• 방송공학회논문지
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• 제8권3호
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• pp.297-305
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• 2003

본 논문에서는 저비트율 부호화에 적합한 웨이블릿 기반의 고속 움직임 예측 기법을 제안한다. 제안한 논문에서는 웨이블릿 계수의 차이를 기반으로 한 중요 블록(significant block : SB) 정보를 사용하여 움직임이 존재하는 블록에 대해 선택적으로 움직임 예측함으로써 움직임 벡터의 수가 증가하는 MRME(multiresolution motion estimation)의 단점을 보완할 수 있었다. 또한 웨이블릿 변환의 특성 중 하나인 해상도 분할 특성을 이용하여 quarter-band까지 움직임을 예측하게 되고, 이에 대한 보간작업으로 영상을 재구성한다. 선택적 움직임 추정과 움직임 보상된 quarter-band의 보간작업을 통해 고주파 부대역에서 존재할 수 있는 예측 오차를 줄일 수 있었으며, 동시에 계산량도 감소시킬 수 있었다. 제안된 기법은 기존의 기법과 비교하여 약 70% 이상의 계산량을 감소시킬 수 있었으며, 영상의 화질 면에서도 0.1 ∼ 1.2dB 정도 향상되어 거의 대등한 PSNR을 유지하는 것을 모의 실험을 통하여 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2759-2764
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• 2014

Aim: This study aims to investigate the manifestation of CT, MRI and dynamic enhanced scans for primary hepatic neuroendocrine cell carcinoma. Methods: CT or MRI arterial and venous phase scan images of 19 cases of pathologically confirmed PHNEC were retrospectively analyzed. Results: 14 cases (73.68%) with single lesion, 5 cases (26.3%) with multiple lesions, with an average diameter of 13.2 cm. Some 12 cases (63.16%) showed inhomogeneous enhancement, seven cases (36.8%) showed homogeneous enhancement, 13 cases (68.4%) demonstrated significant enhancement in the arterial phase, 13 cases (68.4%) had significantly enhanced portal venous phase including 7 cases (36.8 %) with portal venous phase density or signal above the arterial phase and 5 cases (26.3%) with the portal vein density or signal below the arterial phase. Seven cases (36.8%) had continued strengthened separate shadows in the center of the lesion. Thrombosis were not seen in portal veins. Conclusion: CT and MRI images of liver cell neuroendocrine carcinoma have certain characteristics that can provide valuable information for diagnosis and differential diagnosis.

• 한국IT서비스학회지
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• 제8권4호
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• pp.175-185
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• 2009

Objectifying claims filed during the warranty period, analyzing the current circumstances and improving on the problem in question is an activity worth doing that could reduce the likelihood of claims to occur, cut down on the costs, and enhance the corporate image of the manufacturer. Existing analyses of claims are confronted with two problems. First, you can't precisely assess the risks of claims involved by means of the value of claims per 100 products alone. Second, even in a normal state, the existing approach fails to capture the probabilistic conflicts that escape the upper control limit of claims, thus leading to wrong control activities. To solve the first problem, this paper proposed that a time series detection concept where the claim rate is monitored based on the date when problems are processed and a hazard function for expression of the claim rate be utilized. For the second problem, this paper designed a model whereby to define a normal state by making use of PID (Proportion, Integral, Differential) and infer by way of a fuzzy concept. This paper confirmed the validity and applicability of the proposed approach by applying methods suggested in the actual past data of warranty claims of a large-scaled automotive firm, unlike hypothetical simulation data, in order to apply them directly in industrial job sites, as well as making theoretical suggestions for analysis of claims.

• 한국컴퓨터정보학회논문지
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• 제4권2호
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• pp.141-146
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• 1999

본 논문은 움직임 정보를 이용하여 기준 프레임 영상과 상관관계가 적은 프레임 영상에서는 화질을 보장하고, 기준 프레임 영상과 상관관계가 많은 프레임 영상에서는 전체 동영상의 비트율을 보장하는 픽쳐셋 필터를 제안하였다. 실험 결과, 제안한 동영상 부호화 방법은 기존의 전영역 탐색 블럭 정합 알고리즘에 비하여, 화질은 9dB이 항상되고, 압축률은 15배가 증가되었으며. 부호화시간은 70%나 단축되었다. 그리고, 차영상 알고리즘에 비하여, 화질은 25dB이 떨어졌으나, 압축률은 42배가 증가하였으며, 부호화시간은 0.9%가 단축되므로서 좋은 성능을 나타냄을 확인하였다.

• 융합보안논문지
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• 제7권1호
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• pp.83-89
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• 2007

본 논문에서는 영상을 다중 해상도로 표현하는 직교 웨이브렛변환에서, 비밀스럽게 서명데이터를 영상에 삽입하는 방법을 제안한다. 그 원리는 영상의 다중해상도표현에 있어서 차분출력에 편중(집중)이 있음에 주목하여, 그 특징을 이용하여 서명비트계열을 화상에 삽입한다. 이 때, $256{\times}256$화소로 되는 농담화상으로 대략 6K바이트 정도의 문자정보를 합성할 수 있다. 이 방법은 영상의 저작권을 표시하는 서명데이터뿐만 아니라, 영상의 저자나 사용조건, 또는 영상 그 자체의 속성정보를 포함할 수 있어, 영상데이터베이스의 검색 등에 있어서도 유사영상의 식별을 용이하게 할 수 있는 등의 응용을 고려할 수 있다.

