• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.1-12
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• 2024

In this study, we analyzed the water temperature variability in the sea area of the Korean Peninsula in August, before and after the typhoon inflow through Typhoon Soulik, the 19th in 2018 that turned right around the Korean Peninsula and passed through the East Sea, and Typhoon Bavi, the eighth in 2020 that advanced north and passed through the Yellow Sea. The data used in this study included the water temperature data recorded in the real-time information system for aquaculture environment provided by the National Institute of Fisheries Science, wind data near the water as recorded by the automatic weather system, and water temperature data provided by the NOAA/AVHRR satellite. According to the analysis, when typhoons with different movement paths passed through the Korean Peninsula, the water temperature in the East Sea repeatedly upwelled (northern winds) and downwelled (southern winds) depending on the wind speed and direction. In particular, when Typhoon Soulik passed through the East sea, the water temperature dropped sharply by around 10 ℃. When Typhoon Bavi passed through the center of the Yellow Sea, the water temperature rose in certain observed areas of the Yellow Sea and even in certain areas of the South Sea. Warmer water flowed into cold water regions owing to the movement of Typhoon Bavi, causing water temperature to rise. The water temperature appeared to have recovered to normal. By understanding the water temperature variability in the sea area of the Korean Peninsula caused by typhoons, this research is expected to minimize the negative effects of abnormal climate on aquaculture organisms and contribute to the formulation of damage response strategies for fisheries disasters in sea areas.

• Journal of Environmental Science International
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• v.16 no.5
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• pp.593-602
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• 2007

The frequency of tropical nights and tropical days in Busan during summer season (June-August) from 1995 to 2004 were investigated. When air temperature higher than $25^{\circ}C$ continuously maintains at night in summer, it is called the occurrence of tropical night. Tropical day is defined that maximum air temperature is higher than $30^{\circ}C$, In Jin-Gu and Daeyeon-dong shows a lot of frequency of tropical day and tropical night because there were located in downtown. Relatively, the areas where are located in seaside and riverside show very low frequency. This can be explained the cooling effects of sea and river. The main meteorological characteristics during tropical nights and tropical days is proved pattern of reverse tendency through wind rose. We analyzed heat index and discomfort index during tropical night and tropical day. This study is useful to understand the aspect of urban thermal environment but need some more observation to quantify.

• Journal of The Geomorphological Association of Korea
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• v.26 no.3
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• pp.31-42
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• 2019

The geomorphological changes of an unvegetated part of the Okjukdong coastal dune were analyzed between 2008 and 2018. Its natural landscape has been destroyed after artificial forestation, but there is no quantitative evidence on these changes. In this study, we measured the unvegetated area using a total station and a network RTK-GPS in 2008, 2014, and 2018. Using Krging method for the three point data sets, we constructed digital elevation models (DEMs) and analyzed topographic changes between the three years. The results showed that the sand of the study area decreased in volume from 2008 to 2014, because sand supply from the nearby beach was blocked by coastal forests. The sand volume temporarily increased from 2014 to 2018, because of the dune nourishment conducted in 2017. It seems that the upper part of the sand dune has shrunk, but the sand at the bottom has increased over the last decade.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.187-197
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• 1999

To assess the usefulness of tongue inspection for evaluating the Pattern identification in oriental medicine, we observed stroke patient's tongue and tongue coat and compared it with Pattern identification. The test group was composed of 85 acute stroke stage patients(within 72 hours of onset). Subjects were randomly selected from stroke patients admitted in the KyungHee University, Hospital of Oriental Medicine from December 1 1998 to June 30 1999. We took pictures of patient's tongue and tongue coat within 72hours from onset and checked Pattern identification at the same time. Tongues colored pale rose or red greatly outnumbered other colors. Tongue shape tended to be prickly or fissured, and tongue condition tended to be unflexible or deviated. Regarding tongue coat color, there were great amounts of yellow or clark yellow tongue coats, which were moist, thick or greasy in substance. The red tongue was significantly related to Fire-heat and deficiency of Yin syndrome, while faint white tongue to Damp syndrome(P=0.006). In terms of tongue coat, thin coat was related to Wind and Fire-heat syndromes, thick coat to Damp and Blood stasis syndrome, respectively (P=0.002). In conclusion, we thought that tongue inspection could be a useful Oriental medicine diagnosis in stroke.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.356-361
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• 2012

Recently, even though the researches on renewable energy like geothermal, wind, solar energy have been performed widely, its use-rate in total energy is still low. This study was carried out to investigate the performance of hybrid heating system, which consisted of solar collector of thermosyphon tube type and X-L pipe boiler. Especially, new type of solar collector was tried and compared with double tube type and, futhermore, performance and safety on X-L pipe boiler were investigated. As the results, efficiency of solar collector of thermosyphon tube type was higher 20.7% than that of double tube type, mainly due to its structural characteristics. It was also confirmed that temperature of special heat medium used X-L pipe boiler rose up about 20% rapidly in comparison with that of pure water.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.147-156
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• 2014

Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.80-85
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• 2011

As the instability of oil prices rose because of the situation in Libya, oil prices worldwide recorded the highest level due to the interference in supply. And so, in the 21st century, increasing efforts are being made to use clean new renewable energy centered on solar energy in accommodation of the cycle of nature instead of being reliant on the oil exporting nations. In order to reduce city energy internationally, the implementation of a low carbon city under the combined cooperation of industrial. construction, new renewable energy and transportation sectors with continuous development centered on low carbon green urban planning is now becoming established as the paradigm of the times. Recently, the government has begun carrying out the One Million Green Home Project, which is a project where the government with the goal of providing one million renewable energy homes by 2020 gives renewable energy subsidization for a partial amount of the standard unit price of installation when solar ray, solar heat, geothermal heat, small wind power or fuel cell energy is used. Thus, through this thesis which studies the state of and surveys the green village at Shingok-ri Songhak-myun Jaecheon-shi, it is the desire that the One Million Green Homes Project will be more efficiently developed and plans for improvement formed so that a high level of satisfaction in the product will be provided.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.4
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• pp.49-56
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• 2017

