bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Confusional Migraine: Distinct Clinical Entity or Spectrum of Migraine Biology?
Authors: Farooqi Ashar , Padilla Jennifer , Monteith Teshamae
Published: February 2018

The goal of this review is to explore the literature reports of acute confusional migraine (ACM) including patient characteristics, migraine symptomatology, and proposed diagnostic criteria. A literature review was conducted using PubMed, Scopus and Web of Science using the terms “confusional migraine” and “confusional state in migraine”. All the relevant articles from 1970 to 2016 were included. A total of 120 patients were found in the literature. Most of the cases were seen in the pediatric population with a slight male predominance. Personal or family history of migraine was common. Most patients had a headache prior to the confusional state. In addition to confusion and agitation, some developed visual (32.5%) and/or sensory symptoms (19%) and/or speech problems (39%) either prior to or during the confusional state. Data on treatment outcomes is lacking. Patients with most common forms of migraine report attention and cognitive disturbances but awareness remains intact as opposed to patients with ACM. ACM is a distinct entity and should be included as part of the appendix of International Classification of Headache Disoders-3 beta version (ICHD-3β) criteria. Prospective studies are needed to further study this disorder and its association with other migraine forms.
Possible Role of Inflammation and Galectin-3 in Brain Injury after Subarachnoid Hemorrhage
Authors: Nishikawa Hirofumi , Suzuki Hidenori
Published: February 2018

Aneurysmal subarachnoid hemorrhage (SAH) is known as one of the most devastating diseases in the central nervous system. In the past few decades, research on SAH has focused on cerebral vasospasm to prevent post-SAH delayed cerebral ischemia (DCI) and to improve outcomes. However, increasing evidence has suggested that early brain injury (EBI) is an important mechanism contributing to DCI, cerebral vasospasm as well as poor outcomes. Though the mechanism of EBI is very complex, inflammation is thought to play a pivotal role in EBI. Galectin-3 is a unique chimera type in the galectin family characterized by its β-galactoside-binding lectin, which mediates various pathologies, such as fibrosis, cell adhesion, and inflammation. Recently, two clinical studies revealed galectin-3 to be a possible prognostic biomarker in SAH patients. In addition, our recent report suggested that higher acute-stage plasma galectin-3 levels correlated with subsequent development of delayed cerebral infarction that was not associated with vasospasm in SAH patients. We review the possible role and molecular mechanisms of inflammation as well as galectin-3 in brain injuries, especially focusing on EBI after SAH, and discuss galectin-3 as a potential new therapeutic or research target in post-SAH brain injuries.
Instruments for Assessing Historical Built Environments in Emergency Contexts: Non-Destructive Techniques for Sustainable Recovery
Authors: De Berardinis Pierluigi , Bartolomucci Carla , Capannolo Luisa , De Vita Mariangela , Laurini Eleonora , Marchionni Chiara
Published: February 2018

This article looks at a knowledge-based approach to emergency situations caused by earthquakes or other natural disasters, and illustrates how a multidisciplinary approach enables the integration of technical requirements with those of a historical and cultural nature. The case study presented is the recovery of the ex-city hospital of L’Aquila, in Italy, which was hit by an earthquake in 2009. The integrated use of varying investigation methodologies allowed us to establish the effectiveness of a knowledge-based approach, and generated new ideas for the development of the structure and its strategic role within the city.
Oxygen Reduction Reaction Catalyzed by Noble Metal Clusters
Authors: Tang Zhenghua , Wu Wen , Wang Kai
Published: February 2018

Highly-efficient catalysts for the oxygen reduction reaction (ORR) have been extensively investigated for the development of proton exchange membrane fuel cells (PEMFCs). The state-of-the-art Pt/C catalysts suffer from high price, limited accessibility of Pt, sluggish reaction kinetics, as well as undesirable long-term durability. Engineering ultra-small noble metal clusters with high surface-to-volume ratios and robust stabilities for ORR represents a new avenue. After a simple introduction regarding the significance of ORR and the recent development of noble metal clusters, the general ORR mechanism in both acidic and basic media is firstly discussed. Subsequently, we will summarize the recent efforts employing Pt, Au, Ag, Pd and Ru clusters, as well as the alloyed bi-metallic clusters for acquiring highly efficient catalysts to enhance both the activity and stability of ORR. Molecular noble metal clusters with definitive composition to reveal the relevant ORR mechanism will be particularly highlighted. Finally, the current challenges, the future outlook, as well as the perspectives in this booming field will be proposed, featuring the great opportunities and potentials to engineering noble metal clusters as highly-efficient and durable cathodic catalysts for fuel cell applications.
Analysis of the Influence of the Use of Cutting Fluid in Hybrid Processes of Machining and Laser Metal Deposition (LMD)
Authors: Cortina Magdalena , Arrizubieta Jon , Ukar Eneko , Lamikiz Aitzol
Published: February 2018

