곡선 모수를 추정하고 개체별로 추정된 모수를 이용하여 한우 암소의 정확한 성장형태를 추정하기 위해 실시하였다. Gompertz 모형으로 추정한 개체별 성장 곡선 모수 A, b 및 k의 평균치는 각각 383.42${\pm}$97.29kg, 2.374${\pm}$0.340 및 0.0037${\pm}$0.0012였으며, 개체별 변곡점의 평균은 255.63${\pm}$109.09일, 변곡점에서 체중의 평균은 141.05${\pm}$35.79kg, 변곡점에서의 일당증체량의 평균은 0.500${\pm}$0.123 kg이었고, 성장곡선 모수 A, b 및 k의 변이계수는 각각 25.3, 14.3 및 32.4%이었다. von Bertalanffy 모형으로 추정한 개체별 성장곡선 모수 A, b 및 k의 평균치는 각각 410.47${\pm}$117.98kg, 0.575${\pm}$0.057 및 0.003${\pm}$0.001이었고, 개체별 변곡점의 평균은 211.02${\pm}$105.53일, 변곡점에서 체중의 평균은 121.62${\pm}$34.94kg, 최대 증체율의 평균은 0.504${\pm}$0.124kg이었으며, 성장곡선 모수 A, b 및 k의 변이계수는 각각 28.7, 9.9 및 33.3%로 추정되었다. Logistic 모형으로 추정한 개체별 성장곡선 모수 A, b 및 k의 평균치는 각각 347.64${\pm}$97.29kg, 6.73${\pm}$0.34 및 0.006${\pm}$0.0018이었고, 개체별 변곡점의 평균은 324.47${\pm}$3.87일, 변곡점에서 체중의 평균은 173.82${\pm}$1.13kg, 최대 증체율의 평균은 0.508${\pm}$0.003kg이었으며, 성장곡선 모수 A, b 및 k의 변이계수는 각각 27.9, 5.0 및 30.0%이었다. Gompertz 모형, von Bertalanffy 모형 및 Logistic 모형에 의해 추정된 생시체중의 평균치들은 각각 36.40${\pm}$0.33, 31.59${\pm}$0.34 및 49.09${\pm}$0.88kg으로 추정되어 실제체중 23.73${\pm}$0.10kg 보다 컸으며 36개월 체중의 경우 세 모형이 각각 349.73${\pm}$2.01, 356.41${\pm}$2.07 및 336.18${\pm}$1.91kg으로 실제체중 363.67${\pm}$2.08kg보다 작았다. 그러나 세 모형으로 추정된 변곡점이 한우 암소의 실질적인 변곡점인지에 대해서는 좀더 검토가 필요한 부분인데, 최(2001)는 한우 암소의 경우 3개월령에서 4개월령 사이의 일당증체량이 0.590으로서 이 시기에 최대의 성장이 이루어지며 3개월령 체중과 4개월령 체중은 각각 79.31 및 98.91kg이라고 보고하고 있으며, 본 연구에서 Table 4에 제시된 결과를 봐도 3개월령과 6개월령 사이 90일 동안에 50.89kg의 증체가 이루어져 일당증체량으로 환산하면 약 0.56kg이 되어 다른 어느 시기보다도 가장 증체속도가 빠른 시기인 것으로 나타났다. 변곡점이 일당증체량이 최대인 시점으로 해석한다면 각 모형에서 고정되어 있는 변곡점의 위치들인 성숙체중의 38.6%(Gompertz 모형), 29.6% (von Bertalanffy 모형) 및 50%(Logistic 모형)는 한우 암소의 실질적인 변곡점보다 늦는 것으로 판단할 수 있는데, 실제로 세 모형 중 변곡점의 위치가 제일 빠른 von Bertalanffy 모형의 적합도가 제일 좋은 것도 이러한 이유 때문일 수 있다. 따라서 한우 암소의 정확한 성장특성을 파악하기 위해서는 변곡점의 위치가 고정되어 있지 않은 기존의 모형들을 이용하는 방안과 아울러 본 연구에 이용된 모형들을 변형시켜 활용하는 방안에 대한 연구가 필요한 것으로 판단된다.

• 화훼연구
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• 제17권2호
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• pp.141-145
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• 2009

동절기 산취(Chamecereus silvestrii) '희망'의 주 야 온도를 달리하며 처리한 결과 초장은 주간온도 $20^{\circ}C$와 야간온도 $15^{\circ}C$에서 가장 크게 나타났다. 구경은 주간온도 $25^{\circ}C$에서 구직경과 구고의 생육이 우수하였고, 주간온도 $25^{\circ}C$에서는 모든 야간온도에서 구직경 생육이 양호하였으며 구고는 주간온도 $25^{\circ}C$에서는 $20^{\circ}C$에 비해 야간온도가 $25^{\circ}C$로 높을수록 생육이 좋았다. 주 야간온도 조합의 합산온도가 높을수록 구직경과 구고신장이 증가하는 경향을 나타났다. 색도에서 Hunter 'a' 값은 야간온도가 높을수록 낮아졌으나 'b' 값은 높아져 야간온도가 높으면 탁도가 증가하였다. 또한 구직경과 구고변화의 증가가 다시 시작되는 기점은 정식 후 15일로 나타났다.