43 research outputs found
Hierarchical Flexibility Offering Strategy for Integrated Hybrid Resources in Real-time Energy Markets
This paper proposes a hierarchical model for determining the energy flexibility offering strategy of integrated hybrid resources (IHRs) in power distribution systems to participate in real-time energy markets. The proposed model utilizes the scalability, fast response time, and uncertainty observation of deep reinforcement learning (DRL) to overcome the scalability issue of operating numerous flexible resources and deliverability of energy flexibility to the real-time markets in the presence of the network constraints. To that end, the power distribution system is divided into multiple IHRs, where different types of flexible loads, energy storage systems, and solar plants with controllable inverters are operated through local IHR controllers, trained by deep deterministic policy gradient (DDPG) algorithm. Active power request and reactive power capacity of IHRs are then transmitted to a central flexibility controller, where a quadratic optimization model ensures the deliverability of the energy flexibility to the real-time energy market by satisfying the distribution network constraints. The proposed model is implemented on the 123-bus test power distribution system, demonstrating the capability of DRL-based hierarchical model for scalable operation of IHRs in order to offer deliverable energy flexibility to the real-time energy market
A Study of the Evolution of Religiosity in Western European Societies from 1980 to 2010
Examining the role of religion and the evolution of religiosity in Western European societies, as secular societies, has always been important. Given the period from 1980 to 2010, this article seeks to answer the question of what changes religiosity has undergone in Western European societies, especially in the two dimensions of belief in religion and practice of religious beliefs. To answer this question, we have used the survey method and data analysis. In this regard, a survey program entitled "Study of European Values" examined the ideas, attitudes and values of citizens in various fields including religion and religiosity since 1981 and in the form of five study waves (1981, 1990, 1999, 2008 and 2017). The survey data have been used in this article to explain and analyze the discussion. Considering indicators such as theism, religious rites, church attendance rate and adherence to traditional rituals in important matters of life (birth, marriage and death), the findings of this study show that the process of secularization in Western European countries, both in terms of belief in religion and in terms of practice of religious beliefs, has intensified and the role of religion in the lives of Western European societies is much more declining than before
Scalable Grid-Aware Dynamic Matching using Deep Reinforcement Learning
This paper proposes a two-level hierarchical matching framework for
Integrated Hybrid Resources (IHRs) with grid constraints. An IHR is a
collection of Renewable Energy Sources (RES) and flexible customers within a
certain power system zone, endowed with an agent to match. The key idea is to
pick the IHR zones so that the power loss effects within the IHRs can be
neglected. This simplifies the overall matching problem into independent
IHR-level matching problems and an upper-level optimal power flow problem to
meet the IHR-level upstream flow requirements while respecting the grid
constraints. Within each IHR, the agent employs a scalable Deep Reinforcement
Learning algorithm to identify matching solutions such that the customer's
service constraints are met. The central agent then solves an optimal power
flow problem with the IHRs as the nodes, with their active power flow and
reactive power {capacities}, and grid constraints to scalably determine the
final flows such that matched power can be delivered to the extent the grid
constraints are satisfied. The proposed framework is implemented on a test
power distribution system, and multiple case studies are presented to
substantiate the welfare efficiency of the proposed solution and the
satisfaction of the grid and customers' servicing constraints
Increased Demand for Blood Transfusion in Cardiac Surgery: Simple but Unsolved Common Problem
Background: Despite the general concern about the safety of blood transfusion and mounting evidence exist for more restrictive practice; there is no national consensus guideline and uniformity of institutions for blood transfusion associated with coronary artery bypass graft surgery in Iran. The aim of this study is an assessment of current transfusion practice and compares it with one decade ago.Method: The authors retrospectively analyzed the data of all patients undergoing elective surgery (first time operation) during one year, in two different decade interval (2003 and 2015) in a tertiary heart center.Results: A total of 801 patients were evaluated and compared (n=249 in 2015, n=552 in 2003). There is a significant increase in use of blood transfusion in both operating room and at ICU than the last decade (60.6% vs. 42.4%, P<0.001, and 54.4% vs. 39.9%, P <0.001, respectively). The incidence of preoperative anemia was four times higher in patients who received transfusion, compared to those who did not, in both groups. With compared to the past, the patients are older, have less preoperative hematocrit, more diabetic, more need to intra-aortic balloon pump, shorter operation time, and less postoperative bleeding .Conclusion: With advanced knowledge about transfusion complications and conservative approach to transfusion practice, the need to blood transfusion is increased in current cardiac operations in our center, due to association of more co-morbidities
تطابق برنامه های بازآموزی های برگزار شده در حوزه طب اورژانس با سرفصل های ضروری آموزشی در این رشته
