Reduce Resource Requirements Research Articles

Low complexity scalable MIMO sphere detection through antenna detection reordering

This paper describes a novel low complexity scalable multiple-input multiple-output (MIMO) detector that does not require preprocessing and the optimal squared l 2-norm computations to achieve good bit error (BER) performance. Unlike existing detectors such as Flexsphere that use preprocessing before MIMO detection to improve performance, the proposed detector instead performs multiple search passes, where each search pass detects the transmit stream with a different permuted detection order. In addition, to reduce the number of multipliers required in the design, we use l 1-norm in place of the optimal squared l 2-norm. To ameliorate the BER performance loss due to l 1-norm, we propose squaring then scaling the l 1-norm. By changing the number of parallel search passes and using norm scaling, we show that this design achieves comparable performance to Flexsphere with reduced resource requirement or achieves BER performance close to exhaustive search with increased resource requirement.

Scalable Lookahead Regular Expression Detection System for Deep Packet Inspection

Regular expressions (RegExes) are widely used, yet their inherent complexity often limits the total number of RegExes that can be detected using a single chip for a reasonable throughput. This limit on the number of RegExes impairs the scalability of today's RegEx detection systems. The scalability of existing schemes is generally limited by the traditional detection paradigm based on per-character-state processing and state transition detection. The main focus of existing schemes is on optimizing the number of states and the required transitions, but not on optimizing the suboptimal character-based detection method. Furthermore, the potential benefits of allowing out-of-sequence detection, instead of detecting components of a RegEx in the order of appearance, have not been explored. Lastly, the existing schemes do not provide ways to adapt to the evolving RegExes. In this paper, we propose Lookahead Finite Automata (LaFA) to perform scalable RegEx detection. LaFA requires less memory due to these three contributions: 1) providing specialized and optimized detection modules to increase resource utilization; 2) systematically reordering the RegEx detection sequence to reduce the number of concurrent operations; 3) sharing states among automata for different RegExes to reduce resource requirements. Here, we demonstrate that LaFA requires an order of magnitude less memory compared to today's state-of-the-art RegEx detection systems. Using LaFA, a single-commodity field programmable gate array (FPGA) chip can accommodate up to 25n 000 (25 k) RegExes. Based on the throughput of our LaFA prototype on FPGA, we estimate that a 34-Gb/s throughput can be achieved.

Modeling industrial centrifugation of mammalian cell culture using a capillary based scale‐down system

Continuous-flow centrifugation is widely utilized as the primary clarification step in the recovery of biopharmaceuticals from cell culture. However, it is a challenging operation to develop and characterize due to the lack of easy to use, small-scale, systems that can be used to model industrial processes. As a result, pilot-scale continuous centrifugation is typically employed to model large-scale systems requiring a significant amount of resources. In an effort to reduce resource requirements and create a system which is easy to construct and utilize, a capillary shear device, capable of producing energy dissipation rates equivalent to those present in the feed zones of industrial disk stack centrifuges, was developed and evaluated. When coupled to a bench-top, batch centrifuge, the capillary device reduced centrate turbidity prediction error from 37% to 4% compared to using a bench-top centrifuge alone. Laboratory-scale parameters that are analogous to those routinely varied during industrial-scale continuous centrifugation were identified and evaluated for their utility in emulating disk stack centrifuge performance. The resulting relationships enable bench-scale process modeling of continuous disk stack centrifuges using an easily constructed, scalable, capillary shear device coupled to a typical bench-top centrifuge.

