• 한국도로학회논문집
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• 제16권1호
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• pp.111-118
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• 2014

PURPOSES : This study performs fundamental research on ramp-metering design criteria. METHODS : We carefully review previous studies in terms of ramp-metering design criteria and then consider applicability in Korea. For this, traffic simulation model is employed to analyze actual effect according to specific location of stop-line when implementing ramp-metering. RESULTS : When a stop-line moving forward with a 50m interval, travel speed at mainline relative to current stop-line location tends to decrease. However, traveling speed at approach roads increase about 5~18% under the same condition. When a stop-line location moving backward with a 50m interval, mainline travel speed increase approximately 17~32% whereas traveling speed at approach roads decrease. All cases are compared with the current stop-line location. CONCLUSIONS : We believe that both cases are useful with respect to freeway management. For example, moving forward a stop-line case can be used management for queuing area at ramp section and approach roads. Moving backward a stop-line case can be used for traffic control, focusing on mainline of freeways.

• 농업과학연구
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• 제45권4호
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• pp.871-878
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• 2018

The government of Gyeongbuk in Korea increased the financial input in the agricultural sector by 43% from 2008 through 2012. However, the productivity of the agricultural sector in Gyeongbuk rose only about 3.6% during the same period. This study evaluated the agricultural competitiveness of each city or county in Gyeongbuk using six evaluation indices (scale, productivity, finance input, location quotient, technical education, and total) and investigated the relationship between the indices and total values of agricultural productions. The results show that Sangju, Gyeongju, Andong, Uiseong, and Seongju have high competitiveness for the scale index. For the productivity index, Gimcheon, Mungyeong, Ulleung, Yeongju, and Seongju were highly evaluated. For the location quotient index, Yeongcheon, Uiseong, Cheongdo, Seongju, and Sangju have high competitiveness. Uiseong, Yeongdeok, Cheongsong, Gunwi, and Yeongyang were highly evaluated for the agricultural finance input index. For the agricultural technical education index, Chilgok, Sangju, Mungyeong, Uiseong, and Gyeongju have high competitiveness. Finally, Sangju, Euiseong, Yeongcheon, Gyeongju, and Andong were highly evaluated for the total competitive index, while Yeongdeok, Yeongyang, Goryeong, Uljin, and Cheongsong have a low competitiveness for the total competitive index. This study also found that out of five indices, scale, location quotient, and technical education indices have a positive and statistically significant effect on the total values of agricultural production. However, we did not find any statistically significant effect of the productivity and finance input indices on the total values of agricultural production. Hence, we can conclude that the government should focus their agricultural policy on scale, location quotient and education to improve total agricultural production.

• The Journal of the Acoustical Society of Korea
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• 제24권4E호
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• pp.139-143
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• 2005

The present study aims to investigate the effects of speaker location on the speech intelligibility in a classroom. In order to this, acoustic measurements were undertaken in a classroom with three different sound source locations such as center of front wall (FC), both sides of front wall (FS) and the center of ceiling (CC). SPL, RT, $D_{50}$, RASTI were measured in the 9 measurement points with same sound power level of sound source and MLS was used as the sound source signal. Also, subjective listening tests were carried out using Korean language listening materials which were recorded in an anechoic chamber. The recorded syllables were replayed and recorded again in the classroom with same sound source at three different locations and listening tests were undertaken to 20 respondents who were asked to write the correct syllables which were recorded in the classroom. The results show that higher sound intelligibility ($D_{50}$ of $47\%$, RASTI of 0.56) was obtained when sound source was located at the FS. The results also show that high sound intelligibility was obtained at the area nearby walls.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.820-823
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• 2006

Nonlinear internal waves (NLIW) were studied as a unusual phenomena in the ocean decades ago. As the quality, quantity and variety of satellite images improve over decades, it is founded that NLIW is a ubiquitous phenomenon. Over the continental shelf of northern South China Sea (SCS), both optical and microwave images show that there are trains of NLIW packets near Dongsha Atoll (20.7N, 116.8E). Each packet contains several NLIW fronts. These NLIW packets are nearly parallel to each other and they are refracted, reflected or diffracted by the change of ocean bottom topography. Based on Korteweg de Vries (KdV) theory and the assumption that the bright/dark lines in the satellite images are centers of convergence/divergence of NLIW fronts, one may (1) sort NLIW packets in the same satellite image into groups of the same source, but generated at different tidal cycles, (2) relate NLIW packets in consecutive satellite images of one day apart, (3) locating faint signals of NLIW fronts in a satellite image. The NLIWs travel more than 100 km/day near Dongsha Atoll, with higher speed in deeper water. The bias and standard deviation of predicted location of NLIW front from its true location is about 1% and 5.1%, respectively.

• 한국정보통신학회논문지
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• 제19권5호
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• pp.1235-1242
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• 2015

글로벌 해운물류에서 계속적으로 이동하는 화물의 위치 정보를 추적하고 관리하는 것은 물류주체에게 중요한 일이다. 화물에 부착된 태그의 GPS 좌표 흐름을 분석하면 물류거점을 기반으로 한 화물의 위치정보를 쉽게 추적할 수 있다. 즉, 태그와 물류거점간의 동적인 위치변화를 이용하여 거점 단위의 위치 이동을 추적할 수 있다. 본 논문에서는 전세계 물류거점을 대상으로 이러한 거점 단위 위치추적 알고리즘의 정확성과 오동작을 측정하기 위해 시뮬레이션 시스템을 개발하였다. 실제 태그를 제작하여 실험하기에는 많은 제약이 따르기 때문에 실제 태그와 유사하게 동작하는 태그 에뮬레이터를 개발하여 가상 태그를 생성한다. 실제 태그와 같은 통신 프로토콜을 이용하여 위치추적 시스템에 데이터를 전송함으로써 위치추적 시스템이 잘 동작함을 보인다.

• 한국정보과학회논문지:정보통신
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• 제32권1호
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• pp.80-88
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• 2005

편재형 공간에서 사용자는 자유롭게 이동하면서 VOD(Video On Demand) 서비스를 제공받기원한다. 그러나 기존의 VOD 시스템은 사용자의 위치에 종속적이기 때문에 한 세션이 종료될 때까지 서버는 한 클라이언트에게만 데이타를 전송한다. 그래서 만일 사용자가 이동한다면 이전 세션을 종료시키고 새로운 클라이언트에서 다시 세션을 연결해야 한다 그러나 위치 인식 VOD 시스템은 세션의 연결과 종료를 자동으로 수행함으로써 사용자 이동성을 지원한다. 즉, 사용자의 위치 이동을 자동으로 인식하고 사용자 근처의 클라이언트로 데이타 전송 흐름을 바꾸어 연속적으로 서비스를 제공한다. 본 연구는 편재형 공간에서 이동 중인 사용자에게 연속적인 서비스를 제공하기 위하석 위치 인식 VOD 서비스 구조와 세션 핸드오프 기법을 제안하고 자바(Java)와 지니(Jini)를 기반으로 위치 인식 VOD 프로토타입 시스템을 구현한다. 그리고 실험에서 제안된 핸드오프 기법이 다른 기법에 비해 적은 핸드오프 시간을 가짐을 보인다.

