• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.107-118
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• 2016

The advent of 5G mobile communications, which is expected in 2020, will provide many services such as Internet of Things (IoT) and vehicle-to-infra/vehicle/nomadic (V2X) communication. There are many requirements to realizing these services: reduced latency, high data rate and reliability, and real-time service. In particular, a high level of reliability and delay sensitivity with an increased data rate are very important for M2M, IoT, and Factory 4.0. Around the world, 5G standardization organizations have considered these services and grouped them to finally derive the technical requirements and service scenarios. The first scenario is broadcast services that use a high data rate for multiple cases of sporting events or emergencies. The second scenario is as support for e-Health, car reliability, etc.; the third scenario is related to VR games with delay sensitivity and real-time techniques. Recently, these groups have been forming agreements on the requirements for such scenarios and the target level. Various techniques are being studied to satisfy such requirements and are being discussed in the context of software-defined networking (SDN) as the next-generation network architecture. SDN is being used to standardize ONF and basically refers to a structure that separates signals for the control plane from the packets for the data plane. One of the best examples for low latency and high reliability is an intelligent traffic system (ITS) using V2X. Because a car passes a small cell of the 5G network very rapidly, the messages to be delivered in the event of an emergency have to be transported in a very short time. This is a typical example requiring high delay sensitivity. 5G has to support a high reliability and delay sensitivity requirements for V2X in the field of traffic control. For these reasons, V2X is a major application of critical delay. V2X (vehicle-to-infra/vehicle/nomadic) represents all types of communication methods applicable to road and vehicles. It refers to a connected or networked vehicle. V2X can be divided into three kinds of communications. First is the communication between a vehicle and infrastructure (vehicle-to-infrastructure; V2I). Second is the communication between a vehicle and another vehicle (vehicle-to-vehicle; V2V). Third is the communication between a vehicle and mobile equipment (vehicle-to-nomadic devices; V2N). This will be added in the future in various fields. Because the SDN structure is under consideration as the next-generation network architecture, the SDN architecture is significant. However, the centralized architecture of SDN can be considered as an unfavorable structure for delay-sensitive services because a centralized architecture is needed to communicate with many nodes and provide processing power. Therefore, in the case of emergency V2X communications, delay-related control functions require a tree supporting structure. For such a scenario, the architecture of the network processing the vehicle information is a major variable affecting delay. Because it is difficult to meet the desired level of delay sensitivity with a typical fully centralized SDN structure, research on the optimal size of an SDN for processing information is needed. This study examined the SDN architecture considering the V2X emergency delay requirements of a 5G network in the worst-case scenario and performed a system-level simulation on the speed of the car, radius, and cell tier to derive a range of cells for information transfer in SDN network. In the simulation, because 5G provides a sufficiently high data rate, the information for neighboring vehicle support to the car was assumed to be without errors. Furthermore, the 5G small cell was assumed to have a cell radius of 50-100 m, and the maximum speed of the vehicle was considered to be 30-200 km/h in order to examine the network architecture to minimize the delay.

• Journal of the Economic Geographical Society of Korea
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• v.10 no.3
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• pp.263-280
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• 2007

Recently, many cities and regions of the world attempt to promote cultural and arts activities in order to vitalize regional economies and strengthen local identity. Some old industrial cities of the advanced economies in particular often introduce cultural and arts activities in renovating obsolete urban infra-structure, revitalize urban economy, clean polluted urban environment, and advertise various development projects. A small Canadian city, Stratford, Ontario, has shown a spectacular success in such efforts. By hosting Shakespearian festivals every year since 1953, the theatre company, the Shakespearian Festival of Canada in Stratford, sells about 600 thousands tickets, attracting 2 million visitors to the area. With the festivals, the city became able to host a large cultural cluster composed of the theatre company, chef school, summer music festival, and Chicago Associates. The city has also able to maintain one of the most competent theatre companies in the North America.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.35-41
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• 2014

