• Safety and Health at Work
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• v.9 no.1
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• pp.42-52
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• 2018

Background: Maintenance operations on-board ships are highly demanding. Maintenance operations are intensive activities requiring high man-machine interactions in challenging and evolving conditions. The evolving conditions are weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress. For example, extreme weather condition affects seafarers' performance, increasing the chances of error, and, consequently, can cause injuries or fatalities to personnel. An effective human error probability model is required to better manage maintenance on-board ships. The developed model would assist in developing and maintaining effective risk management protocols. Thus, the objective of this study is to develop a human error probability model considering various internal and external factors affecting seafarers' performance. Methods: The human error probability model is developed using probability theory applied to Bayesian network. The model is tested using the data received through the developed questionnaire survey of >200 experienced seafarers with >5 years of experience. The model developed in this study is used to find out the reliability of human performance on particular maintenance activities. Results: The developed methodology is tested on the maintenance of marine engine's cooling water pump for engine department and anchor windlass for deck department. In the considered case studies, human error probabilities are estimated in various scenarios and the results are compared between the scenarios and the different seafarer categories. The results of the case studies for both departments are also compared. Conclusion: The developed model is effective in assessing human error probabilities. These probabilities would get dynamically updated as and when new information is available on changes in either internal (i.e., training, experience, and fatigue) or external (i.e., environmental and operational conditions such as weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress) factors.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.583-592
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• 2011

The radiological characteristics for waste classification were assessed for neutron-activated decommissioning wastes from a CANDU reactor. The MCNP/ORIGEN2 code system was used for the source term analysis. The neutron flux and activation cross-section library for each structural component generated by MCNP simulation were used in the radionuclide buildup calculation in ORIGEN2. The specific activities of the relevant radionuclides in the activated metal waste were compared with the specified limits of the specific activities listed in the Korean standard and 10 CFR 61. The time-average full-core model of Wolsong Unit 1 was used as the neutron source for activation of in-core and ex-core structural components. The approximated levels of the neutron flux and cross-section, irradiated fuel composition, and a geometry simplification revealing good reliability in a previous study were used in the source term calculation as well. The results revealed the radioactivity, decay heat, hazard index, mass, and solid volume for the activated decommissioning waste to be $1.04{\times}10^{16}$ Bq, $2.09{\times}10^3$ W, $5.31{\times}10^{14}\;m^3$-water, $4.69{\times}10^5$ kg, and $7.38{\times}10^1\;m^3$, respectively. According to both Korean and US standards, the activated waste of the pressure tubes, calandria tubes, reactivity devices, and reactivity device supporters was greater than Class C, which should be disposed of in a deep geological disposal repository, whereas the side structural components were classified as low- and intermediate-level waste, which can be disposed of in a land disposal repository. Finally, this study confirmed that, regardless of the cooling time of the waste, 15% of the decommissioning waste cannot be disposed of in a land disposal repository. It is expected that the source terms and waste classification evaluated through this study can be widely used to establish a decommissioning/disposal strategy and fuel cycle analysis for CANDU reactors.

• Journal of the korean society of oceanography
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• v.39 no.4
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• pp.234-242
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• 2004

The pigment composition and concentration of phytoplankton assemblages using HPLC in the adjacent waters of four nuclear power plants (Yonggwang, Kori, Wolsong and Ulchin) were investigated during the spring blooming in 2004. The mean concentration of chlorophyll a ranged from 563.8 to 2,949.0ng $l^{-1}$, with the lowest concentration at Kori and the highest concentration at Wolsong. Among the carotenoids, the amounts of fucoxanthin and chlorophyll $C_2$ were relatively higher than those of other pigments in the study site. As minor pigments, zeaxanthin, chlorophyll b, 19'-butanoyloxyfucoxanthin, diadinoxanthin, 19'-hexanoyloxyfucoxanthin, chlorophyll $C_3$ and peridinin were detected. The results of pigment composition and concentration showed that diatoms had an important proportion of phytoplankton community when a spring bloom occurred. Cyanobacteria was present relatively low density at the Wolsong and the green alga such as chlorophytes and prasinophytes were abundant at the Yonggwang and Kori, while dinoflagellates characterized by peridinin were common at Ulchin and Kori. The pigment composition and concentration of phytoplankton after passing through the cooling-water system of nuclear power plant were highly variable. No distinct trend of the change of each pigment composition and amount was detected but the variation of fucoxanthin and chlorophyll $C_2$ highly coupled with that of chlorophyll a. We pointed out that the diatom controlled the overall variation of phytoplankton biomass during the spring season.

