bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalised Smooth Tests of Goodness of Fit Utilising L‐moments
Authors: Thas O. , Rayner J.C.W. , De Neve J.
Published: January 2016

In this paper we present a semiparametric test of goodness of fit which is based on the method of L‐moments for the estimation of the nuisance parameters. This test is particularly useful for any distribution that has a convenient expression for its quantile function. The test proceeds by investigating equality of the first few L‐moments of the true and the hypothesised distributions. We provide details and undertake simulation studies for the logistic and the generalised Pareto distributions. Although for some distributions the method of L‐moments estimator is less efficient than the maximum likelihood estimator, the former method has the advantage that it may be used in semiparametric settings and that it requires weaker existence conditions. The new test is often more powerful than competitor tests for goodness of fit of the logistic and generalised Pareto distributions.
Model Assessment in Dynamic Treatment Regimen Estimation via Double Robustness
Authors: Wallace Michael P. , Moodie Erica E. M. , Stephens David A.
Published: January 2016

Dynamic treatment regimens (DTRs) recommend treatments based on evolving subject-level data. The optimal DTR is that which maximizes expected patient outcome and as such its identification is of primary interest in the personalized medicine setting. When analyzing data from observational studies using semi-parametric approaches, there are two primary components which can be modeled: the expected level of treatment and the expected outcome for a patient given their other covariates. In an effort to offer greater flexibility, the so-called doubly robust methods have been developed which offer consistent parameter estimators as long as at least one of these two models is correctly specified. However, in practice it can be difficult to be confident if this is the case. Using G-estimation as our example method, we demonstrate how the property of double robustness itself can be used to provide evidence that a specified model is or is not correct. This approach is illustrated through simulation studies as well as data from the Multicenter AIDS Cohort Study.
Addressing Issues Associated with Evaluating Prediction Models for Survival Endpoints Based on the Concordance Statistic
Authors: Wang Ming , Long Qi
Published: January 2016

Prediction models for disease risk and prognosis play an important role in biomedical research, and evaluating their predictive accuracy in the presence of censored data is of substantial interest. The standard concordance (c) statistic has been extended to provide a summary measure of predictive accuracy for survival models. Motivated by a prostate cancer study, we address several issues associated with evaluating survival prediction models based on statistic with a focus on estimators using the technique of inverse probability of censoring weighting (IPCW). Compared to the existing work, we provide complete results on the asymptotic properties of the IPCW estimators under the assumption of coarsening at random (CAR), and propose a sensitivity analysis under the mechanism of noncoarsening at random (NCAR). In addition, we extend the IPCW approach as well as the sensitivity analysis to high-dimensional settings. The predictive accuracy of prediction models for cancer recurrence after prostatectomy is assessed by applying the proposed approaches. We find that the estimated predictive accuracy for the models in consideration is sensitive to NCAR assumption, and thus identify the best predictive model. Finally, we further evaluate the performance of the proposed methods in both settings of low-dimensional and high-dimensional data under CAR and NCAR through simulations.
Benson, Angela D & Whitworth, Andrew ed (2014) Research on course management systems in higher educationIAP (Charlotte, NC & Eurospan, London) isbn 978‐1‐62396‐601‐0 261 pp $39 http://www.infoagepub.com/products/Research‐on‐Course‐Management‐Systems‐in‐Higher‐Education
Authors: Hammer Sara
Published: January 2016

This book examines the role of course management systems (cmss) in higher education. Some chapters consider broader issues such as trends, cms governance, and evaluation; others examine the implementation of pedagogical initiatives using cmss. The case studies in this second group feature initiatives by educators who show more or less familiarity with their cmss. A recurring theme is the “eco‐systemic” quality of cms systems, their institutions, and institutional stakeholders. This book would be of interest to university administrators, information systems professionals, and academics. If the content of this book is likely to be relevant to you, I advise that you will probably find only parts of it of interest or use.

Sara Hammer
Boyanton, Dengting (2015) Teachers and students as co‐learnersPeter Lang (New York & Bern) isbn 978‐1‐4331‐1178‐5 274 pp £26 http://www.peterlang.com/index.cfm?event=cmp.ccc.seitenstruktur.detailseiten&seitentyp=produkt&pk=84053&cid=533&concordeid=311177
Authors: Cowan John
Published: January 2016

This is a readable and reflective volume. It offers, among other things, deep and highly personal participant perspectives on the problems of Chinese learners entering an anglo‐american educational environment, insight into the importance of authenticity in class relationships, and consideration of teaching powerfulness—all in the context of presenting the writer's mutual value theory of education and of learning technology. If you feel that this book is likely to be relevant to you, I recommend that you arrange to borrow a copy for a while.

John Cowan
Caldwell, Helen & Bird, James ed (2015) Teaching with tabletsSage (London & Thousand Oaks CA) isbn 978‐1‐4739‐0679‐2 142 pp £22.99 https://uk.sagepub.com/en‐gb/eur/teaching‐with‐tablets/book243836
Authors: García Laborda Jesús
Published: January 2016

Teaching with tablets is a challenge in many contexts that can be approached through the use by practising teachers and teacher trainees of this useful tool. The volume is full of practical case studies and tips that can guide the teachers' and learners' motivation to new ways of working and learning. If the content of this book is likely to be relevant to you, I recommend that you arrange to borrow a copy for a while.

Jesús García Laborda
Hampel, Regina & Stickler, Ursula ed (2015) Developing online language teachingPalgrave Macmillan (Basingstoke & St Martin's, New York) isbn 978‐1‐137‐41225‐6 206 pp £58 http://www.palgrave.com/page/detail/developing‐online‐language‐teaching‐regine‐hampel/?K=9781137412256
Authors: García Laborda Jesús
Published: January 2016

Computer assisted language learning has been with us for some forty years. However, this book goes beyond the traditional tips that many books offer to give both a theoretical and practical approach based on socio‐cultural theory. In this way, it leaves behind the traditional here‐and‐now use of information technology in language learning to provide a sound construct. If the content of this book is likely to be relevant to you, I recommend that you arrange to borrow a copy for a while.

Jesús García Laborda
McCrudden, Matthew et al ed (2015) Use of visual displays in research and testingIAP (Charlotte, NC & Eurospan, London) isbn 978‐1‐681‐23‐101‐3 346 pp $45.99 (boards $85.99) http://www.infoagepub.com/products/use‐of‐visual‐displays‐in‐research‐and‐testing
Authors: García Laborda Jesús
Published: January 2016

Teachers, researchers, administrators and students will find here an excellent source of ideas to apply to their presentations and research reports. The book is full of examples which will certainly facilitate your work. Whether for your personal or professional use, this volume is worth borrowing.

Jesús García Laborda
Major, Claire Howell (2015) Teaching onlineJohns Hopkins U P (Baltimore, & John Wiley) isbn 978‐1‐4214‐1633‐5 320 pp £19.50 https://jhupbooks.press.jhu.edu/content/teaching‐online
Authors: Dettori Giuliana
Published: January 2016

This book, addressed to teachers and other professionals involved in higher education, concerns the many changes entailed by teaching online. It offers in a clear way a synthesis of theory and practice, based on the literature plus interviews with many experts in the field. It can provide a useful stimulus for deep reflection on its subject. If you think the content of this book may well be likely to be relevant, I recommend that you buy a copy.

Giuliana Dettori
Sahlberg, Pasi (2015) Finnish lessons 2.0Teachers College Press (Columbia University, NY & Eurospan, London) isbn 978‐0‐8077‐5585‐3 237 pp £18.50 http://store.tcpress.com/0807755850.shtml
Authors: Brescia William
Published: January 2016

If you are interested in systematic school reform, you must read this book. Sahlberg tells us how Finland was highly successful—and continues to be highly successful—in school reform; it includes some well chosen advice on how any country can achieve similarly. If this book seems likely to be relevant, I recommend that you buy your own copy.

William Brescia
Gender‐related differential effect of tachykinin NK2 receptor‐mediated visceral hyperalgesia in guinea pig colon
Authors: Bellucci F , Buéno L , Bugianesi R , Crea A , D'Aranno V , Meini S , Santicioli P , Tramontana M , Maggi CA
Published: January 2016

Background and Purpose

The tachykinin NK2 receptor antagonist ibodutant is under Phase III clinical investigation to treat female patients with irritable bowel syndrome. The aim of this study was to investigate the NK2 receptor‐related gender specificity in a model of colitis.

Experimental Approach

Colitis was induced by rectal instillation of 2,4,6‐trinitrobenzenesulfonic acid (TNBS, 0.5 mL, 30 mg·mL−1 in 30% ethanol) in female and male guinea pigs. Electromyographic recording of the responses to colorectal distension (CRD) was made 3 days later. Ibodutant (0.33 , 0.65, 1.9 and 6.5 mg·kg−1) was given s.c., 30 min before CRD. Release of neurokinin A and substance P from isolated mucosal and smooth muscle tissues following treatment with KCl (80 mM) or capsaicin (10 μM) was measured by EIA. Plasma pharmacokinetics of ibodutant following a single s.c. administration (0.73 or 2.1 mg·kg−1) were measured over 24 h.

Key Results

Ibodutant did not affect abdominal contractions in control animals. After TNBS‐induced colitis, ibodutant prevented the increased visceral hypersensitivity to CRD in females, at lower doses than in males. Ibodutant pharmacokinetics did not differ between females and males. Tachykinins release was greater in smooth muscle than in mucosal samples. Capsaicin‐stimulated release of tachykinins from inflamed mucosal samples from females was significantly lower than in males.

Conclusions and Implications

Ibodutant prevented abdominal nociception in a model of visceral hypersensitivity in guinea pigs with a greater efficacy in females than in males. Our results highlight a gender‐related difference in colonic visceral hypersensitivity and mucosal nerve activation.
Applying global criteria to tracking data to define important areas for marine conservation
Authors: Lascelles B. G. , Taylor P. R. , Miller M. G. R. , Dias M. P. , Oppel S. , Torres L. , Hedd A. , Le Corre M. , Phillips R. A. , Shaffer S. A. , Weimerskirch H. , Small C.
Published: January 2016

Aim

Enhanced management of areas important for marine biodiversity are now obligations under a range of international treaties. Tracking data provide unparalleled information on the distribution of marine taxa, but there are no agreed guidelines that ensure these data are used consistently to identify biodiversity hotspots and inform marine management decisions. Here, we develop methods to standardize the analysis of tracking data to identify sites of conservation importance at global and regional scales.

Location

We applied these methods to the largest available compilation of seabird tracking data, covering 60 species, collected from 55 deployment locations ranging from the poles to the tropics.

Methods

Key developments include a test for pseudo‐replication to assess the independence of two groups of tracking data, an objective approach to define species‐specific smoothing parameters (h values) for kernel density estimation based on area‐restricted search behaviour, and an analysis to determine whether sites identified from tracked individuals are also representative for the wider population.

Results

This analysis delineated priority sites for marine conservation for 52 of the 60 species assessed. We compiled 252 data groupings and defined 1052 polygons, between them meeting Important Bird and Biodiversity Area criteria over 1500 times. Other results showed 13% of data groups were inadequate for site definition and 10% showed some level of pseudo‐replication. Between 25 and 50 trips were needed within a data group for data to be considered at least partially representative of the respective population.

Main conclusions

Our approach provides a consistent framework for using animal tracking data to delineate areas of global conservation importance, allowing greater integration into marine spatial planning and policy. The approaches we describe are exemplified for pelagic seabirds, but are applicable to a range of taxonomic groups. Covering 4.3% of the oceans, the sites identified would benefit from enhanced protection to better safeguard the threatened species populations they contain.
Carers' and service users' experiences of early intervention in psychosis services: implications for care partnerships
Authors: Allard Jon , Lancaster Susan , Clayton Sara , Amos Tim , Birchwood Max
Published: January 2016

Aim

To explore carers' and service users' experiences of UK Early Intervention Services following referral for first‐episode psychosis.

Methods

Thirty‐two semi‐structured interviews (16 interviews with service users and 16 corresponding interviews with their carers) were completed and analysed.

Results

Carers spoke retrospectively and prospectively by framing their accounts into the periods before and since their engagement with Early Intervention Services. Desperation was evident as emotive experiences were recalled prior to referral. Relief then emerged as carers described support and engagement with key workers. Hope and optimism for the service user's prognosis and life trajectory were also expressed.Service users described similar positive experiences of Early Intervention Services and the support and insight they had gained through their relationships with key workers. They were however less focused on accounts of desperation and relief and more immersed in their current understanding and attempts to normalize their experiences of first‐episode psychosis. Prognosis and future trajectories were only discussed tentatively.

Conclusion

Communication and ‘partnerships’ with service users and carers are essential for effective service engagement, delivery of care and the reduction in relapse following first‐episode psychosis. This study highlights how key workers from Early Intervention Services are appropriately valued and situated to develop such relationships. Findings also reveal that service users' and carers' focus and expectations of recovery vary during the early stages of engagement with services. How key workers manage awareness and communication around such differing expectations is a crucial consideration for maintaining the ‘partnerships’ necessary for effective service provision.
How Informative Is Floating NAV When Securities Trade Infrequently?
Authors: Allen Kyle D. , Cashman George D. , Winters Drew B.
Published: January 2016

We examine if a floating net asset value (NAV) increases the transparency of risk for investors. Using closed‐income fixed income funds we find little evidence that a floating NAV helps investors better understand the value and risk of a fund when a fund's assets trade infrequently. This potentially informs the debate regarding the adoption of a floating NAV in the money market industry. Our results suggest that it is unlikely that the benefits of floating NAV will outweigh the costs.
Species co‐occurrence analysis: pairwise versus matrix‐level approaches
Authors: Arita Héctor T.
Published: January 2016

Veech (2013, Global Ecology and Biogeography, 22, 252–260) introduced a formula to calculate the probability of two species co‐occurring in various sites under the assumption of statistical independence between the two distributional patterns. He presented his model as a new procedure, a ‘pairwise approach’, different from analyses of whole presence–absence matrices to examine patterns of co‐occurrence. Here I show that: (1) Veech's method is identical to Fisher's exact test, a standard procedure for measuring the statistical association between two discrete variables; (2) in a broad sense, the pairwise approach is very similar to early analyses of spatial association, such as the one advanced by Forbes in 1907; (3) implicit in Veech's formula is a sampling scheme that is indistinguishable from well‐known matrix‐level null models that randomize the distribution of species among equiprobable sites; (4) pairwise co‐occurrence patterns can be analysed using any matrix‐level null model, so pairwise comparisons are not limited to using Veech's formula. The methodological distinction that Veech proposed between pairwise and matrix‐level approaches does not in fact exist, although the conceptual distinction between the two approaches is still a debated topic.
Using a dynamic forest model to predict tree species distributions
Authors: Gutiérrez Alvaro G. , Snell Rebecca S. , Bugmann Harald
Published: January 2016

Aim

It has been suggested that predicting species distributions requires a process‐based and preferably dynamic approach. If dynamic models are to contribute towards understanding species distributions, uncertainties related to their spatial extrapolation and bioclimatic parameters need to be addressed. Here, we analyse the potential of a forest gap model for predicting species distributions.

Location

Pacific Northwest of North America (PNW).

Methods

We used the dynamic forest gap modelForClim, which includes climate, competition and demographic processes, to simulate the distribution of 18 tree species outside the domain of the data used for fitting. We explored model accuracy for species distributions at the regional scale by: (1) estimating species climatic tolerances so as to maximize agreement with regional distribution maps versus (2) employing a bioclimatic parameter set that produces high accuracy at the local scale. We then performed the opposite tests and simulated local forest composition in a small area in thePNW, using (3) the local bioclimatic parameters and (4) the bioclimatic parameters that produced the highest accuracy at the regional scale. We also compared theForClimresults with predictions from a standard correlative species distribution model (SDM).

Results

ForClimproduced regional species distributions with fair to very good agreement for 12 tree species. The optimized bioclimatic parameters consistently improved the accuracy of regional predictions compared with simulations run with the local parameters, and were consistent withSDMresults. At the local scale, predictions using the local parameters conformed to descriptions of forest composition, but accuracy decreased strongly when using the regionally calibrated parameters.

Main conclusions

Forest gap models can predict regional species distributions, but at the cost of reduced accuracy at the local scale. Future applications of gap models to understand regional species distributions should include robust parameterization schemes and additional ecological processes that are important at large spatial scales (e.g. dispersal, disturbances).
A metaheuristic approach to fisheries survey route planning
Authors: Mesquita Marta , Murta Alberto G. , Paias Ana , Wise Laura
Published: January 2016

Every autumn, a research vessel carries out a sampling survey tour to estimate the abundance of groundfish species of the Portuguese continental waters. The sampling operations are carried out at predefined geographical locations, the fishing stations, within predefined multiple time windows. The vessel route starts and ends at the port of Lisbon, and must visit all fishing stations. According to a predefined periodicity, the vessel must enter a port to supply food, refuel, and/or change crew. Given the geographical locations of the fishing stations/ports and current weather conditions, the objective is to minimize the total traveled distance and completion time. We present a mixed integer linear program to describe the problem and propose two sequential heuristic approaches that combine genetic algorithms and adaptive large neighborhood search to solve it. Computational experience with real data shows that the proposed heuristics are suitable tools to solve the problem.
Multiobjective model for solving resource‐leveling problem with discounted cash flows
Authors: Nikoofal Sahl Abadi Niloofar , Bagheri Mohsen , Assadi Mohammad
Published: January 2016

Nowadays, executers are struggling to improve the economic and scheduling situation of projects. Construction scheduling techniques often produce schedules that cause undesirable resource fluctuations that are inefficient and costly to implement on site. The objective of the resource‐leveling problem is to reduce resource fluctuation related costs (hiring and firing costs) without violating the project deadline. In this article, minimizing the discounted costs of resource fluctuations and minimizing the project makespan are considered in a multiobjective model. The problem is formulated as an integer nonlinear programming model, and since the optimization problem is NP‐hard, we propose multiobjective evolutionary algorithms, namely nondominated sorting genetic algorithm‐II (NSGA‐II), strength Pareto evolutionary algorithm‐II (SPEA‐II), and multiobjective particle swarm optimization (MOPSO) to solve our suggested model. To evaluate the performance of the algorithms, experimental performance analysis on various instances is presented. Furthermore, in order to study the performance of these algorithms, three criteria are proposed and compared with each other to demonstrate the strengths of each applied algorithm. To validate the results obtained for the suggested model, we compared the results of the first objective function with a well‐tuned genetic algorithm and differential algorithm, and we also compared the makespan results with one of the popular algorithms for the resource constraints project scheduling problem. Finally, we can observe that the NSGA‐II algorithm presents better solutions than the other two algorithms on average.
Trade‐offs in integer data envelopment analysis
Authors: Alirezaee Mohammadreza , Rafiee Sani Mohammadreza
Published: January 2016

If production trade‐offs—which represent simultaneously feasible exchanges in the inputs and outputs of decision‐making units (DMUs)—are added to an integer production possibility set (IPPS), a new IPPS is produced; conventional axioms of production do not generate a new IPPS, however. This paper develops the axiomatic foundation for data envelopment analysis (DEA) for integer‐value inputs and outputs in the presence of production trade‐offs by introducing a new axiom of “natural trade‐offs.” First, a mixed‐integer linear programming formula called an integer DEA trade‐off (IDEA‐TO) is presented for computing efficiency scores and reference points. The numeration algorithm (NA) method presented in this concept is improved, and an improved numeration algorithm (INA) method for solving integer DEA (IDEA) models is developed. Finally, comparison between the two methods and a generalized INA method for solving the IDEA‐TO model are presented.
Three‐year efficacy and safety of tenofovir in nucleos(t)ide analog‐naïve and nucleos(t)ide analog‐experienced chronic hepatitis B patients
Authors: Wang Hsin‐Ming , Hung Chao‐Hung , Lee Chuan‐Mo , Lu Sheng‐Nan , Wang Jing‐Houng , Yen Yi‐Hao , Kee Kwong‐Ming , Chang Kuo‐Chin , Tseng Po‐Lin , Hu Tsung‐Hui , Chen Chien‐Hung
Published: January 2016

Background and Aims:

This study compared the efficacy and safety of tenofovir disoproxil fumarate (TDF) up to 3 years of innucleos(t)ide analog (NA)‐naïve and NA‐experienced chronic hepatitis B (CHB) patients.

Methods:

Tenofovir disoproxil fumarate‐treated NA‐naïve and NA‐experienced CHB patients were retrospectively analyzed.

Results:

After 3 years of TDF therapy, 97.7%, 71%, and 45.5% NA‐naïve patients achieved a virological response, alanine aminotransferase normalization, and hepatitis B e antigen seroconversion, respectively. Compared with NA‐naïve patients, NA‐experienced patients without drug resistance and infected with lamivudine/telbivudine‐resistant mutants showed similar results. In contrast, patients previously infected with adefovir‐resistant mutants and with a suboptimal entecavir response showed significantly lower rates of virological response and hepatitis B e antigen loss/seroconverion than NA‐naïve patients. Mean estimated glomerular filtration rate markedly reduced within 12 months of TDF therapy; however, it did not decrease significantly during 12–36 months of treatment. Diabetes mellitus was an independent predictor of a ≥ 0.5 mg/dL increase above baseline in serum creatinine level, and age, hypertension, diabetes mellitus, and baseline creatinine level were independent factors for > 20% decline in estimated glomerular filtration rate from baseline. Liver stiffness measurements improved significantly, but bone mineral density did not change significantly during treatment. Hepatocellular carcinoma incidence was low at 36 months. Age of > 60 years, cirrhosis, a low baseline platelet count and a high α‐fetoprotein level at 12 months were significant predictors of hepatocellular carcinoma development.

Conclusions:

Tenofovir disoproxil fumarate is effective and safe for NA‐naïve and NA‐experienced CHB patients and should be used cautiously in patients with comorbidities because of a renal dysfunction risk.
Roan antelope Hippotragus equinus in Africa: a review of abundance, threats and ecology
Authors: Havemann Carl P. , Retief Tarryn A. , Tosh Cheryl A. , de Bruyn P. J. Nico
Published: January 2016

The roan antelope Hippotragus equinus, Africa's second largest antelope species, is widely distributed throughout Africa. Many populations are isolated, occur at low densities, and are declining. The species' interactions with and adaptations to the diverse environmental conditions throughout its geographic range remain largely unknown. Most studies have taken place in southern Africa, near the range limit for the species; few studies have been conducted on the historically large Central and West African populations.

We reviewed available published and accessible unpublished data related to the ecology of roan antelope. We aim to: 1) review available taxonomic, abundance, distribution, and population trend data; 2) describe the threats faced by the roan antelope, and establish whether sufficient data exist to describe its ecological requirements; and 3) highlight the relevance of conserving this species throughout Africa and suggest where research on survival requirements should be focussed.

Roan antelope populations throughout Africa are declining due to natural and anthropogenic threats. Methodological irregularities result in uncertainty and non‐comparable population data between studies. Large gaps exist in our knowledge of roan antelope diet and regional movements. Information on the population genetics of roan antelope is needed in order to assess the connectedness of different populations.

Data deficiency severely impedes our ability to employ powerful analytical methods aimed at understanding and predicting population persistence and viability, and to model envisaged threats from impending climate change. A unified approach to fundamental ecological research is required to inform the conservation and management of large rare mammalian ungulates such as the roan antelope in Africa.
Adolescent “Saxophone Penis” Secondary to Crohn's Disease: Misdiagnosed as Being Posttraumatic
Authors: Marshall Claire , Markiewicz Dorota , Bewley Anthony
Published: January 2016

We describe a patient with a “saxophone penis” mistakenly diagnosed as having posttraumatic changes. A careful history and attention to blood tests at presentation may have alerted clinicians that there was a nontraumatic cause for our patient's disease. It is essential that clinicians consider “metastatic” anogenital Crohn's disease as a possible cause of “saxophone penis”.
Effectiveness of Intralesional Triamcinolone in the Treatment of Keloids in Children
Authors: Acosta Silvana , Ureta Ester , Yañez Ricardo , Oliva Natalia , Searle Susana , Guerra Claudio
Published: January 2016

Background

The current treatment of keloids includes surgery, intralesional steroids, and radiotherapy, among others. Radiotherapy is not recommended in children due to its effects on growing tissues. Our aim was to study intralesional triamcinilone therapy of keloids in children and analyze the impact of body location, age of the lesion, and etiology of the keloid on clinical response.

Methods

We conducted a prospective clinical trial with patients 1 to 14 years of age evaluated for keloid treatment. A soft tissue ultrasound was performed to measure the keloid volume, prior to intralesional infiltration with triamcinolone acetonide. A posttreatment ultrasound quantified the volume differences attributed to therapy. For the analysis, Mann–Whitney/Wilcoxon test for paired samples and a multiple regression analysis were performed.

Results

Twenty‐one patients with a total of 25 keloids were enrolled, with a median age of 12 years (range 6–14 yrs). The initial lesional volume was 1.25 cc (range 0.2–6.3 cc) and the final volume was 0.2 cc (range 0.0–1.53 cc), corresponding to 82.7% of size reduction (p < 0.001). Regarding the relationships between response and body location, etiology and age of the lesion, the multiple regression analyses obtained p‐values of 0.46, 0.16, and 0.87, respectively. One patient failed to improve. Average follow‐up was 30 months.

Conclusions

Triamcinolone acetonide is highly effective for the treatment of pediatric keloids. There is no relationship between clinical response and the factors evaluated, such as lesion location, etiology and age of the keloid.
Guidelines for evaluating performance of oyster habitat restoration should include tidal emersion: reply to Baggett et al.
Authors: Walles Brenda , Fodrie F. Joel , Nieuwhof Sil , Jewell Oliver J. D. , Herman Peter M. J. , Ysebaert Tom
Published: January 2016

Baggett et al. (2015) identified a set of three universal environmental variables to be monitored for evaluating all oyster habitat restoration projects: salinity, temperature, and dissolved oxygen. Perhaps evidencing a bias toward subtidal reefs, this set of parameters omits another first‐order environmental factor, tidal emersion. Intertidal oyster reefs can be the dominant reef habitat in estuaries, with clear zonation in oyster performance across the intertidal exposure gradient. Therefore, we propose to include tidal emersion as a fourth universal environmental parameter when designing and evaluating oyster restoration projects to better encompass the whole environmental spectrum along which reefs occur.
Dynamic Failure Behavior of Cylindrical Glass Fiber Composite Shells Subjected to Internal Blast Loading
Authors: Dong Qi , Wang Penglai , Yi Chenhong , Hu Bayi
Published: January 2016

The dynamic response of open-ended cylindrical glass fiber composite shells subjected to internal blast loading is studied in the current paper. The experimental observation on response characteristics of cylindrical glass fiber shells is presented, in which failure modes of composite structures are especially concerned. It is found that dynamic buckling may occur in the inner steel liner, which may consequently cause delamination and fiber fracture of the outer glass fiber shell and thus limits the blast loading resistant capability of glass fiber explosion containment vessels. The other failure mode is obvious circular plastic expansion of the inner steel liner and fiber fracture of the outer fiber shell. There exists an interesting case that hoop winding fibers fail but fibers with a winding angle do not fail, based on which the hybrid filament wound method for cylindrical composite containment vessels is proposed. The current study may contribute to further understanding on the design and application of glass fiber composite explosion containment vessels (CECVs).
Dynamic Modeling of Torsional Impact and its Stiffness Measurement for Impact Wrench
Authors: Zhang Shengli , Tang Jiong
Published: January 2016

Impact wrench is a popular hand tool whose mechanism is featured with impact characterized by short time duration and large contact torque. The nonlinear impact problem has drawn researchers’ interests for a long time and the investigation is still undergoing. Fully and accurately modeling impact can facilitate the understanding and improving the performance of impact wrench. Under certain circumstance, not only coefficient of restitution is interested but also the whole impact process. Hence, discrete impact model cannot fulfil these requirements and dynamic modeling is indispensable. At the same time, sufficient knowledge about contact parameters such as contact stiffness is necessary for accurately impact modeling. But these parameters are usually not readily available. Moreover, researchers mainly focused on translational impact problem while rotational impact problem is ignored. In this paper, Hunt-Crossley nonlinear contact model is applied and extended in torsional impact dynamic modeling. Based on this model, an experimental method is developed to evaluate the distribution of inertias in lumped parameter models. Contact stiffness is measured based on spectrum results. To obtain reliable experimental data, impact wrench is driven by a servo motor to generate a controllable torque impulse. Contact stiffness is acquired under different impact speed. Results show the nonlinear relationship between contact stiffness and impact speed.
Stick-Slip Interactions of the Soft-Solid Contact: An Integrated LuGre/Beam Network Model Approach
Authors: Trkov Mitja , Han Haijun , Yi Jingang , Liu Yanjie
Published: January 2016

Contact model of the soft-solid interactions plays an important role for robotic and mechatronic systems design. We present a new model of the soft-solid contact that integrates the LuGre dynamic friction model with the beam network model. The LuGre dynamic friction model uses the bristle deformation to capture the friction characteristics and dynamics while the beam network model represents the elastic contact interactions. The new model is applied to a fingertip-like stick-slip interaction application. We present the model prediction and validation results with the experiments. The comparison results demonstrate the effectiveness of the modeling development.
State Estimation for the Homogeneous 1-D Euler Equation by Unscented Kalman Filtering
Authors: Wolff Sascha , Schäpel Jan-Simon , Berndt Phillip , King Rudibert
Published: January 2016

In this article we present a dynamic state estimation method for a one dimensional flow field which is described by the homogeneous Euler equation. The estimated quantities include the pressure, velocity, density and temperature field, which are of interest, for instance, for some combustion concepts. The algorithm relies only on a small number of discrete pressure measurements from the flow field. The influence of the number of used pressure measurements on the convergence speed of the algorithm is investigated. For the state estimation, an Unscented Kalman Filter scheme is exploited. The proposed method is applied in numerical simulations to demonstrate its effectiveness.
A MIMO Sliding Mode Approach to Limit Protection in Aero-Engines
Authors: Du Xian , Richter Hanz , Guo YingQing
Published: January 2016

This paper proposes a scheme for limit protection in aero-engines with two control inputs and two regulated variables. The strategy extends existing results based on single-input sliding mode regulators and the min-max switching logic. The proposed multi-input strategy is able to manage engine limits effectively and offers better transient response than the traditional min-max architecture with linear regulators. The paper presents design guidelines for the multivariable sliding mode controller and the switching logic. The influence of key parameters is described and a simulation-based comparative study is made between the proposed approach and the existing single-input approach. It is shown that the multi-input technique has two clear advantages over the single-input approach, namely the ability to track fan speed (or other output related to thrust) even with harsh constrains, and the possibility of faster responses with smaller fuel flows by adjusting a secondary setpoint reference.
Adaptive Robust Tip Tracking Control for Single-Link Flexible Beam
Authors: Liao Jianfeng , Li Cong , Yao Bin , Zhu Xiaocong
Published: January 2016

This paper presents an inversion-based adaptive robust tip tracking control strategy that results in high tracking performance while guaranteeing the robustness for a class of linear motor driven single-link flexible beam. To address the non-minimum phase characteristics of the system, the inversion control is achieved by applying output redefinition technique as well as defining the new output at the tip of the flexible beam. In addition, the adaptive robust control (ARC) is introduced to deal with the parameter uncertainties and model uncertainties and to guarantee transient and steady state tracking performance. Comparative simulations and actual experiments based on linear motor driven flexible beam system are carried out to verify the effectiveness of the proposed control strategy.
Detecting Behavioral Anomaly in Social Networks Using Symbolic Dynamic Filtering
Authors: Salimi Naneh Karan Farshad , Chakraborty Subhadeep
Published: January 2016

This paper investigates the use of Symbolic Dynamic Filtering (SDF) algorithms in detecting anomalous behavior trends in social networks. Data is generated from an agent-based discrete choice model, which relies on a Markov Decision Process framework for stochastic simulation of decision-making in a social setting, where choices and decisions by individuals are influenced by social interactions. We show that such collective imitative behavior leads to rapid unstable fluctuations in the society, the fluctuation statistics being a weak function of the number of extremist nodes present in the network as well as the prevailing political climate. In this paper, using a time-trace of global opinions in the said society, we investigate the effectiveness of SDF in estimating the number of extremist nodes in a network, and studying the role of unpopular government policies as an enabler of political instability.

Spread of influence and ‘recruiting’ by extremist groups through social networks has become an important political issue in recent years. This study is a step in the direction of building tools to preempt and intervene such efforts.
Control of Multiagent Formations: A Multiplex Information Networks-Based Approach
Authors: Tran Dung , Yucelen Tansel
Published: January 2016

This paper makes the first attempt to show how information exchange rules represented by a network having multiple layers (multiplex information networks) can be designed for enabling spatially evolving multiagent formations. Toward this goal, we consider the invariant formation problem and introduce a distributed control architecture that allows capable agents to spatially alter the resulting formation’s density and orientation without requiring global information exchange ability. Efficacy of the proposed approach is illustrated on numerical examples.
Model Structure Adaptation: A Gradient-Based Approach
Authors: La Cava William G. , Danai Kourosh
Published: January 2016

A gradient-based method of symbolic adaptation is introduced for a class of continuous dynamic models. The proposed Model Structure Adaptation Method (MSAM) starts with the first-principles model of the system and adapts its structure after adjusting its individual components in symbolic form. A key contribution of this work is its introduction of the model’s parameter sensitivity as the measure of symbolic changes to the model. This measure, which is essential to defining the structural sensitivity of the model, not only accommodates algebraic evaluation of candidate models in lieu of more computationally expensive simulation-based evaluation, but also makes possible the implementation of gradient-based optimization in symbolic adaptation. The applicability of the proposed method is evaluated in application to several models which demonstrate its potential utility.
Dynamic Rear-End Collision Mitigation for a Vehicle About to be Struck
Authors: Giugliano Luke , Beal Craig E.
Published: January 2016

Increases in sensing and computing capability in modern vehicles create opportunities for improving safety through active control of the vehicle motion. A system for mitigating rear-end collisions is introduced, focusing on the strategies a vehicle about to be struck could employ to reduce the severity of the crash. Due to high differential speeds and tight space constraints, the timing and precision of control inputs are critical, preventing human drivers from effectively employing these strategies. However, the results of the study presented in this paper suggest that there are relatively unobtrusive strategies that a single vehicle with some limited autonomy could use in joining a roadway queue that would improve the safety of the occupants.
Proof-of-Concept Experimental Validation of a New Active Hydrodynamic Bearing
Authors: Rivenbark N. , Walsh C. , de Queiroz M.
Published: January 2016

Flow-induced instabilities known as ‘whirl’ and ‘whip’ are the main contributors to self-excited vibrations in fluid-film bearings. In this paper, we experimentally evaluate a new active hydrodynamic bearing designed to lessen flow-induced vibrations in rotating machines. The active system consists of a fluid-film bearing with a motor-actuated rotating bushing that serves as the control input. This input is used to adjust the mean flow velocity in the bearing and indirectly control the whirl vibration. A PID-type control law is used to adjust the bushing speed. An experimental test rig that realizes the active bearing concept is introduced. Experimental results are presented comparing the active bearing with PID-type control and open-loop control to the passive bearing operation. The results show that the active bearing with feedback control is effective in eliminating whirl vibrations.
Minimization of Muscle Fatigue as the Criterion to Solve Muscle Forces-Sharing Problem
Authors: Sharif Razavian Reza , McPhee John
Published: January 2016

The application of functional electrical stimulation (FES) to muscles quickly fatigues them. Our research goal is to determine the optimal control of FES signals that delay the fatigue for as long as possible. In this research we have used a physiology-based mathematical model of muscle fatigue, to study the behaviour of a musculoskeletal system during a prolonged exercise. To solve the redundant problem of muscle force sharing, we have used a time-dependent fatigue minimization objective instead of the usual activation-based minimization criteria. Our results showed that muscle co-activation, as seen in natural human motion, does not necessarily minimize muscle fatigue.
Impedance Behavior of Controllers for Compliant Positioning of a Pneumatically Actuated System
Authors: Daepp Hannes G. , Book Wayne J.
Published: January 2016

Pneumatic actuators are frequently selected for use in machines intended for human interaction because of their clean operation and natural compliance. However, the compliance, coupled with friction, can also make motion control difficult, leading to the use of more aggressive controllers, such as high-gain PID or sliding mode control, which result in stiff closed-loop system behavior. Model-based options are needed to obtain behavior that provides a better trade-off of compliance and accurate position control. In particular, Model Predictive Control (MPC) is suggested; through the use of constrained optimal control, it offers a framework for minimizing tracking error while enforcing force constraints that ensure low impedance behavior.

This paper assesses the suitability of controllers for pneumatic systems to positioning applications in which human-machine interaction is anticipated. MPC is compared against commonly-used alternatives for such scenarios: sliding mode, PID, and impedance control. Results are shown in simulation, and use spectral analysis of the impedance and closed loop tracking to characterize the balance of compliance and accuracy for each of the controllers.
A Multi-Mode Smooth Command Shaper With an Adjustable Maneuver Time
Authors: Alhazza Khaled A. , Masoud Ziyad N.
Published: January 2016

Input shaping and command shaping are important techniques in reducing residual vibrations in rest-to-rest maneuvers. Jerks in these shapers can reduce the life time for the crane motors and electronic boards. In this work, a totally smooth command shaper with an independent adjustable maneuvering time is introduced to eliminate residual vibration in multimode system. The proposed technique is solved analytically and simulated numerically through several examples. Furthermore, the proposed technique requires only the resonant frequency of the system to produce a control profile. The results through several examples show a great controller performance. It is important to mention that the proposed controller can be applied on any discretized multi-degree-of-freedom system.
Optimal Design of All-Wheel-Drive Hybrid Pick-Up Trucks
Authors: Pan Ziheng , Zhang Xiaowu , Silvas Emilia , Peng Huei , Ravi Nikhil
Published: January 2016

Both fuel economy and launching/towing performance are important for pick-up trucks. All-wheel-drive (AWD) and multimode operations are important to ensure efficient operations in a wide range of speeds and road loads. In this paper, a systematic methodology is developed and applied to the screening and evaluation of AWD multi-mode hybrid trucks. It is a four-step design process that uses automated modeling techniques, exhaustive search, and a near-optimal control strategy to obtain optimal designs. A case study was conducted to identify superior designs for an imagined hybrid electric Ford F-150 light truck.
Battery Charge Control With an Electro-Thermal-Aging Coupling
Authors: Hu Xiaosong , Perez Hector E. , Moura Scott J.
Published: January 2016

Efficient and safe battery charge control is an important prerequisite for large-scale deployment of clean energy systems. This paper proposes an innovative approach to devising optimally health-conscious fast-safe charge protocols. A multi-objective optimal control problem is mathematically formulated via a coupled electro-thermal-aging battery model, where electrical and aging sub-models depend upon the core temperature captured by a two-state thermal sub-model. The Legendre-Gauss-Radau (LGR) pseudo-spectral method with adaptive multi-mesh-interval collocation is employed to solve the resulting highly nonlinear six-state optimal control problem. Charge time and health degradation are therefore optimally traded off, subject to both electrical and thermal constraints. Minimum-time, minimum-aging, and balanced charge scenarios are examined in detail. The implications of the upper voltage bound, ambient temperature, and cooling convection resistance to the optimization outcome are investigated as well.