Receiving Operating Characteristic

This article reports on the development of a revised version of the Obsessive-Compulsive Inventory (OCI; E. B. Foa, M. J. Kozak, P. Salkovskis, M. E. Coles, & N. Amir, 1998), a psychometrically sound, theoretically driven, self-report measure. The revised OCI (OCI-R) improves on the parent version in 3 ways: It eliminates the redundant frequency scale, simplifies the scoring of the subscales, and reduces overlap across subscales. The reliability and validity of the OCI-R were examined in 215 patients with obsessive-compulsive disorder (OCD), 243 patients with other anxiety disorders, and 677 nonanxious individuals. The OCI-R, which contains 18 items and 6 subscales, has retained excellent psychometric properties. The OCI-R and its subscales differentiated well between individuals with and without OCD. Receiver operating characteristic (ROC) analyses demonstrated the usefulness of the OCI-R as a diagnostic tool for screening patients with OCD, utilizing empirically derived cutscores.

Background: The aim of this study was to compare the validity of the Hospital Anxiety and Depression Scale (HADS), the WHO (five) Well Being Index (WBI-5), the Patient Health Questionnaire (PHQ), and physicians' recognition of depressive disorders, and to recommend specific cut-off points for clinical decision making. Methods: A total of 501 outpatients completed each of the three depression screening questionnaires and received the Structured Clinical Interview for DSM-IV (SCID) as the criterion standard. In addition, treating physicians were asked to give their psychiatric diagnoses. Criterion validity and Receiver Operating Characteristics (ROC) were determined. Areas under the curves (AUCs) were compared statistically. Results: All depression scales showed excellent internal consistencies (Cronbach's a: 0.85 -0.90). For 'major depressive disorder', the operating characteristics of the PHQ were significantly superior to both the HADS and the WBI-5. For 'any depressive disorder', the PHQ showed again the best operating characteristics but the overall difference did not reach statistical significance at the 5% level. Cut-off points that can be recommended for the screening of 'major depressive disorder' had sensitivities of 98% (PHQ), 94% (WBI-5), and 85% (HADS). Corresponding specificities were 80% (PHQ), 78% (WBI-5), and 76% (HADS). In contrast, physicians' recognition of 'major depressive disorder' was poor (sensitivity, 40%; specificity, 87%). Limitations: Our sample may not be representative of medical outpatients, but sensitivity and specificity are independent of disorder prevalence. Conclusions: All three questionnaires performed well in depression screening, but significant differences in criterion validity existed. These results may be helpful in the selection of questionnaires and cut-off points. D

This paper introduces an air cargo supply chain operations reference (ACSCOR) model to examine the integrated impact of airport operating strategies and industrial forces on airport performances, and quantifies the economic benefits of the air cargo service business. In the light of Singapore and Hong Kong statistics, it is shown that the cargo traffic at an airport is significantly influenced by its operating characteristics, the performances of its downstream airfreight and supporting logistics industry, and the economic environment that it is functioning within. Through the traditional economic models, it is found that on average Hong Kong experiences a higher accelerator effect but lower multiplier effect in airport investment compared to Singapore. While the multiplier effect may signify that Singapore can benefit from higher returns in terms of the spillover effect to the overall air cargo supply chain, the higher accelerator effect in Hong Kong corresponds to the empirical results from the ACSCOR model that advocate Chek Lap Kok airport increasing its physical inputs relative to human inputs.

Receiver operating characteristic (ROC) analysis is being used increasingly to examine the memory processes underlying recognition memory. The authors discuss the methodological issues involved in conducting and analyzing ROC results, describe the various models that have been developed to account for these results, review the behavioral empirical literature, and assess the models in light of those results. The empirical literature includes studies of item recognition, relational recognition (e.g., source and associative tests), as well as exclusion and remember-know tasks. Nine empirical regularities are described, and a number of unresolved empirical issues are identified. The results indicate that several common classes of recognition models, such as pure threshold and pure signal detection models, are inadequate to account for recognition memory, whereas several hybrid models that incorporate a signal detection-based process and a threshold recollection or attention process are in better agreement with the results. The results indicate that there are at least 2 functionally distinct component/processes underlying recognition memory. In addition, the ROC results have various implications for how recognition memory performance should be measured.

Stand-alone power system PEM Electrolyzer PEM fuel cell Lead-acid accumulator Hydrogen production Power management strategy a b s t r a c t A stand-alone power system based on a photovoltaic array and wind generators that stores the excessive energy from renewable energy sources (RES) in the form of hydrogen via water electrolysis for future use in a polymer electrolyte membrane (PEM) fuel cell is currently in operation at Neo Olvio of Xanthi, Greece. Efficient power management strategies (PMSs) for the system have been developed. The PMSs have been assessed on their capacity to meet the power load requirements through effective utilization of the electrolyzer and fuel cell under variable energy generation from RES (solar and wind). The evaluation of the PMS has been performed through simulated experiments with anticipated conditions over a typical four-month time period for the region of installation. The key decision factors for the PMSs are the level of the power provided by the RES and the state of charge (SOC) of the accumulator. Therefore, the operating policies for the hydrogen production via water electrolysis and the hydrogen consumption at the fuel cell depend on the excess or shortage of power from the RES and the level of SOC. A parametric sensitivity analysis investigates the influence of major operating variables for the PMSs such as the minimum SOC level and the operating characteristics of the electrolyzer and the fuel cell in the performance of the integrated system. ª A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e

Power system protection relays have changed significantly during the last ten years. Processor based designs are now highly reliable integrated protection, control and monitoring systems that significantly outperform the suite of relays and control equipment from the electromechanical and static era. Technological advances and utility restructuring ensures protection remains an immensely challenging field, especially for young IT literate electrical power engineers.

