• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.243-262
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• 2012

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.206-208
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• 2002

Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool , carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, Protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the result ins level of exposure) depends on many factors. To reduce the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum Quantity in all over the mechanical machining field including high speed type heavy cult ing process.

• Journal of Korea Technology Innovation Society
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• v.8 no.1
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• pp.237-260
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• 2005

This paper aims to review and analyse the introduction process of performance management system(PMS) in the R&D sector. It also examines initial problems and future policy directions of the new system. Theory part deals with various approaches to the PMS and the relation between research evaluation and performance management. The paper then describes how the PMS has been introduced in the National R&D Program by the MOST in terms of the contents of strategic goal, performance goal and performance indicator together with their development process. After this, it captures problems arising in the initial phase and then suggests how they should be solved on the ministerial and cross-ministerial level. Discussed are following topics: lack of strategic planning, grouping of heterogeneous sub-programs, duplication between the OMS and other existing research or performance evaluation. The paper finally suggests policy implications using the logic model which has been developed in a series of recent international conferences.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.494-501
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• 2003

Web casting has become an important opportunity to apply the user-centered concept to broadcasting because it provides real-time interactive service through time and space. It is also necessary to have a new understanding about user who is not a passive viewer any more but an active user. The amount and quality of contents are also important, but usability is a competitive factor as well as the fundamental customer services that have user best experience at the site. Nevertheless most of web casting sites show the low level of usability. In this study we had a comparative evaluation among these sites, MBC, KBS and SBS, which are the representative broadcasting systems. The tests were carried out as heuristic evaluation and usability testing. We analyzed causes and problems of web usability for customer satisfaction and reliability exaltation, and expected the basic knowledge of developing and improving sites.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.119-124
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• 1999

Quantitative evaluation of the tribological conditions at the tool-workpiece interface in metal forming is usually accomplished by the ring-compressinon. test This paper describes an experimental investigation into shear friction factor under cold and hot forming conditions according to materials and lubricants using the ring compression test. Six different materials and five different lubricants were applied in the experiments. calibration curves with the friction coefficient were obtained using FEM analysis and verified by the verified by the experimental results. The influence of materials and lubricants level on friction are discussed. In the ring compression test the shear friction factor has a different from steels and aluminum water base graphite lubricants on cold working conditions and hot working conditions.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.774-775
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• 2015

In this paper, a series of electromagnetic analyses carried out for a high efficiency 22.9/0.38kV mold transformer are presented. The simulations were performed in order to calculate the losses which eventually verify the performance(efficiency) of the designed product. Here, losses include core loss, stray losses of non-current carrying metallic structural parts(core plate and clamp), ohmic loss and eddy current loss of current carrying metallic parts(busbars, leads, terminals and windings). The obtained results of the simulations were compared to the test results and showed high level of accuracy. The loss evaluation technology will allow designers avoid any potential over-design or under-design of the high efficiency products, reducing the manufacture cost and development period compared to the conventional experience-based design procedures.

• Journal of Information Technology Applications and Management
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• v.9 no.4
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• pp.103-126
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• 2002

Information technology becomes more important to small and medium-sized enterprises. Due to the limit of manpower and capital investment in small and medium sized enterprises, how to successfully implement information systems is very critical issue. Previous research shows that lack of systematic methodology for evaluating and directing informatization is a major obstacle for successful implementaion of information systems. This study developed the methodology for evaluating and directing informatization in small and medium-sized enterprises. Empirical study has been conducted to find out major measurement of evaluation as well as validate the model. Finally the systematic guideline, evaluating information level and directing informatization, has been developed in order to help enterprises successfully implement information systems.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.96-100
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• 2015

In the present study, we developed a real-time radiation-monitoring sensor for an underwater radiation-monitoring system and evaluated its effectiveness using reference radiation sources. The monitoring sensor was designed and miniaturized using a silicon photomultiplier (SiPM) and a cerium-doped-gadolinium-aluminum-gallium-garnet (Ce:GAGG) scintillator, and an underwater wireless monitoring system was implemented by employing a remote Bluetooth communication module. An acrylic water tank and reference radiation sources ($^{137}Cs$, $^{90}Sr$) were used to evaluate the effectiveness of the monitoring sensor. The underwater monitoring sensor's detection response and efficiency for gamma rays and beta particles as well as the linearity of the response according to the gammaray intensity were verified through an evaluation. This evaluation is expected to contribute to the development of base technology for an underwater radiation-monitoring system.

• Korean Journal of Veterinary Research
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• v.61 no.3
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• pp.20.1-20.9
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• 2021

This study is to develop a new scoring system for rating Hazard analysis and critical control points prerequisite evaluation items for meat shops to provide a more objective and accurate evaluation of food safety compliance. The importance of each item was measured by looking at the hazard severity level and the rate of non-compliance associated with it. It was found that the new scoring system is more stringent and gives a clearer picture of compliance with the most critical safety standards, and therefore is expected to have a positive effect on the hygiene and safety of livestock products.

• Advances in aircraft and spacecraft science
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• v.8 no.1
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• pp.31-51
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• 2021

Selective laser melting (SLM), one of the most widely used powder bed fusion (PBF) additive manufacturing (AM) technology, enables the fabrication of customized metallic parts with complex geometry by layer-by-layer fashion. However, SLM inherently poses several problems such as the discontinuities in the molten track and the steep temperature gradient resulting in a high degree of residual stress. To avoid such defects, thisstudy proposes a temperature thread multiscale model of SLM for the evaluation of the process at different scales. In microscale melt pool analysis, the laser beam parameters were evaluated based on the predicted melt pool morphology to check for lack-of-fusion or keyhole defects. The analysis results at microscale were then used to build an equivalent body heat flux model to obtain the residual stress distribution and the part distortions at the macroscale (part level). To identify the source of uneven heat dissipation, a liquid lifetime contour at macroscale was investigated. The predicted distortion was also experimentally validated showing a good agreement with the experimental measurement.