A STEP-based manufacturing information system to share flexible manufacturing resources data

The paper describes the design and implementation of a Manufacturing Information System as a solution to share and exchange manufacturing data. The Manufacturing Information System possesses relevant features for data sharing and exchanging, that are compliant to the standard ISO 10303, known as STEP¹. It is known that manufacturing planning and execution activities require data from machine-tools, robots, ASRSs², AGVs³ and, on the other hand, computer-based applications (CAM⁴, CAPP⁵ or PAC⁶) use proprietary formats to store flexible manufacturing resources data. The way the proprietary formats are built has lead to incompatibilities and interoperability problems among the applications. It is argued that by solving these problems a qualitative functional synergy will result during manufacturing planning and execution activities. The suggested solution is using a STEP-based information system, a server and a prototype client application. These three programs are implemented in Java classes to facilitate data sharing and exchanging of flexible manufacturing resources.This revised version was published in June 2005 with corrected page numbers.     

A particle swarm optimization algorithm for minimizing makespan of nonidentical parallel batch processing machines

This research is motivated by our interactions with an electronics manufacturer who assembles and tests printed circuit boards (PCBs) used in consumer products. Environmental stress screening (ESS) chambers are commonly used to test PCBs to detect early failures before they are used in the field. The chambers are capable of testing multiple PCBs simultaneously (i.e., batch processing machines). The minimum testing time of each PCB and their size are known. The objective is to group these PCBs into batches and schedule the batches formed on ESS chambers such that the makespan is minimized. The ESS chambers can process a batch of jobs as long as its capacity is not violated. Each ESS chamber is unique with respect to its capacity. The problem is NP-hard. Consequently, a particle swarm optimization (PSO) algorithm is proposed. The effectiveness of the PSO algorithm is evaluated by comparing its results to a random-key genetic algorithm and a commercial solver used to solve a mixed-integer linear program. A thorough experimental study conducted indicates that the PSO algorithm reports better quality solution in a short time on larger problem instances.     

CdS thin film post-annealing and Te–S interdiffusion in a CdTe/CdS solar cell

Small area CdTe/CdS solar cells were fabricated using chemical bath deposited CdS and CSS deposited CdTe thin films to investigate the interface properties related to the CdS processing. The effect of post deposition annealing of CdS on the junction properties and the possible interdiffusion at the interface is discussed. The hypothesis of hardening of CdS due to annealing against the diffusion of “S” and “Te” is discussed using the quantum efficiency data in the blue and red regions. Devices prepared using as-deposited CdS films exhibited evidences of higher “S” and “Te” diffusion compared to devices made using CdS films annealed in oxygen. The maximum efficiency of the devices used in this study was 9.8%.     

Effective conversion efficiency enhancement of solar cell using ZnO/PS antireflection coating layers

Zinc oxide (ZnO) film was deposited on a porous silicon (PS) layer using a radio frequency sputtering system while the PS layer was prepared by a photoelectrochemical etching method. The ZnO/PS layers were found to be an excellent antireflection coating (ARC), exhibiting exceptional light trapping at wavelengths ranging from 400 to 1000 nm because of their lowest effective reflectance. This, in turn, leads to increase the efficiency of solar cell to 18.15%. The ZnO film was highly oriented with the c-axis perpendicular to the PS layer. The average crystallite size of the PS and ZnO/PS layers were 17.06 and 17.94 nm, respectively. Photoluminescence emission peaks proved the nanocrystalline characteristic of the PS layer and the ZnO film. Raman measurements of the ZnO/PS layers were determined at room temperature and indicate that a high-quality ZnO nanocrystalline film was formed. In the current paper, ZnO/PS ARC layers are attractive and offer a promising technique to produce high-efficiency, low-cost solar cells.     

Adoption and sustained use of improved cookstoves

The adoption and sustained use of improved cookstoves are critical performance parameters of the cooking system that must be monitored just like the rest of the stove technical requirements to ensure the sustainability of their benefits. No stove program can achieve its goals unless people initially accept the stoves and continue using them on a long-term basis. When a new stove is brought into a household, commonly a stacking of stoves and fuels takes place with each device being used for the cooking practices where it fits best. Therefore, to better understand the adoption process and assess the impacts of introducing a new stove it is necessary to examine the relative advantages of each device in terms of each of the main cooking practices and available fuels. An emerging generation of sensor-based tools is making possible continuous and objective monitoring of the stove adoption process (from acceptance to sustained use or disadoption), and has enabled its scalability. Such monitoring is also needed for transparent verification in carbon projects and for improved dissemination by strategically targeting the users with the highest adoption potential and the substitution of cooking practices with the highest indoor air pollution or greenhouse gas contributions.     

A machine learning framework for improving refinery production planning

We propose a framework that relies on machine learning techniques and statistical modeling to enhance industrial production planning. Supervised learning is employed to improve the production planning model, whereas unsupervised learning is used to achieve economic synchronization between the process control and production planning layers. Finally, an upgraded production planning decision-making structure is formulated where model uncertainty, the effect of process control/disturbances, and time correlation are considered. The proposed framework is implemented on an industry-relevant refinery model demonstrating that the performance of the framework is substantially better than established industrial production planning techniques.     

Angiojet™ mechanical thrombectomy-induced hemolysis triggering blood-leak alarms

Blood leak alarms are increasingly rare and may be triggered by rupture of the dialyzer membrane, or intravascular hemolysis. We report two patients who developed hemolysis following Angiojet™ thrombolysis and thrombectomy of thrombosed arteriovenous fistulas, triggering blood leak alarms on hemodialysis, the occurrence of which has not been reported before. AngioJet™-induced hemolysis should be considered in the differential diagnosis for blood leak alarms occurring soon after an intervention on an arterio-venous (AV) fistula.     

Modified quality video: transmission control protocol (TCP) friendly for controlling a congestion

Multimedia Tools and Applications - Real-time data transmission through telepresence surgery consideration as an important issue due to using low video quality transmission techniques for...     

A novel approach of steganography by using strong edge detection and chaos theory

Multimedia Tools and Applications - The growth of the Internet and rapid development of digital devices and network technology led to increase the risks and threats of attackers, therefore the...