• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.97-103
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• 2018

In satellite communication, modulated beacon signal is spreaded by gold sequence and the modulated beacon is transmitted via linear phase modulation. Due to the difference in characteristics of the satellite and the receiver on the ground, frequency offset (FO) occurs. An existing modulated beacon receiver is a method of synchronizing the frequency of a modulated beacon signal using FFT(Fast Fourier Transform), which not only increases the delay and complexity in terms of system implementation but also has a separate circuit for compensating the phase difference due to FO and phase offset from FFT points. In order to overcome this problem, this paper proposes and analyzes a scheme for compensating and demodulating the coarse FO and phase offset at one time using the 2-phase shaped characteristics of the modulated beacon signal. Also, through the simulation, the modulation index suitable for the proposed method is analyzed and the appropriate cumulative number is also analyzed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2122-2136
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• 2010

Existing model formula in the 4 phase model is limited in the estimation of the demand for urban railway because the administrative region-based formula reflects no spatial characteristics of station surrounding area(SSA) that urban railway forms. The purpose of this study is both to analyse the behavior in selecting the method regarding spatial range of SSA and to do the basic research for the development of new model through the survey conducted in the stations of the metropolitan area. This study will review the domestic and foreign cases about designation of SSA, study the spatial range of SSA through case studies, analyze the selection of methods by the spatial range and estimate the demand of the station on the basis of social and economic indices regarding SSA. This study focuses on the verification of real results and model estimates, due to the time constraint and lack of resources for collecting and analysing the data. According to this study, 500m,1000m division of SSA shows the closest results of the model estimates to the real demand of the targeted stations.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.33-42
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• 2012

This study proposed a model for estimating the unit value of social cost for mobile emission considering local geographical and social characteristics, together with a method to evaluate the air quality value. The model was built based on benefit transfer methods, the population density, and green space ratio of each area, which are reflected through independent variables. While applying the model, the unit value of social cost for mobile emissions in both densely populated areas of Seoul and Busan was found to be 18.68 times and 10.71 times higher than the national average, respectively. It is highly expected that this study can contribute to providing more reliable guidelines to decision makers when evaluating various green transportation policies and projects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1087-1094
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• 2013

This study aims at enhancing the objective estimation of social cost of air quality due to mobile emission. More specifically, it examines the difference between the daily oriented and hourly oriented estimation results of social air quality cost and draws implications from the comparative analysis. The result indicates that the social cost of air quality differs up to approximately 24 times depending on the analysis time period. Moneywise, the difference between daily and hourly assignments amounts to the average of 653.5 billion won whereas only 1% of error occurred in the estimation result based on peak and nonpeak based hourly assignment. This study reaffirms the need for time-based travel demand management for emission reduction, and confirms the feasibility of emission estimation by travel demand forecasting method over the conventional method employed by the CAPSS.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.20-32
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• 2013

This study is aimed at identifying the relationship of transit accessibility types to its related travel frequency in the Seoul metropolitan area. A multi-level poisson regression model is employed after categorizing transit accessibility into 18 types based on locations of residential and work workplace. Analysis results offer three policy implications in improving transit use in the Seoul metropolitan area. First, increase in transit ridership can be more effectively attained when policies concerning both competitive and complementary relationships between bus and rail transit are incorporated. Second, transfer system needs to be focused on such two modal perspectives as one travels from Seoul to suburban area and residential areas given the fact that walking accessibility to bus transit is good but that to rail transit is poor. Third, it is more effective to emphasize rail transit priority rather than bus transit, especially for the travel from suburban area to the city of Seoul in order to increase transit ridership.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.141-154
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• 2018

In order to meet the ever-increasing demand for international air travel, several plans are underway to open new airports and expand existing provincial airports. However, existing air demand forecasts have been based on the total air demand in Korea or the air demand among major cities. There is not much forecast of regional air demand considering local characteristics. In this study, the outbound air travel demand in the southeastern region of Korea was analyzed and the fixed-effects model using panel data was proposed as an optimal model that can reflect the inherent characteristics of metropolitan areas which are difficult to observe in reality. The results of model validation show that panel data analysis effectively addresses the spurious regression and unobserved heterogeneity that are difficult to handle in a model using only a few macroeconomic indicators with time series characteristics. Various statistical validation and conformance tests suggest that the fixed-effects model proposed in this study is superior to other econometric models in predicting demand for international demand in the southeastern region.

• International Journal of Railway
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• v.6 no.2
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.4
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• pp.515-528
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• 2010

This study analyzes the impacts of mixed-use development and transportation on housing values in Seoul, Korea. An index measuring the land use mix is proposed using three components of land uses, residence, office, and retail, which are the essential elements for everyday urban life. This index offers a relatively easy way in measuring the level of mixed-use and proves itself useful providing sensible and reliable results in this empirical study. Also surface and underground transportation accessibilities are measured. By covering both surface and underground, a comprehensive view of Seoul's transportation accessibility is provided. Finally, housing value models are constructed with developed variables, i.e. land use mix index and accessibility measures, as well as relevant socio-economic variables. The empirical outcomes verifies that mixed-use development and transportation accessibility positively affect housing values.

• KIEAE Journal
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• v.9 no.5
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• pp.85-96
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• 2009

This study analyzed a characteristic by types of urban regeneration helping the establishment of urban identity under social condition change. It will be foundation of sustainable urban development with strategy that secures world-wide competitive power. For this, sample cases that established identity from urban regeneration were reviewed about the main subject and the supporting subject in business side and hardware, software, system, and finance in design factors. 4samples each in inheritance intensification type and change creation type were selected and analyzed. The result said it is most effective to establish urban identity when inheritance intensification type is the private-centered for urban regeneration. And it is better to do the project that the main subject and the supporting subject are taken by the private or the private-leading partnership. It is necessary to manage the region and plan events with software design factors more than hardware design factors. In addition, for urban identity, it was found to be desirable to utilize and preserve fully current resources such as historical scenery and activate the communities than making new facilities. On the contrary, the project based on change creation type needs to be under the public management with innovative idea. Also, when it comes to design factors, facilities related to culture and art and community spaces should open and run actively. It is important for the region to improve its image by New design style such as TOD. In software side, it is important to manage the region by monitoring about urban regeneration business and solve social mix and employment problem. On the other hand, in terms of system and administration, both types don't show a difference in urban identity establishment, since it is same that both should make partnership and get a support of subsidy to be most effective.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.257-263
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• 2013

In case of image observation equipments, CCTV for short distance visual field is usually installed and operated mostly as the means of crime-prevention. However, the extensive demand for monitoring problems in case of the increase in intelligent crimes and disasters has led to the necessity of the development of long-distance observation equipments embedded with Night View functions. In case of the Night View equipments, the relevant market is set up to be focused mostly on Thermal Observation Device(hereinafter, TOD), but some shortcomings such as the limitation of image visibility and excessive maintenance cost, etc. have actually caused the necessity of new long distance Night View equipment. Moreover there might follow lots of difficulties in long-distance visualization in the event that irregular reflection is generated by minute particles in the atmosphere such as fog, smog, and dust, etc. These factors are motivate the work presented in this study. Our study is aimed at the realization of Pulsed Laser Illuminator and newly proposed Range-Gated image acquisition technology. And also the implementation of Tracker for continuous trace of the objects of interest from the obtained sequence images.