• 한국환경보건학회지
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• 제32권6호
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• pp.533-538
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• 2006

The nano-particles are known to influence the environmental protection and human health. The relationships between transient vehicle operation and nano-particle emissions are not well-known, especially for diesel passenger vehicles with DPF(Diesel Particulate Filter). In this study, two diesel passenger vehicles were measured on a chassis dynamometer test bench. The particulate matter (PM) emission of these vehicles was investigated by number and mass measurement. The mass of the total PM was evaluated using the standard gravimetric measurement method, and the total number concentrations were measured on a ECE15+EUDC driving cycle using Condensation Particle Counter (CPC). According to the investigation results, total number concentration was $1.14{\times}10^{11}$M and mass concentration was 0.71mg/km. About 99% of total number concentration was emitted during the $0{\sim}400s$ because of engine cold condition. In high temperature and high speed duration, the particulate matter was increased but particle concentration was emitted not yet except initial engine cold condition According to DPF performance deterioration, the particulate matter was emitted 2 times and particle concentration was emitted 32 times. Thus DPF performance deterioration affects particle concentration more than PM.

• 한국염색가공학회지
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• 제25권2호
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• pp.134-139
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• 2013

A tenter is very important to dry and heat-set fabrics in textile dyeing and finishing industry. However, the tenter machine typically utilizes more than 80% of all the power in dyeing system, and yet is one of the primary machine which affects quality of fabrics. Therefore, performance optimization of the tenter machine is required to reduce energy consumption and enhance quality of fabrics. To optimize the tenter machine, it is important to maintain the uniform flow rate, which can be obtained by optimizing a nozzle geometry. In this study, emboss hole angle was investigated as main parameter in flow rate uniformity and heat flux efficiency. The analysis results were compared with those acquired from bench-scale dryer test in the laboratory. The tenter machine performance simulated by Computational Fluid Dynamics(CFD) was optimized by controlling emboss hole angle.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.523-526
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• 2006

The target of this work was the process development of demonstration plant to produce the high quailty alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70t/y and the pi lot plant of 360 t/v had been developed. Main research contents in this step were the process performance test of pilot plant ot 360ton/year and the development of demonstration plant of 3 000 t/y which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/v showed components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권7호
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• pp.655-666
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• 2007

RacerPro, Pellet 등 지금까지의 전혈적인 추론 시스템들은 주로 Tableaux Algorithm 기반의 추론 시스템으로 Tableaux Algorithm의 특성상 대용량 ABox 추론에서 문제점을 나타낸다. 이를 해결하기 위한 연구로 Tableaux Algorithm 기반에 DBMS를 함께 사용한 영국 Manchester 대학의 Instance Store와 Disjunctive Datalog Approach를 사용한 독일 Karlsruhe 대학의 KAON2가 있다. 현재 추론 시스템들에 대한 벤치마크 실험은 대부분 Tableaux Algorithm 기반의 TBox 추론 위주이며 ABox 추론에 대한 평가는 거의 진행되지 않았다. 특히 최근 이슈로 부각된 (대용량 ABox 추론을 위한 추론 시스템)의 특성별 벤치마크 실험은 거의 보고되지 않았다. 이에 본 논문에서는 각 추론엔진들의 이론적 배경을 근간으로 전형적 추론엔진들과 최근 이슈에 따른 대용량 ABox론 위한 추론엔진들을 상호 비교를 통해 살펴보며 특히, 대용량 ABox 처리론 위한 추론엔진인 Manchester 대학의 Instance Store와 Karlsruhe 대학의 KAON2를 LUBM을 통하여 분석 평가함으로 사용자의 요구에 따른 대용량 ABox 추론엔진을 제시한다. 평가방법에서는 LUBM(Lehigh University BenchMark)에 대한 소개와 이를 이용한 벤치마크 실험 방법 및 평가 시스템에 대하여 소개한다. 본 논문은 결론을 통해 실험 결과와 각 추론엔진의 사용 Algorithm 특성을 기초로 다양한 환경에서의 대용량 ABox 처리에 적합한 추론엔진을 제시한다.

