2,711 research outputs found
A simple state-based prognostic model for filter clogging
In today's maintenance planning, fuel filters are replaced or cleaned on a regular basis. Monitoring and implementation of prognostics on filtration system have the potential to avoid costs and increase safety. Prognostics is a fundamental technology within Integrated Vehicle Health Management (IVHM). Prognostic models can be categorised into three major categories: 1) Physics-based models 2) Data-driven models 3) Experience-based models. One of the challenges in the progression of the clogging filter failure is the inability to observe the natural clogging filter failure due to time constraint. This paper presents a simple solution to collect data for a clogging filter failure. Also, it represents a simple state-based prognostic with duration information (SSPD) method that aims to detect and forecast clogging of filter in a laboratory based fuel rig system. The progression of the clogging filter failure is created unnaturally. The degradation level is divided into several groups. Each group is defined as a state in the failure progression of clogging filter. Then, the data is collected to create the clogging filter progression states unnaturally. The SSPD method consists of three steps: clustering, clustering evaluation, and remaining useful life (RUL) estimation. Prognosis results show that the SSPD method is able to predicate the RUL of the clogging filter accurately
Fiscal Policy, Default and Emerging Market Business Cycles
Developing country fiscal policy outcomes documented in data point to stark differences compared with developed ones. Most prominent difference is the excessive volatility of government consumption and transfer payments and their positive correlation relative to output. This seemingly non-optimal behavior is puzzling since it is in contrast with standard theory prescriptions and likely to contribute to aggregate volatility. To study the possible roots of this I build a model by incorporating a detailed explicit fiscal sector to what is otherwise a standard sovereign default setup. The environment I define is one of incomplete markets that resembles small open developing economies with respect to existence of short-maturity non-state contingent defaultable debt as the only tradable asset for the sovereign government and financial frictions on private sector. I use this model to identify the contribution of market incompleteness due to the commitment problem of the sovereign. The findings point that the endogenous state-contingent borrowing constraints that sovereigns face as a result of commitment problem in debt repayment is a major factor in accounting for the pro-cyclicality of transfer payments and excessive relative volatility of transfers and government consumption in these countries. The effect of financial frictions of the type defined as working capital constraint on an imported input combined with debt sensitive private borrowing cost is increased volatility of fiscal policy due to debt loosing its buffer-stock property in smoothing out shocks to fiscal revenues
Surface morphological evolutions on single crystal films by strong anisotropic drift-diffusion under the capillary and electromigration forces
The morphological evolution of voids at the unpassivated surfaces and the
sidewalls of the single crystal metallic films are investigated via computer
simulations by using the novel mathematical model developed by Ogurtani relying
on the fundamental postulates of irreversible thermodynamics. The effects of
the drift-diffusion anisotropy on the development of the surface morphological
scenarios are fully explored under the action of the electromigration (EM) and
capillary forces (CF), utilizing numerous combination of the surface textures
and the directions of the applied electric field. The interconnect failure time
due to the EM induced wedge shape internal voids and the incubation time of the
oscillatory surface waves, under the severe instability regimes, are deduced by
the novel renormalization procedures applied on the outputs of the computer
simulation experiments.Comment: 41 pages, 18 figures. related simulation movies utilizing numerous
combination of the surface texture, see
http://www.csl.mete.metu.edu.tr/aytac/thesis/movies/index.ht
Recent Advances in Photovoltaic-Trombe Wall System: A Review
Management of energy consumption for building’s air conditioning is a vital issue for resource saving and environmental protection. The use of solar energy to generate electricity by solar cells is essential nowadays. However, the disadvantage of solar panels is the elevated temperature in work, especially in the hot sunny climate that leads to efficiency decline. Also, there is a problem with heating during the night and cloudy days. For the last 20 years, there has been a rapid development in the field of integrated solar technologies. A hybrid PV/Trombe wall (PV/TW) system suggested being an efficient and durable conversion system of solar energy. The design of the PV/TW system considered one of the focusing areas of the present research to make it more economically feasible. The idea of building the photovoltaic-Trombe wall has appeared as one of the green technologies. Several published works at that time are included for integrating PV/TW system. This chapter devoted to reviewing the theoretical and practical studies conducted on this system for developing and improving electrical and thermal performance
Managing Service-Heterogeneity using Osmotic Computing
Computational resource provisioning that is closer to a user is becoming
increasingly important, with a rise in the number of devices making continuous
service requests and with the significant recent take up of latency-sensitive
applications, such as streaming and real-time data processing. Fog computing
provides a solution to such types of applications by bridging the gap between
the user and public/private cloud infrastructure via the inclusion of a "fog"
layer. Such approach is capable of reducing the overall processing latency, but
the issues of redundancy, cost-effectiveness in utilizing such computing
infrastructure and handling services on the basis of a difference in their
characteristics remain. This difference in characteristics of services because
of variations in the requirement of computational resources and processes is
termed as service heterogeneity. A potential solution to these issues is the
use of Osmotic Computing -- a recently introduced paradigm that allows division
of services on the basis of their resource usage, based on parameters such as
energy, load, processing time on a data center vs. a network edge resource.
