An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China

Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved.

Zircon and Apatite U-Pb Geochronology and Geochemistry of the Mafic Dykes in the Shuangxiwu Area, Northwestern Zhejiang Province: Constraints on the Initial Time of Neoproterozoic Rifting in South China

Previous studies have shown that there are some ca.770–750 Ma mafic dykes at the western segment of the Neoproterozoic Jiangnan orogen(JO),and they represent post-orogenic magmatism due to orogenic collapse(Wang

Implementing Discretionary Access Control with Time Character in Linux and Performance Analysis

DAC （Discretionary Access Control Policy） is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T （Discretionary Access Control Policy with Time Character） is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC （General Framework for Access Control）, and the algorithm is put forward. Finally, the performance analysis for the DAC T Linux is carried out. It is proved that the DAC T Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.

Broadcast Scheduling Strategy Based on the Priority of Real-Time Data in a Mobile Environment

Data broadcast is an important data dissemination approach in mobile environment. On broadcast channel, scalability and efficiency of data transmission are satisfied. In a mobile environment, there exists a kind of real-time database application in which both the transactions and data can have their timing constraints and priorities of different levels. In order to meet the requirement of real-time data disseminating and retrieving, a broadcast scheduling strategy HPF-ED F (Highest Priority First with Earlier Deadline and Frequency) is proposed under the BoD (Broadcast on Demand) model. Using the strategy, data items are scheduled according to their priority the transaction imposed on them or system set for them. The strategy also considers other characteristics of data items such as deadline and popularity of data. The extensive simulation experiments have been conducted to evaluate the performance of the proposed algorithm. Results show that it can achieve excellent performance compared with existing strategies.

Monitoring time property in time-sensitive LSC

In order to accurately describe the software require- ments and automatically extract property formulas, the time prop- erty of the live sequence chart （LSC） is focused. For the time- sensitive LSC （TLSC）, the formal syntax and semantic are defined by introducing the formal definitions of clock and timing constraints. The main function of the TLSC is to extract the temporal logic formula, so basic rules and combination rules are proposed to translate the TLSC into the universal fragment of computation tree logic （CTL） formula. To improve the efficiency of model check, transitivity is also used to optimize the formula. The optimization method could reduce the size of the formula under the condition of equivalence. Finally, a case study is introduced to illustrate how to establish the TLSC of requirements. In terms of the proposed transformation rules, the time property formula is extracted from the TLSC, and the design model is assured which is consistent with the property formula. The results show that the method with respect to the automatic extraction of the logic formula from the TLSC can efficiently monitor the time property of software systems.

Network-based structure optimization method of the anti-aircraft system

The anti-aircraft system plays an irreplaceable role in modern combat. An anti-aircraft system consists of various types of functional entities interacting to destroy the hostile aircraft moving in high speed. The connecting structure of combat entities in it is of great importance for supporting the normal process of the system. In this paper, we explore the optimizing strategy of the structure of the anti-aircraft network by establishing extra communication channels between the combat entities.Firstly, the thought of combat network model(CNM) is borrowed to model the anti-aircraft system as a heterogeneous network. Secondly, the optimization objectives are determined as the survivability and the accuracy of the system. To specify these objectives, the information chain and accuracy chain are constructed based on CNM. The causal strength(CAST) logic and influence network(IN) are introduced to illustrate the establishment of the accuracy chain. Thirdly, the optimization constraints are discussed and set in three aspects: time, connection feasibility and budget. The time constraint network(TCN) is introduced to construct the timing chain and help to detect the timing consistency. Then, the process of the multi-objective optimization of the structure of the anti-aircraft system is designed.Finally, a simulation is conducted to prove the effectiveness and feasibility of the proposed method. Non-dominated sorting based genetic algorithm-Ⅱ(NSGA2) is used to solve the multiobjective optimization problem and two other algorithms including non-dominated sorting based genetic algorithm-Ⅲ(NSGA3)and strength Pareto evolutionary algorithm-Ⅱ(SPEA2) are employed as comparisons. The deciders and system builders can make the anti-aircraft system improved in the survivability and accuracy in the combat reality.

Economical Requirements Elicitation Techniques During COVID-19: A Systematic Literature Review

Requirements elicitation is a fundamental phase of software development in which an analyst discovers the needs of different stakeholders and transforms them into requirements.This phase is cost-and time-intensive,and a project may fail if there are excessive costs and schedule overruns.COVID-19 has affected the software industry by reducing interactions between developers and customers.Such a lack of interaction is a key reason for the failure of software projects.Projects can also fail when customers do not know precisely what they want.Furthermore,selecting the unsuitable elicitation technique can also cause project failure.The present study,therefore,aimed to identify which requirements elicitation technique is the most cost-effective for large-scale projects when time to market is a critical issue or when the customer is not available.To that end,we conducted a systematic literature review on requirements elicitation techniques.Most primary studies identified introspection as the best technique,followed by survey and brainstorming.This finding suggests that introspection should be the first choice of elicitation technique,especially when the customer is not available or the project has strict time and cost constraints.Moreover,introspection should also be used as the starting point in the elicitation process of a large-scale project,and all known requirements should be elicited using this technique.

