bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the influence of trigger level in distribution vibration surveys
Authors: Rouillard Vincent , Lamb Matthew 
Published: February 2009

AbstractThis paper follows on from recently published research that examined the effects of recording parameters on the outcomes of distribution vibration surveys. Whereas the previous research focused on the effects of the sampling period at which sub‐records of the process are captured, this paper deals with another often‐used recording parameter, namely, the vibration level trigger. The paper describes the development of a software tool that was designed specifically to study the influence of various sampling parameters on continuously recorded vibration data. This software tool was used to undertake a thorough statistical analysis on a vibration record set consisting of continuously sampled data measured from a wide variety of vehicle types and routes. The paper shows that the outcomes of vibration surveys are very sensitive to the trigger level and can produce highly distorted results by introducing a bias that nearly always overestimates the overall vibration levels. This is reflected in estimates of common descriptors of random vibration processes such as the average power spectral density (PSD), the peak‐hold PSD and the overall root‐mean‐square values. The main outcome of this analysis is the formulation of a correction method based on relationships between the true mean and peak‐hold PSDs and estimates from sampled data. The effect and significance of the proposed correction procedure is demonstrated, especially in the context of laboratory simulation of distribution vibrations. The paper concludes by making specific recommendations for configuring high‐capacity field data recorders and applying correction strategies to ensure that vibration surveys yield statistically sound results. Copyright © 2009 John Wiley & Sons, Ltd.
Mechanism of rhodium‐catalyzed hydroacylation of propylene using formaldehyde: A computational study
Authors: Wang Fen , Meng Qingxi , Li Ming 
Published: February 2009

AbstractDensity functional theory was used to study Rh(I)‐catalyzed hydroacylation of propylene and formaldehyde. All the intermediates and the transition states were optimized completely at the B3LYP/6‐311++G(d,p) level (LANL2DZ(d) for Rh, P). Calculation results confirm that Rh(I)‐catalyzed hydroacylation of propylene and formaldehyde is exothermic, and the total released Gibbs free energy is about −33 kJ mol−1. This hydroacylation have eight possible pathways, and pathways (1), (2), (3), and (4) are the dominant reaction channels. The dominant product predicted theoretically is butyl aldehyde, and it is a linear product, which agrees well with these experiments. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Theoretical study of two‐dimensionally fused zinc porphyrins: DFT calculations
Authors: Yamaguchi Yoichi 
Published: February 2009

AbstractElectronic structures of D4h square‐fused zinc porphyrin sheets of two types (SA, SB), where SA is a directly meso‐meso‐, β‐β‐, and β‐β‐linked array and SB is a directly β‐fused array, were compared using density functional theory (DFT). The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of oligomeric SAn are characteristically delocalized at the cyclooctatetraene‐like sites composed of β‐pyrrolic carbons and their nearest‐neighbor nitrogens. Those of oligomeric SBn remain solitary monomeric features, reflecting weakly interacting porphyrin units. These two‐dimensionally (2D) square‐fused sheets, especially for SAn, show effective reduction of both the HOMO–LUMO energy gaps (Eg) and the lowest Q‐like excitation energies because of LUMO's greater stabilization with increasing number of porphyrins than the corresponding one‐dimensionally (1D) linear‐fused tapes. To estimate the minimum value of Eg, the electronic band structures of the infinite‐fused SA∞ and SB∞ were examined in detail using modern periodic DFT. Results indicate a full metal for SA∞, with HOMO and LUMO bands crossing the Fermi level, and a semiconductor with Eg ≈ 0.5 eV for SB∞. Furthermore, the phonon modes and the electron–phonon coupling (EPC) constant of SA∞ were calculated throughout the Brillouin zone using density functional perturbation theory (DFPT), yielding a weak EPC constant, λ = 0.35. Within the standard phonon‐mediated BCS mechanism, the superconducting transition temperature, Tc is demonstrated using the McMillan formula, predicting ≈0.5 K. Results show that SA∞ will become a rare synthetic metal/superconductor without a metal‐insulator transition coming from Peierls lattice instability because it has no serious imaginary phonon modes. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Coupled‐cluster and many‐body perturbation study of energies, structures, and phonon dispersions of solid hydrogen fluoride
Authors: Sode Olaseni , Keçeli Murat , Hirata So , Yagi Kiyoshi 
Published: February 2009

AbstractA linear‐scaling electron‐correlation method based on a truncated many‐body expansion of the energies of molecular crystals has been applied to solid hydrogen fluoride. The energies, structures, harmonic, and anharmonic frequencies of the infrared‐ and/or Raman‐active vibrations, phonon dispersions, and inelastic neutron scattering (INS) of the solid have been simulated employing an infinite, periodic, one‐dimensional zigzag hydrogen‐bonded chain model. The Hartree–Fock, second‐order Møller–Plesset (MP2), coupled‐cluster singles and doubles (CCSD), and CCSD with a noniterative triples correction [CCSD(T)] methods have been combined with the aug‐cc‐pVDZ and aug‐cc‐pVTZ basis sets and, in some instances, the counterpoise corrections of the basis‐set superposition errors. The computed structural parameters agree with the observed within 0.1–0.2 Å and a few degrees, and the anharmonic frequencies obtained by vibrational MP2 allowing two‐phonon couplings reproduce the observed frequencies semiquantitatively if the potential energy surface is obtained by a correlated theory. They support the revised infrared and Raman band assignments of librational modes made by Hirata and Iwata (J Phys Chem A 1998, 102, 8426) and provide more detailed assignments of the observed INS features. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Modelling of floating seed dispersal in a fluvial environment
Authors: Groves Jeremy H. , Williams David G. , Caley Peter , Norris Richard H. , Caitcheon Gary 
Published: February 2009

AbstractRiparian revegetation is an important component of river restoration. The success of restoration efforts may be affected by outside sources of propagules (e.g. seeds dispersed by water). Water can be an important transport vector for many native and alien riparian species. However, there is limited understanding of the dynamics of seed distribution in river systems. Accordingly, we have developed a semi‐empirical model of seed dispersal by water, which predicts the parameters of the dispersal kernel. The model is based on aerial dispersal and hydrological approaches, with the core parameters as a function of flow velocity. Development and calibration of the model has been carried out in the Wingecarribee River and two of its tributaries, in the Southern Highlands of New South Wales, Australia, through releases of Helianthus annus (sunflower) achenes. The model, of skewed Gaussian form with stream flow and channel dimensions as core parameters, showed good overall fit to be observed (R2 ranging from 0.61 to 0.98) for the main river and its tributaries. This model increases our fundamental understanding of seed dispersal along rivers and is a tool that can help predict seed dispersal of native and alien plant species along waterways. Copyright © 2009 John Wiley & Sons, Ltd.
Channel adjustments and alteration of sediment fluxes in gravel‐bed rivers of North‐Eastern Italy: potentials and limitations for channel recovery
Authors: Surian Nicola , Ziliani Luca , Comiti Francesco , Lenzi Mario A. , Mao Luca 
Published: February 2009

AbstractThe aim of this paper is to explore possibilities and limitations of restoring physical processes in five gravel‐bed rivers (Brenta, Piave, Cellina, Tagliamento and Torre Rivers) in north‐eastern Italy. The selected rivers were analysed through a range of techniques, specifically analysis of historical maps and aerial photographs with geographical information systems (GIS), comparison of topographic surveys and geomorphological surveys. After illustrating channel adjustments and sediment fluxes, we discuss how the understanding of physical processes can be used for channel restoration.The studied river channels have undergone notable adjustments in the last 100 years, specifically narrowing by up to 76%, incision by up to 8.5 m, and changes in channel configuration. Alteration of sediment fluxes, mainly due to in‐channel mining, has been the main factor driving such channel adjustments. Evolutionary trends show that channel recovery is on‐going in several of the selected reaches, since widening and aggradation have occurred over the last 15–20 years. This channel recovery has been possible because sediment mining has significantly decreased or ceased along the study reaches. However, several constraints still exist on sediment fluxes (e.g. dams).Four categories of river channel were defined, taking into account the recent evolution of the studied channels (from ‘A’, high channel recovery, to ‘D’, no channel recovery). The impact of different sediment management strategies on channel dynamics over the next 40–50 years was then analysed. Without any intervention, channel recovery would only be possible in those reaches that have a relatively high degree of connectivity with upstream sediment sources or tributaries, while further incision and narrowing would be expected in those reaches where connectivity is low. A more substantial channel recovery could be obtained through interventions at reach (e.g. removal of bank protection) and basin (e.g. sediment transfer downstream of dams) scales. Notwithstanding such actions, it is likely that channels will not recover in the next few decades to the morphology they exhibited in the first half of the 20th century, when bed‐load yield and connectivity were higher. Copyright © 2009 John Wiley & Sons, Ltd.
The development of hydraulic and geomorphic complexity in recently formed streams in Glacier Bay National Park, Alaska
Authors: Klaar Megan J. , Maddock Ian , Milner Alexander M. 
Published: February 2009

AbstractGeomorphic and hydraulic complexity within five streams representing 200 years of stream development were examined in Glacier Bay National Park, Alaska. Channel geomorphic units (CGUs) were mapped using a hierarchical approach, which defined stream habitat according to morphological and hydraulic characteristics. Detailed hydraulic assessment within the geomorphic units allowed differences in hydraulic characteristics across the 200‐year chronosequence to be documented. Channel geomorphology and hydrology changed as stream age increased. Younger streams were dominated by fast flowing geomorphic units such as rapids and riffles with little hydraulic or landscape diversity. As stream age increased, slower flowing habitat units such as glides and pools became more dominant, resulting in increased geomorphic, hydraulic and landscape diversity. These results suggest that geomorphic and hydraulic complexity develop over time, creating habitat features likely to be favoured by instream biota, enhancing biodiversity and abundance. Copyright © 2009 John Wiley & Sons, Ltd.
Lessons from an interdisciplinary system dynamics course
Authors: Hovmand Peter S. , O'Sullivan Joseph A. 
Published: February 2009

AbstractSystem dynamics has long held a promise of solving social problems. Such efforts benefit from interdisciplinary teams that can combine strong technical skills for modeling and analysis with people skills for working with stakeholders and understanding the substantive issues of social problems. In this note we describe a joint graduate system dynamics course between social work and electrical and systems engineering that emphasizes students learning how to develop and work in interdisciplinary teams to address social problems. We discuss the advantages of such teams, some of the challenges, and share lessons from the experience. Copyright © 2009 John Wiley & Sons, Ltd.
Using system dynamics to develop policies that matter: global management of poliomyelitis and beyond
Authors: Thompson Kimberly M. , Tebbens Radboud J. Duintjer 
Published: February 2009

AbstractWe offer an example of modeling that influenced global health policy related to polio and we provide some insights about the modeling process. Although system dynamics lies at the heart of our modeling, we emphasize that downplaying the modeling to focus on the policy questions played a critical role in the use of the results by decision makers. Here we provide details of the system dynamics modeling that underlies our research on polio, and discuss the process we followed to bring scientific modeling of a highly complex issue to policymakers. We hope that providing a better understanding of our efforts and describing our continuing analytical journey provides useful insights for others who seek to use system dynamics to develop policies that matter. Copyright © 2009 John Wiley & Sons, Ltd.
Using camouflaging mobility to protect privacy in mobilead hocnetworks
Authors: Tang Lei , Hong Xiaoyan , Vrbsky Susan 
Published: February 2009

AbstractThe open nature of wireless medium has left wireless communications vulnerable to various privacy attacks. Much research work has been proposed to protect the identity anonymity of communicating parties, the anonymity of network routes and the location privacy of the message source and destination. However, with the advent of new radio identification and localization techniques, more advanced privacy attacks are possible. We describe a new privacy attack in which the adversary tries to infer the itineraries of the nodes in the network. To protect itinerary privacy, we design an algorithm, called$\Delta$‐camouflaging mobility algorithm, which changes the original motion segments of a node into$\Delta$‐shaped camouflaging paths. Itinerary privacy, correspondent privacy, and route privacy are closely related so we propose a comprehensive anonymous routing scheme, calledMARS, to protect these privacy goals. MARS exploits camouflaging mobility to protect itinerary privacy and usesmotion pseudonymsgenerated from the camouflaging mobility to protect correspondent privacy and route privacy without using cryptography. Our analysis results show that$\Delta$‐camouflaging mobility algorithm is cost‐effective, which can significantly reduce the itinerary exposure probability at a small cost of extra travel distance. Moreover, our network simulation results illustrated that MARS anonymous routing scheme and$\Delta$‐camouflaging mobility algorithm did not reduce network layer performance. Copyright © 2009 John Wiley & Sons, Ltd.
MULEPRO: a multi‐channel response to jamming attacks in wireless sensor networks
Authors: Alnifie Ghada , Simon Robert 
Published: February 2009

AbstractThe shared wireless medium used by sensor networks makes it easy for adversaries to launch jamming attacks that can partially or completely block communication leading to a denial‐of‐service (DoS) condition. This paper presents MULEPRO (MULti‐channel Exfiltration PROtocol), a fully distributed network based protocol designed to rapidly exfiltrate data from a jammed area using multiple communication channels simultaneously. The basic idea is to assign scheduling symbols to the different nodes based on their vertex color to produce conflict‐free transmission schedules between sensor nodes, up to two‐hop distance in order to address the terminal hidden problem. MULEPRO targets sensor network applications that require an immediate and robust response to such jamming‐based DoS attacks and is designed to operate with any number of channels. When an attack is launched nodes can effectively coordinate exfiltration transmissions without needing to exchange network protocol information. We have extensively evaluated MULEPRO under a variety of attack configurations. Results show that MULEPRO can maintain pre‐attack data transmission rates in the case of standard jamming attack models, and can exfiltrate data even for the case of multiple jammers. Copyright © 2009 John Wiley & Sons, Ltd.
Towards a classification of energy aware MAC protocols for wireless sensor networks
Authors: Yahya Bashir , Ben‐Othman Jalel 
Published: February 2009

