Comprehensive Analytic Model Research Articles

Unveiling benefits: A framework for analyzing small hydropower refurbishment activities

Small hydropower is a crucial renewable energy source in China and plays a significant role in achieving social, economic, and ecological sustainable development goals. However, rapid Small hydropower development has led to various issues, resulting in closure or dismantling of many Small hydropower plants. To maximize the positive impact of Small hydropowers, green transformation and Small hydropower plant upgrades are urgently required. Hence, Small hydropower refurbishment activities are performed to enhance overall benefits. Therefore, this study integrated grounded theory, a qualitative research method, with a comprehensive decision-making trial and evaluation laboratory-fuzzy analytic hierarchy process evaluation model. This formed a new framework to analyse refurbishment activities and was applied in Tangban and Maoyandong plants. Small hydropower refurbishment activity benefits were categorized as internal (direct economic and indirect production benefits) and external (social and ecological benefits), with interconnections and trade-offs. The most critical factors influencing benefits were internal factors, whereas social benefits had a greater influence on external factors. The refurbishment activities at Tangban and Maoyandong were rated high and moderate, respectively, owing to differences in corporate nature, location, and primary business focus. This study not only provides a theoretical model for China’s Small hydropower to achieve the United Nations Sustainable Development Goals under the premise of sustainable operations, but also offers a new global framework for evaluation and decision-making in Small hydropower plants.

Effect of two-photon absorption on trapping of plasmonic nanoparticles

In this paper, we introduce a theoretical framework for optical trapping that integrates nonlinear polarization within the dipole approximation. This theory represents the most comprehensive analytic model to date capable of resolving the discrepancies between the observed and simulated trapping of plasmonic nanoparticles. Our theory elucidates how two-photon absorption can account for the stable trapping of gold nanoparticles, including their longitudinal stability, especially near their plasmon resonance. Furthermore, the experimentally observed split potential wells in the transverse plane, which are attributed to two-photon absorption, are in close agreement with our model’s predictions. Finally, this study provides new insights into the mechanism of optical trapping under conditions of intense light–matter interactions.

The propagation of relativistic jets in expanding media

ABSTRACT We present a comprehensive analytic model of relativistic jet propagation in expanding homologous media (ejecta). This model covers the entire jet evolution as well as a range of configurations that are relevant to binary neutron star mergers. These include low- and high-luminosity jets, unmagnetized and mildly magnetized jets, time-dependent luminosity jets, and Newtonian and relativistic head velocities. We also extend the existing solution of jets in a static medium to power-law density media with index α < 5. Our model provides simple analytic formulae (calibrated by 3D simulations) for the jet head propagation and breakout times. We find that the system evolution has two main regimes: strong and weak jets. Strong jets start their propagation immediately within the ejecta. Weak jets are unable to penetrate the ejecta at first, and breach it only after the ejecta expands significantly, thus their evolution is independent of the delay between the onset of the ejecta and the jet launching. After enough time, both strong and weak jets approach a common asymptotic phase. We find that a necessary, but insufficient, criterion for the breakout of unmagnetized (weakly magnetized) jets is $E_{j,{\rm iso,tot}} \gtrsim 3[0.4]\, {E_{ej,{\rm tot}}}\left({\, {\theta _{j,0}}}/{0.1{\rm ~rad}}\right)^2$, where Ej, iso, tot is the jet total isotropic equivalent energy, $\, {\theta _{j,0}}$ is its opening angle, and $\, {E_{ej,{\rm tot}}}$ is the ejecta energy. Applying our model to short gamma-ray bursts, we find that there is most likely a large diversity of ejecta mass, where mass ≲10−3 M⊙ (at least along the poles) is common.

Unified Modeling Technique for Axially Uniform and Nonuniform Eccentricity Faults in Three-Phase Squirrel Cage Induction Motors

Many mechanical faults cause eccentricity in squirrel cage induction motors (SCIMs), so it is reasonable to design and implement reliable eccentricity fault diagnosis systems for the SCIMs. Accurate modeling and simulation techniques help to reach this aim more easily. It is common to assume that the eccentricity fault is uniform along the motor length when modeling and simulation that is often far from real situation. In this paper, experimental inspection is performed first to show that having the same severity of eccentricity at one end of the motor, the axially nonuniform eccentricity may produce lower fault indices than the axially uniform eccentricity. Then, the two-dimensional (2-D) modified winding function theory is presented and used to obtain analytic expressions for various self-/mutual inductances of the stator windings and the rotor meshes and their derivatives versus the rotor position. The expressions are applicable under various axially uniform and nonuniform eccentricities as well as the healthy condition. Multiple coupled circuit model is used along with these expressions to develop a comprehensive analytic model for the SCIMs. Simulation results obtained by this model are in good agreement with corresponding experimental results and confirm accuracy of the attained modeling and simulation technique.

