• 한국가스학회지
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• 제11권4호
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• pp.17-22
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• 2007

비예혼합 대향류화염에서 산소부화에 따른 NOx 생성특성에 관한 수치해석이 수행되었다. 순산소의 연소과정에서 공기침투에 의한 부득이한 질소 유입의 상황을 체계적으로 고려하기 위하여, 산화제의 $O_2$는 체적비 21%에서 100%까지 변화되었다. 결과적으로 NO 배출지수$(EI_{NO})$는 산소부화율 75%까지 증가하다가 급격히 감소하는 경향을 보여준다. 이러한 경향은 화염온도, 화염두께 및 체류시간 보다는 NOx 생성과 관련된 $N_2$ 소모율 변화에 의해 설명될 수 있음을 확인하였으며, 특히 N+NO=$N_2+O$ 반응이 가장 크게 기여함을 알 수 있었다.

• 약학회지
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• 제52권5호
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• pp.345-354
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• 2008

This study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng extract through transcriptomics in C57BL/KsJ db/db mice. The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. At the end of treatment, we measured blood glucose, insulin, hemoglobin A1c (HbA1c), triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). RGL-treated group lowered the blood glucose and HbA1c levels by 19.6% and 11.4% compared to those in diabetic control group. In addition, plasma adiponectin and leptin levels in RGL-treated groups were increased by 20% and 12%, respectively, compared to those in diabetic control. Morphological analyses of liver, pancreas and epidydimal adipose tissue were done by hematoxylin-eosin staining, and pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. RGL-treated group revealed higher insulin contents and lower glucagon contents compared to diabetic control. To elucidate an action mechanism of Korean red ginseng, DNA microarray analyses were performed in liver and fat tissues, and western blot and RT-PCR were conducted in liver for validation. According to hierarchical clustering and principal component analysis of gene expression Korean red ginseng treated groups were close to metformin treated group. In summary, Korean red ginseng lowered the blood glucose level through protecting destruction of islet cells and shifting glucose metabolism from hepatic glucose production to glucose utilization and improving insulin sensitivity through enhancing plasma adiponectin and leptin levels.

• 치과방사선
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• 제28권1호
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• pp.87-109
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium­deficient diet on the dentin and cementum formation of rat molar. The pregnant three-week old Sprague­Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group and irradiation/calcium-deficient diet group. The control group was non­irradiation/normal diet group. The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin antibody. The results were as follows; 1. The Hertwig's epithelial root sheath cells, which are related to the differentiation of the tooth-forming cells, showed irregular cellular arrangement, decrease of intercellular junctional complex, and decreased immunoreactivity to the fibronectin after irradiation. These were more severe in the irradiation/calcium-deficient diet group. 2. The cementoblasts at the cementum-forming area showed chromatin clumpings after irradiation. The immu noreactivity to the fibronectin was weaken after irradiation, especially irradiation/calcium-deficient diet group. 3. The odontoblasts at the dentin-forming area showed increase of lysosomes in the cytoplasm and destruction of intercellular junctional complex. The irradiation/calcium-deficient diet group showed decrease of number and density of the electron dense particles and a large number of vacuoles scattered in the dentin matrix. The immunoreactivity was weaken.

• 대한안전경영과학회지
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• 제16권2호
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• pp.43-52
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• 2014

In weapon systems development, live fire tests have been frequently adopted to evaluate the performance of the systems under development. Therefore, it is necessary to ensure safety in the test ranges where the live fire tests can cause serious hazards. During the tests, a special care must be taken to protect the test and evaluation (T&E) personnel and also test assets from potential danger and hazards. Thus, the development and management of the range safety process is quite important in the tests of guided missiles and artillery considering the explosive power of the destruction. Note also that with a newly evolving era of weapon systems such as laser, EMP and non-lethal weapons, the test procedure for such systems is very complex. Therefore, keeping the safety level in the test ranges is getting more difficult due to the increased unpredictability for unknown hazards. The objective of this paper is to study on how to enhance the safety in the test ranges. To do so, an approach is proposed based on model-based systems engineering (MBSE). Specifically, a functional architecture is derived utilizing the MBSE method for the design of the range safety process under the condition that the derived architecture must satisfy both the complex test situation and the safety requirements. The architecture developed in the paper has also been investigated by simulation using a computer-aided systems engineering tool. The systematic application of this study in weapon live tests is expected to reduce unexpected hazards and test design time. Our approach is intended to be a trial to get closer to the recent theme in T&E community, "Testing at the speed of stakeholder's need and rapid requirement for rapid acquisition."

