Reliability and Failure Probability Functions of the m-Consecutive-k-out-of-n: F Linear and Circular Systems

في هذه الورقة ، تم دراسة الانواع الخطية والدائرية  للنظام m لعدد k التتابعي  من n من المكونات، حيث تم تصنيف عناصر فضاء عينة فشل مكونات النظام الى تجمعين من التصنيفات، الأول للحالات التي يكون فيها النظام في حالة العمل والآخر للحالات التي يكون فيها النظام وصل لمرحلة الفشل، ومن ثم  تم استخدام هذه التصنيفات لحساب دالة كثافة احتمال موثوقية النظام ودالة كثافة احتمال فشل النظام، وفي النهاية تم اقتراح خوارزمية رياضية لحساب ذلك، تتضمن عمليات التصنيفات هذه وكيفية حساب الدالتين المذكورين من خلال عملية التصنيف.The m-consecutive-k-out-of-n: F linear and circular system consists of n sequentially connected components; the components are ordered on a line or a circle; it fails if there are at least m non-overlapping runs of consecutive-k failed components. This paper proposes the reliability and failure probability functions for both linearly and circularly m-consecutive-k-out-of-n: F systems. More precisely, the failure states of the system components are separated into two collections (the working and the failure collections); where each one is defined as a collection of finite mutual disjoint classes of the system states. Illustrative example is provided

Gratings: Theory and Numeric Applications, Second Revisited Edition

International audienceThe second Edition of the Book contains 13 chapters, written by an international team of specialist in electromagnetic theory, numerical methods for modelling of light diffraction by periodic structures having one-, two-, or three-dimensional periodicity, and aiming numerous applications in many classical domains like optical engineering, spectroscopy, and optical telecommunications, together with newly born fields such as photonics, plasmonics, photovoltaics, metamaterials studies, cloaking, negative refraction, and super-lensing. Each chapter presents in detail a specific theoretical method aiming to a direct numerical application by university and industrial researchers and engineers.In comparison with the First Edition, we have added two more chapters (ch.12 and ch.13), and revised four other chapters (ch.6, ch.7, ch.10, and ch.11

Spatial and Spatial-Temporal Analysis of Grizzly Bear Movement Patterns as Related to Underlying Landscapes Across Multiple Scales

Studying the movements of grizzly bears (Ursus arctos) in Alberta is imperative for scientifically informed management practices. To properly balance industry requirements with conservation imperatives, it is necessary to understand the spatial and spatial-temporal movement patterns of grizzly bears as they relate to underlying landscape properties. As part of the Foothills Research Institute Grizzly Bear Research Program, this dissertation explored both fine and largescale movement patterns generated from global positioning system (GPS) radiotelemetry data. Between 1999 and 2005, grizzly bears were captured and radio-collared across western Alberta. The temporal resolution of GPS data collection had a large impact on the amount of information available for analysis. A significant decrease in available information was demonstrated as time between locations increased. The presence of serial autocorrelation indicated the presence of prolonged movement behavior in fine-scale vector structures. The ability to identify internal vector clusters dramatically decreased as temporal resolution decreased. The relationship between level of human activity and grizzly bear movement rate across multiple spatial and temporal scales was studied in detail. Resulting movement patterns of grizzly bears were found to be intrinsically linked to both internal and external factors. Overall, grizzly bears residing in mountain environments were found to have significantly slower movement rates and smaller home ranges sizes when compared to grizzly bears residing in foothills environments. Temporally, movement rates also varied significantly according to season, month, and time of day. These findings have significance for modeling efforts which attempt to replicate grizzly bear spatial and temporal movement patterns across Albertan landscapes. The use of time sequence graphs aided in differentiating between different types of movement behaviors and allowed for the quantification and assessment of consecutive vector data. Results emphasized that slow movement clusters occurred more often and for longer periods of time when compared to fast travel segments. While some movement-habitat relationships were identified, results were highly individual by bear. Overall models tended to respond the best when working with mountain bears over foothills bears. Results further suggested that vector-based movements should be separated according to type (slow versus fast) for future modeling efforts

