Inventory optimization for perishables subject to supply disruptions

We study a retailer selling perishable products with fixed lifetime. The retailer’s supply system is subject to random disruptions. Assuming a base-stock policy, deterministic demand and stationary cost parameters, we determine the expression for the optimal base-stock level. We show that if the retailer manages to make the system safer, it is possible to operate with the same expected cost even with products with shorter lifetimes. We conclude that the retailer should concentrate on reducing disruptions’ durations instead of their occurrence rate.</p

The Effects Of Collaboration In The Constructivist Web-Based Learning Environment Of An Undergraduate Physics Course.

The effects of the student-facilitator and student-peer collaboration in the constructivist Web-based learning environment of an undergraduate Physics course are reported

The Web-Based Learning Environment: A Comparative Study Between The Constructivist And Content-Based Approaches.

This article reports on the investigation into the differences in students' perceptions when they are subjected to two different instructional designs of the Web-based Learning Environments (WBLEs)

Evaluation of Bioactive Compounds in Nutrition Physiology

Many peptides released from animal or plant proteins in vitro or in vivo have therapeutic functions in humans beyond bioactivity and adequate nutrition. Different health effects have been attributed to foodborne peptides, including antimicrobial properties, blood pressure lowering (ACE inhibitor) effects, cholesterol lowering ability, antithrombotic and antioxidant activities, increased mineral absorption, immunomodulatory effects and opioid activities. For this reason, nutritional counseling practices deal with these issues. Specific protein fractions with therapeutic effects on body function and health are termed biological peptides and have been shown to have a direct positive effect on health. Angiotensin I-converting enzyme (ACE) is a carboxy-dipeptidyl metallopeptidase associated with the renin angiotensin system that regulates the production of angiotensin II from vasoconstrictor angiotensin-II and peripheral blood pressure that catalyzes the inactivation of vasodilator bradykinin. For this reason, the ACE inhibitor substance in the diet may inhibit hypertension by inhibiting the renin-angiotensin system. Milk proteins are now the main source of bioactive peptides. Such peptides are seen as natural and non-effective alternatives to drugs in the treatment of hypertension. The natural consumption of biological peptides will not be expected to cause side effects of synthetically produced drugs used to control hypertension. Therefore, it can be used as a powerful functional food additive and the ACE inhibitor is a natural and healthy alternative to drugs

Modelling multiscale aspects of colorectal cancer

Colorectal cancer (CRC) is responsible for nearly half a million deaths annually world-wide [11]. We present a series of mathematical models describing the dynamics of the intestinal epithelium and the kinetics of the molecular pathway most commonly mutated in CRC, the Wnt signalling network. We also discuss how we are coupling such models to build a multiscale model of normal and aberrant guts. This will enable us to combine disparate experimental and clinical data, to investigate interactions between phenomena taking place at different levels of organisation and, eventually, to test the efficacy of new drugs on the system as a whole

Evaluation of Bioactive Compounds in Nutrition Physiology

Many peptides released from animal or plant proteins in vitro or in vivo have therapeutic functions in humans beyond bioactivity and adequate nutrition. Different health effects have been attributed to foodborne peptides, including antimicrobial properties, blood pressure lowering (ACE inhibitor) effects, cholesterol lowering ability, antithrombotic and antioxidant activities, increased mineral absorption, immunomodulatory effects and opioid activities. For this reason, nutritional counseling practices deal with these issues. Specific protein fractions with therapeutic effects on body function and health are termed biological peptides and have been shown to have a direct positive effect on health. Angiotensin I-converting enzyme (ACE) is a carboxy-dipeptidyl metallopeptidase associated with the renin angiotensin system that regulates the production of angiotensin II from vasoconstrictor angiotensin-II and peripheral blood pressure that catalyzes the inactivation of vasodilator bradykinin. For this reason, the ACE inhibitor substance in the diet may inhibit hypertension by inhibiting the renin-angiotensin system. Milk proteins are now the main source of bioactive peptides. Such peptides are seen as natural and non-effective alternatives to drugs in the treatment of hypertension. The natural consumption of biological peptides will not be expected to cause side effects of synthetically produced drugs used to control hypertension. Therefore, it can be used as a powerful functional food additive and the ACE inhibitor is a natural and healthy alternative to drugs

Conceptualizing a model for Continuance Use of Cloud Computing in Higher Education Institutions

Resource management optimization is a key concern for educational establishments. Cloud computing as the next generation in computing technology has emerged as the main standard of service and resource delivery. As cloud computing has grown into a mature technology being rapidly adopted in many education institutions across the world, retaining customers of this innovation has become a challenge to the cloud service providers. Current research trends on cloud computing have sought to study the technology’s acceptance or adoption; however, little research attention has been given to the continuance use in an organizational setting. To fill this gap, we established a positivist quantitative-empirical study to investigate the antecedents of cloud continuance use in higher education institutions. Accordingly, drawing on prior literature in organizational-level continuance, this research developed a conceptual model that extends and contextualizes the IS continuance model. We structured our model based on the TOE framework, integrating the established theoretical lenses of the IS success model and the IS discontinuance model to explicate cloud computing continuance use in the context of Higher Education Institutions. To test this model, using a non-probability purposive sampling method, data was collected from the decision-makers of universities that have adopted cloud computing service. We used Structural Equation Modeling (SEM) based on the Partial Least Squares (PLS) to analyze the data. The findings of a preliminary study, conducted through a survey with ICT decision-makers, and based on the proposed conceptual model, indicate that the research instrument is both reliable and valid, and so point the way towards further research. The paper closes with a discussion of the research limitations, contributions, and future directions

A study of the ICT profile of the Open University Malaysia learners

his article reports on the study undertaken to elucidate the ICT profile of the Open University Malaysia (OUM) learners. The information is imperative for the building of the learning communities and bridging the digital divide among learners separated in space and time. The aspects studied were the computer availability and Internet accessibility at home and at the workplace, the usage of standalone and Internet-linked applications and the frequency of usage. The results revealed that a high proportion of the learners have computers both at home and at the workplace with sufficiently high rates of Internet connection at the home computer but substantially lower rates for the computer at the workplace. In terms of the usage of the standalone computer applications, a substantially higher proportion of the respondents use word processing applications, followed closely by educational CD-ROM and entertainment applications. The results also revealed that slightly more than seventy-five percent of the respondents use the Internet Browser as well as the asynchronous communication application but only a few of them utilise the synchronous chat application. In terms of the frequency of usage, the majority of the respondents use the computer at home at least three times a week but considerably less frequently at the workplace. The implications of these findings in relation to the formation of online learning communities and bridging the digital divide in the delivery of open and distance learning courses will be discussed and highlighted. (Authors' abstract

Single CNC machine scheduling with controllable processing times and multiple due dates

In this study, we solve the single CNC machine scheduling problem with controllable processing times. Our objective is to maximize the total profit that is composed of the revenue generated by the set of scheduled jobs minus the sum of total weighted earliness and weighted tardiness, tooling and machining costs. Customers offer multiple due dates to the manufacturer, each coming with a distinct price for the order that is decreasing as the date gets later, and the manufacturer has the flexibility to accept or reject the orders. We propose a number of ranking rules and scheduling algorithms that we employ in a four-stage heuristic algorithm that determines the processing times for each job and a final schedule for the accepted jobs simultaneously, to maximize the overall profit