• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.5-10
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• 2012

Whiplash is the most frequent injury among occupants in low speed rear-end car collision. The aim of this paper is to analyze thecorrelation between influence parameters of head restraints and whiplash injury criteria.In this paper, DFSS (Design for Six Sigma) method is used for optimum design of head restrains. Four control factors of head restraints have selected by function matrix method. The effects of the control factors have been experimentally evaluated by using a sled pulse from 16km/h relative velocity which is suggested by KNCAP (Korean New Car Assessment Program). In order to reduce the noise factors of dynamic tests, whiplash tests were repeated twice. By using DFSS, the correlation between control factors and injury criteria has been comprehended.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.642-653
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• 2008

This study deals with modeling of head-related transfer functions(HRTFs) using principal components analysis(PCA) in the time and frequency domains. Four PCA models based on head-related impulse responses(HRIRs), complex-valued HRTFs, augmented HRTFs, and log-magnitudes of HRTFs are investigated. The objective of this study is to compare modeling performances of the PCA models in the least-squares sense and to show the theoretical relationship between the PCA models. In terms of the number of principal components needed for modeling, the PCA model based on HRIR or augmented HRTFs showed more efficient modeling performance than the PCA model based on complex-valued HRTFs. The PCA model based on HRIRs in the time domain and that based on augmented HRTFs in the frequency domain are shown to be theoretically equivalent. Modeling performance of the PCA model based on log-magnitudes of HRTFs cannot be compared with that of other PCA models because the PCA model deals with log-scaled magnitude components only, whereas the other PCA models consider both magnitude and phase components in linear scale.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.443-448
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• 2014

This paper is a study related to fault tolerant design based on PSTR using virtualization techniques. If the fault tolerant PSTR based on virtualization techniques is implemented the communication performance between primary and shadow will improves and monitoring function is easy to available about activities of primary and shadow. The legacy PSTR model is implemented in its hardware. The primary play a main role and shadow play a switched action when the errors occurrs in the primary. The switched action of shadow make it possible to restart the primary function newly. This paper implements fault tolerant primary-shadow model using virtualization techniques on the embedded environment.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.417-418
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• 2007

본 논문에서는 입체음향을 2채널로 재생할 때 이동음이 부드럽게 생성되도록 하는 방법에 대해 연구한다. 일반적으로 이동음 효과 생성을 위해 머리전달함수(Head Related Transfer Function : HRTF)의 주파수 영역에서의 보간을 사용한다. 하지만 특정 점에서 측정된 머리전달함수를 이용하여 이동하는 음을 생성하기 때문에 클릭음 발생, 보간 특성의 변화 등의 문제점이 발생하게 된다. 이 같은 문제점을 해결하기 위해 본 논문에서는 이동음의 궤적 상에 있는 머리전달 함수들을 그룹화하여 이동음의 구현에 사용한다. 위와 같은 방법으로 구현된 이동음의 성능 평가 결과 보다 자연스러운 이동음이 생성되는 것을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.6
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• pp.94-103
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• 2001

The goal of using numerical methods in this study is two-fold: to replicate a set of measured, individualized HRTFs by a computer simulation, and also to visualise the resultant sound field around the head. Two methods can be wed: the Boundary Element Method (BEM) and the Infinite-Finite Element Method (IFEM). This paper presents the results of a preliminary study carried out on a KEMAR dummy-head, the geometry of which was captured with a high accuracy 3-D laser scanner and digitiser. The scanned computer model was converted to a few valid BEM and IFEM meshes with different polygon resolutions, enabling us to optimise the simulation for different frequency ranges. The results show a good agreement between simulations and measurements of the sound pressure at the blocked ear-canal of the dummy-head. The principle of reciprocity provides an effect method to simulate HRTF database. The BEM was also used to investigate the total sound field around the head, providing a tool to visualise the sound field for different arrangements of virtual acoustic imaging systems.

• The Journal of the Acoustical Society of Korea
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• v.28 no.6
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• pp.557-565
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• 2009

To perceive the direction and the distance of a sound, we always use a couple of information. Head Related Transfer Function (HRTF) contains the information that sound arrives from a sound source to the ears of the listener, like differences of level, phase and frequency spectrum. For a reproduction system using 2 channels, we apply HRTF to many algorithms which make 3d sound. But it causes a problem to localize a sound source around a certain places which is called the cone-of-confusion. In this paper, we proposed the new algorithm to reduce the confusion of sound image localization. The difference of frequency spectrum and psychoacoustics theory are used to boost the spectral cue among each directions. To confirm the performance of the algorithm, informal listening tests are carried out. As a result, we can make the improved 3d sound in 2 channel system based on a headphone. Also sound quality of improved 3d sound is much better than conventional methods.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.116-119
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• 2006

본 논문에서는 자동차후면추돌이나 에어백시험 등에서 인체모형의 중요한 평가지수인 목 상해를 평가 할 수 있는 평가시스템에 대하여 연구하였다. 목 상해($N_{ij}$) 기준만족여부를 판단하기 위하여 Diadem 프로그램을 이용하여 더미(Dummy)의 종류별, 시험의 조건별로 자동으로 계산되는 평가시스템을 개발하여 목 상해 기준을 보다 편리하고 정확하게 계산 할 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.538-540
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• 1998

본 논문은 고개를 상/하로 끄덕이거나 좌/우로 가로 저어서 긍정과 부정을 구별하기 위한 것이다. 다시 말해서, 마우스나 키보드 대신에 머리의 움직임을 사용해서 '예/아니오'를 인식한다. 본 논문에서는 정규화된 칼라 공간(chromatic color space)과 조도(illumination)를 이용하여 얼굴 영역을 찾고 분할하는 자동 얼굴 영역 찾기와 영상차의 위치 비교와 움직임 량을 이용하여 우선 순위를 갖는 단순한 방향성을 구별하는 자동 의사 인식의 두 단계로 구성되어 있다. 이러한 단순한 방향성의 조합으로 '예/아니오'를 구분한다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.574-576
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• 2000

디지털 영상 처리에서 사람 얼굴 인식은 여러 응용 분야에 요구되어 활발한 연구가 진행되어 왔다. 본 논문에서는 얼굴이 있는 칼라 영상에서 얼굴 영역을 자동으로 추출하기 위한 알고리즘을 기술한다. 영상에 있는 얼굴 및 복잡한 배경과 다른 구성 성분들을 분류시켜 표현할 수 있도록 하기 위해 다변수 히스토그램 기법을 이용하여 얼굴 후보 영역과 머리 후보영역을 추출하고, 머리와 얼굴 후보 영역들간의 상관관계를 고려하여 최종 얼굴 영역을 검출한다. 본 논문에서 제안된 방법의 성능을 검증하기 위하여 인터넷상에 있는 128개의 영상을 입력 데이터로 실험한 결과, 인식 시간이 빠르고 영상의 배경에도 강건한(robust) 효율적인 방법임을 알 수 있었다.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.207-214
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• 2008

To create 3D sound, we usually use two methods which are two channels or multichannel sound systems. Because of cost and space problems, we prefer two channel sound system to multi-channel. Using a headphone or two speakers, the most typical method to create 3D sound effects is a technology of head related transfer function (HRTF) which contains the information that sound arrives from a sound source to the ears of the listener. But it causes a problem to localize a sound source around a certain places which is called cone-of-confusion. In this paper, we proposed the new algorithm to reduce the confusion of sound image localization. HRTF grouping and psychoacoustics theory are used to boost the spectral cue with spectrum difference among each directions. Informal listening tests show that the proposed method improves the front-back sound localization characteristics much better than conventional methods.