Hybrid manufacturing processes that combine additive and machining operations are gaining relevance in modern industry thanks to the capability of building complex parts with minimal material and, many times, with process time reduction. Besides, as the additive and subtractive operations are carried out in the same machine, without moving the part, dead times are reduced and higher accuracies are achieved. However, it is not clear whether the direct material deposition after the machining operation is possible or intermediate cleaning stages are required because of the possible presence of residual cutting fluids. Therefore, different Laser Metal Deposition (LMD) tests are performed on a part impregnated with cutting fluid, both directly and after the removal of the coolant by techniques such as laser vaporizing and air blasting. The present work studies the influence of the cutting fluid in the LMD process and the quality of the resulting part. Resulting porosity is evaluated and it is concluded that if the part surface is not properly clean after the machining operation, deficient clad quality can be obtained in the subsequent laser additive operation.
Evaluating the Efficiency of Physical and Cryptographic Security Solutions for Quantum Immune IoT
Authors: Suomalainen Jani , Kotelba Adrian , Kreku Jari , Lehtonen Sami
Published: February 2018

The threat of quantum-computer-assisted cryptanalysis is forcing the security community to develop new types of security protocols. These solutions must be secure against classical and post-quantum cryptanalysis techniques as well as feasible for all kinds of devices, including energy-restricted Internet of Things (IoT) devices. The quantum immunity can be implemented in the cryptographic layer, e.g., by using recent lattice-based key exchange algorithms NewHope or Frodo, or in the physical layer of wireless communication, by utilizing eavesdropping-resistant secrecy coding techniques. In this study, we explore and compare the feasibility and energy efficiency of selected cryptographic layer and physical layer approaches by applying an evaluation approach that is based on simulation and modeling. In particular, we consider NewHope and Frodo key exchange algorithms as well as novel physical layer secrecy coding approach that is based on polar codes. The results reveal that our proposed physical layer implementation is very competitive with respect to the cryptographic solutions, particularly in short-range wireless communication. We also observed that the total energy consumption is unequally divided between transmitting and receiving devices in all the studied approaches. This may be an advantage when designing security architectures for energy-restricted devices.
An Auxiliary Variable Method for Markov Chain Monte Carlo Algorithms in High Dimension
Authors: Marnissi Yosra , Chouzenoux Emilie , Benazza-Benyahia Amel , Pesquet Jean-Christophe
Published: February 2018

In this paper, we are interested in Bayesian inverse problems where either the data fidelity term or the prior distribution is Gaussian or driven from a hierarchical Gaussian model. Generally, Markov chain Monte Carlo (MCMC) algorithms allow us to generate sets of samples that are employed to infer some relevant parameters of the underlying distributions. However, when the parameter space is high-dimensional, the performance of stochastic sampling algorithms is very sensitive to existing dependencies between parameters. In particular, this problem arises when one aims to sample from a high-dimensional Gaussian distribution whose covariance matrix does not present a simple structure. Another challenge is the design of Metropolis–Hastings proposals that make use of information about the local geometry of the target density in order to speed up the convergence and improve mixing properties in the parameter space, while not being too computationally expensive. These two contexts are mainly related to the presence of two heterogeneous sources of dependencies stemming either from the prior or the likelihood in the sense that the related covariance matrices cannot be diagonalized in the same basis. In this work, we address these two issues. Our contribution consists of adding auxiliary variables to the model in order to dissociate the two sources of dependencies. In the new augmented space, only one source of correlation remains directly related to the target parameters, the other sources of correlations being captured by the auxiliary variables. Experiments are conducted on two practical image restoration problems—namely the recovery of multichannel blurred images embedded in Gaussian noise and the recovery of signal corrupted by a mixed Gaussian noise. Experimental results indicate that adding the proposed auxiliary variables makes the sampling problem simpler since the new conditional distribution no longer contains highly heterogeneous correlations. Thus, the computational cost of each iteration of the Gibbs sampler is significantly reduced while ensuring good mixing properties.
Digital Control Techniques Based on Voltage Source Inverters in Renewable Energy Applications: A Review
Authors: Tahir Sohaib , Wang Jie , Baloch Mazhar , Kaloi Ghulam
Published: February 2018

In the modern era, distributed generation is considered as an alternative source for power generation. Especially, need of the time is to provide the three-phase loads with smooth sinusoidal voltages having fixed frequency and amplitude. A common solution is the integration of power electronics converters in the systems for connecting distributed generation systems to the stand-alone loads. Thus, the presence of suitable control techniques, in the power electronic converters, for robust stability, abrupt response, optimal tracking ability and error eradication are inevitable. A comprehensive review based on design, analysis, validation of the most suitable digital control techniques and the options available for the researchers for improving the power quality is presented in this paper with their pros and cons. Comparisons based on the cost, schemes, performance, modulation techniques and coordinates system are also presented. Finally, the paper describes the performance evaluation of the control schemes on a voltage source inverter (VSI) and proposes the different aspects to be considered for selecting a power electronics inverter topology, reference frames, filters, as well as control strategy.
Robust Allocation of Reserve Policies for a Multiple-Cell Based Power System
Authors: Hu Junjie , Lan Tian , Heussen Kai , Marinelli Mattia , Prostejovsky Alexander , Lei Xianzhang
Published: February 2018

