大規模観測対象のための幾何および光学情報の統合

University of Tokyo (東京大学

Development of parameterized level-set method based on 3D CAD reconstruction for analysis of detonation transition of high energy materials

학위논문(석사)--서울대학교 대학원 :공과대학 기계항공공학부,2019. 8. 여재익.We have developed a 3D STL parameterized level-set algorithm that is applied to multi-phase flow interface setup method using generally used stereolithography (STL) file instead of setting the boundary of the material by a mathematical formula in Eulerian based hydrodynamic code operated in 3D Cartesian coordinate system. Numerical simulation of rate-stick test was extended to three dimensions and the validity of newly developed algorithm was verified by comparing the detonation velocity of the boundaries set in the conventional equation and the boundaries set in the STL format. After various tubes interface is set by applying the new algorithm, Effect of geometry for deflagration to detonation transition (DDT) phenomenon according to the interaction of the flame and the shock wave on combustible gas-air mixture were numerically simulated. This study confirmed the role of obstacles in the tube to develop detonation by judging Go-No Go of DDT phenomenon according to shock wave intensity and shape. Complex facility modeling boundary using New algorithm is applied to the situation of a real size, and the situation of flame spreading is visualized in three dimensions. Numerical experiments were carried out to determine the effect of detonation shock waves on the equipment when one tank of the plant inside was given extreme pressure conditions3차원 카르테시안 좌표계에서 구현된 오일러리안 기반의 하이드로 다이나믹 코드에서 수학적인 수식으로 물질의 경계면을 설정하는 방식을 벗어나 보편적인 형상 저장 포맷인 스테레오리소그래피(STL) 파일을 이용한 다상 유동 경계면 설정 기법에 적용할 수 있는 3차원 형상 재현 알고리즘을 개발하였다. 새롭게 개발된 고폭 화약의 성능을 확인하기 위한 반응막대실험 모사를 3차원으로 확장하였고, 기존의 수학식으로 설정한 경계와 STL 형식으로 설정한 경계와의 반응속도를 비교하여 3차원 경계면 설정의 타당성을 확보하였다. 이를 적용하여 장애물이 포함된 덕트 및 굽은관의 형상을 3차원에서 구현하고 이에 가연성 기체인 에틸렌-공기 혼합물을 채운 후, 초기 설정된 화염과 충격파의 상호작용에 따른 연소폭발천이(DDT) 현상의 변화를 수치적으로 모사하였다. 이를 통해 충격파 강도와 형상에 따른 DDT 현상의 Go-No Go를 판정함으로써 관내의 장애물이 데토네이션으로 발전함에 미치는 역할을 확인하였다. 이를 실제 크기의 공장 설비로 확장하여 화염이 퍼지는 상황을 3차원으로 가시화 하였다. 공장 설비 중 하나의 탱크 안에서 초 고압의 극한상황에서 폭발이 일어나는 조건을 주었을 때, 데토네이션에 의한 충격파가 설비에 미치는 영향을 수치적 실험을 통해 확인하였다.제 1 장 서 론 1 제 2 장 수치적 기법 4 2.1 지배방정식 4 2.2. 3차원 레벨-셋 경계 설정 기법 5 2.2.1 간단한 부호 거리 함수 6 2.2.2 첫번째 부호 거리 함수 8 2.2.3 두번째 부호 거리 함수 11 제 3 장 3차원 형상 재현 검증 15 3.1 3차원 레벨 셋 알고리즘 적용 결과 15 3.2 반응막대 실험 시뮬레이션 18 3.2.1 초기 조건 및 경계 조건 설정 18 3.2.2 시뮬레이션 결과 및 토의 20 제 4 장 적용 및 결과 23 4.1 구조 영향에 따른 DDT 현상과 화염 가속 모델링 23 4.1.1 반응 모델 검증 23 4.1.2 초기조건 및 경계조건 설정 25 4.1.3 시뮬레이션 결과 및 토의 27 4.2 공장 폭발 피해 예측 시뮬레이션 32 4.2.1 초기 설정 및 화염 전파 시뮬레이션 결과 32 4.2.2 공장 구조물 피해 예측 시뮬레이션 초기 설정 및 결과 35 제 5 장 결 론 39 참고문헌 39 Abstract 43Maste

Manufactured Exports and FDI in Southern Mediterranean Countries: Evolution, determinants and prospects. MEDPRO Technical Report No. 14/April 2012

