• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.209-220
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• 2013

Handover is the technology to minimize data lose of mobile devices and make continuous communication possible even if the device could be moved from one digital cell site to another one. That is, it is a function that enables the mobile user to avoid the disconnection of phone conversations when moving from a specific mobile communication area to another. Today, there are a lot of ongoing researches for fast and efficient hand-over, in order to address phone call's delay and disconnection which are believed to be the mobile network's biggest problems, and these should essentially be resolved in all mobile networks. Thanks to recent technology development in mobile network, the LTE network has been commercialized today and it has finally opened a new era that makes it possible for mobile phones to process data at high speed. In LTE network environment, however, a new authentication key must be generated for the hand-over. In this case, there can be a problem that the authentication process conducted by the hand-over incurs its authentication cost and delay time. This essay suggests an efficient key caching hand-over method which simplifies the authentication process: when UE makes hand-over from oMME to nMME, the oMME keeps the authentication key for a period of time, and if it returns to the previous MME within the key's lifetime, the saved key can be re-used.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.2
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• pp.57-68
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• 2004

Recently in order to more effectively and scientifically process forest official tasks, which have been focused on documents and inventories, they should be applied with the up-to-date spatial information technologies. Especially, the forest resource information management based on GIS(geographic information system) and aerial orthophoto is expected not only to play an important role as DSS(decision support system) for domestic forest conservation policy and forestry development industry but also to service forest resource information toward people such as the owners of a mountain rapidly. In this study, the important forest information such as digital topography map, digital forest type map, digital forest cadastral map, digital aerial photographs and attribute data were first reprocessed and constructed in DBMS(data base management system). In addition, forest officials could analyze and retrieve forest information by using detail sub-application systems such as forest cadastral retrieval, forest land development information management, reserved forest information management and forest resource information retrieval. For this, the user interface is developed by using Visual Basic 6.0 and MapObjects 2.1 of ESRI based on CBD(component based development) technology. The result of developing this system will not only perform constructing economical forest and better environment but also be the foundation of domestic spatial technology for forest resource management.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.11-18
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• 2018

The Dutch treat culture, which pays for the cost of having meetings with a large number of people, is located in the daily life of many modern people. In particular, the execution of Kim Young-ran is a more active Dutch treat. However, when going dutch, there is a case where the amount of money to be paid per person is not divided equitably and there is an ambiguous situation about who should pay more. Also if one person have to pay all of the payments because of the different payment method such as a cash or card, there is inconvenience to keep a record of the financial relationship each time. In this paper, we introduce an application that allows several people to easily calculate the amount of money to pay per person when eating together or calculating something. From our service, you can easily access with web-based service, manage the user's debts more conveniently through forming the group. In addition, we focused on convenient calculation of cost by setting remaining unit and reserve function which is a function to overcome the disadvantages of existing application. Also, we maintain fairness through games in situations where the users need to make a choice.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.791-800
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• 2013

Needs for developing a better way of cost estimating process for public construction projects have been widely recognized. Those needs are mainly from the early phases of the project through the construction life cycle due to the its importance to the control process. In contrast to the traditional estimating method based on unit-price references, this research utilized this following process. The first step is analyzing the real cost data from actual cost activities (2000~2010) about the statement of P.S.C(Prestressed Concrete) Box Girder Bridge. The collected data was broken into four categories based on technical construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). The second, actual design documents including the actual cost estimating documents, drawings and specifications were carefully reviewed to cluster the cost itemized statement from four categories. It was also attempted to seek the proper breakdown of standard works that are responsible for more than 95 percentage in each categories in terms of its cost. The third, this research comes up the index for standard unit materials and unit price of standard work and develops the approximate estimating model applying for the specification(length and breadth of bridges) per square area that the user takes as well as suggests the practical application plan within the original time alloted.

• Journal of Service Research and Studies
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• v.5 no.2
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• pp.111-118
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• 2015

Although the development of mobile devices are made us a free life, they were displayed the subject of this financial crime and attacking forces in the other side. Among finance-related crime is become a serious crime that are targeting smartphones by SMS phishing, phishing, pharming, voice phishing etc. In particular, SMS phishing is increased according to phenomenon using the nature of a text message in the mobile. SMS phishing is become new crime due to the burden to the smartphone user. Their crime is also the advanced way from the existing fraud, such as making the malicious apps. Especially it generates loopholes in the law by a method such as using a foreign server. For safe from SMS phishing attacks, proactive pre-diagnosis is even more important rather than post responses. It is necessary to deploy blocking programs for detecting SMS phishing attacks in advance to do this. In this paper we are investigating the process of block types and block apps that are currently deployed and presenting the evaluation of the application of the detection block setting app.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.425-438
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• 1999

In recent days network computing technologies have bee developed rapidly and the extended use of Internet applications for enterprises such as internet/extarnet in and between enterprises has been increased enormously. Therefore the business in the future will be executed by virtual enterprise. Virtual enterprises which is based on information sharing between enterprises are composed of work processes related to information exchange between virtual enterprises, the team members who are representatives of the organizations that are participated in the actual business of virtual enterprises, and members who are representatives of the organizations that are participated in the actual business of virtual enterprises, and environment that are provided by supporting CALS(continuous Acquisition and Life cycle Support or commerce At light Speed). Supporting system of IDE(Integrated Data Environment)for CALS implementation that is provided as an environment of virtual enterprises has to ensure the autonomies of local data and to provide the accessibility of heterogeneous database of enterprises on network transparently for giving user a single global view of data. This paper introduce the design and implementation of the database broker system that can be accessed data transparently by the suers of participated enterprises in the integrated data environment supporting virtual enterprises. The system uses java/CORBA technology in Web environment and Object Query language (OQL) to process the queries of relational database system, object-oriented database system, and file information.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11S
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• pp.3633-3650
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• 2000