• Membrane and Water Treatment
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• 제9권2호
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• pp.69-77
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• 2018

The use of membrane as an innovative technology for water treatment process has now widely been accepted and adopted to replace the conventional water treatment process in increasing fresh water production for various domestic and industrial purposes. In this study, ultrafiltration (UF) membranes with different formulation were fabricated via phase inversion method. The membranes were fabricated by varying the polymer concentration (16 wt%, 18 wt%, 20 wt%, and 21 wt%). A series of tests, such as field emission scanning electron microscope (FESEM), pore size and porosity, contact angle, and zeta potential were performed to characterize the membranes. The membrane performance in terms of permeation flux and rejection were evaluated using a laboratory bench-scale test unit with mine water, lake water and tube well as model feed solution. Long hour filtration study of the membranes provides the information on its fouling property. Few pore blocking mechanism models were proposed to examine the behaviour of flux reduction and to estimate the fouling parameters based on different degree of fouling. 21 wt% PVDF membrane with smaller membrane pore size showed an excellent performance for surface water treatment in which the treated water complied with NWQS class II standard.

• 생명과학회지
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• 제19권12호
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• pp.1821-1828
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• 2009

본 연구는 육상 투척선수들의 plometric training과 weight training 프로그램 훈련이 순발력 및 민첩성과 최대 근력의 운동능력 향상에 어떠한 영향을 가져오는지 검증하기 위하여 고등학교 재학 중인 투척선수 21명을 대상으로 plyometric training과 weight training을 10주간의 트레이닝을 실시하여 여자 집단(10명)과 남자 집단(11명)으로 분류하여 다음과 같은 결론을 얻었다. 순발력에 있어서 제자리멀리뛰기, 서전트 점프, 30 m 달리기는 트레이닝 전에 비해 두 집단 모두 향상도를 보였으며, 여자 집단이 더 높은 향상도를 나타냈다. 민첩성에 있어서 사이드스텝, 버피 스텝, 전신반응 테스트는 트레이닝 전에 비해 모두 향상도를 보였으며, 사이드스텝과 버피 스텝은 여자 집단이 더 높은 향상도를 나타냈으며, 전신반응 테스트는 남자 집단이 더 높은 향상도를 나타냈다. 하지 근력에 있어서 squat, leg press는 트레이닝 전에 비해 모두 향상도를 보였으며, 여자 집단이 더 높은 향상도를 나타냈다. 무릎 관절 등속성 근력에 있어서 왼쪽, 오른쪽 신근력과 굴근력은 트레이닝 전에 비해 모두 향상도를 보였으며, 왼쪽 신근력은 남자 집단이 더 높은 향상도를 나타냈으며, 왼쪽 굴근력, 오른쪽 신근력, 오른쪽 굴근력은 여자 집단이 더 높은 향상도를 나타냈다. 상지의 근력에 있어서 Bench press, 배근력은 트레이닝전에 비해 모두 향상도를 보였으며, 여자집단이 더 높은 향상도를 나타냈다.

• 설비공학논문집
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• 제23권12호
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• pp.791-798
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• 2011

In this study, performance of R410A(50%R32/50%R125) and HFC32/HFC125 mixture is measured to examine the effect of composition shift of R410A used for various air-conditioners and heat pumps. The composition of HFC32/HFC125 mixture varies from the reference composition of R410A ${\pm}10%$ with 5% interval. Tests carried out in a heat pump bench tester at the evaporation and condensation temperatures of $7/45^{\circ}C$ and $-7/41^{\circ}C$ for summer and winter conditions, respectively. Test results show that both the coefficient of performance (COP) and compressor power of the HFC32/HFC125 mixture have the maximum difference of 2.0% as compared to those of R410A. Compressor discharge temperatures of HFC32/HFC125 mixture are increased up to $6.7^{\circ}C$ as compared to that of R410A. The amount of charge for HFC32/HFC125 mixture vary within 5.6% as compared to that of R410A. Overall, performance of R410A is not appreciably affected by the composition shift of ${\pm}10%$ of R32 under both air-conditioning and heat pumping conditions.

• 한국광학회지
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• 제33권4호
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• pp.167-176
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• 2022

