• The Journal of the Korea Contents Association
• /
• v.20 no.3
• /
• pp.1-9
• /
• 2020

The purpose of this study is to verify the effects of ventilation corridor and derive adequate policy alternatives to its application for the city of Sejong, which is located in an inland of Korean Peninsula. In order to introduce the ventilation corridor in the city, it is necessary both to understand change on fresh air flow affected by the construction of new cities and to show its effects which are able to circulate air flow of the city. The study identified ventilation effects using computational fluid dynamics models. In particular, it analyzed change on wind speed and direction after constructing of a new town and cool air flow along the lowlands generated after sunset. In addition, it identified those of reducing particulate matter when arranging buildings conforming to the ventilation corridor at block level. The policy implications derived from simulation can be summarized as follows. First, it is desirable to plan ventilation corridors so that fresh air from mountains, forests, and valleys can flow into cities and mitigate the concentration of particulate matter. Furthermore, public facilities covering parks, plazas, and playgrounds should be installed preferentially to attract safe outdoor activities near to areas with low levels of particulate matter. Finally, it is adequate to prepare for a number of alternative plans by analyzing ventilation corridors when setting out district unit plan.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.30 no.3
• /
• pp.31-45
• /
• 2017

Objectives : Adenophorae Radix(AR) is the dried root of Adenphora triphylla var. japonica HARA. AR has the efficacy of clarifying lung, emitting pus, expelling wind, stopping pruitus and so on. Recently, various studies are being done about anti-oxidative, immunomodulatory and anti-inflammatory effects of AR. So, we expected AR has an availability that can improve symptoms of atopic dermatitis(AD). Methods : In this study, we measured body weight, weight of ear, thickness of ear skin and dorsum skin, symptom score, reproduction rate of splenocytes in vivo and in vitro of mouse with AD induced by DNCB. We experimented with five groups of 9 mice, such as normal group, control group, AR spread(ARS) group, AR feeding(ARF) group, AR spread&feeding(ARSF) group. Results : Control group of body weight significantly reduced and APSF group significantly increased in the first and second week. In weight of ear and thickness of ear skin and dorsum skin, control group significantly increased and ARSF group significantly decreased. In macrophotography viewpoint of dorsal skin, ARS group, ARF group and ARSF group decreased severe pigmented skin lesion, erythema and desquamation as compared with control group. Especially ARSF group showed significant drop. ARS group, ARF group and ARSF group compared to control group were improved in histopathology observation. In vitro and in vivo, treatment group of AR increased proliferation rate of splenocytes, specially in vitro significantly. Conclusions : This experiment indicates Adenophorae Radix extracts is effective on AD induced by DNCB in mice.

• Atmosphere
• /
• v.16 no.2
• /
• pp.97-110
• /
• 2006

This study investigates the response of a typhoon model to the change of the sea surface temperature (SST) throughout the model integration. The SST change is parameterized as a formulae of which the magnitude is given as a function of not only the intensity and the size but the moving speed of tropical cyclone. The formulae is constructed by referring to many previous observational and numerical studies on the SST cooling with the passage of tropical cyclones. Since the parameterized cooling formulae is based on the mathematical expression, the resemblance between the prescribed SST cooling and the observed one during the period of the numerical experiment is not complete nor satisfactory. The agreements between the prescribed and the observed SST even over the swath of the typhoon passage differ from case to case. Numerical experiments are undertaken with and without prescribing the SST cooling. The results with the SST cooling do not show clear evidence in improving the track prediction compared to those of the without-experiments. SST cooling in the model shows its swath along the incomplete simulated track so that the magnitude and the distribution of the sea surface cooling does not resemble completely with the observed one. However, we have observed a little improvement in the intensity prediction in terms of the central pressure of the tropical cyclone in some cases. In case where the model without the SST treatment is not able to yield a correct prediction of the filling of the tropical cyclone especially in the decaying stage, the pulling effect given by the SST cooling alleviates the over-deepening of the model so that the central pressure approaches toward the observed value. However, the opposite case when the SST treatment makes the prediction worse may also be possible. In general when the sea surface temperature is reduced, the amount of the sensible and the latent heat from the ocean surface become also reduced, which results in the weakening of the storms comparing to the constant SST case. It turns out to be the case also in our experiments. The weakening is realized in the central pressure, maximum wind, horizontal temperature gradient, etc.

