• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2A
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• pp.123-130
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• 2012

A cooling system is indispensable for the fossil and nuclear power plants which produce electricity by rotating the turbines with hot steam. A cycle of the typical cooling system includes pumping of seawater at the intake pump house, exchange of heat at the condenser, and discharge of hot water to the sea. The cooling type of the nuclear power plants in Korea recently evolves from the conventional surface intake/discharge systems to the submerged intake/discharge systems that minimize effectively an intake temperature rise of the existing plants and that are beneficial to the marine environment by reducing the high temperature region with an intensive dilution due to a high velocity jet and density differential at the mixing zone. It is highly anticipated that the future nuclear power plants in Korea will accommodate the submerged cooling system in credit of supplying the lower temperature water in the summer season. This study investigates the approach flow patterns at the velocity caps and discharge flow patterns from diffusers using the 3-D computational fluid dynamics code of $FLOW-3D^{(R)}$. The approach flow test has been conducted at the velocity caps with and without a cap. The discharge flow from the diffuser was simulated for the single-port diffuser and multi-ports diffuser. The flow characteristics to the velocity cap with a cap demonstrate that fish entrainment can significantly be minimized on account of the low vertical flow component around the cap. The flow pattern around the diffuser is well agreed with the schematic diagram by Jirka and Harleman.

• Toxicological Research
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• v.34 no.3
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• pp.221-229
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• 2018

Tenofovir nanoparticles are novel therapeutic intervention in human immunodeficiency virus (HIV) infection reaching the virus in their sanctuary sites. However, there has been no systemic toxicity testing of this formulation despite global concerns on the safety of nano drugs. Therefore, this study was designed to investigate the toxicity of Tenofovir nanoparticle (NTDF) on the liver and kidney using an animal model. Fifteen adult male Sprague-Dawley (SD) rats maintained at the animal house of the biomedical resources unit of the University of KwaZulu-Natal were weighed and divided into three groups. Control animals (A) were administered with normal saline (NS). The therapeutic doses of Tenofovir (TDF) and nanoparticles of Tenofovir (NTDF) were administered to group B and C and observed for signs of stress for four weeks after which animals were weighed and sacrificed. Liver and kidney were removed and fixed in formal saline, processed and stained using H/E, PAS and MT stains for light microscopy. Serum was obtained for renal function test (RFT) and liver function test (LFT). Cellular measurements and capturing were done using ImageJ and Leica software 2.0. Data were analysed using graph pad 6, p values < 0.05 were significant. We observed no signs of behavioural toxicity and no mortality during this study, however, in the kidneys, we reported mild morphological perturbations widening of Bowman's space, and vacuolations in glomerulus and tubules of TDF and NTDF animals. Also, there was a significant elevation of glycogen deposition in NTDF and TDF animals when compared with control. In the liver, there were mild histological changes with widening of sinusoidal spaces, vacuolations in hepatocytes and elevation of glycogen deposition in TDF and NTDF administered animals. In addition to this, there were no significant differences in stereological measurements and cell count, LFT, RFT, weight changes and organo-somatic index between treatment groups and control. In conclusion, NTDF and TDF in therapeutic doses can lead to mild hepatic and renal histological damage. Further studies are needed to understand the precise genetic mechanism.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.365-374
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• 2016

In high-latitude regions, temperature has risen ($0.6^{\circ}C$ per decade) and this leads to the increase in microbial degradability against soil organic carbon (SOC). Furthermore, the decomposed SOC is converted into green-house gases ($CO_2$ and $CH_4$) and their release could further increase the rate of climate change. Thus, understanding the microbial diversity and their functions linked with SOC degradation in soil-thawing model is necessary. In this study, we divided tundra soil from Council, Alaska into two depth regions (30-40 cm and 50-60 cm of depth, designated as SPF and PF, respectively) and incubated that for 108 days at $0^{\circ}C$. A total of 111,804 reads were obtained through a pyrosequencing-based metagenomic study during the microcosm experiments, and 574-1,128 of bacterial operational taxonomic units (OTUs) and 30-57 of archaeal OTUs were observed. Taxonomic analysis showed that the distribution of bacterial taxa was significantly different between two samples. In detail, the relative abundance of phyla Actinobacteria and Firmicutes largely increased in SPF and PF soil, respectively, while phyla Crenarchaeota was increased in both soil samples. Weight measurement and gel permeation chromatography of the SOC extracts demonstrated that polymerization of humic acids, main component of SOC, occurred during the microcosm experiments. Taken together our results indicate that these bacterial and archaeal phyla could play a key function in SOC degradation and utilization in cold tundra soil.

• Archives of design research
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• v.15 no.1
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• pp.163-170
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• 2002

Virtual Reality is the technique which makes the man experience the similar interaction behavior to the experience in the real world through virtual space. The users participating in the 3D virtual space using virtual reality technique can have the various experiences in the space desired without restrictions on time and space and then it has been applied in many application areas such as video industry, entertainment simulator, medical treatment, construction and design. The area of video among them has been highlighted as a high-added value industry. Therefore this study classifies video industry into four including movie, broadcasting, advertisement and internet and is to examine their characteristics, application cases and developmental potential. In the industry using virtual reality technique in video industry, it is implied for special elect in the area of movie and for providing the various graphic virtual word to audiences with the introduction of virtual studio and character in the area of broadcasting. It can give audiences a synergy effect by inserting 3D advertisement into virtual space in the area of advertisement. Also the implementation of 3D virtual reality such as virtual museum, virtual model house, virtual home shopping and entertainment on the web is possible with the emergence of Virtual Reality Modeling Language (VRML) and it plays the roles of more entertainments. Accordingly, this study is to seek the application methods using virtual reality technique in video industry.

