Showing papers in "Wuhan University Journal of Natural Sciences in 2008"
TL;DR: The heavy metal bioaccumulation levels of 13 species of mushrooms were studied in this article, and the results showed that the capability of Boletus griseus for Cd accumulation was very strong with BCF of 300.
Abstract: The heavy metal bioaccumulation levels of 13 species of mushrooms were studied. 13 different species of wild mushrooms growing in China were analyzed for Cu, Zn, Pb, Cd, and As. Contents of Cu, Zn, Cd and Pb in mushroom and Cu, Zn in soil were tested by atomic absorption spectrometer (AAS), and As in samples by atomic fluorescent light (AFL). Contents of Cd and Pb in soil were analyzed by graphite furnace AAS. The results showed that contents of Cu, Pb, Cd, and As in Termitomyces microcarpus were the highest in the tested mushroom samples, which were 135.00, 13.28, 65.30, and 1.60 mg·kg−1 (dry biomass) respectively, and the corresponding bioconcentration factor (BCF) for Cu and Cd was 57 and 1 674 separately, which was the highest data in 13 mushroom species. The capability of Boletus griseus for Cd accumulation was very strong with BCF of 300. when people consume the wild edible mushrooms, contents of Cd and Pb should be greatly considered.
48 citations
TL;DR: In this article, the authors empirically investigated the relationship between 15 design metrics and maintainability of 148 Java open source software and found that size and complexity metrics are strongly related to maintainability.
Abstract: This paper empirically investigates the relationships between 15 design metrics and maintainability of 148 Java open source software. The results show that size and complexity metrics are strongly related to the maintainability of open source software. However, cohesion and coupling, as currently captured by existing metrics, do not seem to have a significant impact on maintainability. When used together, these metrics can predict system maintainability fairly accurately (mean MREs below 30%).
45 citations
TL;DR: In this paper, the synthesis and surface activity of gemini surfactants with ester bond as spacer are described and the physicico-chemical properties such as Krafft points, foaming abilities and emulsifying power are also investigated.
Abstract: The synthesis and surface activity of gemini surfactants with ester bond as spacer are described. Their critical micelle concentrations (CMC) are much lower than that of conventional surfactants, i.e., 1.62×10−5, 1.38×10−5, 1.28×10−5 mol · L−1 for gemini I, II and III respectively. Surface tension at the CMC of gemini I, II and III were 36.4, 38.5, 41.2 mN · m−1. The physico-chemical properties such as Krafft points, foaming abilities and emulsifying power were also investigated. It is found that the title compounds have low Krafft points and show good solubility in water. The gemini surfactants synthesized also exhibit good foaming properties and excellent emulsifying power toward toluene. The foaming abilities and emulsifying power increase with the increase in carbon number of hydrophobic chain, and this might be caused by the sheer viscosity of different gemini surfactant solution.
44 citations
TL;DR: It is indicated that autophagy plays a potential role in the “melting” process for sea cucumber body wall induced by UV irradiation.
Abstract: The changes of tissue appearances and structures in the process of UV-induced “melting” for sea cucumber (Stichopus japonicus) body wall were studied. And the localization and determination of acid phosphatase (ACP), Cathepsin B and Cathepsin L activities were also investigated. The results show that the connective tissue was damaged with many hollows emerging and the regular collagen bundles were broken apart into irregular fragments. Margination of condensed chromatin at the nuclear membrane was observed. Both Golgi’s body and endoplasmic reticulum swelled, curled, and eventually double-or multi-lamellar vesicles were formed. A number of autophagic vesicles distributed in all through the whole cytoplasm. ACP becomes more active after UV irradiation. The activities of cathepsin B and cathepsin L increased in UV-treated sea cucumbers and both achieved their maximum under certain conditions. It indicates that autophagy plays a potential role in the “melting” process for sea cucumber body wall induced by UV irradiation.
38 citations
TL;DR: A new attribute-based proxy re-encryption scheme, where a semi-trusted proxy, with some additional information, can transform a ciphertext under a set of attributes into a new ciphertext on the same message, but not vice versa.
