There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various ...There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various techniques are scattered over a number of texts and manuals, and the courses for database designers are often somewhat incomplete. The present paper shows a didactical experience which tackles this kind of limitations. In particular, the authors have prepared a textbook that includes twenty-one different index formats; it discusses advantages and disadvantages of each indexing technique, and has been positively validated during advanced courses on relational database design.展开更多
Several planar waveguides have been fabricated. The waveguides have been polished for determination of their refractive index profiles (RIP) by wedge method. The RIP determined by inserting the sample in a Mach-Zehnde...Several planar waveguides have been fabricated. The waveguides have been polished for determination of their refractive index profiles (RIP) by wedge method. The RIP determined by inserting the sample in a Mach-Zehnder interferometer and applying fringe analysis methods.展开更多
This work aims to identify the main factors influencing the energy-related carbon dioxide （CO2） emissions from the iron and steel industry in China during the period of 1995-2007. The logarithmic mean divisia index ...This work aims to identify the main factors influencing the energy-related carbon dioxide （CO2） emissions from the iron and steel industry in China during the period of 1995-2007. The logarithmic mean divisia index （LMDI） technique was applied with period-wise analysis and time-series analysis. Changes in energy- related CO2 emissions were decomposed into four factors： emission factor effect, energy structure effect, energy consumption effect, and the steel production effect. The results show that steel production is the major factor responsible for the rise in CO2 emissions during the sampling period; on the other hand the energy consump- tion is the largest contributor to the decrease in C02 emissions. To a lesser extent, the emission factor and energy structure effects have both negative and positive contributions to C02 emissions, respectively. Policy implications are provided regarding the reduction of C02 emissions from the iron and steel industry in China, such as controlling the overgrowth of steel production, improving energy-saving technologies, and introducing low-carbon energy sources into the iron and steel industry.展开更多
文摘There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various techniques are scattered over a number of texts and manuals, and the courses for database designers are often somewhat incomplete. The present paper shows a didactical experience which tackles this kind of limitations. In particular, the authors have prepared a textbook that includes twenty-one different index formats; it discusses advantages and disadvantages of each indexing technique, and has been positively validated during advanced courses on relational database design.
文摘Several planar waveguides have been fabricated. The waveguides have been polished for determination of their refractive index profiles (RIP) by wedge method. The RIP determined by inserting the sample in a Mach-Zehnder interferometer and applying fringe analysis methods.
文摘This work aims to identify the main factors influencing the energy-related carbon dioxide （CO2） emissions from the iron and steel industry in China during the period of 1995-2007. The logarithmic mean divisia index （LMDI） technique was applied with period-wise analysis and time-series analysis. Changes in energy- related CO2 emissions were decomposed into four factors： emission factor effect, energy structure effect, energy consumption effect, and the steel production effect. The results show that steel production is the major factor responsible for the rise in CO2 emissions during the sampling period; on the other hand the energy consump- tion is the largest contributor to the decrease in C02 emissions. To a lesser extent, the emission factor and energy structure effects have both negative and positive contributions to C02 emissions, respectively. Policy implications are provided regarding the reduction of C02 emissions from the iron and steel industry in China, such as controlling the overgrowth of steel production, improving energy-saving technologies, and introducing low-carbon energy sources into the iron and steel industry.
