• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2697-2700
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• 2003

이 논문에서는 3 차원 CT/CTA 영상 데이터에 대하여 고속 자동 정합 기법을 제안한다. 제안하는 기법은 다해상도 (multi-resolution) 구조의 정규 상호 정보량(normalized mutual information) 을 최대화하는 정합 방식에서, 정합 유사도를 계산하는 볼륨 영역을 효율적으로 줄여 정합 속도를 증가시키는 방법이다. 제안된 정합방식을 CT/CTA (CT angiography) 팬텀 데이터와 7 세트의 실제 CT/CTA 임상 데이터에 적용하여 테스트하였다. 이로부터 제안하는 방식이, 정합 정확도를 유지하는 동시에 정합 속도를 10 ∼ 60％ 로 감소시킴을 확인 할 수 있었다. 또한 제안된 정합 방식을 DS-CTA (digital subtraction CT angiography) 에 적용하여, CT/CTA 영상으로부터 혈관 영상을 성공적으로 추출하였다.

• Journal of Korean Neurosurgical Society
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• v.29 no.3
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• pp.345-352
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• 2000

Objective : The purpose of this study was to compare computed tomographic angiography(CTA) with conventional cerebral angiography(CCA) and to assess usefulness of CTA in detection and anatomic definition of intracranial aneurysms of the circle of Willis in subarachnoid hemorrhage. Patients and Methods : Fifty consecutive patients with known or suspected intracranial saccular aneurysms underwent CTA with preoperative CCA from 1997 to 1999. Using surface shaded display post-processing technique, CTA was interpreted for the presence, location of aneurysms and anatomic features. The image obtained with CTA was then compared with CCA image. Results : In 47 patients, CCA revealed 57 cerebral aneurysms and CTA revealed 54 aneurysms. Two of the 57 cerebral aneurysms were located outside of the imaging volume of CTA and one case was misdiagnosed. The sensitivity of CTA was 94.7% and the specificity was 100%. The results obtained with CTA were, compared with the results obtained with CCA, equal in determining dome shape, direction and lobularity. However, CTA provided a 3-dimensional representation of aneurysmal lesion very useful for surgical planning. Moreover, CTA was useful for rapid and relatively noninvasive detection of aneurysms in the circle of Willis. Conclusion : CTA can be a diagnostic tool for the patients with acute subarachnoid hemorrhage due to a ruptured aneurysm of the circle of Willis and provides adequate anatomic detail for surgical planning, especially to complex cerebral aneurysms. However, we think CCA is necessary because of CTA limitations including its difficulty in detecting unusually located aneurysms(including those in cavernous sinus or distal artery) and combined vascular lesion (including arteriovenous malformation) and acquiring dynamic flow information.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.115-125
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• 2009

Purpose: The purpose of the study is to evaluate the usefulness of CT arthrography (CTA) by conducting a comparative study of CTA and MR arthrography (MRA) with the arthroscopic findings in the same patients. Materials and methods: Forty nine patients who suffered from shoulder disease underwent MRA and CTA concurrently. The sensitivity and specificity of CTA was evaluated, as compared to MRA, in the case of four types of shoulder pathological lesions. The accuracy of CTA was evaluated by analyzing the arthroscopic findings of thirty four patients. Results: Compared to MRA, CTA showed a sensitivity of 90% and a specificity of 100% for diagnosing supraspinatus tendon (SST) full thickness tear, and CTA showed a sensitivity of 100% and a specificity of 97.5% for making the diagnosis of superior labrum anterior to posterior (SLAP) lesion. For diagnosing partial articular side supraspinatus avulsion (PASTA) lesion, some studies have shown the usefulness of CTA with a sensitivity of 71.4% and a specificity of 97.7%. However, for diagnosing SST bursal side partial tear, the sensitivity of CTA was as low as 10%. CTA has been shown to be relatively accurate when the diagnoses were verified with the arthroscopic findings; diagnosing SST full thickness tear and SLAP lesion with CTA has shown an accuracy of 100% and87.5% respectively, and CTA showed 71.4% diagnostic accuracy for PASTA lesion. Conclusion: CTA was a useful tool and it was equivalent to MRA for the assessment of SST full thickness tear, SLAP lesion and PASTA lesion, but not bursal side partial tear. Thus, it may be used preferably to diagnose shoulder pathology and for follow up as an inexpensive tool after operation.

• Journal of Distribution Science
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• v.21 no.6
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• pp.83-89
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• 2023

Purpose: This paper considers the issue of corporate tax avoidance (CTA) in the distribution of the tax burden across companies in Vietnam because the high level of CTA leads to unfairness in taxation. In particular, we aim for discussing the way to measure the extent of CTA and explore the determinants of CTA that reflect the features of high-tax risk-taking companies. Research design, data and methodology: The study investigates factors influencing the CTA behavior of legal entities listed on the Vietnam stock market between 2012 and 2018 to fill the empirical research vacuum in the country. we employ the dynamic GMM estimate method. Interestingly, CTA is considered through three approaches, including two effective-tax-rate-based methods and especially accrual earnings Results: The results highlight tax - accounting book disparities have significant effects on CTA. In addition, firm size, net asset value, debt leverage, and tax-accounting books are related to CTA. Conclusions: Tax avoidance is shown to have a positive correlation with financial distress in this case. The higher a company's capital adequacy ratio, the fewer tax avoidance opportunities it has. The paper draws some recommendations to deal with tax avoidance that improves the fairness in the distribution of the tax burden among corporations.

• Journal of Life Science
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• v.13 no.6
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• pp.865-870
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• 2003

Opuntia ficus-indica is widely used as folk medicine for burned wound, edema and indigestion, etc. After the adaptation of rats for seven days, OF (200mg/kg) was administered into rats intraperitoneally every day for two weeks. On the 14th day, $3.3m\ell$ of $CCl_4$ (50% $CCl_4$ : Olive oil = 1 : 1) was treated to rats and on the 15th day, they were operated. We measured the levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, total lipid and triglyceride (TG) in serum and Malondialdehyde (MDA) in liver tissue. Opuntia ficus-indica and $CCl_4$-treated group (OFC) significantly decreased lipid peroxidation by 32.6% compared to $CCl_4$-treated abnomal group (CTA). Total lipid and TC of OFC administered group were lower than those of CTA group. Cholesterol levels showed significant effect in OFC group. Total cholesterol and LDL-cholesterol in OFC administered group were decreased by 12.7% and 17.4%, respectively, compared to those of CTA group. HDL-cholesterol in OFC administration group was increased by 19.7% compared to CTA group. This finding suggests that lipid peroxidation was inhibited in the significant level when $CCl_4$-induced rats were treated with OF. Based on this analysis, further study to identify the active components in this sample is warranted.

• Journal of the Korea Society of Computer and Information
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• v.21 no.2
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• pp.9-16
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• 2016

Recently, many research groups have focused on GPGPUs in order to improve the performance of computing systems. GPGPUs can execute general-purpose applications as well as graphics applications by using parallel GPU hardware resources. GPGPUs can process thousands of threads based on warp scheduling and CTA scheduling. In this paper, we utilize the traditional CTA scheduler to assign a various number of CTAs to SMs. According to our simulation results, increasing the number of CTAs assigned to the SM statically does not improve the performance. To solve the problem in traditional CTA scheduling schemes, we propose a new IPC-based dynamic CTA scheduling scheme. Compared to traditional CTA scheduling schemes, the proposed dynamic CTA scheduling scheme can increase the GPU performance by up to 13.1%.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.711-716
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• 2001

Objectives : Three-dimensional computed tomographic angiography(3D-CTA) is recently developed diagnostic imaging modality. We have studied this noninvasive method for possible role in replacing conventional angiography( CA) in the detection of aneurysms of the circle of Willis in patients with subarachnoid hemorrahge(SAH). Methods : We studied retrospectively, the 100 patients with SAH or unruptured aneurysms admitted to our hospital from October 1997 to December 1998. Among there, 85 patients underwent CTA, 82 patients underwent CA and 67 patients underwent both of CTA and CA. 3D-CTA was obtained using maximum intensity projection(MIP) and shaded-surface display(SSD) reconstruction. Results : Total 107 aneurysms were detected in 92 patients, and 64 aneurysms were detected in 67 patients underwent both CTA and CA. In five cases of those 67 cases, aneurysms were detected by CA but not by 3D-CTA. The detection rate of aneurysms(91.8%) and the detection rate of parent artery in cases of anterior communicating artery aneurysms(86.9%) with total 3D-CTA were relatively compatible with that of CA. But 3D-CTA was not enough in detection of posterior communicating artery aneurysms, internal carotid artery aneurysms as well as small sized aneurysm(<3mm). Conclusion : We consider CTA is valuable in as a screening test for cerebral aneurysm and follow-up test. And it is also valuable in early surgery for patients with aneurysmal rebleeding because of simple, quick, non-invasive method.

