Large Frame Size Research Articles

Decision of mobile devices enabling high throughput and non-high throughput medium access control of 802.11n based on the consideration of energy efficiency

To be compatible with the legacy 802.11, there are two major medium access control (MAC) behaviors, high throughput (HT) and non-high throughput (non-HT), in the 802.11n. In this paper, we analyze and compare the energy efficiencies of different MAC behaviors in 802.11n on the basis of the Bianchi model and our previous works to evaluate the performance of the different MAC behaviors regarding HT and non-HT. Our studies try to provide the decision for the mobile stations to enable the HT of 802.11n or not based on the consideration of energy efficiency. Studies show that owing to the large power consumption in HT, it is not suitable for limited power devices to carry WWW traffics by multiple-input multiple-output transmission because of large overheads of physical layer in the HT mode. However, if large file transmissions by File Transfer Protocol are considered, the energy efficiency in HT MAC can be very high because of the large aggregated frame size. It is especially true when the number of active stations is large because of the decrease in idle listening time by using the techniques applied in HT MAC such as Aggregate MAC Protocol Data Unit and Block-ACK. These characteristics in the HT mode can overwhelm the larger overheads of physical layer compared with that in the non-HT mode when large files are needed to be uploaded. Copyright © 2012 John Wiley & Sons, Ltd.

Analysis and Comparison between the Energy Efficiency of HT and Non-HT MAC in 802.11n

In order to be compatible with the legacy 802.11, there are two major MAC behaviors, High-throughput (HT) and non-high throughput (non-HT) in the 802.11n. In this paper, we analyze and compare the energy efficiencies of different MAC behaviors in 802.11n based on the Bianchi model and our previous works [6] to evaluate the performance of the different MAC behaviors regarding HT and non-HT. Studies show that owing to the large power consumption in HT, it is not suitable for limited power devices to carry WWW traffics by MIMO transmissions. However, if large file transmissions by FTP are considered, the energy efficiency in HT MAC can be very high due to the large aggregated frame size. It is especially true when the number of active stations is large. Our works can indicate the mobile devices with limited battery endurance to reduce the energy consumption by the decision to enable HT mode or not for the transmission of data frames based on the cross-layer integration.

Effects of USDA feeder cattle frame and muscle grades on stocker and feeder cattle performance and profitability

A total of 395 calves (180 ± 25 kg) were purchased from sale barns in Oklahoma and Texas in the fall of 3 consecutive years to measure the effect of USDA feeder cattle frame and muscle grades on performance and profitability. Individual purchase weight and price were recorded, and steers were assigned USDA feeder cattle grades of Large (LG), Medium (MED), or Small (SM) frame size and Number 1 or Number 2 muscle thickness by the same official USDA market graders. Steers were grazed on rye pasture and were then valued by commercial order buyers in frame and muscle grade groups. Muscle grade did not affect (P > 0.60) animal performance or profitability during the grazing phase. Grazing ADG increased linearly (P < 0.001) as frame grade increased, but purchase price was lower (P < 0.001) for SM steers than for MED and LG frame steers, respectively, resulting in greater (P < 0.001) grazing-phase net returns for SM steers. Following finishing on a high-concentrate diet, the lesser total weight gain during finishing of SM steers (P < 0.001) resulted in lesser per animal revenue. Feed and interest costs were also less (P < 0.001) and marbling score greater (P < 0.001) for SM steers, resulting in greater finishing net returns and carcass price. In a post hoc analysis in which frame and muscle grades were reassigned to cattle based on HCW and LM area, only 44% of the cattle remained in their original grade.

Multiple RFID Tags Access Algorithm

One of the main problems that affect the data integrity of passive RFID systems is the collision between the tags. A popular anticollision algorithm which dominates the standards in HF and UHF passive RFID systems is framed slotted Aloha (FSA) and some variations of FSA. Throughput and average time delay of the RFID system which determines the performance/efficiency of the system are reduced rapidly when the number of tags inside the interrogation zone is increased. Using larger frame sizes is not always the solution. This paper discusses and compares the existing protocols, and proposes a variation of FSA, called progressing scanning (PS) algorithm. The PS algorithm divides the tags in the interrogation zone into smaller groups and gives the reader the ability to communicate with each of them. For performance analysis, the PS algorithm was evaluated with the parameters of a typical passive RFID system at 2.5 GHz. The results showed that the PS algorithm can improve the efficiency of the RFID system and provide a reliable solution for cases with a high density of tags in the area (over 800 tags).

