• Journal of KIISE:Databases
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• v.35 no.5
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• pp.432-446
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• 2008

Queries for tracing tag locations are among the most challenging requirements in RFID based applications, including automated manufacturing, inventory tracking and supply chain management. For efficient query processing, a previous study proposed the index scheme for storing tag objects, based on the moving object index, in 3-dimensional domain with the axes being the tag identifier, the reader identifier, and the time. In a different way of a moving object index, the ranges of coordinates for each domain are quite different so that the distribution of query regions is skewed to the reader identifier domain. Previous indexes for tags, however, do not consider the skewed distribution for query regions. This results in producing many overlaps between index nodes and query regions and then causes the problem of traversing many index nodes. To solve this problem, we propose a new disproportional insertion and split policy of the index for RFID tags which is based on the R*-tree. For efficient insertion of tag data, our method derives the weighted margin for each node by using weights of each axis and margin of nodes. Based the weighted margin, we can choose the subtree and the split method in order to insert tag data with the minimum cost. Proposed insertion method also reduces the cost of region query by reducing overlapped area of query region and MBRs. Our experiments show that the index based on the proposed insertion and split method considerably improves the performance of queries than the index based on the previous methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.274-280
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• 2017

The smart-car industry has emerged as the important variable that will decide the future industrial contour of the automotive industry, together with commercialization of electronic vehicles, connected cars, infotainment, telematics, and the autonomous/self-driving car. This study analyzes the strategic position of platform companies and car manufacturers that would determine the future of the smart-car market. The findings of this study show that despite the entry barriers in industrial factors, such as economies of scale, the industrial infrastructure, and global production networks, and technical factors like exclusive head-sector information, car manufacturers may be deprived of their industrial leadership by platform companies with map and user data, big data capabilities, and user interface experience if they lag behind ICT innovation. This insight is based on the emerging importance of software and platforms, and the simplification of car structures, proven by the successful commercialization of electronic vehicles. This study complements existing studies mainly focused on technical aspects of the smart-car industry by examining the strategic dimensions of platform companies and their approach to the future smart-car market by comparing them with existing car manufacturing multinationals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.48-54
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• 2020

DMSMS (Diminishing Manufacturing Sources and Material Shortage) is increased by developing the scientific technique and downsizing the military part market. DMSMS affects the increase in total life cycle costs and serviceability. Therefore, advance control for parts is important to reduce the cost, and a database is needed to share information on the DMSMS. A task needs to be performed continuously by setting the major control item to management more efficiently. The purpose of this study was to deduce the major control item for the DMSMS management system. Thus, the pre-control item basis of the DAPA (Defense Acquisition Program Administration) Manual and the SD-22 Manual were first selected, and the results of the survey were analyzed by AHP (Analytic Hierarchy Process) method. Fifteen of the detailed items were stratified into three criteria (Impact, Probability, and cost of the DMSMS), and each weight for the items was calculated using a nine-point scale survey. The AHP survey was executed with 25 specialists in the DMSMS management field, and the score of consistency ratio over 0.1 was excluded. The model explained the results and suggested future directions for development.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.1-12
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• 2018

During few decades, Korean economy has been growing with heavy and manufacturing industries. However, the economy meets limitations of growth rate, and employment rate. The Korean government has been trying to overcome these limitations using development of venture businesses and re-organization of industrial ecosystem. These efforts make high survival rate of recent venture companies. There are previous researches about relation between characteristics of entrepreneur and managerial performance, there are several limitations. Firstly, most of papers were based on survey with specific region or industry. Secondly, related researches were carried out with unable to distinguish among firm's survival periods. This paper uses the '2017 Survey of Korea Venture Firms' data that is approved by the Korean government. This data includes whole industries and survival periods. The aim of this research is finding the effect of characteristics of entrepreneur on managerial performance of venture firms by different survival periods using data envelopment analysis (DEA). If entrepreneur has doctoral degree, the firm's managerial performance is lower than bachelor degree. In addition, over 10 years of working career, and joint-venture have positive effect on firm's performance. This paper can provide valuable information to venture related policy makers and investment decision makers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.27-36
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• 2019

The demand for a low dispersion lens with a small refractive index and a high refractive index is increasing, and accordingly, there is an increasing need for a releasable protective film with high heat resistance and abrasion resistance. On the other hand, the optical industry has not yet established a clear standard for the manufacturing process and quality standards for mold-releasing protective films used in aspheric glass lens molding. Optical lens manufacturers treat this technology as proprietary information. In this study, an experiment was conducted regarding the optimization of ion etching, magnetron, and arc current at each source and filter part, and bias voltage in FCVA (filtered cathode vacuum arc)-based Ta-C thin film coatings. This study found that compared to iridium-rhenium alloy thin film sputtering products, the coating conditions were improved by approximately 50%, 20%, and 40% in terms of thickness, hardness, and adhesive strength of the film, respectively. The thin-film coating process proposed in this study is expected to contribute significantly to the development and utilization of glass lenses, which will help enhance the minimum mechanical properties and quality of the mold-release thin film layer required for glass mold surface forming technology.

• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.33-58
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• 2004

This paper tests Van Home's hypothesis, a negative correlation between degrees of operating leverage(DOL) and financial leverage(DFL). For an empirical analysis, we extract information from financial statements of manufacturing companies listed in the Korea Stock Exchange. Data extend from 1980 to 2001. The DOL continued to increase until 1997, but decreased dramatically after the IMF financial crisis. However, the DOL has been at a higher level than companies of other countries such as USA and Japan. The DFL has been maintained at a much higher level, as expected. The empirical results indicate a positive correlation between the DOL and the DFL, which is inconsistent with the VanHorne's hypothesis. To further investigate, we divide the whole sample into subgroups according to such management elements as asset size, level of leverages, earnings and cash flow. The results for sub-samples are different from those of whole sample. This indicates we need to incorporate specific managerial factors in order to correctly explain financial decision processes.

• Journal of Internet Computing and Services
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• v.12 no.5
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• pp.21-28
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• 2011

Recently medical and entertainment applications using conducting textile are suggested, but the data of conducting threads are not characterized, classified and verified. Only the data sheet published by manufacturing companies is available. Thus we need to verify the performances of the threading threads in communication. And we need a guideline if the existing communication protocols can be used for the conducting threads communication or the new specific communication protocols have to be developed for the communication. This paper classifies the characteristics of conducting threads made by domestic and overseas companies. Based on the criteria we classified conducting threads into three classes: class A, class B and class C. Further we carried out experiments to verify the adaptability of existing simple serial communication protocols such as RS232. Six different conducting threads are used in experiments and the length of each thread was 0.5m, 1m, 2m and 3m. The data transmission rate and error rate are collected and analyzed. RS485 is very prone to error due to static electricity from human and environment. So it may not be appropriate as long-distance communication protocol up to 12km which is possible in theory. RS232 shows stable and error-less data transmission ability even though every conducting thread didn’t show transmission capability over RS232. USB protocol shows high data rate transmission but the distance cannot be exceeded over 2m. Additionally, USB requires stable power supply. But if the power is supplied through conducting thread, its function is not.

• Journal of Engineering Education Research
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• v.13 no.3
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• pp.3-10
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• 2010

Human resources specialized in product development (PD) being essential in industry to enhance their competitiveness in the market with differentiated products, the PD curricula of domestic universities are in need of restructuring to better provide a comprehensive and diverse spectrum of knowledge as well as practical experiences for PD. We compared the PD curricula of selected domestic and foreign universities and identified advanced features of PD curricula. The major portion of the information used in our benchmarking of the seven, three domestic and four foreign, universities is obtained through their official websites. At domestic universities, the PD curricula comes in different sizes and is administered at the departmental level. On the other hand, each foreign university has her own unique form of PD curricula which is formulated on the firm basis of multidisciplinary collaboration among schools of Engineering, Management, and Arts with diversified program options ranging from giving course credits to offering various certificates and degrees. The industrial sponsorship in the form of financial support and mentorship at foreign universities is much more noticeable than at domestic universities. The survey results of the present study can be effectively utilized to develop an effective PD curriculum.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.8
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• pp.171-180
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• 2020

Smart Factory consists of digital automation solutions throughout the production process, including design, development, manufacturing and distribution, and it is an intelligent factory that installs IoT in its internal facilities and machines to collect process data in real time and analyze them so that it can control itself. The smart factory's equipment works in a physical combination of numerous hardware, rather than a virtual character being driven by a single object, such as a game. In other words, for a specific common goal, multiple devices must perform individual actions simultaneously. By taking advantage of the smart factory, which can collect process data in real time, if reinforcement learning is used instead of general machine learning, behavior control can be performed without the required training data. However, in the real world, it is impossible to learn more than tens of millions of iterations due to physical wear and time. Thus, this paper uses simulators to develop grid sortation systems focusing on transport facilities, one of the complex environments in smart factory field, and design cooperative multi-agent-based reinforcement learning to demonstrate efficient behavior control.

• Journal of Biosystems Engineering
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• v.26 no.1
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• pp.21-28
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• 2001

Major deficiencies of current automation scheme including various robots for bioproduction include the lack of task adaptability and real time processing, low job performance for diverse tasks, and the lack of robustness of take results, high system cost, failure of the credit from the operator, and so on. This paper proposed a scheme that could solve the current limitation of task abilities of conventional computer controlled automatic system. The proposed scheme is the man-machine hybrid automation via tele-operation which can handle various bioproduction processes. And it was classified into two categories. One category was the efficient task sharing between operator and CCM(computer controlled machine). The other was the efficient interface between operator and CCM. To realize the proposed concept, task of the object identification and extraction of 3D coordinate of an object was selected. 3D coordinate information was obtained from camera calibration using camera as a measurement device. Two stereo images were obtained by moving a camera certain distance in horizontal direction normal to focal axis and by acquiring two images at different locations. Transformation matrix for camera calibration was obtained via least square error approach using specified 6 known pairs of data points in 2D image and 3D world space. 3D world coordinate was obtained from two sets of image pixel coordinates of both camera images with calibrated transformation matrix. As an interface system between operator and CCM, a touch pad screen mounted on the monitor and remotely captured imaging system were used. Object indication was done by the operator’s finger touch to the captured image using the touch pad screen. A certain size of local image processing area was specified after the touch was made. And image processing was performed with the specified local area to extract desired features of the object. An MS Windows based interface software was developed using Visual C++6.0. The software was developed with four modules such as remote image acquisiton module, task command module, local image processing module and 3D coordinate extraction module. Proposed scheme shoed the feasibility of real time processing, robust and precise object identification, and adaptability of various job and environments though selected sample tasks.