• Earthquakes and Structures
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• v.1 no.1
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• pp.21-41
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• 2010

Multi-span steel-concrete composite (SCC) bridges are very sensitive to earthquake loading. Extensive damage may occur not only in the substructures (piers), which are expected to yield, but also in the other components (e.g., deck, abutments) involved in carrying the seismic loads. Current seismic codes allow the design of regular bridges by means of linear elastic analysis based on inelastic design spectra. In bridges with superstructure transverse motion restrained at the abutments, a dual load path behavior is observed. The sequential yielding of the piers can lead to a substantial change in the stiffness distribution. Thus, force distributions and displacement demand can significantly differ from linear elastic analysis predictions. The objectives of this study are assessing the influence of piers-deck stiffness ratio and of soil-structure interaction effects on the seismic behavior of continuous SCC bridges with dual load path, and evaluating the suitability of linear elastic analysis in predicting the actual seismic behavior of these bridges. Parametric analysis results are presented and discussed for a common bridge typology. The response dependence on the parameters is studied by nonlinear multi-record incremental dynamic analysis (IDA). Comparisons are made with linear time history analysis results. The results presented suggest that simplified linear elastic analysis based on inelastic design spectra could produce very inaccurate estimates of the structural behavior of SCC bridges with dual load path.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.597-603
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• 2015

This study investigates the actual domestic and overseas cyclewear wearing conditions for male high school cyclists. The study results provide factors and degree of dissatisfaction as basic data for cyclewear development. This study was conducted on 35 male high school cyclists (freshman to seniors) by a questionnaire and interview method. Study results were: Male high school cyclists considered functionality as most important when they bought cyclewear and the brand they most often bought was a cheap domestic brand. Dissatisfaction with the crotch, thigh circumference and minimum leg circumference was higher than other parts during wearing. A cyclist is more sensitive to wear because they require more lower body motion than other parts. Cyclewear should be: less transformed even by frequent laundering, made of breathable material and use a sewing technique that minimizes air resistance and increases fit the body. Functional pads ergonomically designed with high tactile materials should be developed to prevent 'saddle sore' and groin soreness region that happens because of a lower body bending posture when cycling. A follow-up study is recommended to further develop excellence in cyclewear functionality and dimension suitability for male high school cyclists through the size system.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.3
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• pp.518-528
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• 2010

This study analyzes the work environment and the work clothes wearing conditions of shipyard painters. In addition to this, three types of experimental painting work clothes were evaluated by painters in terms of the material performance and wearing functions. The findings on the harmful painting work environmental factors were organic solvents, noise, heavy dust, high temperatures, and noxious fumes. The body parts damaged during painting operations were the skin, arms, whole body, and face. In general, the satisfaction with the wearing performance of work clothes for painting was low especially in regards to sweat absorbency, sweat permeability, body protection, covering, and the work motion suitability. The satisfaction with the wearing sense of painting working clothes (regardless of the type of material) was high in the order of movement comfort> sensual comfort> physiological comfort. The satisfaction in overall comfort according to the types of material was high in the order of nylon> SMS nonwoven fabric> SF nonwoven fabric.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.8
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• pp.1378-1391
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• 2010

This study examines the wearing conditions of working clothes according to the working environment and working processes at machinery, automobile, shipbuilding industry sites. It also investigates the relationship between the wearing sense of working clothes and the overall comfort according to work processes. The hazardous working environment was high in the order of the shipbuilding industry, machinery, and automobiles. The findings on the harmful overall work environmental factors were the noise, heavy dust, and noxious fumes, respectively. In general, the satisfaction with the wearing performance of working clothes was low especially with regard to sweat absorbency, sweat permeability, body protection and covering, and the work motion suitability. In respect of the correlation between the overall comfort and the wearing sense of working clothes, the satisfaction was decreased in the order of movement comfort, sensual comfort, and physiological comfort.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.580-583
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• 2017

To compensate the degraded SAR image due to the residual errors and the spatial variant errors remaining after the motion compensation in the airborne SAR, we have introduced the autofocus method based on the partition processing. Thus, after we perform the spatial partition for the spotlight SAR data and the time partition for the stripmap SAR data, we reconstruct the subpatch images for the partitioned data. Then, we perform the local autofocus with the suitability analysis process for the phase errors estimated by the autofocus. Moreover, if the estimated phase errors are not properly compensated for the subpatch images, we perform the phase compensation method with the weight to the estimated phase error close to the degraded subpatch image to increase the SAR image quality.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.173-178
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• 2000

