Distributed Predictive Control for MVDC Shipboard Power System Management

Shipboard Power System (SPS) is known as an independent controlled small electric network powered by the distributed onboard generation system. Since many electric components are tightly coupled in a small space and the system is not supported with a relatively stronger grid, SPS is more susceptible to unexpected disturbances and physical damages compared to conventional terrestrial power systems. Among different distribution configurations, power-electronic based DC distribution is considered the trending technology for the next-generation U.S. Navy fleet design to replace the conventional AC-based distribution. This research presents appropriate control management frameworks to improve the Medium-Voltage DC (MVDC) shipboard power system performance. Model Predictive Control (MPC) is an advanced model-based approach which uses the system model to predict the future output states and generates an optimal control sequence over the prediction horizon. In this research, at first, a centralized MPC is developed for a nonlinear MVDC SPS when a high-power pulsed load exists in the system. The closed-loop stability analysis is considered in the MPC optimization problem. A comparison is presented for different cases of load prediction for MPC, namely, no prediction, perfect prediction, and Autoregressive Integrated Moving Average (ARIMA) prediction. Another centralized MPC controller is also designed to address the reconfiguration problem of the MVDC system in abnormal conditions. The reconfiguration goal is to maximize the power delivered to the loads with respect to power balance, generation limits and load priorities. Moreover, a distributed control structure is proposed for a nonlinear MVDC SPS to develop a scalable power management architecture. In this framework, each subsystem is controlled by a local MPC using its state variables, parameters and interaction variables from other subsystems communicated through a coordinator. The Goal Coordination principle is used to manage interactions between subsystems. The developed distributed control structure brings out several significant advantages including less computational overhead, higher flexibility and a good error tolerance behavior as well as a good overall system performance. To demonstrate the efficiency of the proposed approach, a performance analysis is accomplished by comparing centralized and distributed control of global and partitioned MVDC models for two cases of continuous and discretized control inputs

A Proposed Model For Strategic Planning In Educational Organizations

AbstractThis paper is proposing a comprehensive framework in order to formulate strategy in Educational organizations. This approach is based on Malcolm Baldrige National Quality Award (MBNQA) Education Criteria for selecting competitive strategies. In this method, firstly, by using SWOT matrix, we have formulated initial strategies of the organization. After that, we have allocated these strategies to four BSC perspectives. Then making use of these strategies in the House Of Quality (HOQ) as “Whats/alternatives”, we subsequently considered MBNQA Education Criteria with the role of “Hows/criteria” in the HOQ as a criteria for selection of strategies. Finally we performed screening and selection of initial strategies by using fuzzy screening technique. A case study is utilized to show the efficiency of the proposed model

Assessing Translation of Advertising Text (English-persian) based on House's Functional-Pragmatic Model of TQA

AbstractThis study aimed at assessing Persian translations of English advertising texts of cosmetic products based on House's functional-pragmatic model of TQA. Several advertising catalogues were collected by three translators who were all university instructors. Profiles of both source texts and target texts were recognized and their overtly erroneous errors, covertly erroneous errors and translation type (overt vs. covert) were identified. Collected data indicated that overtly erroneous errors outnumbered covertly erroneous errors. Results of chi-square test showed that the existing difference was statistically significant. So it was concluded that House's functional-pragmatic model of TQA were not applied when translating English advertising texts into Persian

