A Comparison of Protocols for Updating Location Information

Detailed location information of mobile objects, for example that of a user with a mobile computer or phone, is an important input for many location-aware applications. However, constantly updating the location information for thousands of mobile objects is not feasible. Therefore, special update protocols for location information are required that transmit the information as efficiently as possible, that is requiring only few update messages, while still being effective in returning the location information with the desired accuracy. Different classes of such update protocols are described in this paper and a new combined protocol is proposed. To be able to compare their effectiveness and efficiency, we present an analysis for the minimum and average resulting accuracy of the location information in comparison with the number of messages transmitted. We also present the results of simulations that we have performed to back up our analysis.     

Energy-efficient hybrid coherence protocol for multicore processors

In multicore processors, a cache coherence protocol is used for maintaining the data coherence in private caches. Traditional snoop-based protocols used broadcasting messages for maintaining data coherence to result in many tag comparisons in private caches. However, the use of broadcasting messages consumes a considerable amount of energy as well as execution time because of tag comparisons. In this paper, an energy-efficient hybrid coherence protocol (EEHCP) is proposed to reduce energy consumption for maintaining the data coherence of private caches by reducing the amount of broadcasting messages and tag comparisons. According to the simulation results, the proposed EEHCP consumes 27, 18, and 46% less energy than the SFT (snoop filter table) protocol, the snoop-based protocol with the hybrid write strategy, and the traditional snoop-based protocol with MESI, and 18, 17, and 32% less execution time than these three protocols, respectively.     

Configurable Network Processing for Mobile Agents on the Internet

This paper presents a framework for building and deploying protocols for migrating mobile agents over the Internet. The framework enables network protocols for agent migration to be naturally implemented within mobile agents and then dynamically deployed at remote hosts by migrating the agents that perform the protocols. It is built on a hierarchical mobile agent system, called MobileSpaces, and several protocols for migrating agents for managing cluster computing systems have been designed and implemented based on the framework. This paper describes the framework and its prototype implementation, which uses Java as both the implementation language and the protocol development language.     

Exploiting application buffer reuse to improve MPI small message transfer protocols over RDMA-enabled networks

To avoid the memory registration cost for small messages in MPI implementations over RDMA-enabled networks, message transfer protocols involve a copy to intermediate buffers at both sender and receiver. In this paper, we propose to eliminate the send-side copy when an application buffer is reused frequently. We show that it is more efficient to register the application buffer and use it for data transfer. The idea is examined for small message transfer protocols in MVAPICH2, including RDMA Write and Send/Receive based communications, one-sided communications and collectives. The proposed protocol adaptively falls back to the current protocol when the application does not frequently use its buffers. The performance results over InfiniBand indicate up to 14% improvement for single message latency, close to 20% improvement for one-sided operations and up to 25% improvement for collectives. In addition, the communication time in MPI applications with high buffer reuse is improved using this technique.     

Simulative performance analysis of gossip failure detection for scalable distributed systems

Three protocols for gossip-based failure detection services in large-scale heterogeneous clusters are analyzed and compared. The basic gossip protocol provides a means by which failures can be detected in large distributed systems in an asynchronous manner without the limits associated with reliable multicasting for group communications. The hierarchical protocol leverages the underlying network topology to achieve faster failure detection. In addition to studying the effectiveness and efficiency of these two agreement protocols, we propose a third protocol that extends the hierarchical approach by piggybacking gossip information on application-generated messages. The protocols are simulated and evaluated with a fault-injection model for scalable distributed systems comprised of clusters of workstations connected by high-performance networks, such as the CPlant system at Sandia National Laboratories. The model supports permanent and transient node and link failures, with rates specified at simulation time, for processors functioning in a fail-silent fashion. Through high-fidelity, CAD-based modeling and simulation, we demonstrate the strengths and weaknesses of each approach in terms of agreement time, number of gossips, and overall scalability. This revised version was published online in July 2006 with corrections to the Cover Date.     