Multiple-Criteria Decision Support for a Sustainable Supply Chain: Applications to the Fashion Industry

With increasing globalization and international cooperation, the importance of sustainability management across supply chains has received much attention by companies across various industries. Companies therefore strive to implement effective and integrated sustainable supply chain management initiatives to improve their operational and economic performance while also minimizing unnecessary damage to the environment and maintaining their social reputation and images. The paper presents an easy-to-use decision-support approach based on multiple-criteria decision-making (MCDM) methodologies that aim to help companies develop effective models for timely decision-making involving sustainable supply chain management strategies. The proposed approach can be used by practitioners to ultimately build a comprehensive Analytic Network Process model that will adequately capture and reveal all the interrelationships and interdependency among the elements in the problem, which is often a very difficult task. To facilitate and simplify this complex process, we propose that hierarchical thinking be used first to structure the essences of the problem capturing only the major issues, and an Analytic Hierarchy Process (AHP) model be built. Users can learn from the modeling process and gain much insight into the problem. The AHP can then be extended to an Analytic Network Process (ANP) model so as to capture the relationships and interdependencies among the elements. Our approach can reduce the sustainable expertise, effort and information that are often needed to build an ANP model from scratch. We apply our approach to the evaluation of sustainable supply chain management strategies for the fashion industry. Three main dimensions of sustainability—environmental, economic and social—are considered. Based on the literature, we identified four alternative supply chain management strategies. It was found that the Reverse Logistics alternative appears to be the recommended solution by the AHP model. However, the Socially Leagile Supply Chain is recommended by the ANP model, thereby demonstrating the necessity and importance of considering interdependencies in the model.

Cost-Utility Analysis of Bariatric Surgery in Italy: Results of Decision-Analytic Modelling

Objective: To evaluate the cost-effectiveness of bariatric surgery in Italy from a third-party payer perspective over a medium-term (10 years) and a long-term (lifetime) horizon. Methods: A state-transition Markov model was developed, in which patients may experience surgery, post-surgery complications, diabetes mellitus type 2, cardiovascular diseases or die. Transition probabilities, costs, and utilities were obtained from the Italian and international literature. Three types of surgeries were considered: gastric bypass, sleeve gastrectomy, and adjustable gastric banding. A base-case analysis was performed for the population, the characteristics of which were obtained from surgery candidates in Italy. Results: In the base-case analysis, over 10 years, bariatric surgery led to cost increment of EUR 2,661 and generated additional 1.1 quality-adjusted life years (QALYs). Over a lifetime, surgery led to savings of EUR 8,649, additional 0.5 life years and 3.2 QALYs. Bariatric surgery was cost-effective at 10 years with an incremental cost-effectiveness ratio of EUR 2,412/QALY and dominant over conservative management over a lifetime. Conclusion: In a comprehensive decision analytic model, a current mix of surgical methods for bariatric surgery was cost-effective at 10 years and cost-saving over the lifetime of the Italian patient cohort considered in this analysis.

Pedestrian Distribution in High-Rise Commercial Complexes: An Analysis of Integrating Spatial and Functional Factors

School of Civil Engineering and Architecture, Changzhou Institute of Technology, Changzhou 213002, ChinaAbstractOne of the key problems in the design of high-rise commercial complex is how to guide reasonable pedestrian distributionin commercial space. In this study, pedestrian distribution in three high-rise commercial complexes in Shanghai and Hong Kongwas studied using spatial configuration analysis software Space Syntax and quantification of physical elements in commercialspaces, such as functional attractiveness, entrances, escalators, level variations and passage width. Additionally, in an attemptto integrate functions with spatial integration and spatial depth, two combination variables, the spatial coefficient of function(IF) and spatial depth coefficient of function (F/D), were proposed. The results of the correlation analysis and multipleregression analyses reflected the following: (1) Regarding the influence on pedestrian distribution, there was a synergistic andcomplementary relationship between function and space; (2) The comprehensive flow distribution analytic model couldsuccessfully interpret flow distribution in high-rise commercial complexes and its R Square ranged up to about 70% in the threecases; (3) The spatial coefficient of function (IF) and spatial depth coefficient (F/D) could effectively integrate functions andspatial configuration, which could help close the gap between over-emphasis on function in commercial research and the lackof consideration of function in space-syntax analysis.Keywords: High-rise commercial complex, Function, Space, Configuration, Pedestrian distribution

