bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonblocking collectives for scalable Java communications
Authors: Ramos Sabela , Taboada Guillermo L. , Expósito Roberto R. , Touriño Juan 
Published: April 2014

SummaryThis paper presents a Java implementation of the recently published MPI 3.0 nonblocking message passing collectives in order to analyze and assess the feasibility of taking advantage of these operations in shared memory systems using Java. Nonblocking collectives aim to exploit the overlapping between computation and communication for collective operations to increase scalability of message passing codes, as it has been carried out for nonblocking point‐to‐point primitives. This scalability has become crucial not only for clusters but also for shared memory systems because of the current trend of increasing the number of cores per chip, which is leading to the generalization of multi‐core and many‐core processors. Message passing libraries based on remote direct memory access, thread‐based progression, or implementing pure multi‐threading shared memory support could potentially benefit from the lack of imposed synchronization by nonblocking collectives. But, although the distributed memory scenario has been well studied, the shared memory one has not been tackled yet. Hence, nonblocking collectives support has been included in FastMPJ, a Message Passing in Java (MPJ) implementation, and evaluated on a representative shared memory system, obtaining significant improvements because of overlapping and lack of implicit synchronization, and with barely any overhead imposed over common blocking operations. Copyright © 2014 John Wiley & Sons, Ltd.
Design and analysis of an improved smartcard‐based remote user password authentication scheme
Authors: Islam SK Hafizul 
Published: April 2014

SummaryWith the fast development of the Internet and the telecommunication technologies, internet users are carrying out various electronic transactions over internet by means of the authentication protocols. To ensure efficient and robust online transaction, security of authentication protocol turns out to be a great concern nowadays. As a result, smartcard‐based password authentication and session key agreement scheme receives significant attention in recent years. In the literature, various authentication schemes have been proposed by the cryptographic research community. Recently, Li et al. analyze some security weaknesses of the authentication scheme of Chen et al. and propose an enhancement based on the discrete logarithm problem and computational Diffie–Hellman problem. This paper further cryptanalyzes the scheme of Li et al. and identifies various security loopholes and then constructs a modified authentication scheme as a remedy. The security and efficiency evaluations demonstrate that our scheme has more security features and low computation costs than the related schemes. Copyright © 2014 John Wiley & Sons, Ltd.
Development and Control of Multi‐Degree‐of‐Freedom Mobile Robot for Acquisition of Road Environmental Modes
Authors: Murata Naoya , Katsura Seiichiro 
Published: April 2014

SUMMARYThe acquisition of information about the environment around a mobile robot is important for purposes such as controlling the robot from a remote location and in situations such as that when the robot is running autonomously. In some research, audiovisual information has been used. However, the acquisition of information about force sensation, which is included in environmental information, has not been well investigated. The mobile‐hapto, which is a remote control system with force information, has been proposed, but the robot used for the system can acquire only the horizontal components of forces. For this reason, in this research a three‐wheeled mobile robot consisting of seven actuators was developed and a control system was created for it. The robot can acquire information about horizontal and vertical forces without using force sensors. By using this robot, detailed information on the forces in the environment can be acquired and the operability of the robot and its ability to adjust to the environment are expected to improve.
Relationship Between Reaction Rate of Perfluorocarboxylic Acid Decomposition at a Plasma–Liquid Interface and Adsorbed Amount
Authors: Matsuya Yuriko , Takeuchi Nozomi , Yasuoka Koichi 
Published: April 2014

SUMMARYPerfluorooctanoic acid (PFOA: C7F15COOH) in water is effectively decomposed by plasma generated at a gas–liquid interface. During the decomposition of PFOA, perfluorocarboxylic acids (PFCAs: ) with shorter carbon chains (n = 1–6) are generated as by‐products. Since these PFCAs are surfactants, they are adsorb onto the gas–liquid interface and show high surface concentrations. This study investigated the relationship between the adsorbed amount of PFCA and the rate of decomposition by a direct current plasma. The adsorbed amount of PFCA at the gas–liquid interface increased as the length of the carbon chain increased, resulting in a higher rate of decomposition. However, the reaction rate reached saturation at a certain adsorption amount, depending on the discharge current.
Electrical Breakdown and Space Charge Formation at High‐Temperature Region in Long‐Time Heating Treatment PVC
Authors: Miura Masakazu , Fukuma Masumi , Kishida Satoru 
Published: April 2014

SUMMARYPolyvinyl chloride (PVC) is widely used as an insulating material in various electrical products. It is reported that an exothermic reaction reaching temperatures above 150 °C can be caused by overload currents or inferior electrical wire connections before the ignition of electrical products. The exothermic phenomenon may cause deterioration of insulating properties in PVC due to its chemical decomposition. It is necessary to clarify the degradation of insulating properties in PVC under thermal stress exceeding 150 °C for the safe use of electric products. In this investigation the space charge distribution and conduction current in the heat‐treated PVC sheet were measured in the range from room temperature to 200 °C in the presence of a dc electric field, using a high‐temperature PEA system. Positive charge injection and increasing conduction currents were observed before breakdown above 100 °C in 100 °C 300‐h heat‐treated samples and in non–heat‐treated samples. The results indicate the thermal breakdown process from the analysis of conduction currents and electric fields. In samples exposed to higher temperatures (150 °C 100 h), the breakdown strength deteriorated strongly in the range from room temperature to 90 °C. Increases in conduction current were observed in the entire temperature range before breakdown of the 150 °C 100‐h heat‐treated PVC. This indicates that heat treatment above 150 °C degrades the breakdown properties in the range from room temperature to 90 °C due to thermal decomposition accompanied by dehydrochlorination in PVC. The electric field is intensified near the cathode due to positive charge accumulation, and the breakdown strength begins to deteriorate only above 90 °C. This shows that thermal stress exceeding 150 °C causes deterioration of insulating properties and that the breakdown process is affected by space charge formation in PVC.
Experimental Study of Islanding‐Prevention Method by Harmonic Injection Synchronized with Exciting Current Harmonics of Pole Transformer
Authors: Yoshida Yoshiaki , Suzuki Hirokazu , Fujiwara Koji , Ishihara Yoshiyuki 
Published: April 2014

SUMMARYAs distributed generators (DGs) such as photovoltaic (PV) systems are increasingly used in distribution systems, quick prevention of islanding caused by power system failure is essential to assure electrical safety. Various islanding protection methods have been used practically, but the conventional active systems tend to increase the detection time, because mutual interference occurs between active signals due to asynchronous states. A new active islanding detection method, the frequency feedback method with step reactive power injection, also has the possibility of extending the detection time in the so‐called perfect balance area (PBA). Thus we propose a novel method of islanding‐prevention by harmonic injection synchronized with the exciting current harmonics of the pole transformer. We performed an experimental study using prototype inverters equipped with the proposed method. We have shown the feasibility of detecting islanding quickly and reliably, even if the islanding state is in the PBA. The experimental results demonstrate that mutual interference does not occur due to asynchronous states between active signals, and also that the proposed method is applicable to islanding detection system in clustered installation of PV systems.
Influence of root characteristics and soil variables on the uprooting mechanics of Avena sativa and Medicago sativa seedlings
Authors: Edmaier Katharina , Crouzy Benoît , Ennos Roland , Burlando Paolo , Perona Paolo 
Published: April 2014

ABSTRACTThe success of seedlings and rejuvenated woody debris growing on river bedforms depends on the resistance to uprooting by flow provided by their simple root architecture. Avena sativa and Medicago sativa seedlings were used in flume experiments as prototypes for juvenile riparian plants. Very little is known about the magnitude of root anchoring forces and the role of secondary roots of such simple root systems.We performed 1550 vertical uprooting experiments on Avena sativa and Medicago sativa seedlings grown in quartz sand. Seedlings were pulled up by direct traction using a wheel driven by a computer‐controlled motor and the force was recorded. Roots were scanned and architectural parameters (root length and number of roots) determined. Uprooting force and work (the integral of the applied force times the distance over which it is applied) were then related to root architecture and soil variables.Resistance to uprooting increased with decreasing sediment size and sediment moisture content. The initial response of the root–soil system to uprooting showed linear elastic behaviour with modulus increasing with plant age. While the maximum uprooting force was found to increase linearly with total root length and be mainly dependent on the length of the main root, uprooting work followed a power law and has to be related to the whole root system. Thus, for the young plants we considered, secondary roots are responsible for the ability to withstand environmental disturbances in terms of duration rather than magnitude. This distinction between primary and secondary roots can be of crucial importance for seedlings of riparian species germinating on river bars and islands where inundation is a main cause of mortality. Beyond clarifying the biomechanical role of soil and root variables, the uprooting statistics obtained are useful in interpreting and designing ecomorphodynamic flume experiments. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling planform evolution of a mud‐dominated meandering river: Quinn River, Nevada, USA
Authors: Matsubara Yo , Howard Alan D. 
Published: April 2014

