• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.69-75
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• 2019

Since gasoline engines are based on a combination of a cast iron liner and an aluminum block, which have different thermal properties and stiffnesses, bore shape distortion is likely to occur during honing due to uneven thermal deformation. To solve this problem, many tests and evaluations are needed to support the development of a high-performance honing stone with low heat generation. Moreover, performance evaluation, which depends on inspection and observation after work, often requires much trial and error to optimize tool design, due to challenges in the accurate interpretation of results. This study confirmed that the assessment of grinding capability was clarified by evaluating performance under severe work conditions and by in-situ measurement and recording of current consumption (workload) and heat generation during operation. As a result of using a honing stone with excellent grinding performance in engine block manufacture-in which cylinder bore distortion caused by thermal deformation during manufacture is a problem-a noticeable improvement in the degree of cylindricity was observed.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.16-26
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• 2024

This study aims to introduce a method for risk assessment analysis aimed at preventing electrical fires within the manufacturing industry. Initially, we provided a functional block diagram illustrating the electrical equipment employed in various processes within a food manufacturing company in Chungcheongbuk-do. Subsequently, we categorized the components of each machine outlined in the functional block diagram and determined the priority of failure for each classified component. Upon implementing the model in the frying process of the food manufacturing company, specific components, including MC, motor, mixer heater, electric wiring, and terminal block, exhibit a risk priority number (RPN) of 40 or higher. This identified an electrical issue within the manufacturing process and environment. Consequently, we propose a methodology to identify latent failure modes that could escalate into fires or systemic issues if not promptly addressed. It is essential to note that while the FMEA presented in this study may not immediately impact food manufacturing, its applicability extends to various workplaces.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.11-14
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• 2001

Direct torque control (DTC) scheme provides a very quick torque response without the complex field-orientation block and inner current regulation loop. DTC is known as an appropriate scheme for high power induction motor drives because it can be used at lower switching frequency There are a major drawbacks with the application of DTC schemes it is large current harmonics due to flux drooping in a low speed range. In order to solve the problem, the fuzzy variable switching sector scheme are adopted in this paper. A meaningful contribution of this paper is to propose a simple realization scheme of the fuzzy variable switching sector technique. Experimental results show the effectiveness of this proposition.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.279-282
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• 2004

This paper presents load torque observer that is used to deadbeat load torque observer in the induction motor position control system. The simulation has been obtained by simulink. A digital control is composed by trigger method in the continuous block diagram. The results show that proposed system has good effectiveness for the disturbance in induction servo motor system.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.845-847
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• 2015

A suspending force control based on fuzzy logic control is proposed to apply on a novel hybrid bearingless switched reluctance motor(BLSRM) which has separated torque and suspending force pole. Due to the unique structure, the suspending force control system can be easily decoupled from torque control system. In this paper, two fuzzy controller targeted at x-axis direction and y-axis direction are adopted to maintain the shaft at center position, which is very necessary for stable operation of BLSRM. By replacing the traditional PI block with modified fuzzy logic controller, the suspending system can behave a good performance, and the proposed scheme can be verified by simulation results.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.217-221
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• 2002

In this research a Matlab/Simulink/RTW - based on the realtime control system was developed for an induction motor vector control. On the Simulink window, the control system is designed In the form of block diagrams, program codes are produced automatically with the RTW(Real Time Workshop), then a DSP c compiler complies the program codes.

• Journal of Korean Physical Therapy Science
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• v.4 no.3
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• pp.499-509
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• 1997

The facial nerve have a long pathway. Thus facial nerve fibers easily involved at any point along their course will lead to a facial palsy of lower motor neuron type and upper motor neuron type. The electrophysiologic examination can evaluate and anticipating that prognosis of facial nerve palsy. The electrophysiologic examination are Nerve Excitability Test(NET), Elecctroneurography(ENG), Electro-myography(EMG), Blink Reflex, and Electrogustometry et.al. The NET is very useful method for assessment of prognosis and distinguish between nerve degeneration and physiological block as early as 72 hour after onset of the facial palsy. And other examination also give objectively information of facial nerve for prognosis and treatment. Treatment goal of physiotherapy are prevent contracture and disuse atrophy of facial muscle with muscle reeducation and strengthening and maintain symmetry facial motion. The treatment better start as early as possible.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.362-362
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• 2000

The purpose of this thesis is to reduce force ripple of linear pulse motor(LPM) using neural network and to enhance precision. In order to this, we propose a new controller using a neural network to compensate disturbances. The structure includes adaptation block which learns the dynamics of the periodic disturbance and forces the interferences, caused by disturbances. The proposed controller compensates an unmodeled dynamics in the LPM. The neural network changes a current command to reduce position error and force ripple of the LPM. We compare proposed controller with PI controller. Simulation result shows that the proposed controller has better performance than a PI controller without neural network.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.201-212
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• 2012

In general solid propulsion offers cost effective, large thrust capabilities comparing to the liquid propulsion which offers high specific impulse and restart capabilities. Therefore solid propulsion is well fitted for the first stage and boosters. BBL approach has been studied for the launch vehicle because of cost effectiveness, limited development time and low risk. Using of the carbon fiber epoxy resin in the solid rocket motor case is expanded, and specially high strength fibers are more attracted since its inert mass reduction.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.104-109
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• 2001

We describe the accidental injection of local anesthetics containing steroid into the subdural space during an attempted lumbar epidural injection for intractable radiculopathy in a patient with failed back surgery syndrome. A 24-year-old man complained of severe radiating pain to left lower extremity and showed a walking disturbance and severe lumbar scoliosis. The MRI finding was a left paramedian recurred disc herniation on L4-5 in a laminectomy state. Several therapeutic modalities such as epidural steroid injection, transforaminal injection, L2 root block, medication, and exercise therapy, etc failed. Initially, during epidural block at L4-5 under fluoroscopic guidance, a railroad track appearance appeared on epidurogram suggesting the presence of a subdural space. A second epidural block was tried at L5-S1. Following confirmation of epidural space upon epidurogram, 6 ml of 0.5% lidocaine including triamcinolone 40 mg was injected. The patient showed signs of the subdural injection including an unexpectedly high sensory block (T2) and a motor weakness of both lower extremities. Following this event, the severe radiculopathy and lumbar scoliosis were improved. Therefore, we conclude that subdural injection of steroid could be helpful in intractable radiculopathy, especially in the failed back surgery syndrome. However, it must be used cautiously with careful patient selection.