Добірка наукової літератури з теми "Code with t-availability"

Locally repairable codes (LRCs) are a new family of erasure codes used in distributed storage systems which have attracted a great deal of interest in recent years. For an [ n , k , d ] linear code, if a code symbol can be repaired by t disjoint groups of other code symbols, where each group contains at most r code symbols, it is said to have availability- ( r , t ) . Single-parity LRCs are LRCs with a constraint that each repairable group contains exactly one parity symbol. For an [ n , k , d ] single-parity LRC with availability- ( r , t ) for the information symbols (single-parity LRCs), the minimum distance satisfies d ≤ n - k - ⌈ k t / r ⌉ + t + 1 . In this paper, we focus on the study of single-parity LRCs with availability- ( r , t ) for information symbols. Based on the standard form of generator matrices, we present a novel characterization of single-parity LRCs with availability t ≥ 1 . Then, a simple and straightforward proof for the Singleton-type bound is given based on the new characterization. Some necessary conditions for optimal single-parity LRCs with availability t ≥ 1 are obtained, which might provide some guidelines for optimal coding constructions.

Abstract Motivation Non-parametric dimensionality reduction techniques, such as t-distributed stochastic neighbor embedding (t-SNE), are the most frequently used methods in the exploratory analysis of single-cell datasets. Current implementations scale poorly to massive datasets and often require downsampling or interpolative approximations, which can leave less-frequent populations undiscovered and much information unexploited. Results We implemented a fast t-SNE package, qSNE, which uses a quasi-Newton optimizer, allowing quadratic convergence rate and automatic perplexity (level of detail) optimizer. Our results show that these improvements make qSNE significantly faster than regular t-SNE packages and enables full analysis of large datasets, such as mass cytometry data, without downsampling. Availability and implementation Source code and documentation are openly available at https://bitbucket.org/anthakki/qsne/. Supplementary information Supplementary data are available at Bioinformatics online.

In the diameter-to-thickness range 250 < D/t < 1000, internally pressurized torispherical shells can fail either by plastic buckling or by axisymmetric yielding. However, the present Code rules cater only for the axisymmetric yielding mode and they also restrict the D/t ratios to being less than 500. The rules are based on limit analysis results and these can be conservative for this problem. With regard to internal pressure buckling, there are as yet no design rules in either the American or the British pressure vessel Codes to prevent its occurrence. To provide guidance for a more accurate formulation of design rules for both of these failure modes over the range 300 < D/t < 1500, the authors have made a series of calculations to determine the values of Pcr (the internal buckling pressure) and pc (the axisymmetric yielding pressure) for perfect torispherical shells. The availability of these results, obtained with a finite-deflection shell theory, enables curves to be drawn showing when buckling is the controlling failure mode and when axisymmetric yield controls. A comparison is also made, for D/t < 600, between the controlling failure pressures mentioned above and the Drucker-Shield limit pressures. The ratio between the former and the latter varied between 1.2 and 1.8, depending on the geometry of the shell and the magnitude of the yield point, σyp. Considerable economies in the designs of many torispherical shells could, therefore, be achieved if the relevant sections of the Codes were to be modified to take advantage of the foregoing results. The controlling failure pressure curves also indicate how Code rules to prevent plastic buckling for D/t > 500 might be formulated. For the benefit of designers, the numerical values of pcr and pc were transformed, using curve-fitting techniques, into simple approximate equations. Although these equations are for perfect torispherical shells, they should be very beneficial when analysing the related problems of fabricated torispheres in practice.

Introduction:The use of tourniquets by the civilian population has been deemed a critical aspect of the initial response during an active shooter situation. Tourniquet deployment in public-access must be accompanied by education. Studies indicate that the act itself is not an intuitive process and enclosed instructions may be inadequate. However, civilians for diverse reasons may not avail themselves of accepted training programs.Aim:To develop an alternative means of “Just-In-Time” education to enable a naïve responder to apply a commercial tourniquet efficaciously.Methods:A video (~40 seconds long) was created highlighting the actual application of a C-A-T® (Combat Application Tourniquet) on a human model. It was uploaded to YouTube on a public channel. A QR® code was generated using https://www.qr-code-generator.com, embedding the link for the YouTube® video. An appropriately-sized QR® code was printed and applied with packaging tape (Scotch®) to the exterior wrapping of a C-A-T® device. The C-A-T® with code was then accessed with the iPhone®.Results:With the iPhone® camera app activated and focused on the C-A-T’s QR® code, a request popped-up to open “YouTube.com” in Safari. When pressed, the full-screen video appeared immediately with audio of excellent quality.Discussion:The use of a QR® code and its video link is a feasible option to provide “Just-In-Time” training to a naïve civilian population who are responding to an active shooter situation. This offers the naïve responder two options of immediate education: the enclosed instructions and the QR® code. Redundancy in communications is essential in any emergency response. An important limitation of this innovation is the inability to obtain Internet® access and therefore, the availability of the enclosed instructions is still critical. Research to prove that this innovation will allow the application of a tourniquet to proceed expeditiously with few errors is currently underway.