This paper applies a robust optimization technique for coordinating reserve allocations in multiple-cell based power systems. The linear decision rules (LDR)-based policies were implemented to achieve the reserve robustness, and consist of a nominal power schedule with a series of linear modifications. The LDR method can effectively adapt the participation factors of reserve providers to respond to system imbalance signals. The policies considered the covariance of historic system imbalance signals to reduce the overall reserve cost. When applying this method to the cell-based power system for a certain horizon, the influence of different time resolutions on policy-making is also investigated, which presents guidance for its practical application. The main results illustrate that: (a) the LDR-based method shows better performance, by producing smaller reserve costs compared to the costs given by a reference method; and (b) the cost index decreases with increased time intervals, however, longer intervals might result in insufficient reserves, due to low time resolution. On the other hand, shorter time intervals require heavy computational time. Thus, it is important to choose a proper time interval in real time operation to make a trade off.
A Structural Design Concept for a Multi-Shell Blended Wing Body with Laminar Flow Control
Authors: Bishara Majeed , Horst Peter , Madhusoodanan Hinesh , Brod Martin , Daum Benedikt , Rolfes Raimund
Published: February 2018

Static and fatigue analyses are presented for a new blended wing body (BWB) fuselage concept considering laminar flow control (LFC) by boundary layer suction in order to reduce the aerodynamic drag. BWB aircraft design concepts profit from a structurally beneficial distribution of lift and weight and allow a better utilization of interior space over conventional layouts. A structurally efficient design concept for the pressurized BWB cabin is a vaulted layout that is, however, aerodynamically disadvantageous. A suitable remedy is a multi-shell design concept with a separate outer skin. The synergetic combination of such a multi-shell BWB fuselage with a LFC via perforation of the outer skin to attain a drag reduction appears promising. In this work, two relevant structural design aspects are considered. First, a numerical model for a ribbed double-shell design of a fuselage segment is analyzed. Second, fatigue aspects of the perforation in the outer skin are investigated. A design making use of controlled fiber orientation is proposed for the perforated skin. The fatigue behavior is compared to perforation methods with conventional fiber topologies and to configurations without perforations.
A Key Review of Non-Industrial Greywater Heat Harnessing
Authors: Mazhar Abdur , Liu Shuli , Shukla Ashish
Published: February 2018

The ever-growing concerns about making buildings more energy efficient and increasing the share of renewable energy used in them, has led to the development of ultra-low carbon buildings or passive houses. However, a huge potential still exists to lower the hot water energy demand, especially by harnessing heat from waste water exiting these buildings. Reusing this heat makes buildings more energy-efficient and this source is considered as a third-generation renewable energy technology, both factors conforming to energy policies throughout the world. Based on several theoretical and experimental studies, the potential to harness non-industrial waste water is quite high. As an estimate about 3.5 kWh of energy, per person per day could be harnessed and used directly, in many applications. A promising example of such an application, are low temperature fourth generation District Heating grids, with decentralized sources of heat. At the moment, heat exchangers and heat pumps are the only viable options to harness non-industrial waste heat. Both are used at different scales and levels of the waste-water treatment hierarchical pyramid. Apart from several unfavourable characteristics of these technologies, the associated exergetic efficiencies are low, in the range of 20–50%, even when cascaded combinations of both are used. To tackle these shortcomings, several promising trends and technologies are in the pipeline, to scavenge this small-scale source of heat to a large-scale benefit.
Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus
Authors: Birien Tiphaine , Thiel Axel , Henneke Ghislaine , Flament Didier , Moalic Yann , Jebbar Mohamed
Published: February 2018

A gene disruption system for Thermococcus barophilus was developed using simvastatin (HMG-CoA reductase encoding gene) for positive selection and 5-Fluoroorotic acid (5-FOA), a pyrF gene for negative selection. Multiple gene mutants were constructed with this system, which offers the possibility of complementation in trans, but produces many false positives (<80%). To significantly reduce the rate of false positives, we used another counterselective marker, 6-methylpurine (6-MP), a toxic analog of adenine developed in Thermococcus kodakarensis, consistently correlated with the TK0664 gene (encoding a hypoxanthine-guanine phosphoribosyl-transferase). We thus replaced pyrF by TK0664 on our suicide vector and tested T. barophilus strain sensitivity to 6-MP before and after transformation. Wild-Type (WT) T. barophilus is less sensitive to 6-MP than WT T. kodakarensis, and an increase of cell resistance was achieved after deletion of the T. barophilus TERMP_00517 gene homologous to T. kodakarensis TK0664. Results confirmed the natural resistance of T. barophilus to 6-MP and show that TK0664 can confer sensitivity. This new counterselection system vastly improves genetic manipulations in T. barophilus MP, with a strong decrease in false positives to <15%. Using this genetic tool, we have started to investigate the functions of several genes involved in genomic maintenance (e.g., polB and rnhB).
The Challenge of Folklore to Medieval Studies
Authors: Lindow John
Published: February 2018

