• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.365-370
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• 2004

The integration of intelligent devices, devices-level networks, and software into motor control systems can deliver improved diagnostics, fast warnings for increased system reliability, design flexibility, and simplified wiring. Remote access to motor-control information also affords an opportunity for reduced exposure to hazardous voltage and improved personnel safety during startup and trouble-shooting. This paper presents LonWorks fieldbus networked intelligent induction control system architecture. Experimental bed system with two inverter motor driving system for controlling 1.5kW induction motor is configured for LonWorks networked intelligent motor control. In recent years, MCCs have evolved to include component technologies, such as variable-speed drives, solid-state starters, and electronic overload relays. Integration was accomplished through hardwiring to a programmable logic controller (PLC) or distributed control system (DCS). Devicelevel communication networks brought new possibilities for advanced monitoring, control and diagnostics. This LonWorks network offered the opportunity for greatly simplified wiring, eliminating the bundles of control interwiring and corresponding complex interwiring diagrams. An intelligent MCC connected in device level control network proves users with significant new information for preventing or minimizing downtime. This information includes warnings of abnormal operation, identification of trip causes, automated logging of events, and electronic documentation. In order to show the application of the multi-motors control system, the prototype control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using LonWorks network.

• Journal of Chest Surgery
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• 제13권2호
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• pp.134-137
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• 1980

This represents a case report of the retained polyethylene catheter fragment in superior vena cava. A 39 year old male was admitted to this Korea University Hospital a short time after compression wound on abdomen with heavy cement material in emergency room, a polyethylene catheter was introduced into the right subclavian vein through a needle. But when the polyethylene catheter was attempted to withdraw the catheter was severed by the beveled tip of the needle. Later that day, chest X-ray disclosed the presence of the fragment extending from right subclavian vein to the superior vena cava. {Fig. 1 and Fig. 2]. Local exploration by way of an infraclavicular incision was unsuccessful in locating the catheter fragment. Another attempt was then made remove the catheter by means a biotome, which is originally a device for the biopsy of the myocardium, introduced through the right great saphenous vein. This procedure, though well tolerated by the patient, was in vain. After 11 days later, during that time he was taken a laparotomy with drain, another operation for removal of retained catheter fragment was performed through median sternotomy. After exposure of the right subclavian vein, innominate vein, and superior vena cava, an incision 1 cm in |length was made directly over the palpated catheter. The catheter immediately was picked upward and removed. The length of the catheter was approximately 8 cm. [Fig 3 ] There was no evidence of thromboembolism from the catheter or other complications. The patient made an uneventful recovery, and was discharged asymptomatic on the 9th postoperative day.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.209-216
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• 1999

A self-travelling sprayer was developed to avoid the exposure of an operator to agricultural chemicals and exhaust gas, to improve safety and to increase working efficiency during the application and transport work in the greenhouses. This system consists of self-travelling system and the control system for application and safety device. The auto-spray car is equipped with a liquid chemical tank of 80l capacity. The travelling system adopted mechanical steering system which link mechanism of front wheel is guided by guide rollers. The sprayer travels along the guiding pipe which is set on the furrow in the greenhouses. The sprayer stops automatically applying and traveling when the liquid chemical tank becomes empty or when the sprayer reach the turning point. The spray booms swings in a vertical plane. The control system of safety devices controls the automatic stop of the sprayer when there is an obstacle on the traveling path, or when the battery becomes discharged. The auto-spray car traveled smoothly and steadily along the guide pipe during traveling straightly and turning on the ground.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.304-309
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• 2014

Purpose: Weeds cause significant losses in agricultural production. In this study, we investigated the effect of microwaves on the germination rates of cress and arugula seeds to determine whether microwaves could be developed as an effective alternative to conventional chemical-based herbicides. Methods: Seeds were planted at equal depths (8-10 mm) in a soil-turf mixture, and seeds were exposed to microwaves for 126 s, 70 s, and 50 s in a device constructed specifically for this study. A microwave tunnel was built using a variable speed conveyor belt and 4 magnetrons with a combined output power of 2.8 kW. Seeds that were not exposed to microwaves were germinated with regulated irrigation, temperature, and humidity controls in parallel with the treated seeds, and the germination rates were compared among the treatment groups. Results: We found that the exposure of cress and arugula seeds to microwaves for 126 s inhibited germination close to 100%. Cress seeds treated with microwaves for 50 s showed 95% germination compared to 65% germination of the untreated cress seeds. Conclusions: We predict that the thermal effect of microwave energy affects the germination ratio and germination rate of seeds.

