bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Analysis of Ionosphere Monitoring with BeiDou CORS Observational Data
Authors: Tang Weiming , Jin Lei , Xu Kun
Published: January 2014

This paper focuses on the performance analysis of ionosphere monitoring using the measurements from a BeiDou Continuously Operating Reference Stations (CORS) network. Combined pseudo-range and carrier phase observations are used to estimate total electron content (TEC) and the hardware delay deviation is also computed. Using the observations from five BeiDou CORS in China, the TEC monitoring results were obtained from each station and compared with GPS monitoring results and also those from the Global Ionosphere Maps (GIM) model. Numerical computation shows that the BeiDou system has the ability to precisely detect the TEC diurnal variation trend on each station. The Residual Mean Square (RMS) difference between the BeiDou and the GIM model at a higher latitude station is about four TEC Units (TECU), while the RMS difference between the GPS and the GIM is about three TECU; at a lower latitude station this difference increases to six TECU for BeiDou and four TECU for the Global Positioning System (GPS); at the lowest latitude station in this study, the differences for both systems are about six TECU.
Putting theory to the test: Examining family context, caregiver motivation, and conflict in the Family Check-Up model
Authors: Fosco Gregory M. , Van Ryzin Mark , Stormshak Elizabeth A. , Dishion Thomas J.
Published: January 2014

This study examined contextual factors (caregiver depression, family resources, ethnicity, and initial levels of youth problem behavior) related to the effectiveness of the Family Check-Up (FCU) and evaluated family processes as a mediator of FCU intervention response and adolescent antisocial behavior. We followed a sample of 180 ethnically diverse youths of families who engaged in the FCU intervention. Family data were collected as part of the FCU assessment, and youth data were collected over 4 years, from sixth through ninth grade. Findings indicated that caregiver depression and minority status predicted greater caregiver motivation to change. In turn, caregiver motivation was the only direct predictor of FCU intervention response during a 1-year period. Growth in family conflict from sixth through eighth grade mediated the link between FCU response and ninth-grade antisocial behavior. This study explicitly tested core aspects of the FCU intervention model and demonstrated that caregiver motivation is a central factor that underlies family response to the FCU. The study also provided support for continued examination of family process mechanisms that account for enduring effects of the FCU and other family-centered interventions.
Reducing youth internalizing symptoms: Effects of a family-based preventive intervention on parental guilt induction and youth cognitive style
Authors: McKee Laura G. , Parent Justin , Forehand Rex , Rakow Aaron , Watson Kelly H. , Dunbar Jennifer P. , Reising Michelle M. , Hardcastle Emily , Compas Bruce E.
Published: January 2014

This study utilized structural equation modeling to examine the associations among parental guilt induction (a form of psychological control), youth cognitive style, and youth internalizing symptoms, with parents and youth participating in a randomized controlled trial of a family-based group cognitive–behavioral preventive intervention targeting families with a history of caregiver depression. The authors present separate models utilizing parent report and youth report of internalizing symptoms. Findings suggest that families in the active condition (family-based group cognitive–behavioral group) relative to the comparison condition showed a significant decline in parent use of guilt induction at the conclusion of the intervention (6 months postbaseline). Furthermore, reductions in parental guilt induction at 6 months were associated with significantly lower levels of youth negative cognitive style at 12 months. Finally, reductions in parental use of guilt induction were associated with lower youth internalizing symptoms 1 year following the conclusion of the intervention (18 months postbaseline).
Sémantique temporelle et accord du participe passé en français parlé: une analyse variationniste
Authors: GAUCHER DAMIEN
Published: January 2014

Dans cet article, nous analysons l'influence de la valeur aspectuo-temporelle attribuée aux formes composées sur la fréquence d’accord du participe passé (APP). On sait que l'APP est variable dans les usages de la langue parlée, notamment lorsqu’il est employé avec l'auxiliaireavoir. Partant de l'observation de corpus de langue parlée, et d’une approche variationniste, nous évaluons la fréquence d’accord des participes féminins potentiellement audibles, en fonction de l'effet de sens qui est attribué à la séquence [avoir(pres) + PP], selon qu’il est évalué comme ‘résultant’ ou ‘événementiel’ selon la terminologie de Desclés et Guentcheva (2003). Les résultats de cette analyse laissent entrevoir une influence faible mais relativement constante de ce facteur sémantique sur l'APP, et soulèvent plus avant la question de la présence d’éléments spécifiques au médium oral comme facteurs d’influence sur le marquage morphologique du genre; en d’autres termes, de l'existence d’une grammaire spontanée de l'oral (Branca-Rosoff, 2005).
Cette mesure est-elle vraiment clé? A constructional approach to categorial gradience
Authors: VAN GOETHEM KRISTEL
Published: January 2014

This article investigates the recently developed adjectival properties of the French noun clé ‘key’, as attested in for instance un poste très clé ‘a really key position’ and Cette mesure est-elle vraiment clé? ‘Is this measure really key?’. The main purpose of this study is triple: it consists in analysing (i) which adjectival uses can be found in modern French, (ii) to what extent they are accepted by native speakers (from different geographical varieties) of French, and (iii) how they can be accounted for within the framework of Construction Grammar and Construction Morphology. It will be hypothesised that French clé is subject to categorial gradience as a consequence of an ongoing constructionalisation process.
Native and non-native perceptions of appropriateness in the French second-person pronoun system
Authors: VAN COMPERNOLLE RÉMI A.
Published: January 2014

