• Tribology and Lubricants
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• v.24 no.6
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• pp.374-377
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• 2008

Due to the environmental concerns, especially the greenhouse effect and GWP (Global Warming Potential), the carbon dioxide was investigated as an alternative natural refrigerant to replace HFCs (HydroFluoroCarbons) in refrigerator or air conditioning systems. Because new compressor with carbon dioxide is going to be operated under the high pressure, the tribology of sliding surfaces in the compressor becomes very important. To improve of wear resistance in compressor parts, especially rotary type, the friction and wear characteristics of improved sliding surfaces between vane and flange were evaluated in this paper. The method of reformed sliding surface, such as micro-dimple processes, was applied on surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. The vane-on-flange type lubricated sliding tests were performed with a high pressure wear tester using carbon dioxide. Test results showed that the reformed surfaces were very effective to reduce the friction and the wear amounts of vane surfaces. The method of improved surfaces showed good tribological properties at vane and flange.

• Fashion & Textile Research Journal
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• v.12 no.1
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• pp.86-93
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• 2010

The purpose of this study was to develop torso pattern of Middle-aged obese women by using the virtual twin and 3D virtual garment simulation system. The results were as follows; 1. By using 3D Virtual Garment Simulation, new torso pattern considered obese women was development. The basic numerical formula were as follows ; bust girth B/2+5, armhole depth B/6+5, front waist girth W/4+2+0.5, back waist girth W/4+1-0.5, front hip girth H/4+1+0.5, back hip girth H/4+2-0.5, chest width B/6+2.5, back width B/6+2.5 and back neck width B/20+2.5. 2. According to the results of the new torso pattern's appearance evaluation, it estimated more highly than existing pattern in silhouette and ease amount, confirming that new torso pattern is appropriate for the obese women. Also, new torso pattern was evaluated to allow proper space length of bust, waist, abdomen and hip. Virtual models production through 3D body scan data, pattern draft and virtual garment digital program were applied to prototypic design method so as to enhance the fitness of ready-made garments. This study is expected to serve as one of important basic data for ensuing studies that may utilize 3D Virtual Garment Simulation System with 2D patterns, and also for future 3D Pattern Production Program development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3876-3895
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• 2014

Recently, Heterogeneous Network (HetNet) with Coordinated Multi-Point (CoMP) scheme is introduced into Long Term Evolution-Advanced (LTE-A) systems to improve digital services for User Equipments (UEs), especially for cell-edge UEs. However, Radio Resource Management (RRM), including Resource Block (RB) scheduling and Power Allocation (PA), in this scenario becomes challenging, due to the intercell cooperation. In this paper, we investigate the RRM problem for downlink transmission of HetNet system with Joint Processing (JP) CoMP (both joint transmission and dynamic cell selection schemes), aiming at maximizing weighted sum data rate under the constraints of both transmission power and backhaul capacity. First, joint RB scheduling and PA problem is formulated as a constrained Mixed Integer Programming (MIP) which is NP-hard. To simplify the formulation problem, we decompose it into two problems of RB scheduling and PA. For RB scheduling, we propose an algorithm with less computational complexity to achieve a suboptimal solution. Then, according to the obtained scheduling results, we present an iterative Karush-Kuhn-Tucker (KKT) method to solve the PA problem. Extensive simulations are conducted to verify the effectiveness and efficiency of the proposed algorithms. Two kinds of JP CoMP schemes are compared with a non-CoMP greedy scheme (max capacity scheme). Simulation results prove that the CoMP schemes with the proposed RRM algorithms dramatically enhance data rate of cell-edge UEs, thereby improving UEs' fairness of data rate. Also, it is shown that the proposed PA algorithms can decrease power consumption of transmission antennas without loss of transmission performance.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.2
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• pp.61-74
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• 2011

