• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.51-62
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• 2000

The objective of this study was to reevaluate current Korean design values for lane width widenings on horizontal currie sections and to develop a new method for derivation of design values based on low-speed offtracking. For this purpose, earlier research were reviewed and necessary equations were derived. Also, the method for derivation of widening values of Korea was compared with that for other countries. The result showed that present Korean method could not consider the variation of lane widths and design speeds of roads. In this Paper, to solve such problems, the new concept of widening was developed. That is the current concept of widening which concerns only the dimension of vehicles and radius of curves was replaced by a new concept that lane width widenings on horizontal curve sections is the difference between the width required on curries and tangents. The width required on a curve consists of the swept Path of a vehicle, lateral clearance, and additional allowance. The width of a tangent is calculated by multiplying lane width by the number of lanes The result of applying new concept shows that the values derived from new concept are higher than current design values for curries have same radius. This study was based only on low-speed offtracking. Therefor, it is recommended that further studies which consider the superelevation and high-speed effect on offtracking be made to derive more accurate widening values .

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.47-55
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• 2005

Roads deeply affect the life of people and keep doing an important role to support economic growth of a country. According to the budget plan of the ministry of construction and transportation of Korea, 8.1 trillion won have been allotted for road investment in the year of 2002 which occupy 61% of the transportation infrastructure special account (13.3 trillion won) and 4.7% of the total national budget (1,740 trillion won). It is true that services generated from road investment such as mobility enhancement and increased accessibility have shown positive effects through shortened travel time and decreased vehicle operating cost. However, it is also notable that many negative effects are gradually being discussed and those are nowadays getting severer due to enhanced people interests about road construction, increased concerns on environment and active public involvement that were evoked by traffic accidents, air pollution & noise and destruction of environment. Road construction processes in Korea are normally governed by administrative sectors (suppliers) not by users. These processes ate very weak to accomodate user s needs and community concerns thus easy to fail finalizing a road project without hassles. A public hearing process is supposed to be held in the processes of detailed design step and the environmental impact analysis. However, it is not enough to grab user's needs and community concerns. Increased public involvement frequencies, optimized public involvement timing and enhanced depth of public involvement magnitude are suggested to improve the current poor public involvement schemes in road planning and design processes. The application of these recommended methods to the road planning and design processes may guarantee the change from the current supplier-oriented schemes to the new user-oriented one. Also, this study suggests to reset objectivity and clarity of road construction process, to make conciliation guidelines based on many practical cases that produced good results, to introduce public involvement techniques in a stepwise basis, and to foster the professionals via education and training programs.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.12-23
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• 2019

This study aims to suggest analysis schemes of urban forests acting as wind ventilation corridor(wind ventilation forest). For this purpose, wind corridor forests were classified into three types: wind-generating forests(WGF), wind-spreading forests (WSF), and wind-connecting forests(WCF), and they were classified into three grades. WGF, WSF and WCF were classified based on the density of forest type map, vegetation index, and ventilation networks, respectively. As a result of analyzing wind corridor forests for Daegu Metropolitan City(883.56㎢), the area of WGF was classified as 443.1㎢ and distributed in the northern and southern regions of Daegu Metropolitan City. Among them, the first grade of WGF occupied the largest area(345.59㎢) and the highest rate(54.44%) in Dalseong-gun. On the other hand, WGF was not found in Jung-gu, because this administrative district is isolated from the forest area. WSF was 32.4㎢, which included representative urban parks of Daegu Metropolitan City, and WSF were found relatively much in Suseong-gu and Dalseong-gun. However, WSF were distributed throughout Metropolitan City, and the vegetation index was not high. The ventilation network that can form WCF included major rivers and roads in Daegu Metropolitan City, but this network was not connected to the urban park from the outer forest. Therefore, it was judged that the formation of WCF connecting WGF outside the city and WSF inside the city would be important. The results of this study can be used as a basic data for systematic wind corridor forest projects, and can be used as basic data for establishing guidelines for wind corridor forest analysis at national and local levels.

