• Journal of Korean Neurosurgical Society
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• 제56권2호
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• pp.121-129
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• 2014

Objectives : Patients with cervical ossification of posterior longitudinal ligament (OPLL) are susceptible to cord injury, which often develops into myelopathic symptoms. However, little is known regarding the prognostic factors that are involved in minor trauma. We evaluated the relationship between minor trauma and neurological outcome of OPLL and investigated the prognostic factors with a focus on compressive factors and intramedullary signal intensity (SI). Methods : A total of 74 patients with cervical myelopathy caused by OPLL at more than three-levels were treated with posterior decompression surgeries. We surveyed the space available for spinal cord (SAC), the severity of SI change on T2-weighted image, and diabetes mellitus (DM). The neurological outcome using Japanese Orthopedic Association (JOA) scale was assessed at admission and at 12-month follow-up. Results : Among the variables tested, preoperative JOA score, severity of intramedullary SI, SAC, and DM were significantly related to neurological outcome. The mean preoperative JOA were $11.3{\pm}1.9$ for the 41 patients who did not have histories of trauma and $8.0{\pm}3.1$ for the 33 patients who had suffered minor traumas (p<0.05). However, there were no significant differences in the recovery ratios between those two groups. Conclusions : Initial neurological status and high intramedullary SI in the preoperative phase were related to poorer postoperative outcomes. Moreover, the patients with no histories of DM and larger SACs exhibited better improvement than did the patients with DM and smaller SACs. Although the initial JOA scores were worse for the minor trauma patients than did those who had no trauma prior to surgery, minor trauma exerted no direct effects on the surgical outcomes.

• 한국농촌건축학회논문집
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• 제14권4호
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• pp.1-9
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• 2012

Recently, the central and local government support various improvement projects on existing public buildings and areas. Improving public use and environment of these areas is adequate because financial condition of local city is not enough to build new infrastructures. As one of the projects, Geochang-Eup(Geochang-Gun, Gyeongnam Province) is selected as the project site since most of the public buildings and areas of the city are located close each other in downtown but not streamlined in function and use nor easily accessible. The purpose of this study is to analyze the causes of decline in local city and to present strategies to vitalize the city through improving environment of public areas. And we analyzed the problems by discussion with local officer, field investigation on the site and paper survey. The analysis shows that public infrastructures are grouped by function: administration, education, life support, culture, health, etc, but not well-connected, easily accessible, adequately located, various in use nor enough in quantity. This study summarized the problems into five categories: Access&Linkage, Safe&Comfort, Identity&Image, Usage&Activity and Ownership&Management and proposes strategy in three phases. The first phase is to improve functions and design of public places per each area: more consistent design on public buildings, better civil facilities and better accessibility to public areas. The second is to vitalize of the areas and to improve efficiency in use through linking each other physically and sharing uses. The third is to encourage citizen's participation and by developing civil programs to streamline public areas each other.

• 대한핵의학회지
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• 제22권2호
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• pp.193-197
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• 1988

Measurement of gastric emptying rate has been performed by a variety of techniques. Nuclear medicine method is a major advance in the quantitative evaluation of gastric function and also of pharmacologic intervention. Normal gastric emptying rate was measured in 48 healthy volunteers using live chicken liver labeled with $^{99m}Tc-Tin$ Colloid as a solid phase marker. In vitro studies were performed to evaluate the labeling efficiency and stability in hydrochloric acid and in human gastric juice of intracellularly labeled chicken liver. Anterior image counts only were compared with the geometric mean of anterior and posterior counts in 12 healthy volunteers who were studied by both anterior count and posterior count. The results were as follows: 1) The labeling efficiency in gastric juice and hydrochloric acid were $95.5{\pm}1.23%,\;95.7{\pm}1.15%$, respectively. 2) Half gastric emptying time by anterior count only was $126{\pm}21$ minutes 3) Although standard deviation of geometric mean method was smaller than anterior count method, gastric emptying curves from both method were similar. In daily practice, anterior count method may be useful alternative to geometric mean method in evaluation of gastric emptying rate.

