• Title/Summary/Keyword: AC/A 비

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Effect of Plum Wine on the Lipid Metabolism and Lipid Peroxidation of Rats (자두와인의 섭취가 흰쥐의 지질대사 및 지질과산화에 미치는 영향)

  • Yoon, Ok-Hyun;Kang, Byung-Tae;Lee, Jae-Woo;Kim, Kwang-Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.4
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    • pp.422-427
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    • 2008
  • The effect of plum wine on lipid metabolism and lipid peroxidation in rats with chronic ethanol consumption was evaluated. Sprague-Dawley rats were randomly divided into the following 4 groups; water (NC), alcohol control (AC), low concentration plum wine (LP) and plum wine (P). The alcohol content of experimental drinking water of AC, LP and P were 6%, 6% and 12%, respectively. Animals were fed AIN-76 diet and experimental drinking water for 4 weeks. LP group showed significantly decreased liver weight per 100 g body weight, the levels of total cholesterol and atherogenic index in plasma whereas the ratio of HDL-cholesterol to total cholesterol was significantly increased in comparison to that of AC group. LP and P groups showed significantly decreased total lipid, total cholesterol in liver tissue, AST and ALT activities of plasma as compared with that of AC group. LP and P groups showed a significant decrease in the level of plasma lipid peroxidation products and LP group showed a significant decrease in the level of liver lipid peroxidation products as compared with that of AC group. These results suggest that supplementation of low concentration plum wine may exert more beneficial effects than pure alcohol beverage on lipid metabolism and lipid peroxidation products in chronically alcohol-treated animals by improving lipid profiles in plasma and liver tissues and decreasing plasma and hepatic lipid peroxidation product.

A Study on Compensation of Amplitude in Multi Pulse (멀티펄스의 진폭보정에 관한 연구)

  • Lee, See-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.4119-4124
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    • 2011
  • In a MPC coding using excitation source of voiced and unvoiced, it would be a distortion of speech waveform in case of increasing or decreasing of speech signal amplitude in a frame. This is caused by normalization of synthesis speech signal in the process of restoration the multi-pulses of representation section. To solve this problem, this paper present a method of amplitude compensation(AC-MPC) in a multi-pulses each pitch interval in order to reduce distortion of speech waveform. I was confirmed that the method can be synthesized close to the original speech waveform. And I evaluate the MPC and AC-MPC using amplitude compensation method. As a result, SNRseg of AC-MPC was improved 0.7dB for female voice and 0.7dB for male voice respectively. Compared to the MPC, SNRseg of AC-MPC has been improved that I was able to control the distortion of the speech waveform finally. And so, I expect to be able to this method for cellular phone and smart phone using excitation source of low bit rate.

A Study of Penning gas for the improvement of luminance and luminous efficiency in AC plasma display panel (AC PDP에서의 최적의 페닝 방전가스 혼합비에 대한 휘도와 효율 향상에 관한 연구)

  • Lee, Jae-Kyung;Ham, Jung-Kook;Byun, Ki-Ryang;Kang, Jeong-Won;Hwang, Ho-Jung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1074-1077
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    • 2003
  • 우리는 AC-PDP에서 휘도와 효율을 향상시키기 위하여 Ne-Xe(4%)와 He(7)-Ne(3)-Xe(3%)에 소량의 Ar 또는 Kr를 첨가하여 최적의 페닝 방전가스 혼합비를 연구하였다. 우리는 이것을 증명하기 위해 효율과 Q-V 방법을 이용하여 벽전하를 계산하였으며, 2차원 시뮬레이션에서의 결과값과 비교하였다. 200 Torr 압력에서 He-Ne-Xe 또는 Ne-Xe에 소량의 Ar(0.01-0.1%) 또는 Kr(0.01-0.1%)을 첨가시켰을 때, 우리는 20% 이상의 휘도의 증가와 25% 이상의 효율 증가를 발견하였고, 또한 벽전하도 25% 이상의 증가를 보였다. 400 Torr 압력에서 He-Ne-Xe-Kr(0.005%)에 소량의 Ar(0.005-0.1%)를 첨가시켰을 때는 8% 이상의 휘도의 증가와 18% 이상의 효율 증가, 12% 이상의 벽전하 증가를 확인하였다. 결론적으로 이 결과는 He, Ne, Ar, Kr 사이에 추가적인 페닝효과가 휘도와 효율을 향상시켰다는 것을 보여준다.