Background and Purpose—The purpose of this study was to examine the performance of the Patient Health Questionnaire (PHQ)-9, a 9-item depression scale, as a screening and diagnostic instrument for assessing depression in stroke survivors. Methods—As part of a randomized treatment trial for poststroke depression (PSD), subjects with and without PSD completed the PHQ-9, a 9-item summed scale, with scores ranging

Several state-of-the-art binary classification techniques are experimentally evaluated in the context of expert automobile insurance claim fraud detection. The predictive power of logistic regression, C4.5 decision tree, k-nearest neighbor, Bayesian learning multilayer perceptron neural network, least-squares support vector machine, naive Bayes, and tree-augmented naive Bayes classification is contrasted. For most of these algorithm types, we report on several operationalizations using alternative hyperparameter or design choices. We compare these in terms of mean percentage correctly classified (PCC) and mean area under the receiver operating characteristic (AUROC) curve using a stratified, blocked, ten-fold cross-validation experiment. We also contrast algorithm type performance visually by means of the convex hull of the receiver operating characteristic (ROC) curves associated with the alternative operationalizations per algorithm type. The study is based on a data set of 1,399 personal injury protection claims from 1993 accidents collected by the Automobile Insurers Bureau of Massachusetts. To stay as close to real-life operating conditions as possible, we consider only predictors that are known relatively early in the life of a claim. Furthermore, based on the qualification of each available claim by both a verbal expert assessment of suspicion of fraud and a ten-point-scale expert suspicion score, we can

Background: The double-blind, placebo-controlled food challenge (DBPCFC) is the “gold standard” for diagnosis of food hypersensitivity. Skin prick tests and RASTs are sensitive indicators of food-specific IgE antibodies but poor predictors of clinical reactivity. Previous studies suggested that high concentrations of food-specific IgE antibody were predictive of food-induced clinical symptoms. Because the CAP System FEIA (Pharmacia Diagnostics, Uppsala, Sweden) provides a quantitative assessment of allergen-specific IgE antibody, this study was undertaken to determine the potential utility of the CAP System FEIA in diagnosis of IgE-mediated food hypersensitivity. Methods: Sera from 196 patients with food allergy were analyzed for specific IgE antibodies to egg, milk, peanut, soy, wheat, and fish by CAP System FEIA. Sera were randomly selected from 300 stored samples of children and adolescents who had been evaluated by history, skin prick tests, and DBPCFCs. The study population was highly atopic; all patients had atopic dermatitis, and approximately 50% had asthma and allergic rhinitis at the time of initial evaluation. The performance characteristics of the CAP System FEIA were compared with those of skin prick tests and the outcome of DBPCFCs or “convincing” histories of anaphylactic reactions. Results: The prevalence of specific food allergies in the study population varied from 22% for wheat to 73% for egg. Allergy to egg, milk, peanut, and soy accounted for 87% of confirmed reactions. The performance characteristics of skin prick tests and CAP System FEIA (egg, milk, peanut, fish) were comparable, with excellent sensitivity and negative predictive accuracy but poor specificity and positive predictive accuracy. The performance characteristics of the CAP System FEIA for soy and wheat were poor. For egg, milk, peanut, and fish allergy, diagnostic levels of IgE, which could predict clinical reactivity in this population with greater than 95% certainty, were identified: egg, 6 kilounits of allergen-specific IgE per liter (kUA/L); milk, 32 kUA/L; peanut, 15 kUA/L; and fish, 20 kUA/L. Conclusions: When compared with the outcome of DBPCFCs, results of CAP System FEIA are generally comparable to those of skin prick tests in predicting symptomatic food hypersensitivity. Furthermore, by measuring the concentrations of food-specific IgE antibodies with the CAP System FEIA, it is possible to identify a subset of patients who are highly likely (>95%) to experience clinical reactions to egg, milk, peanut, or fish. This could eliminate the need to perform DBPCFCs in a significant number of patients suspected of having IgE-mediated food allergy. (J Allergy Clin Immunol 1997;100:444-51.)

