(Press-News.org) The train control system is the heart of Chinese high-speed railways, which is a core technology to ensure safe operation as well as high throughput of trains (see Figure 1). The correctness of the train control system is closely related to people's life and property. How to guarantee the correctness of train control system is a grand challenge in both software engineering and control theory. Recently, a group of Chinese researchers proposed an approach to verify the correctness of train control system by combining simulation and formal verification, which was published at Vol.45(3) of SCIENCE CHINA: Information Sciences. This work is undertaken jointly by the research group led by Prof. Zhan NaiJun from Institute of Software, Chinese Academy of Sciences and the research group led by Prof. Tang Tao from Beijing Jiaotong University.
In computer science, formal methods are the techniques for specifying, developing and verifying software and hardware systems based on rigorous mathematical theories. Due to the successful application of formal methods to real-world industrial problems, it has become an agreement that safety-critical systems like train control system should be developed using formal methods. However, due to the increasing complexity of the software and hardware in train control system, it becomes extremely difficult, even impossible to pursue formal verification on train control system directly. Additionally, on one hand, it is very hard for experts from train domain to apply formal methods, as it usually requires solid mathematical background; on the other hand, experts from formal method community lack the domain knowledge on train control system. As a result, it is challenging for either of the two sides to complete the work independently.
The experts on formal methods from Institute of Software Chinese Academy of Sciences and the experts on train control system from Beijing Jiaotong University cooperate on this issue, and recently, they propose an effective method on modeling and verification of train control system. The basic idea is as follows: firstly, it applies the graphical environment Simulink/Stateflow, which is easy to follow by train control domain-specific experts, to model train control system, and then simulation can be performed on the model, till the model meets the expectation of the domain-specific experts, or otherwise, some errors or inconsistency are found through the simulation; secondly, as a remedy of inherent incompleteness of simulation, the Simulink/Stateflow graphical model is transformed to a formal Hybrid CSP model using an automatic translator; finally, whether the formal Hybrid CSP model satisfies some desired properties is verified by using a theorem prover for Hybrid Hoare Logic developed by Institute of Software, Chinese Academy of Sciences. In summary, this method provides a seamless integration of practical engineering method and formal methods.
By applying the above proposed method, they model, simulate and verify some basic scenarios and their combinations in the requirement specification of Chinese high-speed train control system, including Movement Authority, Level Upgrade, Mode Conversion and their combinations. The experiments reveal that abnormal stops and/or failures of level transition may occur in several combined scenarios.
This approach advances the state of the art in the verification of train control system, which provides an effective way to guarantee the coherence, consistency and unambiguity of the requirement specification of train control system. In addition, it is of great significance for designing the next generation of train control system in future.
INFORMATION:
This research is supported partly by Chinese National Programs for Fundamental Research and Development (973 Program) under Grant No. 2014CB340700, Chinese National Programs for High Technology Research and Development (863 Program) under Grant No. 2012AA112801, and Chinese National Natural Science Foundation under Grant No. 91118007, 6110006, 61304185.
Guo Danqing, Lv Jidong, Wang Shuling, Tang Tao, Zhan Naijun, Zhou Datian, Zou Liang: Formal Analysis and Verification of Chinese High-speed Train Control System, SCIENCE CHINA: Information Sciences, 2015?45(3)?417-438.
New research from Uppsala University shows promising progress in the use of stem cells for treatment of spinal cord injury. The results, which are published in the scientific journal Scientific Reports, show that human stem cells that are transplanted to the injured spinal cord contribute to restoration of some sensory functions.
Traffic accidents and severe falls can cause ruptures of nerve fibers that enter/exit the spinal cord. Most commonly, these avulsion injuries affect the innervation of the arm and hand, and lead to paralysis, loss of sensation and cause chronic ...
A fully renewable energy system, including all energy consuming sectors, is not only a possible but a viable solution for Finland, according to a new research. Researchers from Lappeenranta University of Technology (LUT) have investigated renewable energy system options for Finland in 2050. Results indicate that a fully renewable energy system is possible, and represents a competitive solution for Finland with careful planning.
