• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.451-453
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• 2007

This paper describes the design of an asynchronous implementation of a sensor network processor. The main purpose of this work is the reduction of power consumption in sensor network node processors and the research presented here tries to explore the suitability of asynchronous circuits for this purpose. The Handshake Solutions toolkit is used to implement an asynchronous version of a sensor processor. The design is made compact, trading area and leakage power savings with dynamic power costs, targeting the typical sparse operating characteristics of sensor node processors. It is then compared with a synchronous version of the same processor. Both versions are then compared with existing commercial processors in terms of power consumption.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.121-133
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• 2020

Underwater cutting has a different mechanism than dry cutting, and there are more restrictions than benefits. Due to these constraints, research and development of underwater cutting has been very limited. At present, reactor dismantling is emerging as an important task worldwide, and reactor pressure containers, a key part of the reactor, are decommissioned based on underwater cutting. Reactor pressure containers are high-level radioactive waste, which is one of the main goals of today, such as to bridge the gap between environmental, safety, and cutting performance; hence, a process suitable for cutting should be applied. Therefore, many studies are being conducted on underwater cutting in connection with the dismantling of nuclear reactors in various areas in order to find appropriate processes. This paper first introduces the core technology of underwater cutting processes and discusses various processes. The emphasis is then placed on the adequacy of the reactor dismantling application. More specifically, we examine the suitability for the mechanical and thermal cutting processes, respectively, to find a solution suitable for dismantling a reactor. We discuss how each solution can sufficiently perform the specified functions at each stage of reactor dismantling and suggest that these processes can perform all of the work of underwater cutting.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.316-322
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• 2002

This paper presents the temperature-dependent hysteresis identification of an electro-rheological (ER) fluid under various operating temperatures using the Preisach model. As a first step, polymethylaniline (PMA) particles are prepared and mixed with silicone oil to make an ER fluid. A couette type electroviscometer is then employed to obtain the field-dependent shear stress. In order to show the suitability of the Preisach model to predict a physical hysteresis phenomenon of the ER fluid, two significant properties; the minor loop property and the wiping-out property are experimentally examined under three dominant temperature conditions. Subsequently, the Preisach model fur the PMA-based ER fluid is identified using experimental first order descending (FOD) curves. The effectiveness of the identified hysteresis model is verified in the time domain by comparing the predicted field-dependent shear stress with the measured one under the both specified and unspecified temperatures. In addition, the hysteresis model proposed in this work is compared to Bingham model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.1
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• pp.8-22
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• 2015

Most jet spray and atomization simulations are done with the Eulerian method which has inherent disadvantage in representing jet breakups and droplets. Full Lagrangian particles method called Smoothed Particle Hydrodynamics(SPH) is used in this work. We develop the SPH code and perform validations that confirm the suitability of our SPH method for simulating liquid jet atomization problem. Then, we conduct the simulation of liquid-liquid swirl coaxial injector for comparison against the experimental data.

• Smart Structures and Systems
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• v.1 no.4
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• pp.355-368
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• 2005

Large and complex structures are being built now-a-days and, they are required to be functional even under extreme loading and environmental conditions. In order to meet the safety and maintenance demands, there is a need to build sensors integrated structural system, which can sense and provide necessary information about the structural response to complex loading and environment. Sophisticated tools have been developed for the design and construction of civil engineering structures. However, very little has been accomplished in the area of monitoring and rehabilitation. The employment of appropriate sensor is therefore crucial, and efforts must be directed towards non-destructive testing techniques that remain functional throughout the life of the structure. Fiber optic sensors are emerging as a superior non-destructive tool for evaluating the health of civil engineering structures. Flexibility, small in size and corrosion resistance of optical fibers allow them to be directly embedded in concrete structures. The inherent advantages of fiber optic sensors over conventional sensors include high resolution, ability to work in difficult environment, immunity from electromagnetic interference, large band width of signal, low noise and high sensitivity. This paper brings out the potential and current status of technology of fiber optic sensors for civil engineering applications. The importance of employing fiber optic sensors for health monitoring of civil engineering structures has been highlighted. Details of laboratory studies carried out on fiber optic strain sensors to assess their suitability for civil engineering applications are also covered.