Service provisioning can then be divided across different layers of a
computational infrastructure, from edge devices, in-transit nodes, and a data
center, and supported through an Osmotic software layer. In this paper, a
fitness-based Osmosis algorithm is proposed to provide support for osmotic
computing by making more effective use of existing Fog server resources. The
proposed approach is capable of efficiently distributing and allocating
services by following the principle of osmosis. The results are presented using
numerical simulations demonstrating gains in terms of lower allocation time and
a higher probability of services being handled with high resource utilization.Comment: 7 pages, 4 Figures, International Conference on Communication,
Management and Information Technology (ICCMIT 2017), At Warsaw, Poland, 3-5
April 2017, http://www.iccmit.net/ (Best Paper Award
Coming into the Anthropocene
This essay reviews Professor Jonathan Cannon’s Environment in the Balance. Cannon’s book admirably analyzes the Supreme Court’s uptake of, or refusal of, the key commitments of the environmental-law revolution of the early 1970s. In some areas the Court has adapted old doctrines, such as Standing and Commerce, to accommodate ecological insights; in other areas, such as Property, it has used older doctrines to restrain the transformative effects of environmental law. After surveying Cannon’s argument, this review diagnoses the historical moment that has made the ideological division that Cannon surveys especially salient: a time of stalled legislation, political deadlock, and highly contested regulatory and judicial interpretation. This analysis, however, does not limit the interest of Cannon’s analysis to this political moment. Rather, Cannon’s integration of legal and cultural analysis has great promise for the Anthropocene, the dawning era when human decisions and values will be among the most important forces shaping the planet. In the future, it will be necessary to think of environmental law as both reflecting and producing ideas of the value and meaning of the natural world. Cannon’s analysis is an excellent starting point for an Anthropocene approach
Cost Analysis of Multimodal Freight Transportation: A Case of Iskenderun
In this study from Iskenderun to the other Turkey's 80 cities to unimodal and multimodal freight transportation scenarios are being developed. Filter material which is widely used in Ä°skenderun is chosen for the freight. Highway, maritime and railway transport types are used in route scenarios. The costs of the route scenarios are calculated. Cost calculations are based on 5, 10 and 14 freight tonnage. For the value of the 5 ton freight is 40 000 TL, for the value of the 10 ton freight is 145 000 TL and for the value of the 14 ton freight is 250 000 TL. After the cost analysis is done, the most appropriate route for each province is selected and entered into the geographic information system (GIS). Thus, for freight from Iskenderun, the cheapest mode of transportation can be chosen. It is seen that railway and multimodal transport is widespread in general when the cheapest routes are examined. Thus, along with the shift of freight transport to rail and multimodal transport, traffic density on the highway can be reduced
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Effective patient–clinician interaction to improve treatment outcomes for patients with psychosis: a mixed-methods design
BACKGROUND:At least 100,000 patients with schizophrenia receive care from community mental health teams (CMHTs) in England. These patients have regular meetings with clinicians, who assess them, engage them in treatment and co-ordinate care. As these routine meetings are not commonly guided by research evidence, a new intervention, DIALOG, was previously designed to structure consultations. Using a hand-held computer, clinicians asked patients to rate their satisfaction with eight life domains and three treatment aspects, and to indicate whether or not additional help was needed in each area, with responses being graphically displayed and compared with previous ratings. In a European multicentre trial, the intervention improved patients’ quality of life over a 1-year period. The current programme builds on this research by further developing DIALOG in the UK. RESEARCH QUESTIONS:(1) How can the practical procedure of the intervention be improved, including the software used and the design of the user interface? (2) How can elements of resource-oriented interventions be incorporated into a clinician manual and training programme for a new, more extensive ‘DIALOG+’ intervention? (3) How effective and cost-effective is the new DIALOG+ intervention in improving treatment outcomes for patients with schizophrenia or a related disorder? (4) What are the views of patients and clinicians regarding the new DIALOG+ intervention? METHODS:We produced new software on a tablet computer for CMHTs in the NHS, informed by analysis of videos of DIALOG sessions from the original trial and six focus groups with 18 patients with psychosis. We developed