• 제목/요약/키워드: rules of thumb

검색결과 16건 처리시간 0.024초

Scale- Up of Water-Oil Hydrolysis System

  • Hur, Byung-Ki;Kim, Eun-Ki
    • Journal of Microbiology and Biotechnology
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    • 제9권6호
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    • pp.773-777
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    • 1999
  • Scale-up experiments for hydrolysis of beef tallow, fat, and palm kernel with lipase derived from Candida cylindracea were carried out in 1-1, 100-1, and 10,000-1 reactors. The optimum agitation speed for the hydrolysis of the 1-1 reactor was investigated and found to be 350rpm, and this was a basis for the scale-up of agitation speed. The hydrolysis system in this work was the oil-water system in which the hydrolysis seems to process a heterogeneous reaction. An emulsion condition was the most important factor for determining the reaction rate of hydrolysis. Therefore, the scale-up of agitation speed was performed by using the power n = 1/3 in an equation of the rules of thumb method. The geometrical similarity for scaling-up turned out to be unsatisfactory in this study. Thus, the working volume per one agitator was used for the scale-up. In the case of scale-up from a 1-1 reactor to a 100-1 reactor, the hydrolysis of palm kernel was very much scaled-up by initiating the rules of thumb method. However, the hydrolysis of fat and beef tallow in a 100-1 reactor was a little higher than that of the 1-1 reactor because of the difference of geometrical similarity. The scale-up of hydrolysis from the 100-1 reactor to the 10,000-1 reactor was improved compared to that of the 1-1 to 100-1 reactor. The present results indicated that the scale-up of hydrolysis in the oil-water system by the rules of thumb method was more satisfactory under the condition of geometrical similarity. Even in the case where geometrical similarity was not satisfactory, the working volume per one agitator could be used for the scale-up of a heterogeneous enzyme reaction.

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퍼지 신경망을 이용한 맹장염진단에 관한 연구 (A Study on the Diagnosis of Appendicitis using Fuzzy Neural Network)

  • 박인규;신승중;정광호
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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    • pp.253-257
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    • 2000
  • the objective of this study is to design and evaluate a methodology for diagnosing the appendicitis in a fuzzy neural network that integrates the partition of input space by fuzzy entropy and the generation of fuzzy control rules and learning algorithm. In particular the diagnosis of appendicitis depends on the rule of thumb of the experts such that it associates with the region, the characteristics, the degree of the ache and the potential symptoms. In this scheme the basic idea is to realize the fuzzy rle base and the process of reasoning by neural network and to make the corresponding parameters of the fuzzy control rules be adapted by back propagation learning rule. To eliminate the number of the parameters of the rules, the output of the consequences of the control rules is expressed by the network's connection weights. As a result we obtain a method for reducing the system's complexities. Through computer simulations the effectiveness of the proposed strategy is verified for the diagnosis of appendicitis.

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빅데이터 분석을 통한 소방관의 경험법칙 검증 및 화재예방 활용 (Verification of firefighters' heuristics through big data analysis)

  • 박소현;박정훈;;신동일
    • 한국가스학회지
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    • 제24권2호
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    • pp.50-55
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    • 2020
  • 소방관들의 현장 활동에서 활용도가 높은 축적된 경험법칙을 경기도내 화재발생 빅데이터와의 비교분석을 통해 신뢰성을 검토하고, 시기별, 요일별, 대상별로 보다 적절하게 화재 예방 활동에 활용될 수 있도록 개선된 정량적 모델화를 연구하였다. 소방관들의 직접 면담을 통해 공감도가 높은 경험법칙을 수집하였으며, 그 중 화재 모니터링 및 발생시점의 예측 관점에서 가장 중요하다 판단된 "금요일이 가장 화재 발생률이 높다"는 경험법칙을 대상으로, 경기도에서 2018년에 발생한 화재건수, 피해내역 등 빅데이터 비교분석을 실시하였다. 더 나아가 지역별, 시간대별, 건물유형별 요일과의 화재발생 패턴을 도출하였다. 연구를 통해 실효성이 확인된 경험법칙에 대해, 화재발생 빅데이터를 반영한, 지자체와 시기별 인자가 포함된 개선된 정량적 예측모델화 및 경험법칙의 구체화를 통해, 상대적으로 경험이 적은 소방관들도 의사결정에 효과적으로 활용할 수 있는 방안을 제시하였다.

