Regional ecological security anddiagnosisof obstaclefactors in underdevelopedregions：acasestudy in Yunnan Province,China

In order toclarify regional ecological security status and formation mechanism of regional ecological security barriers in underdeveloped regions of China,we took Yunnan province as a case to evaluate its regional ecological security by using entropy matter-element model,comprehensive index and GIS spatial method,and we diagnosed itsobstacle factors through obstacle degree model. We found a low overall level of regional ecological security in Yunnan. Only Kunmingfell into the good level, 68% of the regions were below the critical safe level. For the vast majority of regions in Yunnan, their regional ecological security was unstable. The indexes related to per capita resources, geological and topographyenvironment, economic, and technologywere at the unsafe or dangerous level.The indexes related to urban expansion, level of income, cultivated land quality were at the level of critical safety. The indexes concerning urban management capacity, airqualityand waterenvironment were at the good or ideallevel. Yunnan's regional ecological security was not good due to natural obstructive environment itself, simultaneously lower backward economic and social level restricted the ability of ecological security response to manage ragile ecological environment. The results of the composite index wereroughly consistent with those of the entropy weight matterelement model. The mean values of the classification index,from high to low, were: the state index>the response index>the pressure index. The state index and the response index had a significant mutual promotion to each other.The regions with good composite index, state index and response index mainly distributed in the central regions of Yunnan Province. Spatial autocorrelation of regional ecological security level in Yunnan was not obvious. Water resources, economic and social development were main obstacle factors of the regional ecological security.When distinguishing with obstacle type, Kunming belonged to natural ecological environment barrier type, while other regions belonged to economic and social barrier type.

Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year （2003）, the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

Theory and Method of Power System Integrated Security Region Irrelevant to Operation States:An Introduction

How to comprehensively consider the power flow constraints and various stability constraints in a series of power system optimization problems without affecting the calculation speed is always a problem.The computational burden of probabilistic security assessment is even more unimaginable.In order to solve such problems,a security region(SR)methodology is proposed,which is a brand-new methodology developed on the basis of the classical point-wise method.Tianjin University has been studying the SR methodology since the 1980s,and has achieved a series of original breakthroughs that are described in this paper.The integrated SR introduced in this paper is mainly defined in the power injection space,and includes SRs to ensure steady-state security,transient stability,static voltage stability,and smalldisturbance stability.These SRs are uniquely determined for a given network topology(as well as location and clearing process for transient faults)and given system component parameters,and are irrelevant to operation states.This paper presents 11 facts and related remarks to introduce the basic concepts,composition,dynamics nature,and topological and geometric characteristics of SRs.It also provides a practical mathematical description of SR boundaries and fast calculation methods to determine them in a concise and systematic way.Thus,this article provides support for the systematic understanding,future research,and applications of SRs.The most critical finding on the topological and geometric characteristics of SRs is that,within the scope of engineering concern,the practical boundaries of SRs in the power injection space can be approximated by one or a few hyperplanes.Based on this finding,the calculation time for power system probabilistic security assessment(i.e.,risk analysis)and power system optimization with security constraints can be decreased by orders of magnitude.

New Political Dynamism in Central Asia:Security Issues and Prospects for Regional Cooperation

The article examines the issues of regional security and prospects of cooperation between the countries of Central Asia in the context of a new world order. As factors of sustainable development and security, the author considers the following issues: preservation of the geopolitical balance in Central Asia; development of a multivariate system of transportation and communication corridors; cardinal increase in the efficiency of counterterrorism and religious extremism; a solution to the Afghan problem; and resolution to the problems of fair water use and ecology in the region.

