Research
Analysis and Performance Evaluation of DWDM and Conventional WDM
The need of increasing the capacity of data transmitted within the fiber transmission links became a challenge for researcher. Even though optical fiber communication is the best communication system in transmitting high data rate but still users are hungry thus the researchers are pushing to get the highest bit rate. While the fiber channel may be capable of transmitting terabit-per-second data rates, no existing single communication system can make complete use of this speed. One of the main concerns in an optical network is the high cost of installation of components. The global network is made of a large submarine cable network that is expensive to modify and repair. An alternative solution to this is Wavelength Division Multiplexing (WDM) where each modulated signal is transmitted at an individual frequency, allowing full duplex data transmission. In WDM systems the available fiber bandwidth is divided into separate channels with each channel carrying one signal, thus increasing the overall data rate without increasing the number of fibers. The data rate of each channel can be limited, but with many channels the total data rate is considerably higher.WDM has not always been a popular choice. The invention of Erbium-doped fiber amplifiers (EDFA) with large bandwidth is largely responsible for popularizing this technique. In terms of multiwavelength signals, so long as the EDFA has enough pump energy available to it, it can amplify as many optical signals as can be multiplexed into its amplification band. These properties of EDFAs have enabled us to use Dense WDM (DWDM) technique, which uses denser channel spacing in order to achieve even higher bit rate. It is an interesting solution is to double the capacity of each fiber by using a duplexer. It is a system capable of duplex communication over a single fiber in contrast to two fibers required in the present scenario. The capacity can be further doubled by the application of DWDM techniques as opposed to conven
Human Skin Detection
Skin-color modeling is a crucial task for several applications of computer vision. Problems such as face detection in video are more likely to be solved if an efficient skin-color model is constructed. Most potential applications of skin-color model require robustness to significant variations in races, differing lighting conditions, textures and other factors. Given the fact that a skin surface reflects the light in a different way as compared to other surfaces. As the color of human skin is created by the combination of blood (red) and melanin (brown, yellow) which gives it a restricted range of hues. A skin region can be classified by comparing large image content of skin database and non-skin database. The RGB color space is widely used and most effective to detect skin region from an image. The segmentation is used to localize and identify homogeneous regions in a picture by perceptual attributes which include the size, the shape and the texture and/or color information. The probability of each RGB color space of skin and non-skin database is important to detect skin pixels. For each pixel of testing image, the RGB value is calculated then the probability ratio of that RGB color space for training Skin and non-skin data base is compare with a threshold variable called . The threshold value lies between 0 and 1 but for this analyzing purpose threshold value has been taken as 0.4. If the ratio will be greater than 0.4 then that pixel will be detected as skin pixel elsedetected as non-skin pixel. After segmenting out skin from images, this can be useful for identifying faces, hand sign recognition, offensive content such pornography. The performance curve (ROC curve) reflects the overall accuracy of our analysis.
Performance Analysis and Comparison between Coarse WDM and Dense WDM
Although optical fiber communication is the best for transmitting data at a high rate, we are trying to push the data rate even higher. While the fiber channel may be capable of transmitting terabitper- second data rates, no existing single communication system can make complete use of this speed. Adding more and more fibers to the system as a method of increasing speed is uneconomical as we know the global network is made of a large submarine cable networks that is expensive to modify. An alternative solution to this is Wavelength Division Multiplexing (WDM) where each modulated signal is transmitted at an individual frequency, allowing full duplex data transmission. In WDM systems the available fiber bandwidth is divided into separate channels with each channel carrying one signal, thus increasing the overall data rate without increasing the number of fibers. The data rate of each channel can be limited, but with many channels the total data rate is considerably higher. At the receiver end of the link, a de-multiplexer separates the wavelengths and routes them into different fibers, which all terminate at separate receivers. The spacing between the individual wavelengths transmitted through the same fiber serve as the basis for defining Dense WDM and Coarse WDM. For cost-effective solutions to their transport needs, Coarse WDM is becoming more widely accepted as important transport architecture.
Design and Performance Evaluation of Solar Water Distillation Plant
Pure water is most essential for human life. But it is not available and rare in most of the place in the world. Pure water is not only important for drinking purpose but also for other issue such as boiler make up or feed water, distilled water for medical uses etc. Hence purifying water is the demand of time. Water purifying is an energy consuming process but our conventional energy resource is limited. In that case alternative renewable energy resources can give us better solution. Solar energy is available resource and gives an optimum solution for this experimental purpose. Designed solar water distillation plant has two parts. Upper part is made by glass and a copper plate for absorbing heat inside it. Proper Insulator is attached behind this arrangement. A small container is linked below it by a small elbow, condensed pure water stored in this container. The lower part is made by cellulite. The cellulite box contain wick. This wick spread from the ground to the backside of copper plate. The wick absorbs the ground water and conveys it up to glass box where this water is evaporated in presence of solar energy. Total system is completely air tight. This plant works quit well but its performance is most depended on wick material. A composite wick material can gives better result.