• Journal of the Korean Institute of Gas
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• v.2 no.1
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• pp.14-22
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• 1998

In this work, in order to quantitatively predict the radiation flux and propose an idea about how to reduce the radiation damage, the radiation flux caused by pool fire of an LNG storage tank has been calculated using the RISC (Risk and Industrial Safety Consultant) proposed model under various conditions. Model predictions showed that the most important parameter affecting the radiation flux by the LNG pool fire is the wind speed. The extent of radiation damage to a target from fire flame was more significant with variation of wind speed at a low wind speed than with that at a high wind speed. It was found that the radiation damage by the former is substantially reduced with planting windbreak system around the plant. Since the windbreak is most economical than any other method, it is strongly suggested to plant a tree belt in the factory surroundings, especially near by the area of gas storage facilities, linking with water cooling and fire protection systems.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.2
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• pp.3-11
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• 2018

Korea has achieved a rapid economic development and with the increase in population and national income and the expansion of social and economic activities, energy consumption has rapidly increased too. Energy consumption per head has constantly increased and currently, power consumption per head is 7.5 times bigger than in 1985. Buildings occupy 25% of total energy consumption and especially, 50% of total energy is consumed for heating and cooling. In this situation, multi-family housing, which has constantly been increased, has an energy saving rate of 1.9%, which is the lowest level and this makes the government's energy policy for sustainable energy system development useless. Besides, energy consumption leads to secondary problems, such as air, water and marine pollution and heat pollution and wastewater/drainage and the increased use of fossil fuel is a fundamental reason for ozone layer destruction and global warming. Therefore, efficient energy consumption plans are required. This study aims to analyze energy performance in each block type of high-rise and diversified multi-family housing that accounts for 60% of all the housing forms, depending on the variations in stories through BIM-based energy simulation. For this study, four representative block types were selected, based on the multi-family floor plan, which is certified for energy performance evaluation and they were applied to the floor plan of a multi-family house that is scheduled to be built. Then BIM modeling was conducted from the fifth story to the 40th story at an intervals of 5 stories and based on the finding, energy characteristics of each block type and energy performance depending on the variations in stories were analyzed. It is considered that this would serve as objective data for block type and block story decision of energy performance-based multi-family housing.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.198-218
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• 2002