Statistical analysis of intrinsic and extrinsic coupling losses for step-index polymer optical fibers

The intrinsic and extrinsic coupling losses of step-index polymer optical fibers are statistically examined by Monte Carlo simulations. In contrast to most existing models that linearly scale individual losses, a comprehensive analytic coupling loss model is used that also considers the interdependencies between mismatches in numerical aperture and core diameter, as well as radial and longitudinal offsets. As a typical example, the coupling losses of A4a.2 step-index multimode fibers are analyzed for an equilibrium mode distribution. The results show considerably less conservative coupling loss estimations than with traditional models, improving link power budgeting.

Bariatric Surgery can Lead to Net Cost Savings to Health Care Systems: Results from a Comprehensive European Decision Analytic Model.

BackgroundThe objective of the present study was to evaluate the cost-utility of bariatric surgery in a lifetime horizon from a Swedish health care payer perspective.MethodsA decision analytic model using the Markov process was developed covering cardiovascular diseases, type 2 diabetes, and surgical complications. Clinical effectiveness and safety were based on the literature and data from the Scandinavian Obesity Surgery Registry. Gastric bypass, sleeve gastrectomy, and gastric banding were included in the analysis. Cost data were obtained from Swedish sources.ResultsBariatric surgery was cost saving in comparison with conservative management. It also led to a substantial reduction in lifetime risk of events: from a 16 % reduction in the risk of transient ischaemic attacks to a 62 % reduction in the incidence of type 2 diabetes. Over a lifetime, surgery led to savings of €8408 and generated an additional 0.8 years of life and 4.1 quality-adjusted life years (QALYs) per patient, which translates into gains of 32,390 quality-adjusted person-years and savings of €66 million for the cohort, operated in 2012. Analysis of the consequences of a 3-year delay in surgery provision showed that the overall lifetime cost of treatment may be increased in patients with diabetes or a body mass index >40 kg/m2. Delays in surgery may also lead to a loss of clinical benefits: up to 0.6 life years and 1.2 QALYs per patient over a lifetime.ConclusionBariatric surgery, over a lifetime horizon, may lead to significant cost savings to health care systems in addition to the known clinical benefits.Electronic supplementary materialThe online version of this article (doi:10.1007/s11695-014-1567-5) contains supplementary material, which is available to authorized users.

종합병원 암 종별 수술량이 병원 내 사망에 미치는 영향

Background: Although the mortality rate in cancers has been decreased recently, it is still one of the leading causes of death in most of the countries. This study analyzed the relationship between surgery volume and in hospital mortality of cancer patients. The pur-pose of this study is to investigate the relationship in Korean healthcare environment and to provide information for the policy de-velopment in reducing cancer mortality.Methods: The study sample was the 20,517 cancer patients who underwent surgery and discharged during a month period be-tween 2008-2011. The data were collected in Patient Survey by Korean Institute of Social Affairs. Logistic regression was used to analyse a comprehensive analytic model that includes a binary dependent variable indicating death discharge and independent variables such as surgery volume, organizational characteristics of hospitals, socio-economical characteristics of the patients, and severity of disease indicators.Results: In chi-square test, as the surgery volume increases, the in-hospitals mortality showed a downward trends. In regression analysis, the relationship between surgery volume and mortality showed significant negative associations in all types of cancer ex-cept for pancreatic cancer.Conclusion: In the absence of other information patients undergoing cancer surgery can reduce their risk of operative death by se-lecting a high-volume hospital. Therefore, policies to enhance centralization of cancer surgery services should be considered.Keywords: Surgery volume; Cancer mortality; Discharge summary data

Nonlinear acoustics of combustion instability in solid-propellant rocket motors

Combustion instability, a large oscillation of pressure in a combustion chamber, is known to be a major source of rocket failure. A common approach to analyzing combustion instability is to regard it as an acoustical phenomenon in an enclosure, driven by the combustion process occurring in a thin region near the grain (solid propellant). Because of the large pressure excursion associated with combustion instability, it exhibits many salient features of nonlinear wave process such as waveform distortion, shock formation, and even chaotic behaviors. In this paper, a comprehensive analytic model for combustion instability of a solid rocket motor is presented. Our focus is on the way in which nonlinearity manifests itself under complex grain geometry, where the acoustic modes can be either harmonically or anharmonically related. Predictions from the model are compared with the static test data for a few representative rockets.

