• Journal of Biosystems Engineering
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• 제21권2호
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• pp.123-133
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• 1996

An automatic drum seeder was developed to improve the seeding operation. It consisted of a conveyor to transfer seedling trays, a seed-hopper to supply seeds, a drum to drop seeds on the tray, and an air blower to remove extra seeds. A photo sensor was used to detect the transfer of seedling trays, and its signal was fed into microcomputer which operated a stepping motor driving the drum. The seeds were adhered to the surface of drum by vacuum pressure, and were dropped into tray cells by compressed air. An air connection unit was devised to alternate between vacuum pressure and compressed air. A control program for the system, written in C language, could operate the drum at the given number of revolutions and revolutions per minute. The results showed that the air connection unit could operate well and the seeds were dropped satisfactorily into tray cells. In case of cabbage and perilla seeds, which are regular and spherical shape, the missing rate was low and the single seeding rate was more than 97%. Low missing rate and high multiple seeding rate were observed in lettuce seeds which have narrow ends with tight weight. The missing rate of pepper seed was very high because of heavy weight and irregular shape. To improve the performance of the seeder, adjustment of vacuum pressure based upon shape and weight of the seeds, careful selection of the material of drum, maintenance of consistent air blower pressure, and replacement of stepping motor to DC motor are recommended.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.489-491
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• 2013

본 논문에서 Processing 언어를 이용하여 아두이노 기반의 컴퓨터와의 통신을 이용하여 소리를 내는 전자드럼을 설계 하였다. 먼저 피에조 센서를 이용해서 드럼패드를 구현한다. 이때 드럼패드는 센서가 파손되지 않도록 충격을 완화시킬 수 있는 구조로 제작하였다. 이 패드를 아두이노와 연결하여 센서가 충격을 받으면 감지한 신호를 아두이노로 보낸다. 그러면 신호를 받은 아두이노는 컴퓨터에 신호를 전송하고 신호를 받은 컴퓨터는 저장되어 있는 드럼소리를 출력한다. 이러한 구조를 통해서 마이크로 컨트롤러와 컴퓨터의 통신 기술을 이용한 많은 응용 가능한 부분이 있을 것으로 사료된다.

• 제어로봇시스템학회논문지
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• 제6권9호
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• pp.813-821
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• 2000

In this paper, we developed modeling of tension and speed dynamics for a two-drum winder in a three span continuous web transport system which had not been previously. Dynamic modeling of the time-varying nonlinear system was derived by considering the effect of the radii and mass moment of inertia in the unwinder and the two-drum winder through winding up the web. After linearizing it, we designed with a variable-gain a PID controller for tension control and a PI controller for speed. Simulation is carried out with the variation of radii and moment of inertia at high speed for the proposed tension control system with the two-drum winder and the variavle-gain a PID controller. Results show good performance of tension control during the speed change speed at a start-up and stop.

• 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.

• 한국자동차공학회논문집
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• 제14권5호
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• pp.145-154
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• 2006

Each part of drum brake system is loaded by continual mechanical force and thermal force every time of braking, so enough strength and stability are required. Thermal characteristic is one of the important factors in drum brake systems design. This paper presents the thermal performance such as temperature distribution and thermal contact stress of drum brake system considering several braking patterns; 80th heat braking test mode, heat fade braking test mode, general road mode, steep slope road mode and off road mode. Transient heat transfer analysis and Thermo elastic contact analysis is executed to obtain the temperature distribution, and to evaluate thermal stress of drum brake by using ABAQUS/Standard code. This procedure of analysis can effectively be used to improve the quality problem of brake system and to get design guideline of the new product.

• 한국정밀공학회지
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• 제23권8호
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• pp.154-162
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• 2006

By laying its drum horizontally, front-loaded washing machine mostly used in Europe that uses the head of the water to launder was appropriate for washing only small amount of laundry. However, the demands of customers are requiring front-loaded washing machine to handle big capacity laundry as well, and have faster rotation speed to increase drying ability. To meet such demands, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Shaft is connected from the flange to insert production, transferring power from the motor to drum, and mainly acting as stiffness against the horizontal weight of the shafting system. In this paper, strength analysis and experiment were executed on both the shaft and flange of front-loaded washing machine to suggest the design improvement of shafting system for big capacity, high-rotation drying. Also, verification of this evaluation was executed on fracture strength and fatigue life for studied shaft system.

• 동서간호학연구지
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• 제25권2호
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• pp.174-182
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• 2019

Purpose: The purposes of this study were to develop a drum club activities program for soldiers and to explore the effects of the program on the mental health of soldiers. Methods: This study used one group pretest-posttest design. A drum club activities program for soldiers was offered for 12 weeks with each session of 2 hours. A total of 33 participants were recruited but eighteen participants who did not participate in sessions of the program more than 3 times were dropped out of the study. Finally, data from 15 participants were analyzed using the SPSS 22.0 program. Mental health status (stress, anxiety and aggression) was measured by Vibraimage technology. Vibraimage technology is a useful and objective method to identify the human psychophysiological state by analyzing the movement of various frequencies and amplitudes of head motion and face image using camera. Results: There is statistically significant difference in anxiety (Z=-3.12, p<.001) after implementation of the program. However, there was no statistically significant difference in stress and aggression. Conclusion: The results indicate that the drum club activities program was effective in decreasing anxiety in soldiers. The drum club activities program can be considered as a possible nursing intervention strategy to reduce anxiety for soldiers.

• 대한조선학회논문집
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• 제57권5호
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• pp.254-261
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• 2020

The structural safety of hydraulic winch drum and the gears are estimated by the Finite Element Analysis (FEA) and the winch operation experiment. The mesh convergence test is performed and the applied force is the pressure on the drum converted from the rope tension in working condition. The stress of the drum calculated from the strain values of the winch operation experiment shows the agreement with that from the FEA. Most stress values are under the yield strength except for the small hole made for the wire rope fixation. The life of bearings in the drum is calculated using the life prediction formula with the reaction forces from the operation load. One of the two ball bearings shows the short life for impact condition, yet the real prototype winch system shows more life than the numerical value.

• Fisheries and Aquatic Sciences
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• 제26권9호
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• pp.525-534
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• 2023

Vitamin C plays an important role for fish survival, growth and disease resistance. However, the optimal vitamin C for rearing red drum Sciaenops ocellatus juveniles in Vietnam is not known. To address this issue, a 70-day feeding trial was conducted to evaluate the optimal dietary vitamin C requirements for red drum juveniles. Seven isonitrogenous (55.35% protein) and isolipidic (9.07% lipid) diets were formulated to include graded vitamin C concentrations of 23.2, 124.5, 235.2, 423.8, 626.7, 824.6, and 1,027.3 mg/kg, respectively. The results showed that fish fed on 423.8 mg/kg vitamin C diet had the highest growth rate, which can be linked to the increased feed utilization. Broken-line analysis indicated that the optimal dietary vitamin C requirements of red drum juveniles were 342.92 and 405.80 mg/kg for growth parameters, feed utilization, body composition and biochemical parameters of serum. Based on these parameters the optimal vitamin C supplementation level for red drum juveniles was estimated in the range of 342.92-405.80 mg/kg vitamin C in the diets with direct applications in producing artificial feed for rearing juveniles of this species in Vietnam.