• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.2
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• pp.120-126
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• 2006

In this paper, we propose for improving QoS in hospital wireless network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it has its vulnerability in frequent handoff environment. This handoff state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and most of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.73-75
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• 2014

Marine transportation facility is public goods for the general public and their safety. The study used the Contingent Valuation Method (CVM), a method to estimate economic value of non-market goods, such as environmental goods. In order to analyze economic effects of marine accidents preventable by the VTS, the study estimated costs caused by marine accident cases. It conducted surveys with people and shipping companies in local areas where VTS is to be established in the future. According to a survey with people in areas where marine transportation control center is to be built (Tongyoung), the yearly benefit from building new VTS is estimated at KRW 11billion. If fees are paid in the form of income tax for five years from 2014, corresponding benefits during the same period will reach KRW 47.3 billion in current value. An analysis on economic validity of VTS establishment in Tongyong showed the B/C ration stood at 3.193, far higher than 1. The Net Present Value (NPV) was KRW 32.5 billion and the Internal Rate of Return (IRR) turned out to be 37.4% which was higher than social discount rates of 53.5%. On balance, the establishment has reasonable economic validity.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.306-314
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• 1999

In underground spaces including nuclear waste repository, prediction of air quantity, temperature/humidity and pollutant concentration is utmost important for space construction and management during the normal state as well as for determining the measures in emergency cases such as underground fires. This study aims at developing a model for underground space environment which has capabilities to take into account the effects of autocompression for the natural ventilation head calculation, to find the optimal location and size of fans and regulators, to predict the temperature and humidity by calculating the convective heat transfer coefficient and the sensible and latent heat transfer rates, and to estimate the pollutant levels throughout the network. The temperature/humidity prediction model was applied to a military storage underground space and the relative differences of dry and wet temperatures were 1.5 ~ 2.9% and 0.6 ~ 6.1%, respectively. The convection-based pollutant transport model was applied to two different vehicle tunnels. Coefficients of turbulent diffusion due to the atmospheric turbulence were found to be 9.78 and 17.35$m^2$/s, but measurements of smoke and CO concentrations in a tunnel with high traffic density and under operation of ventilation equipment showed relative differences of 5.88 and 6.62% compared with estimates from the convection-based model. These findings indicate convection is the governing mechanism for pollutant diffusion in most of the tunnel-type spaces.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.214-222
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• 2015

Jeju International Airport has become the most delayed airport in Korea, due to increased demand in air passengers and unexpected local weather condition. Observing the demands continuously grow for a decade, the airport is expected to be saturated in the near future. As a part of effort to prepare effective and timely measure for this expected situation, airport planners seeks the annual runway capacity, i.e., the appropriate number of flight operations in a given year with tolerable delay. In practice, the FAA formula is frequently adopted for the capacity estimation. The method, however, has intrinsic issues: 1) the hourly capacity imbedded in the formula is not clearly defined and thus the estimated value is vulnerable to be subjective judgement, and 2) the formula doesn't consider aircraft delay resulted from runway congestion. In this paper, we explain a novel method for estimating the daily runway capacity and then converting to the annual capacity taking into account the aircraft delay. In this paper, average delay of aircraft was measured using microscopic air traffic simulation model. Daily capacity of the runways were analyzed based on the simulation outputs and the method to assess the yearly capacity is introduced. Using a microscopic simulation model named TAAM, we measure the average aircraft delay at various levels of flight demand, and then estimate the practical daily runway capacity. The estimated daily and annual runway capacities of Jeju airport are about 460 operations a day which is equal to 169,000 operations year. The paper discusses how to verify the simulation model, and also suggests potential enhancement of the method.

• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.117-126
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• 2000

Conventional methods for collecting origin-destination trips have been mainly relied on the surveys of home or roadside interview. However, the methods tend to be costly, labor intensive and time disruptive to the trip makers, thus the methods are not considered suitable for Planning applications such as routing guidance, arterial management and information Provision, as the parts of deployments in Intelligent Transport Systems Motivated by the problems, more economic ways to estimate origin-destination trip tables have been studied since the late 1970s. Some of them, which have been estimating O-D table from link traffic counts are generally Entropy maximizing, Maximum likelihood, Generalized least squares(GLS), and Bayesian inference estimation etc. In the Paper, with user equilibrium constraint we formulate GLS problem for estimating O-D trips and develop a solution a1gorithm by using Genetic Algorithm, which has been known as a g1oba1 searching technique. For the purpose of evaluating the method, we apply it to Seoul inner ringroad and compare it with gradient method proposed by Spiess(1990). From the resu1ts we fond that the method developed in the Paper is superior to other.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.205-216
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• 2008

As the aged and physically disabled people are expected to increase in the next several years, traffic demand especially for the 'mobility handicapped people' will be stronger. According to this trend, our society needs the improvement of social overhead capital for the aged and the disabled. First of all, Barrier-free of public transport facilities is urgent case. The purpose of this study is to estimate value of the Barrier-free facilities at subway stations by using Contingent Valuation Method(CVM) with Double Bounded Dichotomous Choice Question and to analyze the factor which affects the WTP(Willingness To Pay) of subway users by using Survival Analysis. As a result of this study, 'Elevators' and 'Escalators' are higher than 'Handicapped Gate Machines' and 'Ramps for Wheelchair' in the aspect of the average willingness to pay. Therefore the government is recommended to install the Barrier-free facilities for going up and down such as 'Elevators' and 'Escalators', and then supply others for just using subway, and passing such as 'Handicapped Gate Machines' and 'Ramps for Wheelchair'. Also, the average willingness to pay of 'mobility handicapped people' is higher than that of 'normal people'. It indicates that 'mobility handicapped people' value each Barrier-free facility high compared to 'normal people'.

