• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.148-161
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• 2015

The examples that used camera in the vehicle is increasing with the growth of the automotive market, and the importance of the image processing technique is expanding. In particular, the Lane Departure Warning System (LDWS) and related technologies are under development in various fields. In this paper, in order to improve the lane recognition rate more than the conventional method, we extract a Normalized Luminance Descriptor value and a Normalized Contrast Descriptor value, and adjust image gamma values to modulate Normalized Image Quality by using the correlation between the extracted two values. Then, we apply the Hough transform using the optimized accumulator cells to the four-channel ROI. The proposed algorithm was verified in 27 frame/sec and $640{\times}480$ resolution. As a result, Lane recognition rate was higher than the average 97% in day, night, and late-night road environments. The proposed method also shows successful lane recognition in sections with curves or many lane boundary.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.83-94
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• 2016

Providing a voice alarm to drivers approaching a work zone could be an effective alternative to mitigate the potential safety problems of the work zone. This study conceived a voice alarm with a direction sound speaker and a field test was conducted that evaluated the feasibility of the voice alarm at a highway work zone. During the field study, we carried out on-site driver surveys to obtain drivers' perception and preference, collected approaching speeds, and measured sound level during the off-peak 2-hour for two days, respectively. The results showed that while the voice alarm has the potential to be an effective tool in improving safety, the alternative appeared to have the negative effect of noise. Further refinement to a voice alarm with a directional speaker is required to improve feasibility, and the results are expected to be utilized as basic data useful for the refinement.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.114-122
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• 2011

We propose an automatic localization technique based on Uniform Arc Length Sampling (UALS) of 360 degree range sensor data. The proposed method samples 3D points from dense a point-cloud which is acquired by the sensor, registers the sampled points to a digital surface model(DSM) in real-time, and determines the location of an Unmanned Ground Vehicle(UGV). To reduce the sampling and registration time of a sequence of dense range data, 3D range points are sampled uniformly in terms of ground sample distance. Using the proposed method, we can reduce the number of 3D points while maintaining their uniformity over range data. We compare the registration speed and accuracy of the proposed method with a conventional sample method. Through several experiments by changing the number of sampling points, we analyze the speed and accuracy of the proposed method.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.615-624
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• 2014

The fin-tube heat exchanger being used for industrial boiler, radiator, refrigerator has been conducted in various studies to improve it's performance. In this study, the characteristics of heat transfer and pressure drop was theoretically analyzed according to longitudinal pitch, location of vortex generator, bump phase and number of the tube surface about the plain fin-tube heat exchanger. The boundary condition for the CFD (Computational Fluid Dynamics) analysis applied with the SST (Shear Stress Transport) turbulence model assumed as the tube surface temperature of 333 K, the inlet air temperature of 423-438 K and the inlet air velocity of 1.5~2.1 m/s. The analysis results indicated that the heat transfer coefficient is not affected highly by the longitudinal pitch, and the heat transfer characteristics was more favorable when the vortex generator was located in front of the tube. Also the bump phase of the tube surface indicated that circle type was more appropriate than serrated type and triangle type in the characteristics of heat transfer and pressure drop, and the sixteen's bump phase of circle type was most favorable.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.425-433
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• 2009

The purpose of this study was to investigate relation between fastball motion and longtoss motion, and the kinematical analysis using APAS(Ariel Performance Analysis System). Eight people(age: $21.2{\pm}3.6years$, height: $177.1{\pm}3.1cm$, weight $68.6{\pm}2.5kg$) participated in the experiment. Followings are the conclusion. In displacement of fore-aft on COG(Center of Gravity), fastball motion moved more forward than longtoss motion. In displacement of vertical on COG(Center of Gravity), fastball motion was lower than longtoss motion In velocity of right hand, greater release velocity was measured for fastball motion than for longtoss motion. In displacement of elbow and shoulder joint, more extended displacement was exhibited in fastball motion than longtoss motion. In displacement of trunk tilt, fastball motion showed foreward tilt, longtoss motion showed backward tilt. In stride, fastball showed longer than longtoss.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.127-135
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• 2009

Most traffic information that drivers receive while driving are stored in their short-term memory and disappear within a few seconds. Contemporary modeling approaches using a dummy variable can't fully explain this phenomenon. As such, this study proposes to use utility functions of real-time in-vehicle traffic safety information (IVTSI), analyzing its safety impacts based on empirical data from an on-site driving experiment at signalized intersection approach with a limited visibility. For this, a driving stability evaluation model is developed based on driver's driving speed choice, applying an ordered probit model. To estimate the specified utility functions, the model simultaneously accounts for various factors, such as traffic operation, geometry, road environment, and driver's characteristics. The results show three significant facts. First, a normal density function (exponential function) is appropriate to explain the utility of IVTSI proposed under study over time. Second, the IVTSI remains in driver's short-term memory for up to nearly 22 second after provision, decreasing over time. Three, IVTSI provision appears more important than the geometry factor but less than the traffic operation factor.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.575-582
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• 2008

