An exact momentum update useful for particle codes was previously given. The expressions involved were unwieldy. By treating the momentum as a representation of SU(2)⊗SU(2) instead of SO(3,1), a more compact expression for the exact momentum update is obtained. An expansion in powers of the timestep can be formulated such that invariance properties are exactly preserved, and push rates comparable to

In recent years, increased attention is being given to software quality assurance and protection. With considerable verification and protection schemes proposed and deployed, today’s software unfortunately still fails to be protected from cyberattacks, especially in the presence of insecure organization of heap metadata. In this paper, we aim to explore whether heap metadata could be corrupted and

A sitemap represents an explicit specification of the design concept and knowledge organization of a website and is therefore considered as the website’s basic ontology. It not only presents the main usage flows for users, but also hierarchically organizes concepts of the website. Typically, sitemaps are defined by webmasters in the very early stages of the website design. However, during their life

Rumormongers spread negative information throughout the social network, which may even lead to panic or unrest. Rumor should be blocked by spreading positive information from several protector nodes in the network. Users will not be influenced if they receive the positive information ahead of negative one. In many cases, network manager or government may not know the exact positions where rumor will

Cloud manufacturing (CM) is a new service-oriented networked manufacturing mode. The optimal configuration of manufacturing services is one of most challenging topics in CM. Most research focuses on service composition optimization algorithms. However, for different manufacturing tasks, the configuration mode of the manufacturing services is different. For complex parts, effectively using the appropriate

The presence of proper wrinkles is important while modeling realistic virtual garments. Unlike previously used full 3D information methods, our approach achieves detailed garment generation from a single image. First, we retrieve a garment image similar to the initial virtual garment based on content-based image retrieval (CBIR) method. Then, we preprocess the image with a combination of human body

Automatic gunshot detection technology allows incidence response system to counteract the potential of crimes. However, the surveillance systems suffer from various detection problems, such as difficulty in differentiating gunshot, fire work and other similar sounds. To improves the accuracy and reduces processing time, we have proposed hybrid algorithm for automatic detection of gunshots in indoor

There exist many variants of guarding an orthogonal polygon in an orthogonal fashion: sometimes a guard can see within a rectangle, along a staircase, or along an orthogonal path with at most k bends. In this paper, we study all these guarding models for the special case of orthogonal polygons that have bounded treewidth in some sense. As our main result, we show that the problem of finding the minimum

System verification is an ever-lasting system engineering challenge. The increasing complexity in system simulation requires some level of expertise in handling the idioms of logic and discrete mathematics to correctly drive a full verification process. It is recognized that visual modeling can help to fill the knowledge gap between system experts and analysis experts. However, such an approach has

Computer programs have taken an important role in the prediction of future ecological trajectories. This study reviewed the existing computer programs that aim to predict future trajectories of ecosystems, biological populations, or ecological systems. Overall, 106 programs were examined. A rich set of programs exist and most of them are free. A substantial proportion (43%) are distributed open source

Stack Overflow has been heavily used by software developers as a popular way to seek programming-related information from peers via the internet. The Stack Overflow community recommends users to provide the related code snippet when they are creating a question to help others better understand it and offer their help. Previous studies have shown that a significant number of these questions are of low-quality

Smart contracts are automated or self-enforcing contracts that can be used to exchange assets without having to place trust in third parties. Many commercial transactions use smart contracts due to their potential benefits in terms of secure peer-to-peer transactions independent of external parties. Experience shows that many commonly used smart contracts are vulnerable to serious malicious attacks

Raw lines of code (LOC) is a metric that does not, at first glance, seem extremely useful for automated test generation. It is both highly language-dependent and not extremely meaningful, semantically, within a language: one coder can produce the same effect with many fewer lines than another. However, relative LOC, between components of the same project, turns out to be a highly useful metric for

Refactoring aims at improving code non-functional attributes without modifying its external behavior. Previous studies investigated the motivations behind refactoring by surveying developers. With the aim of generalizing and complementing their findings, we present a large-scale study quantitatively and qualitatively investigating why developers perform refactoring in open source projects. First, we

Learning representation for source code is a foundation of many program analysis tasks. In recent years, neural networks have already shown success in this area, but most existing models did not make full use of the unique structural information of programs. Although abstract syntax tree (AST)-based neural models can handle the tree structure in the source code, they cannot capture the richness of

