Miracle-dz/UniFAR-FTUs huggingface dataset:
Development of a Methodology for Improving Photovoltaic Inverter Reliability

In evaluating the energy-generation potential of a photovoltaic (PV) energy system, the system is usually assumed to work without interruptions over its entire life. PV energy systems are fairly reliable, but as any complex system, they may fail. In PV systems, the inverter is responsible for the majority of failures, and most inverter failures are blamed on the aluminum electrolytic capacitors typically used in the dc bus. This paper investigates the effects of common failure modes on the reliability of PV inverters and suggests a model framework for decomposing the inverter into subsystems for more detailed study. The challenges of statistical analysis based on small data sets are discussed, and simulations are performed to illustrate the proposed model using a simple decomposition into subsystems of the inverter used in the 342-kW PV system at the Georgia Tech Aquatic Center.
Optimal and Efficient Probabilistic Distributed Diagnosis Schemes

The distributed self-diagnosis of a multiprocessor/multicomputer system based on interprocessor tests with imperfect fault coverage that permits intermittently faulty processors is addressed. Focusing on probabilistic diagnosis methods, the authors define several different categories of probabilistic diagnosis based on the type of fault syndrome information used in the diagnosis. Rigorous probabilistic analysis is then used to derive diagnosis algorithms optimal in terms of diagnostic accuracy for the diagnosis categories introduced. Analysis and simulations are used to evaluate the performance of the diagnosis algorithms introduced. >
Retrieval by Construction: a Traceability Technique to Support Verification and Validation of Uml Formalizations

Recently, there has been growing interest in formalizing UML, thereby enabling rigorous analysis of its many graphical diagrams. Two obstacles currently limit the adoption and use of UML formalizations in practice. First is the need to verify the consistency of artifacts under formalization. Second is the need to validate formalization approaches against domain-specific requirements. Techniques from the emerging field of requirements traceability hold promise for addressing these obstacles. This paper contributes a technique called retrieval by construction (RBC), which establishes traceability links between a UML model and a target model intended to denote its semantics under formalization. RBC provides an approach for structuring and representing the complex one-to-many links that are common between UML and target models under formalization. RBC also uses the notion of value identity in a novel way that enables the specification of the link-retrieval criteria using generative procedures. These procedures are a natural means for specifying UML formalizations. We have validated the RBC technique in a tool framework called UBanyan, written in C++. We applied the tool to three case studies, one of which was obtained from the industry. We have also assessed our results using the two well-known traceability metrics: precision and recall. Preliminary investigations suggest that RBC can be a useful traceability technique for validating and verifying UML formalizations.
Implementing DSP applications on heterogeneous targets using minimal size data buffers

The paper presents an algorithm to determine the smallest possible data buffer sizes for arbitrary synchronous data flow (SDF) applications, such that we can guarantee the existence of a deadlock free schedule. The presented algorithm fits in the design flow of GRAPE, an environment for the emulation and implementation of digital signal processing (DSP) systems on arbitrary target architectures, consisting of programmable DSP processors and FPGAs. Reducing the size of data buffers is of high importance when the application will be mapped on Field Programmable Gate Arrays (FPGA), since register resources are rather scarce.
Fund Tradeoffs Ľuboš Pástor

We derive equilibrium relations among active mutual funds’ key characteristics: fund size, expense ratio, turnover, and portfolio liquidity. Portfolio liquidity, a concept introduced here, depends not only on the liquidity of the portfolio’s holdings but also on the portfolio’s diversification. As our model predicts, funds with smaller size, higher expense ratios, and lower turnover hold less-liquid portfolios. Additional model predictions are also supported empirically: Larger funds are cheaper. Larger and cheaper funds trade less and are less active, based on our novel measure of activeness. Better-diversified funds hold less-liquid stocks; they are also larger, cheaper, and trade more. JEL classifications: G11, G23. *Pástor is at the University of Chicago Booth School of Business. Stambaugh and Taylor are at the Wharton School of the University of Pennsylvania. Pástor and Stambaugh are also at the NBER. Pástor is additionally at the National Bank of Slovakia and the CEPR. The views in this paper are the responsibility of the authors, not the institutions they are affiliated with. We are grateful for comments from our conference discussants Daniel Andrei, Wayne Ferson, Marcin Kacperczyk, Clemens Sialm, Ashish Tiwari, and Mungo Wilson. We are also grateful for comments from Jonathan Berk, Gene Fama, Laszlo Jakab, Don Keim, Rob Vishny, and Yao Zeng, conference participants at the Western Finance Association, European Finance Association, Duke/UNC Asset Pricing Conference, ESSFM Gerzensee, FARFE (MIT), GSU-CEAR Finance Conference, Conference on Professional Asset Management (Erasmus), Q Group, and seminar participants at Boston University, University of Chicago, University of Illinois at Urbana-Champaign, University of Pennsylvania, University of Utah, and WU Vienna. We are also grateful to Will Cassidy, Yeguang Chi, and Pierre Jaffard for superb research assistance. This research was funded in part by the Fama-Miller Center for Research in Finance and the Center for Research in Security Prices at Chicago Booth.
Effects of Various Forms of Stimulation on the Content of Enolase Isozymes and S‐100 Protein in Superior Cervical Sympathetic Ganglia Excised from Rats

Abstract: Contents of the three forms (αα, αγ, and γγ) of enolase isozymes and S‐100 protein in superior cervical sympathetic ganglia (SCG) excised from rats were determined by the sensitive method of enzyme immunoassay, after application of various forms of stimulation, during incubation for 3 h at 37°C in vitro. The amounts of the three forms of enolase isozymes and of S‐100 protein in the SCG were not altered by preganglionic or postganglionic stimulation (10 Hz) or by the addition of acetylcholine (1 mM) or a high concentration of K+ (70 mM) to the incubation medium. Norepinephrine (NE; 50 μM), as well as isoproterenol (200 μM) or 3,4‐dihydroxy phenylethylamine (dopamine; 200 μM), increased the ganglionic αα and αγ enolase content to 1.5 to 2.0 times the control level, whereas NE tended to slightly decrease the γγ enolase content. The increase in the α isozymes did not appear until after 2 to 3 h of incubation with this agent as a result of an increase in protein synthesis. Propranolol, an adrenergic antagonist, partly inhibited the NE‐induced increase in both αα and αγ enolases. NE and its agonists also considerably increased the S‐100 protein level in the SCG; however, the effect developed within half an hour of incubation as a result of the conversion of the bound S‐100 protein to the water‐soluble form, and did not greatly increase thereafter. Cyclic AMP (1 mM) produced the same kind of increase in the ganglionic S‐100 protein content as NE did. Propranolol, as well as cycloheximide, completely suppressed the NE‐evoked increase in S‐100 protein during 3 h incubation by inducing leakage of the protein into the medium. Axotomy caused greater NE‐induced increases in both act and αγ enolases and a greater decrease in γγ enolase in the SCG than denervation did, especially if examined 1 or 4 days after the operation. Axotomy alone also produced a delayed rise in NE‐induced ganglionic S‐100 protein concentration 7 days after the operation. These results suggest that there are no interconversions between αγ enolase and the αα or γγ forms in response to cholinergic stimulation or cell depolarization in the SCG. Instead, they suggest that NE acts on nonneuronal, glial rather than on neuronal components by increasing the biosynthesis of the α isozymes of enolase proteins, and that NE increases S‐100 protein content in nonneuronal, satellite cells through a receptor‐mediated, cyclic AMP‐dependent solubilization of the bound protein.
A framework for the study of vision in active observers

We present a framework for the study of active vision, i.e., the functioning of the visual system during actively self-generated body movements. In laboratory settings, human vision is usually studied with a static observer looking at static or, at best, dynamic stimuli. In the real world, however, humans constantly move within dynamic environments. The resulting visual inputs are thus an intertwined mixture of self- and externally-generated movements. To fill this gap, we developed a virtual environment integrated with a head-tracking system in which the influence of self- and externally-generated movements can be manipulated independently. As a proof of principle, we studied perceptual stationarity of the visual world during lateral translation or rotation of the head. The movement of the visual stimulus was thus parametrically tethered to self-generated movements. We found that estimates of object stationarity were less biased and more precise during head rotation than translation. In both cases the visual stimulus had to partially follow the head movement to be perceived as immobile. We discuss a range of possibilities for our setup among which the study of shape perception in active and passive conditions, where the same optic flow is replayed to stationary observers.
Insufficient Sleep and Risk of Prostate Cancer in a Large Swedish Cohort.

STUDY OBJECTIVE There are some data to suggest that insufficient sleep, including short sleep duration and sleep disruption, may be associated with an increased risk of cancer. We investigated the association between sleep duration and sleep disruption and risk of prostate cancer. DESIGN Prospective cohort study. SETTING Sweden. PARTICIPANTS A total of 14,041 men in the Swedish National March Cohort. INTERVENTIONS None. MEASUREMENTS AND RESULTS Habitual sleep duration and sleep disruption were self-reported in 1997. Prostate cancer diagnoses, including lethal (metastases at diagnosis or death from prostate cancer) and advanced (stage T4, N1, or M1 at diagnosis or death from prostate cancer), were determined from linkage to nationwide cancer registries through 2010. We conducted Cox proportional hazards regression adjusted for potential confounding variables. During 13 years of follow-up, we identified 785 cases of incident prostate cancer, including 118 lethal and 127 advanced cases. Four percent of men reported sleeping 5 h or less a night, and 2% reported sleeping 9 h or more per night. We found no association between sleep duration and risk of prostate cancer overall or for advanced/lethal disease. We also did not find an association between prostate cancer and sleep disruption, as defined by difficulty falling asleep, difficulty maintaining sleep, sleep quality, and restorative power of sleep. CONCLUSIONS In this large prospective study from Sweden, we found no association between habitual sleep duration or sleep disruption and risk of prostate cancer.
HIV-related knowledge, attitudes and risk perception amongst nurses, doctors and other healthcare workers in rural India.