The unique properties of gold nanoparticles to provide a suitable microenvironment for biomolecules immobilization retaining their biological activity, and to facilitate electron transfer between the immobilized proteins and electrode surfaces, have led to an intensive use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance with respect to other biosensor designs. Recent advances in this field are reviewed in this article. The advantageous operational characteristics of the biosensing devices designed making use of gold nanoparticles are highlighted with respect to non-nanostructured biosensors and some illustrative examples are commented. Electrochemical enzyme biosensors including those using hybrid materials with carbon nanotubes and polymers, sol-gel matrices, and layer-by-layer architectures are considered. Moreover, electrochemical immunosensors in which gold nanoparticles play a crucial role in the electrode transduction enhancement of the affinity reaction as well as in the efficiency of immunoreagents immobilization in a stable mode are reviewed. Similarly, recent advances in the development of DNA biosensors using gold nanoparticles to improve DNA immobilization on electrode surfaces and as suitable labels to improve detection of hybridization events are considered. Finally, other biosensors designed with gold nanoparticles oriented to electrically contact redox enzymes to electrodes by a reconstitution process and to the study of direct electron transfer between redox proteins and electrode surfaces have also been treated.

Product design and service delivery both affect service performance, and therefore a product support strategy must be defined during design stage, in terms of these two dimensions, to ensure the delivery of "promised product performance" to customers. Furthermore, product support strategy should not only be focused around product, or its operating characteristics, but also on assisting customers with services that enhance product use and add additional value to their business processes. This paper examines various issues such as reliability, availability, maintainability, and supportability (RAMS), etc., which directly or indirectly affect product support, maintenance needs and related costs on the basis of a case study conducted in a manufacturing company. The main purpose of the study was to analyse the critical issues related to the product support and service delivery strategy as being practised by the company, and to suggest means for improvements. On the basis of the case study, the paper presents an approach for design and development of product support and maintenance concepts for industrial systems in a multinational environment. The paper emphasizes that the strategy for product support should not be centred only on "product", but should also take into account important issues such as the service delivery capability of the manufacturers, service suppliers, the capability of users' maintenance organization, etc.

The study of power system of relays requires some previous experience in this field. Laboratories focusing on teaching and researching the area of power-system protection have therefore been amply reported. However, these facilities require the actual presence of the students in the laboratories. To overcome this problem, a power-system-relaying remote laboratory has been developed. To implement this laboratory, a testing system of the relay operating characteristic, together with Matlab-based software, was developed. This remote laboratory enables real powersystem-relaying experiments through the Internet. In fact, the user can remotely test a real relay disoperation. This system will therefore allow proficient analysis of sensitivities to relay settings and network configurations.

In this article a statistical multivariate method, i.e., rare events logistic regression, is evaluated for the creation of a landslide susceptibility map in a 200 km 2 study area of the Flemish Ardennes (Belgium). The methodology is based on the hypothesis that future landslides will have the same causal factors as the landslides initiated in the past. The information on the past landslides comes from a landslide inventory map obtained by detailed field surveys and by the analysis of LIDAR (Light Detection and Ranging)-derived hillshade maps. Information on the causal factors (e.g., slope gradient, aspect, lithology, and soil drainage) was extracted from digital elevation models derived from LIDAR and from topographical, lithological and soil maps. In landslideaffected areas, however, we did not use the present-day hillslope gradient. In order to reflect the hillslope condition prior to landsliding, the pre-landslide hillslope was reconstructed and its gradient was used in the analysis. Because of their limited spatial occurrence, the landslides in the study area can be regarded as "rare events". Rare events logistic regression differs from ordinary logistic regression because it takes into account the low proportion of 1s (landslides) to 0s (no landslides) in the study area by incorporating three correction measures: the endogenous stratified sampling of the dataset, the prior correction of the intercept and the correction of the probabilities to include the estimation uncertainty. For the study area, significant model results were obtained, with pre-landslide hillslope gradient and three different clayey lithologies being important predictor variables. Receiver Operating Characteristic (ROC) curves and the Kappa index were used to validate the model. Both show a good agreement between the observed and predicted values of the validation dataset. Based on a qualified judgement, the created landslide susceptibility map was classified into four classes, i.e., very high, high, moderate and low susceptibility. If interpreted correctly, this classified susceptibility map is an important tool for the delineation of zones where prevention measures are needed and human interference should be limited in order to avoid property damage due to landslides.

This paper describes a systematic procedure for recognizing corrugated asbestos-cement roofing sheets and evaluating their deterioration status related to the asbestos fiber air dispersion that can cause lung cancer. To develop this procedure, we made field and laboratory measurements and gathered airborne MIVIS data covering two industrial test areas in Italy.

AbstractÐThe present study is to investigate the treatment of surfactant wastewater by the Fenton process. The surfactants considered here were anionic alkylbenzene sulfonate (ABS) and linear alkylbenzene sulfonate (LAS), both being widely used in the household and industrial detergents. Experiments were conducted to examine the eects of pH, amounts of ferrous sulfate (FeSO 4 ) and hydrogen peroxide (H 2 O 2 ) and temperature on the surfactant removal. Chemical coagulation was also considered as an addition in improving the turbidity and dissolved Fe removal after the Fenton process. A ®rst-order kinetic model was adopted to represent the Fenton oxidation of surfactant wastewater. The relation between the reaction rate coecient and the ferrous sulfate and hydrogen peroxide concentrations and operating temperature was experimentally established using the test data. #