When folklore began to emerge as a valid expression of a people during the early stages of national romanticism, it did so alongside texts and artifacts from the Middle Ages. The fields of folklore and medieval studies were hardly to be distinguished at that time, and it was only as folklore began to develop its own methodology (actually analogous to medieval textual studies) during the nineteenth century that the fields were distinguished. During the 1970s, however, folklore adopted a wholly new paradigm (the “performance turn”), regarding folklore as process rather than static artifact. It is here that folklore offers a challenge for medieval studies, namely to understand better the oral background to all medieval materials and the cultural competence that underlay their uses.
Depressive Symptoms of Chinese Children: Prevalence and Correlated Factors among Subgroups
Authors: Zhou Mi , Zhang Guangsheng , Rozelle Scott , Kenny Kaleigh , Xue Hao
Published: February 2018

Economic growth and socioeconomic changes have transformed nearly every aspect of childhood in China, and many are worried by the increasing prevalence of mental health issues among children, particularly depression. To provide insight into the distribution of depressive symptoms among children in China and identify vulnerable groups, we use data from the 2012 China Family Panel Survey (CFPS), a survey that collected data from a large, nationally representative sample of the Chinese population. Using the CFPS data, we construct a sample of 2679 children aged 10–15 years old from 25 provinces in China. According to our results, the incidence of depression varies by geographic area. Specifically, we find that rates of depressive symptoms are significantly lower in urban areas (14% of sample children) than in rural areas (23% of sample children). Our results also show that children from ethnic minorities, from poorer families, and whose parents are depressed are more likely to be depressed than other children. In contrast, we find that depressive symptoms do not vary by gender.
Clinical Aspects of Foot Health in Individuals with Alzheimer’s Disease
Authors: López-López Daniel , Grela-Fariña Marta , Losa-Iglesias Marta , Calvo-Lobo César , Rodríguez-Sanz David , Palomo-López Patricia , Becerro-de-Bengoa-Vallejo Ricardo
Published: February 2018

Alzheimer’s disease (AD) shows a marked presence of physiologic changes and the start or aggravation of underlying diseases such as physical frailty in diverse anatomical regions. It is believed to have a particularly harmful effect on the health of the foot. We examined the foot health status in older persons with AD, with a specific focus on the extent to which people with AD may be using inadequate footwear in old age. Seventy-three community-dwelling people with probable, mild to moderate AD aged 65–95 years were recruited from a center of excellence for AD. A single trained physician evaluated health status and foot conditions. Current shoe and foot length and width measurements were taken using a calibrated Brannock device. The results indicate that sixty-five participants (89.04%) suffered from feet problems. Also, only twenty-two subjects (30.14%) used the correct shoes in width and size related with the morphology of their feet. Fifty-one participants (69.86%) were using incorrect shoes in length or width. The present study revealed that peoples with AD had a high presence of foot health problems. Also, the use of inappropriate shoes revealed measurable differences of association between shoe size and the morphology of the foot.
Microplastics Reduce Short-Term Effects of Environmental Contaminants. Part II: Polyethylene Particles Decrease the Effect of Polycyclic Aromatic Hydrocarbons on Microorganisms
Authors: Kleinteich Julia , Seidensticker Sven , Marggrander Nikolaj , Zarfl Christiane
Published: February 2018

Microplastic particles in terrestrial and aquatic ecosystems are currently discussed as an emerging persistent organic pollutant and as acting as a vector for hydrophobic chemicals. Microplastic particles may ultimately deposit and accumulate in soil as well as marine and freshwater sediments where they can be harmful to organisms. In this study, we tested the sensitivity of natural freshwater sediment bacterial communities (by genetic fingerprint) to exposure to microplastics (polyethylene, 2 and 20 mg/g sediment) and microplastics loaded with polycyclic aromatic hydrocarbons (PAHs, phenanthrene and anthracene), using a laboratory-based approach. After two weeks of incubation, the bacterial community composition from an unpolluted river section was altered by high concentrations of microplastics, whereas the community downstream of a wastewater treatment plant remained unchanged. Low microplastic concentrations loaded with phenanthrene or anthracene induced a less pronounced response in the sediment communities compared to the same total amount of phenanthrene or anthracene alone. In addition, biodegradation of the PAHs was reduced. This study shows, that microplastic can affect bacterial community composition in unpolluted freshwater sediments. Moreover, the results indicate that microplastics can serve as a vehicle for hydrophobic pollutants but bioavailability of the latter is reduced by the sorption to microplastics.
Smokers’ Views on Personal Carbon Monoxide Monitors, Associated Apps, and Their Use: An Interview and Think-Aloud Study
Authors: Herbeć Aleksandra , Perski Olga , Shahab Lion , West Robert
Published: February 2018

