• BMB Reports
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• 제37권4호
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• pp.422-428
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• 2004

Raw-starch-digesting $\alpha$-amylase (Amyl III) was purified to an electrophoretically pure state from the extract of a koji culture of Aspergillus awamori KT-11 using wheat bran in the medium. The purified Amyl III digested not only soluble starch but also raw corn starch. The major products from the raw starch using Amyl III were maltotriose and maltose, although a small amount of glucose was produced. Amyl III acted on all raw starch granules that it has been tested on. However, it was considered that the action mode of the Amyl III on starch granules was different from that of glucoamylase judging from the observation of granules under a scanning electron microscope before and after enzyme reaction, and also from the reaction products. Glucoamylase (GA I) was also isolated and it was purified to an electrophoretically pure state from the extract. It was found that the electron micrographic features of the granules after treatment with the enzymes were quite different. A synergistic effect of Amyl III and GA I was observed for the digestion of raw starch granules.

• Smart Structures and Systems
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• 제12권5호
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• pp.501-521
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• 2013

This paper is concerned with static and dynamic shape control of a laminated Bernoulli-Euler beam hosting a uniformly distributed array of resistively interconnected piezoelectric patches. We present an analytical one-dimensional model for a laminated piezoelectric beam with material discontinuities within the framework of Bernoulli-Euler and extent the model by a network of resistors which are connected to several piezoelectric patch actuators. The voltage of only one piezoelectric patch is prescribed: we answer the question how to design the interconnected resistive electric network in order to annihilate lateral vibrations of a cantilever. As a practical example, a cantilever with eight patch actuators under the influence of a tip-force is studied. It is found that the deflection at eight arbitrary points along the beam axis may be controlled independently, if the local action of the piezoelectric patches is equal in magnitude, but opposite in sign, to the external load. This is achieved by the proper design of the resistive network and a suitable choice of the input voltage signal. The validity of our method is exact in the static case for a Bernoulli-Euler beam, but it also gives satisfactory results at higher frequencies and for transient excitations. As long as a certain non-dimensional parameter, involving the number of the piezoelectric patches, the sum of the resistances in the electric network and the excitation frequency, is small, the proposed shape control method is approximately fulfilled for dynamic load excitations. We evaluate the feasibility of the proposed shape control method with a more refined model, by comparing the results of our one-dimensional calculations based on the extended Bernoulli-Euler equations to three-dimensional electromechanically coupled finite element results in ANSYS 12.0. The results with the simple Bernoulli-Euler model agree well with the three-dimensional finite element results.

• 전기전자학회논문지
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• 제15권4호
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• pp.305-312
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• 2011

A primary interest of this work is to develop an efficient and powerful repetitive pulser system for the application of ultra wide band generation. The important component of the pulser system is a small-sized coaxial type spark gap with planar electrodes filled with SF6 gas. A repetitive switching action by the coaxial spark gap generates two consecutive pulses in less than a microsecond with rise times of a few hundred picoseconds (ps). A set of several parameters for the repetitive switching of the spark gap is required to be optimized in charging and discharging systems of the pulser. The parameters in the charging system include a circuit scheme, circuit elements, the applied voltage and current ratings from power supplies. The parameters in the discharging system include the spark gap geometry, electrode gap distance, gas type, gas pressure and the load. The characteristics of the spark gap discharge, such as breakdown voltage, output current pulse and recovery rate are too dynamic to control by switching continuously at a high pulse repetition rate (PRR). This leads to a low charging efficiency of the spark gap system. The breakthrough of the low charging efficiency is achieved by a parallel operation of two spark gaps system. The operational behavior of the two spark gaps system is presented in this paper. The work has focused on improvement of the charging efficiency by scaling the PRR of each spark gap in the two spark gaps system.

• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.33-38
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• 2009

근래에 들어 많은 A/V 제품들이 AVRCP의 프로파일을 적용하여 모바일 환경에 맞게 기술이 적용되고 있다. AVRCP는 고품질의 A/V 제품들을 제어하기 위한 표준인터페이스를 제공한다. 이러한 AVRCP는 A2DP와 VDP 기술과 함께 모든 A/V장비들을 손쉽게 사용할 수 있기 때문에 특히 모바일 디바이스에서 콘트롤러와 타켓을 블루투스와 함께 적용해서 활용될 수 있다. 모바일 환경에서 블루투스 기술은 이동성은 물론 소형화와 복합화를 가능케 한다. 이런 블루투스를 적용할 경우 기존의 적외선방식의 리모콘에서 수행했던 것처럼, 콘트롤러를 통해 사용자가 원하는 기능을 A/V 장비에게 손쉽게 전달할 수 있다. 이런 원격 콘트롤러는 이런 AVRCP 프로토콜을 활용해서 A/V를 제어할 수 있도록 설계되어있다. 이런 AVRCP 표준을 적용한 핸즈프리같은 제품에 일반적으로 제기되고 있는 음향반향의 문제를 제거할 수 있도록 개선된 DSP를 설계하였다.

