混合动力汽车能效优化与控制策略研究

随着环境问题和能源危机的日益严重,混合动力汽车作为一种节能环保的交通工具,得到了广泛关注。能效优化和控制策略是混合动力汽车研究的重要方向,对于提高汽车性能、降低能耗、减少排放具有重要意义。本文旨在探讨混合动力汽车的能效优化和控制策略,以提高汽车的整体性能和燃油经济性。

社会组织参与困境儿童社会支持网络构建的服务策略研究--以广州市S组织困境儿童服务项目为例

要妥善回应深化改革过程中困境儿童多元化的需求,须从困境儿童社会支持着手,通过发挥社会组织联动多元主体的作用来筑实困境儿童社会支持网络。研究聚焦S组织困境儿童服务实践策略,分析其回应需求的服务过程,旨在为社会组织参与构建困境儿童支持网络提供实务参考。研究发现,S组织在开展困境儿童服务时能够充分发挥枢纽平台优势,在一定程度上促进了儿童主体发展和多元主体参与,但组织存在建设局限性、服务内容与形式创新不足、服务不够规范、机制缺失等方面的问题。推动儿童福利事业发展的关键在于要坚持政府主导的公共服务供给格局,拓宽社会参与渠道和门槛,整合跨界创新力量,动员多元主体在困境儿童服务中积极投入服务和资源,强化其社会支持网络。

投资组合策略研究

An optimal investment strategy is extremely worth discussing and studying in our actual investment activities, not only for individual investors and companies but also for governments and all other kinds of investors. And there is no doubt that we cannot find the only way and meet the needs of every investor. But if we can get an authoritative ranking according to the needs of investors, we can find the different best investment portfolio for different investors who have different view of risk theoretically and practically. From a typical case. all about these problems is what I will discuss in this article.

畜禽产品中药物残留的控制策略

本刊上期刊登了《兽药残留的危害及解诀对策》一文后,我们陆续接到了一些读者的来电,希望我们在今后应多刊登一些这方面的稿件,以便能够引起有关部门的高度重视,进一步规范兽药市场,正确引导广大的养殖场户正确使用兽药。为满足这些热心读者的要求,我们于本期特刊登了下面这篇文章,借此,我们相信广大读者将对兽筠残留的危害会有更进一步的认识和了解。

元认知策略在高中英语听力教学中的运用

In English language teaching, learning strategies are essential for improving students＇ learning efficiency as well as cultivate students＇ ability of self-regulated learning; and metacognitive strategy is of such strategies, which has attracted many language teachers＇ attention. However, not many research have focus on listening teaching on the level of senior high school in China's Mainland. This research is to fill in this gap with an introduction to listening strategies in metacognitive strategies and a sample of listening class design.

Live-streaming selling strategies for competitive firms

The booming live-streaming commerce has significantly changed the traditional e-commerce model,thus attracting much attention from both industry and academia.In recent years,an increasing number of scholars have applied analytical models to explore live-streaming strategies for firms in different scenarios.However,the previous literature mainly considers monopolists,while in the real world,competition is not rare.To fill this gap between the literature and practical observations,this paper applies a game theoretical model to study live-streaming adoption and pricing strategy for firms under competitive environments.The results show that,for competitive firms,the equilibrium strategy depends on the relation between the commission rate and the intensity of the market expansion effect.Additionally,compared to the case in which no firm adopts live-streaming,competitive firms do not always benefit from the adoption of live-streaming selling.The paper also shows that competition plays a negative role in inducing a firm to adopt live-streaming.

Vascular Calcification:Where is the Cure?

With the progress of aging,the incidence of vascular calcification(VC)gradually increases,which is correlated with cardiovascular events and all-cause death,aggravating global clinical burden.Over the past several decades,accumulating approaches targeting the underlying pathogenesis of VC have provided some possibilities for the treatment of VC.Unfortunately,none of the current interventions have achieved clinical effectiveness on reversing or curing VC.The purpose of this review is to make a summary of novel perspectives on the interventions of VC and provide reference for clinical decision-making.

Tower crane path planning based on improved ant colony algorithm

In order to solve the problem of path planning of tower cranes,an improved ant colony algorithm was proposed.Firstly,the tower crane was simplified into a three-degree-of-freedom mechanical arm,and the D-H motion model was established to solve the forward and inverse kinematic equations.Secondly,the traditional ant colony algorithm was improved.The heuristic function was improved by introducing the distance between the optional nodes and the target point into the function.Then the transition probability was improved by introducing the security factor of surrounding points into the transition probability.In addition,the local path chunking strategy was used to optimize the local multi-inflection path and reduce the local redundant inflection points.Finally,according to the position of the hook,the kinematic inversion of the tower crane was carried out,and the variables of each joint were obtained.More specifically,compared with the traditional ant colony algorithm,the simulation results showed that improved ant colony algorithm converged faster,shortened the optimal path length,and optimized the path quality in the simple and complex environment.

