• Archives of Pharmacal Research
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• 제27권11호
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• pp.1114-1119
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• 2004

This paper describes the quantitative determination of flavonoids, tannins and ellagic acid in the leaves from wild and cultivated variations of Rubus L. species (Rosaceae): raspberry (2 wild and 13 cultivars) and blackberry (3 wild and 3 cultivars). The content of flavonoids was analyzed using spectrophotometric (the Christ-M llers method) and HPLC analysis after acid hydrolysis. The content of tannins was determined by the weight method, with hide powder, described by German Pharmacopoeia 10 (DAB 10). Ellagic acid content was examined using the HPLC method after acid hydrolysis. Flavonoid content, determined using the Christ-Muller's method was higher for the blackberry leaves than for the raspberry leaves and varied between 0.46% and 1.05%. Quercetin and kaempferol were predominant in all samples analyzed using the HPLC method. The highest flavonoid content was found in the leaves of R. nessensis (1.06%); with results in all of the examined samples varying between 0.27% and 1.06%. The concentration of ellagic acid in all species was determined after acid hydrolysis and ranged from 2.06% to 6.89%. The leaves of raspberries are characterized by greater amounts of tannins (varying between 2.62% and 6.87%) than the leaves of other species. The results from this study indicate that the analyzed species are a rich source of flavonoids, ellagic acid and tannins, which may be used for the quality assessment of Rubus L. species leaves.

• 한국언론정보학보
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• 제26권
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• pp.135-156
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• 2004

현재 DMB 도입은 관련 사업자들의 요구와 당국의 정책적 추진방침이 맞물려 일종의 속도경쟁식으로 전개되고 있다. 이러한 와중에서 DMB 도입논리에 허점은 없는지, DMB라는 메체의 정체성과 사회적 의미에 대한 이하는 충분한지, 도입정책의 수립과 집행과정에 문제는 없는지 등의 문제인식과 그에 대한 논의는 상대적으로 간과되고 있다. 첫번째의 문제는 DMB 도입의 근거가 충분하게 타당한 것인가라는 차원에서, 두 번째의 문제는 새로운 매체와 기술을 도입함에 있어 요구되는 매체와 기술의 사회문화적 파장에 대한 신중한 이해를 가지고 있는가라는 차원에서, 세번째의 문제는 새로운 매체와 기술도입의 초기조건 형성이 적절하게 이루어지고 있는가라는 차원에서 중요한 과자들이다. 이 연구는 이러한 세 가지 측면에 초점을 두고 DMB 관련 정책을 반성적으로 살펴보고자 한다.

• 무역상무연구
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• 제27권
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• pp.3-28
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• 2005

It is common that several kind of claims between the parties are arising in carrying out international construction works. Therefore, it is very important for them to settle the claims effectively in order to get expected profits and purposes in international construction works. In this article, the author have studied on the procedures and contents on the settlement of claims between the parties based on the FIDIC contracts for major works which are newly prepared in 1999 by FIDIC. Especially, the arbitration clause in the FIDIC contracts for major works attempts to deal with a number of complex contractual and legal matters, sometimes in a very harsh way, e.g. by cutting off a party's rights. It has never been an easy clause to understand or to observe. Nevertheless, the author hopes he has been able in this article to clarify for the reader some of the issues raised by it. I'd like to suggest that our overseas construction companies refer to the FIDIC contracts for major works(especially article 20 : claims, disputes and arbitration) directly or indirectly for their contract of international construction works with overseas employers.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.370-374
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• 2002

Administration of dopamine agonist, apomorphine (2 mg/kg, s.c.), produces cage climbing behavior in mice that exhibit typical dopaminergic stimulation. The present study investigated the pCREB expression level in several brain regions following apomorphine treatment in order to determine whether the increased the dopaminergic activation produced by apomorphine accompanies the changes in pCREB immunoreactivity. A mouse brain was removed at 0min, 10 min, 30 min, 1 h, 2 h, 7 h, and 24 h after apomorphine treatment. The brain tissue was fixed by an intracardiac perfusion with ice-cold 4％ paraformaldehyde in PBS. Immunohistochemical study was conducted using the ABC-DAB method. The data showed that the immunoreactivity of pCREB increased in the striatum, nucleus-accumbens, piriform cortex and the dentate gyrus of the hippocampus of a mouse brain 30 min after the apomorphine treatment. Increased immunoreactivity began to diminish 2 h after the apomorphine treatment in all the brain regions measured. The time course for the pCREB immunoreactivity was similar to the behavioral response induced by the apomorphine treatment. These results suggest that activation of the dopamine receptor is accompanied by an increase in pCREB expression in the mouse brain.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.289-291
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• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the uses by the various portable terminals in the mobile environment. Integrated complex reception platform is required to receive multimedia broadcasting services transmitted from various transmission media. In this paper, we present the design and implementation technic for providing the both of terrestrial and satellite DMB services simultaneously using the same hardware platform. The implemented complex receiving terminal to accommodate these DMB services simultaneously need composed of it RF module. it baseband module, it complex control module and the complex de-multiplexer module. The complex control module is designed using uClinux operating system. The complex de-multiplexer, which perform the functions of the address decoder and each DMB stream de-multiplexer, is implemented. with FPGA device. The implemented platform is tested in a real environment and its performance is satisfied with required performance criteria.

