• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.89-94
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• 2010

This study deals with the traffic accident according to the improvement projects of frequent accident locations. The objective is to analyze the impact of improvements on the accident reduction. In pursuing the above, the study gives the particular attentions to developing the models based on the data of 70 intersections improved. The main results analyzed are as follows. First, 4 multiple linear regression accident models(total, side right-angle, rear end and side stripe accident) which were statistically significant were developed. Second, total accidents reduction by sight-distance and turning traffic flow improvements, side right-angle by sight-distance, over-speed and lane operation, rear end by turning traffic flow, signal and lane operation, and side stripe by traffic impedance improvements were analyzed. Finally, the above 4 models were evaluated to be statically significant through the correlation analysis and pair-sample t-test.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.455-462
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• 2016

This experimental study aims to evaluate the impact performance of UHPC exterior panels through high velocity impact tests. The impact performance of UHPC was compared with that of granite in terms of panel thickness, and strain histories were recoded on the rear face of panel specimens. The UHPC turned out to be a good exterior facade material, because the appearance of UHPC is natural enough and impact performance was superior to granite. After colliding, compression pulse reached to the rear face but that pulse was reflected in tension pulse with respect to the free point outside the rear face of the panel. This tension pulse caused the scabbing from the rear side, as the strain histories on the rear face showed three different regions as compression region, steady region and tension region. The shear plug deformation by shear force also was one of the primary reasons for the scabbing based on the observation. Therefore, the scabbing seemed to be affected by both tension and shear forces.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.124-125
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• 2017

레이더 센서보다 가격이 저렴한 초음파 센서를 사용하여 센서 운용에 있어 가격을 줄였다. 후측면 사각감시 시스템이 경보를 못하거나 오 경보할 수 있는 상황을 후방 카메라의 객체 인식, 탐지를 통해 초음파 센서가 미치지 못하는 영역에 대해 감지를 한다. 또한 후방 카메라와 후측면 사각감시 시스템이 ECU 내부의 통신을 하여 오류를 줄인 정보를 운전자에게 전달 할 수 있다.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.53-59
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• 2022

This paper describes an integrated control of torque vectoring and rear wheel steering using model predictive control. The control objective is to minimize the yaw rate and body side slip angle errors with chattering alleviation. The proposed model predictive controller is devised using a linear parameter-varying (LPV) vehicle model with real time estimation of the varying model parameters. The proposed controller has been investigated via computer simulations. In the simulation results, the performance of the proposed controller has been compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the lateral stability and handling performance.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2E
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• pp.60-65
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• 2009

The present study aims to investigate the effects of sound diffusers and absorbers on the sound clarity in classrooms. In order to do this, computer simulations were carried out to find the effective area of treatment which could enhance the sound clarity in the room. Acoustic measurements were undertaken in a lecture room with several conditions changing the surface of walls and ceilings with diffusers and absorbers. Diffusion and absorption treatments were applied to the side walls, rear wall and the ceiling of the classroom. SPL, RT, D50, RASTI were measured at 9 measurement points with one sound source and MLS was used as the sound source signal. The results show that higher sound clarity was obtained when diffusers were applied to rear walls and ceiling rather than side walls. Also, it was confirmed that absorption increased sound clarity more effectively with smaller amount in comparison with diffusers. It was also concluded that the effects of sound diffusers and absorbers on the sound clarity could be obtained distinctly at the rear area of the classroom.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.45-49
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• 2010

The automotive industry has shown a growing interest in tube hydroforming during the past years. The advantages of hydroforming (less thinning, a more efficient manufacturing process, etc.) can, for instance, be combined with the high strength of extra high strength steels, which are usually less formable, to produce structural automotive components which exhibit lower weight and improved service performance. Design and production of tubular components require knowledge about tube material and forming behavior during hydroforming and how the hydroforming operation itself should be controlled. These issues are studied analytically in the present paper. In this study, the whole process of rear sub-frame parts development by tube hydroforming using AA6061 material is presented. At the part design stage, it requires feasibility study and process design aided by CAE (Computer Aided Engineering) to confirm hydroformability in details. Effects of parameters such as internal pressure, axial feeding and geometry shape in automotive rear sub-frame by hydroforming process were carefully investigated. Overall possibility of hydroformable rear sub-frame parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of tube material on every forming step such as pre-bending and hydroforming. In addition, all the components of prototyping tool are designed and interference with press is examined from the point of geometry and thinning.

• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.33-39
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• 2015

This study examined the drivers' acceptance level of various active safety features with Korean drivers on Seoul urban and city roads. The test vehicle, 2013 Cadillac ATS, was equipped with FCA(Forward Collision Alert), LDW(Lane Departure Warning), SBZA(Side Blind Zone Alert), FRPA(Front/Rear Park Assist), RCTA(Rear Cross Traffic Alert), ACC(Adaptive Cruise Control), and AEB(Autonomous Emergency Braking). Participants had chances to run the tests on those systems in the parking lot accompanied by the 106km long stretch of predetermined route including local road and interurban highway in Seoul and Gyeonggi-do under normal traffic flowing environment. After the test, participants completed a series of questionnaires about the features they experienced. The results revealed that RCTA and SBZA systems received more favourable ratings compared to the other features in avoiding crashes. The respondents preferred sound alerts to haptic ones even though haptic warning methods were better in providing directional information.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.1
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• pp.97-109
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• 2014

This study developed a functional dress shirt for adult males that reflected the body surface variation of a human body section by motion. This study conducted a 3D body scan for 8 subjects in their 40's based on the Size Korea 2010 database. Data recorded the proper posture change value and body surface change value to develop functional dress shirts for adult males. We scanned the subjects with a 3D body scanner for five primarily male wearing dress shirts and operating postures, right standing, arms raised to $90^{\circ}$ horizontal forward position, arms raised $90^{\circ}$ to the horizontal position side, lift up the arm $180^{\circ}$, and arm forward $90^{\circ}$ in a bent posture. We analyzed the 3D scan data from those motions to examine change of length using 3D software Rapidform XOS. The results indicated that the body surface sections with contraction were the front and rear shoulder area, armpit and central length as well the width of arms at more than 10%. The increased body section included the body and armpit back length; in addition, the rear arm vibration girth and under arm girth were more than 10%. In order to reflect the size variation of for each motion, the ease amount of the front and rear shoulder length and width needs to be reduced 20% because it affects the shoulder length during the right standing. The results suggest that the ease amount of the shoulder length should be minimal. The ease amount of the back size needs to be 0.5-2cm bigger and set 0.5-1.5cm longer than the dress shirt length side drooping to compensate for the side length shortage of each motion. The sleeve length needs to be 0-0.5cm shorter, and ease amount of the girth of sleeve bottom needs to be reduced 0-0.7cm due to the size variation of arms. However, the girth of the rear arms is suggested to be 0-0.6cm longer in the ease amount to the rear arm girth as the extension is more than 10% over the width and length of each motion.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.975-978
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• 2007

This paper investigates stage acoustics in concert halls for ensemble performance in terms of stage support parameters. A concert hall with large stage area was selected. Objective measurements were carried out according to Gade's methods for investigating stage support (ST1). The sound field on the stage was evaluated using stage and audience acoustical parameters. According to the positions at stage, different acoustical characteristics were found. Higher ST1 and lower $IACC_{E3}$ were measured near side and rear stage walls. In case of conductor/soloist vs. orchestra player, objective measurement of acoustical parameters shows that early sound fields depend on the source-receiver distance but late sound fields depend on the location of side and rear walls. In addition, in-situ evaluation of the trio instrumentalists was carried out. Results show that ensemble is favored by higher early reflection of sounds and sound diffusion affecting ‘blending’ of their performance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.158-159
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• 2017

In this study, it evaluate the strain properties of fiber reinforced concrete and fiber reinforced cement composite. The types of fiber are Hooked steel fiber and it was mixed 0.5, 1.0 vol.% in concrete and 1.0, 2.0 vol.% in cement composites. The impact test was conducted by using a projectile (diameter: 25mm, velocity: 170m/s) and strain properties on the rear side of each specimen was evaluated by strain gage. After the impact test, fracture grade, fracture depth was evaluated.