Modelling and improving maintenance decisions:Having foresight with simulation and artificial intelligence

Machine breakdowns are one of the main sources of disruption and throughput fluctuation in highly automated production facilities. One element in reducing this disruption is ensuring that the maintenance team responds correctly to machine failures. It is, however, difficult to determine the current practice employed by the maintenance team, let alone suggest improvements to it. 'Knowledge based improvement' is a methodology that aims to address this issue, by (a) eliciting knowledge on current practice, (b) evaluating that practice and (c) looking for improvements. The methodology, based on visual interactive simulation and artificial intelligence methods, and its application to a Ford engine assembly facility are described. Copyright © 2002 Society of Automotive Engineers, Inc.

Knowledge based improvement:simulation and artificial intelligence for identifying and improving human decision-making in an operations systems

The performance of most operations systems is significantly affected by the interaction of human decision-makers. A methodology, based on the use of visual interactive simulation (VIS) and artificial intelligence (AI), is described that aims to identify and improve human decision-making in operations systems. The methodology, known as 'knowledge-based improvement' (KBI), elicits knowledge from a decision-maker via a VIS and then uses AI methods to represent decision-making. By linking the VIS and AI representation, it is possible to predict the performance of the operations system under different decision-making strategies and to search for improved strategies. The KBI methodology is applied to the decision-making surrounding unplanned maintenance operations at a Ford Motor Company engine assembly plant.

Effect of support and cultural intelligence on the adjustment and performance of expatriates and their family members in Malaysia

Theory suggests that people fear the unknown and no matter how experienced one is, the feelings of anxiety and uncertainty, if not managed well would affect how we view ourselves and how others view us. Hence, it is in human nature to engage in activities to help decipher behaviours that seem contrary to their beliefs and hinder the smooth-flowing of their work and daily activities. Building on these arguments, this research investigates the two types of support that are provided by multinational corporations (MNCs) and host country nationals (HCNs) to the expatriates and their family members whilst on international assignments in Malaysia as antecedents to their adjustment and performance in the host country. To complement the support provided, cultural intelligence (CQ) is investigated to explain the influence of cultural elements in facilitating adjustment and performance of the relocating families, especially to socially integrate into the host country. This research aims to investigate the influence of support and CQ on the adjustment and performance of expatriates in Malaysia. Path analyses are used to test the hypothesised relationships. The findings substantiate the pivotal roles that MNCs and HCNs play in helping the expatriates and their families acclimatise to the host country. This corroborates the norm of reciprocity where assistance or support rendered especially at the times when they were crucially needed would be reciprocated with positive behaviour deemed of equal value. Additionally, CQ is significantly positive in enhancing adjustment to the host country, which highlights the vital role that cultural awareness and knowledge play in enhancing effective intercultural communication and better execution of contextual performance. The research highlights the interdependence of the expatriates? multiple stakeholders (i.e. MNCs, HCNs, family members) in supporting the expatriates whilst on assignments. Finally, the findings reveal that the expatriate families do influence how the locals view the families and would be a great asset in initiating future communication between the expatriates and HCNs. The research contributes to the fields of intercultural adjustment and communication and also has key messages for policy makers.

