• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.6
• /
• pp.887-894
• /
• 2018

An electric vehicle is emerging as an alternative to the response of global climate change and sustainability. However, an Electric vehicle has not been popular due to the constraints such as its price or technical limitations. In order to analyze the effect of purchasing electric vehicles, this study conducted a binary logistic regression model that demonstrates the relation between purchasing and influencing variables. Variables which have high correlation were excluded from the model through the correlation analysis to prevent multicollinearity. Socio-economic variables such as the number of owned vehicles, sex, ages are not significant. On the other hand, Variables related to prices, charging and policy are found to have a significant to effect on the purchase of electric vehicles. In accordance with the model estimated result, it seems to be necessary to improve the charging incentives, or to provide electric car information and to expand opportunities for experience electric vehicles. The result is also expected to be helpful for spreading electric vehicles and formulating policies.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.6
• /
• pp.643-648
• /
• 2013

In this paper, we developed a system which can detect and can alarm about the sailing provocative climate by using a photo. The research on domestic shipbuilding industry and in IT fusion technology is under construction, but a reliable safety device which can alarm a sailor about the circumstances of the fog and rain during ship operation as soon as possible due to the constant state in domestic. In this paper, a compact, for system low-power transceiver and data processing equipment for sensing were developed, also a performance evaluation got accomplished with simulation analysis. In results, it is operating normally at least 32.36[dB] and maximum values f 89.20[dB] in the domestic, and 32.55 to 60.66[dB] in the outdoors.

• Journal of Navigation and Port Research
• /
• v.33 no.8
• /
• pp.519-524
• /
• 2009

Although it is expected to provide fundamental data for advanced VTS system by analyzing traffic accidents in VTS area, there is no quantitative analysis to find it.. In this research, it is examined and analyzed marine casualties records(1999-2004), data of Port-MIS and data of each VTS center. The results of this research are as below. 1) It is necessary to reduce traffic accident and to improve VTS operating system. 2) It is discovered for statistical discrepancy between vessels controlled by VTS and vessels not controlled by VTS in accident cause, visibility, perception distance and cause of late perception in collision accidents 3) It is necessary for VTS assistance to be positive and to made in ample time consecutively. 4) As the result of traffic accident prediction model, it is necessary to develop a system improving VTS operators' ability to identify dangerous ships.

• Korean Journal of Optics and Photonics
• /
• v.30 no.1
• /
• pp.1-7
• /
• 2019

MANPADS (man-portable air defense system) is a counterweapon system against enemy aircraft, tracking the MWIR (mid-wavelength of infrared) signature of the plume. Under foggy conditions, however, multiple scattering phenomenon caused by the particles affects the MWIR transmittance, and the MANPADS detection performance. Therefore, in this study we analyzed the lock-on range of MANPADS with varying fog conditions and plume characteristics. To analyze the optical extinction properties and transmittance in fog, Mie scattering theory and analytic solution of the radiative-transfer equation are utilized. In addition, we used flare signature as an alternative MWIR light source. We confirmed that the lock-on range could be noticeably reduced under conditions of mist, and proportional to the flare temperature.

• Journal of the Korean Regional Science Association
• /
• v.35 no.2
• /
• pp.49-57
• /
• 2019

The young generation in life cycle that social position is rapidly changing is play an important role in a regional development because they can increase social and natural population in the region. This study analyzed the relationship between the movement of young generation and the regional characteristics including housing market characteristics in Seoul. As the results, the movement of young generation was influenced by commuting distance and location of jobs as the gravity model has suggested. In addition, housing supply and housing price (or Jeonse price) is an important factor for the movement of young generation. It can be inferred that the more price gap such as Jeonse price and housing supply gap are increased, the more out-migration of young generation in Seoul is increased. However, the housing demand of young generation in employment centers will be increased because jobs contribute to increasing the inflow of young people. Therefore, the policies of central and Seoul government that supply housing in job rich and high accessibility areas are needed for young generation. In addition, if public housing and affordable housing are supplied in the other areas, it can contribute to reduce the out-migration of young people in Seoul.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3D
• /
• pp.317-323
• /
• 2008

Mass transit information can contribute many benefits to users. Especially, transportation information technology is developing highly with information technology in Korea recently. Hereafter, it is expected to give customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithm in public transportation networks including travel and transfer attributes. In this research, constraints are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding condition arbitrarily is proposed by making the maximum value as variables. In this study, transfer frequency, total travel time, seat confirmation, transfer time and travel time become constraint condition based on k path finding algorithm considering service time constraint condition. Moreover, case study about user customized transfer information is performed in Seoul and metropolitan subway networks.

