bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrating Geographic Information Systems for Transportation and Air Quality Models for Microscale Analysis
Authors: Hallmark Shauna , O'Neill Wende
Published: August 2018

The inherently spatial nature of transportation-related air quality analysis makes the geographic information system (GIS) particularly well suited to enhancing microscale air quality analysis. GIS provides several features ideal for the type of analysis necessary to determine transportation-related air quality impacts. It is an excellent storage, manipulation, modeling, and mapping tool for spatial data. Spatial information such as street coordinates and accompanying attributes can be exported and manipulated as input to air quality models such as CALINE3 and CAL3QHC. Output from air quality models in the form of pollution concentrations at specified receptor locations can be input to GIS for hot-spot identification, estimation of contributions of off-road mobile sources, and impact analysis. GIS tools applied to air quality analysis include contour generation, classification, thematic analysis, point-in-polygon analysis, and polygon overlay. Several case studies demonstrating these capabilities using TRANSCAD, a transportation-based GIS package, are presented for microscale air quality analysis. Incompatibilities exist between current air quality models and most GIS. Differences in coordinate systems and distance metrics necessitate additional manipulation of data transferred between models and GIS. Other incompatibilities are that street segments are represented as centerlines in most planning applications of GIS and as a series of links in CAL3QHC and CALINE3, and that signalization parameters are represented differently from many common signal-analysis packages, which may necessitate additional data collection.
MULTIBAND-96: A Program for Variable-Bandwidth Progression Optimization of Multiarterial Traffic Networks
Authors: Stamatiadis Chronis , Gartner Nathan H.
Published: August 2018

Progression schemes are widely used for traffic signal control in urban arterial streets. Commonly available programs such as the MAXBAND or PASSER programs use the traditional approach, which consists of a uniform bandwidth design for each arterial. The multiband criterion, on the other hand, has the ability to adapt the progressions to the specific characteristics of each link in the network and thus obtain improved performance. The development and application of the multiband signal optimization scheme in multiarterial grid networks are described. The MULTIBAND-96 model optimizes all the signal control variables, including phase lengths, offsets, cycle time, and phase sequences, and generates variable bandwidth progressions on each arterial in the network. It uses the MINOS mathematical programming package for the optimization and offers considerable advantages compared with existing models. Simulation results using TRAF-NETSIM are given.
Current Developments in SCOOT: Version 3
Authors: retherton Dave B
Published: August 2018

The SCOOT urban traffic control system is now operating successfully in more than 130 towns and cities worldwide. The latest version of SCOOT has been extended to include support for bus priority, the automatic SCOOT traffic information data base (ASTRID) system, and the INGRID incident detection system and has been given added flexibility, particularly for use in incident conditions. Bus priority in SCOOT was developed within the European Union DRIVE 2 project PROMPT. This software has now been issued as part of the latest SCOOT version, following the field trials in London and Southampton, United Kingdom, which showed that significant benefits to buses could be obtained. The ASTRID data base has now been integrated with SCOOT and can run in the same machine as the urban traffic control system. As well as providing current and historical information to traffic engineers, ASTRID now can feed historic information back into SCOOT, providing a substitute cyclic flow profile that can be used for optimization when there are faulty detectors. The INGRID incident detection system contains two algorithms to provide an indication of an incident; taking current information directly from SCOOT, INGRID detects abnormal changes in flow and occupancy, and comparing current information with historic information stored in the ASTRID data base, INGRID detects abnormal patterns in these parameters. The SCOOT optimizers have been made more flexible and can now make larger changes to the signal timings if required. This facility can be switched on or off and would be particularly useful where an incident has been detected.
Simulation-Based Methodology for Evaluation of High-Occupancy-Vehicle Facilities
Authors: Sheppard Dennis E. , Head K. Larry , Joshua Sarath , Mirchandani Pitu B.
Published: August 2018

There has been an increasing interest in improving the use of transportation facilities as environmental and social concerns have grown and as financial resources for infrastructure expansion have become increasingly scarce. Numerous programs for increasing carpooling, van-pooling, and transit usage have been undertaken to decrease reliance on single-occupant vehicles and increase the use of multioccupant vehicles. One program has been to develop facilities that give preferential treatment to high-occupancy vehicles (HOVs). Although HOV facilities have been implemented, they often have been found to be unsuccessful in attaining their stated or implied goals. Because interest in the use of HOV facilities is growing, there is a need to improve the ability to evaluate and compare design alternatives in the context of realistic (stochastic) environments. Simulation modeling has long been recognized as a powerful tool for such purposes. A structured simulation-based methodology for the evaluation of HOV design alternatives is presented. An example case study for a corridor in the Phoenix, Arizona, metropolitan area is used to demonstrate the methodology.
Algorithm for Controlling Spillback from Ramp Meters
Authors: Gordon Robert L.
Published: August 2018

