scholarly journals Being Correct Is Not Enough: Efficient Verification Using Robust Linear Temporal Logic

2022 ◽  
Vol 23 (2) ◽  
pp. 1-39
Author(s):  
Tzanis Anevlavis ◽  
Matthew Philippe ◽  
Daniel Neider ◽  
Paulo Tabuada
Keyword(s):  
System Design ◽  
Temporal Logic ◽  
Practical Significance ◽  
Large Fragment ◽  
Fine Grained ◽  
Computational Overhead ◽  
Verification Problem ◽  
System Verification ◽  
Address System ◽  
Efficient Verification

While most approaches in formal methods address system correctness, ensuring robustness has remained a challenge. In this article, we present and study the logic rLTL, which provides a means to formally reason about both correctness and robustness in system design. Furthermore, we identify a large fragment of rLTL for which the verification problem can be efficiently solved, i.e., verification can be done by using an automaton, recognizing the behaviors described by the rLTL formula φ, of size at most O(3 |φ |), where |φ | is the length of φ. This result improves upon the previously known bound of O(5|φ |) for rLTL verification and is closer to the LTL bound of O(2|φ |). The usefulness of this fragment is demonstrated by a number of case studies showing its practical significance in terms of expressiveness, the ability to describe robustness, and the fine-grained information that rLTL brings to the process of system verification. Moreover, these advantages come at a low computational overhead with respect to LTL verification.

scholarly journals Oxidation Roasting of Fine-Grained Carbonaceous Gold Ore: The Effect of Aeration Rate

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 558
Author(s):  
Hui Li ◽  
Wei Xiao ◽  
Jianping Jin ◽  
Yuexin Han
Keyword(s):  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Aeration Rate ◽  
Practical Significance ◽  
Gold Ore ◽  
Fine Grained ◽  
Roasting Process ◽  
Chemical Groups ◽  
Fine Carbon ◽  
Fine Gold

The oxidation roasting of carbon-bearing micro-fine gold can eliminate or weaken the robbing effect of carbonaceous materials and clay, and destroy the encapsulation of micro-fine gold. The micropores produced by gas escaping during the roasting process are conducive to the diffusion of leaching agents, thus enhancing the cyanide leaching of gold. In this paper, the influence of the aeration rate during roasting on the leaching rate of fine-grained carbonaceous gold ore and its mechanism were studied using thermodynamic calculations, crystal structure analysis, surface chemical groups and bonds analysis, microporous structure analysis, and surface morphology detection. Under suitable roasting conditions, the carbonaceous and pyrite in the ore are oxidized, while carbonate minerals such as dolomite and calcite as well as clay minerals are decomposed, and the gold-robbing materials lose their activity. The experimental results have theoretical and practical significance for the popularization and application of oxidation roasting technology of fine carbon-bearing gold ore.

Dynamic Modeling of the NSSS Based on NHR200-II Nuclear Heating Reactor

2018 ◽  
Author(s):  
Zhe Dong ◽  
Yifei Pan ◽  
Miao Liu ◽  
Xiaojin Huang
Keyword(s):  
Control System ◽  
System Design ◽  
Dynamic Modeling ◽  
Primary Circuit ◽  
Control System Design ◽  
Plant Design ◽  
Pressurized Water ◽  
Nuclear Heating Reactor ◽  
System Verification ◽  
Nuclear Heating

The nuclear heating reactor (NHR) is a typical integral pressurized water reactor (iPWR) developed by the institute of nuclear and new energy technology (INET) of Tsinghua University, which has the safety advanced features such as the primary circuit integral arrangement, full-range natural circulation, self-pressurization. Power-level control is crucial for the operational stability and efficiency of the NHR, and the dynamic modeling is a basis for control system design and verification. From the conservation laws of mass, energy and momentum, a lumped-parameter dynamical model is proposed for the nuclear steam supply system (NSSS) based on the 200MWth nuclear heating reactor II (NHR200-II). The steady-state model validation is given by the comparing the parameter values of this model and that for plant design. Then, both the open-loop responses under the disturbances of reactivity and coolant flowrates as well as the closed-loop responses under the case of power ramp are given, where the rationality of the responses are analyzed from the viewpoint of plant physics and thermal-hydraulics. This model can be utilized for not only the control system design but also the development of a real-time simulator for the hardware-in-loop control system verification.

scholarly journals Effects of Tailings Gradation on Rheological Properties of Filling Slurry

