• 대한안전경영과학회지
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• 제13권2호
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• pp.243-249
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• 2011

The purpose of the study was to improve of performance for Magnetic Resonance Imaging (MRI) examination in the department of radiology. It was performed DMAIC (Define, Measure, Analyze, Improve, and Control). In the stage of definition, The fifth kinds of CTQ (critical to quality) by the kindness, the waiting time, the examination explanation, the waiting time and the waiting environment were selected by voice of customer. In the stage of measurement, the performed examinations and the reservation waiting time were measured each 1.77 and 1.69 sigma. In the stage of analysis, the potential key causes were determined the limited working hours and the difference of examination time of various entries. In the stage of improvement, MRI were performed with the operating system of 24 hours examination and the optimization of the difference of examination time by among of 30 minutes, 40 minutes, 50 minutes. Finally, the number of examinations and reserved waiting days were measured by each 3.17 and 1.71 sigma in the control stage.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.16-22
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• 2007

Fuel efficiency is one of the major issues in regard to energy and environment. As customers desire more comfortable vehicles, increase of accessory traction force is necessary. Air conditioning system (ACS) consumes the biggest traction force among accessories, especially during summer. This means ACS is the primary object deteriorating fuel economy among accessories. Since direct measurement of traction force and fuel consumption in practical vehicle is difficult, comparison analysis is taken between vehicle with and without ACS working. For this comparison, real time measurements are carried out to know ACS traction force and fuel consumption. As a result of the comparison, a vehicle without ACS operation was 15.92% superior to a vehicle with ACS operating. It could be used as a fundamental material for improvement ACS for better fuel efficiency.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.335-339
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• 2011

The unique characteristics of the construction industry - such as the fragmentation of its processes, varied scope of works and diversity of its participants - are contributory factors to poor project performance. Several issues are unresolved due to the lack of a comprehensive technique to measure project outcomes including: inefficient decision making, insufficient communication, uncertain site conditions, a continuously changing environment, inharmonious working relationships, mismatched objectives within the project team and a blame culture. One approach to overcoming these problems appears to be to measure performance by gauging contractor satisfaction (Co-S) levels, but this has not been widely investigated as yet. Additionally, the key Co-S dimensions at the project level are still not fully identified. This paper concerns a study of satisfaction dimensions, primarily by a postal questionnaire survey of construction contractors registered by the Malaysian Construction Industry Development Board (CIDB). Eight satisfaction dimensions are identified that are significantly and substantially relate to these contractors - comprising: project cost performance, schedule performance, product performance, design satisfaction, site safety, project profitability, business performance and relationships between participants. -Each of these dimensions is accorded different priority levels of satisfaction by different contractors. The output of this study will be useful in raising the awareness and understanding of project teams regarding contractors' needs, mutual objectives and open communication to help to deliver a successful project.

• 한국태양에너지학회 논문집
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• 제31권6호
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• pp.78-85
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• 2011

In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

• 한국환경과학회지
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• 제16권3호
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• pp.299-310
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• 2007

It will be necessary to make proper management plans to preserve the air quality in good level for the public. In order to make these plans, source information and detail emission inventories of the city and near industrial areas should be given. However, lack of the source measurements data makes us more difficult to complete the source inventory. VOC source Inventory could be utilized for the feasibility study to estimate the contribution of VOC sources presenting to the receptor such as residential area. It may give policy maker an idea how to control the air quality, and improve their social environment in the area. This study shows data that measured VOCs concentrations from the local industrial areas in Jeonju during from May 2005 to January 2006. The samples were collected from the near sources in 7 major factories in the industrial park as well as 5 general sources in near city Jeonju area to elucidate the abundances of speciated VOCs and their spacial and temporal distributions depending on source bases. Industrial sources are as follows; chemical, food, paper, wood, metal, non-metal (glass), and painting (coating) industries. The 5 general sources are sampled from tunnel, gasoline gas station, dry cleaning shop, printing (copy) shop, and road pavement working place in urban area. To understand the near source effect at receptor, samples from the 2 receptor sites (one is at center of the industrial complex and the other site is at distance residential area downwind from the center) were collected and analyzed for the comparison to source concentration. The mass contributions of the speciated VOC to total mass of VOCs measured from the different sources and ambient (2 receptors) were presented and discussed.

