• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.469-476
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• 2020

Research reactors in-core experimental facilities are designed to provide the highest steady state flux for user's irradiation requirements. However, fuel conversion from highly enriched uranium (HEU) to low enriched uranium (LEU) driven by the ongoing effort to diminish proliferation risk, will impact reactor physics parameters. Preserving the reactor capability to produce the needed flux to perform its intended research functions, determines the conversion feasibility. This study investigates the neutron flux in the central experimental facility of two material test reactors (MTR), the IAEA generic10 MW benchmark reactor and the 22 MW s Egyptian Test and Research Reactor (ETRR-2). A 3D full core model with three uranium enrichment of 93%, 45%, and 20% was constructed utilizing the OpenMC particle transport Monte Carlo code. Neutronics calculations were performed for fresh fuel, the beginning of life cycle (BOL) and end of life cycle (EOL) for each of the three enrichments for both the IAEA 10 MW generic reactor and core 1/98 of the ETRR-2 reactor. Criticality calculations of the effective multiplication factor (K_eff) were executed for each of the twelve cases; results show a reasonable agreement with published benchmark values for both reactors. The thermal, epithermal and fast neutron fluxes were tallied across the core, utilizing the mesh tally capability of the code and are presented here. The axial flux in the central experimental facility was tallied at 1 cm intervals, for each of the cases; results for IAEA 10 MW show a maximum reduction of 14.32% in the thermal flux of LEU to that of the HEU, at EOL. The reduction of the thermal flux for fresh fuel was between 5.81% and 9.62%, with an average drop of 8.1%. At the BOL the thermal flux showed a larger reduction range of 6.92%-13.58% with an average drop of 10.73%. Furthermore, the fission reaction rate was calculated, results showed an increase in the peak fission rate of the LEU case compared to the HEU case. Results for the ETRR-2 reactor show an average increase of 62.31% in the thermal flux of LEU to that of the HEU due to the effect of spectrum hardening. The fission rate density increased with enrichment, resulting in 34% maximum increase in the HEU case compared to the LEU case at the assemblies surrounding the flux trap.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.83-95
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• 2018

The aim of this paper is to develop a performance evaluation model for PPP (Public-Private Partnership) projects that appropriately reflects the important traits that are unique to PPP projects. To this end, 1) it defines a set of distinct perspectives involved in the PPP projects and their associated success factors that might differ amongst the perspectives; 2) it identifies the key performance indicators and suggests the performance evaluation criteria for each indicator; and 3) it builds a performance evaluation model by matching the success factors from each perspective with performance measure criteria as well as applies the model to the two selected BTO road projects in Korea. The process of model construction and its application confirms significant differences between the main stakeholder perspectives typically involved in PPP projects, which highlights the need for an evaluation model tailored for PPP projects by taking into account the distinct perspectives. The results from the PPP evaluation model developed in the study is compared against the results from the existing ex-post evaluation model for construction projects in general. The former shows a closer match with the results from the user satisfaction survey conducted. This new evaluation framework and the performance indicators entailed in it permits a balanced evaluation of PPP projects as it takes into account different perspectives involved in PPP projects as well as an understanding of the factors affecting the success of PPP projects. While the construction of the model is based on transport projects, it is applicable to different types of PPP projects through variation with the weight allocation amongst different success factors and/or additions or other adjustments to the performance evaluation criteria as required.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.239-244
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• 2008

We lead a life in our community, beginning a new relationship with a stranger or maintaining or stopping existing relationships. Relationships with others are sustained through social activities based on communication. Generally speaking, by exchanging feelings and information through communication, relationships are formed and continued, and strengthened through active communication As a result of the development of technologies and information technology over the recent 10 years, a mobile phone has stood as a communication channel, and now it has become such a universal, and highly intimate and important means of communication that almost all the Koreans use more often than wired phones. Today, people have their communication channel available for others, by using a mobile phone at any time and anywhere. Like this, mobile phones have been playing a key role in helping people maintain, repair and strengthen their personal relationship, but from the perspective of personal relationship management, they still remain as an aid to help communication, failing to provide a positive help for actual relationship management. This study was designed to provide services supporting user's personal relationship management, focusing on the use of mobile phones as a major tool of communication, aiming to enable users to understand current state of their relationship and make relationship management efforts, or communication behaviors, by informing who needs communication, on the basis of data on mobile phone calls. To this end, the study established a method to extract intimacy between users and callers and develop a prototype of services supporting personal relationship management, using relationship characteristics in terms of mobile communication.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.235-251
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• 2005

German working hour law of 1994(Arbeitszeitgesetz) provides maximum working hour as 8 hours a day and 48 hours per week. The law provides that minimum 11 hours rest-time is required between the end of a day's work and the beginning of the next day's work. Namely, the hour that the workers are put under commanding of the user is restricted within 13 hours per day. In the meantime, article 5, 7, 14, and 15 of the law have some letting the exceptional provisions regarding the working hour and rest-time of flight crew, and 2nd administrative order for the aviation transportation business owner, which is established based on such exceptional provisions(2.DV LuftBO), provides the working hour and rest-time of flight crew quite in detail. The administrative order is detailed quite regarding block time, flight working hour, and rest-time. So, it does not need to interpret additionally. Airlines in Korea should observe the both Labor Standard Act applying to general workers and Aviation Act focused on flight crew, so it is difficult that airlines manages working hour and rest-time of the flight crew efficiently. Therefore, it is desirable that our country refers to and considers adopting this legislation method of Germany which regulates working hour and rest-time of flight crew in detail in the 2.DV LuftBO.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.317-325
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• 2015

