• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.241-242
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• 2011

교통 약자 승객의 편의성 증대, 도심의 매연 감소 및 온실가스 저감 등 대중 교통 선진화를 위해 친환경 초저상 전기버스의 개발이 필요하다. 초저상 전기버스는 초저상 액슬 일체형 휠모터 구동시스템을 탑재한 형태로 구현이 가능하며, 초저상 액슬 일체형 휠모터 구동시스템은 구동 모터를 액슬 허브에 일체화 시킴으로써 기존 구동시스템 대비 무게 및 사이즈가 대폭 줄어들고, 동력 전달 매커니즘을 획기적으로 개선하여 효율 향상 및 차량 연비 개선이 가능하다. 특히 바퀴 중심과 액슬 출력 중심에 단차를 둠으로써 차량의 전방 바닥 뿐만 아니라 후방바닥을 평평하게 유지할 수 있어 실내 공간이 획기적으로 개선되어 교통 약자를 포함한 승객의 편의성을 향상시킬 수 있다. 또한, 액슬 일체형 휠모터 구동시스템은 각 휠의 분산 구동이 가능하므로 동특성 및 구동제어성이 뛰어나고, ESP(Electronic Stability Program), VDC(Vehicle Dynamic Control) 등과 연계하여 통합적인 지능형 시스템을 구현할 수 있다. 액슬 일체형 휠모터 구동시스템은 휠모터와 감속기 및 휠모터제어기 등으로 구성되며, 본 논문에서는 초저상 액슬 일체형 구동시스템용 120kW급 휠모터 및 휠모터제어기의 개발 및 다이나모 환경에서 T-N 특성 및 최대 출력 시험, 효율 시험을 통해 전기버스 등 대형 차량(Heavy Duty Vehicle)에 적용 가능한 전기동력시스템의 성능을 확인하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.46-53
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• 2007

NC (Numerical Control) code for the tool path needs to be generated efficiently for machining of free form pockets with arbitrary wall geometry on a three axis CNC machine. The unified rough and finish cut algorithm and the tool motion is graphically simulated in Part 1. In this paper, a grid based 3D navigation algorithm simulated in Part 1 for generating NC tool path data for both linear interpolation and a combination of linear and circular interpolation for three-axis CNC milling of general pockets with sculptured bottom surfaces is experimentally performed and verified.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.421-429
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• 2004

In Korea, the radiant heating system has been widely used as a residential heating method, which has been modernized to use hot water running into the tubes embedded in the floor structure. According to the recent improvement of living standard of residential buildings, the requirement of the thermal comfort and energy saving in heating system has been raised. Until now, the radiant floor heating system has been controlled by room thermostat installed in the living room, but for better thermal comfort, an individual room control method is adopted as an alternative. Therefore, it is necessary to evaluate the control performance between the current control method and the individual room control method. In this study, the control performance between the two systems is evaluated through the field experiment. And the control performances of room air temperature and energy performances are analyzed through the simulation using TRNSYS. Firstly, the simulations are performed in the various outdoor conditions and the flow rates and the simulation results are analyzed for the control performances. Also, to evaluate the energy performance, the simulations are performed under the operating conditions in which the set-point of the room air temperature is fixed or changed according to the schedule of occupancy, and the simulation results are analyzed between the two methods.

• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.1
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• pp.25-34
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• 2013

As the construction industry develops, environmental pollution gets increasingly serious, giving damage including the increase of incidence of respiratory diseases and skin diseases among children with weakened immune systems, rather than adults. In daycare centers, infants and children spending much of their time, have high frequency of contact with the interior floor finish material. However, the majority of the child care centers don not use eco-friendly flooring but ordinary monorium flooring, because the initial investment cost of the eco-friendly flooring is higher than ordinary monorium flooring. Therefore, in this study, life cycle costs including the initial investment cost of the eco-friendly flooring and ordinary monorium flooring were calculated, demonstrating that the eco-friendly flooring is more economical than ordinary monorium flooring in terms of life-cycle cost. In addition, the analysis of the environmental performance also showed the excellence of the eco-friendly floor finishes. It is expected that the use of the eco-friendly floor finishes will increase due to their excellence in the aspect of life cycle cost and eco-friendly performance, through this study.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.68-75
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• 2015

We conducted a thermal compression of domestic Korean pinewood for a use in flooring. For the evaluation of flooring material, we measured dimensional stability and surface hardness of thermally compressed wood. It is possible to make high-specific gravity woods with a range of 0.82-0.92 after the thermal compression with 50% compression set. The surface hardness increased with an increase in the pressing temperature. The highest value of surface hardness was $23.6N/mm^2$, which was obtained from the thermal compressed wood with pressing temperature of $160^{\circ}C$ and 30 minutes of pressing time. However, the surface hardness of woods treated at high temperature of $180^{\circ}C$ or greater decreased. The recovery of thickness decreased with increasing the pressing temperature. For dimensional stability, compression temperature was more dominant than compression time.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.973-978
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• 2010

