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1.
0 IntroductionIntheprocessofR&Ditem ,thereisusuallycompetition .ManyfirmswanttoinvestR&Dtoobtainapatent.Lury[1 ] gaveanequilibriuminvestmentundertheconditionofone timeinvestmentandcontinuousinvestmentwhenthepayoffwasafixedprize.Ref.[2 ]analyzedtheeffectofinformationsharinginR&D .TherearemanyliteraturesaboutanalysisofR&DlevelswhenfirmscompeteinoutputmarketafterR&Dsucceeds[3 ,4] .Additionally ,todecideinvestmentlevel,therearemanyliteraturesaboutR&Ditem’spricing .MondherBellalah[5] ,K .…  相似文献   

2.
In this paper, we consider a nonlinear size-structured population model with functional response, which describes the dynamics of a predator-prey system living in a common habitat. We present a kind of functional response for the prey being a plant or algae, and explain its biological meanings. When the vital rates depend both on the individual’s size and on the total population or only depend on the former, we obtain the existence of equilibrium solutions.  相似文献   

3.
We propose a continuously deterministic procurement-production-inventory model to optimize the raw material procurement and production problem with raw material inventory and finished products inventory when the raw material purchasing price, the production cost, the raw material inventory holding cost, the finished products holding cost, and the demand rate fluctuate over time. We use Hamilton-Lagrange function and Pontryagin’s maximum principle in optimal control theory to analyze the model, and we obtain the necessary and sufficiency conditions of the optimal solution to the model. We find some optimal policies regarding the procurement and production under some special circumstances. Biography: CAO Xiaogang(1982–), male, Ph. D. candidate, research direction: production and operations management.  相似文献   

4.
This paper presents a two-phase genetic algorithm (TPGA) based on the multi-parent genetic algorithm (MPGA). Through analysis we find MPGA will lead the population’s evolvement to diversity or convergence according to the population size and the crossover size, so we make it run in different forms during the global and local optimization phases and then forms TPGA. The experiment results show that TPGA is very efficient for the optimization of low-dimension multi-modal functions) usually we can obtain all the global optimal solutions. Foundation item: Supported by the National Natural Science Foundation of China (70071042, 60073043,60133010) Biography: Huang Yu-zhen ( 1977-), female, Master candidate, research direction; evolution computation.  相似文献   

5.
Trusted computing (TC) technology is brought out by trusted computing group (TCG) to make computing as safe and reliable as people expect. Attestation is one main function specified by TCG, which is the means by which a trusted computer assures a remote computer whose platform is not tampered with. There are two protocols that implement attestation without disclosing the platform's real identity, which are Privacy CA-based protocol and direct anonymous attestation (DAA) protocol. However, in the first protocol the privacy CA is the bottleneck and the platform's identity will be disclosed if the privacy CA is compromise, while DAA protocol can do profiling when dealing with rogue hardware device. In this paper, we propose a DAA-extended new approach to ensure full anonymous attestation that can not only detect a rogue TPM, but also reveal rogue TPM's real identity.  相似文献   

6.
Based on the practical application of Geology Information System(GIS) throughout the world, combined with the characters of road’s geological hazard and it’s supervision, the paper introduces on the importance of the research on road’s geological hazards information management and decision-making support system. The paper also analyzes the system’s target, the principles and key techniques in developing the system. In the research, we developed the GIS-based road’s geological hazard information management and decision-making support system and applied it to one speedway in the west of China where contains typical geological hazards. The system based on the database of road’s geological hazard on the grounds of spatial graphic information and attribute information. By virtue of the scientific assessment and prediction mathematical model, integrating the GIS’s strongpoint on spatial analyzing, the system is capable of visualizing the regionalization of road according to the geological hazards it contains, and accurately assessing and predicting geological hazards, thus efficiently assists the road construction and management units in the decision making on controlling the geological hazards and reducing the related loss. Biography: WANG Weidong (1971–), male, Associate professor, Ph.D. candidate, research direction: road and railway engineering, management science and engineering.  相似文献   

