• Title/Summary/Keyword: Gyu-Dong Choi

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Unusual MR Features of Extravasation of Contrast Material in Hyperacute Intracerebral Hemorrhage (초급성 두개내 출혈 환자에서 조영제의 혈관외 누출을 동반한 비전형적 자기공명영상)

  • Choi Seung Hong;Chun Woo Sun;Kim Ji-Hoon;Kang Hyun Seung;Kwon Bae Ju;Na Dong Gyu;Kim Jae Hyung;Han Moon Hee;Chang Kee-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.9 no.1
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    • pp.50-56
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    • 2005
  • Contrast extravasation in hyperacute intracerebral hemorrhage (ICH) indicative of active bleeding is a predictor of possible enlargement of hematoma, providing clinician with valid management decisions. We report unusual MR imaging features of contrast extravasation in hyperacute ICH in three patients: Case 1 with hypertension revealed dual foci of contrast extravasation, one in right basal ganglia and the other in left lateral ventricle, suggesting simultaneous bleeding of the two foci. Case 2 with presumed diagnosis of vasculitis showed relatively large area of contrast extravasation mimicking enhancing tumor or vascular lesion. Case 3 with hypertension showed the findings of active bleeding which was likely to occur during the time of MR imaging acquisition.

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Contrast-enhanced Magnetic Resonance Imaging of Brain Metastases at 7.0T versus 1.5T: A Preliminary Result

  • Paek, Sun Ha;Kim, Jhi-Hoon;Choi, Sung-Hong;Yoon, Tae-Jin;Son, Young Don;Kim, Dong Gyu;Cho, Zang-Hee;Sohn, Chul-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.19 no.1
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    • pp.31-36
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    • 2015
  • Purpose: To compare the depiction of brain metastases on contrast-enhanced images with 7.0 tesla (T) and at 1.5T MRI. Materials and Methods: Four consecutive patients with brain metastases were scanned on 7.0T whole-body scanner and 1.5T MRI. A 3D T1-weighted gradient echo sequence (3D T1-GRE) at 1.5T (voxel size = $0.9{\times}0.9{\times}1.5mm^3$ after double-dose, gadoterate meglumine, Gd-DOTA) was compared to a 7.0T 3D T1-GRE sequence (voxel size = $0.4{\times}0.4{\times}0.8mm^3$, single-dose Gd-DOTA) in four patients after a 5 minute delay. The number of contrast-enhancing metastases in MPRAGE images was compared in each patient by two radiologists in consensus. We measured contrast ratio of enhancing brain metastases and white matter in 1.5T and 7.0T. Results: In all four patients 7.0T 3D T1-GRE images after single-dose Gd-DOTA and 1.5T after double-dose Gd-DOTA depicted 11 brain metastases equally. In the quantitative analysis of contrast ratios of enhancing brain metastases and white matter, the 1.5T 3D T1-GRE after double-dose showed an increased contrast ratio compared to 7.0T 3D T1-GRE after single-dose ($0.961{\pm}0.571$ versus $0.885{\pm}0.494$; n = 11 metastases). But this difference was not statistically significant (P = 0.711). Conclusion: Our preliminary results indicate that 7.0T single-dose Gd-enhanced images were not different to 1.5T double-dose Gd-enhanced images for the detection of brain metastases.

The Impacts of Education Service Quality in the Traditional Market Merchant College on Business Performance (전통시장 상인대학 교육서비스 품질이 경영성과에 미치는 영향)