• Journal of Korean Home Economics Education Association
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• v.15 no.4
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• pp.159-174
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• 2003

The purposes of this study were to determine the relationship between school education for life-long education and home economics education. to analyze the present state of the life-long education programs through the school in terms of the home economics education, and to understand the role and obtainable qualification of the home economics teachers as the life-long education leader. The results of this study was intended to provide as fundamental materials for direction and plans for life-long education programs in terms of home economics educations. This study was conducted through the analysis of the literature on life long education and the working reports for-16 model schools nationwide for life long education. The results are as follows : 1. The objectives and contents for programs should be developed systematically on the relationship with society. 2. The structure of programs should be developed by characters of organizations, school levels, and regions. 3. Programs should be classified by the purposes and constructed systematically. 4. The subject of programs should be all the members of a family, not only house wives or female adults. 5. The compensation system should be followed for the home economics teachers participating on the program of life long education. 6. Various opportunities for education should be provided to the home economics teachers who want to obtain the qualification as a family-life educator.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.63-73
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• 2017

In contemporary society, it is increasingly common to spend more time indoors. As such, there is a continually growing desire to build comfortable and safe indoor environments. Along with this trend, however, there are some serious indoor-environment challenges, such as the quality of indoor air and Sick House Syndrome. To address these concerns the government implements various systems to supervise and manage indoor environments. For example, green building certification is now compulsory for public buildings. There are three categories of green building certification related to indoor air in Korea: Health-Friendly Housing Construction Standards, Green Standard for Energy & Environmental Design(G-SEED), and Indoor Air Certification. The first two types of certification, Health-Friendly Housing Construction Standards and G-SEED, evaluate data in a drawing plan. In comparison, the Indoor Air Certification evaluates measured data. The certification using data from a drawing requires a considerable amount of time compared to other work. A 2D tool needs to be employed to measure the area manually. Thus, this study proposes an automatic assessment process using a Building Information Modeling(BIM) model based on 3D data. This process, using open source Industry Foundation Classes(IFC), exports data for the certification system, and extracts the data to create an Excel sheet for the certification. This is expected to improve the work process and reduce the workload associated with evaluating indoor air conditions.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.74-83
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• 2017

The recently introduced public rental housing REITs was just different the business structure from the existing public rental housing system and the basic supply system is the same. So the ownership conversion for public house over 10 years rental duration is possible after half of the obligated rental duration according to the agreement between lessor and lessee. However rental business operators are likely to have a negative attitude to the early ownership conversion because of less expected profit. Thus, there is a need for an analysis of proper early ownership conversion moment that can achieve public purposes while ensuring the profitability of public rental housing REITs. In this study, the characteristics of the ownership conversion rights that can lessee to exercise considered to be options. Also the nature of 'REITs', 'public rental housing REITs' is considered to be affected by the macroeconomic variables. Thus, this study analyzed the value for ownership conversion in the public rental housing REITs according to real option scenarios reflecting macroeconomic variables. As a result, according to the change of the variation rate of the macroeconomic variables, it was found that with adjustable early ownership conversion time using the DCF(Discounted Cash Flow) model. Therefore, it is possible to ensure profitability of early ownership conversion by predicting the variation of variables.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.824-827
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• 2011

Needs for Smart Grid development are increasing all over the world as a solution to its problem according to depletion of energy resources, climatic and environmental rapidly change and growing demand for electrical power. Especially decentralized power is attracting world's attention. In this mood a new era for a unit scale of decentralized power environment is on its way in building. However there is a problem to have to be solved in the uniformity of power quality because the amount of power generated from renewable energy resources such as wind power and solar light is very sensitive to climate fluctuation. And thus this paper tries to suggest an energy management algorithm on basis of real time monitoring for meteorological data. The proposed EMS model embodies the method for predicting the power generation by monitoring and analyzing the climatic data and controling the efficient power distribution between the renewable energy and the existing power. The ultimate goal of this paper is to provide the technological basis for achieving zero-energy house.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.871-874
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• 2010

Needs for Smart Grid development are increasing all over the world as a solution to its problem according to depletion of energy resources, climatic and environmental rapidly change and growing demand for electrical power. Especially decentralized power is attracting world's attention. In this mood a new era for a unit scale of decentralized power environment is on its way in building. However there is a problem to have to be solved in the uniformity of power quality because the amount of power generated from renewable energy resources such as wind power and solar light is very sensitive to climate fluctuation. And thus this paper tries to suggest an energy management method on basis of real time monitoring for meteorological data. In the current situation of lacking in USN-based killer application in Smart Grid field, this paper proposes the USN-based DER management system which collects the meteorological data and control power system througout utilizing wireless sensor network technique this business. This communication technique is regarded to be efficient in aspects of installation cost and tits maintenance cost. The proposed EMS model embodies the method for predicting the power generation by monitoring and analyzing the climatic data and controling the efficient power distribution between the renewable energy and the existing power. The ultimate goal of this paper is to provide the technological basis for achieving zero-energy house.