In order to achieve the national greenhouse gas reduction targets for 2050, all sectors of the energy system need to be nearly emission free ...
Scientists in the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC, http://www.bnl.gov/rhic/), a particle accelerator exploring nuclear physics and the building blocks of matter at the U.S. Department of Energy's Brookhaven National Laboratory, have new evidence for what's called a "chiral magnetic wave" rippling through the soup of quark-gluon plasma created in RHIC's energetic particle smashups.
The presence of this wave is one of the consequences scientists were expecting to observe in the quark-gluon plasma--a state of matter that existed in the early ...
Researchers at the KU Leuven Centre for Surface Chemistry and Catalysis have found a more eco-friendly way to derive lignin - a paper industry waste product - from wood and convert it into chemical building blocks. The resulting chemicals can be used in paint, insulation foam, and several other products. The researchers published their findings in the journal Energy & Environmental Science.
Lignin is a substance in the cell walls of plants that strengthens their structure. When wood is processed into paper pulp, lignin is produced as a waste product. Researchers have ...
CINCINNATI - Children who received general anesthesia for surgery before age 4 had diminished language comprehension, lower IQ and decreased gray matter density in posterior regions of their brain, according to a new study in the journal Pediatrics.
Researchers from Cincinnati Children's Hospital Medical Center report their findings in the journal's June 8 online edition. The authors recommend additional studies to determine anesthesia's precise molecular effects on the brain and contribution to diminished brain function and composition. Researchers say this knowledge ...
Philadelphia, PA, June 8, 2015 - Barrett's esophagus (BE) develops in a subset of patients with gastroesophageal reflux disease (GERD) and can increase the risk of developing cancer of the esophagus. Although periodic surveillance for cancer is recommended for BE patients, these examinations may fail to identify pre-cancerous dysplasia and early cancers. A report in the Journal of Molecular Diagnostics describes a test using next-generation sequencing (NGS) to detect genomic mutations in precancerous esophageal tissue, which may improve cancer surveillance and early detection ...
Just one in 20 people worldwide (4·3%) had no health problems in 2013, with a third of the world's population (2·3 billion individuals) experiencing more than five ailments, according to a major new analysis from the Global Burden of Disease Study (GBD) 2013, published in The Lancet.
Moreover, the research shows that, worldwide, the proportion of lost years of healthy life (disability-adjusted life years; DALYS [1]) due to illness (rather than death) rose from around a fifth (21%) in 1990 to almost a third (31%) in 2013.
As the world's population grows, ...
Sarcopenia is the aging-related loss of skeletal muscle mass and strength. Preventing sarcopenia is important for maintaining a high quality of life (QOL) in the aged population. However, the molecular mechanism of sarcopenia has not yet been unraveled and is still a matter of debate.
Determining whether the levels of autophagy-related mediators (e.g., p62/SQSTM1, LC3, etc.) in muscle change with ageing is important to understanding sarcopenia. Such information could enhance the therapeutic strategies for attenuating mammalian sarcopenia.
In previous studies, autophagic ...
Debates about legalizing marijuana have focused on crime rates, economic benefits, and health effects among adults. But a study published today from researchers at Nationwide Children's Hospital shows that the risk to young children of swallowing, breathing in or otherwise being exposed to marijuana also needs to be considered.
The study, published online today in Clinical Pediatrics, found that the rate of marijuana exposure among children 5 years of age and younger rose 147.5 percent from 2006 through 2013 across the United States. The rate increased almost 610 percent ...
SEATTLE -- People across the world are living longer but spending more time in ill health as rates of nonfatal diseases and injuries - including diabetes and hearing loss - decline more slowly than death rates, according to a new analysis of 301 diseases and injuries in 188 countries.
Using a measurement known as years lived with disability, or YLDs, researchers from around the world quantified the impact of health problems that impair mobility, hearing, or vision, or cause pain in some way but aren't fatal. In 2013, low back pain and major depressive disorder were among ...