• 한국안전학회지
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• 제25권1호
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.436-437
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• 2006

Porcelain insulators have generally been used in Korea but polymer insulators which are superior in that they are light weight, explosion proof, impact proof, economical with construction characteristics, have been in use for the 154kV transmission line since 1999 following a worldwide trend towards the reduced weight, simplification and compact usage of new material insulators. However there have been approximately 500 cases of forest fires in Korea, so the transmission lines that for the most part pass through mountainous areas have been highly effected and the highly polymerized compound polymer insulator has raised concern about reliability in cases of exposure to forest fires. Therefore for the reliability assessment of the effect of forest fires on polymer insulators, mechanical and electrical characteristics are analyzed by an artificial flare test device and transmission facility surrounding conditions along with forest fire characteristics are surveyed. In addition to this, actual 90kV energized transmission line was tested with an artificial forest fire and the expanded usage of polymer insulators is presented through the analysis of mechanical and electrical characteristics and physical properties, and a study on the influence of forest fires on polymer insulators.

• 대한치과교정학회지
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• 제4권1호
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• pp.57-61
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• 1974

The patient, a girl of 19 years in good health, had a class I malocclusion. The maxillary left centra1 incisors and both lateral incisors had already erupted. But the space for the right central incisor was partially closed by the mesial drifting of the neighboring teeth. The caused a shift in the midline and a cross-bite relation on the incisors. X-ray examination revealed the presence of the right central incisor in the alveolar bone and odontoma just above the crown of the right central incisor. After enough space for the impacted incisor was created in the dental arch with a open-coil spring the rectangular incision was made. Removing the odontoma uncovered the flat surface of the labial aspect of the incisor. During the tooth had erupted of its own accord, any unnecessary force had been imposed on the tooth. When it was decided that the tooth should be brought out by the mechanical device, the gold cast onlay with hook was used and run a light elastic between this hook and the main arch wire. Finally the tooth was brought down to the arch level. The result was excellent. Fortunately the esthetic problem and any detrimental effects on the psychological make-up could be avoided.

• 한국보육지원학회지
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• 제16권3호
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• pp.39-58
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• 2020

Objective: The purpose of this study is to investigate the effects of parents' perception of infant's use of digital devices on language development. Methods: For this study, a survey was conducted on 285 parents of 1-2year old infants attending childcare centers in Jeollanam-do. Results: First, the digital devices that infants were exposed to the most was the television, and their first exposure to digital devices was at 13~17 months. The most time spent using digital devices was 30 minutes and they most frequently used them at home. Second, parents perceived the educational value of digital devices as low. Third, language development was high when the initial use of digital devices for infants was late, when the daily use time of digital devices was less than 30 minutes, when digital devices were used with parents, and when parents always managed digital devices and usage time. Fourth, Parents' perception of the use of digital devices has a significant influence on their infants' language development. Conclusion/Implications: Language development due to the use of digital devices and parents' perception of the use of digital devices has a significant impact on infants language development.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.26-26
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• 2010

Cadmium sulfide (CdS) thin film for flexible optical device applications were prepared at $H_2(Ar+H_2)$ flow ratios on polyethersulfon(PES) flexible polymer substrates at room temperature by radio frequency magnetron sputtering technique. The CdS thin films deposited at room temperature showed a (002) preferred orientation and the smooth surface morphologies. Films deposited at a hydrogen flow ratio of 25% exhibited a photo- and dark-sheet resistance of about 50 and $2.7{\times}10^5{\Omega}$/square, respectively. From the result of the bending test, CdS films exhibit a strong adhesion with the PES polymer substrates and the $Al_2O_3$ passivation layer deposited on the CdS films only shows an increase of the resistance of 8.4% after exposure for 120 h in air atmosphere.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.138-143
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• 2007

Microstereolithography technology is similar to the conventional stereolithography process and enables to fabricate a complex 3D microstructure. This is divided into scanning and projection type according to aiming at precision and fabrication speed. The scanning MSL fabricates each layer using position control of laser spot on the resin surface, whereas the projection MSL fabricates one layer with one exposure using a mask. In the projection MSL, DMD used to generate dynamic pattern consists of $1024{\times}768$ micromirrors which have $13.68{\mu}m$ per side. The fabrication range and resolution are determined by the field of view of the DMD and the magnification of the projection lens. If using the projection lens with high power, very fine microstructures can be fabricated. In this paper, the projection MSL system adapted to a large surface for array-type fabrication is presented. This system covers the meso range, which is defined as the intermediate range between micro and macro, with a resolution of a few ${\mu}m$. The fabrication of array-type microstructures has been demonstrated to verify the performance of implemented system.