scholarly journals Operator Assignment Decisions in a Highly Dynamic Cellular Environment

Author(s):  
Gürsel A. Süer ◽  
Omar Alhawari

Operators are assigned to operations in labor-intensive manufacturing cells using two assignment strategies: Max-Min and Max. The major concern is to see how these two approaches impact operators’ skill levels and makespan values in a multi-period environment. The impact is discussed under chaotic environment where sudden changes in product mix with different operation times are applied, and also under non-chaotic environment where same product mix is run period after period. In this chapter, operators’ skill levels are affected by learning and forgetting rates. The Max-Min strategy improved operators’ skill levels more significantly than Max in this multi-period study; particularly in chaotic environment. This eventually led to improved makespan values under Max-Min strategy.

2012 ◽  
pp. 1135-1152
Author(s):  
Gürsel A. Süer ◽  
Omar Alhawari

Operators are assigned to operations in labor-intensive manufacturing cells using two assignment strategies: Max-Min and Max. The major concern is to see how these two approaches impact operators’ skill levels and makespan values in a multi-period environment. The impact is discussed under chaotic environment where sudden changes in product mix with different operation times are applied, and also under non-chaotic environment where same product mix is run period after period. In this chapter, operators’ skill levels are affected by learning and forgetting rates. The Max-Min strategy improved operators’ skill levels more significantly than Max in this multi-period study; particularly in chaotic environment. This eventually led to improved makespan values under Max-Min strategy.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dustin A. Ammendolia ◽  
William M. Bement ◽  
John H. Brumell

AbstractPlasma membrane integrity is essential for cellular homeostasis. In vivo, cells experience plasma membrane damage from a multitude of stressors in the extra- and intra-cellular environment. To avoid lethal consequences, cells are equipped with repair pathways to restore membrane integrity. Here, we assess plasma membrane damage and repair from a whole-body perspective. We highlight the role of tissue-specific stressors in health and disease and examine membrane repair pathways across diverse cell types. Furthermore, we outline the impact of genetic and environmental factors on plasma membrane integrity and how these contribute to disease pathogenesis in different tissues.


2021 ◽  
Author(s):  
Kore Marc Antoine Guei

Abstract The paper assesses the impact of trade liberalization on the labour market by focusing on skill wage premium. The paper tests these effects by developing a monopolistic competition model with two factors of production characterized by their skill levels (skilled and unskilled labour). The paper finds that tariff’s level reductions cause a moderate increase in the wage gap. Thus, our analysis shows that a 10% decrease in tariffs is accompanied by a 16.1 % increase in the skill premium. Also, the same level of tariffs’ cut will on average increase the gender wage gap by 26.8%. The study implies that trade liberalization tends to benefit more workers in the skilled labour market compared to workers in the unskilled labour market.


