bluuebunny/crossref_metadata_2025 huggingface dataset:
eLearning a New Way for Saving: Guild's Survey as a Case Study
Authors: Obedidat Abdelsalam , AbuAli Amer Nizar , Ghwanmeh Sameh
Published: November 2013

In the early days of eLearning, there was an awful lot of hype about expected results from eLearning initiatives. One of the biggest was about how much money organizations could save through eLearning. ELearning provides increased opportunities for delivering and taking part in learning, but building and delivering eLearning is typically not as inexpensive as we were once promised. Here are some of the more common costs associated with eLearning: Content development, Course design and development, Project management processes and tools, Authoring and multimedia development tools, Infrastructure, including Learning Management Systems. Although, better training may drive improved performance, many organizations still find themselves needing to reduce the costs of designing, building, and delivering eLearning. The main objective of this paper is discovering how eLearning could cut down the cost for organizations benefiting from Guild's survey.
Automatic Music Genre Classification of Audio Signals with Machine Learning Approaches
Authors: Chathuranga Dhanith , Jayaratne Lakshman
Published: November 2013

Musical genre classification is put into context by explaining about the structures in music and how it is analyzed and perceived by humans. The increase of the music databases on the personal collection and the Internet has brought a great demand for music information retrieval, and especially automatic musical genre classification. In this research we focused on combining information from the audio signal than different sources. This paper presents a comprehensive machine learning approach to the problem of automatic musical genre classification using the audio signal. The proposed approach uses two feature vectors, Support vector machine classifier with polynomial kernel function and machine learning algorithms. More specifically, two feature sets for representing frequency domain, temporal domain, cepstral domain and modulation frequency domain audio features are proposed. Using our proposed features SVM act as strong base learner in AdaBoost, so its performance of the SVM classifier cannot improve using boosting method. The final genre classification is obtained from the set of individual results according to a weighting combination late fusion method and it outperformed the trained fusion method. Music genre classification accuracy of 78% and 81% is reported on the GTZAN dataset over the ten musical genres and the ISMIR2004 genre dataset over the six musical genres, respectively. We observed higher classification accuracies with the ensembles, than with the individual classifiers and improvements of the performances on the GTZAN and ISMIR2004 genre datasets are three percent on average. This ensemble approach show that it is possible to improve the classification accuracy by using different types of domain based audio features.
Five new species of Utricularia (Lentibulariaceae) from Australia
Authors: Jobson Richard W
Published: November 2013

Utricularia fenshamii R.W.Jobson, U. ameliae R.W.Jobson, U. barkeri R.W.Jobson, U. grampiana R.W.Jobson, and U. lowriei R.W.Jobson (Lentibulariaceae) are described as new and are considered members of Utricularia subg. Polypompholyx section Pleiochasia. The distribution and habitat preferences of these species are discussed. The morphological differences between all five species and species to which they are allied are here discussed and identification keys provided.
Circumscription and phylogenetic relationship of Prostanthera densa and P. marifolia (Lamiaceae)
Authors: Conn Barry John , Wilson Trevor C , Henwood Murray J , Proft Kristin
Published: November 2013

Prostanthera densa A.A.Ham. and P. marifolia R.Br. (Lamiaceae) are endemic species with restricted distributions within the near-coastal regions of New South Wales (Australia). Prostanthera marifolia was previously presumed extinct, but is now known from a small population in the Manly-Warringah area of metropolitan Sydney, and is morphologically very similar to P. densa. Prostanthera densa is known from five disjunct populations, distributed from Port Stephens (in the north) to Jervis Bay (in the south). The sequence variation of two chloroplast spacer regions, trnT-trnL and psbA-trnH, and the external transcribed spacer (ETS) region of nuclear ribosomal DNA were analysed to evaluate the phylogenetic relationship and taxonomic integrity of these species. Although trnT-trnL data were uninformative, trees generated from psbA-trnH data provided support for recognising P. marifolia as a distinct species sister to P. densa. A multivariate evaluation of the variation in morphological characters also supported the distinction of these two morphologically similar and closely related species. The ETS data indicated that each of the disjunct populations of P. densa were genetically isolated. Since there was no gene flow between populations of P. densa, it was concluded that the conservation of this species requires all populations to be protected.
The role of loss of control eating in purging disorder
Authors: Forney K. Jean , Haedt‐Matt Alissa A. , Keel Pamela K.
Published: November 2013

Objective

Purging Disorder (PD), an Other Specified Feeding or Eating Disorder (APA, 2013), is characterized by recurrent purging in the absence of binge eating. Though objectively large binge episodes are not present, individuals with PD may experience a loss of control (LOC) while eating a normal or small amounts of food. The present study sought to examine the role of LOC eating in PD using archival data from 101 women with PD.

Method

Participants completed diagnostic interviews and self‐report questionnaires. Analyses examined the relationship between LOC eating and eating disorder features, psychopathology, personality traits, and impairment in bivariate models and then in multivariate models controlling for purging frequency, age, and body mass index.

Results

Across bivariate and multivariate models, LOC eating frequency was associated with greater disinhibition around food, hunger, depressive symptoms, negative urgency, distress, and impairment.

