• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.155-161
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• 1991

Flexibility has become a key objectives in the design of manufacturing systems and a critical measure of total manufacturing performance. The need for flexibility is increasing due to some environmental change such as changing technical characteristics of the products and the changing nature of market demands. Most importantly, flexibility embodies competitive value for a manufacturer. Although the importance of flexibility has stressed in the various research, very few attempts have been made to synthesize the literature dealing with definitions and measure of flexibility. It is this issue that have motivated us to search for the definition and classification of flexibility.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.185-191
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• 2012

This study deals with the technical approach related to the protection of digital video contents copyright, which has currently become a major issue in the digital contents market. With the production and distribution of digital video contents rapidly increasing, various policies and technical approaches are being made in relation to the protection of intellectual property rights. The technical approach from a DRM (Digital Rights Management) perspective was made from various angles, but its limitations have also been exposed in terms of convenience and quality. In this study, rather than the existing encoding certification and watermark technologies, it introduces technical approaches from a content-based copy detection method, while suggesting a copy detection method using the representative color sequence. In particular, this study takes into consideration the distribution environment of the domestic video market and deals with the technical approach in a direction that can control the illegal distribution of high quality videos.

• Journal of Welding and Joining
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• v.33 no.1
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• pp.35-40
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• 2015

Recently, there have been the increase of ship size and the development of oil and gas in arctic region. These trends have led to the requirements such as high strength, good toughness at low temperature and good weldability for prevent of brittle fracture at service temperature. There has been the key issue of crack arrestability in large size structure such as container ship. In this report for the first time, crack arrest toughness of thick steel plate welds was evaluated by large scale ESSO test for estimate of brittle crack arrestability in thick steel plate. For large structures using thick steel plates, fracture toughness of welded joint is an important factor to obtain structural integrity. In general, there are two kinds of design concepts based on fracture toughness: crack initiation and crack arrest. So far, when steel structures such as buildings, bridges and ships were manufactured using thick steel plates (max. 80~100mm in thickness), they had to be designed in order to avoid crack initiation, especially in welded joint. However, crack arrest design has been considered as a second line of defense and applied to limited industries like pipelines and nuclear power plants. Although welded joint is the weakest part to brittle fracture, there are few results to investigate crack arrest toughness of welded joint. In this study, brittle crack arrest designs were developed for hatch side coaming of large container ships using arrest weld, hole, and insert technology.

• Spatial Information Research
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• v.17 no.3
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• pp.309-317
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• 2009

Recently, convergence phenomena among industries are appeared with the rapid development of information and communication technology and technology convergence also is emerging as a key issue. Especially, geospatial information industry may be expected to conduct a role as a pioneer in this convergence era. In order to do this, all fields of geospatial information should be classified systematically and interoperability and compatibility among geospatial information systems should be acquired. In this paper, a technical reference model of intelligent geospatial information is proposed to show a hierarchical technical system in the field of geospatial information. The model is developed with five core research projects of Korean Land Spatialization Group (KLSG) and includes also the scope and importance of core technology in the system. The model would be helpful to manage and control all projects of KLSG.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.81-88
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• 2020

The Renewable Portfolio Standard(RPS) which is in operated by country for many years is eco-friendly energy business. Although a variety of institute are accessing the RPS, it consists of a centralized system. Also, it shows opacity of data access in user's point of view. And each institutes is possessing their own data collected by themselves. Therefore decentralization and integrated control is demanded. Also, when institutes are attacked, the interruption of RPS can be existed. For resolving this issue, this study proposes the RPS using blockchain. Using the consortium method of blockchain, every institutes has possessing same data inserting REC data in block data, it is resolvable that transparency and security issue as transaction through verification of certain block. Furthermore, in case of one institute is paused by external attack, the role can be replaced by other institutes. This study tried the processing of putting data through ethereum network, therefore it presents the possibility of introducing the blockchain method in RPS.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.551-557
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• 2018