The effect of implementation intentions on prospective memory performance across the lifespan

AbstractDifferences in the amount and availability of cognitive resources may be responsible for age‐related differences in event‐based prospective memory tasks. We hypothesised that a manipulation which reduces resource requirements by enhancing automatic processing will reduce age differences. Implementation intentions are assumed to satisfy this requirement. We tested a total of 563 participants, 185 adolescents, 193 young adults and 185 older adults in order to investigate whether providing participants with implementation intention instructions would improve performance, whether any improvement would vary with age, and whether it would affect the prospective component or the retrospective component. The results showed a benefit of implementation intentions for older adults, but not for adolescents and for young adults. Separate analyses for the prospective and the retrospective components revealed that this effect was based mainly on a performance facilitation of the prospective component. These results suggest that implementation intentions provide a means to reduce age differences in prospective memory. Copyright © 2009 John Wiley & Sons, Ltd.

Initial Laparoscopic Basic Skills Training Shortens the Learning Curve of Laparoscopic Suturing and Is Cost-Effective

Laparoscopic suturing is an advanced skill that is difficult to acquire. Simulator-based skills curricula have been developed that have been shown to transfer to the operating room. Currently available skills curricula need to be optimized. We hypothesized that mastering basic laparoscopic skills first would shorten the learning curve of a more complex laparoscopic task and reduce resource requirements for the Fundamentals of Laparoscopic Surgery suturing curriculum. Medical students (n = 20) with no previous simulator experience were enrolled in an IRB-approved protocol, pretested on the Fundamentals of Laparoscopic Surgery suturing model, and randomized into 2 groups. Group I (n = 10) trained (unsupervised) until proficiency levels were achieved on 5 basic tasks; Group II (n = 10) received no basic training. Both groups then trained (supervised) on the Fundamentals of Laparoscopic Surgery suturing model until previously reported proficiency levels were achieved. Two weeks later, they were retested to evaluate their retention scores, training parameters, instruction requirements, and cost between groups using t-test. Baseline characteristics and performance were similar for both groups, and 9 of 10 subjects in each group achieved the proficiency levels. The initial performance on the simulator was better for Group I after basic skills training, and their suturing learning curve was shorter compared with Group II. In addition, Group I required less active instruction. Overall time required to finish the curriculum was similar for both groups; but the Group I training strategy cost less, with a savings of $148 per trainee. Teaching novices basic laparoscopic skills before a more complex laparoscopic task produces substantial cost savings. Additional studies are needed to assess the impact of such integrated curricula on ultimate educational benefit.

A Perceptual Comparison of Empirical and Predictive Region-of-Interest Video

When viewing multimedia presentations, a user only attends to a relatively small part of the video display at any one point in time. By shifting allocation of bandwidth from peripheral areas to those locations where a user's gaze is more likely to rest, attentive displays can be produced. Attentive displays aim to reduce resource requirements while minimizing negative user perception-understood in this paper as not only a user's ability to assimilate and understand information but also his/her subjective satisfaction with the video content. This paper introduces and discusses a perceptual comparison between two region-of-interest display (RoID) adaptation techniques. A RoID is an attentive display where bandwidth has been preallocated around measured or highly probable areas of user gaze. In this paper, video content was manipulated using two sources of data: empirical measured data (captured using eye-tracking technology) and predictive data (calculated from the physical characteristics of the video data). Results show that display adaptation causes significant variation in users' understanding of specific multimedia content. Interestingly, RoID adaptation and the type of video being presented both affect user perception of video quality. Moreover, the use of frame rates less than 15 frames per second, for any video adaptation technique, caused a significant reduction in user perceived quality, suggesting that although users are aware of video quality reduction, it does impact level of information assimilation and understanding. Results also highlight that user level of enjoyment is significantly affected by the type of video yet is not as affected by the quality or type of video adaptation-an interesting implication in the field of entertainment.