Agile Enterprise and Agile Software Development are concepts with some considerable exposure in the language. Agility in the enterprise context usually refers to a system operational characteristic, while agility in the software context usually refers to a system development characteristic. Both are concerned with systems that must deliver satisfaction in an environment characterized by uncertainty and change. Our interests are not with either specifically, but rather with the general concept of a system life cycle, for any type of system, that must deal throughout with uncertainty and change. The work described in this paper began with the observation that Agile Development processes generally ignore the agility of the resultant system; yet they exhibit a solid foundation in certain generic architectural concepts that have been shown applicable across all types of systems that would be or are agile. The investigation established certain commonalities across a predominate variety of Agile Development processes, then cast these common concepts in the domain independent Response Ability architecture that grew from work at the Agility Forum, and finally modeled how this architectural characterization of development could be seamlessly extended throughout the remainder of the system life-cycle, consistent with observed characterizations of operational agility. The result promises a graceful transition from development into and through operational phases, with a single stable process architecture throughout.

This study presents test results of a Stirling engine with a lever controlled displacer driving mechanism. Tests were conducted with helium and the working fluid was charged into the engine block. The engine was loaded by means of a prony type micro dynamometer. The heat was supplied by a liquefied petroleum gas (LPG) burner. The engine started to run at 118 C hot end temperature and the systematic tests of the engine were conducted at 180 C, 220 C and 260 C hot end external surface temperatures. During the test, cold end temperature was kept at 27 C by means of water circulation. Variation of the shaft torque and power with respect to the charge pressure and hot end temperature were examined. The maximum torque and power were measured as 3.99 Nm and 183 W at 4 bars charge pressure and 260 C hot end temperature. Maximum power corresponded to 600 rpm speed.

This paper reflects on port development in Uruguay in an environment of trilateral interport competition. The regional characteristics of port development in terms of their geographical, functional and operational characteristics are discussed by analysing the port system’s evolution. The case of Montevideo as the success or failure of a regional hub port development strategy is analysed in detail. Particular attention

1993; Shrum, McCarty, and Lowrey, 1995). As these perceptions have increased, the green movement has received a great price reactions, to corporate announcements of green marketing activities. Two procedures for measuring stock price reactions and two different degree of attention by the public in such areas as the media, the political arena, special interest groups, and consumers tests of significance are used in the study. The results for the sample of 73 firms show that the market value for the average firm in the sample (Vandermerwe and Oliff, 1990; Zimmer, Stafford, and Stafford, 1994). declines by 3.14% during the period from 10 days prior to 10 days after the news is announced. Announcements related to green products, recycling The movement has also begun to receive more attention by managers who are increasingly moving from defensive and efforts, and appointments of environmental policy managers result in insignificant stock price reactions. However, announcements for green reactive responses to the concern toward pro-active actions (Vandermerwe and Oliff, 1990). Pro-active actions related to promotional efforts produce significantly negative stock price reactions. Sampling by financial and operational characteristics shows that firms environmental issues is a subset of the well-documented area of environmental management (see Clark, Varadarajan, and with higher growth in earnings, larger firms, and firms with higher advertising-to-sales ratios experience relatively less negative stock price reac-Pride, 1994), which has been successfully applied to marketing (e.g., the seminal article by Zeithaml and Zeithaml, 1984). tions. Managerial implications of the results and directions for future research are also presented.

Objectives. To enhance the specificity of prostate cancer (PCa) detection and reduce unnecessary biopsies in men with prostate-specific antigen (PSA) levels of 2.5 to 4.0 ng/mL, we prospectively evaluated various PSA-based diagnostic parameters. Methods. This study included 273 consecutive men with serum PSA of 2.5 to 4.0 ng/mL referred for early PCa detection or lower urinary tract symptoms. All men underwent prostate ultrasound and sextant biopsy with two additional transition zone (TZ) biopsies. If the first biopsies were negative, repeated biopsies were performed at 6 weeks. Total PSA, PSA density (PSAD), PSA density of the transition zone (PSA-TZ), free/total PSA ratio (f/t PSA), and PSA velocity (PSAV) were determined, and the sensitivity, specificity, and predictive values of these various parameters were calculated. Results. Of 273 patients, 207 had histologically confirmed benign prostatic hyperplasia (BPH) and 66 had PCa. f/t PSA and PSA-TZ were the most powerful predictors of PCa, followed by PSA, PSAD, and PSAV. Areas under the receiver operating characteristic curves for f/t PSA and PSA-TZ were 74.9% and 70.1%, respectively. With a 95% sensitivity for PCa detection, an f/t PSA cutoff of 41% and a PSA-TZ cutoff of 0.095 would result in the lowest number of unnecessary biopsies (29.3% and 17.2% specificity for f/t PSA and PSA-TZ, respectively) compared with all other PSA-related parameters evaluated. Conclusions. Compared with standard total PSA assays, f/t PSA and PSA-TZ significantly enhance the sensitivity and specificity of PCa detection in a referral patient population with a total PSA of 2.5 to 4.0 ng/mL. UROLOGY 54: 517-522, 1999.

Abbreviations used in this paper: ASCA, anti-Saccharomyces cerevisiae antibody; BI, binding index; EU, ELISA unit; HRP, horseradish peroxidase; pANCA, perinuclear antineutrophil cytoplasmic antibody; ROC curve, receiver operating characteristic curve.

