bluuebunny/crossref_metadata_2025 huggingface dataset:
A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA
Authors: Mensing Scott , Korfmacher John , Minckley Thomas , Musselman Robert
Published: December 2011

Future climate projections predict warming at high elevations that will impact treeline species, but complex topographic relief in mountains complicates ecologic response, and we have a limited number of long-term studies examining vegetation change related to climate. In this study, pollen and conifer stomata were analyzed from a 2.3 m sediment core extending to 15,330 cal. yr BP recovered from a treeline lake in the Rocky Mountains of Wyoming. Both pollen and stomata record a sequence of vegetation and climate change similar in most respects to other regional studies, with sagebrush steppe and lowered treeline during the Late Pleistocene, rapid upward movement of treeline beginning about 11,500 cal. yr BP, treeline above modern between ~9000 and 6000 cal. yr BP, and then moving downslope ~5000 cal. yr BP, reaching modern limits by ~3000 cal. yr BP. Between 6000 and 5000 cal. yr BP sediments become increasingly organic and sedimentation rates increase. We interpret this as evidence for lower lake levels during an extended dry period with warmer summer temperatures and treeline advance. The complex topography of the Rocky Mountains makes it challenging to identify regional patterns associated with short term climatic variability, but our results contribute to gaining a better understanding of past ecologic responses at high elevation sites.
Medium- and high-frequency analysis of magnetorheological fluid dampers
Authors: Goldasz Janusz , Alexandridis Alexander A
Published: December 2011

Controllable dampers based on smart fluids contain internal passages through which the working fluid flows and wherein the controlled pressure drop occurs under the influence of magnetic or electric fields. In this paper, the dynamics of such dampers are analysed through a series of theoretical dynamic models of increasing detail and complexity. The models capture the medium- and high-frequency dynamics of the damping force output of the damper and include the lumped mass of the fluid contained in the internal flow passages, the piston and rod assembly mass, and the compressibility of the fluid and pressurized gas contained within the chambers of the damper. The models are derived in state-space form from which transfer functions and natural frequencies are obtained analytically and then calculated for each of the systems. The results are presented in the form of frequency responses (Bode plots). Finally, the effects of the key geometric parameters of the damper and of the relevant fluid properties on the damper force output dynamics are presented and discussed.
The SWAN Captures Variance at the Negative and Positive Ends of the ADHD Symptom Dimension
Authors: Arnett Anne B. , Pennington Bruce F. , Friend Angela , Willcutt Erik G. , Byrne Brian , Samuelsson Stefan , Olson Richard K.
Published: December 2011

Objective: The Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) Rating Scale differs from previous parent reports of ADHD in that it was designed to also measure variability at the positive end of the symptom spectrum. Method: The psychometric properties of the SWAN were tested and compared with an established measure of ADHD, the Disruptive Behavior Rating Scale (DBRS). Results: The SWAN demonstrates comparable validity, reliability, and heritability to the DBRS. Furthermore, plots of the SWAN and DBRS reveal heteroscedasticity, which supports the SWAN as a preferred measure of positive attention and impulse regulation behaviors. Conclusion: The ability of the SWAN to measure additional variance at the adaptive end of the ADHD symptom dimensions makes it a promising tool for behavioral genetic studies of ADHD.
The just war tradition and its modern legacy: Jus ad bellum and jus in bello
Authors: Boucher David
Published: December 2011

The relationship between jus ad bellum and jus in bello has been characterized differently throughout European history. There have been three main positions exemplified by Hugo Grotius, Samuel von Pufendorf and Emer de Vattel. They are, first, both the cause and the conduct of warfare must be just; second, the cause must be just, but the conduct of the war is unconstrained in order to achieve the goal of peace; and, third, we must assume justice on both sides, and concentrate on ensuring just conduct in armed conflict. Each attempted to distil customary practices, which they saw in some relation to Natural Law, the ultimate source of moral obligation. Customary international law now serves the function of Natural Law in that even if treatises in which it is articulated lapse the customary constraining precepts remain, and are equally obligatory. It is contended that the relationship between just war and just conduct in war during the 20th and 21st centuries has mirrored the three classic positions, and since 9/11, with the advent of new dimensions to warfare in the war against terror, the relationship is in flux. Since 9/11 there has been a growing emphasis on jus ad bellum and a relative silence on the principles of jus in bello. Implicitly, there is an informal acceptance of something like Pufendorf’s position in which outlaw combatants are deemed to place themselves outside of the protection of customary law.
The context of an emergent and enduring concept
Authors: Jenks Chris
Published: December 2011

This paper seeks to situate the concept of a ‘moral panic’ within a set of historical and social changes and thus to demonstrate that its impact and subsequent acceptability within the vocabulary of sociology were in part due to the conditions of its emergence. Earlier and more positivistic criminology was unduly committed to the ‘essence’ of an act, whereas the breakthrough afforded by Cohen and Young’s idea was to attend to the ‘appearance’ of an act in an era when image and representation were becoming primary phenomena within the social sciences. The work concludes with an analysis of the social construction of transgression.
Between heat and light: The opportunity in moral panics
Authors: Lumby Catharine , Funnell Nina
Published: December 2011

