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....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.展开更多
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...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.展开更多
Physical education teachers play an important role in helping students＇ development of the motor skills needed to be physically literate individuals. Research suggests that teacher made instructional design decisions...Physical education teachers play an important role in helping students＇ development of the motor skills needed to be physically literate individuals. Research suggests that teacher made instructional design decisions can lead to enhanced motor skill learning. After presenting a model of evidence-based research this paper presents information that will help teachers plan and execute lessons designed to improve students＇ motor skills. Variables that impact motor skill learning in physical education including time, type of practice, content, presentation and organizational strategies, and student skill level are presented and discussed. A brief section on student attitudes, their relation to motor skill learning and to physical literacy is included. Motor skills are needed for physically literate people to enjoy lifelong physical activity. Physical education teachers and the decisions they make contribute to students＇ learning and whether the goal of physical literacy is met.展开更多
It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grou...It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grouping evacuation strategy is proposed. Occupants escape in groups according to the shortest evacuation route is determined by graph theory. In order to evaluate and find the optimal grouping, computational experiments are performed to design and simulate the evacuation processes. A case study shown the application in detail and quantitative research conclusions is obtained. The thoughts and approaches of this study can be used to guide actual high-rise building evacuation processes in future.展开更多
Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a ph...Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a phosgene alternative has attracted extensive attention because of the importance of carbamates in organic synthesis and in the pharmaceutical and agrochemical industries.In recent decades,many multicomponent reaction strategies have been designed for constructing different types of organic carbamate molecules.Most of these methods rely on the in situ generation of carbamate anions from CO_(2) and amines,followed by reactions with other coupling partners.Synthetic strategies for acyclic carbamates include nucleophile‐electrophile coupling,nucleo‐phile‐nucleophile oxidative coupling,difunctionalization of unsaturated hydrocarbons,and C–H bond functionalization.Strategies for the synthesizing cyclic carbamates include carboxylative cyclization of in situ‐generated unsaturated amines and difunctionalization of unsaturated amines with CO_(2) and other electrophilic reagents.This review summarizes the recent advances in the synthesis of organic carbamates from CO_(2) using different multicomponent reaction strategies.Future perspectives and challenges in the incorporation of CO_(2) into carbamates are also presented.展开更多
Documenting the sex and sexual reproduction of the microalgae is very difficult, as most of the results are based on the microscopic observation that can be heavily influenced by genetic, physiological and environment...Documenting the sex and sexual reproduction of the microalgae is very difficult, as most of the results are based on the microscopic observation that can be heavily influenced by genetic, physiological and environmental conditions. Understanding the reproduction strategy of some microalgae is required to breed them in large scale culture industry. Instead of direct observation of sex and sexual reproduction under microscope, the whole set or the majority of core meiosis genes may evidence the sex and sexual reproduction in the unicellular algae, as the meiosis is necessary for maintaining the genomic stability and the advantages of genetic recombination. So far, the available genome sequences and bioinformatic tools （in this study, homolog searching and phylogenetic analysis） allow us to propose that at least 20 core meiosis genes （among them 〉6 must be meiosis specific） are enough for an alga to maintain its sexual reproduction. According to this assumption and the genome sequences, it is possible that sexual reproduction was carried out by Micromonas pusilla and Cyanidiosehyzon merolae, while asexual reproduction was adopted by Bigelowiella natans, Guillardia theta, Nannochloropsis gaditana, N. oeeanica, Chlorella variablis, Phaeodactylum tricornutum and Thalassiosira pseu- donana. This understanding will facilitate the breeding trials of some economic microalgae （e.g., N. gaditana, N. oceanica, C. vari- ablis and P. tricornutum）. However, the reproduction strategies of these microalgae need to be proved by further biological experiments.展开更多
With the increasing growing of the environmental issues and climatic change, sustainable urban development of cities became an urgent demand. Urban development relied on four pillars; the institutional, social, enviro...With the increasing growing of the environmental issues and climatic change, sustainable urban development of cities became an urgent demand. Urban development relied on four pillars; the institutional, social, environmental and economic pillars. Urban regeneration is not a single concept; it is a group of strategies. This study concluded that those strategies include; the public action, certification programs and corporate responsibility theories.展开更多
文摘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.