Many applications in emerging scenarios, such as autonomous vehicles, intelligent robots, and industrial automation, are safety-critical with strict timing requirements. However, the development of real-time systems is error prone and highly dependent on sophisticated domain expertise, making it a costly process. This article utilises the principles of model-driven engineering (MDE) and proposes two

Wireless communication standards such as Long-term Evolution (LTE) are rapidly changing to support the high data-rate of wireless devices. The physical layer baseband processing has strict real-time deadlines, especially in the next-generation applications enabled by the 5G standard. Existing basestation transceivers utilize customized DSP cores or fixed-function hardware accelerators for physical

The problem of estimating a tight and safe Worst-Case Execution Time (WCET), needed for certification in safety-critical environment, is a challenging problem for modern embedded systems. A possible solution proposed in past years is to exploit statistical tools to obtain a probability distribution of the WCET. These probabilistic real-time analyses for WCET are, however, subject to errors, even when

Critical real-time systems require strict resource provisioning in terms of memory and timing. The constant need for higher performance in these systems has led industry to recently include GPUs. However, GPU software ecosystems are by their nature closed source, forcing system engineers to consider them as black boxes, complicating resource provisioning. In this work, we reverse engineer the internal

In recent years, the next-generation non-volatile memory (NVM) technologies have emerged with DRAM-like byte addressability and disk-like durability. Computer architects have proposed to use them to build persistent memory that blurs the conventional boundary between volatile memory and non-volatile storage. However, ARM processors, ones that are widely used in embedded computing systems, start providing

This article addresses the challenges of memory safety in life-critical medical devices. Since the last decade, healthcare manufacturers have embraced the Internet of Things, pushing technological innovations to increase market share. Medical devices, including the most critical ones, tend to be increasingly connected to the Internet. Unfortunately, as critical devices often rely on unsafe programming

Detection of malicious programs using hardware-based features has gained prominence recently. The tamper-resistant hardware metrics prove to be a better security feature than the high-level software metrics, which can be easily obfuscated. Hardware Performance Counters (HPC), which are inbuilt in most of the recent processors, are often the choice of researchers amongst hardware metrics. However, a

There is a growing number of application domains ranging from multimedia to machine learning where a certain level of inexactness can be tolerated. For these applications, approximate computing is an effective technique that trades off some loss in output data integrity for energy and/or performance gains. In this article, we present the approximate cache, which approximates similar values and saves

The complexity of systems now under consideration (be they biological, physical, chemical, social, etc), together with the technicalities of experimentation in the real-world and the non-linear nature of system dynamics, means that computational modelling is indispensible in the pursuit of furthering our understanding of complex systems. Agent-based modelling and simulation is rapidly increasing in

Induced damage during biocomposites drilling is significantly different to that produced on composites based on synthetic reinforcement such as carbon or glass fibers. In composites reinforced with carbon or glass fibers, induced damage increases with feed rate, however damage was observed to decrease with feed rate in biocomposites reinforced with natural fibers. This work is focused on the explanation

The Water Evaluation and Planning (WEAP) system, a modeling and simulation tool, offers certain advantages for studying water systems. These systems are modeled as a collection of supply, demand, and transmission entities. Domain experts can construct whole water system models from template model parts (entities) with built-in constraints for combining them. The parameterized entities are simulated

Cognitive Radio (CR) technology was introduced to effectively exploit the under-utilization portions of the licensed spectrum. A primary challenge in enabling CR networking is how to coordinate the CR communications, in which CR users need to exchange their control information before data exchange can take place. Providing a reliable coordination mechanism in CR networks (CRNs) is not an easy task

Simultaneous effects of non-Newtonian and curvature on unsteady nano-fluid flow through overlapping stenosed channel have been investigated in this letter. In this numerical investigation, a mathematical formulation is developed in order to analyze the influence of blood shear thinning/thickening effects on the rheology of the nano-fluid within curved channel which is not explored yet. Moreover, the

With the rapid development of electronic and information technology, Internet of Things (IoT) devices have become extensively utilised in various fields. Increasing attention has been paid to the performance and security analysis of IoT-based services. Dynamic instrumentation is a common process in software analysis for acquiring runtime information. However, due to the limited software and hardware

There is a looming shortage of well-trained professionals in the wood construction workforce. To challenge this shortage, we developed a simulated learning environment that leverages a novel Virtual Reality (VR) system to train novice workers in wooden wall construction. A comprehensive task analysis was first used to best identify training requirements. Then, a virtual building site was modeled and

