• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1484-1485
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• 2006

Alumina 첨가량의 변화에 따라 국산 경년품 애자와 신품 애자의 특성을 분석하고, 외국산 신품애자와 비교분석하였다. 그 결과 알루미나가 17% 첨가된 2001년도 자기애자가 알루미나 첨가량이 m%된 2004년 신품애자에 비하여 기계적 특성이 10%정도 낮았다. 또한, 2001년도에 제조한 애자의 자기 상대밀도는 이론밀도의 96%에 도달하였으나 2004년도에 제조한 애자의 상대 밀도는 이론 밀도의 98%에 도달하였으며, 애자의 균일성을 나타내는 Qs 값은 5.01로 높게 나타났다.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2037-2039
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• 2005

2004년도 36,0001bs 볼소켓형 국산 애자에 대하여 알루미나(alumina) 첨가량의 변화에 따른 국산 2001년산 및 외국산 2000년산 자기애자의 특성 분석을 실시하였다. 그 결과 2001년도 자기애자의 알루미나 첨가량을 17%로 하고 2004년도 알루미나 첨가량이 20%로 하였을 경우 자기 애자의 기계적 특성은 10% 정도 향상되었다. 그리고 2001년도에 제조한 애자의 자기 상대밀도는 이론밀도의 96%에 도달하였으나 2004년도에 제조한 애자의 상대 밀도는 이론밀도의 98%에 도달하였으며, 애자의 균일성을 나타내는 Qs 값은 5.01로 높게 나타났다.

• Review of KIISC
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• v.16 no.4
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• pp.7-14
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• 2006

NP-Hard 문제인 정수의 소인수분해 알고리즘의 연구와 구현은 1978년 RSA 암호의 개발과 함께 암호학에서 중요한 문제로 부각되었으며 지난 25년간 이 분야에서 많은 발전이 이룩되었다. QS 인수분해 알고리즘과 NFS 인수분해 알고리즘이 최근까지도 RSA-challenge를 분석하기 위한 도구로 사용되었고, NFS가 가장 효율적인 것으로 알려져 있다. 그러나 인수분해 대상 정수의 크기가 커짐에 따라 기존의 소프트웨어 기반의 접근 방법으로 분석하는 것은 점차 어려워지고 있다. 99년도 CHES Rump Session에서 Shamir에 의해 제안된 TWINKLE은 인수분해 알고리즘의 연구에 새 지평을 마련하였다. TWINKLE는 기존과는 근본적으로 다른 접근 방법으로 수행되는 인수분해 전용 하드웨어 장비이다. TWINKLE이 발표된 이후 TWIRL와 SHARK 등 다양한 인수분해 전용 하드웨어들이 제안되었고, 이는 인수분해 방법론 연구에서 새로운 방향이 되고 있다. 본 논문에서는 이와 같은 인수분해 전용 하드웨어 연구 동향에 대해 살펴보고, 각 장비들의 효율성을 비교 분석하도록 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.49
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• pp.169-182
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• 1999

Nowadays most companies are required to acquire the quality assurance system for their survival. It is essential to improvement company's competitive power that Certification of Quality Assurance System but there are many problems. To analysis the effects of ISO 9000 series/QS-9000 QA systems to the Domestic Company Quality Improvement as well as quality consciousness, data has been surveyed form quality assurance engineers who have work on certification activities. The data is analyzed using relevant tabulations of five scale or paired t test method in order to compare level of quality management of pre-certification with that of post-certification. It is analyzed in two parts which are qualitative effects and quality maturity grid. Also, to analysis for the bottlenecks and problems the data is analyzed using frequency analysis method.

• Advances in concrete construction
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• v.5 no.5
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• pp.481-492
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• 2017

The aim of this paper is to investigate the effect of quartz powder (Qp), quartz sand (Qs), and different water curing temperature on mechanical properties including 7, 14, 28-day compressive strength and 28-day splitting tensile strength of Ultra High Performance Concrete and also finding the correlation between these variables on mechanical properties of UHPC. The response surface methodology was monitored to show the influences of variables and their interactions on mechanical properties of UHPC, then, mathematical models in terms of coded variables were established by ANOVA. The offered models are valid for the variables between: quartz powder 0 to 20% of cement substitution by cement weight, quartz sand 0 to 50% of aggregate substitution by crushed limestone weight, and water curing temperature 25 to $95^{\circ}C$.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1195-1198
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• 2022

홀로그램은 빛의 세기와 위상 정보를 모두 기록함으로써 3차원 영상 정보를 기록 및 재현할 수 있는 차세대 영상 시스템이다. 홀로그램은 부동 소수점의 복소 데이터로 실수, 허수 또는 진폭, 위상 신호로 분리되어 압축된다. 본 논문에서는 복소 홀로그램 영상의 표현방식에 따른 압축성능을 비교해보고, 진폭-위상 압축에 대해 압축 친화적인 복소 홀로그램 변환 방식을 제안한다. 이후, 각 표현방식의 압축에서 효율적인 비트량 할당 방법을 제시한다. 본 논문은 제안방식인 QS 진폭-위상 표현이 실수-허수 표현만큼 높은 압축성능을 갖는 것을 확인하였다.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.488-493
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• 2009