Self Organized Terminode Routing

We consider the problem of routing in a wide area mobile ad hoc network called Terminode Network. Routing in this network is designed with the following objectives. First, it should scale well in terms of the number of nodes and geographical coverage; second, routing should have scalable mechanisms that cope with the dynamicity in the network due to mobility; and third, nodes need to be highly collaborative and redundant, but, most of all, cannot use complex algorithms or protocols. Our routing scheme is a combination of two protocols called Terminode Local Routing (TLR) and Terminode Remote Routing (TRR). TLR is used to route packets to close destinations. TRR is used to route to remote destinations. The combination of TLR and TRR has the following features: (1) it is highly scalable because every node relies only on itself and a small number of other nodes for packet forwarding; (2) it acts and reacts well to the dynamicity of the network because as a rule multipath routing is considered; and (3) it can be implemented and run in very simple devices because the algorithms and protocols are very simple and based on high collaboration. We performed simulations of the TLR and TRR protocols using the GloMoSim simulator. The simulation results for a large, highly mobile ad hoc environment demonstrate benefits of the combination of TLR and TRR over an existing protocol that uses geographical information for packet forwarding.     

Undescended testis: comparison of two protocols of treatment with human chorionic gonadotropin. Effect on testicular descent and hormonal response

A randomized study of two protocols of human chorionic gonadotropin (hCG) treatment was performed in 183 prepubertal boys between 7 months and 12 years of age: protocol I, in which the boys were given 7 injections of 1,500 IU every other day, and protocol II consisting of 4 injections of 100 IU/kg at 4- to 5-day intervals. In both protocols, by the end of the test, testosterone had risen significantly to values within the normal adult male range. However, the amplitude of the rise was slightly but significantly lower using protocol II (4.08 +/- 2.07 ng/ml) than protocol I (5.16 +/- 2.73 ng/ml). It would thus appear that repetition of the hCG injection at intervals of less than 4 days is unnecessary, and that a total stimulation period of 2-3 weeks is sufficient. Although not correlated with testosterone levels, the success rates for treatment were similar in both protocols and comparable to rates reported in the literature.     

积分系统参与MDS诊断的可行性研究

目的:骨髓增生异常综合征(MDS)是一种起源于造血干细胞,以高风险向急性髓系白血病转化为特点的难治性血细胞质、量异常的异质性疾病。对不明原因血细胞减少或者有巨幼红细胞血症的老年人,如果得不到明确的诊断就不会获得有效的治疗。探讨对伴有不明原因血细胞减少或大红细胞血症患者采用一种积分系统来预测诊断为骨髓增生异常综合征(MDS)的可行性。方法:应用四个因子即年龄≥65,红细胞平均体积(MCV),红细胞分布宽度(RDW),和乳酸脱氢酶(LDH)的一个积分系统来计算诊断MDS的概率。结果:调查了303个病人,他们都因为不明原因的血细胞减少或者大红细胞血症在过去三年(2010~2012)进行了骨髓检查,最终三分之二患者被诊断为MDS,9%为疑似MDS,采用积分系统前后的MDS诊断率分别为12%和48%。结论:此四个因子的积分系统可以用于指导MDS患者的诊断。提高MDS的诊断率,减少不必要的骨髓穿刺,减轻病人的疼痛和医疗费用。     

Proxy based seamless connection management method in mobile cloud computing

Nowadays, complex smartphone applications are developed that support gaming, navigation, video editing, augmented reality, and speech recognition which require considerable computational power and battery lifetime. The cloud computing provides a brand new opportunity for the development of mobile applications. Mobile Hosts (MHs) are provided with data storage and processing services on a cloud computing platform rather than on the MHs. To provide seamless connection and reliable cloud service, we are focused on communication. When the connection to cloud server is increased explosively, each MH connection quality has to be declined. It causes several problems: network delay, retransmission, and so on. In this paper, we propose proxy based architecture to improve link performance for each MH in mobile cloud computing. By proposed proxy, the MH need not keep connection of the cloud server because it just connected one of proxy in the same subnet. And we propose the optimal access network discovery algorithm to optimize bandwidth usage. When the MH changes its point of attachment, proposed discovery algorithm helps to connect the optimal access network for cloud service. By experiment result and analysis, the proposed connection management method has better performance than the 802.11 access method.     

