• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.390-397
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• 2019

A mechanical model of band sawing saw frame was established according to an analysis of a commonly used saw-frame structure diagram to overcome the problems of low service life, substandard cutting precision and efficiency, and high manufacturing cost caused by the unreasonable design of saw frame. Taking a particular type of sawing machine as an example, stress cycle analysis of the saw blade was carried out according to the mechanical model of the saw frame, and the fatigue analysis model of the most dangerous cross-section point that was most prone to fatigue failure of the saw blade was then established. The fatigue analysis result was used as the basis for the improved design of the saw frame, and the improved detailed saw-frame design parameters were obtained. The results suggested that the saw frame system is much more compact and the saw blade force met the fatigue strength requirements through the improved design. In addition, the service life of the saw blade and the cutting precision were increased. The established mechanical model of the saw frame in this paper is used widely and has high practical application values.

• Fire Science and Engineering
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• v.29 no.6
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• pp.51-56
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• 2015

In Korea, measures to maintain sustainable fire safety performance for apartment buildings are insufficient in terms of fire-fighting products, skilled personnel, and maintenance status. Also, because of the particular features of a fire compartment, it has structural problems that are very likely to cause damage to human life when a fire occurs. Currently, problems with the fire supervisory system installed in an apartment building cannot be checked in real time, so it is difficult to identify the location of a fire accurately. Protected areas are also not assigned to each household, and residents cannot be clearly informed of the occurrence of a fire. As a consequence, safety evacuation cannot be secured. In addition, it is impossible to test the operation performance for water detectors in sprinkler fire extinguishing systems outside of the household. Therefore, an experiment was conducted to evaluate the performance of a remote fire supervisory system. The results show that the system satisfies all performance requirements. Also, an household alarm system was installed in each household to alert of any occurrence of a fire accurately, and the performance of the alarm system was improved to ensure that residents were quickly evacuated.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.67-85
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• 2018

Vehicle platooning through wireless communication and automated driving technology has become realized. Platooning is a technique in which several vehicles travel at regular intervals while maintaining a minimum safety distance. Truck platooning is of keen interest because it contributes to preventing truck crashes and reducing vehicle emissions, in addition to the increase in truck flow capacity. However, it should be noted that interactions between vehicle platoons and adjacent manually-driven vehicles (MV) significantly give an impact on the performance of traffic flow. In particular, when vehicles entering from on-ramp attempt to merge into the mainstream of freeway, proper interactions by adjusting platoon size and inter-platoon spacing are required to maximize traffic performance. This study developed a methodology for establishing operational strategies for truck platoonings on freeway on-ramp areas. Average speed and conflict rate were used as measure of effectiveness (MOE) to evaluate operational efficiency and safety. Microscopic traffic simulation experiments using VISSIM were conducted to evaluate the effectiveness of various platooning scenarios. A decision making process for selecting better platoon operations to satisfy operations and safety requirements was proposed. It was revealed that a platoon operating scenario with 50m inter-platoon spacing and the platoon consisting of 6 vehicles outperformed other scenarios. The proposed methodology would effectively support the realization of novel traffic management concepts in the era of automated driving environments.

• Journal of Technology Innovation
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• v.21 no.2
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• pp.319-354
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• 2013

As creative economy gets attention, the capabilities of transforming creative ideas into intellectual property and utilizing it commercially have become important than ever before. Korea is lack of the capabilities of utilizing intellectual property compared to those of accumulating it. This paper focuses on the strategic implication of an injunctive relief, which has a far-reaching impact on firms' business strategies as well as national industrial competitiveness because losers in lawsuits are expelled from markets. It analyzes the Samsung-Apple global IP lawsuits about smartphones and tablet PCs, which have expanded into 9 countries since 2011 when the Apple filed the IP lawsuit against Samsung in the US for the first time. In particular, this paper analyzes the requirements to get the permanent injunctive relief in the lawsuits of intellectual property from reviewing the ruling in the court of the US in 2012 and draws some implications from the perspective of business/industrial strategies. This paper has some limitations in that the lawsuit are still ongoing and it is the first attempt to find out the clue that connects legal and strategic issues in the rulings. Regardless of the limitations, however, this paper expects to contribute to raising the issues as to the importance of harmonizing the capabilities of managing technology with law, in order to survive under the era of creative economy.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.289-298
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• 2014

Recently, the traditional paradigm in railroad technology is changing as more efficient and cost-effective electric vehicle (EV) technologies have emerged. The original concept of PRT (Personal Rapid Transit) proposed in the past has come to be regarded as unrealistic, but its feasibility is improving through the utilization of an EV platform. In particular, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. However, based on the inductive power transfer (IPT) technology, the fast charging of supercapacitors with high energy density can contribute to overcoming this technical challenge and promote the transition to electric-powered ground transportation by improving the appearance of cities. This study discusses the development process of a power supply system for PRT, including concept design, numerical analysis, and device manufacturing, along with performance predictions and evaluations. In terms of results, the system was found to meet the performance requirements for power supply modules on a test-bed.