• Journal of architectural history
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• v.20 no.2
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• pp.7-22
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• 2011

This study primarily aims to illuminate the characteristics of $Meoreum$ in Korean traditional fitting system according to the respective types and its periodical changes. Using the research findings as a chronological indicator by which to estimate the construction date of the building is the secondary purpose. In this study 42 of $Byeoldang$ and pavilion architecture remaining in $Yeongnam$ district were examined through the field surveys and methods of documentary research. The research results are as follows. First, $Meoreum$, which is located below the windows or doors, provides protection against the outer wind and has the function to prevent some warm air of the room from flowing outside. Second, $Meoreum$ was recorded as $Yoeum$(了音), $Woneum$(遠音), and $Maleum$(末音) in $Yeong-geon-ui-gwe$(營建儀軌) of Joseon period. While $Yoeum$(了音) was used in $Yeong-geon-ui-gwe$(營建儀軌) of 1776 and 1856, $Woneum$(遠音) had been also used continuously since the year of 1800. The word, $Maleum$(末音) can be seen in $Lim-won-gyeong-je-ji$(林園經濟志), published in 1827. $Woneum$(遠音) and $Maleum$(末音) seem to be the $Yi-du$(吏讀) types of expression of $Meoreum$ which is being extensively used now. Third, the kinds of $Meoreum$ can be classified as $TohMeoreum$, $TongMeoreum$, $TongpanMeoreum$, and $JjaneunMeoreum$. $TongMeoreum$ and $TohMeoreum$ were mostly used at the front part of $Ondol-rooms$, the backside of main floor called $Daechung$(大廳), and at the space between $Daechung$ and rooms in the Pavilions and $Byeoldangs$(Annexes) that had been built in the early Joseon dynasty. $TohMeoreum$ was usually used at the bottom parts of windows between $Daechung$ and $Ondol-rooms$. $TongpanMeoreum$ was mainly used in the mid-Joseon period and relatively high height was the distinctive feature of $Meoreum$ at that time. $Jjaneun$ $Meoreum$, used mainly in the late Joseon dynasty, has become lower and lower gradually in height since 19th century, so people could enter the room through the windows(fittings). Such changes in $Meoreums$ types has brought about the flow of human traffic directly from $Toenmaru$, narrow wooden porch running along the outside of a room to $Ondol-rooms$.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.285-291
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• 2015

FTMS, TCS, ITS equipment such as high-pass highway are just a situation that does not lack traceability and passive surveillance is related to fault DB has so far consisted of an integrated operations management to maximize utilization of the facility. In addition, there is no replacement parts are replaced when a failure occurs, increasing the number of parts and repair time I have trouble growing, and becoming a service interruption whenever you replace each time. In this study, proactively manage the failure history of a highway facility ITS tries to preventive maintenance. Therefore, the error history is based on the reliability of the high-pass facilities theory to calculate the reliability of the system through a systematic statistical analysis Operational Availability. The fault number and the time the replacement period through the estimate decreases and can reduce the budget expenses by securing the spare parts quantity, establish a management plan in part by improving the quality of the system through constant preventive maintenance, quality of service at all times It may direct the non-stop operation state of the available state.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.64-77
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• 2017

Domestic railway station calculates average number of passenger per day by considering future regional society and development of industrial economy etc, is carrying out designs on railway station scale. However, problems are being suggested situationally because selected average passenger data does not consider passengers having been diversified for a year. For representative example, confusion of Gwangju-Songjeong Railway Station got worse due to passengers whose number is more than original plan since the opening. Therefore, this study quotes the concept of design hourly factor using in designing roads to consider passengers having been diversified for a year in railway field. In order to calculate factor, collecting railway passenger data and also estimate, reliability verification were executed by using exponential model and 3rd equation model. As a result of deducing design hourly factor through inflection point calculation, utilizing exponen tial model is analyzed to well reflect the value of design hourly factor on railway passengers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.227-235
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• 2018

Along with the recent increase in traffic volume of vehicles, accidents involving rollover of vehicles have been rapidly increased, resulting in an increase casualties. And to prevent this, various technologies such as vehicle crash test equipment and analysis program development have been advanced. In this study, the applied vehicle model is FORD EXPLORER model, and PC-Crash program for vehicle collision analysis is used to predict the rollover accident behavior of SUV and the collision velocity. Compared with the actual rollover behavior of SUV through the FMVSS No 208 regulations, the analysis results showed similar results, the characteristics of the collision velocity and roll angle showed a tendency that the error rate slightly increased after 1000 msec. Then, as a result of considering using the database of NHTSA, it is shown that the rollover accident occur most frequently in the range of the collision velocity of 15~77 km/h and the collision angle of $22{\sim}74^{\circ}$. And it is possible to estimate the vehicle speed and collision time when the vehicle roof is broken by reconstructing the vehicle starting position, the roof failure position and the stop position by applying the actual accident case.