Zero-determinant strategies in iterated multi-strategy games

Self-serving,rational agents sometimes cooperate to their mutual benefit.The two-player iterated prisoner′s dilemma game is a model for including the emergence of cooperation.It is generally believed that there is no simple ultimatum strategy which a player can control the return of the other participants.The zero-determinant strategy in the iterated prisoner′s dilemma dramatically expands our understanding of the classic game by uncovering strategies that provide a unilateral advantage to sentient players pitted against unwitting opponents.However,strategies in the prisoner′s dilemma game are only two strategies.Are there these results for general multi-strategy games?To address this question,the paper develops a theory for zero-determinant strategies for multi-strategy games,with any number of strategies.The analytical results exhibit a similar yet different scenario to the case of two-strategy games.The results are also applied to the Snowdrift game,the Hawk-Dove game and the Chicken game.

Lecturers’Efforts in Building Rapport in the English-Medium Instruction(EMI)Context:Focus on the Use of Communication Strategies

Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on learning outcomes,it is imperative that teachers establish positive emotional rapport with their students.This study explores how experienced and highly rated EMI lecturers at a Chinese university’s overseas campus use communication strategies to build rapport with their students during interactive academic activities.It identifies the strategies used by these lecturers and examines how the strategies facilitate the teaching-learning process.The data,consisting of 10 hours of tutorials and 10 hours of supervisor-student supervision meetings,is analyzed using an adapted Conversation Analysis(CA)approach.The analysis reveals three types of communication strategies(CSs)frequently used by lecturers:back-channeling,codeswitching,and co-creation of messages.By employing these strategies,the lecturers established a strong rapport with the students,which created an encouraging and supportive learning environment.Consequently,this positive atmosphere facilitated students’learning of content knowledge through English.The findings of this study have implications for the training of lecturers who encounter difficulties in establishing rapport with multilingual students in the EMI setting.

An Adaptive Spectral Conjugate Gradient Method with Restart Strategy

As a generalization of the two-term conjugate gradient method(CGM),the spectral CGM is one of the effective methods for solving unconstrained optimization.In this paper,we enhance the JJSL conjugate parameter,initially proposed by Jiang et al.(Computational and Applied Mathematics,2021,40:174),through the utilization of a convex combination technique.And this improvement allows for an adaptive search direction by integrating a newly constructed spectral gradient-type restart strategy.Then,we develop a new spectral CGM by employing an inexact line search to determine the step size.With the application of the weak Wolfe line search,we establish the sufficient descent property of the proposed search direction.Moreover,under general assumptions,including the employment of the strong Wolfe line search for step size calculation,we demonstrate the global convergence of our new algorithm.Finally,the given unconstrained optimization test results show that the new algorithm is effective.

Sampling Strategy Within a Wild Soybean Population Based on Its Genetic Variation Detected by ISSR Markers

In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its genetic diversity through the inter-simple sequence repeat (ISSR) marker analysis of a sample set consisting of 100 randomly collected individuals. A relatively large genetic diversity was detected among the samples based on estimation of DNA products amplified from 15 selected ISSR primers, with the similarity coefficient varying from 0.17 to 0.89. The mean expected heterozygosity (He) was 0.171 4 per locus, and Shannon index (1) was 0.271 4. The Principal Coordinate Analysis (PCA) further indicated that genetic diversity of the Jiangwan wild soybean population was not evenly distributed, instead, was presented by a mosaic or clustered distribution pattern. Correlation study between genetic diversity and number of samples demonstrated that genetic diversity increased dramatically with the increase of number of samples within 40 individuals, but the increase became slow and rapidly reached a plateau when more than 40 individuals were included in the analysis. It is concluded that (i) a sample set of approximately 35-45 individuals should be included to represent possibly high genetic diversity when conservation of a wild soybean population ex situ is undertaken; and (ii) collection of wild soybean samples should be spread out as wide as possible within a population, and a certain distance should be kept as intervals among individuals for sampling.

Countermeasures for Qinghai-Tibet Plateau to Cope with Climate Change and Ecological Environment Safety

The monitoring,prediction and assessment of status about climate changes and ecological environment at home and abroad were discussed in this study,and the scientific significance and countermeasures for Qinghai-Tibet Plateau to cope with these problems were also put forward.

Attribute-based access control policy specification language

This paper first introduces attribute expression to describe attribute-based access control policy.Secondly,an access control policy enforcement language named A-XACML （attribute-XACML）is proposed,which is an extension of XACML.A-XACML is used as a simple,flexible way to express and enforce access control policies,especially attribute-based access control policy,in a variety of environments.The language and schema support include data types,functions,and combining logic which allow simple and complex policies to be defined.Finally,a system architecture and application case of user-role assignment is given to show how attribute expressions and A-XACML work in access control policy description and enforcement.The case shows that attribute expression and A-XACML can describe and enforce the complex access control policy in a simple and flexible way.