Many infra suructure such as road, railway, building and utility foundations have been damaged by the repeated freezing and thawing of the soil during winter and spring every year in seasonal frost region. The frost penetration depth is most important factor in the design of structure such as road, railway and building in seasonal frost region. This paper presents the results of calculation of frost penetration depth and frost heaving in concrete track for railway construction. Model concrete track were installed near the railway track in Gangwon, Gyeonggi, Choongbuk province and frost penetration depth were measured using methylene blue frost penetration depth gauge. Model concrete track in Cheolwon, frost heaving of concrete track were also evaluated. The measure of maximum frost penetration depth and frost heaving can be applied to design railway track for cold region in Korea.

• Spatial Information Research
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• v.13 no.3 s.34
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• pp.283-296
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• 2005

Nowadays, Global Navigation Satellite System(GNSS) which is the new concept of positioning system has been developed because of satisfaction human's intelligent desire and rapid science development. GNSS which is represented by GPS provides 3-Dimension positioning information not expensively in whenever, wherever. The industry of positioning information has extending civil market widely as well as military market. So GNSS is running the role of society infra structure including car and airborne navigation, civil engineering, GIS resource, telematics and LBS, and so on. As USA removes the SA(Selective Availability), GPS has monopolizing the market and other countries have been depended on GPS, absolutely. In this paper, the author developed the software for analysis of influence using next generation, Galileo system. The local analysis was performed according to positioning mode. And GPS/Galileo combined system can implement positioning in the worst mask environment like urban cannon.

• Journal of the Korean Geotechnical Society
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• v.31 no.1
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• pp.53-64
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• 2015

This study presents the experimental results of pervious blocks subjected to a series of unique inflow conditions in urban area. The measured properties include the strength, permeability, drainage capacity and runoff, and evaporation for blocks made of two different size of aggregates. Results revealed that the strength satisfies the Korean Standard regardless of aggregate size whereas the immediate runoff occurred for the block with small size aggregate. On the other hand, the block with large aggregates allowed the drainage upon the initial inflow condition, which became hampered to induce the runoff by subsequent inflow. It was attributed to the fact that the capillary water often served as the hydraulic barrier in partially saturated condition. The salient observation indicated that the runoff highly depended on the evaporation and pre-wetting condition as well as the porosity and pore connectivity. The bilinear evaporate rate that makes the degree of saturation vary also had great influence on deterining the time-dependent runoff.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.1-8
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• 2016

Cloud computing technology offers function that share each other computer resource, software and infra structure based on network. Virtualization is a very useful technology for operation efficiency of enterprise's server and reducing cost, but it can be target of new security threat when it is used without considering security. This paper proposes access control mechanism based on MAC(Mandatory Access Control) for cloud convergence that solve various problem that can occur in cloud environment. This mechanism is composed of set of state rules, security characteristics and algorithm. Also, we prove that the machine system with access control mechanism and an initial secure state is a secure system. This policy module of mechanism is expected to not only provide the maintenance but also provide secure resource sharing between virtual machines.

• Journal of Internet Computing and Services
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• v.11 no.3
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• pp.139-148
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• 2010

In the sensor network security area, previous works were mainly concentrated on achieving authentication, confidentiality, integrity and availability. But the ID exposure issue is recently an increasing concern in research community. To protect the ID exposure from various attacks, the most common approach is to make use of a dynamic pseudonym rather than the real ID. However, if a node's secret key (or hash key) and the current pseudonym (such as a random number) are exposed, the attacker can easily generate the previous/next pseudonyms. In this paper, we propose a security infra-structure scheme for enabling strong anonymity of sensor nodes. Our scheme ensures that the probability being able to generate a pseudonym is very low even if a sensor node has been compromised with an attacker. Security analyses have proven that our scheme is suitable for sensor network environments in terms of preserving of forward anonymity as well as backward anonymity.