• 디자인학연구
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• 제11권3호
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• pp.177-185
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• 1998

영국의 산업혁명에서 태동되어 유럽 각국으로 급속히 보급, 발전된 새로운 조형예술의 개념 즉, 디자인 운동은, 제2차 세계대전 이후 더욱 발달된 산업기술과 국제화시대로 인하여 보다 새로운 국면을 맞이하게 되었다. 기업의 다양화, 전문화 그리고 국제화 등과 함께 등장한 디자인에 있어서의 아이덴티티의 개념은 모든 시각표시물의 표준화라는 작업을 통하여 그 결과의 나타나게 되었고, 또한 이러한 개념은 상품판매에 의한 이윤의 극대화를 목표로 하고 있는 기업에서뿐만 아니라 국가기관이나 학교, 병원 또는 각종 종교단체 등과 같은 공공기관 및 단체에서도 도입하여 적극 활용하고 있는 실정이다. 1910년 개교한 이래 90여 년이라는 역사와 전통을 갖고 있는 서울산업대학교는 그 동안 여러 가지 교 명의 변경과 함께 주변환경과 시대적 특성에 맞는 나름대로의 시각 표시 물을 사용해 왔으나, 1998년 학교 영문명칭의 변경으로 인하여 새로운 도약의 계기를 맞게 되었다. 그러므로 이에 따른 새로운 이미지의 표방과 함께 U.I.)University Identification)라는 개념을 정식으로 도입하여 최초로 매뉴얼을 제작하게 되었으며 이는 시대적 추세에 의한 필연적 결과라 할 수 있다.

• Wind and Structures
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• 제26권6호
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• pp.397-413
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• 2018

Excitation mechanism of interference effect between two tall buildings is investigated with wind tunnel experiments. Synchronized building surface pressure and flow field measurements by particle image velocimetry (PIV) are conducted to explore the relationship between the disturbed wind flow field and the consequent wind load modification for twin buildings in tandem. This reveals evident excitation mechanisms for the fluctuating across-wind loads on the buildings. For small distance (X/D < 3) between two buildings, the disturbed flow pattern of impaired vortex shedding is observed and the fluctuating across-wind load on the downstream building decreases. For larger distance ($X/D{\geq}3$), strong correlation between the across-wind load of the downstream building and the oscillation of the wake of the upstream building is found. By further analysis with conditional sampling and phase-averaged techniques, the coherent flow structures in the building gap are clearly observed and the wake oscillation of the upstream building is confirmed to be the reason of the magnified across-wind force on the downstream building. For efficient PIV measurement, the experiments use a square-section high-rise building model with geometry scale smaller than the usual value. Interference factors for all three components of wind loads on the building models being surrounded by another identical building with various configurations are measured and compared with those from previous studies made at large geometry scale. The results support that for interference effect between buildings with sharp corners, the length scale effect plays a minor role provided that the minimum Reynolds number requirement is met.

• 한국콘텐츠학회논문지
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• 제9권1호
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• pp.215-222
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• 2009

3D 애니메이션은 사실의 완벽한 재현이라는 큰 특징으로 종래에 불가능했던 이미지의 완성을 가능하게하며 보다 큰 환상을 창출한다. 사실의 모방에서 진일보한 창의적인 이미지의 제작은 내용의 중요성을 강조한다. 크리스 랜드레스는 이러한 기술적 만족도와 내용적 우수성 그리고 충격에 가까운 참신함으로 차별화된 3D 애니메이션을 제작한다. 그의 1998년도 작품인 빙고(Bingo)에서 매스미디어의 근원적 아이로니와 인간의 존재론적 고민을 부조리극 표현으로 풀어냄으로써 인간의 상황에 통찰력을 갖게 한다. 크리스 랜드레스의 3D 애니메이션은 이러한 점에서 미술사와 연극사를 넘나드는 폭넓은 포용과 테크놀로지의 확장으로 3D 애니메이션의 새로운 가능성을 보여주고 있다.

• Journal of Computing Science and Engineering
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• 제9권4호
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• pp.204-213
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• 2015

