Identifying traffic count posts for origin-destination matrix adjustments: An approach to actual size networks

For transportation planners, the use of Origin-Destination (OD) matrix adjustment, is receiving considerable attention. However, there are concerns about the validity of results, primarily related to the number and location of traffic count posts. This leads to the question “What would be the best set of traffic count posts to use in OD matrix adjustment modules?” It has been proved that solving this problem is cumbersome. There have been several attempts (either exact or heuristic approaches) to address this problem. But due to the inherent complexities, there is no efficient and easy-to-use methodology able to address situations on the scale of actual cases. This study demonstrates a simple way of identifying traffic count posts tailored to deal w ith real-size cases. The proposed methodology is based on a maximum matrix coverage criterion. Using a limited number of incremental trials, a set of links whose traffic flows give maximum coverage of the demand and maximum fitness to the corresponding traffic count rates are identified as traffic count posts. The results show that more traffic count posts do not necessarily yield a better result. This article reports on a project conducted for the public works ministry of the UAE city of Sharjah

Multibody dynamic modelling of a direct wind turbine drive train

Wind turbines normally have a long operational lifetime and experience a wide range of operating conditions. A representative set of these conditions is considered as part of a design process, as codified in standards. However, operational experience shows that failures occur more frequently than expected, the costlier of these including failures in the main bearings and gearbox. As modern turbines are equipped with sophisticated online systems, an important task is to evaluate the drive train dynamics from online measurement data. In particular, internal forces leading to fatigue can only be determined indirectly from other locations’ sensors. In this contribution, a direct wind turbine drive train is modelled using the floating frame of reference formulation for a flexible multibody dynamics system. The purpose is to evaluate drive train response based on blade root forces and bedplate motions. The dynamic response is evaluated in terms of main shaft deformation and main bearing forces under different wind conditions. The model was found to correspond well to a commercial wind turbine system simulation software (ViDyn

Wind Turbine Drive Train System Dynamics ; Multibody Dynamic Modelling and Global Sensitivity Analysis

To facilitate the design and production of highly efficient and reliable wind turbine drive trains, this thesis deals with the mathematical modelling and analysis of drive train system dynamics. The drive train is considered as the subsystem of the wind turbine that transfers mechanical power from the rotor hub to the generator, and thereby plays an important role in the system dynamics and the efficiency of wind turbine operation.The dynamics of wind turbines is complex and a critical area of study for the wind industry. The multidisciplinary nature of wind turbine design adds to the complexity of this task, as the subsystems of a wind turbine need to be tuned with respect to a common objective to achieve a cost effective, reliable and optimum structural and dynamic performance.The overall performance of a drive train can be evaluated from different perspectives. In this thesis, mathematical model of drive train wind turbine for both direct and indirect drive train has been developed based on multibody dynamic modelling formalism. Afterwards, the dynamics behaviour of the drive train is evaluated by proposed objective functions referring to displacements, loads, fatigue damage indicators, and frequency responses. These objective functions are investigated for several wind operational scenarios such as normal operation, turbulent, vertical inclination cases.The work also contributes to enhanced knowledge in the field with focus on the inter-action between functional components and system dynamic response, faults modelling and detectability of defects in functional components such as bearings, and couplings in wind turbine drive trains. To have a better insight into wind turbine dynamics, the global sensitivity analysis (GSA) of the objective functions with respect to input structural parameters is considered. By introducing defects in functional components and investi-gating sensitivity indices, detectability of faults is proved. GSA also demonstrates the most influential input parameters to the output objective functions. The results of such analysis not only can narrow down the number of input variables for design problems, but also give understanding on which structural parameters are most important to have pre-cise data for, ultimately designing more efficient drive trains in terms of cost and durability

STRUCTURAL DYNAMICS OF A WIND TURBINE DRIVE TRAIN HIGH SPEED SUBSYSTEM: MATHEMATICAL MODELLING AND VALIDATION

The paper studies the dynamics of a wind turbine drive train high speed subsystem, both by modelling and experiments with focus on system torsional vibration and transient events which can reduce fatigue life of functional components (gearbox, bearings, shafts, couplings,others). A scaled down drive train high speed shaft test rig has been developed. Main components of the test rig are six-pole motor with variable frequency drive controller (up to 1000rpm), shafts’ disk coupling and flexible mounting structure representing gearbox housing with output high speed bearing. The test rig is equipped with measurement system comprising a set of accelerometers and displacement sensors, strain gauges and telemeter system, data acquisition hardware and software (SKFWindCon3.0). Mathematical and computational models of the test rig have been developed and went through validation tests. The system dynamic response is studied for different operational scenarios and structural parameters (run-shut down case with and without eccentric mass). The ultimate goal of the test rig is to get insight into interactionbetween internal dynamics of drive train mechanical and electrical functional components and to develop novel methods to detect, predict and prevent faults and failures in wind turbine drive trains arising due to misalignments and transient external loads

