• 자동차안전학회지
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• 제8권3호
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• pp.10-15
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• 2016

The purpose of this study is to evaluate the injury mechanism of facial injury related to an air-bag's deployment in occupant motor vehicle accident (MVA) by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 309 patients with agreement for an investigation, thirty five (11.3 %) were the severe who had ISS over 15. And also, sixteen (5.2%) derived from the reconstructed data (maximum collision energy, maximum acceleration, delta V) by PC-Crash. As a result, ISS including the facial injuries was affected by the condition. It was high when the number of crash extent, the safety belt was not fastened, and the seating position of occupant and the direction of collision is same. For accurate analysis of the relationship between occupant injury and vehicle damage in MVAs, build-up of an in-depth database through carrying out various policies for motor vehicle accidents is necessary for sure.

• 한국재료학회지
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• 제18권5호
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• pp.235-240
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• 2008

This paper presents results and observations obtained from a study of the optical and thermal properties of alkali tellurite depending on the composition. Fourier transform infrared (FT-IR) spectra showed evidence of chemical modification from $TeO_4$ trigonal bipyramids (tbp) to $TeO_3$ trigonal pyramids (tp) in tellurite glasses. The optical band gaps of the different glass samples calculated using Tauc's method were found to range from 3.5-3.8 eV. The glass transition temperature (Tg) and glass stability (${\Delta}T$) of alkali tellurite glasses were investigated, as $M_2O$ [M: Li, Na, K] amounted to 25 mol%, through the use of differential thermal analysis (DTA). The coefficient of thermal expansion (CTE) was measured in a thermo mechanical analysis (TMA) with a slow heating rate after the glass samples were annealed. The results confirm that the optical band gap of alkali tellurite glasses depends on the Te-O-Te structural relaxation related to the ratio of bridging/non bridging oxygen (BO/NBO). In contrast, the thermal properties are related to the ionic field strength of the Te-O-M and M-O-M bonds, and the Te-O-Te breakage depends on the ratio of BO/NBO.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1277-1279
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• 1994

In the structure of ZnO/nip-SiC: H/metal substrate amorphous silicon (a-Si:H) solar cells, the effects of inserting a rear textured ZnO in the p-SiC:H/metal interface and a graded bandgap buffer layer in the i/p-SiC:H have been analysed by computer simulation. The incident light was taken to have an intensity of $100mW/cm^2$(AM-1). The thickness of the a-Si:H n, ${\delta}$-doped a-SiC:H p, and buffer layers was assumed to be $200{\AA},\;66{\AA}$, and $80{\AA}$, respectively. The scattering coefficients of the front and back ZnO were taken to be 0.2 and 0.7, respectively. Inserting the rear buffer layer significantly increases the open circuit voltage($V_{oc}$) due to reduction of the i/p interface recombination rate. The use of textured ZnO markedly improves collection efficiency in the long wavelengths( above ${\sim}550nm$ ) by back scattering and light confinement effects, resulting in dramatic enhancement of the short circuit current density($J_{sc}$). By using the rear buffer and textured ZnO, the i-layer thickness of the ceil for obtaining the maximum efficiency becomes thinner(${\sim}2500{\AA}$). From these results, it is concluded that the use of textured ZnO and buffer layer at the backside of the ceil is very effective for enhancing the conversion efficiency and reducing the degradation of a-Si:H pin-type solar cells.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.47-47
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• 2003

The presenilin 1 (PS1) or PS2 is an essential component of the ${\gamma}$-secretase complex, which mediates the intramembrane proteolysis of selected type-I membrane, including the ${\beta}$-amyloid precursor protein (APP) to yield A${\beta}$. Familial Alzheimer's disease (FAD)-associated mutations in presenilins give rise to an increased production of a highly amyloidogenic A${\beta}$42. In addition to their well-documented proteolytic function, the presenilins play a role in calcium signaling. We have previously reported that presenilin FAD mutations cause highly consistent alterations in intracellular calcium signaling pathways, which include deficits in capacitative calcium entry (CCE), the refilling mechanism for depleted internal calcium stores. However, molecular basis for the presenilin-mediated modulation of CCE remains to be elucidated. In the present study, whole-cell patch clamp method was used to identify a specific calcium-permeable ion channel current(s) that is responsible for the CCE deficits associated with FAD-linked PS1 mutants. Unexpectedly, both voltage-activated and conventional store depletion-activated calcium currents I(CRAC), were absent in HEK293 cells, which were stably transfected either with wild-type or FAD mutant (L286V, M146L, and delta E9) forms of PS1. Recently, magnesium-nucleotide-regulated metal cation current, or I(MagNum), has been described and appears to share many common properties with I(CRAC) including calcium permeability and inhibitor sensitivity (e.g. 2-APB). We have detected I(MagNum) in all 293 cells tested. Interestingly, FAD mutant 293 cells developed only about half of currents compared to PS1 wild type cells.