Interference management has always been a research hotspot in the field of wireless communications. Currently, researches based on interference management mostly focus on an interference management technology, and few studies have combined multiple interference management technologies. This paper proposes an interference management technology that combines Interference Alignment (IA) and Successive

Convolutional neural networks (CNNs) can learn the features of samples by supervised manner, and obtain outstanding achievements in many application fields. In order to improve the performance and generalization of CNNs, we propose a self-learning hybrid dilated convolution neural network (SPHDCNN), which can choose relatively reliable samples according to the current learning ability during training

The internet changed the way that people communicate, and this has led to a vast amount of Text that is available in electronic format. It includes things like e-mail, technical and scientific reports, tweets, physician notes and military field reports. Providing key-phrases for these extensive text collections thus allows users to grab the essence of the lengthy contents quickly and helps to locate

High resolution medical images are expected for accurate analysis results in medical diagnosis. However, the resolution of these medical images is always restricted by the factors such as medical devices, time constraints. Despite these restrictions, the resolution of these medical images can be enhanced with a well-designed super-resolution(SR) algorithm. As a post-processing manner after medical

Vessel extraction from the retinal fundus images plays a significant role in ophthalmologic disease diagnosis. Proliferative Diabetic Retinopathy (PDR) is the ultimate stage of Diabetic Retinopathy where proliferation of new and fragile blood vessels grow in human retina. These new blood vessels often show a tendency to rupture which further leads to severe damage of human eye. Neovascularization at

In this paper, an efficient framework for counting pedestrians crossing a line of interest is proposed. Nowadays, the convolutional neural networks have very good results on pedestrian detection and tracking. However, the major drawback of the neural networks is that they require heavy computing resources. This limits the application of neural networks in low-cost systems. Thus, the low power consuming

The spectacular progress of technology related to the information and communication arena throughout the past epoch made the internet a powerful media for faster communication of data. Though this technology is being admired at one side, there equally exists a challenge for safeguarding the data and privacy of information of a personal without any leak in the data and corresponding mistreatment. Hence

This paper proposes a novel video face identification method, named “3D-2D-DCNN cascade” that serially combines 3D and 2D deep convolutional neural networks (DCNNs) for robust video face recognition (FR). In our method, an input video (face) sequence is first divided into a number of sub-video sequences and each of the sub-video sequences is then used as an input to the 3D-DCNN, aiming to obtain a

Accurate classification of Alzheimer’s Disease (AD) and its prodromal stage, i.e., mild cognitive impairment (MCI) are critical for the effective treatment of AD. However, compared with AD classification tasks, predicting the conversion of MCI to AD is relatively difficult. as there are only minor differences among MCI groups. What’s more, in brain imaging analysis, the high dimensionality and relatively

A convergence result is stated for the numerical solution of space-fractional diffusion problems. For the spatial discretization, an arbitrary family of finite elements can be used combined with the matrix transformation technique. The analysis covers the application of the implicit Euler method for time integration to ensure unconditional stability. The spatial convergence rate does not depend on

This paper considers a temporal discretization of a semilinear fractional diffusion equation with nonsmooth initial data. With appropriately graded temporal grids, first-order temporal accuracy in the norm of L2(0,T;L2(Ω)) is derived by a new discrete Grönwall’s inequality, and then first-order temporal accuracy in the norm of L∞(0,T;L2(Ω)) is established for 1∕2<α<1. Finally, numerical results are

We propose a robust numerical method to find the coefficient of the creation or depletion term of parabolic equations from the measurement of the lateral Cauchy information of their solutions. Most papers in the field study this nonlinear and severely ill-posed problem using optimal control. The main drawback of this widely used approach is the need of some advanced knowledge of the true solution.