HybridFlood: minimizing the effects of redundant messages and maximizing search efficiency of unstructured peer-to-peer networks

Peer-to-peer systems are important Internet applications. A major portion of Internet traffic belongs to such applications. Flooding search is a basic search scheme for unstructured peer-to-peer networks, where a node must send a query message to all its neighbors when seeking a file (in a file sharing situation). Flooding has no knowledge about network topology and files distribution, thus it offers an attractive method for file discovery in dynamic and evolving networks. Although pure flooding can achieve high coverage but it produces exponentially redundant messages in each hop. Consequently, the growth of redundant messages limits system scalability and causes unnecessary traffic in networks. Besides, flooding has no opportunity to get an advantage of node diversity of participating in unstructured P2P networks. To improve this searching scheme and reduce redundant messages, this paper proposes a novel algorithm named HybridFlood. This algorithm is divided into two steps. The first step follows the flooding with a limited number of hops. In the second step, nosey nodes are selected in each searching horizon. The nosey nodes are nodes which have the most links to other nodes. These nodes maintain the data index of all client nodes. We provided analytical studies for flooding and HybridFlood. The analytical results provided the best threshold point of hop for optimum coverage growth rate and redundant messages in flooding. It also proved in HybridFlood broadcasting messages are cut down at least an order of magnitude. Thus, the proposed algorithm extends the search efficiency by reducing redundant messages in each hop. The simulation experiments validated analytical results.     

Resource Management for Ad-Hoc Wireless Networks with Cluster Organization

Boosted by technology advancements, government and commercial interest, ad-hoc wireless networks are emerging as a serious platform for distributed mission-critical applications. Guaranteeing QoS in this environment is a hard problem because several applications may share the same resources in the network, and mobile ad-hoc wireless networks (MANETs) typically exhibit high variability in network topology and communication quality. In this paper we introduce DYNAMIQUE, a resource management infrastructure for MANETs. We present a resource model for multi-application admission control that optimizes the application admission utility, defined as a combination of the QoS satisfaction ratio. A method based on external adaptation (shrinking QoS for existing applications and later QoS expansion) is introduced as a way to reduce computation complexity by reducing the search space. We designed an application admission protocol that uses a greedy heuristic to improve application utility. For this, the admission control considers network topology information from the routing layer. Specifically, the admission protocol takes benefit from a cluster network organization, as defined by ad-hoc routing protocols such as CBRP and LANMAR. Information on cluster membership and cluster head elections allows the admission protocol to minimize control signaling and to improve application quality by localizing task mapping.     

Improving Health Worker Adherence to Malaria Treatment Guidelines in Papua New Guinea: Feasibility and Acceptability of a Text Message Reminder Service

The aim of this study is to assess whether a text message reminder service designed to support health worker adherence to a revised malaria treatment protocol is feasible and acceptable in Papua New Guinea (PNG). The study took place in six purposively selected health facilities located in the Eastern Highlands Province (EHP) of PNG. Ten text messages designed to remind participants of key elements of the new NMTP were transmitted to 42 health workers twice over a two week period (two text messages per day, Monday to Friday) via the country’s largest mobile network provider. The feasibility and acceptability of the text message reminder service was assessed by transmission reports, participant diaries and group discussions. Findings indicate that the vast majority of text messages were successfully transmitted, participants’ had regular mobile phone access and that most text messages were read most of the time and were considered both acceptable and clinically useful. Nevertheless, the study found that PNG health workers may tire of the service if the same messages are repeated too many times and that health workers may be reluctant to utilize more comprehensive, yet complementary, resources. In conclusion, a text message reminder service to support health worker adherence to the new malaria treatment protocol is feasible and acceptable in PNG. A rigorous pragmatic, effectiveness trial would be justified on the basis of these findings.     