This paper attempts to present a review about simulation of different greenhouse parameters and energy supplying techniques by using building energy simulation, to find out the optimal solution for keeping greenhouse microclimate favorable for the crop production. The objectives of conducting this study were, to describe the various energy systems and techniques used for the greenhouse energy management and efficiency analysis of these technologies by using building energy simulation. We describe different models to understand the behavior of the energy saving technologies with respect to the resources available and different outside climatic conditions. We identified main features of the building energy simulation software, that enable users, to simulate hybrid agricultural building projects by using user defined parameters. At the end of the paper we draw some important concluding remarks on the basis of reviewing all the investigators contributions for the developments of simulation model of agricultural greenhouse energy management, using a building energy simulation software specifically TRNSYS. In conclusion, this paper provides information that TRNSYS have great potential for agricultural buildings energy simulation along with the renewable energy resources and energy saving techniques. This review paper provides aid to greenhouse researcher and energy planner for the future studies of greenhouses energy planning.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.509-520
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• 2009

The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.80-97
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• 2010

With the hubbing strategy, construction of "Incheon Airport Railroad(AREX)" was proceeded to expand the accessibility at the level of airports in rivalry like Kansai and Chek Lap Kok. At the present 1st phase which routes from Incheon Airport to Kimpo Airport is opened March 2007. 2nd phase which is planned from Kimpo Airport to Seoul station will be opened at the end of October 2010. But the accessibilty to AREX is delinquent because it is connected only in Seoul station and the maximum operation speed is 110km/h which downgrade the time competitiveness with airport limousine. In addition, transfering of user is necessary to access to AREX from Kyungbu KTX. With these reasons, travel demand in 1st phase section is low(7%). According to reestimation of travel demand, demand analysis result compared with convention condition is insufficient, so required annual average government grant-in-aid amounts to 200 billions won, and it is right time to develop the method for revitalization of Incheon airport railroad. In this paper, facilities plan and operating plan to make new travel demand by speed-up which is able through substitution train now running with high speed train(EMU, 180km/h) and direct connection of KTX, will be suggested. This will contribute to offering high speed railroad service to customers and the reduction of government grant-in-aid by way of demand expansion.

• Korean Journal of Remote Sensing
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• v.36 no.5_2
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• pp.881-891
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• 2020

Recently, the Ministry of Land, Infrastructure and Transport and the Ministry of Science and ICT are developing the Land Observation Satellite (CAS-500) to meet increased demand for high-resolution satellite images. Expected image products of CAS-500 includes precision orthoimage, Digital Surface Model (DSM), change detection map, etc. The quality of these products is determined based on the geometric accuracy of satellite images. Therefore, it is important to make precision geometric corrections of CAS-500 images to produce high-quality products. Geometric correction requires the Ground Control Point (GCP), which is usually extracted manually using orthoimages and digital map. This requires a lot of time to acquire GCPs. Therefore, it is necessary to automatically extract GCPs and reduce the time required for GCP extraction and orthoimage generation. To this end, the Precision Image Processing (PIP) System was developed for CAS-500 images to minimize user intervention in GCP extraction. This paper explains the products, processing steps and the function modules and Database of the PIP System. The performance of the System in terms of processing speed, is also presented. It is expected that through the developed System, precise orthoimages can be generated from all CAS-500 images over the Korean peninsula promptly. As future studies, we need to extend the System to handle automated orthoimage generation for overseas regions.

• Journal of Science and Technology Studies
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• v.10 no.1
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• pp.73-106
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• 2010

Internet users want to use IP sharing routers for reducing their cost and managing their terminals easy. Network service providers(NSPs) forced their subscribers pay extra charges to use extra terminal like IP router, since 1998 in Korea. The NSPs asserted that IP sharing routers would harm their networks or would impose extra load on their networks, but they were unable to prove their assertion. Users and manufacturing companies insisted on the legitimacy of IP routers, because the IP router is a kind of terminal for end-users, and as such, the right of selection of an IP router belongs to the user. The interest in and beliefs of the relevant social groups about IP router will be deduced through their interpretation. It draws the technological frame of two social groups, NSPs and IP router-manufacturing companies. The rough struggle between two social groups come from their frames. The article shows how society constructs a particular information technology.

• Journal of Science and Technology Studies
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• v.18 no.1
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• pp.177-217
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• 2018

This study examines the case of living lab applied in the R&D initiatives for solving societal problems and challenges. It discusses how to use the living lab in national R&D projects. The analyzed cases are 'Develop portable fundus camera for eye disease screening test to resolve health inequalities' and 'Auto-sensing integrated system development in rural pedestrian crosswalk'. As a result of the analysis, both cases were designed as a user participatory R&D structure by utilizing living lab. In other words, living lab has operated as a system that evolves technology-products-services into an infrastructure. It can realize final demand specification, product, service improvement and demonstration through continuous interaction of end users. As a result of the case analysis, the following policy tasks can be derived. First, living lab is a new concept and it is in the early stage of implementation in Korea. Therefore, it is necessary to monitor and evaluate living lab experiments and build suitable models for Korean society by sharing cases and achievements. Second, the strategic niche management are necessary for the introduction of living lab. Third, living lab can be used as a tool to transform the existing technology acquisition centered innovation policy to the policy for customer needs and problem solving. Fourth, there is a need for flexibility and adaptability in strategy and system to correct errors that appear in the living lab processes.