• 한국산업보건학회지
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• 제33권1호
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• pp.19-33
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• 2023

Objectives: The purpose of this study is to systematically identify situations where exposure levels are expected to be high by structuring domestic lead measurement data according to exposure processes and activities. Methods: Occupational exposure data on lead was collected from the results of the Evaluation of Reliability of Working Environment Measurement conducted by the government from 2019 to 2020. Lead exposure characteristics were analyzed by PROC (process category) and activity. The Risk Characterization Ratios (RCRs) of five PROCs according to ventilation type and lead content were evaluated using the MEASE (Metal's EASE) model. Results: The exposure data on lead (n=250) was classified into 12 PROCs and 12 activities, with an average concentration of 0.040 mg/m³ and about 14% exceeding the occupational exposure limit of 0.05 mg/m³. Processes with high exposure levels were PROC 7 (industrial spraying), 23 (open processing and transfer operations of molten metal), 24 (mechanical treatment), 25 (welding), and 26 (handling of powder containing lead). The results of evaluating RCR for the five PROCs were greater than 1 or close to 1 even if local exhaust ventilation was used. Conclusions: There is a possibility that the concentration of exposure is high in the casting and tapping of molten metal containing lead, mechanical treatment such as fracturing and abrasion, handling of powder, spraying, battery manufacturing, and waste battery recycling processes. It is necessary to implement chemical management policies for workplaces with such processes.

• 청정기술
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• 제12권4호
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• pp.250-258
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• 2006

CFC-113과 1,1,1-trichloroethane 등과 같은 CFC 화합물은 화학적 안정성 및 열역학적 특성 등이 우수하고, 불연성이며, 부식성이 없는 화합물로 오랜 시간 동안 전 산업에 걸쳐 널리 사용 되어 왔다. 하지만, 1989년 지구 환경의 보호를 위해 이들의 생산과 사용을 규제하는 국제협약인 '오존층 파괴물질에 관한 몬트리올 의정서'가 체결되어 대체 세정제가 요구되고 있다. 본 연구에서는 세정 시스템을 변화시키지 않고 세정력이 우수하면서 환경 친화적이며 인체 유해도가 낮으며 부식성 물질을 발생 시키지 않는 비수계 세정제를 개발하고자 하였다. 이를 위하여 글리콜 에테르계의 용매와 파라핀계 탄화수소 물질을 일정 비율로 혼합, 배합하면서 실록산을 첨가하여 비수계 세정제를 배합 제조하였다. 그리고 이들 세정제의 물성과 세정성을 평가하여 대체 세정제로서의 가능성을 평가하였다. 배합세정제의 물성측정 결과 밀도와 표면장력이 낮아 오염물에 대한 침투력이 우수할 것으로 예상되었고 인화점과 증기압 측정값으로 세정제의 안전성을 평가할 수 있었다. 플럭스, 솔더 및 그리스에 대한 세정성능 측정결과 높은 세정성능을 보여주었고 피세정물의 표면에 잔류물이 생성되지 않았다. 결과적으로, 규제물질과 동등한 세정능력을 지니며 침투력이 우수하고 인체 유해도가 낮은 세정제를 개발할 수 있었다.