Dwell scheduling algorithm for multifunction phased array radars based on the scheduling gain

A real-time dwell scheduling model, which takes the time and energy constraints into account is founded from the viewpoint of scheduling gain. Scheduling design is turned into a nonlinear programming procedure. The real-time dwell scheduling algorithm based on the scheduling gain is presented with the help of two heuristic rules. The simulation results demonstrate that compared with the conventional adaptive scheduling method, the algorithm proposed not only increases the scheduling gain and the time utility but also decreases the task drop rate.

Task assignment under constraint of timing sequential for cooperative air combat

According to the previous achievement, the task assignment under the constraint of timing continuity for a cooperative air combat is studied. An extensive task assignment scenario with the background of the cooperative air combat is proposed. The utility and time of executing a task as well as the continuous combat ability are defined. The concept of the matching method of weapon and target is modified based on the analysis of the air combat scenario. The constraint framework is also redefined according to a new objective function. The constraints of timing and continuity are formulated with a new method, at the same time, the task assignment and integer programming models of the cooperative combat are established. Finally, the assignment problem is solved using the integrated linear programming software and the simulation shows that it is feasible to apply this modified model in the cooperative air combat for tasks cooperation and it is also efficient to optimize the resource assignment.

MIMO radar dwell scheduling based on novel pulse interleaving technique

According to the signal processing characteristic of MIMO radars,an adaptive dwell scheduling algorithm is proposed.It is based on a novel pulse interleaving technique,which makes full use of transmitting,waiting and receiving durations of radar dwells.The utilization of transmitting duration is unique for MIMO radars and is realized through transmitting duration overlapping.Simulation results show that,compared with the conventional scheduling algorithm,the scheduling performance of MIMO radars can be improved effectively by the proposed algorithm,and the scheduling rule can be chosen arbitrarily when using the proposed algorithm.

Observation Mode and Region Segmentation of New Generation Geostationary Meteorological Satellite of China

Three-axis stabilized Fengyun-4 （FY-4） satellite scries is the new generation of geostationary meteorological satellite in China. The ob-servation flexibility brought by three-axis stabilization makes it possible to design different observation modes for different targets. Important observation modes of the Advanced Geosynchronous Radiation Imager （AGRI）, the core instrument onboard FY-4A, are presented, from the earth obser- vation, navigation and calibration perspective. As the time consumed in full disk and hemisphere observations exceed the time limitation, different region segmentation methods are proposed. Results show the methods are effective, and the full disk as well as hemisphere observations can both be accomplished in the given time. Finally the three-region segmentation method and two-region segmentation method are chosen for full disk and hemisphere observations, respectively, in view of the observation instructions＇ complexity as well as the time consuming. The research results paved the way for the core instrument＇s daily operation, and have been used in FY-4A in-orbit test.

Performance Comparison of a QoS Aware Routing Protocol for Wireless Sensor Networks

Quality of Service (QoS) in Wireless Sensor Networks (WSNs) is a challenging area of research because of the limited availability of resources in WSNs. The resources in WSNs are processing power, memory, bandwidth, energy, communication capacity, etc. Delay is an important QoS parameter for delivery of delay sensitive data in a time constraint sensor network environment. In this paper, an extended version of a delay aware routing protocol for WSNs is presented along with its performance comparison with different deployment scenarios of sensor nodes, taking IEEE802.15.4 as the underlying MAC protocol. The performance evaluation of the protocol is done by simulation using ns-2 simulator.

Growing Sandpile Problem with Local and Non-Local Boundaries Conditions

In this paper, we study a class of Prigozhin equation for growing sandpile problem subject to local and a non-local boundary condition. The problem is a generalized model for a growing sandpile problem with Neumann boundary condition (see [1]). By the semi-group theory, we prove the existence and uniqueness of the solution for the model and thanks to a duality method we do the numerical analysis of the problem. We finish our work by doing numerical simulations to validate our theoretical results.

Accuracy optimization of virtual iterative reduction algorithm under time constraint

The factors like production accuracy and completion time are the determinants of the optimal scheduling of the complex products work-flow,so the main research direction of modern work-flow technology is how to assure the dynamic balance between the factors.Based on the work-flow technology,restraining the completion time,and analyzing the deficiency of traditional minimum critical path algorithm,a virtual iterative reduction algorithm(VIRA)was proposed,which can improve production accuracy effectively with time constrain.The VIRA with simplification as the core abstracts a virtual task that can predigest the process by combining the complex structures which are cyclic or parallel,finally,by using the virtual task and the other task in the process which is the iterative reduction strategy,determines a path which can make the production accuracy and completion time more balanced than the minimum critical path algorithm.The deadline,the number of tasks,and the number of cyclic structures were used as the factors affecting the performance of the algorithm,changing the influence factors can improve the performance of the algorithm effectively through the analysis of detailed data.Consequently,comparison experiments proved the feasibility of the VIRA.

