• 자원환경지질
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• 제47권3호
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• pp.247-254
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• 2014

불균질한 자연균열 저류층에서 암체의 압축률은 매우 작은 값을 가지는 반면에 균열의 압축률은 상대적으로 큰 값을 갖는다. 균열의 압축률을 포함한 유효 압축률을 고려하지 않을 경우에는 균열의 간극 변화로 인한 공극 부피의 변화를 반영할 수 없기 때문에 정확한 오일 회수를 예측할 수 없다. 본 연구에서는 기존의 연구들에서 암체의 압축률만을 고려하여 오일 회수를 분석했던 것과 달리, 암체와 균열의 압축률을 모두 고려한 유효 압축률을 적용해서 오일 회수량을 분석하였다. 폴리머 공법에서 균열의 압축률이 폴리머의 주입에 미치는 영향을 이해하기 위해, 폴리머의 분자량, 농도, 주입속도에 따른 오일 회수량을 분석하였다. 유효 압축률을 고려할 경우 폴리머 분자량, 농도, 주입속도가 높아질수록 유효 압축률을 고려하지 않은 경우가 고려한 경우보다 누적 오일 생산량이 높게 나타났다. 또한 공저 압력의 경우에도 유효 압축률을 고려하지 않은 경우가 고려한 경우보다 빠르게 급감하여 오일 생산량에 영향을 주는 것을 확인할 수 있다.

• 한국대기환경학회지
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• 제27권4호
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• pp.454-459
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• 2011

In this study, the recovery rate of Tedlar bag (T) sampler was investigated in comparison to polyester aluminum bag (P) sampler. To derive the comparative data sets for the relative performance between different samplers, a series of calibration experiments were performed by using 1 ppb standard of four offensive reduced sulfur compounds (RSC) odorants ($H_2S$, $CH_3SH$, DMS, and DMDS) along with $SO_2$ and $CS_2$. All the analysis was made by gas chromatography/pulsed flame photometric detector (GC/PFPD) combined with air server/thermal desorber (AS/TD). The measurement data were obtained by loading gaseous standards (1 ppb) at 3 injection volumes (250, 500 and 1,000 mL) at three intervals (0, 24 and 72 hrs). The recovery rates (RR) of P sampler were computed against the slope values of T sampler. According to our analysis, P sampler exhibits slightly enhanced loss relative to T, especially with light RSCs ($H_2S$ and $CH_3SH$). At day 0, RR for the two were 88 and 85%, respectively. Such reduction proceeded rather rapidly in the case of $H_2S$ through time. However, P sampler was more stable to store $SO_2$ unlike others. Despite slightly reduced recovery, P sampler appears as a good replacement of T sampler.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.43-47
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• 2001

The waste home appliances including television sets, refrigerators, washing machines and air conditioners have increasingly received environmental concerns in Taiwan. In light of the enforcement of Waste Disposal Act (WDA), the Taiwan Environmental Protection Administration (EPA) has certified 60 recycling/storage facilities and given permission for qualified companies to build six treatment plants around the island. Now the recycling and well treatment home appliances are estimated to be 3,342,369 units until May 31, 2001. This paper describes the present status of waste home appliance recycle and its treatment in Taiwan. The principle guidelines and policies regarding recycling, resource recovery and environmental concerns are presented.

• 한국정보처리학회논문지
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• 제6권10호
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• pp.2618-2629
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• 1999

In this paper, we describe the design and implementation of the FDRA(Fault Detection Recovery based on Agent) running on distributed multimedia environment. DOORAE is a good example for distributed multimedia and multimedia distance education system among students and teachers during lecture. It has primitive service agents. Service functions are implemented with objected oriented concept. FDRA is a multi-agent system. It has been environment, intelligent agents interact with each other, either collaboratively or non-collaboratively, to achieve their goals. The main idea is to detect an error by using polling method. This system detects an error by polling periodically the process with relation to session. And, it is to classify the type of error s automatically by using learning rules. The merit of this system is to use the same method to recovery it as it creates a session. FDRA is a system that is able to detect an error, to classify an error type, and to recover automatically a software error based on distributed multimedia environment.