The author analyses the challenging activities of Japanese libraries in this decade by launching two keywords; "product-sharing" and "outcome generation." "Product-sharing" means that libraries share knowledge, skills, and records which are produced as the result of the services or in the process of activities. And "outcome generation" means that libraries generate any efficiency or effectiveness through their services to users. Using these concepts, reported are the current situation and aspects of Japanese libraries which try to make various contributions to the society; research and learning of the people, and education and training for professional librarians, and so on. In the analysis, the author shows some examples of "product-sharing" at first, including the records of reference transaction and the multi-functioned online public access catalogue. Especially, focused is on the various possibility and adoptability of the Collaborative Reference Database System of the National Diet Library of Japan. This system is one of digital reference service in Japan, and the database of reference transaction records is expected to be useful for research and academic studyies as knowledge-base of professional librarians. And the system is also expected to be a platform for LIS education and professional development in the e-learning environment. Secondly, as the examples of "outcome generation", explained are the problem-solving-type activities, and provision of the collection about books on struggling against disease and illness. A few examples of outcome in the problem-solving-type activities are these; increase of sales in the services for shop managers, business persons, and entrepreneurs, contribution to affluent daily life by providing the local information services to residents and neighbourhoods, and etc. And for both the patients with serious cases and their family or those who nurse them, books about other persons' notes or memorandum are the greatest support, and sometime healing. The author discuss the 'raison d'etre' of these activities focusing on public libraries in Japan.

• Journal of Korea Game Society
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• v.11 no.2
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• pp.45-56
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• 2011

The concept, means, value chain, the persons concerned and possible issues of game item trading in cash are analyzed in this study. The trading is characterized by not only being performed with its own unique business model but also causing issues related to delicate social problems, such as digital contents distribution, work place and gambling. The way of game item trading in cash and its value chain have been changed with game market growth for the past years. I analyzed in this article the new concept of game item trading in cash that is different from the past. Also, analysis on several issues related to game item trading in cash is conducted.

• The Journal of Advanced Prosthodontics
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• v.11 no.6
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• pp.331-340
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• 2019

PURPOSE. The purpose of this study is to assess the accuracy of three intraoral scanners along the complete dental arch and evaluate the feasibility of the assessment methodology for further in vivo analysis. MATERIALS AND METHODS. A specific measurement pattern was fabricated and measured using a coordinate measuring machine for the assessment of control distances and angles. Afterwards, the pattern was placed and fixed in replica of an upper jaw for their subsequent scans (10 times) using 3 intraoral scanners, namely iTero Element1, Trios 3, and True Definition. 4 reference distances and 5 angles were measured and compared with the controls. Trueness and precision were assessed for each IOS: trueness, as the deviation of the measures from the control ones, while precision, as the dispersion of measurements in each reference parameter. These measurements were carried out using software for analyzing 3-dimensional data. Data analysis software was used for statistical and measurements analysis (α=.05). RESULTS. Significant differences (P<.05) were found depending on the intraoral scanner used. Best trueness values were achieved with iTero Element1 (mean from 10 ± 7 ㎛ to 91 ± 63 ㎛) while the worst values were obtained with Trios3 (mean from 42 ± 23 ㎛ to 174 ± 77 ㎛). Trueness analysis in angle measurements, as well as precision analysis, did not show conclusive results. CONCLUSION. iTero Element1 was more accurate than the current versions of Trios3 and True Definition. Importantly, the proposed methodology is considered reliable for analyzing accuracy in any dental arch length and valid for assessing both trueness and precision in an in vivo study.

• Journal of Information Technology Applications and Management
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• v.24 no.4
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• pp.41-55
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• 2017

Industrial Revolution is a concept and a development that has fundamentally changed our society and economy. Industry 4.0 focuses on the end-to-end digitization of all physical assets and integration into digital ecosystems with value chain partners. At present, we find ourselves at the beginning of this fourth stage, which is characterized by so-called "Cyber-Physical Systems". These systems are a consequence of the far-reaching integration of production, sustainability and customer-satisfaction forming the basis of intelligent network systems and processes. If South Korea ran toward global ICT with the advent of the Fourth Industrial Revolution, North Korea has adhered to a unique Juche science and technology. ICT in South Korea and North Korea seems very difficult to find common interests. However, as seen in the Internet and intranets, information and communication technology can find similarities in many areas than in general science and technology. There are many differences not only in the level of ICT and science and technology but also in the direction. And IT terminology and all technologies are also different. What are we preparing for the unification of North and South Korea? If we look at the science and technology sector at present, there seems to be no systematic preparation by the government. South Korea and North Korea need to be prepared for science and technology cooperation. First, it is necessary to understand the exact situation of North Korea's science and technology. In this study, we will perform research to establish mid and long term plans for revitalization of ICT cooperation between the two Koreas. In this study, we will determine the extent to which the two Koreas utilize ICT based on available ICT capabilities and technologies. To do this, we conducted research to measure and evaluate the ICT development index of North Korea using ICT international index.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.128-139
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• 2018

