局部δ-连通空间的几个性质

在拓扑空间中,借助δ-连通集给出局部δ-连通空间的定义,并证明局部δ-连通性是可商性和任意可积性。

Reliability supply chain network design model for perishable products

The classical supply chain network(SCN)design problem is extended,where the candidate facilities are subject to failure and the products are prone to elapsed time deteriorion.First,the reliable SCN design problem is defined by introducing the probability that a facility may be prone to inactivity based on the analysis of perishable product characteristics.The perishable product SCN design problem is formulated as a 0-1 integer programming model.The objective is to minimize the weighted sum of the operating cost(the fixed plus transportation cost)and the expected failure cost.And then,the perishable product SCN design model is discussed and solved using the genetic algorithm(GA).The results show how to generate the tradeoff curve between the operating costs and the expected failure costs.And these tradeoff curves demonstrate empirically that substantial improvements in reliability are often possible with minimal increase in the operating costs.

A SOLUTION TO HIGH AVAILABILITY OF OPENSTOCK

High availability is a critical mission for business system. At first, an instance of business system OPENSTOCK for pharmacy is introduced including both client and server sides. Secondly, a solution to the high availability of this system is given in detail, including design and implementation. The essentiality of this solution consists of scope of system information, system parameter tables of service status, schedule strategies of load ba lance and how to acquire system parameters and detect service states. The solution proposed is scalable and application oriented and supporting load balance for high performance and fault tolerate for high reliability. This application system has been applied and verified realistically, and the features of this business system derived in this paper have been achieved.

Topology Based Reliable Virtual Network Embedding from a QoE Perspective

In the network virtualization environments, one of the most challenges is how to map the virtual networks(VNs) onto a shared substrate network managed by an infrastructure provider(In P), which is termed as virtual network embedding problem. Prior studies on this issue only emphasize on maximizing the revenue or minimizing the energy consumption while ignoring the reliability requirements of end-users. In our work, we incorporate the reliability probability into the virtual network embedding process with an aim to improve the Qo S/Qo E of end users from a new perspective. We devised two novel reliable virtual network embedding algorithms called RRW-Max Match and RDCC-VNE based on RW-Max Match and DCC-VNE, respectively. Extensive simulations demonstrated that the efficiency of our proposed algorithms is better than those of two primitive algorithms in terms of the reliability demands, the acceptance ratio of virtual networks and the long-term average revenue.

State of the art for dry tree semi technologies

Dry tree semi is a fast developing technology and becomes more and more appealing to the operators as a solution for producing deepwater reserves. Utilizing a dry tree semi means spending less cost on well mainte-nance and interventions,while the production platform can be integrated and commissioned at quayside. This paper presents a comprehensive overview of various technologies for dry tree semi,such as E-semi,T-semi,paired-column semi and long stroke tensioners. Each dry tree semi concept is briefed in terms of global performance,top tension riser (TTR) tensioner system,quayside integration and feasibility to environment.

The Cloud Storage Ciphertext Retrieval Scheme Based on ORAM

Due to its characteristics distribution and virtualization, cloud storage also brings new security problems. User＇s data is stored in the cloud, which separated the ownership from management. How to ensure the security of cloud data, how to increase data availability and how to improve user privacy perception are the key issues of cloud storage research, especially when the cloud service provider is not completely trusted. In this paper, a cloud storage ciphertext retrieval scheme based on AES and homomorphic encryption is presented. This ciphertext retrieval scheme will not only conceal the user retrieval information, but also prevent the cloud from obtaining user access pattern such as read-write mode, and access frequency, thereby ensuring the safety of the ciphertext retrieval and user privacy. The results of simulation analysis show that the performance of this ciphertext retrieval scheme requires less overhead than other schemes on the same security level.

Jordanian Horticultural Export Competitiveness from Water Perspective

The main objective of this paper is to analyze the relationships between the productive process and the commercial trade with water resources used by them. For that the goal is to find out, by means of the estimation of water embodied in the exported crops which have the highest export competitiveness and lower water consumption. The finding contradicts not only the comparative advantages theory but also the resources sustainability logic. This conclusion is derived from the great exports of water via tomatoes and low profitable vegetables from producers＇ perspective but not economical from social perspectives as shown in domestic resource coefficient. The diversion between financial and economic profitability is due to heavily irrigation water subsidy. The results confirm that Jordan utilizes large amounts of water in its exports, and in turn, it does not export goods with low water requirements. The potential saving would be very significant and agricultural sector need to modify the use of water to a great extent in order to reach significant water savings and an environmental sustainability. Jordan has to implement policies that reduced, or even abandoned, the export and the production of water-intensive crops. Therefore, they have to be replaced with either imports or crops that optimize the water resources.