• Journal of the Korean Geotechnical Society
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• v.30 no.6
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• pp.23-39
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• 2014

An artificial rainwater reservoir installed in urban areas for recycling rainwater is an eco-friendly facility for reducing storm water effluence. However, in order to recycle the rainwater directly, the artificial rainwater reservoir requires an auxiliary system that can remove non-point source pollutants included in the initial rainfall of urban area. Therefore, the conventional soil filtration technology is adopted to capture non-point source pollutants in an economical and efficient way in the purification system of artificial rainwater reservoirs. In order to satisfy such a demand, clogging characteristics of the sand filter layers with different grain-size distributions were studied with real non-point source pollutants. For this, a series of lab-scale chamber tests were conducted to make a prediction model for removal of non-point source pollutants, based on the clogging theory. The laboratory chamber experiments were carried out by permeating two types of artificially contaminated water through five different types of sand filter layers with different grain-size distributions. The two artificial contaminated waters were made by fine marine-clay particles and real non-point source pollutants collected from motorcar roads of Seoul, Korea. In the laboratory chamber experiments, the concentrations of the artificial contaminated water were measured in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) and compared with each other to evaluate the performance of sand filter layers. In addition, the accumulated weight of pollutant particles clogged in the sand filter layers was estimated. This paper suggests a prediction model for removal of non-point source pollutants with theoretical consideration of the physical characteristics such as the grain-size distribution and composition, and change in the hydraulic conductivity and porosity of sand filter layers. The lumped parameter ${\theta}$ related with the clogging property was estimated by comparing the accumulated weight of pollutant particles obtained from the laboratory chamber experiments and calculated from the prediction model based on the clogging theory. It is found that the lumped parameter ${\theta}$ has a significant influence on the amount of the pollutant particles clogged in the pores of sand filter layers. In conclusion, according to the clogging prediction model, a double-sand-filter layer consisting of two separate layers: the upper sand-filter layer with the effective particle size of 1.49 mm and the lower sand-filter layer with the effective particle size of 0.93 mm, is proposed as the optimum system for removing non-point source pollutants in the field-sized artificial rainwater reservoir.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.11-22
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• 2017

A plaza represents the identity of a city, and that reveals a plaza's importance. Gwanghwamun Plaza and Seoul Plaza are two representative plazas where the citizens can freely express their opinions. Many major plazas in the center of Seoul were built under the Japanese occupation. Among these, the plaza of Joseon Bank has different characteristics than Gwanghwamun Plaza and Seoul Plaza. Even though this plaza was built in the center of the commercial, administrational, and cultural district during the Japanese colonial period, the research on this plaza has been limited. This study was conducted to verify the features of this plaza by analyzing its construction and transformation during the Japanese colonial period. The study's results outline how the plaza was constructed by the Japanese administration. The intention of the government is shown by the fact that it purchased land parcels and held a design competition. In the 1910s, the government purchased seven parcels of land during the expansion of roads as the place for the plaza. During the late 1930s, the government accepted a traffic circle to regulate the traffic and eliminate the conflict between crossing movements. In 1939, a fountain was built in the plaza's center, and its design was selected through a design competition. It was planned as a square, but gradually turned into a rotary. Furthermore, the plaza was a landmark and symbol of the power and modernity of Japan. As the main modal point of public transportation, the plaza became surrounded with largescale Western-style buildings, commercial advertising, and neon signs. The plaza became a place where people could experience the modern city. These spectacular displays showed that Japanese imperialism was perceived as a strange and peculiar landscape to the majority of Korean citizens. This study investigates the history and characteristics of the plaza, focusing on its beginning as well as the transformation of its form. As to the limitations of the study, it does not consider political and economic contexts within the transformation of Seoul and in relation to this plaza. Instead, that research remains for a future study.

