39,380 research outputs found

    System Identification of Constructed Facilities: Challenges and Opportunities Across Hazards

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    The motivation, success and prevalence of full-scale monitoring of constructed buildings vary considerably across the hazard of concern (earthquakes, strong winds, etc.), due in part to various fiscal and life safety motivators. Yet while the challenges of successful deployment and operation of large-scale monitoring initiatives are significant, they are perhaps dwarfed by the challenges of data management, interrogation and ultimately system identification. Practical constraints on everything from sensor density to the availability of measured input has driven the development of a wide array of system identification and damage detection techniques, which in many cases become hazard-specific. In this study, the authors share their experiences in fullscale monitoring of buildings across hazards and the associated challenges of system identification. The study will conclude with a brief agenda for next generation research in the area of system identification of constructed facilities

    Identifying the unique characteristics of independent fashion retailers in Scotland by utilising Porter’s generic competitive strategy model and the marketing mix

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    Independent retailers in the fashion sector make a substantial contribution to the UK economy at the time of significant change on the high street due to financial pressures and the growth of online trade. They provide an element of creativity and innovation to a homogenous retail landscape. The independent fashion retailer creates a destination and individual identity by presenting a unique offering and differentiated experience. Whilst independent retailers are important to the future of our high street, research is limited, particularly in the area of fashion independents. Therefore this research examines and identifies the unique characteristics of independent fashion retailers within Scotland. The research adopts a case study approach, qualitative methods of data collection in order to fulfil the aim and objectives of the study. Porter’s Generic Competitive Strategies and the marketing mix were utilised as a means of drawing out the individual aspects and unique characteristics of the independent fashion retailer.Los minoristas independientes en el sector de la moda hacen una contribución sustancial a la economía del Reino Unido en el momento de un cambio significativo debido a las presiones financieras y el crecimiento del comercio en línea. Proporcionan un elemento de creatividad e innovación a un paisaje minorista homogéneo. El distribuidor independiente de moda crea un destino y una identidad individual al presentar una oferta única y una experiencia diferenciada. Mientras que los minoristas independientes son importantes para el futuro, la investigación es limitada, sobre todo en el área de empresas independientes de la moda. Por lo tanto, esta investigación examina e identifica las características únicas de los minoristas independientes de moda en Escocia. La investigación adopta un enfoque de estudio de caso, métodos cualitativos de recolección de datos con el fin de cumplir con los objetivos del estudio. Las Estrategias Competitivas Generales de Porter y la mezcla de mercadeo se utilizaron como un medio de extraer los aspectos individuales y las características únicas del minorista de moda independiente

    NAVIO - A Navigation Service for Pedestrains

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    In the research project NAVIO (Pedestrian Navigation Systems in Combined Indoor/Outdoor Environments) at our university (Vienna University of Technology), we are working on the improvement of navigation services for pedestrians. We are mainly focusing on the information aspect of location-based services, i.e., on the user\u27s task at hand and the support of the user\u27s decisions by information provided by navigation services. Specifications allow us to select appropriate sensor data and to integrate data when and where needed, to propose context-dependent routes fitting to partly conflicting interests and goals as well as to select appropriate communication methods in terms of supporting the user by various multimedia cartography forms. In this paper, these tasks are addressed in three different work packages: Integrated positioning, Pedestrian route modeling, and Multimedia route communication. In this paper we will concentrate on the findings of the first work package. For continuous positioning of a pedestrian suitable location, technologies include GNSS and indoor location techniques, cellular phone positioning, dead reckoning sensors (e.g. magnetic compass, gyro and accelerometers) for measurement of heading and travelled distance as well as barometric pressure sensors for height determination. The integration of these sensors in a modern multi-sensor system can be performed using an adapted Kalman filter. To test and to demonstrate our approach, we take a use case scenario into account, i.e., the guidance of visitors to departments of the University. The results of simulation studies and practical tests will confirm whether such a service can achieve a high level of performance for the guidance of pedestrians in urban areas and in mixed indoor and outdoor environments