• Journal of Society of Preventive Korean Medicine
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• v.11 no.2
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• pp.101-112
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• 2007

Oriental public health programs have been introduced for the purpose of providing comprehensive oriental health care services to community people including vulnerable classes, increasing the accessibility of oriental medicine and the public benefit, and further more elevating the health promotion and the quality of life of community people. Promoting these programs since 2002 in earnest, it is evaluated that it has made a lot of performances. In the other side, it showed many problems and policy issues also. This study is accomplished to analyze the problems made since the system was introduced and until now, 2007, and with this analysis, to examine policy issues and the reasonable recommendations for its development Major problems are as follows. First, fundamental notions and identity of oriental public health programs are not positioned accurately. Second, the infra-structure construction for effective propulsion of business is insufficient. Third, it is short of the capacity for program implementation of oriental public health doctors, related manpower, and health centers. Fourth, oriental health promotion programs that can fulfill the various health needs of community people are deficient. Fifth, active aid of the government and the oriental medical world as well as legal and systematical support for oriental public health programs is insufficient. As a result, to solve the problems and induce the successful settlement of the program, the policy recommendations such as (i) the fundamental notions of the program and establishment of approach strategies, (ii) reinforcement of the foundation of the program implementation, (iii) capacity enhancement of the manpower of the program implementation, and (iv) effective building of supportive system of the program are presented.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1624-1624
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• 2001

Near-infrared spectroscopy (NIRS) was used to investigate the possibility for application in identification of apple cultivars. Three apple cultivars ‘Kamhong, Hwahong, and Fuji’ produced in Korea were scanned over the range of 1100-2500nm using NIRS (Infra Alzer 500). Two types of samples were used for scanning; one was apple with skin and the other was apple without skin. For cultivar identification, the NIR absorbance spectrums were analyzed by qualitative calibration in “Sesame” analysis program, and the various influence properties such as sugar contents, acidity, color, firmness, and micro-structure were compared in scanned samples. The ‘Kamhong’ cultivar could be identified from ‘Hwahong’ and ‘Fuji’ cultivars using the cluster model analysis. The test samples in calibration between ‘Kamhong’ and ‘Fuji’ cultivars could be completely identified. The test samples in calibration between ‘Kamhong’ and ‘Hwahong’ cultivars could be identified most of all. But, ‘Hwahong’ and ‘Fuji’ cultivars could not be quite classified each other. The apple skin influenced the identification process of apple cultivars. The samples without skin were more difficult to classify in calibration than the samples with skin. The physicochemical properties of apple cultivars showed like the result of identification in calibration using NIRS. Some physicochemical properties of ‘Kamhong’ cultivar were different from those of the other cultivars. Those of ‘Hwahong’ and ‘Fuji’ cultivars showed. similar to each other. The sucrose contents of ‘Kamhong’ cultivar were higher and the fructose contents and firmness of skin and flesh were lower than those of the others. The hypodermis layer of skin in ‘Kamhong’ cultivar was thinner than those of the others. In this studies, the identification of all apple cultivars by NIRS was not quite accurate because of the physicochemical properties which were different in the same cultivar, and inconsistent patterns by culivars in some properties. To solve these problems in NIRS application for apple cultivar identification, further study should be focused on the use of peculiar properties among the apple cultivars.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3583-3589
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• 2010

The semi-implicit scheme proposed by Backhaus is introduced to solve two-dimensional shallow water equation. This mothod is applied for the numerical model solving surface elevation and velocity field of Geum River estuary. For the verification of the method, numerical solutions by this model are compared with ones by Heap's well known explicit model. Solutions of two models resemble each other. The time-step chosen for the semi-implicit scheme turned out to be 3 to 6 times longer than explicit model depending on the stringent CFL criterion. The computation time could be reduced at least 50%. It was proved that this scheme is easy to handle dry banks which can be seen in Geum River estuary and numerical stability is obtained for long time computation.