A novel portable multimedia QoS monitor: independent and high efficiency

AbstractIn this paper, a novel multimedia QoS monitor, p3m (Portable MultiMedia Monitor), is presented. The main function of p3m is data package analysis and statistics. Breaking through the conventional method, this new QoS monitor moves jobs into kernel space, by which to meet the real‐time requirements of multimedia services. With the development of broadband Internet, more and more heterogeneous multimedia services and protocols have been widely deployed. As known, there are two traditional QoS monitors. One is server‐based, depending on the specific multimedia server, such as Helix. Another is tcpdump‐based, e.g. mmdump, which can measure the nature of multimedia traffic merely. However, it is still difficult to monitor the QoS of multimedia networks by these two traditional strategies. To resolve the problems, our new system adopts MMPM (MultiMedia Packages Management) mechanism which can make monitor tool become server‐independent and monitor the multimedia packets by preference, thus greatly reducing resource requirements with offering high performance. This paper describes the design and implementation of p3m and demonstrates one instance of its utility in monitoring the QoS of RTSP with Helix Server. The evaluation of p3m is also presented in this paper. Copyright © 2009 John Wiley & Sons, Ltd.

FPGA-Based Intrusion Detection System for 10 Gigabit Ethernet

The present paper describes an implementation of an intrusion detection system (IDS) on an FPGA for 10 Gigabit Ethernet. The system includes an exact string matching circuit for 1,225 Snort rules on a single device. A number of studies have examined string matching circuits for IDS. However, implementing a circuit that processes a large rule set at high throughput is difficult. In a previous study, we proposed a method for generating an NFA-based string matching circuit that has expandability of processing data width and drastically reduced resource requirements. In the present paper, we implement an IDS circuit that processes 1,225 Snort rules at 10 Gbps with a single Xilinx Virtex-II Pro xc2vp-100 using the NFA-based method. The proposed circuit also provides packet filtering for an intrusion protection system (IPS). In addition, we developed a tool for automatically generating the Verilog HDL source code of the IDS circuit from a Snort rule set. Using the FPGA and the IDS circuit generator, the proposed system is able to update the matching rules corresponding to new intrusions and attacks. We implemented the IDS circuit on an FPGA board and evaluated its accuracy and throughput. As a result, we confirmed in a test that the circuit detects attacks perfectly at the wire speed of 10 Gigabit Ethernet.

The island rule: made to be broken?

The island rule is a hypothesis whereby small mammals evolve larger size on islands while large insular mammals dwarf. The rule is believed to emanate from small mammals growing larger to control more resources and enhance metabolic efficiency, while large mammals evolve smaller size to reduce resource requirements and increase reproductive output. We show that there is no evidence for the existence of the island rule when phylogenetic comparative methods are applied to a large, high-quality dataset. Rather, there are just a few clade-specific patterns: carnivores; heteromyid rodents; and artiodactyls typically evolve smaller size on islands whereas murid rodents usually grow larger. The island rule is probably an artefact of comparing distantly related groups showing clade-specific responses to insularity. Instead of a rule, size evolution on islands is likely to be governed by the biotic and abiotic characteristics of different islands, the biology of the species in question and contingency.

Researching “Back Home”

The challenges facing international management researchers conducting research in foreign contexts are increasingly well understood. However, for a growing group of researchers, the problem is very different: Rather than being foreign researchers researching in an unfamiliar context, they are insiders conducting research in their own cultural context for publication in international journals. In this article, the authors draw on their own experiences and on the literature on autoethnography to illustrate the strengths and challenges of researching “back home.” In particular, they argue that autoethnographic approaches have four important strengths— ease of access, reduced resource requirements, ease of establishing trust and rapport, and reduced problems with translation—but at the same time pose three important challenges— lack of critical distance, role conflict, and the limits of serendipity.