Abstract Summary Advances in single-cell technologies have enabled the investigation of T-cell phenotypes and repertoires at unprecedented resolution and scale. Bioinformatic methods for the efficient analysis of these large-scale datasets are instrumental for advancing our understanding of adaptive immune responses. However, while well-established solutions are accessible for the processing of single-cell transcriptomes, no streamlined pipelines are available for the comprehensive characterization of T-cell receptors. Here, we propose single-cell immune repertoires in Python (Scirpy), a scalable Python toolkit that provides simplified access to the analysis and visualization of immune repertoires from single cells and seamless integration with transcriptomic data. Availability and implementation Scirpy source code and documentation are available at https://github.com/icbi-lab/scirpy. Supplementary information Supplementary data are available at Bioinformatics online.

The energy sector of trinidad and tobago (T&amp;T), with its nationally determined contributions (NDCs), is still struggling for its place in mainstream academic literature. The review paper aims to identify the prospects of low-cost energy conservation measures in the residential sector of T&amp;T. The review follows a four-step review methodology to serve as a basis for creating policy and practice guidelines. First, review articles are checked for their quality on a 5-point scale on the mixed methods appraisal tool (MMAT) to check the quality of review articles. Second, Microsoft Excel, R (RQDA) package, and Voyant tools have been used to index code, analyse, and visualise data. The research trends on small islands developing states (SIDS) energy aspect in general and T&amp;T specifically highlight the critical role of energy challenges related to economic and social development, emphasising technology, infrastructure development, and funds availability. Awareness of low-cost energy conservation measures has a high prospect in reducing residential consumption and balancing demand-side management. This paper contributes to facilitating policy direction on energy efficiency and energy conservation for T&amp;T and other SIDS.

The that-trace effect is the fact that many languages (like English) ban the extraction of embedded-clause subjects but not objects over an overt complementizer like that, while many other languages (like Spanish) allow such extractions. The effect and its cross-linguistic variation have been the subject of intense research but remain largely a mystery, with no clear consensus on their underpinnings. We contribute novel evidence to these debates by using Spanish–English code-switching (the use of two languages in one sentence) to test five contemporary theoretical accounts of the that-trace effect. We conducted a formal acceptability judgment experiment, manipulating the extracted argument and code-switch site to test different combinations of linguistic features. We found that subject extraction is only permitted in Spanish–English code-switching when both the C head (que ‘that’) and the T head (i.e., the verb) are in Spanish, but not when either functional head is in English. Our results demonstrate indirect support for two of the five theories we test, failing to support the other three. Our findings also provide new evidence in favor of the view that the that-trace effect is tightly linked to the availability of post-verbal subjects. Finally, we outline how our results can narrow the range of possible theoretical accounts, demonstrating how code-switching data can contribute to core questions in linguistic theory.

Abstract Motivation Low-dimensional representations of high-dimensional data are routinely employed in biomedical research to visualize, interpret and communicate results from different pipelines. In this article, we propose a novel procedure to directly estimate t-SNE embeddings that are not driven by batch effects. Without correction, interesting structure in the data can be obscured by batch effects. The proposed algorithm can therefore significantly aid visualization of high-dimensional data. Results The proposed methods are based on linear algebra and constrained optimization, leading to efficient algorithms and fast computation in many high-dimensional settings. Results on artificial single-cell transcription profiling data show that the proposed procedure successfully removes multiple batch effects from t-SNE embeddings, while retaining fundamental information on cell types. When applied to single-cell gene expression data to investigate mouse medulloblastoma, the proposed method successfully removes batches related with mice identifiers and the date of the experiment, while preserving clusters of oligodendrocytes, astrocytes, and endothelial cells and microglia, which are expected to lie in the stroma within or adjacent to the tumours. Availability and implementation Source code implementing the proposed approach is available as an R package at https://github.com/emanuelealiverti/BC_tSNE, including a tutorial to reproduce the simulation studies. Contact aliverti@stat.unipd.it