Purpose : The aim of this study was to assess the efficacy and safety of recent-generation patent ductus arteriosus (PDA) closure devices applied by a new selection strategy according to the characteristics of each PDA. Methods : From February 2003 to January 2006, 138 patients underwent transcatheter closure of PDA (study group). According to the size and morphology of each ductus, a COOK Detachable Coil or 'flex' PFM Nit-Occlud was used for a small ductus (group 1, n=43); 'medium' PFM Nit-Occlud (group 2, n=49) for a moderate ductus; and an Amplatzer Duct Occluder (group 3, n=46) for a large ductus. The 83 patients who underwent transcatheter closure of PDA from February 2000 to January 2003 were defined as the comparison group. The Qp/Qs ratio, pulmonary/aorta pressure ratio, and MD of the ductus were compared. Immediate and follow-up results including residual shunts and complications were also evaluated and compared among groups. Results : In all 138 patients, complete occlusions were confirmed without major complications, while procedure failure (n=2, 2.2%), device embolization (n=1, 1.1%), and persistent residual shunt (n=4, 4.5%) were documented in the comparison group. Total complication rates were lower in the study group than in the comparison group (study group, 1.4%; comparison group, 9.0%; P<0.05). Conclusion : A novel strategy adopting the merits of various recent-generation devices for transcatheter closure of PDA provides excellent clinical results with minimal risk.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.386-392
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• 1996

Preoperative and postoperative evaluation was done in 60 adult patients above 20 years of age among 152 patients, who had operation for the congenital atrial septal defect from January 1984 to June 1993 in the Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Hospital. Anatomically, the secundum type defect was present In 58 cases and the other two were ostium primum type defect. The defect were closed directly in 45 cases and with patches in 15 cases. Preopera ive EKG findings revealed regular sinus rhythm in 81%, arrhythmia 19%, RVH 32%, RAD 30%, Postoperative findings were regular sinus rhythm in 76%, arrhythmia 24%, RVH 25%. RAD 25%. In hemodynamic data, the mean SPAP in patients over 40 years old was 41.91 $\pm$ 14.33mmHg compared to 31.46 $\pm$ 13.77 mmHg in patients under 40 years old, and the difference between the two groups was stastistically significant. And then the patients were classified into two groups (group A sinus group, and group B : arrhythmia group) according to their preoperative rhythm. The patients in group B were older, had greater value of mean SPAP and Rp/Rs. Mean Qp/qs was higher in group A. But the difference between two groups about the mean Qp/qs and Rp/Rs was not significant. Postoperative complications such as arrhythmia, pneumothorax or hemothorax occurred in 7 cases, but there was no operative mortality. The functional improvement were remarkable in half of the patients who underwent surgery.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.248-257
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• 2009

The inhibitors against Vibrio harveyi quorum sensing (QS) signaling were developed by modifying the molecular structure of the major signal, N-3-hydroxybutanoyl-L-homoserine lactone (3-OH-$C_4$-HSL). A series of structural derivatives, N-(3-hydroxysulfonyl)-L-homoserine lactones (HSHLs) were synthesized by the solid-phase organic synthesis method. The in vivo QS inhibition by these compounds was measured by a bioassay system using the V. harveyi bioluminescence, and all showed significant inhibitory effects. To analyze the interaction between these compounds and LuxN, a 3-OH-$C_4$-HSL receptor protein of V. harveyi, we tentatively determined the putative signal binding domain of LuxN based on the sequence homology with other acyl-HSL binding proteins, and predicted the partial 3-D structure of the putative signal binding domain of LuxN by using ORCHESTRA program, and further estimated the binding poses and energies (docking scores) of 3-OH-$C_4$-HSL and HSHLs within the domain. In comparison of the result from this modeling study with that of in vivo bioassay, we suggest that the in silica interpretation of the interaction between ligands and their receptor proteins can be a valuable way to develop better competitive inhibitors, especially in the case that the structural information of the protein is limited.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1235-1241
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• 2012

Antioxidant properties and antioxidant compound contents in different parts of 14 commercial mushrooms were evaluated. Methanolic extracts from the entire mushroom, the pileus and the stipe, separately, were screened for their DPPH and ABTS free radical scavenging activities. Total ubiquinones (Coenzyme Qs; CoQs), total phenolic, and flavonoid contents were determined, in order to assess the extract's antioxidant activity. The portion of the mushroom selected had an effect on the results, with pileus methanolic extract exhibiting the greatest antioxidant effect (p<0.05). The analyzed mushrooms contained powerful antioxidants such as phenols (144.5~536.6 mg of gallic acid equivalents, mg GAE/100 g of dried weight, dw), flavonoids (3.7~31.2 mg of quercetin equivalents, mg QE/100 g dw) and ubiquinones (65.6~485.1 ${\mu}g$/100 g dw). Content of CoQ9 and CoQ10 in the 14 commercial mushrooms varied from 23.1 to 256.2 ${\mu}g$/100 g and from 16.1 to 238.3 ${\mu}g$/100 g, respectively. Phellinus linteus showed the highest antioxidant activity among all species due to the contribution of antioxidants such as phenols (530.5 mg GAE/100 g dw) and ubiquinones (308.8 ug/100 g dw). A positive linear correlation was demonstrated between free radical scavenging activity and total phenolic ($R^2=0.79$) and ubiquinone ($R^2=0.59$) contents in the pileus of mushrooms (p<0.05). Our data indicate that commercial mushrooms have potential as dietary sources of CoQs and phenolic antioxidants.