This article explores perceptions of appropriateness in the French second-person pronoun system in relation to various sociopragmatic factors among native and nonnative speakers of French between the ages of 18 and 29. Participants completed an online survey in which a series of five social-interactive situations were presented. Analysis focused on the similarities and differences among native, near-native, advanced and intermediate speakers in their perceptions of formality, social distance, power/equality and appropriatetu/voususe, as well as correlations between the sociopragmatic factors and selection oftuorvous. Results indicate a high degree of variation within and across participant groups, with nonnatives tending to be more conservative (e.g., more formality, higher frequencies ofvous) in their choices than their native-speaker counterparts. In concluding, the findings are discussed in relation to pedagogical implications.
Nigra crux mala crux: a comparative perspective on urban conflict in Gdansk in 1411 and 1416
Authors: HESS CORDELIA
Published: January 2014

Between 1411 and 1416, Gdansk was the scene for a complex conflict between town population, council and landlord, eventually resulting in violent riots. The peculiar character of these riots becomes apparent when the Gdansk chronicles are compared to the historical accounts from other, better-known conflicts, particularly sources depicting the LübeckKnochenhauerrebellion, the Hamburg brewer's rebellion of 1481 and the 1449–53Gentse opstand. A key difference is the extent to which chroniclers understood and portrayed the ritualized action that occurred in the urban uprisings. Comparing the contemporary chronicles of the Gdansk events with the town's urban historiography 100 years later also shows that this early conflict with the landlord later played a significant role in urban self-definition.
Post Melody valve implant in a conduit with regurgitant native outflow tract successful closure by Amplatzer muscular device
Authors: Momenah Tarek S. , El Houry Motea T. , Khan Muhammad A. , Galal Mohammed O.
Published: January 2014

We describe the technique of closure of native right ventricular outflow tract by Amplatzer muscular ventricular septal defect device because of severe regurgitation in a patient who had tetralogy of Fallot repair with conduit at 3 years of age followed by percutaneous Melody valve implant 6 years later.
Hypoplastic left heart with intact atrial septum and levoatriocardinal vein: a challenge in identifying aortic arch branches
Authors: Paudel Govinda , Ng Benton Y. , Law Ian H.
Published: January 2014

The levoatriocardinal vein provides alternative egress from the left atrium to the systemic veins in left-sided obstructive lesions. Although rare, it has been described in association with hypoplastic left heart syndrome. We report a case of hypoplastic left heart syndrome with levoatriocardinal vein and aberrant right subclavian artery where cardiac magnetic resonance imaging/angiography proved to be a valuable imaging modality for pre-operative evaluation.
The effect of age on portfolio choices: evidence from an Italian pension fund
Authors: CAPPELLETTI GIUSEPPE , GUAZZAROTTI GIOVANNI , TOMMASINO PIETRO
Published: January 2014

According to optimal portfolio theories, investors should reduce their exposure to stock market risk as they grow old. Indeed, older workers, with only a few years left before retirement, are particularly vulnerable to unexpected falls in stock prices. Despite the theoretical and – as shown by the recent financial crisis – policy relevance of the issue, empirical evidence on this topic has been scant and inconclusive. The aim of the present paper is to assess the effect of age on portfolio choices, using a new panel dataset from an Italian defined-contribution pension plan. We find that on average holdings of risky assets do indeed significantly decrease with age. However, the effect is non-linear, being much stronger in the last part of one's career. Moreover, we also document that inertial behaviour is quite widespread, and can be very costly. Results are confirmed when we control for individual fixed effects and cohort effects.
Comparative determinants of horse-race coverage
Authors: Banducci Susan , Hanretty Chris
Published: January 2014

We investigate the levels of horse-race coverage in 160 different European print and broadcast outlets in 27 different countries at three different points in time. We match information on outlets’ content to survey-based information on the average levels of interest in politics and education of outlets’ audiences. We formulate hypotheses concerning journalists’ and citizens’ preferences over the ideal level of horse-race coverage, as well as hypotheses concerning the information content of horse-race coverage in different party systems. After controlling for the composition of each outlet’s audience, we find that horse-race coverage is most frequent in polarized party systems with close electoral contests, and in large markets with professional journalists. These findings challenge the traditional view of horse-race journalism as a ‘low-quality’ form of news.
Measuring Implementation of a School-Based Violence Prevention Program
Authors: Schultes Marie-Therese , Stefanek Elisabeth , van de Schoot Rens , Strohmeier Dagmar , Spiel Christiane
Published: January 2014

