• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.89-105
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• 2021

In this paper, feasibility study was carried out to evaluate necessity of seismic design of earth retaining structures in a deep excavation. Dynamic behavior of retaining system was analyzed using FLAC, a finite difference analysis program. It was shown that maximum bending moments of retaining walls and axial forces of supports were increased up to 98% and 87% during earthquake, respectively, compared to final excavation step, which indicates that dynamic earth pressure has a large effect on a retaining system. The stability of retaining system designed according to current design specifications was evaluated using structural forces obtained by numerical analysis, and effect of earthquake loading on structural design was analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.478-480
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• 2022

Smart Railway as a next generation railway technology is expected to have rapid evolution with developments of information and communications tehchology. Especially, smart railway will be progressed more evolved transportation means for railway operation and costomer service based with spread of commercial 5G communication. So, it is very important to investigate and analyze trends of smart railway related tehcnology of 5G mobile communication for samrt railway infra structure, server technolgy for AI, big data, deep learning, information security technology, sensor and IoT. In this paper, 5G based communicaion technology and application techology related smart railway is described and trends of new techlogy on this communication tehnology is investigated. The results of this study can be used for smart railway study and implementation, research and development for smart railway communicaion technology, etc.

• Advances in nano research
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• v.13 no.4
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• pp.325-339
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• 2022

Endophytes ascertain a symbiotic relationship with plants as promoters of growth, defense mechanism etc. This study is a first report to screen the endophytic population in Waltheria indica, a tropical medicinal plant. 5 bacterial and 3 fungal strains in leaves, 3 bacterial and 1 yeast species in stems were differentiated morphologically and identified by biochemical and molecular methods. The phylogenetic tree of the isolated endophytes was constructed using MEGA X. Silver nanoparticles were biosynthesized from a rare endophytic bacterium Cupriavidus metallidurans isolated from the leaf of W. indica. The formation of silver nanoparticles was confirmed by UV-Visible spectrophotometer that evidenced a strong absorption band at 408.5 nm of UV-Visible range with crystalline nature and average particle size of 16.4 nm by Particle size analyzer. The Fourier Transform Infra-Red spectrum displayed the presence of various functional groups that stabilized the nanoparticles. X-ray diffraction peaks were conferred to face centered cubic structure. Transmission Electron Microscope and Scanning Electron Microscope revealed the spherical-shaped, polycrystalline nature with the presence of elemental silver analyzed by Energy Dispersive of X-Ray spectrum. Selected area electron diffraction also confirmed the orientation of AgNPs at 111, 200, 220, 311 planes similar to X-ray diffraction analysis. The synthesized nanoparticles are evaluated for antimicrobial activity against 7 bacterial and 3 fungal pathogens. A good zone of inhibition was observed against pathogenic bacteria than fungal pathogens. Thus the study could hold a key aspect in drug discovery research and other pharmacological conducts of human clinical conditions.

• Journal of the Korean Geographical Society
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• v.28 no.1
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• pp.16-39
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• 1993