We revise the structure-preserving finite element method in [K. Hu, Y. MA and J. Xu. (2017) Stable finite element methods preserving ∇⋅B=0 exactly for MHD models. Numer. Math., 135, 371-396]. The revised method is semi-implicit in time-discretization. We prove the linearized scheme preserves the divergence free property for the magnetic field exactly at each time step. Further, we showed the linearized

Optimal closeness query in social networks requires obtaining the social datasets from each user so that he/she finds out a shortest social distance with any target user. For example, we can make friends in terms of the most similar social relationship of family background, education level and hobbies etc. Unfortunately, social data concerning user’s attributes might reveal personal sensitive information

This work presents novel discrete event-based simulation algorithms based on the Quantized State System (QSS) numerical methods. QSS provides attractive features for particle transportation processes, in particular a very efficient handling of discontinuities in the simulation of continuous systems. We focus on High Energy Physics (HEP) particle tracking applications that typically rely on discrete

Furthering our understanding of many of today’s interesting problems in plasma physics—including plasma based acceleration and magnetic reconnection with pair production due to quantum electrodynamic effects—requires large-scale kinetic simulations using particle-in-cell (PIC) codes. However, these simulations are extremely demanding, requiring that contemporary PIC codes be designed to efficiently

A mesh is locally quad-dominant (lqd) if all non-4-sided facets are surrounded by quadrilaterals. Lqd meshes allow for irregular nodes where n≠4 quads meet and for multi-sided facets, called T-gons, that end quad-strips and so adjust mesh density. This paper introduces a new class of bi-cubic (bi-3) Geometric T-joint (GT) splines whose control nets are τ-nets, i.e. T-gons surrounded by quads. These

Developing efficient embedded vision applications requires exploring various algorithmic optimization trade-offs and a broad spectrum of hardware architecture choices. This makes navigating the solution space and finding the design points with optimal performance trade-offs a challenge for developers. To help provide a fair baseline comparison, we conducted comprehensive benchmarks of accuracy, run-time

Context: Generally, there are more non-defective instances than defective instances in the datasets used for software defect prediction (SDP), which is referred to as the class imbalance problem. Oversampling techniques are frequently adopted to alleviate the problem by generating new synthetic defective instances. Existing techniques generate either near-duplicated instances which result in overgeneralization

Context: In search-based software engineering we often use popular heuristics with default configurations, which typically lead to suboptimal results, or we perform experiments to identify configurations on a trial-and-error basis, which may lead to better results for a specific problem. We consider the problem of generating test suites for mobile applications (apps) and rely on Sapienz, a state-of-the-art

Context: There is a growing demand for information on how IT companies look for candidates to their open positions. Objective: This paper investigates which hard and soft skills are more required in IT companies by analyzing the description of 20,000 job opportunities. Method: We applied open card sorting to perform a high-level analysis on which types of hard skills are more requested. Further, we

Context: In integration testing, the order in which classes are integrated and tested is significant for the construction of test stubs. With the existing approaches, it is usually difficult to generate the sub-optimal test orders for real applications, which have large numbers of classes. Objective: There exist moderately large numbers of classes in software systems, which is one of the main factors

Context: The prevalent application of Deep Learning (DL) models has raised concerns about their reliability. Due to the data-driven programming paradigm, the quality of test datasets is extremely important to gain accurate assessment of DL models. Recently, researchers have introduced mutation testing into DL testing, which applies mutation operators to generate mutants from DL models, and observes

First we identify the free algebras of the class of algebras of binary relations equipped with the composition and domain operations. Elements of the free algebras are pointed labelled finite rooted trees. Then we extend to the analogous case when the signature includes all the Kleene algebra with domain operations; that is, we add union and reflexive transitive closure to the signature. In this second

This article presents an alternating direction method of multipliers (ADMM) algorithm for solving large‐scale model predictive control (MPC) problems that are invariant under the symmetric‐group. Symmetry was used to find transformations of the inputs, states, and constraints of the MPC problem that decompose the dynamics and cost. We prove an important property of the symmetric decomposition for the

This article is concerned with the stochastic recursive optimal control problem with mixed delay. The connection between Pontryagin's maximum principle and Bellman's dynamic programming principle is discussed. Without containing any derivatives of the value function, relations among the adjoint processes and the value function are investigated by employing the notions of super‐ and sub‐jets introduced

Modeling agriculture-impacted hydrological processes remains a challenge, as information on irrigation activities is often insufficient. This study developed modules for emulating high-resolution irrigation activities and representing water management policies in integrated hydrologic modeling. The new modeling approach was implemented in China’s second largest endorheic river basin with intensive

Recurrent or non-recurrent temperature and humidity variations trigger various damages on the inside and outside surfaces of buildings, which eventually leads to poor insulation, additional energy consumption, and expensive repairing plan. Formal thermal inspection by professionals are expensive, often inconclusive and inconvenient for continuous or frequent monitoring. Thermal condition monitoring