• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1839-1844
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• 2003

In order to provide a tool for designing more efficient methods of mixing fabric, a simplified discrete element computational model was developed for modeling fabric dynamics in a rotating horizontal drum. Because modeling the interactions between actual pieces of fabric is quite complex, a simplified model was developed where individual pieces of bundled fabric are represented by spherical particles. The simulations are used to investigate fabric bundle kinematics, the power required to drive the rotating drum, and the power dissipated through normal and tangential contacts. Parametric studies indicate only fill percentage, drum rotation speed, and friction coefficient play significant roles in the fabric bundle dynamics.

• 동력기계공학회지
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• 제17권2호
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• pp.63-69
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• 2013

Most washing machines are now produced as a drum-type, where a washing drum mounted on a suspension system with springs and dampers, to minimize the transmittance of the vibration from the drum to the frame. A low-cost MR damper, using magneto-rheological fluids, can produce variable damping forces by changing the current values in the magnetic coil. Experimental results show the comparison of the vibration attenuation performances between two different dampers. One test set-up uses a passive damper and another one uses a MR fluid damper. The test results showed that the vibration amplitude of the washing machine with the MR damper is much smaller than the case with the passive damper.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.996-998
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• 1996

The drum-type hill-drop unit, an important working device of the plastic -film-covered hill planter, can finish filling and separating seed precisely, perforating film and holing , and its seeding depth and spacing are stability . The unit is applied to hole seed many crops, for example, cotton, corn , soybean, etc. The drum-type hill-drop unit(DHU) , the key work unit to the plastic film-covered planter, mainly consists of distributor box , seeding parts, hole forming unit and drum , It can be operated to accomplish seeds distributing, hole forming , plastic film perforating . Moreover , its inner cavity can be used as seed box.

• Journal of Radiation Protection and Research
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• 제22권4호
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• pp.309-317
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• 1997

비파괴적인 방법으로 방사성폐기물드럼에 대한 핵종분석을 수행할 때 드럼내 매질에 의한 방사선의 감쇠에 의해 핵종분석장치로 측정한 계수값은 실제 드럼내 방사능에 의한 계수값보다 작게 나타나 결과적으로 방사능의 측정결과가 과소평가된다. 그러므로 드럼내 매질에 의한 감쇠를 보정해 주어야 하는데 감쇠 보정방법은 드럼내 매질의 분포나 매질의 밀도에 따라 달리 적용해야 한다. 본 연구에서는 원자력발전소에서 발생하는 드럼 종류별로 모델드럼을 제작한 후 모델드럼에 표준감마선원을 넣고 핵종분석장치를 이용해 측정을 하여 드럼내 매질의 밀도를 구하였고, 이 값을 실제 매질의 밀도와 비교해 드럼종류에 따라 매질에 의한 최적의 감쇠 보정방법을 결정하였다. 그 결과 잡고체드럼의 경우에는 전송선원 보정방법과 평균밀도 보정방법, 차폐잡고체드럼의 경우 전송선원 보정방법과 두 감마선피크비교 보정방법이 최적의 감쇠 보정방법임을 알 수 있었고, 고밀도드럼인 폐수지, 농축폐액 및 폐필터드럼의 경우에는 평균밀도 보정방법과 두 감마선피크비교 보정방법을 사용해 드럼내 매질의 감쇠를 보정할 수 있다.

• 가정과삶의질연구
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• 제30권6호
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• pp.85-101
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• 2012

This study was conducted to investigate the effect of group music therapy using the traditional drum on the; social adjustment, self-image, and emotional adjustment, of children with hearing impairment. I participated in this group music therapy using the traditional drum with 7 children with hearing impairment for 3 days a week for 6 weeks(including holidays), and each session was 50 minutes long. The evaluation form of this study is a social-emotional development measurement sheet of Meadow-Kendall, which the children's teacher distributed to the children both pre- and post-examination. With these results, the researcher carried out Window SPSS 19 Version and searched for the experiment's effect of measurement cause (I am not sure what this means.) through paired t-test to identify the experiment's effects (social adjustment, self-image, emotional adjustment) as a result of group music therapy using the traditional drum for children with hearing impairment. This study arrived at the following conclusions. First, after I participated in the group music therapy using the traditional drum, the result of the comparisons of the pre-to-post average for social adjustment showed the statistical significance level of the 0.01 standard. Therefore, it was found that the group music therapy using the traditional drum had a positive effect on the social adjustment of children with hearing Impairment. Second, after I participated in the group music therapy using the traditional drum, the result of the comparisons of the pre-to-post average for self-image development showed the statistical significance level of the 0.01 standard. Therefore, the group music therapy using the traditional drum had a positive effect on the self-image of children with hearing impairment. Third, after I participated in the group music therapy using the traditional drum, the result of the comparisons of the pre-to-post average for emotional adjustment showed the statistical significance level of the 0.01 standard. Therefore, the group music therapy using the traditional drum had a positive effect on the emotional adjustment of children with hearing impairment.