Adrenoceptors and intestinal fluid and electrolyte transport in the rat

Noradrenaline was found to significantly stimulate fluid and Na absorption across everted sacs of rat jejunum. Of a number of a1, and 2-adrenoceptor antagonists tested only prazosin significantly inhibited the stimulant effect of noradrenaline and further experiments revealed an antiabsorptive effect of prazosin alone. Theophylline reduced jejunal fluid and Na absorption and this effect was not reversed by 2-adrenoceptor stimulation in contrast to previous findings in vivo. Evidence suggests the everted sac preparation is not appropriate to the study of intestinal fluid and electrolyte transport. The investigation of Jejunal ion transport in vitro was continued using an Ussing chamber preparation. Selective 2-adrenoceptor stimulation was found to depress electrogenic anion secretion, as neurotoxin tetrodotoxin indicated that this was a direct epithelial effect. 2-adrenoceptor agonists have considerable therapeutic value as antisecretory agents and the model of rat jejunum in vitro represents a convenient experimental model for research in this area. The selective 2-adrenoceptor antagonist ICI 118551 decreased basal SCC and inhibited increases in SCC in response to isoprenaline or salbutamol indicating the presence of a 2-adrenoceptor mechanism mediating both secretory tone and increases in secretory processes. Many intestinal secretagogues elicit electrolyte secretion via the stimulation of intramural secretory nervous pathways. If these pathways involve the activation of 2-adrenoceptorsthe 2-adrenoceptor antagonists may be useful in the treatment of diarrhoeal diseases. A single pass lumen perfusion technique was used to investigate possible sympathetic tone over colonic fluid and electrolyte absorption in the rat colon in vivo. The technique employed appeared to lack the necessary resolution for this study and alternative approaches are discussed

Adrenoceptor influences on fluid and electrolyte transport in the rat intestine

An investigation of rat jejunal and distal colonic electrolyte transport in-vitro was undertaken using an Ussing chamber prepartion. Selective α2-adrenoceptor stimualtion in the jejunum was found to depress theo-phylline elevated anion secretion, as evidenced by decreases in short- circuit current (SCC). or α1 -Adrenoceptor stimulation, after α2 -adrenoceptor antagonism in the jejunum, evoked transient increases in basal anion secretion, as reflected by transient increases in basal SCC. The use of the neurotoxin tetrodotoxin indicated that this was a direct epithelial secretory effect. 5-hydroxytryptamine (5-HT) on the jejunum elicited transient increases in basal anion secretion, as demonstrated by transient increases in basal SCC. The use of tetrodotoxin, reserpine and α1 -adrenoceptor antagonists, indicated that a major component of this epithelial secretory effect by 5-HT, was associated with activation of intramural nervous pathways of the sympathetic nervous system, ultimately stimulating α1-adrenoceptors. This might represent an important secretory mechanism by 5-HT in the jejunum. β2-Adrenoceptor stimulation in the distal colon was found to decrease basal SCC, as evidenced by the metoprolol resistant effect of the selective β2- adrenoceptor agonist salbutamol, and lack of effect of the selective β1-adrenoceptor agonist prenalterol. An investigation of rat distal colonic fluid and electrolyte transport in-vivo was undertaken using an colonic loop technique. Although a basal colonic absorption of Na+ and Cl-, and a secretion of K+ were observed, these processes were not under tonic α-adrenergic regulation, as evidenced by the lack of effect of selective α-adrenoceptor antagonism. The secretory effects of prostaglandin-E2 were inhibited by α-adrenoceptor activation, whereas such stimulation did not evoke pro-absorptive responses upon basal transport, unlike noradrenaline.

Words and intelligence I:selected papers by Yorick Wilks

Yorick Wilks is a central figure in the fields of Natural Language Processing and Artificial Intelligence. His influence extends to many areas and includes contributions to Machines Translation, word sense disambiguation, dialogue modeling and Information Extraction. This book celebrates the work of Yorick Wilks in the form of a selection of his papers which are intended to reflect the range and depth of his work. The volume accompanies a Festschrift which celebrates his contribution to the fields of Computational Linguistics and Artificial Intelligence. The papers include early work carried out at Cambridge University, descriptions of groundbreaking work on Machine Translation and Preference Semantics as well as more recent works on belief modeling and computational semantics. The selected papers reflect Yorick’s contribution to both practical and theoretical aspects of automatic language processing.

Words and intelligence II:essays in honor of Yorick Wilks

Yorick Wilks is a central figure in the fields of Natural Language Processing and Artificial Intelligence. His influence has extends to many areas of these fields and includes contributions to Machine Translation, word sense disambiguation, dialogue modeling and Information Extraction.This book celebrates the work of Yorick Wilks from the perspective of his peers. It consists of original chapters each of which analyses an aspect of his work and links it to current thinking in that area. His work has spanned over four decades but is shown to be pertinent to recent developments in language processing such as the Semantic Web.This volume forms a two-part set together with Words and Intelligence I, Selected Works by Yorick Wilks, by the same editors.