Discussion

LOC eating is a clinically significant feature of PD and should be considered in future definitions of PD. Future research should examine whether LOC eating better represents a dimension of severity in PD or a specifier that may impact treatment response or course. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:244–251)
Concurrent and convergent validity of the eating in the absence of hunger questionnaire and behavioral paradigm in overweight children
Authors: Madowitz Jennifer , Liang June , Peterson Carol B. , Rydell Sarah , Zucker Nancy L. , Tanofsky‐Kraff Marian , Harnack Lisa , Boutelle Kerri N.
Published: November 2013

Objective

This study aimed to assess the concurrent and convergent validity of the Eating in the Absence of Hunger (EAH) questionnaire parent report of child (EAH‐PC) and child self‐report (EAH‐C) with the EAH behavioral paradigm (EAH%) and usual dietary intake.

Method

Data were obtained at baseline assessment for 117 treatment‐seeking overweight and obese (BMI > 85th percentile) 8‐ to 12‐year old children (53% female, 54% white) and their parents. Children participated in the EAH free access paradigm after a standardized ad libitum meal. Parents and children completed EAH questionnaires, and the children completed three 24 h recalls. EAH External Eating subscale and total scores were assessed.

Results

EAH% was inversely associated with the EAH‐PC total score (p < .04), however, it was not associated with the EAH‐PC External Eating scale, EAH‐C total score or EAH‐C External Eating scale. Daily caloric intake was positively related to both the EAH‐C total score (p < .02) and External Eating subscale (p < .007). Daily caloric intake was inversely related to EAH‐PC total score (p < .05), but was not related to EAH‐PC External Eating subscale or EAH%.

Discussion

Concurrent validity was not supported for EAH questionnaires, but convergent validity was supported for EAH‐C and child daily caloric intake. Further research is warranted to assess whether EAH questionnaires and paradigm are measuring different aspects of EAH in treatment‐seeking children. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:287–295)
CCK8 negatively regulates the TLR9‐induced activation of human peripheral blood pDCs by targeting TRAF6 signaling
Authors: Jia Xianxian , Cong Bin , Zhang Jingge , Li Hui , Liu Wenxuan , Chang Heping , Dong Mei , Ma Chunling
Published: November 2013

Plasmacytoid dendritic cells (pDCs) are specialized in rapid and massive secretion of type I interferon in response to foreign nuclei acids. Combined with their antigen presentation capacity, this powerful functionality enables pDCs to orchestrate innate and adaptive immune responses. Cholecystokinin octapeptide (CCK8) is a potent immunomodulator, whose role in pDCs function is unknown. In this study, we found that two different cholecystokinin receptors, CCK1R and CCK2R, are expressed on human peripheral blood pDCs. Exogenous CCK8 was able to modulate the TLR‐induced activation of pDCs, including phenotypic maturation, IFN‐α synthesis and secretion, and could also regulate the potential of pDCs to induce adaptive immune responses in vitro. CCK8 inhibited TLR9‐induced activation of tumor‐necrosis factor receptor‐associated factor 6, which is an important adapter protein in activation of interferon‐regulatory factor (IRF)5 and IRF7, possibly through CCK2R, by evoking the activity of protein kinase (PK)A and reducing the activity of PKC. All these results indicate that CCK8 can inhibit the TLR9‐induced phenotypic maturation and activation of pDCs, acting through CCK2R by modulating the tumor‐necrosis factor receptor‐associated factor 6 signaling pathways.
Exploring transition state structures for intramolecular pathways by the artificial force induced reaction method
Authors: Maeda Satoshi , Taketsugu Tetsuya , Morokuma Keiji
Published: November 2013

Finding all required transition state (TS) structures is an important but hard task in theoretical study of complex reaction mechanisms. In the present article, an efficient automated TS search method, artificial force induced reaction (AFIR), was extended to intramolecular reactions. The AFIR method has been developed for intermolecular associative pathways between two or more reactants. Although it has also been applied to intramolecular reactions by dividing molecules manually into fragments, the fragmentation scheme was not automated. In this work, we propose an automated fragmentation scheme. Using this fragmentation scheme and the AFIR method, a fully automated search algorithm for intramolecular pathways is introduced. This version for intramolecular reactions is called single‐component AFIR (SC‐AFIR), to distinguish it from multicomponent AFIR for intermolecular reactions. SC‐AFIR was tested with two reactions, the Claisen rearrangement and the first step of cobalt‐catalyzed hydroformylation, and successfully located all important pathways reported in the literature. © 2013 Wiley Periodicals, Inc.
A comprehensive conformational analysis of tryptophan, its ionic and dimeric forms
Authors: Purushotham Uppula , Sastry G. Narahari
Published: November 2013

Tryptophan is an essential amino acid, and understanding the conformational preferences of monomer and dimer is a subject of outstanding relevance in biological systems. An exhaustive first principles investigation of tryptophan (W) and its ionized counterparts cations (WC), anions (WA), and zwitterions (WZ) has been carried out. A comprehensive and systematic study of tryptophan dimer (WD) conformations resulted in about 62 distinct minima on the potential energy surface. The hydrogen bonds and a variety of noncovalent interactions such as OH‐π, NH‐π, CH‐π, CH‐O, and π‐π interactions stabilized different forms of tryptophan and its dimers. Over all in monomeric conformers which have NH‐O, hydrogen bonds showed higher stability than other conformers. A cursory analysis reveal that the most stable dimers stabilized by hydrogen bonding interactions while the less stable dimers showed aromatic side chain interactions. Protein Data Bank analysis of tryptophan dimers reveals that at a larger distance greater than 5 Å, T‐shaped orientations (CH‐π interactions) are more prevalent, while stacked orientations (π‐π interactions) are predominant at a smaller distance. © 2013 Wiley Periodicals, Inc.
Effects of propentofylline on CNS remyelination in the rat brainstem
Authors: Fernandes Bondan Eduardo , de Fátima Monteiro Martins Maria , Menezes Baliellas Deborah Eileen , Monteiro Gimenez Caio Fernando , Castro Poppe Sandra , Martha Bernardi Maria
Published: November 2013

Propentofylline (PPF) is a xanthine derivative with pharmacological effects distinct from those of the classical methylxanthines. It depresses activation of microglial cells and astrocytes which is associated with neuronal damage during neural inflammation and hypoxia. The aim of this study was to evaluate whether PPF had the capacity of affecting glial cells behavior during the process of demyelination and remyelination following ethidium bromide (EB) gliotoxic injury. EB injection into the CNS is commonly used as an experimental demyelinating model inducing local oligodendroglial and astrocytic death, which results in primary demyelination, blood–brain barrier and glia limitans disruption and Schwann cells invasion. Sixty Wistar rats were divided into four different groups receiving 10 microlitres of 0.1% EB or 0.9% saline solution into the cisterna pontis and treated or not with the xanthine. PPF treatment was done using 12.5 mg/kg/day by the intraperitonial route for 31 days of the experimental period. The rats were euthanized from 7 to 31 days after EB injection and brainstem sections were collected and processed for light and transmission electron microscopy studies. Results from both groups were compared by using a semi‐quantitative method developed for documenting in semithin sections the extent and nature of remyelination of demyelinating lesions. Results showed that PPF administration after EB injection significantly increased both oligodendroglial and Schwann cell remyelination at 31 days (mean remyelination scores of 3.67 ± 0.5 for oligodendrocytes and 1.27 ± 0.49 for Schwann cells) compared to untreated animals (scores of 3.19 ± 0.57 and 0.90 ± 0.33, respectively). Microsc. Res. Tech. 77:23–30, 2014. © 2013 Wiley Periodicals, Inc.
Long‐term chlorhexidine effect on bond strength to Er:YAG laser irradiated‐dentin
Authors: Galafassi Daniel , Scatena Camila , Colucci Vivian , Rodrigues Antonio Luiz , Campos Serra Mônica , Milori Corona Silmara Aparecida
Published: November 2013

This study evaluates the bond strength of dentin prepared with Er:YAG laser or bur, after rewetting with chlorhexidine on long‐term artificial saliva storage and thermocycling. One hundred and twenty human third molars were sectioned in order to expose the dentin surface (n = 10). The specimens were randomly divided in 12 groups according to treatment and aging: Er:YAG laser rewetting with deionized water (LW) and 24 h storage in artificial saliva (WC); LW and 6 months of artificial saliva storage + 12.000 thermocycling (6M), LW and 12 months of artificial saliva storage + 24.000 thermocycling (12M), Er:YAG laser rewetting with 2% chlorhexidine (LC) and WC, LC and 6M, LC and 12M, bur on high‐speed turbine rewetting with deionized water (TW) and WC, TW6M, TW12M, bur on high‐speed turbine + 2% chlorhexidine (TC) and WC, TC and 6M, TC and12M. The specimens were etched with 35% phosphoric acid, washed, and dried with air. Single Bond 2 adhesive was applied and the samples were restored with a composite. Each tooth was sectioned in order to obtain 4 sticks, which were submitted to microtensile bond strength test (µTBS). The two‐way ANOVA, showed no significant differences for the interaction between the factors and for the aging factor. Tukey 5% showed that the LC group had the lowest µTBS. The rewetting with chlorhexidine negatively influenced the bond strength of the preparation with the Er:YAG laser. The artificial saliva aging and thermocycling did not interfere with dentin bond strength. Microsc. Res. Tech. 77:37–43, 2014. © 2013 Wiley Periodicals, Inc.
The top‐down, middle‐down, and bottom‐up mass spectrometry approaches for characterization of histone variants and their post‐translational modifications
Authors: Moradian Annie , Kalli Anastasia , Sweredoski Michael J. , Hess Sonja
Published: November 2013

Epigenetic regulation of gene expression is, at least in part, mediated by histone modifications. PTMs of histones change chromatin structure and regulate gene transcription, DNA damage repair, and DNA replication. Thus, studying histone variants and their modifications not only elucidates their functional mechanisms in chromatin regulation, but also provides insights into phenotypes and diseases. A challenge in this field is to determine the best approach(es) to identify histone variants and their PTMs using a robust high‐throughput analysis. The large number of histone variants and the enormous diversity that can be generated through combinatorial modifications, also known as histone code, makes identification of histone PTMs a laborious task. MS has been proven to be a powerful tool in this regard. Here, we focus on bottom‐up, middle‐down, and top‐down MS approaches, including CID and electron‐capture dissociation/electron‐transfer dissociation based techniques for characterization of histones and their PTMs. In addition, we discuss advances in chromatographic separation that take advantage of the chemical properties of the specific histone modifications. This review is also unique in its discussion of current bioinformatic strategies for comprehensive histone code analysis.
Magnetic bead assisted labeling of antibodies at nanogram scale
Authors: Dezfouli Mahya , Vickovic Sanja , Iglesias Maria Jesus , Nilsson Peter , Schwenk Jochen M. , Ahmadian Afshin
Published: November 2013

There are currently several initiatives that aim to produce binding reagents for proteome‐wide analysis. To enable protein detection, visualization, and target quantification, covalent coupling of reporter molecules to antibodies is essential. However, current labeling protocols recommend considerable amount of antibodies, require antibody purity and are not designed for automation. Given that small amounts of antibodies are often sufficient for downstream analysis, we developed a labeling protocol that combines purification and modification of antibodies at submicrogram quantities. With the support of magnetic microspheres, automated labeling of antibodies in parallel using biotin or fluorescent dyes was achieved.
Understanding control of calcitic biomineralization—Proteomics to the rescue
Authors: Hincke Maxwell T.
Published: November 2013

The avian eggshell is one of the fastest calcifying processes known and represents a unique model for studying biomineralization. Eggshell strength is a crucial economic trait for table egg production, and ensures that a safe egg reaches the consumer kitchen. However, a common toolkit for eggshell mineralization has not yet been defined. In this issue, label‐free MS‐based protein quantification technology has been used by Sun et al. (Proteomics 2013, 13, 3523–3536) to detect differences in protein abundance between eggshell matrix from strong and weak eggs and between the corresponding uterine fluids bathing strong and weak eggs. Proteins associated with the formation of strong eggshells are identified, which are now candidates for further investigations to define the regulatory relationship between specific eggshell matrix proteins and calcite crystal texture.
Current approaches to managing fear of cancer recurrence; a descriptive survey of psychosocial and clinical health professionals
Authors: Thewes B. , Brebach R. , Dzidowska M. , Rhodes P. , Sharpe L. , Butow P.
Published: November 2013

Objective

Fear of cancer recurrence (FCR) is common amongst cancer survivors and help with this problem is the most frequently reported unmet need in this population. This study investigated how FCR is perceived and managed by clinical health professionals (medical and nursing staff) and psychosocial professionals in oncology settings.

Methods

Clinical health professionals and psychosocial professionals in oncology settings received emailed invitations from their professional organisation to participate in an online survey.

Results

Data from 77 clinical health professionals and 64 psychosocial professionals indicate that FCR is perceived as common and challenging to manage. Thirty‐one percent of psychosocial professionals estimated FCR is present in >50% of cancer survivors seen in their practise. Only a minority (21%) of clinical staff reported always referring patients with high levels of FCR to psychosocial support. Strategies for managing FCR differed considerably amongst psychosocial professionals, and most reported that aspects of acceptance and commitment therapy and/or cognitive behaviour therapy were helpful. Greater than 99% of participants were interested in training to help patients manage FCR.

Conclusions

Fear of cancer recurrence is commonly identified in oncology settings and a common focus of discussion in follow‐up care. However, patients with high levels of FCR are not routinely referred to psychosocial staff, and barriers to referral to psychosocial care should be investigated. The diversity of approaches reported by psychosocial professionals suggests lack of consensus regarding management of FCR, indicating that the development effective, theoretical‐based intervention and evidence‐based intervention for FCR is a matter of priority. Copyright © 2013 John Wiley & Sons, Ltd.
Factoring Central Asia into China's Afghanistan Policy
Authors: Dhaka Ambrish
Published: November 2013

China's footprints in Afghanistan are vied by many, both, friends and rivals as it cautiously reveals its geostrategic goals. It would like to emulate the African and Central Asian success story in Afghanistan as well, which is not terra incognito. Afghanistan has been the fulcrum of geopolitical balance of power during the Cold war days. China's Afghanistan policy (CAP) is marked by its insecurities of terrorism, extremism and separatism in Xinjiang province. It has heavily invested in procuring Central Asian energy resources. Both, the concerns go well in formulation of CAP. However, the presence of the US and Russia make the scenario competitive, where its ‘Peaceful Rise’ may be contested. Besides, China sees South Asian Region as its new Geoeconomic Frontier. All these concerns get factored into CAP. It remains to be seen what options partake in CAP, as China prepares for durable presence in Afghanistan in the long run.
Resilienz fördern
Authors: Kobelt Neuhaus Daniela
Published: November 2013

Resilienz umschreibt die Tatsache, dass es Menschen trotz belastender Lebensumstände gelingt, ihr Leben erfolgreich zu meistern. Resilienzförderliche Faktoren werden nicht nur in der Person selbst, sondern auch im Umfeld gefunden. Verlässliche, optimistische Bezugspersonen und ressourcenorientierte Fachkräfte tragen dazu bei, dass Kinder und Familien Eigenschaften und Kompetenzen entwickeln, die trotz Krankheit oder Behinderung eine nach vorne gerichtete Entwicklung ermöglichen.
Familien mit einem chronisch kranken oder behinderten Kind
Authors: Büker Christa
Published: November 2013

Familien mit einem gesundheitlich beeinträchtigten Kind haben spezifische Unterstützungserfordernisse. Gesundheits- und Kinderkrankenpfleger/innen aus ambulanten Pflegediensten können wertvolle Hilfestellung leisten.
Primary Nursing als Form der Angehörigenintegration nutzen
Authors: Wilhelm Beate
Published: November 2013

Primary Nursing ist ein personenbezogenes Pflegesystem. Von der Aufnahme bis zur Entlassung ist eine Pflegekraft für den Patienten, das Kind und dessen Familie verantwortlich. Die Umsetzung von Primary Nursing stellt vielfältige Anforderungen an die Institution und den Einzelnen. Damit und mit der Frage, wie diese Anforderungen gewinnbringend gehandhabt werden können beschäftigt sich der nachfolgende Artikel ebenso wie mit den Möglichkeiten der Angehörigenintegration im Pflegesystem Primary Nursing.
Psychosoziale Elternberatung in der Neonatologie
Authors: von der Hude Kerstin
Published: November 2013

Die psychosoziale Elternberatung (EB) im Perinatalzentrum der Charité Berlin betreut Familien von frühgeborenen Kindern, sowie sehr kranken Neugeborenen. Die Mitarbeiterinnen sind speziell geschulte Intensivkinderkrankenschwestern, die ausschließlich für die psychosoziale Beratung und Begleitung dieser Eltern zur Verfügung stehen.
Commitment, Motivation und Kompetenz von Dozenten in der Weiterbildung
Authors: Oehmen Ulrike
Published: November 2013

Diese empirische Untersuchung im Rahmen der Promotion der Autorin, beschäftigte sich mit den festangestellten und freiberuflichen Dozenten im Gesundheitswesen. Im Fokus lag die Frage, welche Wirkung die Art des Beschäftigungsverhältnisses auf Commitment, Motivation und Kompetenz hat. Eines der Resultate: Das Verständnis der pädagogischen Kompetenz wird im Wesentlichen von fachlichem, weniger von wissenschaftlichem Wissen geprägt.
Was bietet die Pflegedidaktik?
Authors: Walter Anja , Altmeppen Sandra , Arens Frank , Bohrer Annerose , Brinker-Meyendriesch Elfriede , Dütthorn Nadin , Käding Heiko , Pohl Maria , Schwarz-Govaers Renate , Welling Karin
Published: November 2013

Die Mitglieder der Sektion Bildung der Deutschen Gesellschaft für Pflegewissenschaft präsentieren in diesem Artikel die verdichteten Ergebnisse der Analyse pflegedidaktischer Arbeiten im Sinne einer Standortbestimmung der Pflegedidaktik für PflegepädagogInnen in (Hoch)Schule und Pflegepraxis.
Bildmaterial für pflegebezogene Patienten- und Familienedukation
Authors: Kocks Andreas , Abt-Zegelin Angelika
Published: November 2013

Bilder umgeben uns täglich, sie erzeugen Emotionen, stellen Fragen oder regen zu Gedanken, Wünschen und Sorgen an. Im Zusammenhang mit Broschüren zur Patienten- und Familienedukation können Bilder komplexe Sachverhalte darstellen, Interesse für Themen wecken oder einfach ansprechend sein. Wichtig ist es, die Zielgruppe mit den Bildern anzusprechen.
Pflegepublizistik-Preis 2013
Authors: Georg Jürgen
Published: November 2013

Anlässlich des Drei-Länderkongresses am 15.9.2013 in Konstanz wurde Prof. Dr. Angelika Zegelin mit dem Pflegepublizistik-Preis geehrt. Der folgende Beitrag dokumentiert die Laudatio von Jürgen Georg.
Performance of varifocal lenses using KTa1 − xNbxO3 crystals with response times faster than 2 μs
Authors: Imai T. , Takayama Y. , Miyazu J. , Kobayashi J.
Published: November 2013

A varifocal lens (previously reported by the authors) made of a single crystal of potassium tantalite niobate (KTa1−xNbxO3, KTN) is characterised by its fast responses and large apertures (∼ 3 mm). Presented is a report on the focus shift performance of this varifocal lens with response times of < 2 μs. To investigate this quick response, a strobe technique was introduced. It was confirmed that the KTN lens changed its lens power in 2 μs as predicted by the theory stating that the lens power is proportional to the square of the applied voltage. The lens power can be controlled from 0 to 0.8 m−1 at a wavelength of 1.06 μm.
Accurate calibration of mutual coupling for conformal antenna arrays
Authors: Huang Qiulin , Zhou Hongxing , Bao Jian , Shi Xiaowei
Published: November 2013

The element pattern reconstruction method is proposed to calibrate the mutual coupling effect of conformal antenna arrays. The calibration matrix due to the proposed calibration method is obtained through the transformation of element patterns rather than the analysis of currents or voltages on the antenna array, which is different from previous calibration methods. The new method can provide effective mutual coupling calibrations for conformal antenna arrays. A conformal microstrip array is designed to verify the effectiveness of the new calibration method.
VCO utilising bilaterally coupled transformer‐based resonator
Authors: Yen T.‐A. , Wang T. , Feng W.‐S.
Published: November 2013

The bilateral transformer coupling technique is proposed to improve the phase noise of the transformer‐based voltage controlled oscillator (VCO). Current‐reuse and self‐injection locking techniques are also included and demonstrated in CMOS 0.18 µm technology. The oscillation frequency ranges from 5.02 to 5.41 GHz. The output power is − 1.2 dBm, the phase noise at 1 MHz offset frequency is − 128 dBc/Hz and the chip size is 0.478 mm2. The power consumption is 3.6 mW. The figure‐of‐merit of this oscillator is − 197.
Fast genetic algorithm for robot path planning
Authors: Lee J. , Kang B.‐Y. , Kim D.‐W.
Published: November 2013

An efficient genetic algorithm‐based robot path planning method is proposed that finds collision‐free paths while minimising the distance of the paths obtained. By using an improved evaluation and natural selection process, the proposed robot path planning method provides markedly faster computation and better success rates than well‐known conventional methods.
Cross‐relation‐based frequency‐domain blind channel estimation with multiple antennas in orthogonal frequency division multiplexing systems
Authors: Park Jaehyun , Chun Joohwan , Jeong Byung Jang
Published: November 2013

Frequency domain blind channel estimation methods for orthogonal frequency division multiplexing (OFDM) systems with multiple antennas are proposed, in which the cross relation between the channel gains and a single snapshot of the received signal on each subcarrier is utilised. Necessary and sufficient conditions for the identifiability of a single‐input multiple‐output OFDM channel estimator are derived and, furthermore, using a first‐order perturbation analysis, the approximation of mean‐squared‐error (MSE) is analytically obtained, which shows that the proposed estimator is approximately unbiased at high signal‐to‐noise ratio. The proposed estimator exhibits lower MSEs than those of both the existing subspace‐based and deterministic blind channel estimators and is less sensitive to the estimation error of the number of multipaths. Finally, the extension of the proposed channel estimation to multiple‐input–multiple‐output OFDM is presented.
Non‐cooperative uplink interference protection framework for fair and energy efficient orthogonal frequency division multiple access networks
Authors: Vaca Ramírez Rodrigo A. , Thompson John S. , Ramos Ramos Víctor M.
Published: November 2013

In this study, the authors consider a low complexity resource allocation scheme for reducing the uplink cochannel interference (CCI). The goal is to obtain improvements in energy efficiency by controlling the level of CCI affecting vulnerable mobile stations (MSs). This is done with a combined scheduler and a two layer power allocation scheme, which is based on non‐cooperative game theory. The authors approach forces users with good propagation conditions to reduce transmission power, to protect users experiencing high levels of interference. Thus, the MSs’ uplink throughputs are equalised under the max–min fairness optimisation criterion. The scheme they propose works with minimum channel knowledge, since only base‐mobile channel path gains are required for the optimisation process. Furthermore, they show analytically and by simulation that the power reductions applied to users with good propagation conditions provide an increase in energy efficiency and fairness in the system. In addition, the simulation results show that their scheme provides a higher fairness index and a comparable system energy efficiency to a centralised signal interference noise ratio balancing scheme.
On the capacity of multiple‐input multiple‐output Gaussian X channels
Authors: Li Jing , Ge Jianhua , Sun Chuiqiang , Zhu Bin
Published: November 2013

Finding the capacity region of a Gaussian X network is an open problem in information theory. In this study, the authors characterise the capacity regions of 2 × 2 user multiple‐input multiple‐output Gaussian X channels for very strong interference and generally strong interference. Moreover, the sum capacity is established for noisy interference. Sufficient conditions for Gaussian X networks to have very strong interference, generally strong interference and noisy interference are derived.
Two time slots distributed time‐reversal space‐time block coding for single‐carrier block transmissions
Authors: Wang Qiucai , Yuan Chaowei , Zhang Jinbo , Du Jianhe
Published: November 2013

Distributed space‐time block coding (STBC) is a promising technique for future broadband wireless communication system, because of its substantially improving the reliability of wireless channel by exploiting cooperative spatial diversity. In this study, the authors propose a novel two time slots distributed time‐reversal STBC scheme for amplify‐and‐forward relay‐assisted single‐carrier (SC) block transmissions over frequency‐selective fading channel. They first exploit the discrete Fourier transform extended properties to construct a linear precoding matrix. They then employ a low‐complexity suboptimal frequency domain decision feedback equalisation (FD‐DFE) to collect potential multipath diversity at high signal‐to‐noise ratio. Simulation results demonstrate that the proposed scheme provides better performance than the conventional distributed SC‐STBC scheme with minimum‐mean‐square error FD linear equalisation.
Wireless local area network service providers’ price competition in presence of heterogeneous user demand
Authors: Kumar Abhinav , Mallik Ranjan K. , Schober Robert
Published: November 2013

Consider wireless local area network (WLAN) service providers (SPs) operating in an overlapping service area. The SPs compete with each other to attract users. The price charged is utilised by the SPs as a tool to maximise revenue, resulting in a price competition between the WLAN SPs. The users are assumed to be selfish, trying to maximise their individual utility. They have varied sensitivity towards quality of service experienced and the price charged. In such a scenario, the user demand distribution is the one that achieves Wardrop equilibrium. Approximate analytical expressions are obtained for the best response of SPs to each other's price. Existence of a Nash equilibrium (NE) between the competing SPs is proved and the price vector at which the NE occurs is obtained. It is found that, while in one extreme monopoly leads to very high revenue for WLAN SPs with minimal consumer surplus, in the other extreme unregulated duopoly/oligopoly leads to high consumer surplus at the cost of minimal revenue generation for the competing SPs. Thus, price regulation is proposed in the WLAN market for equitable distribution of the surplus among the SPs and the users.
New concept on sinusoidal modulation for three‐phase DC/AC converters: analysis and experiments
Authors: Eskandari Bahman , Tavakoli Bina Mohammad , Golkar Masoud Aliakbar
Published: November 2013

Various modulation schemes have already been developed for conventional three‐phase buck‐type converters such as sinusoidal pulse‐width modulation and space vector modulation (SVM). However, SVM is not applicable to boost‐type converters. This study proposes a new concept on sinusoidal modulation for both buck and boost‐type three‐phase DC–AC converters. A novel optimised modulation technique is introduced by using basic equations of conventional buck and boost. By solving the optimisation problem, pulse widths will be obtained for a given modulation index. The significant point is that the optimisation problem should not be solved for every modulation index because the answer of the optimisation problem obeys a certain pattern. Also, this method has a positive effect on reducing losses, especially in boost‐converters. Analysis and simulations are first introduced for three‐phase boost‐converters, and then is extended to a buck converter. Furthermore, practical verification takes place on two implemented 1 kVA boost and buck‐converters in order to confirm the proposed technique as well as theoretical analysis and simulations. The experiments and simulations both verify the suggested optimised modulation technique.
Should unit commitment be endogenously included in wind power transmission planning optimisation models?
Authors: Burke Daniel J. , Tuohy Aidan , Dillon Jody , O'Malley Mark J.
Published: November 2013

The historical time series data or Monte Carlo simulation approaches that are often used to represent wind power in transmission planning models will lead to large‐scale optimisation problems. The complexity of such problems will be further compounded if advanced techniques for wind variability and wind forecast uncertainty management are also endogenously included, corresponding to a merging of the traditionally separate ‘real‐time operations’ and ‘long‐term planning’ analysis timeframes in power system analysis. A stochastic mixed‐integer scheduling model is applied here to investigate the likely transmission planning model formulation impacts of advanced wind forecast techniques, and to determine whether any additional optimal transmission planning model precisions offered justify the associated very‐large‐scale computational burden. Results indicate that power‐flow modelling is only significantly influenced in a small subset of the network branches associated with major interconnections and flexible/inflexible conventional generation locations. Model sensitivity analysis also suggests that even at high wind penetrations, such power‐flow modelling differences may be overshadowed by the impact of general uncertainty in fuel price volatility and demand profile that is systemic to long‐term planning problems. Such trade‐offs have significant practical relevance to the many researchers currently investigating formulations of this class of optimisation problem.
Electrospun metallic nanowires: Synthesis, characterization, and applications
Authors: Khalil Abdullah , Singh Lalia Boor , Hashaikeh Raed , Khraisheh Marwan
Published: November 2013

Metals are known to have unique thermal, mechanical, electrical, and catalytic properties. On the other hand, metallic nanowires are promising materials for variety of applications such as transparent conductive film for photovoltaic devices, electrodes for batteries, as well as nano-reinforcement for composite materials. Whereas varieties of methods have been explored to synthesize metal nanowires with different characteristics, electrospinning has also been found to be successful for that purpose. Even though electrospinning of polymeric nanofibers is a well-established field, there are several challenges that need to be overcome to use the electrospinning technique for the fabrication of metallic nanowires. These challenges are mainly related to the multi-steps fabrication process and its relation to the structure evolution of the nanowires. In addition to reviewing the literature, this article identifies promising avenues for further research in this area with particular emphasis on the applications that nonwoven metal wires confined in a nano-scale can open.
Dynamic neutron scattering from conformational dynamics. I. Theory and Markov models
Authors: Lindner Benjamin , Yi Zheng , Prinz Jan-Hendrik , Smith Jeremy C. , Noé Frank
Published: November 2013

The dynamics of complex molecules can be directly probed by inelastic neutron scattering experiments. However, many of the underlying dynamical processes may exist on similar timescales, which makes it difficult to assign processes seen experimentally to specific structural rearrangements. Here, we show how Markov models can be used to connect structural changes observed in molecular dynamics simulation directly to the relaxation processes probed by scattering experiments. For this, a conformational dynamics theory of dynamical neutron and X-ray scattering is developed, following our previous approach for computing dynamical fingerprints of time-correlation functions [F. Noé, S. Doose, I. Daidone, M. Löllmann, J. Chodera, M. Sauer, and J. Smith, Proc. Natl. Acad. Sci. U.S.A. 108, 4822 (2011)]. Markov modeling is used to approximate the relaxation processes and timescales of the molecule via the eigenvectors and eigenvalues of a transition matrix between conformational substates. This procedure allows the establishment of a complete set of exponential decay functions and a full decomposition into the individual contributions, i.e., the contribution of every atom and dynamical process to each experimental relaxation process.
Dynamic neutron scattering from conformational dynamics. II. Application using molecular dynamics simulation and Markov modeling
Authors: Yi Zheng , Lindner Benjamin , Prinz Jan-Hendrik , Noé Frank , Smith Jeremy C.
Published: November 2013

Neutron scattering experiments directly probe the dynamics of complex molecules on the sub pico- to microsecond time scales. However, the assignment of the relaxations seen experimentally to specific structural rearrangements is difficult, since many of the underlying dynamical processes may exist on similar timescales. In an accompanying article, we present a theoretical approach to the analysis of molecular dynamics simulations with a Markov State Model (MSM) that permits the direct identification of structural transitions leading to each contributing relaxation process. Here, we demonstrate the use of the method by applying it to the configurational dynamics of the well-characterized alanine dipeptide. A practical procedure for deriving the MSM from an MD is introduced. The result is a 9-state MSM in the space of the backbone dihedral angles and the side-chain methyl group. The agreement between the quasielastic spectrum calculated directly from the atomic trajectories and that derived from the Markov state model is excellent. The dependence on the wavevector of the individual Markov processes is described. The procedure means that it is now practicable to interpret quasielastic scattering spectra in terms of well-defined intramolecular transitions with minimal a priori assumptions as to the nature of the dynamics taking place.
High power operation of an X-band coaxial multi-beam relativistic klystron amplifier
Authors: Liu Zhenbang , Huang Hua , Jin Xiao , Zhao Yucong , He Hu , Lei Lurong , Chen Zhaofu
Published: November 2013

An X-band coaxial multi-beam relativistic klystron amplifier is designed in order to increase output microwave power and operating frequency of the amplifier tube. The experiment is performed on a Tesla-type accelerator. The amplifier is driven by an electron beam of 2.8 kA at 720 kV, and a microwave power of 30 kW and frequency of 9.384 GHz is injected into an input cavity by means of an external source, then a microwave power of over 800 MW is extracted, the amplifier gain is about 44 dB, and conversion efficiency is 40%. The experiment proves that output power of nearly GWs can be generated with the X-band coaxial multi-beam relativistic klystron amplifier driven by a kW-level input power.
Relative energies, structures, vibrational frequencies, and electronic spectra of pyrylium cation, an oxygen-containing carbocyclic ring isoelectronic with benzene, and its isomers
Authors: Bera Partha P. , Head-Gordon Martin , Lee Timothy J.
Published: November 2013

We have studied relative energies, structures, rotational, vibrational, and electronic spectra of the pyrylium cation, an oxygen-containing six-membered carbocyclic ring, and its six isomers, using ab initio quantum chemical methods. Isoelectronic with benzene, the pyrylium cation has a benzenoid structure and is the global minimum on the singlet potential energy surface of C5H5O+. The second lowest energy isomer, the furfuryl cation, has a five membered backbone akin to a sugar, and is only 16 kcal mol−1 above the global minimum computed using coupled cluster theory with singles, doubles, and perturbative triple excitations (CCSD(T)) with the correlation consistent cc-pVTZ basis set. Other isomers are 25, 26, 37, 60, and 65 kcal mol−1 above the global minimum, respectively, at the same level of theory. Lower level methods such as density functional theory (B3LYP) and second order Møller-Plesset perturbation theory performed well when tested against the CCSD(T) results. The pyrylium and furfuryl cations, although separated by only 16 kcal mol−1, are not easily interconverted, as multiple bonds must be broken and formed, and the existence of more than one transition state is likely. Additionally, we have also investigated the asymptotes for the barrierless ion-molecule association of molecules known to exist in the interstellar medium that may lead to formation of the pyrylium cation.
Discrete-contact nanowire photovoltaics
Authors: Chitambar Michelle J. , Wen Wen , Maldonado Stephen
Published: November 2013

A series of finite-element simulations have been performed to assess the operational characteristics of a new semiconductor nanowire solar cell design operating under high-level injection conditions. Specifically, the steady-state current-voltage behavior of a cylindrical silicon (Si) nanowire with a series of discrete, ohmic-selective contacts under intense sunlight illumination was investigated. The scope of the analysis was limited to only the factors that impact the net internal quantum yield for solar to electricity conversion. No evaluations were performed with regards to optical light trapping in the modeled structures. Several aspects in a discrete-contact nanowire device that could impact operation were explored, including the size and density of ohmic-selective contacts, the size of the nanowire, the electronic quality and conductivity of the nanowire, the surface defect density of the nanowire, and the type of ohmic selectivity employed at each contact. The analysis showed that there were ranges of values for each parameter that supported good to excellent photoresponses, with certain combinations of experimentally attainable material properties yielding internal energy conversion efficiencies at the thermodynamic limit for a single junction cell. The merits of the discrete-contact nanowire cell were contrasted with “conventional” nanowire photovoltaic cells featuring a uniform conformal contact and also with planar point-contact solar cells. The unique capacity of the discrete-contact nanowire solar cell design to operate at useful energy conversion efficiencies with low quality semiconductor nanowires (i.e., possessing short charge-carrier lifetimes) with only light doping is discussed. This work thus defines the impetus for future experimental work aimed at developing this photovoltaic architecture.
Sub-picowatt/kelvin resistive thermometry for probing nanoscale thermal transport
Authors: Zheng Jianlin , Wingert Matthew C. , Dechaumphai Edward , Chen Renkun
Published: November 2013

Advanced instrumentation in thermometry holds the key for experimentally probing fundamental heat transfer physics. However, instrumentation with simultaneously high thermometry resolution and low parasitic heat conduction is still not available today. Here we report a resistive thermometry scheme with ∼50 μK temperature resolution and ∼0.25 pW/K thermal conductance resolution, which is achieved through schemes using both modulated heating and common mode noise rejection. The suspended devices used herein have been specifically designed to possess short thermal time constants and minimal attenuation effects associated with the modulated heating current. Furthermore, we have systematically characterized the parasitic background heat conductance, which is shown to be significantly reduced using the new device design and can be effectively eliminated using a “canceling” scheme. Our results pave the way for probing fundamental nanoscale thermal transport processes using a general scheme based on resistive thermometry.