  • Choi, Dong-Gyu;Hwang, Hee-Jung;Song, In-Am
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.81-92
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    • 2013
  • Purpose - This study empirically analyzes the effect of improvements in the quality of service management performance of college education on traders' conscious change of business management innovation and diverse sales expertise for a year. The use of traders' conscious changes and sales expertise as variables for the verification of the effects of parameters related to the active trader's traditional education market is a desirable direction. The method of research reflects the quality of education service, management result, traders' conscious changes, and sales expertise to understand the precise essence and definition of teaching quality at merchant colleges through theoretical consideration. Moreover, its impact on traders' conscious changes and sales expertise in empirical analysis acts as an intermediary. Research design, data, methodology - The hypothesis of this study leverages the SPSS statistical program. To gather actual proof, sample survey for theoretical research examined 262 valid papers of the 300 papers written by 10 merchants who graduated from merchant's university. First, using the SERVQUAL model, Parasuraman et al. (1996) indicated that for quality of education service, the configuration of factors is the same as the sympathetic performance, that is, responsiveness and empathy, and traders are aware of these elements. However, our preliminary investigation revealed that traders' university education has been excluded as a component of quality of service in the earlier studies. Moreover, we found that certainty of knowledge, reliability, and sympathy are influenced by challenges and by the changing intentions of merchant consciousness. In addition, our study confirms that improvements in convincing abilities and sales technique have a positive impact. Second, merchants' and traders' expertise are proven to affect business performance. In other words, university education of traders and merchants affects the consciousness of consumers, and changes patterns of sales. Third, the quality of service management education and change in the consciousness has a considerable impact on the trader, thereby maximizing business performance and acting as an intermediary for verification. Fourth, the quality of service management education affects the trader's sales expertise to maximize business performance. Results - To summarize, the quality of college educational services relates to the improvement of business performance and the role of the resulting virtuous cycle. Consequently, we can look for suggestions in the traditional markets, where the Government pays attention to the exterior environmental factors as well as to the changing business environment. However, the most important aspect is the merchant awareness. That is, a merchant should understand the distribution environment. Several competitor and trend analyses should be conducted to meet customers' expectations positively and proactively cope with any challenges related to changes. Further, expertise in sales and marketing skills need to be acquired to improve customer convincing abilities and develop a customer-oriented mindset. Conclusions - According to the changes in consumption trends of business enterprises, new management techniques are required to survive competition by improving traditional markets, which will necessitate more competitive education programs in merchant universities.

High Performance Liquid Chromatographic Determination of Free Sugars in Ginseng and Its Products (고속액체(高速液體) 크로마토그래피에 의(依)한 인삼(人蔘) 및 인삼제품중(人蔘製品中)의 유리당(遊離糖)의 정량(定量))

  • Choi, Jin-Ho;Jang, Jin-Gyu;Park, Kil-Dong;Park, Myung-Han;Oh, Sung-Ki
    • Korean Journal of Food Science and Technology
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    • v.13 no.2
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    • pp.107-113
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    • 1981
  • Free sugars were isolated from ginseng root and its products and analyzed by using high performance liquid chromatogrphy. To isolate free sugars from aqueous sample solution fat-soluble components, crude saponin and protein were removed from the solution by extracting with benzene, water-saturated butanol and 80% ethanol, respectively. Free sugars found from both ginseng root and its products were fructose, glucose, sucrose and maltose, and the only sugar detected from red ginseng root and its products was rhamnose. Major sugar detected from fresh ginseng and white ginseng roots was sucrose, while sucrose and maltose were major sugars of red ginseng root.

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Geochemistry of Cu-Pb-Zn-Ag Deposits from the Euiseong Mineralized Area (의성 광화대 동-연-아연-은 광상의 지화학적 연구)