• 농업과학연구
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• 제47권2호
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• pp.361-373
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• 2020

Integrins such as lymphocyte function-associated antigen -1 (LFA-1) have an essential role in T cell immunity. Integrin activation, namely, the transition from the inactive conformation to the active one, takes place when an intracellular signal is generated by specific receptors such as T cell receptors (TCRs) and chemokine receptors in T cells. In an effort to explore the molecular mechanisms underlying the TCR-mediated LFA-1 activation, we had previously established a high-throughput cell-based assay and screened a chemical library deposited in the National Institute of Health in the United States. As a result, several hits had been isolated including HIKS-1 (Benzo[b]thiophene-3-carboxylic acid, 2-[3-[(2-carboxyphenyl) thio]-2,5-dioxo-1-pyrrolinyl]-4,5,6,7-tetrahydro-,3-ethyl ester). In an attempt to reveal the mode of action of HIKS-1, in this study, we did drug affinity responsive target stability (DARTS) assay finding that HIKS-1 interacted with the IQ motif containing GTPase activating protein 1 (IQGAP1), a 189 kDa multidomain scaffold protein critically involved in various signaling mechanisms. Furthermore, the cellular thermal shift assay (CETSA) provided compelling evidence that HIKS-1 also interacted with IQGAP1 in vivo. Taken together, it can be concluded that HIKS-1 interferes with the TCR-mediated LFA-1 activation by interacting with IQGAP1 and thereby disrupting the signaling pathway for LFA-1 activation.

• Nuclear Engineering and Technology
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• 제2권2호
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• pp.97-106
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• 1970

원자력연구, 개발, 응용 및 이용사업이 시작된지 10년이 된 오늘날, 방사선을 포함한 오염사고등이 수많이 일어났고(Tablet 참조) 이들 방사선 사고로 인하여 인체 및 시설, 기구등에 까지도 자그마한 피해나마 장해 및 손상을 주었을 것이다. 이들 방사선 사고 가운데 비교적 주요한 4건의 방사선 피폭을 포함한 신체오염 사고, 말하자면 1) Cobalt-60 gamma선으로 부터의 전신피폭사고 (130 rem), 2) iodine-131에 의한 실험실내의 표면오염사고(13 mrad/hr), 3) 기체상의 iodine-131로 인한 전신오염 사고(흡입때문에 갑상선에 집적된 방사능량: 0.36$\mu$Ci) 4) 치료용 Radium 선원의 누출로 인한 Capsule이 텅빈사고［3 mg(\ulcorner)］, 등에 대하여 발견하는 즉시 최대의 노력과 최소의 비용으로써 조사, 측정하고 아울러 사고의 확대를 줄이기 위하여 가능한 모든 조처를 취하였으며, 사고의 요인분석, 평가를 하였다.

• Journal of Ginseng Research
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• 제17권1호
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• pp.1-12
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• 1993

The Preventive effect of the saponin fraction of Panax ginseng C.A. Meyer against hyperchole- sterolemia was demonstrated by assaying the cholesterol and triacylglyceride level of the blood serum and liver of rats fed high-cholesterol diet with and/or without ginsenoside. To understand the mechanism of the preventive action of ginsenoside, ginsenoside effect on LDL receptor binding ability, cholesterol level, and cAMP level of Chinese hamster ovary (CHO) cells cultured under various conditions were examined. When LDL (20 $\mu$g/ml) was added to the culture medium for CHO cell culture, LDL receptor binding activity of the cell was suppressed down to 58% of that of normal group. Ginsenosides at 10--2% and 10-3% level (w/v) were shown to exert an appreciable stimulatory effect on CHO cell LDL receptor activity, which partially overcame the suppression due to the presence of LDL (20 $\mu\textrm{g}$/ml) in the medium. Ginsenosides also reduced the increased cholesterol level of test group almost to that of normal group, and it increased cAMP level, which was usually reduced to 55% of that of the normal group due to the presence of LDL in the medium. Comparison of Kd and Bmax value of CHO cells cultured under different conditions revealed that this stimulation was due not to the receptor's binding affinity but to its number. Addition of ginsenoside (10-2%) decreased the uptake of taurocholic acid as much as 20% at the actively transporting everted ileal sacs, but it failed to form a large mixed micelles with taurocholic acid, which was one of the proposed mechanisms by which ginsenoside inhibits bile acid reabsorption. From the above results, it seemed likely that ginsenoside prevented hypercholestrolemia by decreasing cholesterol level in cells thereby relieving the inhibition of LDL receptor synthesis by cholesterol and also by inhibiting bile acid reabsorption from the small intestine.

