Sequence-based clustering for Web usage mining: A new experimental framework and ANN-enhanced K-means algorithm

We develop a general sequence-based clustering method by proposing new sequence representation schemes in association with Markov models. The resulting sequence representations allow for calculation of vector-based distances (dissimilarities) between Web user sessions and thus can be used as inputs of various clustering algorithms. We develop an evaluation framework in which the performances of the algorithms are compared in terms of whether the clusters (groups of Web users who follow the same Markov process) are correctly identified using a replicated clustering approach. A series of experiments is conducted to investigate whether clustering performance is affected by different sequence representations and different distance measures as well as by other factors such as number of actual Web user clusters, number of Web pages, similarity between clusters, minimum session length, number of user sessions, and number of clusters to form. A new, fuzzy ART-enhanced K-means algorithm is also developed and its superior performance is demonstrated.     

Modeling and simulation of separation process in flotation system

In order to design a flotation circuit to remove ink and contaminants from slushed old corrugated container (OCC) pulp suspension, a model based on mass balance was developed. The model is a five fractional model, which handles mass flow rate of ink, fiber, fines, filler and dichloromethane (DCM) extractives. A detailed method of calculating the deinking selectivity of a material from experimental data, described in terms of reject ratio, is presented. Three flotation deinking systems were simulated. In a single stage flotation system, increasing the number of flotation cells improved cleanness of the accept pulp suspension while it decreased yield at the same time. Yield can be increased by adding a second stage and by introducing the accept flow of the second stage into the feed flow of the first stage. However, the cleanness of the accept pulp was deteriorated. It was shown that yield can be increased without compensating the cleanness of the accept pulp by utilizing the accept pulp from the second stage for another paper machine line instead of sending back to the feed flow of the first stage.     

Factors influencing deflaking kinetics in repulping to produce molded pulp

Process variables affecting the deflaking or defibering kinetics of recovered papers in repulping to produce molded pulp were investigated with laboratory low and high consistency pulpers and a pilot high consistency pulper. The defibering kinetics at various repulping conditions were compared in terms of the deflaking rate coefficient, which can be easily obtained by measuring flake contents as a function of slushing time and then by performing a non-linear regression analysis on the data. The two main variables affecting defibering rate are found to be the repulping concentration and the rotational speed of rotor, which have to be chosen as manipulated variables to optimize a repulping process. Increasing repulping concentration and rotor speed generally promotes the defibering of recovered paper.     

Evaluating visualization approaches to detect abnormal activities in network traffic data

International Journal of Information Security - Designing innovative approaches to detect intrusive network activities is considered as one of the most significant research topics in network...     

Analysis of the effectiveness of preventive and deterrent piracy control strategies: Agent-based modeling approach

We use agent-based modeling approach to analyze the impact of various digital piracy control strategies on consumers, retailers, record labels, and artists. We model heterogeneous agent behavior, motives, and interactions to examine the consequences in terms of aggregate system behavior. Using a multi-agent programmable modeling environment (Netlogo), several experiments were conducted to test the simulation model and develop managerial insights. We show that an educational strategy is more effective when consumers are resistant to anti-piracy efforts and budgets for combating piracy are small. Furthermore, value-added service and low-price strategies should be used to encourage legitimate purchases since legal and educational strategies alone deter piracy but do not provide consumers’ incentives to purchase legitimate products. Therefore, effectiveness of piracy control strategies can be improved by combining a legal or an educational strategy with a value-added or a low-price strategy. We also find that the profit-maximizing strategies are different for different players in the supply chain. While the record label prefers a low-cost strategy, it is optimal for the whole supply chain to use combined legal or educational strategy with a value-added strategy. Therefore, there is potential for all parties in the supply chain being better off if the record label and the retailer cooperate in combating piracy.     

Improvement of ink and heavy metal removal from old corrugated container stock by alkali kneading

One of the possible ways to strengthen competitiveness of Kraft paper industry is to replace the expensive virgin unbleached kraft pulp (UKP) with old corrugated container (OCC), a cheaper and lower grade raw material. When OCC is utilized to produce kraft paper, the main problems are the impaired appearance of the products, and heavy metals and hazardous materials in the products caused by the printed ink and other contaminants. In order to improve the removal efficiency of ink and heavy metals from old corrugated container stock, the effect of adding alkali during kneading of OCC stock was investigated. It was found that adding NaOH and sodium silicate during kneading could improve detachment of ink from fiber surface and removal of it from stock and hence improve heavy metal removal from OCC stock. Since alkali addition improves ink detachment, effective residual ink concentration (ERIC) of pulp was decreased and brightness was increased. Tensile strength and tensile energy absorption (TEA) were increased with addition of alkali.     

Market reaction to application service provider (ASP) adoption: An empirical investigation

We examined the impact of ASP adoption on the market value of the firms and explored contextual factors in the positive abnormal returns. We employed event study methodology to analyze 268 ASP adoption announcements from 1998 to 2007. The results indicated that ASP adoption announcements were associated with positive increases in the market value of the firm. In addition, differences in market returns to ASP adoption were found to depend on strategic adoption intent, firm size, industry, and vendor status. These results provide useful implications for making decisions about whether, when, and how to adopt ASP to maximize the business value.     

Molecular structure of bent-shaped liquid crystal dimers

Liquid crystalline behavior of dimesogenic compounds opens a new area of research in liquid crystals science. The term ‘dimesogenic compounds’ describes thermotropic compounds consisting of two mesogenic units linked through a central spacer such as polymethylene and oligosiloxyl groups. The two mesogenic units may or may not be identical. When they are identical, they are occasionally called twin or siamese compounds.     

A low cost wearable wireless sensing system for paretic hand management after stroke

This paper describes the design of a low cost wearable hand exercise device that can assist repetitive wrist and finger exercise for stroke patients. The design of this device was guided by neurobiological principles of motor learning, such as sensory-motor integration, movement repetition, and cognitive interaction. This pilot study tested the efficacy of a wireless sensing system in the device to serve as a facilitator of repetitive hand exercise, which is an essential part of rehabilitation after stroke. The results from healthy young adults showed that the device with a wireless sensing system yielded quantitatively better motor function with the repetitive wrist and finger joint movements.This proof-of-concept study shows potential therapeutic evidence for stroke rehabilitation as well as the potential utility of sensing system for stroke rehabilitation.     

Graft polymerization of acrylic acid onto corn starch in aqueous isopropanol solution

The graft polymerization of acrylic acid (AA) onto corn starch well-swollen in aqueous isopropanol (IPA) was carried out by controlling reaction variables such as the concentrations of AA, initiator (a mixture of ammonium persulfate and sodium metabisulfite) and IPA as well as the temperature and time of reaction for the acquirement of products with good efficiency. Homopoly(acrylic acid) existing in the product mixture was removed by extraction with aqueous ethanol. In the temperature range of 30°C to 60°C the conversion gradually increased with increasing both reaction temperature and reaction time. The graft reaction showed a tendency to give high conversions even at reaction temperatures above 40°C. The reaction in aqueous IPA solution was more homogeneous and efficient than that in water. In addition, even though an equivalent quantity of initiator was used, the reaction conversion increased with increasing the concentration ratio of AA to corn starch. It was also found that the average distance between grafted sites decreased as the quantity of initiator and reaction temperature were increased.