Some comments on the journal weighted impact factor proposed by Habibzadeh and Yadollahie

In a recent paper in the Journal of Informetrics, Habibzadeh and Yadollahie [Habibzadeh, F., & Yadollahie, M. (2008). Journal weighted impact factor: A proposal. Journal of Informetrics, 2(2), 164–172] propose a journal weighted impact factor (WIF). Unlike the ordinary impact factor, the WIF of a journal takes into account the prestige or the influence of citing journals. In this communication, we show that the way in which Habibzadeh and Yadollahie calculate the WIF of a journal has some serious problems. Due to these problems, a ranking of journals based on WIF can be misleading. We also indicate how the problems can be solved by changing the way in which the WIF of a journal is calculated.     

System design and analysis of the trans-critical carbon-dioxide automotive air-conditioning system

As an environmentally harmless and feasible alternate refrigerant, CO₂ has attracted worldwide attention, especially in the area of automobile air-conditioning (AAC). The thermal property of CO₂ and its trans-critical refrigeration cycle is very different from that of the traditional CFC or HCFC system. The detailed process of CO₂ system thermal cycle design and optimization is described in this paper. System prototype and performance test bench were developed to analyze the performance of the CO₂ AAC system.     

An efficient method for parallel CRC automatic generation

The State Transition Equation (STE) based method to automatically generate the parallel CRC circuits for any generator polynomial or required amount of parallelism is presented. The parallel CRC circuit so generated is partially optimized before being fed to synthesis tools and works properly in our LAN transceiver. Compared with the cascading method, the proposed method gives better timing results and significantly reduces the synthesis time, in particular. Project (No. 60271010) supported by the National Natural Science Foundation of China     

Retrieval,visualization, and mining of large radiation dosage data

Radiation dose monitoring has become an essential service that hospitals must perform. Depending on the system in place, this can result in the collection of large quantities of data, ripe for analysis. These data should include a wide variety of variables for each study because assessment of the propriety of the patient’s dose is dependent on many factors, including patient age and size, as well as the body section that is being scanned. Moreover, the scanners themselves have many properties that affect patient dose, such as model, pitch and kVp. In this paper, we propose an engine that seamlessly integrated with a clinical PACS to retrieve radiation dosage data. We devised several schemes to analyze these data through visualization and mining techniques that examine it at different scopes. We demonstrate the utility of such visual methods at examining large, noisy, and multi-dimensional data, which is embodied in the collected radiation data.     

The Bricklayer Effect: How Accounting for Method Bias Affects First-Order Cultivation Relationships

Although the issue of method bias is a well-known threat to the validity of self-reports, it has seldom been addressed in empirical media effects studies. This may be problematic because independent and dependent variables are often measured using similar methods. Thus, reported correlations may not only reflect common variance between the constructs of interest but also indicate common variance between the measurement methods. In this article, we present two cultivation studies investigating to what extent first-order cultivation relationships are influenced by common method variance. In both studies, controlling for a theoretically unrelated marker variable (Study 1: the estimated prevalence of bakers; Study 2: the estimated prevalence of bricklayers) diminished correlations between television-viewing frequency and prevalence estimates. This finding, referred to as the bricklayer effect, suggests a more thorough discussion on common method variance in cultivation research is needed.     

Location refinement and power coverage analysis based on distributed antenna

To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel impulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin.     

Pressure angle in parallel mechanisms: From planar to spatial

This paper presents the evolution process of pressure angles from planar parallel mechanisms to spatial parallel mechanisms. Manipulability and condition number, which are frequently used in the optimum design of parallel mechanisms, are introduced from serial robots at first. Then, both theoretical analysis and practical experiences demonstrate that these concepts seem imperfect when they are used in parallel mechanisms. For this reason, this paper introduces the pressure angles in planar 4-bar mechanisms to spatial parallel mechanisms, which include redundant parallel mechanisms. Two kinds of pressure angles extracted from the determinant of direct and indirect Jacobian matrices are investigated. Moreover, two comprehensive and visible global performance indices are defined, showing the advantages in evaluating the workspace, singularity and motion/force transmission capabilities. With a 2-DOF planar and a 3-DOF spatial parallel mechanism as examples, the application of the performance indices is investigated and compared with the condition number at last. The proposed concept can be extended to other spatial parallel mechanisms.     

英语语法研究与大学英语教学

英语语法研究大体经历了从借鉴到描写到解释三个阶段。通过对早期规定语法、描写语法、转换 -生成语法和系统功能语法的历史演变与发展过程的分析和阐述 ,以说明在现代语法研究和我国英语教学中应把语法运用放在首位 ,培养学生在交际活动和与自然语言接触中运用语法规则的能力     

A systematic review of school-based interventions targeting physical activity and sedentary behaviour among older adolescents

Lack of physical activity (PA) and high levels of sedentary behaviour (SB) have been associated with health problems. This systematic review evaluates the effectiveness of school-based interventions to increase PA and decrease SB among 15–19-year-old adolescents, and examines whether intervention characteristics (intervention length, delivery mode and intervention provider) and intervention content (i.e. behaviour change techniques, BCTs) are related to intervention effectiveness. A systematic search of randomised or cluster randomised controlled trials with outcome measures of PA and/or SB rendered 10 results. Risk of bias was assessed using the Cochrane risk of bias tool. Intervention content was coded using Behaviour Change Technique Taxonomy v1. Seven out of 10 studies reported significant increases in PA. Effects were generally small and short-term (Cohen's d ranged from 0.132 to 0.659). Two out of four studies that measured SB reported significant reductions in SB. Interventions that increased PA included a higher number of BCTs, specific BCTs (e.g., goal setting, action planning and self-monitoring), and were delivered by research staff. Intervention length and mode of delivery were unrelated to effectiveness. More studies are needed that evaluate long-term intervention effectiveness and target SBs among older adolescents.