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Bingwen Wang ◽  
Tingyong Xiong ◽  
Lijing Gao ◽  
Yuepeng Chai ◽  
Xiangyu Cui ◽  
...  
Keyword(s):  
Particle Size ◽  
System Design ◽  
Rheological Properties ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Analysis Software ◽  
Key Technology ◽  
Fine Grained ◽  
Viscosity Coefficients ◽  
Filling System

The key technology in filling mining is the gravity transportation of high-density slurries, and the filling system design is a significant part of this technology. The filling effect depends on the fluidity of the filling slurry. To investigate the influence of the gradation of tailings on the rheological properties of the filling slurry, this study uses particle size analysis to prepare three types of tailings: powder-, relatively fine-, and fine-grained tailings, which are then mixed in different proportions. The rheological properties of the resulting filling slurries are tested; the viscosity coefficients and yield stresses of the slurries are obtained using the analysis software provided with the MCR102 advanced rheometer that is used to measure the rheological properties of the slurries. The experimental results demonstrate that there is no absolute relationship between the rheological properties of the slurry and the size of the tailings particles, but the rheological properties are related to the gradation of tailings. Lubricating effect is weakened with an insufficient content of powder-grained particles in the tailings. On the contrary, when the content of powder-grained particles in the tailings is too high, the viscous substances in the slurry increase. Both of these conditions can increase the friction loss of the slurry.

The Research of System Design on a Turbine Based on CATIA

2014 ◽  
Vol 602-605 ◽  
pp. 743-746
Author(s):  
Dong Dong Xu ◽  
Tong Wang
Keyword(s):  
System Design ◽  
Modular Design ◽  
Technology Development ◽  
Rapid Development ◽  
Optimal Solution ◽  
Practical Significance ◽  
Modern Theory ◽  
Concept Design ◽  
Product System ◽  
Complex Product

With the rapid development of science and technology, modern design has become increasingly complex, with the factors needed to be considered more various, find the optimal solution to solve problems, which is the real meaning of product design. In this paper, by analyzing the domestic and foreign research present situation of the modern theory of the modular design, according to the characteristics of complex product system, it will be introduced to the concept design of complex product system modular design, proposed in view of the function of the turbine division method, based on CATIA software research and development of the system design of a turbine, that can effectively shorten the development time, reduce development costs, to lay a good foundation for its innovation, having great theoretical and practical significance for turbine technology development.

scholarly journals Tourists’ Behavioral Characteristics Regarding Island-Based Tourism Destinations through the Perspective of Spatial Constraints: A Case Study of Yangma Island in China

2021 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Xintao Ma ◽  
Yuna Hu ◽  
Yongwei Liu
Keyword(s):  
Spatial Interaction ◽  
Practical Significance ◽  
Gps Tracking ◽  
Spatial Constraints ◽  
Factors Affecting ◽  
Tourist Behavior ◽  
Fine Grained ◽  
Spatial Attributes ◽  
Tourism Destinations

The factors affecting tourist behavior are complex and diverse, but research on its effect from a purely spatial perspective is still limited. The aim of this paper is to explore the dichotomous interaction between tourists and islands: the behavioral patterns of tourists in island destinations and the mechanisms by which island spaces constrain tourist behavior. This study uses fine-grained global positioning system (GPS) tracking data actively authorized and released by tourists. We empirically studied tourist behavior from a spatial constraint perspective and discovered the following: island space has a strong influence and constraining effect on tourist behavior; different spatial attributes have different constraining effects on tourist behavior; and people with different identities interact with different attributes of space to produce different spatial properties, resulting in a ‘harmony-contradiction’ model of spatial interaction. These findings are of great value in expanding the perspective of spatial constraints and exploring the interactions between people and land. They are also of great practical significance in promoting spatial planning synergy, facilitating the construction of high-quality island-based tourism destinations, and building a harmonious relationship between people and land.

scholarly journals Benchmarks for Temporal Logic Requirements for Automotive Systems

10.29007/xwrs ◽  
2018 ◽  
Author(s):  
Bardh Hoxha ◽  
Houssam Abbas ◽  
Georgios Fainekos
Keyword(s):  
Temporal Logic ◽  
Fault Tolerant ◽  
Automatic Transmission ◽  
Transmission Model ◽  
Benchmark Problems ◽  
Metric Temporal Logic ◽  
Automotive Systems ◽  
Verification Methods ◽  
System Output ◽  
System Verification

We propose to standardize two Matlab/Simulink models of automotive systems as benchmark problems for hybrid system verification. Bothmodels can be simulated quickly, making them ideal for testing-based verification methods that require a significant number of system output trajectories. One of the benchmarks is the Automatic Transmission model, which is deterministic. The other benchmark is the Fault-Tolerant Fuel Control System, which exhibits stochastic behavior. Our benchmark standardization defines a number of Metric Temporal Logic requirements that must be satisfied by the models.