Improved QoS-Secure Routing in MANET Using Real-Time Regional ME Feature Approximation

Mobile Ad-hoc Network(MANET)routing problems are thoroughly studied several approaches are identified in support of MANET.Improve the Quality of Service(QoS)performance of MANET is achieving higher performance.To reduce this drawback,this paper proposes a new secure routing algorithm based on real-time partial ME(Mobility,energy)approximation.The routing method RRME(Real-time Regional Mobility Energy)divides the whole network into several parts,and each node’s various characteristics like mobility and energy are randomly selected neighbors accordingly.It is done in the path discovery phase,estimated to identify and remove malicious nodes.In addition,Trusted Forwarding Factor(TFF)calculates the various nodes based on historical records and other characteristics of multiple nodes.Similarly,the calculated QoS Support Factor(QoSSF)calculating by the Data Forwarding Support(DFS),Throughput Support(TS),and Lifetime Maximization Support(LMS)to any given path.One route was found to implement the path of maximizing MANET QoS based on QoSSF value.Hence the proposed technique produces the QoS based on real-time regional ME feature approximation.The proposed simulation implementation is done by the Network Simulator version 2(NS2)tool to produce better performance than other methods.It achieved a throughput performance had 98.5%and a routing performance had 98.2%.

Strategic Agricultural Commodity Value Chains in Africa for Increased Food: The Regional Approach for Food Security

The challenge Africa faces the most is how to feed the 2.4 billion people in 2050. This will require a transformational agriculture. Africa doesn’t need subsistence agriculture, but rather agriculture linked to the market where market demand and the consuming habits are taken in consideration. Agriculture evolves in an environment where small holders are linked to markets (national and regional), where economies of complementarity and economies of scale are taken advantage of by producers and private sector. In short, Africa will need a paradigm shift to industrialise and commercialise its agriculture sector in order to increase food production, and income and to create jobs in and outside the sector. Africa needs agribusiness and agro-industries to domesticate the benefits of the sector, to create wealth in the sector and retain that wealth in the continent. Agricultural commodities regional value chains for increased food should be the target for Africa. The continent remains the region with the highest prevalence of under-nourishment. Since agriculture remains the mainstay of most African economies except the mineral producers, the sector deserves a close attention from leaders. It accounts for 65% of employment and 40% of Africa’s export earnings and accounts for 17% of the GDP. This shows how important the sector is. Agriculture needs to be seen as a conduit for farmers to get connected to markets, a conduit for revenue, for jobs and for transformation. Africa needs to come back on the international scene as food sufficient continent and even food exporter. This can be achieved only with a stable, productive agricultural resource base. Thus, achieving and sustaining food security and economic prosperity in Africa will require significant efforts to modernize the continent’s agriculture sector through injection of agribusiness and agro-industries and through the application of science and technology in agriculture. In essence, agriculture needs to be viewed as knowledge based entrepreneurial activity. Smart investments in agriculture will have multiplier effects for the whole economy and hence induce prosperity to other sectors. In recent years, a renewed focus on agriculture has been evident in policy and development agendas across the African continent. This paper outlines the status of agriculture, agribusiness and agro-industries in Africa, their role in the agenda of agricultural transformation and economic transformation and the focus on regional value chain to increase food production, transformation and trade. The paper adopts a new thinking in agriculture, which reflects a regional value chain approach. The author covers such issues as: need for agricultural transformation, the role of value chain in agricultural sector, the need for regional value chain for increased income and increased food, the role of markets and the common denominator of all, the regional integration to push forward the African agriculture agenda. Evidence shows that it is agricultural growth, through its leverage effects on the rest of the economy that typically enables poor countries, poor regions and ultimately poor households to take the first steps toward economic transformation. Therefore agricultural productivity, at the small holder’s level, has the potential to lift millions of Africa’s vulnerable out of poverty and provide sustainable jobs. Other factors, namely “the rapid urbanization” and “increased population growth”, are quoted to be of critical importance. Africa population is projected to double, attaining the 2.3 billion people mark over the next 40 years representing half of the globe’s total population. This could trigger competition for resources and can have devastating effects on natural resources if not rightly channelled.