This paper investigates the evolution and determinants of manufactured exports and foreign direct investment (FDI) in 11 southern Mediterranean countries over the period 1985–2009, as well as their prospects under different scenarios pertaining to the development of the determinants. The econometric analysis confirms the role of exchange rate depreciation, the openness of the economy and the quality of institutions and infrastructure in fostering manufactured exports and FDI inflows in the region. The assessment of the prospects suggests that a scenario of deeper integration with the EU entails superior performance for manufactured exports and FDI compared with either the status quo or less integration with the EU but greater integration within the region

STRATEGY MAKING IN PRACTICE: THE CASE OF CRETAN HOTEL MANAGERS

This study investigates how managers contribute to the strategy of their firm, specifically focusing on an occupational group of hotel managers. Following the call of the Strategy-as-Practice (S-a-P) research community for heightened awareness of the managers' role and contribution to strategy, and based on the observation that strategy formation is context-specific, it attempts to generalise about the managers' contribution within a specific context. Generalising about the practitioners' contribution to strategy is problematic, however, requiring a conceptual linkage between managerial activity and organisational strategy. Drawing upon the S-a-P literature and the literature on managerial work activity, this study suggests that the managers' response to uncertainty provides that integrative link. This is supported by a simplifying assumption, namely the unitary view of organisation, whereby the central role of the managers within a firm is assured, assuming that power is concentrated upon them. The research inquiry itself spans levels of analysis: the level of the individual manager, the organisation, and the organisation's context. In turn, it requires breadth to account for the reciprocal influence among those levels of analysis. This need is accommodated by a case study approach. Nine independent hotels from the island of Crete were chosen as the sample for the study, while the data collection methods used included observation, interviews and document analysis. The results show that the hotel managers' contribution focuses on developing valuegenerating strategies for their firm; a necessity as they are at disadvantage: they are fragmented, in a saturated sector, equipped with an undifferentiated product, and ultimately reliant upon their suppliers to reach their markets. Value-generating strategies are developed through the management of the intangible resources of the firm and by building a positive history of collaboration with the suppliers. In addition, the managers' contribution is inextricably linked to their everyday activity, which supports the development of value-generating strategies. It is argued that an activity-based view of strategy can unearth some otherwise unobservable constructs that become apparent only through its micro-analytic approach. A focus on practitioners and their contribution can also be an additional level of analysis in strategy research, perceiving strategy formed through the practitioners' activity. As such, strategy can be redefined as an outcome, formed at multiple levels, with strategy practice (or the practitioners' activity) to partly account for that outcome. Generalising about the managers' contribution to strategy requires a trade-off, a choice between content and context specific generalisations. This choice ultimately depends on the reference group of practitioners in question, which delineates the boundaries of the context. In pluralist organisational contexts, that reference group is confined within the organisation's boundaries. On the other hand, unitary organisational contexts allow the selection of wider reference groups. In either case, only local generalisations can be made, taking into account the bounded nature of strategy formation. The study concludes with an analysis of its contribution to the existing body of knowledge, its limitations, and further proposes potential avenues for future research

