Resonant Raman of OH/OD vibrations and photoluminescence studies in LiTaO3 thin film

Resonant Raman spectra (RRS) of O-H and O-D vibration and libration modes, their combinations and higher harmonics have been observed in LiTaO3 polycrystalline thin films. RRS peaks are superimposed on photoluminescence (PL) spectrum. Monochromatic light from a xenon lamp is used as excitation source. PL spectrum shows two broad peaks, first near the band gap in UV (4.4-4.8eV) and another in the sub band gap region (< 4.0 eV). Band gap PL along with RRS peaks are reported for the first time. Photoluminescence excitation spectrum (PLE) shows a peak at 4.8 eV. Peak positions and full width at half maximum (FWHM) of RRS peaks depend upon the excitation energy. Dispersions of the fundamental and the third harmonic of the stretching mode of O-H with excitation energy are about 800 cm-1/eV and 2000 cm-1/eV respectively. This dispersion is much higher than reported in any other material.Comment: 20 page

SAR-based Wind Resource Statistics in the Baltic Sea

Ocean winds in the Baltic Sea are expected to power many wind farms in the coming years. This study examines satellite Synthetic Aperture Radar (SAR) images from Envisat ASAR for mapping wind resources with high spatial resolution. Around 900 collocated pairs of wind speed from SAR wind maps and from 10 meteorological masts, established specifically for wind energy in the study area, are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a root mean square error of 1.17 m s−1, bias of −0.25 m s−1, standard deviation of 1.88 m s−1 and correlation coefficient of R2 0.783. Wind directions from a global atmospheric model, interpolated in time and space, are used as input to the geophysical model function CMOD-5 for SAR wind retrieval. Wind directions compared to mast observations show a root mean square error of 6.29° with a bias of 7.75°, standard deviation of 20.11° and R2 of 0.950. The scale and shape parameters, A and k, respectively, from the Weibull probability density function are compared at only one available mast and the results deviate ~2% for A but ~16% for k. Maps of A and k, and wind power density based on more than 1000 satellite images show wind power density values to range from 300 to 800 W m−2 for the 14 existing and 42 planned wind farms

Supporting meetings in Virtual Worlds with enhanced Communication features

With the rapid growth in the use of computer for addressing our day to day needs and the increased use of technology in our daily life, we cannot imagine a day without the use of the internet for our routine needs. Today, without any doubt in our mind we can say that technology has taken over human lives completely. A new era of computing has evolved where computers and the internet have a huge impact on everyone‟s life. A lot of research has been done and is in process for generated tools and devices which will bring the world even closer. It started with telephone in the last century and since then till today there have been huge number of tools and devices that try to give the users who are geographically far away a sense of co-presence. The latest technology making rounds is the Virtual World technology. The popularity and impact of online virtual worlds is worth making a note of. It needs to be seen now, how does it really betters people lives. One such persistent virtual world is Second Life. The number of users and organizations associated with this world is impressive. It provides users with the right amount of collaborative content with a set of communication features. Second Life provides its users with unique meeting support which gives them a sense of co-presence achieved nowhere else. This thesis focuses upon the kind of meeting support, collaborative content and the communication features provided by the virtual world that will allow its users to avoid the need for travel and long distance meetings can be achieved successfully in such an environment. This will help the travel time to be converted to productive office time as well as the costs involved in such meetings can also be reduced drastically. Such kind of meetings will also prove eco-friendly as they will save on fuel consumption and benefit from reduced pollution

A Case Study of Group Processes and Student Evaluation of Teaching

This paper documents a case study undertaken to understand the effect of group processes on student evaluation of teaching (SET). The study used interviews to investigate the experiences of students in a cohort model Master of Science in Accountancy degree program and how those experiences influenced SET. The cohort served as an extreme example in which group processes played out intensely, allowing the researchers better to examine them. The results showed that the participants’ common experience led to frequent discussion about various aspects of the classes and the program. A common topic of discussion was instructor performance. This discussion about instructors, in turn, appeared to affect SET. It also appeared that a mismatching of expectations and realized student–instructor relationships also affected SET

Design and validation of a hybrid interactive reference point method for multi-objective optimization

This paper offers a classification of the main representatives of interactive classical and evolutionary methods. After a crossfertilization of these two fields a new hybrid interactive reference point method is designed. The method combines the reference point idea with the relative speed of a (1+1) - EA and is implemented with a graphical user interface. Finally, it is validated on two well-known real-world test problems