When school-based prevention programs are put into practice, evaluation studies commonly only consider one indicator of program implementation. The present study investigates how two different aspects of program implementation – fidelity and participant responsiveness – jointly influence proximal outcomes of the school-based violence prevention program ViSC. The program was implemented in 20 schools across Austria. Trainers conducted in-school teacher trainings with varying implementation fidelity to the program schedule. In a two-wave evaluation study, 370 teachers provided data about their participant responsiveness and the program’s proximal outcomes. The latter comprised their self-efficacy to stop violence among students and their behavior in bullying situations. Multilevel analyses showed that teachers’ self-efficacy was significantly more enhanced in schools where the ViSC program had been implemented with high fidelity. Furthermore, only teachers with high participant responsiveness significantly changed their behavior in bullying situations. Implications for program developers and suggestions for further research on implementation are discussed.
In situ study of defect migration kinetics in nanoporous Ag with enhanced radiation tolerance
Authors: Sun C. , Bufford D. , Chen Y. , Kirk M. A. , Wang Y. Q. , Li M. , Wang H. , Maloy S. A. , Zhang X.
Published: January 2014

Defect sinks, such as grain boundaries and phase boundaries, have been widely accepted to improve the irradiation resistance of metallic materials. However, free surface, an ideal defect sink, has received little attention in bulk materials as surface-to-volume ratio is typically low. Here by using in situ Kr ion irradiation technique in a transmission electron microscope, we show that nanoporous (NP) Ag has enhanced radiation tolerance. Besides direct evidence of free surface induced frequent removal of various types of defect clusters, we determined, for the first time, the global and instantaneous diffusivity of defect clusters in both coarse-grained (CG) and NP Ag. Opposite to conventional wisdom, both types of diffusivities are lower in NP Ag. Such a surprise is largely related to the reduced interaction energy between isolated defect clusters in NP Ag. Determination of kinetics of defect clusters is essential to understand and model their migration and clustering in irradiated materials.
Chemical signatures and new drug targets for gametocytocidal drug development
Authors: Sun Wei , Tanaka Takeshi Q. , Magle Crystal T. , Huang Wenwei , Southall Noel , Huang Ruili , Dehdashti Seameen J. , McKew John C. , Williamson Kim C. , Zheng Wei
Published: January 2014

Control of parasite transmission is critical for the eradication of malaria. However, most antimalarial drugs are not active against P. falciparum gametocytes, responsible for the spread of malaria. Consequently, patients can remain infectious for weeks after the clearance of asexual parasites and clinical symptoms. Here we report the identification of 27 potent gametocytocidal compounds (IC50 < 1 μM) from screening 5,215 known drugs and compounds. All these compounds were active against three strains of gametocytes with different drug sensitivities and geographical origins, 3D7, HB3 and Dd2. Cheminformatic analysis revealed chemical signatures for P. falciparum sexual and asexual stages indicative of druggability and suggesting potential targets. Torin 2, a top lead compound (IC50 = 8 nM against gametocytes in vitro), completely blocked oocyst formation in a mouse model of transmission. These results provide critical new leads and potential targets to expand the repertoire of malaria transmission-blocking reagents.
Proteomic evaluation of citrate-coated silver nanoparticles toxicity in Daphnia magna
Authors: Rainville Louis-Charles , Carolan Darragh , Varela Ana Coelho , Doyle Hugh , Sheehan David
Published: January 2014

Using a redox-proteomics approach, this study demonstrates that silver nanoparticles and AgNO3affect the proteome differently, indicating different biological impacts.
Chip based single cell analysis for nanotoxicity assessment
Authors: Shah Pratikkumar , Kaushik Ajeet , Zhu Xuena , Zhang Chengxiao , Li Chen-Zhong
Published: January 2014

A microfluidic CoC system was developed for nanotoxicity assessment at single and multiple cell levels which can measure and compare the microscopic and macroscopic effects of nanoparticles interaction with cells, without interference from neighbor cells' cues and also overall integrative effects produced by nanoparticles and cell–cell communication.
An application of eosin Y for the selective spectrophotometric and spectrofluorimetric determination of mebeverine hydrochloride
Authors: Derayea Sayed M. S.
Published: January 2014

Two rapid and simple methods were developed and validated for the selective determination of mebeverine hydrochloride based on a binary complex formation with eosin Y.
Stability-indicating HPLC-DAD method for the simultaneous determination of fluoroquinolones and corticosteroids in ophthalmic formulations
Authors: Sversut Rúbia Adrieli , Serrou do Amaral Marcos , César de Moraes Baroni Adriano , Rodrigues Patrik Oening , Rosa Aline Marques , Galana Gerlin Mirella Carla , Singh Anil Kumar , Kassab Nájla Mohamad
Published: January 2014

We develop and validate a stability-indicating assay method for simultaneous determination of gatifloxacin and prednisolone acetate, or of ciprofloxacin hydrochloride and dexamethasone in combination and in the presence of degradation products.
Suppressing triplet state extension for highly efficient ambipolar phosphine oxide host materials in blue PHOLEDs
Authors: Han Chunmiao , Zhu Liping , Zhao Fangchao , Zhang Zhen , Wang Jianzhe , Deng Zhaopeng , Xu Hui , Li Jing , Ma Dongge , Yan Pengfei
Published: January 2014

A series of aryl phosphine oxide hosts named DPExPOPhCzn were constructed to rationally investigate the significant correlation between T1 excited state locations and EL performance of their PHOLEDs.
An amyloid inhibitor octapeptide forms amyloid type fibrous aggregates and affects microtubule motility
Authors: Biswas Atanu , Kurkute Prashant , Jana Batakrishna , Laskar Aparna , Ghosh Surajit
Published: January 2014