Introduction: Currently, there is a lack of data on the agreement between the continuous medical education (CME) programs and the necessary training topics in the field of emergency medicine in Iran. The present study aimed to evaluate the mentioned agreement in CME programs held during 2010-2014, all over the country. Methods: In the present cross-sectional study, the data recorded regarding emergency medicine-related CME programs were extracted from continuous training database of the Ministry of Health. Then, 30 items from the most important topics taught in emergency medicine training were selected by 3 emergency medicine specialists. Subsequently, the agreement of the selected training topics and CME programs was evaluated regarding duration of training, annual changes, and efficiency. Results: During 2010-2014, a total of 10147 hours of CME programs were held in relation to emergency medicine topics in Iran, which were most frequently (1015 hours) related to surgical emergencies. The next most frequent emergency-related CME programs were in the fields of toxicology with 810 hours (8.0%), neurology with 700 hours (6.9%), pediatric emergencies with 695 hours (6.8%), internal medicine with 675 hours (6.7%), and cardiopulmonary resuscitation with 555 hours (5.5%). In addition, it was determined that none of the CME programs were in complete agreement with the expected standards. Cohen’s kappa test showed that the agreement between the current conditions of CME programs with the standard was only 46.7% (95% confidence interval: 40.9 – 52.55) which shows a weak agreement (p = 0.19). Conclusion: The findings of the present study show the weak agreement of the CME programs held in the field of emergency medicine with the expected standards. مقدمه: در حال حاضر اطلاع دقیقی از میزان تطابق دوره های بازآموزی رشته طب اورژانس با سرفصل های ضروری آموزشی این رشته وجود ندارد. لذا مطالعه حاضر در نظر دارد تا میزان تطابق بازآموزی های برگزار شده طی سال های 1389 تا 1393 با سرفصل های آموزشی رشته تخصصی طب اورژانس را مورد بررسی قرار داد. روش کار: در مطالعه مقطعی حاضر اطلاعات ثبت شده از بازآموزی های مرتبط با رشته تخصصی طب اورژانس از سامانه آموزش مداوم وزارت بهداشت جمع آوری گردید. سپس 30 آیتم از مهمترین مباحث آموزشی رشته طب اورژانس با نظر 3 متخصص طب اورژانس انتخاب شد و اقدام به ارزیابی تطابق بازآموزی ها از لحاظ مدت زمان آموزش، روند تغییرات سالیانه و کفایت با سرفصل های آموزشی رشته طب اورژانس گردید. يافته ها: طی سال های 1389 تا 1393 به طور مجموع، 10147 ساعت بازآموزی مرتبط با سرفصل های آموزشی رشته طب اورژانس ارائه شده بود. بیشترین فراوانی (1015 ساعت) بازآموزی ها مرتبط با اورژانس های جراحی بود. در رتبه بعدی بازآموزی در زمینه اورژانس مسمومیت با میزان 810 ساعت (8/0درصد) اورژانس های نورولوژیک با میزان 700 ساعت (6/9 درصد)، اورژانس های اطفال با میزان 695 ساعت (6/8 درصد)، اورژانس های داخلی با 675 ساعت (6/7 درصد) و احیا قلبی ریوی با 555 ساعت (5/5 درصد) قرار داشتند. علاوه بر این مشخص گردید که هیچ یک از باز آموزی ها تطابق کامل با استانداردهای مورد انتظار ندارند. آزمون کاپای کوهن نشان داد میزان توافق بین وضعیت موجود بازآموزی ها با استاندارد تنها 46/7 درصد (با فاصله اطمینان 95 درصدی برابر 52/55-40/9) بود که در طبقه موافقت ضعیف قرار می گیرد (0/19=p). نتيجه گيری: یافته های پژوهش حاضر حاکی از توافق ضیف باز آموزی های انجام شده در حوزه طب اورژانس با استانداردهای مورد انتظار بود
Active Aging Index and Related Factors Among Aged People in Shiraz in 1397
Background & Objective: Aging is one of the important stage in human life. Nowadays world society regards that matter as an important problem. This study aimed at measuring Active Aging Index in Shiraz and its related and affected factors.
Materials & Methods: This survey has been done by quantitative method among a sample of Shirazi elders involving 600 cases. Sampling method was hierarchal cluster sampling. Data were collected by questionnaire and interview. Variables were context information, living arrangement, active ageing, social support, mental health, spiritual health and self-efficacy.
Results: Mean of AAI was 51.01± 15.2 (from 100). Social support was the most effective factor on AAI and then education, spiritual health, self-efficacy, mental health, age and income be effected respectively. Consequently, those factors explained over 70% of Active Aging variation.
Conclusion: Elders in Shiraz have median activity number. This number of activity is not acceptable for development. Iran population is increasing rapidly. We have to work on this problem more and more. Attention to social support, education and awareness can be very effective in this situation
Integration of Smart Energy Hubs in Distribution Networks Under Uncertainties and Demand Response Concept
Application of information gap decision theory in practical energy problems: A comprehensive review
The uncertainty quantification and risk modeling are hot topics in operation and planning of energy systems. The system operators and planners are decision makers that need to handle the uncertainty of input data of their models. As an example, energy consumption has always been a critical problem for operators since the forecasted values, and the actual consumption is never expected to be the same. The penetration of renewable energy resources is continuously increasing in recent and upcoming years. These technologies are not dispatch-able and are highly dependent on natural resources. This would make real-time energy balancing more complicated. Another source of uncertainty is related to energy market prices which are determined by the market participants’ behaviors. To consider these issues, uncertainty modeling should be performed. Various approaches have been previously utilized to model the uncertainty of these parameters such as probabilistic approaches, possibilistic approaches, hybrid possibilistic-probabilistic approach, information gap decision theory, robust and interval optimization techniques. This paper reviews the research works that used information gap decision theory for uncertainty modeling in energy and power systems.Science Foundation Irelan