• Journal of Environmental Health Sciences
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• 제41권2호
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• pp.116-125
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• 2015

Objective: This study was carried out to use pine needles as a passive air sampler (PAS) for atmospheric polychlorinared dibenzo-p-dioxins/furans (PCDD/Fs). Methods: PCDD/Fs concentrations in ambient air ($C_a$, $pg/m^3$) and deposited pine needles ($C_p$, pg/g dry) were analyzed simultaneously from June 1 to December 31. Air samples were taken using two low volume PUF active air samplers with an overall average air volume of approximately $1,200Sm^3$. Pine needles were collected the end of December near the air sampler. PCDD/Fs was analyzed by HRGC/HRMs. Results: A good correlation was shown ($R^2=0.6357$, p=0.0001) between $C_a$ and $C_p$, but a better correlation ($R^2=0.7372$, p<0.0001) existed between the logarithm of octanol-air partitioning coefficient ($LogK_{oa}$) and Log($C_p/C_a$). The average PCDD/Fs sampling rates from air to pine needles were 0.045($0.018-0.185m^3/day-g\;dry$). Conclusion: It was found that pine needles can be used as PAS for atmospheric PCDD/Fs, and they are especially suitable for long time PAS compared to PUF disk PAS.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.160-160
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• 2010

ELVs (End-of-Vehicles) in Korea incrasease continusely because of increase of used car. Automobile Shredder Residue (ASR) is final product of ELVs (End-of-Vehicles) after recycling. Automobile Shredder Residue are composed of light and heavy fluffs and soil/dust. In this study, 5 ton/day pilot plant of shaft type has been designed and constructed and 15 times of test run were performed. For the stable operation, operation conditions such as the amount of fed ASR and cokes, air flow and temperature in the gasification melting system have been changed and the composition of the produced gas such as $H_2$, CO and $CH_4$ and air pollution compound including dioxin discharged from the stack have been analyzed.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.231-233
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• 2005

For the low-power design of the mobile multimedia system architecture, this paper modeling the mobile multimedia system and analysis the power consumption profile about the whole communication environment. The mobile system model consist of air interface, RIP front-end, base-band processing module and human interface. For the result of power consumption profile analysis, the power consumption of multimedia processing is above 60% compare to the whole power consumption in mobile multimedia system. To minimize the power consumption in processing module which consumes the large power, this paper proposed the Microscopic DVS technique which applies the optimum voltage for the each multimedia frame. For the simulation result, proposed power minimization technique reduce the power consumption about 30%.

• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.910-918
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• 2012

Carbon monoxide (CO) is a primary air pollutant as an indicator of air quality released from motor vehicle combustion. A comparative study of the distributions of CO concentration with no heat source in two tunnel models open and closed at both end sides is simulated with a commercial CFD code. The tunnel models are used to investigate the CO concentration distributions at three Reynolds numbers, which are computed by the inlet velocities of 0.3, 0.6 and 1.0 m/s. For a better tunnel design, the CFD predictive approaches are available in qualitatively studying the distributions of CO concentration. In the case of the tunnel open at both end sides in sixty seconds, the total CO concentrations are approximately twenty eight percent higher than those in the closed case.

• Proceedings of the KSME Conference
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• 대한기계학회 2003년도 춘계학술대회
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• pp.956-961
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• 2003

Recently, environmental pollution has become a significant problem in industry and many researches have been investigated in order to preserve the environment. Environmentally conscious machining and technology have more and more important position in machining process. In the milling process, the cutting fluid has greatly bad influence on the environment. In this study, the machining of blade parts(12Cr steel) using the cutting fluid, compressed cold air and oil mist etc., also, the productivity and the surface topography was improved by using new end-mil tool considering tool material and shape.

• Proceedings of the KSR Conference
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1499-1504
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• 2007

This dissertation explains the construction of the expert system which can manage diagnosis and administration of trouble using circuit diagram through connection between BOM and ability term and makes up for problem which have designed RIMS with name of parts. Also this dissertation explains that existing BOM has no regard organic relation of parts and functional and systematic appearance of the flow of electricity or air. Construction of expert system and "Be enlivened BOM" with flowing electricity and air can solve problems about overlapping parts carrying out other functions with the same name of parts following to simple and physical BOM　management and having mistaken trouble of the end caused by basis for trouble of the end.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제15권1호
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• pp.25-31
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• 2003

This paper addresses an oil supply enhancement device to resolve a shortage of oil supply or no oil supply at all encountered at low speed operation for a variable speed reciprocating compressor used for household refrigerators. The oil supply enhancement device comprises a moving cylinder attached to the lower end of crankshaft and two of fluid diodes, each one at the inlet and outlet of the cylinder. Up-and-down movement of the cylinder against the lower end of the crankshaft together with the functioning of the two fluid diodes produces net oil flow from oil reservoir to inside the crankshaft. The experiment on the test bench has shown that enough oil supply into the oil feeding hole cu be made by using this device even at low speed range. Some analytical study has also been carried out to under-stand its oil supply mechanism.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.63-70
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• 2000

In Korea, researches for year-round leaf vegetables production system are in progress and the most of them are focused on environment control. Automation technologies for harvesting , transporting and grading need to be developed. This study was conducted to develop harvesting process automation system profitable to a competitive price. 1. Manipulator and end-effector are to be designed and fabricated , and fuzzy logic controller for controlling these are to be composed. 2. The entire system constructed is to be evaluated through a performance test. A robot system for harvesting a lettuce was developed. It was composed of a manipulator with 20DOF (degrees of freedom) an end-effector, a lettuce feeding conveyor , an air blower , a machine vision device, 6 photoelectric sensors and a fuzzy logic controller. A fuzzy logic control was applied to determined appropriate grip force on lettuce. Leaf area index and height index were used as input parameters, and voltage was used as output parameter for the fuzzy logic controller . Success rate of the lettuce harvesting system was 93.06% , and average harvesting time was about 5 seconds per lettuce.

• Journal of the Korean Home Economics Association
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• 제19권2호
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• pp.143-149
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• 1981

Consumer consider the purpose for which they plan to use clothes when they purchase it, and the socks in textile products is evaluated in the same way. serviceability is judged by the extent to which the socks will be useful for its intended purpose. It should retain its original shape and size, good air permeability, good absorbency, good abrasion resistance, high fastness etc. Owing to importance of serviceability in socks, in this paper, these end-use requirement characteristics were tested. The results obtained were as follows: 1. Blend ratios were different between the indicated fiber contents on labels and the testing ones. 2. Air permeability was higher in the samples which contain less stitch density, and hydroscopicity was higher in those which contain natural fibers such as cotton and wool. 3. Shrinkage depended on the blend ratios of cotton and wool, and elastic recovery was better in the course direction than in the wale direction. 4. Pilling was conspicuous in the synthetic fibers such as polyester and nylon, and fastness of laundering and perspiration was higher in the fading grade than in the staining grade.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제20권3호
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• pp.22-27
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• 2012

In oceanic flight routes, HF radio and satellite data links have been used for air-to-ground communication, but these systems have long propagation delay and low data throughput. In this paper, we propose a reliable system to overcome the weakness of current HF radio and satellite communication systems for oceanic aeronautical flight routes. The proposed scheme uses only one aeronautical VHF channel in multi-hop oceanic communication environments and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. The proposed system improves performance on delay and throughput as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.