• 한국컴퓨터그래픽스학회논문지
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• 제17권4호
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• pp.31-40
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• 2011

프로젝터 기반의 가시화 시스템은 가상현실 흑은 체험형 응용에서 널리 사용된다. 그러나 스크린 재질과 반사 성질에 따라 스크린 상의 투사 밝기의 불균일성이 때때로 체험자의 체험을 방해할 수 있다. 이러한 현상은 체험자의 위치를 추적하는 시스템인 CAVE 혹은 운동판 체험 시스템의 체험자가 시스템 안에서 계속적으로 움직일 경우에는 특별히 문제가 될 수 있다. 스크린 화상 상에 밝기의 불균일성을 만드는 이유 중에 하나는 참여자의 눈의 위치로의 프로젝터와 스크린의 스펙큘라 반사이며, 이에 대한 분석은 높은 계산 복잡도가 요구된다. 그래픽 프로세서의 프로그래머블 쉐이더를 이용하여 스펙큘라 라이팅 요소를 계산하는 것과 마찬가지로, 본 연구에서는 밝기의 불균일성을 줄이기 위하여 주어진 스크린 환경 3D 모델을 가지고 수행 시간에 모든 화소의 밝기를 조정하였다. 이러한 목적을 위하여 개개의 스크린 응용에 따른 각도 기반의 밝기 보정 함수를 고안하였으며, GPU 상에서 수행과 접근을 용이하도록 하였다. 두가지 기법이 구현되었는데, 각도 기반의 접근에서 프로덕트 기반의 접근으로 변환과 구간 선형 보간 근사 기법을 구현하였다.

• 대한원격탐사학회지
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• 제28권1호
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• pp.39-54
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• 2012

본 연구의 목적은 KOMPSAT-2 위성영상에 가장 일반적으로 적용 가능한 영상융합기법을 제시하는 것이다. 가장 널리 사용되는 영상융합기법인 HPF, modified IHS, pan-sharpened, wavelet을 지역적, 계절적 특성이 서로 다른 4장의 KOMPSAT-2 위성영상에 적용하였고, 각각의 융합결과를 공간적, 분광적으로 비교분석하였다. 영상융합기법의 품질평가는 시각적 분석과 정량적 분석을 병행하여 수행하였으며, 정량적 분석에는 spatial ERGAS, spectral ERGAS, SAM, Q4가 사용되었다. 종합적인 분석결과를 고려할 때, pan-sharpened가 색상정보와 공간정보의 균형적인 보존 측면에서 다른 융합기법들에 비해, 상대적으로 우수한 결과를 나타냈다. modified-IHS의 경우, 공간정보는 잘 보존하였지만 다소 큰 색상 왜곡이 발생되었고, HPF와 wavelet은 색상 왜곡은 적었지만, 공간정보의 왜곡이 발생하였다.

• BMB Reports
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• 제50권2호
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• pp.60-70
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• 2017

Glaucoma is characterized by a slow and progressive degeneration of the optic nerve, including retinal ganglion cell (RGC) axons in the optic nerve head (ONH), leading to visual impairment. Despite its high prevalence, the biological basis of glaucoma pathogenesis still is not yet fully understood, and the factors contributing to its progression are currently not well characterized. Intraocular pressure (IOP) is the only modifiable risk factor, and reduction of IOP is the standard treatment for glaucoma. However, lowering IOP itself is not always effective for preserving visual function in patients with primary open-angle glaucoma. The second messenger cyclic adenosine 3',5'-monophosphate (cAMP) regulates numerous biological processes in the central nervous system including the retina and the optic nerve. Although recent studies revealed that cAMP generated by adenylyl cyclases (ACs) is important in regulating aqueous humor dynamics in ocular tissues, such as the ciliary body and trabecular meshwork, as well as cell death and growth in the retina and optic nerve, the functional role and significance of cAMP in glaucoma remain to be elucidated. In this review, we will discuss the functional role of cAMP in aqueous humor dynamics and IOP regulation, and review the current medications, which are related to the cAMP signaling pathway, for glaucoma treatment. Also, we will further focus on cAMP signaling in RGC growth and regeneration by soluble AC as well as ONH astrocytes by transmembrane ACs to understand its potential role in the pathogenesis of glaucoma neurodegeneration.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 추계학술발표회
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• pp.9-13
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• 2006

해양사고에 있어서 사고조사는 선박충돌사고 원인을 알아내는 중요한 절차 중에 하나이다. 본 논문에서는 선박조종 시뮬레이터 기술을 이용한 선박충돌사고 재현 시스템이 해양사고가 해양안전심판정에서 쉽게 시각적으로 표현되는 것을 서문으로 붙인다. 이 시스템에서는 사용자가 선박의 종류와 사고의 위치를 선택하게 되면 선박 충돌 진행 상황이 2D 와 3D Visual 화면으로 제공된다. 이 시스템은 또한 사고의 원인을 알아내는데 유용하게 이용되는 다양한 View Point를 포함하여 안개상황 흑은 주야간 등 시각적인 환경도 제공된다.

• 대한의용생체공학회:의공학회지
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• 제38권2호
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• pp.57-61
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• 2017

The purpose of this study was to investigate the effect of direction (pitch and roll) on the perception of support surface rotation while standing. Thirty young healthy subjects participated in this study. Support surface was rotated at an unexpected instant in a very slow speed (0.2 deg/s). The direction of support surface rotation was randomly chosen among pitch (forward and backward) and roll (right and left) directions. The experiment was performed with eyes open and closed. Perception performance was evaluated by the perception threshold, defined as the rotation angle of the surface at the instant when a subject recognized that the support surface was moving. Results showed that the perception threshold was smaller for roll directions than pitch directions irrespective of vision and gender (p < 0.01). This indicates that the perception of support surface rotation is more sensitive in roll direction than in pitch direction. Among three sensory functions related to postural perception, the effect of vestibular and visual functions on the direction difference of the perception should be little because of the very slow surface rotation and independence on visual conditions. Therefore, the direction dependence of perception would have been affected mainly by the somatosensory function.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1303-1308
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• 2007

Recently, precast concrete tracks are replacing ballast track for efficient and economic maintenance of track. Precast concrete railroad tracks are manufactured in factory, and transported to railroad construction site for installation. Therefore, quality of precast concrete track itself should be sufficiently good. On the contrary to the convenient manufacturing of precast concrete track, the installation of a precast concrete track requires careful steps. Typically, a precast concrete track is placed on an approximately 15-cm thick lean concrete layer. A mortar is filled between lean concrete layer and precast concrete track to adjust the sloping angle of a precast concrete track for a safe train operation at a curvy section. Then, the use of filled mortarproduces a void underneath a precast concrete track, which is harmful to structural safety of a precast concrete track undercyclic loading. Therefore, it is essential to make sure that there is no void left beneath a precast concrete track after mortar filling. In the continuous resonance method, the amplitude of frequency response measured using an instrumented hammer and an accelerometer is plotted against a pseudo-depth, which is half of the wave velocity divided by frequency. The frequency response functions are measured at consecutive measurement locations, 6-cm interval between measurement points, and then combined together to generate a 2-D plot of frequency response. The sections with strong reflections or large amplitude of frequency response are suspicious areas with internal voids and unfilled areas. The 2-D frequency response plot was efficient in locating problematic sections just by examining the color shade of a visualized plot in 2-D format. Some of the problematic sections were drilled to make a visual inspection of mortar filling. The visual image of interface between mortar and precast concrete track was verified using the validity of the continuous resonance technique adopted in this research.

• 한국안광학회지
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• 제13권4호
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• pp.9-12
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• 2008

목적: 현재의 방독면은 안경을 착용하는 사람들에게는 매우 불편한 구조로 되어 있다. 이를 개선하여 군인이나 소방관들이 자신을 보호하고 인명을 구조하는데 도움이 되도록 하였다. 방법: 외면렌즈와 내면의 시력보정용 렌즈의 2중 구조로 되어 있는 것을 아크릴 프레임을 방독면에 부착하는 단일 구조로 변경하고 실리콘 차단제를 이용하여 렌즈와 프레임 사이를 밀폐하여 가스의 유입을 방지하게 하였다. 렌즈에서 발생하게 되는 비점수차제거와 정간거리 유지를 위해 S자형의 프레임으로 개발하였다. 결과: 완전한 시력교정과 가스차단이 가능하고 일반 안경처럼 안경렌즈를 교환하여 사용할 수 있게 되었으며 시선과 렌즈면의 경사로 발생하던 비점수차 0.53D~1.78D, 짧은 정간거리로 발생하던 0.07D~0.66D의 과교정, 전경각 미설정으로 발생하던 0.1D~0.3D의 비점수차를 제거할 수 있게 되었다. 결론: 방독면을 쓴 상태에서도 밝은 시야의 확보가 가능하여 전투력 향상과 인명구조 활동 등에서 큰 도움이 될 수 있을 것으로 예상된다.