Joint Control of Transmit Power and Frame Size for Energy-Optimized Data Transfer in Wireless Sensor Networks

Energy efficiency is one of the most important attributes in sensor network protocols. In sensor nodes, communication related activities consume the major share of battery energy. Therefore, judicious choice of transmit power and frame size are very important to maximize the energy efficiency and hence the lifetime of nodes. While there have been a few recent studies on transmit power control implementation in sensor nodes, no report has thoroughly investigated transmit power control and the effect of its interplay with frame size on nodal energy saving. In this paper, we report our implementation of automatic transmit power control in wireless sensor nodes based on open loop parameters — namely, link layer frame size, and close loop parameters — namely, number of consecutive positive acknowledgments and receive signal strength. Our extensive indoor and outdoor experimental results show that, for low to moderate transmission distances, transmit power control has the energy saving benefit, and the larger the frame size the more the energy saving. At a higher transmission distance or at a more error-prone communication scenario, transmit power control as well as a large frame size are detrimental to energy saving performance. The results from this study could be useful in deciding power control strategies and optimum frame length. key words: implementation studies, automatic transmit power control, frame size control, open loop power control, close loop power control, minimum energy transmission

Control over unreliable networks affected by packet erasures and variable transmission delays

This paper describes a novel control strategy aimed at achieving good performance over an unreliable communication network affected by packet loss and variable transmission delays. The key ingredient in the method described here is to use the large data packet frame size of typical modern communication protocols to transmit control sequences which cover multiple data-dropout and delay scenarios. Stability and performance of the resultant scheme are addressed under nominal networked conditions. Simulations verify that the strategy performs exceptionally well under realistic conditions with noise and unmeasured disturbances.

Effect of heifer frame size on their subsequent reproductive performance and preweaning performance of their calves

The effects of heifer frame size on subsequent performance and the preweaning growth of calves were evaluated using records collected from the Waterburg Estates at Otjiwarongo, Namibia. Based on hip height at 18 months of age, heifers were assigned to three different frame size groups: small (&lt;124 cm), medium (124 to 135 cm), or large (&gt;135 cm). Calving rate (CR), calving date (CD), postnatal calf survival rate (CSR), reproductive efficiency (Sandex), weaning rate (WR), birthweight (BW), weaning weight (WT) and preweaning average daily gain (ADG) were collected from first (n = 830), second (n = 623) and third and greater parity (n = 571) cows. Frame size of heifers significantly influenced (P &lt; 0.001) CR in second and third and greater parity. The postnatal CSR was similar for all frame size and parity groups. WR of large frame size, second-parity cows was less (P &lt; 0.001) than that of small and medium frame size animals. Birthweights of calves born to large frame size animals were significantly higher (P &lt; 0.05) than the small and medium frame size animals. Small frame size animals, as first parity cows, had calves with lower (P &lt; 0.05) WT than those weaned by medium and larger frame size animals. In first parity cows, calves of large frame size had greater ADG (P &lt; 0.05), but in second parity cows the calves from medium frame size (P &lt; 0.05) out performed those of small and large frame size, while calves from third and greater parity cows of medium and larger frame size had greater (P &lt; 0.05) ADG than cows with a small frame size. Male calves were heavier (P &lt; 0.05) at birth, at weaning and grew faster (ADG) than their female counterparts. Due to the later calving dates (P &lt; 0.05), the reproductive efficiency (Sandex) of large frame size at second and third and greater parity groups was lower (P &lt; 0.001). Therefore, selecting cattle for the extensive hot and dry climatic regions of Southern Africa, the recommended cow frame size should be a medium frame.

