Organization Mining Using Online Social Networks

Complementing the formal organizational structure of a business are the informal connections among employees. These relationships help identify knowledge hubs, working groups, and shortcuts through the organizational structure. They carry valuable information on how a company functions de facto. In the past, eliciting the informal social networks within an organization was challenging; today they are reflected by friendship relationships in online social networks. In this paper we analyze several commercial organizations by mining data which their employees have exposed on Facebook, LinkedIn, and other publicly available sources. Using a web crawler designed for this purpose, we extract a network of informal social relationships among employees of targeted organizations. Our results show that it is possible to identify leadership roles within the organization solely by using centrality analysis and machine learning techniques applied to the informal relationship network structure. Valuable non-trivial insights can also be gained by clustering an organization’s social network and gathering publicly available information on the employees within each cluster. Knowledge of the network of informal relationships may be a major asset or might be a significant threat to the underlying organization.     

Study of mechanical properties of urethane-chlorinated rubber graft copolymer system. I

The isocyanate-terminated urethane prepolymer was prepared from toluene diisocyanate and a mixture of castor oil-polypropylene glycol (PPG) (MW 2000). The chlorinated rubber (CR) graft copolymers (A and B) containing small percentage of hydroxyl groups were mixed with the urethane prepolymer in different proportions (1:1, 2:3, and 1:2), and the films were cast using these systems. Tensile strength and percent elongation were evaluated for A and B series with and without triethanolamine (TEA). Morphological characteristics of the films were also studied by using a scanning electron microscope (SEM). Deviations noticed in tensile strength values at yield as well as at break for A and B series and for the samples cured with additional TEA have been discussed.     

Kinetic studies on the condensation reaction of 2-methylol-4-t-butylphenol with 4-t-butylphenol using acid catalysts. I

The rates of the individual reactions of 2-methylol-4-t-butylphenol with 4-t-butylphenol were measured under varying mole ratios of reactants in the presence of different acid catalysts (5.0 × 10^?3 N to 2.0 × 10^?4 N) at five different temperatures (60, 65, 70, 75, and 80°C). In all the experiments, the reactions were found to obey second-order rate law. The values of the Arrhenius parameters and the entropy of activation for the overall reaction were calculated. The relative catalytic efficiencies of the acid catalysts followed the order HNO₃ > HCl > H₂SO₄.     

Role of fibers in controlling unrestrained expansion and arresting cracking in Portland cement concrete undergoing alkali-silica reaction

An experimental study was undertaken to investigate the role of polypropylene or brass-coated steel fibers in controlling unrestrained expansions and delaying and arresting cracking in Portland cement concrete due to alkali-silica reaction. Portland cement concrete and fiber-reinforced concrete (FRC) mixtures were prepared at a w/c ratio of 0.40 using modified Type I cement, reactive fine particles, and coarse limestone aggregates. Prism (5×5×30 cm) and plate (13.5×13.5×3 cm) specimens were prepared and cured for 7 or 28 days before exposure to a special treatment to accelerate ASR. Expansion, time of cracking, and ultrasonic pulse velocity were determined over a treatment period of 65 days using prism specimens. Ultimate cracking pattern and extent were determined after a treatment period of 85 days using plate specimens. The results showed that while fibers did not contribute significantly to controlling pre-cracking and post-cracking expansions, they played a significant role in delaying cracks formation and limiting their extent. Considering its lower cost and content, the performance of polypropylene fibers was superior to that of brass-coated steel ones. The potential of brass-coated fibers in arresting ASR cracking was significantly affected by age of concrete when subjected to treatment.     

License plate localization using a statistical analysis of Discrete Fourier Transform signal

License Plate Recognition (LPR) is a well-known problem and it has developed as a coherent framework. Research continues on the topic due to the diversity of license plates and outdoor illumination conditions which require attention. One of the most important steps in LPR is the localization part where license plates are extracted from video captured images. In this article we introduce a new approach of plate localization using a statistical analysis of Discrete Fourier Transform of the plate signal. The plate signal is represented by five statistics: strength of the signal, normalized maximum amplitude, frequency of maximum amplitude, frequency center and frequency spread. Combining with the color-based histogram thresholding, the method achieves 97.27% accuracy using plate signals from binary images. Comparative analysis is also reported.     

Hydrogen evolution reaction on Ni-Al electrodes

The hydrogen evolution reaction (h.e.r) was studied in alkaline solutions on two types of electrodes: (1) obtained by alloying Raney nickel without or with nickel and (ii) by pressing Raney nickel and nickel powders at room temperature. The obtained electrodes are usually very active for the h.e.r. The most active electrode was obtained by pressing Raney nickel with nickel powder (50 wt %). It was characterized by a large roughness factor, R 10 000 and a very low overpotential at the current density of 250 mA cm^–2, ₂₅₀ = 56 mV. The mechanism of the h.e.r. was studied using a.c. impedance measurements. The high electrode activity is connected with the increase in the intrinsic activity of the porous electrode surface.     

Advanced hashing schemes for packet forwarding using set associative memory architectures

Building a high performance IP packet forwarding (PF) engine remains a challenge due to increasingly stringent throughput requirements and the growing size of IP forwarding tables. The router has to match the incoming packet’s IP address against all entries in the forwarding table. The matching process has to be done at increasingly higher wire speed; hence, scalability and low power consumption are critical for PF engines.Various hash table based schemes have been considered for use in PF engines. Set associative memory can be used for hardware implementations of hash tables with the property that each bucket of a hash table can be searched in a single memory cycle. However, the classic hashing downsides, such as collisions and worst case memory access time have to be dealt with. While open addressing hash tables, in general, provide good average case search performance, their memory utilization and worst case performance can degrade quickly due to collisions (that lead to bucket overflows).The two standard solutions to the overflow problem are either to use predefined probing (e.g., linear or quadratic probing) or to use multiple hash functions. This work presents two new simple hash schemes that extend both aforementioned solutions to tackle the overflow problem efficiently. The first scheme is a hash probing scheme that is called Content-based HAsh Probing (CHAP). As the name suggests, CHAP, based on the content of the hash table, avoids the classical side effects of predefined hash probing methods (i.e., primary and secondary clustering phenomena) and at the same time reduces the overflow. The second scheme, called Progressive Hashing (PH), is a general multiple hash scheme that reduces the overflow as well. The basic idea of PH is to split the prefixes into groups where each group is assigned one hash function, then reuse some hash functions in a progressive fashion to reduce the overflow. Both schemes are amenable to high-performance hardware implementations with low overflow and constant worst-case memory access time. We show by experimenting with real IP lookup tables and synthetic traces that both schemes outperform other existing hashing schemes.     

The fractional Boltzmann transport equation

The fractional Boltzmann transport equation is derived making use of the fractional Hamilton’s equations based on the fractional actionlike variational approach. By simply defining a distribution function and inspecting its time derivative, many important results in statistical physics can be derived.