Feedforward Neural Network Implementation in FPGA Using Layer Multiplexing for Effective Resource Utilization

This paper presents a hardware implementation of multilayer feedforward neural networks (NN) using reconfigurable field-programmable gate arrays (FPGAs). Despite improvements in FPGA densities, the numerous multipliers in an NN limit the size of the network that can be implemented using a single FPGA, thus making NN applications not viable commercially. The proposed implementation is aimed at reducing resource requirement, without much compromise on the speed, so that a larger NN can be realized on a single chip at a lower cost. The sequential processing of the layers in an NN has been exploited in this paper to implement large NNs using a method of layer multiplexing. Instead of realizing a complete network, only the single largest layer is implemented. The same layer behaves as different layers with the help of a control block. The control block ensures proper functioning by assigning the appropriate inputs, weights, biases, and excitation function of the layer that is currently being computed. Multilayer networks have been implemented using Xilinx FPGA "XCV400hq240". The concept used is shown to be very effective in reducing resource requirements at the cost of a moderate overhead on speed. This implementation is proposed to make NN applications viable in terms of cost and speed for online applications. An NN-based flux estimator is implemented in FPGA and the results obtained are presented.

The Application of the Six Sigma Program for the Quality Management of the PACS

We implemented a Six Sigma-based quality management program for the PACS to improve the quality of and lessen the necessary resources for its management. With the Six Sigma-based PACS quality management program, we were able to reduce resource requirements while maintaining quality.

Pooling samples within microarray studies: a comparative analysis of rat liver transcription response to prototypical toxicants

Combining or pooling individual samples when carrying out transcript profiling using microarrays is a fairly common means to reduce both the cost and complexity of data analysis. However, pooling does not allow for statistical comparison of changes between samples and can result in a loss of information. Because a rigorous comparison of the identified expression changes from the two approaches has not been reported, we compared the results for hepatic transcript profiles from pooled vs. individual samples. Hepatic transcript profiles from a single-dose time-course rat study in response to the prototypical toxicants clofibrate, diethylhexylphthalate, and valproic acid were evaluated. Approximately 50% more transcript expression changes were observed in the individual (statistical) analysis compared with the pooled analysis. While the majority of these changes were less than twofold in magnitude ( approximately 80%), a substantial number were greater than twofold (approximately 20%). Transcript changes unique to the individual analysis were confirmed by quantitative RT-PCR, while all the changes unique to the pooled analysis did not confirm. The individual analysis identified more hits per biological pathway than the pooled approach. Many of the transcripts identified by the individual analysis were novel findings and may contribute to a better understanding of molecular mechanisms of these compounds. Furthermore, having individual animal data provided the opportunity to correlate changes in transcript expression to phenotypes (i.e., histology) observed in toxicology studies. The two approaches were similar when clustering methods were used despite the large difference in the absolute number of transcripts changed. In summary, pooling reduced resource requirements substantially, but the individual approach enabled statistical analysis that identified more gene expression changes to evaluate mechanisms of toxicity. An individual animal approach becomes more valuable when the overall expression response is subtle and/or when associating expression data to variable phenotypic responses.

05/00535 Recycling for sustainability — a long run perspective?: Kuhn, T. et al. International Journal of Global Environmental Issues, 2003, 3, (3), 339–355

In our paper we analyse the prospects for sustainable growth offered by recycling promoting environmental policies where the main objective of the government is to assure for sustainability in the sense of a non deteriorating state of the environment. The environment is important for economic production in a twofold way: firstly, it supplies resources as inputs for the production process and secondly, it serves as a sink for all kinds of waste products generated by economic activities. It is shown that in the absence of environmental policy the overexploitation of the renewable resource stock and the dumping of waste will drive nature beyond the limits of its assimilative and regenerative capacity. Therefore we focus on these phenomena by modelling on the one hand recycling processes that decrease the flow of waste to the environment and considering on the other hand requirements for a sustainable extraction of raw materials. Hence, by including the intention to spare resources and the aim of reducing waste we deal with an input problem - sometimes referred to as the primary problem - and an output problem - referred to as the secondary problem. Both problems can be considered to have local, regional and global impacts. For example reduced resource requirements might decrease the dependency of resource-importing countries (local or regional effect) and will also help to maintain the supply of resources in all world regions (global effect). Alternatively consider the example of a reduction in the combustion of waste which is due to an increase in recycling. The reduction will cause the mitigation of local and regional air pollution as well as of global warming causing emissions of CO 2. Hence, one far-reaching policy additionally induces ancillary benefits on different geographical levels. We use the framework of an endogenous growth model where waste is generated as an undesired byproduct in the production of the desired output. Nature is assumed to have a certain regenerative capability which depends on the state of the environment. Furthermore, environmental quality is negatively affected by the amount of waste dumped and the amount of resources extracted. The amount of dumped waste can be reduced by recycling firms which process the waste and sell it to the intermediate sector where it serves as substitute for natural resources as an input in production. We show that balanced sustainable growth is only possible if governmental policy ensures a recycling rate of unity. By reviewing the debate on complete recycling, we finally discuss this result from an ecological economics point of view. It is shown that the feasibility of complete recycling depends critically on the nature of wastes, a sufficient storing space for wastes and the availability of sufficient energy.

Recycling for sustainability - a long run perspective?

In our paper, we analyse the prospects for sustainable growth offered by recycling promoting environmental policies where the main objective of the government is to assure for sustainability in the sense of a non deteriorating state of the environment. The environment is important for economic production in a twofold way: firstly, it supplies resources as inputs for the production process and, secondly, it serves as a sink for all kinds of waste products generated by economic activities. It is shown that in the absence of environmental policy the overexploitation of the renewable resource stock and the dumping of waste will drive nature beyond the limits of its assimilative and regenerative capacity. Therefore, we focus on these phenomena by modelling on the one hand recycling processes that decrease the flow of waste to the environment and considering on the other hand requirements for a sustainable extraction of raw materials. Hence, by including the intention to spare resources and the aim of reducing waste, we deal with an input problem - sometimes referred to as the primary problem - and an output problem - referred to as the secondary problem. Both problems can be considered to have local, regional and global impacts. For example, reduced resource requirements might decrease the dependency of resource-importing countries (local or regional effect) and will also help to maintain the supply of resources in all world regions (global effect). Alternatively consider the example of a reduction in the combustion of waste which is due to an increase in recycling. The reduction will cause the mitigation of local and regional air pollution as well as of global warming causing emissions of CO2. Hence, one far-reaching policy additionally induces ancillary benefits on different geographical levels. We use the framework of an endogenous growth model where waste is generated as an undesired byproduct in the production of the desired output. Nature is assumed to have a certain regenerative capability which depends on the state of the environment. Furthermore, environmental quality is negatively affected by the amount of waste dumped and the amount of resources extracted. The amount of dumped waste can be reduced by recycling firms which process the waste and sell it to the intermediate sector where it serves as substitute for natural resources as an input in production. We show that balanced sustainable growth is only possible if governmental policy ensures a recycling rate of unity. By reviewing the debate on complete recycling, we finally discuss this result from an ecological economics point of view. It is shown that the feasibility of complete recycling depends critically on the nature of wastes, a sufficient storing space for wastes and the availability of sufficient energy.

무선 단말기를 위한 웹 페이지의 자동 재구성

Recently, with the wide spread of the Internet and development of wireless network technology, it has now become possible to access web pages anytime, anywhere through devices with small display such as PDA But, since most existing web pages are optimized for desktop computers, browsing web pages on the small screen through wireless network requires more scrolling and longer loading time. In this paper, we propose a page reconstruction scheme called PageMap to make it feasible to navigate existing web pages through small screen devices even on the wireless connection. Reconstructed pages reduce the file and page size and thus eventually reduce resource requirements. We have Implemented a prototype system and performed several experiments for typical web sites. We report some of the results.