Innovation in China： Evidence From the Provincial Data

China has made remarkable gains in industrialization and development. In the last years, in order to ensure the sustainability of its economic and social development, China gave more importance to the innovativeness of business enterprises. In the domestic arena, the sustainability of the growth model that China has followed over the past decades has been criticized because of its excessive reliance on capital and resources as opposed to knowledge and innovation. In 2006, that transformation has been at the centre of the government＇s ＂scientific development strategy＂. Today, in fact, innovation and promotion of entrepreneurship are essential conditions for competitiveness of firms and nations, for the long-term growth and, therefore, for the economy as a whole. This paper investigates the level of potential innovation reached in China in 2008 through a disaggregated analysis, evaluating the production capacity of the Chinese provinces. ＂Innovation＂ has been widely studied by economic literature, specially with reference to the output. In this paper, we will refer to the European Innovation Scoreboard （EIS） index, to measure the progress of innovation, which represents the skill to innovate of a territory, but not the achieved innovation. First, we will propose some methodological changes of this method, that allows to obtained a ranking, in order to better understand the results reached by the Chinese provinces; Then we will test a different methodology in order to measure the level of potential innovation overcoming the limits of current practice--from a composite index obtained through a mean of disaggregated indices to multivariate analysis.

Physicochemical Analysis of Selected Durian Hybrids at Bukit Tangga, Kedah, Malaysia

The physicochemical analysis was carried out to quantify the total soluble solids, acidity, pH, ascorbic acid contents and pulp colour of eight selected durian hybrid clones. The aim of this study was to select the most promising durian hybrids for commercialization. The durian hybrid fruits were collected in an established durian research plot. All tested characteristics with the exception for total soluble solids （TSS） showed significant differences （P 〈 0.05） amongst the eight durian hybrids with four check cultivars. F1 hybrid 15-3 had significantly higher pH （7.25） and lower titratable acidity （0.09%） than other hybrids. While for ascorbic acid content, durian hybrid 7-3 （26.13 rag/100 g） showed significantly higher than other hybrids. As for pulp colour, hybrids 1-15, 1-17 and 7-20 were yellowish orange/deep yellow. Even though there was no significant differences for TSS, three durian hybrids showed value above 39.00 °Brix and there were hybrid 14-3 （39.97 °Brix）, hybrid 8-16 （39.83 °Brix） and hybrid 7-3 （39.50 °Brix）. Based on the results of this study, Fl hybrids durian 1-15, 7-3, 8-16, 14-3 and 15-3 shall become successful candidates for recommendation to farmers for commercial production in Malaysia. However, further evaluations on fruit eating quality and stability of the hybrids should be completed prior to recommendation for commercialization.

Reliability Evaluation Metrics for Open Source Software Selection

Recently, Open Source Software （OSS） is so widely used not only by companies for development but also by common users instead of commercial software. However, the number of OSS is vast, and its quality varies from low to high. So how people can evaluate OSS and ensta-e that it is reliable for use becomes necessary. This paper proposes a set of reliability evaluation metrics considering the states of OSS selected in the early stage. Understandability, Fault tolerance ＆ Recoverability and Community Matmrity as sub-attributes of reliability are defined, and then several evaluation criteria for each of them are identified. A process of reliability evaluation in our study is proposed. For application, we select four OSS projects and evaluate them with our metrics. As a result of compadrison with other evaluation model for OSS, our research presents an easy, effective and trustworthy way for selecting a reliable OSS.

Reflections on the Connotations of Ecotourism

As the most desirable option for sustainable development of tourism industry, ecotourism still suffers from lack of a clear-cut and widely accepted definition, posing many risks and threats in its practices. Based on collection and collation of various concepts and explanations of ecotourism both at home and abroad, this paper reflects on the current connotations of ecotourism in terms of four aspects, namely, objects of ecotourism, ecotourists, nature of ecotourism as well as the relationship between ecotourism and communities. In-depth analysis was performed in an effort to revise the misinterpretation of ecotourism and provide implications for ecotourism initiatives. The main conclusions and fruits of this article include： 1） The objects of eeotourism should go beyond natural, pristine, or even only primitive natural areas to including cultural resources together with their natural context which also deserve preservation. 2） Tourism operators, compared to tourists, have more leverage and hence should shoulder more responsibilities for conservation. 3） Ecotourism should serve as a principle to guide tourism initiatives towards sustainability, rather than merely a special tour package. 4） The theoretic foundation was laid for community participation in ecotourism.