The queue control algorithms that are commonly used by ramp-metering controllers often permit the queue to extend a considerable distance upstream of the queue detector on the ramp. This detector senses the presence of a queue with the intent of preventing queue spillback onto the surface street or intersection that is located upstream of the ramp. Queue control is usually obtained by switching between the desired metering rate and a higher metering rate. In some cases metering is terminated. This type of limit cycle control often results in considerable variation in the length of the queue, even for a constant average vehicle arrival rate at the ramp. This high-amplitude limit cycle operation is indicated, by simulation, to result from the relatively long detector sampling and computation period (typically 1 min) that is commonly used. A control algorithm using a 10-sec sampling period is indicated to substantially reduce the limit cycle amplitude. Performance is further improved when the control algorithm anticipates the buildup of the queue over the spillback detector.
Systemwide Analysis of Freeway Improvements
Authors: Yagar Sam , Hui Richard
Published: August 2018

Determining where to restripe or widen freeway sections to strategically relieve bottlenecks is a far more complicated problem than simply estimating the local capacity effects of specific lane additions. The pros and cons of reducing lane and shoulder widths to obtain an extra travel lane are discussed, with an emphasis on the effects on the overall freeway system. This study describes how increasing capacity at an upstream location can overload a downstream bottleneck and cause flow breakdown. An evaluation of potential local improvements at a number of existing bottlenecks in the westbound Highway 401 corridor in Toronto is provided; it finds that in a systems context about one-half are worthwhile, and the others have net negative effects.
Using Probe-Measured Travel Times to Detect Major Freeway Incidents in Houston, Texas
Authors: Balke Kevin , Dudek Conrad L. , Mountain Christopher E.
Published: August 2018

As a prelude to installing an automatic vehicle identification system for collecting traffic and travel time information from probe vehicles, the Texas Transportation Institute, in conjunction with the Texas Department of Transportation, initiated a pilot study to test the feasibility of using probe-provided travel time information to detect freeway incidents. As part of this pilot study, 200 commuters equipped with cellular telephones were used to collect travel time and incident information from three facilities [I-45 (both the main lanes and the high-occupancy-vehicle lane), the Hardy Toll Road, and US-59] on the north side of Houston, Texas. Historical travel time patterns were developed for each link using data from known incident-free conditions. The statistical principle of standard normal deviates was applied to 11 months of data to determine when a probe travel time exceeded the expected travel time under incident-free conditions. Whereas this approach resulted in detection rates that were lower and false alarm rates that were higher than those reportedly produced by other incident detection algorithms, this study illustrated that some level of incident detection could be achieved using travel time information provided by probe vehicles. Because of limitations in the data, it was not possible to determine the number of incidents that were not detected by the system or the detection times for the known incident conditions.
Analysis of Major Freeway Incidents in Houston, Texas
Authors: Ullman Gerald L. , Ogden Michael A.
Published: August 2018

An analysis of major freeway incidents in Houston, Texas, was conducted. The data base analyzed was provided by the Houston Police Department solo motorcycle patrol division. This division responds to all freeway lane-blocking incidents that are expected to last more than approximately 45 minutes. Over a 7-year period between 1986 and 1992, the division documented the details of 612 major freeway incidents to which it responded. From these data, it was estimated that major freeway incidents occur in Houston at a rate of 0.68 incident per 100 million vehicle-kilometers (MVK). That is equivalent to a major incident every 147 MVK. Major incidents were nearly 3.5 times as likely to occur within the interchanges (based on vehicle-kilometers driven) as between them. Of the 612 major incidents included in the data base, 498 (81.5 percent) involved trucks only (even though large truck traffic accounts for only 7.7 percent of the total vehicle-kilometers traveled on Houston freeways). Furthermore, lost or spilled loads and truck overturns account for nearly one-half of the major incidents in Houston. Information on incident severity and duration is also presented.
Improved Modeling of Non-Home-Based Trips
Authors: Schultz Gordon W. , Allen William G.
Published: August 2018

Non-home-based (NHB) trip making typically accounts for about 25 to 30 percent of travel by individuals in urban areas. However, the NHB trip purpose is usually treated as a large unknown category, and little attention is paid to the nature of these trips. An effort to better understand the characteristics of NHB trips by subdividing the NHB trip category is described. It is hoped that this effort will serve as a useful precursor to improving the analysis of trip chaining behavior. By definition, NHB trips are almost always part of a chain of trips that usually starts or ends at the trip maker's place of residence or work. By examining this chain more closely, it is possible to group NHB trips into two or three categories. More detailed analysis of these categories reveals that they have very different trip length, mode choice, and time of day characteristics. Making this subdivision improves the accuracy of the model, increases the sensitivity of the forecast to important factors, and provides a greater understanding of trip chaining behavior.
Implementation of Highway Capacity Manual–Based Volume-Delay Functions in Regional Traffic Assignment Process
Authors: Kurth David L. , van den Hout At , Ives Berry
Published: August 2018