• 대한화학회지
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• 제24권3호
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• pp.225-232
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• 1980

化學發癌物質인 縮合炭化水素, 헤테로고리化合物 그리고 디메틸아미노아조벤젠 및 그의 유도체들의 電子狀態를 HMO로 調査하고 그들의 發癌活性을 論議하였다. K-領域의 두 原子와 그의 이웃한 L-領域의 原子들의 親核反應의 프론티어 전자밀도의 合의 값이 0.5 以上인 化合物들은 發癌活性에 있어서 實驗結果와 一致함을 알았다. 따라서 K-領域과 L-領域이 發癌作用의 첫단계로서 化學發癌物質과 生體成分과의 結合이 얻어진다는 것이 보고되어 있는 分子錯物의 形成에 重要한 役割을 한다고 생각한다.

• BMB Reports
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• 제28권6호
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• pp.504-508
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• 1995

The electrophoretic patterns of plasma membrane surface proteins of normal rat liver cells and rat hepatomas were compared in 10% non-denaturing and 7-15% gradient non-denaturing gel. Chemical carcinogens, 2-Me DAB (2-methyl-4-dimethylaminoazobenzene) and DENA (diethylnitrosamine), were used to induce hepatoma in rats. One protein which disappeared in hepatoma was identified in normal rat liver by non-denaturing gel electrophoresis. Rabbit antisera were raised against this specific protein, and the protein was purified by Sephacryl S-200 column and immunoaffinity chromatography using the purified antibody. The purified protein showed two bands of molecular weights approximately 50 $kD_{\alpha}$ and 52 $kD_{\alpha}$ by SDS-polyacrylamide gel electrophoresis, which reacted specifically with the antibody. However only one band was observed in non-denaturing gel and also in isoelectric focusing with a pI value of 6.6. This study showed the existence of an unique protein on the plasma membrane surface of normal rat liver cells which disappeared in rat hepatomas induced by chemical carcinogens.

• 한국통신학회논문지
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• 제35권8B호
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• pp.1188-1196
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• 2010

본 논문에서는 DMB 방송장치의 대역외발사강도에 대한 국내외 기준을 고찰하였으며, 10mW/MHz 이하의 지상파 소출력 중계기 방사 마스크 요구조건들을 분석하였다. 이를 토대로 소출력 DMB 중계기에 적합한 대역외방사특성 기준을 제안하였으며, 3개 블록들을 포함하는 멀티블록 중계기에 대한 기준도 함께 제안하였다. 제안된 기술기준의 타당성 및 유용성은 다양한 실험들을 통하여 입증하였다. 제안된 기술기준값을 이용하면 DMB 중계기의 소형화 및 저가화가 가능하며, 향후 DMB 음영지역 해소를 통한 방송구역 확대 등에 유용하게 사용될 수 있다.

• Journal of Power Electronics
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• 제15권1호
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• pp.18-30
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• 2015

This paper focuses on a systematical and in-depth analysis of the reactive power and soft-switching regions of Dual Active Bridge (DAB) converters with dual-phase-shift (DPS) control to achieve high efficiency in a wide operating range. The key features of the DPS operating modes are characterized and verified by analytical calculation and experimental tests. The mathematical expressions of the reactive power are derived and the reductions of the reactive power are illustrated with respect to a wide range of output power and voltage conversion ratios. The ZVS soft-switching boundary of the DPS is presented and one more leg with ZVS capability is achieved compared with the CPS control. With the selection of the optimal operating mode, the optimal phase-shift pair is determined by performance indices, which include the minimum peak or rms inductor current. All of the theoretical analysis and optimizations are verified by experimental tests. The experimental results with the DPS demonstrate the efficiency improvement for different load conditions and voltage conversion ratios.

• Journal of Power Electronics
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• 제14권3호
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• pp.468-477
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• 2014

This study proposes an optimized design of a dual active bridge converter for a low-voltage charger in a military uninterrupted power supply (UPS) system. The dual active bridge converter is among various bi-directional DC/DC converters that possess a high-efficiency isolated bi-directional converter. In the general design, the zero-voltage switching(ZVS) region is reduced when the battery voltage is high. By contrast, efficiency is low because of high conduction losses when the battery voltage is low. Variable switching frequency is applied to increase the ZVS region and the power conversion efficiency, depending on battery voltage changes. At the same duty, the same power is obtained regardless of the battery voltage using the variable switching frequency. The proposed method is applied to a 5 kW prototype dual active bridge converter, and the experimental results are analyzed and verified.