• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권2호
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• pp.498-514
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• 2012

Machine to machine (M2M) communications is the hottest issue in the standardization and industry area, it is also defined as machine-type communication (MTC) in release 10 of the 3rd Generation Partnership Project (3GPP). Recently, most research have focused on congestion control, sensing, computing, and controlling technologies and resource management etc., but there are few studies on security aspects. In this paper, we first introduce the threats that exist in M2M system and corresponding solutions according to 3GPP. In addition, we present several new security issues including group access authentication, multiparty authentication and data authentication, and propose corresponding solutions through modifying existing authentication protocols and cryptographic algorithms, such as group authentication and key agreement protocol used to solve group access authentication of M2M, proxy signature for M2M system to tackle authentication issue among multiple entities and aggregate signature used to resolve security of small data transmission in M2M communications.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제10권11호
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• pp.3331-3339
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• 2009

This study analyzed relation with performance on the job by strategy of outsourcing as study about outsourcing and system operation performance of mid-size ERP systems. To summarize the results of this study, first, mid-size ERP outsourcing companies in stages, rather than the big bang approach to introducing more effective measures could get the conclusion. Second, ERP outsourcing, the business strategies of the big bang as significant were analyzed in terms of partnership. This section introduces the methodology and business partners, regardless of outsourcing could be distinguished from the very important variables. As a result, the standard for business enterprises mid-size mad to keep a systematic business analysis is very difficult. Therefore, a gradual introduction of a step by step implementation of such a methodology capable of performing reliable business methods are needed.

• Journal of the Korean Society for Railway
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• 제9권1호
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• pp.36-42
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• 2006

Studied was a strategic plan for the Korean High-Speed Train system to penetrate the Chinese railway market in exchange of the technology of KHST. Firstly, taken was a glance at Chinese Government plans to extend total length of his railway lines and to construct the Beijing~Shanghai high-speed railway line. Then, disparity of railway technology in Korea and China was reviewed. From the review, SWOT Analysis were carried out to penetrate the foreign markets. Countermeasures to cope with SWOT were also considered. Strategical governmental supports and the establishment of the special organization to be in charge of penetration of KHST into foreign markets were proposed. Finally, also proposed was the transfer of KHST technology to Chinese counterparts in exchange of tangible benefits for Korean side. The benefits may include (1) adoption of KHST as the type of rolling stock for the Beijing~Shanghai line, (2) guarantee of participation in the project and royalty for the KHST technology used for the future high-speed railway line construction, (3) prior written approval and partnership when making its way to third country, and (4) participation of Korean construction companies in Chinese railway construction project, etc. Adoption of KHST in China indeed gives chance to integrate the high-speed railway network after reunification of Korean peninsular, and enhance the economic ties between two countries.

• Journal of Korean Society of Water and Wastewater
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• 제25권1호
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• pp.51-61
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• 2011

A project constructing sewerage facilities in 9 upstream areas of 7 multi-purpose dams will have been completed by 2011. After all constructing and retrofitting of the new and the existing sewerage facilities, integrated management system with operation and control functions for the each levels of facilities will also be utilized. In this study, we studied how to compose the organization taking responsibility of the integrated management system and analysed human resources saving effect against conventional method of individual management of each sewerage facility. As a result, a method estimating the human resources in employing the integrated management among several sewerage facilities at upstream areas of dams were presented and some 23% of human resources could be saved by integrated management. Commissioning to a specialized public institute showed the highest B/C ratio of 4.5 among commissioning to local public corporations, commissioning to private corporations, and role-sharing partnership, etc.

