• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.570-576
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• 2017

Gas turbine system with steam injection has shown outstanding advantages such as high specific power and NOx reduction. In the present work, a comparative exergetic analysis was carried out for Steam Injected Gas Turbine (STIG), Regenerative Steam Injected Gas Turbine (RSTIG), and Regenerative After Fogging Gas Turbine (RAF). Effects of pressure ratio, steam injection ratio and steam injection method on the system performance was theoretically investigated. The results showed that the order of the highest exergy efficiency is RSTIG, RAF, and STIG for low pressure ratios but STIG, RSTIG, and RAF for high pressure ratios. In each arrangement, the combustion chamber has the highest exergy destruction and the compressor has the second one.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.299-305
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• 2005

The work described in this paper is to investigate the additional iron losses and consequent temperatures in core ends of a turbo-generator wound with high voltage cables. Electromagnetic calculations are made with 3D FE models, which include the lamination material with anisotropic properties both in magnetic permeability and electric conductivity. The models also include the geometry of the stator teeth and eventually the axial steps designated to reduce the core end losses. The 3D model of the rotor consists of field windings with straight in-slot parts and end windings. The thermal models are simplified into two dimensions and include the heat sources dumped from the 3D electromagnetic solutions. The influences of power factor on additional iron losses are studied for this cable wound machine and conventional machines. The calculation results show that the additional iron losses can be reduced to about $15\%$ by introducing some small steps around the airgap corner of core ends.

• 스마트미디어저널
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• 제11권3호
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• pp.54-61
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• 2022

공공기관과 기업에서 관리하는 정보 시스템 종류의 증가로, 국내에서는 보안 점검의 미흡으로 발생할 수 있는 취약성에 신속하게 대응하기 위한 보안 인증제도를 시행하고 있다. ISMS-P와 같은 국내의 정보보호체계 평가는 기술적 점검 항목들에 대해 범주를 나누어 평가함으로써 각 범주에 대한 체계적인 보안성 평가를 수행하고 있다. 미국의 NIST에서는 보안 점검 목록을 작성하고 취약성 점검을 자동화할 수 있는 프로토콜인 SCAP을 개발했으며 SCAP에 사용되는 보안 점검 목록은 OVAL로 작성할 수 있다. 제조사 별로 보안 점검 목록을 작성하여 SCAP 커뮤니티를 통해 공유하고 있지만, 국내 보안평가체제에 맞게 범주화되어있지 않아 국내에서는 실질적으로 사용하기에 어려움이 있다. 이에 본 논문에서는 국내 정보보호체계에 SCAP을 적용하기 위해 OVAL로 작성된 점검 항목인 OVAL 정의를 범주화하는 메커니즘을 제시한다. 레드햇 8 STIG 파일을 대상으로 230개 항목 중 189개의 OVAL 정의를 국내 보안 평가체제에 적용할 수 있음을 보였고, 범주화된 레드햇 정의 파일의 통계를 분석하여 범주별 시스템 취약성 추이를 확인할 수 있었다.

• 한국측량학회지
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• 제35권5호
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• pp.375-388
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• 2017

United States of America started NSDI in 1994 for the first time in the world. EU and other many countries invested lots of budget on NSDI due to necessity to manage countries and social economy. As skepticism for effect of such investment has risen, developed countries predicted higher effect compared to investment using ROI and other methods. FGDC clarified that geospatial information is a critical national assets. USA has managed NSDI by introducing portfolio concept for it recognizing NSDI as financial assets from fixed assets. Currently directions of NSDI and its advancement has been proceeded variably depending on corresponding organizations, human resources, budget and national policies. This study analyzed recent trends regarding NSDI assessment methods from developed countries and researchers. Assessment of NSDI is introduced only by some countries such as EU, USA and Canada. This study analyzed USA's assessment model and indicator that assess NSDI in a way that various external organizations (COGO, URISA) participate, EU INSPIRE Directives, monitoring and Canada's CGDI assessment methods. Besides these, this study analyzed STIG that adopted Financial Infrastructure from European studies and Korea's NSDI monitoring assessment indicator research. Further this study suggested assessment directions for future NSDI through implications of NSDI assessment method analysis.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.332-345
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• 2002