Back to School on Construction Blasting Rules of Thumb Revisited

  • Wallace, Jerry
    • 화약ㆍ발파
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    • 제19권4호
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    • pp.31-36
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    • 2001
  • This article was presented by the author at the ISEE\`s 27th Annual Conference on Explosives and Blasting Technique in January, 2001 in Orlando, Florida. This article has been updated from tits original version. The opinions and ideas expressed are not necessarily those of the International Society of Explosives Engineers or the editorial/publishing staff of the Journal of Explosives Engineering. Your esponse in form of letters to editor is encouraged.

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A Sparse Target Matrix Generation Based Unsupervised Feature Learning Algorithm for Image Classification

  • Zhao, Dan;Guo, Baolong;Yan, Yunyi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권6호
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    • pp.2806-2825
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    • 2018
  • Unsupervised learning has shown good performance on image, video and audio classification tasks, and much progress has been made so far. It studies how systems can learn to represent particular input patterns in a way that reflects the statistical structure of the overall collection of input patterns. Many promising deep learning systems are commonly trained by the greedy layerwise unsupervised learning manner. The performance of these deep learning architectures benefits from the unsupervised learning ability to disentangling the abstractions and picking out the useful features. However, the existing unsupervised learning algorithms are often difficult to train partly because of the requirement of extensive hyperparameters. The tuning of these hyperparameters is a laborious task that requires expert knowledge, rules of thumb or extensive search. In this paper, we propose a simple and effective unsupervised feature learning algorithm for image classification, which exploits an explicit optimizing way for population and lifetime sparsity. Firstly, a sparse target matrix is built by the competitive rules. Then, the sparse features are optimized by means of minimizing the Euclidean norm ($L_2$) error between the sparse target and the competitive layer outputs. Finally, a classifier is trained using the obtained sparse features. Experimental results show that the proposed method achieves good performance for image classification, and provides discriminative features that generalize well.

GIS를 이용한 토공 운반로 탐색 방법론 - 단지공사 사례를 중심으로 - (A GIS-Based Planning Methodology to Determine the Haul Route Layout in Complex Construction Projects)

  • 강상혁;백경근;백현기;서종원
    • 대한토목학회논문집
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    • 제30권6D호
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    • pp.631-639
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    • 2010
  • 토공사는 단지조성 프로젝트에서 단일 공종으로는 가장 큰 비중을 차지하는 공정 중 하나이다. 토공사의 순조로운 진행을 위해 시공계획자는 적재 및 운반장비의 효율적인 조합, 공종과의 연계를 고려한 순차적 시공, 그리고 운반로 레이아웃과 같은 토공사 운영관련 문제들을 해결해야 한다. 특히 단지내 운반로는 토공생산성 및 공사비에 직접적인 영향을 미칠 뿐 아니라 한번 정해지면 그 관성 때문에 다른 경로로 변경하기 어려운 특성이 있기 때문에 신중한 의사결정이 요구된다. 본 연구는 시공계획자의 단지내 운반경로와 관련된 의사결정을 지원하기 위해 지형정보 분석에 기초한 효율적 운반로 발굴 방법론 개발을 목적으로 한다. 이를 위해 단지내 운반경로 레이아웃 결정시 고려되어야 할 필수 요소들을 설계 및 시공 전문가들의 경험법칙에 근거하여 5가지로 구분하여 설명하였다. 또한 효과적인 운반경로 도출을 위하여 GIS 환경에서 상기한 영향요소들을 적절히 반영, 분석할 수 있는 방법론을 제안하였다. 제안된 방법론을 현재 시공이 이루어지고 있는 사례현장에 적용하여 실용성을 검증한 결과 미세한 생산성 향상을 보인 것으로 분석되었다. 본 연구는 개선된 운반효율을 보장하고, 신뢰할 수 있는 단지내 운반로 레이아웃 시공계획 프레임웍을 제공하였다는 점에서 의미가 있다.

Optimum design of reinforced concrete columns subjected to uniaxial flexural compression

  • Bordignon, R.;Kripka, M.
    • Computers and Concrete
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    • 제9권5호
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    • pp.327-340
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    • 2012
  • The search for a design that meets both performance and safety, with minimal cost and lesser environmental impact was always the goal of structural engineers. In general, the design of conventional reinforced concrete structures is an iterative process based on rules of thumb established from the personal experience and intuition of the designer. However, such procedure makes the design process exhaustive and only occasionally leads to the best solution. In such context, this work presents the development and implementation of a mathematical formulation for obtaining optimal sections of reinforced concrete columns subjected to uniaxial flexural compression, based on the verification of strength proposed by the Brazilian standard NBR 6118 (ABNT 2007). To minimize the cost of the reinforced concrete columns, the Simulated Annealing optimization method was used, in which the amount and diameters of the reinforcement bars and the dimensions of the columns cross sections were considered as discrete variables. The results obtained were compared to those obtained from the conventional design procedure and other optimization methods, in an attempt to verify the influence of resistance class, variations in the magnitudes of bending moment and axial force, and material costs on the optimal design of reinforced concrete columns subjected to uniaxial flexural compression.

