The Design of I/O Subsystem in Satellite Real-Time Microkernel Operating System

One of the most important features of modern minor satellites is to realize autonomous moving. The performance of the satellite autonomous computer operating system acting as the control center is utmost important. The recent trend in operating system development is adopting microkernel architecture which holds such advantages as microminiaturization, modularity, portability and extendibility. The performance of I/O subsystem is currently receiving considerable research attention. Object-orientation offers an approach to application development in which software system can be constructed by composing and refining the pre-designed plug-compatible software components.It also starts with some basic notions fairly well accepted in computer science, namely encapsulation and reuse. In this paper, a new object-oriented real-time I/O subsystem model has been designed.In this model, the traditional I/O subsystem framework is discarded and a stream mechanism based on the object-oriented concept is introduced. In addition, the I/O requests are classified according to their time emergency to obtain real-time performance. So, this model meets such satelliteperformance requirements as reliability, flexibility, portability and real-time performance.

Research on typical operating conditions of hydrogen production system with off-grid wind power considering the characteristics of proton exchange membrane electrolysis cell

Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.

Research and analysis about embedded operating computer system

Embedded operating system EOS （Embedded Operating System） is widely used system software which in the past is mainly used in fields of industrial control and defense system. EOS is responsible for the entire software and hardware resource allocation, scheduling work and coordinating concurrent control activities; some more successful applied EOS products have been presently launched. With the development of lnternet technology, information appliances and the universal application of miniaturization and specialization of EOS, EOS started from a single weak situation to a higher professional direction with strong functions.

Implementing Operating System Support for Extended Trusted Path in TPM-Capable Environments

Trusted path is one of the crucial features that operating systems must provide for fundamental security support. In order to explore the possibility of implementing a trusted path mechanism with the support of trusted platform module （TPM） technologies, and to support TPM capabilities in operating systems, the paper extended the scope of the conventional trusted path to cover the situation in which a user communicates with software residing on a remote host. The paper combined the concept of operating system support for trusted path with that for TPM platforms, and proposed the architecture of an extended trusted path mechanism in operating system with considerations on TPM-capable platforms support. As part of the author＇s research in secure operating systems, the work of the paper was carried out with Linux as an experimental prototype system. The research result shows that TPM capabilities can strengthen extended trusted path mechanisms of operating systems.

Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology

In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.

Elements and Experiments of Shenzhen Continuous Operating Reference Stations (SZCORS) System

Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) system has been established and consists of GPS reference stations, system control center, user’s data center, and real-time datacom network. The SZCORS system provides users the real-time centimeter positioning or post-processing millimeter positioning. This paper makes discussion on the structure of SZCORS system. Some experiments have been made to test the usablity, and then the data has been analyzed.

Analysis and Comparison of Five Kinds of Typical Device-Level Embedded Operating Systems

Today, the number of embedded system was applied in the field of automation and control has far exceeded a variety of general-purpose computer. Embedded system is gradually penetrated into all fields of human society, and ubiquitous embedded applications constitute the 'ubiquitous' computing era. Embedded operating system is the core of the em-bedded system, and it directly affects the performance of the whole system. Our Liaoning Provincial Key Laboratory of Embedded Technology has successfully developed five kinds of device-level embedded operating systems by more than ten years’ efforts, and these systems are Webit 5.0, Worix, μKernel, iDCX 128 and μc/os-II 128. This paper mainly analyses and compares the implementation mechanism and performance of these five kinds of device-level embedded operating systems in detail.

A Methodology to Measure the Environmental Impact of ICT Operating Systems across Different Device Platforms

A new methodology was created to measure the energy consumption and related green house gas （GHG） emissions of a computer operating system （OS） across different device platforms. The methodology involved the direct power measurement of devices under different activity states. In order to include all aspects of an OS, the methodology included measurements in various OS modes, whilst uniquely, also incorporating measurements when running an array of defined software activities, so as to include OS application management features. The methodology was demonstrated on a laptop and phone that could each run multiple OSs, results confirmed that OS can significantly impact the energy consumption of devices. In particular, the new versions of the Microsoft Windows OS were tested and highlighted significant differences between the OS versions on the same hardware. The developed methodology could enable a greater awareness of energy consumption, during both the software development and software marketing processes.