ABSTRACTA depth‐averaged linearized meander evolution model was calibrated and tested using the field data collected at the Quinn River in the Black Rock Desert, Nevada. Two approaches used to test the model were: (1) simulating meander evolution and comparing the results with the observed 38 year migration pattern; and (2) fitting the model parameters to present bank asymmetry (the ratio of the maximum bank gradients on opposite sides of the channel). The data required as input were collected in the field during a high flow in May 2011 and from aerial photographs and LiDAR data. Both approaches yielded similar results for the best fit parameter values. The bank asymmetry analysis showed that the bank asymmetry and the velocity perturbation have high correlation at close to zero spatial lag while the maximum correlation between the bank asymmetry and maximum bend curvature is offset by about 25 m. The model sufficiently replicated 38 years of channel migration, with a few locations significantly under‐ or over‐predicted. Inadequacies of the flow model and/or variation in bank properties unaccounted for are most likely the causes for these discrepancies. Flow through the Quinn River was also simulated by a more general 3D model. The downstream pattern of near‐bank shear stresses simulated by the 3D model is nearly identical to those resulting from the linearized flow model. Topographic profiles across interior bends are essentially invariant over a wide range of migration rates, suggesting that the traditional formulation that cut bank erosion processes govern migration rates is appropriate for the Quinn River. Copyright © 2014 John Wiley & Sons, Ltd.
On multiple‐access relay channel with common message
Authors: Osmani‐Bojd Mohammad , Hodtani Ghosheh Abed 
Published: April 2014

AbstractIn this paper, we obtain a general achievable rate region for discrete memoryless multiple‐access relay channel (DM‐MARC) with common message via partial decode and forward strategy and regular block Markov encoding/backward decoding. This general achievable rate region, as an extension of the achievability part of the relay channel via partial decode and forward strategy to the MARC, subsumes the previous known achievable rate regions for multiple‐access channel with common message and MARC. Also, by applying Fano's inequality, we derive an outer bound for DM‐MARC with common message. By extending the discrete alphabet results to the continuous alphabet, an inner bound for Gaussian MARC (GMARC) is achieved. As expected, our results for the Gaussian MARC includes the previous results for the Gaussian multiple‐access channel with and without common message and the Gaussian relay channel as special cases. Finally, by considering a specific topology for MARC, performance of GMARC with common message versus the position of the relay is investigated numerically. Also, it is shown that our achievable rate region is larger than the previous rate region of GMARC with common message with irregular encoding/successive decoding. Copyright © 2014 John Wiley & Sons, Ltd.
A compressive sensing‐based approach to end‐to‐end network traffic reconstruction utilising partial measured origin‐destination flows
Authors: Nie Laisen , Jiang Dingde , Guo Lei 
Published: April 2014

AbstractTraffic matrices describe the volume of traffic flowing from origin nodes to destination nodes. As one of the most crucial input parameters for network activities, it is employed to perform a great number of network management tasks. However, traffic matrix estimation is unavailable and has a highly ill‐posed nature, which means that it is significantly difficult to ensure the accuracy for estimating traffic matrices. Thus, it is a challenge to obtain the precise end‐to‐end network traffic. In this paper, we investigate the problem of network traffic estimation and propose a novel compressive sensing‐based approach using partial measured origin‐destination (OD) flows. As a purely data‐driven method, we first propose a strategy to select a small subset of the measured OD flows. We then put forward an optimal greedy adaptive dictionary learning algorithm in order to make the traffic matrix sparse. Furthermore, we model the traffic matrix estimation problem by a fundamental inference problem, which is ill‐posed and obeys the constraints of compressive sensing. In other words, the estimation model is a convex optimisation problem. In the process, we validate the performance of our method by real traffic data. Simulation results indicate that our method can trace the shape of each OD flow much more precisely. Copyright © 2014 John Wiley & Sons, Ltd.
Ant mounds as a source of sediment in a tropical rainforest?
Authors: Schmidt Lena Katharina , Zimmermann Alexander , Elsenbeer Helmut 
Published: April 2014