• Journal of Conservation Science
• /
• v.32 no.3
• /
• pp.395-402
• /
• 2016

The impact of a large water control project on surrounding environment(temperature and relative humidity, precipitation, wind speed, present weather and visibility) was monitored. The survey have targeted on Silleuksa temple which is located in the waterside. The number of foggy days emerged as an environmental factor that can cause damage to cultural heritage. Under construction of weir since 2011, monthly relative humidity of Yeoju and Icheon was dropped to 9.6%. It depends on decrease in the number of raining days and precipitation of each year. Silleuksa temple is contiguous to Namhan River and only 100 m away from the waterside. Average wind speed is 0.5 m/s. Silleuksa has a site environmental factors which is often foggy. The number of foggy days of Silleuksa temple declined to 53 days soon after weir's completion. In case of fog, relative humidity of outside was higher than that of outside and inside of Josadang Shrine. Relative humidity difference of outside and inside of Josadang Shrine was 5.4% on average. Relative humidity of the number of foggy days is 6.3% higher on average than that of fine days. The width and dimensions of Namhan River increased by 1.45 times after weir's construction. It can change the number of foggy days. A long-term monitoring is positively necessary on fog occurrence and relative humidity.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.2
• /
• pp.171-178
• /
• 2015

This research is the first research on developing the speed limit select model and also it is the result of the research on the importance of each element and consideration factors when selecting the speed limit. For the consideration factor discrimination and calculation of the importance, the delphi method and AHP method was used. The delphi survey was processed through third round survey, 5 high consideration factor(Level 1) and 23 low consideration factor(Level 2) was discriminated. During the process of the third delphi survey, when the CVR cost was in the range between 0.4~1.0 it was treated as the consideration factor when selecting the speed limit and less than 0.4 cost was eliminated. In the process of the second delphi survey, 33 consideration factors were discriminated but was reordered into 23 categories through the third survey. Based on the 23 categories earned through the third delphi analysis, the AHP survey was processed. The result of the AHP survey was that out of the importance of the 5 high consideration factor(Level 1), the traffic condition was evaluated as the number one factor and the vessel condition, waterway condition, environment condition, supporting condition and etc. conditions were evaluated following the traffic condition. Out of the 23 low consideration factor(Level 2) consideration, the visibility was evaluated to be the first important and the performance of the vessel steering, objective factors within the harbor, amount of traffic and density, distance between the passing vessel, speed of the steering capacity and tidal current were the following evaluated factors.

• Korean Journal of Environment and Ecology
• /
• v.17 no.4
• /
• pp.366-374
• /
• 2004

The purpose of this study is to develop effective destination management strategies for three typical tourist destinations in Kangwon province based on the importance-performance analysis. The results show that overall performance levels of 21 management attributes in three destinations is relatively low, compared to the importance levels of the attributes. 6 attributes place in Concentrate Here, 4 attributes in Possible Overkill, 6 attributes in Keep Up Good Work, and 5 attributes in Low Priority. There is no significant difference in the importance level among three destinations, while performance levels are the lowest at Naksan & Kyungpo beaches, and highest at Ganhyun area. Findings of the survey expect to be used as fundamentals in management policy making process for each destinations.

• Korean Journal of Environment and Ecology
• /
• v.17 no.3
• /
• pp.276-284
• /
• 2003

The purpose of this study is to develop effective destination management strategies for three typical tourist destinations in Kangwon province based on the importance-performance analysis. The results show that overall performance levels of 21 management attributes in three destinations is relatively low, compared to the importance levels of the attributes. 6 attributes place in Concentrate Here, 4 attributes in Possible Overkill, 6 attributes in Keep Up Good Work, and 5 attributes in Low Priority. There is no significant difference in the importance level among three destinations, while performance levels are the lowest at Naksan & Kyungpo beaches, and highest at Ganhyun area. Findings of the survey expect to be used as fundamentals in management policy making process for each destinations.