• Journal of Soil and Groundwater Environment
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• v.20 no.5
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• pp.34-40
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• 2015

It is reported that the intensity of rainfall will likely increase, on average, over the world on 2000. For water resources security, many studies for flow paths from rainfall or snowmelt to subsurface have been conducted. In Korea, few isotopic studies for characterizations of flow path have been undertaken. For a better understanding of how water derived from atmosphere moves to subsurface and from subsurface to stream, an analysis of precipitation and stream water using oxygen-18 and deuterium isotopes in a small watershed, Dorim-cheon, Seoul, was conducted with high resolution data. Variations of oxygen-18 in precipitation greater than 10‰ (δ¹⁸O_max = −1.21‰, δ¹⁸O_min = −11.23) were observed. Isotopic compositions of old water (groundwater) assumed as the stream water collected in advance were −8.98‰ and −61.85‰ for oxygen and hydrogen, respectively. Using a two-component mixing model, hydrograph separation of the stream water in Dorim-cheon was conducted based on weighted mean value of δ¹⁸O. As a result, except of instant dominance of rainfall, contribution of old water was dominant during the study period. On average, 71.3% of the old water and 28.7% of rainfall contributed to the stream water. The results show that even in the small watershed, which is covered with thin soil layer in granite mountain region, the stream water is considerably influenced by old water inflow rather than rainfall.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5865-5872
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• 2011

Multi-hop communication in clustering system is the technique that forms the cluster to aggregate the sensing data and transmit them to base station through midway cluster head. Cluster head around base station send more packet than that of far from base station. Because of this hot spot problem occurs and cluster head around base station increases energy consumption. In this paper, I propose a cluster group head selection using trajectory clustering technique(CHST). CHST select cluster head and group head using trajectory clustering technique and fitness function and it increases the energy efficiency. Hot spot problem can be solved by selection of cluster group with multi layer and balanced energy consumption using it's fitness function. I also show that proposed CHST is better than previous clustering method at the point of network energy efficiency.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.61-72
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• 2020

The fear of crime, discussed in the early 1960s in the United States, is a psychological response, such as anxiety or concern about crime, the potential victim of a crime. These anxiety factors lead to the burden of the individual in securing the psychological stability and indirect costs of the crime against the society. Fear of crime is not a good thing, and it is a part that needs to be adjusted so that it cannot be exaggerated and distorted by the policy together with the crime coping and resolution. This is because fear of crime has as much harm as damage caused by criminal act. Eric Pawson has argued that the popular impression of violent crime is not formed because of media reports, but by official statistics. Therefore, the police should watch and analyze news related to fear of crime to reduce the social cost of fear of crime and prepare a preemptive response policy before the people have 'fear of crime'. In this paper, we propose a deep - based news classification system that helps police cope with crimes related to crimes reported in the media efficiently and quickly and precisely. The goal is to establish a system that can quickly identify changes in security issues that are rapidly increasing by categorizing news related to crime among news articles. To construct the system, crime data was learned so that news could be classified according to the type of crime. Deep learning was applied by using Google tensor flow. In the future, it is necessary to continue research on the importance of keyword according to early detection of issues that are rapidly increasing by crime type and the power of the press, and it is also necessary to constantly supplement crime related corpus.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.61-71
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• 2017

ARP Spoofing is a basic and core hacking technology for almost all sniffing. It makes change the flow of packets by faking the 2nd layer MAC address. In this paper we suggested an efficient hacking technology for sniffing remote servers in the switched network environment. The suggested 'Faked ARP Reply Unicast Spoofing' makes the bidirectional packets sniffing possible between the client and server, and it makes simplify the procedures for ARP sniffing and hacking program. In this paper we researched the network hacking and implementation technologies based on the suggested ARP spoofing. And we researched various types of servers hacking such as Root ID and PW of Telnet/FTP server, Root ID and PW of MySQL DB server, ID and PW of Web Portal Server, and account information and transaction history of Web Banking Server. And also we researched the implementation techniques of core hacking programs for the ARP Spoofing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.26-35
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• 2007

The vehicle of urban transit is a complex system that consists of various electric, electronic, and mechanical equipments, and the maintenance cost of this complex and large-scale system generally occupies sixty percent of the LCC (Life Cycle Cost). For reasonable establishing of maintenance strategies, safety security and cost limitation must be considered at the same time. The concept of system reliability has been introduced and optimized as the key of reasonable maintenance strategies. For optimization, three preceding studies were accomplished; standardizing a maintenance classification, constructing RBD (Reliability Block Diagram) of VVVF (Variable Voltage Variable Frequency) urban transit, and developing a web based reliability evaluation system. Historical maintenance data in terms of reliability index can be derived from the web based reliability evaluation system. In this paper, we propose applying inverse problem analysis method and hybrid neuro-genetic algorithm to system reliability optimization for using historical maintenance data in database of web based system. Feed-forward multi-layer neural networks trained by back propagation are used to find out the relationship between several component reliability (input) and system reliability (output) of structural system. The inverse problem can be formulated by using neural network. One of the neural network training algorithms, the back propagation algorithm, can attain stable and quick convergence during training process. Genetic algorithm is used to find the minimum square error.

