Solar cell of 6.3% efficiency employing high deposition rate (8 nm/s) microcrystalline silicon photovoltaic layer

Microcrystalline silicon (μc-Si) films deposited at high growth rates up to 8.1 nm/s prepared by very-high-frequency-plasma-enhanced chemical vapor deposition (VHF-PECVD) at 18–24 Torr have been investigated. The relation between the deposition rates and input power revealed the depletion of silane. Under high-pressure deposition (HPD) conditions, the structural properties were improved. Furthermore, applying μc-Si to n–i–p solar cells, short-circuit current density (J_SC) was increased in accordance with the improvement of microstructure of i-layer. As a result, a conversion efficiency of 6.30% has been achieved employing the i-layer deposited at 8.1 nm/s under the HPD conditions.     

Soft authentication and behavior analysis using a chair with sensors attached: hipprint authentication

An authentication system using a chair with sensors attached is described. Pressure distribution (hipprint) measured by network-connected sensors on the chair is used for identifying the person sitting on the chair. Hipprint information is not sufficient for maintaining a high level of security but is sufficient for providing personalized services such as automatic log-in at home or in a small office. In experiments, we obtained correct identification rates of 99.6% for five people and 93.2% for ten people. A false rejection rate of 9.2% and a false acceptance rate of 1.9% were achieved using another group of 20 people. The results also showed that changes in hipprints can be used to estimate what the person sitting on the chair is doing, for example, using a mouse or leaning back.     

Improvement of transformation efficiency by bioactive-beads-mediated gene transfer using DNA-lipofectin complex as entrapped genetic material

The efficiency of bioactive-beads-mediated plant transformation was improved using DNA-lipofectin complex as the entrapped genetic material instead of naked DNA used in the conventional method. In the improved method, beads aggregated and formed clusters around the protoplasts resulting in a 4-fold higher transformation efficiency than that by the conventional method.     

Gaze awareness for video-conferencing: a software approach

Previous attempts at bringing gaze awareness to desktop videoconferencing have relied on hardware solutions. In this article, the authors describe their software approach, which tracks participants' head and eye movements using vision techniques, then uses this information to graphically place the head and eyes in a 3D environment     

High-speed pumping to UHV

Development of a high-speed pumping system for ultra high vacuum (UHV) process dose not reduce only cost and waiting time for experiment and production, but also reduces CO₂ emission that is known as one of the serious causes in the global warming problem. Reduction of vapor water concentration in a purge gas line would be one of the most effective measures to reduce pumping time to UHV. We carried out control of water vapor in a nitrogen gas purge line in addition to surface treatments of chambers using buff polishing and electrolytic polishing, followed by measurement of outgassing rate of the chambers. Under the reasonable control of the water vapor, the pumping time to reach the pressure of 1 × 10⁻⁶ Pa was able to be shortened with two orders of the magnitude. And it was also found that the main residual gas in the chamber was hydrogen after pumping down with the low concentration of water vapor. The quality of residual gas was equivalent to the quality in a baked UHV system. The introduction of well controlled nitrogen gas to the vacuum system which was not baked out during its pumping has proved a pressure of 3 × 10⁻⁸ Pa for 24 h in the chamber without orifice.     

Energy efficiency technologies for road vehicles

A key message of the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change is that improved energy efficiency is one of society’s most important instruments for combating climate change. This article reviews a range of energy efficiency measures in the transportation sector as discussed in AR4 and assess their potentials for improving fuel efficiency. The primary focus is on light-duty vehicles because they represent the largest portion of world transport energy use and carbon dioxide emissions; freight trucks, a rapidly expanding source of greenhouse emissions, are also discussed. Increasing energy efficiency can be achieved by improving the design and technology used in new vehicles, but vehicle technology is only one component of fleet fuel economy. Measures that create strong incentives for customers to take energy efficiency into consideration when buying and operating their vehicles will be crucial to policy success.

Performance analysis of minimum /spl lscr//sub 1/-norm solutions for underdetermined source separation

Results of the analysis of the performance of minimum /spl lscr//sub 1/-norm solutions in underdetermined blind source separation, that is, separation of n sources from m(相似文献   

High-quality software development system-AYUMI

AYUMI, a mechanism that improves software quality and productivity and by which the development process is refined, is described. A series of methods which span activities from data evaluation to the feedback of findings has been developed. This methodology has approximately 100 evaluation items, including both quantitative and qualitative types. These items are categorized into about 40 groups and scored on a scale from one to five. The evaluation results are compiled into tables and reported to the project team. Work in the field is monitored, and feedback improves the development process. The operation of AYUMI is described, and some possible applications are discussed     

The Methods of Measuring Tackiness of Pressure Sensitive Adhesive Tapes

Tackiness of adhesive tapes has been measured by many investigators using many different methods. Therefore, the tackiness of the same sample may vary widely, depending on the test method used. In general, the tackiness is measured by the finger test. Since the finger test involves many complicated factors such as psychological factors and individual differences, etc., it is difficult to quantitize the results of the finger test. The authors measured the tackiness of commercial plastic film adhesive tapes and cloth adhesive tapes by the use of several tack test methods. The results were compared with those obtained from the finger test. It was found that the rolling ball tack tester with a sine curved surface of y = 86.7 cos (π/300 x x) + 86.7 and an average slope of 30° gave results closest to those obtained by the finger test.