Recent model development efforts for the travel demand forecasting process have focused on increasing the consistency and reasonableness of the results. A major target of these efforts has been the traffic assignment process and, more specifically, improving the estimates of congested travel speeds resulting from traffic assignments. A number of studies and enhancements have centered on the volume-delay functions used for the assignment process. Many of these studies have used the workhorse volume-delay function, the BPR function, and have investigated modifications to the function coefficients. In its recent update of the Albuquerque Area Travel Models, the Middle Rio Grande Council of Governments successfully implemented a regional traffic assignment process based on capacity estimation techniques and volume-delay functions documented in the Highway Capacity Manual. The assignment procedures developed for the Albuquerque area resulted in volume-delay functions that produced accurate traffic volumes while producing accurate congested speeds on the network. The capacity estimation procedures increase the realism of the network representation and provide increased analysis flexibility. Commercially available travel demand modeling software has been used to implement the Highway Capacity Manual–based volume-delay functions.
Incorporating Work Trip Accessibility in Nonwork Trip Generation Models in San Francisco Bay Area
Authors: Purvis Charles L. , Iglesias Miguel , Eisen Victoria A.
Published: August 2018

Efforts to include disaggregate work trip accessibility in models of non-work trip generation are described. Reported household-level, one-way, average home-based work trip duration is used in home-based shop/other and home-based social/recreation models for the San Francisco Bay Area. The survey data and models show an inverse relationship between work trip duration and home-based nonwork trip frequency: as work trip duration increases, nonwork trip frequency decreases. Hybrid trip generation models using multiple regression techniques, cross-classified by workers in household level and vehicles in household level, are estimated using data from the 1981 and 1990 household travel surveys. Work trip duration is excluded in models estimated for nonworking households and is included in models estimated for single-worker and multiworker households. Elasticity analyses show that a 10 percent decrease in the regional work trip duration yields a 1.2 percent increase in regional home-based shop/other trips and a 0.9 percent increase in regional home-based social/recreation trips. The research helps to identify practical means to incorporate workplace accessibility in regional travel demand model forecasting systems, to better analyze the issue of induced trip making, and to provide a better understanding of the linkage between congestion and trip frequency choice behavior.
Trip End Mode Split
Authors: Shalaby Amer S. , Steuart Gerald N.
Published: August 2018

Trip interchange models and their underlying assumption that relative level of service (LOS) of travel modes is a major determinant of mode choice for the work trip are examined. The investigation is done through a comparative analysis of trip end and trip interchange mode split for work trips in the greater Toronto area (GTA). Two model sets are developed; one includes trip end models and the other includes trip interchange models. The models are developed using a relatively new statistical procedure for nonparametric analysis of data referred to as classification and regression trees. The results show that the explanatory power enjoyed by trip end models is virtually the same as that of trip interchange models. Relative LOS is found to have an insignificant role in explaining heterogeneity in mode split, particularly outside the central business district of the study area. It is recommended that predictions made by trip interchange models of mode shift following changes in LOS attributes be approached with caution. Trip end models, which attribute less significance to relative LOS than trip interchange models and are thus conservative with respect to mode shift, could be considered in planning studies, particularly in areas of low transit use. The interaction between the decisions of residential and employment locations, car ownership, and mode choice is emphasized, and the need for more research to investigate and model such interactions is stressed.
Analysis of Stated Preferences for Intermodal Bicycle-Transit Interfaces
Authors: Taylor Dean , Mahmassani Hani
Published: August 2018

One proposed means of increasing use of both transit and bicycles is to replace long automobile trips with “bike and ride” trips. In this study, a stated-preference survey was conducted using hypothetical scenarios within which respondents ranked their preferences for making a work trip by automobile only, park and ride, or bike and ride. The survey addressed numerous potential factors that might influence this choice, including three policy variables that were systematically varied in the scenarios: on-street bicycle facility type, bicycle parking facility type, and bicycle access distance to transit. The survey data are summarized and used to estimate discrete choice models. A nested logit choice model was developed as the preferred model. From this model, inferences are drawn about many factors. Conclusions are drawn about the three main policy variables. In short, the results support the notion that bicycle lockers are the preferred parking facility to increase bike and ride use. The results also indicate that bike lanes are superior to wide curb lanes as an incentive for casual and inexperienced cyclists, but that bike lanes and wide curb lanes are an identical incentive for experienced cyclists.
Fuzzy Feedback Control for Real-Time Dynamic Traffic Routing: User Equilibrium Model Formulations and Controller Design
Authors: Kachroo Pushkin , Özbay Kaan
Published: August 2018