• Journal of the Korean Institute of Educational Facilities
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• v.15 no.4
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• pp.38-47
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• 2008

The idea that a school could take a role of educating each community personnel as well as students and the school building could be a center in a community is discussed in this paper. Also, as rental housings being included in the community and placed near school buildings, school facilities can be shared and cover the shortage of social welfare facilities. Thus urban social facilities including schools, social and cultural facilities, and rental housings should be planned as a bundled scheme. The objective of this Paper is to find the suitability of building a complex of school, gymnasium, cultural facilities, welfare facilities in school sites, and building rental housing in public building sites, such as cultural facilities and welfare facilities, gymnasium sites in the City of Pyeong Teak. It is found that this assumption can be proved when building a public school of 6 to 7 story or a rental apartment with a floor area ratio of 150% - 200%.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.8
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• pp.648-656
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• 2002

This paper presents the identification of temperature-dependent hysteresis of an electro-rheological (ER) fluid under various operating temperatures using the Preisach model. As a first step, polymethylaniline (PMA) particles are prepared and mixed with silicone oil to make an ER fluid. A couette type electroviscometer is then employed to obtain the field-dependent shear stress. In order to show the suitability of the Preisach model to predict a physical hysteresis phenomenon of the ER fluid, two significant properties; the minor loop property and the wiping-out property are experimentally examined under three dominant temperature conditions. Subsequently, the Preisach model for the PMA-based ER fluid is identified using experimental multiple first order descending (FOD) curves. The effectiveness of the identified hysteresis model is verified in the time domain by comparing the predicted field-dependent shear stress with the measured one under the both specified and unspecified temperatures. In addition, the hysteresis model proposed in this work is compared to Bingham model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.3
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• pp.42-57
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• 2005

The National Education Information System(NEIS) has been utilized in primary and secondary schools. In this paper, we consider the NEIS should be used not only for educational administration affairs, but also for a lifelong management of national human resource. The current School Information Management System(SIMS), including the NEIS, is unsatisfactory due to the insufficiency of actual field suitability and end-user's conveniency. To this, we have devised improvements of the SIMS in the seven problem areas: ) The core business process of the school should be analyzed sufficiently and reflected in SIMS. (2) We should fully utilize groupware functions which activate the learning organization. (3) We might apply and use the CRM techniques of enterprises in SIMS. (4) The SIMS should be easy to make necessary school assessment data. (5) We should complement functions of the SIMS for a lifelong healthcare information management of national human resource. (6) The SIMS should support the school lunch management. (7) We should bring BOM and work-flow concepts into the SIMS.

• Smart Structures and Systems
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• v.11 no.4
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• pp.365-386
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• 2013

Monitoring systems currently applied to concrete bridges include strain gauges, inclinometers, accelerometers and displacement transducers. In general, vertical displacements are one of the parameters that more often need to be assessed because their information reflects the overall response of the bridge span. However, the implementation of systems to continuously and directly observe vertical displacements is known to be difficult. On the other hand, strain gauges and inclinometers are easier to install, but their measurements provide no more than indirect information regarding the bridge deflection. In this context, taking advantage of the information collected through strain gauges and inclinometers, and the processing capabilities of current computers, a procedure to evaluate bridge girder deflections based on polynomial functions is presented. The procedure has been implemented in an existing software system - MENSUSMONITOR -, improving the flexibility in the data handling and enabling faster data processing by means of real time visualization capabilities. Benefiting from these features, a comprehensive analysis aiming at assessing the suitability of polynomial functions as an approximate solution for deflection curves, is presented. The effect of boundary conditions and the influence of the order of the polynomial functions on the accuracy of results are discussed. Some recommendations for further instrumentation plans are provided based on the results of the present analysis. This work is supported throughout by monitoring data collected from a laboratory beam model and two full-scale bridges.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.5
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• pp.623-634
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• 1999

The purpose of this study is to explore the culture of clothing of subgroups among adolescents by residence. In this research informants were selected by selective sampling and ethnographic methods such as field work depth interviews and open-ended descriptions were employed to interpret their culture of clothing. The results were followed. First our adolescents enjoyed the popular song as leisure and these popular culture was their inspiration source of style. Second adolescents were grouping the Kang-Bouk and the adolescents group preferred the style of popular singers and the Kang-Nam adolescents group preferred the musical competence of singers and specific type particularly Hip-Hop style. And in acception pattern of fashion style the Kang-Bouk groups accepted the recent fashion style continuously and wanted to be striking while the Kang-Nam groups accepted the various Hip-Hop styles and sought to comfort and suitability of that style. Third to consider the connotations of marketing the Kan-Bouk groups shopped on the street perceived as fashionable among peer groups and sought to the lower price but the Kang-Nam groups used the shops selling their original ip-Hop style without regard to the price and sites. Although there existed a two years' difference between the first and the second research(1996-1998) subgroups among adolescents according to the residence have had their own culture of clothing constantly. And a segmentation tendency by clothing behavior within the same adolescent generation is revealed more visibly.