HDL modeling for analysis and optimization of asynchronous controllers

Journal ArticleWe propose a simulation-based technique for analysis and optimization of extended burst-mode (XBM) asynchronous controllers. In asynchronous controllers of this sort, timing information on control signals is significant both for performance enhancement and timing validation. Timing information, specifically information about relative signal arrival times, helps us improve the controller's response time and to detect delay faults within controllers in the early synthesis stage. If the timing information of the controller's environment is also known, we can use this information to identify fundamental mode violations. Our approach uses stochastic simulation of HDL programs derived from the original XBM specifications to gather information about signal timing and long-term transition probabilities

Self-timed circuits using DCVSL semi-bundled delay wrappers

Journal ArticleWe present a technique for generating robust self-timed completion signals for general dynamic datapath circuits. The wrapper circuit is based on our previous domino semi-bundled delay (SBD) circuits, but uses DCVSL circuits in the wrapper for higher performance. We describe the basic SBD-DCVSL building blocks in the template with respect to their circuit structures and operational behavior. These DCVSL SBD circuits show better performance, exhibit reduced overhead, and require reduced operating margins for the matched delay compared with the domino version. The DCVSL wrapper can also identify a class of delay faults in the data path

Self-timed design with dynamic domino circuits

Journal ArticleWe introduce a simple hierarchical design technique for building high-performance self-timed components using dynamic domino-style circuits. This technique is useful for building handshaking style functional blocks and for self-timed data path components. We wrap the dynamic domino circuit in a wrapper that communicates using a request/acknowledge protocol and mediates the precharge/ evaluate cycle of the dynamic logic. We apply standard bundled delay matching for completion detection but add an early completion feature that can signal completion if function validity can be determined from the output value. The circuit overhead required for this early-acknowledge feature is relatively small, but can provide measurable speedup in some situations. We call this approach semi-bundled delay (SBD)

Work-related correlates of occupational sitting in a diverse sample of employees in Midwest metropolitan cities

The worksite serves as an ideal setting to reduce sedentary time. Yet little research has focused on occupational sitting, and few have considered factors beyond the personal or socio-demographic level. The current study i) examined variation in occupational sitting across different occupations, ii) explored whether worksite level factors (e.g., employer size, worksite supports and policies) may be associated with occupational sitting. Between 2012 and 2013, participants residing in four Missouri metropolitan areas were interviewed via telephone and provided information on socio-demographic characteristics, schedule flexibility, occupation, work related factors, and worksite supports and policies. Occupational sitting was self-reported (daily minutes spent sitting at work), and dichotomized. Occupation-stratified analyses were conducted to identify correlates of occupational sitting using multiple logistic regressions. A total of 1668 participants provided completed data. Those employed in business and office/administrative support spent more daily occupational sitting time (median 330 min) compared to service and blue collar employees (median 30 min). Few worksite supports and policies were sitting specific, yet factors such as having a full-time job, larger employer size, schedule flexibility, and stair prompt signage were associated with occupational sitting. For example, larger employer size was associated with higher occupational sitting in health care, education/professional, and service occupations. Work-related factors, worksite supports and policies are associated with occupational sitting. The pattern of association varies among different occupation groups. This exploratory work adds to the body of research on worksite level correlates of occupational sitting. This may provide information on priority venues for targeting highly sedentary occupation groups

Photo-patternable gelatin as protection layers in surface micromachinings

This paper describes a newly developed low-temperature photo-patternable Gelatin technology that is useful to produce a thick (greater than 10 microns) Gelatin protecting and strengthening layer for weak MEMS micro-structures. Example demonstrated here is the Gelatin process integrated with the Parylene MEMS technology. What is reported here is the complete processing details and formulae that allow anyone to use Gelatin like photo-resist. We find that it is a chemical-resistant and mechanical-robust material for MEMS applications

Tree Ring Characteristics of 30-Year-Old Swietenia Macrophylla Plantation Trees

Ring characteristics of mahogany (Swietenia macrophylla K.) plantation trees grown in Taiwan were explored. Significant differences in average ring width (RW) and ring density (RD) occurred among three tree-diameter classes and three radial stages of ring numbers. RW in the radial direction decreased from the pith outward to the bark and followed a distinctive three-stage variation pattern (juvenile, transition, and mature zones). RD in the radial direction increased slowly from the pith outward to the bark. Wider tree rings and lower density are associated with juvenile wood close to the pith, whereas narrower tree rings and higher density are typical for mature wood outward toward the bark. RD in overtopped trees was higher than that in dominant trees. However, RW in dominant trees was wider than that in intermediate and overtopped trees. Earlywood density, latewood density, maximum density, and minimum density were the most important factors determining overall RD. There was a weak relationship between RW and RD, indicating that it is unlikely for growth rates of mahogany plantation trees to have a significant impact on wood density

The Development of Fundamental Movement Skills by Children Aged Six to Nine

Abstract The main purpose of the present study is to elucidate any differences which may exist in the FMSs of children between the ages of six and nine. Purposive sampling was used to recruit a total of 485 participants (244 boys and 241 girls) in Chiayi City and Chiayi County. All of the participants were between the ages of six and nine and had no disabilities or major health problems. Of these, 92 were between the ages of six and seven; 197 were between the ages of seven and eight; and 196 were between the ages of eight and nine. The average age was seven years and eight months. The main research tool used in this study was the Test of Gross Motor Development-2 (TGMD-2). There was a significant difference in both overall object control skills (t = 9.08, p < .001) and overall performance (t = 5.45, p < .001), with the boys performing better than the girls in both overall object control skills (M = 31.48 ＞ M = 20.29) and overall performance (M = 56.84 ＞ M = 52.47). Significant differences were also found for overall locomotor skills (F = 12.29, p < .001), overall object control skills (F = 12.81, p < .001), and overall FMSs (F = 20.44, p < .001). For locomotor skills the Scheffé post hoc test revealed that those aged eight and nine performed better than those aged between six and eight, and that those aged between seven and eight performed better than those aged between six and seven. For object control skills and overall FMSs the Scheffé post hoc test revealed that those aged between eight and nine performed better than those aged between six and eight. Thus it would be desirable for physical education teachers at elementary schools to have girls participate in a variety of ball games, and also to encourage girls to engage in simple catching, throwing, and dribbling activities after school. In sum, schools need to provide a variety of movement activities which students find interesting, and also encourage students to participate in sports after class and outside of school

Marching velocity of capillary meniscuses in microchannels

[[abstract]]This paper describes a new method and an analytical model for characterizing the surface energy inside a microchannel using the measurement of the marching velocity of a capillary meniscus. This method is based on the fact that surface tension of a liquid meniscus in a hydrophilic case produces pressure to pull liquid into the channel and the velocity of the meniscus is related to the surface energy. Both Parylene and silicon nitride microchannels with different surface conditions were fabricated to perform the liquid-filling experiments. It is shown that our model agrees well with the data and this is a valid method.[[conferencetype]]國際[[conferencedate]]20020120~20020124[[iscallforpapers]]Y[[conferencelocation]]Las Vegas, NV, US