Optimal configuration of firewall, IDS and vulnerability scan by game theory

The integrated linkage control problem based on attack detection is solved with the analyses of the security model including firewall, intrusion detection system （IDS） and vulnerability scan by game theory. The Nash equilibrium for two portfolios of only deploying IDS and vulnerability scan and deploying all the technologies is investigated by backward induction. The results show that when the detection rates of IDS and vulnerability scan are low, the firm will not only inspect every user who raises an alarm, but also a fraction of users that do not raise an alarm; when the detection rates of IDS and vulnerability scan are sufficiently high, the firm will not inspect any user who does not raise an alarm, but only inspect a fraction of users that raise an alarm. Adding firewall into the information system impacts on the benefits of firms and hackers, but does not change the optimal strategies of hackers, and the optimal investigation strategies of IDS are only changed in certain cases. Moreover, the interactions between IDS ＆ vulnerability scan and firewall ＆ IDS are discussed in detail.

Biomass Allocation of Scirpus mariqueter Along an Elevational Gradient in a Salt Marsh of the Yangtse River Estuary

Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stress, the biomass allocations to different plant components and some related morphological parameters were examined along an elevational gradient within a salt marsh. Authors found that S. mariqueter performed best at medium elevation within the marsh, with relatively high density of shoot and individual ramet dry mass. Biomass allocation to corm was the highest at low elevations, and the least at high elevations, suggesting that a conservative strategy was adopted by the species to cope with the harsh physical conditions at the low elevation. The investment in rhizome decreased from low to high elevations, while the proportion of inflorescence mass increased, indicating that during the life history, the species shifts from predominant asexual reproduction to predominant sexual reproduction. This may be favourable for the species to colonize larger area, and to spread and persist at a meta_population level. Correlation analyses showed that sexual reproduction was inversely related to growth and asexual reproduction. However, it is difficult to determine the relationship between asexual reproduction and growth possibly because of the varied function of the corms of the species in different life history stages.

EVOLUTIONARY GAME OF DYNAMIC KNOWLEDGE EXCHANGING IN KNOWLEDGE INTERACTION

Characteristics of knowledge exchanging behavior among individual agents in a knowledge dynamic interaction system are studied by using the game theory. An analytic model of evolutionary game of continuous dynamic knowledge interaction behavior is founded based on the structure of the evolutionary game chain. Possible evolution trends of the model are discussed. Finally, evolutionary stable strategies （ESSs） of knowledge transactions among individual agents in the knowledge network are identified by simulation data. Stable charicteristics of ESS in a continuous knowledge exchanging team help employee to communicate and grasp the dynamic regulation of shared knowledge.

Optimal quasi-periodic maintenance policies for two-unit series system

To investigate the effects of various random factors on the preventive maintenance （PM） decision-making of one type of two-unit series system, an optimal quasi-periodic PM policy is introduced. Assume that PM is perfect for unit 1 and only mechanical service for unit 2 in the model. PM activity is randomly performed according to a dynamic PM plan distributed in each implementation period. A replacement is determined based on the competing results of unplanned and planned replacements. The unplanned replacement is trigged by a catastrophic failure of unit 2, and the planned replacement is executed when the PM number reaches the threshold N. Through modeling and analysis, a solution algorithm for an optimal implementation period and the PM number is given, and optimal process and parametric sensitivity are provided by a numerical example. Results show that the implementation period should be decreased as soon as possible under the condition of meeting the needs of practice, which can increase mean operating time and decrease the long-run cost rate.

Multi-objective integrated optimization based on evolutionary strategy with a dynamic weighting schedule

The evolutionary strategy with a dynamic weighting schedule is proposed to find all the compromised solutions of the multi-objective integrated structure and control optimization problem, where the optimal system performance and control cost are defined by H2 or H∞ norms. During this optimization process, the weights are varying with the increasing generation instead of fixed values. The proposed strategy together with the linear matrix inequality （LMI） or the Riccati controller design method can find a series of uniformly distributed nondominated solutions in a single run. Therefore, this method can greatly reduce the computation intensity of the integrated optimization problem compared with the weight-based single objective genetic algorithm. Active automotive suspension is adopted as an example to illustrate the effectiveness of the proposed method.

Novel scheme to specify and integrate RBAC policy based on ontology

To describe and integrate various policies applied in different domains, the definition of the family of OntoRBAC based on the ontology of a general role-based access control （RBAC） policy is proposed, which can support and extend the RBAC96 model. The uniform ontology-based description mechanism of secure policies is applied in OntoRBAC, which can be used to describe different secure policies in distributed systems and integrate policies in semantic level with upper concepts. In addition, some rules have been defined to reason within the OntoRBAC to extend the inference algorithms in ontology, which makes the system accommodate itself to RBAC policies better.