• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.427-433
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• 2002

An inverter-driven induction motor is usually adapted to the traction motor for a high speed drive system requiring safety, reliability, performance, compact size owing to the space and weight alloted for attaching to train, etc. and AC Traction motor for G7 train will be operated in the worst condition such as mechanical vibration, limited mounting space, severe thermal stress, inverter with non-sinusoidal voltage waveform, dust and so on. therefore, design procedure must be carefully carried out wi th considering the motor size, vibration and thermal expansion of rotor bars, insulation system, reliability of frame, as well as output characteristics. In this paper, we will inform the characteristics and design of the traction motor for G7 train and also analyze the test result of it.

• 생물환경조절학회지
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• 제17권1호
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• pp.32-37
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• 2008

참외 재배시설에서 시설 내부 필름 표면에 결로현상으로 부착된 수적량과 시설 외부 필름 표면에 부착된 분진 부착량이 적었던 PO-2에서 투광률이 71.2%로 가장 높았다. 겨울철 시설 터널에서 온도가 가장 낮은 새벽 시간의 기온은 노지보다 $11.8{\sim}14.5^{\circ}C$ 정도 높게 나타났으며, 피복자재에 따라서는 최고 $2.7^{\circ}C$차이가 났는데 PO-2에서 가장 높았다. 지온은 터널이 노지보다 $13.0{\sim}15.3^{\circ}C$ 정도 높았으며, PO-2에서 가장 높아 PE보다 $2.3^{\circ}C$ 높았다. 참외 과실 전체에서 엽산을 분석한 결과 엽산함량은 품종에 따라 $68.9{\sim}113.4{\mu}g/100g$ 정도로 나타났다. 저온기에 참외 과육에서 $45{\sim}53{\mu}g/100g$ 정도로 나타났으며, 보온성과 광환경이 우수한 PO-2에서 PE보다 17% 정도 높은 수준을 보였다. 그러나 외기 온도가 $15^{\circ}C$ 이상 확보된 시기에는 $55.2{\sim}75.2{\mu}g/100g$ 정도로 나타났으며, PO-2에서 PE보다 과육에서 36% 높은 수준을 보였다.

• 생물환경조절학회지
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• 제16권2호
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• pp.96-100
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• 2007

피복자재별로 전광선투과율은 차이가 거의 없었으나, 물방울과 먼지의 부착량이 적은 J-2에서 시설 내 광투과율은 78.2%로 가장 높았다. 자외선 투과율이 완전히 차단된 필름은 J-2이었고, 나머지의 자외선 투과율은 $62{\sim}76%$ 정도이었다. 무가온 참외재배시기에 터널 안이 노지보다 기온은 $15{\sim}21^{\circ}C$, 지온은 $20{\sim}25^{\circ}C$ 정도 높았다. 피복자재별로 기온은 $6^{\circ}C$, 지온이 $5^{\circ}C$ 정도 차이가 나타났으며 기온과 지온 모두 J-2 에서 가장 높았다.

• 한국산업보건학회지
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• 제29권2호
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• pp.159-166
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• 2019

Objectives: The purpose of this study was to evaluate the personal exposure to $PM_{10}$ by body parts for the development of dust monitoring wearable device for swine farmers. Methods: Tasks were classified by using motion pictures taken by action cameras attached to swine farmers. Concentrations of $PM_{10}$ were measured by attaching direct-reading instruments at the head, neck and waist of worker. Differences of $PM_{10}$ exposure between body parts were analyzed with linear regression. Results: We identified three tasks(vaccination, moving pigs, and manure treatment). $PM_{10}$ concentration during vaccination was the highest among the tasks, and the body part showing the highest concentration of $PM_{10}$ was the waist regardless of task. In all tasks, the closer distance between the body parts, the higher were the R-squared values(vaccination 0.4221, moving pigs 0.6990, and manure treatment 0.2164). Conclusions: We presumed that $PM_{10}$ concentrations were affected by the parts of the body in which they were measured. In order to develop swine farmer's wearable device for monitoring dust concentration in air, the determination of the positions of monitoring sensor to ensure accurate measurement is essential. Considering the results of this study, wearable sensor should be positioned at the waist.

• 한국컴퓨터정보학회논문지
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• 제24권9호
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• pp.83-95
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• 2019

Recently, a variety of IoT data is collected by attaching geosensors to many vehicles that are on the road. IoT data basically has time and space information and is composed of various data such as temperature, humidity, fine dust, Co2, etc. Although a certain sensor data can be retrieved using time, latitude and longitude, which are keys to the IoT data, advanced search engines for IoT data to handle high-level user queries are still limited. There is also a problem with searching large amounts of IoT data without generating indexes, which wastes a great deal of time through sequential scans. In this paper, we propose a unified spatial index model that handles both grid and trajectory queries using a cell-based space-filling curve method. also it presents a visualization method that helps user grasp intuitively. The Trajectory query is to aggregate the traffic of the trajectory cells passed by taxi on the road searched by the user. The grid query is to find the cells on the road searched by the user and to aggregate the fine dust. Based on the generated spatial index, the user interface quickly summarizes the trajectory and grid queries for specific road and all roads, and proposes a Web-based prototype system that can be analyzed intuitively through road and heat map visualization.

• 한국건축시공학회지
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• 제8권2호
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• pp.113-119
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• 2008

Recently, fiber reinforced polymers(FRP) composite materials are used extensively in the rehabilitation of concrete structural members. A main application is to wrap beams and columns using the continuous fibers sheets to improve their strength and ductility. The corner chamfering affects significantly the performance of the continuous fibers sheets, and could lead to environmental problem with waste and dust. The main purpose of this paper is to verify the effect of corner conditions on the strength of the continuous fiber sheets, and to introduce new attached components which can avoid environmental problem. A total of 15 specimens were tested and carefully checked for three types of continuous fiber sheets(carbon, glass, and aramid) and three types of corner conditions(non-chamfering, chamfering, and device attaching). It is proved that the devices proposed in this research have some capabilities to use for RC member. But additional research will be needed for commercializing.