Steady-state Voltage Security-constrained Optimal Frequency Control for Weak HVDC Sending-end AC Power Systems

Due to the fact that a high share of renewable energy sources(RESs)are connected to high-voltage direct current(HVDC)sending-end AC power systems,the voltage and frequency regulation capabilities of HVDC sending-end AC power systems have diminished.This has resulted in potential system operating problems such as overvoltage and overfrequency,which occur simultaneously when block faults exist in the HVDC link.In this study,a steady-state voltage security-constrained optimal frequency control method for weak HVDC sending-end AC power systems is proposed.The integrated virtual inertia control of RESs is employed for system frequency regulation.Additional dynamic reactive power compensation devices are utilized to control the voltage of all nodes meet voltage security constraints.Then,an optimization model that simultaneously considers the frequency and steady-state voltage security constraints for weak HVDC sending-end AC power systems is established.The optimal control scheme with the minimum total cost of generation tripping and additional dynamic reactive power compensation required is obtained through the optimization solution.Simulations are conducted on a modified IEEE 9-bus test system and practical Qing-Yu line commutated converter based HVDC(LCC-HVDC)sending-end AC power system to verify the effectiveness of the proposed method.

A Method of Auxiliary Planning for Intelligent Substation Access System Based on Security Region

This paper presents an auxiliary planning method for intelligent substation access system based on security region. Firstly, the method of resolving the static voltage security region is proposed. Secondly, the method of constructing the optimal index of substation accession is given, which is used to describe the priority of the node into the substation. Finally, a complete set of intelligent substation access system auxiliary planning strategy is given, which takes into account the constraints of the normal operation of the grid on the voltage amplitude.

Study on the Risk of Regional Energy Security Cooperation

Energy security is an issue that many countries pay more attention to. Cooperation is a good way to solute it. According to the complex system theory, the regional energy cooperation means a state or process of balance system formed by the interaction and behavior coordination between agents. The features of the regional energy cooperation risk include: uncertainty, potential, fuzziness, diversity, relevance and particularity. And the regional energy cooperation risk can be divided into risk inside the system such as main body ability structure of the risk and main body decision-making risk, and the risk outside the system such as external environment factors and cooperation pattern factors.

Study on the Real-Time Security Evaluation for the Train Service Status Using Safety Region Estimation

For the important issues of security service of rail vehicles, the online quantitative security assessment method of the service status of rail vehicles and the key equipments is urgently needed, so the method based on safety region was proposed in the paper. At first, the formal description and definition of the safety region were given for railway engineering practice. And for the research objects which their models were known, the safety region estimation method of system stability analysis based on Lyapunov exponent was proposed;and for the research objects which their models were unknown, the data-driven safety region estimation method was presented. The safety region boundary equations of different objects can be obtained by these two different approaches. At last, by real-time analysis of the location relationship and generalized distance between the equipment service status point and safety region boundary, the online safety assessment model of key equipments can be established. This method can provide a theoretical basis for online safety evaluation of trains operation;furthermore, it can provide support for real-time monitoring, early warning and systematic maintenance of rail vehicles based on the idea of active security.

The Romania-US Strategic Partnership and the Security of the Wider Black Sea Region: Historical Landmarks

The Strategic Partnership,launched in 1997 with the purpose of becoming an advanced mechanism of bilateral cooperation between Romania and the United States regarding fields of strategic interest for both countries,is an important element of maintaining peace and stability in South-Eastern Europe and in the Black Sea area.The Partnership determined a substantial evolution of the bilateral relations based on an intense political speech,as an important aspect for the regional security,and promoted democracy near the Euro-Atlantic community.Romania’s relation with the United States,being focused on security aspects,proves its utility,considering that to this day the North Atlantic Alliance and the European Union do not have a common strategic vision regarding the Wider Black Sea Region.This is due to conceptual differences and to the fact that,unlike Central and Eastern Europe—where the integrations of NATO and EU were linked,in the Black Sea area,the situation is different,having in mind that only Romania and Bulgaria have been part of these structures.This study’s purpose is to present both the evolution of this cooperation format between Romania and the United States in the last two decades and its relevance for the new regional security system.In the circumstances in which the events in Ukraine in 2014 lead to unprecedented tension(Post-Cold War)between the Russian Federation and the Occident,the USA’s involvement in ensuring the security of the extended Black Sea Region gains even more relevance.

