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The contribution presents the representative research progress on global static gravity field modeling, regional geoid/quasigeoid determination, vertical datum study, as well as the theory, algorithm and software for gravity field study in China from 2019 to 2023, which are the highlights of the chapter 6 "Progress in Earth Gravity Model and Vertical Datum" in the "2019-2023 China National Report on Geodesy" that submitted to the International Association of Geodesy(IAG). In addition, suggestions are proposed to promote the research in the fields of earth gravity field, geoid/quasigeoid and vertical datumin China according to trends of international geodesy and related disciplines. [ABSTRACT FROM AUTHOR]

Software testing focuses on detecting defects or failures during code execution. Testing is a challenging creative task, requiring automation. The adoption of good practices and testing strategies contributes to increasing the efficiency of software development companies. MTest.search model for automatic unit test generation has defined domain model extension, test, and execution mechanisms. In this work, mechanisms to extend the search-based reduction model are presented. The proposed extensions take into account the objects and sets involved in the source code, and enhance the detection of defects or failures based on the significance of the values and paths / scenarios involved in the test. To validate the proposal, three case studies were defined using classical methods and real projects. [ABSTRACT FROM AUTHOR]

The article presents different section introduction of the periodical, which discusses articles on the topics including reflections on the use of software in research; and teaching tasks of the History of America through the publication of peer-reviewed contributions national and foreign academics.

The detection of the endless loop has been an important issue in software research. In order to ensure the quality of software and improve the accuracy of endless loop detection, a method based on the basic path of the endless loop detection is proposed. Firstly, the source code is preprocessed, we cleaned the annotations, and detect the absolute endless loop; secondly, the intermediate code by the GCC compiler is generated, and the structural features of the program and generated the control flow graph are abstracted. Then we get the set of basic path and circle by the depth-first method. Finally, we backtracked from the end of the control flow graph which is used to find the exit of the loop structure and determine whether the exit condition is satisfied. Experiments demonstrate that the method improves the efficiency and accuracy of the endless loop detection. [ABSTRACT FROM AUTHOR]

In this paper, we build analytical models to examine the impact of network externalities on the competition between open source software (OSS) and proprietary software. We investigate the competing OSS and proprietary software products with comparable functionalities in four different scenarios depending on whether they are compatible with each other and whether the underlying market is fully covered (i.e., all consumers adopt one of the two products). Furthermore, we study which party has the most incentive to make its product compatible with its counterpart. When the market is fully covered, the installed base and the profit of proprietary software increase at the expense of a decreasing user base for OSS in the presence of network externalities. This competitive imbalance becomes more pronounced when OSS and proprietary software are incompatible and the market is partially covered. Finally, we find that in the presence of network externalities, being compatible with its rival is not desirable for the proprietary software, but highly beneficial to the OSS community. [ABSTRACT FROM AUTHOR]

As information technology develops rapidly and smart devices become popular, the traditional publishing industry is changing form. It has become very common for newspapers, books, magazines and pictures to transmit on the network. Because the network is easy to copy and spread text resources, the lawful interests of owners are liable to violate. In order to solve this problem, copyright protection technology represented by the text watermark has been invented. In this paper, a novel digital text watermarking algorithm utilizing word processing software is researched, which can ignore some faults in the documents to some extent. By means of this new algorithm, users can keep the copyright information in the reserved words of files and properly use the documents. The embedded watermark can be extracted and the copyright can be verified. [ABSTRACT FROM AUTHOR]

Abstract Recognition and interpretation of paleoclimate signals in sedimentary proxy datasets are time consuming and subjective. Acycle is a comprehensive and easy-to-use software package for time series analysis in paleoclimate research and education. It is designed to speed paleoclimate time series analysis, especially cyclostratigraphy, and to provide objective methods for estimating astrochronology. Acycle provides for detrending with multiple options to track and remove secular trends. A selection of power spectral analysis methodologies is offered for the detection of periodic signals. Many of the functions are specific to cyclostratigraphy and astrochronology that are not found in standard statistical packages. A specialized function is provided to assess the astronomical (Milankovitch) forcing of paleoclimate series and search for the most likely sedimentation rate by evaluating the correlation coefficient between power spectra of an astronomical solution and sedimentary proxy data. Sedimentary noise modeling (for past sea-level changes) is also provided in Acycle. As an example, Acycle is applied to a sedimentary proxy series from the cyclostratigraphy of the Paleocene-Eocene thermal maximum (PETM) in Core BH9/05 from the Paleogene Central Basin, Svalbard. Acycle detects significant astronomical forcing in the proxy series and relatively stable sedimentation rates during and after the PETM. Acycle runs in the MATLAB environment or as stand-alone software on Windows and Macintosh OS X, and is open-source software. Highlights • Acycle is signal processing software for paleoclimate research and education. • Many of the functions are specific to cyclostratigraphy and astrochronology. • Acycle includes models for sedimentary noise and sedimentation rate. • A fully implemented graphical user interface facilitates operator use. [ABSTRACT FROM AUTHOR]

