Clustering of high throughput gene expression data

High throughput biological data need to be processed, analyzed, and interpreted to address problems in life sciences. Bioinformatics, computational biology, and systems biology deal with biological problems using computational methods. Clustering is one of the methods used to gain insight into biological processes, particularly at the genomics level. Clearly, clustering can be used in many areas of biological data analysis. However, this paper presents a review of the current clustering algorithms designed especially for analyzing gene expression data. It is also intended to introduce one of the main problems in bioinformatics – clustering gene expression data – to the operations research community.     

On colloid-chemical properties of some polymer composites

The influence of the vibrowave action on the properties of some disperse systems used in the textile industry has been considered. It has been noted that excitation of nonlinear oscillation in the audio band under resonant conditions leads to an increase in the degree of dispersion of distributed systems and an increase in their colloid stability. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 1, pp. 133–138, January–February, 2006.     

Readout responses of inclined strips in position-sensitivedetectors

Readout responses for the inclined strips in position-sensitive detectors have been studied using theoretical predictions and experimental results. Inclined strips are almost along the displacement direction of incident particles. Rotating conventional strips to near horizontal strips decreases the number of strips by a tangential factor for long-length position sensing. In addition to the channel reduction, the inclined strips modify about 10% in the readout linearity compared to the long-length zigzag patterns. There is resolution degradation because of the inherent high sensitivity of these strips to the avalanche size (about 8% of the detector full length). Double peak responses were observed for sensing the positions of the incident particles. Our theoretical predictions and experimental results are discussed in this paper     

Secure sensors data acquisition and communication protection in eHealthcare: Review on the state of the art

Recent advances in hardware technology have led to the development of low cost, power efficient and more feature rich devices that are amongst the most critical parts of communication networks. These devices or sensors can now sense data with more accuracy, process it by themselves and send it to the neighboring node or the sink node. However, robust and reliable security mechanisms are not yet properly implemented on these sensors due to their limited energy and computation power. Sensors also play a very important role in eHealthcare systems where ubiquitous patient monitoring is performed. As data is generated from the sensor nodes, reliable, secure and attack-resistant data acquisition and transmission is important for an efficient eHealthcare systems. This survey focuses on security issues of sensors data acquisition and transmission protocols, describing their main security features and comparing them in the context of a secure eHealthcare system. A taxonomy of open issues and future challenges is also discussed with respect to specific security metrics described in the paper.     

A grey wolf optimizer approach for optimal weight design problem of the spur gear

The weight of gears is an important issue for high performance of the machine elements. Thus, the design of the gear pairs with respect to the minimum weight is an important and attractive subject to study. Various analytical and heuristic approaches were utilized to optimize the weight of gears in previous studies. In this study, the problem of gear optimization as per the minimum weight was solved with Grey Wolf Optimizer (GWO). GWO is a meta-heuristic optimization method that stands out with its successful performance in engineering applications. In this study, the performance of GWO was investigated in the case of constituting a spur gear with respect to minimum weight for the first time. Compared with the previous studies, the results obtained in the study show that it is possible to design a lighter gear with GWO.     

Resonance condition of a microfiber knot resonator immersed in liquids

Effects of immersing a microfiber knot resonator (MKR) in liquid solutions that have refractive indices close to that of silica are experimentally demonstrated and theoretically analyzed. Significant improvement in resonance extinction ratio within 2 to 10 dB was observed. To achieve a better understanding, a qualitative analysis of the coupling ratio and round-trip attenuation of the MKR is performed by using a curve-fitting method. It was observed that the coupling coefficient at the knot region increased when immersed in liquids. However, depending on the initial state of the coupling and the quantity of the increment in the coupling coefficient when immersed in a liquid, it is possible that the MKR may experience a deficit in the coupling parameter due to the sinusoidal relationship with the coupling coefficient.     

Dual wavelength erbium-doped fiber laser using a tapered fiber

A tapered fiber is fabricated by heating and stretching a piece of optical fiber after the polymer protective cladding has been removed. An equidistant comb-like transmission spectrum, with a spacing of 1.6?nm and an extinction ratio of more than 5?dB, was obtained by the tapered fiber due to the multibeam interferences of the cladding modes. The tapered fiber was applied in a ring erbium-doped fiber laser (EDFL) to generate dual-wavelength lasing oscillations. The EDFL operates at wavelengths of 1557.0?nm and 1558.6?nm with a stable peak power and a signal-to-noise ratio of more than 40?dB.     

ASE spectral slice gain-clamping of EDFA

An erbium-doped (Er-doped) fiber amplifier operating in the C-band is gain clamped, at about 26 dB with noise figures below 6 dB by multiple fiber Bragg gratings. These gratings are placed at the amplifier output with center wavelengths in between communication channels so that unwanted amplified spontaneous emission is removed but put to good use. A 0.5-dB gain compression point at -15 dBm of input signal powers for two simultaneous signal channels is also demonstrated.     

Flow and Thermal Errors in Current National Weather Service Wind Chill Models

The two National Weather Service (NWS) wind chill models in operation since 2001 have inherent errors. The first model attempted and failed to make a facial surface temperature correction on the existing Siple and Passel model. The second model, intended as an improvement on the first, erred by mistakenly defining the wind chill temperature in terms of an internal body temperature rather than the facial surface temperature. To account for a boundary-layer reduction in the free-stream velocity at head level, both models incorrectly apply a constant high-percentage reduction to this velocity as measured at the NWS 10 m level. As a result of these errors, both models predict wind chill temperatures much warmer than the actual values. These warmer temperatures can instill a public complacency whereby facial freezing is viewed as a remote possibility when in reality it may be imminent.