Processes of problem-solving and instructional change in physics

Doctor of PhilosophyDepartment of PhysicsEleanor C. SayreThis research presents an investigation of how students solve physics problems and how physics instructors approach changes in their teaching. In particular, the first part of this dissertation focuses on three major projects looking at students' processes of problem-solving in upper-division physics courses. The second part focuses on the processes of instructional change. In the first project described in part I, I discuss the clusters of resources that emerge when upper-division students write about electromagnetic fields in linear materials. I use a resource theory perspective to describe the ways students link pieces of information (or resources) to form more complex ideas, improve their understanding, and solve physics problems. The evidence shows that students benefit from activating resources related to the internal structure of the atom when thinking about electric fields to complete their mental model. Physics as a discipline embeds conceptual meaning about the physical world in mathematical formalism. In the second project, I use Sherin's symbolic forms theory to present an analysis of the different physical meanings associated with the equal signs across a physics context. Sherin's symbolic forms framework links mathematical equations to intuitive conceptual ideas. I delineate types of equal signs as used in five undergraduate level physics textbooks and develop a categorization scheme. Six distinct meanings are identified: causality, balancing, definitional, assignment, hybrid, and calculation. After considering five physics textbooks, I then analyze students' solutions in their written homework in an upper-division electrostatics course and compare them to textbook solutions. In doing so, I am able to look for patterns and compare the ways students use the equal signs to the textbook solution manual. In the last section of Part I, I examine students' epistemological framing when solving physics problems as a group. I analyze videos of students solving electrodynamics problems. I consider two epistemic frames which are common in students' discussions during problem solving in group: sense-making and answer-making. I first characterize the markers of each frame, focusing on analyzing students' group frame. Then, I present a pair of examples that show how often students transition between these frames. I notice moments that students change their attitude towards the problem to move forward in their activities. While there are many ways to view how students practice physics, the results of this project provide deeper insight into students' problem-solving processes in an upper-division course. In Part II, I use phenomenography as a methodology to explain how physics instructors approach making changes in their teaching and the different kinds of support that they would like to have. The purpose of phenomenography is to describe the qualitative variation in people's experiences. For example, what are the ways in which physics instructors think and talk about their teaching practices? Our phenomenography study explored six different major categories: how instructors approach their teaching, their motivation to make changes, resources that they have used, how they have implemented those resources, challenges they experience during a semester, and their attitudes towards implementing new changes. We ultimately aim to use our findings to redesign the PhysPort website

The effect of Ginger (Zingiber officinale) on electrophoretic pattern of serum proteins of male mice

چکیده: زمینه و هدف: زمینه و هدف: زنجبیل (Zingiber officinale) به عنوان ادویه در رژیم غذایی بسیاری از مناطق دنیا استفاده می شود. تحقیقات اخیر نشان داده است که زنجبیل بسته به ترکیبات فعال مختلف (شامل شوگاال ها و جینجرول ها)، اثرات دارویی مختلفی دارد. هدف این مطالعه تعیین اثر عصاره الکلی زنجبیل بر روی الگوی الکتروفورتیک اجزای پروتئینی سرم در موش های کوچک آزمایشگاهی بوده است. روش بررسی: در این مطالعه تجربی چهار گروه موش کوچک آزمایشگاهی نر بالغ (8 موش در هر گروه) برای آزمایش استفاده شد. گروه یک (گروه کنترل) نرمال سالین و سه گروه دیگر سه دوز متفاوت mg/kg 10 (گروه 2)، mg/kg 20 (گروه 3) و mg/kg 40 (گروه 4) عصاره الکلی زنجبیل را هر 4 ساعت به مدت بیست روز از طریق تزریق داخل صفاقی دریافت نمودند. سپس خون گیری از طریق سینوس چشمی انجام و سطوح پروتئینی پره آلبومین، آلفا-1، آلفا-2، بتا و گاما گلبولین ها با روش الکتروفورز جدا و به کمک برنامه ویژه کامپیوتری تفکیک پروتئین های سرم اندازه گیری شد. نسبت A/G (نسبت آلبومین به گلبولین) با استفاده از الگوی الکتروفورتوگرام محاسبه گردید. داده ها با استفاده از آزمون توکی و آزمون تعقیبی تجزیه و تحلیل شدند. یافته ها: عصاره الکلی زنجبیل به طور معنی داری سطوح آلبومین و پروتئین تام سرم را در گروه سوم (g/dl 25/0±7/3) و چهارم (g/dl 37/0±71/3) در مقایسه با گروه کنترل افزایش داد (05/0P). نسبت A/G به طور معنی داری در گروه سه (g/dl 48/0±05/2) بیشتر از گروه کنترل (g/dl 16/0±37/1) بود (05/0