Background: Analyses of replicates in sets of discrete data, typically acquired in multi-well plate formats, is a recurring task in many contemporary areas in the Life Sciences. The availability of accessible cross-platform data analysis tools for such fundamental tasks in varied projects and environments is an important prerequisite to ensuring a reliable and timely turnaround as well as to provide practical analytical tools for student training. Results: We have developed an easy-to-use, interactive software tool for the analysis of multiple data sets comprising replicates of discrete bivariate data points. For each dataset, the software identifies the replicate data points from a defined matrix layout and calculates their means and standard errors. The averaged values are then automatically fitted using either a linear or a logistic dose response function. Conclusions: DRfit is a practical and convenient tool for the analysis of one or multiple sets of discrete data points acquired as replicates from multi-well plate assays. The design of the graphical user interface and the built-in analysis features make it a flexible and useful tool for a wide range of different assays. [ABSTRACT FROM AUTHOR]

This paper presents a software library as a research and educational tool for Multi-Skill Resource-Constrained Scheduling Problem. The following useful tools have been implemented in Java: instance Generator, solution validator, solution visualizer and example solvers: Greedy algorithm and Genetic Algorithm. All tools are supported by iMOPSE dataset which consists of 36 instances and additional 'small' 6 instances for educational purpose. In the paper, three test studies are described: (1) educational use of 6 'small' instances, (2) optimization of cost or duration of a schedule, and (3) simple bicritieria optimization of cost/duration of a final schedule. All described tools/examples are freely published on iMOPSE homepage. [ABSTRACT FROM AUTHOR]

Abstract Offshore development and growing prospects of commercial shipping in the Arctic pose the challenge of optimal ship routing in ice. Route selection in spatially distributed ice conditions significantly affects the voyage time and determines the efficiency of shipping. Most of the applied methods of ice routing solve the problem of a single vessel route selection without considering icebreaker support. At the same time, the real practice of ice navigation is closely connected with icebreaker assistance. It allows reducing the voyage time and fuel consumption, while having additional costs for icebreaker services. Such opposite trends set an optimization task that has not been studied in detail before. In this article, we presented the formulation of a Single Vessel and Icebreaker Assisted Ice Routing optimization problem in non-stationary ice conditions. We considered the icebreaker assistance as an integral part of the overall route optimization problem, and used the economic criterion to optimize both ship route and amount of icebreaker involvement. The article contains the adapted mathematical formulations of classical graph-based and wave-based routing problems in order to consider icebreaker assistance. To prove the practical applicability of these formulations, we developed special subject-oriented research software and implemented there both graph-based (Dijkstra, A*) and the wave-based ice routing methods. Using this developments, we conducted several case studies and made the analysis of strengthens and weaknesses of the alternative routing methods in case of ice operation. The results of the study may serve an additional step to the practical implementation of ice routing technologies and planning of icebreaker resources. [ABSTRACT FROM AUTHOR]

Reuse is the activity of developing new software systems using software components (or artifacts) that are already proven and reliable. However, traditional reuse-based software development has difficulties in finding the components that have the proper information (feature) to match the developers' needs, or reusing a component without modification, because it has various and mixed information (features). In order to solve these problems, this paper proposes a dynamic control technique to enhance the reusability of software components. In particular, this technique focuses on the reuse of software documents that are created during the software research and development processes. We define a new unit of document reuse as a microComponent; this is a basic unit of reuse defined with a section of a software document. Based on the microComponent, it is possible to fast find more suitable components from a large-scale document repository; to control the reuse granularity from a section to an entire document; and finally, to improve the reusability of existing reusable assets. [ABSTRACT FROM AUTHOR]