• Journal of the Korean Geographical Society
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• v.40 no.2 s.107
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• pp.221-241
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• 2005

Land Use and Land Cover Changes (LUCC) occur over a wide range of space and time scales, and involve complex natural, socio-economic, and institutional processes. Therefore, modelling and predicting LUCC demands an understanding of how various measured properties behave when considered at different scales. Understanding spatial and temporal variability of driving forces and constraints on LUCC is central to understanding the scaling issues. This paper aims to 1) assess the heterogeneity of land cover change processes over the landscape in northern Ghana, where intensification of agricultural activities has been the dominant land cover change process during the past 15 years, 2) characterise dominant land cover change mechanisms for various spatial scales, and 3) identify the optimal spatial scale for LUCC modelling in a savanna landscape. A multivariate statistical method was first applied to identify land cover change intensity (LCCI), using four time-sequenced NDVI images derived from LANDSAT scenes. Three proxy land use change predictors: distance from roads, distance from surface water bodies, and a terrain characterisation index, were regressed against the LCCI using a multi-scale hierarchical adaptive model to identify scale dependency and spatial heterogeneity of LUCC processes. High spatial associations between the LCCI and land use change predictors were mostly limited to moving windows smaller than 10$\times$10km. With increasing window size, LUCC processes within the window tend to be too diverse to establish clear trends, because changes in one part of the window are compensated elsewhere. This results in a reduced correlation between LCCI and land use change predictors at a coarser spatial extent. The spatial coverage of 5-l0km is incidentally equivalent to a village or community area in the study region. In order to reduce spatial variability of land use change processes for regional or national level LUCC modelling, we suggest that the village level is the optimal spatial investigation unit in this savanna landscape.

• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.16-38
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• 1994

The spatial structure of Korea has been changed drastically during the second half of this century. The events such as the Korean War and the resultant division of the Korean Peninsular into two Koreas, rapid industrialization and urbanization are the major causes among others for the spatial changes of the nation. The changes in turn have spawned a number of spatial problems. It is time, we argue, to diagnose how much the nation is now ill-structured, and to discuss of which directions the long-term spatial management be reoriented. A delphi survey was conducted during the early 1993 to fulfill such research needs. Questionnaires were distributed among geographers, planners, and high governmental officials throughout the nation. These 'experts of spatial problems' were requested to evaluate the past spatial policies and strategies, and to identify spatial and environmental problems at the national, regional and local levels. The survey included questions with regard to the spatial problems in North Korea too. A complementary literature survey in the fields of spatial sciences was accomplished as well in order to identify the major research interests and issues with regard to the nations's spatial structure. The delphi survey results indicatee that the present spatial structure: in relation to consumption, housing and economic activities is satisfactory in overall, while rather poor in terms of education, leisure and community activities. Most of the experts consider infrastructural improvements are urgent in the areas of roads, waste disposal facilitles, railroads, harbors, water supply and drainage systems. The over-concentration of economic, social and political function in the Seoul Metropolitan Region is perceived to be the most serious spatial problem in Korea. The long-term solutions suggested are strategies toward a more balanced regional development as well as toward a cleaner environment. The concensus among the experts for the short-term solution is the redistribution of population and industries from the Seoul Metropolitan Region to the intermediate and small cities. The land use policies and concurrent large-scale infrastructural projects are evaluated largely pertinent and desirable in general. It is, however, suggested that development projects be conducted in a more harmonious way with environment. The survey respondents suggest that the present environmental management policies should be reexamined critically. With regard to regional and local problems, transportation and pollutions are thought to be most serious in the Seoul Metropolitan Region, while employment opportunities, and information, education and health care services are most deprived in small cities and rural areas. The majority of the experts consider a city size of 250, 000-500, 000 population is desirable to live within. Respondents beileve that North Korea's physical environment is still not aggravated much whereas its infrastructural provisions are largely pool. The co-authors of this research figure a "environmentaly sound and spatially balanced Korean Penninsular" as the ideal type of spatial structure in Korea. The basic guidelines toward this ideal prototype are suggested: the recovery of spetial integrity, progressive restructuring of the nation, land uses geared to public welfare rather than private interests, and eco-humanistic approach in spatial policies.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.140-147
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• 2018