This study aims to analyze the locational factors which the small firm enterpreneurs in Pusan City mainly consider in deciding location choices for their plants, and then to grasp the differences of the factors in terms of nature of firms, managerial personal characteristics and zoning areas. In order to implement the purpose of the rescarch, data are collected from selected small firm enterpreneurs throughthe questionaire. The main results are summerized as follows. First, it is pointed out that small firm indu-strialists for the regional choice consider crucial rationale as non-economic factor of personal reson with additional consideration of transpor-tation, infrastructure, service, market and labor forces. But in selection of site, they are apt to have high regard on the such factors as infra-structure, service, land and transportation factor. These factors to select the site demonstrate differentiation in terms of character of enter-prises, managerial characteristics and zoning areas. For example, land in the light of indu-strial sector is regarded as an important factor with longer the time of the establishment of firms or more aged or experienced enterpreneurs, wheras infrastructure and service in the heavy and chemical industrial sector are taken up as an important one with shorter the time of establishment of firms or less aged or experienced or higher educational background of enterpren-eurs. In addition, the non-economic factors such as the residential livebility and personal reason are picked up as important factors with smaller the firm or more aged or experienced, lesser educational background of entrepreneurs. Taking into consideration zoning area, infra-structure and service in the industrial area such as the exclusive and semi-industrial areas, land in green belt area, and transportation in the commercial and residential areas are singled out as the most important factors respectively. In addition, the non-economic factors of the resi-dential livability and personal reason in the non-industrial areas are also highly regarded. Second, land is picked up as the most impor-tant one of pulling factors toward the present site while other factors such as infrastructure, service, personal reason are also regarded as the secondary reason for the move-in decision; the pulling factors for the present plant location show somewhat differences in terms of the charcter of the enterprises, managerial chara-cteristics and zoning areas. Policy measures including land, infrastructure under the environmental aspects, service and transportations are, in turn, pointed out as the important ones for pushing factors. Meanwhile, as the important staying factor in the present place, transportation, infrastructure and service under the aspect of the agglomeration benefit, market, personal reason are considered. The pushing and staying factors also shows somewhat distinctive differences in terms of the character of enterprises, managerial chracteristics and zoning area. In the case of zoning area, land is regarded as the most important factor to move out, especially in the non-industrial areas inclu-ding the commerical and residential areas policy measures, infrastructure and service are indicated as important factors to move out. In the mean-time, as the important staying factor, industria-lists in the exclusive and semi-industrial areas point out transportation, infrastructure and service. Whereas the counterparts in the com-mercial area regard transportation and market as important factor, those in the residential area consider the non-economic factors such as personal reason and residential livability. Taking into consideration the result of this analysis, it is identified that the locational chara-cteristics of the intraurban small firm industries are not only associated with the character of enterprises, but also with manager's personal character and the trait of zoning area. Therefore, it seems that the thorough review or examination of enterprises, industrialists' characteristics and zoning areas will have meanin-gful significance in attemption explanation of small firm industries at the intrauban scale in the future. Especially, it appears that the eco-nomic factors such as land, infrastructure, service, transportation, and the non-economic factors such as residential livability and personal reason play together important parts to determine the locational choice of small firm industries along with non-industrial benefit. Thus, such status reveals the obvious implication for the intraurban industrial policy in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.86-99
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• 2016

This study was for analyzing the external environment and internal space structure and improving the way of use efficiency in waterfront through the Dragon boat festival to utilize waterfront actively. Through from the four target area, Hongkong, Busan, Incheon and Daejeon, this study was for an importance and satisfaction analysis for users about the element effect on the waterfront use efficiency and the contribution to cultural contents revitalization of waterfront by giving basic data. The result is as follows. First, in the importance analysis about 12 items, modern cultural infra around the waterfront was ranked highest, 8.26 and waterfront landscape, square & openspaces, convenience facilities, transport, green area, quality of viewing space, historic resources, pedestrian, suitability of width, wave, depth, water quality, berth & mooring were ranked in descending order. Second, waterfront landscape was interpreted by rather the external environmental impact according to city size than the matter of spatial structure in target area and judged as an important factor effect on site selection for waterfront. In the analysis of waterfront landscape, the reason of the high satisfaction about domestic target area was that riverside parks were recently made considering their waterfront activities. Viewing space was major infra where people could experience the pleasant waterfront and watch dynamic water leisure sports like Dragon boat three dimensionally and was thought to be improved for the use efficiency. Third, tourism resources were very important element that affect the use efficiency of waterfront, so waterfront users react sensitively to modern tourism resources rather than to historic resources. This meant that tourism infrastructure for shopping and leisure of the young affected the use efficiency of waterfront, so Hongkong and Busan were in a better position in terms of using waterfront that was near the tourism infrastructure. Fourth, in the analysis of traffic accessibility, both Hongkong and Busan were high evaluated in terms of excellent traffic accessibility by subway. Daejeon was low rated in terms of the satisfaction of use efficiency, because of the relative lower place awareness compared with transportation infrastructure. In Hongkong, waterfront was connected with downtown and in Busan, housing complex and shopping centers were located in the place for users in an easily accessible on foot, so the satisfaction was high-pitched. Finally, in the importance of water surface width and the analysis of satisfaction, except Incheon, all the three were over 200m in width of water surface and this meant the surface width above certain level was interpreted to interrupt the concentration of enjoying the water leisure sports. In the analysis of surface condition such as water quality, water depth and wave, through a survey, Busan had a problem with water quality and Gapcheon in Daejeon had a problem with optimal water depth by the festival participants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.105-111
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• 2018

This study aims to evaluate the safety for cable stayed bridge due to damages on the cable system. Many cable supported bridges, including cable stayed bridge and suspension bridge, have been built in the Korean peninsula. This requires efficient maintenance and management since this structure has complex structural components and system. This large structure also often faces risks either from manmade or natural phenomenon. In 2015 one cable-stayed bridge in South Korea had been struck by a bolt of lightning on the cables. This event had led to fire on cables. These cables had been damaged and putting the bridge at risk. This bridge was back in used after a few weeks of investigations and replacements of the cables. However, enormous social and economic expense were paid for recovery. After this event risk based management for infra structures is required by public demands. Therefore, this study was initiated and aimed to evaluate risks on the cable system due to potential damages. In this paper one cable-stayed bridge in South Korea was selected and investigated its safety based on the damage scenarios of cable system for efficient and prompt management, and for supporting decision making. FEM analysis was conducted to evaluate the safety of the bridges due to damages on the cable system.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.471-480
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• 2016