7.
Sticker model is one of the basic models in the DNA computer models. This model is coded with single-double stranded DNA molecules. It has the following advantages that the operations require no strands extension and use no enzymes; What‘s more, the materials are reusable.Therefore it arouses attention and interest of scientists in many fields. In this paper, we will systematically analyze the theories and applications of the model, summarize other scientists‘ contributions in this field, and propose our research results. This paper is the theoretical portion of the sticker model on DNA computer, which includes the introduction of the basic model of sticker computing. Firstly, we systematically introduce the basic theories of classic models about sticker computing; Secondly, we discuss the sticker system which is an abstract computing model based on the sticker model and formal languages; Finally, extend and perfect the model, and present two types of models that are more extensive in the applications and more perfect in the theory than the past models: one is the so-called k-bit sticker model, the other is full-message sticker DNA computing model.  相似文献   

8.
考虑了一类带有饱和治疗项的SIS反应扩散传染病模型。根据最小特征值得到疾病流行阈值——基本再生数,当基本再生数R01时,疾病的无病平衡点局部稳定;当R01时,无病平衡点不稳定且存在地方病平衡点。通过数值模拟,讨论了治疗项对疾病传播的影响。当疾病流行时,加强治愈率可以有效控制疾病的发展,然而扩大医院规模会促使疾病更大规模的流行。  相似文献   

9.
So far, most of the proposed group key exchange (GKE) protocols do not consider the attack when the adversary reveals the parties’ephemeral private keys without their long-term private keys, so these GKE protocols are insecure on this attack. In this paper, for resisting above attack, we propose a dynamic authenticated group key exchange (AGKE) protocol in the ID-based setting. Different from previous ID-based protocols, our protocol does not utilize bilinear pairings, which makes it more efficient. At last, we analyze the security of the protocol in the eCK (enhanced Canetti-Krawczyk) security model.  相似文献   

10.
Existing commitment schemes were addressed under the classic two-party scenario, However, popularity of the secure multi-party computation in today's lush network communication is motivating us to adopt more sophisticate commitment schemes. In this paper, we study for the first time multireceiver commitment in unconditionally secure setting, i.e., one committer promises a group of verifiers a common secret value (in computational setting it is trivial). We extend the Rivest model for this purpose and present a provably secure generic construction using multireceiver authentication codes (without secrecy) as building blocks. Two concrete schemes are proposed as its immediate implementations, which are almost as efficient as an optimal MRA-code. We believe using other primitives to construct variants of this concept will open doors for more interesting research.  相似文献   

11.
Combining the concept of partially blind signature with the concept of directed signature, we introduce a new concept of convertible directed partially blind signature (CDPBS), in which only the signer and the user can verify, confirm and disavow the validity of given signatures and convert given signatures into universally verifiable ones, to meet the need of signing personally or commercially sensitive messages. We give a formal definition of CDPBS and propose a concrete provably secure CDPBS scheme. The proposed scheme is efficient and secure, in which its unforgeability is the same as that of the Schnorr's signature scheme and its untransferability relies on the hardness of the decisional Diffie-Hellman problem. Furthermore, by letting the user's private key be a common constant, the proposed scheme can be used as a normal partially blind signature scheme.  相似文献   

12.
大多数序贯拍卖模型中的标的只具有一个属性,本文构造了一个标的兼有共同价值和私人价值两个属性的序贯拍卖模型.考虑在拍卖过程中公开标的信息,分别给出此模型下买家Agent在第一价格密封拍卖规则(The First Price sealed Auction,FPSA)和第二价格密封拍卖规则(The second Price sealed Auction,sPsA)中的竞价策略函数.提出一个基于标的信息增益比率的分类算法LIWNB,使得买家Agent在提交竞价时能准确分类当前拍卖信息,精确估计标的的共同价值.实验结果显示,算法LIWNB在一定条件下具有较高的分类性能.  相似文献   

13.
Combined public key (CPK) cryptography does not need certificates to guarantee the authenticity of public keys and avoids the inherent key escrow problem of identity-based cryptography. Based on the efficient CPK scheme, we present an efficient three-round two-party authenticated key exchange protocol with strong security, which is provably secure in the standard model under the decisional Diffie-Hellman (DDH) assumption. The protocol can keep the session key secret from the adversary except that one party’s ephemeral private key and static private key are all revealed to the adversary. Compared to the existing protocols, this protocol not only assures strong security but also is more efficient.  相似文献   

