• 대한핵의학회지
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• 제30권1호
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• pp.1-14
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• 1996

Since the publication of the first bone scintiscans in 1962 three decades have elapsed. The bone scan has made great strides during this period, becoming one of the most commonly used nuclear imaging tests. In spite of the progress, however, the specificity of bone scan has remained relatively low. As the result it is a common practice to seek additional information from radiograph, CT scan and MR image, which is euphemistically termed as "image fusion or co-location." The basic reason is the inapplicability of the classical piecemeal analysis to interpreting planar and SPECT bone scans. Such analysis has its base on the observation of elemental features of morphology, which include the size, shape, contour, location, topography and internal architecture. The physiochemical profile may well also be included. Understandably, however, the miniatured images of the planar bone scan cannot provide these features in acceptable detail and the same holds true even with SPECT Images which are but sliced views of the reconstructed planar scans. Fortunately pinhole scanning has the capacity to portray both the morphological and chemical profiles of bone and joint diseases in greater detail through true magnification. The magnitude of pinhole scan resolution is practically comparable to that of radiography as far as gross anatomy is concerned. Thus, we feel strongly that pinhole scanning is a potential breakthrough of the long-lamented low specificity of bone scan. This presentation will discuss the fun-damentals, advantages and disadvantages and the most recent advances of pinhole scanning. It high-lights the actual clinical applications of pinhole scanning in relation to the diagnosis of infective and inflammatory diseases of bone and joint.

• 한국안전학회지
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• 제34권2호
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• pp.40-47
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• 2019

The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.

• 치과방사선
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• 제21권1호
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• pp.65-72
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• 1991

For the enhancement of a comprehension in temporomandibular joint radiographs, the author has compared and analysed the roentgenographic images of the temporomandibular joint of human dry skull which was taken by submentovertex projection, panoramic radiography, oblique lateral transcranial projection, corrected anterio-posterior tomogram and corrected lateral tomogram. The obtained results were as follows. 1. The submentovertex projection represented in detail the both poles and the posterior surface of the condylar head of the mandible. 2. The oblique lateral transcranial projection represented the articular space, the outer contour of the condylar head and the position of the condylar head within the mandibular fossa, but the relationship of the temporomandibular joint was not revealed accurate, because of the oblique direction of a central ray in taking radiographs. 3. The corrected antero-posterior tomogram was superior method in representation of roent- genographic images of the superior surface and the both poles of the condylar head and the corrected lateral tomogram was considered as the most accurate method among some radiographic techniques for the interpretation of articular space and condyle-fossa relationship. 4. It was possible to observe three-dimensionally the head of condyle with the combinated use of submentovertex projection, corrected antero-posterior tomogram and corrected lateral tomogram.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1825-1827
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• 1996

In this study, the Joint of 345kV OF $1C{\times}2000mm^2$ cable was developed to keep up with the trends that need higher-voltage & capacity underground transmission line. The type of joint developed was based on the two kinds of models that have had a good reliability internationally. The mechnic and electric characteristics of the sample specimen was managed in detail when it was manufactured and estimated. Especially, in order to prove the reliability of usage for 30 years, the method of long term aging test was studied. As a result of test, we knew that the joint developed had a good performance. From this study, it can be thought that future ultra-high voltage underground transmission line could be constructed by domestic technology.

• 한국멀티미디어학회논문지
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• 제5권2호
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• pp.147-157
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• 2002

영상 시퀀스에 포함된 잡음은 화질을 열화시키고 중요한 영상의 미세 정보를 훼손시킨다. 또한 잡음은 영상의 복잡성을 증가시키므로 영상의 압축효율을 저하시킨다. 본 논문에서는 특성이 서로 다른 두개의 적응형 잡음제거 필터를 결합적으로 연결하여 잡음을 제거하는 공간결합필터와 시간결합필터를 제시하고, 이 결합필터들을 연결한 IIR필터 구조를 갖는 3차원 잡음제거 필터를 제시한다. 제시된 잡음제거 필터는 영상의 에지와 미세정보를 유지하면서도 평탄한 영상영역에 대해서는 강한 잡음제거를 수행하며 이웃한 프레임 사이에서도 잡음에 의한 시간적인 깜박임을 억제한다. 실험결과 제안된 잡음제거 필터는 기존 방식들에 비하여 객관적 화질뿐만 아니라 주관적인 화질을 크게 향상시킴을 알 수 있었다.