Queuing Models for Dimensioning Interactive and Streaming Services in High-Speed Downlink Packet Access Networks

We consider modeling the statistical behavior of interactive and streaming traffics in high-speed downlink packet access (HSDPA) networks. Two important applications in these traffic categories are web-browsing (interactive service) and video streaming (streaming service). Web-browsing is characterized by its important sensitivity to delay. Video streaming on the other hand is less sensitive to delay, however, due to its large frame sizes, video traffic is more affected by the packet loss resulting from a limited buffer size at the base station. Taking these characteristics into account, we consider modeling the queuing delay probability density function (PDF) of the Web-browsing traffic, and modeling the queuing buffer size distribution of video streaming traffic. Specifically, we show that the queuing delay of the Web-browsing traffic follows an exponential distribution and that the queuing buffer size of video streaming traffic follows a weighted Weibull distribution. Model fitting based on simulated data is used to provide simple mathematical formulations for the different parameters that characterize the PDFs under consideration. The provided equations could be used, directly, in HSDPA network dimensioning and, as a reference, to satisfy a certain quality of service (QoS).

Complement block coding for reduction in peak-to-average power ratio of OFDM signals

In this article a new coding scheme, complement block coding (CBC), is proposed to reduce the PAPR of OFDM signals. This method utilizes the complement bits that are added to the original information bits, which can effectively reduce the PAPR of OFDM signals with random frame size N and the coding rate R /spl les/ (N - k)/N, where k is a positive integer and k /spl les/ N/2. The performance results obtained with CBC are given and compared with that of some well known schemes, such as simple block coding, modified simple block coding, simple odd parity code, and cyclic coding, for the same purpose. The results show that at the same coding rate 3/4, CBC can achieve almost the same performance as SBC and MSBC, but with lower complexity, and the same performance can be obtained with a higher coding rate using CBC. The PAPR reductions of CBC with coding rate (N - 1)/N are almost the same as with a coding rate less than (N - 1)/N, but almost the twice as these of SOPC when N /spl ges/ 16. Moreover, we can find that PAPR is the lowest for all block codes using CBC with coding rate 3/4. So modified CBC (MCBC) is also proposed and analyzed, combined with the subblock processing technique to make CBC effective for OFDM systems with large frame sizes. The flexibility in coding rate choice and low complexity make the proposed CBC more suitable for random frame size with high coding rate and can also provide error detection.

Complement block coding scheme for reducing peak-to-average power ratio of OFDM systems

A new scheme termed as Complement Block Coding (CBC) technique is proposed to reduce the Peak-to-Average Power Ratio (PAPR) of OFDM signals. Utilizing the complement bits which are added to the original information bits, this method can effectively reduce the PAPR of OFDM systems with random frame size N and the coding rate R≤(N−κ)/N, where κ is a positive integer and κ≤N/2. The performance results obtained with CBC are given and compared with that of some well known schemes, such as Simple Block Coding (SBC), Modified Simple Block Coding (MSBC) and Simple Odd Parity Code (SOPC) for the same purpose. The results show that, at the same coding rate 3/4, the CBC can achieve almost the same performance as SBC, MSBC, but with lower complexity, and that the same performance can be obtained with higher coding rate by using CBC. At the same coding rate (N−1)/N, the PAPR reduction of CBC is almost the twice as that of SOPC when N≥16. Further more, the PAPR reductions with coding rate (N−1)/N are almost the same as that with coding rate less than (N−1)/N, so the proposed scheme CBC is more suitable for the large frame size with high coding rate and can provide error detection.

Blind source separation in frequency domain

A blind source separation method based on cross-correlation in frequency domain is performed in this paper. Firstly, the pseudo-solution is described and possible treatment is proposed. Then the oscillation of the un-mixing matrix is proved to be the basic aspect that degrades the separation performance for larger frame size. Finally, a novel average of frequency bin method is addressed. Simulations are provided to confirm the validity of the method.

