• 지구물리
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• 제8권1호
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• pp.7-14
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• 2005

Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG) sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.19-21
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• 2004

This paper considers pulse width modulation (PWM) methods which are used in 3-phase brushless DC motor controller. Due to many disadvantages of bipolar PWM method, unipolar PWM method is mostly used in industrial field. In constant speed control application, the unipolar PWM method shows a good performance of speed control. But in the wide range of speed control application, it shows a poor performance especially when deceleration is needed. So we propose hybrid PWM method that utilizes two PWM methods according to the sign of speed controller output. The simulation and experimental result shows that the proposed method improves a speed control performance of the brushless DC motor which is applied to industrial sewing machines.

• 센서학회지
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• 제32권3호
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• pp.180-186
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• 2023

Test devices can perform various functions, such as research on detection targets, sensors that detect detection targets, combined products containing sensors, and certification for the launch of combined products. However, the scope of use of test devices is limited because they perform only a single role or could only serve a particular purpose in the past. Therefore, studies on test devices that can perform various functions, such as research on detection targets, sensors that detect detection targets, combined products containing sensors, and certification for the release of combined products are necessary. Accordingly, this study proposes a test device that can increase the scope of use in the technical field of electric fires. In addition, we examine various outcomes of the proposed test device.

• 대한토목학회논문집
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• 제14권5호
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• pp.1177-1189
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• 1994

본 논문은 충적하천에서 수로의 양상조건에 따른 유사 및 흐름특성을 해석함으로써 수로의 변이를 예측할 수 있는 수치모형을 개발하기 위한 연구이다. 하천의 흐름은 하상 및 제방재료 특성과의 상호작용에 의해 복잡한 관계를 이루면서 수로변이를 통하여 형태학적으로 안정적인 형상을 유지하고 흐르기 때문에 대부분의 경우 직선형수로는 드물고 사행 또는 망류상을 이루고 있다. 본 연구에서는 수로변이를 모의할 수 있는 모형을 개발하기 위해 수로중심선 곡률반경 $r_c$값의 양과 음의 부호수에 따라 수로를 구분 즉, $r_c$의 양 또는 음의 값이 하나 만으로 이루어진 단만곡수로(single-bend channel)와 양과 음이 둘 이상의 값을 갖는 복만곡수로(multi-bend channel)로 구분하여 이들 수로에서의 편수위상승, 나선운동, 하상 및 수심평균유속의 불규칙 현상의 영향에 의한 유사이동과 흐름특성을 해석한다. 단만곡수로는 타 _모형의 실험자료와 복만곡수로는 금강의 매포수위관측소를 시점으로하는 연구구간에서 실측치 현장자료와 비교분석함으로써 본 모형의 적용성을 검증하였으며, 그 결과는 대체로 잘 일치하는 것으로 나타났다.

• 대한전자공학회논문지TC
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• 제43권7호
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• pp.143-149
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• 2006

터보부호는 디지털 이동통신 시스템에서 사용되는 오류정정 부호화 기법의 일종으로서 반복복호가 진행됨에 따라 AWGN 채널 환경에서 우수한 BER 성능을 나타낸다. 그러나 다양한 채널 환경에서 반복 횟수가 증가하면 복호하는데 필요한 지연시간과 계산량이 증가하는 단점을 가진다. 이를 해결하기 위해서는 적절한 반복 후에 반복복호를 효율적으로 중단시킬 수 있는 중단조건이 필요하게 된다. 본 논문에서는 터보 복호기의 현재 복호 과정에서 첫 번째 복호기와 두번째 복호기의 외부정보 값에 대한 부호변화율을 중단조건으로 이용하여 BER 성능의 손실없이 낮은 SNR 영역에서 평균 반복복호 횟수를 크게 감소 시킬 수 있는 효율적인 반복중단 알고리즘을 제안한다. 모의실험 결과, 낮은 SNR 영역에서 제안된 알고리즘의 평균 반복복호 횟수는 CE 알고리즘과 비교하여 약 $12.48%{\sim}22.22%$ 정도의 감소효과를 나타냈으며 SDR 알고리즘과 비교하여 약 $20.43%{\sim}54.02%$ 정도의 감소효과를 나타내었다.