基金The National Natural Science Foundation of China(No.71071033)the Innovation Project of Jiangsu Postgraduate Education(No.CX10B_058Z)
文摘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.
文摘Physical education teachers play an important role in helping students＇ development of the motor skills needed to be physically literate individuals. Research suggests that teacher made instructional design decisions can lead to enhanced motor skill learning. After presenting a model of evidence-based research this paper presents information that will help teachers plan and execute lessons designed to improve students＇ motor skills. Variables that impact motor skill learning in physical education including time, type of practice, content, presentation and organizational strategies, and student skill level are presented and discussed. A brief section on student attitudes, their relation to motor skill learning and to physical literacy is included. Motor skills are needed for physically literate people to enjoy lifelong physical activity. Physical education teachers and the decisions they make contribute to students＇ learning and whether the goal of physical literacy is met.
基金supported by Beijing University of Civil Engineering and Architecture Nature Science(ZF16078,X18067)
文摘It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grouping evacuation strategy is proposed. Occupants escape in groups according to the shortest evacuation route is determined by graph theory. In order to evaluate and find the optimal grouping, computational experiments are performed to design and simulate the evacuation processes. A case study shown the application in detail and quantitative research conclusions is obtained. The thoughts and approaches of this study can be used to guide actual high-rise building evacuation processes in future.
文摘Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a phosgene alternative has attracted extensive attention because of the importance of carbamates in organic synthesis and in the pharmaceutical and agrochemical industries.In recent decades,many multicomponent reaction strategies have been designed for constructing different types of organic carbamate molecules.Most of these methods rely on the in situ generation of carbamate anions from CO_(2) and amines,followed by reactions with other coupling partners.Synthetic strategies for acyclic carbamates include nucleophile‐electrophile coupling,nucleo‐phile‐nucleophile oxidative coupling,difunctionalization of unsaturated hydrocarbons,and C–H bond functionalization.Strategies for the synthesizing cyclic carbamates include carboxylative cyclization of in situ‐generated unsaturated amines and difunctionalization of unsaturated amines with CO_(2) and other electrophilic reagents.This review summarizes the recent advances in the synthesis of organic carbamates from CO_(2) using different multicomponent reaction strategies.Future perspectives and challenges in the incorporation of CO_(2) into carbamates are also presented.
基金financially supported by National Science and Technology Supporting Program of China (2011BAD14B01)National Natural Science Foundation of China (31270408)Key Laborotary of Marine Bioactive Substance of State Oceanic Administration of China, The First Institute of Oceanography
文摘Documenting the sex and sexual reproduction of the microalgae is very difficult, as most of the results are based on the microscopic observation that can be heavily influenced by genetic, physiological and environmental conditions. Understanding the reproduction strategy of some microalgae is required to breed them in large scale culture industry. Instead of direct observation of sex and sexual reproduction under microscope, the whole set or the majority of core meiosis genes may evidence the sex and sexual reproduction in the unicellular algae, as the meiosis is necessary for maintaining the genomic stability and the advantages of genetic recombination. So far, the available genome sequences and bioinformatic tools （in this study, homolog searching and phylogenetic analysis） allow us to propose that at least 20 core meiosis genes （among them 〉6 must be meiosis specific） are enough for an alga to maintain its sexual reproduction. According to this assumption and the genome sequences, it is possible that sexual reproduction was carried out by Micromonas pusilla and Cyanidiosehyzon merolae, while asexual reproduction was adopted by Bigelowiella natans, Guillardia theta, Nannochloropsis gaditana, N. oeeanica, Chlorella variablis, Phaeodactylum tricornutum and Thalassiosira pseu- donana. This understanding will facilitate the breeding trials of some economic microalgae （e.g., N. gaditana, N. oceanica, C. vari- ablis and P. tricornutum）. However, the reproduction strategies of these microalgae need to be proved by further biological experiments.
文摘With the increasing growing of the environmental issues and climatic change, sustainable urban development of cities became an urgent demand. Urban development relied on four pillars; the institutional, social, environmental and economic pillars. Urban regeneration is not a single concept; it is a group of strategies. This study concluded that those strategies include; the public action, certification programs and corporate responsibility theories.