The Central Asian Regional Security Complex Revisited:Understanding the Implications of the US Retreat From Afghanistan

On February 29,2020,President Donald Trump announced the United States signed a peace agreement with the Taliban,signifying the United States‟intention of leaving Afghanistan in the near future.Though the global pandemic has altered US withdrawal plans,the question still remains:What will become of the Central Asian regional security complex following America‟s exit?Buffered by the presence of the United States since 2001,the Central Asian republics now once again find themselves at a crossroads to either rely on individual defense services or to develop increased military cooperation with interested states.Recognizing Central Asia‟s history of collaboration among its regional and near-regional countries,I argue that the Central Asian Republics of Afghanistan,Kazakhstan,Kyrgyzstan,Tajikistan,Turkmenistan,and Uzbekistan will seek to develop stronger security ties with neighboring regional security complexes(RSCs),namely the South Asian,Russian,and Chinese RSCs.With decreased American influence,each of the states in these RSCs is rushing to fill the void of influence in order to capitalize on Central Asia‟s geostrategic position in Eurasia as well as secure itself from the threat of non-state actors still prevalent in the region.I further argue that the states in the Central Asian RSC additionally seek these same benefits and security,but receive them to a much lesser extent than their more powerful regional neighbors.Understanding how the American withdrawal from Afghanistan will impact Central Asian RSC relations can provide insight into how great power vacuums are filled both by great powers and regional powers alike.

Bilateral and Regional Strategic and Security Relationship Between China and the US after the Cold War

Sino-US relations are complex relations with multi-aspects between the two bigcountries in the world. It has three levels: the global level, the Asia-Pacificlevel and the bilateral level. The critical relationship between China and the US isembodied in the regional and bilateral levels that are more specific and essential.Beyond the field of economy and trade, their relationship is mainly embodied in thestrategic and security field.

NATO and EU Strategies for the Black Sea Region： The Challenge of Power Balance in New Security Environment

文章在在这个区域提出不稳定性担心的一些主要地缘政治学的变化以后在黑海区域在动态政治过程上给概述。目的是向俄国总结国际组织(北约和 EU ) 的政策趋势并且在当前的欧元大西洋策略上介绍一些分析想法。求婚是基于 congagement 途径想的一个不同方法。

Prediction of Instability Separation Modes and Its Application in Practical Dynamic Security Region

The transient critical boundary of dynamic security region (DSR) can be approximated by a few hyper planes correlated with instability separation modes. A method to fast predict instability separation modes is proposed for DSR calculation in power injection space. The method identifies coherent generation groups by the developed K-medoids algorithm, taking a similarity matrix derived from the reachability Grammian as the index. As an experimental result, reachability Grammian matrices under local injections are approximately invariant. It indicates that the generator coherency identifications are nearly consistent for different injections. Then instability separation modes can be predicted at the normal operating point, while average initial acceleration is considered as the measure of the critical generator group to amend the error. Moreover, based on these predicted instability separation modes, a critical point search strategy for DSR calculation is illustrated in the reduced injection space of the critical generators. The proposed method was evaluated using New England Test System, and the computation accuracy and speed in determining the practical DSR were improved.

Quantitative analysis of the dynamic change and spatial differences of the ecological security: a case study of Loess Plateau in northern Shaanxi Province

Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows： （1） the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; （2） the ecological footprint appears an increasing trend; （3） ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and （4） the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv.