An approach to studying scale for students in higher education: a Rasch measurement model analysis

A questionnaire comprising 80 self-report items was designed to measure student Approaches to Studying in a higher education context. The items were conceptualized and designed from five learning orientations: a Deep Approach, a Surface Approach, a Strategic Approach, Clarity of Direction and Academic Self-Confidence, to include 40 attitude items and 40 corresponding behavior items. The study aimed to create a scale and investigate its psychometric properties using a Rasch measurement model. The convenience sample consisted of 350 students at an Australian university in 1998. The analysis supported the conceptual structure of the Scale as involving studying attitudes and behaviors towards five orientations to learning. Attitudes are mostly easier than behaviors, in line with the theory. Sixty-eight items fit the model and have good psychometric properties. The proportion of observed variance considered true is 92% and the Scale is well-targeted against the students. Some harder items are needed to improve the targeting and some further testing work needs to be done on the Surface Approach. In the Surface Approach and Clarity of Direction in Studying, attitudes make a lesser contribution than behaviors to the variable, Approaches to Studying.     

数字电视系列(7)HDMI兼容性测试

HDMI Licensing LLC目前授权两家HDMI授权测试中心(ATC),其中一家位于日本大阪,由Matsushita Electric Industries经营,另一家则位于美国加州Sunnyvale,由晶像公司(Silicon Image,Inc.)主持。HDM ILicensing LLC可能在日后授权其它ATC。     

Relation between bit and symbol error probabilities for DPSK andFSK with differential phase detection

In M-ary, Gray coded DPSK, and FSK with differential phase detection the bit error probability is usually approximated by the symbol error probability divided by the number of bits in a symbol. This approximation is known to be excellent for PSK with large signal-to-noise ratios in a Gaussian channel. In other cases this approximation may be questionable. Here we compute the exact values of bit error probability for DPSK and FSK in Gaussian, Rayleigh, and Rician channels. We also compute the relative error involved in this approximation. The conclusion is that except for very low values of signal-to-noise ratio the approximation is good for all channels     

Error motion of a kinematic spindle

A prototype spindle for low-force, low-speed applications that is kinematically constrained in accordance with the principles of exact constraint was designed, fabricated, and tested. In the prototype spindle, the position and orientation of the shaft (rotor) are constrained at five contact points; four constraints are arranged radially around the rotor, and one constraint is located at the end of the rotor. This paper describes the design of the prototype spindle and presents a study of its error motion for the hardened steel rotor sliding on brass and UHMW-PE bonded to ceramic. The error motion is observed to be highly repeatable with less than 100 nm asynchronous errors, and a simple analytical model enables the prediction of the synchronous error motion using measurements of the rotor’s roundness profiles.     

基于有效特征子集提取的高效推荐算法

推荐系统是根据用户的历史信息对未知信息进行预测.用户项目评分矩阵的稀疏性是目前推荐系统面临的主要瓶颈之一.跨域推荐系统是解决数据稀疏性问题的一种有效方法.本文提出了基于有效特征子集选取的高效推荐算法（FSERA）,FSERA是提取辅助域的子集信息,来扩展目标域数据,从而对目标域进行协同过滤推荐.本文采用K-means聚类算法将辅助域的数据进行提取来降低冗余和噪声,获取了辅助域的有效子集,不仅降低了算法复杂度,而且扩展了目标域数据,提高了推荐精度.实验表明,此方法比传统的方法有更高的推荐精度.     

EXAMINING THE ROLE OF CUTTING FLUIDS IN MACHINING AND EFFORTS TO ADDRESS ASSOCIATED ENVIRONMENTAL/HEALTH CONCERNS

ABSTRACT

Cutting fluids have seen extensive use and have commonly been viewed as a required addition to high productivity and high quality machining operations. Cutting fluid related costs and health concerns associated with exposure to cutting fluid mist and a growing desire to achieve environmental sustainability in manufacturing have caused industry and academia to re-examine the role of these fluids and quantify their benefits. This work summarizes the traditional purposes of cutting fluids and reports on recent analytical and experimental research to critically examine these functions. To minimize or even eliminate the concerns associated with cutting fluid usage, several recent and novel approaches have been proposed and are examined.     

Effects of different carbohydrases on the physicochemical properties of rice flour,and the quality characteristics of fermented rice cake

Food Science and Biotechnology - The rice flours were hydrolyzed using α-amylase (A), α-amylase and xylanase (AX), and α-amylase, xylanase and β-amylase (AXB). The effects of...