Recently, the damage of cyber attack toward infra-system, national defence and security system is gradually increasing. In this situation, military recognizes the importance of cyber warfare, and they establish a cyber system in preparation, regardless of the existence of threaten. Thus, the study of Intrusion Detection System(IDS) that plays an important role in network defence system is required. IDS is divided into misuse and anomaly detection methods. Recent studies attempt to combine those two methods to maximize advantagesand to minimize disadvantages both of misuse and anomaly. The combination is called Hybrid IDS. Previous studies would not be inappropriate for near real-time network environments because they have computational complexity problems. It leads to the need of the study considering the structure of IDS that have high detection rate and low computational cost. In this paper, we proposed a Hybrid IDS which combines C4.5 decision tree(misuse detection method) and Weighted K-means algorithm (anomaly detection method) hierarchically. It can detect malicious network packets effectively with low complexity by applying mutual information and genetic algorithm based efficient feature selection technique. Also we construct upgraded the the hierarchical structure of IDS reusing feature weights in anomaly detection section. It is validated that proposed Hybrid IDS ensures high detection accuracy (98.68%) and performance at experiment section.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.55-64
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• 2006

It is very Important to predict the damage zone of a rock mass induced by blasting for the excavation of an underground cavity such as a tunnel, as the damage zones incur mechanical and hydraulic instability of the rock mass potentially. Complicated blasting processes that can hinder the proper characterization of the damage zone can be effectively represented by two loading mechanisms. The first mechanism is the dynamic impulsive load-generating stress waves that radiate outwards immediately after detonation. This load creates a crushed annulus along with cracks around the blasthole. The second is the gas pressure that remains for an extended time after detonation. As the gas pressure reopens some arrested cracks and extends these, it contributes to the final structure of the damage zone induced by the blasting. This paper presents a simple method to evaluate the damage zone induced by gas pressure during rock blasting. The damage zone is characterized by analyzing crack propagations from the blasthole. To do this, a model of a blasthole with a number of radial cracks that are equal in length in a homogeneous infinite elastic plane is considered. In this model, crack propagation is simulated through the use of only two conditions: a crack propagation criterion and the mass conservation of the gas. The results show that the stress intensity factor of a crack decreases as the crack propagates from the blasthole, which determines the crack length. In addition, it was found that the blasthole pressure continues to decrease during crack propagation.

• Management & Information Systems Review
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• v.30 no.2
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• pp.57-79
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• 2011

One of the fastest growing sector in tourism industry is MICE industry due to globalization among the countries in various parts including business, politics, and cultural exchange. The objectives of this research can be in two fold: firstly, to evaluate the convention service quality and categorize them into three groups, basic service, performance service and exciting service; secondly, to provide the exciting service as a recovery program to restore customer satisfaction and their intention to reuse when the basic or performance service failure occurs. The results are as follows: among the four dimensions of the service quality, only the availability of information and the employee's performance were effected by the exciting service quality. Secondly, employees's performance can only be effected by the exciting service when customer service factor is included prior to the events. Thirdly, the following dimensions of services were not selected to be effective by the exciting services: conditions of physical facility, related infra-structure, the process of customer service and the program. Fourthly, only the additional services and events were selected to be the effective exciting services for the recovery program.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.4
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• pp.553-567
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• 2011

Since their establishment in 1999, Regional Development Agencies in England have been a critical catalyst for sustaining regional development, by linking the central government and the region. Nevertheless, the new Coalition Government formed in May 2010 is to abolish RDAs and is to be replaced by Local Enterprise Partnerships(LEP). This article looks at the performance and the present reform process of the English Regional Development Agencies(RDA). It argues that RDAs have been a sort of laboratory to expose the possibility of realizing the new regionalist approach away from the government-centered approach. Nevertheless, the case of RDAs in England shows that the RDA model is less likely to be effective without substantial devolution. It shows that the extent to which RDAs contribute to the regional economy tends to be much higher in soft infra-centered projects, such as business supports and skills development, than physical infrastructure projects. It argues that the LEP model, which is to replace RDAs, is controversial, especially in terms of spatial boundary and financial structure.