An efficient one-pass method for discovering bases of recently frequent episodes over online data streams

The knowledge embedded in an online data stream is likely to change over time due to the dynamic evolution of the stream. Consequently, infrequent episode mining over an online stream, frequent episodes should be adaptively extracted from recently generated stream segments instead of the whole stream. However, almost all existing frequent episode mining approaches find episodes frequently occurring over the whole sequence. This paper proposes and investigates a new problem: online mining of recently frequent episodes over data streams. In order to meet strict requirements of stream mining such as one-scan, adaptive result update and instant result return, we choose a novel frequency metric and define a highly condensed set called the base of recently frequent episodes. We then introduce a one-pass method for mining bases of recently frequent episodes. Experimental results show that the proposed method is capable of finding bases of recently frequent episodes quickly and adaptively. The proposed method outperforms the previous approaches with the advantages of one-pass, instant result update and return, more condensed resulting sets and less space usage.

Key predistribution scheme using finite fields and reed muller codes

Resource constraint sensors of a Wireless Sensor Network (WSN) cannot afford the use of costly encryption techniques like public key while dealing with sensitive data. So symmetric key encryption techniques are preferred where it is essential to have the same cryptographic key between communicating parties. To this end, keys are preloaded into the nodes before deployment and are to be established once they get deployed in the target area. This entire process is called key predistribution. In this paper we propose one such scheme using unique factorization of polynomials over Finite Fields. To the best of our knowledge such an elegant use of Algebra is being done for the first time in WSN literature. The best part of the scheme is large number of node support with very small and uniform key ring per node. However the resiliency is not good. For this reason we use a special technique based on Reed Muller codes proposed recently by Sarkar, Saha and Chowdhury in 2010. The combined scheme has good resiliency with huge node support using very less keys per node.

An EM-based algorithm for clustering data streams in sliding windows

Cluster analysis has played a key role in data understanding. When such an important data mining task is extended to the context of data streams, it becomes more challenging since the data arrive at a mining system in one-pass manner. The problem is even more difficult when the clustering task is considered in a sliding window model which requiring the elimination of outdated data must be dealt with properly. We propose SWEM algorithm that exploits the Expectation Maximization technique to address these challenges. SWEM is not only able to process the stream in an incremental manner, but also capable to adapt to changes happened in the underlying stream distribution.

Texture evolution and grain refinement of ultrafine-grained copper during micro-extrusion

Samples of oxygen-free high conductivity (OFHC) coarse-grained (CG) and ultrafine-grained (UFG) copper were micro-extruded to an equivalent strain of 2.8 in one pass at room temperature. Samples of the OFHC copper were annealed at 650C for 2 h to produce CG copper. Some samples were subsequently processed by equal channel angular pressing of eight passes, route Bc, at room temperature to produce the UFG material. Crystallographic texture and misorientation distributions were obtained locally from EBSD mappings at different radial positions after micro-extrusion. To model the strain path during micro-extrusion, the analytic flow line model of Altan etal. [J Mater. Process. Tech. 33 (1992) p.263] was used and also validated by finite element calculations. Modelling was carried out using the viscoplastic self-consistent (VPSC) model and a recently developed grain refinement model. The results showed large texture variations along the cross-section of the extruded sample for both UFG and CG copper. These cyclic drawing textures in UFG copper were simulated in good agreement with experiments using the presented modelling framework.

Rainfall-runoff modeling using dynamic evolving neural fuzzy inference system with online learning