• Korean Journal of Childcare and Education
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• 제14권6호
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• pp.19-34
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• 2018

Objective: The purpose of this study is to investigate the six-week educare practicum revised in 2017 and perception of the effects of the change on public child care training centers. Methods: Surveys were conducted on the directors and teachers from national public child care centers within Seoul. And in-depth interviews were conducted on six participants. Results: Firstly, public child care training centers had generally received trainees through industry-academy partnership schools, and had planned to receive the same number of trainees as in the previous system. They had trained according to their planned program, and self-evaluation had also been conducted on a regular basis. Additionally, they perceived that the quality control of the centers was carried out by the trainees. Secondly, they perceived that the new system would improve the professionalism of the teachers and have a positive effect on their personality issues and the reliability of the evaluation accreditation institute. Hence, it was believed that it would help to develop the professional knowledge and qualifications of first-time teachers. Conclusion/Implications: The results showed that the public child care training centers recognized that the six-week educare practicum would enhance the professionalism and quality of teachers, and the child care operation management.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1929-1943
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• 2021

Millimeter wave (mmWave) communication based on the wide bandwidth of >28 GHz is one of the key technologies for cellular-connected unmanned aerial vehicles (UAVs). The selection of mmWave beams in such cellular-connected UAVs is challenging and critical, especially when downlink transmissions toward aerial user equipment (UE) suffer from poor signal-to-interference-plus-noise ratio (SINR) more often than their terrestrial counterparts. This study proposed a coordinated mmWave beam selection scheme using fingerprint for cellular-connected UAV. The scheme comprises fingerprint database configuration and coordinated beam selection. In the fingerprint database configuration, the best beam index from the serving cell and interference beam indexes from neighboring cells are stored. In the coordinated beam selection, the best and interference beams are determined using the fingerprint database information instead of performing an exhaustive search, and the coordinated beam transmission improves the SINR for aerial UEs. System-level simulations assess the UAV effect based on the third-generation partnership project-new radio mmWave and UAV channel models. Simulation results show that the proposed scheme can reduce the overhead of exhaustive search and improve the SINR and spectral efficiency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제20권1호
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• pp.21-28
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• 2009

DFT-spread OFDM(Discrete Fourier Transform-Spread Orthogonal Frequency Division Multiplexing) is very effective for solving the PAPR(Peak-to-Average Power Ratio) problem. Therefore, the SC-FDMA(Single Carrier-Frequency Division Multiple Access) which is basically same to the DFT spread OFDM was adopted as the uplink standard of the 3GPP LTE ($3^{rd}$ Generation Partnership Project Long Term Evolution). Unlike the ordinary OFDM system, the SC-FDMA using DFT spreading method is vulnerable to the ICI(Inter-Carrier Interference) problem caused by the phase noise and IQ(In-phase/Quadrature) imbalance and effected FDE(Frequency Domain Equalizer). In this paper, the ICI effects from the phase noise and IQ imbalance which can be problems in uplink transmission are analyzed according the back-off level of HPA. Next, we propose the equalizer algorithm to remove the ICI effects. This proposed equalizer based on the FDE can be considered as up-graded and improved version of PNS(Phase Noise Suppression) algorithm. This proposed equalizer effectively compensates the ICI resulting from the phase noise and IQ imbalance. Finally, through the computer simulation, it can be shown that about SNR=14 dB is required for the $BER=10^{-4}$ after ICI compensation when the back-off is 4.5 dB, $\varepsilon=0.005$, $\phi=5^{\circ}$, and $pn=0.06\;rad^2$.

• The Journal of Fisheries Business Administration
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• 제36권2호
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• pp.1-24
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• 2005

The purpose of the study are summarized as follows : First, it has researched the possibility of the Distribution Information application in Sea Food Wholesale Market. Second, the effects which the Wholesale Market Company and the Intermediary Wholesaler Corporations can obtain in Sea Food Wholesale Market by building up a Distribution Information are classified into the effects of task, cost, and competition. It has analyzed the influence of these effects in direct and indirect Trust between the Wholesale Market Company and the Intermediary Wholesaler. Third, it has recognized the upcoming problems in Sea Food Wholesale Market by building up a Distribution Information, and it has suggested a plan to make the Distribution Information application successful in Sea Food Wholesale Market. This study has used a questionnaire to verify 5 hypotheses. Research model, factor analysis, correlation relationship analysis. The result of this study are summarized as follows : Building up the Distribution Information influences positively on the effectiveness of task, cost and competitiveness regardless of it being the Wholesale Market Company or the Intermediary Wholesaler corporation. However, the results of this analysis are to verify differences according to the degree of construction of the Distribution Information and the degree of the perception of the problems between the Wholesale Market Company and the Intermediary Wholesaler corporations have shown that there were distinct differences in the degree of computerization and of efforts to build a Distribution Information. Also there were distinct differences according to the degree of perceiving problems relating to building up the Distribution Information and the stages of the Distribution Information between the Wholesale Market Company and the Intermediary Wholesaler corporations. This study suggest three important steps that will help to establish a successful Distribution Information. First, the Wholesale Market Company and the Intermediary Wholesaler corporations should make efforts to increase mutual profits in partnership, and make direct Trust by sharing mutual information. Second, the lack of understanding of the Distribution Information between departments within the company requires educating employees about the Distribution Information. It is necessary to expand the communication networks of the Distribution Information between the Wholesale Market Company and the Intermediary Wholesaler. Third, mutual exchange of Information should be possible to offer systematic exchange of Information between the Wholesale Market Company and the Intermediary Wholesaler corporations.