Sustained release of the CCR5 inhibitors CMPD167 and maraviroc from vaginal rings in rhesus macaques

Antiretroviral entry inhibitors are now being considered as vaginally administered microbicide candidates for the prevention of the sexual transmission of human immunodeficiency virus. Previous studies testing the entry inhibitors maraviroc and CMPD167 in aqueous gel formulations showed efficacy in the macaque challenge model, although protection was highly dependent on the time period between initial gel application and subsequent challenge. In this paper, we describe the sustained release of maraviroc and CMPD167 from matrix-type silicone elastomer vaginal rings both in vitro and in vivo. Both inhibitors were released continuously during 28 days from rings in vitro at rates of 100 to 2,500 µg/day. In 28-day pharmacokinetic studies in rhesus macaques, the compounds were measured in the vaginal fluid and vaginal tissue; steady-state fluid concentrations were ~10(6)-fold greater than the 50% inhibitory concentrations (IC(50)s) for simian human immunodeficiency virus 162P3 inhibition in macaque lymphocytes in vitro. Plasma concentrations for both compounds were very low. The pretreatment of macaques with Depo-Provera (DP), which is commonly used in macaque challenge studies, was shown to significantly modify the biodistribution of the inhibitors but not the overall amount released. Vaginal fluid and tissue concentrations were significantly decreased while plasma levels increased with DP pretreatment. These observations have implications for designing macaque challenge experiments and also for ring performance during the human female menstrual cycle.

Modelling and measurements on a condensing counter-flow heat exchanger

Experimental investigations and computer modelling studies have been made on the refrigerant-water counterflow condenser section of a small air to water heat pump. The main object of the investigation was a comparative study between the computer modelling predictions and the experimental observations for a range of operating conditions but other characteristics of a counterflow heat exchanger are also discussed. The counterflow condenser consisted of 15 metres of a thermally coupled pair of copper pipes, one containing the R12 working fluid and the other water flowing in the opposite direction. This condenser was mounted horizontally and folded into 0.5 metre straight sections. Thermocouples were inserted in both pipes at one metre intervals and transducers for pressure and flow measurement were also included. Data acquisition, storage and analysis was carried out by a micro-computer suitably interfaced with the transducers and thermocouples. Many sets of readings were taken under a variety of conditions, with air temperature ranging from 18 to 26 degrees Celsius, water inlet from 13.5 to 21.7 degrees, R12 inlet temperature from 61.2 to 81.7 degrees and water mass flow rate from 6.7 to 32.9 grammes per second. A Fortran computer model of the condenser (originally prepared by Carrington[1]) has been modified to match the information available from experimental work. This program uses iterative segmental integration over the desuperheating, mixed phase and subcooled regions for the R12 working fluid, the water always being in the liquid phase. Methods of estimating the inlet and exit fluid conditions from the available experimental data have been developed for application to the model. Temperature profiles and other parameters have been predicted and compared with experimental values for the condenser for a range of evaporator conditions and have shown that the model gives a satisfactory prediction of the physical behaviour of a simple counterflow heat exchanger in both single phase and two phase regions.

Automobile friction materials: a test instrument and technique for determining dynamic mechanical properties in relation to brake squeal

This study is primarily concerned with the problem of break-squeal in disc brakes, using moulded organic disc pads. Moulded organic friction materials are complex composites and due to this complexity it was thought that they are unlikely to be of uniform composition. Variation in composition would under certain conditions of the braking system, cause slight changes in its vibrational characteristics thus causing resonance in the high audio-frequency range. Dynamic mechanical propertes appear the most likely parameters to be related to a given composition's tendency to promote squeal. Since it was necessary to test under service conditions a review was made of all the available commercial test instruments but as none were suitable it was necessary to design and develop a new instrument. The final instrument design, based on longitudinal resonance, enabled modulus and damping to be determined over a wide range of temperatures and frequencies. This apparatus has commercial value since it is not restricted to friction material testing. Both used and unused pads were tested and although the cause of brake squeal was not definitely established, the results enabled formulation of a tentative theory of the possible conditions for brake squeal. The presence of a temperature of minimum damping was indicated which may be of use to braking design engineers. Some auxilIary testing was also performed to establish the effect of water, oil and brake fluid and also to determine the effect of the various components of friction materials.