Realization and Application of RSA in Chip Operating System

As an outstanding asymmetric cryptography, RSA algorithm has a lot of virtues and thus is well applied in the scope of IC card applications. The paper deals with the application of RSA in smart cards and the approach in which the modular exponentiation of huge number is simplified by using the Chinese Remainder Theorem. We have already succeeded in completing RSA in IC cards. Results indicate that RSA algorithm applied in IC cards has the equivalent speed of DES algorithm with the same environment.

Simulation Operating System and Integrated Simulation Software

In this paper, a new concept of simulation operating system (SIMOS) is described. A detailed definition of SIMOS is given, and two integrated simulation software (IPSOS and IMSS) are introduced based on SIMOS.

Digital arc welding power supply based on real-time operating system

A digital arc welding power supply was designed with the advanced reduced instruction set computer machine （ARM） and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS- Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments ,the ARM and the micro C/OS- Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder.

Research on Security Assessment Index System for Operating Reserve in Large Interconnected Power Grid

Optimization and placement of spinning reserve is an important issue in power system planning and operation. Systematic way for security assessment of operating reserve needs to study. A security assessment index system for operating reserve in large interconnected power grids is presented in this paper. Firstly, classification and determination methods of operating reserve at home and abroad are investigated, and operating reserve is divided into transient state operating reserve and quasi-steady state operating reserve from the view of security assessment. Secondly, assessment indexes and optimization methods for transient state operating reserve are studied. Thirdly, optimization model, deterministic and probabilistic optimization methods for quasi-steady state operating reserve are explored. Finally, some principles for determination of operating reserve are suggested, and a security assessment index system is put forward. The proposed index system, considering both transient and quasi-steady state, both deterministic and probabilistic methods, provides a systematic way to assessment and arrangement of operating reserve.

Evaluation of Operating Domains in Power Systems

This paper presents the results of a recent major industry-supported study with the aim to provide power system operators with more meaningful and effective means to quickly identify feasible operating boundaries as well as more flexibility to select alternate operating scenarios. In this regard, the paper outlines the main theoretical basis and computational framework for the development of innovative computerized schemes capable of identifying and processing various system integrity domains. The novel framework allows system operators to determine – in a fast and reliable manner – the most favorable operating scenarios which maintain system security, reliability and operating performance quality. For demonstration purposes, and without loss of generality, an emphasis is given to the dynamic system security problem where the Transient Energy Function (TEF) method is used to define quantitative measures of the level (degree) of system security for a given operating scenario. Nonetheless, the framework presented is applicable quite as well to other system performance functions and criteria that may be considered. A demonstrative application is presented for a 9-bus benchmark system, widely used in the literature. In addition, a practical application is also presented for the Saudi Electricity Company (SEC) power system where the operating security domain was evaluated in the operating parameter space spanned by two major interface flows in the system.

An Efficient Memory Management for Mobile Operating Systems Based on Prediction of Relaunch Distance

Recently,various mobile apps have included more features to improve user convenience.Mobile operating systems load as many apps into memory for faster app launching and execution.The least recently used(LRU)-based termination of cached apps is a widely adopted approach when free space of the main memory is running low.However,the LRUbased cached app termination does not distinguish between frequently or infrequently used apps.The app launch performance degrades if LRU terminates frequently used apps.Recent studies have suggested the potential of using users’app usage patterns to predict the next app launch and address the limitations of the current least recently used(LRU)approach.However,existing methods only focus on predicting the probability of the next launch and do not consider how soon the app will launch again.In this paper,we present a new approach for predicting future app launches by utilizing the relaunch distance.We define the relaunch distance as the interval between two consecutive launches of an app and propose a memory management based on app relaunch prediction(M2ARP).M2ARP utilizes past app usage patterns to predict the relaunch distance.It uses the predicted relaunch distance to determine which apps are least likely to be launched soon and terminate them to improve the efficiency of the main memory.

