• 대한관절경학회지
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• 제16권1호
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• pp.47-51
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• 2012

지방종은 연부 조직에서 발생하는 양성 종양의 절반을 차지하는 가장 흔한 종양이나 관절 내 발생은 매우 드문 것으로 알려져 있다. 관절내 수지상 지방종(lipomal arborescens)의 경우 간혹 보고되고 있다. 그러나 진정한 의미의 관절 내 윤활막 지방종(intra-articular synovial lipoma)과는 명확히 다른 병리 소견 및 임상 양상을 보이므로 관절 내 윤활막 지방종과 수지상 지방종과 같은 지방 침착증성 질환들과는 구별되어야 한다. 본 연구에서 저자들은 슬관절에 발생한 관절 내 윤활막 지방종 환자 1예를 치료하였기에 보고하고자 한다.

• 한국정보과학회논문지:시스템및이론
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• 제29권11호
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• pp.601-610
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• 2002

태스크내부에서 공급 전압을 조절하는 태스크내 전압 스케쥴링(IntraVS)은 저전력 프로그램을 구현하는 데 효과적인 방법이다. 본 논문에서는 경성 실시간 응용프로그램에서 평균 실행 시간에 대한 정보를 이용하여 전력 소모를 효과적으로 줄이는 새로운 태스크내 전압 스케쥴링 알고리즘을 제시한다. 최악 실행 시간을 사용하여 전압 조절의 결정을 내렸던 기존의 태스크내 전압 스케줄링과는 달리, 제안된 알고리즘은 평균 실행 시간에 바탕을 두고 실행 속도를 조절함으로써 주어진 시간 제약 조건을 만족시키면서도 기존 방법보다 에너지 효율성을 높일 수 있다. MPEG-4 디코더를 이용한 실험 결과, 제안된 알고리즘은 기존의 태스크내 전압 스케줄링에 비해서 전력 소모를 최대 34% 감소시켰다.

• 전자공학회논문지CI
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• 제46권2호
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• pp.1-9
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• 2009

본 논문에서는 H.264/AVC의 I-slice의 모든 블록들을 복원하지 않고 블록의 경계 부분만을 복원하여 intra prediction을 고속으로 수행하는 방법을 개발한다 이를 위하여 intra prediction의 참조 화소들로 구성될 수 있는 차이 블록의 경계를 고속으로 복원하는 고속 역 정수 DCT를 개발한다. 고속으로 복원된 차이 경계 화소들과 각 예측 모드에 알맞게 구한 예측 화소들을 더하여 경계 화소들을 update하며, intra prediction에 필요한 참조 화소들로 구성한다. 개발된 기법은 H.264/AVC의 정수 DCT와 호환성을 유지하고, 고화질 영상 부호화시 사용되는 대표적인 HD 시퀀스에 적용 가능함을 실험으로 검증하였다.

• ETRI Journal
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• 제30권4호
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• pp.506-515
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• 2008

The H.264/AVC standard has adopted new coding tools such as intra-prediction, variable block size, motion estimation with quarter-pixel-accuracy, loop filter, and so on. The adoption of these tools enables an H.264/AVC-coded bitstream to have more information than was possible with previous standards. In this paper, we propose an effective spatial error concealment method with low complexity in H.264/AVC intra-frame. From information included in an H.264/AVC-coded bitstream, we use prediction modes of intra-blocks to recover a damaged block. This is because the prediction direction in each prediction mode is highly correlated to the edge direction. We first estimate the edge direction of a damaged block using the prediction modes of the intra-blocks adjacent to a damaged block and classify the area inside the damaged block into edge and flat areas. Our method then recovers pixel values in the edge area using edge-directed interpolation, and recovers pixel values in the flat area using weighted interpolation. Simulation results show that the proposed method yields better video quality than conventional approaches.

• The Journal of Korean Physical Therapy
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• 제33권4호
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• pp.187-192
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• 2021

Purpose: The purpose of the current study was to determine the intra- and inter-rater reliability of muscle thickness measurement of the TA using ultrasonography (US) conducted at different inward pressures of approximately 0.5 kg, 1.0 kg, and no pressure control. Methods: Twenty healthy subjects were recruited for this study. Two different examiners measured the thicknesses of the dominant TA of each subject randomly to assess the intra- and inter-rater reliability. The measurement values were analyzed using the intra-class correlation coefficient (ICC) with a 95% confidence interval, standard error of measurement, minimal detectable change, and coefficient of variance. Results: All intra-rater reliability ICC values showed high reliability above 0.9. Inter-rater reliability ICC values showed high reliability above 0.9 with 0.5 and 1.0 kg of inward pressure. In contrast, Inter-rater reliability ICC values showed poor reliability (0.23) with no pressure control of inward pressure. Conclusion: The findings showed that maintaining consistent inward pressure is essential for reliable results when the muscle thickness of the TA is measured by different examiners in a clinical setting.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1355-1364
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• 2019

A recently published nuclear forensics methodology for source discrimination of separated weapons-grade plutonium utilizes intra-element isotope ratios and a maximum likelihood formulation to identify the most likely source reactor-type, fuel burnup and time since irradiation of unknown material. Sensitivity studies performed here on the effects of random measurement error and the uncertainty in intra-element isotope ratio values show that different intra-element isotope ratios have disproportionate contributions to the determination of the reactor parameters. The methodology is robust to individual errors in measured intra-element isotope ratio values and even more so for uniform systematic errors due to competing effects on the predictions from the selected intra-element isotope ratios suite. For a unique sample-model pair, simulation uncertainties of up to 28% are acceptable without impeding successful source-reactor discrimination. However, for a generic sample with multiple plausible sources within the reactor library, uncertainties of 7% or less may be required. The results confirm the critical role of accurate reactor core physics, fuel burnup simulations and experimental measurements in the proposed methodology where increased simulation uncertainty is found to significantly affect the capability to discriminate between the reactors in the library.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.384-393
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• 2019

