• Toxicological Research
• /
• v.6 no.2
• /
• pp.143-157
• /
• 1990

Effective measure to prevent oxygen toxicity is greatly required as there increase chances to be exposed to high oxygen pressure, for example, space travel, deep sea diving and hyperbaric oxygen therapy. In the present study, in an attempt to evaluate glutathione and chlorpromazine as protective agents against oxygen toxicity, effects of the agents were tested on various toxicities (death rate, convulsion rate, time to convulsion, increase in weight of lung and brain and pathological changes in the organs) observed in rats exposed to 5 Absolute Atmosphere (ATA) of 100% oxygen for 120 minute. Glutathione reduced mortality rate and convulsion rate and also markedly suppressed the increase in lung and brain weight. The pathological changes observed in these organs were ameliorated by administration of glutathione. Chlorpromazine also reduced mortality rate but its effects appeared to be limited mainly to pulmonary toxicities. Thus glutathione seems to be more effective than chlorpromazine as a protective agent. The results obtained may support that oxygen toxicity is mediated by oxygen free radicals.

• Journal of Korea Water Resources Association
• /
• v.30 no.2
• /
• pp.131-141
• /
• 1997

In this study, the Storage Function Method and Loopnet Model (Unsteady flow analysis model) were used to construct the flood prediction system which can predict the effects of the water release in the downstream region of Teachong Dam. The regional frequency analysis (L-moment) was applied to compute frequency-based precipitation, and the flood prediction system was also used for flood routing of the down stream region of Teachong Dam in the Kum River Basin to calculate frequency based flood. The magnitude of flood, water level, discharge, and travel time to the major points of the downstream region of Teachong Dam, which can be used as an imdex of flood control management of Teachong Dam, were calculated.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1805-1816
• /
• 2009

The Bimodal Tram being developed in Korea is a new transit system that provides both benefits of rail and bus systems in terns of accessibility and fixed time schedule. The Bimodal Tram will change the role of transit system in Korea. This study developed a strategy of introducing the Bimodal Tram system by considering the travel demand and existing transit system at a city level. The transport/transit system varies depending on cities with respect to demographic characteristics, financial capabilities, etc. The strategies introduced here will help any cities where transport agencies are trying to introduce the Bimodal Tram as a new transit system.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.2109-2113
• /
• 2008

As the standard of living is higher, the passengers using public transportations desire better qualities of environment as well as more comfortable indoor environment. In case of train, the passengers' comfort in passenger cabin is one of the most important elements to be competitive with other transport systems. The indoor air quality of the cabin should be managed properly, because many passengers travel for a long time in the small space of $144\;m^3$. For proper management of the air quality, the heating, ventilation and air conditioning (HVAC) system is required for the ventilation of the compartment. To maintain comfortable environment in the compartment, the automatic ventilation system is needed to exchange the indoor air with fresh air or clean indoor air. In this study, we investigated the indoor air quality (PM-10, $CO_2$, and VOCs) in the compartment of train. In addition, type and pattern of PM-10 has been analyzed through the clustering analysis. Based on the analysis, we could found that the fine particulate matters in the compartment can be a serious hazard to human. To control the concentration of PM-10 and $CO_2$ air cleaners were developed. Through this study, it is expected that people who take a train will be in a more comfortable environment.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2007.12a
• /
• pp.43-51
• /
• 2007

In order to investigate the velocity structure of the southern part of the Korean peninsula, exploded seismic signals were recorded for 120 s along a 294-km WNW-ESE line and 150 s along a 335-km NNW-SSE line in 2002 and 2004, respectively. Velocity tomograms were derived from inverting P-wave and S-wave first arrival times. The raypaths indicate several midcrust interfaces. The shallowest one is at the approximate depth of $2{\sim}3\;km$ with refraction velocities of approximately Vp=6.0 and Vs=3.5 km/s, respectively. The second one of $15{\sim}17\;km$ depth has refraction velocities of approximately Vp=7.1 and Vs=3.7 km/s, respectively. The deepest significant interface varies in depth from 30.8 km to 36.1 km. The critically refracting Vp of $7.8{\sim}8.1\;km/s$ and Vs of $4.2{\sim}4.6\;km/s$ along this interface which may correspond to the Moho discontinuity. The velocity tomograms show (1) existence of a low-velocity zone centered at $6{\sim}7\;km$ depth under the Okchon fold belt and the Yeongnam massif, (2) extension of the Yeongdon fault down to greater than 10 km, and (3) existence of high-velocity materials under the Gyeongsan basin less than 4.2 km thick.