Connection-dependent threshold model: a generalization of the Erlang multiple rate loss model

In this paper first, we review two extensions of the Erlang multi-rate loss model (EMLM), whereby we can assess the call-level quality-of-service (QoS) of ATM networks. The call-level QoS assessment in ATM networks remains an open issue, due to the emerged elastic services. We consider the coexistence of ABR service with QoS guarantee services in a VP link and evaluate the call blocking probability (CBP), based on the EMLM extensions. In the first extension, the retry models, blocked calls can retry with reduced resource requirements and increased arbitrary mean residency requirements. In the second extension, the threshold models, for blocking avoidance, calls can attempt to connect with other than the initial resource and residency requirements which are state dependent. Secondly, we propose the connection-dependent threshold model (CDTM), which resembles the threshold models, but the state dependency is individualized among call-connections. The proposed CDTM not only generalizes the existing threshold models but also covers the EMLM and the retry models by selecting properly the threshold parameters. Thirdly, we provide formulas for CBP calculation that incorporate bandwidth/trunk reservation schemes, whereby we can balance the grade-of-service among the service-classes. Finally, we investigate the effectiveness of the models applicability on ABR service at call set-up. The retry models can hardly model the behavior of ABR service, while the threshold models perform better than the retry models. The CDTM performs much better than the threshold models; therefore we propose it for assessing the call-level performance of ABR service. We evaluate the above-mentioned models by comparing each other according to the resultant CBP in ATM networks. For the models validation, results obtained by the analytical models are compared with simulation results.

An Assessment of Larval Fish Density and Assemblage Structure within Mid-Channel and Backwater Habitats in a Mississippi Stream

ABSTRACT We investigated larval fish density and assemblage structure in mid-channel and backwater areas of Luxapallila Creek, Mississippi to better understand larval fish distribution across these two stream habitats. Our results showed backwater and mid-channel habitats not to differ with respect to total larval fish density, but rather in how larval fish taxa were apportioned across habitats. This research suggests stream alterations that reduce backwater habitats, which has occurred in Luxapallila Creek, may affect fish assemblage structure by reducing resource requirements of some fish larvae.

The influence of body mass, climate, and distribution on the energetics of South Pacific pigeons

Rate of metabolism and temperature regulation were studied in 16 species of South Pacific pigeons, which constitute 13 fruit-eaters, 1 seed-eater, 1 fruit/nut-eater, and 1 fruit/leaf-eater; 14 tropical and two temperate species; and ten mainland and six intermediate- or small-island species. The data presented here and those from 11 additional columbids indicate in an analysis of covariance that log10 basal rate of metabolism is correlated with log10 body mass (P≤0.0001), distribution (P=0.0023), and climate (P=0.0016). These factors account for 94.3% of the variation in log10 basal rate of metabolism. In this analysis the lowest basal rates, corrected for body mass, are found in tropical pigeons living on small oceanic islands, whereas the highest basal rates are found in temperate species living on continents. The reduction of basal rate in large columbids facilitates their long-term persistence on small islands characterized by a limited resource base and unstable weather. Some small-island specialists have a smaller mass than their continental relatives, which further reduces resource requirements. The question whether a reduction in basal rate occurs in small columbids on small islands is unresolved. Log10 minimal thermal conductance is apparently correlated only with log10 body mass (P≤0.0001); r2=89.4%. The mean nocturnal body temperature of columbids is 39.7°C.

Mmdump

Internet multimedia traffic is increasing as applications like streaming media and packet telephony grow in popularity. It is important to monitor the volume and characteristics of this traffic, particularly because its behavior in the face of network congestion differs from that of the currently dominant TCP traffic. To monitor traffic on a high-speed link for extended periods, it is not practical to blindly capture all packets that traverse the link. We present mmdump , a tool that parses messages from RTSP, H.323 and similar multimedia session control protocols to set up and tear down packet filters as needed to gather traces of multimedia sessions. Unlike tcpdump, dynamic packet filters are necessary because these protocols dynamically negotiate TCP and UDP port numbers to carry the media content. Our tool captures only packets of interest for optional storage and further analysis, thus greatly reducing resource requirements. This paper presents the design and implementation of mmdump and demonstrates its utility in monitoring live RTSP and H.323 traffic on a commercial IP network. The preliminary results obtained from these measurements are presented.