• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.21-28
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• 2015

In the semi-conductor process, a simulation process is performed to detect defects by analyzing the behavior of the impurity through the physical quantity calculation of the inner element. In order to perform the simulation, Finite-Difference Time-Domain(FDTD) algorithm is used. The improvement of semiconductor which is composed of nanoscale elements, the size of simulation is getting bigger. Problems that a processor such as CPU or GPU cannot perform the simulation due to the massive size of matrix or a computer consist of multiple processors cannot handle a massive FDTD may come up. For those problems, studies are performed with parallel/distributed computing. However, in the past, only single type of processor was used. In GPU's case, it performs fast, but at the same time, it has limited memory. On the other hand, in CPU, it performs slower than that of GPU. To solve the problem, we implemented a computing model that can handle any FDTD simulation regardless of size on the cluster which consist of heterogeneous processors. We tested the simulation on processors using MPI libraries which is based on 'point to point' communication and verified that it operates correctly regardless of the number of node and type. Also, we analyzed the performance by measuring the total execution time and specific time for the simulation on each test.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.570-577
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• 2004

CT angiography is now available to evaluate the early graft patency after coronary bypass surgery. We investigated whether patency or occlusion of the bypass grafts can be visualized by CT angiography and what factors effect the visuality. Material and Method: Fifty patients underwent scanning with a 4-slice computed tomographic scanner (Somatom Volume ZoomTM; Siemens, Germany) before being discharged after coronary artery bypass grafting. To evaluate graft patency and relationship between the quality of graft image and the characteristics of the diseased coronary vessels, 50 internal thoracic artery grafts, 18 radial artery grafts, and 56 vein grafts were included in this study. Result: All vein grafts (24 grafts; 32 anastomoses) to left coronary artery system were well visualized, but 3 grafts (4.7%) of 30 vein grafts (35 anastomoses) to right coronary artery system were not visualized. The latter was also occluded in invasive coronary angiographic study. Thirty-nine (78%) internal thoracic artery grafts were well visualized, 8 (16%) faintly visualized, and 3 (6%) not visualized, but all the internal artery grafts were well patent in invasive coronary angiographic study. Conclusion: Unvisualized vein grafts in CT angiography means occlusion of the grafts, but unvisualized arterial grafts in CT angiography may not mean occlusion of the graft but result from competitive flow between the graft and coronary artery. To confirm patency of the unvisualized arterial grafts, invasive coronary angiography is needed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.105-112
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• 2009

In this paper, we investigated abnormal ESD failure on guard-rings in the smart power IC fabricated with $0.35{\mu}m$ Bipolar-CMOS-DMOS (BCD) technology. Initially, ESD failure occurred below 200 V in the Machine Model (MM) test due to current crowding in the parasitic diode associated with the guard-rings which are generally adopted to prevent latch-up in high voltage devices. Optical Beam Induced Resistance Charge (OBIRCH) and Scanning Electronic Microscope (SEM) were used to find the failure spot and 3-D TCAD was used to verify cause of failure. According to the simulation results, excessive current flows at the comer of the guard-ring isolated by Local Oxidation of Silicon (LOCOS) in the ESD event. Eventually, the ESD failure occurs at that comer of the guard-ring. The modified comer design of the guard-ring is proposed to resolve such ESD failure. The test chips designed by the proposed modification passed MM test over 200 V. Analyzing the test chips statistically, ESD immunity was increased over 20 % in MM mode test. In order to avoid such ESD failure, the automatic method to check the weak point in the guard-ring is also proposed by modifying the Design Rule Check (DRC) used in BCD technology. This DRC was used to check other similar products and 24 errors were found. After correcting the errors, the measured ESD level fulfilled the general industry specification such as HBM 2000 V and MM 200V.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.4
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• pp.329-338
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• 1985

This study was undertaken in order to research formation of nitrosamine and its related compounds by salt concentration and nitrate content during Korean native soysauce fermentation. The results from measuring the changes of nitrite and dimethylamine content can be summerized as follows. As the nitrate content in used water was getting higher and the salt concentration was getting lower, the soysauce fermentation was abnormal. As the salt concentration was getting higher, the reduction of nitrate and formation of nitrite were delayed. But whether the nitrate content in used water was higher or not, the nitrite was continuously remained. An addition of ascorbic acid restrained the reduction of nitrate, and simultaneously, it could eliminate the nitrite effectively. As the nitrate content in used water, was getting higher, the content of dimethylamine was getting lower. Nitrosodimethylamine was detected from 0 to 261.34 ppb.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.4
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• pp.223-232
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• 1998