Peptide in dual action: an amyloid inhibitor octapeptide spontaneously forms amyloid like fibrillar aggregates in solution and slows down the microtubule gliding speed through strong peptide–tubulin interaction.
Experimental modelling of single-particle dynamic processes in crystallization by controlled colloidal assembly
Authors: Zhang Tian Hui , Liu Xiang Yang
Published: January 2014

A comprehensive review of the experimental modeling of single particle dynamics in crystallization is presented.
A highly emissive inorganic hexamolybdenum cluster complex as a handy precursor for the preparation of new luminescent materials
Authors: Efremova O. A. , Shestopalov M. A. , Chirtsova N. A. , Smolentsev A. I. , Mironov Y. V. , Kitamura N. , Brylev K. A. , Sutherland A. J.
Published: January 2014

The synthesis of a new octahedral molybdenum cluster and a cluster–polymer hybrid is described, both materials possess excellent photoluminescent properties.
Geochemical variability of heavy metals in soil after land use conversions in Northeast China and its environmental applications
Authors: Jiao Wei , Ouyang Wei , Hao Fanghua , Liu Bing , Wang Fangli
Published: January 2014

Unlike most other areas in the world, the long-term agricultural reclamation in Northeast China has significantly decreased some metal concentrations in soil.
Shear-induced endothelial NOS activation and remodeling via heparan sulfate, glypican-1, and syndecan-1
Authors: Ebong Eno E. , Lopez-Quintero Sandra V. , Rizzo Victor , Spray David C. , Tarbell John M.
Published: January 2014

This work uncovers new mechanisms of endothelial cell glycocalyx mediated conversion of fluid forces into diverse biomolecular and biomechanical responses, such as caveola associated signaling and cytoskeleton reorganization.
Structural, magnetic and theoretical calculations of a ferromagnetically coupled tetranuclear copper(ii) square complex
Authors: Salmon Lionel , Thuéry Pierre , Rivière Eric , Costes Jean-Pierre , . Mota Antonio J , Ephritikhine Michel
Published: January 2014

Ferromagnetic interactions in a tetranuclear copper(ii) square complex containing a Schiff base ligand.
Three-dimensional metal/oxide nanocone arrays for high-performance electrochemical pseudocapacitors
Authors: Qiu Yongcai , Zhao Yihua , Yang Xiaowei , Li Wanfei , Wei Zhanhua , Xiao Junwu , Leung Siu-Fung , Lin Qingfeng , Wu Hongkai , Zhang Yuegang , Fan Zhiyong , Yang Shihe
Published: January 2014

3D electrodes are critical to high-performance power sources. Now by combining imprint and soft-printing technologies, 3D nanocone arrays have been designed and fabricated for high performance pseudocapacitors.
Effects of l-lactide and d,l-lactide in poly(lactide-co-glycolide)-poly(ethylene glycol)-poly(lactide-co-glycolide) on the bulk states of triblock copolymers, and their thermogellation and biodegradation in water
Authors: Chen Chang , Chen Lin , Cao Luping , Shen Wenjia , Yu Lin , Ding Jiandong
Published: January 2014

In this study, the effects of l-lactide and d,l-lactide on the thermogelling and biodegradation behaviors of PLGA-PEG-PLGA copolymers were revealed.
Resin supported acyl carrier protein labeling strategies
Authors: Rothmann Michael , Kosa Nicolas M. , Burkart Michael D.
Published: January 2014

The post-translational modifying enzymes phophopantetheinyl transferase and acyl carrier protein hydrolase show utility as resin supported conjugates in the functional modification of acyl carrier proteins.
Pyrene-labeled pyrrolidinyl peptide nucleic acid as a hybridization-responsive DNA probe: comparison between internal and terminal labeling
Authors: Boonlua Chalothorn , Ditmangklo Boonsong , Reenabthue Nisanath , Suparpprom Chaturong , Poomsuk Nattawee , Siriwong Khatcharin , Vilaivan Tirayut
Published: January 2014

Internally pyrene-labeled pyrrolidinyl PNA yields much larger fluorescence increase than terminally labeled PNA upon hybridization with complementary DNA.
An expanded isoindigo unit as a new building block for a conjugated polymer leading to high-performance solar cells
Authors: Li Shugang , Yuan Zhongcheng , Yuan Jianyu , Deng Ping , Zhang Qing , Sun Baoquan
Published: January 2014

An expanded isoindigo unit (IBTI) has been incorporated into a donor–acceptor conjugated polymer for the first time. The PCE of the solar cell device based on the new polymer reached 6.41% with a fill factor of 0.71.
Mature VLDL triggers the biogenesis of a distinct vesicle from the trans-Golgi network for its export to the plasma membrane
Authors: Hossain Tanvir , Riad Aladdin , Siddiqi Shaila , Parthasarathy Sampath , Siddiqi Shadab A.
Published: January 2014