    ‘Engage the World’: examining conflicts of engagement in public museums

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    Public engagement has become a central theme in the mission statements of many cultural institutions, and in scholarly research into museums and heritage. Engagement has emerged as the go-to-it-word for generating, improving or repairing relations between museums and society at large. But engagement is frequently an unexamined term that might embed assumptions and ignore power relationships. This article describes and examines the implications of conflicting and misleading uses of ‘engagement’ in relation to institutional dealings with contested questions about culture and heritage. It considers the development of an exhibition on the Dead Sea Scrolls by the Royal Ontario Museum, Toronto in 2009 within the new institutional goal to ‘Engage the World’. The chapter analyses the motivations, processes and decisions deployed by management and staff to ‘Engage the World’, and the degree to which the museum was able to re-think its strategies of public engagement, especially in relation to subjects,issues and publics that were more controversial in nature

    보행자 항법에서 계단 보행 시 진행 방향 신호의 형상 분석을 통한 층 결정 알고리즘

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    학위논문(석사) -- 서울대학교대학원 : 공과대학 항공우주공학과, 2022.2. 박찬국.This master’s thesis presents a new algorithm for determining floors in pedestrian navigation. In the proposed algorithm, the types of stairs are classified by shape analysis, and the floors are determined based on the stair type. In order to implement our algorithm, the walking direction estimated through the Pedestrian Dead Reckoning (PDR) system is used. The walking direction signal has different shapes depending on the stair types. Then, shape analysis is applied to the signal shapes of the walking direction to identify the types of stairs and determine the floor change. The proposed algorithm is verified through simulations and experiments, and it is confirmed that it works well even when moving through multiple floors with several different types of stairs. It is also verified that the performance is superior to the conventional floor determination algorithm.본 논문에서는 관성 측정 장치(IMU: Inertial Measurement Unit)를 이용한 실내 보행자 항법에서 계단을 통한 층 이동 시 계단의 종류를 파악하여 층을 결정하는 새로운 알고리즘을 제안한다. 이를 위해 보행자항법(PDR: Pedestrian Dead Reckoning) 시스템에서 추정된 고도, 걸음 검출 시간, 그리고 방향각을 사용한다. 이때 추정된 고도는 계단 보행을 시작하거나 마칠 때 평지 보행과 구분될 정도의 정확도만 필요하다. 따라서 본 알고리즘에서는 기존의 층 구분 알고리즘에서 필요로 하는 고도 추정치에 대한 의존성을 최소화할 수 있다. 제안한 알고리즘에서는 계단 보행 시에 나타나는 방향각의 신호에 통계적 형상 분석(statistical shape analysis) 기법을 적용하여 계단의 종류를 파악한 후 층을 구분하게 된다. 시뮬레이션과 실험을 통해 제안한 알고리즘의 정확도를 검증하며 여러 종류의 계단을 여러 층 오르내리는 경우에도 알고리즘이 잘 동작함을 확인한다. 그리고 기존의 층 구분 알고리즘에서 발생하는 시간 지연 문제를 해결하고 층 구분 정확도가 높아진 것을 확인한다. 또한 본 연구는 관성 측정장치 이외의 다른 센서나 무선통신 장치를 사용하지 않으며 층 높이와 같은 건물에 대한 기본 정보를 가정하지 않고도 층을 잘 결정할 수 있다는 유효성을 가진다.Chapter 1 Introduction 1 1.1 Motivation 1 1.2 Objectives and Contributions 2 Chapter 2 Pedestrian Dead Reckoning System 4 2.1 Overview of Pedestrian Dead Reckoning 4 2.2 Integration Approach 5 2.2.1 Strapdown inertial navigation system 5 2.2.2 Extended Kalman filter 6 2.2.3 INS-EKF-ZUPT 7 Chapter 3 Shape Analysis 10 3.1 Euclidean Similarity Transformation 11 3.2 Full Procrustes Distance 12 Chapter 4 Floor Determination 14 4.1 Stair Types 15 4.2 Stair Type Classification Algorithm 17 4.3 Floor Determination Algorithm 18 Chapter 5 Simulation and Experimental Results 22 5.1 Simulation Results 22 5.2 Experimental Results Single Floor Change 30 5.3 Experimental Results Multiple Floor Changes 32 5.3.1 Scenario 1 32 5.3.2 Scenario 2 37 Chapter 6 Conclusion 40 6.1 Conclusion and Summary 40 6.2 Future Work 41 Bibliography 42 국문초록 46석

