• 제목/요약/키워드: Trap problem

검색결과 63건 처리시간 0.022초

EffECTIVE PARTICULATES REDUCTION IN DIESEL ENGINES THROUGH THE USE OF FUEL CATALYSED PARTICULATE FILTERS

  • Vincent, M.-W.;Richards, P.-J.;Rogers, T.-J.
    • International Journal of Automotive Technology
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    • 제3권1호
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    • pp.1-8
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    • 2002
  • There is Increasing world-wide interest in diesel particulate filters (DPF) because of their proven effectiveness in reducing exhaust smoke and particulate emissions. Fine particulates have been linked to human health . DPF use requires a means to secure the bum-out of the accumulated soot, a process called regeneration. If this is not achieved, the engine cannot continue to operate. A number of techniques are available, but most are complex, expensive or have a high electrical demand. The use of fuel additives to catalyse soot bum-out potentially solves the problem of securing regeneration reliably and at low cost. Work on organo-metallic fuel additives has shown that certain metals combine to glove exceptional regeneration performance. Best performance was achieved with a combination of iron and strontium based compounds. Tests were carried out un a bed engine and on road vehicles, which demonstrated effective and reliable regeneration from a tow dose fuel additive, using a single passive DPF. No control valves, flow diverters. heaters or other devices were employed to assist regeneration. Independent particle size measurements showed that there were no harmful side effects from the use of the iron-strontium fuel additive.

냉각된 종이의 잉크수리성에 관한 연구 (Ink Transfer Problem on Cooled Papers and its Causes)

  • 전성재;손창만;홍기안;윤종태
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 추계학술발표논문집
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    • pp.17-27
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    • 2006
  • Paper could be situated in a cooled environment seasonally or regionally otherwise it is forced to be in a controlled circumstance. In this paper, printing problems on a cooled paper are investigated and characterized in terms of paper properties. For this purposes, various kinds of sample are cooled down under a specially designed freezing device and printed for observing their printability. Causes for poor ink transfer on a cooled paper are suggested due to condensation, surface inactivity, and rheological change in ink film. Paperboards with higher amount of binder, thick and/or multi coat layers are more vulnerable to poor ink trap. Severe drying could cause the same effect as that of higher binder formulation. It is shown that more absorptive porous structure is desirable for better ink receptivity in a cooled status. Printing on a dampened surface may be an indicator for ink transferability on a cooled paper. Finally, desirable directions for papermaker and printshop are suggested.

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생분해 어구 보급 확대에 따른 경제적 효과 분석 (Analysis of economic effects of expanding of biodegradable fishing gear)

  • 박수봉;김현영;양용수;어승섭;강다영
    • 수산해양기술연구
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    • 제55권4호
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    • pp.372-377
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    • 2019
  • Recently, as the global problem of marine debris and marine plastics is getting serious, various ways to solve them have been proposed, and the use of the biodegradable fishing gear is proposed as an alternative. Currently, 13 types of biodegradable fishing gears are available, but their penetration rate is only 8.7%. However, the need for the use of the biodegradable fishing gear is growing as awareness of protecting marine ecosystems is growing. Therefore, in this study, the economic effects of the expansion of biodegradable fishing gear distribution in Korea's coastal areas were analyzed through the conservation of marine ecosystems, augmentation of fisheries resources, and augmentation of fishing efficiency. According to the analysis, the economic effects of 52,795 million won, 105,590 million won, and 158,385 million won was generated as the distribution of biodegradable fishing gear were expanded to 10%, 20% and 30% across all gill net and trap.

정기검사 시설기준 개선이 입자상물질(PM10) 배출에 미치는 영향 (Effects of Regular Inspection Facility Standards Improvement on Particulate Matter (PM10) Emissions)

  • 최성규;김용달;이재영;김호경;노기성;박정수
    • 자동차안전학회지
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    • 제11권1호
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    • pp.36-39
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    • 2019
  • The particulate matter that was emitted always come up by atmospheric environmental problem. Running on the road vehicles must have regular inspection at regular period and make sure the emissions of exhaust gases exceed the legal standards. Emission test for the atmospheric environment, but it is not free from the particulate matter. Currently, emission test of vehicle inspection is divided into regular inspection and close inspection. Regular inspection and close inspection differ not only the method of emission test, but also the facility standards that must have for this inspection. According to the "Regulations on the Implementation of Comprehensive vehicle Inspection, etc.", close inspection must have trapping device that is trap particulate matter by emission test to vehicle. However, regular inspection is different. Regular inspection do not specify any criteria for trapping facilities. Therefore, this study is confirm how to prevent the emission of particulate matter to the atmosphere during the year when mandatory trapping facilities are required to trapped particulate matter in the regular inspection.