The emission of volatile organic compounds (VOCs) from building materials is one of great concerns due to maintain airtight condition of a building to reduce energy consumption, and it causes the deterioration of indoor air quality. Therefore, the emission characterization of VOCs from building materials is necessary to improve indoor air quality. Emission characteristics of VOCs from a plywood flooring that is one of the most commonly used materials in an under-heating system, and from an adhesive that is generally used to stick a plywood flooring to a concrete floor were investigated using an emission chamber test in this study. It was found that the VOCs emission factor was dependent upon and proportional to indoor temperature, and the emission characteristics were closely related to the existing places and conditions of VOCs sources inside the building materials. Maximum emission factors of hexane and toluene from building materials were generally observed at the beginning, however, only that of toluene from a plywood flooring was shown after 6 hours from the beginning. It could be considered that the existing place and condition of toluene source inside a plywood flooring could influence on the VOCs emission. From this study, bake-out time more than 72 hours could be recommended before moving in to avoid the exposure to high concentration of VOCs emitted from an under-heating system.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.315-319
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• 2007

Transgastric endoscopic cholecystectomy was successfully accomplished in a 1-year-old, 15 kg, female, mongrel dog. Single-working channel flexible gastric endoscope was used with the aid of one abdominal laparoscopic port. Gastrotomy was performed using endoscopic needle knife at the ventral antral region. Through the gastric incision endoscope was advanced and retroflexed for the visualization of gallbladder. For the better exposure of surgical field, gentle traction was applied at the fundus of the gallbladder using laparoscopic grasping forceps. Cystic duct and artery was ligated using endoclips. After transecting the duct and artery, gallbladder was dissected using endoscopic coagulating grasping forceps and needle knife. Resected gallbladder was retrieved through the mouth and gastric incision site was sutured using endoclips. There was no evidence of bile leakage or stomach leakage on postoperative day (POD) 3. On POD 16, gastric endoscopy and laparoscopy was performed. Gastric endoscopy revealed complete adhesion of incision site. The content of the peritoneum appeared healthy, with no sign of infection, bile staining, or organ injury. The omentum was adhered over resected gallbladder fossa and the serosal surface of gastrotomy site. This is the first report of NOTES cholecystectomy in the dog and provides new concept of cholecystectomy of the dog.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.173-180
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• 2009

Very-early strength latex-modified concrete(below ; VES-LMC) was developed for possible early-opening-to-traffic after overlay of bridge deck concrete. The purpose of this study is to analyze the cause of map, transverse and longitudinal cracking in VES-LMC and to provide a control method for minimizing occurrence of cracking. The proposed prevention method against map and transverse cracking was verified by field data. VES cement was modified as the unit cement content was reduced from 390kg/$m^3$ to 360kg/$m^3$. The maximum size of coarse aggregate was increased from 13mm to 19mm. The wire mesh and steel fiber were adopted in concrete mixture. From the results, the proposed prevention method against map and transverse cracking was verified since structural cracking was not occurred until 3 years after overlay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.585-594
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• 2000

The exact path following of an autonomous mobile robot in a factory and an unreliable environment has many disadvantages in case of a classical control algorithm. In this paper, a neural network control approach based on an error back propagation algorithm is proposed for controlling a mobile robot to follow a line installed on the road. Since not only the three recognized informations from three sensors attached on a mobile robot but also the ten detailed informations in non recognition area are learned with input patterns, a mobile robot moves smoothly an installed line in spite of non perception space. The mobile robot has an effect of error minimization with a short time till a destination. To test an effectiveness of the proposed controller, the two motor velocity changes which is affected from a moving angle change of a mobile robot are simulated with computer.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.155-160
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• 1998

본 연구는 대 용량화와 다 기능화의 추세에 따라 점차 대형화, 복잡화되고 있는 세탁기 에 대한 사용편리성을 고려한 사용자 중심 제품개발의 일차적 접근으로, 인체측정 자료를 근거로 하여 세탁기의 외부 규격을 제안하였다. 결정 대상인 세탁기 외부규격은 높이, 폭 세탁조 바닥 높이, 컨트롤 패널의 위치 등이었으며, 이를 위하여 고려된 인체 자료는 신장, 어깨 높이, 눈 높이, 팔꿈치 높이, 팔 길이 등이 었다. 기존의 인체 자료들은 세탁기의 외부규격을 결정하는 데 많은 부족함이 나타났으며, 인체 자세의 단순화와 자료의 가정이 요구되었다. 이러한 제한은 3차원 컴퓨터 인체모형을 활용한 세탁동작의 시뮬레이션을 수행하여 사용자의 동작범위를 파악하므로서 보완하였다. 특정의 제품을 설계하는 과정에 서는 일반적으로 입수할 수 있는 인체측정자료에 비하여 보다 정밀하고 많은 항목의 자료가 요구도히었으여, 이러한 자료의 한계를 극복하는 데는 3 차원 컴퓨터 인체모형을 이용한 시 뮬레이션이 유용하게 활용될 수 있었다.