Parameter-free search of time-series discord

Time-series discord is widely used in data mining applications to characterize anomalous subsequences in time series. Compared to some other discord search algorithms, the direct search algorithm based on the recurrence plot shows the advantage of being fast and parameter free. The direct search algorithm, however, relies on quasi-periodicity in input time series, an assumption that limits the algorithm's applicability. In this paper, we eliminate the periodicity assumption from the direct search algorithm by proposing a reference function for subsequences and a new sampling strategy based on the reference function. These measures result in a new algorithm with improved efficiency and robustness, as evidenced by our empirical evaluation.

Directed search, coordination failure, and seller profits: an experimental comparison of posted pricing with single and multiple prices

We experimentally examine posted pricing and directed search. In one treatment, capacity-constrained sellers post fixed prices, which buyers observe before choosing whom to visit. In the other, firms post both “single-buyer” (applied when one buyer visits) and “multibuyer” (when multiple buyers visit) prices. We find, based on a 2 × 2 (two buyers and two sellers) market and a follow-up experiment with 3 and 2 × 3 markets, that multibuyer prices can be lower than single-buyer prices or prices in the one-price treatment. Also, allowing the multibuyer price does not affect seller profits and increases market frictions.

High activity and Levy searches : jellyfish can search the water column like fish

Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d−1, more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean μ = 1.96, range 1.2–2.9) close to the theoretical optimum for searching for sparse prey (μopt ≈ 2.0). Complex movements in these ‘simple’ animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems.

Growing Self Organizing Map with an Imposed Binary Search Tree for Discovering Temporal Input Patterns

In this paper the Binary Search Tree Imposed Growing Self Organizing Map (BSTGSOM) is presented as an extended version of the Growing Self Organizing Map (GSOM), which has proven advantages in knowledge discovery applications. A Binary Search Tree imposed on the GSOM is mainly used to investigate the dynamic perspectives of the GSOM based on the inputs and these generated temporal patterns are stored to further analyze the behavior of the GSOM based on the input sequence. Also, the performance advantages are discussed and compared with that of the original GSOM.

An efficient and distributed file search in unstructured peer-to-peer networks

Peer-to-peer (P2P) networks are gaining increased attention from both the scientific community and the larger Internet user community. Data retrieval algorithms lie at the center of P2P networks, and this paper addresses the problem of efficiently searching for files in unstructured P2P systems. We propose an Improved Adaptive Probabilistic Search (IAPS) algorithm that is fully distributed and bandwidth efficient. IAPS uses ant-colony optimization and takes file types into consideration in order to search for file container nodes with a high probability of success. We have performed extensive simulations to study the performance of IAPS, and we compare it with the Random Walk and Adaptive Probabilistic Search algorithms. Our experimental results show that IAPS achieves high success rates, high response rates, and significant message reduction.

In search of best practices in responsible gambling ( RG ) : a report on a comparative study of RG among Macau, Las Vegas, and Melbourne, presented to the MSAR Bureau of Gaming Inspection and Coordination (DICJ).

This is a project sponsored by the Asia Pacific Association for Gambling Studies (APAGS) and supported by funds from the MSAR’s Bureau of Gambling Inspection and Coordination (DICJ). The research team comprises as Chief Investigators: Prof. Zhidong Hao of the University of Macau; Prof. Linda Hancock of Deakin University, Australia, and Prof. William Thompson, University of Las Vegas (UNLV). The project research was conducted between the end of December 2012 and July 2013.
The starting point for the research was to select four out of the six casino companies licensed to operate in Macau that also operate transnationally, that is, either in Las Vegas or Melbourne. Hence, the Venetian, Wynn, MGM, and the Melco-Crown Entertainment are the focus of research. The main objectives of the project are to explore how responsible gambling is framed in each of the three jurisdictions (Macau, Las Vegas and Melbourne); how it is approached cross-jurisdictionally by each of the companies; and to assess current approaches within a broader comparative context against international best practice. The research explores Responsible Gambling measures taken by a range of stakeholders including the government/regulators in each of the three jurisdictions, casino managements, problem gambling counselling services, unions and community organizations. The research emphasizes what problems prevail, and the implications of this research for enhancing Responsible Gambling in Macau.