On the data reuse and memory bandwidth analysis for full-search block-matching VLSI architecture

This work explores the data reuse properties of full-search block-matching (FSBM) for motion estimation (ME) and associated architecture designs, as well as memory bandwidth requirements. Memory bandwidth in high-quality video is a major bottleneck to designing an implementable architecture because of large frame size and search range. First, the memory bandwidth in ME is analyzed and the problem is solved by exploring data reuse. Four levels are defined according to the degree of data reuse for previous frame access. With the highest level of data reuse, one-access for frame pixels is achieved. A scheduling strategy is also applied to data reuse of the ME architecture designs and a seven-type classification system is developed that can accommodate most published ME architectures. This classification can simplify the work of designers in designing more cost-effective ME architectures, while simultaneously minimizing memory bandwidth. Finally, a FSBM architecture suitable for high quality HDTV video with a minimum memory bandwidth feature is proposed. Our architecture is able to achieve 100% hardware efficiency while preserving minimum I/O pin count, low local memory size, and bandwidth.

Influence of frame size and body condition score on performance of Brahman cattle.

The effects of frame size (FS) and body condition score (BCS) on performance of Brahman cows were evaluated using records collected from 1984 to 1994 at the Subtropical Agricultural Research Station, Brooksville, Florida. Age at puberty (AP), calving rate (CR), calving date (CD), survival rate (SR), weaning rate (WR), birth weight (BWT), weaning weight (WWT), preweaning ADG, and kilograms of calf produced per cow exposed (PPC) were obtained from first- (n = 215), second- (n = 130), and third or greater-parity (n = 267) dams. Based on hip height at 18 mo of age, heifers were assigned to three FS groups: small (115 to 126 cm), medium (127 to 133 cm), or large (134 to 145 cm). Small and medium FS heifers attained puberty at younger (P<.05) ages (633.2+/-12.3 and 626.4+/-12.0 d) than large FS heifers (672.3+/-17.1 d). Calving rate in large FS second-parity dams was 27% less (P<.05) than in small and medium FS dams. In third or greater-parity dams, CR was greater (P<.05) for small FS cows than for medium and large FS cows. Across the three parity groups, CR improved with increasing BCS. Except for the first-parity dams, animals with better fall BCS calved earlier (P<.05). In first-parity dams, SR was less (P<.01) in large (47.9+/-11.0%) than in small (80.7 +/-5.2%) and medium (83.4+/-4.7%) FS groups. Weaning rates of large FS first- and second-parity dams were less (P<.05) than those of small and medium FS dams. Second-parity dams with BCS 3 had lower (P<.05) WR than dams with BCS 4 and 5. Within first- and third or greater-parity dams, BWT of calves born to small FS cows were the lightest, and those born to large FS dams were the heaviest; those born to medium FS dams were intermediate (P<.05). In second-parity dams, BWT of calves of large FS dams were greater (P<.05) than those of small and medium FS dams. In first-parity dams, calves weaned by small FS cows had lower (P<.05) WWT than those weaned by higher FS cows. In the third or greater-parity group, large FS dams weaned heavier calves (P<.05) than other dams. In all parity groups of dams, calves out of large FS cows had greater ADG (P<.05) than those from small and medium FS cows. In first-parity dams, PPC was comparable between small and medium FS dams, but both tended to be greater (P<.10) than PPC of large FS dams. Small and medium FS females reached puberty at an earlier age, calved earlier, and had greater calving, survival, and weaning rates, as well as greater kilograms of calf produced per cow exposed than the large FS females. As the large FS cows matured, they seemed to have overcome the negative effects imposed by FS that were observed at younger ages. Their performance traits were generally all comparable to those of smaller cows once they had reached maturity.

Evaluation of growth curves of Brahman cattle of various frame sizes.