• 한국조경학회지
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• 제35권6호
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• pp.74-83
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• 2008

As urban residents' standard of living has recently risen, efforts to improve urban landscapes have increased. It is very important to manage streetscapes to improve the urban landscape because they are one of the essential elements in city construction and urban landscaping. This study focuses on the indicators that manage streetscapes more accurately and realistically. To achieve this purpose, this study used dynamic simulations considering shape and layout of buildings, the primary factors in streetscapes. This study can be summarized as follows: 1. Two indicators to manage streetscape were investigated in previous studies: one to increase visual openness and the other to reduce visual overstimulation. These indicators had high correlation with scenic beauty. Therefore, increasing openness and reducing overstimulation are essential to improve streetscapes. 2. Two household tower type buildings should be arranged along roadsides to increase openness and scenic beauty. However, low tower buildings with two household are not suitable along roadsides because they create monotony and intervals are needed between buildings. 3. To increase openness, the angled arrangement of buildings is suggested $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for low buildings, $30^{\circ}{\sim}45^{\circ}(135^{\circ}{\sim}150^{\circ})$ for mid-sized buildings, and $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for high buildings. 4. To reduce overstimulation, the height and setback control regulations should be at an angle of less than $45^{\circ}$. This study suggests more accurate management guidelines by organizing the indicators that could effectively manage streetscapes and by overcoming limitations of reality shown in a static simulation.

• KIEAE Journal
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• 제7권1호
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• pp.65-72
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• 2007

As ecological design elements, daylighting can be applied to provide adequate illumination on visual tasks to create an attractive visual environment and to save electrical energy. Daylighting control systems reject direct sunlight and penetrate it onto the ceiling or to deep into the room. This study aims to evaluate the luminance environment of sloped light guide with automated venetian blind systems according to sun angle changes. For evaluation, a mock-up model was used and the south facing side-window mounted between the clerestory window and the view window. To assess luminance performance, 3 view points of luminance were monitored. As results, the conventional and lightshelves show ideal luminance ratio between workplane and surroundings(3:1) and workplane and darkness area(2:1) due to total ratio of surroundings and darkness area has lower ratio than workplane. Compared to the lightshelves window, conventional window shows unrelieved effect in between the workplane and brightness area(1:5). It means that there has low deviation according to the required standards. Also, compared to the ratio between the brightness area and darkness area(2~6:1) conventional window with high deviation(10~20:1) provide discomfort glare due to the excessively strong contrast, while lightshelves window shows a required luminance ratio that provide a three-dimensional effect to occupants. Therefore, luminance distribution indicate that application of a lightshelves and blinds not only has a significantly positive effect but also offers higher luminance quality in a daylit room

• 대한물리치료과학회지
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• 제16권1호
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• pp.11-20
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• 2009

Background: The purpose of this study was to investigate the effect of stretching and strengthening exercise on the static flexibility and pain intensity for the iliopsoas muscle, which is one of the main reasons for the chronic low back pain. Methods: The subjects of this study were 15 male adult patients with showed 6 score or higher in the visual analogue scale(VAS) and complained of low back pain over three months who visited department of the physical therapy, KIA motors Industrial Health Center, from October, 2008 through December, 2008. Fifteen subjects were trained stretching, mat exercises and sling exercises for iliopsoas muscle at 4-5 times a week for 4 weeks. I measured the changes on the extensibility of iliopsoas muscle, static flexibility of low back and VAS between pre- and post exercise treatment. Date were analyzed using the Wilcoxon's signed rank test considering the size of the samples. Results: 1. The angle of the hip joint that showed the extensibility of iliopsoas muscle was relieved, which was significant statistically (p<.05). 2. The static flexibility was statistically significantly improved in the trunk flexion test, trunk extension test and Schober-Test (p<.05). 3. The VAS showed decrease, which is significant statistically (p<.05). Conclusion: It is believed that the exercise treatment of iliopsoas muscle has the significant effects on the improvement of static flexibility and decrease of pain intensity for the chronic low back pain patients.