Smartphone-based personal carbon monoxide (CO) monitors and associated apps, or “CO Smartphone Systems” (CSSs) for short, could enable smokers to independently monitor their smoking and quitting. This study explored views and preferences regarding CSSs and their use among 16 adult, UK-based smokers. First, semi-structured interviews explored participants’ expectations of CSSs. Secondly, a think-aloud study identified participants’ reactions to a personal CO monitor and to existing or prototype apps. Framework Analysis identified five themes: (1) General views, needs, and motivation to use CSSs; (2) Views on the personal CO monitor; (3) Practicalities of CSS use; (4) Desired features in associated apps; and (5) Factors affecting preferences for CSSs and their use. Participants had high expectations of CSSs and their potential to increase motivation. Priority app features included: easy CO testing journeys, relevant and motivating feedback, and recording of contextual data. Appearance and usability of the personal CO monitor, and accuracy and relevance of CO testing were considered important for engagement. Participants differed in their motivation to use and preferences for CSSs features and use, which might have non-trivial impact on evaluation efforts. Personal CO monitors and associated apps may be attractive tools for smokers, but making CSSs easy to use and evaluating these among different groups of smokers may be challenging.
Incidence Rates of and Mortality after Hip Fracture among German Nursing Home Residents
Authors: Jacobs Hannes , Zeeb Hajo , Hoffmann Falk
Published: February 2018

Little is known about hip fracture rates and post-fracture mortality among nursing home residents. This retrospective cohort study examined incidence rates (IR) of and mortality after hip fracture in this population focusing on sex differences. A cohort of >127,000 residents ≥65 years, newly admitted to German nursing homes between 2010 and 2014 were used to calculate age-, sex-, care-need- and time after admission-specific IR. To determine mortality, the Kaplan-Meier-method was applied. Using Cox regression, we studied mortality and estimated time-dependent hazard ratios (HRs). For this purpose, to each person with a hip fracture, one resident without a hip fracture was matched by sex, age and care-need using risk-set sampling. 75% were women (mean age: 84.0 years). During 168,588 person-years (PY), 8537 residents with at least one hip fracture were observed. The IR for women and men were 52.9 and 42.5/1000 PY. For both sexes, IR increased with rising age and decreased with increasing care-level. IR were highest in the first months after admission and subsequently declined afterwards. The impact of hip fractures on mortality was time-dependent. Mortality of residents with hip fracture was highest in the first two months after fracture compared to those without (HR): 2.82; 95% CI 2.57–3.11) and after six months, no differences were found (HR: 1.10; 95% CI 0.98–1.22) Further research should always include analyses stratified by sex, age and time period after admission.
Characteristics of Stress and Suicidal Ideation in the Disclosure of Sexual Orientation among Young French LGB Adults
Authors: Charbonnier Elodie , Dumas Florence , Chesterman Adam , Graziani Pierluigi
Published: February 2018

Background: Lesbians, gays, and bisexual people (LGB) present high levels of suicidal ideation. The disclosure of sexual orientation is a stressful experience which presents a high suicide risk. Research has not paid sufficient attention to stress during this disclosure in order to understand suicide among LGB people. The aims of this study were to investigate: (1) the characteristics of stress during this revelation, more precisely cognitive appraisal, emotions, and coping; and (2) associations between these characteristics and suicidal ideation. Method: A total of 200 LGB young adults answered the “Stressful situation assessment questionnaire”, focusing on the most stressful disclosure of sexual orientation they have ever experienced. Results: Avoidance coping is a good predictor of suicidal ideation, and mediates the association between primary appraisal (risk “Harm myself and others”) and suicidal ideation. Conclusions: Our study illustrates the need to better understand stress during the disclosure of sexual orientation to prevent and care for suicide risk among LGB young adults.
Daily Patterns of Preschoolers’ Objectively Measured Step Counts in Six European Countries: Cross-Sectional Results from the ToyBox-Study
Authors: Van Stappen Vicky , Van Dyck Delfien , Latomme Julie , De Bourdeaudhuij Ilse , Moreno Luis , Socha Piotr , Iotova Violeta , Koletzko Berthold , Manios Yannis , Androutsos Odysseas , Cardon Greet , De Craemer Marieke
Published: February 2018

This study is part of the ToyBox-study, which is conducted in six European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain), aiming to develop a cost-effective kindergarten-based, family-involved intervention to prevent overweight and obesity in four- to six-year-old preschool children. In the current study, we aimed to examine and compare preschoolers’ step count patterns, across the six European countries. A sample of 3578 preschoolers (mean age: 4.8 ± 0.4) was included. Multilevel analyses were performed to take clustering of measurements into account. Based on the average hourly steps, step count patterns for the six European countries were created for weekdays and weekend days. The step count patterns during weekdays were related to the daily kindergarten schedules. Step count patterns during weekdays showed several significant peaks and troughs (p < 0.01) and clearly reflected the kindergartens’ daily schedules, except for Germany. For example, low numbers of steps were observed during afternoon naptimes and high numbers of steps during recess. In Germany, step count patterns did not show clear peaks and troughs, which can be explained by a less structured kindergarten schedule. On weekend days, differences in step count patterns were observed in the absolute number of steps in the afternoon trough and the period in which the evening peak occurred. Differences in step count patterns across the countries can be explained by differences in (school) policy, lifestyle habits, and culture. Therefore, it might be important to respond to these step count patterns and more specifically to tackle the inactive periods during interventions to promote physical activity in preschoolers.
A Logistic Regression Based Auto Insurance Rate-Making Model Designed for the Insurance Rate Reform
Authors: Duan Zhengmin , Chang Yonglian , Wang Qi , Chen Tianyao , Zhao Qing
Published: February 2018