Partial stage and complete life-cycle growth curves of Brahman cattle were obtained for small, medium, and large frame sizes for a herd under grazing conditions in a subtropical environment. Data were grouped into three stages: birth to weaning (stage 1), weaning to 20 mo (males) or 32 mo (females) of age (stage 2), and 32 mo of age to maturity (females only; stage 3). Within each stage, multiplicative growth models were developed for each frame size and sex. Body weight growth on age t was represented as exp(a + bt + ct2) for stages 1 and 2, and as exp(A + B exp(kt)) for stage 3. The effects of sire and progeny within sire were considered in all models. For stages 2 and 3, the effect of season was also included. To obtain complete life-cycle curves, a growth stage-multiplicative model with stages 1 and 2 was defined; stage 3 was also included for females. Due to a 1-mo adaptation period after weaning, a transition stage between stages 1 and 2 was defined and represented by the model exp(a + bt). In stage 1, the shape of the growth curve differed (P < .05) among frame size groups; sex did not affect the shape of the growth curves, but bull calves had heavier (P < .05) weights than heifer calves. In stage 2, the shape of the growth curves did not differ among frame sizes, but BW differed among frame sizes (P < .05) and sex affected (P < .05) the shape of the growth curves. In stage 3, the shape of the growth curves differed (P < .05) among frame sizes. There were sire effects (P < .05) for stages 1 and 2, but sire effects were not significant for stage 3. Season effects were important (P < .05) for stages 1 and 2. These results suggest that variability in growth patterns provides an opportunity to use management and nutrition to improve production efficiency in cattle of different frame sizes.

A practical algorithm for maximum-likelihood HREM image reconstruction

Reconstruction in HREM of the complex wave function at the exit face of a crystal foil out of a focal series of HREM images, and with correction for the microscope's aberrations, can be performed with a variety of algorithms depending on the approximations involved for the HREM image formation. The maximum-a-posteriori (MAP) recursive reconstruction algorithm of Kirkland is the most general one with the full benefit of the effects of non-linear imaging and partial coherence, which are correctly treated in terms of a transmission-cross-coefficient (TCC). However, the routine application of the Kirkland algorithm has thusfar been hampered by its enormous computational demands, especially when large image frame sizes (5122) and a large number of HREM images (≥20) are aimed at. In this paper, we present a modified version of the Kirkland method within a maximum-likelihood (MAL) framework, and with a new numerical implementation yielding a workable algorithm with a much higher computational efficiency.

Comparison of market hog characteristics of pigs selected by feeder pig frame size or current USDA feeder pig grade standards.

Two feeder pig grading systems were tested. Forty-five barrows were selected using current USDA Feeder Pig Grade Standards (U.S. No. 1, No. 2 and No. 3). Additionally, 45 barrows were selected using three frame sizes (large, medium and small). Pigs were slaughtered at 100, 113.5 of 127 kg live weight. Trimmed four lean cuts were separated into soft tissue, skin and bone. The skinless belly and soft tissue from the four lean cuts were ground separately and analyzed chemically. Data from each grading system were analyzed separately in a 3 X 3 factorial plan. Pigs selected using current USDA grade standards differed (P less than .05) for last rib backfat, 10th rib fat depth, longissimus muscle area, percentage of trimmed four lean cuts and USDA carcass grade. In the frame size system, pigs with large frame size had less last rib backfat, less 10th rib fat depth, longer carcasses, higher percentage of four lean cuts and superior USDA carcass grades than pigs with small frame size did (P less than .05). The Bradley and Schumann test of sensitivity showed that selection by frame size was more sensitive than current USDA grade standards for discriminating feeder pig foreleg length, body depth and ham width. In addition, selection by frame size was more sensitive than current USDA grade standards for discriminating carcass length and carcass radius length. No increase in sensitivity (P greater than .10) was noted for carcass composition or growth traits over the current USDA Feeder Pig Grade Standards.

Effects of feeding restricted energy and elevated calcium and phosphorus during growth on gait characteristics of culled sows and those surviving three parities.