AntibIoTic: The Fog-enhanced distributed security system to protect the (legacy) Internet of Things

2021 ◽  
pp. 1-37
Author(s):  
Michele De Donno ◽  
Xenofon Fafoutis ◽  
Nicola Dragoni
Keyword(s):  
Internet Of Things ◽  
Fog Computing ◽  
Security System ◽  
Security And Privacy ◽  
Aggregated Data ◽  
Fine Grained ◽  
Computational Overhead ◽  
Distributed Security ◽  
Cloud Server ◽  
Iot Devices

The Internet of Things (IoT) is evolving our society; however, the growing adoption of IoT devices in many scenarios brings security and privacy implications. Current security solutions are either unsuitable for every IoT scenario or provide only partial security. This paper presents AntibIoTic 2.0, a distributed security system that relies on Fog computing to secure IoT devices, including legacy ones. The system is composed of a backbone, made of core Fog nodes and Cloud server, a Fog node acting at the edge as the gateway of the IoT network, and a lightweight agent running on each IoT device. The proposed system offers fine-grained, host-level security coupled with network-level protection, while its distributed nature makes it scalable, versatile, lightweight, and easy to deploy, also for legacy IoT deployments. AntibIoTic 2.0 can also publish anonymized and aggregated data and statistics on the deployments it secures, to increase awareness and push cooperations in the area of IoT security. This manuscript recaps and largely expands previous works on AntibIoTic, providing an enhanced design of the system, an extended proof-of-concept that proves its feasibility and shows its operation, and an experimental evaluation that reports the low computational overhead it causes.

Inducing and Refining Topics for Web Query Classification Using a Semantic Network

2018 ◽  
Vol 15 (2) ◽  
pp. 595-600
Author(s):  
R. Sathish Kumar ◽  
M. Chandrasekaran
Keyword(s):  
Query Expansion ◽  
Web Search ◽  
Semantic Network ◽  
Machine Learning Techniques ◽  
Search Query ◽  
Fine Grained ◽  
Computational Overhead ◽  
Learning Techniques ◽  
Query Classification ◽  
The Web

Web query classification, the task of inferring topical categories from a web search query is a non-trivial problem in Information Retrieval domain. The topic categories inferred by a Web query classification system may provide a rich set of features for improving query expansion and web advertising. Conventional methods for Web query classification derive corpus statistics from the web and employ machine-learning techniques to infer Open Directory Project categories. But they suffer from two major drawbacks, the computational overhead to derive corpus statistics and inferring topic categories that are too abstract for semantic discrimination due to polysemy. Concepts too shallow or too deep in the semantic gradient are produced due to the wrong senses of the query terms coalescing with the correct senses. This paper proposes and demonstrates a succinct solution to these problems through a method based on the Tree cut model and Wordnet Thesarus to infer fine-grained topic categories for Web query classification, and also suggests an enhancement to the Tree Cut Model to resolve sense ambiguities.

scholarly journals Multi-Level Attribute-Based Encryption Access Control Scheme for Big Data

2018 ◽  
Vol 173 ◽  
pp. 03047
Author(s):  
Zhao Li ◽  
Shuiyuan Huan
Keyword(s):  
Big Data ◽  
Access Control ◽  
Data Processing ◽  
Data Access ◽  
Big Data Processing ◽  
Fine Grained ◽  
Computational Overhead ◽  
Data Access Control ◽  
Attribute Based Encryption ◽  
Multi Level

There are many security threats such as data’s confidentiality and privacy protection in the new application scenario of big data processing, and for the problems such as coarse granularity and low sharing capability existing in the current research on big data access control, a new model to support fine-grained access control and flexible attribute change is proposed. Based on CP-ABE method, a multi-level attribute-based encryption scheme is designed to solve fine-grained access control problem. And to solve the problem of attribute revocation, the technique of re-encryption and version number tag is integrated into the scheme. The analysis shows that the proposed scheme can meet the security requirement of access control in big data processing environment, and has an advantage in computational overhead compared with the previous schemes.

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