Since its foundation in September 1986, the Korean Society of Water and Wastewater has made a significant contribution to the water sector in Korea over the past 30 years. The 30th anniversary commemorative committee reviewed the establishment goal of the society and its development strategy for organization and present the "Future Vision of Korean Society of Water and Wastewater" for the next 30 years. The future vision of the society is defined as "Aiming for the healthy life and preservation of the environment through the development of water and wastewater technology and experience". Promotion strategies for implementing the future vision are as follows: 1. Leading water and wastewater technology, 2. Develop water and wastewater policy, 3. Strengthen water and wastewater capacity, 4. Reinforce institutional governance. The driving target to be achieved through the implementation strategy is "To lead the global standards of water and wastewater." We also presented national issue, policy issue, and technical issues in the water sector. Climate change, unified Korea, water safety, and national welfare were selected as national issues related to water and wastewater. This approach was taken from the perspective of policy consumers such as citizens, civil society, experts, and local government/industry. By presenting policy issues and technical issues that address national issues, authors have proposed a future policy direction for the Korean Water and Wastewater Society to make critical contributions to national development.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.1-10
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• 2020

National R & D data covers information in all fields from basic science research to industrialization, but it is expressed in technical terms, which make it difficult for the public to use. Accordingly, NTIS developed and launched the data curation service 'R&D issue service', which selects national R&D information on national and social issues and provides them to the public. Therefore, this study aims to analyze the effect of a data curation service on NTIS users' access to R&D data and suggest how to develop the curation service. The R&D issue service extracts issue from the news article and provide related national R&D projects, achievements and major research institute. All raw data used for the service are open to the public, organized in a report format and provided as PDF files. In addition, automative process is developed for all NTIS users to make individual issue packaging like administrator. The results show that 'R&D issue service' launching increases users' access and convenience to R&D data related to major issues, and the number of page views of users increased after the service was opened.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.1921-1929
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• 2015

The smart substation is the heart of a transmission system, which is particularly emphasized as the most significant composition of smart grids in China. In order to assess the functionality performance of substation technologies, this paper presents methods used to identify the most promising solutions for smart substation design and to evaluate the technical levels of available technologies. The multi-index optimization model is presented to address the issue of smart substation planning. A mathematical model of the planning decision problem is established with multiple objectives consisting of economic, reliability, and green key indices, and many kinds of concerns including physical and environmentally friendly operations are formulated as a set of constraints. With respect to the assessment of the technical level regarding integration of advanced technologies into a substation, a modified grey whitenization weight function is adopted to structure a novel grey clustering method. The proposed grey clustering approach is used to overcome the difficulty of insufficient quantitative assessment capacity for traditional methods. The evaluation of technical effects provides the classification definition for the development phase and the maturity level of the smart substation. The effectiveness of the proposed approaches in planning decision-making and evaluation of construction efforts is demonstrated with case studies involving the actual smart substation projects of Wenchongkou substation in China Southern Power Grid (CSG) and Mengzi substation in State Grid Corporation of China (SGCC).

• Journal of Broadcast Engineering
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• v.15 no.6
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• pp.749-756
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• 2010

The signal space diversity is one of the promising transmission techniques in next generation mobile TV service. However, DVB-T2 does not consider the multiple antennas (MIMO) so that the cyclic Q-delay method, a component interleaver in DVB-T2, causes a critical issue in detecting symbols at the receiver side by increasing the inter-symbol dependency. To solve this problem, the component-swapping technique is proposed, which limits the inter-symbol dependency in order to reduce detection complexity. In this paper, the achievable gain of a component-swapping technique combined with 16K LDPC code defined in DVB-T2 is evaluated by computer simulations. From the results, the gain is confirmed in terms of BER and receive complexity compared to legacy component interleaver methods.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.41-49
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• 2008

According to the demand for services. a single point contract between a user and provider spreads over the industry, and the relationship between them is a main issue. The user wants to make a deal with the contributor which can provide the effective services to the user. This study is to estimate the efficiency of global logistics industry with Data Envelopment Analysis, by nations from 2001 to 2005. Furthermore, it tries to estimate the inefficiency affected by macro factors, and proves the association between them using Tobit model. Global logistics industry has made growth both externally and internally more than doubled for the last 5years. Technical inefficiency of global logistics industry is more influenced by pure technical inefficiency than inefficiency of scale. Therefore technical efficiency can be increased by decreasing pure technical inefficiency. Through this study, it found that the logistics industry got influenced to its efficiency by high price of oil, and courier and transportation service market is formed stably. Furthermore, it advocates policy planners to consider effectiveness and clearness of policy which influence to inefficiency of logistics industry. Also, it found that labor and financial support can give critical effect.