Under the conditional independence assumption among local features, the Naive Bayes Nearest Neighbor (NBNN) classifier has been recently proposed and performs classification without any training or quantization phases. While the original NBNN shows high classification accuracy without adopting an explicit training phase, the conditional independence among local features is against the compositionality of objects indicating that different, but related parts of an object appear together. As a result, the assumption of the conditional independence weakens the accuracy of classification techniques based on NBNN. In this work, we look into this issue, and propose a novel Bayesian network for an NBNN based classification to consider the conditional dependence among features. To achieve our goal, we extract a high-level feature and its corresponding, multiple low-level features for each image patch. We then represent them based on a simple, two-level layered Bayesian network, and design its classification function considering our Bayesian network. To achieve low memory requirement and fast query-time performance, we further optimize our representation and classification function, named relation-based Bayesian network, by considering and representing the relationship between a high-level feature and its low-level features into a compact relation vector, whose dimensionality is the same as the number of low-level features, e.g., four elements in our tests. We have demonstrated the benefits of our method over the original NBNN and its recent improvement, and local NBNN in two different benchmarks. Our method shows improved accuracy, up to 27% against the tested methods. This high accuracy is mainly due to consideration of the conditional dependences between high-level and its corresponding low-level features.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.758-761
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• 2007

디지털 신호처리 기술은 음성 및 영상 처리와 스펙트럼 분석 등과 같은 폭넓은 분야에서 활용되고 있다. 이에 따라 디지털 필터가 아날로그 필터를 대신하여 주파수 선택적 연산을 수행하기 위해 사용되고 있으며, 급준한 필터특성을 실현할 수 있다. 비재귀형으로 구성되는 FIR 디지털 필터는 항상 안정하고 선형위상응답 특성을 나타내므로, 데이터 전송과 같이 파형정보를 중요시하는 분야에 사용된다. 그리고 불연속점 부근에서 발생하는 깁스현상을 감소시키기 위해, 창함수 기법을 통해 필터를 설계한다. 따라서 본 논문에서는 FIR 필터의 성능을 향상시키기 위해, 변형된 창함수를 적용하였으며, 시뮬레이션에서 최대부엽의 크기와 천이특성을 이용하여 기존의 방법과 비교하였다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.1105-1110
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• 2009

Time Resolved Imaging of Contrast Kinetics 기법을 이용한 4차원 자기공명혈관조영술(TRICKS -MRA)영상과 기존 TOF-MRA영상을 비교하여 임상적 유용성에 대해 알아보고자 하였다. 총 17명 중 뇌 혈관 질환이 의심되는 11명과 뇌 종양을 의심하는 6명을 대상으로 TOF-MRA와 TRICKS -MRA을 시행한 후 17대상자 중 11명에서 DSA를 추가적으로 시행하였다. TOF-MRA는 공간해상력보다 시간해상력이 부족하였고, TRICKS-MRA에서는 TOF-MRA보다 공간분해능은 부족한 점이 많지만 영상판독에 큰 영향은 없었고 모든 대상자에서 동맥과 정맥의 구별이 가능하여 시간분해능이 우수 한 것을 나타났다. 또한 종양과 혈관과의 관계성 평가에서 TOF-MRA보다 좋은 것으로 나타났다. TRICKS-MRA방법은 시간대별로 동맥, 모세혈관, 정맥기를 신속하면서 쉽게 4차원적으로 영상화가 가능하여 앞으로 임상에서 이용도가 더욱 증가 할 것으로 사료된다.

• 전자공학회논문지CI
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• 제42권1호
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• pp.67-78
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• 2005

본 논문에서는 복소 가우시안 영상 (Complex Extended Gaussian Image, CEGI)을 이용한 3D 메쉬 모델의 블라인드 워터마킹을 제안하였다. CEGI는 메쉬의 법선 벡터 분포를 나타내는 3차원 방향 히스토그램으로, 이는 메쉬의 면적 및 임의의 기준점에 대한 거리로 표현되는 복소 가중치의 합으로 구현된다. 제안한 방법에서는 먼저 3D 메쉬 모델을 모델의 형상에 따라 여러개의 패치로 분할한다. 그리고 워터마크를 삽입하기 위하여 각 패치별로 CEGI를 구한 후에 복소 가중치의 크기가 큰 셀을 선택하여, 각 패치 CEGI 상에 통일한 순위의 셀들에 각각 삽입한다. 그리고 패치의 중점 좌표 및 셀 순위표를 이용하여 원 메쉬 모델없이 워터마크를 추출한다. 이 때, 회전과 같은 아핀 변환된 모델에서는 오일러 각을 이용한 재배열 과정을 수행한다. 실험 결과에서 제안한 방법이 절단, 아핀 변환, 및 랜덤 잡음 첨가등의 기하학적 공격 및 메쉬 간단화 등의 위상학적 공격에 견고하였으며 또한 워터마크의 비가시성을 확인하였다.