Photonic Crystals Based on Periodic Arrays of MWCNTs: Modeling and Simulation

Based on existing model for dielectric function of an effective medium in response to H-polarized (TE) mode, we have developed a new comprehensive analytic model for dielectric function (ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TE</sub> ) of an individual multi-wall carbon nanotube (MWCNT) that satisfies the Kramers-Kronig relation. Taking advantage of this model and utilizing the 2D Finite difference time domain (FDTD) method we have calculated the photonic response of β-aligned ordered arrays of MWCNTs to TE mode, over the frequency range of 0.5-10 PHz. Dependence of the photonic response on the lattice periodicity, CNTs' inner and outer radii, and the lattice orientation with respect to the propagation direction have been studied, systematically. Furthermore, using an existing model for ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sub> , similar dependencies for the photonic response to E-polarized (TM) mode, have also been obtained. The numerical results can be used in designing photonic devices applicable in the range of near to deep UV, such as filtering, switching, superlensing, plasmonic antennas, and optical sensors.

Principles of supernova-driven winds

The formation of galaxies is regulated by a balance between the supply of gas and the rate at which it is ejected. Traditional explanations of gas ejection equate the energy required to escape the galaxy or host halo to an estimate for the energy yield from supernovae. This yield is usually assumed to be a constant fraction of the total available from the supernova, or is derived from the assumption of a consistent momentum yield. By applying these ideas in the context of a cold dark matter cosmogony, we derive a 1st-order analytic connection between these working assumptions and the expected relationship between baryon content and galaxy circular velocity, and find that these quick predictions straddle recent observational estimates. To examine the premises behind these theories in more detail, we then explore their applicability to a set of gasdynamical simulations of idealised galaxies. We show that different premises dominate to differing degrees in the simulated outflow, depending on the mass of the system and the resolution with which it is simulated. Using this study to anticipate the emergent behaviour at arbitrarily high resolution, we motivate more comprehensive analytic model which allows for the range of velocities with which the gas may exit the system, and incorporates both momentum and energy-based constraints on the outflow. Using a trial exit velocity distribution, this is shown to be compatible with the observed baryon fractions in intermediate-mass systems, but implies that current estimates for low-mass systems can not be solely accounted for by supernova winds under commonly-held assumptions.

Nonlocal analysis to study of the impact ionization and avalanche characteristics of deep submicron Si devices

In this paper, we have presented electric field dependence of the electron and hole impact ionization coefficients and threshold energies in submicron Si diodes with intrinsic region thicknesses down to 31 nm. To do so, we have used a nonlocal analysis, in order to take the effects of arbitrary distribution of ionization events in both space and time domains and the effects of enhancement in the average speed of those carriers which ionize early in their trajectories as well as nonuniform electric fields in the multiplication region and its surrounding ambient, carrier’s dead space history and its spatial ionization rate, into consideration all in one comprehensive analytic model.

Cost-Effectiveness of Lenalidomide in the Treatment of Patients with Transfusion-Dependent Myelodysplastic Syndromes (MDS) in the United States.

Background: Effective treatment for patients with low- or intermediate-1 (IPSS) risk MDS with transfusion-dependent anemia is limited, forcing reliance upon red blood cell (RBC) transfusions and chelation therapy with attendant complications and adverse impact on quality of life (QOL) and health care costs. Lenalidomide is a new immunomodulatory drug, which received fast track designation from the FDA for the treatment of transfusion-dependent MDS associated with chromosome 5q31 deletion. We evaluated the cost-effectiveness of lenalidomide therapy for transfusion-dependent patients with MDS.Methods: A comprehensive decision analytic model was developed to evaluate and compare the costs and health benefits of lenalidomide with best supportive care (BSC) versus BSC with blood transfusions only over a 1-year period. Data on efficacy and blood transfusion requirements before and after the administration of lenalidomide were estimated from a phase II clinical trial (MDS-003). Health outcome measure used was rate and duration of response as manifested in transfusion-independent time gained, which is associated with important clinical and QOL benefits. The model incorporated direct medical costs related to medication, transfusions (blood components, iron chelation therapy, laboratory procedures, administration of transfusions), diagnostic tests, office visits and other medical resource use. Unit costs were taken from Medicare fee schedules that are standardized and closely reflect provider costs across the US. All costs were expressed in 2005 US dollars.Results: Major and minor response was observed in 66% and 9% of patients treated with lenalidomide. Time to response was 4.1 weeks. The median duration of response was reached beyond one year (78 weeks). After excluding assessments beyond the 1-year timeframe of the model, the mean duration of transfusion independence among responders was 41.8 weeks. Previous QOL studies in MDS suggest that transfusion-independence is associated with 33% better QOL as measured by the QOL-E. In the first year, an average of 56 % reduction in RBC transfusion requirements was also observed in the lenalidomide group compared to BSC. The costs of lenalidomide therapy were largely offset by savings in blood transfusion costs. Multi-way sensitivity analyses on model parameter estimates showed that the incremental cost-effectiveness ratio of lenalidomide versus BSC is between $1,137 and $9,076 per transfusion-independent year gained. Based on a range of assumptions on QOL associated with living in transfusion independence versus transfusion-dependency, this translates into an incremental cost-effectiveness ratio between $3,240 to $38,799 per quality-adjusted life year (QALY) gained, well within usual acceptable ranges of cost-effectiveness for new technologies.Conclusions: These results suggest that, through its oral drug administration, reduced transfusion requirements, and increased efficacy, lenalidomide is a cost-effective treatment option in transfusion-dependent MDS associated with chromosome 5q31 deletion in the US. Further research is warranted to confirm these results as longer-term comparative data on efficacy, QOL, and medical resource utilization become available from currently ongoing phase III randomized trials.