In Korea, mowing the grass of a grave (Beolcho) is a very important event preceded by Chuseok (Korean thanks giving day) and Si-Hyang (annual ancestral feast). Because Beolcho usually takes place one or two weeks before Chuseok, the traffic accidents on roads are getting worse and safety accidents are getting more and more. Erroneous Beolcho methods can cause the soil to be exposed and cause the loss of soil or the low shoot density of graveyard grass or weed occurrence. Therefore, the dispersion of the Beolcho timing and the approprite method can be import issues. The present study assessed the effects of grass mowing timing and height before Chuseok on the growth of Zoysia japonica and Z. matrella. The mowing timing was evaluated at 1 week, 2 weeks, 3 weeks, and 4 weeks before Chuseok, and the mowing height differently according to the two type of grass. In Z. japonica, the faster mowing before Chuseok, the longer the plant height, and the coverage rate and shoot density were higher. In Z. matrella, the faster mowing, the longer the shoot length, but the coverage rate and shoot density did not show any difference or tendency. As compared to Z. japonica, the plant height of Z. matrella was kept short regardless of the time of mowing. In both grasses, the plant height was shortened when mowing was done at low cutting height, but the coverage rate and shoot density were decreased. In addition, it was shown that it is advantageous to maintain the shoot density of graveyard lawn by 40-50 mm or 30-40 mm cutting above the ground for Z. japonica or Z. matrella, respectively.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.97-107
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• 2011

Nowadays there are a lot of issues about copyright infringement in the Internet world because the digital content on the network can be copied and delivered easily. Indeed the copied version has same quality with the original one. So, copyright owners and content provider want a powerful solution to protect their content. The popular one of the solutions was DRM (digital rights management) that is based on encryption technology and rights control. However, DRM-free service was launched after Steve Jobs who is CEO of Apple proposed a new music service paradigm without DRM, and the DRM is disappeared at the online music market. Even though the online music service decided to not equip the DRM solution, copyright owners and content providers are still searching a solution to protect their content. A solution to replace the DRM technology is digital audio watermarking technology which can embed copyright information into the music. In this paper, the author proposed a new audio watermarking algorithm with two approaches. First, the watermark information is generated by two dimensional barcode which has error correction code. So, the information can be recovered by itself if the errors fall into the range of the error tolerance. The other one is to use chirp sequence of CDMA (code division multiple access). These make the algorithm robust to the several malicious attacks. There are many 2D barcodes. Especially, QR code which is one of the matrix barcodes can express the information and the expression is freer than that of the other matrix barcodes. QR code has the square patterns with double at the three corners and these indicate the boundary of the symbol. This feature of the QR code is proper to express the watermark information. That is, because the QR code is 2D barcodes, nonlinear code and matrix code, it can be modulated to the spread spectrum and can be used for the watermarking algorithm. The proposed algorithm assigns the different spread spectrum sequences to the individual users respectively. In the case that the assigned code sequences are orthogonal, we can identify the watermark information of the individual user from an audio content. The algorithm used the Walsh code as an orthogonal code. The watermark information is rearranged to the 1D sequence from 2D barcode and modulated by the Walsh code. The modulated watermark information is embedded into the DCT (discrete cosine transform) domain of the original audio content. For the performance evaluation, I used 3 audio samples, "Amazing Grace", "Oh! Carol" and "Take me home country roads", The attacks for the robustness test were MP3 compression, echo attack, and sub woofer boost. The MP3 compression was performed by a tool of Cool Edit Pro 2.0. The specification of MP3 was CBR(Constant Bit Rate) 128kbps, 44,100Hz, and stereo. The echo attack had the echo with initial volume 70%, decay 75%, and delay 100msec. The sub woofer boost attack was a modification attack of low frequency part in the Fourier coefficients. The test results showed the proposed algorithm is robust to the attacks. In the MP3 attack, the strength of the watermark information is not affected, and then the watermark can be detected from all of the sample audios. In the sub woofer boost attack, the watermark was detected when the strength is 0.3. Also, in the case of echo attack, the watermark can be identified if the strength is greater and equal than 0.5.