Verification and validation of numerical models of the transport of insulation debris

Damage to insulation materials located near to a primary circuit coolant leak may compromise the operation of the emergency core cooling system (ECCS). Insulation material in the form of mineral wool fiber agglomerates (MWFA) maybe transported to the containment sump strainers, where they may block or penetrate the strainers. Though the impact of MWFA on the pressure drop across the strainers is minimal, corrosion products formed over time may also accumulate in the fiber cakes on the strainers, which can lead to a significant increase in the strainer pressure drop and result in cavitation in the ECCS. An experimental and theoretical study performed by the Helmholtz-Zentrum Dresden-Rossendorf and the Hochschule Zittau/Görlitz is investigating the phenomena that maybe observed in the containment vessel during a primary circuit coolant leak. The study entails the generation of fiber agglomerates, the determination of their transport properties in single and multi-effect experiments and the long-term effect that corrosion and erosion of the containment internals by the coolant has on the strainer pressure drop. The focus of this paper is on the verification and validation of numerical models that can predict the transport of MWFA. A number of pseudo-continuous dispersed phases of spherical wetted agglomerates represent the MWFA. The size, density, the relative viscosity of the fluid-fiber agglomerate mixture and the turbulent dispersion all affect how the fiber agglomerates are transported. In the cases described here, the size is kept constant while the density is modified. This definition affects both the terminal velocity and volume fraction of the dispersed phases. Note that the relative viscosity is only significant at high concentrations. Three single effect experiments were used to provide validation data on the transport of the fiber agglomerates under conditions of sedimentation in quiescent fluid, sedimentation in a horizontal flow and suspension in a horizontal flow. The experiments were performed in a rectangular column for the quiescent fluid and a racetrack type channel that provided a near uniform horizontal flow. The numerical models of sedimentation in the column and the racetrack channel found that the sedimentation characteristics are consistent with the experiments. For channel suspension, the heavier fibers tend to accumulate at the channel base even at high velocities, while lighter phases are more likely to be transported around the channel.

OCT retinal thickness ratios and frequency of follow-up in Wet AMD

Poster Introduction: In neovascular age-related macular degeneration (nAMD), optical coherence tomography (OCT) is an important tool to determine when intravitreal injections of ranibizumab should be administered. Current guidelines recommend that patients should be reviewed four weekly and OCT indications for further treatment include subretinal fluid and intraretinal fluid or cysts. Purpose: We have reviewed the OCT scans of subjects who have successfully responded to ranibizumab to look for factors that might predict which patients will not require injection and could have extended appointments. Method: This was a prospective study in which we observed for 6 consecutive months the OCT images of 28 subjects who had received intravitreal ranibizumab for nAMD and were judged to be clinically inactive at recruitment to the study. Ratios between full retinal thickness (FRT = neurosensory retina + outer reflective band) and outer reflective band (ORB) thickness at the fovea were calculated for each subject at the moment of entering the study and at each successive visit for 6 consecutive months. Results: Patients with lower FRT/ORB ratios were found to be less likely to require an additional injection of ranibizumab and no subject with a ratio of 1.75 or less needed further injections. Conclusion: This small pilot study suggests that on macular OCT, the FRT/ORB ratio, and in particular values of 1.75 or less, may prove to be a useful, practical tool when deciding the follow up period for subjects undergoing treatment with intravitreal ranibizumab for nAMD.

