Software Hint-Driven Data Management for Hybrid Memory in Mobile Systems

Hybrid memory systems, comprised of emerging non-volatile memory (NVM) and DRAM, have been proposed to address the growing memory demand of current mobile applications. Recently emerging NVM technologies, such as phase-change memories (PCM), memristor, and 3D XPoint, have higher capacity density, minimal static power consumption and lower cost per GB. However, NVM has longer access latency and limited write endurance as opposed to DRAM. The different characteristics of distinct memory classes render a new challenge for memory system design. Ideally, pages should be placed or migrated between the two types of memories according to the data objects’ access properties. Prior system software approaches exploit the program information from OS but at the cost of high software latency incurred by related kernel processes. Hardware approaches can avoid these latencies, however, hardware’s vision is constrained to a short time window of recent memory requests, due to the limited on-chip resources. In this work, we propose OpenMem: a hardware-software cooperative approach that combines the execution time advantages of pure hardware approaches with the data object properties in a global scope. First, we built a hardware-based memory manager unit (HMMU) that can learn the short-term access patterns by online profiling, and execute data migration efficiently. Then, we built a heap memory manager for the heterogeneous memory systems that allows the programmer to directly customize each data object’s allocation to a favorable memory device within the presumed object life cycle. With the programmer’s hints guiding the data placement at allocation time, data objects with similar properties will be congregated to reduce unnecessary page migrations. We implemented the whole system on the FPGA board with embedded ARM processors. In testing under a set of benchmark applications from SPEC 2017 and PARSEC, experimental results show that OpenMem reduces 44.6% energy consumption with only a 16% performance degradation compared to the all-DRAM memory system. The amount of writes to the NVM is reduced by 14% versus the HMMU-only, extending the NVM device lifetime.

Background-oriented schlieren technique in experimental research regarding the effect of explosion pressure

In the following paper, experimental results regarding the effect of explosion pressure are obtained from open field experiments with detonation of explosive charges. In addition, sensors that can be used for security applications for the detection of toxic and explosive compounds, as well as mobile systems for the detection of shock waves due to explosions were used to acquire more detailed results. Sensors are the main components in products and systems used to detect chemicals and volatile organic compounds (VOCs) targeting applications in several fields, such as: industrial production and the automotive industry (detection of polluting gases from cars, medical applications, indoor air quality control. The sensory characteristics of a robot depend very much on its degree of autonomy, the applications for which it was designed and the type of work environment. The sensors can be divided into two categories: internal status sensors (sensors that provide information about the internal status of the mobile robot); external status sensors (sensors that provide information about the environment in which the robot operates). Another classification of these could be: distance sensors, position sensors, environmental sensors - sensors that provide information about various properties and characteristics of the environment (example: temperature, pressure, color, brightness), inertial sensors.

Analyzing Isolation in Mobile Systems

As a safety-critical issue in complex mobile systems, isolation requires two or more mobile objects not to appear in the same place simultaneously. To ensure such isolation, a scheduling policy is needed to control and coordinate the movement of mobile objects. Unfortunately, existing task scheduling theories fails in providing effective solutions, because it is hardly possible to decompose a complex mobile system into multiple independent tasks. To solve this problem, a more fine-grained event scheduling is proposed in this paper to generate scheduling policies which can ensure the isolation of mobile objects. After defining event scheduling based on event-based formal models called dependency structures, a new event scheduling theory for mobile systems is developed accordingly. Then an algorithm for generating an event scheduling policy is proposed to implement the required isolation. Simulation experiments are conducted to prove the result of our theoretical analysis and show the effectiveness and scalability of the approach.

A Mobile Robot with Omnidirectional Tracks—Design and Experimental Research

This article deals with the design and testing of mobile robots equipped with drive systems based on omnidirectional tracks. These are new mobile systems that combine the advantages of a typical track drive with the advantages of systems equipped with omnidirectional Mecanum wheels. The omnidirectional tracks allow the robot to move in any direction without having to change the orientation of its body. The mobile robot market (automated construction machinery, mobile handle robots, mobile platforms, etc.) constantly calls for improvements in the manoeuvrability of vehicles. Omnidirectional drive technology can meet such requirements. The main aim of the work is to create a mobile robot that is capable of omnidirectional movement over different terrains, and also to conduct an experimental study of the robot’s operation. The paper presents the construction and principles of operation of a small robot equipped with omnidirectional tracks. The robot’s construction and control system, and also a prototype made with FDM technology, are described. The trajectory parameters of the robot’s operation along the main and transverse axes were measured on a test stand equipped with a vision-based measurement system. The results of the experimental research became the basis for the development and experimental verification of a static method of correcting deviations in movement trajectory.

3D Surveying of Underground Built Heritage: Opportunities and Challenges of Mobile Technologies

Among the existing Cultural Heritage settings, Underground Built Heritage (UBH) represents a peculiar case. The scarce or lack of knowledge and documentation of these spaces frequently limits their proper management, exploitation, and valorization. When mapping these environments for documentation purposes, the primary need is to achieve a complete, reliable, and adequate representation of the built spaces and their geometry. Terrestrial laser scanners were widely employed for this task, although the procedure is generally time-consuming and often lacks color information. Mobile Mapping Systems (MMSs) are nowadays fascinating and promising technologies for mapping underground structures, speeding up acquisition times. In this paper, mapping experiences (with two commercial tools and an in-house prototype) in UBH settings are presented, testing the different handheld mobile solutions to guarantee an accurate and reliable 3D digitization. Tests were performed in the selected case study of Camerano Caves (Italy), characterized by volumetric complexity, poor lighting conditions, and difficult accessibility. The aim of this research activity is not only to show the differences in the technological instruments used for 3D surveying, but rather to argue over the pros and cons of the systems, providing the community with best practices and rules for 3D data collection with handheld mobile systems. The experiments deliver promising results when compared with TLS data.

Methods and technologies for ensuring cybersecurity of industrial and web-oriented systems and networks

The subject matter of the article is methods and technologies of ensuring the cybersecurity of industrial and web-oriented systems and networks, training of cybersecurity specialists during the acquisition of professional knowledge. The purpose of the article is to ensure the cybersecurity of industrial and web-oriented systems and networks by developing and implementing appropriate methodologies (concepts, principles, set of models, methods) and technologies in the industry, as well as in training the cybersecurity specialists during the acquisition of professional knowledge. The problem of developing models, methods, and technologies for ensuring the cybersecurity of mobile systems, web-oriented systems based on content management systems, virtual networks that provide their interaction, and a methodology for training cybersecurity specialists are formulated. Based on the analysis the particular tasks of developing convolutional neural network model, information technology methods and models for ensuring the cybersecurity of web-oriented systems and networks, a methodological framework of creating information technology, and a model of digital knowledge platform for use in the field of cybersecurity specialists training and security of industrial systems were formulated. The basic theoretical decisions, which underlie the construction of real industrial and web-oriented systems and networks, were described in the article. The results of work are increased reliability value of detecting the malware in the Android operating system, reduced rates of false positives, provided an allowable value of the success rate of attacks at a minimum cost, reduced time spent on building and rebuilding the structure of the virtual network, increased efficiency of cybersecurity specialists training and security of industrial systems. From the above, it is possible to conclude that the obtained results can be used in a line of existing and prospective approaches at designing difficult, complex, hybrid, technical, cyber-physical systems with a web-oriented interface for users and administrators.

AUV localisation: a review of passive and active techniques

Localisation, i.e. estimation of one’s position in a given environment is a crucial element of many mobile systems, manned and unmanned. Due to the high demand for autonomous exploration, patrolling and inspection services and a rapid improvement of batteries, sensors and machine learning algorithms, the quality of localisation becomes even more important for smart robotic systems. The underwater domain is a very challenging environment due to the water blocking most of the signals over short distances. Recent results in localisation techniques for underwater vehicles are summarised in two principal categories: passive techniques, which strive to provide the best estimation of the vehicle’s position (global or local) given the past and current information from sensors, and active techniques, which additionally produce guidance output that is expected to minimise the uncertainty of estimated position.

Providing acceleration for mobile gaming as a service

<p>In recent years, the mobile gaming industry has made rapid progress. Developers are now producing numerous mobile games with increasingly immersive graphics. However, these resource-hungry applications inevitably keep pushing well beyond the hardware limits of mobile devices. The limitations causes two main challenging issues for mobile game players. First, limited computational capabilities of smart devices are preventing rich multimedia applications from running smoothly. Second, the minuscule touchscreens impede the players from smoothly interacting with devices as they can do with PCs. This thesis aims to address the two issues. Specifically, we implement two systems, one for the application accelerations via offloading and the other for alternative interaction approach for mobile gaming. We identify and describe the the challenging issues when developing the systems and describe our corresponding solutions. Regarding the first system, it is well recognized the performance of GPUs on mobile devices is the bottleneck of rich multimedia mobile applications such as 3D games and virtual reality. Previous attempts to tackle the issue mainly mirgate GPU computation to servers residing in remote datacenters. However, the costly network delay is especially undesirable for highly-interactive multimedia applications since a crisp response time is critical for user experience. In this thesis, we propose GBooster, a system that accelerates GPU-intensive mobile applications by transparently offloading GPU tasks onto neighboring multimedia devices such as SmartTV and Gaming Consoles. Specifically, GBooster intercepts and redirects system graphics calls by utilizing the Dynamic Linker Hooking technique, which requires no modification of the apps and mobile systems. Besides, GBooster intelligently switches between the low-power Bluetooth and the high-bandwidth WiFi interface to reduce energy consumption of network transmissions. We implemented the GBooster on the Android system and evauluate its performance. The results demonstrate that GBooster can boost applications' frame rates by up to {85\%}. In terms of power consumption, GBooster can achieve {70\%} energy saving compared with local execution. Second, we investigate the potential of built-in mobile device sensors to provide an alternative interaction approach for mobile gaming. We propose UbiTouch, a novel system that extends smartphones with virtual touchpads on desktops using built-in smartphone sensors. It senses a user's finger movement with a proximity and ambient light sensor whose raw sensory data from underlying hardware are strongly dependent on the finger's locations. UbiTouch maps the raw data into the finger's positions by utilizing Curvilinear Component Analysis and improve tracking accuracy via a particle filter. We have evaluate our system in three scenarios with different lighting conditions by five users. The results show that UbiTouch achieves centimetre-level localization accuracy and poses no significant impact on the battery life. We envisage that UbiTouch could support applications such as text-writing and drawing.</p>