• 천문학회보
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• 제38권1호
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• pp.43.2-43.2
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• 2013

The local environmental effects on the triggering of active galactic nucleus(AGN) activity has been studied with many authors, but there still be controversy. We perform statistical analysis for nearby(0.01 < z < 0.05) volume limited(Mr < -19) samples with visual inspection based on Sloan Digital Sky Survey Data Release7. We inspect ~60,000 galaxy images visually to find peculiar objects which show not only ongoing merging features and tidal features, but also post merging features like ring or shell structures. We found that these peculiar features were shown at least 2 times more frequently among AGN host galaxies than non AGN galaxies, and this trend was still visible when galaxy properties such as color or stellar mass are fixed. Furthermore, L[OIII] and L(Ha) of peculiar galaxies are found to be more increased than those of normal galaxies. In order to ensure this results, we also checked it for a smaller subsample with ~2mag deeper monochromatic images provided from SDSS Stripe82 database, and found consistent results. At last, we perform the same work for pair(r_p<80kpc/h, delta_v<200km/s) systems. Because of some pair systems which do not interact gravitationally in actuality but fulfill the criteria for identification of pair system, the trends are found to be slightly weaker. We also found that line luminosities are increased consistently as projected distance between central and companion galaxy decreased, and as companion color gets bluer. Overall, the results of this study tell us that the local environment of galaxies affect the frequency as well as the strength of AGN activity. Local environmental effects, however, may not be the dominant triggering mechanism for AGN activity since the majority of peculiar galaxies are non AGN galaxies.

• 한국통신학회논문지
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• 제28권3C호
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• pp.239-247
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• 2003

본 논문에서는 기존에 제안한 바 있는 EHC(Efficient Harmonic-CELP) 부호화기에 기반한 이중 전송률(2.4/4.0 kbps)의 개선된 하모닉-CELP(Improved Harmonic-CELP: IHC) 음성 부호화기를 제안한다. 제안된 IHC는 유/무성음 판별에 따라 유성음에서는 하모닉 추정, 하모닉 양자화, 하모닉 합성 및 잡음 혼합을 통한 자연성 제어 등의 과정을 통해, 무성음에서는 고속 CELP 방식을 통해 음성신호를 부호화/복호화한다. 또한 제안된 IHC는 EHC의 유/무성음 판별과 하모닉 추정 성능을 개선한다. 피치 이득과 에너지 등을 이용한 유/무성음 판별은 프레임 내의 에너지 변화 등에 의해 재판별된다. 하모닉 부호화에서는 첨점 추출과 델타 조정 방법을 이용하여 정확한 하모닉 추정을 하고, 혼합하는 잡음의 대역과 양을 적절하게 조절하여 자연성을 제어한다. 제안된 IHC 부호화기에 성능평가 결과, 비교 부호화기인 HVXC 연산량의 약 40%이내의 연산량으로 우수한 음질을 보임을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제15권5호
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• pp.13-21
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• 2010

도립진자 시스템에서 칼만 필터링 최적의 결과를 얻기 위해서는 잡음 공분산 행열 Q, 측정잡음 공분산 행열 R과 초기 에러 공분산 행열 $P_0$와 같은 인자가 필요하다. 이러한 인자는 실제 상황에서 근사화된 값을 사용하거나 정확한 값을 알 수 없기 때문에 칼만 필터의 최적화에 영향을 미치지 않거나 이러한 공분산 행열의 스칼라 이득변화에 덜 민감한 경우를 연구의 대상으로 하고 있다. 또한 상태 측정시 에러를 예측하는 방법으로 구해진 에러 공분산 행열은 상태측정 값 보다는 공분산 행열의 이득과 연관성을 가지게 된다. 따라서 3가지 공분산 행열과 칼만 이득 그리고 에러 공분산 행열 간의 상관관계가 잡음인자인 스칼라 이득과의 연관성을 해석하고자 하였다. 본 연구는 3절에서 도립진자 시스템 모델을 간략하게 정리를 하였고 4절에서는 이러한 모델을 기반으로 하여 컴퓨터 시뮬레이션을 위한 도립진자 시스템에 대한 수학적 동적모델을 구성하고 5절에서는 이러한 인자와 스칼라 이득 값을 이용한 다양한 시뮬레이션 결과를 통하여 잡음인자의 연관성을 해석하였다.

• 천문학논총
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• 제30권2호
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• pp.565-568
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• 2015

In this work, we study the correlation between the photon index (${\Gamma}$) of the X-ray spectrum and the 2-10 keV X-ray luminosity ($L_X$) for black hole X-ray binaries (BHBs). The BHB sample is mainly from the quiescent, hard and intermediate states, with values of $L_X$ ranging from ${\sim}10^{30.5}$ to $10^{37.5}$ erg $s^{-1}$. We find that the photon index ${\Gamma}$ is positively or negatively correlated with the X-ray luminosity $L_X$, for $L_X$ above or below a critical value, ${\sim}10^{36.5}$ erg $s^{-1}$. This result is consistent with previous works. Moreover, when $L_X{\leq}{\sim}10^{33}$ erg $s^{-1}$, we found that the photon index is roughly independent of the X-ray luminosity. We interpret the above correlations in the framework of a coupled hot accretion flow - jet model. Besides, we also find that in the moderate-luminosity region, different sources may have different anti-correlation slopes, and we argue this diversity is caused by the different value of ${\delta}$, which describes the fraction of turbulent dissipation that directly heats electrons.

• 한국항공우주학회지
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• 제31권1호
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• pp.113-119
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• 2003

위성의 추진제량은 위성의 임무운용기간을 결정하는 주요 변수들 중의 하나이며, 현재 운용중인 위성의 추진제 잔량을 정확하게 예측하는 일은 향후 위성의 운용계획을 수립함에 있어 매우 중요하다. 일반적으로 인공위성의 추진제 소모량을 계측하기 위해서는 PVT 방식이나 회계식 방법이 이용되어지며, 본 논문에서는 다목적실용위성 1호의 실제 원격 측정 자료에 근거하여 상기의 두 가지 계측법을 비교, 분석하고 각각의 특징들에 대해 고찰하고 있다. 또한 위성의 주된 추력기 작동 모드인 안전모드에서 추력기를 사용하지 않는 과학임무모드로 복귀하는 과정에서 여러 단계의 자세제어모드에 따른 추진제 소모율에 대해 상세히 검토하였다. 계산결과 지구찾기모드에서 추진제 소모율이 최고치를 보였다.

• Journal of Welding and Joining
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• 제18권2호
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• pp.176-176
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• 2000

Recently developed Austenite stainless steel,309L was to overlay on 3Cr-1Mo-V-Ti-B steels, using Electroslag welding process, which wide electrodes were adopted. Transition region in welding interlayer relating to disbonding crack was investigated. Also. the effect of welding condition on the width of transition region and coarsening grains of the austenite were studied.1) With increasing welding speed the width of martensite at transient region was increased, but the amount of delta ferrite in weld metal was reduced, being fine grained.2) The form of martensite at the transition region was occured by reversible transition region, leading to increasing Ms point.3) With increasing welding speed, the grain of austenite formed at the welding interface was finer. With increasing welding current under the same welding speed, the grain size of the austenite was finer. At high current, original grain size of the austenite is coarse, but the austenite has fine grains because the austenite was transformed to martensite during cooling.4) In the case of high welding speed, the width of martensite at the welding interface was increased, but the grain size of austenite at the welding interface was finer. This indicates that the inhibition of disbonding crack may be achieved through dispersening fine carbides in the grain boudary.(Received August 3, 1999)