Impact of the living history online project on students\u27 computer use, skills, attitudes towards computer technology and history learning in four Western Massachusetts public schools.

This study examined the impact of a local history project on students\u27 computer use, skills, attitudes toward computer technology and history learning. The variables of gender, grade level, etc. were also investigated. This one-year project integrated computer technology into history curriculum using primary sources. The participants were 64 students from four Western Massachusetts public schools. The Likert scale pre and post surveys were used to gather quantitative data as a main research method. Class observations and informal interviews were conducted for qualitative data as supplementary information for the research. To analyze the pre-post differences at the item level, approximation to binomial distribution was applied. To analyze the data at the aggregate level, One-way ANOVA, a univariate analysis of variance tests was employed. The data results showed significant differences in students\u27 computer use and computer skills between the pre and post surveys. However, the data didn\u27t show significant differences in students\u27 attitudes towards computer technology and history learning. The reason for this may be due to the fact that the students already had positive attitudes prior to the project. The trend for computer skills indicated that as girls got older their skill level went up, but as boys got older, their skill level went down. The same trend was also reflected in students\u27 attitudes toward computer technology. As for students\u27 attitudes toward history learning, the older students had more positive attitudes than the younger students. The qualitative data also indicate the positive impact of the project on student learning. Most of the students “enjoyed working on the project” and believed “computer technology was useful”. Many students commented that they “learned not only the local history, but also computer technology”, and they “learned much more from researching on the Internet than from the textbook”. However, the biggest challenge for the students in doing this project seemed to be teamwork, and some students had difficulty cooperating with other people in the group

Controlling PM2.5 in Chengdu: Analysis and Recommendations from the China, U.S. and California Experience

Chengdu, China, is experiencing rapid economic growth and urbanization at a cost of serious air pollution problems. China has developed a series of policies to reduce PM2.5 emissions and to reform energy structure. However, problems exist which may prevent effectively implementation of the PM2.5 policies, include poor PM2.5 monitoring, isolated environmental management, lack of health improvement target, unclear consequence of non-compliance, and unequally distributed PM2.5 management. This research reviews U.S. PM2.5 emission control technologies related to coal-fired boilers and iron and steel manufacturing industries, which represent major emission sources of Chengdu. Chengdu’s choice of PM2.5 control technology should always consider its local characteristics. By learning the U.S. and California PM2.5 control experiences, their effective policy features are identified, include clear consequence of failure to compliance, strong states and local authorities, comprehensive monitoring and reporting system, health-based standards, and regional air quality management district. U.S. practice also shows innovative policy tools, such as technology standards, use of economic incentives, and cap and trade programs. These U.S. and California policy mechanisms can help to address problems and challenges existing in Chengdu and China’s PM2.5 management. Based on the analysis of the China, U.S. and California policies related to PM2.5, I make the following recommendation: develop integrated policy framework and giving stronger authority to environmental protection agencies; consider health effects as a qualification of the PM2.5 standards; establish comprehensive and accurate PM2.5 monitoring and reporting system; specify clear consequences for non-compliance and strengthening enforcement; divide provinces and big areas into regional air quality management districts by considering local characteristics; use technology-based emission standards to reflect emission limitation and performance; use economic incentives to drive emission reduction; and enhance public disclosure of information

Power vs. Spectrum 2-D Sensing in Energy Harvesting Cognitive Radio Networks

Energy harvester based cognitive radio is a promising solution to address the shortage of both spectrum and energy. Since the spectrum access and power consumption patterns are interdependent, and the power value harvested from certain environmental sources are spatially correlated, the new power dimension could provide additional information to enhance the spectrum sensing accuracy. In this paper, the Markovian behavior of the primary users is considered, based on which we adopt a hidden input Markov model to specify the primary vs. secondary dynamics in the system. Accordingly, we propose a 2-D spectrum and power (harvested) sensing scheme to improve the primary user detection performance, which is also capable of estimating the primary transmit power level. Theoretical and simulated results demonstrate the effectiveness of the proposed scheme, in term of the performance gain achieved by considering the new power dimension. To the best of our knowledge, this is the first work to jointly consider the spectrum and power dimensions for the cognitive primary user detection problem

Expected-loss-based accounting for the impairment of financial instruments:: the FASB and IASB IFRS 9 Approaches

This paper outlines the work of the FASB and the IASB on the development of expected-loss methods for measuring the impairment of financial instruments arising from credit losses, and describes and compares key features of the different approaches developed by the two standard setters. It also provides information indicative of the possible effect of differences between the two approaches and summarises arguments for and against the main elements of the approaches proposed by the two standard setters

Continuous particle manipulation and separation in a hurdle-combined curved microchannel using DC dielectrophoresis

This paper presents a novel dielectrophoresis (DEP)-based microfluidic device which combines round hurdle with an S-shaped curved microchannel for continuous manipulation and separation of microparticles. Local nonuniform electric fields are generated by means of both constricted gaps and curved sections having equal width. Under the effect of negative DEP, particles transporting throughout the microchannel electrokinetically will be directed away from either inner wall or hurdle edge. Both experiment and numerical simulation were conducted, the results of which showed that the trajectories of fix-sized (i.e. 10 or 15 μm) polystyrene (PS) particles could be controlled by adjusting applied voltage, and continuous size-based separation of 10 and 15 μm particles was achieved. Compared to other microchannel designs that make use of either obstacle or curvature individually for electric field gradient, the developed microchannel offers advantages such as improved controllability over particle motion, lower requirement of applied voltage, reduced fouling and particle adhesion, etc. © 2013 AIP Publishing LLC