• Korean Journal of Organic Agriculture
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• 제14권2호
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• pp.159-177
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• 2006

Governance systems are basically an autonomous cooperation type among the government, civil society and market, also a new paradigm for efficient and democratic administration of policies. The governance mainly consists of the central operating body, institutions, operating principles and so on. The constituents are the nation(government), civil society(NGO) and market(firm). Institutional conditions are a legitimate base, financial stability and independency. And as a operating principle, governance systems have common goals and issues from a national and social point of view. This governance has been recently emerged due to financial risk of government, diffusion of new liberalism going with the globalization, localization-decentralization, and development of civil society and information-oriented society. We have to grope fur the framework of participatory agri- policy confronting globalization and localization as well as developing our agriculture and rural village. This agri-policy governance should be theoretically focused on policy network or self-organizing network or multi-lateral governance (MLG) based on NPM. Also, it is proper to have connection of nation-central type and civil society-central type. And it is necessary to have a MLG type with local governance corresponding to localization and decentralization. Governance should have the type whose participants have authority and responsibility as well. Basic directions of environmentally friendly agri-policy governance are as follows : first, its purposes are constructing the democratic and efficient framework of participatory environmentally friendly agri-policy based on consensus of all the related groups, embodying environmentally friendly agri-policy adjusted to local field, raising farmer's real interest, and improving their position. Second, its form should have a council or an agreement system, not an advisory or a consultation organ. Thus, public sector(eg. government) and voluntary sector(eg. farmers' organization) jointly execute agricultural policy and are responsible together. Environmentally friendly agri-policy governance is mainly made up of farmers' organization, cooperative and civil society(NGO). And secondary bodies are agribusinesses and academic groups. Government interacts with the main bodies on administrative execution. And environmentally friendly agri-policy governance has MLG type with a central unit, province and county units. Environmentally friendly agri-policy governance has several main functions such as agri-policy partnership, speaking for farmer's rights and interests, investigation and research on domestic and foreign agricultural streams, and etc. Especially, local unit will play roles in activation for regional agriculture, consulting on technique and management, education and training services, services entrusted by government, and so on.

• Journal of the Institute of Electronics and Information Engineers
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• 제53권10호
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• pp.15-23
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• 2016

To support the telematics and infotainment services, vehicle-to-everything (V2X) communication requires a robust and reliable network. To do this, the 3rd Generation Partnership Project (3GPP) has recently developed V2X communication. For reliable communication, accurate channel estimation should be done. However, because vehicle speed is very fast, radio channel is rapidly changed with time. Therefore, it is difficult to accurately estimate the channel. In this paper, we propose the new linear minimum mean square error (LMMSE) channel interpolation scheme based on the Long Term Evolution (LTE) sidelink system in vehicle-to-vehicle (V2V) environments. In our proposed reduced decision error (RDE) channel estimation scheme, LMMSE channel estimation is applied in the pilot symbol, and then in the data symbol, smoothing and LMMSE channel interpolation scheme is applied. After that, time and frequency domain averaging are applied to obtain the whole channel frequency response. In addition, the LMMSE equalizer of the receiver side can reduce the error propagation due to the decision error. Therefore, it is possible to detect the reliable data. Analysis and simulation results demonstrate that the proposed scheme outperforms currently conventional schemes in normalized mean square error (NMSE) and bit error rate (BER).