Author(s):  
А.И. Дубских

Стремительное развитие информационно-коммуникационных технологий, расширение международных связей в области экономики, науки, культуры и образования сделало владение иностранным языком одним из ключевых компонентов профессиональной компетентности специалиста. Иностранный язык в вузе превращается из просто дисциплины в инструмент получения профессиональной информации. Предметно-языковое интегрированное обучение (Content and Language Integrated Learning - CLIL) представляет один из целесообразных способов, позволяющих успешно устанавливать связи между профилирующими дисциплинами, а также осуществлять эффективную подготовку будущего специалиста к ведению профессионального общения с коллегами на иностранном языке, что и определяет актуальность нашей работы. В статье описываются принципы предметно-языкового интегрированного обучения, его преимущества и проблемы использования в учебном процессе. Цель статьи - определить влияние CLIL на улучшение изучения учащимися лексики и выяснить, есть ли разница между прогрессом студентов, применявших CLIL на занятиях, и теми, кто опирался на традиционные методы. Для проведения исследования были отобраны студенты, которые прошли обучение в экспериментальной и контрольной группах. Студенты экспериментальной группы активно использовали методы CLIL. Результаты показали, что студенты экспериментальной группы демонстрируют более высокий уровень квалификации и более высокую коммуникативную компетентность, чем их сверстники. Однако в процессе использования методики CLIL и преподаватели, и учащиеся столкнулись с рядом трудностей. Тем не менее автор приходит к выводу, что у CLIL есть потенциал для лучшего понимания профессионального контента при изучении иностранного языка. Полученными выводами могут воспользоваться преподаватели, методисты, исследователи, разработчики образовательных программ. The rapid development of information and communication technologies, the expansion of international ties in the field of economy, science, culture and education have made foreign language knowledge one of the key components in a specialist’s professional competence. Foreign language in the university is transformed from simply discipline into a tool for obtaining professional information. Content and Language Integrated Learning (CLIL) is one of the most expedient ways to successfully establish links between majoring disciplines, as well as effectively prepare a future specialist to conduct professional communication with colleagues in a foreign language, which determines the relevance of our work. The article describes the principles of students’ Content and Language Integrated Learning, their advantages and problems of implementation. The purpose of the article is to determine the impact of CLIL on improving students’ study of vocabulary and to find out if there is a difference between the progress in students’ using CLIL in classes and those who have relied on traditional methods. The study selected students who were trained in experimental and control groups. Students in the experimental group actively used CLIL methods. The results showed that students in this experimental group demonstrate higher skill levels and higher communicative competence than their peers. However, in the process of using the CLIL methodology, both teachers and students faced a number of difficulties. The author concludes that CLIL has the potential to better understand professional content through foreign language learning. These results can be used by teachers, methodologists, researchers, and developers of educational programs.


2019 ◽  
Vol 20 (15) ◽  
pp. 3764 ◽  
Author(s):  
Mona Ebadi ◽  
Kalaivani Buskaran ◽  
Bullo Saifullah ◽  
Sharida Fakurazi ◽  
Mohd Zobir Hussein

One of the current developments in drug research is the controlled release formulation of drugs, which can be released in a controlled manner at a specific target in the body. Due to the diverse physical and chemical properties of various drugs, a smart drug delivery system is highly sought after. The present study aimed to develop a novel drug delivery system using magnetite nanoparticles as the core and coated with polyvinyl alcohol (PVA), a drug 5-fluorouracil (5FU) and Mg–Al-layered double hydroxide (MLDH) for the formation of FPVA-FU-MLDH nanoparticles. The existence of the coated nanoparticles was supported by various physico-chemical analyses. In addition, the drug content, kinetics, and mechanism of drug release also were studied. 5-fluorouracil (5FU) was found to be released in a controlled manner from the nanoparticles at pH = 4.8 (representing the cancerous cellular environment) and pH = 7.4 (representing the blood environment), governed by pseudo-second-order kinetics. The cytotoxicity study revealed that the anticancer delivery system of FPVA-FU-MLDH nanoparticles showed much better anticancer activity than the free drug, 5FU, against liver cancer and HepG2 cells, and at the same time, it was found to be less toxic to the normal fibroblast 3T3 cells.


Author(s):  
Jeffery Hsu

The role of the user interface (interaction mode) is of considerable importance, since the method of interaction can have an impact on both performance and satisfaction with regards to using a programming language. While markup languages are now widely used for Web page and site design and electronic publishing applications, they have not been studied adequately compared with other kinds of languages. The impact of interaction mode, in this case command-based coding, versus using a form-fill-in wizard, is examined, with respect to performance and satisfaction while performing a survey-oriented task. Skill level, which classified users as being either a novice or experienced, was another factor, which was taken into account in this study. The results showed the use of wizards brought about better performance than using the command language, and the difference between modes was far greater for novices rather than experienced users. In addition, using the wizard tended to equalize performance across skill levels. With regards to system satisfaction, there were significant differences between interaction modes, however no differences were reported between skill levels. These differences in performance and satisfaction should be noted and considered when designing interactive systems for programming-related applications.