In this paper we develop an approximate model of an inventory control system in which there exist two options for resupply, with one having a shorter lead time. Because the optimal policy appears to be extremely complex, we consider a reasonable extension of the standard (Q, R) policy to allow for two different lot sizes QI and Q2, and two different reorder levels, R I and R2. Expressions for the expected on hand inventory and the expected backorders are developed and a procedure for determining the policy parameters is given. The model is validated by simulation, and calculations are included which compare the average annual cost with and without emergency ordering. (INVENTORY PRODUCTION; OPERATING CHARACTERISTICS; LEADTIME POL-ICY; ORDERING POLICY; STOCHASTIC MODELS)

This study examines the effect of the state of the international reinsurance market on the demand for reinsurance by U.S. insurers using data from the years 1993 through 2000. Both the overall demand for reinsurance and the utilization of foreign reinsurance by U.S. insurers are explored. In addition to supporting the findings of prior literature related to the traditional motives for the corporate demand for insurance, evidence indicates that the state of the U.S. reinsurance industry impacts the amount of reinsurance demanded by U.S. insurers. The study also investigates reasons why U.S. insurers utilize a reinsurance program composed of both U.S. and foreign reinsurers. The results indicate that the decision to utilize some percentage of foreign reinsurance is driven primarily by the financial and operational characteristics of the ceding company such as firm size, group affiliation, and organizational form. However, no support is found for the hypothesis that possible differences between the foreign and U.S. reinsurance markets impact the decision to utilize foreign reinsurance. and [email protected]. We would like to gratefully acknowledge the helpful comments of the editors, an anonymous referee,

Objectives. To assess the utility of prostate-specific antigen (PSA) as a predictor of prostate volume by characterizing the relationship between prostate volume and serum PSA in men with symptomatic benign prostatic hyperplasia (BPH) and no evidence of prostate cancer, stratified by decade of life. Methods. Placebo-controlled multicenter trials in patients with BPH and a safety study in normal young men provided baseline measurements of serum PSA and prostate volume. The analyses included patients with a baseline prostate volume measured by either transrectal ultrasound (TRUS) or magnetic resonance imaging and baseline serum PSA. A common central laboratory was used for all but one of the individual studies; both laboratories used the Hybritech method. Patients 80 years of age or older were excluded. Patients with a baseline serum PSA greater than 10 ng/mL were excluded to reduce the likelihood of including occult prostate cancer cases. The patients in the BPH trials were screened at baseline by digital rectal examination (DRE) and serum PSA. Those with suspicious findings underwent TRUS-guided biopsy; only patients with negative biopsies are included in these analyses. Results. The analyses included 4627 patients, 4448 from the BPH trials and 179 from the safety study. The men in the BPH trials were older (mean age Ϯ SE, 63.7 Ϯ 0.10 years) than the men in the safety study (mean age Ϯ SE, 30.8 Ϯ 0.43), had larger prostates (mean volume Ϯ SE, 43.7 Ϯ 0.38 mL versus 26.3 Ϯ 0.49 mL in the safety study), and had higher serum PSA values (mean Ϯ SE, 2.6 Ϯ 0.03 ng/mL versus 0.7 Ϯ 0.39 ng/mL in the safety study). The relationship between prostate volume and serum PSA was evaluated using only the BPH trial data. Prostate volume and serum PSA have an age-dependent log-linear relationship (ie, their logarithms are linearly related, and the parameters of the relationship depend on age). Older men tend to have a steeper rate of increase in prostate volume with increasing serum PSA (P Ͻ 0.001 for differences between slopes), and there was a slight tendency for PSA density to increase with age. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of serum PSA to predict threshold prostate sizes in men with BPH. The ROC curve analyses revealed that PSA had good predictive value for assessing prostate volume, with areas under the curve ranging from 0.76 to 0.78 for various prostate volume cutoff points (30, 40, and 50 mL). Conclusions. Prostate volume is strongly related to serum PSA in men with BPH and no evidence of prostate cancer, and the relationship depends on age. Since treatment outcome or risk of long-term complications depend on baseline prostate volume, serum PSA can estimate the degree of prostate enlargement sufficiently accurately to be useful for therapeutic decision making. To achieve a specificity of 70% while maintaining a sensitivity between 65% and 70%, approximate age-specific criteria for detecting men with prostate glands exceeding 40 mL are PSA Ͼ1.6 ng/mL, Ͼ2.0 ng/mL, and Ͼ2.3 ng/mL for men with BPH in their 50s, 60s, and 70s, respectively.

Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of left ventricular dysfunction. The factors resulting in impaired left ventricular function are unclear. Whether a critical burden of PVCs can result in cardiomyopathy has not been determined.The objective of this study was to determine a cutoff PVC burden that can result in PVC-induced cardiomyopathy.In a consecutive group of 174 patients referred for ablation of frequent idiopathic PVCs, the PVC burden was determined by 24-hour Holter monitoring, and transthoracic echocardiograms were used to assess left ventricular function. Receiver-operator characteristic curves were constructed based on the PVC burden and on the presence or absence of reversible left ventricular dysfunction to determine a cutoff PVC burden that is associated with left ventricular dysfunction.A reduced left ventricular ejection fraction (mean 0.37 ± 0.10) was present in 57 of 174 patients (33%). Patients with a decreased ejection fraction had a mean PVC burden of 33% ± 13% as compared with those with normal left ventricular function 13% ± 12% (P <.0001). A PVC burden of >24% best separated the patient population with impaired as compared with preserved left ventricular function (sensitivity 79%, specificity 78%, area under curve 0.89) The lowest PVC burden resulting in a reversible cardiomyopathy was 10%. In multivariate analysis, PVC burden (hazard ratio 1.12, 95% confidence interval 1.08 to 1.16; P <.01) was independently associated with PVC-induced cardiomyopathy.A PVC burden of >24% was independently associated with PVC-induced cardiomyopathy.

Emission factors of CO 2 , SO 2 and NO x emitted from Iran's thermal power plants are fully covered in this paper. To start with, emission factors of flue gases were calculated for fifty thermal power plants with the total installed capacity of 34,863 MW over the period 2007e2008 with regard to the power plants' operation characteristics including generation capacity, fuel type and amount and the corresponding alterations, stack specifications, analysis of flue gases and physical details of combustion gases in terms of g kWh À1 . This factor was calculated as 620, 2.57 and 2.31 g kWh À1 for CO 2 , SO 2 and NO x respectively. Regarding these results, total emissions of CO 2 , SO 2 and NO x were found to be 125.34, 0.552 and 0.465 Tg in turn. To achieve an accurate comparison, these values were compared with their alternatives in North American countries. According to this comparison, emission factor of flue gases emitted from Iran's thermal power plants will experience an intensive decline if renewable, hydroelectric and nuclear types of energy are more used, power plants' efficiency is increased and continuous emission monitoring systems and power plant pollution reduction systems are utilized.

Government's engagement with tourism and in the development of the sector is widely accepted but academic debate about the form and level of such involvement is limited. This is particularly the case when specific facets of state engagement, relating for example to support for human resource development (HRD) in tourism, are concerned. The purpose of this paper is to explore the substantially neglected role of the state and its agencies in creating an enabling environment for effective HRD within tourism, through policy and planning as well as the delivery of actual HRD initiatives. In this paper, we briefly address the contested role of government in economic development and, in particular, in HRD. We address the nature of tourism as a sector within the economy and identify its salient features in terms of the key themes in this paper. The role of human resources in enabling tourism businesses, destinations and countries to operate effectively and competitively in the contemporary global economy is addressed and the paper considers the impact that tourism's defining structural and operational characteristics have on the role of people. Finally, building on the experience of the Irish Republic over the past 40 years, we will consider whether government and its agencies can play a useful role in guiding policy and delivering programmes that act to enhance the quality and productivity of people in the delivery of products and services to guests within tourism and, if they can, how this role can best be defined and operationalised.

Objective: Despite high rates of co-occurring substance use disorder in people with severe mental illness, substance use disorder is often undetected in acute-care psychiatric settings. Because underdetection is related to the failure of traditional screening instruments with this population, the authors developed a new screen for detection of substance use disorder in people with severe mental illness. Method: On the

Recent medical advances and the easy availability of evidence-based information at the point of care are believed to provide physicians with improved tools for risk communication. However, evidence indicates that physicians still display marked variability in ordering tests. Factors that determine a physician&#39;s test-ordering tendencies vary by specialization, practice, geographical location, defensive practice, and tolerance of uncertainty and are also modified by patient requests. Understanding of statistical terms on the part of both physicians and patients remains limited. Physicians may display limited ability to assess pretest and posttest probabilities, especially in low- and intermediate-risk patients, even after attending short courses in epidemiology, or may find the process impractical. Presentation of diagnostic-test results in a natural-frequency format might improve understanding. Both physicians and patients have difficulty grasping the term &quot;number needed to ...

A flexible and powerful dynamic simulation approach to grinding circuit simulation has recently been developed in CSIRO Minerals. The MATLAB/SIMULINK graphical programming environment has been used to construct a library of dynamic mathematical models of a number of key grinding and separation devices and to link them into various complex dynamic grinding circuits. True real-time dynamic simulation and visualisation of interlinked unit process operations in grinding circuits of arbitrary complexity can readily be achieved.

Rifled evaporating tubes are applied in the steam boilers with the aim to increase the steam-water mixture turbulization and to prevent the burnout of tubes walls. The rifled evaporating tubes and the working fluid forced circulation are applied in the steam boiler at the Thermal Power Plant ''Kolubara B'' that is being built by the Electric Power Utility of Serbia. In order to investigate operating characteristics of the steam boiler of such an advanced design, a simulation and analysis of complex coupled thermal processes on the furnace gas side and thermal-hydraulics inside the evaporating tubes were performed for the whole range of plant operating loads. In this paper a methodology for hydraulic calculations of both forced and natural circulation loops is presented. The increased thermal safety margin of rifled tubes is predicted and compared with the safety margin of smooth tubes for uniform and variable heat loads among walls of the boiler furnace. The rifled tube provides an acceptable temperature of its wall even under a high void fraction of the coolant and prevents the occurrence of critical heat transfer conditions. The influence of the rifled tubes on an increase of the hydraulic resistance in the circulation loop is analyzed. Also, a range of operating conditions under which there is no need for the circulation pumps operation is determined.

