A patchboard-based expert-systems model for manufacturing applications

Expert systems have proved to be effective for many problems in manufacturing. Blackboard models are perhaps one of the most widely used paradigms for building expert systems. However, there are situations in which the blackboard model is not applicable because of the dynamic nature of a problem. In this paper, the authors present a patchboard expert-system model in an effort to capture the dynamics of this class of problems. The difference between these two models is discussed, and the theoretical foundation of the patchboard model is detailed.     

Radioimmunoassay for glutamic acid decarboxylase (GAD65) autoantibodies as a diagnostic aid for stiff-man syndrome and a correlate of susceptibility to type 1 diabetes mellitus

OBJECTIVE: To establish and validate a double-antibody radioimmunoassay (RIA) for detecting serum auto-antibodies against glutamic acid decarboxylase (GAD65). This enzyme catalyzes synthesis of the neurotransmitter gamma-aminobutyric acid in neurons and pancreatic islet cells. MATERIAL AND METHODS: We compared the frequency of GAD65 and other "thyrogastric" autoantibodies in adult patients with stiff-man (Moersch-Woltman) syndrome, type 1 diabetes, or polyendocrine disorders and in healthy subjects. The frequency of pancreatic islet cell antibody (ICA) detection was also assessed. The GAD65 RIA was validated by testing blinded samples, by confirming the specificity of low-titered positive results by "cold" antigen inhibition, and by comparing the RIA results with results of a kit assay incorporating staphylococcal protein A as immunoprecipitant. Recombinant GAD65 protein labeled with 125I was used as antigen, and a combination of anti-human IgG and IgM was used as immunoprecipitant. Seropositivity was determined for ICA and gastric parietal cell antibodies by indirect immunofluorescence assays and for thyroid peroxidase (microsome) and thyroglobulin antibodies by agglutination assays. RESULTS: We detected GAD65-specific antibodies in all but 1 of 46 local patients with stiff-man syndrome (98%); 16 had evidence of diabetes. Positive values exceeded 20 nmol/L in 96%, and 89% were ICA-positive; 76% had additional thyrogastric antibodies. Of 41 patients with type 1 diabetes (17 local and 24 workshop serum specimens), 33 were GAD65 antibody-positive (80%); 85% of these positive values were 20 nmol/L or lower. Only 18% of sera from patients with type 1 diabetes were ICA-positive, but 59% had other thyrogastric autoantibodies. Of 20 patients with autoimmune endocrinopathies without diabetes or stiff-man syndrome, 35% were GAD65 antibody-positive, 5% were ICA-positive, and 90% were thyrogastric antibody-positive. Of 117 healthy control subjects, 8% were GAD65 antibody-positive, and a third of those had other thyrogastric antibodies (14% overall); none was ICA-positive. CONCLUSION: Seropositivity in the double-antibody RIA for GAD65 autoantibody is a sensitive and specific marker of predisposition to type 1 diabetes and related organ-specific autoimmune disorders. As such, this RIA is complemented by assays for thyroid and gastric parietal cell autoantibodies.     

Stochastic Screen Halftoning for Electronic Imaging Devices

For numerous digital imaging applications, there is a need to maintain the highest quality perceived image, while utilizing a printer or display that can only achieve a limited number of output states. Digital halftoning is the approach that has been widely used to meet this demand. In this focus paper, we provide a short summary of halftone techniques, then we concentrate on the newer and expanding roles of stochastic halftone screens—which are free of regular periodic structures and have numerous advantages in quality color rendering. We address some theoretical issues, design and optimality issues, printer compensation issues, and color quality issues that pertain to the development and use of stochastic screens for electronic imaging devices.     

Receptor-specific adhesion and clinical disease in Plasmodium falciparum

Rapid detection of single-base changes is fundamental to molecular medicine. PASA (PCR Amplification of Specific Alleles) is a rapid method of genotyping single-base changes, but one reaction is required for each allele. Bidirectional PASA (Bi-PASA) was developed to distinguish between homozygotes and heterozygotes in one PCR reaction by utilizing novel primer design with appropriate cycling conditions. In Bi-PASA, one of the alleles is amplified by a PASA reaction in one direction while the second allele is amplified by a PASA reaction in the opposite direction. Two outer (P and Q) and two inner allele-specific (A and B) primers are required. In heterozygotes, three segments are amplified: a segment of size AQ resulting from one allele, another segment of size PB resulting from the second allele, and a combined segment of size PQ. In homozygotes, segment PQ and either segments AQ or PB amplify. The two inner primers (A and B) contain a relatively short complementary region and a 10-nucleotide G + C-rich 5' tail. The inner primers "switch" from low-efficiency to high-efficiency amplification when genomic DNA is replaced by previously amplified template DNA. In addition, the 5' tails prevent "megapriming". The parameters for optimizing Bi-PASA were investigated in detail for common mutations in the human factor V and catechol-O-methyltransferase genes. Guidelines for optimization of Bi-PASA also were developed and tested in a prospective study. Three additional Bi-PASA assays were optimized rapidly by utilizing these guidelines. In conclusion, Bi-PASA is a simple and rapid method for detecting the zygosity of known mutations in a single PCR reaction.     