An experimental validation of a nuclear forensics methodology for the source reactor-type discrimination of separated weapons-useable plutonium is presented. The methodology uses measured values of intra-element isotope ratios of plutonium and fission product contaminants. MCNP radiation transport codes were used for various reactor core modeling and fuel burnup simulations. A reactor-dependent library of intra-element isotope ratio values as a function of burnup and time since irradiation was created from the simulation results. The experimental validation of the methodology was achieved by performing two low-burnup experimental irradiations, resulting in distinct fuel samples containing sub-milligram quantities of weapons-useable plutonium. The irradiated samples were subjected to gamma and mass spectrometry to measure several intra-element isotope ratios. For each reactor in the library, a maximum likelihood calculation was utilized to compare the measured and simulated intra-element isotope ratio values, producing a likelihood value which is proportional to the probability of observing the measured ratio values, given a particular reactor in the library. The measured intra-element isotope ratio values of both irradiated samples and its comparison with the simulation predictions using maximum likelihood analyses are presented. The analyses validate the nuclear forensics methodology developed.

• Journal of Korea Trade
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• 제25권4호
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• pp.88-107
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• 2021

Purpose - Using a model that highlights Ricardian comparative advantage and Cournot competition, I derive theoretical predictions on how bilateral measures of trade intensity, specialization, and intra-industry are interrelated, and how Ricardian productivity differences affect these measures. We test the predictions using trade and production data, and confirm them. Design/methodology - A simple two-country general equilibrium model is constructed to derive theory-based bilateral indexes. We then test the relationships among them using panel data for 35 countries and 14 industries between 1996 and 2008. Findings - Bilateral trade intensity is increasing in specialization, as in the classical trade theory, and in intra-industry trade, as in the new trade theory. However, productivity differences positively affect specialization, and negatively affect intra-industry trade. These effects cancel each other; thus productivity differences have little impact on trade intensity. Originality/value - This paper provides a comprehensive conceptual framework for understanding the relationship among trade intensity, specialization, intra-industry trade, and productivity differences. We derive theory-consistent measures of specialization, intra-industry trade, and productivity differences. Moreover, we reevaluate the empirical relevance of these variables for the study of gravity equations. This paper is also an effort to capture oligopolistic competition in a general equilibrium framework, interests in which recently resurged.

• 한국임상보건과학회지
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• 제11권1호
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• pp.1632-1638
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• 2023

Purpose: The aim of this study was to determine the distribution of the cornea thickness and intra ocular pressure Korean adult of 20 to 24 year old using the Pentacam and tonometer. Methods: The subjects of this study were 43 Korean adults with healthy eyes. Corneal thickness was measured with Pentacam device. The intra ocular pressure was measured with tonometer. Data was analyzed by means of the Pearson's correlation cofficient. P-values<0.001 were considered statistically significant. Results: Mean age of subjects was 20.41±0.86 years. The mean +/- intra ocular pressure of the right eye and left eye were 16.236±2.523mmHg and 16.971±1.992mmHg, respectively. The mean central corneal thickness of the right eye and left eye was 545.324±38.682㎛ and 547.442±33.778㎛, respectively. No significant difference in central corneal thickness was found between the right and left eyes. But, there was a statistically significant difference between central cornea thickness and peripheral cornea thickness around 4 mm of central cornea(p<0.001, Pearson's correlation). However there was no statistically significant difference between central cornea thickness and intra ocular pressure. Conclusion: The results of this study could be used as a clinical reference data for diagnosis and treatment of cornea in Korean adult.

• 방송공학회논문지
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• 제15권3호
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• pp.380-390
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• 2010

가장 최근에 표준화가 완료된 동영상 압축 코덱인 H.264/AVC는 율-왜곡 최적화를 사용하여 압축률이 상당히 향상되었다. 율-왜곡 최적화는 다수의 후보 모드들 중에서 최적의 모드를 결정하기 위한 수단이며, 모든 모드에 대하여 라그랑지안 비용을 계산하여 그 비용이 가장 적은 모드를 최적의 모드로 결정한다. 하지만 이 방법의 사용으로 인하여 H.264/AVC 부호기의 계산 복잡도가 상당히 증가하였다. 본 논문에서는 H.264/AVC의 화면 내 예측 부호화의 율-왜곡 최적화의 사용으로 인한 계산 복잡도를 감소시키는 고속 화면 내 예측 모드 결정 방법을 제안한다. 제안된 방법은 Intra$4{\times}4$와 Chroma Intra의 부호화 속도를 향상시키기 위하여 최고 확률 모드(MPM)가 가장 최적의 예측 모드인 경우를 미리 판단하여, 이 경우에는 율-왜곡 최적화 과정을 생략하고 최고 확률 모드를 사용하여 부호화한다. 또한 이 방법을 색차 화면 내 예측 모드에 유사하게 적용하였다. 실험 결과, 제안된 방법은 PSNR (Peak Signal-to-Noise Ratio) 손실이 거의 없이 평균 약 63%의 부호화 시간을 절약하였다.