• 한국식품과학회지
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• 제18권5호
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• pp.351-356
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• 1986

단(單)원통형 및 원통형 드럼건조기를 이용하여 잘게 저민 생선으로부터 플레이크를 성공적으로 만들 수 있었다. 생선의 높은 지방함량으로 인해 저민 생선이 드럼에 잘 들러붙지 않는 문제점은 타피오카가루의 형태로 2.5%의 전분을 저민 생선에 첨가함으로서 건조양상에는 영향을 미치지 않으면서 해결될 수 있었다. 제품의 수분함량을 일정한 수준으로 유지할 경우 건고형분(乾固形分)의 생산속도는 드럼간의 간격을 최소로 줄였을때 최고에 도달하였다. 건고형분(乾固形分)의 생산속도는 드럼의 회전속도가 증가할수록 선형적으로 증가하였고 제품의 품질이 손상되지 않는 범위에서 스팀의 압력이 높을수록 증가하였다. 총괄 열전달계수는 드럼의 회전수가 증가함에 따라 증가한 반면에 드럼간의 간격이 커짐에 따라 증가하지는 않았다. $MR\;=\;A\;\exp(\;-k{\theta})$로 표시되는 가장 보편적인 건조 모델식이 드럼건조에도 적용될 수 있었다.

• 한국의류산업학회지
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• 제12권3호
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• pp.389-397
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• 2010

This study was carried out to investigate the effect of washing machine type (drum or pulsator) on the behavior of clothing management and consumer satisfaction. The data were collected via questionnaires from 408 consumers and were analyzed through factor analysis, ANOVA, Cronbach's Alpha, utilizing SPSS 10.0. The results of this study were as follows: 1) 39.2% of consumers used drum washer and the number of users has increased sharply in five years. Drum washer consumers hold larger capacity washer than pulsator washer consumers. 2) Young people(under 40) showed statistically significant differences in terms of washing concern and the kinds of detergents, while old people(40 and above) showed statistically significant differences in terms of checking the label, preparing the laundry, and hand-washing. Married women showed statistically significant differences in checking the label, preparing the laundry, and hand-washing. 3) In terms of clothing management behavior with the type of washing machine, drum washer consumers showed statistically significant the amount of detergents, while pulsator washer consumers showed statistically significant handwashing and kinds of detergents. 4) In terms of customer satisfaction with the type of washing machine, drum washer consumers showed statistically significant brand satisfaction.

• Smart Structures and Systems
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• 제17권2호
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• pp.275-296
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• 2016

This paper focuses on developing a new configuration on magnetorheological (MR) brake damper as prosthetic knee. Prosthetic knee uses magnetic fields to vary the viscosity of the MR fluid, and thereby its flexion resistance. Exerted transmissibility torque of the knee greatly depends on the magnetic field intensity in the MR fluid. In this study a rotary damper using MR fluid is addressed in which a single rotary disc will act as a brake while MR fluid is activated by magnetic field in different walking gait. The main objective of this study is to investigate a prosthetic knee with one activating rotary disc to accomplish necessary braking torque in walking gait via T-shaped drum with arc surface boundary and implementing of Newton's equation of motion to derive generated torque at the inner surface of the rotary drum. For this purpose a novel configuration of a T-shaped drum based on the effects of a material deformation process is proposed. In this new design, the T-shaped disc will increase the effective areas of influences in between drum and MR fluid together and the arc wall crushes the particles chains (fibrils) of the MR fluid together instead of breaking them via strain in a conventional MR brake. To verify the proposed MR brake, results of the proposed and conventional MR brakes are compared together and demonstrated that the resisting torque of the proposed MR brake is almost two times greater than that of the conventional brake.

• 한국기계가공학회지
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• 제19권7호
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• pp.52-59
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• 2020

Automatic tool changers (ATCs) can be divided into drum and chain types. Drum-type ATCs contain a magazine, where the tools are mounted, and a cam gearbox, which swaps the tools via roller gear and grooved plate cams. Drum-type ATCs are advantageous in that the operating time for the tool magazine is more rapid than that of chain-type ATCs and the length of the unit is shorter. Thus, drum-type ATCs can be fabricated into various shapes and forms depending on the number of tools and the magazine size in accordance with machining center requirements and consumer demand. In particular, the price competitiveness of a machining center with a drum-type ATC is higher, while drum-type ATCs are more rigid with fewer parts, possibly reducing the need for regular servicing. This study aims to verify the structural stability and design validity of the magazine base, which is the main structure of a drum-type ATC, using finite element analysis. This study kinematically verifies the specifications of the selected drive motor and reducer and assessed the design of the cam gearbox. It also conducts a structural analysis of the roller camp, which is the core component of the cam gearbox, based on the results of the kinetodynamic analysis, thus validating the structural design.

• Agricultural and Biosystems Engineering
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• 제6권1호
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• pp.22-26
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• 2005

A wind-heat generation system was developed and the system consisted of an electric motor, a heat generation drum, a heat exchanger, two circulation pumps and a water storage tank. The heat generation drum is an essential element determining performance of the system. Frictional heat was generated by rotation of a rotor in the drum filled with a working fluid, and the heat stored in the fluid was used to increase water temperature through the heat exchanger. Effects of some factors such as rotor shape, kind and amount of working fluid, rotor rpm and water flow rate in the heat exchanger, affecting the system performance were investigated. Amounts of heat generated were varied, ranging from 126,000 to 32,760 kJ/hr, depending on combination of the factors. Statistical analysis using GLM procedure revealed that the most influential factor to decide the system performance was amount of the fluid in the drum. Experiments showed that the faster the speed of the rotor, the greater heat was obtained. The greatest efficiency of the heat generation system, electric power consumption rate vs gained heat amount of water, was about 70%. Though the heat amount was not enough for plant bed heating of a 0.1-ha greenhouse, the system would be promising if some supplementary heat source such as air- water heat pump is added.