As The Fourth Industrial Revolution and Intelligent Information Age came into full-scale, the policy of open government data has become a hot topic for each country. The United States, the United Kingdom, and other countries are shifting policy direction to "creating value" of open government data. Also, in the age of the digital economy where the data market is soaring, open government data is gradually being recognized as a new raw material for new business and start-ups. In addition, Korea ranked first in the OECD open government data evaluation twice in a row, and was highly evaluated in the international evaluation. However, domestic firms are still lacking in qualitative openness of government data, data is dispersed among institutions, lack of public-private data linkage, and development of app-oriented development. This study attempts to analyze major national policies for the creation of a data ecosystem that considers data lifecycle, from production to storage, distribution and utilization of data. First, the target countries were the leading public data countries among the OGP member countries, the USA, the UK, Australia and Canada. The results of this study are as follows. As a result of analyzing the results and comparing Korea's policies, it was concluded that most of Korea is superior in open government data policy. However, improvement of data quality, development of open data portal as an open platform, support for finding various users including apps and web development companies, and cultivation of open government data utilizing personnel are analyzed as policy issues. In addition, the direction of policy for the balanced ecosystem of Korea is presented together.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.12
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• pp.842-849
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• 2007

For a $CO_2$ two-stage twin rotary compressor used for heat pump water heater system, changes of $CO_2$ solubility in PAG oil were investigated along the gas passages from the first stage suction to final discharge. Only slight changes in solubility took place in suction chambers for both of the first and second stages, but for compression chambers, solubility variation ranged from 0.115 to 0.136, and from 0.133 to 0.182, respectively for the first and second stages. Calculation of gas flashing in parts of leakage oil flows and of oil contained in control volumes due to solubility changes was conducted and included in gas pressure calculation. For the second stage, gas flashing amounts to around $5%\sim6%$ for most leakage flows. Cooling capacity, compressor input, and COP obtained by calculation were well compared to the experimental results. Effects of operation speed on the compressor performance was also studied: as the shaft speed increased, adiabatic efficiency decreased rapidly due to increased over-compression loss.

• The Research Journal of the Costume Culture
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• v.19 no.5
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• pp.1009-1018
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• 2011

The purpose of this study was to develop slacks patterns for middle-aged abdomen-obese adult males by using the 3D virtual-twin and virtual-garment simulation system. The criteria for subjects in this study were males who had over $25kg/m^2$ of BMI, over 90cm of waist, and over 0.90 of WHR. A total of 211 adult males who met these criteria were enrolled. The results were as follows: first, a new slacks pattern considerate of abdomen-obese men was development. The basic numerical formula were as follows: front and back hip girth H/4+3.5, front waist girth W/4+1+0.5, back waist girth W/4+1-0.5, front crotch extension H/16, back crotch extension H/8-0.5, front pleats amount 2.7, and back dart amount 1.5. Second, according to the results of the new slacks patterns appearance evaluation, the new slacks pattern scored more highly than the existing pattern in silhouette and ease amount, confirming that the new slacks pattern is appropriate for the abdomen-obese men. Also, the new slacks pattern was evaluated allowing proper space length of waist, abdomen and hip. Virtual models of production through data from a 3D body scan, pattern draft and virtual garment digital program were applied to a prototypic design method in order to enhance the fitness of ready-made garments. The use of the virtual twin made it impossible to comprehend the appearances and ease correspondent to motions. In order to evaluate wearing fitness, therefore, the system should be improved so as to change arm positions and perform various motions.