• Spatial Information Research
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• v.21 no.4
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• pp.35-45
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• 2013

Most multimedia contains location information whether they are implicit or explicitly, and which are very useful for several purposes. In particular, we may use location information in defining query conditions to retrieve relevant multimedia. For this reason, a number of works have been done to organize and retrieve geo-referenced multimedia data. However, they mostly focus on outdoor space where position is identified by (x, y, z) coordinates. In this paper, we focus on multimedia in an alternative space, indoor space, which differs from outdoor space in several aspects. First indoor space is considered as symbolic space, where location is identified by a symbolic code such as room number rather than coordinates. Second, topological information is a crucial element in providing indoor spatial information services. Third, indoor space is in more micro-scale than outdoor space, which influences on determining the visibility of cameras. Based on these different characteristics of indoor space, we survey the requirements of management systems of indoor geo-referenced multimedia. Then we propose a geo-coding scheme for multimedia in indoor space as an extension of IndoorGML, an OGC(Open Geospatial Consortium) candidate standard for indoor spatial information. We also present a prototype system called, IngC (INdoor Geo-Coding) developed to store and manage indoor geo-referenced multimedia.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.835-845
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• 2013

Association rule of data mining techniques is the method to quantify the relevance between a set of items in a big database, andhas been applied in various fields like manufacturing industry, shopping mall, healthcare, insurance, and education. Philosophers of science have proposed interestingness measures for various kinds of patterns, analyzed their theoretical properties, evaluated them empirically, and suggested strategies to select appropriate measures for particular domains and requirements. Such interestingness measures are divided into objective, subjective, and semantic measures. Objective measures are based on data used in the discovery process and are typically motivated by statistical considerations. Subjective measures take into account not only the data but also the knowledge and interests of users who examine the pattern, while semantic measures additionally take into account utility and actionability. In a very different context, researchers have devoted a lot of attention to measures of confirmation or evidential support. The focus in this paper was on asymmetric confirmation measures, and we compared confirmation measures with basic association thresholds using some simulation data. As the result, we could distinguish the direction of association rule by confirmation measures, and interpret degree of association operationally by them. Futhermore, the result showed that the measure by Rips and that by Kemeny and Oppenheim were better than other confirmation measures.

• The Journal of Sustainable Design and Educational Environment Research
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• v.15 no.1
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• pp.30-39
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• 2016

Students receiving plan is not based on short-term indicators, such as student-centered, student-induced factor to address school needs new complaint, it is necessary to establish the school in the center of a long-term (30 years) perspective. Therefore, analysis of Cheongju students can examine the entire 30 years of the elementary school in this study are as follows: First, given the increasing number of students in seven models and presented the case to its types. Second, considering the geographical characteristics and the development of regional characteristics classify 55 elementary Schools in Cheongju City by dividing the number of students increase or decrease trend to 10 zones the results are as follows: Students Number increasing school group of 4 schools, 15 schools students Number fell in shot Term, the Students Number dropped in middle Term 26 schools, 10 was a small school. In particular, it is urgently necessary to establish measures for these small schools. Third, despite the reduced number of students indicated in the analysis result, caused the social conflict factors by excessive new school requirements. It also caused a number of students from schools when the Curve of Students Number are to remain flat or decline. It shows that no additional new demand of School in the region. Fourth, the number of students increasing trend forecasting model

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.3
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• pp.129-138
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• 2014

After global economic crisis, China has become one of the two pillars in the global economies and the country contributing to the Korean economy. Nevertheless, the research on Chinese financial market, particularly capital market, is rare to date. This study examined the growth enterprise market that emergedat the Shenzhen stock exchange and made comparative analysis on before and after listing for the Chinese small and medium sized firms and venture firms. The listing requirements at the Chinese growth enterprise market for the technologically innovative venture firms and fast-growing small and medium sized firms with financing purpose were more alleviated than the main board of Shenzhen stock exchange. Moreover, the listing procedures are simplified as well. Accordingly, many Chinese enterprises tend to list and the competition for listing is also intense. In particular, with the 36 initially listed firms at growth enterprise market as the research target, the investigation for the business performance before and after listing reveals that the three indexes including return on common equity, debt ratio and operating profit growth rate dropped dramatically for most all the firms. That is, the profitability and growth for the venture firms and small and medium sized firms listed on the Chinese growth enterprise market decreased rapidly after going public, only the stability improved due to the great financing. Taking a step forward, this phenomenon may result from the exaggerated reporting for the business performance before listing with the purpose of going public by the venture firms and small and medium sized firms. Thus, Chinese Securities Regulatory Commission should strengthen the accounting evaluation standard and regulation for the listing firms before going public. In addition, strict sanctions should be imposed on the firms with fraudulent accounting to establish healthy capital market.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.8-14
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• 2017

Gearboxes for power transmission of a rotorcraft transfer power generated by an engine to the fan and the pusher for up, down and forward flight. The gearboxes are divided into the main gearbox and the sub-gearbox. The main goal of the gearbox design is to design the weight as light as possible within a range that satisfies all given requirements (transmission power, mounting space, etc.). In particular, the initial conceptual design is very important to reduce the weight of the gearbox, since the weight can vary greatly depending on the system configuration, even if it has the same function. In this study, various conceptual designs of the gearbox according to the installation position of the engine were presented. Also, the element parts such as gears and bearings in each concept design were designed by sizing for their life, and the estimated weights of the conceptual system configuration were compared.