The formulation of a system dynamics model for the dynamic traffic routing (DTR) problem is addressed, specifically for the application of real-time feedback control. Also addressed is the design of fuzzy feedback control laws for this problem. Fuzzy feedback control is suitable for solving the DTR problem, which is nonlinear and time varying and contains uncertainties. To illustrate the applicability of fuzzy logic in the design of feedback control for DTR, a simple software simulation was conducted that provided encouraging results.
Cluster Analysis as Tool in Traffic Engineering
Authors: Prassas Elena Shenk , Roess Roger P. , McShane William R.
Published: August 2018

Regression analysis is a very common tool in traffic engineering analysis, partly because of the professional backgrounds of those doing the analysis but, perhaps, primarily because of an underlying premise that traffic can be described by deterministic models on which the observations have some randomness or imprecision superimposed. In this view, the “noise” can be filtered out by more observations and more precise observations, and the underlying deterministic model can then be identified. Another totally different underlying premise is that there are a finite number of distinct “states” or conditions in which the system may rest, with significant truly random deviations around each such equilibrium. If this premise is adopted, regression analysis is not a tool suitable for analysis and can provide misleading insights and meaningless relations. This paper applies the tool of cluster analysis to a set of traffic engineering data (specifically, left-turn factors in shared lanes) in which deterministic modeling and regression analysis have been applied in the past. Cluster analysis proved to be a powerful exploratory technique and helped identify several distinct modalities within the data. These can be explained by an underlying model based on a finite number of equilibrium states with significant random components or by an underlying model in which the process is truly stochastic and not at all deterministic, so that mild trends with considerable data scatter are to be routinely expected.
Hybrid Model for Estimating Permitted Left-Turn Saturation Flow Rate
Authors: Chang Gang-Len , Chen Chien-Yu , Perez Cesar
Published: August 2018

This study explored the integration of analytical formulations with simulation results for estimating the complex permitted saturation flow rate. The proposed hybrid model captured most tractable interactions between the permitted flow rate and the opposing flows with the widely used formulation by Drew, which serves as one of the primary explanatory variables. To further consider the complex interactions between the permitted flow rate and all other associated factors, which often are not consistent with the assumptions used in analytical derivations, this study modeled the intractable relations as multiplicative adjustment terms and estimated their parameters with log-linear regression. Such a hybrid formulation offers the flexibility to incorporate various additional critical factors on the permitted flow rate, including the variation of driving behavior, the number of opposing lanes, the progression quality, and the heavy vehicle percentage. The preliminary tests with extensive simulation experiments have shown very promising results.
Group, basic assumptions and complexity science
Authors: de Felice Giulio , De Vita Giuseppe , Bruni Alessandro , Galimberti Assunta , Paoloni Giulia , Andreassi Silvia , Giuliani Alessandro
Published: August 2018

This article represents the first complete systematization of the basic assumptions as theorized by Wilfred R. Bion and post-Bionian authors. The authors reviewed, compared and systematized all the Bionian developments concerning the basic assumptions taking the prevailing anxieties, group topology, leader peculiarities, interactions with the work-group mentality into account. The analysis evinced five main ba(s) and five subsets (i.e. their features resemble one of the five main basic assumptions). Briefly, in the first paragraph the authors summarize Bionian thought and its underlying logical criteria while in the second they reviewed all the new proposals for basic assumptions emerging from the psychoanalytic literature (i.e. Lawrence, Bain and Gould, 1996; Romano, 1997; Sandler, 2002; Sarno, 1999; Turquet, 1974; Hopper, 2009). In conclusion the authors focus on the main strengths and critical points of the systematization. In the last section ‘Promising developments’ they address the methodology of the study of basic assumptions, its main features and potential developments. The article rounds off with a clinical appendix.
The kinetics of typical medical waste pyrolysis based on gaseous evolution behaviour in a micro-fluidised bed reactor
Authors: Qin Linbo , Han Jun , Zhao Bo , Chen Wangsheng , Xing Futang
Published: August 2018

In order to obtain the kinetic parameters during typical medical waste pyrolysis, the typical medical waste is pyrolysed in a micro-fluidised bed reactor. The gases evolved from the typical medical waste pyrolysis are analysed by a mass spectrometer, and only H2, CH4, C2H2, C2H4, C2H6, C3H6, C3H8 and C4H4 are observed. According to the gaseous product concentration profiles, the activation energies of gaseous formation are calculated based on the Friedman approach, and the average activation energies of H2, CH4, C2H2, C2H4, C2H6, C3H6, C3H8 and C4H4 formation during typical medical waste pyrolysis are in sequence as 65.10, 39.98, 35.17, 38.71, 40.75, 41.79, 58.57 and 63.95 kJ mol−1. Moreover, the activation energy with respect to the gases mixture formation is 52.70 kJ mol−1. Hence, it is concluded that the activation energy of typical medical waste pyrolysis is 52.70 kJ mol−1. The model-fitting method is used to determine the mechanism model of medical waste pyrolysis. The results indicate that the chemical reaction ( n = 1) model (G(x) = –ln(1–x)) is the optimum.
Single-stage electrospun innovative combination of polyurethane and neem oil: Synthesis, characterization and appraisal of blood compatibility
Authors: Mani Mohan Prasath , Jaganathan Saravana Kumar , Khudzari Ahmad Zahran , Rathanasamy Rajasekar , Prabhakaran Praseetha
Published: August 2018