• Journal of Ecology and Environment
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• 제29권6호
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• pp.511-520
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• 2006

주왕산국립공원 탐방로중 가장 높은 가메봉을 대상으로 포유류의 고도별 분포 현황을 분석한 결과 총 22종의 서식을 확인하였다. 해발 200 m에서 800 m 구간을 100 m 단위로 세분화하여 분석한 결과 다람쥐(Tamias sibiricus)가 가장 많은 구간에서 우점종으로 나타났으며, 조사지역내 전 구간에서 서식이 확인된 종은 족제비(Mustela sibirica), 노루(Caproelus pygargus), 다람쥐였다. 확인된 Field Sign을 관찰 지점을 기준으로 분석한 결과, 고도의 증가에 따른 종 및 개체수는 유의적인 관계가 있는 것으로 나타났다(y=-0.0234X+25.552, $R^2$=0.9296, $F_{0.05}$(1, 4)=7.71, p<0.05). 그러나 100 m 단위로 세분화한 6구간중 5구간 이상에서 관찰된 9종을 대상으로 분석한 결과Apodemus agrarius(y=-0.034X+25.2, $R^2$=0.905, $F_{0.05}$(1, 4)=38.169, p<0.01)와 Sciurus vulgarie (y=-0.0154X+12.819, $R^2$=0.781, $F_{0.05}$(1, 4)=14.270, p<0.05) 2종만 유의적 영향을 받는 것으로 나타나 종별 고도에 따른 제한적 분포보다는 주변 식생 현황 및 서식지 구조에 따라 종의 분포가 이루어지는 것으로 판단된다. Box and Whisker Diagram분석 결과200$\sim$300 m 구간내 탐방객의 출입이 금지되어 있는 자연 휴식년제(Nature Restoration Area) 지역에서의 사분위 편차($Q_U-Q_L$)가 가장 적은 것으로 나타났으며, 주변 식생 및 탐방로 형태가 유사한 해발 500$\sim$600 m 구간에서 가장 광범위한 분포를 보였다. 특히 이 구간내 탐방로 상에서 멸종 위기 야생동물 II인 삵(Prionailurus bengalensis)의 배설물이 집중적으로 관찰되어 이에 대한 연구가 연계되어야 할 것으로 사료된다.

• 대한예방한의학회지
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• 제20권1호
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• pp.145-159
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• 2016

Objectives : The aim was to investigate the characteristics of low dose effect and non monotonic dose responses(NMDRs) and to predict the influence it might have on the health and medicine, traditional Korean medicine. Methods : By investigating recently published major literatures related to low dose effect and NMDRs, the definition, mechanism, major related fields, and the influence on public health and medicine has been categorized and summarized. Results : Although there are still heated debates about the definition of low dose, it implies the biological responses in environmental exposure level and the NDMDRs means the nonlinear relationship between the dose-response in the slope sign change. Also, it implies the new form of the curve showing a U, reverse U shape, and the slop sign constantly changing showing various forms. This mechanism is because the two acceptor shows opposing effects to toxic materials and the affinity is different along with the numerical value that increase and decrease being different. These characteristics generally appear in endocrine disrupters such as bisphenol A, agricultural pesticides, metal, and radiation. The research field in the public health and medical treatment is obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause and phytoestrogen. Conclusions : As a result of discussing implications, NMDRs is a particular effect in low dose and heated debates surround this response, research is being conducted surrounding the field of obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause, and phytoestrogen. More research and interest in needed as it can have a massive influence in the public health and medicine.

