We present a concise and self-contained definition of the ideal class group, which is useful for proving facts about zero sets of Diophantine equations, and discuss a few relevant key facts. We approach this by first assembling some preliminary definitions regarding algebraic integers, and subsequently delving into several useful results about lattices, including Minkowski’s lemma. Then, return...

Using a fan effect paradigm, three experiments tested whether younger and older adults differ in the retrieval of integrated and nonintegrated facts, where integration refers to the development of a mental model. Earlier work by G. A. Radvansky and R. T. Zacks ( 1991 ) had found that as long as facts can be integrated into a single mental model, young adults show no increase in retrieval time o...

در صنعت پالایشگاه و پتروشیمی‌ها به دلیل وجود تجهیزات تمام فلزی محیط اسیدی خوردگیتنشی زیاد است با توجه افزایش کاربرد فولادهای زنگ نزن این صنایع پژوهش بررسی اثر ضربات امواج اولتراسونیک بر رفتار خوردگی فولاد 316 (S.S 316) می‌پردازیم. هدف از تأثیر روش تنش‌زدایی برافزایش مقاومت قطعات محیط‌های خورنده است. لازم ذکر که، تنش پسمان نمونه‌ها جوش‌کاری ایجادشده ابتدا نمونه مدنظر استفاده ارتعاش تحت فرکانس 20...

In this paper a new and efficient method for the reliable load flow solution of power network branches controlled by flexible AC transmission systems (FACTS) is presented. In the various methods proposed in past, the formulations was derived in which the Jacobian matrix is in UDU form, where U is a constant upper triangular matrix depending solely on system topology and D is a block diagonal ma...

Received Jan 18, 2017 Revised Mar 18, 2017 Accepted Apr 2, 2017 In recent years, applications of facts systems have been developed for the compensation of active and reactive power. Facts systems are electronics devices that are connected to the wind farm. This paper presents the impacts of some of these devices on the stability of a wind farm, especially D-STATCOM, Static Var Compensator and F...

This review aims to explore the relationship between anthropology and genetics, an intellectual zone that has been occupied in different ways over the past century. One way to think about it is to contrast a classical “anthropological genetics” (Roberts 1965), that is to say, a genetics that presumably informs anthropological issues or questions, with a “genomic anthropology” (Pálsson 2008), th...

هدف این پژوهش، طراحی مدل بهینه‌سازی دوسطحی برای زنجیره تأمین است؛ به‌طوری‌که تصمیم‌گیری غیرمتمرکز کمّی و کیفی را در سطوح استراتژی تاکتیکی ادغام کند. کارخانه تولیدی نقش تصمیم‌گیرنده سطح بالا با ارائه تخفیف مقداری، به دنبال ترغیب مشتریان سفارش خرید بیشتر است. پایین، به‌عنوان پایین تمایل دارند مقادیر از طریق مشارکتی، مقیاس اقتصادی دست یابند. یکی نخستین پژوهش­هایی است که یافتن راه‌حل‌های بهینه مسئله...

Endüstriyel uygulamalarda kullanılan yüklerin büyük bir kısmı gelişen teknolojiyle birlikte endüktif yüklerden oluşmaktadır. Endüktif yükler, yapıları gereği reaktif enerji tüketmektedirler. Tüketilen bu enerji, sistemin kalitesinde ve verimliliğinde düşüşe güç faktöründe sorunlara neden olmaktadır. Esnek alternatif akım iletim sistemleri (FACTS), sisteminin performansını kalitesini arttırmada ...

this paper presents a new component within the flexible ac-transmission system (FACTS) family, called distributed power-flow controller (DPFC). The DPFC is derived from the uni-fied power-flow controller (UPFC). The DPFC can be considered as a UPFC with an eliminated common dc link. The active power ex-change between the shunt and series converters, which is through the common dc link in the UP...