ESTABLISHMENT OF CONSTRUCTION INDUSTRY CREDIT GUARANTEE SYSTEM-BASED ON TAIWAN'S CONSTRUCTION INDUSTRY

  • Ting-Ya Hsieh;Tsung-Shi Liu
    • 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.399-406
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    • 2011
  • Various construction bonds and warranties critically burden the general contractor. Also, sporadic or cumulative delays of progress payment by the owner can further trap the contractor in a financial quagmire. Facing the possibility of cash flow deficiency and callous response from the banks, most construction firms may become financially incapable of market competition, and attractive project tenders become a bidding game among few deep-pocket players. The downside of such market environment is that the depth of pocket, rather than that of professional competency dictates the choice of market winners. In Taiwan, this has been a potential crisis to the construction industry after the financial crisis which started out since 2008. To encounter this problem, this research will examine the means to better manage the construction industry. Essentially, a credit guarantee system (CGS) is the prime solution to strengthen a bank's confidence in any particular construction firm. Thus establishing a national platform which evaluates and rewards a construction firm's overall credibility is pivotal, and this third-party rated credit can help a bank to render a loan more wisely. Finally, this paper will propose the ideal operating schemes of construction-specific CGS in Taiwan and a credit scoring prototype model for construction industry, as reference for the government and banks, respectively.

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승용디젤엔진의 연료분사 제어를 통한 LNT 촉매의 NOx 저감 특성에 관한 연구 (A Study on NOx Reduction Characteristics of LNT Catalyst with Fuel Injection Control in Light-duty Diesel Engine)

  • 황승권;고아현;윤주웅;명차리;박심수;김은석
    • 한국자동차공학회논문집
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    • 제20권4호
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    • pp.150-155
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    • 2012
  • Lean NOx Trap (LNT) catalysts are capable of reducing exhaust NOx emissions from diesel engines. LNT stores NOx in lean condition and exhausts N2 by reducing NOx in rich condition. NOx reduction characteristic of LNT catalysts using throttle position sensor and fuel injection timing control for light-duty diesel engine was investigated. In contrast to SCR system, LNT catalyst uses diesel fuel in resuctant. Also if the concentration of reductant is exceeded, excessive amount of reductant will slip throughout LNT and cause another emission problem. Thus LNT regeneration with precise engine control established that can make higher NOx conversion efficiency and lower fuel penalty, prevent another emission problem. NOx and reductant concentration were measured by the NOx sensor and Mexa7100D equipped inlet and outlet of catalyst. As a result of engine test, regeneration strategy has reached high of 77.8% NOx conversion efficiency according to engine operation condition. Moreover, we have proved that it is possible to use regeneration strategy of LNT within 5% fuel penalty.

융합 인공벌군집 데이터 클러스터링 방법 (Combined Artificial Bee Colony for Data Clustering)

  • 강범수;김성수
    • 산업경영시스템학회지
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    • 제40권4호
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    • pp.203-210
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    • 2017
  • Data clustering is one of the most difficult and challenging problems and can be formally considered as a particular kind of NP-hard grouping problems. The K-means algorithm is one of the most popular and widely used clustering method because it is easy to implement and very efficient. However, it has high possibility to trap in local optimum and high variation of solutions with different initials for the large data set. Therefore, we need study efficient computational intelligence method to find the global optimal solution in data clustering problem within limited computational time. The objective of this paper is to propose a combined artificial bee colony (CABC) with K-means for initialization and finalization to find optimal solution that is effective on data clustering optimization problem. The artificial bee colony (ABC) is an algorithm motivated by the intelligent behavior exhibited by honeybees when searching for food. The performance of ABC is better than or similar to other population-based algorithms with the added advantage of employing fewer control parameters. Our proposed CABC method is able to provide near optimal solution within reasonable time to balance the converged and diversified searches. In this paper, the experiment and analysis of clustering problems demonstrate that CABC is a competitive approach comparing to previous partitioning approaches in satisfactory results with respect to solution quality. We validate the performance of CABC using Iris, Wine, Glass, Vowel, and Cloud UCI machine learning repository datasets comparing to previous studies by experiment and analysis. Our proposed KABCK (K-means+ABC+K-means) is better than ABCK (ABC+K-means), KABC (K-means+ABC), ABC, and K-means in our simulations.