• 한국통신학회논문지
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• 제29권7B호
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• pp.650-659
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• 2004

국내 무선 네트워크 환경은 사용자의 서비스 요구 수용과 시장 성장으로 인해 빠르게 변화하고 있다. 이에 따라 무선 구간에서 TCP(transmission control protocol)를 이용한 신뢰성 있는 데이터 전송도 늘어날 전망이다. TCP는 유선 네트워크에서 사용함을 가정으로 만들어졌기 때문에 무선에서 발생할 수 있는 비 혼잡 손실에 의해 많은 성능 저하를 겪을 수 있다. 특히 RTO(retransmission timeout)은 TCP의 성능에 많은 영향을 미친다. 본 논문에서는 송신단에서 fast recovery과정 중에 발생한 패킷 손실을 빠르게 감지하여 RTO없이 복구함으로써 성능저하를 줄일 수 있는 DAC$^{＋}$(Duplicate Acknowledgement Counting)와 EFR(Extended Fast Recovery)을 제안한다. 제안 알고리듬을 TCP NewReno와 비교했을 때 정상 상태에서 fast recovery 확률이 높고, 이에 따른 RTO 감소로 인해 response time이 줄어드는 것을 확인할 수 있다.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2000년도 정기총회 및 학술논문 발표회
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• pp.106-108
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• 2000

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2000년도 정기총회 및 학술논문 발표회
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• pp.165-167
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• 2000

• Environmental Engineering Research
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• 제22권3호
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• pp.288-293
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• 2017

In this study, we report the industrial application of an efficient technology for the recovery of gallic acid from Chinese nutgall processing wastewater. The recovery of gallic acid by industrial scale extraction and stripping devices was performed, with tributyl phosphate as the extractant and kerosene as the diluent. The results showed that the theoretical extraction stage was four, while the theoretical stripping stage was two. A closed-cycle system was studied for the continuous countercurrent extraction and stripping, with a five-stage extraction device and a three-stage reflux stripping device. The results showed that the multistage extraction-stripping system could steadily run for a long period, the average gallic acid level in the raffinate was $0.85g{\cdot}L^{-1}$, and the gallic acid content recovered in the strip liquor was higher than $120g{\cdot}L^{-1}$. The average extraction yield of gallic acid was 94.14%. When the strip liquor was used as raw material for production, the average production yield increased by 8.64%. In addition, after extraction, the $COD_{Cr}$ in the wastewater decreased by 38.19%, and the biodegradability of wastewater improved by 1.6 times. This study provided a new impetus for the sustainable development of the Chinese nutgall processing industry.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E4호
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• pp.181-190
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• 2002

A novel portable device for the direct measurement of alveolar breath carbon monoxide (CO) was developed. The major components of the device include a mouthpiece, non-rebreathing two-way valve, Teflon tube, and CO dosimeter. An alveolar CO measurement can be completed within 1.5 min when using the proposed device and measurement protocol. Measurements could be read to the nearest 0.1 ppm. Humidity did not influence the CO measurements taken by the CO dosimeter, plus there were no problems associated with the recovery and carryover of CO through the device. The criterion for significance in statistical analyses was p< 0.05. The average recovery was 103 and 99% for recovery and carryover experiments, respectively. Test results using the proposed alveolar CO measurement system reflected a good reproducibility. This reproducibility was also supported by the finding that the relative standard deviations (RSDs) of the data sets were less than 7％ for the loss experiment and less than 8% for the carryover experiment. Consequently, it would appear that the proposed device can be effectively applied to measure CO levels found in breath, thereby overcoming several disadvantages associated with the conventional bag and adsorbent tube sampling methods.

• 디지털콘텐츠학회 논문지
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• 제6권1호
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• pp.85-88
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• 2005

분산 멀티미디어 응용에 대한 요구는 정교한 QoS 관리를 위해서 필요하다. 분산 멀티미디어 시스템 견지에서 보면, QoS의 가장 중요한 범주는 시간성, 볼륨, 신뢰성이다. 본 논문에서는 결함 허용을 통해서 신뢰성을 향상시키는 방법에 대해서 기술한다. ERA는 분산 멀티미디어에서 하나의 소프트웨어 오류를 자동적으로 복구할 수 있는 시스템이다. 본 논문은 규칙-기반 DEVS 모델링과 시뮬레이션 기법을 사용하면서 분산 멀티미디어 상에서의 오류 복구 시스템의 성능 분석을 설명한다. DEVS에서 하나의 시스템은 시간 입력, 상태, 출력 및 함수들을 가지고 있다.