• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.348-356
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• 2012

This study is identifying early takeoff phenomenon in relational network like SNS and investigates influence of innovator or hub at early takeoff and diffusion size at takeoff point. The major finding of this study are as follows. First, multinominal-logit analysis conducted to explore the impact of innovator and hub at early stage of information diffusion and early takeoff. Hub in early stage of information diffusion impact early takeoff. Second, our study shows that innovator and hub at early stage of information diffusion impact diffusion size at takeoff point. Third, hub is more impact early takeoff and diffusion size at takeoff point then innovator. This study provides implication for professionals by confirming hub's influence in study of successful information diffusion by early takeoff. The limitation and future direction are discussed.

• Asian Journal of Innovation and Policy
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• v.8 no.1
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• pp.141-161
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• 2019

A considerable amount of research has been directed at subsistence markets in the recent past with the belief that these markets can be tapped profitably by marketers. Consequently, such markets have seen the launch of a number of innovative products. However, marketers of such forecasts need timely and accurate forecasts regarding the diffusion of their products. The Bass model has been widely used in marketing management to forecast diffusion of innovative products. Given the idiosyncrasies of subsistence markets, such forecasting requires an understanding of effective estimation techniques of the Bass model and their use in subsistence markets. This article reviews the literature to achieve this objective and find out gaps in research. A finding is that there is a lack of timely estimates of Bass model parameters for marketers to act on. Consequently, this article sets a research agenda that calls for timely forecasts at the takeoff stage using appropriate estimation techniques for the Bass model in the context of subsistence markets.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.115-124
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• 2006

This study was conducted to investigate the running motion in the max-velocity phase(150-160m) and the fatigue phase(350-360m) during 400m sprint by performed elementary school athletes. Eighteen elementary school male athletes who achieved at least the 3rd place in the sprint at the Korea Gangwon-Do elementary school track and field meetings during 2004 and 2005 were selected as subjects. The running motions performed by the subjects were recorded using two 8mm high speed cameras at the nominal speed of 100 frames per second. The Direct Linear Transformation technique was adopted from the beginning of filming to the final stage of data extraction. KWON 3D motion analysis package program was used to compute the 3 Dimensional coordinates, smoothing factor in which lowpass filtering method was used and cutoff frequency was 6.0 Hz. The movement patterns during foot touchdown and takeoff for the running stride were related with the biomechanical consideration. Within the limitations of this study it is concluded: In order to increase running velocity, several conditions must be fullfilled at the instant of leg touchdown and takeoff during the fatigue phase(350-360m). First, the body C.O.G(Center of Gravity) height should be raised at the instant of leg touchdown and takeoff during the fatigue phase. Second, the foot contact time should be shortened and the takeoff distance should be increased at the foot takeoff during the fatigue phase. Third, the shank angular velocity with respect to a transverse axis through the center of gravity should be increased during the leg touchdown and takeoff in the fatigue phase. Forth, the active landing style described as clawing the ground with the sole of the foot should be performed during the leg touchdown and takeoff in the fatigue phase) phase. Fifth, In order to increase running velocity in the fatigue phase while taking a slightly greater leg knee angle and body lean angle within the range of the subject's running motion during the fatigue phase would result in greater flight distance.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.124-132
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• 2015

When Building Information Modeling (BIM) was introduced at the early stage, it was only utilized as a three-dimensional visualization tool. Nowadays, however, BIM is being studied for increasing design productivity and managing enormous information on building life cycle. One of the representative research is developing 'common prototype BIM libraries'. BIM data made of common prototype libraries should be utilized in various ways, quantity takeoff, code checking, energy analysis and so on. However, common prototype BIM libraries are not enough to estimate accurate cost. For example, composite wall libraries should be divided into several single objects, wall structure and finishes, for the quantity takeoff and construction cost calculation. In this paper, we are suggesting an automated division algorithm of composite wall and developing a system prototype for it. This study is expected to reduce extra modeling work and contribute to fast and accurate cost calculation in the construction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.26-29
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• 2017

KARI has been conducting R&D for independent development of KSLV-II since 2010. Vehicle holding device is a device for vertically standing SLV on the launch pad of launch complex and fixing the lower part of vehicle in order to firmly fix vehicle so that SLV does not fall from an external load such as a wind load. When thrust generated after the 1st stage engine ignition of SLV must exceed the takeoff weight of vehicle, and holding device should be quickly released so that it does not interfere with takeoff of vehicle like other ground equipment at the beginning of the launch. Pyro-valve is one of the key components constituting VHD, and it should have high reliability and quick response characteristics with similar functional parts applied to launch vehicle separation device and satellite separation device. Through this paper, I intend to broaden the overall understanding of the development process of pyro-valve for VHD and KSLV-II.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.330-339
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• 2008