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Spatial Measurement of Plasma Temperature & Density in a microdischarge AC-PDP cell

  • 김진구
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.231-231
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    • 1999
  • PDP(Plasma Display Panel)는 21세기 디스플레이 시장을 대체할 차세대 디스플레이 장치로서 넓은 시야각, 얇고, 가볍고, 메모리기능이 있다는 여러 가지 장점들을 가지고 있지만 현재 고휘도, 고효율, 저소비전력 등의 문제점들을 해결하여야 한다. 이러한 문제점들의 해결을 위해서는 명확한 미세방전 PDP 플라즈마에 대한 정확한 진단 및 해석이 필요하다. 따라서 본 연구에서는 미세 면방전 AC-PDP 플라즈마의 기초 변수들 (플라즈마 밀도 & 온도, 플라즈마 뜬 전위, 플라즈마 전위 등의 측정을 통해 고휘도, 고효율 PDP를 위한 최적의 방전환경을 알아내는 데 있다. 일반적으로 전자의 밀도는 방전전류에 비례하는 관계를 보인다. 전류에 대해 방전전압이 일정하다면 전자밀도가 커짐에 따라서 휘도는 포화되며 상대적으로 휘도와 전류의 비로 표시되는 발광효율은 감소하게 된다. 반면 전자밀도가 상당히 작다면 휘도는 전자밀도에 비례하고 효율은 최대값을 보인다. 따라서 미세구조 PDP에서 휘도와 발광효율, 양쪽에 부합하는 최적의 방전환경을 플라즈마 전자밀도와 온도의 측정을 통해서 해석하는 것이 필요하다. 본 실험에서는 방전기체의 종류와 Ne+Xe 방전기체의 조성비에 따른 플라즈마 밀도, 온도의 공간적인 분포특성을 진단하기 위해서 초미세 랑뮈에 탐침(지름: 수 $mu extrm{m}$)을 제작하였다. 제작된 초미세 탐침을 컴퓨터로 제어되는 스텝핑모터를 장착한 정밀 X, Y, Z stage에 부착하여서 수 $\mu\textrm{m}$간격의 탐침 삽입위치에 따라서 미세면방전 AC-PDP의 플라즈마 밀도 및 온도분포 특성을 진단하였다. PDP 방전공간에 초미세 랑뮈에 탐침을 삽입해서 -200~+200V의 바이어스 전압을 가해준다. 음의 바이어스 전압구간에서 이온 포화전류를 얻어내어 여기서 플라즈마 이온 밀도를 측정하고 양의 바이어스 전압구간에서 플라즈마 전자온도를 측정하면 미세면방전 AC-PDP 플라즈마의 기초 진단이 가능하다.

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Development of the Pattern Matching Engine using Regular Expression (정규 표현식을 이용한 패턴 매칭 엔진 개발)

  • Ko, Kwang-Man;Park, Hong-Jin
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.33-40
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    • 2008
  • In various manners, string pattern matching algorithm has been proven for prominence in speed of searching particular queries and keywords. Whereas, the existing algorithms are limited in terms of various pattern. In this paper, regular expression has been utilized to improve efficiency of pattern matching through efficient execution towards various pattern of queries including particular keywords. Such as this research would enable to search various harmful string pattern more efficiently, rather than matching simple keywords, which also implies excellent speed of string pattern matching compared to that of those existing algorism. In this research, the proposed string search engine generated from the LEX are more efficient than BM & AC algorithm for a string patterns search speed in cases of 1000 with more than patterns, but we have got similar results for the keywords pattern matching.

Natural Radioactivity of Soils by Bed Rocks Distributed in the Keum River Area (금강유역 기반암 토양의 자연방사능 특성)

  • Lee, Kil-Yong;Yoon, Yoon-Yeol;Cho, Soo-Young;Lee, Jung-Hwa;Lee, Jin-Soo;Koh, Kyung-Seok;Kim, Yong-Je
    • Journal of Soil and Groundwater Environment
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    • v.14 no.2
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    • pp.10-16
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    • 2009
  • Characteristics of natural radioactivity were investigated for soils collected from seven sites of different bed rocks distributed in the Keum River area of Korea by the use of a Gamma-ray spectrometry. Specific activity (SA) and SA ratio (SAR) of typical naturally occurring radioactive nuclide such as $^{226}$Ra, $^{228}$Ac and $^{40}$K were determined for the soil samples. The SA values of $^{226}$Ra, $^{228}$Ac and $^{40}$K in 41 soils of 7 sites are 26.7-485 (74.2 ${\pm}$ 72.2), 30.9-157 (90.7 ${\pm}$ 32.7) and 203-1558 (990 ${\pm}$ 203) Bq/kg, respectively. The SA of $^{226}$Ra has very different values by the soils and the sites. Especially the SA of $^{226}$Ra in a soil sample of Ogcheon site is 485 Bq/kg while most SA of 41 soil samples are < 100 Bq/kg. SA of $^{228}$Ac has a little different values with the soils and sites, however the SA of $^{40}$K has almost constant values in all soil samples. The SAR values of $^{26}$Ra/$^{228}$Ac, $^{226}$Ra/$^{40}$K and $^{228}$Ac/$^{40}$K in 41 soils of 7 sites are 0.343-6.11 (0.865 ${\pm}$ 0.883), 0.0258-0.759 (0.0814 ${\pm}$ 0.1l17) and 0.0373-0.178 (0.0945 ${\pm}$ 0.0373), respectively. The SARs of $^{226}$Ra/$^{228}$Ac and $^{226}$Ra/$^{40}$K have very different values by the soils and the sites, however the SAR of $^{228}$Ac/$^{40}$K has a little difference by the soil and sites.