Each country in the world currently concentrates on shifting into clean energy, which can be alternative energy, for global environment protection and solution to the problem of fossil fuel depletion. The Korean government is predicted to develop renewable energy, such as solar power, ground power, and offshore wind power, and to increase their supply ratios by ending the use of coals and nuclear power plants. This study conducted experiments on thermal storage performance of Trombe wall thermal storage materials using solar power and simulations in order to offer baseline data for the development of a hybrid air circulation system for heating that can maximize efficiency by simultaneously using solar and geothermal power. The study results are as follows: (1) In all the specimens with 3m, 5m, and 7m in the length of thermal storage pipe, $5.7^{\circ}C$, $7.8^{\circ}C$, and $10.5^{\circ}C$ rose, respectively, as the thermal storage effect of the specimens attaching insulation film and black tape to the general funnel. They were most excellent in terms of thermal storage effect. (2) As a result of thermal performance evaluation on the II type specimens, II-3 ($7.8^{\circ}C$ rise) > II-4 ($5.3^{\circ}C$ rise) > II-1 ($3.9^{\circ}C$ rise) > II-2 ($2.3^{\circ}C$ rise) was revealed, and thus II-3 (insulation film + black tape) was most effective as shown in the I type. (3) This study analyzed air current and temperature distribution inside of the greenhouse by linking actually measured values and simulation interpretation results through the interpretation of CFD (computational fluid dynamics). As a result, the parts absorbing heat and discharging heat around the thermal storage pipe could be visibly classified, and temperature distribution inside of the greenhouse around the thermal storage pipe could be figured out.

• Safety and Health at Work
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• v.12 no.1
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• pp.119-126
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• 2021

Background: During the period 2001 to 2016, the maximum temperatures in Thailand rose from 38-41℃ to 42-44℃. The current occupational heat exposure standard of Thailand issued in 2006 is based on wet bulb globe temperature (WBGT) defined for three workload levels without a work-rest regimen. This study examined whether the present standard still protects most workers. Methods: The sample comprised 168 heat acclimatized workers (90 in construction sites, 78 in foundries). Heart rate and auditory canal temperature were recorded continuously for 2 hours. Workplace WBGT, relative humidity, and wind velocity were monitored, and the participants' workloads were estimated. Heat-related symptoms and signs were collected by a questionnaire. Results: Only 55% of the participants worked in workplaces complying with the heat standard. Of them, 79% had auditory canal temperature ≤ 38.5℃, compared with only 58% in noncompliant workplaces. 18% and 43% of the workers in compliant and noncompliant workplaces, respectively, had symptoms from heat stress, the trend being similar across all workload levels. An increase of one degree (C) in WBGT was associated with a 1.85-fold increase (95% confidence interval: 1.44-2.48) in odds for having symptoms. Conclusion: Compliance with the current occupational heat standard protects 4/5 of the workers, whereas noncompliance reduces this proportion to one half. The reasons for noncompliance include the gaps and ambiguities in the law. The law should specify work/rest schedules; outdoor work should be identified as an occupational heat hazard; and the staff should include occupational personnel to manage heat stress in establishments involving heat exposure.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.1
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• pp.28-39
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• 2019

In the design process of counter measures against the beach erosion, information like the main sediment transport mode and yearly net amount of longshore and cross shore transport is of great engineering value. In this rationale, we numerically analyzed the yearly sediment budget of the Mang-Bang beach which is suffering from erosion problem. For the case of cross sediment transport, Bailard's model (1981) having its roots on the Bagnold's energy model (1963) is utilized. In doing so, longshore sediment transport rate is estimated based on the assumption that longshore transport rate is determined by the available wave energy influx toward the beach. Velocity moments required for the application of Bailard's model (1981) is deduced from numerical simulation of the nonlinear shoaling process over the Mang-Bang beach of the 71 wave conditions carefully chosen from the wave records. As a wave driver, we used the consistent frequency Boussinesq Eq. by Frelich and Guza (1984). Numerical results show that contrary to the Bailard's study (1981), Irribaren NO. has non negligible influence on the velocity moments. We also proceeds to numerically simulate the yearly sediment budget of Mang-Bang beach. Numerical results show that for ${\beta}=41.6^{\circ}$, the mean orientation of Mang-Bang beach, north-westwardly moving longshore sediment is prevailing over the south-eastwardly moving sediment, the yearly amount of which is simulated to reach its maxima at $125,000m^3/m$. And the null pint where north-westwardly moving longshore sediment is balanced by the south-eastwardly moving longshore sediment is located at ${\beta}=47^{\circ}$. For the case of cross shore sediment, the sediment is gradually moving toward the shore from the April to mid October, whereas these trends are reversed by sporadically occurring energetic wind waves at the end of October and March. We also complete the littoral drift rose of the Mang-Bang beach, which shows that even though the shore line is temporarily retreated, and as a result, the orientation of Mang-Bang beach is larger than the orientation of null pont, south-eastwardly moving longshore sediment is prevailing. In a case that the orientation of Mang-Bang beach is smaller than the orientation of null pont, north-westwardly moving longshore sediment is prevailing. And these trend imply that the Mang-Bang beach is stable one, which has the self restoring capability once exposed to erosion.