• Journal of Welding and Joining
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• 제17권3호
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• pp.79-89
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• 1999

The study was carried out to examine in more detail metallurgical and mechanical properties of brazed joints of diamond cutting wheel. In this work, shank(mild steel) and sintered bronze-base tips were brazed with three different filler materials(W-40, BAgl and BAg3S). The machine used in this work was a high frequency induction brazing equipment. The joint thickness, porosities and microstructure of brazed joints with brazing variables(brazing temperature, holding time) were evaluated with OLM, SEM, EDS and XRD. Bending(torque) test was also performed to evaluate strength of brazed joints. Further wetting test was performed in a vacuum furnace in order to evaluate the wettability of filler metals on base metals9shank and tips). The brazing temperature had a strong influence on the joint strength and the optimum brazing temperature range was about $700~850^{\circ}C$ for the bronze/steel combinations. The strength of the brazed joint was found to be influenced by the three factors : degree of reaction region, porosity content, joint thickness. The reaction region was formed in the bronze-base tip adjacent to the joint. The reaction region resulted in a bad influence on the strength due to the formation of Cu5.6Sn, CuZn4, $\beta(CuZn)$ and CdAg, etc. Porosities increased as brazing variables(brazing temperature, holding time) increased, and the brazed joints with porosities of less than about 3-5% had an optimum strength for the bronze-base tip.

• 한국정보과학회논문지:시스템및이론
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• 제34권3호
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• pp.124-131
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• 2007

군중 애니메이션을 위한 연구분야는 동작의 사실성 제공과 속도향상의 두 가지 측면으로 구분된다. 최근 엔터테인먼트 산업의 발달로 군중 애니메이션은 디지털 콘텐츠 제작의 필수요소로 자리 잡았으며, 애니메이션의 속도향상을 위한 노력이 계속되고 있다. 이러한 추세에 맞춰, 본 논문에서는 군중 애니메이션의 속도저하에 영향을 미치는 요인들을 실험을 통해 검증하고, 실험 분석을 토대로 전처리 시스템을 설계한다. 동작 전처리 모듈은 제시된 애니메이션 시스템의 핵심 모듈로서 관절의 개수를 동작의 상세도에 따라 다양한 레벨(level-of-detail)의 동작들로 재구성한다. 실제 애니메이션 과정에서는 카메라와 가상환경 내부에 존재하는 캐릭터의 관계를 토대로 적절한 레벨의 동작을 적용하여 전체 시스템의 속도를 향상시킨다. 동작전처리 방법(motion level-of-detail)은 동작분석과 동작단순화 과정으로 분류되는데, 비선형 최적화 방법의 하나인 SQP를 활용하여 다양한 상세도 레벨의 동작들을 계산한다. 본 논문에 제시한 전처리 방법은 동작편집 등 캐릭터 애니메이션의 다양한 분야에 유용하게 활용될 수 있다.

• 대한기계학회논문집A
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• 제33권8호
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• pp.842-848
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• 2009

Fatigue failures are often occurred at welded joints where stress concentrations are relatively high due to the joint geometry. Although employing good detail design practices by upgrading the welded detail class enables to improve the fatigue performance, in many cases, the modification of the detail may not be practicable. As an alternative, the fatigue life extension techniques that reduce the severity of the stress concentration at the weld toe region, remove imperfections and introduce local compressive welding residual stress, have been applied. These techniques are also used as definite measures to extend the fatigue life of critical welds that have failed prematurely and have been repaired. In this study, a hammer peening procedure for using commercial pneumatic chipping hammer was developed, and the effectiveness is quantitatively evaluated. The pneumatic hammer peening makes it possible to give the weld not only a favorable shape reducing the local stress concentration, but also a beneficial compressive residual stress into material surface. In the fatigue life calculation of non-load carrying cruciform specimen treated by the pneumatic hammer peening, the life was lengthened about ten times at a stress range of 240MPa, and fatigue limit increased over 65% for the as-welded specimen.

• Structural Engineering and Mechanics
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• 제14권3호
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• pp.307-330
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• 2002

This study aims at postulating a simple methodology for predicting the failure modes of monotonically loaded reinforced concrete beam-column joints. All the factors that affect the failure modes of joints are discussed in detail using an experimental database of monotonically loaded exterior beam-column joints. The relative contributions of the strut and truss mechanisms to joint shear strength are determined based on the test results. A simple design equation for the beam longitudinal reinforcement ratio for joints with low, medium and high amount of stirrups is developed. The factors influencing the failure modes of monotonically loaded exterior beam-column joints are investigated in detail. Design charts that predict the failure modes of exterior beam-column connections both with and without stirrups are developed. Experimental data are compared with the design charts. The results show that the simple methodology gives very accurate predictions of the failure modes.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.127-132
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• 2003

The purpose of current study is about how to construct wall-type APT in slip form and Deck plate applied different connection of materials that wall and slab. A proposal construct's solution is using the continuous a binding string that the main of contents are slab or stairs which horizon structure part construction is joined the vertical structure part, new we Proposed of 2 solution that new technology development. We'll suggest that the development is in the construct of higher stories APT more better other construction method. We expect that the new method is good but we have many things to solute themes. Thus, we decided that this development contents are needed that correct structural investigation and constructor's security of speciality and through a fact construct, correct verification.