• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1557-1563
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• 2005

Ovarian follicular fluid contains both stimulatory and inhibitory agents that influence the growth and maturation of oocyte. In the present study, an attempt was made to isolate and study the biological properties of ovarian follicular fluid peptide(s) in buffaloes. Bubaline ovarian follicular was made steroid- and cell-free. A protein fraction was obtained by saturation (30-35% level) of the follicular fluid with ammonium sulfate. The protein fraction was purified with Sephadex-G 50 gel filtration chromatography and a single peak was obtained in the eluant volume, which was lyophilized. SDS-PAGE of the lyophilized fraction revealed a single band and the molecular weight of the peptide was 26.6 kDa. The peptide stimulated the cumulus cell expansion and in vitro maturation rate of oocytes in buffaloes in a dose dependent manner when it was incorporated at different dose levels (0, 10, 25, 50, 100 and 1,000 ng $ml^{-1}$ of maturation medium). The basic culture medium consisted of TCM 199 with Bovine serum albumin (0.3%). The in vitro maturation rates were comparable to those obtained with a positive control medium (TCM 199+20 ng EGF $ml^{-1}$+steer serum (20%)). Further purification and biological assays may throw more light on the nature and functions of this peptide.

• 설비공학논문집
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• 제16권5호
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• pp.444-451
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• 2004

Flow condensation heat transfer coefficients (HTCs) of R22, R134a, R407C, and R410A were measured on horizontal plain and microfin tubes. The experimental apparatus was composed of three main parts; a refrigerant loop, a water loop and a water/glycol loop. The test section in the refrigerant loop was made of both a plain and a microfin copper tube of 6.0∼6.16 mm inside diameter and 1.0 m length. Refrigerants were cooled by passing cold water through an annulus surrounding the test section. Tests were performed at a fixed refrigerant saturation temperature of 4$0^{\circ}C$ with mass fluxes of 100, 200, and 300 kg/m2s. Test results showed that at similar mass flux the flow condensation HTCs of R134a were similar to those of R22 for both plain and microfin tubes. On the other hand, HTCs of R407C were lower than those of R22 by 4∼16% and 16∼42% for plain and microfin tubes respectively. And HTCs of R410A were similar to those of R22 for a plain tube but lower than those of R22 by 3∼9% for a microfin tube. Heat transfer enhancement factors of a microfin tube were 1.3∼1.9.

• 방송공학회논문지
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• 제18권4호
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• pp.550-558
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• 2013

가시광 영상과 원적외선 영상은 각각 질감 정보와 열 정보를 가지므로 서로 다른 정보를 표현한다. 그러므로 가시광 영상 개선을 위해 가시광 영상의 정보만을 이용하는 것보다 가시광 영상에서 존재하지 않는 원적외선 영상의 열 정보를 이용하는 것이 보다 좋은 결과를 얻을 수 있다. 본 논문에서는 원적외선 영상을 이용한 효과적인 가시광 영상 개선을 위해 가시광 영상에서 개선이 필요한 정도에 따라 가중치 맵을 만든다. 가중치 맵은 채도와 밝기를 이용하여 계산하며 원적외선 영상에서 열 정보를 고려하여 값을 조정한다. 마지막으로 조정된 가중치 맵을 이용하여 원적외선 영상의 정보와 가시광 영상의 정보를 융합함으로써 두 영상의 정보를 효과적으로 포함한 결과 영상을 생성한다. 실험결과에서는 가시광 영상에서 개선이 필요한 영역을 원적외선 영상 정보와의 융합으로 원본의 가시광 영상보다 향상된 결과를 보여준다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권3호
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• pp.1043-1064
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• 2020

A kind of Subjective Imaging Effect Assessment (SIEA) method and its applications on intelligent imaging terminal design in engineering site are presented. First, some visual assessment indices are used to characterize the imaging effect: the image brightness, the image brightness uniformity, the color image contrast, the image edge blur, the image color difference, the image saturation, the image noise, and the integrated imaging effect index. A linear weighted function is employed to carry out the SIEA computation and the Analytic Hierarchy Process (AHP) technique is used to estimate its weights. Second, a SIEA software is developed. It can play images after the settings of assessment index or assessment reaction time, etc. Third, two cases are used to illustrate the application effects of proposed method: the image enhancement system design for surveillance camera and the imaging environment perception system design for intelligent lighting terminal. A Prior Sequential Stimulus (PSS) experiment is proposed to improve the evaluation stability of SIEA method. Many experiment results have shown the proposed method can realize a stable system design or parameters setting for the intelligent imaging terminal in engineering site.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E1호
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• pp.10-15
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• 2007

The gas hydrates are probably most sensitive to climate change since they are stable only under specific conditions of high pressure and low temperature. One of the main factors responsible for formation of gas hydrates is the saturation of the gases with water vapor. Quantitative phase equilibrium data and understanding of the roles of water component in the phase behavior of the heterogeneous water-hydrocarbon-hydrate mixture are of importance and of engineering value. In this study, the water content of ethylene gas in equilibrium with hydrate and water phases were analyzed by theoretical and experimental methods at temperatures between 274.15 up to 291.75 K and pressures between 593.99 to 8,443.18 kPa. The experimental and theoretical enhancement factors (EF) for the water content of ethylene gas and the fugacity coefficients of water and ethylene in gas phase were determined and compared with each other over the entire range of pressure carried out in this experiment. In order to get the theoretical enhancement factors, the modified Redlich-Kwong equation of state was used. The Peng-Robinson equations and modified Redlich-Kwong equations of state were used to get the fugacity coefficients for ethylene and water in the gas phase. The results predicted by both equations agree very well with the experimental values for the fugacity coefficients of the compressed ethylene gas containing small amount of water, whereas, those of water vapor do not in the ethylene rich gas at high temperature for hydrate formation locus.