It is a recent observation that about 80 per cent of the body's immune system is localized in the gastrointestinal tract. This explains to a large extent why eating right is important for the modulation the immune response and prevention of disease. In addition it is increasingly recognized that the body has an important digestive system also in the lower gastrointestinal tract where numerous important substances are released by microbial enzymes and absorbed. Among these substances are short chain fatty acids, amino acids, various carbohydrates, poly-amines, growth factors, coagulation factors, and many thousands of antioxidants, not only traditional vitamins but numerous flavonoids, carotenoids and similar plant- and vegetable produced antioxidants. Also consumption of health-promoting bacteria (probiotics) and vegetable fibres (prebiotics) from numerous sources are known to have strong health-promoting influence. It has been calculated that the intestine harbours about 300,000 genes, which is much more than the calculated about 60,000 for the rest of the human body, indicating a till today totally unexpected metabolic activity in this part of the GI tract. There are seemingly several times more active enzymes in the intestine than in the rest of the body, ready to release hundred thousand or more of substances important for our health and well-being. In addition do the microbial cells produce signal molecules similar to cytokines but called bacteriokines and nitric oxide, with provide modulatory effects both on the mucosal cells, the mucosa- associated lymphoid system (MALT) and the rest of the immune system. Identification of various fermentation products, and often referred to as synbiotics, studies of their role in maintaining health and well-being should be a priority issue during the years to come.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.187-231
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• 2001

It is a recent observation that about 80 per cent of the body's immune system is localized in the gastrointestinal tract. This explains to a large extent why eating right is important for the modulation the immune response and prevention of disease. I addition it is increasingly recognized that the body has an important digestive system also in the lower gastrointestinal tract where numerous important substances are released by microbial enzymes and absorbed. Among these substances are short chain fatty acids, amino acids, various carbohydrates, polyamines, growth factors, coagulation factors, and many thousands of antioxidants, not only traditional vitamins but numerous flavonoids, carotenoids and similar plant- and vegetable produced antioxidants. Also consumption of health-promoting bacteria (probiotics) and vegetable fibres (prebiotics) from numerous sources are known to have strong health-promoting influence. It has been calculated that the intestine harbours about 300 000 genes, which is much more than the calculated about 60000 for the rest of the human body, indicating a till today totally unexpected metabolic activity in this part of the GI tract. There are seemingly several times more active enzymes in the intestine than in the rest of the body, ready to release hundred thousand or more of substances important for our health and well-being. In addition do the microbial cells produce signal molecules similar to cytokines but called bacteriokines and nitric oxide, with provide modulatory effects both on the mucosal cells, the mucosa-associated lymphoid system (MALT) and the rest of the immune system. Identification of various fermentation products, and often referred to as synbiotics, studies of their role in maintaining health and well-being should be a priority issue during the years to come.

• Safety and Health at Work
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• 제10권2호
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• pp.224-228
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• 2019

Background: European policymakers encourage individuals to become self-employed because it is a way to promote innovation and job creation. It can be assumed that health and well-being among the self-employed and managers in small-scale enterprises are particularly crucial in this enterprise group because the smallness of the enterprise makes its members vulnerable. Earlier studies have indicated that the self-employed have a high working pace and work for long and irregular hours, indicating that it can be difficult to stay at home because of sickness. The purpose of this study is to investigate the occurrence of sickness presenteeism among the self-employed in relation to the organizationally employed and to analyze whether any differences can be explained by higher work demands among the self-employed. Methods: The study is based on the fifth European survey on working conditions (2010) and includes the northwestern European countries in the survey. The questions cover a wide range of topics designed to meet the European Union's political needs. The main variables in this study are sickness presenteeism and several indicators of time demands. Results: The results show that the self-employed report a higher level of sickness presenteeism than the employed: 52.4 versus 43.6%. All indicators of time demands are significantly related to the risk for sickness presenteeism, also when controlling for background characteristics. Conclusion: The results confirm that the level of sickness presenteeism is higher among the self-employed and that high time demands are a major explanation to this.

• 한국IT서비스학회지
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• 제21권4호
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• pp.63-74
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• 2022

Globally researchers at medical institutions are actively sharing COHORT data of patients to develop vaccines and treatments to overcome the COVID-19 crisis. OMOP-CDM, a common data model that efficiently shares medical data research independently operated by individual medical institutions has patient personal information (e.g. PII, PHI). Although PII and PHI are managed and shared indistinguishably through de-identification or anonymization in medical institutions they could not be guaranteed at 100% by complete de-identification and anonymization. For this reason the security of the OMOP-CDM database is important but there is no detailed and specific OMOP-CDM security inspection tool so risk mitigation measures are being taken with a general security inspection tool. This study intends to study and present a model for implementing a tool to check the security vulnerability of OMOP-CDM by analyzing the security guidelines for the US database and security controls of the personal information protection of the NIST. Additionally it intends to verify the implementation feasibility by real field demonstration in an actual 3 hospitals environment. As a result of checking the security status of the test server and the CDM database of the three hospitals in operation, most of the database audit and encryption functions were found to be insufficient. Based on these inspection results it was applied to the optimization study of the complex and time-consuming CDM CSF developed in the "Development of Security Framework Required for CDM-based Distributed Research" task of the Korea Health Industry Promotion Agency. According to several recent newspaper articles, Ramsomware attacks on financially large hospitals are intensifying. Organizations that are currently operating or will operate CDM databases need to install database audits(proofing) and encryption (data protection) that are not provided by the OMOP-CDM database template to prevent attackers from compromising.