This is an open access article under the CC BY-NC-ND license.Neuro-Fuzzy Systems (NFS) are computational intelligence tools that have recently been employed in hydrological modeling. In many of the common NFS the learning algorithms used are based on batch learning where all the parameters of the fuzzy system are optimized off-line. Although these models have frequently been used, there is a criticism on such learning process as the number of rules are needed to be predefined by the user. This will reduce the flexibility of the NFS architecture while dealing with different data with different level of complexity. On the other hand, online or local learning evolves through local adjustments in the model as new data is introduced in sequence. In this study, dynamic evolving neural fuzzy inference system (DENFIS) is used in which an evolving, online clustering algorithm called the Evolving Clustering Method (ECM) is implemented. ECM is an online, maximum distance-based clustering method which is able to estimate the number of clusters in a data set and find their current centers in the input space through its fast, one-pass algorithm. The 10-minutes rainfall-runoff time series from a small (23.22 km2) tropical catchment named Sungai Kayu Ara in Selangor, Malaysia, was used in this study. Out of the 40 major events, 12 were used for training and 28 for testing. Results obtained by DENFIS were then compared with the ones obtained by physically-based rainfall-runoff model HEC-HMS and a regression model ARX. It was concluded that DENFIS results were comparable to HEC-HMS and superior to ARX model. This indicates a strong potential for DENFIS to be used in rainfall-runoff modeling.

Parameter optimization of kernel-based one-class classifier on imbalance learning

Compared with conventional two-class learning schemes, one-class classification simply uses a single class in the classifier training phase. Applying one-class classification to learn from unbalanced data set is regarded as the recognition based learning and has shown to have the potential of achieving better performance. Similar to twoclass learning, parameter selection is a significant issue, especially when the classifier is sensitive to the parameters. For one-class learning scheme with the kernel function, such as one-class Support Vector Machine and Support Vector Data Description, besides the parameters involved in the kernel, there is another one-class specific parameter: the rejection rate v. In this paper, we proposed a general framework to involve the majority class in solving the parameter selection problem. In this framework, we first use the minority target class for training in the one-class classification stage; then we use both minority and majority class for estimating the generalization performance of the constructed classifier. This generalization performance is set as the optimization criteria. We employed the Grid search and Experiment Design search to attain various parameter settings. Experiments on UCI and Reuters text data show that the parameter optimized one-class classifiers outperform all the standard one-class learning schemes we examined.

Role of the ATP-binding cassette drug transporters in the intestinal absorption of tanshinone IIB, one of the major active diterpenoids from the root of Salvia miltiorrhiza

There is an increasing use of herbal medicines worldwide, and the extracts from the root of Salvia miltiorrhiza are widely used in the treatment of angina and stroke. In this study, we investigated the mechanism for the intestinal absorption of tanshinone IIB (TSB), a major constituent of S. miltiorrhiza. The oral bioavailability of TSB was about 3% in rats with less proportional increase in its maximum plasma concentration (C_max) and area under the plasma concentration-time curve (AUC) with increasing dosage. The time to C_max (T_max) was prolonged at higher oral dosage. In a single pass rat intestinal perfusion model, the permeability coefficients (P_app) based on TSB disappearance from the lumen (P_lumen) were 6.2- to 7.2-fold higher (p < 0.01) than those based on drug appearance in mesenteric venous blood (P_blood). The uptake and efflux of TSB in Caco-2 cells were also significantly altered in the presence of an inhibitor for P-glycoprotein (PgP) or for multi-drug resistance associated protein (MRP1/2). TSB transport from the apical (AP) to basolateral (BL) side in Caco-2 monolayers was 3.3- to 5.7-fold lower than that from BL to AP side, but this polarized transport was attenuated by co-incubation of PgP or MRP1/2 inhibitors. The P_app values of TSB in the BL-AP direction were significantly higher in MDCKII cells over-expressing MDR1 or MRP1, but not in cells over-expressing MRP2-5, as compared with the wild-type cells. The plasma AUC_0-24hr in mdr1a and mrp1 gene-deficient mice was 10.2- to 1.7-fold higher than that in the wild-type mice. Furthermore, TSB significantly inhibited the uptake of digoxin and vinblastine in membrane vesicles containing PgP or MRP1. TSB also moderately stimulated PgP ATPase activity. Taken collectively, our findings indicate that TSB is a substrate for PgP and MRP1 and that drug resistance to TSB therapy and drug interactions may occur through PgP and MRP1 modulation.