본 논문은 시맨틱 웹 기술이 어떻게 국가 표준(KS) 정보 검색 서비스 내 정보들을 연계시키고 사용자 접근성을 향상시키는 데 도움을 줄 수 있는지를 실증적으로 보여준다. 기존 표준 정보 검색 서비스는 용어 검색의 유연성이 부족하여 표준 정보에서 사용된 용어와 사용자 용어 간의 괴리를 해소하지 못했으며 표준, 기관, 인력 등 상호 관련성을 가진 개체 정보들을 개별적으로 서비스하였다. 이러한 상황은 사용자의 표준 정보 검색 서비스 접근성을 떨어뜨리는 요인으로 작용한다. 본 연구에서는 유의어, 관련어를 중심으로 한 표준 용어 사전 구축을 통해 사용자 용어와 표준 정보 내 용어 간의 원활한 매칭을 지원하며, 표준 관련 개체들을 온톨로지와 추론을 통해 연계시키는 방안을 제시한다. 개선된 표준 정보 검색 서비스는 개선된 표준 정보 검색 서비스는 개체 중심적 통합 검색 결과 제공 방식으로 관련 정보들을 단일 웹 페이지 내에서 확인할 수 있도록 해준다. 예를 들어, 특정 KS 표준 검색 결과 페이지에서는 기존에 DB 접근이나 검색 엔진을 통해 바로 획득할 수 없었던 정부 표준들, 기관들의 해당 KS 표준 인용 현황, 해당 KS 표준 전문가들, 부합화를 위해 참조된 국제 표준들, 해당 KS 표준 전문가들, 부합화를 위해 참조된 국제 표준들, 해당 KS 표준 전문가 네트워크, 해당 KS 표준 내 표준 용어 사전 정보 등 다양한 관련 정보들을 조합하여 서비스한다. 본 연구를 위해 모델링된 온톨로지와 시맨틱 웹기반 서비스 프레임워크인 OntoFrame 상에서 추론 작업이 표준 정보 적재 시에 전방 추론 (Forward-chaining) 방식으로 수행되었으며, 표준 온톨로지 질의 언어인 SPARQL (SPARQL Protocol and RDF Query Language)을 이용해 일반 검색 서비스 수준의 속도로 서비스될 수 있었다.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.199-204
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• 2019

In the boundary layer, vortical system has been analyzed by the statistical methods to identify the vortex interaction. However, there are the limitations in explaining vortices by the mean velocity or the standard deviation. This paper proposed a method to establish a frequency analysis by Fourier transform in order to simultaneously investigate various scale vortices. For this purpose, the flow visualization conducted to reveal a standing vortex, a hairpin vortex and a wake region around a hemisphere attached on a flat plate in a water channel. In addition, the velocity where the hairpin vortex was being generated in the wake region was measured by a hot-film anemometer. To observe changes in the vortex interaction, suction was applied through a hole in front of the hemisphere. For the evaluation of the proposed frequency analysis, the existing statistical results were compared to the frequency analysis that corresponds to the qualitative results of the flow visualization.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.311-322
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• 2009

Using the 3-D analysis, this study winpared and analyzed the 'fade-shot swing' which is one of the golf technique. The subjects of this study were 3 male pro golfers they experimented with only a 7 iron. The purpose was to enhance their performance by producing the important kinematical parameters, finding out the features in them and providing the data to a coach and players. As a result, the position of the club head showed from the outside orbit to the inside orbit. When position of the center of mass moved backwards, the probability of the failure of the fade-shot increased. Cocking angle had an effect on easing the wrist for a smooth follow-through after the impact. It showed that the changes in the shoulder movement was made first and followed by the waist. The hip joint angular velocity achieved a smooth fade-shot motion due to the hitting delay also the velocity of the club-head was faster when uncocking was released at the time of impact.

• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.171-178
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• 2003

Lately most Asian countries have tried to develop their ports into a hub port in their region. However, only a few studies examined the theoretical rationale for hub port strategy. Thus, this paper aim to identify the effectiveness of hub port development strategy in global and regional perspectives, respectively. For this aim, the paper conducts regression analysis on the relationship between port size and growth ad calculates the Hirshman-Herfindahal Index on Asian container ports. According to the empirical results, larger ports have grown faster than smaller ports in the world container ports und European/North American ports. However, in the case of the Asian container ports, the result was opposite. And port concentration in Northeast Asian ports is decreasing gradually during the last two decades. Consequently, the effectiveness of hub port development strategy was not very strong in Northeast Asian region.