Post-Golgi trafficking of mature VLDL (very-low-density lipoprotein) is crucial in maintaining normal TAG (triacylglycerol) homoeostasis of hepatocytes; however, the mechanism that regulates the exit of mature VLDL from the TGN (trans-Golgi network) is not known. We developed an in vitro TGN-budding assay that allowed us to examine the formation of secretory vesicles from the TGN in primary rat hepatocytes. We isolated TAG-rich PG-VTVs (post-TGN VLDL transport vesicles) using a continuous sucrose density gradient. PG-VTVs were distributed in low-density fractions, whereas protein transport vesicles were present in relatively higher-density fractions of the same sucrose gradient. EM revealed large intact PG-VTVs ranging 300–350 nm in size. The biogenesis of PG-VTVs from the TGN required cytosol, ATP, GTP hydrolysis and incubation at 37°C. PG-VTVs concentrated the VLDL proteins: apolipoproteins apoB100, apoAIV, apoAI and apoE, but did not contain either albumin or transferrin. Proteinase K treatment did not degrade VLDL core proteins, suggesting that PG-VTVs were sealed. PG-VTVs were able to fuse with and deliver VLDL to the PM (plasma membrane) in a vectorial manner. We conclude that we have identified a new TGN-derived vesicle, the PG-VTV, which specifically transports mature VLDL from the TGN to the PM.
A dual-targeted aminoacyl-tRNA synthetase in Plasmodium falciparum charges cytosolic and apicoplast tRNACys
Authors: Pham James S. , Sakaguchi Reiko , Yeoh Lee M. , De Silva Nilushi S. , McFadden Geoffrey I. , Hou Ya-Ming , Ralph Stuart A.
Published: January 2014

Plasmodium parasites possess two endosymbiotic organelles: a mitochondrion and a relict plastid called the apicoplast. To accommodate the translational requirements of these organelles in addition to its cytosolic translation apparatus, the parasite must maintain a supply of charged tRNA molecules in each of these compartments. In the present study we investigate how the parasite manages these translational requirements for charged tRNACys with only a single gene for CysRS (cysteinyl-tRNA synthetase). We demonstrate that the single PfCysRS (Plasmodium falciparum CysRS) transcript is alternatively spliced, and, using a combination of endogenous and heterologous tagging experiments in both P. falciparum and Toxoplasma gondii, we show that CysRS isoforms traffic to the cytosol and apicoplast. PfCysRS can recognize and charge the eukaryotic tRNACys encoded by the Plasmodium nucleus as well as the bacterial-type tRNA encoded by the apicoplast genome, albeit with a preference for the eukaryotic type cytosolic tRNA. The results of the present study indicate that apicomplexan parasites have lost their original plastidic cysteinyl-tRNA synthetase, and have replaced it with a dual-targeted eukaryotic type CysRS that recognizes plastid and nuclear tRNACys. Inhibitors of the Plasmodium dual-targeted CysRS would potentially offer a therapy capable of the desirable immediate effects on parasite growth as well as the irreversibility of inhibitors that disrupt apicoplast inheritance.
Nanowatt multi‐scale continuous wavelet transform chip
Authors: Casson A. J. , Rodriguez‐Villegas E.
Published: January 2014

A four‐scale continuous wavelet transform filter bank implemented in a 0.18 μm CMOS process is presented. Experimental results demonstrate the real‐time multi‐scale analysis of electrocardiogram signals with a power consumption of 1.3 nW, the lowest reported power consumption for a complete wavelet filter bank. In addition, the results demonstrate for the first time the use of pico‐amp scale currents in a 0.18 μm CMOS process for providing advanced signal processing functions.
Interpreting area of pinched memristor hysteresis loop
Authors: Biolek D. , Biolek Z. , Biolková V.
Published: January 2014

It is shown that the area of the pinched hysteresis loop of the current‐controlled ideal memristor represents the quantity ‘content’, which was introduced into the theory of nonlinear systems by Millar in 1951. Two parts of the content are identified which correspond to distinct parts of the area below the v–i characteristic of the memristor: one is related to the power conditions and the other to the instantaneous state of the memristor memory. It is demonstrated for a memristor driven by the sinusoidal current that the power part of the content depends on the fundamental harmonic of the voltage, whereas the memory part of the content is given only by the higher harmonics of the voltage, and only by the even harmonics in the case of entirely closed loops. The analogous conclusions also hold for the voltage‐controlled memristor.
Depth map upsampling using depth local features
Authors: Kang Y.S. , Lee S.B. , Ho Y.S.
Published: January 2014

A depth map upsampling method using depth local features is proposed. Depth discontinuity and depth variance are extracted from a low‐resolution depth map and a colour image as the depth local features. They are incorporated into an energy function for the Markov random field (MRF)‐based depth upsampling. The high‐resolution depth map is obtained by optimising the energy function using belief propagation. The experimental results show that the proposed method outperforms other depth upsampling approaches in terms of the bad pixel rate.
Coding advantage decomposition inequality for the space–frequency block codes
Authors: Morsali Alireza , Tofigh Sadegh , Mohammadian Zahra , Talebi Siamak
Published: January 2014

In this study, the authors present a new criterion which can be used to decompose the coding advantage (CA) of space–frequency block codes (SFBCs). The proposed decomposition separates the CA into two parts, called precoder‐CA and channel‐CA. The precoder‐CA represents the effects of the precoder and the signal constellation, and can be used in the design of the precoder of SFBCs. The channel‐CA, on the other hand, gives an indication of the effects of the channel characteristics, and can be utilised for optimising the permutation parameter. The authors have shown that the proposed decomposition method leads to a lower computational complexity for the optimisation procedure compared with the general form of the CA. As an application of the proposed method, the authors used it to optimise the channel‐CA of a high‐rate SFBC. Simulation results confirmed better performance for the modified high‐rate SFBC compared with recently proposed SFBCs in the literature.
Joint user scheduling and power allocation with quality of service guarantees in downlink distributed antennas system
Authors: Yan Jilei , Li Jiandong , Zhao Linjing
Published: January 2014

In this study, the authors study the downlink joint user scheduling and power allocation in a single‐cell distributed antennas system. Considering that all users are delay sensitive and without any assumption on the feasibility of the system, they formulate an optimisation problem to minimise the total power consumption while maximising the number of satisfied users. Given a user scheduling result, a deflation‐based joint user removal and power allocation algorithm and a conservative power allocation algorithm are proposed. Owing to the complexity in full enumeration of all user scheduling results, they further propose a joint heuristic user scheduling and power allocation algorithm, in which a priority parameter is defined to determine the user scheduling order and the conservative power allocation algorithm is applied to execute the power allocation. The user with the worst quality of experience is iteratively removed away from the active user set until all the remaining users are guaranteed with their quality of service requirements. Simulation results show that the authors proposed heuristic algorithm obtains a near optimal system performance in both user outage ratio and total power consumption.
Control of high voltage direct current links with overall large‐scale grid objectives
Authors: Arioua Leyla , Marinescu Bogdan , Monmasson Eric
Published: January 2014

When a high voltage direct current (HVDC) link connects two distinct power systems, the latter are usually modelled by two infinite buses. However, in some context of use, the HVDC links are no longer separating two systems but they are embedded into meshed AC systems in parallel with other AC lines and interact with other elements of the power system. This led us to enhance the control objectives by considering stability requirements. In this context, the previous modeling assumption presents serious limitations. Instead, a more efficient control model is used. It is developed such that the concerned dynamics of the system are taken into account during the synthesis. It is shown how the controllers of the HVDC converters can be synthesised using the control model mentioned above such that global grid performances are ensured, in addition to the local objectives like power and DC voltage control. In order to avoid remote measures, an output feedback control which uses only local measures is developed. The new controller is tested in comparison with the standard vector control and a non‐linear feedback linearisation control via simulation tests. The tests showed that the controller synthesised using the new control model contributes to a better coordination of the control actions and thus improve grid performances. In particular, the transient stability of the neighbour zone is a priori taken into account at the synthesis level.
Exploring the influence of traveller information on macroscopic fundamental diagrams
Authors: Zhao Ting‐ting , Li Zhi‐heng , Huang Bing‐yan , Mu Bei‐peng , Zhang Yi
Published: January 2014

Macroscopic fundamental diagrams (MFD), proposed by Geroliminis and Daganzo, describe the network‐wide average relation between the number of vehicles in the network and the output flow of the network. As pointed out by Geroliminis and Daganzo, several factors may influence MFD. The authors study the influence of traveller information on MFDs. The authors use microscopic simulation software TransModeler to model and simulate the dissemination of traveller information as well as the drivers’ route choice behaviours that had been affected by the information. The influences of several model parameters, including the informed percentage, the reroute time interval and the acceptable delay level, are also examined. To help preliminarily understand the information's influence, the homogeneity of road sections’ density distribution under different model parameters is also investigated. To further understand information's influence, incident information dissemination is investigated as a special case. An iterative model is proposed to depict traffic information's influence on incident‐induced congestion propagation. The analysis results are compared with simulation results to validate this model's effectiveness.
Driver fatigue and drowsiness monitoring system with embedded electrocardiogram sensor on steering wheel
Authors: Jung Sang‐Joong , Shin Heung‐Sub , Chung Wan‐Young
Published: January 2014

Real time driver health condition monitoring system with drowsiness alertness was proposed. A new embedded electrocardiogram (ECG) sensor with electrically conductive fabric electrodes on the steering wheel of a car was designed to monitor the driver's health condition. The ECG signals were measured at a sampling rate of 100 Hz from the driver's palms as they stay on a pair of conductive fabric electrodes located on the steering wheel. Practical tests were conducted using an embedded ECG sensor with a wireless sensor node, and their performance was assessed under non‐stop 2 h driving test. The ECG signals were measured and transmitted wirelessly to a base station connected to a server PC in personal area network environment. The driver's health condition such as the normal, fatigued and drowsy states was analysed by evaluating the heart rate variability in the time and frequency domains.
On‐line passenger estimation in a metro system using particle filter
Authors: Reyes Francisco , Cipriano Aldo
Published: January 2014

Urban metro rail systems are subject to high and growing demand as the populations of major cities increase. A point may be reached where improving system management using advanced control is more attractive than expanding the network. Control schemes for strengthening system performance and therefore user satisfaction typically involve measuring certain system state variables such as the numbers of passengers aboard trains and waiting at stations. Given the high cost of installing the necessary sensors, an alternative methodology is proposed for online estimation of the two variables using a particle filter. Experiments performed on a dynamic simulator show that the variable values can be inferred by measuring only train dwell‐times and passengers entering stations, data on which are generally accessible without major investment. The level of accuracy of the estimates generated by the methodology is high enough to enable a model‐based controller implemented in a real metro system to achieve significant performance improvements.
How does the use of a continuously updating database allow for the analysis of a user's changing behaviour in electric vehicles?
Authors: Hill Graeme A. , Blythe Phil T. , Suresh Visalakshmi
Published: January 2014

Environmental considerations mean that continuing to use internal combustion is, in the long term, unviable because of availability and cost of the fuel and the environmental effects of their emissions. If full electric vehicles (EVs) are to be a more sustainable method of transport then some of the perceived problems of EVs must be addressed, such as ‘range anxiety’ and ‘technical performance’. To do this it is necessary to understand how drivers behave in EVs, both through their overall trip statistics and their driving behaviour within trips. This has been achieved in this project through instrumenting the EVs with a direct link to the vehicle's controller area network bus, a global positioning system and a networked link to an always on database. Through analysis of the vehicle data, it has been possible to build up a quantitative picture of how the vehicles are typically used. Quantitative examples include trip lengths, trip efficiency correlated to the braking techniques and general driving behaviour changes such as improved efficiency at low battery levels. From this study it can be shown that it is possible to monitor EVs and selectively produce derived statistics which can be used to analyse the behaviour of drivers.
Polar format algorithm based on fast Gaussian grid non‐uniform fast Fourier transform for spotlight synthetic aperture radar imaging
Authors: Fan Bo , Wang Jiantao , Qin Yuliang , Wang Hongqiang , Xiao Huaitie
Published: January 2014

Conventional polar format algorithm (PFA) and its variations normally assume an ideal imaging geometry of a linear flight path, which cannot counteract the non‐uniformity of samples existing in the circumstance of a highly non‐linear aperture. This scenario may occur because of various factors such as rugged topography, atmospheric turbulence and intended manoeuvres. To address this challenge, this study develops a novel PFA with aperture accommodation for spotlight synthetic aperture radar (SAR) imaging. The proposed algorithm provides a new adaption of the fast Gaussian grid (FGG) non‐uniform fast Fourier transform (NUFFT) scheme to two‐dimensional (2D) SAR imaging of 3D scene, whose main idea is to convolve the non‐uniform samples onto a uniform grid with a Gaussian kernel and then exploit the efficient 2D FFT for image reconstruction. In virtue of the 2D FGG NUFFT, a favourable tradeoff between reconstruction precision and computational efficiency is gained. Simulations illustrate the superiority of the proposed algorithm over the conventional non‐uniform Sinc interpolation method. Also, the public real Gotcha dataset validates the effectiveness of the authors method.
Space‐time adaptive processing for phased‐multiple‐input–multiple‐output radar in the non‐homogeneous clutter environment
Authors: Ahmadi Moein , Mohamed‐pour Kamal
Published: January 2014

This study presents some new methods for space‐time adaptive processing for airborne multiple‐input–multiple‐output (MIMO) radar with co‐located antennas in the non‐homogeneous environment. The presented signal model is a general model for airborne phased‐MIMO radar which can easily switch between conventional phased‐array radar and MIMO radar to enjoy the advantages of the MIMO radar without sacrificing the main advantage of the phased‐array radar which is the coherent processing gain at the transmitting side. In the non‐homogeneous environment, the training data with the same statistical interference characteristics is not available to estimate interference covariance matrix, the authors present two space‐time adaptive processing (STAP) approaches. The first one is based on the orthogonal projection on the clutter subspace which is applicable for known clutter signature scenarios. The matrix which describes the signature of ground clutter for airborne phased‐MIMO radar is derived. For unknown clutter subspace, they propose the deterministic phased‐MIMO STAP (also known as direct data domain approach) which suppresses the interference signal without the requirement for an interference covariance matrix. The parameters of deterministic phased‐MIMO STAP are determined to maximise the degree of freedoms. Simulations are provided to demonstrate the performance of the proposed STAP approaches in the non‐homogeneous environments.
Multiply associating electrolytes in the binding mean spherical approximation: Thermodynamic properties and speciation
Authors: Bernard O. , Torres-Arenas J. , Simonin J.-P.
Published: January 2014

Ionic solutions exhibiting multiple association are described within the binding mean spherical approximation (BiMSA). This model is based on the Wertheim formalism, in the framework of the primitive model at the McMillan-Mayer level. The cation and the anion form the various complexes according to stepwise complexation-equilibria. Analytic expressions for the Helmholtz energy, the internal energy, the speciation, and for the osmotic and activity coefficients are given considering a binary solution with an arbitrary number of association sites on one type of ion (polyion) and one site on the ions of opposite sign (counterions). As an alternative, mean field expressions, as developed in SAFT-type theories, are also presented. The result obtained from the latter approximate method exhibits a reasonable agreement with those from BiMSA for the speciation, and a remarkable one for the osmotic coefficient.
Suppression of unimolecular decay of laser desorbed peptide and protein ions by entrainment in rarefied supersonic gas jets under weak electric fields
Authors: Hieke Andreas
Published: January 2014

Unimolecular decay of sample ions imposes a limit on the usable laser fluence in matrix-assisted laser desorption/ionization (MALDI) ion sources. Traditionally, some modest degree of collisional sample ion cooling has been achieved by connecting MALDI ion sources directly to gas-filled radio frequency (RF) multipoles. It was also discovered in the early 1990s that gas-filled RF multipoles exhibit increased ion transmission efficiency due to collisional ion focusing effects. This unexpected experimental finding was later supported by elementary Monte Carlo simulations. Both experiments and simulations assumed a resting background gas with typical pressures of the order of 1 Pa. However, considerable additional improvements can be achieved if laser desorbed sample ions are introduced immediately after desorption, still within the ion source, in an axisymmetric rarefied supersonic gas jet with peak pressure of the order of 100 Pa and flow velocities >300 m/s, and under weak electric fields. We describe here the design principle and report performance data of an ion source coined “MALDI-2,” which incorporates elements of both rarefied aerodynamics and particle optics. Such a design allows superb suppression of metastable fragmentation due to rapid collisional cooling in <10 μs and nearly perfect injection efficiency into the attached RF ion guide, as numerous experiments have confirmed.
Characterization of InGaN/GaN quantum well growth using monochromated valence electron energy loss spectroscopy
Authors: Palisaitis J. , Lundskog A. , Forsberg U. , Janzén E. , Birch J. , Hultman L. , Persson P. O. Å.
Published: January 2014

The early stages of InGaN/GaN quantum well growth for In-reduced conditions have been investigated for varying thickness and composition of the wells. The structures were studied by monochromated scanning transmission electron microscopy–valence electron energy loss spectroscopy spectrum imaging at high spatial resolution. It is found that beyond a critical well thickness and composition, quantum dots (width >20 nm) are formed inside the well. These are buried by compositionally graded InGaN, which is formed as GaN is grown while residual In is incorporated into the growing structure. It is proposed that these dots act as carrier localization centers inside the quantum wells.
Inverted time-of-flight spectrometer for mass-to-charge analysis of plasma
Authors: Gushenets V. I. , Burachevsky Yu. A. , Vizir A. V. , Oks E. M. , Savkin K. P. , Tynkov A. V. , Yushkov G. Yu.
Published: January 2014

The paper describes the principle of operation, design special features, and parameters of an inverted time-of-flight spectrometer. The spectrometer is designed in such way that its deflecting plates, drift tube, and primary measuring system are at high potential with respect to the ground potential, whereas plasma is formed near grounded electrodes. This type of configuration greatly extends the application range of the device, making it possible to measure the mass-to-charge composition of plasma with wide range of parameters.
Thermoelectric properties of the Heusler-type Fe2VTaxAl1−x alloys
Authors: Renard Krystel , Mori Arinori , Yamada Yuichiro , Tanaka Suguru , Miyazaki Hidetoshi , Nishino Yoichi
Published: January 2014

This study focuses on the thermoelectric properties of the Heusler-type Fe2VTaxAl1−x alloys (0≤x≤0.12). By means of Rietveld analyses on synchrotron X-ray diffraction patterns, it is shown that the Ta atoms enter sites occupied by V atoms in the stoichiometric Fe2VAl alloy, while the ejected V atoms are transferred to the vacant Al sites. This Ta substitution leads to an improvement of the n-type thermoelectric properties owing to two mechanisms. On the one hand, the atoms position in the structure leads to an off-stoichiometric effect such as already observed in V-rich Fe2V1+yAl1−y compounds: the Seebeck coefficient is increased towards negative absolute values and the electrical resistivity is decreased, with a large shift of their peak temperature towards higher temperature. The maximum power factor is 6.5 × 10−3 W/mK2 for x = 0.05 at 340 K. On the other hand, the heavy element Ta substitution combined with this off-stoichiometric effect leads to a large decrease of the thermal conductivity, owing to an increase of the scattering events. Consequently, the dimensionless figure of merit is seen to reach higher values than for the Fe2V1+yAl1−y alloys, i.e., 0.21–0.22 around 400–500 K for x = 0.05 and 500 K for x = 0.08.
Solvation of Coumarin 480 within nano-confining environments: Structure and dynamics
Authors: Elola M. Dolores , Rodriguez Javier
Published: January 2014

Equilibrium and dynamical characteristics pertaining to the solvation of the fluorescent probe Coumarin 480 within different confining environments are investigated using molecular dynamics simulations. Three kinds of confining systems are examined: (i) the cetyltrimethylammonium bromide (CTAB)/isooctane/1-hexanol/water; cationic inverse micelle (IM) (ii) a CTAB/water direct micelle (DM), and (iii) a silica-surfactant nanocomposite, comprising a cylindrical silica pore (SP) containing small amounts of water and CTAB species adsorbed at the pore walls. The solvation structures in the three environments differ at a qualitative level: an exchange between bulk- and interface-like solvation states was found in the IM, whereas in the DM, the solvation states of the probe are characterized by its embedding at the interface, trapped among the surfactant heads and tails. Within the SP structure, the coumarin exhibits alternations between internal and interfacial solvation states that occur on a ∼20 ns time scale and operate via 90° rotations of its molecular plane. The solvation responses of the environment following a vertical excitation of the probe are also investigated. Solvation times resulted between 2 and 1000 times longer than those found in bulk water, with a fast-to-slow trend IM→DM→SP, which can be interpreted in terms of the solvation structures that prevail in each case.