Selection of Conductive Composite Through Weighed Normalized Fuzzy Method in Order to be used in Electrostatics Filters Absorbing Plates

In this paper, due to some problems deriving from using multiple inputs in fuzzy logic procedure, a simpler high demanding method, which can eliminate some complicated fuzzy membership functions trends is represented. This method is so-called weighed normalized fuzzy method. Despite simple calculations used in the method and user capability to use fuzzy membership functions, ranking utilized in this method is as authentic as other conventional fuzzy logic procedures. Regarding suitable properties of composites which can solve problems happening due to intrinsic characteristic of materials used in electrostatic precipitators, in this investigation wide spectrum of resins and fibres used in manufacturing conductive composites is studied. In addition, some of them are selected through material selection methods with regard to their attributes and high conductivity property, which is suitable for absorbing plates. Selecting best conductive composites among considered conductive composites through this novel method is the final aim of this paper. The results show that vinyl ester, which belongs to Vinyl Ester Resin Woven Carbon and Glass (VRWCG) series, has the most beneficial specification in comparison with other thermoset resins for this intended application. Moreover, vinyl ester resins show better stability in acidic electro filter media

Aplicación de varios métodos de procesamiento de imágenes por satélite en datos aster y landsat ETM + para identificar y separar las zonas de alteración en torno a la mina de oro de Akhtarchi, Khomein, Irán

The study area is located 100 km southeast of Arak and in two structural zones of Central Iran in the north and Sanandaj-Sirjan in the southern part. Regarding its geological structures, the area has become the source of important mines including the Akhtarchi gold mine, Aliabad iron mine, Ochestan feldspar mine, and Dali gold and copper mines. Therefore, promising areas for exploration activities are identified using the analysis of satellite images of ASTER and Landsat ETM + in the region to identify alteration areas. For this purpose, the necessary corrections were applied to the satellite images. Then, to identify the alteration parts related to the gold deposits, different satellite image processing methods of ETM + and ASTER were used.  These methods include making a false-color composite, band ratio, Selective Principal Components Analysis (SPCA), Spectral Angle Mapper (SAM) method, Spectral Information Divergence Classification (SID), Endmember Collection Dialog Components (ECDC), and innovative methods such as Principal Component Analysis (PCA) and Spectral Angle Mapper, as well as unsupervised classification methods. In the end, the major alterations in the region were observed. In the obtained images, the prophylitic zone and the phyllic and argillic zones in the region were observed. To introduce the optimal method, the results of the various methods mentioned were compared with each other and with the current situation of the mines. The alteration zones were identified through band ratio and SAM methods and the combined methods with more power. Finally, SAM, 2:1 ratio, and the combined methods were identified as successful methods for more accurate separation of the alteration zones.El área de estudio se encuentra a 100 km al sureste de Arak y en dos zonas estructurales del centro de Irán en el norte y Sanandaj-Sirjan en la parte sur. En cuanto a sus estructuras geológicas, la zona se ha convertido en la fuente de importantes minas, como la mina de oro Akhtarchi, la mina de hierro Aliabad, la mina de feldespato Ochestan y las minas de oro y cobre de Dali. Por lo tanto, las áreas prometedoras para las actividades de exploración se identifican mediante el análisis de imágenes satelitales de ASTER y Landsat ETM + en la región para identificar áreas de alteración. Para ello, se aplicaron las correcciones necesarias a las imágenes de satélite. Luego, para identificar las partes de alteración relacionadas con los depósitos de oro, se utilizaron diferentes métodos de procesamiento de imágenes satelitales de ETM + y ASTER. Estos métodos incluyen hacer una composición de color falso, relación de banda, análisis selectivo de componentes principales (SPCA), método de mapeador de ángulo espectral (SAM), clasificación de divergencia de información espectral (SID), componentes de diálogo de colección de miembros finales (ECDC) y métodos innovadores como Análisis de componentes principales (PCA) y mapeador de ángulos espectrales, así como métodos de clasificación no supervisados. Al final, se observaron las mayores alteraciones en la región. En las imágenes obtenidas se observó la zona profilítica y las zonas fílica y argílica de la región. Para introducir el método óptimo, se compararon los resultados de los diversos métodos mencionados entre sí y con la situación actual de las minas. Las zonas de alteración se identificaron mediante métodos de relación de bandas y SAM y los métodos combinados con más potencia. Finalmente, SAM, relación 2: 1, y los métodos combinados fueron identificados como métodos exitosos para una separación más precisa de las zonas de alteración

