• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.189-192
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• 2024

Objectives: To protect researchers using chemicals, it is necessary to monitor whether the working environment is well managed through the performance evaluation of the local exhaust system in the research laboratory. These results need to be reflected in the work environment management policy of research laboratories in the future. Methods: By measuring the capture velocities of fume hoods and arm hoods, which are the most commonly used local exhaust systems in research laboratories in a domestic research institute, we tried to confirm the degree to which the actual capture velocity values and legal standards were satisfied. The capture velocities were measured using a hot wire wind speedometer (TSI 9565-P, USA, 2016 with all exhaust systems in operation in the laboratory. As for the measurement position for each local exhaust system, in the case of the fume hood, the wind speed in the center of the opening surface was measured after opening 50% of the door of the hood. For the arm hood the capture velocities were measured at a distance of 10 cm vertically from the opening surface of the hood Conclusions: The total number of arm hoods measured was 546, and the average capture velocity was 0.61 m/sec with an S.D of 0.49. Among them, 99 satisfied the capture velocity standard of 1m/sec, meaning only 18.1% of the total satisfied with the standard. The total number of fume hoods measured was 625, and the average control wind speed was 0.48 m/sec with an S.D. of 0.17. Among them, the number of fume hoods that satisfied the capture velocity standard of 0.4 m/sec was 518, meaning 82.9% of the total satisfied the standard. Therefore, research institutes that operate local exhaust systems to protect researchers from chemicals should further strengthen the capture velocity management of hoods, and government agencies need to reflect this in work environment management policies based on further evaluation results.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1785-1789
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• 1991

Recently, a number of papers on adaptive control scheme of manipulators are proposed. Slotine and Li[1] showed an adaptive control scheme for robot manipulator. The controller was described in closed form. And later Niemeyer and Slotine discussed about a computational implementation of the controller in recursive form[2]. Walker proposed another adaptive control scheme which can be implemented by a recursive-form controller[4]. Closed-form description is used for the analysis or design of adaptive control systems while recursive-form realization is used for implementation of the controller. The relation between the closed-form realization and the recursive-form one seems to be inadequately referred. Hence, it makes sense to consider the relation between the closed-form description and the recursive-form one. In this paper, first, we make a simple derivation of an closed-form dynamics description of a robot arm from its recursive-form description. And then we derive the closed-form realization of Walker's scheme applied to manipulators having no kinematic loop. We clarify the difference between the Walker's scheme and Slotine's and evaluate the convergence under the controllers.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.273-280
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• 1997

Recently the importance of the cargo handling equipments in a port has been increasing to get strong competition from other ports. Many ports are making efforts to modernize their cargo handling equipments. The kernel technology of such equipments is the speed control of DC motor which is used as an essential part of them. In this paper, we discuss the speed control of a DC motor as a basic work for building cargo handling equipments in a port. DC Motors are still widely used in industrial fields, as driving power motor for electrical fields. DC drives, being easy to control, are widely used in many variable-speed and position control drive system. Traditional analog control circuits used in such applications have many disadvantages. Complex control schemes are difficult to implement with analog components. All these factor and invention of the microprocessor has made it possible to use digital control circuits, using microprocessing system. These digital circuits have been found to be reliable, flexible, and also immune to noise. In this paper it presents the speed control of a SCR DC motor driver which using dual converter by 80c196kc microprocessor. We developed a thyristor power amplifier which does not cause damage thyristor because it is designed to prevent triggering the two SCRs in the same arm simultaneously. And it was analyzed voltage and currents wave at reactive load.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1202-1209
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• 2004

This paper presents a design methodology of a Digital Servo Signal Processor for high speed CD-RW drive systems. The proposed Digital Servo Signal Processor enables us to develop CD-related systems for the very high speed applications and is one of the key components of the CD-RW systems. The proposed center compensation servo control is newly built for an actuator shaking due to the fast response of a step motor when it jumps to a long distance. A control method compensating for eccentricity of a disc is implemented for operating robustly at a higher rotational speed. This servo mechanism is more size efficient and less power consumed because it is implemented using a ARM7 embedded processor and hardware digital filters. Furthermore, it is convenient to upgrade firmware for the future required functions. From experimental results, we can see that the performance of the control system is improved greatly. The proposed servo algorithm shows a shorter setting time including a pull-in time and a faster access time. It can be applied easily to the DVD-ROM and the DVD-RAM which have the same optical structure.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.13-24
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• 2001

The purpose of this study was to set up an effective marketing strategy targeting college women by researching the relationship between weight control behavior and satisfaction with fit of apparel. The results showed that 1) 85.5% of the college women participated in weight control behavior, and 53.5% of them wanted to lose more than 3kg of their weight, 2) both body cathexis and fit satisfaction of college women were generally low. College women were less satisfied with their body and fit of apparel according to the increase of weight control degree. The weight control parts and unsatisfied body parts were almost matched : thigh, abdomen, hip, calf, and weight. The unsatisfied fit of apparel parts were also found to be thigh, hip, abdomen, crotch, pant length that matched each parts, 3) fit satisfaction of neckline, shoulder, midriff, hip, crotch, thigh, calf, and skirt length decreased according to the increase of weight control degree, and 4) weight control group which wanted to lose weight at neck, shoulder, arm, breast, waist, abdomen, hip, thigh, and calf also had low fit satisfaction of neckline, shoulder, armhole, sleeve, breast, waist, abdomen, midriff, hip, thigh, crotch, calf, and skirt length in clothing.

• Journal of Drive and Control
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• v.21 no.1
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• pp.31-37
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• 2024

In this study, to prevent accidents in underground facilities during excavation, we developed a Lv.3 automated control system that can be configured as an electronic control system without changing the existing hydraulic system in a general excavator and utilized digital map information of underground facilities. We aimed to develop a strategy to prevent accidents caused by operator error. To implement this, a real-time excavator bucket end position recognition and control system was developed through angle measurement of the boom, arm, and bucket using an electronic joystick, RTK-GPS, and angle sensors. In addition, excavators are large, machine-based equipment, and it is difficult to control overshoot due to inertia with feedback control using position recognition information of the bucket tip. Therefore, feed-forward control is used to calculate the moving speed of the bucket tip in real-time to determine the target position. We developed a technology that can converge and verified the performance of the developed system through actual vehicle installation and field tests.

• Journal of Drive and Control
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• v.13 no.4
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• pp.95-101
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• 2016

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1355-1358
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• 2003

This paper presents performance analysis of the embedded application, called EEMBC consisting of 5 categories and total 34 applications. We measured various performance metrics, such as code sizes, TLP(Thread Level Parallelism) using OpenMP API and ILP(Instruction Level Parallelism) on ARM-modeled SimpleScalar in detail. We show that the embedded applications have the similar characteristics as integer applications to deliver low ILP and TLP in our environment. They have many small loops, which result in large instruction overhead in TLP and loop control overhead in ILP.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1719-1723
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• 2005

An automatic target sensing and triggering system for small fire arms is proposed. The system consists of an optical collector, an infrared ray sensor responsive to human body temperature, an electric actuator and a trigger mechanism. TRIZ methodologies are used to develop solutions to several contradictory problems. Experimental results on the system performance is compared with predictions.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.104-109
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• 1997

A robust controller design to corrdinate a robot manipulator under unknown system parameters and bounded disturbance inputs is presented in this paper. Generally, robust controllers require high input torque so that they may face input saturation in actual application due to the power limitation of the actuator. To solve this problem, an improved robust controller with saturated input torque using a fuzzy logic control is proposed. Numerical examples are shown to validate the proposed controller using two degree-of-freedom planar arm.