• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.14-24
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• 2008

After 2001, the world aircraft industry grows consistently with world's economic recovery. The environmental changes after 9.11, including the market decent and revival, rise in oil price, and the environmental problems, make the aircraft industry change gradually. The increasing demand of point-to-point flight needs over 200 seat class large jets and changes the main model of regional jet over 100 seat class. And the needs of various flight schedule raises the demand of business jet and VLJ. The competition between airliners including the main streams, the regionals and the low prices goes harder and it needs more efficient airplanes which reduce the cost. In the military side, still the development of 5th generation fighter is proceeding and it diffuses to the more countries. Before its popularization, the 4th generation fighter is chosen for good alternatives of it. And there are some changes in the military demand after the war against terrorism. The army needs more unmanned reconnaissance and they want new aircraft which gives more accessibility.

• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.65-75
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• 2012

Since the modem reinforced soil wall technology was introduced in domestic civil engineering society in the year 1980, the reinforced soil walls have been extensively used because these technologies have advantages such as economical efficiency, graceful appearance, and easy construction. This paper describes the application of reinforced soil wall, design criteria, and construction problems. Many cases of troubles, which include a severe deformation of facing, cracks of facing block, overall sliding failure and so on, have been reported. Inappropriate design and construction management mainly induce these problems. The technological level of design and quantity control for reinforced soil wall is not sufficiently supported to cope with the growth quantity of reinforced soil wall construction market and the increasing number of construction companies. The unified standard design and construction criteria of reinforced soil wall should be established with the detail consideration of overall performance and stability. The quality control of design and construction, and cost of construction must be seriously executed to construct a high quality of reinforced soil wall.

• Journal of Computing Science and Engineering
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• v.4 no.2
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• pp.173-187
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• 2010

Recent technological advances in mobile communication systems have made explosive growth in the number of mobile device users worldwide. One of the most important issues in designing a mobile computing system is location management of users. The hierarchical systems had been proposed to solve the scalability problem in location management. The scalability problem occurs when there are too many users for a mobile system to handle, as the system is likely to react slow or even get down due to late updates of the location databases. In this paper, we propose a top-down clustering algorithm for hierarchical location database systems in a wireless network. A hierarchical location database system employs a tree structure. The proposed algorithm uses a top-down approach and utilizes the number of visits to each cell made by the users along with the movement information between a pair of adjacent cells. We then present a modified algorithm by incorporating the exhaustive method when there remain a few levels of the tree to be processed. We also propose a capacity constraint top-down clustering algorithm for more realistic environments where a database has a capacity limit. By the capacity of a database we mean the maximum number of mobile device users in the cells that can be handled by the database. This algorithm reduces a number of databases used for the system and improves the update performance. The experimental results show that the proposed, top-down, modified top-down, and capacity constraint top-down clustering algorithms reduce the update cost by 17.0%, 18.0%, 24.1%, the update time by about 43.0%, 39.0%, 42.3%, respectively. The capacity constraint algorithm reduces the average number of databases used for the system by 23.9% over other algorithms.

• Korean Journal of Construction Engineering and Management
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• v.12 no.4
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• pp.117-129
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• 2011

Building Information Modeling technology (BIM) is one of the most effective solutions to deal with the trend that buildings are getting more and more complicated, large-scaled, and multiple-purposed. BIM in the construction industry is increasingly adopted since the Korea Public Procurement Service announced that BIM would be obligated in a construction project whose total cost is over 50 billion won from 2012. This fact has boosted BIM related research projects as well. However, the majority of the studies have been focusing on the solutions with technological points of view and there has been lack of research on how much degree project stakeholders are satisfied with the BIM adoption in their projects. Therefore, the objective of this study is to investigate the current status and satisfaction degree of stakeholders in a synthesized point of view in BIM-based projects in order to identify critical factors and weak points in the BIM adoption process. The results of this study would greatly help to improve the strategies and processes in BIM-based projects as well as to increase the satisfaction degree of BIM utilization in a project.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.595-606
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• 2005

The scale of game development are rapidly increasing as the blockbuster games which cost $7\~20$ billion won, often appear on the markets. The game mechanics which is concentrated on technological elements of the game, necessarily requires the management of quality. In this paper, we propose a computer simulator for the quality evaluation of game mechanics which can analyze the quality accurately and economically in the design phase. The proposed simulator provides Petri net[7,8] and Smalltalk[9] for convenient modeling. The simulator gives the realistic evaluation like play test because it uses the realistic data of gameplay environment such as player action-pattern, game world map, and item DB but the previous evaluation methods can not consider the realistic gameplay environment and can only cover a limited scope of evaluation. To prove good performance of the proposed simulator, we have 80 simulations for the quality evaluation of the game mechanics of Dungeon & Dragon[13,14] in a given world map. The simulation results show that the proposed simulator can evaluate the faultlessness, optimization, and play balance of the game mechanics and gives better good performance than other evaluation methods.