14.
研究考虑风险偏好的Stackelberg博弈模型和均衡策略,针对公私合作制(PPP)项目补偿决策问题,根据前后补偿的特点,建立相应的补偿策略数学模型.分别进行集中决策和分散决策分析,得出PPP项目的最优补偿方案.通过数值分析比较和分析私人风险厌恶对于PPP补偿机制的影响.研究表明:私人投资者风险厌恶会导致政府方补偿成本增加,期望收益减少;私人投资者风险厌恶程度会影响补偿的配置方式,厌恶程度越低越倾向单一补偿,厌恶程度越高越倾向混合补偿.  相似文献   

15.
We give some theorems of strong law of large numbers and complete convergence for sequences of φ-mixing random variables. In particular, Wittmann's strong law of large numbers and Teicher's strong law of large nnumbers for independent random variables are generalized to the case of φ -minxing random variables.  相似文献   

16.
Under the global circumstances where data leakage gets more and more severe, we present a trustworthiness-based distribution model that aims at data leakage prevention (DLP). In our model, first, the distributor calculates the user’s trustworthiness based on his historical behaviors; second, according to the user’s trustworthiness and his obtained file set overlapping leaked file set, the distributor accesses the probability of the user’s intentional leak behavior as the subjective risk assessment; third, the distributor evaluates the user’s platform vulnerability as an objective element; last, the distributor makes decisions whether to distribute the file based on the integrated risk assessment. The experiments indicate that the model can distinguish users of different types and make the probability of malicious users’ requirements being denied much higher than that of honest users’ requirements being denied, so that the model is capable of preventing data leakage validly.  相似文献   

17.
It has very realistic significance for improving the quality of users' accessing information to filter and selectively retrieve the large number of information on the Internet. On the basis of analyzing the existing users' interest models and some basic questions of users' interest (representation, derivation and identification of users' interest), a Bayesian network based users' interest model is given. In this model, the users' interest reduction algorithm based on Markov Blanket model is used to reduce the interest noise, and then users' interested and not interested documents are used to train the Bayesian network. Compared to the simple model, this model has the following advantages like small space requirements, simple reasoning method and high recognition rate. The experiment result shows this model can more appropriately reflect the user's interest, and has higher performance and good usability.  相似文献   

18.
As a member of robot families, climbing robots have become one of the research hot-spots in the robotic field recently and Gekko gecko (G. gecko) has been broadly seen as an ideal model for climbing robot development. But for gecko-mimic robots, one of the key problems is how to design the robot's foot. In this paper, (1) high-speed camera recording and electrophysiological method are used to observe motion patterns of G. gecko's foot when it climbs on different oriented surfaces; (2) nerve innervations of gecko's toes to motion and reception are studied. It is found that the five toes of the G. gecko can be divided into two motion and reception divisions, and also its motion and reception are modulated and controlled hierarchically. The results provide important information and exclusive ideas for the foot design and control algorithm of gecko-mimic robots.  相似文献   

19.
This paper analyzes PROFIBUS-DP network delay in detail and presents the calculational formula of its maximum time-delay, which is significant to the research of PROFIBUS-DP. At the same time, the paper puts forward a method of simplifying the network induced time-varying indeterminate system according to the features of the network. Through the analysis of a pump-control-motor system which is composed of PROFIBUS-DP network, it illustrates the network's influence on the performance of control systems. This method helps to design and analyze the network's influence on the performance of control systems, which is of considerable practical value in a time when network control systern is widely used.  相似文献   

20.
Web-tog contains a lot of information related with user activities on the Internet. How to mine user browsing interest patterns effectively is an important and chattengeable research topic. On the analysis of the present algorithm‘s advantages and disadvantages, we propose a new concept: support-interest. Its key insight is that visitor will backtrack if they do not find the information where they expect. And the point from where they backtrack is tbe expected location for the page. We present User Access Matrix and the corresponding algorithm for discovering such expected locations that can handle page caching by the browser. Since the URL-URL matrix is a sparse matrix which can be represented by List of 3 tuples, we can mine user preferred sub-paths from the computation of this matrix. Accordinglyo all the sub-paths are merged, and user preferred paths are formed. Experiments showed that it was accurate and scalable. It‘s suitable for website based application, such as to optimize website‘s topologicat structure or to design personalized scrvices.  相似文献   

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