Software is the key crosscutting technology that enables advances in mathematics, computer science, and domain-specific science and engineering to achieve robust simulations and analysis for science, engineering, and other research fields. However, software itself has not traditionally received focused attention from research communities; rather, software has evolved organically and inconsistently, with its development largely as by-products of other initiatives. Moreover, challenges in scientific software are expanding due to disruptive changes in computer hardware, increasing scale and complexity of data, and demands for more complex simulations involving multiphysics, multiscale modeling and outer-loop analysis. In recent years, community members have established a range of grass-roots organizations and projects to address these growing technical and social challenges in software productivity, quality, reproducibility, and sustainability. This article provides an overview of such groups and discusses opportunities to leverage their synergistic activities while nurturing work toward emerging software ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Hydrographic Surveying & Charting / Haiyang Cehui is the property of Hydrographic Surveying & Charting Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In software development, models are often used to represent multiple views of the same system. Such models need to be properly related to each other in order to provide a consistent description of the developed system. Models may contain contradictory system specifications, for instance, when they evolve independently. Therefore, it is very crucial to ensure that models conform to each other. In this context, we focus on consistency checking of behavior models. Several techniques and approaches have been proposed in the existing literature to support behavioral model consistency checking. This article presents a Systematic Literature Review (SLR) that was carried out to obtain an overview of the various consistency concepts, problems, and solutions proposed regarding behavior models. In our study, the identification and selection of the primary studies was based on a well-planned search strategy. The search process identified a total of 1770 studies, out of which 96 have been thoroughly analyzed according to our predefined SLR protocol. The SLR aims to highlight the state-of-the-art of software behavior model consistency checking and identify potential gaps for future research. Based on research topics in selected studies, we have identified seven main categories: targeted software models, types of consistency checking, consistency checking techniques, inconsistency handling, type of study and evaluation, automation support, and practical impact. The findings of the systematic review also reveal suggestions for future research, such as improving the quality of study design and conducting evaluations, and application of research outcomes in industrial settings. For this purpose, appropriate strategy for inconsistency handling, better tool support for consistency checking and/or development tool integration should be considered in future studies. [ABSTRACT FROM AUTHOR]

The use of Aloha-based random access protocols is interesting when channel sensing is either not possible or not convenient and the traffic from terminals is unpredictable and sporadic. In this paper an analytic model for packet interference calculation in asynchronous random access protocols using diversity is presented. The aim is to provide a tool that avoids time-consuming simulations to evaluate packet loss and throughput in case decodability is still possible when a certain interference threshold is not exceeded. Moreover the same model represents the groundbase for further studies in which iterative interference cancellation is applied to received frames. [ABSTRACT FROM AUTHOR]

This article analyzes the simultaneous control of several correlated Poisson variables by using the Variable Dimension Linear Combination of Poisson Variables (VDLCP) control chart, which is a variable dimension version of the LCP chart. This control chart uses as test statistic, the linear combination of correlated Poisson variables in an adaptive way, i.e. it monitors either p1 or p variables ( p1 < p) depending on the last statistic value. To analyze the performance of this chart, we have developed software that finds the best parameters, optimizing the out-of-control average run length (ARL) for a shift that the practitioner wishes to detect as quickly as possible, restricted to a fixed value for in-control ARL. Markov chains and genetic algorithms were used in developing this software. The results show performance improvement compared to the LCP chart. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Software obfuscation has always been a controversially discussed research area. While theoretical results indicate that provably secure obfuscation in general is impossible, its widespread application inmalware and commercial software shows that it is nevertheless popular in practice. Still, it remains largely unexplored to what extent today's software obfuscations keep up with state-of-the-art code analysis and where we stand in the arms race between software developers and code analysts. The main goal of this survey is to analyze the effectiveness of different classes of software obfuscation against the continuously improving deobfuscation techniques and off-the-shelf code analysis tools. The answer very much depends on the goals of the analyst and the available resources. On the one hand, many forms of lightweight static analysis have difficulties with even basic obfuscation schemes, which explains the unbroken popularity of obfuscation among malware writers. On the other hand, more expensive analysis techniques, in particular when used interactively by a human analyst, can easily defeat many obfuscations. As a result, software obfuscation for the purpose of intellectual property protection remains highly challenging. [ABSTRACT FROM AUTHOR]