Ambipolar carrier transport in an optically controllable diarylethene thin film transistor

Ambipolar carrier transport is demonstrated in an optically controllable organic field-effect transistor, where a benzothienothiophene-substituted diarylethene (BTT-DAE) thin film is employed directly as the transistor channel. A closed-ring isomer, which is produced by ultraviolet (UV) light irradiation, allows the carrier injection of both holes and electrons from source-drain electrodes into the BTT-DAE layer. Moreover, alternate UV or visible (VIS) light irradiation induces marked switching in the drain currents caused by reversible photoisomerization between closed-ring (semiconductor) and open-ring (insulator) isomers. The light-driven on/off ratio, which is defined by the ratio of the drain currents in the sample after UV or VIS light irradiation, reaches 240 for hole transport. The value is comparable to the gate-voltage-induced on/off ratio of 160. Our findings, therefore, have a potential to lead to the construction of new optoelectronic devices such as photoreconfigurable logic circuits and light emitting transistors.     

MAC-layer rate control for 802.11 networks: a survey

Rate control at the MAC-layer is one of the fundamental building blocks in many wireless networks. Over the past two decades, around thirty mechanisms have been proposed in the literature. Among them, there are mechanisms that make rate selection decisions based on sophisticated measurements of wireless link quality, and others that are based on straight-forward heuristics. Minstrel, for example, is an elegant mechanism that has been adopted by hundreds of millions of computers, yet, not much was known about its performance until recently. The purpose of this paper is to provide a comprehensive survey and analysis of the existing solutions from the two fundamental aspects of rate control—metrics and algorithms. We also review how these solutions were evaluated and compared against each other. Based on our detailed studies and observations, we share important insights on future development of rate control mechanisms at the MAC-layer. This discussion also takes into account the recent developments in wireless technologies and emerging applications, such as Internet-of-Things, and shows issues that need to be addressed in the design of new rate control mechanisms suitable for these technologies and applications.

     

Argon Plasma Treatment to Tune Perovskite Surface Composition for High Efficiency Solar Cells and Fast Photodetectors

The surface composition of perovskite films is very sensitive to film processing and can deviate from the optimal, which generates unfavorable defects and results in efficiency loss in solar cells and slow response speed in photodetectors. An argon plasma treatment is introduced to modify the surface composition by tuning the ratio of organic and inorganic components as well as defect type before deposition of the passivating layer. It can efficiently enhance the charge collection across the perovskite–electrode interface by suppressing charge recombination. Therefore, perovskite solar cells with argon plasma treatment yield enhanced efficiency to 20.4% and perovskite photodetectors can reach their fastest respond speed, which is solely limited by the carrier mobility.     

Controlling the material removal and roughness of Inconel 718 in laser machining

Nickel alloys including Inconel 718 are considered as challenging materials for machining. Laser beam machining could be a promising choice to deal with such materials for simple to complex machining features. The machining accuracy is mainly dependent on the rate of material removal per laser scan. Because of the involvement of many laser parameters and complexity of the machining mechanism it is not always simple to achieve machining with desired accuracy. Actual machining depth extremely varies from very low to aggressively high values with reference to the designed depth. Thus, a research is needed to be carried out to control the process parameters to get actual material removal rate (MRR_act) equals to the theoretical material removal rate (MRR_th) with minimum surface roughness (SR) of the machined surfaces. In this study, five important laser parameters have been used to investigate their effects on MRR and SR. Statistical analysis are performed to identify the significant parameters with their strength of effects. Mathematical models have been developed and validated to predict the machining responses. Optimal set of laser parameters have also been proposed and confirmed to achieve the actual MRR close to the designed MRR (MRR_% = 100.1%) with minimum surface roughness (R_a = 2.67 µm).     

Magnetostriction via Magnetoelectricity: Using Magnetoelectric Response to Determine the Magnetostriction Characteristics of Composite Multiferroics

Technical Physics Letters - We propose a new method for determining the magnetostriction characteristics of composite multiferroics by measuring the magnetoelectric (ME) response of the material...     

PLGA film/Titanium nanotubues as a sustained growth factor releasing system for dental implants

Ti-based implants sometimes fail to integrate with surrounding bone tissue due to insufficiency of new bone formation and surface bonding. To overcome this problem, this research focused on establishing a sustained bone growth factor delivery system by applying anodized TiO2 nanotube arrays and PLGA film on the titanium implant surface. TiO2 nanotube arrays were made by anodic oxidation method, and were then filled with rhBMP2 by vacuum freeze-drying. Next, PLGA was deposition on the surface of this material. The designed system was characterized, pharmacokinetic release rate of rhBMP2 was determined. Adhesion, proliferation, and differentiation activity of osteoblasts cultured on the new surfaces and traditional titanium surfaced were compared. SEM showed that a surface of TiO2 nanotube arrays were successfully generated. PLGA membranes of 50?nm, 250?nm, 800?nm thickness were successfully deposited on the surfaces of TiO2 nanotube layers by using 1%, 3%, 10% PLGA solutions. PLGA film of 250?nm thickness showed ideally controlled release of rhBMP2, lasting for 4 weeks. Furthermore, 250?nm thickness PLGA film improved osteoblast adhesion, proliferation, and levels of alkaline phosphatase. In conclusion, the PLGA film / TiO2 nanotube growth factor delivery system can effectively sustain the release of rhBMP-2, and promote proliferation and differentiation of MC3T3-E1 osteoblasts.

Open image in new window