AbstractIn Lutzito catchment on Barro Colorado Island, Panama, extraordinarily high suspended‐sediment yields of 1–2 Mg ha−1 year−1 were generated despite the dense forest cover coinciding with erosion‐resistant soils. We hypothesized that ant mounding activity is an important zoogeomorphological mechanism in this area, providing relevant quantities of easily transportable material at the soil surface. To test this hypothesis, all ant mound material was collected collected for dry mass determination from thirty 4 m2 plots installed in the study area every 1–3 days during the 39‐day sampling period. Additionally, three ground‐nesting ant species responsible for mounds in the study area, Ectatomma ruidum, Trachymyrmex cornetzi and Strumigenys marginiventris, were identified. On the basis of the total of 1.38 kg of material collected in the wet season of 2011, the estimate for the whole 8 months wet season amounts to 725 kg ha−1. As this value is in the same order of magnitude as sediment output, it shows that ants may act as important ecosystem engineers and contribute to sediment production here by providing large quantities of fine‐grained, readily erodible material at the soil surface for subsequent transport to the streambed. Copyright © 2014 John Wiley & Sons, Ltd.
Efficacy of occlusion of hepatic artery and risk of carbon dioxide gas embolism during laparoscopic hepatectomy in a pig model
Authors: Makabe Kenji , Nitta Hiroyuki , Takahara Takeshi , Hasegawa Yasushi , Kanno Shoji , Nishizuka Satoshi , Sasaki Akira , Wakabayashi Go 
Published: April 2014

AbstractBackgroundThe important point in safely performing laparoscopic hepatectomy (LH) is to control bleeding. The aims of this study were: (i) to assess the bleeding reduction effect by occlusion of the hepatic artery in LH; and (ii) to evaluate the risk of carbon dioxide (CO2) gas embolism (GE) in the case of high pneumoperitoneum (PP).MethodsNine piglets underwent laparoscopic left medial lobe and left lateral lobe resection, receiving either occlusion of the hepatic artery (hepatic artery clamping group: HACG, n = 9) or no occlusion (hepatic artery declamping group: HADCG, n = 9) using a PP of 15 mmHg. In addition, we observed changes in hemodynamics induced by PP. The state of GE was observed using transesophageal echocardiography (TEE) during LH (n = 8). GE was graded as grade 0 (none), grade 1 (minor), and grade 2 (major).ResultsThe HACG had significantly less bleeding compared to the HADCG (P < 0.01). During LH, four animals showed grade 1 (37.5%) and one animal showed grade 2 (12.5%) GE at 15 mmHg. At 20 mmHg, all animals showed grade 2 (100%) GE.ConclusionThe occlusion of the hepatic artery in LH reduces blood loss. The control of bleeding from the hepatic vein is feasible with a high PP, but there is a possibility of GE.
Density and demography of snowshoe hares in central Colorado
Authors: Ivan Jacob S. , White Gary C. , Shenk Tanya M. 
Published: April 2014