On the basis of Imjeungjinamuian(臨證指南醫案), authors investigated the pathogenesis and treatment of ophthalmotolaryngobgic diseases from the viewpoint of Onbyeong(溫病). 1. The symptoms and diseases investigated according to department were as follows;. 1) Ophthalmology : blepharitis, blepharedema, lacrimal hypersecretion, hyperemia, ophthalmalgla, photopsia, visual disturbance, mydriasis 2) Otology : full-feeling, otorrhea, otalgla, mastoiditis, tinnitus, hearing disturbance, vertigo 3) Rhinology : rhinorrhea, nasal obstruction, sinusitis, epistaxis 4) Laryngology : sore throat, hoarseness 5) The Others : headache, cough, asthma 2. The pathogenesis and treatment of ophthalmotolaryngologic diseases were as follows. 1) When the pathogenesis of hyperemia, otorrhea, otalgia, mastoiditis, hearing disturhance. epistaxis, sore throat, headache and cough are wind-stagnanc(風鬱), wind-warm(風溫), wind-fire(風火), wind-dryness(風燥), dryness-heat(燥熱), the treatment of pungent-cool-evaporating(辛凉解表) with Dajosan(茶調散), Mori Folium(桑葉), Lonicerae Flos(金銀花), Forsythiae Fructus(連翹), Viticis Fructus(蔓荊子), Prunellae Spica(夏枯草), Arctii Fructus(牛蒡子), etc can be applied. 2) When the pathogenesis of hoarseness, cough and asthma are cold(寒), cold with endogenous heat(寒包熱, 外冷內熱), water retention(水邪), fluid retention(伏飮), impairment of YangKi by overexertion(勞傷陽氣), the treatment of pungent-warm-evaporating(辛溫解表) with Mahaenggamseoktang(麻杏甘石湯), Socheongryongtang(小靑龍湯), Jeongryeokdaejosapyetang(정력대조사폐탕), Gyejitang(桂枝湯), Armeniacae Amarum Semen(杏仁), etc can be applied. 3) When the pathogenesis of photopsia, otorrhea, otalgia, rhinorrhea, sinusitis, epistaxis, sore throat, hoarseness, headache and cough are stagnancy-induced heat(鬱熱), wind-dryness(風燥), wind-heat(風熱), summer heat(暑熱), summer wind(暑風), insidious summer heat(伏暑), autumn heat(秋暑), autumn wind(秋風), autumn dryness(秋燥), dryness-heat(燥熱), heat in Ki system(氣分熱), insidious warm(溫伏), brain discharge by fire in Ki system(氣火 腦熱), heat in stomach(胃熱), endogenous fire by deficiency of Yin(陰虛內火), deficiency of Yin in stomach(胃陰虛), the treatment of Ki-cooling(淸氣) with Bangpungtongseongsan(防風通聖散), Ikweonsan(益元散), Gyejibaekhotang(桂枝白虎湯), Geumgwemaekmundongtang(금궤맥문동탕), Gyeongokgo(瓊玉膏), Sojae Semen Praeparatum(두시), Scutellariae Radix(黃芩), Phyllostachys Folium(竹葉), Adenophorae Radix(沙參), Mori Cortex(桑白皮), Fritillariae Cirrhosae Bulbus(貝母), etc can be applied. 4) When the pathogenesis of blepharitis, hyperemia, ophthalmalgia, full-feeling, otorrhea, otalgia, tinnitus, hearing disturbance, sinusitis, hoarseness, headache and cough are fire in liver(肝火), fire in gallbladder(膽火), ministerial fire in Soyang system(少陽相火), wind-stagnancy(風鬱), stagnancy-induced fire(鬱火), brain discharge by phlegm-fire(痰火 腦熱), the treatment of mediation(和解) with Gardeniae Fructus(梔子), Moutan Cortex(牧丹皮), Saigae Tataricae Cornu(羚羊角), Artemisiae Annuae Herba(靑蒿), Cyperi Rhizoma(香附子), Poria(적복령), etc can be applied. 5) When the pathogenesis of blepharedema and cough are dampness in both spleen and lung(脾肺濕) damp-heat(濕熱), damp-phlegm(濕痰), the treatment of dampness-resolving(化濕) with Poria(백복령), Coicis Semen(薏苡仁), Tetrapanacis Medulla(通草), Armeniacae Amarum Semen(杏仁), Talcum(滑石), etc can be applied. 6) When the pathogenesis of vertigo and cough are deficiency of Yong(營虛), heat in Yong, system(營熱), the treatment of Yong-cooling(淸營) with Rehmanniae Radix(生地黃), Liriopis Tuber(麥門冬), Biotae Semen(柏子仁), Lilii Bulbus(百合), Phyllostachys Folium(竹葉), etc can be applied. 