• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.228-231
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• 2004

For the bolted joint of the composite structure, quasi-isotropic stacking is generally used to increase the bearing strength. For the bolted joint of uni-directional composite, the fatigue life limit of the bolted joint can be improved by applying clamping force though the static strength is still very low. In this paper, the static and fatigue characteristics of hybrid joint are investigated which can overcome the disadvantage of the bolted joint of uni-directional composite under static loading by applying adhesive joining. The experimental result shows that the static strength and fatigue life can be improved by applying clamping force to the hybrid joint and the hybrid joint is a good solution for the efficiency of the composite structures.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.31-38
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• 2001

This paper deals with the micro turning property of setting angle using diamond tool. The bed of the system has used the granite which has the thermal and vibrational characteristics superior to the cast iron bed for the common machine tool. To minimize the inner and outer vibration of the fuming system, an air pad system was manufactured and tested. The aero-static spindle system which has the excellent rotation accuracy was designed and manufactured. As a result of the micro-cutting test on aluminum alloy, tool setting angel have effected on surface roughness. From the results, the micro-cutting conditions hope to provide the useful actual data using in industrial fields.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.5
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• pp.320-326
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• 2000

The canned motor of 3-phase induction is used for main coolant pump(MCP). The type of motor is canned-motor that stator and rotor are welded by sealed can. So, cooling water flows in the air gap of the canned motor as an independent cycling cooling system from the air gap to yoke of the motor to prevent high temperature of stator can and to lubricate bearing. Heat exchange is occurred between cooling water in the air gap and cooling water from the exterior pump to prevent rising of temperature in the motor. I has to analyze the characteristics of can exactly because the loss and the heat in the can are very important to design MCP. Therefore, thermal analysis is studied considering the effect of eddy-current los induced in the can.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.329-336
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• 1998

The characteristics of vibration and sound signals which occurs at the driving system of electric train are investigated in this study since the vibration of driving system is one of the main sources of vibration and sound in electric train. The vibration signals are changed its signal patterns during the transmission from the source to passengers due to noise or several unknown factors. To avoid the complexity of actual signals of electric train, signals from experimental apparatus of motor/gear driving system are analyzed to find the appropriate method of analysis and to characterize the signal patterns. The used methods are waterfall diagram, transfer function and modal analysis. The results shows that the vibration signals are usually originated from motor bearing and gear meshing and these signals are transmitted to bottom or bogie. Also, the sound signal is similar to the vibration of bottom or bogie, but it is not so clear to figure out the source of vibration.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.91-94
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• 2019

An asteroid specimen was collected by using a fishing net from the waters near Daejin harbor, in the East Sea of Korea on 3 Mar 2017. Based on morphological characteristics, the specimen was identified as Aleutihenricia beringiana (Djakonov, 1950), belonging to the family Echinasteridae, of the order Spinulosida. The genus Aleutihenricia was first described by Clark and Jewett, 2010. This species can be distinguished from other Aleutihenricia species by having a roundish protruding shape of abactinal and actinal plates, the number of abactinal spines bearing three to eight spinelets, and the number of adambulacral spines comprising six to eight spinelets. This is the first report of the genus Aleutihenricia and A. beringiana in Korea.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.372-381
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• 2020

Two cymothoid isopods, Rocinela niponia Richradson, 1909 and Bopyrus squillarum Latreille, 1802, are first reported from Korean waters. Rocinela niponia can be distinguished from its congeners by the following characteristics: the rostral point is round; the eyes are separated from each other; and each pereopods 1-3 has the propodal blade bearing eight robust setae. Bopyrus squillarum is distinguishable from its related species by the following characteristics: the head is separated from pereonite 1, but partially fused on the lateral margins; the first pleonite on the short side is much smaller than other segments; and it is parasitic on the branchial chamber of Palaemon serrifer. Detailed descriptions and figures of these two species are provided in this paper.

• Korean Management Science Review
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• v.22 no.1
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• pp.67-81
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• 2005

This study aims at defining the factors affecting adoption intentions for portable Internet services based on the characteristics of individuals creating the markets and developing strategies of the service, which is expected to be the next-generation telecommunication service. For this Purpose, two types of sub-factors are defined : characteristics of individuals including demographic statistics, usage of existing services, prior cognition, adoption attitudes and service assessments : and adoption Intentions including willingness for subscription, subscription period, willingness to pay, types of usage and preferred device. The results of the study indicate that demographical statistical variables vary depending upon the levels of adoption intentions, and that users of mobile Internet services via mobile phones and wireless LANs are highly probable of being targets for the portable Internet services. Furthermore, the results demonstrate demands for enhancing recognition of the usefulness and ease of use of the services and intense marketing activities for potential users bearing innovativeness to stimulate the market of the portable Internet service. The author is confident that this study will significantly contribute to the successful market entrance of portable Internet service, and also to growth in the market.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.183-196
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• 2004

Sand Compaction Pile (SCP) is a soft-ground improvement technique used for not only accelerating consolidation but also increasing bearing capacity of soils. In this study, laboratory tests and 3-D finite element analysis were peformed to investigate the characteristics of load transfer in SCP with an emphasis on free-strain behavior of piles with low replacement ratios in the range of 30 to $50\%$. Through these focused tests and numerical analyses, we proposed a simplified method to analyze the load transfer characteristics of SCP in soft ground. Moreover, it was shown that estimated normal stresses in SCP using the proposed method were in a reasonable agreement with actual values.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.865-868
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• 2005

This paper presents analysis of dynamic characteristics of a high-speed milling spindle with a built-in motor. The spindle system with a built-in motor can be used to simplify the structure of machine tools. to improve tire machining flexibility of machine. tools, and to perform the high speed machining. In this system the shaft is usually assumed as a rigid rotor. In the spindle system design, it is very important to improve modal characteristics, and modal analysis is performed in the first place. Therefore in this paper, on the assumption that supporting bearings of spindle was selected most suitable condition, analyzed dynamic characteristics of a high-speed spindle according to its position. Optimal design was applicated to select most suitable position of bearings. Considered tile mass and stiffness effects of the built-in motor's rotor are analyzed by numerical method. The result shows the natural frequency of 1st bending mode of spindle.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.239-246
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• 2021

The immunological sperm separation method is economical compared to the existing sorting method, and it is promising for the development of new technologies by reducing sperm damage. Wholemom (WM) is a sex-regulating protein that comprises on immunoglobulin G coupled with magnetic nanoparticles (MNPs) that responds to surface proteins derived from the Y chromosome in cattle. Y sperms are restricted in motility as the WM aggregates them, and the magnet could separate the non-aggregated cells. This study was conducted to investigate the effect of WM treatment on the characteristics of bull sperm. After treating sperm with WM and incubation for 6 h, the motility parameters including total motility, progressive motility, velocity average path, velocity straight line, amplitude of lateral head displacement, and linearity were significantly higher in the WM treatment group than in the control group (p < 0.05). Sperm viability and acrosome reaction rates were similar in both groups during each incubation period (p > 0.05). In conclusion, the immunological sperm sexing procedure using a monoclonal antibody conjugated with MNPs did not affect the characteristics of bull sperm. This study suggests that compared to other techniques, the immunological method for sperm sexing could classify sperm quickly and efficiently without the use of expensive equipment.