BACKGROUND AND OBJECTIVE People with HIV in India frequently encounter discrimination while seeking and receiving healthcare services. The knowledge and attitudes of healthcare workers (HCWs) influences the willingness and ability of people with HIV to access care, and the quality of the care they receive. Previous studies of HIV-related knowledge and attitudes amongst Indian HCWs have been conducted primarily in large urban hospitals. The objective of this study was to asses HIV-related knowledge, attitudes and risk perception among a group of rural north Indian HCWs, and to identify predictors of willingness to provide care for patients with HIV infection. METHODS A cross-sectional survey of 266 HCWs (78% female) from seven rural north Indian health settings was undertaken in late 2002. A self-administered written questionnaire was made available in English and Hindi, and the response rate was 87 per cent. Information was gathered regarding demographic details (age, sex, duration of employment, job category); HIV-related knowledge and attitudes; risk perception; and previous experience caring for HIV-positive patients. Logistic regression modelling was undertaken to identify factors associated with willingness to care for patients with HIV. RESULTS The HCWs in this study generally had a positive attitude to caring for people with HIV. However, this was tempered by substantial concerns about providing care, and the risk of occupational infection with HIV was perceived by most HCWs to be high. After controlling for confounding, HCWs willingness to provide care for patients with HIV was strongly associated with having previously cared for patients with HIV (P = 0.001). Knowledge of HIV transmission and perception of risk were not associated with willingness to provide care. INTERPRETATION AND CONCLUSION The findings of this study showed a general willingness of HCWs to provide care for patients with HIV, tempered by concerns regarding provision of such care. Strategies to address HCWs concerns are likely to ameliorate the discrimination experienced by people with HIV when accessing healthcare services. These include the development of programmes to promote occupational safety of HCWs and involving people with HIV in awareness training of HCWs.
New WIMP population in the solar system and new signals for dark-matter detectors

We describe in detail how perturbations due to the planets can cause a sub-population of WIMPs captured by scattering in surface layers of the Sun to evolve to have orbits which no longer intersect the Sun. We argue that such WIMPs, if their orbit has a semi-major axis less than 1/2 of Jupiter's, can persist in the solar system for cosmological timescales. This leads to a new, previously unanticipated WIMP population intersecting the Earth's orbit. The WIMP-nucleon cross sections required for this population to be significant are precisely those in the range predicted for SUSY dark matter, lying near the present limits obtained by direct underground dark matter searches using cyrogenic detectors. Thus, if a WIMP signal is observed in the next generation of detectors, a potentially measurable signal due to this new population must exist. This signal, lying in the keV range for Germanium detectors, would be complementary to that of galactic halo WIMPs. A comparison of event rates, anisotropies, and annual modulations would not only yield additional confirmation that any claimed signal is indeed WIMP-based, but would also allow one to gain information on the nature of the underlying dark matter model.
Participation bias, durable opinion shifts and framing effects in citizens' juries

Estimates of the impact of deliberation on attitude change in real political settings are potentially biased. Those who participate in deliberation may differ in important ways from the population on whose behalf they are seen to be deliberating. In addition to obvious demographic differences, deliberators may be more predisposed to particular attitudes, or to shifts in attitudes, than the population as a whole. We investigate these problems by analyzing the first large-scale citizens’ jury to take place in Ireland. The jury was a random sample drawn from the 2002 Irish Election Study (IES), itself a random sample of Irish electors. Before jury selection the issue for deliberation, the treatment of domestic waste, was included in an IES follow-up panel study, along with questions on environmental attitudes. Jurors were also surveyed on key attitudes, immediately before and after the jury event. The core questions for deliberation were also part of a further IES panel study conducted nine months after the jury deliberations and including all jurors. This enabled us to use a well-structured control/treatment group research design. Large opinion shifts against waste incineration were observed on the day of deliberation, and these shifts remained observable nine months later. However, a troubling feature of the experiment, with potential implications for deliberation more generally, was the extent to which key “stakeholders” who expected to be on the “losing” side were able to influence and probably de-legitimize the eventual outcome by withholding their cooperation in the entire process.
Did the No Child Left Behind Act Miss the Mark? Assessing the Potential Benefits From an Accountability System for Early Childhood Education