Aplicación de varios métodos de procesamiento de imágenes por satélite en datos aster y landsat ETM + para identificar y separar las zonas de alteración en torno a la mina de oro de Akhtarchi, Khomein, Irán

The study area is located 100 km southeast of Arak and in two structural zones of Central Iran in the north and Sanandaj-Sirjan in the southern part. Regarding its geological structures, the area has become the source of important mines including the Akhtarchi gold mine, Aliabad iron mine, Ochestan feldspar mine, and Dali gold and copper mines. Therefore, promising areas for exploration activities are identified using the analysis of satellite images of ASTER and Landsat ETM + in the region to identify alteration areas. For this purpose, the necessary corrections were applied to the satellite images. Then, to identify the alteration parts related to the gold deposits, different satellite image processing methods of ETM + and ASTER were used.  These methods include making a false-color composite, band ratio, Selective Principal Components Analysis (SPCA), Spectral Angle Mapper (SAM) method, Spectral Information Divergence Classification (SID), Endmember Collection Dialog Components (ECDC), and innovative methods such as Principal Component Analysis (PCA) and Spectral Angle Mapper, as well as unsupervised classification methods. In the end, the major alterations in the region were observed. In the obtained images, the prophylitic zone and the phyllic and argillic zones in the region were observed. To introduce the optimal method, the results of the various methods mentioned were compared with each other and with the current situation of the mines. The alteration zones were identified through band ratio and SAM methods and the combined methods with more power. Finally, SAM, 2:1 ratio, and the combined methods were identified as successful methods for more accurate separation of the alteration zones.El área de estudio se encuentra a 100 km al sureste de Arak y en dos zonas estructurales del centro de Irán en el norte y Sanandaj-Sirjan en la parte sur. En cuanto a sus estructuras geológicas, la zona se ha convertido en la fuente de importantes minas, como la mina de oro Akhtarchi, la mina de hierro Aliabad, la mina de feldespato Ochestan y las minas de oro y cobre de Dali. Por lo tanto, las áreas prometedoras para las actividades de exploración se identifican mediante el análisis de imágenes satelitales de ASTER y Landsat ETM + en la región para identificar áreas de alteración. Para ello, se aplicaron las correcciones necesarias a las imágenes de satélite. Luego, para identificar las partes de alteración relacionadas con los depósitos de oro, se utilizaron diferentes métodos de procesamiento de imágenes satelitales de ETM + y ASTER. Estos métodos incluyen hacer una composición de color falso, relación de banda, análisis selectivo de componentes principales (SPCA), método de mapeador de ángulo espectral (SAM), clasificación de divergencia de información espectral (SID), componentes de diálogo de colección de miembros finales (ECDC) y métodos innovadores como Análisis de componentes principales (PCA) y mapeador de ángulos espectrales, así como métodos de clasificación no supervisados. Al final, se observaron las mayores alteraciones en la región. En las imágenes obtenidas se observó la zona profilítica y las zonas fílica y argílica de la región. Para introducir el método óptimo, se compararon los resultados de los diversos métodos mencionados entre sí y con la situación actual de las minas. Las zonas de alteración se identificaron mediante métodos de relación de bandas y SAM y los métodos combinados con más potencia. Finalmente, SAM, relación 2: 1, y los métodos combinados fueron identificados como métodos exitosos para una separación más precisa de las zonas de alteración

Aplicación de varios métodos de procesamiento de imágenes por satélite en datos aster y landsat ETM + para identificar y separar las zonas de alteración en torno a la mina de oro de Akhtarchi, Khomein, Irán

