• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.24-32
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• 2007

In this study, computational structural vibration analyses of a smart unmanned aerial vehicle (SUAV) with tilt-rotors due to dynamic hub loads have been conducted considering detailed supporting structures of installed equipments. Three-dimensional dynamic finite element model has been constructed for different fuel conditions and tilting angles corresponding to helicopter, transition and airplane flight modes. Practical computational procedure for modal transient response analysis is successfully established. Also, dynamic loads generated by rotating blades and wakes in the transient and forward flight conditions are calculated by unsteady computational fluid dynamics technique with sliding mesh concept. As the results of present study, transient structural displacements and accelerations of the vibration sensitive equipments are presented in detail. In addition, vibration characteristics of structures and installed equipments of which safe operation is normally limited by the vibration environment specifications are physically investigated for different flight conditions.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.141-144
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• 2005

Sensing and interfacial evaluation of Ni nanowire strands/polymer composites were investigated using Electro-micromechanical technique. Electro-micromechanical techniques can be used as sensing method for micro damage, loading, temperature of interfacial properties. Using Ni nanowire strands/silicone composites with different content, load sensing response of electrical contact resistivity was investigated under tensile and compression condition. The mechanical properties of Ni nanowire strands with different type/epoxy composites were measured using uniformed cyclic loading and tensile test. Ni nanowire strands/epoxy composites showed humidity and temperature sensing within limited ranges, 20 vol% reinforcement. Some new information on temperature and humidity sensing plus loading sensing of Ni nanowire strands/polymer composites could be obtained from the electrical resistance measurement as a new concept of the nondestructive interfacial evaluation.

• IE interfaces
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• v.21 no.3
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• pp.283-293
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• 2008

It is important to choose and develop right business model in the process of implementing the ubiquitous service concept. In particular, it is also required to build a method which can assist in establishing a business model in a competitive perspective to differentiate business strategy. However, we could not find the existing studies which tried to develop business model including methods on how to differentiate business strategy in a competitive environment. In this study, we propose an ontology for repository of ubiquitous business model and address on how to apply the proposed business model repository to real ubiquitous industry. We also built a repository of unlicensed wireless device industry to check the applicability of proposed ubiquitous business model ontology and to show the various examples. We expect that building the business model repository contributes to reduce the redundancy and inefficiency for industry as well as to increase likelihood of business success for an individual company.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2136-2142
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• 2011

Smart Device Communications using the development of anti-theft system for vehicles have been investigated. because Progress of Smart Device If someone get the Key for Vehicle theft, he can be easily stolen vehicle. We thought about the concept of dual security devices. Using vehicle's identifier ID of CAN, when Comparing Smat phone identifier ID value and identifier ID received from the Can in the Head, If the same ID is compared. At this point after the activity of the vehicle's ACC On/Off the system allows the vehicle's ignition.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.29-35
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• 2004

Materials and Methods: Total number of peroneal perforator flap is 14 cases, which 10 cases were man, 4 cases were woman. The range of age was 12 years old minimally and until 63 years old. The trauma was most common etiology, which was like traffic accidents, 9 cases. We confirmed tibialis anterior artery patency by doppler flow meter, angiography as preoperative evaluation. Results: 1. The success rate was 91%, that in 14 cases, 13 cases were succeded. 2. To obtain successful result of peroneal flap, one must have the anatomic concept for vascular pattern, 8 cases were between peroneus muscle and soleus muscle branch type but, 3 cases were through soleus muscle branch type, so we treated these cases by using soleus muscle including peroneal perforating branch not to injury perforating artery directly. 3. The pedicle size was between minimally $2{\times}2.5cm$ and maximally $6.5{\times}8.5cm$ so we could treat large recipient site. 4. The pedicle length was between minimally 3.2 cm and maximally 11.5cm, average 7.5 cm. 5. The diameter of perforating artery was estimated by inspection, that was about 0.2-0.5 cm Conclusion: The peroneal perforating artery flap has merits that we can approach in avascular zone and has wide movable range from foot to distal femur and little donor site mobidity and can harvest osteocutaneous flap. The weak point was the irregular anatomy of nutrient artery and not to contain sensory nerve.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.1
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• pp.57-63
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• 2007

The oxidizer-rich preburner is applied to the high efficiency closed cycle rocket propulsion system. This system is generally operated on oxidizer-fuel mixture ratio over than 50. The spray quality and mixing performance are very important for stable combustion of this preburner. This paper presents basic design concept and spray characteristic of the oxidizer-rich preburner injector and this result could be applied to the development of the oxidizer rich preburner system.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.51-58
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• 2005

The use of geogrid for SRW systems and bridge abutment has increased rapidly over the past 10 years in Korea. The concept of segmental retaining walls and reinforced soil is very old and for example The Ziggurats of Babylonia(i.e. Tower of Babel) were built some 2,500 to 3,000 years ago using soil reinforcing methods very similar to those described in current design. Modern SRW(Semental Retaining Wall) units were introduced in 1960's as concrete crib retaining wall systems. In this paper, the friction properties between segmental concrete units and geogrid are investigated by performing various tests.

• Journal of the Korean housing association
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• v.21 no.3
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• pp.41-52
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• 2010

The purpose of this study is to clarify multi-habitation, a new phenomenon in which inhabitants in urban areas reside in primarily condominiums on weekdays and retreat to dwellings in rural areas on weekends, and to examine the various life styles related to multi-habitation. Through the interviews and site surveys, three major subtypes of multi-habitation were identified to support the theoretical framework: interchange style, sedentary style, and special style. Findings include that first, in order to discuss multi-habitation, the terms primary home and secondary home are introduced. Based on the concept of primary home and secondary home, a variety of multi-habitation can be described using spatial locations in urban and rural areas. Second, systematic deregulation for the second home ownership should be made to promote citizens' interchange. Also urban residents should make more efforts to integrate into rural communities. Third, for some remote areas such as Cheju Island, it is observed that multi-habitation is limited by cost, time, and lifestyle.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.641-654
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• 2014

A new computer code, named CORONA (Core Reliable Optimization and thermo-fluid Network Analysis), was developed for the core thermo-fluid analysis of a prismatic gas cooled reactor. The CORONA code is targeted for whole-core thermo-fluid analysis of a prismatic gas cooled reactor, with fast computation and reasonable accuracy. In order to achieve this target, the development of CORONA focused on (1) an efficient numerical method, (2) efficient grid generation, and (3) parallel computation. The key idea for the efficient numerical method of CORONA is to solve a three-dimensional solid heat conduction equation combined with one-dimensional fluid flow network equations. The typical difficulties in generating computational grids for a whole core analysis were overcome by using a basic unit cell concept. A fast calculation was finally achieved by a block-wise parallel computation method. The objective of the present paper is to summarize the motivation and strategy, numerical approaches, verification and validation, parallel computation, and perspective of the CORONA code.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.823-826
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• 2012

In this paper, we propose an efficient network virtualization model in cloud computing environments. Virtualization is a key technology for the implementation of service-oriented architecture. It is a standardized framework that can be reused or integrated with changing business priorities through a IT infrastructure. Network virtualization has emerged as an important technical issues of the future virtualization technology in Internet. The concept of network virtualization and related technologies stay in ambiguous status since network virtualization is in its early stage. Thus, we propose a network virtualization model for cloud environment by analyzing the existing network virtualization technologies.