2010 ◽  
Author(s):  
Elizabeth Ty Wilde ◽  
Lily Batchelder ◽  
David Ellwood
Keyword(s):  

Author(s):  
Amit Bhandwale ◽  
Thenkurussi Kesavadas

The identification of part families and machine groups that form the cells is a major step in the development of a cellular manufacturing system. The primary input to cell formation algorithms is the machine-part incidence matrix, which is a binary matrix representing machining requirements of parts in various part families. One common assumption of these cell formation algorithms is that the product mix remains stable over a period of time. In today’s world, the market demand is being shaped by consumers, resulting in a highly volatile market. This has given rise to a class of products characterized by low volume and high variety, which presents engineers with lots of problems and decisions in the early stages of product development. This can have an adverse effect on manufacturing like high investment in new machinery and material handling equipment, long setup times, high tooling costs, increased intercellular movement and excessive scrap which increases the cost without adding any value to the parts. Any change to the product mix results in a change in the machine-part incidence matrix, which may change the part families and machine groups, which form the cells. The manufacturing system needs to be flexible in order to handle large product mix changes. This paper discusses the impact of product mix variations on cellular manufacturing and presents a methodology to incorporate these variations into an existing cellular manufacturing setup.


1996 ◽  
Vol 25 (2) ◽  
pp. 187-199 ◽  
Author(s):  
Bruno Larue ◽  
Jean-Philippe Gervais

Trade theorists have demonstrated that different trade policy instruments have different effects on the quality and source of imports. Countervailing duties (CVDs), like specific tariffs, should induce quality upgrading. However, the magnitude and timing of the quality adjustments are influenced by the credibility of the duties that can be legally contested and modified after annual administrative reviews. Index numbers are used to assess the timing and magnitude of the product mix and country mix substitution effects in U.S. pork imports in response to the U.S. CVDs on Canadian exports of live hogs and fresh, chilled, and frozen pork.


mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Rong Gao ◽  
Ann M. Stock

ABSTRACT Cells rely on accurate control of signaling systems to adapt to environmental perturbations. System deactivation upon stimulus removal is as important as activation of signaling pathways. The two-component system (TCS) is one of the major bacterial signaling schemes. In many TCSs, phosphatase activity of the histidine kinase (HK) is believed to play an essential role in shutting off the pathway and resetting the system to the prestimulus state. Two basic challenges are to understand the dynamic behavior of system deactivation and to quantitatively evaluate the role of phosphatase activity under natural cellular conditions. Here we report a kinetic analysis of the response to shutting off the archetype Escherichia coli PhoR-PhoB TCS pathway using both transcription reporter assays and in vivo phosphorylation analyses. Upon removal of the stimulus, the pathway is shut off by rapid dephosphorylation of the PhoB response regulator (RR) while PhoB-regulated gene products gradually reset to prestimulus levels through growth dilution. We developed an approach combining experimentation and modeling to assess in vivo kinetic parameters of the phosphatase activity with kinetic data from multiple phosphatase-diminished mutants. This enabled an estimation of the PhoR phosphatase activity in vivo , which is much stronger than the phosphatase activity of PhoR cytoplasmic domains analyzed in vitro . We quantitatively modeled how strong the phosphatase activity needs to be to suppress nonspecific phosphorylation in TCSs and discovered that strong phosphatase activity of PhoR is required for cross-phosphorylation suppression. IMPORTANCE Activation of TCSs has been extensively studied; however, the kinetics of shutting off TCS pathways is not well characterized. We present comprehensive analyses of the shutoff response for the PhoR-PhoB system that reveal the impact of phosphatase activity on shutoff kinetics. This allows development of a quantitative framework not only to characterize the phosphatase activity in the natural cellular environment but also to understand the requirement for specific strengths of phosphatase activity to suppress nonspecific phosphorylation. Our model suggests that the ratio of the phosphatase rate to the nonspecific phosphorylation rate correlates with TCS expression levels and the ratio of the RR to HK, which may contribute to the great diversity of enzyme levels and activities observed in different TCSs.


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