Order batching algorithms and travel-time estimation for automated storage/retrieval systems

In this paper we present heuristics and analytical models for the order batching problem. Orders are batched into tours such that the total travel time is minimized. Four heuristics are developed for the order batching problem, for which no exact solution exists. All heuristics are based on the time-saving criterion of combining two or more orders in a single tour rather than processing them one order at a time. Among the heuristics that are presented, the SL algorithm has the best performance. An analytical model is developed to estimate the travel time of the S/R machine as a function of the number of locations to be visited and the physical specifications of the structure. Expressions for upper and lower bounds for travel time are presented.     

The long‐term effects of arteriovenous fistula creation on the development of pulmonary hypertension in hemodialysis patients

The aim of this prospective study was to evaluate long‐term effects of arteriovenous fistula (AVF) on the development of pulmonary arterial hypertension (PAH) and the relationship between blood flow rate of AVF and pulmonary artery pressure (PAP) in the patients with end‐stage renal disease (ESRD). This prospective study was performed in 20 patients with ESRD. Before an AVF was surgically created for hemodialysis, the patients were evaluated by echocardiography. Then, an AVF was surgically created in all patients. After mean 23.50 ± 2.25 months, the second evaluation was performed by echocardiography. Also, the blood flow rate of AVF was measured at the second echocardiographic evaluation. Pulmonary arterial hypertension was defined as a systolic PAP above 35 mmHg at rest. Mean age of 20 patients with ESRD was 55.05 ± 13.64 years; 11 of 20 patients were males. Pulmonary arterial hypertension was detected in 6 (30%) patients before AVF creation and in 4 (20%) patients after AVF creation. Systolic PAP value was meaningfully lower after AVF creation than before AVF creation (29.95 ± 10.26 mmHg vs. 35.35 ± 7.86 mmHg, respectively, P: 0.047). However, there was no significant difference between 2 time periods in terms of presence of PAH (P>0.05). Pulmonary artery pressure did not correlate with blood flow rate of AVF and duration after AVF creation (P>0.05). In hemodialysis patients, a surgically created AVF has no significant effect on the development of PAH within a long‐term period. Similarly, blood flow rate of AVF also did not affect remarkably systolic PAP within the long‐term period.     

BOND-GRAPHS FOR INFORMATION SYSTEMS

Abstract

In this paper, an approach dealing with the dynamical aspect of information systems modelling is described. The main idea that governs this article is that the bond-graphs language can be applied to information systems theory. An extension of bond-graphs words is presented to cope with information exchanges. The aim of this task is to show that bond-graphs concepts can be used to model all the aspects of the information system model (static, dynamical,.).

After a brief introduction, the bond-graph language for information systems is dealt with. Particular cases and a short comparison with the Jackson software development method constitute the subject of the sections that follow, then the tools required to model the running of the information system modelled by Bond-graphs are presented. The problem is clearly presented as follows: can the energetic point of view be applied to information systems? If so, is it possible to apply the bond-graph language to those systems?     

Using Quality Function Deployment to Select the Courses and Topics that Enhance Program Effectiveness

Decision science methods can be effective tools for enhancing organizational participation during strategic and complex decision processes. This involvement promotes development of group consensus for issues as difficult as relating organizational goals and the best methods to achieve them. In an academic context, such a process supports and enhances collegial participation. This paper describes an application of Quality Function Deployment (QFD) decision model to prioritize both courses and course content based on degree of impact on program objectives. The model was developed to quantify curricular decisions involved in restructuring a Masters of Engineering Management degree program. QFD supports selection of the courses and the curricular content that has the highest impact on program goals. The model provides a practical and quantitative methodology for developing faculty consensus in the selection of curricular topics based on a strategic program focus.     

Nucleus geometry and mechanical properties of resistance spot welded coated–uncoated DP automotive steels

In this study, mechanical properties of resistance spot welding of DP450 and DP600, galvanized and ungalvanized automotive sheets have been investigated. The specimens have been joined by resistance spot welding at different weld currents and times. Welded specimens have been examined for their mechanical, macrostructure and microstructure properties. Depending on the weld current and time, effects of zinc coating on tensile properties, microhardness values as well as microstructure nugget geometry and nucleus size ratio have been investigated. X-ray diffraction analysis has been used to investigate the phase that formed at the joint interface. Result of the experiment show that nugget diameter, indentation depth and tensile load-bearing capacity are affected by weld parameters. Coating prevents full joining at low parameters. Microhardness increased in heat-affected zone and weld metal.     

Modification of the renneting process in Berridge substrate by transglutaminase

The influence of enzymatic cross‐linking on the rennet coagulation of Berridge substrate was investigated in the rennet gel samples prepared by three different methods using a microbial Tgase. Protein cross‐linking was carried out at each of three stages: before the addition of rennet, simultaneously with rennet and after the addition of rennet. The results showed that the cross‐linking of milk proteins before the addition of rennet inhibited the primary enzymatic phase of rennet coagulation. It was observed that enzymatic cross‐linking affected both the primary and the secondary phases of rennet coagulation. The most suitable application method was the addition of transglutaminase at the 5th minute after the addition of rennet.     

PREDICTION OF THE QUALITY OF SOME TURKISH WHEAT GENOTYPES BY ELECTROPHORETIC SEPARATION OF PROTEIN FRACTIONS

An exploratory study was conducted to compare Konya‐Bezostoya and Tokat‐Bezostoya, bread making varieties of wheat, and Sofu, a Turkish local strain used for pasta making plus four breeding lines to ascertain which of the breeding lines most likely merits carrying forward for further refinement of the line. The wheat was analyzed for weight per unit of volume, kernel weight, impurities, kernel size and shape and hardness; for moisture, ash and protein content; sedimentation values and wet and dry gluten content to provide background information on kernel characteristics. The chief purpose of the study was to examine the electrophoretic properties of the standard varieties and breeding lines to relate genetic characteristics to bread‐ or pasta‐making potential. Glutenin profiles and gliadin subunits were among the factors studied. Low and high‐molecular‐weight (HMW) alleles were considered. Two of the