The dynamics of prey–predator interactions are often modeled using differential or difference equations. In this paper, we investigate the dynamical behavior a two-dimensional discrete system. model is formulated in terms equations and derived by nonstandard finite scheme (NSFD), which takes into consideration non-overlapping generations. existence fixed points as well their local asymptotic st...

This study aims to ascertain the determinants affecting liquidity of Vietnamese Commercial Banks by their bank ownership structures, CEO characteristics, and bank-specific variables. Using panel data consisting 29 commercial banks, we measure using most up-to-date method – Net Stable Funding Difference (NSFD), according Basel III standards. Correlating relationship between CEOs’ characteristics...

اواسط شهریور 1401 و در نزدیکی ساحل ماسه‌ای رودخانۀ نکا شمال ایران، به روش تورزدن روی گل‌آذین بوته‌های کاهوک (.Lactuca serriola L) میان تمشک وحشی (.Rubus idaeus انار (.Punica granatum L)، نمونه‌ای جیرجیرک جمع‌آوری شد که بررسی توسط کلیدهای شناسایی شکل‌شناسی مقایسه با نمونه‌های از قبل تعیین نام شدۀ موزۀ حشرات هایک میرزایانس رکورد جدید جنس گونه را تایید کرد. این اولین گزارش گونۀ Arachnocephalus ves...

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...

Chapman’s paper, “Planning for Conjunctive Goals,” has been widely acknowledged as a major step towards understanding the nature of nonlinear planning, and it has been one of the bases of later work by others—but it is not free of problems. This paper discusses the following problems with modal truth and the modal truth criterion. 1. It is NP-hard to tell, given a plan P and a ground atom p, wh...

In this paper, we examine how the complexity of domain-independent planning with STRIPS-style operators depends on the nature of the planning operators. We show conditions under which planning is decidable and undecidable. Our results on this topic solve an open problem posed by Chapman [5], and clear up some difficulties with his undecidability theorems. For those cases where planning is decid...

In this paper we address the constructive controllability problem for drift-free, leftinvariant systems on nite-dimensional Lie groups with fewer controls than state dimension. We consider small ( ) amplitude, low-frequency, periodically time-varying controls and derive average solutions for system behavior. We show how the pth-order average formula can be used to construct open-loop controls f...

In this paper, we show that in the best-known version of the blocks world (and several related versions), planning is difficult, in the sense that finding an optimal plan is NP-hard. However, the NP-hardness is not due to deleted-condition interactions, but instead due to a situation which we call a deadlock. For problems that do not contain deadlocks, there is a simple hill-climbing strategy t...