• Molecules and Cells
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• 제37권11호
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• pp.795-803
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• 2014

To withstand ever-changing environmental stresses, plants are equipped with phytohormone-mediated stress resistance mechanisms. Salt stress triggers abscisic acid (ABA) signaling, which enhances stress tolerance at the expense of growth. ABA is thought to inhibit the action of growth-promoting hormones, including brassinosteroids (BRs). However, the regulatory mechanisms that coordinate ABA and BR activity remain to be discovered. We noticed that ABA-treated seedlings exhibited small, round leaves and short roots, a phenotype that is characteristic of the BR signaling mutant, brassinosteroid insensitive1-9 (bri1-9). To identify genes that are antagonistically regulated by ABA and BRs, we examined published Arabidopsis microarray data sets. Of the list of genes identified, those upregulated by ABA but downregulated by BRs were enriched with a BRRE motif in their promoter sequences. After validating the microarray data using quantitative RT-PCR, we focused on RD26, which is induced by salt stress. Histochemical analysis of transgenic Arabidopsis plants expressing RD26pro:GUS revealed that the induction of GUS expression after NaCl treatment was suppressed by co-treatment with BRs, but enhanced by co-treatment with propiconazole, a BR biosynthetic inhibitor. Similarly, treatment with bikinin, an inhibitor of BIN2 kinase, not only inhibited RD26 expression, but also reduced the survival rate of the plant following exposure to salt stress. Our results suggest that ABA and BRs act antagonistically on their target genes at or after the BIN2 step in BR signaling pathways, and suggest a mechanism by which plants fine-tune their growth, particularly when stress responses and growth compete for resources.

• 한국포장학회지
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• 제19권1호
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• pp.51-56
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• 2013

본 실험에서는 청과물의 포장 완충재로 사용되고 있는 골판지의 압축 및 충격특성을 이용하여 완충곡선(peak acceleration - static stress curve)을 구현하기 위한 알고리즘을 제시하였다. 본 연구에서 알 수 있듯이 한 개의 동적계수로도 완충곡선을 구현할 수 있음을 알 수가 있었으며, 기존의 완충곡선의 구현시 정적응력 범위 내에서의 실험횟수를 현저하게 줄일 수 있음을 알 수가 있었다. 또한, 골판지 완충재료 외에 플라스틱 발포체 완충재료에도 적용이 가능할 것으로 판단되었다.

• 한국산업정보학회논문지
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• 제25권4호
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• pp.49-63
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• 2020

오늘날 지방 자치 기관은 재원이 계속 줄어들고 시민의 서비스 품질 기대치가 높아지면서 복잡한 문제에 직면하고 있어 문제해결을 효율적으로 관리할 수 있는 도구를 개발하고 실행해야 한다. 문제해결을 위해 린식스시그마 이론과 도구들이 영리 집단에는 광범위하게 사용되고 있지만, 공공기관에 사용된 사례는 희박하다. 본 연구는 린식스시그마 방식과 도구들을 미국의 한 소도시 산하 지방자치단체의 효율적인 운영 프로세스와 서비스 품질 그리고 시민의 고객 만족을 향상하기 위하여 사용된 사례를 다룬다. 본 사례 연구는 DMAIC (Define, Measure, Analyze, Implement, and Control) 방식을 채택하여 문제를 파악하고 수행지표를 개발 및 측정하여 시행할 수 있는 계획을 제안한다. 본 사례 연구의 결과 지방 정부 공공 업무에 린식스시그마의 이론과 방법을 적용하는 것이 서비스를 제공하는 프로세스의 효율성과 서비스 품질을 개선할 수 있는 훌륭한 방법이 될 수 있음을 보여준다.