• 천문학회보
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• 제35권2호
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• pp.61.2-61.2
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• 2010

CQUEAN (Camera for Quasars in EArly uNiverse) is an optical CCD camera system which has its own auto-guiding system. Guiding system consists of a 1k*1k CCD camera, FLI PL1001E, a flat mirror to feed the image of an off-axis field to the camera and baffle. The whole system lies on a moving arm which rotates 90 degree effectively to enlarge the field of view. A motor, IMS MDRIVE 34, and a differential decelerator, APEX AD140-050, are used for the moving mechanism. Auto-guiding is controlled by Agdr program. We had a first light from Aug. 10 to Aug 17, 2010 at McDonald Observatory, USA. In this presentation, we describe about the auto-guiding system for CQUEAN and its performance on the 2.1m telescope.

• 한국게임학회 논문지
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• 제14권6호
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• pp.59-68
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• 2014

초고해상도 UHD($096{\times}2160$) 게임 영상의 메모리 대역폭 요구량은 기하급수적으로 늘어난다. 본 논문에서는 화질 저하 없이 메모리 대역폭 문제를 해결하기 위하여 CUDA 환경에서 비트 병렬 파이프라인을 지원하는 논문 [4]의 DDPCM-GR 압축 알고리즘을 변형한 DPCM-GR 방식을 적용한 무손실 압축을 구현하였다. CUDA 공유메모리 사용을 통한 효율성을 증대하였으며, paged-locked 호스트 메모리 비동기 전송을 통한 커널과 데이터 전송 중첩의 다양한 구성을 구현하였다. 실험을 통하여 CPU 방식에 비하여 최대 31.3배 속도 향상을 이루었으며, 비동기 전송 구성의 변화를 통하여 최대 30.3% 수행 시간이 감소하였다.

• 대한기계학회논문집B
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• 제28권5호
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• pp.501-509
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• 2004

Unipolar diffusion charging of non-spherical particles was investigated for various particle shapes. We researched with TiO$_2$agglomerates produced by the thermal decomposition of titanium tetraisopropoxide (TTIP) vapor. TTIP was converted into TiO$_2$, in the furnace reactor and was subsequently introduced into the sintering furnace. Increasing the temperature in the sintering furnace, aggregates were restructured into higher fractal dimensions. The aggregates were classified according to their mobility using a differential mobility analyzer. The projection area and the mass fractal dimension of particles were measured with an image processing technique performed by using transmission electron microscope (TEM) photograph. The selected aggregates were charged by the indirect photoelectric-charger and the average number of charges per particle was measured by an aerosol electrometer and a condensation particle counter. For the particles of same mobility diameter, our results showed that the particle charge quantity decreases as the sintering temperature increases. This result is understandable because particles with lower fractal dimension have larger capacitance and geometric surface area.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.244-252
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• 1999

Intensive selection for muscle development and against fat deposition in pigs during the last 50 years has contributed to the increased incidence of porcine stress syndrome (PSS) and pale soft exudative pork (PSE). Genetics, nutrition and management, preslaughter animal handling, stunning, dehairing and carcass chilling influence the incidence and magnitude of the PSE condition. The normal incidence of PSE has been reported to range from 10 to 30%, but in some isolated instances is up to 60%. The elimination of halothane-positive pigs in breeding programs has reduced PSS and PSE. Further improvements in meat quality by terminal sire evaluation and selection can be achieved within halothane-negative populations because around 20% of the variation in meat color and water binding capacity seems to be genetically related. Pre-slaughter handling on the farm, during transit to the packing plant and at the packing plant can greatly influence the meat quality, contributing 10 to 25% of the variation. An effective stunning method, skinning instead of scalding/dehairing and rapid post-slaughter chilling further reduce the incidence of PSE pork. In addition to proper care and handling a carcass-merit based marketing system, that reflected the value differential between desirable and undesirable meat quality in the pricing system for pigs, would provide a great incentive to change pork production systems in order to improve meat quality, thus improving the image and usefulness of pork as food.

• Journal of Korean Neurosurgical Society
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• 제53권5호
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• pp.305-308
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• 2013

Myositis ossificans (MO) is a benign condition of non-neoplastic heterotopic bone formation in the muscle or soft tissue. Trauma plays a role in the development of MO, thus, non-traumatic MO is very rare. Although MO may occur anywhere in the body, it is rarely seen in the lumbosacral paravertebral muscle (PVM). Herein, we report a case of non-traumatic MO in the lumbosacral PVM. A 42-year-old man with no history of trauma was referred to our hospital for pain in the low back, left buttock, and left thigh. On physical examination, a slightly tender, hard, and fixed mass was palpated in the left lumbosacral PVM. Computed tomography showed a calcified mass within the left lumbosacral PVM. Magnetic resonance imaging (MRI) showed heterogeneous high signal intensity in T1- and T2-weighted image, and no enhancement of the mass was found in the postcontrast T1-weighted MRI. The lack of typical imaging features required an open biopsy, and MO was confirmed. MO should be considered in the differential diagnosis when the imaging findings show a mass involving PVM. When it is difficult to distinguish MO from soft tissue or bone malignancy by radiology, it is necessary to perform a biopsy to confirm the diagnosis.