Wound healing is a complex process and it requires proper scaffolding for regeneration. An ideal scaffold should provide optimal environmental conditions in order to assist cellular attachment, proliferation and differentiation. In this work, a new composite based on polyurethane and neem oil was fabricated using one-step electrospinning technique. Fabricated composite patch along with the pristine polyurethane was characterized through scanning electron microscopy, Fourier transform and infrared spectroscopy, thermogravimetric analysis, contact angle measurement and atomic force microscopy. Moreover, the blood compatibility was evaluated using activated partial thromboplastin time, partial thromboplastin time and haemolysis assay. Scanning electron microscopy studies of composites revealed the existence of fibres with a smaller diameter (635  ± 105 nm) compared to the pristine polyurethane (969 ± 217 nm). Fourier transform and infrared analysis revealed the formation of hydrogen bond and peak shifting characteristics confirming the interaction of the neem oil with the polyurethane. Contact angle analysis showed the decrease in contact angle indicating the hydrophilic nature of the fabricated patch compared to pristine polyurethane. Thermal gravimetric analysis depicted the better thermal stability of the novel composite patch due to the existence of neem oil in the pristine polyurethane. The presence of neem oil in polyurethane matrix also resulted in an increase in the surface roughness as observed in the AFM analysis. The novel composite patch showed an ability to reduce the thrombogenicity and promoting the anticoagulant nature signified by blood compatibility assays like activated partial thromboplastin time and partial thromboplastin time. Finally, the haemolytic percentage of the fabricated composite (1%) was found to be reduced compared to control (2.733%) indicating better blood compatibility and safety with the red blood cells. Following the results, the fabricated patches offered enhanced physicochemical and blood compatible nature making it as a promising candidate for wound healing application.
Reversible nonlinear electrical conductive behavior of high-density polyethylene composites
Authors: Liang Ji-Zhao
Published: August 2018

The reversible nonlinear electrical conductive properties of high-density polyethylene composites filled separately with carbon black (CB), ethylene-vinyl acetate copolymer, and carbon fiber (CF) were measured using a four-electrode method. It was found that these composites presented significant reversible nonlinear electrical conductive behavior under these experimental conditions; the correlation between the current density and the electrical field intensity was linear in a bi-logarithmic coordinate system; both the crossover current density and the conductivity were approximately a linear function of the conductivity in a bi-logarithmic coordinate system; there was a synergic effect in the electrical conductivity percolation threshold between the CB and CF in the matrix, and the percolation threshold decreased with increasing the Brunauer–Emmett–Teller specific area of the CB.
A study of friction microslip modeling for dynamic analysis of bladed discs with root joints
Authors: Chen Junjie , Zang Chaoping , Zhou Biao , Petrov EP
Published: August 2018

In machinery structures with joints, the contact pressures at contact interfaces are usually high enough to ensure that the contacting components stay joined and the gross slip does not occur. Nevertheless, the small relative slip over parts of the contact interface, i.e. the microslip, contributes significantly to the vibration damping. In the high-fidelity analysis of practical bladed discs, the macroslip model cannot provide sufficient accuracy for the predictive analysis of the properties of the friction damping in the contact interfaces. In this article, numerical studies of microslip damping effects is performed using 2D and 3D models of blade root joints. Analysis of hysteresis loops is performed to assess the influence of modeling parameters: choice of reference points, mesh configurations, and other physical parameters. The impact of the physical parameters, such as the contact geometry, friction coefficient, contact stiffness and tangential and normal loading, on the friction damping is numerically examined. The numerical results demonstrate the possibilities of microslip prediction using finite element modeling and show the microslip friction damping effects using simplified and realistic blade root models.
Becoming intelligible woman: Gender, disability and resistance at the border zone of youth
Authors: Slater Tig , Ágústsdóttir Embla , Haraldsdóttir Freyja
Published: August 2018

This paper considers young disabled women navigating ableist and heteronormative constructs of adult womanhood. We consider adult womanhood at the embodied intersection of gender, sexuality and dis/ability (categories themselves mediated by race, class, coloniality, etc.). For young disabled women, questions of gender and sexuality were more often than not denied. Gendered and sexual identities were therefore politically and strategically used to claim “adult” and “woman.” Yet, such identities often felt restricted to binary gendered frameworks. Already positioned through ableism as non-normative, to exist outside of heteronormativity felt dangerous, risking paternalism and non-consensual bodily intervention. Drawing on the cases of Ashley X and Marie Adams, we argue that these dangers are often more severe for those with labels of intellectual impairment and/or considered to have the most “severe” impairments. Adulthood needs to be understood, not as a natural state of development (the endpoint of youth), but as a heteronormative and ableist socio-cultural-political construct, as well as a complex site of negotiation, conflict and resistance, which (differently) restricts how young people are able to become in the world. We fill a gap in scholarship by exploring the intersection of critical disability studies, crip theory and youth studies from a feminist perspective.
Book Review: Hans Landström, Advanced Introduction to Entrepreneurial Finance
Authors: Dwivedi Amit Kumar
Published: August 2018