• 한국유통학회:학술대회논문집
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• 한국유통학회 2006년도 춘계학술대회 발표논문집
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• pp.57-70
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• 2006

본 연구는 내실 있는 기업 유치를 증대시키기 위한 입지마케팅 정책을 수립하는데 적절한 함의를 제공할 목적으로 시도되었다. 구체적으로 본 연구는 충북지역의 기업체를 대상으로 기업의 입지환경수준을 기초자치단체의 지원정책, 광역자치단체의 지원정책, 중앙정부의 지원정책 등의 '지원정책요인', 동종 혹은 관련 산업의 집적, 풍부한 판매시장, 개방적 혁신적인 산업분위기, 대학, 연구소 등의 다양한 혁신기관의 집적 등의 '집적요인', 양호한 정보 통신망, 공항, 철도, 고속도로 등의 광역교통망과의 근접성, 저렴한 지가 혹은 임대료 등의 '입지기반요인' 등 세 가지로 구분하여 분석하였다. 이러한 기업의 입지환경수준을 세 가지 요인으로 구분하여 기업규모에 미치는 영향은 어떻게 존재하는 지에 대하여 실증적인 분석을 했다. 기업성장을 촉진시킬 수 있는 입지환경의 역할이 중요한 현실 하에서 입지환경수준과 기업규모의 관계를 분석하는 것은 중요하다고 할 수 있다. 이러한 연구결과는 기업에게 가장 적합한 입지마케팅 정책을 수립하고 방향을 설정하는데 도움을 제공할 수 있을 것이다.

• Journal of Photoscience
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• 제9권2호
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• pp.302-304
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• 2002

pharaonis phoborhodopsin (ppR), a photophobic sensor of haloalkaliphilic bacteria, Natronobacterium phar-aonis, has retinal as a chromophore covalently bound to Lys in G-helix via a protonated Schiff base (PSB), as is the same as bacteriorhodopsin (bR). For ppR, the corresponding counter-ion is Asp residue (Asp75) located in C-helix. Here we investigated the influence of the protonated state of this counter-ion and its location on the chromophore configuration. Under alkaline condition, the chromophore configuration of D75E mutant was analyzed by HPLC. D75E had a much larger content of 13-cis isomer: the ratio of 13-cis to all-trans was 6:4 while the wild-type had this ratio of 1 :9. On the other hand, under acidic condition where Glu was associated, D75E had no 13-cis retinal isomer. Mutants whose Asp75 was replaced by neutral amino acids (D75N and D75Q) did not contain 13-cis retinal. Furthermore, retinal isomer compositions and the change in the visible ab- sorption spectra (indicating the dissociation state of Glu75) were measured under varying pH, and these were almost the same dependencies. These results indicate that an important factor determining the 13-cis isomer content is the presence of negative charge of the counter-ion against PSB, but not the size of this residue. Com- parison between the wild-type and D75E in alkaline solutions indicates the influence of the location of the counter-ion.

• Imaging Science in Dentistry
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• 제48권3호
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• pp.185-190
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• 2018

Purpose: The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography. Materials and Methods: The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test. Results: The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients. Conclusion: The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively.

• 한국철도학회논문집
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• 제20권5호
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• pp.595-601
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• 2017

전철화 확대의 영향으로 전차선로 변의 고장발생 빈도는 지속적으로 증가하여, 고장위치를 표정하는 시스템의 중요도는 향상되고 있다. 그럼에도 전차선로의 정확한 고장위치 표정은 매우 어려운 현실이다. 본 논문에서는 기존 회로방정식으로 제안된 전차선로 임피던스 계산이론에 대해 현장실측 데이터를 활용하여 보편화 정리하고 변전소 및 운행차량의 전압, 전류 데이터를 동기화 실측하여 전차선로의 임피던스를 예측 하였다. 또한 예측된 전차선로 임피던스값의 유효성 확인을 위해 동일지점에서 열차전류에 따른 임피던스 변화 정도를 시뮬레이션으로 확인하였다. 끝으로 측정 데이터와 지락시험을 통한 데이터를 비교 분석하였다. 본 기법은 강제지락시험, 인공지락시험을 통해 임피던스를 예측하는 현행 방식 대비 열차운행 중단 없이 다수의 데이터를 확보할 수 있고 시간경과에 따른 임피던스 변화에 대해서도 신속하고 편리하게 대응할 수 있는 장점이 있는 것으로 판단된다.