Performance study of multiple route dynamic source routing protocols for mobile ad hoc networks

Design and analysis of routing protocols are the key issues for a mobile ad hoc network (MANET). The Dynamic Source Routing (DSR) protocol is one of the important on-demand routing protocols. In this paper, we develop a comprehensive analytic model for the performance study of the DSR protocol with multiple routes. Two performance metrics, called probability of a successful data transmission and probability that the multiple routes can support the next data transmission, are introduced. We derive both of the two probabilities for the general case over n multiple routes for the DSR protocol. These analytic results provide insights into the mechanics of the multiple DSR routing protocol. It is also useful for the design and implementation of the on-demand routing for MANET.

Parametric investigations and simulations of ion beam etching and reactive ion etching mechanisms for GaAs compounds

This work introduces a comprehensive analytic model of the sputtering mechanism present in ion beam etching and reactive ion etching processes. Our final objective is to correlate the etch rate to the plasma reactor parameters. Experimental verifications for GaAs etching show a good agreement for ion beam etching. In the case of reactive ion etching, the non-perfect agreement is explained by the influence of effects such as flow rate and temperature not taken into account in the theoretical approach. We also present parametric investigations of GaAs etched in SiCl 4 plasma.

An improved analytic model for the metal-insulator-semiconductor tunnel junction

Two improvements to a comprehensive analytic model that describes the steady-state current in a metal-insulator-semiconductor tunnel junction are reported. The first modification replaces the conventional two-band representation of the thin oxide band structure with a one-band model. In this approach, the electron barrier height for tunneling is always less than the hole barrier height by an amount equal to the semiconductor bandgap. The second improvement enables the energy dependence of the electron and hole tunneling probability factors to be taken into account. This is accomplished by expressing the tunneling probabilities as short-series expressions. The capability of the model to accurately predict the current-voltage characteristics of MIS tunnel junctions is demonstrated by simulating the DC performance of a tunnel emitter transistor. The results are in good agreement with experimental data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A comprehensive analytic model of accumulation-mode MOSFET's in PolySilicon thin films

A comprehensive analytic description of the polysilicon (poly-Si) MOSFET, operating in the accumulation mode is presented. The model is not a single crystalline analog. Rather, the formulation is based upon structural and electronic properties inherent in poly-Si thin films. The model is capable of quantitatively explaining the bulk of reported device characteristics, specifically the temperature coefficient of current (TCC). Drive and leakage current as a function of doping level are also quantitatively discussed. In addition, transconductance, drain admittance, and ON/OFF current ratio are described extensively at room temperature and above and are compared with experimental data. The role of grain boundary hydrogenation in effecting the device performance is quantified. Finally, a few pertinent design guidelines are presented.

Family Socialization among Mexican Americans

This article introduces some theoretical presuppositions and a comprehensive analytic model to integrate available literature on family socialization of Mexican Americans and to guide future research. The theoretical postulates derive from a sociohistorical approach that describes human growth as a continuous process of socialization by which individuals become members of multiple social systems in the context of social relations. The analytic model incorporates multiple variables from different levels – the individual, the microsocial, and the macrosocial – stressing their interrelatedness and interconnectedness as reflected in linguistic communications. Literature dealing only with Mexican Americans is reviewed to demonstrate the usefulness of the model and to suggest guidelines for future research.