Ground-based interceptors(GBI) comprise a major element of the strategic defense against hostile targets like Intercontinental Ballistic Missiles(ICBM) and reentry vehicles(RV) dispersed from them. An optimum design of the subsystems is required to increase the performance and reliability of these GBI. Propulsion subsystem design and optimization is the motivation for this effort. This paper describes an effort in which an entire GBI missile system, including a multi-stage solid rocket booster, is considered simultaneously in a Genetic Algorithm(GA) performance optimization process. Single goal, constrained optimization is performed. For specified payload and miss distance, time of flight, the most important component in the optimization process is the booster, for its takeoff weight, time of flight, or a combination of the two. The GBI is assumed to be a multistage missile that uses target location data provided by two ground based RF radar sensors and two low earth orbit(LEO) IR sensors. 3Dimensional model is developed for a multistage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The monostatic radar cross section (RCS) data of a three stage ICBM is used. For preliminary design, GBI is assumed to have a fixed initial position from the target launch point and zero launch delay. GBI carries the Kill Vehicle(KV) to an optimal position in space to allow it to complete the intercept. The objective is to design and optimize the propulsion system for the GBI that will fulfill mission requirements and objectives. The KV weight and volume requirements are specified in the problem definition before the optimization is computed. We have considered only continuous design variables, while considering discrete variables as input. Though the number of stages should also be one of the design variables, however, in this paper it is fixed as three. The elite solution from GA is passed on to(Sequential Quadratic Programming) SQP as near optimal guess. The SQP then performs local convergence to identify the minimum mass of the GBI. The performance of the three staged GBI is validated using a ballistic missile intercept scenario modeled in Matlab/SIMULINK.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.738-743
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• 2008

Recently BIM is utilized to improve productivity for Life Cycle Cost of construction projects. Therefore, the establishment of BIM process by each construction project is a necessary element. However, cases and the pertinent researches that BIM process by each project is established are still not enough in Korea. The study proposed construction of BIM process through how to set up BIM application, how to organize a BIM team, how to set up a family and modeling method in the early stage. To achieve the purpose, the study examined application ability of BIM process by carrying out basic setting and modeling work through pilot study model, examination of the amount of materials and information interchange with IFC. The study attempted making a foundation of domestic BIM guideline construction through the above examination.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.79-92
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• 2011

Quantity take-off is one of the critical tasks that determine the cost of a construction project, and its result should be accurate and reliable. BIM-based quantity take-off is a very attractive process for practitioners since the quantity take-off can be done automatically in a fast and accurate way. However, the result of BIM-based quantity take-off can be varied depending on how BIM was modeled. As a project progresses, more detailed design information is getting available, and it can be expected that the degree of completeness and accuracy for the BIMbased quantity take-off is going to be improved as well. However, when estimation is performed at each stage of a project life-cycle, there is no way to measure or forecast how accurate of the quantity take-off result from the BIM data given at the current stage. Therefore, this research derived factors that affect the BIM-based quantity takeoff and developed a methodology and framework to measure and forecast the completeness of BIM-based quantity take-off. The measurement framework and index that are proposed by this research was verified and validated for their consistency and feasibility through six pilot projects.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.151-165
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• 2014

Korean traditional alcohol's growth gets declined after Makgeolli's boom and it's time to enter the takeoff stage using cup based on the characteristics of each alcohols in order to their globalization and quality improvement. For now, there are 3 features of Korean traditional alcohol's cup design development; subdivision, quality improvement, systematization. However, there's no product design case that reflect the characteristics of the alcohol from the planning phase. Therefore, it needs to establish process technology for storytelling and emotion based cup design. This research aims to extract the specification for cup design and to find out the visualization element of cup's shape and material by studying 5 senses and traditional alcohol's objective informations. Through the study, the elements that can maximize the specific traditional alcohol's marketability: cup's label, pattern, decorative element based on the storytelling like history and tale were found. As a result, those result can give a new export strategy by developing competitive design that has emotional element and storytelling from the traditional alcohol's characteristics in a situation of stagnant export of the small sized home-brewed liquor business.

• Korean Journal of Construction Engineering and Management
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• v.14 no.3
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• pp.53-64
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• 2013

In building construction project, there are numerous information or data parts across many different software applications and professional specialists. BIM (Building Information Modeling), as a medium for managing information generated during construction project, it is intended to enhance the effectiveness of construction management and reap a lot of advantages such as, automatic quantity takeoff, error-free estimation, 4D(3D+Time), 5D(4D+Cost) simulation. Nevertheless, the overall and practical effectiveness of BIM utilization is difficult to justify at this stage. While helpful, there are some limitation when BIM applied to construction management due to the differences of data processing process between BIM and work in the field, limitations of information generated from BIM object and interoperability problem among BIM application. Therefore, this paper propose a framework integrating BIM with cost-schedule information using IFC. And we construct the system prototype based on the framework and performed case study to examine the framework. The proposed framework provides the information basis for BIM based cost-schedule integration. ultimately, the framework increase the utilization of BIM and work efficiency of construction industry by supporting an understanding of information.