  • Chi, Se-Jung;Doh, Seong-Jae;Choi, Seon-Gyu;Lee, Jae-Ho
    • Economic and Environmental Geology
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    • v.22 no.3
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    • pp.253-266
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    • 1989
  • The Cu-Pb-Zn-Ag hydrothermal vein type deposits which comprise the Dongil and Dong-cheogogsan mines occur within the Cretaceous sedimentary rocks in the Euiseong Basin of the southern Korean peninsula. The ore mineralization is contained within three stage(I,II and III) quartz and calcite veins. Ore minerals occur as dominant chalcopyrite, galena, sphalerite, tetrahedrite and Pb, Ag, Sb and Bi-bearing sulfosalts. Stage I ore minerals were deposited between $400^{\circ}C$ and $200^{\circ}C$ from the fluid with moderate salinities(7.0 to 4.5 eq. wt. % NaCl). Evidence of boiling suggests pressure of less than 150 bars during stage I mineralization. This pressure corresponds to maximum depths of 650 m and 1700 m, respectively, assuming lithostatic and hydrostatic loads. The data on mineralogy, temperature and salinity, together with information on the solubility of Cu complex, suggest that Cu deposition is a result of boiling coupled with declining temperature from $350^{\circ}$ to $250^{\circ}C$ or declining log $a_{o_2}$(from -29.8 to -35.9 atm.)and increasing in pH. Pb, Ag, Sb and Bi-bearing sulfosalts were deposited by cooling and dilution at temperature of less than $250^{\circ}C$ from the ore fluid with less than -35.9 atm. of log $a_{o_2}$.

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Changes in Quality Properties of Brown Rice after Germination (발아에 따른 현미의 품질 변화)

  • Kim, Dae-Jung;Oh, Sea-Kwan;Lee, Jeong-Heui;Yoon, Mi-Ra;Choi, Im-Soo;Lee, Dong-Hyen;Kim, Yeon-Gyu
    • Korean Journal of Food Science and Technology
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    • v.44 no.3
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    • pp.300-305
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    • 2012
  • The objective of this study was to evaluate quality properties, including amylose, alkali digestion value (ADV), and amylogram, of brown rice and germinated brown rice of some cultivars in Korea for rice processing products. The protein content of brown rice was significantly higher than those of germinated brown rice. The amylose content of the samples ranged from 17.09 to 18.85%. Alkali digestion value (ADV) of brown rice and germinated brown rice were described as a grade of 2-5 and 4-7, respectively. In a rapid visco analyzer (RVA) examination, pasting temperature of brown rice and germinated brown rice was $67.93-68.05^{\circ}C$. In addition, the pasting characteristics of brown rice were significantly higher than those of germinated brown rice. A texture analysis test showed that germinated brown rice Haiami had the lowest hardness and germinated brown rice Samkwang had the highest adhesiveness.

De-blocking Filter for Improvement of Coding Efficiency and Computational Complexity Reduction on High Definition Video Coding (고화질 비디오의 부호화 효율성 증대와 연산 복잡도 감소를 위한 디블록킹 필터)

  • Jung, Kwang-Su;Nam, Jung-Hak;Jo, Hyun-Ho;Sim, Dong-Gyu;Oh, Seoung-Jun;Jeong, Sey-Yoon;Choi, Jin-Soo
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.513-526
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    • 2010
  • In this paper, we propose a de-blocking filter for improvement of coding efficiency and computational complexity reduction on a high definition video coding. Recently, the H.264/AVC standard-based research for high definition video coding method is under way because the amount of used of high definition videos is on the increase. The H.264/AVC de-blocking filter is designed for low bitrate video coding and it improves not only the subjective quality but also coding efficiency by minimizing the blocking artifact. However, the H.264/AVC de-blocking filter that strong filtering is performed is not suitable in a high definition video coding which occurs relatively low blocking artifact. Also, the conventional de-blocking filter has high computational complexity in decoder side. The computational complexity of the proposed method is reduced about maximum 8.8% than conventional method. Furthermore, the coding efficiency of the proposed method is about maximum 7.3% better than H.264/AVC de-blocking filter.