As computer systems continue to grow in scale and complexity, performance problems become common and a major concern for large-scale computing. Performance anomalies caused by application bugs, hardware or software faults, or resource contention can have great impact on system-wide performance and could lead to significant economic losses for service providers. While many detection methods have been presented in the past, the newly emerging challenges are detection scalability and practical use. In this paper, we propose a scalable, non-parametric method for effectively detecting performance anomalies in large-scale systems. The design is generic for anomaly detection in a variety of parallel and distributed systems exhibiting peer-comparable property. It adopts a divide-and-conquer approach to address the scalability challenge and explores the use of non-parametric clustering and two-phase majority voting to improve detection flexibility and accuracy. We derive probabilistic models to quantitatively evaluate our decentralized design. Experiments with a suite of applications on production systems demonstrate that this method outperforms existing methods in terms of detection accuracy with a negligible runtime overhead. [ABSTRACT FROM AUTHOR]

Background: Whole brain volume (WBV) estimates in patients with multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. Numerous algorithms to measure WBV have been developed over the past two decades. We compare Structural Image Evaluation using Normalisation of Atrophy-Cross-sectional (SIENAX) to NeuroQuant and MSmetrix, for assessment of cross-sectional WBV in patients with MS.Methods: MRIs from 61 patients with relapsing-remitting MS and 2 patients with clinically isolated syndrome were analysed. WBV measurements were calculated using SIENAX, NeuroQuant and MSmetrix. Statistical agreement between the methods was evaluated using linear regression and Bland-Altman plots. Precision and accuracy of WBV measurement was calculated for (1) NeuroQuant versus SIENAX and (2) MSmetrix versus SIENAX.Results: Precision (Pearson's r) of WBV estimation for NeuroQuant and MSmetrix versus SIENAX was 0.983 and 0.992, respectively. Accuracy (Cb) was 0.871 and 0.994, respectively. NeuroQuant and MSmetrix showed a 5.5% and 1.0% volume difference compared with SIENAX, respectively, that was consistent across low and high values.Conclusions: In the analysed population, NeuroQuant and MSmetrix both quantified cross-sectional WBV with comparable statistical agreement to SIENAX, a well-validated cross-sectional tool that has been used extensively in MS clinical studies. [ABSTRACT FROM AUTHOR]

Purpose – By studying the drivers of social collaboration the purpose of this paper is to describe how, and for what job-related purposes, social software is employed in the digital workplace. Focussing on consultants, who are considered to be part of a knowledge-intensive and innovative industry, factors that may influence the adoption of professional social software are explored. In addition, insights about socio-demographic differences as well as distinct consulting segments and use categories are provided. Design/methodology/approach – The Unified Theory of Acceptance and Use of Technologies (UTAUT) is the theoretical backbone of this research. The UTAUT model is expanded to fit the research goals, and the results from a quantitative study (n=341) are used to test the model. Findings – The results suggest that the adoption of social software is associated with the expectation that one’s work performance will improve. There are significant differences regarding age and gender in the use of social software for job-related purposes. Practical implications – Using the results of the study, social software suites can be tailored to users’ needs and preferences, which, in turn, may lead to higher levels of acceptance and intensity of use. Originality/value – Social software is already widely adopted for private purposes, and it is being used more and more within the digital workplace, too. However, little research has been conducted into how, and for what job-related purposes, social software is employed, or into the potential drivers for its adoption. The stakeholders in the research include scholars and practitioners alike. [ABSTRACT FROM AUTHOR]

Background: The Alberta Stroke Program Early CT score (ASPECTS) is an established 10-point quantitative topographic computed tomography scan score to assess early ischemic changes. We compared the performance of the e-ASPECTS software with those of stroke physicians at different professional levels. Methods: The baseline computed tomography scans of acute stroke patients, in whom computed tomography and diffusion-weighted imaging scans were obtained less than two hours apart, were retrospectively scored by e-ASPECTS as well as by three stroke experts and three neurology trainees blinded to any clinical information. The ground truth was defined as the ASPECTS on diffusion-weighted imaging scored by another two non-blinded independent experts on consensus basis. Sensitivity and specificity in an ASPECTS region-based and an ASPECTS score-based analysis as well as receiver-operating characteristic curves, Bland--Altman plots with mean score error, and Matthews correlation coefficients were calculated. Comparisons were made between the human scorers and e-ASPECTS with diffusion-weighted imaging being the ground truth. Two methods for clustered data were used to estimate sensitivity and specificity in the region-based analysis. Results: In total, 34 patients were included and 680 (34-20) ASPECTS regions were scored. Mean time from onset to computed tomography was 172-135 min and mean time difference between computed tomographyand magnetic resonance imaging was 41-31 min. The region-based sensitivity (46.46% [CI: 30.8;62.1]) of e-ASPECTS was better than three trainees and one expert (p-0.01) and not statistically different from another two experts. Specificity (94.15% [CI: 91.7;96.6]) was lower than one expert and one trainee (p<0.01) and not statistically different to the other four physicians. e-ASPECTS had the best Matthews correlation coefficient of 0.44 (experts: 0.38-0.08 and trainees: 0.19-0.05) and the lowest mean score error of 0.56 (experts: 1.44-1.79 and trainees: 1.97-2.12). Conclusion: e-ASPECTS showed a similar performance to that of stroke experts in the assessment of brain computed tomographys of acute ischemic stroke patients with the Alberta Stroke Program Early CT score method. [ABSTRACT FROM AUTHOR]

