Plant Landscape Design Language of Small Street Parks in Tropical Coastal Regions:A Case Study of Zhanjiang City

Small urban street parks play an irreplaceable role in protecting ecological environment of cities and beautifying living spaces of citizens, in these parks plant is an essential landscaping element that can not only improve environmental quality, but also provide visual enjoyment for viewers. There are many small street parks in Zhanjiang City, however, plant landscapes in such parks lack in regional characteristics because of blind copy and random planting. By analyzing plant landscapes in typical street parks in Zhanjiang, and borrowing the theoretical research framework of linguistics, this paper concluded the vocabulary, sentence,chapter and grammatical rules of plant landscape design, in order to explore new methods for the plant landscape design of small parks in tropical coastal regions.

The Role of Communicative Drills in Communicative Language Teaching

This paper focuses on the role of communicative drills in communicative language teaching. It first analyzes the necessity and roles of communicative drills in communicative language teaching, and then emphasizes the importance of designing communicative drills in language teaching.

IoT-Enabled Autonomous System Collaboration for Disaster-Area Management

Timely investigating post-disaster situations to locate survivors and secure hazardous sources is critical,but also very challenging and risky.Despite first responders putting their lives at risk in saving others,human-physical limits cause delays in response time,resulting in fatality and property damage.In this paper,we proposed and implemented a framework intended for creating collaboration between heterogeneous unmanned vehicles and first responders to make search and rescue operations safer and faster.The framework consists of unmanned aerial vehicles(UAVs),unmanned ground vehicles(UGVs),a cloud-based remote control station(RCS).A light-weight message queuing telemetry transport(MQTT)based communication is adopted for facilitating collaboration between autonomous systems.To effectively work under unfavorable disaster conditions,antenna tracker is developed as a tool to extend network coverage to distant areas,and mobile charging points for the UAVs are also implemented.The proposed framework’s performance is evaluated in terms of end-to-end delay and analyzed using architectural analysis and design language(AADL).Experimental measurements and simulation results show that the adopted communication protocol performs more efficiently than other conventional communication protocols,and the implemented UAV control mechanisms are functioning properly.Several scenarios are implemented to validate the overall effectiveness of the proposed framework and demonstrate possible use cases.

Effect of the distribution parameter of heat source on temperature profiles in GTAW

Taking lower speed gas tungsten arc welding of thin stainless steel plate as study case, two dimensional and symmetric Gaussian distribution mode of heat flux from the arc is applied to calculate the temperature field and thermal cycles. APDL of three or two dimensional array is effective to express the planar load of heat flux. The dynamic variation of welding temperature field and thermal cycles at different points are numerically simulated. The effect of the distribution parameter σq of Gaussian heat flux on the temperature profiles is investigated. The increasing of σ q causes the dropping of the maximum temperature, and this decreasing is clearer at the range of distance 0 -4 mm away from the weld centerline. Beyond the range with a distance 4 - 10 mm along the transverse direction, minor vibration of temperature occurs, but the temperature difference is limited. As the value of σq rises, the calculated weld pool shape gets contracted. The predicted weld widths at both top and bottom surfaces match well with the experimentally measured ones.

AADL2TASM: a Verification and Analysis Tool for AADL Models

Architecture analysis and design language （AADL） is an architecture description language standard for embedded real-time systems and it is widely used in safety-critical applications. For facilitating verifcafion and analysis, model transformation is one of the methods. A synchronous subset of AADL and a general methodology for translating the AADL subset into timed abstract state machine （TASM） were studied. Based on the arias transformation language （ ATL ） framework, the associated translating tool AADL2TASM was implemented by defining the meta-model of both AADL and TASM, and the ATL transformation rules. A case study with property verification of the AADL model was also presented for validating the tool.

Validation of static properties in unified modeling language models for cyber physical systems

Cyber physical systems (CPSs) can be found nowadays in various fields of activity. The increased interest for these systems as evidenced by the large number of applications led to complex research regarding the most suitable methods for design and development. A promising solution for specification, visualization, and documentation of CPSs uses the Object Management Group (OMG) unified modeling language (UML). UML models allow an intuitive approach for embedded systems design, helping end-users to specify the requirements. However, the UML models are represented in an informal language. Therefore, it is difficult to verify the correctness and completeness of a system design. The object constraint language (OCL) was defined to add constraints to UML, but it is deficient in strict notations of mathematics and logic that permits rigorous analysis and reasoning about the specifications. In this paper, we investigated how CPS applications modeled using UML deployment diagrams could be formally expressed and verified. We used Z language constructs and prototype verification system (PVS) as formal verification tools. Considering some relevant case studies presented in the literature, we investigated the opportunity of using this approach for validation of static properties in CPS UML models.

Architecture-level particular risk modeling and analysis for a cyber-physical system with AADL

Cyber-physical systems(CPSs)are becoming increasingly important in safety-critical systems.Particular risk analysis(PRA)is an essential step in the safety assessment process to guarantee the quality of a system in the early phase of system development.Human factors like the physical environment are the most important part of particular risk assessment.Therefore,it is necessary to analyze the safety of the system considering human factor and physical factor.In this paper,we propose a new particular risk model(PRM)to improve the modeling ability of the Architecture Analysis and Design Language(AADL).An architecture-based PRA method is presented to support safety assessment for the AADL model of a cyber-physical system.To simulate the PRM with the proposed PRA method,model transformation from PRM to a deterministic and stochastic Petri net model is implemented.Finally,a case study on the power grid system of CPS is modeled and analyzed using the proposed method.

Integrating behavior analysis into architectural modeling

Architectural modeling and behavior analysis are two important concerns in the software development. They are often implemented separately, and specified by their own supporting notations. Architectural modeling helps to guarantee the system design to satisfy the requirement, and behavior analysis can ensure the interaction correctness. To improve the trustworthiness, methods trying to combine architectural modeling and behavior analysis notations together have been proposed, e.g., establishing a one-way mapping relation. However, the one-way relation cannot ensure updating one notation specifications in accordance with the other one, which results in inconsistency problems. In this paper, we present an approach to integrating behavior analysis into architectural modeling, which establishes the interoperability between architectural modeling notation and behavior analysis notation by a bidirectional mapping. The architecture is specified by the modeling language, architecture analysis and design language （AADL）, and then mapped to behavior analysis notation, Darwin/FSP （finite state process） through the bidirectional transformation. The bidirectional transformarion provides traceability, which makes behavior analysis result provided by a model checker can be traced and reflected back to the original AADL specifications. In this way, the behavior analysis is integrated into architectural modeling. The feasibility of our approach is shown by a control system example.