• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1171-1180
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• 2014

The NRCS-CN method is generally used to estimate effective rainfalls in a basin. However, since the curve number which plays a critical role in the NRCS-CN method was originally developed for US watersheds, it is limited to be directly applied to other basins outside the United States. Therefore various modifications have been suggested to revise the NRCS-CN for specific watershed condition. This study introduced the weighted average method and the slope-based CN to estimate effective rainfalls available for Korean watersheds and compared with the observed direct runoff. The overall results achieved from this study indicated that the adjusted slope-based CN considerably increases effective rainfalls in general and makes the duration of effective storm longer. Based on the statistical error analysis performed for various modifications of NRCS-CN, the weighted average method with the adjusted slope-based CN has highest precision with the observed direct runoff. In addition, after analyzing the relation between the initial loss estimated from rainfall-runoff observations and the potential maximum retention from GIS-based data, it turns out that the assumption of linear relationship between the initial loss and the potential maximum retention is not available for Korean watersheds.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1289-1298
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• 2014

Pavement crack sealing method, which is one of the methods to maintain and repair the road, prevents the extending of cracks by repairing cracks in its early occurrence and has already been applied to many roadworks in advanced foreign country for a long time. But in the conventional crack sealing method, traffic accidents occur frequently during the repair because it's commonly performed on the heavy traffic road or highway. It also has some difficulties in securing the safety of workers from the risk of burns caused by heated sealant. In an effort to solve these problems, automated pavement crack sealing machines such as ARMM, OCCSM, TTLS have been developed in advanced foreign country since early 1990s. Also APCS in 2004 and ACSTM in 2013 were already developed domestically. However, since these automated crack sealers developed from a number of research institutions have different test-bed conditions and productivity measurement models, it's difficult to compare and evaluate them objectively. In this study, the image processing time of the respective machines and the movement time of each motion on the work process were estimated by using fully autonomous mapping and semi-automatic mapping in order to measure the productivity in the same environmental conditions. In addition, the productivity measurement test-bed reflected domestic road characteristics was designed to estimate and compare the productivity of the automated crack sealing machines.

• Journal of Cadastre & Land InformatiX
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• v.48 no.1
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• pp.201-213
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• 2018

In recent years, the number of traffic accidents caused by car accidents has been decreasing steadily due to traffic accident prevention activities in Korea. However, the number of accidents in Seoul is higher than that of other regions. Various studies have been conducted to prevent traffic accidents, which are human disasters. In particular, previous studies have performed the spatial analysis of traffic accidents by counting the number of traffic accidents by administrative districts or by estimating the density through kernel density method in order to identify the traffic accident cluster areas. However, since traffic accidents take place along the road, it would be more meaningful to investigate them concentrated on the road network. In this study, traffic accidents were assigned to the nearest road network in two ways and analyzed by hotspot analysis using Getis-Ord Gi* statistics. One of them was investigated with a fixed road link of 10m unit, and the other by computing the average traffic accidents per unit length per road section. As a result by the first method, it was possible to identify the specific road sections where traffic accidents are concentrated. On the other hand, the results by the second method showed that the traffic accident concentrated areas are extensible depending on the characteristic of the road links. The methods proposed here provide different approaches for visualizing the traffic accidents and thus, make it possible to identify those sections clearly that need improvement as for the traffic environment.

• Membrane Journal
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• v.26 no.4
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• pp.239-252
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• 2016

Two-dimensional materials offer unique characteristics for membrane applications to water technology. With its atomic thickness, availability and stackability, graphene in particular is attracting attention in the research and industrial communities. Here, we present a brief overview of the recent research activities in this rising topic with bringing two membrane architecture into focus. Pristine graphene in single- and polycrystallinity poses a unique diffusion barrier property for most of chemical species at broad ambient conditions. If well designed and controlled, physical and chemical perforation can turn this barrier layer to a thinnest feasible membrane that permits ultimate permeation at given pore sizes. For subcontinuum pores, both molecular dynamics simulations and experiments predict potential salt rejection to envisage a seawater desalination application. Another novel membrane architecture is a stack of individual layers of 2D materials. When graphene-based platelets are chemically modified and stacked, the interplanar spacing forms a narrow transport pathway capable of separation of solvated ions from pure water. Bearing unbeknownst permeance and selectivity, both membrane architecture - ultrathin porous graphene and stacked platelets - offer a promising prospect for new extraordinary membranes for water technology applications.

• Spatial Information Research
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• v.21 no.1
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• pp.23-36
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• 2013

Recently, the VWORLD was built to ensure competition on the advance of domestic enterprise into foreign markets with rapid expansion of spatial information industry of the world. However, the policy to secure user is insufficient because the VWORLD's service is embryonic stages. Then again, tourist industry is growing rapidly and leading the world economy and number of domestic tourists are also steadily increasing. Although the size was expanded, Korean tourist industry's competition is relatively weak, so some scholars insist that raising the tourist industry's quality. This backgrounds make a study of the tourism information service. So, this paper progressed a study on the development of the tourism information service based on a service science and used VWORLD as a test model. This paper drew the customer's demands on the tourism information service and strategic points of the development from those by using a Quality Function of Deployment of service science's new service development methodologies. After that this study prioritized those strategic points. As a result, 'Face Map' that is a service model was made. Moreover, this study have try to raise the development's effectiveness and efficiency based on service science's a new service development process.

