The (nonlinear) response behavior of a piecewise-linear system is investigated under both deterministic and stochastic excitations in this study. A semi-analytical procedure is developed to predict the system behavior by evaluating the joint probability density functions of the Fokker-Planck equations of the stochastic piecewise-linear system under random excitations via a path-integral solution procedure. From an analysis of the deterministic system, nonlinear system behavior is derived for further analysis of the corresponding stochastic system. The influence of variations in other parameters on the response behavior are also examined. In the stochastic system analysis, which represents a more realistic approach to understanding the system behavior, a Markov process approach is used. By introducing random perturbations in the harmonic excitation, the stochastic responses are examined and compared to those of the corresponding deterministic system. Stability of the various responses including regular and chaotic motions, is investigated by varying the noise intensity. Routes to chaos in period-doubling processes with and without external random perturbations are studied and compared. Stationarity and ergodicity of the chaotic responses of the system are examined via time domain and probability domain simulations. Potential coexisting responses of the piecewise-linear system are examined via the path-integral solutions. It is found that the path-integral solutions can provide global information of the system behavior in the probability domain, and can also verify the potential coexisting responses and discern the relative strength of the coexisting response attractors. / Graduation date: 1996

Thesis (M.S.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982. / Includes bibliographical references (leaves 151-153).

Un dels avantatges d'usar plataformes virtuals o prototipat virtual enlloc del maquinari real pel desenvolupament de programari encastat és la capacitat d'alguns simuladors de fer captures del seu estat. Si el model del sistema complet és prou detallat, pot tardar uns quants minuts (inclús hores) per simular l'engegada d'un Sistema Operatiu. Si es pren una captura just després de que ha acabat d'engegar, cada cop que calgui corre el programari encastat, els dissenyadors poden simplement recuperar la captura i continuar-la. Recuperar una captura normalment porta pocs segons. Aquest guany es trasllada en una major productivitat, especialment quan es treballa amb sistemes encastat, amb programari complex sobre Sistemes Operatius com en els dispositius actuals. En aquesta tesi es presenta en primer lloc el treball realitzat per afegir un llenguatge de descripció de sistemes anomenat SystemC a dues plataformes virtuals diferents. Aquesta tasca es realitzà per una eina comercial i desprès es traslladà a una plataforma de codi obert. També es presenta una sèrie de modificacions al llenguatge SystemC per suportar la captura d'instantànies. Aquestes modificacions faran possible poder agafar l'estat de la simulació en SystemC i salvar-les al disc. Més tard, la simulació es pot recuperar en el mateix estat on es trobava, sense canvis en els seus components. Aquestes millores ajudaran al llenguatge SystemC a ser més àmpliament usat en el món de les Plataformes Virtuals. / One advantage of using a virtual platform or virtual prototype over real hardware for embedded software development and testing is the ability of some simulators to take checkpoints of their state. If the entire system model is detailed enough, it might take several minutes (or even hours) to simulate booting the O.S. If a snapshot of the simulation is saved just after it has finished booting, each time it is necessary to run the embedded software, designers can simply restore the snapshot and go. Restarting a checkpoint typically takes a few seconds. This can translate into a major productivity gain, especially when working with embedded system with complex SW stacks and O.S. like modern embedded devices. In this dissertation we present in firstly our work on adding a description level language as SystemC to two Virtual Platforms. This work was done for a commercial Virtual Platform, and later translated to a open-sourced Platform. This thesis also presents a set of modifications to SystemC language to support checkpointing. These modifications will make it possible to take the state of a SystemC running simulation and save it to disk. Later, the same simulation can be restored to the same point it was before, without any change to the simulated modules. These changes would help SystemC to be suitable for use by Virtual Platforms as a description language.

Thesis (M.Eng.) -- Memorial University of Newfoundland, 1985. / Typescript. Bibliography : leaves 46-49. Also available online.