ABSTRACTTo improve understanding of snowshoe hare ecology in the Southern Rockies and enhance the ability of agency personnel to manage subalpine landscapes for snowshoe hares (Lepus americanus) and lynx (Lynx canadensis) in the region, we estimated snowshoe hare density, survival, and recruitment in west‐central Colorado, USA from July 2006–March 2009. We sampled 3 types of forest stands that purportedly provide good habitat for hares: 1) mature Engelmann spruce (Picea engelmannii)–subalpine fir (Abies lasiocarpa), 2) early seral, even‐aged lodgepole pine (Pinus contorta), and 3) mid‐seral, even‐aged lodgepole pine that had been pre‐commercially thinned. In all forest types and all seasons, snowshoe hare densities were <1.0 hares/ha. During summer, hare densities [±SE] were highest in early seral lodgepole pine (0.20 [0.01] to 0.66 [0.07] hares/ha), lowest in mid‐seral lodgepole pine (0.01 [0.04] to 0.03 [0.03] hares/ha), and intermediate in mature spruce‐fir (0.01 [0.002] to 0.26 [0.08] hares/ha). During winter, densities were more similar among the 3 stand types. Annual survival of hares was highest in mature spruce‐fir (0.14 [0.05] to 0.20 [0.07]) and similar between the 2 lodgepole stand types (0.10 [0.03] to 0.16 [0.06]). Stand attributes indicative of dense cover were positively correlated with density estimates and explained relatively more spatial process variance in hare densities than other attributes. These same attributes were not positively correlated with hare survival. Both density and survival of hares in early seral lodgepole stands were positively correlated with the extent of similar stands in the surrounding landscape. Recruitment of juvenile hares occurred during all 3 summers in early seral lodgepole stands, 2 of 3 summers in mature spruce‐fir stands, and in only 1 of 3 summers in mid‐seral lodgepole. Based on estimates of density and demography specific to each forest type, we conclude that managers should maintain mature spruce‐fir and early seral lodgepole stand types rather than thinned, mid‐seral lodgepole stands to benefit snowshoe hares (and by association lynx) in central Colorado. Given the more persistent nature of spruce‐fir compared to early seral lodgepole, and the fact that such stands cover considerably more area, mature spruce‐fir may be the most valuable forest type for snowshoe hares in the region. © 2014 The Wildlife Society.
Detection probability of least tern and piping plover chicks in a large river system
Authors: Roche Erin A. , Shaffer Terry L. , Anteau Michael J. , Sherfy Mark H. , Stucker Jennifer H. , Wiltermuth Mark T. , Dovichin Colin M. 
Published: April 2014

ABSTRACTMonitoring the abundance and stability of populations of conservation concern is often complicated by an inability to perfectly detect all members of the population. Mark‐recapture offers a flexible framework in which one may identify factors contributing to imperfect detection, while at the same time estimating demographic parameters such as abundance or survival. We individually color‐marked, recaptured, and re‐sighted 1,635 federally listed interior least tern (Sternula antillarum; endangered) chicks and 1,318 piping plover (Charadrius melodus; threatened) chicks from 2006 to 2009 at 4 study areas along the Missouri River and investigated effects of observer‐, subject‐, and site‐level covariates suspected of influencing detection. Increasing the time spent searching and crew size increased the probability of detecting both species regardless of study area and detection methods were not associated with decreased survival. However, associations between detection probability and the investigated covariates were highly variable by study area and species combinations, indicating that a universal mark‐recapture design may not be appropriate. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Incorporating environmental considerations in managing Egyptian geese on golf courses in South Africa
Authors: Mackay Beth , Little Rob M. , Amar Arjun , Hockey Phil A. R. 
Published: April 2014

ABSTRACTEgyptian geese (Alopochen aegyptiaca) occur in large numbers on golf courses in southwestern South Africa. They cause physical and financial damage to the courses and are a nuisance to golfers and golf course managers. Most control measures used to reduce the problem have been unsuccessful. We investigated the potential for environmental management options by determining which landscape features attract geese to certain areas within golf courses and cause them to avoid others. Goose vigilance levels were lower in use than in non‐use areas regardless of group size (t1 = 5.837, P ≤ 0.001, F1 = 53.877, P ≤ 0.001). This behavior suggested that geese were attracted to some areas because they perceive them to be safer. Landscape features that attracted Egyptian geese were large open patches of lawn (>1.5 ha) and proximity to water bodies (<100 m). Water bodies should not be adjacent to open foraging or loafing areas. Other modifications may include planting herbaceous vertical vegetation around water bodies and open fairways to reduce habitat openness and predator visibility. Our results suggest that the level of the goose problem at any golf course is a consequence of the intrinsic properties of that course and not influenced by the extent of the problem at nearby golf courses. © 2014 The Wildlife Society.