Early Termination Algorithm of Merge Mode Search for Fast High Efficiency Video Coding (HEVC) Encoder (HEVC 인코더 고속화를 위한 병합 검색 조기 종료 결정 알고리즘)

  • Park, Chan Seob;Kim, Byung Gyu;Jun, Dong San;Jung, Soon Heung;Kim, Youn Hee;Seok, Jin Wook;Choi, Jin Soo
    • Journal of Broadcast Engineering
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    • v.18 no.5
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    • pp.691-701
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    • 2013
  • In this paper, an early termination algorithm for merge process is proposed to reduce the computational complexity in High Efficiency Video Coding (HEVC) encoder. In the HEVC, the same candidate modes from merge candidate list (MCL) are shared to predict a merge or merge SKIP mode. This search process is performed by the number of the obtained candidates for the both of the merge and SKIP modes. This may cause some redundant search operations. To reduce this redundant search operation, we employ the neighboring blocks which have been encoded in prior, to check on the contextual information. In this study, the spatial, temporal and depth neighboring blocks have been considered to compute a correlation information. With this correlation information, an early termination algorithm for merge process is suggested. When all modes of neighboring blocks are SKIP modes, then the merge process performs only SKIP mode. Otherwise, usual merge process of HEVC is performed Through experimental results, the proposed method achieves a time-saving factor of about 21.25% on average with small loss of BD-rate, when comparing to the original HM 10.0 encoder.

Phylogenetic Analysis of Korean Black Cattle Based on the Mitochondrial Cytochrome b Gene (mtDNA cytochrome b에 기초한 한국흑우의 계통유전학적 분석)

  • Kim, Jae-Hwan;Byun, Mi Jung;Kim, Myung-Jick;Suh, Sang Won;Kim, Young-Sin;Ko, Yeoung-Gyu;Kim, Sung Woo;Jung, Kyoung-Sub;Kim, Dong-Hun;Choi, Seong-Bok
    • Journal of Life Science
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    • v.23 no.1
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    • pp.24-30
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    • 2013
  • The purpose of this study was to identify genetic polymorphisms of the mitochondrial cytochrome b (mtDNA cyt b) gene in Korean black (KB) cattle breed and to analyze the genetic relationship between the KB and other breeds. We determined the complete sequence of the mtDNA cyt b gene in 38 KB cattle. We also analyzed their genetic diversity, and phylogenetic analysis was performed by comparison with Korean cattle (KC, called Hanwoo) and breeds from China and Japan. A nucleotide substitution was detected in the KB cattle, and two haplotypes were defined. In the neighbor-joining (NJ) tree, the haplotypes of KB were located in Bos taurus lineage with those of KC, Japanese black (JB), Yanbian and Zaosheng breeds. However, the haplotypes of Chinese breeds, excluding Yanbian and Zaosheng, were separated into B. taurus and B. indicus lineages. In the NJ tree of breeds based on Dxy genetic distances, Chinese breeds mixed with B. taurus and B. indicus lineages were located between B. indicus and B. taurus lineages. KB was contained within B. taurus lineage and was determined to be genetically more closely related to two Chinese (Yanbian and Zaosheng) breeds than to KC and JB. The haplotype distribution and the results of the phylogenetic analysis suggest that KB and KC have genetic differences in their mtDNA cyt b gene sequences.

Load Sharing Analysis of Piled Rafts Based on Non-linear Load-Settlement Characteristics (Piled Raft 기초의 비선형 하중-침하 특성을 고려한 하중분담 해석)

  • Choi, Kyu-Jin;Park, Dong-Gyu;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.28 no.11
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    • pp.33-40
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    • 2012
  • The design of Piled Raft foundations considering the load sharing between raft and piles provides a more economical solution than the conventional design approach based on bearing capacity of piles only. Generally, numerical methods are used to analyze the behavior of Piled Rafts due to its complexity and load sharing ratio is also estimated by numerical methods about some limited cases under specific load level and soil conditions. In this study, a method to estimate the load sharing between the raft and piles was developed which is based on load-settlement characteristics of foundation elements. Normalized load-settlement curves of the raft and pile groups were derived individually, and the relationship between load sharing ratio and foundation settlement was proposed by using these curves. For each load-settlement curves, hyperbolic type was adopted in order to describe the non-linear behavior of foundations. Centrifuge test results were compared with the results from proposed method, and the trends of variation of load sharing ratio with settlement presented from both were similar.