• Corrosion Science and Technology
• /
• v.10 no.4
• /
• pp.136-142
• /
• 2011

Al alloys have been used widely for commercial and military ships in most ocean countries since mid-1950s, and the value as light metal with high mechanical strength has been proven. As the safety and fuel efficiency of Al ships have improved, she can carry more freight, sail faster and travel longer distances. Furthermore, in the shipbuilding industry, Al alloys are applied as structural materials for ships to various areas including the deck of luxurious cruises, battleships and leisure ships. In addition, Al alloys are being spotlighted as environmental-friendly material as they can be recycled even after end of lifespan. However, Al alloys for ships must be carefully selected after considering corrosion resistance, endurance, strength, and weldability in sea water environment. Al alloys to satisfy these conditions are used widely include 5000 series Al-Mg alloy and 6000 series Al-Mg-Si alloy. Thus, this study selected and evaluated the cavitation characteristics of the 5000 series Al alloys that are used in hulls that directly contact seawater and the 6000 Al alloys that are used in the upper structures of ships. Results of cavitation test with time, weightloss and cavitation rate of 5456-H116 showed the smallest damage among 5052-O, 5456-H116 and 6061-T6.

• Journal of Distribution Science
• /
• v.11 no.7
• /
• pp.15-22
• /
• 2013

Purpose - The study investigates the influence of tourism and hospitality industry on economic growth and CO2 emissions. Research design, data, and methodology - In the empirical analysis, unit root tests, cointegration test and vector error correction model regression using time series data of South Korea from the first quarter of 1970 to the third quarter of 2010 are performed to examine the long-run equilibrium relationship and short-run dynamics among the tourism and hospitality industry, CO2 emissions, economic growth and other industry sectors. Results - Results indicate that a long-run equilibrium relationship exists among these variables. Furthermore, the tourism and hospitality industry and CO2 emissions have high significant positive effect on economic growth. The tourism and hospitality industry in Korea, in turns, shows a high significant positive impact on economic growth while the industry sector incursa high significant negative impact on CO2 emissions. Conclusions - The tourism and hospitality industry in Korea may havebeen prompted by several factors such as accelerated process of technological innovation or energy and environmental policies. These findings suggest that the effectively managed tourism and hospitality sector in Korea has resulted in both economic growth and a reduction in CO2 emissions.

• Proceedings of the KSR Conference
• /
• 2001.05a
• /
• pp.80-87
• /
• 2001

The purposes of this primary study are the selection of rail station and train operation management techniques for express-rail operation service at the convectional railway electrification. For these analyses, we used the KNR statistics and KROIS data of rail stations and train users by rail line. Therefore, we chose the important stations for express-rail operation of Kyongbu conventional rail line (esp. Seoul-Jochiwon section) through the rail transportation demand. and then, suggested primary operational management plan thorough the effects analyses of decreasing total travel time and increasing transportation demand by train speed-up. This study has some bounds and limits for proceeding, as it does, we excluded as followings: the conditionals of fate system, headways and train diagram, economic/financial analysis and technological assessment, and other railway technological infrastructures and a certain railcar specification, etc. . We propose to enlarge this study into a feasibility study of express or skip-stop operation service and compatible vehicle system decision considering with the best possible investment rail line, furthermore. in front of Kyongbu (Seoul-Busan) high-speed rail open in 2004, we have to try to progress the efficiencies of railway operation applying various train operation management plan.

• Journal of Agricultural Extension & Community Development
• /
• v.23 no.3
• /
• pp.295-308
• /
• 2016

The purposes of this research are to not only investigate the time-based and regional characteristics in process of development of rural tourism in China, but also explain the significances of rural tourism in China by economic-political significance and social-cultural significance. The characteristics and significances investigated throughout this research are as follows. First, the development of rural tourism in China can be divided by three stages: the first stage(1980-1990), the second stage(1990-2000), the third stage (2000 -). Second, the rural tourism in China has been mainly developed around the metropolitan city such as Beijing, Chengdu. But, they showed different characteristics in process of development of rural tourism. Third, rural tourism in China has been used in solving san-nong(三農) problems which are the most urgent issues in contemporary China and reducing the gaps of living standard between urban and rural area. Forth, rural tourism in China has contributed in satisfying the needs of travel and leisure caused by the improvement of living standard of people due to China's rapid economic growth. Last, it is suggested in this research that the legal and institutional systems be prepared to guarantee the benefits of farmers.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.3
• /
• pp.327-334
• /
• 2011

It is necessary that UGV(Unmanned Ground Vehicle) should generate a real-time travesability index map by analyzing raw terrain information to travel autonomously tough terrain which has various slope and roughness values. In this paper, we propose a local path planning method, $MA^*$(Modified $A^*$) algorithm, using DVGM (Directional Velocity Grid Map) for unmanned ground vehicle. We also present a path optimization algorithm and a path smoothing algorithm which regenerate a pre-planned local path by $MA^*$ algorithm into the reasonable local path considering the mobility of UGV. Field test is conducted with UGV in order to verify the performance of local path planning method using DVGM. The local path planned by $MA^*$ is compared with the result of $A^*$ to verify the safety and optimality of proposed algorithm.