Survival strategies for unmanned surface vehicles in harsh ocean environments

Unmanned Surface Vehicles (USVs) have seen fast development in the past decades, and they have opened up new ways for observing the ocean. A USV can run autonomous missions on the water surface with different payload sensors for characterizing the chemical and physical properties of the water column. With a group of USVs operated simultaneously in a fleet, the ocean observation work can be extended to much larger areas to achieve diverse scientific objectives. The ocean has very challenging environments, and to enable a USV to successfully complete each survey mission under adverse weather conditions, it is of great importance to investigate accurate and robust path-following control algorithms. Further, the unexpected ocean disturbances on a USV can potentially lead to critical motions, which may cause a USV to capsize. Therefore, the safety analysis of a USV that runs a mission in the seaway becomes a particularly important subject. This thesis provides a comprehensive investigation into the operation of a USV executing autonomous missions in adverse ocean environments. We investigate a USV’s dynamic motion modeling and validation in 6 degrees of freedom (DOF), examine three path-following control algorithms and their real-world performance in adverse weather conditions, as well as establish the safe operational condition for a USV that operates in dynamic ocean environments. We hope that our accomplished work can assist the USV practitioners in choosing appropriate motion dynamics models and robust path-following control strategies, and potentially implementing our safety analysis results to improve a USV’s operational safety and survivability during its ocean exploration mission. The planar motion dynamics are derived from the 6 DOF rigid-body motion equations, based on which a hybrid identification method that combines the tow tank and field tests has been carried out to determine the model parameter values. Depending on the constructed planar dynamic motion model, we develop and test three path-following control algorithms, i.e. Vector Field Method (VF), Carrot Chasing Method (CC) and Line-of-Sight Method (LOS). Our investigation involves investigating their mathematical origins, performing simulation tests and carrying out field experiments in adverse weather conditions to examine each algorithm’s robustness. Understanding the uncontrollable oscillatory motions in heave, roll and pitch are critical for the safety of a USV that operates in harsh ocean environments. The major influence on a USV’s oscillatory motion comes from the ocean waves. Since this highly nonlinear interactive dynamics are quite complicated, we implement three mathematical tools for the safety analysis, which includes the Analytical Method, Melnikov’s Method and Erosion Basin Method. Using the approximated analytical solution, we demonstrate the wellknown jump phenomenon for the nonlinear oscillatory motion. Using Melnikov’s function, we determine a conservative critical condition to predict the occurrence of chaotic motion, which can be regarded as a USV’s safe operation boundary condition. The erosion basin numerical analysis has been implemented as a supplement for the Melnikov’s method, and the results show that the achieved Melnikov boundary condition corresponds to the 90% safe region proportion contour. The boundary condition has been successfully combined together with the wave excitation moments to determine the safe and unsafe operational regions for a USV. These results are summarized in a series of unsafe region contour plots in the 2D polar coordinates

LIPIcs, Volume 244, ESA 2022, Complete Volume

LIPIcs, Volume 244, ESA 2022, Complete Volum

Wave Propagation in Materials for Modern Applications

In the recent decades, there has been a growing interest in micro- and nanotechnology. The advances in nanotechnology give rise to new applications and new types of materials with unique electromagnetic and mechanical properties. This book is devoted to the modern methods in electrodynamics and acoustics, which have been developed to describe wave propagation in these modern materials and nanodevices. The book consists of original works of leading scientists in the field of wave propagation who produced new theoretical and experimental methods in the research field and obtained new and important results. The first part of the book consists of chapters with general mathematical methods and approaches to the problem of wave propagation. A special attention is attracted to the advanced numerical methods fruitfully applied in the field of wave propagation. The second part of the book is devoted to the problems of wave propagation in newly developed metamaterials, micro- and nanostructures and porous media. In this part the interested reader will find important and fundamental results on electromagnetic wave propagation in media with negative refraction index and electromagnetic imaging in devices based on the materials. The third part of the book is devoted to the problems of wave propagation in elastic and piezoelectric media. In the fourth part, the works on the problems of wave propagation in plasma are collected. The fifth, sixth and seventh parts are devoted to the problems of wave propagation in media with chemical reactions, in nonlinear and disperse media, respectively. And finally, in the eighth part of the book some experimental methods in wave propagations are considered. It is necessary to emphasize that this book is not a textbook. It is important that the results combined in it are taken “from the desks of researchers“. Therefore, I am sure that in this book the interested and actively working readers (scientists, engineers and students) will find many interesting results and new ideas

Recent Advances in Multi Robot Systems

To design a team of robots which is able to perform given tasks is a great concern of many members of robotics community. There are many problems left to be solved in order to have the fully functional robot team. Robotics community is trying hard to solve such problems (navigation, task allocation, communication, adaptation, control, ...). This book represents the contributions of the top researchers in this field and will serve as a valuable tool for professionals in this interdisciplinary field. It is focused on the challenging issues of team architectures, vehicle learning and adaptation, heterogeneous group control and cooperation, task selection, dynamic autonomy, mixed initiative, and human and robot team interaction. The book consists of 16 chapters introducing both basic research and advanced developments. Topics covered include kinematics, dynamic analysis, accuracy, optimization design, modelling, simulation and control of multi robot systems

Connected-X-out-of-(m; n):F システムの信頼度評価と最適設計に関する研究

首都大学東

The 1st Advanced Manufacturing Student Conference (AMSC21) Chemnitz, Germany 15–16 July 2021

The Advanced Manufacturing Student Conference (AMSC) represents an educational format designed to foster the acquisition and application of skills related to Research Methods in Engineering Sciences. Participating students are required to write and submit a conference paper and are given the opportunity to present their findings at the conference. The AMSC provides a tremendous opportunity for participants to practice critical skills associated with scientific publication. Conference Proceedings of the conference will benefit readers by providing updates on critical topics and recent progress in the advanced manufacturing engineering and technologies and, at the same time, will aid the transfer of valuable knowledge to the next generation of academics and practitioners. *** The first AMSC Conference Proceeding (AMSC21) addressed the following topics: Advances in “classical” Manufacturing Technologies, Technology and Application of Additive Manufacturing, Digitalization of Industrial Production (Industry 4.0), Advances in the field of Cyber-Physical Systems, Virtual and Augmented Reality Technologies throughout the entire product Life Cycle, Human-machine-environment interaction and Management and life cycle assessment.:- Advances in “classical” Manufacturing Technologies - Technology and Application of Additive Manufacturing - Digitalization of Industrial Production (Industry 4.0) - Advances in the field of Cyber-Physical Systems - Virtual and Augmented Reality Technologies throughout the entire product Life Cycle - Human-machine-environment interaction - Management and life cycle assessmen