Hans Landström, Advanced Introduction to Entrepreneurial Finance, Cheltenham, UK: Edward Elgar Publishing, 2017, 203 pp.
Book Review: Daniel Stokols, Social Ecology in the Digital Age: Solving Complex Problems in a Globalized World
Authors: Misra Shalini
Published: August 2018

Daniel Stokols, Social Ecology in the Digital Age: Solving Complex Problems in a Globalized World, London, UK: Elsevier Academic Press, 2018, 399 pp.
Social Capital and Entrepreneurial Outcomes: Evidence from Informal Sector Entrepreneurs in Ethiopia
Authors: Kebede Getahun Fenta
Published: August 2018

In Africa, social capital (SC) is an important resource for the informal economy. It substitutes the limited formal business support systems as factor inputs for enterprise development. This article investigates the effect of Burt’s structural holes theory of social capital in the context of the Ethiopian informal economy. Data were collected from street entrepreneurs in Addis Ababa using multiple name generators constructed on the basis of entrepreneurs’ frequent interaction with people related to resources needed for entrepreneurial activities. Social network analyses and statistical procedures of instrumental variables estimation were used to analyse the data. By controlling the potential endogeneity problem between structural holes and enterprise outcomes, the findings of the study show that entrepreneurs’ dense network structure, which lacks structural holes, has a significant negative effect on entrepreneurial outcome. Accordingly, policies that aim at supporting informal entrepreneurs need to consider the benefits of social contacts while taking into account the downside of being excessively embedded in dense networks.
Imagining Sound through thePharmaish: Radios and Request-postcards in North India,c. 1955–1975
Authors: Duggal Vebhuti
Published: August 2018

In this essay, I look at the practice of writing requests for Hindi film songs to the radio, particularly during the first two decades after Independence. I attempt to reconstruct this radio-listening practice from narrative accounts of listeners, radio personnel and fan magazines produced during this period. The article argues that the pharmaish indicated practices of listening and publicity that provided the contours for (a) a mediatised form that emerges in a distinct manner on the radio, (b) a sonic map and (c) an act of ‘recognition’. It is in these ways that the pharmaish may illuminate the elusive terrain of cinematic reception, through the film song as metonym, away from the physical site and time of the cinema hall.
miR-142-3p attenuates breast cancer stem cell characteristics and decreases radioresistance in vitro
Authors: Troschel Fabian M , Böhly Nicolas , Borrmann Katrin , Braun Timo , Schwickert Alexander , Kiesel Ludwig , Eich Hans Theodor , Götte Martin , Greve Burkhard
Published: August 2018

Effectively targeting cancer stem cells, a subpopulation of tumorigenic, aggressive, and radioresistant cells, holds therapeutic promise. However, the effects of the microRNA miR-142-3p, a small endogenous regulator of gene expression on breast cancer stem cells, have not been investigated. This study identifies the influence of miR-142-3p on mammary stemness properties and breast cancer radioresistance to establish its role in this setting. miR-142-3p precursor transfection was performed in MDA-MB-468, HCC1806, and MCF-7 cells, and stem cell markers CD44, CD133, ALDH1 activity and mammosphere formation were measured. β-catenin, the canonical wnt signaling effector protein, was quantified by Western blots and cell fluorescence assays both in miR-142-3p–overexpressing and anti–miR-142-3p–treated cells. Radiation response was investigated by colony formation assays. Levels of BRCA1, BRCA2, and Bod1 in miR-142-3p–overexpressing cells as well as expression of miR-142-3p, Bod1, KLF4, and Oct4 in sorted CD44+/CD24–/low cells were determined by quantitative polymerase chain reaction. miR-142-3p overexpression resulted in a strong decline in breast cancer stem cell characteristics with a decrease in CD44, CD133, ALDH1, Bod1, BRCA2, and mammosphere formation as well as reduced survival after irradiation. miR-142-3p expression was strongly reduced in sorted CD44+/CD24–/low stem cells, while Bod1, Oct4, and KLF4 were overexpressed. β-catenin levels strongly decreased after miR-142-3p overexpression, but not after anti–miR-142-3p treatment. We conclude that miR-142-3p downregulates cancer stem cell characteristics and radioresistance in breast cancer, mediated by a reduced role of β-catenin in miR-142-3p–overexpressing cells. miR-142-3p might therefore help to target cancer stem cells.
Parameter distribution characteristics of material fatigue life using improved bootstrap method
Authors: Zhang Minghui , Liu Xintian , Wang Yansong , Wang Xiaolan
Published: August 2018