생명과학과 '두 문화' 문제 (Bio-Science and the Problem of 'Two Cultures')

  • 김환석
    • 과학기술학연구
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    • 제1권2호
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    • pp.311-342
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    • 2001
  • 우리나라에서 진행중인 생명과학의 윤리 논쟁에는 과학문화/인문문화라는 '두 문화' 차원만이 아니라, 고급문화/대중문화의 또 다른 '두 문화' 차원이 서로 중첩되어 있다. 이 글은 이렇게 보다 확대된 '두 문화'의 틀을 가지고 우리나라 생명과학 논쟁의 문제점을 분석하고 바람직한 대안을 모색하려는 시도이다. 스노우의 과학문화/인문문화 틀로만 생명과학 논쟁을 들여다본다면 왜 과학자와 윤리학자 사이의 갈등이 생겨났는지를 이해하는 데 도움은 되지만, 그 대안을 모색하는 과정에서는 이 두 전문가 집단의 의사소통과 신뢰를 위한 어떤 제안으로 머물고 마는 '전문가주의의 함정에 빠질 수가 있다. 따라서 여기에 고급문화/대중문화라는 제2의 틀을 합침으로써 전문가와 시민대중 사이의 괴리와 갈등이라는 문제가 비로소 부각이 될 뿐 아니라, 이를 통해 보다 근본적이고 종합적인 대안을 구상하는 데 도움을 얻을 수 있다. 아울러 이리한 분석이 기존의 '두 문화' 논의에 대해서는 물론이요, STS의 문화적 역할에 대한 함의를 고찰하는 데에도 큰 시사점을 던져준다.

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톱다리개미허리노린재 방제용 페로몬트랩의 효율증대를 위한 끈끈이트랩 활용 (Utilization of Sticky Traps to Increase the Efficiency of Pheromone Traps Against Riptortus clavatus (Hemiptera: Alydidae))

  • 박보선;조정래;심창기;윤지영;김용욱;최호정;박종호
    • 한국응용곤충학회지
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    • 제59권3호
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    • pp.257-264
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    • 2020
  • 단감 과수원에서 문제가 되고 있는 노린재의 방제 목적으로 사용되는 페로몬트랩의 유인거리를 확인하고, 페로몬트랩의 효율을 증가시킬 수 있는 끈끈이트랩의 사용효과에 대하여 알아보고자 수행되었다. 노린재에 마커로 표시한 후 방사하여 페로몬트랩과 끈끈이트랩에 재포획된 개체수를 조사하였다. 그 결과, 페로몬트랩에 톱다리개미허리노린재가 60 m까지 유인되는 것을 확인하였으며, 끈끈이트랩의 포획률은 0주차 35%, 1주에서 27%, 2주에서 34%, 3주에서 2.9%, 4주에서 0.6%로, 3주 이후부터 급격히 낮아지는 것을 확인하였다. 페로몬트랩과 끈끈이트랩을 동시에 사용한 경우가 페로몬트랩만 단일로 사용한 경우보다 약 12배 높은 포획률을 보였다.

스팸 메일 차단을 위한 RBL개념의 확장에 관한 연구 (Studying on Expansion of Realtime Blocking List Conception for Spam E-mail Filtering)

  • 김종민;김형근;김봉기
    • 한국정보통신학회논문지
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    • 제12권10호
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    • pp.1808-1814
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    • 2008
  • 본 논문에서는 스팸 차단을 위해서 사용되고 있는 RBL의 기능에 더하여, 최근 유행하는 스팸 형태에 효과적으로 대응할 수 있는 방법으로 메일원문에 포함된 URL을 추출하여 RBL에 적용하여 확장할 수 있는 방법을 제안한다. 최근 스팸메일발송에 많이 사용되고 있는 봇넷은 이메일 스팸에서 메일 발송 주소분포로 해결할 수 없는 문제점을 가지고 있다. 일반적으로 이러한 스팸 메일은 각 개인의 감염된 좀비 PC에서 발송되므로, 발송 주소 자체가 RBL에서 사용하기에 효율성이 떨어지고 무의미 하다. 따라서 봇넷에 의해 발송되는 스팸메 일을 효과적으로 차단하기 위한 방법으로써, 스팸메일의 원문에 포함된 URL을 분석하고, 사용자를 유인하는 URL 사이트에 대한 분포자료를 바탕으로 효과적으로 차단률을 향상시킬 수 있는 방법을 제안한다. 본 논문에서는 봇넷에서의 스팸메일 발송 메커니즘과, 이러한 유형의 스팸메일을 판단하기 위하여 사용할 수 있는 방법을 제안하고 분석 가능한 스팸메 일의 수집을 위하여 이메일스팸 트랩 시스템을 구성하여 실험한다. 일정한 실험기간 동안 수신된 스팸메일의 분석을 통하여 스팸메일에 포함된 URL을 이용한 확장된 RBL기법이 스팸메일의 검출 분포를 높이는데 효과적임을 보여준다.은 요약문입니다.