• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.28-34
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• 2020

In this study, hole-boss locking washers were developed to prevent vibrational loosening, and a benchmark test was conducted to compare these washers with existing wedge locking washers, which are imported and high-priced. The developed washers consist of an upper washer with bosses and a lower washer with holes, and the bosses are caught in the holes so that the bolt is not loosened. Additionally, the top side of the upper washer and the underside of the lower washer have small wedges perpendicular to the direction of the bolt loosening, suppressing slips. A test by the Korea Test Laboratory indicated that the ratio of the loosening torque to the joining torque is greater than 70%, confirming that the developed washers have a sufficiently high anti-loosening performance. A Junker test apparatus was manufactured for the testing of vibrational loosening and a test comparison between the proposed washers and the existing wedge locking washers shows that the proposed washers have a slower reduction in the clamping force and a higher loosening-resistance in a vibrational circumstance compared with the wedge locking washers. These results indicate that the developed washers demonstrate a high performance and boast price competitiveness.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.457-462
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• 1995

Unlike the usual bone plate and screw fracture fixation, an improved plate fixation method, which can transfer gradually physiological load to bones, is described. The key feature of the present method is to use washers between the plate and the screw. Bio-absorbable materials or non-ferrous materials with good damping characteristics are used to manufacture the washers. The purpose of this paper is to discuss potential advantages of the proposed method, and to show experimentally its improved impact-absorbing characteristics. Vibration experiments are carried out for pig femurs and cow tibias with and without the proposed washers. This experiments show that the washers can drop the first peak value suite substantially in the FRF plots. Although in-vivo experiments have not been conducted, the present fixation method appears to be a simple and effective alternative to the presently used method.

• Design & Manufacturing
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• v.6 no.2
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• pp.37-41
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• 2012

Usually compound dies are used in clinch washer production. However, in this study, a fine blanking die is designed and manufactured, and clinch washers are produced by the die. Clinch washers are for electric exhaust gas recirculation (EEGR) and they recirculate some of exhaust gas to reduce harmful substances. Fine blanking automation production eliminates difficulties operators face on conventional press.

• Structural Engineering and Mechanics
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• v.46 no.3
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• pp.387-402
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• 2013

A dynamic load protocol has been used to experimentally simulate fatigue behavior in cold-formed metal panels with screwed connections under wind loading. The specific protocol adopted is an adaptation of SIDGERS, originally developed for non-metallic membranes, which is composed of levels each under increasing load values. A total of 19 tests were performed on 3.35 m long by 0.91 m wide panels, identified as Type B-wide rib and Type E, both with screw connections at the edge and at the center, thus conforming two-span specimens. In some configurations the panels were fixed at the valleys, whereas crest-fixed connections were also investigated. Reinforcing the connections by means of washers was also investigated to evaluate their efficiency in improving fatigue capacity. The experimental results show maximum load capacities in improved connections with washers of approximately twice of those with classical connections.

• Conservation Science in Museum
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• v.21
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• pp.17-28
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• 2019

The term jinjuseon(眞珠扇), meaning literally a pearl fan, refers to a fan decorated with precious stones for use in royal wedding ceremonies. This study examined a jinjuseon housed in the National Palace Museum of Korea (NPMK) which currently lacks jeweled ornaments. In order to determine whether pearls or other gemstone settings originally ornamented the fan,the surface and composition of the gray materials remaining on the washers were investigated and the fan was compared with other artifacts decorated using similar techniques. The analysis revealed that the gray materials visible around the round rims of the washers contain tin-lead alloys. The traces of folded nails suggest that soldering was not applied. The remains of the infill observed in other artifacts with bezel settings indicate that this jinjuseon in the NPMK collection was produced using abezel setting technique wherein pearls or other gemstones were affixed by filling cylindrical bezels with tin-lead alloys.

