• 제목/요약/키워드: Bottom-up approach

검색결과 231건 처리시간 0.025초

Linear Feature Extraction from Satellite Imagery using Discontinuity-Based Segmentation Algorithm

  • Niaraki, Abolghasem Sadeghi;Kim, Kye-Hyun;Shojaei, Asghar
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
    • /
    • pp.643-646
    • /
    • 2006
  • This paper addresses the approach to extract linear features from satellite imagery using an efficient segmentation method. The extraction of linear features from satellite images has been the main concern of many scientists. There is a need to develop a more capable and cost effective method for the Iranian map revision tasks. The conventional approaches for producing, maintaining, and updating GIS map are time consuming and costly process. Hence, this research is intended to investigate how to obtain linear features from SPOT satellite imagery. This was accomplished using a discontinuity-based segmentation technique that encompasses four stages: low level bottom-up, middle level bottom-up, edge thinning and accuracy assessment. The first step is geometric correction and noise removal using suitable operator. The second step includes choosing the appropriate edge detection method, finding its proper threshold and designing the built-up image. The next step is implementing edge thinning method using mathematical morphology technique. Lastly, the geometric accuracy assessment task for feature extraction as well as an assessment for the built-up result has been carried out. Overall, this approach has been applied successfully for linear feature extraction from SPOT image.

  • PDF

조응관계 실타래 풀기 (Untangling Anaphoric Threads)

  • 정소우
    • 한국언어정보학회지:언어와정보
    • /
    • 제8권2호
    • /
    • pp.1-25
    • /
    • 2004
  • This paper examines two different approaches to resolving a theoretical problem which the bottom-up approach version of Discourse Representation Theory of Kamp et al. (2003) faces in dealing with anaphoric relations between pronouns and their potential antecedents in conditional sentences where consequent clauses precede their corresponding conditional clauses. In one of the approaches, every element is processed in the order of occurrence and conditional operators in a non-sentence-initial position cause the ongoing DR to split in two with the same index. The definition of accessibility is accordingly modified so that the right DR can be accessible from the left DR. In the other approach, a different type of discourse representation structure, K ${\Leftarrow}$ K, is introduced, which allows us to resolve the target problem without modifying accessibility proposed in Kamp et al. (2003). Compatibility of these two approaches with the bottom-up version of DRT is evaluated by examining their applicability to the analysis of quantified sentences where pronominal expressions precede generalized quantifiers.

  • PDF

모노폰 거리를 이용한 트라이폰 클러스터링 방법 연구 (Efficient Triphone Clustering Using Monophone Distance)

  • 방규섭;육동석
    • 대한음성학회:학술대회논문집
    • /
    • 대한음성학회 2006년도 춘계 학술대회 발표논문집
    • /
    • pp.41-44
    • /
    • 2006
  • The purpose of state tying is to reduce the number of models and to use relatively reliable output probability distributions. There are two approaches: one is top down clustering and the other is bottom up clustering. For seen data, the performance of bottom up approach is better than that of top down approach. In this paper, we propose a new clustering technique that can enhance the undertrained triphone clustering performance. The basic idea is to tie unreliable triphones before clustering. An unreliable triphone is the one that appears in the training data too infrequently to train the model accurately. We propose to use monophone distance to preprocess these unreliable triphones. It has been shown in a pilot experiment that the proposed method reduces the error rate significantly.

  • PDF

가정용 분산전원시스템의 성능 모사를 위한 전력부하 프로파일 예측 (Prediction of Electrical Load Profile for Use in Simulating the Performance of Residential Distributed Generation Systems)

  • 이상봉;조우진;이관수
    • 설비공학논문집
    • /
    • 제23권4호
    • /
    • pp.265-272
    • /
    • 2011
  • The electrical load profiles of end-users must be analysed properly to introduce distributed generation system efficiently. In this study, numerical simulation for predicting a residential electrical load profile was developed to satisfy categorized electricity consumption range. We applied bottom-up approach to compose electrical load profile by using data from official reports and statistics. The electrical load profile produced from the simulation predicted peak times of public report accurately and agreed well with the standard residential electrical load profile of official reports within average error of 16.2%.

농촌개발사업 참여 주체의 역량 강화 방안 (Strategies and measures for capacity building in rural development project)

  • 김정섭;권인혜
    • 농촌지도와개발
    • /
    • 제17권3호
    • /
    • pp.385-418
    • /
    • 2010
  • This study aimed to find the way to help participants build capacity in rural development projects, through some case studies and Q-methodology. Decentralization and diffusion of bottom-up approach in rural development projects are the main contextual factors in this study. With the ethos of bottom-up approach in rural development, the human and financial inputs for capacity building increased drastically in the area of rural development policy. Four types of capacity building methods were identified in this study; training, consulting, learning organization, and forum. Theses methods were used more at planning step than implementation step in rural development projects. The government's effort to strengthen leadership in rural areas should be continued. The existing government's training program for capacity building had better include more diverse clients. Actions for capacity building should be centered on the needs of the participants in fields. Especially, organizing learning units is very important. Governments' rural development policy should establish the proper process which can help local actors plan their projects with enough time span.

ECC 기능을 갖춘 IEEE-796 버스용 메모리 시스템 설계에 관한 연구 (The Study on a Main Memory System with ECC Capability Based on IEEE-796 Bus)

  • 박병권;방성영
    • 대한전자공학회논문지
    • /
    • 제20권6호
    • /
    • pp.29-32
    • /
    • 1983
  • 본 논문은 작년도 국책 과제의 하나인 "16 bit 따이크로컴퓨터 개발"에서 개발친 16bit 마이 크로컴퓨터를 위한 주기억 시스템 개발에 관하여 기술한다. 이 주기억 시스템은 ECC 기능을 갖고 있으au IEEE-796 bus를 이용했다. 설계과정에서는 top-down 방식을 따랐으며 시험과정에 bottom-up 방식을 따랐다. 이렇게 해서 개발된 기억 보오드는 미국에서 시판되고 있는 것보다도 좋은 성능을 발휘했으며 가격도 저렴하다.

  • PDF

연속체 개념에 기반한 나노 임프린트 공정해석 연구 (Numerical Analysis Based on Continuum Hypothesis in Nano-imprining process)

  • 김현칠;이우일
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2003년도 추계학술대회논문집
    • /
    • pp.333-338
    • /
    • 2003
  • Nano-imprint lithography(NIL) is a polymer embossing technique, capable of transferring nano-scale patterns onto a thin film of thermoplastics such as polymethyl methacrylate(PMMA) using this parallel process. Feature size down 10 nm have been demonstrated. In NIL, the pattern is formed by displacing polymer material, which can be squeeze flow of a viscous liquid. Due to the size of the pattern, a thorough understood of the process through experiments may be very different. Therefore we nead to resort to numerical simulation on the embossing process. Generally, there are two ways of numerical simulation on nano-scale flow, namely top-down and bottom-up approach. Top-down approach is a way to simulate the flow assuming that polymer is a continuum. On the contrary, in the bottom-up approach, simulation is peformed using molecular dynamics(MD). However, as latter method is not feasible yet. we chose the top-down approach. For the numerical analysis, two dimensional moving grid was used since the moving grid can predict the flow front. Effects of surface tension as well as the slip at the boundary were also considered.

  • PDF

체육학 연구에서의 연구부정행위 방지를 위한 근거이론적 접근 (Promoting research integrity in sport and leisure studies: From the perspectives of academia)

  • 이원일;진연경;이경준
    • 한국체육학회지인문사회과학편
    • /
    • 제55권4호
    • /
    • pp.227-240
    • /
    • 2016
  • 연구 부정행위는 체육학 연구에서 지속돼야 할 연구주제이지만 연구 부정행위의 복잡한 매커니즘과 연구 진실성을 확보하기 위한 방안에 관한 연구는 미진한 실정이다. 이에 본 연구는 체육학에서의 연구부정행위의 발생원인 및 해결방안을 학계 구성원의 관점에서 살펴보는데 목적을 두었다. 이를 위해서 근거이론 방법의 적용을 통해 13명의 학자 및 대학원생들에 집단인터뷰(focus group interview), 개인인터뷰(follow-up one-on-one interview), 서술적 설문조사(qualitative questionnaire)를 통하여 수집하였다. 연구결과 연구부정행위는 사회구조적(socio-political), 사회문화적(socio-cultural), 개인적(personal) 맥락에서 발생하는 것으로 인식되었으며, 해결 방안은 첫째, 위로부터의 변화(Top-down approach), 둘째, 아래로부터의 변화(Bottom-up approach), 셋째, 지속적인 교육 및 점검(Continuous education)의 변화가 제시되었다. 본 연구 결과를 통해 제시된 경험적 지식이 체육학을 연구하는 개인 연구자의 연구윤리 의식 제고에 활용되고, 대학의 교육 및 학계 차원의 향후 노력들에 기초자료로 사용되어지기를 기대한다.

건설조직을 위한 상향식 접근방식의 지식관리시스템 구축 (A Bottom-up Approach Based Knowledge Management System for Construction Organizations)

  • 박문서;안창범;이현수;이규성
    • 한국건설관리학회논문집
    • /
    • 제10권2호
    • /
    • pp.3-13
    • /
    • 2009
  • 조직의 지속가능한 경쟁력 확보를 위한 지식경영(Knowledge Management)의 중요성에 대한 인식은 건설산업 내에서도 높아져 가고 있다. 하지만, 이러한 지식경영을 실행하기 위해 도입된 IT 도구들의 활용도나 효과성은 만족스럽지 않은 수준에 그치고 있고, 이는 전체 지식경영 성과에 대한 불만족으로 이어지고 있다. 이에 본 연구에서는 현재 한국 건설산업에서의 지식경영 사례에 대한 조사를 토대로 현재의 하향식 지식관리 방법론과 이를 반영하는 지식관리시스템이 갖는 문제점을 분석하고, 이러한 문제점을 개선할 수 있는 상향식 지식관리 방법론을 제시하고, 이를 시스템으로 구현하고자 한다. 또한 본 연구에서는 제안된 시스템과 기존 사례의 지식관리시스템과의 사용성 비교를 통해 그 사용성과 효과성에 대한 검증을 하고자 한다.

Solid-State Ball-Mill Synthesis of Prussian Blue from Fe(II) and Cyanide Ions and the Influence of Reactants Ratio on the Products at Room Temperature

  • Youngjin Jeon
    • 대한화학회지
    • /
    • 제68권2호
    • /
    • pp.82-86
    • /
    • 2024
  • This paper presents the solid-state synthesis of insoluble Prussian blue (Fe4[Fe(CN)6]3·xH2O, PB) in a ball mill, utilizing the fundamental components of PB. Solid-state synthesis offers several advantages, such as being solvent-free, quantitative, and easily scalable for industrial production. Traditionally, the solid-state synthesis of PB has been limited to the reaction between iron(II/III) ions and hexacyanoferrate(II/III) complex ions, essentially an extension of the solution-based coprecipitation method to solid-state reaction. Taking a bottom-up approach, a reaction is designed where the reactants consist of the basic building blocks of PB: Fe2+ ions and CN- ions. The reaction, with a molar ratio of Fe2+ and CN- corresponding to 1:2.8, yields PB, while a ratio of 1:6.6 results in a mixture of potassium hexacyanoferrate(II) (K4Fe(CN)6), potassium chloride (KCl), and potassium cyanide (KCN). This synthetic approach holds promise for environmentally friendly methods to synthesize multimetallic PB with maximum entropy in nearly quantitative yield.