Signalling corporate collapse using a dual classification scheme:Australian evidence

Regardless of the technical procedure used in signalling corporate collapse, the bottom line rests on the predictive power of the corresponding statistical model. In that regard, it is imperative to empirically test the model using a data sample of both collapsed and non-collapsed companies. A superior model is one that successfully classifies collapsed and non-collapsed companies in their respective categories with a high degree of accuracy. Empirical studies of this nature have thus far done one of two things. (1) Some have classified companies based on a specific statistical modelling process. (2) Some have classified companies based on two (sometimes – but rarely – more than two) independent statistical modelling processes for the purposes of comparing one with the other. In the latter case, the mindset of the researchers has been – invariably – to pitch one procedure against the other. This paper raises the question, why pitch one statistical process against another; why not make the two procedures work together? As such, this paper puts forward an innovative dual-classification scheme for signalling corporate collapse: dual in the sense that it relies on two statistical procedures concurrently. Using a data sample of Australian publicly listed companies, the proposed scheme is tested against the traditional approach taken thus far in the pertinent literature. The results demonstrate that the proposed dual-classification scheme signals collapse with a higher degree of accuracy.

Levy grant training scheme evolution : focus on Fiji and Singapore

This thesis examines the evolution of national training policy in Fiji since 1973 with a particular emphasis on the national levy-grant scheme that was introduced in Fiji in that same year. Developments in the Fiji National Training Council (FNTC) levy-grants scheme since its inception, including substantive amendments to the legislation in late 2002, form part of the scholarship. The thesis will provide an analytical narration of the training policy objectives and their transformation over a time span of almost three decades in the context of a small island nation. To inform this study, it was considered essential to compare the Fiji experience of levy grants schemes with other levy grants scheme. The author decided to use as the focal comparative benchmark the case of the Skills Development Fund (SDF) in Singapore. The SDF has been increasingly portrayed, by the World Bank, the International Labour Organisation and other influential agencies, as the best practice case when it comes to managing a training levy grants scheme. The thesis adopted a qualitative approach that utilized elements of case study, historical research, and key person interviews. The challenges of doing 'insider* research were explored because of its pertinence to the study. Because the study also involved the comparison of the policy experiences of two distinct countries, it was imperative to consider the issues and challenges of undertaking comparative research with particular reference to training matters- Given that training is often enmeshed with other human resources management issues, cognisance was taken of some of the broader debates in this regard. Following consideration of the methodological issues, the research paper explores the objectives of national training strategies and, in particular, issues relating to national competitiveness and skills development. The purpose is to situate the issue of training and skills development within the broader discourse of national development. Alternative approaches to the strategic role of training are considered both at the national and organisational level and some of the classic and current debates surrounding human capital investment are visited. The thesis then proceeds to examine the forms of, and rationale for government interventions in the area of training. One of the challenges both in practice and theoretically is to arrive at a consensual definition of training because of the constantly evolving context and boundaries in which training policies are fashioned. This provides the setting to examine the role that governments can and do play in skills development and how levy-grant schemes, in particular, contribute to the process. Three forms of levy grants schemes are identified and examined: levy-generating; levy-exemption; and levy-grant and reimbursement schemes. The levy-grant and reimbursement variant is the basic thrust of this thesis. In this regard, the UK experience with the levy-grant system from 1964 to 1981 is also reviewed. Some of the issues in relation to training levies are scrutinized including the levy as a sheltered source of training finance, levy rates, duration of levy, impact of levy on the quality and quantity of training, benefits to small businesses, links between training and strategic business objectives, repackaging of training to qualify for grants, and the process by which training levy policies are devised. In looking at the policy formulation, it was necessary to unpack the processes involved and explore the role of the state further. In relation to policy development and implementation, the consultation processes, role of bureaucrats, the policy context, and approaches to policy transfer are examined. In looking at the role of the state in policy development, the alternative roles of government are explored and the concepts of the 'developmental state' and the 'corporatist state* evaluated. The notion of the developmental state has particular relevance to this study given the emphasis placed by the Singaporean government on human resource development policies. This sets the scene for a detailed examination of the role of levy-grant training schemes in Fiji and Singapore. The Skills Development Fund in Singapore was developed as an integral component of national economic policy when the Singaporean government decided to break out of the 'low-skills' trap and move the economy towards a higher value adding structure. The levy-grant system was designed to complement the strategy by focusing on upgrading the skills of employees on lower incomes, the assumption being that employees on lower remuneration were more likely to need skills upgrading. The study notes that the early objectives of the SDF were displaced when it was revealed that the bulk of SDF expenditure was directed at higher level supervisory and management training. As a result, the SDF had to refocus its activities on small and medium enterprises and the workers who were likely to miss out on formal training opportunities. The Singaporean context also shows trade unions playing a significant role in worker education and literacy programmes financed under the SDF. To understand this requires some understanding of the historical linkages between the present Singaporean government and trade union leadership. Another aspect of the development of the SDF has been the constant shifting of the institutional responsibility for the scheme. As late as September 2003, the SDF was again moved, this time to the newly created Singapore Workforce Development Agency, with the focus turning to lifelong learning and assisting Singaporeans who are unemployed or made redundant as a result of the economic restructuring. The Fiji experience with the FNTC scheme is different. It evolved in the context of perceived skills shortages but there was a degree of ambiguity over its objectives. There were no specific linkages with economic policy. Relationships with other public training institutions and more recently, private training providers, have been fraught with difficulties. The study examines the origins of the policy, the early difficulties including perceived employer grievances, and the numerous external assessments of the Fiji levy-grant scheme noting that some of them were highly critical. The thesis also examines an attempted reform of the scheme in 1992-93 that proved unsuccessful and the more recent legislative reforms to the scheme in 2002 that have expanded the role of the scheme to encompass, inter alia, national occupational standards and accreditation activities. The thesis concludes by comparing the two schemes noting that the SDF is well entrenched as a policy instrument in Singapore whilst the FNTC is facing a struggle to assert its legitimacy in Fiji.