• Steel and Composite Structures
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• v.20 no.6
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• pp.1323-1343
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• 2016

This paper presents the results of an extensive numerical analysis program devoted to the investigation of the mechanical behaviour of bolted ball-cylinder joints. The analysis program is developed by means of finite element (FE) models implemented in the non-linear code ABAQUS. The FE models have been accurately calibrated on the basis of available experimental results. It is indicated that the FE models could be used effectively to describe the mechanical performance of bolted ball-cylinder joints, including failure modes, stress distributions and load-displacement curves. Therefore, the proposed FE models could be regarded as an efficient and accurate tool to investigate the mechanical behavior of bolted ball-cylinder joints. In addition, to develop a further investigation, parametric studies were performed, varying the dimensions of hollow cylinders, rectangular tubes, convex washers and ribbed stiffener. It is found that the dimensions of hollow cylinders, rectangular tubes and ribbed stiffener influenced the mechanical behaviour of bolted ball-cylinder joints significantly. On the contrary, the effects of the dimensions of convex washers were negligible.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.232-234
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• 2001

인터넷 정보 가전 기술은 제품과 IT분야의 다양한 기술을 이용하여 가전제품, 네트워크 인프라 구축, 가전제품간 인터페이스, 사용자와 가전제품의 인터페이스, 인터넷과의 연동 여부, 인터넷을 통한 제어, 휴대폰을 통한 제어 등을 실현하고자 하는 것이다. LG전자에서 출시한 인터넷 터보드럼 세탁기의 원격제어 인터페이스 개발에 대한 내용을 다루고 있는데, 실제 세탁기와 똑같은 모양과 구동 방식을 채택하여 주부들이 인터넷을 이용한다 하더라도 실제 가정내 세탁기를 제어하는 것에 비해 어렵지 않도록 하고 있다. 정보가전의 주 사용자가 가정 주부라고 본다면 정보가전 인터페이스 개발 방법론은 매우 중요하다고 본다.

• The Research Journal of the Costume Culture
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• v.21 no.6
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• pp.950-960
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• 2013

The purpose of this research is to provide accurate information of household washers and detergents for consumers, so that help the producers who make washing machine and detergent to get basic material and also help consumers to choose washing machine. Experiment was proceed with two type of washers to compare energy consumption, washing performance, rinsing effectiveness further, damage caused by entanglement of laundry and fabric was assessed. Detergent P and T were used to compare the performance related to differences of ingredients of detergent. Soiled fabrics of EMPA 108 set were used to evaluate performance of washing by different types of contamination. A summary of experimental results are : First, for the consumption of water, drum-type washer consumed 53% less than pulsator-type washer. On the other hand, the washing time was almost similar for both these machines, but pulsator-type washer showed shorter progress, implying that power saving was more efficient in this case. Second, the drum-type washer showed better performance for contamination with all types of detergent, but the pulsator-type washer showed better rinsing performance. Third, the drum-type washer performed less data of tangle level and fabric damage. Fourth, detergent "P" exhibited better washing performance than did detergent "T", regardless of the type of soil. And with no limit of detergent variety, water-soluble protein soil showed high removal rate, liposoluble soil especially pigment was hardly removed.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.43-53
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• 2008

Because the torque control method, which is also caled the clamping method in domestic construction sites, is affected by a variation of the torque coefficient, quality control of the torque coefficient is essential. This study was focused to evaluate the effects of several environmental factors and errors when installing bolts while tightening high-strength bolts. Conditioning environmental parameters include wet, rusty and exposure-to-air-only conditions. In addition, because of errors in workability such as instalation of two washers, upset washers are selected. During the tests, torque, torque coefficient, tension and angle of nut rotation were obtained using a bolt testing machine. Test specimens of four types of bolts (High-Strength Hexagon bolt on KS B 1010, Torque Shear Bolt on KS B 2819, High-Strength Hexagon bolt coated with zinc, and ASTM 490 bolt) were recomended. Based on test results, the tightening characteristics subjected to environmental parameters were investigated and compared with the results in normal condition.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3413-3417
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• 2007

In recent semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from the outdoor air introduced into clean room. In the present study, an experiment was carried out to examine the improvement of removal efficiency for the gaseous contaminants. In order to improve the gas removal efficiency, a hot water contact heat exchanger was installed upstream of the air washer to heat and humidify the incoming outdoor air before entering the air washer.