بخش اورژانس یکی از شلوغ‌ترین بخش‌های یک بیمارستان است و بهبود عملکرد این تأثیر بسیاری در کیفیت ارائه خدمات دارد. اخیراً پژوهشگران به­‌دلیل تمرکز مهندسی تاب‌آوری مدیریت ناب بر کارایی سیستم‌ها توجه بسیار زیادی به دو دیدگاه کنار یکدیگر داشته‌اند. هدف پژوهش، رویکردی یکپارچه برای ارزیابی مبتنی شاخص‌های با ارتقای رضایت شغلی کاهش هزینه‌های درمانی واحد خصوصی است. منظور، ابتدا شناسایی مؤثر، مدل مفهومی مس...

The permutation flow shop problem (PFSSP) is an NP-hard problem of wide engineering and theoretical background. In this paper, a biogeography based optimization (BBO) based on memetic algorithm, named HBBO is proposed for PFSSP. Firstly, to make BBO suitable for PFSSP, a new LRV rule based on random key is introduced to convert the continuous position in BBO to the discrete job permutation. Sec...

We investigate the geometry of a particular class of null surfaces in space-time called vacuum Non-Expanding Horizons (NEHs). Using the spin-coefficient equation, we provide a complete description of the horizon geometry, as well as fixing a canonical choice of null tetrad and coordinates on a NEH. By looking for particular classes of null geodesic congruences which live exterior to NEHs but ha...

The work described in this paper attempts to validate the implicit assumption in traditional flow shop scheduling research that there is a buffer of infinite capacity between any two adjacent machines. The modified NEH (Nawaz, Encore and Ham) algorithm is used to generate an initial permutation schedule which is then improved by tabu search. For any given sequence, a limited equal buffer size i...