Subjective correspondence among visual variables, auditory variables and vibratory feedback to a hand was experimentally examined to improve usability of a remote controller. First, we studied the correspondence among visual variables represented on a screen or auditory variables and the duration of vibratory stimulus to the subjects' hand by subjective evaluation. Subjective rating method was used in ten items; suitability, comprehensibility, ease-to-use, naturalness, variety, activity, usualness, interest, wish-to-use and feeling of pleasure. Second, to show the effects of multi-modal interface using visual sense, the sense of auditory and vibratory sense, we combined positive stereotype of visual variables and auditory variables provided with the first experiment. The results showed some stereotype between visual variables or auditory variables and duration of vibratory stimulus. Some of the variables such as size, direction of motion, hue, brightness of color and volume of sound had high correspondence with the duration of vibration.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1948-1952
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• 2012

The paper presents modal testing and analysis in order to obtain the dynamic characteristics of a middle spacer grids of a nuclear fuel rod. A spacer grid is one of the important structural elements supporting nuclear fuel rods. Such a fuel rod can be oscillated by its thermal expansion, neutron irradiation and etc. due to cooling water flow under the operation of a nuclear power plant. When the fuel rod vibrates, fretting wear due to repeated friction motion between the fuel rods and spacer grids can be occurred, and so the fuel rod is damaged. In this paper, through modal analysis and testing, natural frequencies and modes of a middle spacer grid were calculated, and the following conclusions were obtained. Firstly the numerical first-seven natural frequencies for spacer grids of a fuel rod having complicated structures have a small difference within 3.8% with experimental natural frequencies, and so the suitability of simulation results was verified. Secondly, experimental mode shapes for a middle spacer grid of a nuclear fuel rod were verified by obtaining lower non-diagonal terms through MAC(Modal Assurance Criteria), and were confirmed by the simulation modes.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.734-745
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• 2021

In order to achieve a good and competitive FPSO design, the building cost and the motion performances are the two most critical and conflicting KPIs to be considered. In this study, the author's previous work (Lee, et al., 2021) on the optimization of an FPSO's hull dimensions with 1800 MBBLs storage capacity at Brazil field was extended using a multi-objective parametric optimization with the hull steel weight and the operability which are closely related to the building cost and the operational cost during the lifetime, respectively. For the purpose of more realistic and practical FPSO design, the constraints related to crew comfort and the safe helicopter take-off and landing operation were newly added. Also, the green water on deck was calculated accurately to check the suitability of the designed freeboard height using a newly developed real-time calculation module for the relative wave elevations. With aids of this updated optimization formulation, we presented multiple optimal FPSO dimensions expressed as a Pareto set which aids FPSO designers to conveniently select the practical and competitive dimensions. The excellence of the developed approach was verified by comparing the optimization results with those of FPSOs dimensioned for operation at West Africa and Brazil field.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.56-66
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• 2010

The various total replacement artificial discs have developed because spinal fusion has shown a lesser mobility of an operated segment and an accelerated degeneration at adjacent discs. But almost artificial discs have not yet been reached on the substitute surgery of fusion because many problems such as those clinical success rates were not more than them of fusion have not solved. In this paper, vertically inserted assemble-screw fixture in vertebrae was proposed to improve the fixed capability of artificial disc. And also, to evaluate the design suitability of newly designed screw-type, including fixtures of commercial discs such as wedge and plate type, the 1/4 finite element model with a vertebra and various implanted fixtures were generated, and next, 3 bending motions such as flexion, bending and twisting under the moment of 10Nm and compression under the force of 1000N were considered, respectively and finally, FE analyses were performed. Results of three fixture types were compared, such as Range of Motion and maximal stress, and so on. For ROM, the screw type was average 58% less than the wedge type and was average 42% less than the plate type under all loading conditions. For average stress ratio at closer nodes between vertebra and each fixture, the wedge type was the lowest as minimum 0.02 in twisting, screw types were the highest as maximum 0.28 in compression. As the results of using cement material, it was predicted that the instability problem of the wedge type was better solved. The screw type which could be increased by implanting depth according to the number of assembling mid screws, showed that the decreased tendency of ROMs and maximal cancellous bone stresses. In further study, controlling the number of assembling screws that was suitable for a patient's bone quality, development of surgical tools and keeping on design supplementations, which will be able to develop the competitive artificial disc.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.8-14
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• 2020

According to the statistics provided by Korean Maritime Safety Tribunal for the year 2018, the majority of marine accidents in the past four years have occurred in fishing boats and small-sized boats. Negligent behavior resulting from not looking outside and non-compliance with navigation laws are the primary reasons behind ship collisions. Although safety education and training are reinforced to prevent such accidents, they still occur frequently. Hence, technical methods are continuously being developed to reduce ship collisions caused by human cause. The objective of this study is to reduce ship collisions by employing the WAVE communication system, which has short transmitting and receiving periods that can be incorporated for high-speed small-sized vessels. In this study, the suitability of the communication range was examined, and the appropriate range and timing for avoidance motion were accordingly selected, and a control algorithm based on the same was thereby designed. Consequently normal operation of the collision avoidance system was verified by connecting and simulating the proposed WAVE communication router-controller-steering equipment.