Gossip-Style Failure Detection and Distributed Consensus for Scalable Heterogeneous Clusters

Gossip protocols provide a means by which failures can be detected in large, distributed systems in an asynchronous manner without the limits associated with reliable multicasting for group communications. However, in order to be effective with application recovery and reconfiguration, these protocols require mechanisms by which failures can be detected with system-wide consensus in a scalable fashion. This paper presents three new gossip-style protocols supported by a novel algorithm to achieve consensus in scalable, heterogeneous clusters. The round-robin protocol improves on basic randomized gossiping by distributing gossip messages in a deterministic order that optimizes bandwidth consumption. Redundant gossiping is completely eliminated in the binary round-robin protocol, and the round-robin with sequence check protocol is a useful extension that yields efficient detection times without the need for system-specific optimization. The distributed consensus algorithm works with these gossip protocols to achieve agreement among the operable nodes in the cluster on the state of the system featuring either a flat or a layered design. The various protocols are simulated and evaluated in terms of consensus time and scalability using a high-fidelity, fault-injection model for distributed systems comprised of clusters of workstations connected by high-performance networks.     

Chromatographic comparison of atenolol separation in reaction media on cellulose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase using ultra fast liquid chromatography

Because chiral liquid chromatography (LC) could become a powerful tool to estimate racemic atenolol quantity, excellent enantiomeric separation should be produced during data acquisition for satisfactory observation of atenolol concentrations throughout the racemic resolution processes. Selection of chiral LC column and analytical protocol that fulfill demands of the ultra fast LC analysis is essential. This article describes the characteristics of atenolol chromatographic separation that resulted from different resolution media and analytical protocols with the use of a Chiralcel® OD column. The chromatograms showed quite different characteristics of the separation process. The single enantiomer and racemic atenolol could be recognized by the Chiralcel® OD column in less than 20 min. Symmetrical peaks were obtained; however, several protocols produced peaks with wide bases and slanted baselines. Observations showed that efficient enantioresolution of racemic atenolol was obtained at slow mobile phase flow rate, decreased concentration of amine‐type modifier but increased alcohol content in mobile phase and highest ultraviolet detection wavelength were required. The optimal ultra fast LC protocol enables to reduce and eliminate the peaks of either the atenolol solvent or the buffers and provided the highest peak intensities of both atenolol enantiomers. Chirality 24:356–367, 2012. © 2012 Wiley Periodicals, Inc.     

Prediction bands and intervals for the scapulo-humeral coordination based on the Bootstrap and two Gaussian methods

Quantitative motion analysis protocols have been developed to assess the coordination between scapula and humerus. However, the application of these protocols to test whether a subject's scapula resting position or pattern of coordination is “normal”, is precluded by the unavailability of reference prediction intervals and bands, respectively. The aim of this study was to present such references for the “ISEO” protocol, by using the non-parametric Bootstrap approach and two parametric Gaussian methods (based on Student's T and Normal distributions).     

Corticosterone Assimilation by a Voluntary Oral Administration in Palatable Food to Rats

Drug delivery in research on nonhuman animals in the laboratory is still challenging because it is usually invasive and stressful. Stress-free voluntary oral drug administration in water lacks precise control of dose and timing of substance ingestion. Voluntary oral consumption of corticosterone has been previously successfully applied in mice using oat flakes, but protocols for oral corticosterone administration in rats remain unavailable. This study assessed the effectiveness of voluntary oral administration to rats of a palatable piece of bread soaked with corticosterone that can be rapidly prepared and is reliably dose- and timing-controllable. After three familiarization days, all rats ate the bread within 120 seconds of presentation, irrespective of the presence or absence of corticosterone or vehicle. Corticosterone plasma levels remained at basal levels with consumption of vehicle-containing bread, and they were significantly increased with corticosterone-containing bread. Hence, the method enabled corticosterone bodily assimilation while avoiding stress, making it a possible alternative for invasive and stressful procedures. This article includes a methodological refinement that lessens unnecessary discomfort to laboratory animals and is potentially suitable for acute and chronic protocol studies.     