AbstractPower management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. Provided that, the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit.MAC protocols for sensor networks differ greatly from typical wireless networks access protocols in many issues. MAC protocols for sensor networks must have built‐in power conservation, mobility management, and failure recovery strategies. Furthermore, sensor MAC protocols should make performance trade‐off between latency and throughput for a reduction in energy consumption to maximize the lifetime of the network. This is in general achieved through duty cycling the radio transceiver.Many MAC protocols with different objectives were proposed for wireless sensor networks in the literature. Most of these protocols take into account the energy efficiency as a main objective. There is much more innovative work should be done at the MAC layer to address the hard unsolved problems. In this paper, we first outline and discuss the specific requirements and design trade‐offs of a typical wireless sensor MAC protocol by describing the properties of WSN that affect the design of MAC layer protocols. Then, a typical collection of wireless sensor MAC protocols presented in the literature are surveyed, classified, and described emphasizing their advantages and disadvantages whenever possible. Finally, we present research directions and identify open issues for future medium access research. Copyright © 2009 John Wiley & Sons, Ltd.
Power distribution methods for MIMO‐OFDM systems and field experimentations
Authors: Bocquet Wladimir , Hayashi Kazunori , Sakai Hideaki 
Published: February 2009

AbstractIn this paper, we propose several power allocation schemes for multi‐input multi‐output (MIMO) orthogonal frequency division multiplexing (OFDM) transmission based on the minimization of an approximated bit error rate (BER) expression, and we evaluate the different solutionsviafield trial experimentations. The methods illustrated in this paper, serve to allocate power among the different transmit antennas and the different subcarriers which compose the MIMO OFDM transmitted signal. Several solutions are available to perform power allocation. Frequency domain power allocation, spatial domain power allocation and combined spatial and frequency power allocation are evaluated. We first review and describe the analytical solution for each power allocation scheme and then evaluate the complexity in terms of both computational operations and BER performances. Simulation results show the performance in term of BER and link the advantage of each possibility of power distribution with the associated complexity. Copyright © 2009 John Wiley & Sons, Ltd.
Opportunistic distributed power control with adaptive QoS and fairness for wireless networks
Authors: Chaves F. de S. , Cavalcanti F. R. P. , de Oliveira Neto R. A. , Santos R. B. 
Published: February 2009

AbstractThis paper presents a class of distributed power control algorithms for wireless networks which provides quality of service (QoS) fulfillment by exploiting the channel variability opportunistically. It is suitable for traffic sources requiring either a minimum or a prescribed QoS provision, and at the same time provides a fair resource allocation. Practical system constraints such as limitations on transmission power and modulation and coding schemes are considered in this framework. Moreover, it is analytically shown to be more energy efficient than the opportunistic power control. Two algorithms of this class are described and have their performance confronted with opportunistic algorithms. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of substance P on osteoblastic differentiation and heme oxygenase‐1 in human periodontal ligament cells
Authors: Kook Yoon‐Ah , Lee Sun‐Kyung , Son Dae‐Hyung , Kim Youngho , Kang Kyung‐Hwa , Cho Jin‐Hyung , Kim Sang‐Cheol , Kim Young‐Suk , Lee Hwa‐Jeong , Lee Suk‐Keun , Kim Eun‐Cheol 
Published: February 2009

AbstractAlthough substance P (SP) is associated with osteoclast differentiation and bone resorption, little is known about the osteogenic differentiation‐inducing effects of SP in periodontal ligament (PDL) cells. This study investigated whether PDL cells could differentiate into osteoblastic‐like cells by SP. The expression of osteoblastic differentiation markers such as osteopontin (OPN), osteonectin (ON), osteocalcin (OCN) and bone sialoprotein (BSP) were evaulated by Western blotting. Additionally, SP‐mediated heme oxygenase‐1 (HO‐1) pathways were further clarified.SP increased HO‐1 and osteogenic differentiation in concentration‐ and time‐dependent manners, as determined by OPN, ON, OCN and BSP expression. Furthermore, treatment with inhibitors of p38, ERK MAPK, and NF‐κB abolished SP‐induced osteogenic differentiation and HO‐1 expression. SP‐induced translocation of Nrf‐2 was also observed. The combined results suggest that SP activates the stress‐response enzymes HO‐1 and Nrf‐2, subsequently leading to upregulation of osteogenic differentiation in human PDL cells.