The bootstrap method is mostly used to estimate statistical characteristics of small sample data. However, the limitations of the bootstrap method itself lead to a reduction in the reliability of small-sample estimates. In this article, an improved bootstrap method is developed to address this problem. In the statistically significant error range (the sample average error and the limit error of sampling) of the original single sample data, expanding the virtual test data that obey two distributions to overcome the limitations of the bootstrap method itself. This article compares and analyses these two methods through the case; the result indicates that the improved bootstrap method can enhance the reliability of the estimation results without changing its probability distribution. We also discussed how to reduce the fluctuation of the improved bootstrap method. And the effectiveness and feasibility of this improved method are discussed in the analysis of fatigue life test data.
Tootling With a Randomized Independent Group Contingency to Improve High School Classwide Behavior
Authors: Lum John D. K. , Radley Keith C. , Tingstrom Daniel H. , Dufrene Brad A. , Olmi D. Joe , Wright Sarah J.
Published: August 2018

The present study examined the effects of tootling, a peer-mediated positive behavior intervention, on students’ classwide disruptive and academically engaged behavior in three general education high school classrooms. A withdrawal design was used to assess the effects of the intervention. Students wrote tootles anonymously on paper slips and placed them into a marked container. A randomized independent group contingency was used to reward students. At the end of the class period, teachers randomly drew three of the submitted tootles and rewarded students about whom the tootles were written. Teachers also randomly drew the names of two students who submitted a tootle and rewarded them as well. All three classrooms displayed decreases in classwide disruptive behavior and increases in academically engaged behavior during intervention phases. Effect size calculations for both disruptive and academically engaged behavior indicated very large overall effects. The results of this study suggest that a modified tootling procedure utilizing a randomized independent group contingency can be an effective intervention for teachers to improve the classwide behavior of students in high school classrooms. Teachers found the intervention at least moderately socially valid and students rated it highly acceptable.
Enhancing resiliency and promoting prosocial behavior among Tanzanian primary-school students: A school-based intervention
Authors: Berger Rony , Benatov Joy , Cuadros Raphael , VanNattan Jacob , Gelkopf Marc
Published: August 2018

Children in Sub-Saharan Africa are living under chronic adversity due to poverty, serious health issues, physical and sexual abuse, and armed conflicts. These highly stressful conditions have deleterious effects on their mental health and socio-emotional adjustment. Since many children lack adequate access to mental health care, culturally adapted school-based resiliency programs could provide a resource to scaffold their development and promote their mental health. This study evaluated the efficacy of a universal school-based intervention in enhancing the resiliency of Tanzanian primary school children and cultivating prosocial behaviors. A total of 183 students from grades 4 to 6 were randomly assigned to either the 16-session “ERSAE-Stress-Prosocial (ESPS)” structured intervention or to a Social Study curriculum (SS) active control group. The original ESPS program was adapted by Tanzanians mental health professionals who modified the program based on local idioms of distress and indigenous practices. Students' resilience was evaluated before, after and 8 months following the intervention by assessing social difficulties, hyperactivity, somatization, level of anxiety, prosocial behaviors and school functioning as well as academic achievements and disciplinary problems. There was significant improvement on all outcome measures for the ESPS group compared to the control group post-intervention and at the 8-month follow up. The ESPS intervention was equally effective on most measures for students experiencing different adversity levels. The results indicate that a culturally adapted universal school-based intervention can be effective in enhancing Tanzanian students' resiliency and promoting prosocial behaviors. Should these results be replicated and found enduring, the modified ESPS could be a valuable mental health-promoting intervention in other low-income countries.
Continuous monitoring of tightening condition of single-lap bolted composite joints using intrinsic mode functions of acoustic emission signals: a proof-of-concept study
Authors: Zhang Zhen , Xiao Yi , Su Zhongqing , Pan Yongdong
Published: August 2018