Sistema de digitalização 3D usando super-resolução em imagens RGBD

Orientador : Prof. Dr. Luciano SilvaCo-orientadora : Profª. Drª. Olga R. P. BellonDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Informática. Defesa: Curitiba, 10/09/2013Inclui referênciasResumo: Com o advento de novos sensores de profundidade de baixo custo e com o aumento do poder de processamento paralelo das placas gr_a_cas, houve um aumento signi_cativo em pesquisas na _area de reconstru_c~ao 3D em tempo real. No grupo de pesquisa IMAGO, existe um sistema de reconstru_c~ao 3D para a preserva _c~ao digital, adaptado aos scanners a laser de alta resolu_c~ao. Visando aumentar a exibilidade deste sistema, o objetivo deste trabalho _e a amplia_c~ao do atual pipeline de reconstru_c~ao 3D do IMAGO para permitir a cria_c~ao de modelos utilizando os novos sensores em tempo real. Outro objetivo _e a aplica_c~ao de um m_etodo para o tratamento das imagens de baixa qualidade desses sensores, proporcionando modelos reconstru__dos a partir das novas imagens de melhor resolu_c~ao. A principal meta da preserva_c~ao digital _e a _delidade tanto na geometria quanto na textura do modelo _nal, o tempo e custo computacional s~ao objetivos secund_arios. Portanto, o novo pipeline se resume a tr^es etapas: a modelagem geom_etrica em tempo real, a super-resolu_c~ao e a reconstru_c~ao 3D de alto custo. O objetivo da primeira _e proporcionar a captura completa e o armazenamento de todas as imagens, ambos em tempo real, usando o modelo atualizado apenas para guiar o usu_ario. Na segunda etapa, aumentamos a qualidade e resolu_c~ao das imagens capturadas para a cria_c~ao de um modelo mais _dedigno na etapa _nal, a etapa de reconstru_c~ao 3D utilizando o atual sistema do IMAGO.Abstract: With the advent of new low-cost depth sensors and with the increasing parallel processing power of graphics cards, there was a signi_cant increase in research involving the _eld of real-time 3D reconstruction. In the IMAGO research group, there is a 3D reconstruction system for digital preservation, applied to high resolution laser scanners. To increase the exibility of the mentioned system, our goal is to contributes to the expansion of IMAGO's current 3D reconstruction pipeline to enable the creation of models using new real-time depth sensors. Another objective is the employment of a method that process the sensor's low resolution images, providing reconstructed models using higher resolution images. The aim of digital preservation is the accuracy in both geometry and texture for the _nal model, the computational time and cost are secondary goals. Therefore, the new pipeline is summarized in three steps: a real-time geometric modeling, a super-resolution technique, and high-cost geometric modeling. The goal of the _rst step is to provide a complete capture and image storage, using the real-time model to guide the user. In the second step, we increase the quality and resolution of the captured images to create smooth and accurate models in the 3D reconstruction step using IMAGO's current system

Information metrics for localization and mapping

Decades of research have made possible the existence of several autonomous systems that successfully and efficiently navigate within a variety of environments under certain conditions. One core technology that has allowed this is simultaneous localization and mapping (SLAM), the process of building a representation of the environment while localizing the robot in it. State-of-the-art solutions to the SLAM problem still rely, however, on heuristic decisions and options set by the user. In this thesis we search for principled solutions to various aspects of the localization and mapping problem with the help of information metrics. One such aspect is the issue of scalability. In SLAM, the problem size grows indefinitely as the experiment goes by, increasing computational resource demands. To maintain the problem tractable, we develop methods to build an approximation to the original network of constraints of the SLAM problem by reducing its size while maintaining its sparsity. In this thesis we propose three methods to build the topology of such approximated network, and two methods to perform the approximation itself. In addition, SLAM is a passive application. It means, it does not drive the robot. The problem of driving the robot with the aim of both accurately localizing the robot and mapping the environment is called active SLAM. In this problem two normally opposite forces drive the robot, one to new places discovering unknown regions and another to revisit previous configurations to improve localization. As opposed to heuristics, in this thesis we pose the problem as the joint minimization of both map and trajectory estimation uncertainties, and present four different active SLAM approaches based on entropy-reduction formulation. All methods presented in this thesis have been rigorously validated in both synthetic and real datasets.Dècades de recerca han fet possible l’existència de nombrosos sistemes autònoms que naveguen eficaçment i eficient per varietat d’entorns sota certes condicions. Una de les principals tecnologies que ho han fet possible és la localització i mapeig simultanis (SLAM), el procés de crear una representació de l’entorn mentre es localitza el robot en aquesta. De tota manera, els algoritmes d’SLAM de l’estat de l’art encara basen moltes decisions en heurístiques i opcions a escollir per l’usuari final. Aquesta tesi persegueix solucions fonamentades per a varietat d’aspectes del problema de localització i mappeig amb l’ajuda de mesures d’informació. Un d’aquests aspectes és l’escalabilitat. En SLAM, el problema creix indefinidament a mesura que l’experiment avança fent créixer la demanda de recursos computacionals. Per mantenir el problema tractable, desenvolupem mètodes per construir una aproximació de la xarxa de restriccions original del problema d’SLAM, reduint així el seu tamany a l’hora que es manté la seva naturalesa dispersa. En aquesta tesi, proposem tres métodes per confeccionar la topologia de l’approximació i dos mètodes per calcular l’aproximació pròpiament. A més, l’SLAM és una aplicació passiva. És a dir que no dirigeix el robot. El problema de guiar el robot amb els objectius de localitzar el robot i mapejar l’entorn amb precisió es diu SLAM actiu. En aquest problema, dues forces normalment oposades guien el robot, una cap a llocs nous descobrint regions desconegudes i l’altra a revisitar prèvies configuracions per millorar la localització. En contraposició amb mètodes heurístics, en aquesta tesi plantegem el problema com una minimització de l’incertesa tant en el mapa com en l’estimació de la trajectòria feta i presentem quatre mètodes d’SLAM actiu basats en la reducció de l’entropia. Tots els mètodes presentats en aquesta tesi han estat rigurosament validats tant en sèries de dades sintètiques com en reals

Information metrics for localization and mapping

Aplicat embargament des de la defensa de la tesi fins al 12/2019Decades of research have made possible the existence of several autonomous systems that successfully and efficiently navigate within a variety of environments under certain conditions. One core technology that has allowed this is simultaneous localization and mapping (SLAM), the process of building a representation of the environment while localizing the robot in it. State-of-the-art solutions to the SLAM problem still rely, however, on heuristic decisions and options set by the user. In this thesis we search for principled solutions to various aspects of the localization and mapping problem with the help of information metrics. One such aspect is the issue of scalability. In SLAM, the problem size grows indefinitely as the experiment goes by, increasing computational resource demands. To maintain the problem tractable, we develop methods to build an approximation to the original network of constraints of the SLAM problem by reducing its size while maintaining its sparsity. In this thesis we propose three methods to build the topology of such approximated network, and two methods to perform the approximation itself. In addition, SLAM is a passive application. It means, it does not drive the robot. The problem of driving the robot with the aim of both accurately localizing the robot and mapping the environment is called active SLAM. In this problem two normally opposite forces drive the robot, one to new places discovering unknown regions and another to revisit previous configurations to improve localization. As opposed to heuristics, in this thesis we pose the problem as the joint minimization of both map and trajectory estimation uncertainties, and present four different active SLAM approaches based on entropy-reduction formulation. All methods presented in this thesis have been rigorously validated in both synthetic and real datasets.Dècades de recerca han fet possible l’existència de nombrosos sistemes autònoms que naveguen eficaçment i eficient per varietat d’entorns sota certes condicions. Una de les principals tecnologies que ho han fet possible és la localització i mapeig simultanis (SLAM), el procés de crear una representació de l’entorn mentre es localitza el robot en aquesta. De tota manera, els algoritmes d’SLAM de l’estat de l’art encara basen moltes decisions en heurístiques i opcions a escollir per l’usuari final. Aquesta tesi persegueix solucions fonamentades per a varietat d’aspectes del problema de localització i mappeig amb l’ajuda de mesures d’informació. Un d’aquests aspectes és l’escalabilitat. En SLAM, el problema creix indefinidament a mesura que l’experiment avança fent créixer la demanda de recursos computacionals. Per mantenir el problema tractable, desenvolupem mètodes per construir una aproximació de la xarxa de restriccions original del problema d’SLAM, reduint així el seu tamany a l’hora que es manté la seva naturalesa dispersa. En aquesta tesi, proposem tres métodes per confeccionar la topologia de l’approximació i dos mètodes per calcular l’aproximació pròpiament. A més, l’SLAM és una aplicació passiva. És a dir que no dirigeix el robot. El problema de guiar el robot amb els objectius de localitzar el robot i mapejar l’entorn amb precisió es diu SLAM actiu. En aquest problema, dues forces normalment oposades guien el robot, una cap a llocs nous descobrint regions desconegudes i l’altra a revisitar prèvies configuracions per millorar la localització. En contraposició amb mètodes heurístics, en aquesta tesi plantegem el problema com una minimització de l’incertesa tant en el mapa com en l’estimació de la trajectòria feta i presentem quatre mètodes d’SLAM actiu basats en la reducció de l’entropia. Tots els mètodes presentats en aquesta tesi han estat rigurosament validats tant en sèries de dades sintètiques com en reals.Postprint (published version

Information metrics for localization and mapping

Decades of research have made possible the existence of several autonomous systems that successfully and efficiently navigate within a variety of environments under certain conditions. One core technology that has allowed this is simultaneous localization and mapping (SLAM), the process of building a representation of the environment while localizing the robot in it. State-of-the-art solutions to the SLAM problem still rely, however, on heuristic decisions and options set by the user. In this thesis we search for principled solutions to various aspects of the localization and mapping problem with the help of information metrics. One such aspect is the issue of scalability. In SLAM, the problem size grows indefinitely as the experiment goes by, increasing computational resource demands. To maintain the problem tractable, we develop methods to build an approximation to the original network of constraints of the SLAM problem by reducing its size while maintaining its sparsity. In this thesis we propose three methods to build the topology of such approximated network, and two methods to perform the approximation itself. In addition, SLAM is a passive application. It means, it does not drive the robot. The problem of driving the robot with the aim of both accurately localizing the robot and mapping the environment is called active SLAM. In this problem two normally opposite forces drive the robot, one to new places discovering unknown regions and another to revisit previous configurations to improve localization. As opposed to heuristics, in this thesis we pose the problem as the joint minimization of both map and trajectory estimation uncertainties, and present four different active SLAM approaches based on entropy-reduction formulation. All methods presented in this thesis have been rigorously validated in both synthetic and real datasets.Dècades de recerca han fet possible l’existència de nombrosos sistemes autònoms que naveguen eficaçment i eficient per varietat d’entorns sota certes condicions. Una de les principals tecnologies que ho han fet possible és la localització i mapeig simultanis (SLAM), el procés de crear una representació de l’entorn mentre es localitza el robot en aquesta. De tota manera, els algoritmes d’SLAM de l’estat de l’art encara basen moltes decisions en heurístiques i opcions a escollir per l’usuari final. Aquesta tesi persegueix solucions fonamentades per a varietat d’aspectes del problema de localització i mappeig amb l’ajuda de mesures d’informació. Un d’aquests aspectes és l’escalabilitat. En SLAM, el problema creix indefinidament a mesura que l’experiment avança fent créixer la demanda de recursos computacionals. Per mantenir el problema tractable, desenvolupem mètodes per construir una aproximació de la xarxa de restriccions original del problema d’SLAM, reduint així el seu tamany a l’hora que es manté la seva naturalesa dispersa. En aquesta tesi, proposem tres métodes per confeccionar la topologia de l’approximació i dos mètodes per calcular l’aproximació pròpiament. A més, l’SLAM és una aplicació passiva. És a dir que no dirigeix el robot. El problema de guiar el robot amb els objectius de localitzar el robot i mapejar l’entorn amb precisió es diu SLAM actiu. En aquest problema, dues forces normalment oposades guien el robot, una cap a llocs nous descobrint regions desconegudes i l’altra a revisitar prèvies configuracions per millorar la localització. En contraposició amb mètodes heurístics, en aquesta tesi plantegem el problema com una minimització de l’incertesa tant en el mapa com en l’estimació de la trajectòria feta i presentem quatre mètodes d’SLAM actiu basats en la reducció de l’entropia. Tots els mètodes presentats en aquesta tesi han estat rigurosament validats tant en sèries de dades sintètiques com en reals

The politicisation of evidence: A critical realist approach to data-driven education planning, practice and exclusion in Syria

Grounding aid planning in empirical evidence on ‘what works’ has gained currency in the field of education and conflict. However, mainstream debates on the evidence base rarely investigate the politicisation of data, even though it may be more at play than in non-conflict settings. This research aims to examine what forms of discourse play out behind data-driven education planning and practice, and whether and in what ways the politicisation of evidence may enact educational exclusion. I take a critical realist approach to analysing aid professionals’ presuppositions of evidence and the reality it claims. I draw on semi-structured interviews with 31 stakeholders in and outside Syria. The findings reveal that the Government of Syria, Western pro-opposition donors and aid agencies deploy political, emotional and managerial discourses for their advantage. These discourses generate methodological bias in evidence production and use. Stakeholders fabricate, politically reinterpret or selectively deny particular data, justifying their allocation of education resources and services in ways that favour their partisan groups over others. Consequently, vulnerable children in siege, hard-to-reach opposition-held areas and government-retaken areas were kept out of the equation of education assistance. Another emerging finding is that stakeholders position themselves strategically to both use the rhetoric of objectivity implicit in numerical data and recognise its politicisation. Analysing the complexities around how evidence is constructed and used in policies and programming, the research offers critical realist insights into aid professionalism. Measurable data are susceptible to methodological and political contestations in conflict-affected contexts, and therefore cannot objectively represent the whole reality. Aid professionals should reflect on what data tell and do not tell, and what presuppositions are inscribed in evidence. This helps professionals to attend to conflict-affected children’s realities and educational needs that they cannot simply observe and quantify, thereby making education planning and practice fairer and more just

Mining the future: post-market society and the capital-labour conflict

Graeme Cotter investigated a history of the recurrent conflict between capital and labour. In a study of the mining industry he found that in the 21st-century capitalists are sidestepping this conflict by an increasing focus on technology-labour substitution which is threatening a future society without work for many who want it