• The Journal of the Convergence on Culture Technology
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• v.3 no.2
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• pp.49-54
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• 2017

In Korea, partial self-driving feature is added on Genesis G80, Tivoli 2017, and others, and full implementation is under evaluation. Tesla already completed test for full self-driving car, Tesla Model 'X'. Further adoption of self-driving car in market will bring benefits to the elderly and disabled, meanwhile traffic accident will be decreased. However, related regulations for traffic accident with autonomous car including ethical responsibility is not fully established yet. In addition, security and privacy issue of self-driving cars should be improved as well. In this paper, domestic researches and analysis status on autonomous car will be summarized, and proper activation model will be proposed for the previously described issues.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.77-82
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• 2013

PKMv2 security protocol was adopted by the WiMax2 mobile internet communication standard. A base station and a mobile station protect communication data using key based encryption according to the PKMv2 protocol. Consequently, each development of a base station and/or mobile station includes implement of the PKMv2 protocol, and the station must qualifies various interoperable tests. Furthermore, communication bandwidth of the station can be limited by the encryption module when the station implemented based on a low-performance processor. Thus, a correspondence measurement of the encryption module must be carried on the target processor. In this paper, we implement a testbed which affords throughput measurement as well as the interoperable tests by PKMv2.

• Journal of the Korean Society of Costume
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• v.54 no.4
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• pp.63-74
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• 2004

This study shows that clothes to be just the same as the real thing can be Produced through the third dimension computer graphics, and then presents that not only the area of fashion design can be expanded in the virtual reality field by doing the simulation of the fashion show, but also the information can be made the real time public ownership and the communication can be fulfilled smoothly. In this study, analyzing the third dimension computer graphic programs to be used much at present, Alias Wavefront Company's Maya software which was the most effective in the clothes simulation and the clothes CAD SGS OptiTex 8.7 which went well substitutive for it were used of them. The conclusions of this study that got through the work manufacture are as follows： The first, if the file manufacturing in the clothes CAD by using the computer was stored, the pattern used 3D simulation was available because it could be summoned in 3D software. The second, if the data of DXF form in Maya program was summoned, they could not be applied by Maya Cloth supported in Nurbs only because they were recognized as the DXF＿layer. So the curve along the outer lines of the pattern was drawn and Maya Cloth was applied to be possible to get the natural silhouette of clothes. The third, when the clothes were manufactured by 3D, if the draping character was applied according to the textile special quality, not only the control of textile's thickness, weight, quality feeling, and silhouette was available, but also the clothes were available to graft the special textile materials. The fourth, the natural motion of model was produced by capturing the actual model's walking action In order to produce the fashion show motion and also the dynamic fashion show was available by the angle of camera, the establishment of lighting, and etc. in the final rendering. The clothes manufactured by 3D are available to change the design by changing the materials, or by adding the details, or by utilizing the special materials on clothes. Therefore, the trial and error following at the clothes manufacture can be reduced. But the elevation of the rendering speed, the price down, the strengthening of personal security, and etc. are required.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.733-738
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• 2013

In this paper, we consider a physical layer security of an amplify-and-forward (AF) transmission in a presence of an eavesdropper in a wiretap channel. The proposed wiretap channel consists of a source, a destination, a relay, and an eavesdropper. Specifically, we consider that the relay has multiple antennas to exploit a diversity gain and a receive/transmit antenna selection schemes are applied to maximize a signal-to-noise ratio. In a practical point of view, we focus on the practical scenario where the relay does not have any channel state information of the eavesdropper while performing an AF protocol at the relay. For a secrecy performance analysis, we analyze a secrecy outage probability of the proposed system in one-integral form and verify our analysis with the computer-based simulation.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.267-282
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• 2012

In this study, RPS system, one of the renewable energy support systems, is utilized for economic analysis of solar generation equipment and the fuel cost savings plan for controlled horticulture farms with high fuel-cost dependency and facility applicability were evaluated. On the exterior of the upper layer of glass greenhouse (9917$m^2$) of controlled horticulture farms using bunker C oil, half of the area (4958$m^2$) was utilized for theoretical installation and operation of 450kW-level solar power generator, and as the result, first, the effect of investment cost only of solar generation system was found to be quite excellent, but it was analyzed that there were limits to saving the fuel costs of the controlled horticulture farms. Second, when geothermal system was first introduced in the farm and solar system was additionally introduced, it was analyzed that the effect of introducing solar system was excellent. In order to apply such effects to the sites of farming, partial supplementation of RPS system which is being uniformly applied regardless of the purpose of renewable energy is necessary. When the subject of use directly install facilities where it is directly connected to national added-value such as food security created by the farming industry, it is necessary to introduce appropriate system that corresponds to such. Moreover, it was studied that the quick development of demonstrative complex that can practically evaluate the applicability of renewable energy in farming industry and interest and preparation of related institutions in financial support structure for its site application would lead to success.