적응 광학(adaptive optics, AO)은 대기 외란을 실시간으로 보정하는 기술을 말하고, 이러한 적응광학의 효율적 개발을 위하여, 다양한 성능 예측 기법을 도입하여 적응광학이 적용된 시스템 성능 예측을 실시한다. 적응광학의 성능 예측 기법으로 자주 사용되는 기법으로는 통계분석, 전산모사 및 광학 벤치 테스트가 있다. 통계분석에서는 적응광학 시스템을 통계 분석 모델로 가정하여 오차값(분산)의 제곱을 전부 합쳐 스트렐비를 간단하게 추정한다. 다만, 하위 변수 간의 상관 관계는 무시되어 이에 따른 추정의 오류는 존재한다. 다음으로, 전산모사는 대기 난류, 파면센서, 변형거울, 폐쇄 루프 등 모든 구성요소를 가능한 한 실제와 가깝게 모델링하고, 시간 흐름에 따른 적응광학 시스템의 변화를 모두 구현하여 성능 예측을 수행한다. 다만, 전산모사 모델과 현실 사이에는 여전히 일부 차이가 있어, 광학 벤치 테스트를 통하여 시스템 성능을 확인한다. 최근 국내에서 개발된 변형 거울을 적용한 1.6 m 지상 망원경용 적응광학 시스템을 개발 중에 있어, 이에 적용 가능한 적응광학 시스템을 통하여 성능 예측 기법이 요구되며 동시에 성능 예측 기법의 비교를 진행하고자 한다. 앞서 언급된 통계분석 및 전산모사를 이용하여 시스템 성능 예측을 수행하였으며, 성능 예측의 분석을 위해 각각의 성능 예측 기법의 망원경 및 적응광학 시스템 모델링 과정 및 결과를 제시하였다. 이때 성능 예측을 위한 대기 조건으로는 보현산 관측 중앙값(median)을 적용하였다. 그 결과 통계 분석 방법의 경우 평균 스트렐 비가 0.31이 도출됨을 확인하였고, 전산모사 방법의 경우 평균 스트렐 비가 0.32를 가짐을 확인함으로써 두 방법에 의한 예측이 거의 유사함을 확인할 수 있었다. 추가적으로, 전산모사의 경우 해석 결과의 신뢰성을 확보하기 위하여, 모사 시간이 대기 임계 시간 상수의 약 240배인 0.9초 이상 수행되어야 함을 알 수 있었다.

• 한국대기환경학회지
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• 제17권2호
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• pp.213-222
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• 2001

Cylindrical type ceramic filers, that is 60 O.D$\times$10t$\times$600L and 60 O.D$\times$10t$\times$1,000L were manufactured by vacuum forming processes using ceramic ray materials. For cylindrical type ceramic filters, porosity and bulk density were measured for, 80 to 90% and 0.3 to 0.4 g/㎤, respectively at uniform pore size of 41 to 45${\mu}{\textrm}{m}$. Bench scale candle filters (60$\psi$ $\times$10t$\times$600L) were tested using different dusts collected from many industries including chemical processing, glass processing and metal manufacturing pants. Collection efficiencies found out to range from 99.87% to 99.90%, while resistance coefficients from 1.1$\times$10(sup)11/$m^2$ to 1.7$\times$10(sup)11/$m^2$ . Full scale low density ceramic filters (60$\psi$ $\times$10t$\times$1,000L) were also tested at 1 atm, $600^{\circ}C$ to reveal the filtration efficiency, conditioning, and resistance coefficients using two different types of dust as chemical processing and metal refined processing. Darcys law resistance coefficients were measured to range 1.44$\times$10(sup)11/$m^2$ to 2.74$\times$10(sup)11/$m^2$, and collection efficiencies on the range 99.84 to 99.96%, Finally, results of long term performance test showed that filters were conditioned after 170hrs. Experimental conditions for effective filtration were examined under the condition 10 cm/sec face velocity, 3kg/$\textrm{cm}^2$ pulsing pressure, 5 min filtration cycle, and 300msec pulse opening time.

• 설비공학논문집
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• 제24권5호
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• pp.391-400
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• 2012

In this study, performance of HFC32/HFC152a mixture is measured in the composition range of 20 to 50% R32 with an interval of 10% for the comparison with the conventional HCFC22 in water-source heat pumps. Tests are carried out under the same capacity in a heat pump bench tester equipped with a variable speed compressor at the evaporation and condensation temperatures of 7/$45^{\circ}C$ and -7/$41^{\circ}C$ for summer and winter conditions, respectively. Test results show that the compressor power of the HFC32/HFC152a mixture is 13.7% lower than that of HCFC22 while the coefficient of performance(COP) the HFC32/HFC152a mixture is 15.8% higher than that of HCFC22. Hence, from the view point of energy efficiency, the HFC32/HFC152a mixture is excellent as compared to HCFC22. Compressor discharge temperatures of HFC32/HFC152a mixture are increased up to $15.4^{\circ}C$ as compared to that of HCFC22. The amount of charge for HFC32/HFC152 mixture decrease up to 27% as compared to that of HCFC22. Overall, HFC32/ HFC152a mixture is an excellent long term candidate to replace HCFC22 in water-source heat pumps.