The Okmyong Waste Landfill which is one of major industrial waste landfills in Korea has been used for 10 years since January, 1988. The groundwater in range of 2∼3 km from the landfill is a little acidic and has high concentrations of EC, NO$_3$, and SO$_4$ because of acidic rain in Pohang. The groundwater pattern in Piper's trilinear diagram belongs to Ca-SO$_4$and Na-SO$_4$types, but Ca-SO$_4$type is more predominant. The groundwater of five monitoring wells at the landfill area is a litle alkaline and has high concentrations of TS, COD, Na, Cl, SO$_4$, Alkalinity and F because of the effect of the leachates. They also have high heavy metals of Mn, Zn, Pb, Cr and Ni but toxic organic compounds are not detected. Their groundwater pattern is Na-SO$_4$type and distinguished from the groundwater pattern Na-Cl types of the Nanjido and the Seokdae Municipal Waste Landfills. The range of groundwater contamination which is validated up to now is about 120m west from the entrance of the Okmyong Waste Landfill. To prevent the dispersion of the leachates to the outside, cutoff walls should be constructed at the boundary of the landfill. Several pumping wells should also be developed at the landfill so that the contaminated groundwater can be pumped and treated at a leachate-treatment plant in the landfill.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.181-186
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• 1998

The effects of sewage treatment on characteristics of sludge as a composting material were investigated for a year during the initial operation at the full-scale Chunan sewage treatment plant. Due to the shortage of design capacity of belt press, a sludge dewatering unit, non-volatile solids were recirculating and concentrating in the treatment plant, resulting in an increase of MLSS and a decrease in F/M ratio at the activated sludge system. Special attention is required for long term operations since the increase of non-volatile solids in the plant would deteriorates the treatment efficiency. The sewage sludge of the Chunan sewage treatment plant showed 79.5% of water content, 11.6% of organic content, and C/N ratio of 6.1, and contained As 1.8 mg/kg, Cd 27 mg/kg, Hg <0.1 mg/kg, Pb 54 mg/kg, T-Cr 370 mg/kg, and Cu 1,100mg/kg of heavy metals. In order to be used as raw material for optimum composting, the sewage sludge requires bulking agents for moistrure/porosity control and a carbon source for adjusting C/N ratio. However, the sewage sludge is not adequate as a soil conditioner after composing due to a high content of heavy metals. If the sewage sludge has to he used as a soil conditioner after composting, it as required to identify and remove tire industrial wastewater portions in tire influent of the plant since heavy metals in the influent were mostly concentrated in dewatered sludge.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1045-1051
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• 1997

Three kinds of model melanoidins adjusted to have the same brown color intensity were made from glucose-glycine, glucose-lysine, xylose-arginine and their antioxidative properties were determined. The antioxidative activities of these model melanoidins in linoleic acid emulsion system were determined by ferric thiocyanate method, conjugated diene contents, peroxide value and electron donating ability by DPPH. Xylose-arginine melanoidin showed the strongest antioxidative activity and electron donating ability. The antioxidative effect of melanoidin could be reliably predicted by determining peroxide value and DPPH method. Each melanoidin was separated on Sephadex G-50 column, and brown color intensity, reducing power, ninhydrin positive reaction and antioxidative activity of each fraction were determined. The antioxidative activities of melanoidin fractions showed strong correlation with their brown color intensity and especially to their reducing power. In spite of same brown color intensity, there is no big differences between these model melanoidins, thus xylose-arginine showing strongest antioxidative activity followed by glucose-lysine and glucose-glycine melanoidin. Xylose-arginine melanoidin also showed the strongest electron donating activity and broad range of reducing power when fractionated on Sephadex G-50, which was different tendency from the other model melanoidin.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.77-77
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• 2018