Analytic models are developed for optimizing bus services with time dependence and elasticity in their demand characteristics. Some supply parameters, i.e. vehicle operating costs and speeds are also allowed to vary over time. The multiple period models presented here allow some of the optimized system characteristics (e.g. route structure) to be fixed at values representing the best compromise over different time periods, while other characteristics (e.g. service headways) may be optimized within each period. In a numerical example the demand is assumed to fluctuate over a daily cycle (e.g. peak, offpeak and night), although the same models can also be used for other cyclical or noncyclical demand variations over any number of periods. Models are formulated and compared for four types of conditions, which include steady fixed demand, cyclical fixed demand, steady equilibrium demand and cyclical equilibrium demand. When fixed demand is assumed, the optimization objective is minimum total system cost, including operator cost and user cost, while operator profit and social welfare are the objective functions maximized for equilibrium demand. The major results consist of closed form solutions for the route spacings, headways, fares and costs for optimized feeder bus services under various demand conditions. A comparison of the optimization results for the four cases is also presented. When demand and bus operating characteristics are allowed to vary over time, the optimal functions are quite similar to those for steady demand and supply conditions. The optimality of a constant ratio between the headway and route spacing, which is found at all demand densities if demand is steady, is also maintained with a multi-period adjustment factor in cyclical demand cases, either exactly or with a relatively negligible approximation. These models may be used to analyze and optimize fairly complex feeder or radial bus systems whose demand and supply characteristics may vary arbitrarily over time.

Background: Normal metabolism generates several volatile organic compounds (VOCs) that are excreted in the breath (e.g. alkanes). In patients with lung cancer, induction of high-risk cytochrome p450 genotypes may accelerate catabolism of these VOCs, so that their altered abundance in breath may provide biomarkers of lung cancer. Methods: VOCs in 1.0 L alveolar breath were analyzed in 193 subjects with primary lung cancer and 211 controls with a negative chest CT. Subjects were randomly assigned to a training set or to a prediction set in a 2:1 split. A fuzzy logic model of breath biomarkers of lung cancer was constructed in the training set and then tested in subjects in the prediction set by generating their typicality scores for lung cancer. Results: Mean typicality scores employing a 16 VOC model were significantly higher in lung cancer patients than in the control group (p < 0.0001 in all TNM stages). The model predicted primary lung cancer with 84.6% sensitivity, 80.0% specificity, and 0.88 area under curve (AUC) of the receiver operating characteristic (ROC) curve. Predictive accuracy was similar in TNM stages 1 through 4, and was not affected by current or former tobacco smoking. The predictive model achieved near-maximal performance with six breath VOCs, and was progressively degraded by random classifiers. Predictions with fuzzy logic were consistently superior to multilinear analysis. If applied to a population with 2% prevalence of lung cancer, a screening breath test would have a negative predictive value of 0.985 and a positive predictive value of 0.163 (true positive rate = 0.277, false positive rate = 0.029). Press and the authors. All rights reserved

Variable speed drives are growing and varying. Drives expanse depend on progress in different part of science like power system, microelectronic, control methods, and so on. Artificial intelligent contains hard computation and soft computation. Artificial intelligent has found high application in most nonlinear systems same as motors drive. Because artificial intelligent techniques can use as controller for any system without requirement to system mathematical model, it has been used in electrical drive control. With this manner, efficiency and reliability of drives increase and volume, weight and cost of them decrease. Due to the improved operating characteristics they give to the equipment control, electronic motor soft starters are increasingly widely applied. Escalators, pumps, elevators and conveyor belts all operate more effectively if they are soft started. However, it is not simply the ergonomics of an airport, process plant or shopping mall that are improved by soft starters. A major factor in the growth in popularity of soft starters is the reduced wear and tear that they place on motors and their associated drive systems. In turn, this reduces maintenance, conserves energy and plays a significant part in improving plant performance and operating costs.

The advantages of a navigation system that can monitor its own integrity are obvious. Integrity monitoring requires that the navigation system detect faulty measurement sources before they corrupt the outputs. This paper describes a parity approach to measurement error detection when redundant measurements are available. The general form of the detector operating characteristic (DO0 is developed. This equation relates the probability of missed detection to the probability of false alarm, the measurement observation matrix, and the ratio of the detectable bias shift to the standard deviation of tbe measurement noise.

Inventory constraints, costs of lost production, safety and environmental objectives, strategies of maintenance adopted, logistics aspects of spare parts are some of the criteria taken into account, and spare parts classification is thus defined with respect to multiple attributes. In virtue of the large number of the potential operational characteristics to be considered, the decision diagram is integrated with a set of analytic hierarchy process models used to solve the various multi‐attribute decision sub‐problems at the different levels/nodes of the decision tree. An inventory policy matrix is defined to link the different classes of spare parts with the possible inventory management policies so as to identify the “best” control strategy for the spare stocks. The principles of the theory and an actual application in a company operating in the paper industry are reported in the paper.