With growing evidence that human capital investment is more efficiently spent on younger children coupled with wide variation in preschool access across states, this article uses a neoliberal approach to examine the potential social costs and benefits that could accrue should the United States decide to implement a centralized preschool accountability system. Conceptual agency-based arguments that support implementing a preschool accountability system are compared and contrasted with conceptual arguments that oppose centralized accountability. In spite of credible conceptual arguments that local control over preschool access maximizes efficiency, we find the most support for an accountability system that enhances equity through universal access to preschool.
An Adaptive Demand-Based Caching Mechanism for NAND Flash Memory Storage Systems

During past decades, the capacity of NAND flash memory has been increasing dramatically, leading to the use of nonvolatile flash in the system’s memory hierarchy. The increasing capacity of NAND flash memory introduces a large RAM footprint to store the logical to physical address mapping. The demand-based approach can effectively reduce and well control the RAM footprint. However, extra address translation overhead is also introduced which may degrade the system performance. In this article, we present CDFTL, an adaptive Caching mechanism for Demand-based Flash Translation Layer, for NAND flash memory storage systems. CDFTL adopts both the fine-grained entry-based caching mechanism to exploit temporal locality and the coarse-grained translation-page-based caching mechanism to exploit spatial locality of workloads. By selectively caching the on-demand address mappings and adaptively changing the space configurations of two granularities, CDFTL can effectively utilize the RAM space and improve the cache hit ratio. We evaluate CDFTL under a real hardware embedded platform using a variety of I/O traces. Experimental results show that our technique can achieve an 11.13% reduction in average system response time and a 35.21% reduction in translation block erase counts compared with the previous work.
Acute Renal Failure in the Hospital: Diagnosis and Management

A 69-year-old man with a history of coronary artery disease, hypertension, and stage 3 chronic kidney disease presented to the emergency department with acute onset of chest pain, dyspnea, and dizziness. The patient was hypotensive (68/36 mm Hg) with clinical evidence of pulmonary edema. Electrocardiogram revealed an acute anterior wall myocardial infarction. The patient underwent emergent cardiac catheterization during which an intra-aortic balloon pump (IABP) was placed for management of cardiogenic shock. Two coronary artery stents were placed and 380 mL of low-osmolar contrast were administered. Blood pressure improved over the next 24 hours and the IABP was removed. Urine output declined to less than 400 mL/day and the serum creatinine concentration increased from a baseline of 1.5 mg/dL to 6.8 mg/dL over 4 days. Serum potassium concentration increased to 6.8 mEq/L. The patient became anorexic with nausea and vomiting. Uremic symptoms and metabolic abnormalities developed, and acute hemodialysis was initiated.
Design and Production of the ECCOFLOW Resistive Fault Current Limiter

The European project ECCOFLOW aims at a versatile resistive-type superconducting fault current limiter. For the first time, such a device will be tested at two different sites. The project partners have developed a superconducting fault current limiter design based on REBCO tapes with respect to the specifications provided by two hosting utilities. The limiter will operate at 1 kA at a rated voltage of 24 kV, and will be tested in both a busbar and a transformer feeder application. The design started with extensive investigations on the superconductor tape properties, especially with respect to the limitation behavior in all possible scenarios, and subsequent wide-range modeling of its in-grid behavior. The general integrated layout provides a limitation time of up to 1 s. The limiter is cooled using Gifford-McMahon cryocoolers to recondense the evaporated nitrogen. The present status of production and testing will be presented as well.
Global stabilization of partially linear composite systems

It is shown that a cascade system consisting of a linearly controllable system and a nonlinearly asymptotically stable system is globally stabilizable by smooth dynamic state feedback if the linear subsystem is right-invertible and weakly minimum phase and the only linear variables entering the nonlinear subsystem are the output and the zero dynamics corresponding to this output. Both of these conditions are coordinate-free, and there is freedom of choice for the linear output variable. This result generalizes several earlier sufficient conditions for stabilizability. The weak minimum-phase condition for the linear subsystem cannot be relaxed unless a growth restriction is imposed on the nonlinear subsystem. <<ETX>>
Development of a Rear Wall for the KATRIN Rear Section and investigation of tritium compatibility of Rear Section components

The aim of the KArlsruhe TRItium Neutrino experiment is to improve the current neutrino mass sensitivity limit to 0.2 eV/c2 (90%C.L.). For that, the required proof of suitability of several components for a low pressure tritium atmosphere is furnished. In addition, an optical design for an e-gun is developed and the resulting electron rate is calculated. Also, a final Rear Wall with temporally stable and homogeneous work function is developed and characterized within the scope of this thesis.
Deciding k-colourability of -free graphs in polynomial time

The problem of computing the chromatic number of a -free graph is known to be NP-hard. In contrast to this negative result, we show that determining whether or not a -free graph admits a -colouring, for each fixed number of colours , can be done in polynomial time. If such a colouring exists, our algorithm produces it.