• Journal of Conservation Science
• /
• v.32 no.4
• /
• pp.491-500
• /
• 2016

Fog is atmospheric in which tiny drops of water vapor are suspended in the air near the ground. Its form, occurrence, etc., change according to the temperature, relative humidity, wind and geographical features of the space around it. In particular, fog tends to occur near a source of water because of temperature and relative humidity difference. These days, climate change is increasingly affecting the occurrence of fog. Therefore the purpose of this study was to investigate how fog affects materials that are part of our cultural properties through outdoor exposure tests and artificial degradation. The degradation evaluation of materials as a function of fog occurrence frequency, showed that the color of metals changed noticeably, whereas dyed silk and Dancheong showed degradation on the surface and color differences but no particular tendencies. Therefore, damage prediction by color differences as a function of fog occurrence frequency was based on metal samples, which showed constant color differences. Through a comparison of the predictive value and color difference by outdoor exposure, the accuracy and applicability of the damage prediction formula was confirmed. If a more complex damage prediction formula is created, it is expected that prediction of the degree of material damage in the field would be possible.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.3
• /
• pp.95-100
• /
• 2009

Fine fuel moisture code (FFMC), a main component of forest fire weather index(FWI) in the Canadian forest fire danger rating system(CFFDRS), indicated a probability of ignition through expecting a dryness of fine fuels. According to this code, a rising of temperature and wind velocity, a decreasing of precipitation and decline of humidity in a weather condition showed a rising of a danger rate for the forest fire. In this study, we analyzed a weather condition during 5 years in Kangwon province, calculated a FFMC and examined an application of FFMC. Very low humidity and little precipitation was a characteristic during spring and fall fire season in Kangwon province. 75% of forest fires during 5 years occurred in this season and especially 90% of forest fire during fire season occurred in spring. For developing of the prediction model for a forest fire occurrence probability, we used a logistic regression function with forest fire occurrence data and classified mean FFMC during 10 days. Accuracy of a developed model was 63.6%. To improve this model, we need to deal with more meteorological data during overall seasons and to associate a meteorological condition with a forest fire occurrence with more research results.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.7 no.1 s.24
• /
• pp.21-28
• /
• 2007

It is very difficult to forecast accurately a damage from the natural disaster which occurs frequently due to the climate change. When the significant weather event is forecast, it will be able to minimize a damage with the suitable prevention action. But 2000's our country meterological disaster damage is a several trillion won. Therefore, this paper analyzes Korea Meterological Administration, Japan Meterological Agency, television and newspaper have reported, information substance, transmission system, an ex post facto valuation about typhoon Nabi between september $5{\sim}7$ in 2005 and heavy rainfall in 1998 at Japan. Through the investigation, we want to present basic data order to rises the application effect of disaster prevention meterological information. We think KMA must present many information report to promote a people's understanding about the meterological information and the serious disaster situation. Also the disaster damage estimation model development is necessary, which forecasts the accurate damage scale due to the weather event, such as typhoon, heavy rainfall, strong wind. And also we think the KMA, National Emergency Management Agency, related agency, television and newspaper must positive reports the contents which is suitable to disaster response phases and an ex post facto examination. Then it grasps the problem of disaster prevention meterological information and must improve effectively.