• 복식
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• 제56권3호
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• pp.1-11
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• 2006

Che Guevara spearheading the Cuban Revolution was not only the icon as the revolutionary to the New-leftists of the 1960s advocating the ideology of Marxism but, as the cultural revolutionary, had a tremendous influence on the younger generation living in the digital age Che Guevara take on a figure of both the symbol of the Leftist but the romantic revolutionary because he had the external features such as black beret, red stars, military upper jackets and trousers, beard and pipe tobacco. In fact, the symbolic image of Che Guevara was made as the popular image by the avantgarde artists and political vanguard forces of the times under the necessity of Cuban government. Afterwards, the image of Che Guevara has been patronized in making people of aware of the resistant and revolutionary image to capital, power and the power of the media and symbolized as the resistant image to the American capital as well as the revolutionary guerrilla. And his image has continued to be reproduced and symbolized for the commercial and political purposes and as the enthusiastic image of youth culture. This can be seen as having been created as a new image by the popular culture formed by the development of the cyber culture and mass media in the cyberspace shaped by contemporary 'N' generations. The use of Che Guevara's symbolic image was made in the fashion field as well as in the cultural and artistic circles. The borrowing of the icon of Che Guevara represented in a fashion field is attributed to his free spirit, and it can be seen that fashion exists as the vehicle for representing both the symbol system and the sign system containing ideologies and texts as the communicator of resistance to the regime and to social issues. Therefore, this study attempted to investigate the commercial iconization of Che Guevara in the 1990s by comparing the ideology of the symbol in the 1960s and the 1990s and inquire into the borrowing of his image by the fashion domain as well as the fashion worn by him by reference to domestic books and materials on the fashion site. Thereby, this study attempted to make clear that the borrowing of Che Guevara in the realm of fashion since the 1990s not only contained the meaningful interpretation as the symbolic code in the culture of young people living in a digital era but fashion performs an intervening role in the cultural phenomenon.

• 한국도로학회논문집
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• 제18권6호
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• pp.87-96
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• 2016

OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

• 한국동물위생학회지
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• 제14권2호
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• pp.159-174
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• 1991

A field trial of norfloxacin on bovine 206, swine 222 and poultry 205 with respiratory diseases and diarrhea was conducted from Sept 1, 1990 to Jan 30, 1991 in Inchon and Kyonggi-do. The results are as follows. 1. Guinea pigs and rabbits were dosages 10 and 20 times normal. Ten days of observation saw no side effect. 2. Oral treatment on bovine, swine and poultry showed a curing rate of 82.00∼89.06%(Mean 86.00%), compared with 87.27∼96.36%(Mean 92.24%) by Injection. 3. The curing rate was 81.92% by the fourth treatment. 4. The curing rate with and without the use of adjuvant was 80.00∼100% and 83.60∼93. 10%, respectively, for swine, and 81.82∼100% and 82.00∼97.14% for bovine. 5. The curing rate was more dependent on seriousness of illness, environment and time than age. 6. The main disease causing bacteria of bovine respiratory diseases： Haemolytic Sta 27.62%, Haemolytic Str 33.33%, sum of this bacteria is 60.95%, diarrhea: Haemolytic coliform 80.20%, swine respiratory diseases； Haemophilus Spp 20.95%, Haemolytic Sta 72%, Haemolytic Str 21.90%, Sum of these bacteria is 68.57％, diarrhea; Haemolytic coliform 57.26%, poultry respiratory diseases； mycoplasma Spp 29.52%, Haemolytic Sta 13.33％, Sum of this bacteria is 42.85%, diarrhea； Haemolytic coliform 53.00%. 7. The curing rate of norfloxacin by species of strain, the unidentified bacteria on bovine respiratory diseases was the lowest with 77.78％, the others ranged from 84.21％ to 100％ with most of them over 90%. 8. The loss of clinical sign on bovine and swine was the highest when after 2∼4 application. 9. In terms of antibiotic sensitivity test, norfloxacin was the highest with 84.62∼100％ (mean 90.09％) among eight bacterias, only 5 of 15 antibiotics had a sensitivity of over 56.25%, showing a high degree of tolerance.