Behavioral scientists are interested in answering three basic questions when examining the relationships between variables . First, is an observed result real or should it be attributed to chance (i.e., statistical significance)? Second, if the result is real, how large is it (i.e., effect size)? Third, is the result large enough to be meaningful and useful (i.e., clinical or practical significance)? In this last column in the series, we treat clinical significance as equivalent to practical significance.

The Nottingham health profile has been portrayed as a multipurpose measure of health status, capable of being used in population surveys and in evaluation of medical interventions. This paper examines basic operating characteristics of the profile, using data collected in a large survey of the community.

PEM water electrolyzer Water electrolysis Pure hydrogen a b s t r a c t This paper presents the development of key components, specifications, configuration and operation characteristics of an 80 l/h Proton Exchange Membrane (PEM) water electrolyzer system for portable application. The developed PEM water electrolyzer can produce 80 l/h hydrogen (purity > 99.99%) with moderate pressure range up to 500 kPa (73 psi) at an operating current of 100 A with energy efficiency of 77.48%. The reliability in operation of developed PEM water electrolyzer system is tested for running the stack about 3000 h with 100 A current. The results indicate the reasonable stability of MEA fabrication and cell design method. (G. Sozhan).

The development of shielding gases for welding applications has been of increasing interest for two main reasons: to improve the productivity and the operating characteristics of the process and to reduce the healthy and safety problems due to fume and particle emissions. The present paper outlines some of the most important features of seven shielding gas mixtures used and gives information about the influence of these mixtures on the process characteristics, namely on the metal transfer modes and fume emissions. The focus of this work is an experimental study of shielding gases aimed at analysing arc stability and transfer modes, as well as, fume formation, having in view the achievement of a better working environment for welders.

Background: For children younger than 12 years old with asthma, there are several quality-of-life instruments, clinical diaries, and questionnaires assessing symptoms; however, a validated tool for assessing asthma control is currently lacking. Objective: To develop and validate the Childhood Asthma Control Test (C-ACT), a self-administered tool for identifying children aged 4-11 years whose asthma is inadequately controlled. Methods: A 21-item questionnaire was administered to 343 patients with asthma and their caregivers, randomly assigning 75% (n 5 257) for development and cross-sectional validation of the tool and 25% (n 5 86) to a confirmatory sample.

This paper presents a summary of the most important characteristics of wind turbine generators applied in modern wind power plants. Various wind turbine generator designs, based on classification by machine type and speed control capabilities, are discussed along with their operational characteristics, voltage, reactive power, or power factor control capabilities, voltage ride-through characteristics, behavior during short circuits, and reactive power capabilities.

Researchers and clinicians have been investigating and implementing various methods of early diagnosis for sepsis before documentation of infection. The aim of this study was to outline the efficiency of procalcitonin (PCT), C-reactive protein (CRP), and white blood cell count (WBC) in determining the early diagnosis of sepsis in the emergency department. Between January 1999 and September 2000, 34 patients with signs of systemic inflammatory response syndrome (SIRS) were enrolled in the study. The patients were divided into 2 groups according to nonsuspected sepsis and suspected sepsis clinically. Admission PCT was significantly higher in suspected sepsis group (median 68.7 g/L; lower [L] ‫؍‬ 15.24 g/L, upper [U] ‫؍‬ 120.54 g/L) compared with the unsuspected sepsis group (.23 g/L; L ‫؍‬ .10 g/L, U ‫؍‬ .44 g/L). PCT values were compared with WBC and CRP levels. Predictive accuracy for sepsis expressed as area under the receiver operating characteristic (ROC) curve was .88 for PCT, .44 for WBC, and .34 for CRP. PCT can probably be used as a predictive marker in bacterial infections in emergency departments. (Am J Emerg Med 2002;20:202-206.

This paper specifically addresses the thermal characteristics of the miniature Loop Heat Pipe (mLHP) with the flat disk shaped evaporator, 10 mm thick and 30 mm in diameter, for the thermal control of the compact electronic equipments. The loop was made of copper with nickel wick and water as the working fluid. Detailed study was conducted on the start-up reliability of the mLHP at high as well as low heat loads. It was found that the device was able to start-up at input power as low as 5 W, however the start-up time was very high at such heat loads. During the testing of mLHP under step and random power cycles, the thermal response presented by the loop to achieve steady state was very short. At low heat loads, thermal and hydraulic oscillations were observed throughout the loop. The amplitudes of these fluctuations were very high at condenser inlet and liquid line exit. It is expected that the extent and nature of the oscillations occurrence is dependent on the thermal and hydrodynamic conditions inside the compensation chamber. Overall, the effect of these oscillations on the thermal performance of the mLHP was not very significant. In the horizontal orientation, the device was able to transfer maximum heat load of 70 W with evaporator temperature below 100 ± 5 • C limit. The thermal resistance (R mLHP ) of the mLHP lies between 0.17 to 5.66 • C/W.