• 한국안전학회지
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• 제36권5호
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• pp.71-78
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• 2021

There are regularly planned overhaul periods in thermal power plants, which involve the maintenance of the boiler of the power plants. However, thermal power plants workers are always exposed to risk during overhaul periods owing to the narrow space and significant dust inside the boiler. Therefore, it is essential to develop a safety monitoring system that is suitable for operating in this type of environment. In this study, we developed not only a worker three-dimensional (3D)-location monitoring system that can monitor and record the entry/exit of workers, their 3D-location, and fall accidents but also a method to secure the working environment and operation efficiency. This system comprises of a worker tag, which was equipped with an inertial measurement unit, a barometric pressure sensor, and a Bluetooth low energy (BLE), and the tags were given to each worker. In addition, the location of workers inside the boiler was measured using a pedestrian dead reckoning (PDR) method and BLE beacons. The location data of the workers tag were transmitted to the integrated database (DB) server through a gateway, and to the administrator monitoring system. The performance of the system was demonstrated inside an actual thermal power plant boiler, and the accuracy and reliability of the system were verified through a number of repeated tests. These results provide insights on designing a new system for monitoring enclosed spaces.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.138-142
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• 2004

In this paper, we present a new method for monitoring of ECU's sensor signals of vehicle. In order to measure the ECU's sensor signals, the interfaced circuit is designed to communicate ECU and the Embedded Linux is used to monitor communication result through Web the Embedded Linux system and this system is said "ECU Interface Part". In ECU Interface Part the interface circuit is designed to match voltage level between ECU and SA-1110 micro controller and interface circuit to communicate ECU according to the ISO, SAE communication protocol standard. Because Embedded Linux does not allow to access hardware directly in application level, anyone who wants to modify any low level hardware must develop device driver. To monitor ECU's sensor signals the most important thing is to match serial level between ECU and ECU Interface Part. It means to communicate correctly between two hardware we need to match voltage and signal level, and need to match baudrate. The voltage of SA-1110 is 0 ${\sim}$ +3.3V and ECU is 0 ${\sim}$ +12V and, ECU's communication Line K does multiple operation so, the interface circuit is used to match voltage and signal level. In Addition to ECU's baudrate is 10400bps, it's not standard baudrate in computer environment. So, we need to develop a device driver to control the interface circuit, and change baudrate. To monitor ECU's sensor signals through web there's a network socket program is working in Embedded Linux. It works as server program and manages user's connections and commands. Anyone who wants to monitor ECU's sensor signals he just only connect to Embedded Linux system with web browser then, Embedded Linux webserver will return the ActiveX webbased measurement software. It works in web browser and inits ECU, as a result it returns sensor signals through web. All the programs are developed with GCC(GNU C Compiler) and, webbased measurement software is developed with Borland C++ Builder.

• 농업과학연구
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• 제50권3호
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• pp.425-436
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• 2023

In Korea, the U.S. Tier-4 Final emission standards have been applied to agricultural machinery since 2015. This study was conducted to analyze the emission characteristics of agricultural tractors during plow tillage operations using PEMS (portable emissions measurement systems). The tractor working speed was set as M2 (5.95 km/h) and M3 (7.60 km/h), which was the most used gear stage during plow tillage operation. An engine idling test was conducted before the plow tillage operation was conducted because the level of emissions differed depending on the temperature of the engine (cold and hot states). The estimated level of emissions for the regular area (660 m²), which was the typical area of cultivation, was based on an implement width of 2.15 m and distance from the work area of 2.2 m. As a result, average emission of CO (carbon monoxide), THC (total hydrocarbons), NOx (nitric oxides), and PM (particulate matter) were approximately 6.17×10-2, 3.36×10^-4, 2.01×10^-4, and 6.85×10^-6 g/s, respectively. Based on the regular area, the total emission of CO, THC, NOx, and PM was 2.62, 3.76×10^-2, 1.63, and 2.59×10^-4 g, respectively. The results of total emission during plow tillage were compared to Tier 4 emission regulation limits. Tier 4 emission regulation limits means maximum value of the emission per consumption power (g/kWh), calculated as ratio of the emission and consumption power. Therefore, the total emission was converted to the emission per power using the rated power of the tractor. The emission per power was found to be satisfied below Tier 4 emission regulation limits for each emission gas. It is necessary to measure data by applying various test modes in the future and utilize them to calculate emission because the emission depends on various variables such as measurement environment and test mode.