• 수산해양교육연구
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• 제5권2호
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• pp.119-127
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• 1993

This work studies for heat transfer and pressure drop performance of integral inner and outer fin tubes, designed to enhance the heat transfer performance of smooth tubes for in recipro and turbo refrigerator or high performance compact heat exchangers. Eight different inner spiral fin copper tubes with integral fin at outside surfaces were employed to improve boiling heat transfer coeffcient. For comparison, tests were made using a plain tube having the inside diameter and an outside diameter equal to that at the root of the fins for the finned tubes. Pool boiling heat transfer is investigated experimentally and theoretically on single tube arrangement. The refrigerant evaporates at a saturation state of 1 bar on the outside tube surface heated by hot water. The refrigerant R11 ($CFCl_3$) was used at a pressure of $P_s=1bar$ as a convenient test fluid with a boiling temperature of $T_s=23.6^{\circ}C$. The observed heat transfer enhancement of boiling for finned tubes significantly exceeded that to be expected on grounds of increased area. The maximum Vapor - side enhancement(i.e., vapor - side heat transfer coefficient of finned tube/vapor - side coefficient for plain tube) was found to be around 4 at 1299fpm - 30grooves tube.

• 반도체디스플레이기술학회지
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• 제12권3호
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• pp.23-27
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• 2013

This paper is for enhancing the breakdown voltage of MHEMTs with an InP-etchstop layer. Gate-recess structures has been simulated and analyzed for the breakdown of the devices with the InP-etchstop layer. The fully removed recess structure in the drain side of MHEMT shows that the breakdown voltage enhances from 2V to almost 4V and that the saturation current at gate voltage of 0V is reduced from 90mA to 60mA at drain voltage of 2V. This is because the electron-captured negatively fixed charges at the drain-side interface between the InAlAs barrier layer and the $Si_3N_4$ passivation layer deplete the InGaAs channel layer more and thus decreases the electron current passing the channel layer. In the paper, the fully-recessed asymmetric gate-recess structure at the drain side shows the on-breakdown voltage enhancement from 2V to 4V in the MHEMTs.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.192-194
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• 2003

Since the details in quasi-homogeneous region will be destroyed from the conventional global image enhancement method such as histogram equalization. This defect is caused by the saturation of gray level in equalization process. So the local histogram equalization for each quasi-homogeneous region will be used in order to improve the details in the region itself. To obtain the quasi- homogeneous regions, the original image must be segmented. Here we applied the watershed transform to the interesting image. Since the watershed transform is based on mathematical morphology, therefore, the regions touch can be effectively separated. Hence two adjacent regions which have the similar gray pixels will be split off. The process will be independently applied to three different spectral images. Then three different colors are assigned to each processed image in order to produce a color composite image. By the proposed algorithm, the result image shows the better perception on image details. Therefore, the high efficiency of image classification can be obtained by using this color image.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.525-528
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• 2004

The photoluminescence (PL) emission of Si nanocrystals synthesized by 400 keV Si ion implanted in $SiO_2$ is studied as a function of ion dose and annealing time. The formation of nanocrystals at around 600 nm from the surface was confirmed by RBS and HRTEM, and the Si nanocrystals showed a wide and very intense PL emission at 700-900 nm. The intensity of this emission showed a typical behaviour with a fast transitory increase to reach a saturation with the annealing time, however, the red shift increased continuously because of the Ostwald ripening. The oversaturation of dose derived a decrease of PL intensity because of the diminishment of quantum confinement. A strong enhancement of PL intensity by H passivation was confirmed also, and the possible mechanism is discussed.

• 한국컴퓨터산업학회논문지
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• 제6권5호
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• pp.783-790
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• 2005

In this paper, we have simulated a Symmetric Dual-gate Single-Si TFT which has three split floating n+ zones. This structure reduces the kink-effect drastically and improves the on-current. Due to the separated floating n+ zones, the transistor channel region is split into four zones with different lengths defined by a floating n+ region, This structure allows an effective reduction of the kink-effect depending on the length of two sub-channels. The on-current of the proposed dual-gate structure is 0.9mA while that of the conventional dual-gate structure is 0.5mA at a 12V drain voltage and a 7V gate voltage. This result shows a 80% enhancement in on-current. Moreover we observed the reduction of electric field in the channel region compared to conventional single-gate TFT and the reduction of the output conductance in the saturation region. In addition, we also confirmed the reduction of hole concentration in the channel region so that the kink-effect reduces effectively.