• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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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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• v.5B no.4
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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.

• Smart Media Journal
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• v.11 no.3
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• pp.54-61
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• 2022

With the increase in the types of information systems managed by public institutions and companies, a security certification system is being implemented in Korea to quickly respond to vulnerabilities that may arise due to insufficient security checks. The korea security evaluation system, such as ISMS-P, performs a systematic security evaluation for each category by dividing the categories for technical inspection items. NIST in the United States has developed SCAP that can create security checklists and automate vulnerability checks, and the security checklists used for SCAP can be written in OVAL. Each manufacturer prepares a security check list and shares it through the SCAP community, but it's difficult to use it in Korea because it is not categorized according to the korea security evaluation system. Therefore, in this paper, we present a mechanism to categorize the OVAL definition, which is an inspection item written in OVAL, to apply SCAP to the korea security evaluation system. It was shown that 189 out of 230 items of the Red Hat 8 STIG file could be applied to the korea security evaluation system, and the statistics of the categorized Redhat definition file could be analyzed to confirm the trend of system vulnerabilities by category.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.5
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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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• v.7 no.3
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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.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2001.12a
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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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• v.10 no.2
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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.

• Journal of Information Technology Services
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• v.21 no.4
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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.