Intelligent Server Management Framework over Extensible Messaging and Presence Protocol

With the increasing importance of cloud services worldwide, the cloud infrastructure and platform management has become critical for cloud service providers. In this paper, a novel architecture of intelligent server management framework is proposed. In this framework, the communication layer is based on the Extensible Messaging and Presence Protocol (XMPP), which was developed for instant messaging and has been proven to be highly mature and suitable for mobile and large scalable deployment due to its extensibility and efficiency. The proposed architecture can simplify server management and increase flexibility and scalability when managing hundreds of thousands of servers in the cloud era.

Stumbling Blocks in Cloud Computing Adoption Pathway： A Charter

Cloud computing is currently an embryonic domain in the area of information technology that possesses the power of transforming the way information technology （IT） services are delivered and maintained in the business world. Pay as per the usage kind of cost structure coupled with delivery of computing services through internet makes cloud computing an exciting and potential growth oriented information technology model compared with conventional computing services delivery models. Various additional features like scalability, flexibility and easy deployment process creates a window for the organizations even relatively smaller in size to get benefitted by the highly advanced ＆ modern technologies without incurring substantial cost. In spite of so many benefits of this new delivery model, concerns are beginning to grow about how safe an environment it is. Despite of all the hype surrounding the cloud, enterprise customers are still reluctant to deploy their business in the cloud. Security is one of the major issues which reduces the growth of cloud computing and complications with data privacy and data protection continue to plague the market. Other related concerns associated with the adoption of cloud computing include trust on service providers, loss of control and compliance issues. This paper is an attempt to explore security ＆ trust issues linked with cloud computing adoption in the Small and Medium Enterprises （SME） sector.

COMPLETE LIE ALGEBRAS WITH l-STEP NILPOTENT RADICALS

The authors first give a necessary and sufficient condition for some solvable Lie algebras with l-step nilpotent radicals to be complete, and then construct a new class of infinite dimensional complete Lie algebras by using the modules of simple Lie algebras. The quotient algebras of this new constructed Lie algebras are non-solvable complete Lie algebras with l-step nilpotent radicals.

Sharp Observability Inequalities for the 1-D Plate Equation with a Potential

This paper deals with the problem of sharp observability inequality for the 1-D plate equation wtt ＋ wxxxx ＋ q（t, x）w = 0 with two types of boundary conditions w = wxx = 0 or w = wx = 0, and q（t, x） being a suitable potential. The author shows that 2 the sharp observability constant is of order exp（C｜｜q｜｜^2/7∞） for ｜｜q｜｜∞〉 1. The main tools to derive the desired observability inequalities are the global Carleman inequalities, based on a new point wise inequality for the fourth order plate operator.

Rationality of quotients by linear actions of affine groups

LetG = SLn(C)Cn be the (special) affine group. In this paper we study the representation theory of G and in particular the question of rationality for V/G, where V is a generically free G-representation. We show that the answer to this question is positive (Theorem 6.1) if the dimension of V is sufficiently large and V is indecomposable. We explicitly characterize two-step extensions 0 → S → V → Q → 0, with completely reducible S and Q, whose rationality cannot be obtained by the methods presented here (Theorem 5.3).

A scalable and efficient IPv4 address sharing approach in IPv6 transition scenarios

IPv6 has been an inevitable trend with the depletion of the global IPv4 address space. However, new IPv6 users still need public IPv4 addresses to access global IPv4 users/resources, making it important for providers to share scarce global IPv4 addresses effectively. There are two categories of solutions to the problem, carrier-grade NAT （CGN） and ＇A＋P＇ （each customer shaving the same IPv4 address is assigned an excluded port range）. However, both of them have limitations. Specifically, CGN solutions are not scalable and can bring much complexity in managing customers in large-scale deployments, while A＋P solutions are not flexible enough to meet dynamic port requirements. In this paper, we propose a hybrid mechanism to improve current solutions and have deployed it in the Tsinghua University Campus Network. The real traffic data shows that our mechanism can utilize limited IPv4 addresses efficiently without degrading the performance of applications on end hosts. Based on the enhanced mechanism, we propose a method to help service providers make address plans based on their own traffic patterns and actual requirements.