    Pozicioniranje i praćenje pješaka u zatvorenom prostoru koristeći senzore pametnih telefona, otkrivanje koraka i algoritam za geokodiranje

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    The paper deals with indoor navigation using inertial sensors (accelerometers, gyroscopes, etc.) built in a smartphone. The main disadvantage of the use of inertial sensors is the accuracy, which rapidly decreases with the increasing time of the measurement. The reason of the deteriorating accuracy is the presence of errors in inertial measurements, which are accumulated in the integration process. The paper describes the determination of a pedestrian trajectory using step detection method, which is improved with utilization of the adaptive step length estimation algorithm. This algorithm reflects the change of the step length with different types of movement. The proposal of the data processing uses information from floormap, what allows the verification of the pedestrian position and detects the collision of the trajectory with the floormap. The proposed algorithm significantly increases the accuracy of the resulting trajectory. Another extension of the proposed algorithm is the implementation of the barometer measurements for determination of the height differences. This fact allows change the floor in a multi-storey buildings. The experimental measurement was realized with a smartphone Samsung Galaxy S4.Rad se bavi navigacijom u zatvorenom prostoru koristeći inercijalne senzore (akcelerometre, žiroskope, itd.) ugrađene u pametne telefone. Najveći nedostatak korištenja inercijalnih senzora je netočnost koja se ubrzano povećava produljenjem vremena mjerenja. Razlog smanjenja točnosti je prisutnost pogrešaka inercijalnih mjerenja koje se akumuliraju kroz proces integracije. Rad opisuje određivanje putanje pješaka koristeći metodu praćenja koraka koja je poboljšana korištenjem algoritma za procjenu prilagodljive duljine koraka. Ovaj algoritam odražava promjene u duljini koraka s različitim vrstama kretanja. Prijedlog obrade podataka koristi informacije iz tlocrta katova što omogućava potvrdu položaja pješaka i otkriva koliziju putanje s tlocrtom. Predloženi algoritam znatno povećava točnost dobivene putanje. Drugi dodatak predloženog algoritma se odnosi na upotrebu barometarskih mjerenja pri određivanju visinskih razlika. Ova činjenica omogućava promjenu kata u višekatnoj zgradi. Eksperimentalno mjerenje je izvršeno uz pomoć pametnog telefona Samsung Galaxy S4

    Investigating the ability of high-rate GNSS-PPP for determining the vibration modes of engineering structures: small scale model experiment

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    This study evaluates the performance of the Precise Point Positioning method using Global Navigation Satellite System measurements (GNSS-PPP) for monitoring vibration modes of shear type buildings excited by harmonic ground motions and hammer tests. For experimental testing, the shear type lumped-mass building system is represented by a specially designed metal frame model, resembling a three story building, which was excited on a small scale shaking table. The excitation protocols applied were harmonic motions with different frequencies and amplitudes. The metal model has special deformation plates at the column tips to prevent the nonlinear rotations and out-of-plane motions for the entire system. The fundamental vibration periods of the model structure were computed by a Finite Element Mathematical (FEM) model, which were compared with the position variations determined by GNSS-PPP. Two GNSS receivers were mounted on top of the model structure on the line perpendicular to the motion axis to measure the rotation motion. The GNSS data comprised dual-frequency observations with a 10 Hz sampling rate. GNSS-derived positioning was obtained by processing the data using a post-mission kinematic PPP method with fixed phase ambiguities. Analysis of the characteristics of the vibration frequencies showed that the high-rate GNSS PPP method can capture the frequencies of first motion mode of shear type structural response when compared with the FEM output. Results demonstrate the efficiency of the high-rate GNSS PPP method in monitoring first motion mode of a natural frequency
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