Internet is no longer a network for special communities but became a global means of communication infrastructure for everyday life. People are exchanging their personal messages using e-mails, students are getting their educational aids through the web, people are buying a variety of goods from cyber shopping malls, and companies are conducting their businesses over the Internet. Recently, such an explosive growth of the traffic in the Internet raised a big concern on how to accommodate ever-changing user's needs in terms of an amount of the traffic, characteristics of the traffic, and various service quality requirements, Over provisioning can be a simple solution but it is too expensive and inefficient. Thus many new technologies to solve this very difficult puzzle have bcen introduced recently, Any single solution, however, can be insufficient and a carefully designed architecture, which integrates a group of solutions, is required. In this paper, we propose a policy-based Internet QoS provisioning, traffic engineering and perfonnance management system as our solution to this problem. Our integrated management QoS solution can provide highly responsive flow-through service provisioning, more realistic service and resource policy control based on the real network performance information, and centralized control of traffic engineering for heterogeneous networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.536-543
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• 2017

This study developed a new methodology to evaluate the carbon storage using a Mobile Mapping System according to the life cycle of street trees. The system for calculating the carbon storage of a roadside tree using the MMS developed in this study consisted of a database, memory, processor, user interface, and communication module. The carbon storage was calculated for 261 trees in the Cheonan-Asan New Town (distance: 2.1 km, area: $283,698m^2$). The average biomass and carbon storage of Metasequoia glyptostroboides were highest at 34.5 kg and 17.3 kg C and Chionanthus retusa were lowest at 19.5 kg and 9.8 kg C, respectively. The total biomass and total carbon storage of Ginkgo biloba were highest at 5028.8 kg and 17.3 kg C and Chionanthus retusa were lowest at 780.7 kg and 390.3 kg C, respectively. Based on the roadside tree database, the amount of carbon storage in a given area was converted to Google format and visualized in 3D by GIS analysis.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.13-29
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• 2018

This study presented evaluation procedure for selecting appropriate GCMs and downscaling method by focusing on the climate extreme indices suitable for climate change adaptation. The procedure includes six stages of processes as follows: 1) exclusion of unsuitable GCM through raw GCM analysis before bias correction; 2) calculation of the climate extreme indices and selection of downscaling method by evaluating reproducibility for the past and distortion rate for the future period; 3) selection of downscaling method based on evaluation of reproducibility of spatial correlation among weather stations; and 4) MME calculation using weight factors and evaluation of uncertainty range depending on number of GCMs. The presented procedure was applied to 60 weather stations where there are observed data for the past 30 year period on Korea Peninsula. First, 22 GCMs were selected through the evaluation of the spatio-temporal reproducibility of 29 GCMs. Between Simple Quantile Mapping (SQM) and Spatial Disaggregation Quantile Delta Mapping (SDQDM) methods, SQM was selected based on the reproducibility of 27 climate extreme indices for the past and reproducibility evaluation of spatial correlation in precipitation and temperature. Total precipitation (prcptot) and annual 1-day maximum precipitation (rx1day), which is respectively related to water supply and floods, were selected and MME-based future projections were estimated for near-future (2010-2039), the mid-future (2040-2069), and the far-future (2070-2099) based on the weight factors by GCM. The prcptot and rx1day increased as time goes farther from the near-future to the far-future and RCP 8.5 showed a higher rate of increase in both indices compared to RCP 4.5 scenario. It was also found that use of 20 GCM out of 22 explains 80% of the overall variation in all combinations of RCP scenarios and future periods. The result of this study is an example of an application in Korea Peninsula and APCC Integrated Modeling Solution (AIMS) can be utilized in various areas and fields if users want to apply the proposed procedure directly to a target area.

• Korea Real Estate Review
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• v.27 no.4
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• pp.35-50
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• 2017

The Korean society is currently at the level of discussing the living environment and the housing welfare as factors for improving the quality of life, in addition to most individuals or households residing in a living environment and housing welfare, according to industrialization and urbanization. However, even though the overall housing welfare of Korea has improved, the number of households with disabilities belonging to the social special class is not as high as that of the non-disabled households. It is a reality that cannot be done. Therefore, this study aims to identify the present condition and demand characteristics of the housing for disabled people whose social importance is currently emphasized among the social special people who can be called the social special class, as well as present the housing welfare policy to them and explain the purpose of the improvement plan. In this study, 4,277 out of 8,004 households with disabilities surveyed by the Ministry of Land, Infrastructure, and Transport in 2015 were analyzed. The result of the analysis showed that the economic characteristics (permanent income indicating the income and the user cost indicating the expenditure) of the housing demand of a household with a handicapped individual are important. This analysis will provide more effective policy formulation and policy direction for the families of the disabled.