• The Journal of Korean Association of Computer Education
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• v.16 no.5
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• pp.17-29
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• 2013

Cyberbullying has a negative influence on teens. However, the academic approach and try is still an its early stages in spite of the issue of the seriousness and importance. Accordingly, this study conducted a survey of 1,112 elementary, middle and high school students. According to the survey, Internet bullying violence experience was from 20.3% to 39.0%, victim experience from 11.0% to 23.4%, mobile phone bullying violence experience was from 15.9% to 44.1%, victim experience from 5.5% to 21.8%. The factors affecting Internet bullying violence experience were gender, academic stress, internet accessibility, anonymity, use time of internet. The factors affecting mobile phone bullying violence experience were school table, academic stress, mobility, anonymity, use time of mobile phone. Finally, this study grasped the relation between Internet and mobile phone bullying. It was found that Internet bullying violence victim experience had something to do with mobile phone bullying violence victim experience. Especially, Internet bullying violence experience had a lot to do with mobile phone bullying violence experience, Internet bullying victim experience had a lot to do with mobile phone bullying victim experience.

• Korean journal of communication and information
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• v.42
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• pp.44-78
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• 2008

The present study explored the agenda setting effects of replies called "Daet-Gul", and perception of the news replies. This study has established three research questions: 1) the recognition of the online communication 2) the degree of the reading and writing on online spare 3) the amount of the effects on the online communication. This study is performed using survey method. The survey results indicated in that the participants are very passive readers and writers on the online spare. In addition, the survey repliers evaluated that replies' mechanical device and antigravitational speed have high score, whereas they marked low store in the content and credibility of 'the replies. Therefore, they did not estimate the effects of the replies highly. All the results indicate that 'the replies' is not the fundamental factors of the deliberative democracy. It's because online communication with 'the replies' are thought to be fated the abuse and slander. Therefore, it's essential to improve the online communication with 'the replies', through the introduction of the 'trackback', which is a sort of the 'remote replies'

• Journal of Digital Convergence
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• v.15 no.6
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• pp.121-132
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• 2017

In this study, there is a purpose of research to secure competitiveness through the effective utilization of intangible corporate resources of founded enterprises. For this research, we conducted a survey on the way the customers who used the products of the BI center and founders less than 7 years evaluated the founded company. Schmitt's empirical element was examined as a theoretical background, and it was examined whether these empirical factors and attitudes acted as a preprocess in the decision-making process as a repurchase intention. The Result of research is as follows. First, It clearly indicated that customer experience and search experience affected the degree of re-purchase. Second, customer's experience (use experience, search experience, contact experience) were grasped with significant influence on customer's attitude. Third, we discovered that customer's attitude had mediated between customer's experience (use experience, search experience) and re-purchase. This research suggests that if we manage empirical factors well, we can increase the degree of re-purchase and cope appropriately with the limitations of small and medium enterprises.

• Progress in Medical Physics
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• v.9 no.1
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• pp.55-64
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• 1998

In recent, the demand of development of the high dose rate brachytherapy source increased for substitute for Co-60 source by iridium source, since the supplying Co-60 source is very depressed and the high dose rate brachytherapy sources are entirely imported from the abroad. This study investigated the exposure rates and isotropic dose distributions for the Ir-192 source produced from $\^$191/Ir(n,r)$\^$192/Ir by nuclear reactor in Korea Atomic Energy Research Institute. The activity of source was obtained an 1.012 Ci (the initial activity without encapsulation was 2,87Ci) by measurement with encapsuled stainless steel. The exposure rate of provided Ir-192 source was determined on 6.36 ${\pm}$ 0.147 Rm$^2$/h-GBq (2.350 ${\pm}$ 0.054 Rcm$^2$/mCi-hr) within ${\pm}$ 2.2% discrepancy with IC-10 ion chamber (0.14 cc) which was mounted on the acrylic jig to 5, 10 and 20 cm from the center of source. The calculated doses with 22 most significant spectrum lines were corrected with intrinsic efficiency of the germanium detector were compared to measured exposure dose rates within ${\pm}$3.8 % discrepancy. The authors confirmed the high dose rate Ir-192 source could be replaced the long decayed Co-60 source via investigation of the isotropic dose distributions in lateral, source axis and diagonal direction of source center are very closed to within 3% uncertainties. Especially, this exposure rate constant and isotropic dose distribution will be fundamental to build the high dose rate source and develop the computed therapy planning system.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.1
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• pp.67-82
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• 2009

This paper examines the regional economic development policies of the Welsh Development Agency for attracting companies from the perspective of industrial location theory. The Welsh Development Agency has succeeded in attracting domestic or international capital, as a core actor for the regional economic development, and responded to the changing business environment and to the specific and various needs of the investors. The analysis of the Welsh case provides an important theoretical and practical implications. First, the Welsh case shows the importance of the role of the public sectors for the regional economic development. As the behavioral approach and the industrial location theory argue, the attraction of domestic or international capital led to the regional economic development. Second, the effective activities for attracting capital played an important role in the development. The quality and quantity of the information, in the industrial location theory, and the capacity of the business groups, in the behavioral approach, are significant factors of the development. Third, incentives by the Agency are also important. This finding not only supports the classical location model based on the cost and profits, but also the behavioral approach. Finally, the Welsh case could not succeeded in gaining regional economic competitiveness, even though attracting companies, by disregarding the industrial specialization strategy at the local level. This implies that we need to build industrial clusters. In sum, the behavioral approach has significant implications to the understanding of the public policies for attracting companies.