Intrinsic mode functions of acoustic emission signals, extracted from signals using empirical mode decomposition, were used to characterize the contact conditions of asperities (e.g. sliding friction or collision) in the mating parts of bolted composite joints undergone flexural vibration, whereby to evaluate the tightening condition of the joints quantitatively. Specifically, the sliding friction–related intrinsic mode functions, generated in the mating parts of the two joining composite components (termed as C-C contact), were ascertained from those generated from the contacts between the joining components and metallic fasteners (termed as M-C contact), via a Hilbert–Huang transform. Subsequently, the C-C contact–related intrinsic mode functions were linked to the contact behaviors of asperities at the joining interfaces, reflecting quantitatively the degree of the residual torque of the bolted joints. The fatigue performance of the joints was further evaluated according to the changes in the energy ratios of the C-C contact–related intrinsic mode functions. Experimental results have revealed that the gross energy of acoustic emission signals is capable of evaluating the residual torque of the joints within a limited range. Vibration loosening of composite joints was found to result in an increase in the energy ratios of C-C contact–related high-frequency intrinsic mode functions, on which basis the detectability of the acoustic emission–based structural health monitoring is further improved, making it possible to evaluate the tightening condition of a bolted joint when the joint undergoes vibration fatigue. This proof-of-concept study provides a promising solution to evaluate the contact conditions of bolted composite joints during assembly and to continuously monitor the tightening condition throughout the service life of the joints using the acoustic emission technique.
Feasibility use of in-line Mach–Zehnder interferometer optical fibre sensor in lightweight foamed concrete structural beam on curvature sensing and crack monitoring
Authors: PNG WH , Lin HS , Pua CH , Lim JH , Lim SK , Lee YL , Rahman FA
Published: August 2018

This article presents a novel study on curvature sensing and crack monitoring in lightweight foamed concrete structural beam using the packaged fibre-based in-line Mach–Zehnder interferometer curvature sensor. The Mach–Zehnder interferometer sensors which consist of two abrupt biconic tapers were fabricated and packaged into polypropylene slabs to protect the sensors under harsh condition of the real sensing environment, as the sensors were embedded into lightweight foamed concrete structural beams for field tests. Pretest characterizations of Mach–Zehnder interferometer sensors based on the packaging thicknesses at different operating wavelengths (1310, 1490 and 1550 nm) were done before the field tests. Three packages with different thicknesses were prepared to justify the effect of the packaging thicknesses on the curvature sensitivity of sensors. Results showed that the Mach–Zehnder interferometer sensor with a thicker bottom slab has the highest sensitivity of up to 3.53 µW m−1 which is capable of detecting a minimum curvature of 0.25 km−1 and a maximum curvature radius of up to 4 km. In the field tests, three Mach–Zehnder interferometer sensors were embedded into the lightweight foamed concrete structural beams with different polypropylene percentages (0.4%, 0.25% and 0%, respectively) to characterize the sensor performance according to the concrete environments with different tensile capacities. Mach–Zehnder interferometer sensor managed to hold up to a maximum loading force of 26 kN in the concrete environment before stopping functioning. Optical powers in response to the loading forces imposed to the beams were mapped to the strains measured by the lead wire alloy foil strain gauges (brand: TML, model: FLK-6-11) with a good correlation value of up to 0.968. Furthermore, the double-sided sensing property of Mach–Zehnder interferometer sensors preponderates over the conventional strain gauges in detecting the internal cracking within the concretes before any earlier sighting of the macrocracks.
Kinematic performance evaluation of 2-degree-of-freedom parallel mechanism applied in multilayer garage
Authors: He Tianhua , Shao Junpeng , Zhang Yongde , Jiang Jingang
Published: August 2018

In this article, our recent work on a kind of 2-degree-of-freedom lower-mobility parallel mechanism, which has one rotation degree of freedom and one translational degree of freedom, used in multilayer garage is presented. It has the following characteristics: lower-mobility, non-symmetric structure but can realize symmetric movement and a good compatibility for different kinds of lifting work. Kinematic performance should be considered in the first of designing a new kind of mechanism, the optimal kinematic design and analysis of this lower-mobility parallel mechanism are primarily investigated. In process of study, the global conditioning index over workspace is adopted, we establish a new evaluation method for the lower-mobility parallel mechanism, called global symmetry index and simulation results are shown. In addition, the flexible workspace of this lower-mobility parallel mechanism is also proposed. The evaluation index can be also applied on other lower-mobility parallel mechanism, which needs steady and symmetric movement.
Influence of fabric pretreatment on adhesion of three-dimensional printed material on textile substrates
Authors: Kozior Tomasz , Döpke Christoph , Grimmelsmann Nils , Juhász Junger Irén , Ehrmann Andrea
Published: August 2018

Adding three-dimensional printed objects on existing surfaces enables creation of multi-material objects with tailored mechanical properties. Especially, the tensile strength of a textile fabric is advantageous in comparison with three-dimensional printed polymeric parts, while the latter can increase the stiffness of the composite. The adhesion forces between both material partners, however, are crucial for the reliability of the multi-material object. While several printing and material properties have been shown to influence the adhesion previously, this article concentrates on the possible pretreatment methods for three-dimensional printing on a cotton fabric. In our experiments, we have shown that especially pretreatments which made the textile surface more hydrophobic or more hydrophilic resulted in significant modifications of the adhesion forces. In addition, the adhesion is influenced by the infill orientation, with an orientation of 90° being significantly advantageous compared to 0°. While surface roughness was also shown to depend on the infill angle, no significant differences of the tensile strength or the elongation at break were measured.