Determination of strut efficiency factor for concrete deep beams with and without fibre

  • Sandeep, M.S.;Nagarajan, Praveen;Shashikala, A.P.;Habeeb, Shehin A.
    • Advances in Computational Design
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    • 제1권3호
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    • pp.253-264
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    • 2016
  • Based on the variation of strain along the cross section, any region in a structural member can be classified into two regions namely, Bernoulli's region (B-region) and Disturbed region (D-region). Since the variation of strain along the cross section for a B-region is linear, well-developed theories are available for their analysis and design. On the other hand, the design of D-region is carried out based on thumb rules and past experience due to the presence of nonlinear strain distribution. Strut-and-Tie method is a novel approach that can be used for the analysis and design of both B-region as well as D-region with equal importance. The strut efficiency factor (${\beta}_s$) is needed for the design and analysis of concrete members using Strut and Tie method. In this paper, equations for finding ${\beta}_s$ for bottle shaped struts in concrete deep beams (a D-region) with and without steel fibres are developed. The effects of transverse reinforcement on ${\beta}_s$ are also considered. Numerical studies using commercially available finite element software along with limited amount of experimental studies were used to find ${\beta}_s$.

개선된 테스트 용이화를 위한 점진적 개선 방식의 데이타 경로 합성 알고리즘 (Stepwise Refinement Data Path Synthesis Algorithm for Improved Testability)

  • 김태환;정기석
    • 한국정보과학회논문지:시스템및이론
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    • 제29권6호
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    • pp.361-368
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    • 2002
  • 본 논문은 세 가지 중요한 설계 기준인 테스트 용이화, 설계 면적, 및 전체 수행 시간을 동시에 고려한 새로운 데이터 경로 합성 알고리즘을 제시한다. 우리는 테스트 용이화를 위한 선행 연구들에서 제시한 세 가지 기초적 척도들에 근거하여 새로운 테스트 용이화의 우수성에 대한 척도를 정의한다. 이 척도를 이용하여, 스케쥴링과 할당의 통합된 형태의, 단계식이며 점진적 개선을 통한, 합성 알고리즘을 제시한다. 벤치마크 설계와 다른 회로의 예를 통한 실험에서, 우리는 설계 면적과 수행 시간에 대해 매우 적은 추가 부담으로, 회로의 테스트 용이화가 향상됨을 보인다.

Participatory Web Users’ Information Activities and Credibility Assessment

  • Rieh, Soo-Young
    • 한국문헌정보학회지
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    • 제44권4호
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    • pp.155-178
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    • 2010
  • Assessment of information credibility is a ubiquitous human activity given that people constantly make decisions and selections based on the value of information in a variety of information seeking and use contexts. Today, people are increasingly engaging in diverse online activities beyond searching for and reading information, including activities such as creating, tagging and rating content, shopping, and listening to and watching multimedia content. The Web 2.0 environment presents new challenges for people because the burden of information evaluation is shifted from professional gatekeepers to individual information consumers. At the same time, however, it also provides unprecedented opportunities for people to use tools and features that help them to make informed credibility judgments by relying on other people's ratings and recommendations. This paper introduces fundamental notions and dimensions of credibility, and contends that credibility assessment can be best understood with respect to human information behavior because it encompasses both the level of effort people exert as well as the heuristics they employ to evaluate information. The paper reports on a survey study investigating people's credibility judgments with respect to online information, focusing on the constructs, heuristics, and interactions involved in people's credibility assessment processes within the context of their everyday life information activities. Using an online activity diary method, empirical data about people's online activities and their associated credibility assessments were collected at multiple points throughout the day for three days. The results indicate that distinct credibility assessment heuristics are emerging as people engage in diverse online activities involving more user-generated and multimedia content. A heuristic approach suggests that people apply mental shortcuts or rules of thumb in order to minimize the amount of cognitive effort and time required to make credibility judgments. The paper discusses why a heuristic approach is key to reaching a more comprehensive understanding of people's credibility assessments within the information-abundant online environment.