미역의 뿌리부분인 미역귀에는 알긴산과 후코이단 성분이 풍부하고 고혈압과 당뇨등과 같은 성인병을 예방하는데 도움이 된다. 후코이단은 미역과 다시마 같은 갈조류에서 추출된 천연물질로 특히 면역력을 활성화하고 항암작용으로 잘 알려져 있다. 알긴산 등 유용성분이 함유된 것으로 알려진 미역귀의 유용성분을 분석하여, 향후 미역귀를 활용한 제품개발의 기초자료를 제공하고자 본 연구를 수행하였다. 본 연구에 사용된 미역귀는 2015년 12월 완도 금일수산에서 제공받아 연구재료로 활용하였다. AOAC방법에 따라 분석한 미역귀의 일반성분은 수분이 대부분을 차지하였으며, 조섬유와 가용성 무질소물 함량이 높게 나타났다. 이는 시료로 사용한 미역귀가 수확 후 바로 냉동보관 되어서 수분함량이 높은 것으로 보여진다. 유리당은 미역귀 1g에 증류수를 가하여 $60^{\circ}C$에서 4시간 추출 한 후, 원심분리(3,000 rpm, 30 min)하여 $0.45{\mu}m$ membrane filter (Millipore Co., USA)로 여과한 여액을 HPLC (High Performance Liquid Chromatography)를 이용하여 분석한 결과, 미역귀의 유리당은 Galactose 1종만이 검출되었다. 미역귀의 구성아미노산과 유리아미노산은 $0.45{\mu}m$ membrane filter로 여과하여 얻은 여액을 일정량 취하여 AccQ-Tag 시약을 사용하여 유도체화 시킨 후 HPLC로 분석하였다. 미역귀의 구성아미노산은 glutamic acid, aspartic acid, alanine, lysine, threonine, valine, arginine 순으로 높은 함량을 나타내었으며, 유리아미노산은 glutamic acid, alanine, threonine, arginine, lysine 순으로 높은 함량을 나타내었다. 미역귀의 유리아미노산함량은 표고에 비하여 현저히 낮은 함량이 나타났으며, 주요아미노산은 해조류의 풍미를 대표하는 아미노산인 glutamic acid와 alanine으로 나타났다.

• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.86-97
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• 1991

To obtain the basic data of prognosis of acute carbon monoxide(CO) intoxication, one hundred and sixteen cases of CO intoxication defined by carboxyhemoglobin(COHb) and admitted via emergency room of Yeungnam University Hospital from Oct. '85 to April' 89 have been clinically analyzed and evaluated, including delayed postanoxic encephalopathy(DPE) and the following results were obtained. 1. The ratio of male to female was 1:1.5 and mental state was drowsy mostly(26.2% of 116 cases) 2. The more disturbed the mental state, the more decreased was the arterial pH and $PaCO_2$, which may be the result of metabolic acidosis. 3. The early laboratory findings in patients of CO intoxication were as follows : leukocytosis-65.5%, increase of hematocrit-23.3%, hyperglycemia-19.8%, increase of GPT-19.8% increase of creatinine-0.9%, and glucosuria-12.1%. 4. The early findings of EKG were abnormal in 35.3% : change of rhythm-25.0%, abnormal ST segment-15.5% (change of rhythm and abonormal ST segment-5.2%) but the conduction disorder was not present. 5. The abnormal EEG above mild degree was 93.1%, of which moderate was most frequent(80.2%). 6. The incidence of DPE was 7.8% among all admitted CO patients. DPE cases had long duration of exposure time(8 hours), severe leukocytosis(20,000) and an abnormal EEG(MA).

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.499-506
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• 2021

Hackers' cyber attack techniques are becoming more sophisticated and diversified, with a form of attack that has never been seen before. In terms of information security vulnerability standard code (CVE), about 90,000 new codes were registered from 2015 to 2020. This indicates that security threats are increasing rapidly. When new security vulnerabilities occur, damage should be minimized by preparing countermeasures for them, but in many cases, companies are insufficient to cover the security management level and response system with a limited security IT budget. The reason is that it takes about a month for analysts to discover vulnerabilities through manual analysis, prepare countermeasures through security equipment, and patch security vulnerabilities. In the case of the public sector, the National Cyber Safety Center distributes and manages security operation policies in a batch. However, it is not easy to accept the security policy according to the characteristics of the manufacturer, and it takes about 3 weeks or more to verify the traffic for each section. In addition, when abnormal traffic inflow occurs, countermeasures such as detection and detection of infringement attacks through vulnerability analysis must be prepared, but there are limitations in response due to the absence of specialized security experts. In this paper, we proposed a method of using the security policy information sharing site "snort.org" to prepare effective countermeasures against new security vulnerability attacks.