Abstract Summary Recent advances in modelling VDJ recombination and subsequent selection of T- and B-cell receptors provide useful tools to analyse and compare immune repertoires across time, individuals and tissues. A suite of tools—IGoR, OLGA and SONIA—have been publicly released to the community that allow for the inference of generative and selection models from high-throughput sequencing data. However, using these tools requires some scripting or command-line skills and familiarity with complex datasets. As a result, the application of the above models has not been available to a broad audience. In this application note, we fill this gap by presenting Simple OLGA & SONIA (SOS), a web-based interface where users with no coding skills can compute the generation and post-selection probabilities of their sequences, as well as generate batches of synthetic sequences. The application also functions on mobile phones. Availability and implementation SOS is freely available to use at sites.google.com/view/statbiophysens/sos with source code at github.com/statbiophys/sos.

Abstract Availability of markers such as cardiac troponin T (cTnT) has brought new insights into ischemic heart disease (IHD). cTnT is a distinct protein that differs from other markers in biological function, molecular mass, and cytosolic pool. cTnT has been utilized for diagnosis of acute myocardial infarction (AMI) and risk stratification of patients with IHD. For AMI diagnosis, cTnT showed high sensitivity (94-100%) but generally lower specificity (46-99%), possibly because of increases in non-AMI patients with minor myocardial damage. Outcome studies have demonstrated that IHD patients with increased cTnT are at significantly greater risk for cardiac events; revascularization in patients with increased cTnT may improve outcome. Estimated costs for batched ES 300 cTnT results and for a cTnT rapid assay run "on demand" were $17.48 and $21.65, respectively. cTnT currently has no specific common procedure test code; expected reimbursement is $18.32 for the ES 300 and is not established for the rapid assay.

The reliable storage of Big Data across a spatially distributed network of nodes, calls for erasure-correcting codes that in addition to protecting against data loss, can also efficiently handle node repair. The need for node repair could arise on account of device failure, need for a maintenance reboot, or simply because the node is busy serving other demands. An important consideration here is the rate of the code, which is the ratio of the number of data symbols to the total amount of storage needed to reliably store these data symbols. In response, coding theorists have come up with two new classes of codes, known respectively as regenerating codes and Locally Recoverable Codes (LRC). While the focus of the thesis is on LRC, there are also contributions to the theory of regenerating codes. Contributions to LRC: A LRC is quite simply, a code where a given code symbol can be recovered by contacting at most r other code symbols, where the parameter r is much smaller than the dimension k of the code. A LRC with sequential recovery, is a code that can recover from an arbitrary set of trerasures in t steps in a sequential fashion. Each step recovers an erased symbol and makes use of at most r other code symbols comprising of unerased symbols as well as previously recovered symbols. In this thesis, a tight upper bound on the rate of LRC with sequential recovery is provided, for any value of the number t of erasures and any value of the locality parameter r ≥ 3. This bound proves an earlier conjecture due to Song, Cai and Yuen. While the bound is valid irrespective of the field over which the code is defined, a matching construction of binary codes that achieve the upper bound on rate is also presented. Contributions to Regenerating Codes: Regenerating codes aim to minimize the amount of data download needed to repair a failed node. Regenerating codes are linear codes that operate over a vector alphabet, i.e., each code symbol in a regenerating code is a vector of α symbols drawn from a field F. An important open question relates to the minimum possible value of α for a given storage overhead. Here we present tight lower bounds on α for the case when the codes belong to a certain class of codes called MSR codes as well as have the property of optimal access, i.e., symbols are accessed and transmitted as such without any computation by helper node for repair of a failed node. Contribution to availability Codes: A code in which each code symbol can be recovered in t different ways using respectively t pairwise disjoint set of code symbols with each set of size at most r is called a code with t-availability. The contributions of the thesis in the direction of t-availability codes include improved upper bounds on the minimum distance dmin of this class of codes, both with and without a constraint on the size q of the code-symbol alphabet. An improved upper bound on code rate R is also provided for a subclass of t-availability codes, termed as codes with strict availability. Among the class of t-availability codes, codes with strict availability typically have high rate. A complete characterization of optimal tradeoff between rate and fractional minimum distance for a special class of t-availability codes is also provided. There are additional results which are not mentioned above including results relating to a class of codes called maximum recoverable codes.