Semantic linking through spaces for cyber-physical-socio intelligence:a methodology

Humans consciously and subconsciously establish various links, emerge semantic images and reason in mind, learn linking effect and rules, select linked individuals to interact, and form closed loops through links while co-experiencing in multiple spaces in lifetime. Machines are limited in these abilities although various graph-based models have been used to link resources in the cyber space. The following are fundamental limitations of machine intelligence: (1) machines know few links and rules in the physical space, physiological space, psychological space, socio space and mental space, so it is not realistic to expect machines to discover laws and solve problems in these spaces; and, (2) machines can only process pre-designed algorithms and data structures in the cyber space. They are limited in ability to go beyond the cyber space, to learn linking rules, to know the effect of linking, and to explain computing results according to physical, physiological, psychological and socio laws. Linking various spaces will create a complex space — the Cyber-Physical-Physiological-Psychological-Socio-Mental Environment CP3SME. Diverse spaces will emerge, evolve, compete and cooperate with each other to extend machine intelligence and human intelligence. From multi-disciplinary perspective, this paper reviews previous ideas on various links, introduces the concept of cyber-physical society, proposes the ideal of the CP3SME including its definition, characteristics, and multi-disciplinary revolution, and explores the methodology of linking through spaces for cyber-physical-socio intelligence. The methodology includes new models, principles, mechanisms, scientific issues, and philosophical explanation. The CP3SME aims at an ideal environment for humans to live and work. Exploration will go beyond previous ideals on intelligence and computing.

Pharmacokinetics of a CCR5 inhibitor in rhesus macaques following vaginal, rectal and oral application

Objectives: This study measured and compared the pharmacokinetics of CMPD167, a small molecule antiretroviral CCR5 inhibitor with potential as an HIV microbicide, following vaginal, rectal and oral administration in rhesus macaques. Methods: Avaginal hydroxyethylcellulose (HEC) gel, a rectal HEC gel, a silicone elastomer matrix-type vaginal ring and an oral solution, each containing CMPD167, were prepared and administered to rhesus macaques pretreated with Depo-Provera. CMPD167 concentrations in vaginal fluid, vaginal tissue (ring only), rectal fluid and blood plasma were quantified by HPLC-mass spectrometry. Results: CMPD167 concentrations measured in rectal fluid, vaginal fluid and blood plasma were highly dependent on both the route of administration and the formulation type. Although rectal and vaginal fluid concentrations were highest when CMPD167 was administered locally (via either gel or ring), lower concentrations of the drug were also measured in these compartments following administration at the remote mucosal site or orally. CMPD167 levels in the vaginal and rectal fluid following oral administration were relatively low compared with local administration. Conclusions: The study provides clear evidence for vaginal-rectal and rectal-vaginal drug transfer pathways and suggests that oral pre-exposure prophylaxis with CMPD167 may be less efficacious at preventing sexual transmission of HIV-1 than topically applied products. ©The Author 2013.

Design and development of logistics workflow systems for demand management with RFID

This paper discusses demand and supply chain management and examines how artificial intelligence techniques and RFID technology can enhance the responsiveness of the logistics workflow. This proposed system is expected to have a significant impact on the performance of logistics networks by virtue of its capabilities to adapt unexpected supply and demand changes in the volatile marketplace with the unique feature of responsiveness with the advanced technology, Radio Frequency Identification (RFID). Recent studies have found that RFID and artificial intelligence techniques drive the development of total solution in logistics industry. Apart from tracking the movement of the goods, RFID is able to play an important role to reflect the inventory level of various distribution areas. In today’s globalized industrial environment, the physical logistics operations and the associated flow of information are the essential elements for companies to realize an efficient logistics workflow scenario. Basically, a flexible logistics workflow, which is characterized by its fast responsiveness in dealing with customer requirements through the integration of various value chain activities, is fundamental to leverage business performance of enterprises. The significance of this research is the demonstration of the synergy of using a combination of advanced technologies to form an integrated system that helps achieve lean and agile logistics workflow.