Abstract: In this paper, we propose a new attribute-based proxy re-encryption scheme, where a semi-trusted proxy, with some additional information, can transform a ciphertext under a set of attributes into a new ciphertext under another set of attributes on the same message, but not vice versa, furthermore, its security was proved in the standard model based on decisional bilinear Diffie-Hellman assumption. This scheme can be used to realize fine-grained selectively sharing of encrypted data, but the general proxy re-encryption scheme severely can not do it, so the proposed scheme can be thought as an improvement of general traditional proxy re-encryption scheme.
32 citations
TL;DR: This paper proposes a new identity-based anonymous signcryption scheme from bilinear pairings, which is the organic combination of identity- based ring signature and encryption scheme, and its unforgeability relies on the computational Diffie-Hellman problem.
Abstract: Signcryption is a cryptographic primitive that performs encryption and signature in a single logical step more efficiently than sign-then-encrypt approach. Till now, various kinds of signcryption schemes have been proposed. Among them, the requirement of signcrypter’s privacy protection is needful in some practical applications. In this paper, a new identity-based anonymous signcryption scheme from bilinear pairings, which is the organic combination of identity-based ring signature and encryption scheme, is proposed. The proposed scheme is indistinguishable against the chosen ciphertext attack under the Decisional Bilinear Diffie-Hellman assumption in the random oracle model. Its unforgeability relies on the computational Diffie-Hellman problem. Compared with the previous schemes, the new scheme is more efficient in computation.
16 citations
TL;DR: The first UDMVS scheme is presented in the standard model (i.e. without random oracles) based on Waters’ signature scheme, and the security is based on the Gap Bilinear Diffie-Hellman assumption.
Abstract: In this paper, we re-formalize the security notions of universal designated multi verifier signature (UDMVS) schemes. Then the first UDMVS scheme is presented in the standard model (i.e. without random oracles) based on Waters’ signature scheme. In this setting, a signature holder can to designate the signature to multi verifiers. Moreover, the security of our proposed scheme is based on the Gap Bilinear Diffie-Hellman assumption.
15 citations
TL;DR: The security of international date encryption algorithm (IDEA(16), a mini IDEA cipher, against differential cryptanalysis is investigated and the results show that IDEA(16) is secure against differential Cryptanalysis attack after 5 rounds while IDEA (8) needs 7 rounds for the same level of security.
Abstract: The security of international date encryption algorithm (IDEA(16)), a mini IDEA cipher, against differential cryptanalysis is investigated. The results show that IDEA(16) is secure against differential cryptanalysis attack after 5 rounds while IDEA(8) needs 7 rounds for the same level of security. The transition matrix for IDEA(16) and its eigenvalue of second largest magnitude are computed. The storage method for the transition matrix has been optimized to speed up file I/O. The emphasis of the work lies in finding out an effective way of computing the eigenvalue of the matrix. To lower time complexity, three mature algorithms in finding eigenvalues are compared from one another and subspace iteration algorithm is employed to compute the eigenvalue of second largest module, with a precision of 0.001.
15 citations
TL;DR: An improved protocol with a simple modification of their protocol is proposed and is proved to be immune to the K-CI attack and at the same time possess other security properties.
Abstract: The certificateless authenticated key agreement protocol proposed by Mandt et al does not have the property of key-compromise impersonation (K-CI) resilience. An improved protocol with a simple modification of their protocol is proposed in this paper. In particular, our improved protocol is proved to be immune to the K-CI attack and at the same time possess other security properties.
15 citations
TL;DR: This paper presents an approach for learning activity sequencing based on ontology and activity graph in personalized education system, and an algorithm is proposed to realizelearning activity sequencing and learner ontology dynamically updating.
Abstract: Personalized education provides an open learning environment which enriches the advanced technologies to establish a paradigm shift, active and dynamic teaching and learning patterns. E-learning has a various established approaches to the creation and sequencing of content-based, single learner, and self-paced learning objects. However, there is little understanding of how to create sequences of learning activities which involve groups of learners interacting within a structured set of collaborative environments. In this paper, we present an approach for learning activity sequencing based on ontology and activity graph in personalized education system. Modeling and management of learning activity and learner are depicted, and an algorithm is proposed to realize learning activity sequencing and learner ontology dynamically updating.
13 citations
TL;DR: The results of model updating show that the proposed updating method is more simple and effective, the updated finite element model can reflect the dynamic characteristics of the bridge better, and the analytical results can provide the theoretical basis for damage identification and health condition monitoring of the road.
Abstract: The dynamic characteristics of bridge structures, such as the natural frequencies, mode shapes and model damping ratio, are the basis of structural dynamic computation, seismic analysis, vibration control and structural health condition monitoring. In this paper, a three-dimensional finite-element model is established for a highway bridge over a railway on No.312 National Highway and the ambient test is carried out in site, the dynamic characteristics of the bridge are studied using the finite-element analysis and ambient vibration measurements. Comparison between the theoretical and experimental results shows that the frequency differences of the modes range between 0.44% and 8.77%. If the measurement is more reliable, the finite element model updating is necessary. Thus, a set of design variables is selected based on sensitivity analysis, then the finite element model of the bridge is updated based on optimization algorithm. The results of model updating show that the proposed updating method in this paper is more simple and effective, the updated finite element model can reflect the dynamic characteristics of the bridge better, the analytical results can provide the theoretical basis for damage identification and health condition monitoring of the bridge.
TL;DR: In this paper, the authors proposed a multibits watermarking algorithm providing robustness against geometric attacks by choosing the inscribed disk of the host image as the Zernike moments computation domain and the square in the disk as the watermark embedding domain.
Abstract: This paper proposed a novel multibits watermarking algorithm providing robustness against geometric attacks. The robustness is achieved from three aspects: ① Choosing the inscribed disk of the host image as the Zernike moments computation domain and the square in the disk as the watermarking embedding domain. ② Embedding the watermark in the cascade discrete wavelet transform-discrete cosine transform (DWT-DCT) domain by modulating the specified coefficient pair in each sub block. ③ Saving two selected Zernike moments of the original watermarked image to estimate and correct the geometric attacks before watermark extraction. Experimental results show that the proposed algorithm is robust to any angle of rotation attacks and wide range of scaling attacks, and as well, a variety of other attacks such as lossy compression, common signal processing.
TL;DR: Through the security analysis, it is proved that the scheme can offer confidentiality, integrity, unforgeability, non-repudiation and public verifiability.
Abstract: In a blind signcryption, besides the functions of digital signature and encryption algorithm for authentication and confidentiality, a user can delegates another user’s capability with the anonymity of the participants guaranteed. Some blind signcryptions were proposed but without public verifiability. In this paper, a blind signcryption with public verifiability that is proved to be efficient and secure is proposed. Through the security analysis, we proved that the scheme can offer confidentiality, integrity, unforgeability, non-repudiation and public verifiability. The coming research direction is also summarized.
TL;DR: Simulation results show that the devised model of dropping packets attack-resistance can effectively resist the dropping packets attacks (DPA) by choosing reasonable configuration parameters.
Abstract: Focusing on dropping packets attacks in sensor networks, we propose a model of dropping packets attack-resistance as a repeated game based on such an assumption that sensor nodes are rational. The model prevents malicious nodes from attacking by establishing punishment mechanism, and impels sensor networks to reach a collaborative Nash equilibrium. Simulation results show that the devised model can effectively resist the dropping packets attacks(DPA) by choosing reasonable configuration parameters.
TL;DR: In this paper, the structural properties of steel fiber reinforced concrete (SFRC) deep beams were discussed in terms of the crack load and ultimate bearing capacity by the nonlinear finite element analysis (FEA).
Abstract: By the nonlinear finite element analysis (FEA) method, the mechanical properties of the steel fiber reinforced concrete (SFRC) deep beams were discussed in terms of the crack load and ultimate bearing capacity. In the simulation process, the ANSYS parametric design language (APDL) was used to set up the finite element model; the model of bond stress-slip relationship between steel bar and concrete was established. The nonlinear FEA results and test results demonstrated that the steel fiber can not only significantly improve the cracking load and ultimate bearing capacity of the concrete but also repress the development of the cracks. Meanwhile, good agreement was found between the experimental data and FEA results, if the unit type, the parameter model and the failure criterion are selected reasonably.
TL;DR: For an odd integer n ≥ 7, this paper presented a class of n-variable rotation symmetric Boolean functions (RSBFs) with optimum algebraic immunity and the nonlinearity of the constructed functions is determined.
Abstract: For an odd integer n ≥ 7, this paper presented a class of n-variable rotation symmetric Boolean functions (RSBFs) with optimum algebraic immunity. The nonlinearity of the constructed functions is determined.
TL;DR: A scheme of trust calculation and delivery control is proposed, which is simpler and more flexible, and also easier to be implemented.
Abstract: Trust management system has been a promising approach to solve the access control problems in open multi-domain environments. However, the calculation of trust and the delivery of the trust are not addressed effectively in the existing trust management systems. To address the problems, this paper proposes a scheme of trust calculation and delivery control. Compared with the other schemes, it is simpler and more flexible, and also easier to be implemented.
TL;DR: In this paper, the authors investigated the factors leading to the strong gully erosion in the arid-hot basin of Jinshajiang valley and found that the widely distributed Yuanmou group stratum, which promotes the development of gully eroding, is one of the most important factors.
Abstract: Some factors (i.e. lithology, topography, climate, the change of population as well as land use during the past 50 years) that could have great influence on the development of gully in the arid-hot basin of Jinshajiang valley were investigated. The results show that the factors leading to the strong gully erosion in this area include: the widely distributed Yuanmou group stratum, which promotes the development of gully erosion; the unique geomorphologic configuration that is prone to rock fall and gully erosion; the strong and time-concentrated rainfall; the arid-humid alternate climate characteristics that prepares the ground for the development of fissures in soils; the arid-hot climate that goes against the growth and recovery of vegetation; and the unreasonable and abusive human activities.
TL;DR: A network of energy constrained sensors deployed over a region is considered, and low-energy adaptive clustering hierarchy’s stochastic clusterhead selection algorithm is extended by a factor with distance-based deterministic component and the cost function is proposed so that it balances the energy consumption of nodes for energy efficiency of cluster member.
Abstract: In the paper, we consider a network of energy constrained sensors deployed over a region. Each sensor node in such a network is systematically gathering and transmitting sensed data to a base station (via clusterhead) for further processing. The key problem focuses on how to reduce the power consumption of wireless microsensor networks. The core includes the energy efficiency of clusterheads and that of cluster members. We first extend low-energy adaptive clustering hierarchy (LEACH)’s stochastic clusterhead selection algorithm by a factor with distance-based deterministic component (LEACH-D) to reduce energy consumption for energy efficiency of clusterhead. And the cost function is proposed so that it balances the energy consumption of nodes for energy efficiency of cluster member. Simulation results show that our modified scheme can extend the network life around up to 40% before first node dies. Through both theoretical analysis and numerical results, it is shown that the proposed algorithm achieves better performance than the existing representative methods.
TL;DR: Wang et al. as discussed by the authors proposed a method of data-flow testing for Web services composition, where the existing model representation of business process execution language (BPEL) is modified in company with the analysis of data dependency and an exact representation of dead path elimination (DPE).
Abstract: This paper proposes a method of data-flow testing for Web services composition. Firstly, to facilitate data flow analysis and constraints collecting, the existing model representation of business process execution language (BPEL) is modified in company with the analysis of data dependency and an exact representation of dead path elimination (DPE) is proposed, which overcomes the difficulties brought to dataflow analysis. Then defining and using information based on data flow rules is collected by parsing BPEL and Web services description language (WSDL) documents and the def-use annotated control flow graph is created. Based on this model, data-flow anomalies which indicate potential errors can be discovered by traversing the paths of graph, and all-du-paths used in dynamic data flow testing for Web services composition are automatically generated, then testers can design the test cases according to the collected constraints for each path selected.
TL;DR: Four novel entropy-based features extracted from anchor data and click-through data are proposed, and a support vector machines (SVM) classifier is used to identify the user’s goal based on these features.