In this study, several aspects of Saxion spin-offs have been analysed, the numbers, workplaces, location, migration, gender issues, different economic sectors and survival rates. The main question underlying all these analyses was what the impact of Saxion as university of applied sciences is on the regional economy of the two regions in which it is located. From the literature, the concept of an entrepreneurial ecosystem, as explanatory factor for the observations that in certain regions more graduates or staff members start their own business and that such an ecosystem helps small fledgling businesses to survive and grow is an interesting concept. Unfortunately, the theoretical foundations are still not fully crystallized, therefore measuring the actual influence of such entrepreneurial ecosystems is still a difficult exercise. In this study, Saxion spin-offs from two regions, Twente and the Cleantech Region, have been analysed, and several differences in terms of number of spin-offs, employment, migration patterns and survival rates have been identified. Since the spin-offs are from the same university of applied sciences, with the same policy regarding support of entrepreneurship and both regions are located outside of the economic core regions of the country, it appears as if the strength of the regional context, the regional entrepreneurial ecosystem and the business opportunities it provides is a factor in explaining why there are more spin-offs in Twente (even when controlling for the larger size of the Saxion campus in this region). If one assumes that the strength of the entrepreneurial ecosystem is stronger in Twente (among others because of existing business networks, the availability of a world class research university, the University of Twente and a business support organization like Novel-T), it would explain why spin-offs located in this region on average offer more workplaces, and have a higher survival rate than in the Cleantech Region. Gender differences related to entrepreneurship are present in Saxion spin-offs, female graduates and staff members are much less likely to start a spin-off company than their male counterparts. When females do start, their spin-offs are on average much smaller in terms of workplaces offered. Their businesses have on average an equal survival rate than those started by a male entrepreneur. Findings from the literature on the subject and the numbers found in this study suggest that there is a need for specific programs in Saxion targeting females, to at least think about starting their own business. Also, specific mentoring programs for spin-offs with female entrepreneurs may help to let these businesses grow and increase their regional economic impact. Saxion spin-offs can be found in many different sectors, something understandable given the broad spectrum of study programs in Saxion. Even though most spin-offs remain micro sized businesses, certain economic sectors seem to offer better scalable business models, especially in sectors such as industry, information and communication technology businesses and business support services. The number as well as employment in the more innovative and internationally competitive topsectors is much higher in the region Twente than in the Cleantech Region, possibly another consequence of the – apparently – stronger regional entrepreneurial ecosystem in Twente. An often-stated argument for regional economic development is that investing in spin-off companies will help to create workplaces in the region, since companies are not very likely to move. In this study, the data on migration of spin-offs have been compared with the migration of graduates, based on the HBO-monitor survey. It is not possible to one-on-one compare the two datasets, as the migration of spin-offs is calculated for the first five years of their existence and the HBO-monitor is held around one and a half year after graduation. Still, w

One of the most promising sectors in the global economy is Tourism, yet in Russia, the sector's potential is far from fulfilled. Tourism should be at the heart of the core priority areas of Russia's economic development, particularly true in view of the current economic slump. Russia has no shortage of regions with visibly high potential for developing tourism, yet there are a number of problems, characteristic of Russia, which impede its progress: malnourished tourism coupled with an unsophisticated infrastructure, a shortage of personnel, weak marketing, a gloomy business climate, and a lack of adequate regulatory frameworks. Be this as it may, the slump, rather than being a hindrance, should be considered a fresh opportunity for the Russian tourism sector. Russia has been ranked 45th in the latest edition of the biennial Travel and Tourism Competitiveness Report, improving its performance by 18 points from its 2013 ranking of 63rd. The ranking, which includes 141 countries, is compiled by the World Economic Forum and Strategy Partners Group every two years, and assesses “the set of factors and policies that enable the sustainable development of the Travel and Tourism (T&T) sector, which in turn, contributes to the development and competitiveness of a country.” In 2013, the WEF cited hefty prices as one of the main disadvantages of the Russian tourist market. The availability of natural and cultural heritage sites has ensured additional points for Russia in the overall ranking; in these areas the country ranked 34th and 21st, respectively. Tours to Russia have become more affordable following the recent devaluation of the ruble – the value of the national currency against the U.S. dollar has fallen by 44 percent since May 2014. As a result, accommodation in hotels has become markedly cheaper. In addition, the consultants noted an improvement in air links (22nd). The present research is an attempt to analyze the development of domestic and inbound tourism in Russian Federation.