Vehicle flow formulation for two-echelon time-constrained vehicle routing problem

Two-echelon routing problems,including variants such as the two-echelon vehicle routing problem(2E-VRP)and the two-echelon location routing problem(2E-LRP),involve assignment and location decisions.However,the two-echelon time-constrained vehicle routing problem(2E-TVRP)that caters to from-linehaul-to-delivery practices does not involve assignment decisions.This routing problem variant for networks with two eche-lons has not yet attracted enough research interest.Localized or long-distance services suffer from the lack of the assignment decisions between satellites and customers.Therefore,the 2E-TVRP,rather than using assignment decisions,adopts time constraints to decide the routes on each of the two interacting echelons:large-capacity vehicles trans-port cargoes among satellites on the first echelon,and small-capacity vehicles deliver cargoes from satellites to customers on the second echelon.This study introduces a mixed integer linear programming model for the 2E-TVRP and proposes a heuristic algorithm that incorporates the savings algorithm followed by a variable neighborhood search phase.Illustrative examples are used to test the mathematical formulation and the heuristic and a case study is used to demonstrate that the heuristic can effectively solve realistic-size instances of the 2E-TVRP.

Design of Time-constrained Guidance Laws via Virtual Leader Approach

Guidance problems with flight time constraints are considered in this article. A new virtual leader scheme is used for design of guidance laws with time constraints. The core idea of this scheme is to adopt a virtual leader for real missiles to convert a guidance problem with time constraints to a nonlinear tracking problem,thereby making it possible to settle the problem with a variety of control methods. A novel time-constrained guidance （TCG） law, which can control the flight time of missiles to a prescribed time,is designed by using the virtual leader scheme and stability method. The TCG law is a combination of the well-known proportional navigation guidance（PNG） law and the feedback of flight time error. What＇ s more, this law is free of singularities and hence yields better performances in comparison with optimal guidance laws with time constraints. Nonlinear simulations demonstrate the effectiveness of the proposed law.

Cooperative Guidance for Multimissile Salvo Attack

Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordination algorithms and local guidance laws are combined together, is proposed. This scheme actually builds up a hierarchical cooperative guidance architecture, which may provide a general solution to the multimissile cooperative guidance problems. In the case of salvo attacks which require missiles to hit the target simultaneously, both centralized and distributed coordination algorithms are derived based on the impact-time-control guidance （ITCG） law. Numerical simulations are performed to demonstrate the effectiveness of the proposed approaches.

Cooperative guidance strategy for multiple hypersonic gliding vehicles system

Cooperative guidance strategy for multiple hypersonic gliding vehicles system with flight constraints and cooperative constraints is investigated.This paper mainly cares about the coordination of the entry glide flight phase and driving-down phase.Different from the existing results,both the attack time and the attack angle constraints are considered simultaneously.Firstly, for the entry glide flight phase, a two-stage method is proposed to achieve the rapid cooperative trajectories planning, where the control signal corridors are designed based on the quasi-equilibrium gliding conditions.In the first stage, the bank angle curve is optimized to achieve the attack angle coordination.In the second stage, the angle of attack curve is optimized to achieve the attack time coordination.The optimized parameters can be obtained by the secant method.Secondly, for the driving-down phase, the cooperative terminal guidance law is designed where the terminal attack time and attack angle are considered.The guidance law is then transformed into the bank angle and angle of attack commands.The cooperative guidance strategy is summarized as an algorithm.Finally, a numerical simulation example with three hypersonic gliding vehicles is provided for revealing the effectiveness of the acquired strategy and algorithm.

Process engineering in circular economy

Driven by increasing global population and by growing demand for individual wealth, the consumption of energy and raw materials as well as the steadily growing CO2 concentration in atmosphere pose great challenges to process engineering. This complex multi-scale discipline deals with the transformation of mass by energy to manifold products in different industrial fields under economical and ecological sus- tainable conditions. In growing circular economy, process engineering increasingly plays an important role in recovering valuable components from very diffuse material flows leaving the user stocks following widely variable time periods of use. As well it is engaged in thermal recovery of energy therefrom and in environmentally safe disposal of residual solid wastes whose recovery economically is not feasible. An efficient recovery of materials and energy following the laws of entropy is a must. A complex network of mass, energy, transportation and information flows has to be regarded with growing traded quantities of used goods even on global level. Important constraints in time, however, exist for a necessary realization of innovative new processes and communal mobility and industrial infrastructure on medium and large scale. Based on reasonable long term and highly reliable statistics from industrial organizations repre- senting steel and paper industry, some limits and trends of possible developments in processing of those industries with long recycling experience will be discussed.

Schedulability Analysis Method of Timing Constraint Petri Nets

Timing constraint Petri nets (TCPNs) can be used to model a real-time system specification and to verify the timing behavior of the system. This paper describes the limitations of the reachability analysis method in analyzing complex systems for existing TCPNs. Based on further research on the schedulability analysis method with various topology structures, a more general state reachability analysis method is proposed. To meet various requirements of timely response for actual systems, this paper puts forward a heuristic method for selecting decision-spans of transitions and develops a heuristic algorithm for schedulability analysis of TCPNs. Examples are given showing the practicality of the method in the schedulability analysis for real-time systems with various structures.