Using a generalized linear model to determine the claim frequency of auto insurance is a key ingredient in non-life insurance research. Among auto insurance rate-making models, there are very few considering auto types. Therefore, in this paper we are proposing a model that takes auto types into account by making an innovative use of the auto burden index. Based on this model and data from a Chinese insurance company, we built a clustering model that classifies auto insurance rates into three risk levels. The claim frequency and the claim costs are fitted to select a better loss distribution. Then the Logistic Regression model is employed to fit the claim frequency, with the auto burden index considered. Three key findings can be concluded from our study. First, more than 80% of the autos with an auto burden index of 20 or higher belong to the highest risk level. Secondly, the claim frequency is better fitted using the Poisson distribution, however the claim cost is better fitted using the Gamma distribution. Lastly, based on the AIC criterion, the claim frequency is more adequately represented by models that consider the auto burden index than those do not. It is believed that insurance policy recommendations that are based on Generalized linear models (GLM) can benefit from our findings.
An Effective Privacy Architecture to Preserve User Trajectories in Reward-Based LBS Applications
Authors: Hasan A , Qu Qiang , Li Chengming , Chen Lifei , Jiang Qingshan
Published: February 2018

How can training performance data (e.g., running or walking routes) be collected, measured, and published in a mobile program while preserving user privacy? This question is becoming important in the context of the growing use of reward-based location-based service (LBS) applications, which aim to promote employee training activities and to share such data with insurance companies in order to reduce the healthcare insurance costs of an organization. One of the main concerns of such applications is the privacy of user trajectories, because the applications normally collect user locations over time with identities. The leak of the identified trajectories often results in personal privacy breaches. For instance, a trajectory would expose user interest in places and behaviors in time by inference and linking attacks. This information can be used for spam advertisements or individual-based assaults. To the best of our knowledge, no existing studies can be directly applied to solve the problem while keeping data utility. In this paper, we identify the personal privacy problem in a reward-based LBS application and propose privacy architecture with a bounded perturbation technique to protect user’s trajectory from the privacy breaches. Bounded perturbation uses global location set (GLS) to anonymize the trajectory data. In addition, the bounded perturbation will not generate any visiting points that are not possible to visit in real time. The experimental results on real-world datasets demonstrate that the proposed bounded perturbation can effectively anonymize location information while preserving data utility compared to the existing methods.
Characterizing 3D City Modeling Projects: Towards a Harmonized Interoperable System
Authors: Julin Arttu , Jaalama Kaisa , Virtanen Juho-Pekka , Pouke Matti , Ylipulli Johanna , Vaaja Matti , Hyyppä Juha , Hyyppä Hannu
Published: February 2018

3D city models have become common geospatial data assets for cities that can be utilized in numerous fields, in tasks related to planning, visualization, and decision-making among others. We present a study of 3D city modeling focusing on the six largest cities in Finland. The study portrays a contradiction between the realized 3D city modeling projects and the expectations towards them: models do not appear to reach the broad applicability envisioned. In order to deal with contradiction and to support the development of future 3D city models, characteristics of different operational cultures in 3D city modeling are presented, and a concept for harmonizing the 3D city modeling is suggested.
Changes in Gross Primary Production (GPP) over the Past Two Decades Due to Land Use Conversion in a Tourism City
Authors: Nuarsa I , As-syakur Abd. , Gunadi I , Sukewijaya I
Published: February 2018

Understanding the changes in gross primary production (GPP), which is the total carbon fixation by terrestrial ecosystems through vegetation photosynthesis, due to land use conversion in a tourism city is important for carbon cycle studies. Satellite data from Landsat 5, Landsat 7 and Landsat 8 and meteorological data are used to calculate annual GPP for 1995, 2003 and 2014, respectively, using the vegetation production model (VPM) in the tourism city Denpasar, Bali, Indonesia. Five land use types generated from topographic maps in three different years over the past two decades are used to quantify the impacts of land use changes on GPP estimation values. Analysis was performed for two periods to determine changes in land use and GPP value as well as their speed. The results demonstrated that urban land development, namely, the increase of settlement areas due to tourism activity, had overall negative effects on terrestrial GPP. The total GPP of the whole area decreased by 7793.96 tC year−1 (12.65%) during the study period. The decline is due to the conversion of agriculture and grassland area into settlements, which caused the city to lose half of its ability to uptake carbon through vegetation. However, although forest area is declining, forest maintenance and restoration by making them protection areas has been helpful in preventing a drastic decline in GPP value over the past two decades. This study provides information that is useful for carbon resource management, tourism, policy making and scholars concerned about carbon reduction in a tourism city.
Moderating Climate Hazard Risk through Cooperation in Asian Drylands
Authors: Sternberg Troy
Published: February 2018