Some safety systems of the Ignalina Nuclear Power Plant (NPP) operate in standby mode. An equipment of such systems is periodically tested and that allows timely detect and repair equipment failures. The periodic testing is an important measure of ensuring systems’ operability and reliability. However, during the test and repair the equipment cannot perform it’s safety function, therefore too often testing decreases the availability of the system. This paper describes the mathematical model that represents how availability and reliability of the systems and their components depend on testing interval, taking into account different failure modes of the equipment. This model allows to find the optimal testing interval for the safety. As an example, the auxiliary feedwater pumps, that are a part of the Ignalina NPP Reactor Emergency Core Cooling System, are analysed. The model parameters calculation is based on Ignalina NPP data regarding pumps operation and failure as well as on general Nordic NPPs reliability data (T-Book) appling Bayesian approach for parameters updating. The analysed safety system is a redundant system that consists of six pumps and other equipment. Therefore a model for multiple components failure was developed. The model accounts for actual operational requirements of the system. The results of this model are compared with usually used binominal model.

DONG Energy owns and operates seven power stations in Denmark fueled by internationally traded bituminous coal. Since the early 1980s, competitiveness has been supported by an efficient conversion from coal to wire in super critical boilers and turbines. DONG Energy also operates a double reheat plant with ultra super critical steam parameters, and based on experience from this plant, a revised concept for the double reheat steam cycle has been developed. The revised design (named the Master Cycle or MC) solves the problems with the very strong superheating of the bleed steam from the IP turbines and paves the way for an affordable double reheat technology. The core component of the revised design is a small separate turbine (named the tuning turbine or T-turbine) driving a 100% boiler feed pump in combination with a balancing motor/generator and delivering relatively cold bleed steam for the heaters normally bleeding on the IP turbines. The T-turbine is fed with steam from the first cold reheat steam line meaning reduced steam flow through the reheaters and higher main steam flow which is advantageous for cooling of the furnace walls. Based on the Master Cycle and Ultra Super Critical (USC) steam parameters, net efficiency of a single reheat plant can be improved from 47% to 48.5% without any deterioration of availability. Many double reheat plants with elements similar to those of the Master Cycle are in operation in the USA and their operational records are excellent. Higher net efficiency of a Master Cycle plant would mean solid CO2 reductions of 4% by comparison with a new single reheat plant. Much higher reductions could be achieved by replacing an old plant.

Sodium cooled fast breeder reactors constitute the second stage of India’s three-stage nuclear energy programme, for effective utilization of the country’s limited reserves of natural uranium and exploitation of its large reserves of thorium. The Fast Breeder Test Reactor (FBTR) at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, is a sodium cooled, loop type fast reactor. Its main aim is to provide experience in fast reactor operation and large scale sodium handling and to serve as a test bed for irradiation of fast reactor fuels and materials. FBTR was built on the lines of the French Rapsodie-Fortissimo reactor, with modifications to make it a generating plant. FBTR heat transport system consists of two primary sodium loops, two secondary sodium loops and one common tertiary steam and water circuit. The steam water system mainly consists of a once-through steam generator, which produces super heated steam at a pressure of 125 bars and temperature of 480° C, feed water system and condensate system. The steam produced is supplied to a condensing turbine coupled to an alternator. The reactor achieved first criticality in Oct 85 with a small core of 22 fuel subassemblies (SA) having a unique carbide fuel rich in Pu. This fuel (called MK-I) was developed and made in India and has a composition of 70% PuC-30% UC. The steam generator was put in service in Jan.1993 and turbine generator was synchronized to the grid in July 1997. In the light of the excellent performance of the carbide fuel, which has endured a burn-up of 155 GWd/t without any clad failure, the core has been gradually expanded by the addition of mark II (55% PuC-45% UC) and MOX (44% PuO2−56% UO2) fuel SA to compensate for the burn-up reactivity loss, and the reactor power has been progressively raised from 10.6 MWt to a maximum of 17.4 MWt. Over the years, several safety related experiments have been conducted. These include natural convection tests and experiments to validate the Failed Fuel Detection System. The challenges faced include a major fuel handling incident, primary sodium leak and reactivity transients. Two major modifications were carried out — one on the Steam Generator Leak Detection System and the other in the steam-water circuit. These helped in improving the campaign availability from less than 50% to more than 90%. The main component limiting the life of reactor is the grid plate supporting the core. The fast flux at the grid plate was measured using Np foils. The residual life of the grid plate has been estimated as 11 effective full power years. The paper presents operating experience of the reactor, performance of the carbide fuel, safety related experiments done in the reactor, various challenges faced, various modifications carried out to improve system reliability and availability and residual life assessment of the reactor.