the new ‘DIALOG+’ intervention in consultation with experts, incorporating principles of solution-focused therapy when responding to patients’ ratings and specifying the procedure in a manual and training programme for clinicians. We conducted an exploratory cluster randomised controlled trial with 49 clinicians and 179 patients with psychosis in East London NHS Foundation Trust, comparing DIALOG+ with an active control. Clinicians working as care co-ordinators in CMHTs (along with their patients) were cluster randomised 1 : 1 to either DIALOG+ or treatment as usual plus an active control, to prevent contamination. Intervention and control were to be administered monthly for 6 months, with data collected at baseline and at 3, 6 and 12 months following randomisation. The primary outcome was subjective quality of life as measured on the Manchester Short Assessment of Quality of Life; secondary outcomes were also measured. We also established the cost-effectiveness of the DIALOG intervention using data from the Client Service Receipt Inventory, which records patients’ retrospective reports of using health- and social-care services, including hospital services, outpatient services and medication, in the 3 months prior to each time point. Data were supplemented by the clinical notes in patients’ medical records to improve accuracy. We conducted an exploratory thematic analysis of 16 video-recorded DIALOG+ sessions and measured adherence in these videos using a specially developed adherence scale. We conducted focus groups with patients (n = 19) and clinicians (n = 19) about their experiences of the intervention, and conducted thematic analyses. We disseminated the findings and made the application (app), manual and training freely available, as well as producing a protocol for a definitive trial. RESULTS:Patients receiving the new intervention showed more favourable quality of life in the DIALOG+ group after 3 months (effect size: Cohen’s d = 0.34), after 6 months (Cohen’s d = 0.29) and after 12 months (Cohen’s d = 0.34). An analysis of video-recorded DIALOG+ sessions showed inconsistent implementation, with adherence to the intervention being a little over half of the possible score. Patients and clinicians from the DIALOG+ arm of the trial reported many positive experiences with the intervention, including better self-expression and improved efficiency of meetings. Difficulties reported with the intervention were addressed by further refining the DIALOG+ manual and training. Cost-effectiveness analyses found a 72% likelihood that the intervention both improved outcomes and saved costs. LIMITATIONS:The research was conducted solely in urban east London, meaning that the results may not be broadly generalisable to other settings. CONCLUSIONS:(1) Although services might consider adopting DIALOG+ based on the existing evidence, a definitive trial appears warranted; (2) applying DIALOG+ to patient groups with other mental disorders may be considered, and to groups with physical health problems; (3) a more flexible use with variable intervals might help to make the intervention even more acceptable and effective; (4) more process evaluation is required to identify what mechanisms precisely are involved in the improvements seen in the intervention group in the trial; and (5) what appears to make DIALOG+ effective is that it is not a separate treatment and not a technology that is administered by a specialist; rather, it changes and utilises the existing therapeutic relationship between patients and clinicians in CMHTs to initiate positive change, helping the patients to improve their quality of life. FUTURE RESEARCH:Future studies should include a definitive trial on DIALOG+ and test the effectiveness of the intervention with other populations, such as people with depression. TRIAL REGISTRATION:Current Controlled Trials ISRCTN34757603. FUNDING:The National Institute for Health Research Programme Grants for Applied Research programme
A Literature Review of Numerical Modeling Techniques for Vapor Compression Systems with Focus on Heat Exchanger Modeling
Vapor compression systems are the most widely used system type in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) applications. Experimental and numerical modeling techniques are used to analyze the performance of the vapor compression systems. With the introduction of high-performance computers, numerical modeling techniques are used extensively to develop cost-effective and efficient HVAC&R equipment. Experimental iterations on the design of vapor compression systems are costly; however, numerical techniques can reduce the number of experimental iterations, substantially decreasing the development cost and time. Because of the benefits associated with the numerical simulation, many researchers working in the HVAC&R field have attempted to develop efficient, robust, and accurate simulation models. This paper provides an in-depth review of heat exchanger modeling techniques as well as integration strategies to develop holistic system models
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