• Journal of Information Technology Services
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• v.13 no.3
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• pp.343-357
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• 2014

As science and technology infiltrates every aspects of modern society in terms of economic and social growth and development, funding for research and development (R&D) is growing rapidly. Republic of Korea is not an exception in this trend and the R&D funding in Korea has been grown about 10% every year, recently. However, as the scope and size of funding grows exponentially, need for monitoring and managing these R&D projects becoming more and more imminent. Though different types of project management systems were developed by a variety of agencies and departments and used in monitoring and managing, these systems were developed as standalone silo type systems. These systems are not connected to each other while the same researchers may involved in different projects across agencies and department. Also, these management systems are not linked to the banking systems in which real transactions of funding occurs, such as cost reimbursement and financial audit of each R&D accounts. Historically, a few fraud and malappropriation cases were found and indicted. However, as the number of these incidents grows along with the growth of R&D funding, a large scale integration/linking of project management systems and banking systems. Realizing the importance of systems integration among agencies as well as with the banking systems, situational requirements analyses were conducted concerning the current state of R&D management system. As a results, a Real-time Case Management System (RCMS) was proposed as a solution to current problems. In this paper, the collected systems requirements were documents with analyses of the situation, the architecture of the integrated systems with more user-friendly technological alternatives. This large scale linkage requires interface standardization as well as modularization of interfaces. Proposed systems architecture is introduced here with technical details of Jex Framework used,, followed by resulting technical and economic performance of the Realtime Cashflow Management System (RCMS).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.129-136
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• 2012

In the US, Japan and Germany the Aerial-Based Vehicle Detection System, which collects real-time traffic data using the Unmanned Aerial Vehicle (UAV), helicopters or fixed-wing aircraft has been developed for the last several years. Therefore, this study was done to find out whether the Aerial-Based Vehicle Detection System could be used for real-time traffic data collection. For this purpose the study was divided into two parts. In the first part the possibility of retrieving real-time traffic data such as travel speed from the aerial photographic image using the image processing technique was examined. In the second part the quality of the retrieved real-time traffic data was examined to find out whether the data are good enough to be used as traffic information source. Based on the results of examinations we could conclude that it would not be easy for the Aerial- Based Vehicle Detection System to replace the present Vehicle Detection System due to technological difficulties and high cost. However, the system could be effectively used to make the emergency traffic management plan in case of incidents such as abrupt heavy rain, heavy snow, multiple pile-up, etc.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.15-31
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• 2017

This study analyzes 45 Korea IT service companies from 2012 to 2016 using DEA analysis. Large enterprises, medium enterprises and small and medium enterprises (SMEs). CCR model and BCC model were used for efficiency analysis. Among the various analytical objects, the decision objects which yield the maximum output with minimum input are compared with other analysis objects. The relative inefficiency was measured through this, and Technical Efficiency (TE), Pure Technology Efficiency (PTE), Scale Efficiency (SE), scale profit, reference frequency were analyzed. Also, we analyzed the Technology Gap Ratio (TGR), which is the distance between production function and Meta-Frontier for each firm, using Meta-Frontier analysis. Finally, the Tobit model is used to analyze the sources of efficiency and inefficiency. The inputs are assets, capital, and employees, and the output factor is sales. The analysis shows that large firms are achieving technological achievements more efficiently than small and medium enterprises. As a result, medium-sized enterprises and SMEs can improve efficiency overall through efficient operation of workforce and appropriate combination of inputs such as assets and capital. Also, as a result of the influence factor analysis, it was found that the ratio of the managed asset ratio and the management cost ratio were significant factors influencing the efficiency of the IT service companies. This study suggests the efficiency analysis using DEA for many Korea IT service companies. Inefficient parts of each company are classified according to size and technology. Also, we identify the most efficient companies and analyze the causes of those companies whose profits are lower than their size.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4389-4411
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• 2018

High dynamic range (HDR) images are becoming pervasive due to capturing or rendering of a wider range of luminance, but their special display equipment is difficult to be popularized because of high cost and technological problem. Thus, HDR images must be adapted to the conventional display devices by applying tone mapping (TM) operation, which puts forward higher requirements for intellectual property protection of HDR images. As the robustness presents regional diversity in the low dynamic range (LDR) watermarked image after TM, which is different from the traditional watermarking technologies, a concept of watermarking activity is defined and used to distinguish the essential distinction of watermarking between LDR image and HDR image in this paper. Then, a novel robust HDR image watermarking algorithm is proposed against TM operations. Firstly, based on the hybrid processing of redundant discrete wavelet transform and singular value decomposition, the watermark is embedded by modifying the structure information of the HDR image. Distinguished from LDR image watermarking, the high embedding strength can cause more obvious distortion in the high brightness regions of HDR image than the low brightness regions. Thus, a perceptual brightness mask with low complexity is designed to improve the imperceptibility further. Experimental results show that the proposed algorithm is robust to the existing TM operations, with taking into account the imperceptibility and embedded capacity, which is superior to the current state-of-art HDR image watermarking algorithms.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.93-103
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• 2014

This paper establishes the empirical model based on Hall's(1990) and Basu' s(1996) models, estimates the five types of productivity in the medical service industry over the period 1975:1-2010:4, and analyzes the cyclicality of measured productivities and their correlations with the industrial real wage. The empirical results are summarized as the followings. First, there proved to be substantial market power in pricing and returns to scale in production for the medical service industry. Second, the three types of productivity among 5 types showed to be procyclical. Third, the average labor productivity, the original Solow residual, and the cost-based Solow residual are expected to provide reasonable indexes in analyzing the relationship between productivity and real wage.