Crossbred gilts (n = 288) were weaned at 4 to 5 wk of age and retained through three parities. They were used to determine the effects of feeding restricted energy (ad libitum vs 75% ad libitum) and elevated calcium-phosphorus levels (100 vs 150% of the dietary percentage suggested by NRC, 1979) from weaning to 100 kg of body weight on subsequent sow gait characteristics obtained from 16-mm motion pictures. After 100 kg, all females were fed and managed similarly throughout breeding, gestation and lactation. At 50 and 100 kg body weight and 21 d after weaning, females were filmed from the side and rear as they walked on a treadmill (traveling at the rate of .90 cm/s with zero slope) using two 16-mm Arriflex cameras. Objective measurements were taken from the film by projecting it on a reverse screen. Visual appraisal of structural soundness were scored subjectively for each female at each time period. The front foot pastern angle was correlated positively with structural soundness scores, suggesting that sows with smaller angles (more sloping) were given more desirable soundness scores. Early dietary energy and Ca-P levels did not influence number of sows completing three parities or culled for various reasons, front and hind pastern angles, the angles at the hock and carpal joint or rear view measurements, but sows fed ad libitum to 100 kg had a larger frame size even after three parities. Sows that survived three parities tended to have larger body capacity (girth diameter and width across hams) and smaller front and bind pastern angles and angles of the carpal joint and hock at maximum flex than did culled sows. Structural soundness scores did not differ between culled and surviving sows.

Phenotypic relationships of scrotal circumference to frame size and body weight in performance-tested bulls

The objective of this study was to determine if frame size (height) is related to scrotal circumference. A total of 695 bulls (425 Angus, 65 Hereford, 70 Charolais, 135 Simmentals) were tested for postweaning gain in five stations over a period of 1 to 3 years. Variables examined included hip height, weight and scrotal circumference at beginning and completion of a 140-d feeding period. Correlations among these traits, adjusted for age (7 to 10 months at entry), year, station and management were estimated for each breed. Both height and weight were correlated positively with scrotal circumference at the start and the end of the test period in all four breeds. When height and scrotal circumference were adjusted for weight, correlations were negligible, with the exception of end-of-test values for Charolais bulls (−0.26). Negative correlations were obtained between the scrotal circumference at the start of the test and the change in height during the test after adjustment for weight in Angus bulls (−0.18) and in Charolais bulls (−0.15). These small negative phenotypic relationships indicate that a bull's fertility is not seriously reduced by large frame size at the completion of a feedlot performance test. For maximum fertility in bulls, scrotal circumference needs to be evaluated independently of frame size.

The Performance of Random and Optimal Scheduling in a Time-Multiplex Switch

In a time-multiplex switching system, the incoming traffic must be scheduled to avoid conflict at the switch output (two or more users converging simultaneously upon a single output). Two scheduling algorithms, random scheduling and optimal scheduling, are explored in this paper. Random scheduling is computationally simple, whereas optimal scheduling is currently very difficult. We have found, using a traffic model appropriate for circuit switched traffic that increases of typically 10 to 15 percent in offered load can be obtained through optimal scheduling (as compared to the much simpler random scheduling algorithm). The improvement is a function of the number of time slots (or circuits) per time-multiplexed frame, and falls to zero for both very small and very large frame sizes. Thus, in many circuit switching applications, providing a computationally expensive optimal schedule may not be warranted. This conclusion has important ramifications for both electronic and emerging photonic switching systems since it reduces the importance of the costly design feature of optimal scheduling.

Plasma growth hormone, insulin, glucocorticoids and thyroid hormones in large, medium and small breeds of steers with and without an estradiol implant

Growth hormone secretory patterns and plasma concentrations of insulin, adrenal corticosteroids, thyroxine and triiodothyronine were measured in three types of steers with and without estradiol implants. The three types of cattle were large (Simmental), medium (Limousin) and small (Angus) frame size with medium, low and high propensity to deposit fat. Simmental steers had higher (P<.01) concentrations of growth hormone and lower (P<.01) concentrations of insulin as compared with Angus. Implanting the steers with estradiol increased (P<.01) growth hormone concentrations in all three groups, tended to decrease glucocorticoids and had no effect on insulin or thyroid hormone concentrations. There tended to be less frequent release of growth hormone, with secretory spikes of greater magnitude in the Simmental steers. The implants tended to increase the frequency of release of growth hormone in all three groups.