El área de estudio se encuentra a 100 km al sureste de Arak y en dos zonas estructurales del centro de Irán en el norte y Sanandaj-Sirjan en la parte sur. En cuanto a sus estructuras geológicas, la zona se ha convertido en la fuente de importantes minas, como la mina de oro Akhtarchi, la mina de hierro Aliabad, la mina de feldespato Ochestan y las minas de oro y cobre de Dali. Por lo tanto, las áreas prometedoras para las actividades de exploración se identifican mediante el análisis de imágenes satelitales de ASTER y Landsat ETM + en la región para identificar áreas de alteración. Para ello, se aplicaron las correcciones necesarias a las imágenes de satélite. Luego, para identificar las partes de alteración relacionadas con los depósitos de oro, se utilizaron diferentes métodos de procesamiento de imágenes satelitales de ETM + y ASTER. Estos métodos incluyen hacer una composición de color falso, relación de banda, análisis selectivo de componentes principales (SPCA), método de mapeador de ángulo espectral (SAM), clasificación de divergencia de información espectral (SID), componentes de diálogo de colección de miembros finales (ECDC) y métodos innovadores como Análisis de componentes principales (PCA) y mapeador de ángulos espectrales, así como métodos de clasificación no supervisados. Al final, se observaron las mayores alteraciones en la región. En las imágenes obtenidas se observó la zona profilítica y las zonas fílica y argílica de la región. Para introducir el método óptimo, se compararon los resultados de los diversos métodos mencionados entre sí y con la situación actual de las minas. Las zonas de alteración se identificaron mediante métodos de relación de bandas y SAM y los métodos combinados con más potencia. Finalmente, SAM, relación 2: 1, y los métodos combinados fueron identificados como métodos exitosos para una separación más precisa de las zonas de alteración

Estrategias competitivas de conocimiento y comercialización de la innovación: un dofa unificado y un enfoque de proceso de análisis jerárquico difuso (fuzzy ahp)

Universities have shown a strong desire to commercialize researches and innovations. As a result, they are increasingly weaning themselves from public budgets. Commercialization has become the gateway for privatization, but the improper selection of commercialization strategies often results in the elimination of resources and time. The correct evaluation and ranking of strategies for the best resources is essential for the competitive performance of a university. The hybrid SWOT and Fuzzy AHP model adopted in this study provides a clear categorization of these university strategies. The first and relevant criteria as well as sub-criteria are identified using SWOT analysis. Fuzzy AHP tool is then used to evaluate and rank the internal and external factors that affect competition in Iranian universities. Based on the IE matrix, the growth and the process of building strategies are important priorities when considering commercializing. The results of this study revealed that academic startups, joint technology, joint research laboratories, strategic alliances, recruiting pundit and contracting with industry are the best strategies for Iranian universities.Las universidades han mostrado un fuerte deseo de comercializar investigaciones e innovación. Como resultado de esto, cada vez más buscan depender menos de los presupuestos públicos. La comercialización se ha convertido en la entrada a la privatización, sin embargo, la selección incorrecta de las estrategias de comercialización con frecuencia resulta en la eliminación de recursos y tiempo. La correcta evaluación y ranking de estrategias para los mejores recursos es esencial para el desempeño competitivo de una universidad. El híbrido entre el DOFA y el modelo proceso de análisis jerárquico difuso (Fuzzy AHP) adoptado en este estudio, provee una categorización clara de las estrategias de estas universidades. Los criterios principales y relevantes, al igual que los subcriterios, son identificados utilizando el análisis DOFA. La herramienta Fuzzy AHP se utiliza luego para evaluar y valorar los factores internos y externos que afectan la competencia en las universidades de Irán. Teniendo como base la matriz IE, el crecimiento y el proceso de construcción de las estrategias son prioridades cuando se tiene en cuenta la comercialización. Los resultados de este estudio revelan que los emprendimientos académicos, la tecnología conjunta, los laboratorios de investigación conjunta, las alianzas estratégicas, los expertos en reclutamiento y las contrataciones con la industria son las mejores estrategias para las universidades iraníes.

Autonomous vehicles: challenges, opportunities, and future implications for transportation policies

This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle (AV) technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure (connected vehicles). A major knowledge gap exists in AV technology with respect to routing behaviors. Connected-vehicle technology provides a great opportunity to implement an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization. This study contributes to the literature on two fronts: (i) it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and (ii) it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations