bluuebunny/crossref_metadata_2025 huggingface dataset:
SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs
Authors: Aslam Muhammad , Hu Xiaopeng , Wang Fan
Published: December 2017

Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN). Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs) utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR) routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR’s routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS). This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR) to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime and stability period when compared to existing routing protocols.
Fiber-Optic Sensor-Based Remote Acoustic Emission Measurement in a 1000 °C Environment
Authors: Yu Fengming , Okabe Yoji
Published: December 2017

Recently, the authors have proposed a remote acoustic emission (AE) measurement configuration using a sensitive fiber-optic Bragg grating (FBG) sensor. In the configuration, the FBG sensor was remotely bonded on a plate, and an optical fiber was used as the waveguide to propagate AE waves from the adhesive point to the sensor. The previous work (Yu et al., Smart Materials and Structures 25 (10), 105,033 (2016)) has clarified the sensing principle behind the special remote measurement system that enables accurate remote sensing of AE signals. Since the silica-glass optical fibers have a high heat-resistance exceeding 1000 °C, this work presents a preliminary high-temperature AE detection method by using the optical fiber-based ultrasonic waveguide to propagate the AE from a high-temperature environment to a room-temperature environment, in which the FBG sensor could function as the receiver of the guided wave. As a result, the novel measurement configuration successfully achieved highly sensitive and stable AE detection in an alumina plate at elevated temperatures in the 100 °C to 1000 °C range. Due to its good performance, this detection method will be potentially useful for the non-destructive testing that can be performed in high-temperature environments to evaluate the microscopic damage in heat-resistant materials.
Extreme Environment Sensing Using Femtosecond Laser-Inscribed Fiber Bragg Gratings
Authors: Mihailov Stephen , Grobnic Dan , Hnatovsky Cyril , Walker Robert , Lu Ping , Coulas David , Ding Huimin
Published: December 2017

The femtosecond laser-induced fiber Bragg grating is an effective sensor technology that can be deployed in harsh environments. Depending on the optical fiber chosen and the inscription parameters that are used, devices suitable for high temperature, pressure, ionizing radiation and strain sensor applications are possible. Such devices are appropriate for aerospace or energy production applications where there is a need for components, instrumentation and controls that can function in harsh environments. This paper will present a review of some of the more recent developments in this field.
Analysis of Landscape Patterns of Arid Valleys in China, Based on Grain Size Effect
Authors: Fang Shu , Zhao Yonghua , Han Lei , Ma Chaoqun
Published: December 2017

Landscape metrics are useful tools in investigating spatial structure and in describing the heterogeneity of landscapes, but are sensitive to grain size. Thus, it is necessary to determine the appropriate grain size before researching landscape patterns. However, there have been few large-scale investigations in high-precision research about the effect of grain size on landscape patterns, especially in arid valleys in China. Thus, we selected three representative sample areas according to the basic characteristics of arid valleys, and we chose 22 grain sizes from 15 to 450 m to calculate twelve landscape metrics at the landscape level and six landscape metrics at the class level to analyze the most appropriate grain size for the arid valleys. All basins in the study area were converted to an appropriate-sized grid to analyze the landscape patterns. Our results showed that the effect of grain size on landscape metrics can be categorized as: no law, increasing, decreasing, or no change. The majority of the fitted landscape index curves were good, with high R2 values. The most appropriate grain size at both levels was 75 m. The landscape pattern of arid valleys was scale-dependent. At the landscape level, arid valley landscape patterns changed from northwest to southeast due to topography and hydrothermal conditions. While the value of aggregation for different size classes was high, the other metrics showed significant differences due to area and degree of human activity at the class level.
Do Sustainable Procurement Practices Improve Organizational Performance?
Authors: Islam Md. Mazharul , Turki Abalala , Murad Md. Wahid , Karim Azharul
Published: December 2017

This exploratory study investigates the impacts of sustainable procurement (SP) practices on organizational performance by using the established scales of SP practices and organizational performances, taking Saudi Arabia as a case country. Data used in the study was collected through a questionnaire survey from procurement directors and managers. Regression and multivariate-based path analysis was performed to assess the impacts of SP practices. From the preliminary results, a significant association between combined SP practices and organizations’ financial performance was found. A mediational analysis was conducted to discover the direct and indirect effects of SP practices on financial performance. There was no evidence of a significant direct impact of the summary measures of SP practices on financial performance, while the indirect impact of SP practices via organizational nonfinancial performance on financial performance was found to be statistically significant. This study contributes to SP practice literature by developing a conceptual model for the outcomes of SP practices and establishing statistically significant relationships between SP practices, organizational financial performance, and mediating factors.
Passive Optimization Design Based on Particle Swarm Optimization in Rural Buildings of the Hot Summer and Warm Winter Zone of China
Authors: Lu Shilei , Wang Ran , Zheng Shaoqun
Published: December 2017

The development of green building is an important way to solve the environmental problems of China’s construction industry. Energy conservation and energy utilization are important for the green building evaluation criteria (GBEC). The objective of this study is to evaluate the quantitative relationship between building shape parameter, envelope parameters, shading system, courtyard and the energy consumption (EC) as well as the impact on indoor thermal comfort of rural residential buildings in the hot summer and warm winter zone (HWWZ). Taking Quanzhou (Fujian Province of China) as an example, based on the field investigation, EnergyPlus is used to build the building performance model. In addition, the classical particle swarm optimization algorithm in GenOpt software is used to optimize the various factors affecting the EC. Single-objective optimization has provided guidance to the multi-dimensional optimization and regression analysis is used to find the effects of a single input variable on an output variable. Results shows that the energy saving rate of an optimized rural residence is about 26–30% corresponding to the existing rural residence. Moreover, the payback period is about 20 years. A simple case study is used to demonstrate the accuracy of the proposed optimization analysis. The optimization can be used to guide the design of new rural construction in the area and the energy saving transformation of the existing rural houses, which can help to achieve the purpose of energy saving and comfort.
Experimental Study on Electrode Method for Electrical Resistivity Survey to Detect Cavities under Road Pavements
Authors: Park Chang-Seon , Jeong Jin-Hoon , Park Hae-Won , Kim Kyoungchul
Published: December 2017

There are two types of electrode methods for electrical resistivity survey (ERS): the pole electrode method (PEM) and flat electrode method (FEM). During the past few decades, most studies were conducted by using PEM for various purposes while only a few were conducted by using FEM. Laboratory and field experiments were performed in this study to investigate the advantage of FEM in detecting cavities under pavements. In the laboratory experiment, the results of PEM and FEM were compared graphically and statistically. A significant difference between the results of PEM and FEM was observed for concrete at an age of seven days, while there was no significant difference in the results for soil materials. Electrical resistivity could not be obtained from asphalt because it is an insulator. In a field experiment, four different cases were simulated: field ground with/without cavity and concrete pavement with/without cavity. The results of PEM and FEM for these cases were compared using 2D electrical resistivity contour images. It was observed that the distribution of electrical resistivity obtained using FEM was wider than that using PEM. Moreover, the locations of the cavities artificially made in the ground and under the pavement were accurately detected using both PEM and FEM.
Earnings Management and CSR Disclosure. Family vs. Non-Family Firms
Authors: Gavana Giovanna , Gottardo Pietro , Moisello Anna Maria
Published: December 2017

Building on Institutional theory and Signaling theory, integrated with the socioemotional wealth (SEW) approach, we studied the effect of earnings management (EM) practices on a firm’s Corporate Social Responsibility (CSR) disclosure behavior. In so doing, we analyzed a sample of 226 non-financial, family and non-family listed firms for the period, 2006–2015. Our results suggest that family firms, in instances of downward earnings management, are more prone to diverting attention from these practices by means of CSR disclosure, compared to non-family firms, although the level of family ownership exerts a moderating effect. Moreover, we found that a firm’s visibility, in terms of size, significantly enhances this behavior and that the effect is higher for family firms.
Characteristics of Particulate Pollution (PM2.5 and PM10) and Their Spacescale-Dependent Relationships with Meteorological Elements in China
Authors: Li Xiaodong , Chen Xuwu , Yuan Xingzhong , Zeng Guangming , León Tomás , Liang Jie , Chen Gaojie , Yuan Xinliang
Published: December 2017

Particulate matter (PM) pollution in China has an obvious characteristic of spatial distribution. It is well known that intensive anthropogenic activities, such as fossil fuel combustion and biomass burning, have great influence on the spatial distribution of PM pollution. However, the spacescale-dependent relationships between PM concentrations and weather conditions remain unclear. Here, we investigated the characteristics of two types of particulate pollution, including PM2.5 and PM10, and their spatial relationships with meteorological elements in 173 cities throughout China from March 2014 to February 2015. Results: (1) High PM2.5 concentrations were distinctly located southeast of the Hu Line, and high PM10 concentrations were distinctly situated north of the Yangtze River; (2) Spacescale-dependent relationships were found between PM pollution and meteorological elements. The influence of temperature had similar inverted V-shaped characteristics, namely, there was serious PM pollution when temperature was about 15 °C, and there was slight PM pollution when temperature was less or more than 15 °C. Annual precipitation, wind speed, and relative humidity were negatively correlated with PM, while annual atmospheric pressure was positively correlated with PM; (3) The ideal meteorological regions were identified according to the quantified spatial relationships between PM and meteorological elements, which could be defined by a combination of the following conditions: (a) temperature <10 °C or >21 °C; (b) precipitation >1500 mm; (c) atmospheric pressure <900 hPa; (d) wind speed >3 m/s; and (e) relative humidity >65%, where air pollutants can easily be scavenged. The success of this research provides a meteorological explanation to the spatial distribution characteristics of PM pollution in China.
Ambidextrous Leadership and Sustainability-Based Project Performance: The Role of Project Culture
Authors: Zheng Junwei , Wu Guangdong , Xie Hongtao , Xu Hui
Published: December 2017

Most studies in the project management field emphasized the effects of leaders or managers, but these effects have rarely been examined at the project level. To cover this research gap, this study applies organizational ambidexterity theory to examine the effects among ambidextrous leadership, ambidextrous culture and sustainability-based project performance. Using a valid sample of 217 project leaders and members from Chinese construction projects, the method of multiple linear regression was adopted to assess the direct relationship among ambidextrous leadership, ambidextrous culture and project performance. Moreover, the bootstrapping technique through structural equation modeling, has been used to analyze the mediating effect of ambidextrous culture. Additionally, the sample data was divided into different groups according to the median value of the variables to conduct the ANOVA and to assess the within-group differences. The results indicated a positive and direct relationship that ambidextrous leadership has on project performance and ambidextrous culture. In addition, there was also a mediating impact of ambidextrous leadership on project performance via ambidextrous culture. Thus, ambidextrous leadership combined with transformational leadership as well as transactional leadership likely has a stronger positive impact on project performance through fostering the adaptive culture and consistent culture. Our findings contribute to an in-depth understanding of the role of the leader and culture for project outcomes. The project-based organization in construction projects could train project leaders’ ambidextrous leadership behavior to facilitate the formation of an ambidextrous culture and to increase project performance. Moreover, this study enriches the existing literature on leadership and project management by highlighting the important path of ambidextrous leadership and ambidextrous culture on the performance at the project level and going beyond the single leadership behavior or single culture.
Photodegradation of 1-Butyl-3-methylimidazolium Chloride [Bmim]Cl via Synergistic Effect of Adsorption–Photodegradation of Fe-TiO2/AC
Authors: Zawawi Azhar , Ramli Raihan , Yub Harun Noorfidza
Published: December 2017

Ionic liquids (ILs) have attracted interest among researchers due to their tunable properties, which enable them to be used in a wide variety of applications. However, toxicity and biodegradation studies of ILs proved that most of the aromatic ILs, such as imidazolium, are highly toxic and non-biodegradable. Researchers have investigated several advance oxidation processes (AOPs) in order to evaluate the efficiency of the systems used to remove ILs from wastewater. However, their relatively high cost and environmental concerns have limited the application of these AOPs in industry. This research conducted a photocatalytic study using hybrid nanomaterials to evaluate the efficiency of this system as an alternative AOP system for the removal of ILs from wastewater. The synergistic effect of adsorption–photodegradation was introduced by depositing Fe-TiO2 onto functionalized activated carbon (AC). Nano-TiO2 was synthesized using the microemulsion method, then modified with a transition metal, and deposited onto oxidized AC. The photodegradation reaction of 1-butyl-3-methylimidazolium chloride [bmim]Cl was then investigated under simulated visible light irradiation. It was observed that the overall efficiency of the system increased with the increasing amount of Fe loading. Our investigation revealed that extrinsic factors such as solution pH, the initial concentration of ILs, and photocatalyst dosage significantly affect the overall efficiency of the system. The optimum condition for the system was observed at pH 10, with initial ILs at 1 mM at 1 g/L of photocatalyst. The best performance photocatalyst was 0.2Fe-TiO2/AC.
Peripapillary Retinal Nerve Fiber Measurement with Spectral-Domain Optical Coherence Tomography in Age-Related Macular Degeneration
Authors: Law Simon , Small Kent , Caprioli Joseph
Published: December 2017

Purpose: To evaluate the relationship between the peripapillary retinal nerve fiber layer (RNFL) measurements with Spectral-domain Optical Coherence Tomography (OCT) and Age-related macular degeneration (AMD). Methods: Patients >60 years of age without glaucoma or record of intraocular pressure >21 mmHg and no systemic or intraocular diseases or treatment or surgical intervention that affected the RNFL underwent OCT measurement of the RNFL. The severity of AMD was staged with the Clinical Age-Related Maculopathy Staging System. The relationship between RNFL measurements and AMD stages of one eye per patient was analyzed. Results: Eighty-six eyes (46 patients) with AMD and no glaucoma or other exclusion criteria received OCT RNFL measurements. Nine eyes (10.5%) were excluded because of distorted peripapillary anatomy from exudative AMD (7 eyes) or failure of the RNFL segmentation algorithm (2 eyes). Mean age ± S.D. of the 43 patients analyzed was 81.2 ± 7.3 years. The mean stage ± S.D. of AMD of the 77 eyes was 3.77 ± 1.05. Higher stages of AMD were statistically significantly associated with lower average RNFL and inferior sector RNFL (p = 0.049, 0 0015, respectively). The association of inferior sector RNFL and AMD stage remained statistically significant after adjusting for age. Conclusions: Spectral domain OCT is generally useful in measuring the peripapillary RNFL in eyes with different stages of AMD. Higher stage of AMD is associated with thinner peripapillary RNFL, which may masquerade as early glaucomatous damage.
Design and Modeling of an Adaptively Controlled Rainwater Harvesting System
Authors: Roman David , Braga Andrea , Shetty Nandan , Culligan Patricia
Published: December 2017

Management of urban stormwater to mitigate Combined Sewer Overflows (CSOs) is a priority for many cities; yet, few truly innovative approaches have been proposed to address the problem. Recent advances in information technology are now, however, providing cost-effective opportunities to achieve better performance of conventional stormwater infrastructure through a Continuous Monitoring and Adaptive Control (CMAC) approach. The primary objective of this study was to demonstrate that a CMAC approach can be applied to a conventional rainwater harvesting system in New York City to improve performance by minimizing discharge to the combined sewer during rainfall events, reducing water use for irrigation of local vegetation, and optimizing vegetation health. To achieve this objective, a hydrologic and hydraulic model was developed for a planned and designed rainwater harvesting system to explore multiple potential scenarios prior to the system’s actual construction. Model results indicate that the CMAC rainwater harvesting system is expected to provide significant performance improvements over conventional rainwater harvesting systems. The CMAC system is expected to capture and retain 76.6% of roof runoff per year on average, as compared to just 14.8% and 41.3% for conventional moisture and timer based systems, respectively. Similarly, the CMAC system is expected to use 81.4% and 18.0% less harvested rainwater than conventional moisture and timer based irrigation approaches, respectively. The flexibility of the CMAC approach to meet competing objectives is promising for widespread implementation in New York City and other heavily urbanized areas challenged by stormwater management issues.
Seroprevalence and risk factors for Hepatitis B and C among health care workers
Authors: Anwar Manal Mohamed , Ahmed Doaa , Sheemy Mostafa , El-Tayeb Mohamed
Published: December 2017

Health care workers (HCWs) are at high risk of exposure to Hepatitis B & C virus transmission due to injuries and frequency of exposure. We aimed to assess seroprevalence of hepatitis B and C infection among nurses and housekeepers in Beni-Suef university hospital, and to identify possible risk factors. A cross sectional study was conducted from March to July 2016 using a self-administered questionnaire. A blood sample was withdrawn from each participant and was tested for hepatitis B surface antigen (HBsAg) and anti-HCV antibodies. ELISA seropositivity to HCV was confirmed by PCR. The study involved 175/255 participants with a response rate of 68.5%. Nurses constituted 76% and 24% were housekeepers. Overall prevalence of HCV seropositivity was 4.6%; detected by “ELISA". Confirmatory PCR testing revealed positivity in 75% (6/8) of them. Cut injuries was a risk factor for HCV positivity (OR 4.388, 95% CI 0.859 - 22.4, P= 0.05). Previous training and use of gloves was a protective factor (OR 0.135, 95% CI .016- 1.118, P= 0.03 and OR 0.241, 95% CI 0.055- 1.04, P= 0.04 respectively). None of the participants were found to be HBV seropositive. Practices and behaviours posing risk for HCWs included needle stick injury (NSI) and cut injuries. Focus on improving safety training programs to HCWs and provision of infection prevention equipment is needed. In addition regular reporting, follow up and assessment of occupational exposures should be in place.
Rice TCM1 Encoding a Component of the TAC Complex is Required for Chloroplast Development under Cold Stress
Authors: Lin Dongzhi , Zheng Kailun , Liu Zhaohui , Li Zhikang , Teng Sheng , Xu Jianlong , Dong Yanjun
Published: December 2017

Transcriptionally active chromosome (TAC) is a component of protein–DNA complexes with RNA polymerase activity, expressed in the plastid. However, the function of rice TAC proteins is still poorly understood. In this paper, we first report the identification of a new rice (Oryza sativa L.) mutant (tcm1) in the gene encoding TAC. The tcm1 mutant displayed an albino phenotype and malformed chloroplasts before the three‐leaf stage when grown at low temperatures (20°C) and a normal phenotype at higher temperatures (>28°C). Map‐based cloning revealed that TCM1 encodes a novel chloroplast‐targeted TAC protein in rice. In addition, the transcript levels of all examined plastid‐encoded polymerase (PEP)‐dependent genes were clearly downregulated in tcm1 mutants at low temperatures, although partially recovering levels were obtained at high temperatures, comparable to wild‐type plants. Furthermore, the TCM1 transcripts were ubiquitously expressed in all examined tissues, with high expression levels in green tissues. The data suggest that the rice nuclear‐encoded TAC protein TCM1 is essential for proper chloroplast development and maintaining PEP activity under cold stress.
Single Nucleotide Polymorphism Markers Associated with Seed Quality Characteristics of Cultivated Lentil
Authors: Khazaei Hamid , Fedoruk Michael , Caron Carolyn T. , Vandenberg Albert , Bett Kirstin E.
Published: December 2017

The dimensions of lentil (Lens culinaris Medik.) seeds are important quality parameters that are major determinants of market preference, cooking time, and post‐harvest milling quality. Knowledge of the genetic control of traits related to seed dimensions would be useful for crop improvement. The principal aim of this study was to identify single nucleotide polymorphism (SNP) markers linked to genes that control seed diameter, seed thickness, and seed plumpness. Association mapping analysis with SNP markers was used to study the seed dimensions of 138 diverse cultivated lentil accessions grown at two locations in Saskatchewan, Canada, in 2011 and 2012. Six marker–trait associations were shown to be significant for the studied seed dimension characteristics. Two SNP markers closely associated with seed diameter across locations and years identified in previous work were validated in this study. Three additional marker–seed thickness associations were identified. Using the association mapping strategy, we confirmed the presence of two genomic regions controlling seed diameter and plumpness. This information can be used worldwide as a resource for lentil seed quality improvement programs.
OGLE-2017-BLG-0173Lb: Low-mass-ratio Planet in a “Hollywood” Microlensing Event
Authors: Hwang K.-H. , Udalski A. , Shvartzvald Y. , Ryu Y.-H. , Albrow M. D. , Chung S.-J. , Gould A. , Han C. , Jung Y. K. , Shin I.-G. , Yee J. C. , Zhu W. , Cha S.-M. , Kim D.-J. , Kim H.-W. , Kim S.-L. , Lee C.-U. , Lee D.-J. , Lee Y. , Park B.-G. , Pogge R. W. ,   (KMTNet Collaboration), Skowron J. , Mróz P. , Poleski R. , Kozłowski S. , Soszyński I. , Pietrukowicz P. , Szymański M. K. , Ulaczyk K. , Pawlak M. ,   (OGLE Collaboration), Bryden G. , Beichman C. , Novati S. Calchi , Gaudi B. S. , Henderson C. B. , Jacklin S. , Penny M. T. ,   (UKIRT Microlensing Team)
Published: December 2017

We present microlensing planet OGLE-2017-BLG-0173Lb, with planet–host mass ratio of either

or

, the lowest or among the lowest ever detected. The planetary perturbation is strongly detected, Δχ
2 ∼ 10000, because it arises from a bright (therefore, large) source passing over and enveloping the planetary caustic: a so-called “Hollywood” event. The factor ∼2.5 offset in q arises because of a previously unrecognized discrete degeneracy between Hollywood events in which the caustic is fully enveloped and those in which only one flank is enveloped, which we dub “Cannae” and “von Schlieffen,” respectively. This degeneracy is “accidental” in that it arises from gaps in the data. Nevertheless, the fact that it appears in a Δχ
2 = 10000 planetary anomaly is striking. We present a simple formalism to estimate the sensitivity of other Hollywood events to planets and show that they can lead to detections close to, but perhaps not quite reaching, the Earth/Sun mass ratio of

. This formalism also enables an analytic understanding of the factor ∼2.5 offset in q between the Cannae and von Schlieffen solutions. The Bayesian estimates for the host mass, system distance, and planet–host projected separation are

,

, and

, respectively. The two estimates of the planet mass are

and

. The measured lens-source relative proper motion

will permit imaging of the lens in about 15 years or at first light on adaptive-optics imagers on next-generation telescopes. These will allow one to measure the host mass but probably will not be able to resolve the planet–host mass-ratio degeneracy.
Resonant Electron Impact Excitation of 3d Levels in Fe14+ and Fe15+
Authors: Tsuda Takashi , Shimizu Erina , Ali Safdar , Sakaue Hiroyuki A. , Kato Daiji , Murakami Izumi , Hara Hirohisa , Watanabe Tetsuya , Nakamura Nobuyuki
Published: December 2017

We present laboratory spectra of the 3p–3d transitions in Fe14+ and Fe15+ excited with a mono-energetic electron beam. In the energy-dependent spectra obtained by sweeping the electron energy, resonant excitation is confirmed as an intensity enhancement at specific electron energies. The experimental results are compared with theoretical cross sections calculated based on fully relativistic wave functions and the distorted wave approximation. Comparisons between the experimental and theoretical results show good agreement for the resonance strength. A significant discrepancy is, however, found for the non-resonant cross section in Fe14+. This discrepancy is considered to be the fundamental cause of the previously reported inconsistency of the model with the observed intensity ratio between the

and

transitions.
Mass Profile Decomposition of the Frontier Fields Cluster MACS J0416-2403: Insights on the Dark-matter Inner Profile
Authors: Annunziatella M. , Bonamigo M. , Grillo C. , Mercurio A. , Rosati P. , Caminha G. , Biviano A. , Girardi M. , Gobat R. , Lombardi M. , Munari E.
Published: December 2017

We present a high-resolution dissection of the two-dimensional total mass distribution in the core of the Hubble Frontier Fields galaxy cluster MACS J0416.1−2403, at z = 0.396. We exploit HST/WFC3 near-IR (F160W) imaging, VLT/Multi Unit Spectroscopic Explorer spectroscopy, and Chandra data to separate the stellar, hot gas, and dark-matter mass components in the inner 300 kpc of the cluster. We combine the recent results of our refined strong lensing analysis, which includes the contribution of the intracluster gas, with the modeling of the surface brightness and stellar mass distributions of 193 cluster members, of which 144 are spectroscopically confirmed. We find that, moving from 10 to 300 kpc from the cluster center, the stellar to total mass fraction decreases from 12% to 1% and the hot gas to total mass fraction increases from 3% to 9%, resulting in a baryon fraction of approximatively 10% at the outermost radius. We measure that the stellar component represents ∼30%, near the cluster center, and 15%, at larger clustercentric distances, of the total mass in the cluster substructures. We subtract the baryonic mass component from the total mass distribution and conclude that within 30 kpc (∼3 times the effective radius of the brightest cluster galaxy) from the cluster center the surface mass density profile of the total mass and global (cluster plus substructures) dark-matter are steeper and that of the diffuse (cluster) dark-matter is shallower than an NFW profile. Our current analysis does not point to a significant offset between the cluster stellar and dark-matter components. This detailed and robust reconstruction of the inner dark-matter distribution in a larger sample of galaxy clusters will set a new benchmark for different structure formation scenarios.
Model-independent Measurement of Internal Stellar Structure in 16 Cygni A and B
Authors: Bellinger Earl P. , Basu Sarbani , Hekker Saskia , Ball Warrick H.
Published: December 2017

We present a method for measuring internal stellar structure based on asteroseismology that we call “inversions for agreement.” The method accounts for imprecise estimates of stellar mass and radius as well as the relatively limited oscillation mode sets that are available for distant stars. By construction, the results of the method are independent of stellar models. We apply this method to measure the isothermal sound speeds in the cores of the solar-type stars 16 Cyg A and B using asteroseismic data obtained from Kepler observations. We compare the asteroseismic structure that we deduce against best-fitting evolutionary models and find that the sound speeds in the cores of these stars exceed those of the models.
Understanding Breaks in Flare X-Ray Spectra: Evaluation of a Cospatial Collisional Return-current Model
Authors: Alaoui Meriem , Holman Gordon D.
Published: December 2017

Hard X-ray (HXR) spectral breaks are explained in terms of a one-dimensional model with a cospatial return current. We study 19 flares observed by the Ramaty High Energy Solar Spectroscopic Imager with strong spectral breaks at energies around a few deka-keV, which cannot be explained by isotropic albedo or non-uniform ionization alone. We identify these breaks at the HXR peak time, but we obtain 8 s cadence spectra of the entire impulsive phase. Electrons with an initially power-law distribution and a sharp low-energy cutoff lose energy through return-current losses until they reach the thick target, where they lose their remaining energy through collisions. Our main results are as follows. (1) The return-current collisional thick-target model provides acceptable fits for spectra with strong breaks. (2) Limits on the plasma resistivity are derived from the fitted potential drop and deduced electron-beam flux density, assuming the return current is a drift current in the ambient plasma. These resistivities are typically 2–3 orders of magnitude higher than the Spitzer resistivity at the fitted temperature, and provide a test for the adequacy of classical resistivity and the stability of the return current. (3) Using the upper limit of the low-energy cutoff, the return current is always stable to the generation of ion-acoustic and electrostatic ion-cyclotron instabilities when the electron temperature is nine times lower than the ion temperature. (4) In most cases, the return current is most likely primarily carried by runaway electrons from the tail of the thermal distribution rather than by the bulk drifting thermal electrons. For these cases, anomalous resistivity is not required.
Convective Velocity Suppression via the Enhancement of the Subadiabatic Layer: Role of the Effective Prandtl Number
Authors: Bekki Y. , Hotta H. , Yokoyama T.
Published: December 2017

It has recently been recognized that the convective velocities achieved in current solar convection simulations might be overestimated. The newly revealed effects of the prevailing small-scale magnetic field within the convection zone may offer possible solutions to this problem. The small-scale magnetic fields can reduce the convective amplitude of small-scale motions through the Lorentz-force feedback, which concurrently inhibits the turbulent mixing of entropy between upflows and downflows. As a result, the effective Prandtl number may exceed unity inside the solar convection zone. In this paper, we propose and numerically confirm a possible suppression mechanism of convective velocity in the effectively high-Prandtl number regime. If the effective horizontal thermal diffusivity decreases (the Prandtl number accordingly increases), the subadiabatic layer which is formed near the base of the convection zone by continuous depositions of low entropy transported by adiabatically downflowing plumes is enhanced and extended. The global convective amplitude in the high-Prandtl thermal convection is thus reduced, especially in the lower part of the convection zone via the change in the mean entropy profile, which becomes more subadiabatic near the base and less superadiabatic in the bulk.
L’Irak a-t-il jamais pu exister ?
Authors: Howorth Jolyon
Published: December 2017

Né de la décomposition de l’empire ottoman gérée par les impérialismes occidentaux, l’Irak, espace composite, a vu se succéder les régimes sans créer les bases psychologiques et politiques d’un État-nation. Les événements des deux dernières décennies n’ont fait, avec une lourde responsabilité occidentale, que creuser le fossé entre les communautés et les affiliations. L’Irak a-t-il jamais vraiment existé pour ses populations, et les conflits régionaux le laisseront-ils survivre ?
Yémen : imbroglio politico-juridique, désastre humanitaire, impasse militaire
Authors: Frison-Roche François
Published: December 2017

La guerre civile yéménite a évolué en conflit régional. Les Houthis, alliés à l’ancien président Saleh et soutenus par l’Iran, font face aux forces du président Hadi, épaulées par une coalition menée par l’Arabie Saoudite et les Émirats arabes unis. La situation humanitaire est catastrophique. Des millions de personnes sont menacées par la famine et le choléra. Dans ce chaos prospèrent les groupes terroristes comme Al-Qaïda dans la péninsule arabique et, dans une moindre mesure, Daech.
Quelles caractéristiques distinctives pour les micro-entrepreneurs ?
Authors: Hentic-Giliberto Michelle , Paturel Robert
Published: December 2017

Le cadre juridique instauré par la loi n° 2008-776 du 4 août 2008 semble plébiscité par les créateurs d’entreprises. Choisi par la majeure partie des créateurs, le régime de l’auto-entrepreneur, devenu micro-entrepreneur, aux formalités très simplifiées séduit. Cette étude, sur la base de données collectées de fin 2008 à début 2012 en région bretonne, positionne le créateur d’activité auto-entrepreneuriale par rapport aux autres types d’entrepreneurs. Grâce à une taxonomie, cette recherche vise à caractériser ces micro-entrepreneurs par comparaison aux entrepreneurs plus classiques.
Des tweets et des likes en bibliothèque
Authors: Audouard Marie-Françoise , Rimaud Mathilde , Wiart Louis
Published: December 2017

Être sur les réseaux sociaux, pour une institution culturelle, ce serait être là où se trouvent les usagers... Si, depuis une dizaine d’années, les bibliothèques investissent le web social, comment qualifier au juste leur « présence » ? Pour le savoir, faut-il se tourner vers les métriques quantitatives que mettent à disposition les plateformes sociales ? Faut-il s’attacher aux stratégies numériques que mettent en place les bibliothécaires ? Faut-il enquêter auprès des publics ? Des internautes ? Des inscrits ? Sans doute ces trois approches méritaient elles d’être explorées tant les contraintes se révèlent nombreuses : l’évolution en continu des plateformes sociales rend délicate la seule évaluation quantitative ; les ancrages territoriaux des établissements pèsent d’une autre manière sur les initiatives entreprises auprès des internautes ; la simplicité du Like, en même temps qu’elle banalise les signes de complicité, est surinvestie par ceux qui se connaissent et s’apprécient déjà.Sur la base d’un corpus de quatre établissements de lecture publique actifs sur les réseaux sociaux (réseaux de Brest et de Metz, médiathèque de Quimperlé et de Louise-Michel à Paris), l’étude Des tweets et des likes en bibliothèque, issue d’une enquête (notamment à base d’entretiens) menée en 2016, propose un bilan en trois volets : les réseaux sociaux numériques permettent aux bibliothèques d’établir une communication moins institutionnelle mais toujours descendante avec leurs publics ; ils instituent des modes de travail plus autonomes et moins hiérarchiques ; ils révèlent une communauté d’usagers très concernés par leur bibliothèque, qu’ils entendent défendre et protéger. Par leur investissement, ces usagers convaincus rappellent les « ambassadeurs de marque », tels qu’ils existent dans certains secteurs marchands : ils sont « là », par eux-mêmes, sans avoir besoin d’être sollicités, séduits ou investis d’une quelconque mission par les établissements qu’ils décident de suivre.
Crafting a Framework for Copyright Literacy and Licensed Content
Authors: Patnaik K. Rama
Published: December 2017

Copyright literacy as one of the tenets of user instruction in the digital domain has been passive in Indian Libraries. There have been sporadic efforts on the part of libraries amidst lack of policies or fair use and scholarly communication committees at institution level to address the issues relating to copyright. The important factor is the emergence of license agreements as contracts trumping the copyright laws and digital communication involving the copyrighted content. The chapter discusses the complex terrain of copyright literacy involving cross-jurisdictional copyright laws for drafting a user instruction guideline by analysing framework to address the issues often encountered by users of the content at IIMB. This case study assumes importance as library acquires content which is heterogeneous not only in format but also the terms of use and usage rights The objective of this effort is to encourage ethical use of copyright protected and licensed content in teaching, research, and learning and also creating awareness about the rights of content creators.
Contemporary Media for Library Users' Instruction in Academic Libraries in South-West Nigeria
Authors: Omeluzor Saturday U. , Abayomi Imam , Gbemi-Ogunleye Philomena
Published: December 2017

This chapter focused on contemporary media for library users' instruction in academic libraries in South-west of Nigeria. Library user instruction is a complex activity that entails educating the users how to utilize library information resources and enlightening them on the benefits of using information resources in the library. Prior to the use of contemporary media in library instruction, several other methods were predominantly used including teaching and library tour, etc. Advancement in information communication and technology (ICT) has augmented those instructional methods. Some of the contemporary methods are articulated in this chapter and its application in Federal University libraries in South-west, Nigeria is examined. Findings showed that contemporary media such as OPAC, ask a librarian, FAQ and Blog, etc. are important in library instruction and were used for instructing users in academic libraries. Some challenges facing contemporary media in academic libraries are inadequate Internet access, inadequate training of librarians, lack of skill and unreliable power supply.
Multi-Sensor Integrated Navigation in Urban and Indoor Environments
Authors: Atia Mohamed
Published: December 2017

The art of multi-sensor processing, or “sensor-fusion,” is the ability to optimally infer state information from multiple noisy streams of data. One major application area where sensor fusion is commonly used is navigation technology. While global navigation satellite systems (GNSS) can provide centimeter-level location accuracy worldwide, they suffer from signal availability problems in dense urban environment and they hardly work indoors. While several alternative backups have been proposed, so far, no single sensor or technology can provide the desirable precise localization in such environments under reasonable costs and affordable infrastructures. Therefore, to navigate through these complex areas, combining sensors is beneficial. Common sensors used to augment/replace GNSS in complex environments include inertial measurement unit (IMU), range sensors, and vision sensors. This chapter discusses the design and implementation of tightly coupled sensor fusion of GNSS, IMU, and light detection and ranging (LiDAR) measurements to navigate in complex urban and indoor environments.
Information Attacks and Defenses on the Social Web
Authors: Poggi Agostino , Tomaiuolo Michele
Published: December 2017

Social web sites are used daily by many millions of users. They have attracted users with very weak interest in technology, including absolute neophytes of computers in general. Common users of social web sites often have a carefree attitude in sharing information. Moreover, some system operators offer sub-par security measures, which are not adequate for the high value of the published information. For all these reasons, online social networks suffer more and more attacks by sophisticated crackers and scammers. To make things worse, the information gathered from social web sites can trigger attacks to even more sensible targets. This work reviews some typical social attacks that are conducted on social networking systems, describing real-world examples of such violations and analyzing in particular the weakness of password mechanisms. It then presents some solutions that could improve the overall security of the systems.
Exploring the Impact of Security Policy on Compliance
Authors: Yaokumah Winfred , Kumah Peace
Published: December 2017

Extant studies on compliance with security policies have largely ignored the impact of monitoring, security operations, and roles and responsibilities on employees' compliance. This chapter proposes a theoretical model that integrates security policy, monitoring, security operations, and security roles to examine employees' security compliance. Data were collected from 233 IT security and management professionals. Using partial least square structural equation modelling and testing hypotheses, the study finds that information security policy has significant indirect influence on information security compliance. The effect of security policy is fully mediated by security roles, operations security activities, and security monitoring activities. Security policy strongly influences operations security activities and has the greatest effect on security roles and responsibilities. Among the three mediating variables, monitoring has the most significant influence on security compliance. Conversely, the direct impact of security policy on compliance is not significant.
Prioritizing the Roles of Control Mechanisms in Digital Platform
Authors: Mukhopadhyay Sandip , Nikou Shahrokh , Bouwman Harry
Published: December 2017

Existing literature on control in software development considers only the principal-agency relationship between controller and controlee and this view does not hold true between ecosystems leader and partners, which are independent organizations. This chapter aims to study the critical role played by inter-organizational control mechanisms in the context of mobile platform ecosystems. By utilizing opinions of 38 experts and employing an Analytic Hierarchy Process (AHP) approach, this chapter identifies and ranks the most important roles played by control mechanisms in digital platform. The findings show that ecosystems´ leaders primarily use control to manage or improve its central position in the network to capture a higher share of value of the service. The findings provide further insights on two other roles of control in platform ecosystems: (1) accessing complementary resources and (2) managing interdependency between partners. This chapter contributes to organizational control theory in the context of emerging platform-based ecosystem.
Terrestrial vs. Online Gamblers
Authors: Saprikis Vaggelis
Published: December 2017

It goes without saying that the advances of Information and Communication Technologies have brought many changes in various forms of traditional commerce including gambling industry. Nowadays, e-gambling has dramatically changed the way of wagering and is considered as one of the fastest growing sectors of contemporary e-commerce. Every day even more individuals are moving from terrestrial to online gambling venues or start wagering exclusively online taking advantage of the numerous playing options. Characteristically, the global internet gambling gross market is expected to exceed US$51 billion by 2018. Consequently, its dynamics has forced many researchers to investigate e-gambling scientific field from different perspectives trying to gain an improved insight into gamblers behavior in the cyberspace. This chapter aims to investigate the perceived advantages and disadvantages of terrestrial versus online gamblers towards e-gambling activities focusing on university students. Furthermore, it aims to identify possible similarities and differences between the two groups examined.