AC/DC Converter Suitable for a Pulsed Mode Switching DC Power Supply (펄스모드 스위칭 직류전원 장치에 적합한 AC/DC 컨버터)

  • 문상호;강성관;노의철;김인동;김흥근;전태원
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.5
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    • pp.389-396
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    • 2003
  • This paper describes a novel ac/dc power converter suitable for frequent output short-circuit faults. The output dc power of the proposed converter can be disconnected from the load within several hundred microseconds at the instant of short-circuit fault. The rising time of the dc load voltage is as small as several hundred microseconds, and there Is no overshoot of the dc voltage because the dc output fillet capacitors stay at a undischarged state. The proposed converter has the characteristics of a simplified structure, reduced cost, weight, and volume compared to the conventional power supplies for frequent output short-circuit. Analysis, simulations, and experiments are carried out to investigate the operation and usefulness of the proposed scheme.

Optimal Section of Ballasted Asphalt Track Considering Design Lifetime and Economic Feasibility (설계수명 및 경제성을 고려한 유도상 아스팔트 궤도의 최적 단면 산정)

  • Lee, Seonghyeok;Lee, Jinwook;Lee, Hyunmin
    • Journal of the Korean Society for Railway
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    • v.18 no.3
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    • pp.241-251
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    • 2015
  • Compared with ballasted track (BT), ballasted asphalt track (BAT) has been increasingly adopted in many countries due to its more greatly reduced reinforced roadbed thickness and smaller cumulative plastic deformation, and its advantages in terms of maintenance. In this respect, the authors' previous research includes analysis of BAT sections that show performance similar to that of BT sections of the present specifications; reliability verification of the analysis results through real-sized static and dynamic train-load tests were performed. Based on previous research, this paper estimates the track lifetime using the strain of the lower roadbed according to reinforced roadbed thickness; using probabilistic LCC analysis, this paper presents a BAT section that satisfies the design lifetime and that has performance similar to or higher than that of BT.

Relationship Between Subjective Symptoms with Near Work and Binocular Function (근업시 자각 증상과 양안시 기능의 관계)

  • Shin, Jin-Ah;Lee, Ok-Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.3
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    • pp.125-130
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    • 2007
  • The aim of this work was to study the relationship between subjective symptoms and binocular function during near work in forty one(12-17yr) schoolchildren. CISS symptom survey, amplitude of accommodation, accommodative facility, neagative relative accommodation(NRA)/positive relative accommodation(PRA) near point of convergence(NPC), heterophoria, AC/A ratios were measured. The results of measurement were compared with normal expected value of each test and classified into normal and abnormal group. Accommodative insufficiency was more general than convergence insufficiency and esophoria was greater than exophoria. NRA/PRA showed very high and AC/A ratios were very low compare with normal expected value. The results of CISS was as follows; most frequent symptom was tired, mean score was $16.63{\pm}7.49$, mean number of symptoms were $10.07{\pm}3.04$, and mean number of serious symptoms were $1.98{\pm}2.13$. After classified into 4 groups according to score of symptoms, number of symptoms, and degree of symptoms and then analyze the correlation compare with binocular vision test results. NRA was most correlated with group comparison, accommodative facility was most correlated with score of symptoms, NRA was most correlated with number of symptoms, and near horizontal phorias were most correlated with serious symptoms. NRA showed most correlative relation with near symptoms.

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A Study on Fault Location Estimation Technique Using the distribution Ratio of Catenary Current in AC Feeding System (전차선 전류 분류비를 이용한 교류전기철도 고장점 표정기법에 관한 연구)

  • Jung, Ho-Sung;Park, Young;Kim, Hyeng-Chul;Min, Myung-Hwan;Shin, Myong-Chul
    • Journal of the Korean Society for Railway
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    • v.14 no.5
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    • pp.404-410
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    • 2011
  • In AC feeding system, the fault location is calculated by using ratio of current absorbed in the neutral point of AT(Automatic Transformer) or by measuring reactance. In this way, however, an estimation error can be happened due to the many reasons. In addition, for measuring currents in the neutral point of AT, other measuring devices and communication equipments are additionally required. In order to solve the disadvantages, this paper suggests a novel technique using the distribution ratio of catenary current. The proposed technique uses existing protective relays and measures catenary current. With the measured data, we can calculate the distribution ratio of catenary current and determine fault location. Through the simulated results, we derived the correlation between current ratio and fault location. Using this technique, additional equipments and expenses can be reduced. Besides, fault location can be determined more correctly.