An Extra Power Saving Scheme for Prolonging Lifetime of Mobile Handset in the 4G Mobile Networks

In the fourth generation or next generation networks, services of non-real-time variable bit rate (NRT-VBR) and best effort (BE) will dominate over 85% of the total traffic in the networks. In this paper, we study the power saving mechanism of NRT-VBR and BE services for mobile handsets (MHs) to prolong their battery lifetime (i.e., the sustained operation duration) in the fourth generation networks. Because the priority of NRT-VBR and BE is lower than that of real-time VBR (RT-VBR) or guaranteed bit rate (GBR) services, we investigate an extended sleep mode for lower priority services (e.g., NRT-VBR and BE) in an MH to conserve the energy. The extended sleep mode is used when the MH wakes up from the sleep mode but it cannot obtain the bandwidth from base station (BS). The proposed mechanism, named extra power saving scheme (EPSS), uses the Markovian queuing model to estimate the extended sleep duration to let MHs conserve their battery energy when the networks traffic is congested. To study the performance of EPSS, an accurate analysis model of energy is presented and validated by taking a series of simulations. Numerical experiments show that EPSS can achieve 43% extra energy conservation at most when downlink resource is saturated. We conclude that the energy of MHs can be conserved further by applying EPSS when the traffic load is saturated. The effect of energy saving becomes more obvious when the portion of NRT-VBR and BE services is greater than that of RT-VBR and GBR services.     

Cascading tripartite binomial classification plans to monitor European red mite (Acari,Tetranychidae) through a season; development and evaluation of a new methodology for pest monitoring

A monitoring protocol that schedules future sample bouts based on the outcome of density classification and expected population growth has been developed and applied to monitoring European red mite (Panonychus ulmi Koch) through a growing season. The monitoring protocol is based on concatenating through time tripartite sequential classification sampling plans that use binomial counts in lieu of complete enumeration. Binomial counts are scored positive when the number of organisms (mites) on a sample unit (leaves) exceeds a tally number. At each sample occasion the monitoring procedure leads to one of three possible decisions; intervene when the density is high, sample at the next sample occasion (after one week) when the density is intermediate, and sample at the second next sample occasion (after two weeks) when the density is low. Evaluation of the monitoring protocol under field conditions showed that the protocol with constituent tally 0 binomial count sampling plans was quite successful in timing intervention at the moment when population densities were about to exceed an established threshold that dictated intervention. The performance of this monitoring protocol and another protocol in which constituent sampling plans used binomial counts with a tally number of 4 were compared using simulation. Sampling plans that used a tally number of 4 were more precise than plans that used a tally number of 0. However, the overall performance of the monitoring protocol based on tally 0 sampling plans did not greatly differ from the monitoring protocol based on tally 4 sampling plans. Simulated performance of the tally 0 protocol was corroborated by field evaluation. The monitoring protocol based on tripartite classification required 30 to 45 percent fewer sample bouts than a protocol based on conventional sequential classification at weekly intervals. The monitoring protocol based on tripartite classification was also better able to schedule intervention when needed compared to a protocol based on conventional classification at two week intervals. Using the tally 0 protocol and current thresholds forP. ulmi, cumulative mite density was kept below 300 mite-days per leaf, which is well below levels regarded damaging. A tally 0 protocol with raised thresholds, developed on the basis of this finding, gave the best simulated performance of all protocols evaluated.     

Multidimensional Human Dynamics in Mobile Phone Communications

In today''s technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today''s information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.