• Investigative Magnetic Resonance Imaging
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• v.24 no.3
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• pp.154-161
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• 2020

Purpose: A CT angiography spot sign (CTA-spot) is a significant predictor of the early expansion of an intracerebral hemorrhage (ICH-Ex). Dynamic-susceptibility-contrast magnetic resonance imaging (DSC-MRI) can track the real-time leaking of contrast agents. It may be able to indicate active bleeding, like a CTA-spot. Materials and Methods: From September 2014 to February 2017, we did non-contrast CT, CTA, and DSC-MRI examinations of seven patients with acute ICH. We investigated the time from symptom onset to the first contrast-enhanced imaging. We evaluated the time course of the contrast leak within the ICH at the source image of the DSC-MRI and the volume change of ICH between non-contrast CT and DSC-MRI. We compared the number of slices showing CTA-spots and DSC-MRI leaks. Results: The CTA-spot and DSC-MRI leak-sign were present in four patients, and two patients among those showed ICH-Ex. The time from the symptom onset to CTA or DSC-MRI was shorter for those with a DSC-MRI leak or CTA-spot than for three patients without either (70-130 minutes vs. 135-270 minutes). The leak-sign began earlier, lasted longer, and spread to more slices in the patients with ICH-Ex than in those without ICH-Ex. The number of slices of the DSC-MRI leak and the number of the CTA-spot were well correlated. Conclusion: DSC-MRI can demonstrate the leakage of GBCA within hyperacute ICH, showing the good contrast between hematoma and contrast. The DSC-MRI leakage sign could be related to the hematoma expansion in patients with ICH.

• Textile Coloration and Finishing
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• v.16 no.5
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• pp.28-34
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• 2004

The polarizing film application exploits the unique physicochemical properties between PVA(Poly vinyl alcohol) film and CTA(Cellulose triacetate) film. However, hardly any research was aimed at improving the adhesion characteristics of the CTA film by radio frequency(RF) plasma treatment at argon(Ar) gaseous state. In this report, we deal with surface treatment technology for protective CTA film developed specifically for high adhesion applications. After Ar plasma, surface of the films is analyzed by atomic force microscopy(AFM), roughness parameter and peel strength. Furthermore, the wetting properties of the CTA film were studied by contact angle analysis. Results obtained for CTA films treated with a glow discharge showed that this technique is sensitive to newly created physical functions. The roughness and peel strength value increased with an increase in treatment time for initial treatment, but showed decreasing trend for continuous treatment time. The result of contact angle measurement refer that the hydrophilicity of surface was increased. AFM studies indicated that no considerable change of surface morphology occurred up to 3 minutes of treatment time, but a considerable uneven of surface structure resulted from treating time after 5 minutes.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.177-182
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• 2003

Saururus chinensis Baill (Saururaceae) is a perennial plant that has been used for therapy of edema, jaundice and gonorrhea in Korean folk medicine. This study was carried out to investigate the inhibitory effects of Saururus chinensis Baill(SCB) on hepatoprotective effects in accutely Carbone Tetrachloride ($CCl_4$) treated rats. Saururus chinensis Baill (100 mg/kg) was administered into rats intraperitoneally for 2 weeks, after the injection of CCl4 (3.3 ml/kg). We dxamined the biochemical parameters by measuring the levels of Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Total cholesterol, Triglyceride (TG), HDL-cholesterol, and LDL-cholesterol in serum and Malonedialdehyde (MDA) in liver tissue of rats. cholesterol was siginificantly elevated in $CCl_4$-treated abnormal group (CTA). The higher level of HDL-cholesterol was found is Saururus chinensis Baill and CCl4 administered group (SCT), which showed the lower levels of Total-cholesterol and LDL-cholesterol. TG content in the SCT was decreased compared to CTA by 0.93 times. MDA content in the SCT was inhibited compared to CTA by 33.00%. These findings indicate that Saururus chinensis. Baill may have a protective effect against CCl4-treated hepatotoxicity in rats.