HCOS:A Unified Model and Architecture for Cloud Operating System

Currently, Infrastructure as a Service(IaaS) and Platform as a Service(PaaS) platforms play a role as a cloud operating system(COS).They are separated from each other in resource management,which may cause inconsistent resource status and result in the decrease of performance. Moreover, heterogeneous resources are not managed well in existing cloud computing platforms. Referring to the theory of operating system, we propose a unified architecture model of cloud operating system, which has six layers corresponding to the layered architecture of legacy operating system. Based on this architecture, a new cloud operating system called Hua-Cloud Computing System(HCOS) is realized. In HCOS, the hybrid resources are managed in a unified way. This method improves the unified scheduling capability of heterogeneous resources and eliminates the problem of resource status inconsistency.The main characteristics of HCOS are introduced and two typical applications are illustrated in this paper.

Operating Rule Classification System of Water Supply Reservoir Based on Learning Classifier System

An operating rule classification system based on learning classifier system （LCS）, which learns through credit assignment （bucket brigade algorithm, BBA） and rule discovery （genetic algorithm, GA）, is established to extract water-supply reservoir operating rules. The proposed system acquires an online identification rate of 95% for training samples and an offline rate of 85% for testing samples in a case study. The performances of the rule classification system are discussed from the rationality of the obtained rules, the impact of training samples on rule extraction, and a comparison between the rule classification system and the artificial neural network （ANN）. The results indicate that the LCS is feasible and effective for the system to obtain the reservoir supply operating rules.

Reform and Practice of Operating System Course

In recent years,with the changes in the international competitive environment,the development strategic focuses of the national software industry have also shifted.To adapt to these changes,we analyze and summarize the problems existing in the teaching content and methods of the traditional“Operating System”course and carry out the reform and practice of this core course for software engineering majors.First,we design and integrate domestic operating system examples into the course to meet the needs of national strategic development,thus cultivating operating system software talents in line with China’s national conditions and needs.Second,we reconstruct the teaching content of the course,strengthen the assessment of comprehensive ability,and establish a 3-level progressive teaching structure.Third,we carry out the deep integration of university and enterprise to realize the combination of theory and practice and establish a comprehensive and whole process university-enterprise course co-construction mode.Through the above reform measures,students show a strong interest in learning the operating system course.The operating system course has won the honor of the first-class course of Beijing Jiaotong University and has been approved for 4 industry-education cooperation projects of the Ministry of Education.

Application of Mobile Learning System in Operating System Course

With the rapid development of mobile communication and computer network technologies, the new mobile learning mode has been accepted by more and more people. In this paper, taking the learning system under mobile environment and from the perspective of necessary theoretic knowledge and relative technologies for mobile learning, the structural frame of the mobile learning system was discussed and constructed. According to this structural frame, the learning system under mobile environment was designed and applied into the OS course.

A Smart Phone-oriented Embedded Real-time Operating System

This article presents an embedded Smart Phone Operating System (SPOS) independently designed by ZTE Corporation. The SPOS is based on single kernel architecture with its multi-task real-time kernel supporting hardware platforms and resources of mainstream mobile phones. It has remarkable advantages such as highly efficient and dynamic power management, priority - based preemptive scheduling, fast startup, a variety of drivers, and excellent system stability and operability. For the development of upper layer communication protocols and application software, the SPOS provides wireless communication interfaces and the application program framework.

Comparative Analysis of Operating System of Different Smart Phones

Nowadays rapidly increasing technology is mobile phone technology in telecommunication sector. This mobile device technology has great effect on everyone’s life. This technology has reduced the burden of people in their daily life. To manage the rising demand for such mobile devices, numerous operating systems came in the market as a platform upon which modern application can be produced. As a result, numbers of platforms and essential depository describe these platforms;customers may or may not be aware of these platforms that are appropriate for their needs. In order to solve this issue, we examine the most famous mobile phone operating systems to decide which operating system is most suitable for developers, business applications as well as casual use. In this paper we make assessment on the popular operating systems of mobile devices available in the business market, and on behalf of such assessment we distinguish that operating system OS is much useful of its particular characteristics compared with other systems.