Researchers have proposed many tools and techniques that work by traversing the heap, including checkpointing systems, heap profilers, heap assertion checkers, and dynamic software updating systems. Yet building a heap traversal for C remains difficult, and to our knowledge, extant services have used their own application-specific traversals. This paper presents C-strider, a framework for writing C heap traversals and transformations. Writing a basic C-strider service requires implementing only four callbacks; C-strider then generates a program-specific traversal that invokes the callbacks as each heap location is visited. Critically, C-strider is type aware - it tracks types as it walks the heap, so every callback is supplied with the exact type of the associated location. We used C-strider to implement heap serialization, dynamic software updating, heap checking, and profiling, and then applied the resulting traversals to several programs. We found that C-strider requires little programmer effort, and the resulting services are efficient and effective. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Distributed systems, especially clusters, can be used to execute ray tracing tasks in parallel for speeding up the image computation. Because ray tracing is a computational expensive and memory consuming task, ray tracing can also be used to benchmark clusters. This paper introduces task-distributor, a free software solution for the parallel execution of ray tracing tasks in distributed systems. The ray tracing solution used for this work is the Persistence Of Vision Raytracer (POV-Ray). Task-distributor does not require any modification of the POV-Ray source code or the installation of an additional message passing library like the Message Passing Interface or Parallel Virtual Machine to allow parallel image computation, in contrast to various other projects. By analyzing the runtime of the sequential and parallel program parts of task-distributor, it becomes clear how the problem size and available hardware resources influence the scaling of the parallel application. [ABSTRACT FROM AUTHOR]

A computer program was developed for the performance analysis and design optimization of a cylindrical shell and helical tube type HFC134a condenser and its predicted results were verified against the experimentally determined data. The computer model is based on a numerical method of cell discretization. The local values of variables like heat transfer rate, pressure drop, and the properties of refrigerant are calculated on the basis of appropriate theoretical and empirical correlations available in the literature and the mass, momentum, and energy balance is applied to each cell. The whole sequential and iterative procedure to satisfy the boundary conditions of each cell and of the whole condenser has been transformed into a computer program written in C++. This computer model was used in a parametric study to analyze the effects of varying the input parameters of both fluids on the performance of the condenser. It gives the optimal values of refrigerant mass velocity and of the tube diameter against the available conditions of external cooling fluid, mass flow rate of refrigerant, and degree of subcooling of the refrigerant at the condenser outlet. Its utility was found in the performance optimization of an existing condenser as well as in the design optimization of a new condenser. [ABSTRACT FROM AUTHOR]

The article describes the main requirements of the software subsystems management development. Standard IEC 61508-3 provides an overview at all stages of the life cycle of all security systems, including E/E/PE of a security system from initial concept, design, and implementation to operation maintenance. In this paper we analyzed set out requirements for the drafting of a software architecture that is consistent with the hardware architecture while meeting specified requirements for software safety. [ABSTRACT FROM AUTHOR]

Distributed in-memory key-value stores (KVSs) have become a critical data-serving layer in cloud computing and big data infrastructure. Unfortunately, KVSs have demonstrated a gap between achieved and available performance, QoS, and energy efficiency on commodity platforms. Two research thrusts have focused on improving key-value performance: hardware-centric research has started to explore specialized platforms for KVSs, and software-centric research revisited the KVS application to address fundamental software bottlenecks. Unlike prior research focusing on hardware or software in isolation, the authors aimed to full-stack (software through hardware) architect high-performance and efficient KVS platforms. Their full-system characterization identifies the critical hardware/software ingredients for high-performance KVS systems and suggests optimizations to achieve record-setting performance and energy efficiency: 120~167 million requests per second (RPS) on a single commodity server. They propose a future many-core platform and via detailed simulations demonstrate the capability of achieving a billion RPS with a single server platform. [ABSTRACT FROM PUBLISHER]