• 산업경영시스템학회지
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• 제20권43호
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• pp.211-218
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• 1997

Since Industrial Revolution, the sudden industrialization and population explosion have brought about a serious environmental pollution on the air of the earth, the quality of water and the soil, and the greenhouse effect by the destruction of the ozone layer and the greenhouse gas, the organism diversity decline, the desertification by the ruining of woods and the overall global environmental pollution such as the contamination of the ocean and rivers have been come to the front. So the new recognition on the environment is being spreaded in construction business and the efforts for certification acquisition of ISO 14000 being followed by ISO 9000 are progressing, Accordingly, with an example of H Company where integration system is built so that it can minimize the efforts and cost at the construction of the management system, operation and management after the fact, this paper shall suggest the practical scheme of 3 steps through a study to integrate both existing quality management system and new environmental management system. As the integration system of the quality and environment which is constructed by this method is executed, the number of the established and managed document is cut by about a third and so the disorder to encounter between these documents is prevented and unnecessary efforts is reduced in constructing a system, consequently the efficiency of the system is accomplished. Also as the dualization of quality management system and environmental management system additionally needs more men and money after certification acquisition, the non-construction of the integration system may give rise to a cause to aggravate the burden of the company and hereafter when a new system is imported, it may be very difficult to integrate the system. This system integration enables a efficient and effective system to be constructed , operated , and managed after the fact.

• 대한치과의사협회지
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• 제49권10호
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• pp.618-627
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• 2011

Cigarette smoking is a significant risk factor for periodontaldiseases and implant treatments. Smoking control is regarded as a key to the success of dental treatments as well as the well-being of the patients. The aim of this study was to reviewthe effects of smoking on periodontal health, and the results of periodontal therapy and implant treatments. Also, in vitro, microbiological, immunological and epidemiological relationships were studied. In vitro studies show that smoking interferes with normal healing process and increased tissue destruction. There is still controversy on the population of microbes of smokers. Smokers showed significantly less gingival inflammation and bleeding on probing compared with non-smokers. After periodontal treatments, a compromised clinical outcome was noted for smokers in terms of pocket depth reduction and gain in attachment levels. In conclusion, data from in vitro, epidemiological, cross-sectional and case-control studies strongly suggest that quitting smoking is beneficial to patients before periodontal and implant treatments.

• 한국정보통신학회논문지
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• 제16권5호
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• pp.1102-1112
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• 2012

미국의 한반도 정책은 비핵화이다. 미국정부는 북한의 핵위협을 제거하기 위해 군사행동의 가능성을 고려했었다. 군사행동 고려는 1993년 중반부터 1994년 중반까지 정점에 달했다. 그러한 공격은 직접적으로 한국전을 일으켰을 것이다. 당시 북핵위기는 북미협상과 한미동맹에 의해 해결되었다. PSI의 목적은 지구적 또는 지역적 안보에 심각한 위협을 일으키는 국가나 비국가행위자에게 대량살상무기, 운반체계, 관련 물질의 확산을 막거나 적어도 억제하는 것이다. PSI의 가장 논쟁의 여지가 있는 활동은 차단이다. 북한은 구상에 대해 심각한 우려를 표명하면서 다음과 같이 언급하였다. 무기를 개발하고, 배치하고, 수출하는 것은 주권이다. 그리고 자신들의 선박에 대한 차단은 선전 포고로 간주할 것이다. 한국이 북한선박에 대한 차단을 시행하면 북한은 도발로 대응할 것이므로 한반도의 긴장은 극적으로 증가할 것이다. 한국은 한미동맹과 남북관계를 고려해야하기 때문에 PSI에 매우 조심스럽게 접근하지 않을 수 없다.

• 한국식품위생안전성학회지
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• 제1권2호
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• pp.133-141
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• 1986

주요 농산 건조가공품에 오염된 미생물의 효과적인 살균법 개발을 목적으로, 현행방법인 ethylene oxide 훈증처리와 감마선 조사에 따른 미생물의 살균효과와 이화학적 품질에 미치는 영향을 검토한 결과는 다음과 같다. 시료의 미생물 오염도는 고추장 분말, 참깨, 느타리버섯 분말, 당근 flake의 순이었으며, 전세균이 $4.6{\times}10^{3}/g~1.5{\times}10^{6}/g$, 내열성 세균이 $1.3{\times}10^{3}/g~1.4{\times}10^{6}/g$, 산저항성 세균이 $8.4{\times}10^{2}.g~8.8{\times}10^{5}/g$, 내삼투압성 곰팡이를 포함한 곰팡이류는 $4.0{\times}10^{2}/g~1.5{\times}104/g$, 대장균군은 당근 flake를 제외한 나머지 시료에서 $4.0{\times}10^{3}/g~2.7{\times}10^{5}/g$ 정도로 오염되어 있어 위생적인 살균처리가 요구된다. 살균효과 실험에서는 대부분의 시료가 7~10 kGy의 감마선 조사로서 모든 미생물의 사멸이 가능하였으나 ethylene oxide 처리구에서는 전반적으로 전세균과 내열성 포자균 및 곰팡이의 살균이 불충분하였다. Ethylene oxide 처리는 시료의 색소, 아미노산, 무기질, 색도 등에 상당한 영향을 미쳤으나 적정선량의 감마선 조사는 이들에 대해 비교적 안전하였으며, 실온에서 3개월 동안 저장된 시료의 전반적인 기호도는 감마선 조사구가 ethylene oxide 처리구나 대조구보다 우수하게 나타났다.

• 식품과학과 산업
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• 제53권3호
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• pp.277-283
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• 2020

식품의 보존성 및 안전성 증대를 위해 살균이 필수적이다. 일반적으로 가열 살균 기술이 가장 많이 사용되고 있으나, 공정 중 식품의 품질 저하를 막기 위한 살균 기술로 신공정 기술을 활용한 비가열 살균 기술의 중요성이 대두되고 있다. 그 중에서도 초음파 기술은 특유의 캐비테이션 현상으로 미생물의 파괴가 촉진되어 살균 효과를 내는 것으로 알려져 있다. 초음파 기술 단독으로는 사멸 효과가 낮으며, 다양한 공정기술과 함께 적용하여 사멸 효과를 극대화할 수 있는 기술 개발을 위한 연구가 활발히 진행되고 있다. 초음파와 함께 처리할 수 있는 공정으로는 가열, 고압, 화학적 처리 등 전통적인 살균 방법 뿐 아니라 자외선 조사, PEF 등 신공정 기술이 있다. 초음파 기술을 적용한 다른 공정과 달리 살균 기술은 아직 실험실 수준에 머물러 있어 산업적 적용을 위한 장치의 개발, 최적 공정 확립 등 추가 연구가 필요하다.

• 대한두경부종양학회지
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• 제37권1호
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• pp.33-37
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• 2021

Intraosseous hemangioma is a rare, benign vascular tumor of endothelial origin. It accounts for fewer than 1% of all hemangiomas, and very rarely occurs in the face. Intraosseous hemangioma usually presents as an asymptomatic lesion, but symptoms can occur due to the mass effect. The authors describe a case of intraosseous hemangioma of the zygoma with a review of the relevant literature. A 44-year-old man presented with a chief complaint of painless swelling on the left zygomatic region that had been slowly growing for the past year. On physical examination, a hard, non-movable mass in a deep layer was palpated. On computed tomography performed to evaluate its layers and extent, trabeculation was found inside the mass, but the lack of destruction of the surrounding bone suggested that the mass was benign. Complete surgical excision was performed under local anesthesia. After complete excision of the mass, slight erosions remained on the cortical bone of the zygoma, but because it was small enough not to cause a facial deformity such as depression or asymmetry, no additional reconstructive procedure was performed. There were no symptoms or recurrence during a 8-month follow-up period.