Thesis (M.Sc.Eng.)PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The exploration and production of oil and gas resources require innovative information acquisition strategies for wellbore environments to improve reservoir management. In this study, a microfluidic channel data retrieval platform was proposed for multiple sensor chip manipulation, wireless charging and information extraction in fluidic mediums. The working principle of near-field magneto inductive coupling was investigated and a prototype of a microfluidic channel integrated with a spiral reader antenna was designed and fabricated. Sensor chip manipulations and dynamic couplings between readers and sensors were demonstrated inside the proposed microfluidic channel. Furthermore, solid fluidic interaction between sensors and flows was analyzed. Comsol simulation was conducted to quantitatively characterize flow drag forces inside the channel. To prevent communication interference between sensors in the proposed coupling region, sensor separation strategies based on side channel and meander channel design were proposed and realized to separate sensors one by one by the desired distance. To enhance the efficiency of the sensor separation process, a new channel design based on a spinning blade with real-time image processing was also developed for feedback control of separation. Additionally, a 500-micron cubic sensor antenna was cut by a dicing saw and assembled into an 800-micron cubic package. Magneto inductive couplings between readers and the assembly package were conducted out of the channel. The results show that the coupling effect is strongly related with the orientation between the reader and the assembly package. Finally, the assembly package control with desired velocity and direction in oil mediums was successfully realized inside the channel. / 2031-01-01

The use of customer ratings to evaluate worker performance is increasingly worrisome because of its widespread use in the gig-economy. As scholars in computer and social sciences denounce, this practice entails the risk of producing discriminatory outcomes, by reproducing biases existing in society. By drawing an analogy with discriminatory practices adopted by an employer to satisfy its customers' preferences, we propose a legal analysis of this phenomenon grounded in EU non-discrimination law. Thus, we first analyse the issues related to the application of non-discrimination law to (alleged) self-employed workers. Then, we address the lack of access for the individual worker to the data regarding customers' ratings. We conclude by arguing that the use of customer ratings should be considered as a suspect criterion, while the current (EU) non-discrimination laws should be modernised through a clearer inclusion of (alleged) self-employed workers. / Series: ohne Reihe

Crowdfunding is a method for financing a product, investment or project. It means that all people, individuals or companies that have an idea and Internet connection can outsource the idea on a crowdfunding platform. The purpose with this crowdfunding is that the creator turn to many people with small amounts of money. This paper focus on the users of crowdfunding platforms though. There are a lot of articles on the Internet about Crowdfunding but not so much information about the users. In a try to identify the people who uses this kind of financial method I have made a survey with 200 respondents. In the empirical chapter, every single question and the answer is displayed in a respective figure.

This paper is based on another paper I have written, what can we say about the users of crowdfunding platforms? This paper focuses on advantages and disadvantages with crowdfunding and the users of crowdfunding platforms. Previously researchers mean that there are both positive and negative things about crowdfunding and these will be analyzed and raised in this paper. There is not much information about the users of crowdfunding platforms. In a previous paper I did a survey to try to identify who the users of crowdfunding are. In this paper the result from that survey will be analyzed and hopefully succeed in identifying the characteristics of users of crowdfunding platforms.

Master of Science

On-site sensing systems provide fast and timely information about a myriad of applications ranging from chemical and biological to physical phenomena in the environment or the human body. Such systems are embedded in our daily life for detecting pollutants, monitoring health, and diagnosing diseases. Especially in the field of health care, the development of portable and affordable diagnosing systems, also known as point-of-care (PoC) devices, is a major challenge. Moreover, to this day, systems for therapeutic drug monitoring (TDM) have remained bulky and highly expensive, mostly due to the need for exceptionally precise, rapid, and highly accurate real-time on-site measurements. This dissertation focuses on the design, development, and implementation of miniaturized PoC devices for achieving high sensitivity, selectivity, and reliability through a combination of hardware and software strategies at the edge. The first part of the dissertation introduces the design of single and multi-channel electrochemical readout platforms with a high voltage range, fast scan rates, and with nano-ampere resolution, covering a broad range of electrochemical excitation techniques. These platforms were paired with electrochemical-based sensors to detect SARS‑CoV‑2, bisphenol A, and ascorbic acid. The low power feature of the proposed platforms is demonstrated by powering the complete detection system with energy harvested from natural and artificial ambient light. The second part of the dissertation introduces the design and development of a miniaturized wearable device with a pico-ampere resolution, high-speed electrochemical frequency interface, and highly stable sensing circuitry. A complete in-vivo system is demonstrated for long-term (>4 hours) measurement, wherein molecules are detected and monitored directly from a probe inserted in the subcutaneous abdomen region of a Sprague-Dawley rat. A solution for sensor drift due to biofouling and interference is demonstrated thought to the integration with real-time processing software. Furthermore, integrating the aforementioned platforms with highly reduced dense neural network models is demonstrated to increase the robustness of the sensors, allowing the detection of contaminants in complex samples, improving the sensor selectivity, and providing timely diagnoses in-situ.