Asia drylands face increasing climate hazard risk, changing socio-economic forces, and environmental challenges that affect community viability. As home to >1 billion residents, deserts are at the centre of the continent’s climate-human predicament. Extreme water scarcity, dependence on food imports and now conflict increase hazard exposure across shared drylands, yet management differs from state to state. This paper argues that a more coherent strategy for mitigating risk would be based on natural environments. Linking hazards with livelihoods and social stability identifies how recent drought events disrupted ecosystems and societies. This results in borders rather than geography defining risk and response. Developing a dryland perspective across the continent can be an effective approach to reduce hazard risk and improve cooperation across Asia’s extensive arid lands.
Mechanism-Based FE Simulation of Tool Wear in Diamond Drilling of SiCp/Al Composites
Authors: Xiang Junfeng , Pang Siqin , Xie Lijing , Gao Feinong , Hu Xin , Yi Jie , Hu Fang
Published: February 2018

The aim of this work is to analyze the micro mechanisms underlying the wear of macroscale tools during diamond machining of SiCp/Al6063 composites and to develop the mechanism-based diamond wear model in relation to the dominant wear behaviors. During drilling, high volume fraction SiCp/Al6063 composites containing Cu, the dominant wear mechanisms of diamond tool involve thermodynamically activated physicochemical wear due to diamond-graphite transformation catalyzed by Cu in air atmosphere and mechanically driven abrasive wear due to high-frequency scrape of hard SiC reinforcement on tool surface. An analytical diamond wear model, coupling Usui abrasive wear model and Arrhenius extended graphitization wear model was proposed and implemented through a user-defined subroutine for tool wear estimates. Tool wear estimate in diamond drilling of SiCp/Al6063 composites was achieved by incorporating the combined abrasive-chemical tool wear subroutine into the coupled thermomechanical FE model of 3D drilling. The developed drilling FE model for reproducing diamond tool wear was validated for feasibility and reliability by comparing numerically simulated tool wear morphology and experimentally observed results after drilling a hole using brazed polycrystalline diamond (PCD) and chemical vapor deposition (CVD) diamond coated tools. A fairly good agreement of experimental and simulated results in cutting forces, chip and tool wear morphologies demonstrates that the developed 3D drilling FE model, combined with a subroutine for diamond tool wear estimate can provide a more accurate analysis not only in cutting forces and chip shape but also in tool wear behavior during drilling SiCp/Al6063 composites. Once validated and calibrated, the developed diamond tool wear model in conjunction with other machining FE models can be easily extended to the investigation of tool wear evolution with various diamond tool geometries and other machining processes in cutting different workpiece materials.
On the Stability of c-BN-Reinforcing Particles in Ceramic Matrix Materials
Authors: Wolfrum Anne-Kathrin , Matthey Björn , Michaelis Alexander , Herrmann Mathias
Published: February 2018

Cubic boron nitride (c-BN) composites produced at high pressures and temperatures are widely used as cutting tool materials. The advent of new, effective pressure-assisted densification methods, such as spark plasma sintering (SPS), has stimulated attempts to produce these composites at low pressures. Under low-pressure conditions, however, transformation of c-BN to the soft hexagonal BN (h-BN) phase can occur, with a strong deterioration in hardness and wear. In the present work, the influence of secondary phases (B2O3, Si3N4, and oxide glasses) on the transformation of c-BN was studied in the temperature range between 1100 °C and 1575 °C. The different heat treated c-BN particles and c-BN composites were analyzed by SEM, X-ray diffraction, and Raman spectroscopy. The transformation mechanism was found to be kinetically controlled solution–diffusion–precipitation. Given a sufficiently low liquid phase viscosity, the transformation could be observed at temperatures as low as 1200 °C for the c-BN–glass composites. In contrast, no transformation was found at temperatures up to 1575 °C when no liquid oxide phase is present in the composite. The results were compared with previous studies concerning the c-BN stability and the c-BN phase diagram.
High Temperature Growth of Graphene from Cobalt Volume: Effect on Structural Properties
Authors: Amato Giampiero
Published: February 2018

Several transition metals other than the largely used Cu and Ni can be, in principle, employed to catalyze carbon precursors for the chemical vapor deposition of graphene, because the thermodynamics of their alloying with carbon is well known. For example, the wealth of information in the Co-C phase diagram can be used to predict the properties of graphene grown in this way. It is, in fact, expected that growth occurs at a temperature higher than in Ni, with beneficial consequences to the mechanical and electronic properties of the final product. In this work, the growth of graphene onto Co film is presented together with an extensive Raman characterization of the structural properties of the material so far obtained. Previous results reporting the full coverage with negligible defective areas, in spite of discontinuities in the underlying metal, are confirmed, together with the occurrence of strain in the graphene sheet. Strain is deeply investigated in this work, in view of possible employment in engineering the material properties. The observed strain is ascribed to the high thermal mismatch with the substrate, even if an effect of the crystallographic transition of Co cannot be excluded.
Fracture Energy and Fracture Morphology after Three-Point Bending Test of Welded Joints Made of Cast Steel Designed for Use in Power Sector, with and without the Addition of Rare Earth Metals
Authors: Kasińska Justyna , Skrzypczyk Andrzej
Published: February 2018

The paper reports the three-point bending test results of welded joints. The joints were made of chromium-molybdenum cast steel designed for the use at elevated temperatures. TIG (tungsten inert gas) welding technique was used. The fracture energy for particular joint zones and the stretch zone width (SZW) under the notch bottom were determined in a qualitative fracture toughness assessment. Fracture surface morphology was analyzed. The stretch zone measurement indicated a qualitative relationship between its width and the values of fracture energy. The results confirmed the influence of the modification on the character of fracture and the portions of brittle and ductile fracture in particular areas of welded joints.
Anaerobic Degradation of Bicyclic Monoterpenes in Castellaniella defragrans
Authors: Puentes-Cala Edinson , Liebeke Manuel , Markert Stephanie , Harder Jens
Published: February 2018

The microbial degradation pathways of bicyclic monoterpenes contain unknown enzymes for carbon–carbon cleavages. Such enzymes may also be present in the betaproteobacterium Castellaniella defragrans, a model organism to study the anaerobic monoterpene degradation. In this study, a deletion mutant strain missing the first enzyme of the monocyclic monoterpene pathway transformed cometabolically the bicyclics sabinene, 3-carene and α-pinene into several monocyclic monoterpenes and traces of cyclic monoterpene alcohols. Proteomes of cells grown on bicyclic monoterpenes resembled the proteomes of cells grown on monocyclic monoterpenes. Many transposon mutants unable to grow on bicyclic monoterpenes contained inactivated genes of the monocyclic monoterpene pathway. These observations suggest that the monocyclic degradation pathway is used to metabolize bicyclic monoterpenes. The initial step in the degradation is a decyclization (ring-opening) reaction yielding monocyclic monoterpenes, which can be considered as a reverse reaction of the olefin cyclization of polyenes.
Classification of Flotation Frothers
Authors: Drzymala Jan , Kowalczuk Przemyslaw
Published: February 2018

In this paper, a scheme of flotation frothers classification is presented. The scheme first indicates the physical system in which a frother is present and four of them i.e., pure state, aqueous solution, aqueous solution/gas system and aqueous solution/gas/solid system are distinguished. As a result, there are numerous classifications of flotation frothers. The classifications can be organized into a scheme described in detail in this paper. The frother can be present in one of four physical systems, that is pure state, aqueous solution, aqueous solution/gas and aqueous solution/gas/solid system. It results from the paper that a meaningful classification of frothers relies on choosing the physical system and next feature, trend, parameter or parameters according to which the classification is performed. The proposed classification can play a useful role in characterizing and evaluation of flotation frothers.
Evaluation of Multi-Frequency SAR Images for Tropical Land Cover Mapping
Authors: Hagensieker Ron , Waske Björn
Published: February 2018

Earth Observation (EO) data plays a major role in supporting surveying compliance of several multilateral environmental treaties, such as UN-REDD+ (United Nations Reducing Emissions from Deforestation and Degradation). In this context, land cover maps of remote sensing data are the most commonly used EO products and development of adequate classification strategies is an ongoing research topic. However, the availability of meaningful multispectral data sets can be limited due to cloud cover, particularly in the tropics. In such regions, the use of SAR systems (Synthetic Aperture Radar), which are nearly independent form weather conditions, is particularly promising. With an ever-growing number of SAR satellites, as well as the increasing accessibility of SAR data, potentials for multi-frequency remote sensing are becoming numerous. In our study, we evaluate the synergistic contribution of multitemporal L-, C-, and X-band data to tropical land cover mapping. We compare classification outcomes of ALOS-2, RADARSAT-2, and TerraSAR-X datasets for a study site in the Brazilian Amazon using a wrapper approach. After preprocessing and calculation of GLCM texture (Grey Level Co-Occurence), the wrapper utilizes Random Forest classifications to estimate scene importance. Comparing the contribution of different wavelengths, ALOS-2 data perform best in terms of overall classification accuracy, while the classification of TerraSAR-X data yields higher accuracies when compared to the results achieved by RADARSAT-2. Moreover, the wrapper underlines potentials of multi-frequency classification as integration of multi-frequency images is always preferred over multi-temporal, mono-frequent composites. We conclude that, despite distinct advantages of certain sensors, for land cover classification, multi-sensoral integration is beneficial.