Soldier settlement after World War One in south western Victoria

This thesis addresses the physical aspects of farming on soldier settlement blocks in south west Victoria. The undeveloped land, high establishment costs, stock losses through animal diseases and lack of managerial skills all contributed to the settlers' inability to meet their financial commitments. These factors are analysed, as are the effects of declining rural commodities prices during the 1920s and 1930s. In addition, the relationship between the settlers and the successive administrative agencies is examined. The scheme was administered by the Closer Settlement Board from its inception until 1932 and much of the discussion during this period concerns the interaction between settler and inspector. Soldier settlement after World War One represented one of the last attempts to create a large body of 'yeoman' farmers. From the early 1920s there was an increasing dichotomy between the 'yeoman' and the 'managerial' ideologies. This dichotomy placed additional pressure on soldier settlers who were expected to be 'efficient' without adequate finances. In the post C.S.B. era, the focus shifts to the attempts by the Closer Settlement Commission to salvage the scheme and its greater understanding of the problems faced by the settlers. While this part of the thesis necessarily becomes more political, the physical and financial environment in which the soldier settlers worked was still an important factor in their success or failure. Unlike the C.S.B. which tended to blame soldier settlers for their situation, the Commission acknowledged that settlers' ability to succeed was often constrained by circumstances beyond their control. Under the latter administration, instalments were written off, additional land was allocated and finally the blocks were revalued to guarantee the men at least some equity in their farms. Those settlers who had survived until these changes were instituted received a 'successful outcome of their life's work'.

Evolution of cooperation in reputation system by group-based scheme

Reputation systems are very useful in large online communities in which users may frequently have the opportunity to interact with users with whom they have no prior experience. Recently, how to enhance the cooperative behaviors in the reputation system has become to one of the key open issues. Emerging schemes focused on developing efficient reward and punishment mechanisms or capturing the social or economic properties of participants. However, whether this kind of method can work widely or not has been hard to prove until now. Research in evolutionary game theory shows that group selection (or multilevel selection) can favor the cooperative behavior in the finite population. Furthermore, some recent works give fundamental conditions for the evolution of cooperation by group selection. In the paper, we extend the original group selection theory and propose a group-based scheme to enhance cooperation for online reputation systems. Related concepts are defined to capture the social structure and ties among participants in reputation system, e.g., group, assortativity, etc. Also, we use a Fermi distribution function to reflect the bounded rationality of participants and the existence of stochastic factors in evolutionary process. Extended simulations show that our scheme can enhance cooperation and improve the average performance of participants (e.g. payoff) in reputation system.

A digital watermarking scheme for Bezier surfaces

Owners and vendors are increasingly publishing their materials in digital form. Because such materials can be exactly copied, a mechanism is required that will protect the legitimate owners of these works, by providing proof of original ownership. Digital watermarking has now become one accepted method of establishing ownership of digital materials. The owner of a work embeds a pattern, called a digital watermark, in the content. This embedded watermark is normally undetectable, but its presence can be demonstrated by the owner of the work or his agent, thereby proving ownership. Digital watermarking has been used for many types of multimedia content, primarily audio, video and flat images. Recently, interest has been shown in applying digital watermarking schemes to 3D surfaces, in various formats. In this paper, we examine a method whereby a digital watermark can be embedded in a Bezier surface. A prototype watermarking method for such surfaces is presented, with some experimental results, and a discussion of directions for future research.

CAFS : a novel lightweight cache-based scheme for large-scale intrusion alert fusion

In this paper, we present some practical experiences on implementing an alert fusion mechanism from our project. After investigation on most of the existing alert fusion systems, we found the current body of work alternatively weighed down in the mire of insecure design or rarely deployed because of their complexity. As confirmed by our experimental analysis, unsuitable mechanisms could easily be submerged by an abundance of useless alerts. Even with the use of methods that achieve a high fusion rate and low false positives, attack is also possible. To find the solution, we carried out analysis on a series of alerts generated by well-known datasets as well as realistic alerts from the Australian Honey-Pot. One important finding is that one alert has more than an 85% chance of being fused in the following five alerts. Of particular importance is our design of a novel lightweight Cache-based Alert Fusion Scheme, called CAFS. CAFS has the capacity to not only reduce the quantity of useless alerts generated by intrusion detection system, but also enhance the accuracy of alerts, therefore greatly reducing the cost of fusion processing. We also present reasonable and practical specifications for the target-oriented fusion policy that provides a quality guarantee on alert fusion, and as a result seamlessly satisfies the process of successive correlation. Our experiments compared CAFS with traditional centralized fusion. The results showed that the CAFS easily attained the desired level of simple, counter-escapable alert fusion design. Furthermore, as a lightweight scheme, CAFS can easily be deployed and excel in a large amount of alert fusions, which go towards improving the usability of system resources. To the best of our knowledge, our work is a practical exploration in addressing problems from the academic point of view. Copyright © 2011 John Wiley & Sons, Ltd.

One image reduction algorithm for RGB color images

We investigate the problem of combining or aggregating several color values given in coding scheme RGB. For this reason, we study the problem of averaging values on lattices, and in particular on discrete product lattices. We study the arithemtic mean and the median on product lattices. We apply these aggregation functions in image reduction and we present a new algorithm based on the minimization of penalty functions on discrete product lattices.

The 1947 bank nationalisation scheme : a prehistory of issues management?

Industry-wide crises emanating from legislative proposals are rare in Australia, and can be classed as once in a generation events, and so merit consideration and research. Currently, there is one such debate over the Mineral Resources Rent Tax, proposed by Prime Minister’s Julia Gillard’s government. Prior to this, the closest comparable event was the 1974 proposal for the establishment of a universal health insurance scheme. The 1947 proposal, by the Ben Chifley-led Labor Government, aimed to nationalise Australia’s banks, and it brought a crisis of massive proportions to Australia’s conservative financial service industry. Although the High Court of Australia finally found Chifley’s proposed legislation unconstitutional, the banks realised they must win in the court of public opinion, generate press coverage in favour of their position, and help defeat the Labor Government at the 1949 election. At the time, and for some decades to come, this was the most expensive and largest public relations campaign waged in Australia. After such a campaign there could be few Australians who could claim that they had not been exposed to the powers of public relations in a modern world. This paper looks at what can be learned from the banks’ collective response to the proposed nationalisation. It does so by applying contemporary issues management evaluation techniques.