7) When the pathogenesis of epistaxis are heat in blood system of heart(心血熱), reversed flow of fire(火上逆), overexertion(努力), the treatment of blood-cooling(凉血) with Rhinoceri Cornu(犀角), Rehmanniae Radix(生地黃), Moutan Cortex(牧丹皮), Salviae Miltiorrhizae Radix(丹參), Scrophulariae Radix(玄蔘), etc can be applied. 8) When the pathogenesis of nasal obstruction is pathogen-stagnancy(邪鬱), the treatment of resuscitation(開竅) with Sosang(少商, LU11) acupuncture can be applied. When the pathogenesis of hoarseness is evil Ki(穢濁), the treatment of resuscitation(開竅) with Arctii Fructus(牛蒡子), Lasiosphaera Seu Calvatia(馬勃), Curcumae Radix(鬱金), etc can be applied. When the pathogenesis of headache is stasis of both Ki and blood(氣血瘀痺), the treatment of resuscitation(開竅) with Cnidii Rhizoma(川芎), Asari Herba Cum Radice(細辛), Scorpio(全蝎), moxibustion(灸), etc can be applied. 9) When the pathogenesis of lacrimal hypersecretion, visual disturbance, mydriasis, tinnitus, hearing disturbance, sinusitis, epistaxis, hoarseness and cough are deficiency of Yin(陰虛), deficiency of kidney(腎虛), deficiency of both liver and kidney(肝腎虛), deficiency of both heart and kidney(心腎虛), brain discharge by deficiency of Yin(陰虛 腦熱), exuberance of Yang in liver(肝陽上亢), overexertion(勞損), the treatment of Yin-replenishing(滋陰) with Yukmijihwanghwan(六味地黃丸), Hojamhwan(虎潛丸), Jeobutang(猪膚湯), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Rehmanniae Radix(生地黃), Schizandrae Fructus(五味子), Liriopis Tuber(麥門冬), Asini Gelatinum(阿膠), etc can be applied. 10) When the pathogenesis of ophthalmalgia, mydriasis, vertigo and headache are deficiency of Yin in liver(肝陰虛), exuberance of Yang in liver(肝陽上亢), endogenous wind(內風), excess in upper and deficiency in lower part(上實下虛), the treatment of Yin-replenishing(滋陰) and endogenous wind-calming(熄風) with Rehmanniae Radix Preparat(熟地黃), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Paeoniae Radix Alba(白芍藥), Ostreae Concha(牡蠣), Saigae Tataricae Cornu(羚羊角), Chrysanthemi Flos(菊花), etc be applied. 11) When the pathogenesis of mydriasis, sinusitis, hoarseness, headache, cough and asthma are exhaustion of vital essence(精氣無收藏), brain discharge(腦髓不固), floating Yang(陽虛浮), exsanguination(失血), deficiency of both Yin and Yang(陰陽不足), overexertion(勞損), deficiency of Yang in kidney(腎陽虛), the treatment of Yang-restoring and exhaustion-arresting(回陽固脫) with Yangyeongtang(養營湯), Cheonjinhwan(天眞丸), Bokmaektang(복맥탕), Geonjungtang(建中湯), Dogihwan(都氣丸), Singihwan(腎氣丸), Jinmutang(眞武湯), Ostreae Concha(牡蠣), Nelumbinis Semen(蓮子肉), etc can be applied. 12) When the pathogenesis of lacrimal hypersecretion, vertigo and headache are deficiency of stomach and endogenous wind(胃虛內風), endogenous wind with phlegm(內風挾痰), liver check of stomach(肝木橫擾), the treatment of concomitant-treating of both liver and stomach(肝胃同治) with Paeoniae Radix Alba(白芍藥), Uncariae Ramulus Et Uncus(釣鉤藤), Gastrodiae Rhizoma(天麻), Astragali Radix(황기), Pinelliae Rhizoma(半夏), etc can be applied. When the pathogenesis of asthma is failure of kidney to promote inspiration(腎不納氣), the treatment of kidney-tonifing and inspiration-promoting(補腎納氣) with Singihwan(腎氣丸), Psoraleae Fructus(補骨脂), Juglandis Semen(胡桃), Aquilariae Resinatum Lignum(沈香), etc can be applied. When the pathogenesis of asthma is deficiency of Ki(氣虛), the treatment of Ki-reinforcing(補氣) with Sagunjatang(四君子湯), Insamgeonjungtang(人參建中湯), etc can be applied.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.400-406
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• 2017

The model used in this study was reversed to analyze the cause of excessive damage that occurred inside the rotating system and pipe system of a centrifugal-type seawater pump on a ship. For this purpose, internal flow analysis on a cooling seawater pump was performed using CFD. As a result, the shape and boundary conditions of the target pump were set by reverse engineering, and pump efficiency at a design operating point of $125m^3/h$ was calculated as 85.3 % with a head of 32.0 m. The maximum efficiency point of the target pump was estimated to be 86.2 % at $150m^3/h$, but this differed from the actual operating point. At $112.5m^3/h$, which was the lowest flow point, flow was unstable due to the characteristics of the low flow point and analysis convergence was not good. The purpose of this study was to clarify the cause of ongoing cavitation in seawater pumps and piping systems in operation. Future research will be needed to clarify causes for pipe systems in the future by performing calculations for the total piping system of an inlet and outlet, in addition to measuring the flow rate of each branch pipe.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.711-719
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• 2012

A thermodynamic analysis and a feasibility study on the organic Rankine cycle (ORC) as a waste heat recovery system for a marine diesel engine were carried out. The ORC and its combined cycle with the engine were simulated, and its performance was estimated theoretically using R245fa. A parametric study on the performance of the ORC system was carried out under different temperature conditions of the heat transfer loop and specification of the heat exchanger. According to the thermodynamic analysis, ~10% of the thermal efficiency of the cycle was able to be realized with the low temperature heat source below $250^{\circ}C$. The electric power output of the ORC was estimated to be about 4% of the mechanical power output of the engine, considering additional pumps for cooling water and circulation of the heat transfer medium. According to the present study, the electric power generated by the ORC is about 59%-69% of the required power, and it is possible to reduce the fuel consumption under normal seagoing conditions.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.67-76
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• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.

• Journal of the Korean earth science society
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• v.29 no.2
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• pp.128-139
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• 2008

Intercomparison among the three radiative transfer models (RTMs) which have been used in the studies for COMS, was carried out on the condition of aerosol-laden atmospheres. Also the role of aerosols in the atmospheric radiation budget was analyzed. The results (hereafter referred to as H15) from Halthore et al.'s study (2005) were used as a benchmark to examine the models. Aerosol Radiative Forcing (ARF) values from the three RTMs, calculated under two conditions of Aerosol Optical Thickness (AOT=0.08, 0.24), were systematically underestimated in comparison to H15 in the following shortwave components; 1) direct and diffuse irradiance at the surface, 2) diffuse upward fluxes at the surface and the top of the atmosphere, and 3) atmospheric absorbance. The ARF values for the direct and diffuse fluxes at the surface was $-10{\sim}-40Wm^{-2}$. The diffuse upward values became larger with increasing both AOT and Solar Zenith Angle (SZA). Diffuse upward/downward fluxes at the surface were more sensitive to the SZA than to the atmospheric type. The diffuse downward values increased with increasing AOT and decreasing SZA. The larger AOT led to surface cooling by exceeding the reduction of direct irradiance over the enhancement of diffuse one at the surface. The extinction of direct solar irradiance was due mainly to water vapor in tropical atmospheres, and to both ozone and water vapor in subarctic atmospheres. The effect of water vapor in the tropics was $3{\sim}4$ times larger than that of the ozone. The absorbance values from the three RTMs agree with those from H15 within ${\pm}10%$.