Abstract: Understanding the underlying goal behind a user’s Web query has been proved to be helpful to improve the quality of search. This paper focuses on the problem of automatic identification of query types according to the goals. Four novel entropy-based features extracted from anchor data and click-through data are proposed, and a support vector machines (SVM) classifier is used to identify the user’s goal based on these features. Experimental results show that the proposed entropy-based features are more effective than those reported in previous work. By combining multiple features the goals for more than 97% of the queries studied can be correctly identified. Besides these, this paper reaches the following important conclusions: First, anchor-based features are more effective than click-through-based features; Second, the number of sites is more reliable than the number of links; Third, click-distribution-based features are more effective than session-based ones.
TL;DR: This paper analyzes the relationships of resource attributes to user attributes based on access policies for Web services, and proposes a general attribute based role-based access control (GARBAC) model.
Abstract: Growing numbers of users and many access policies that involve many different resource attributes in service-oriented environments cause various problems in protecting resource. This paper analyzes the relationships of resource attributes to user attributes based on access policies for Web services, and proposes a general attribute based role-based access control(GARBAC) model. The model introduces the notions of single attribute expression, composite attribute expression, and composition permission, defines a set of elements and relations among its elements and makes a set of rules, assigns roles to user by inputing user’s attributes values. The model is a general access control model, can support more granularity resource information and rich access control policies, also can be used to wider application for services. The paper also describes how to use the GARBAC model in Web services environments.
TL;DR: Wang et al. as discussed by the authors take soil crack quads in Yuanmou add-hot valley region as examples and select several morphological indicators, including soil crack area density, area weighted mean fractal dimension and connectivitv index.
Abstract: Quantification of complicated surface morphology of soil crack is a prerequisite and key to soil crack study．This paper takes soil crack quads in Yuanmou add-hot valley region as examples，selecting several morphological indicators．an d an alyzes the soil crack’s morphological featm'es under various development degrees．By statistic analysis，three quantitative indicators for surface morphology are selected,namely soil crack area density,area weighted mean fractal dimension and connectivitv index R．which can not only express the development intensity of soil cracks，but also efectively describe its morphological complexity an dconnectivity．The research results set a good base for the establishment of soil crack assessment system in Yuanmou ad d-hot valley region．
TL;DR: Two important models, namely trustworthy metrics hierarchy model of components (TMHMC) with computing steps and local-global trustworthy metrics model of platform (LGTMMP) with algorithm respectively, are employed to evaluate the internal and external trustworthiness of Internetware.
Abstract: To measure the trustworthiness of Internetware, we need to understand the existing problems and design appropriate trustworthy metrics. The developing and running system of Internetware is analyzed in terms of process, keystone, methods and techniques. According to the main related factors of Internetware trustworthiness, two important models, namely trustworthy metrics hierarchy model of components (TMHMC) with computing steps and local-global trustworthy metrics model of platform (LGTMMP) with algorithm respectively, are employed to evaluate the internal and external trustworthiness of Internetware benefiting for the development of Internetware.
TL;DR: Based on Chinese soil loss equation (CSLE) model, this paper utilized technical advantages of RS and geographic information system (GIS) on data access and erosion factors database building to study prediction methods of regional soil erosion.
Abstract: Based on Chinese soil loss equation (CSLE) model, this paper utilized technical advantages of RS and geographic information system (GIS) on data access and erosion factors database building to study prediction methods of regional soil erosion. The spatial analysis module of ARCGIS platform was applied to study the spatial distribution of erosion and the inter-relations of the factors influencing regional soil erosion in the research area. As a result, the mean soil erosion modulus of Bin County is 3 555.42 t/(km2·a), which suggests moderate degree erosion. The mean soil erosion modulus of clayey meadow soil is higher than those of dark brown soil and black soil. Vegetation factor values are between 0.1–0.2. The mean slope gradient and slope length values are respectively 1.335 and 6.061 which shows slope length is a dominant factor. And soil type, vegetation coverage and topographic factors have remarkable relevance to each other. Therefore, RS, GIS and CSLE are applicable in regional scale to disclose spatial distribution characteristics of soil erosion and to analyze the characteristics of dominant soil erosion factor quantitatively.
TL;DR: Simulation results show this scheme not only can keep stable reputation but also can prevent the system from some attacks as bad mouthing and reputation cheating.
Abstract: In this paper, a formal system is proposed based on beta reputation for the development of trustworthy wireless sensor networks (FRS-TWSN) Following this approach, key concepts related to reputation are formal described step by step for wireless sensor networks where sensor nodes maintain reputation for other sensors and use it to evaluate their trustworthiness By proving some properties of beta reputation system, the beta distribution is founded to fit well to describe reputation system Also, a case system is developed within this framework for reputation representation, updates and integration Simulation results show this scheme not only can keep stable reputation but also can prevent the system from some attacks as bad mouthing and reputation cheating
TL;DR: The method provides a new idea for breaking away from the predicament appeared in the construction of present enterprise informatization and exploring the way of software industrialization.
Abstract: Considering the special requirements of group enterprise information management software, a new method of massive software development was put forward basing on the component technology and facing the “assemblage”. It generalizes five key parts of the method system including the overall strategy, the application project method basing on the operation “assemblage”, the field project method basing on component, the development method facing the component on the basis of the visible component platform, and the software development process model basing on the component “assemblage”. Besides, this paper describes the process and principle of this method application with an example of the construction of a Communications Investment Group enterprise’s management information system. The method provides a new idea for breaking away from the predicament appeared in the construction of present enterprise informatization and exploring the way of software industrialization.
TL;DR: A comparison shows that the efficiency of the proposed scheme is better than all known paring-based certificateless public key encryption schemes in the random oracle model.
Abstract: Certificateless public key cryptography (CL-PKC) enjoys the advantage of identity based cryptography without suffering from its inherent key escrow problem In this paper, a new efficient certificateless public key encryption scheme is proposed and its security can reach chosen-ciphertext (CCA2) secure in the random oracle model assuming the CDH and p-BDHI problem are difficult A comparison shows that the efficiency of the proposed scheme is better than all known paring-based certificateless public key encryption schemes in the random oracle model
TL;DR: In this paper, the vegetation restoration technique system in the arid-hot valleys and studied the anti-erosion function, environmental function and biological diversity effects of vegetation restoration on the ecosystem in arid hot valleys.
Abstract: This paper concluded the vegetation restoration technique system in the arid-hot valleys and studied the anti-erosion function, environmental function and biological diversity effects of vegetation restoration on the ecosystem in the arid-hot valleys. The results showed that the soil erodibility decreased significantly after the vegetation restoration. The climate environment of the small watershed had a great improvement after the vegetation restoration, of which the temperature decreased, the humidity increased, the harsh environment of dry and hot in this region changed. The studies of the ecosystem biodiversity were mainly on the analysis of the relations between biodiversity and ecological function of the artificial ecological forest pattern and the natural enclosed treatment mode on the severely of degraded land. It could conclude that the natural enclosed treatment mode is helpful to the biodiversity of the ecosystem and the improvement and stability of the ecosystem, and Leucaena artificial forest restoration pattern reduced the species diversity but optimized the ecological function. Therefore, as to the severely and extremely severely degraded ecosystem in the arid-hot valleys, Leucaena pattern of gully control and natural enclosed treatment mode are the relatively optimal choices.
TL;DR: Observations of passenger flow in the Wuchang railway station in Wuhan, China during the Chinese Traditional Spring Festival in 2006 are reported to verify a crowd dynamics model previously developed and good agreement between the predictions and observations validates the prediction model.
Abstract: This paper reports observations of passenger flow in the Wuchang railway station in Wuhan, China during the Chinese Traditional Spring Festival in 2006. The data collected are used to verify a crowd dynamics model previously developed. The crowd dynamics model is based on simulating the global movement of each individual under the influence of the surrounding crowd, and the good agreement between the predictions and observations validates the prediction model. The crowd dynamics model suggests that the crowd movement speed is dominated by two factors: the front-back inter-person effect, and the pedestrian’s self-motive. The first effect gives logarithmic relationship between the crowd speed and crowd density. The second factor depends on the individual motive driven with which people try to divorce themselves from the control of the crowd movement. The prediction model are helpful to guide the design of public traffic systems for effective crowd dispersal.