• Korean Journal of Environment and Ecology
• /
• v.32 no.1
• /
• pp.77-96
• /
• 2018

We investigated and analyzed three Korean island sites (Bijin-do, Ae-do, and Bogil-do) and one Japanese site (Tachibanayama) of sword-leaf litsea (Actinodaphne lancifolia) forests, known as the climax forest, to discuss the vegetation succession sere of warm-temperature evergreen broad-leaved forests. We then reviewed the literature in Korea, Japan, China, and Taiwan to consider the distribution characteristics of evergreen broad-leaved forests, vegetation succession sere, and climax tree species. Although Mt. Tachibana and Ae-do showed the most advanced vegetation structure, the soil and ordination (CCA) analysis indicated that it was not enough to consider that the sword-leaf litsea forest was at the climax stage in the warm-temperature region. The Actinodaphne lancifolia forest is sparsely distributed in Korea and Japan while the common types of vegetation in the warm temperate zone region in East Asia are Machilus spp., Castanopsis spp., and Cyclobalanopsis spp. The vegetation succession sere of the Korean warm-temperature region is thought to have a secondary succession such as Pinus thunbergii, P. densiflora, Q. serrata (early stage) through Machilus thunbergii, innamomum yabunikkei, Neolitsea sericea, Actinodaphne lancifolia (middle stage) to Castanopsis sieboldii, Q. acuta, Q. salicina (climax stage). However, Machilus thunbergii will be the climax species as an edaphic climax in places where there is a strong influence of the sea wind, or it is difficult to supply the seeds of Castanopsis spp. and Cyclobalanopsis spp.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.6
• /
• pp.91-100
• /
• 2012

Wireless monitoring system for the structural health evaluation has a limit to the reliability of measured response. The objective of this study is to evaluate an effective measurement range of the wireless monitoring system on the analyzed data. For the wireless monitoring system, Bluetooth and Wi-Fi are applied to datalogger-receiver and receiver-personal computer, respectively. For the model of the monopile structure response, a laboratory-scale monopile is manufactured with Mono Cast Nylon and a lateral loading is applied by hammer impacting. Strain gauges attached on the model monopile are connected with the datalogger. The distances of datalogger-receiver and receiver-personal computer are changed for the evaluation of the measurement range. Experimental results show that the receiving rates of the response remain almost constant within limited distance, while the receiving rates dramatically decrease out of effective range. In addition, the receiving rates affect on the measured natural frequencies of the model monopile. This study suggests that the effective range evaluation of the wireless monitoring system may be used for the determination of a monitoring distance to the monopile installed in the offshore wind farm.

• Journal of the Korean Institute of Gas
• /
• v.24 no.2
• /
• pp.22-28
• /
• 2020

In this study, quantitative risk assessment was carried out for city gas high-pressure pipelines crossing through urban rivers. The risk assessment was performed based on actual city gas properties, traffic volume and population and weather data in the worst case scenario conditions. The results confirmed that the social and individual risks were located in conditionally acceptable areas. This can be judged to be safer considering that the risk mitigation effect of protecting the pipes or installing them in the protective structure at the time of the construction of the river buried pipe is not reflected in the result of the risk assessment. Also, SAFETI v8.22 was used to analyze the effects of wind speed and pasquil stability on the accident damage and dispersion distances caused by radiation. As a result of the risk assessment, the safety of the pipelines has been secured to date, but suggests ways to improve safety by preventing unexpected accidents including river bed changes through periodic inspections and monitoring.

• Clean Technology
• /
• v.20 no.1
• /
• pp.13-21
• /
• 2014

Because of the water scarcity caused by the increase of salinity in the underground water, seawater desalination stands out as one of the most promising solution. As there are so much energy costs in operating desalination plants, new hybrid process which is more effective should be researched. A geothermal VMD (vacuum membrane distillation) hybrid process is a competitive alternative for seawater desalination. Because geothermal energy has significant characteristics of high capacity factor to operate the power plant at full capacity for 24 hour per day, it can be a priority heat source of VMD superior to any other renewable energies such as solar and wind power. In this study, we design a geothermal VMD hybrid process, analyze it economically and finally compare the result with a case of conventional VMD process. Geothermal VMD hybrid process generates $23,822,409 of NPV (net present value) more than the conventional VMD process in case of 5% discount rate. The break-even point between these processes is 5.36 year. Sensitivity analysis indicates that steam cost is the most decisive influence variable to the economic outcome.