This paper argues that contemporary moral panic theorists are often too narrowly focused on either refining the sociological framings of moral panic theory or, alternatively, on applying that theory to case studies without asking how the theory might be used to frame strategic interventions into public debate and policy. It examines the way that conservative politicians and media commentators have appropriated the accusation that they are fuelling moral panic as proof that they are actively engaged in a fight for morality. It contends that moral panic theorists need to use their knowledge of how moral panics work in order to engage in strategic interventions into public debate and policy. It concludes with a call for scholars working on specific issues in the field to apply their research and redouble their efforts to ensure that evidence-based research is heard and understood.
Between the exceptional and the ordinary: A model for the comparative analysis of moral panics and moral regulation
Authors: Lundström Ragnar
Published: December 2011

This article aims to further develop the understanding of the relationship and distinction between moral panics and moral regulation. To this end, a model for the comparative analysis of discursive changes over time, and between different discursive fields, is outlined. The model consists of three steps: (1) mapping general trends in news reporting; (2) analysing thematical relations in full-text news articles; and (3) conducting closer qualitative readings of news articles indicated to be of specific importance in the first two steps. Results from the presented case study – in which news reporting on benefit fraud in Sweden and the United Kingdom is analysed using the outlined model – suggest that there is a close relationship between moral panic discourse and moral regulation discourse. Using different strategies to construct social relations and deviant subjectivities through moralizing articulations, momentary outbursts of moral panics, and the more common, routine, forms of moral regulation, draw and depend upon each other to organize consensus and the management of risks in processes of discursive legitimization.
Assessment of the requisites of microbiology based infectious disease training under the pressure of consultation needs
Authors: Erdem Hakan , Tekin-Koruk Suda , Koruk Ibrahim , Tozlu-Keten Derya , Ulu-Kılıc Aysegul , Oncul Oral , Guner Rahmet , Birengel Serhat , Mert Gurkan , Nayman-Alpat Saygin , Eren-Tulek Necla , Demirdal Tuna , Elaldi Nazif , Ataman-Hatipoglu Cigdem , Yilmaz Emel , Mete Bilgul , Kurtaran Behice , Ceran Nurgul , Karabay Oguz , Inan Dilara , Cengiz Melahat , Sacar Suzan , Yucesoy-Dede Behiye , Yilmaz Sibel , Agalar Canan , Bayindir Yasar , Alpay Yesim , Tosun Selma , Yilmaz Hava , Bodur Hurrem , Erdem Huseyin A , Dikici Nebahat , Dizbay Murat , Oncu Serkan , Sezak Nurbanu , Sari Tuba , Sipahi Oguz R , Uysal Serhat , Yeniiz Esma , Kaya Selcuk , Ulcay Asim , Kurt Halil , Besirbellioglu Bulent A , Vahaboglu Haluk , Tasova Yesim , Usluer Gaye , Arman Dilek , Diktas Husrev , Ulusoy Sercan , Leblebicioglu Hakan
Published: December 2011

Background

Training of infectious disease (ID) specialists is structured on classical clinical microbiology training in Turkey and ID specialists work as clinical microbiologists at the same time. Hence, this study aimed to determine the clinical skills and knowledge required by clinical microbiologists.

Methods

A cross-sectional study was carried out between June 1, 2010 and September 15, 2010 in 32 ID departments in Turkey. Only patients hospitalized and followed up in the ID departments between January-June 2010 who required consultation with other disciplines were included.

Results

A total of 605 patients undergoing 1343 consultations were included, with pulmonology, neurology, cardiology, gastroenterology, nephrology, dermatology, haematology, and endocrinology being the most frequent consultation specialties. The consultation patterns were quite similar and were not affected by either the nature of infections or the critical clinical status of ID patients.

Conclusions

The results of our study show that certain internal medicine subdisciplines such as pulmonology, neurology and dermatology appear to be the principal clinical requisites in the training of ID specialists, rather than internal medicine as a whole.
Summary Statistics for Endpoint-Conditioned Continuous-Time Markov Chains
Authors: Hobolth Asger , Jensen Jens Ledet
Published: December 2011

Continuous-time Markov chains are a widely used modelling tool. Applications include DNA sequence evolution, ion channel gating behaviour, and mathematical finance. We consider the problem of calculating properties of summary statistics (e.g. mean time spent in a state, mean number of jumps between two states, and the distribution of the total number of jumps) for discretely observed continuous-time Markov chains. Three alternative methods for calculating properties of summary statistics are described and the pros and cons of the methods are discussed. The methods are based on (i) an eigenvalue decomposition of the rate matrix, (ii) the uniformization method, and (iii) integrals of matrix exponentials. In particular, we develop a framework that allows for analyses of rather general summary statistics using the uniformization method.
Additive Functionals for Discrete-Time Markov Chains with Applications to Birth-Death Processes
Authors: Liu Yuanyuan
Published: December 2011

In this paper we are interested in bounding or calculating the additive functionals of the first return time on a set for discrete-time Markov chains on a countable state space, which is motivated by investigating ergodic theory and central limit theorems. To do so, we introduce the theory of the minimal nonnegative solution. This theory combined with some other techniques is proved useful for investigating the additive functionals. This method is used to study the functionals for discrete-time birth-death processes, and the polynomial convergence and a central limit theorem are derived.
Distribution of Clump Statistics for a Collection of Words
Authors: Martin Donald E. K. , Coleman Deidra A.
Published: December 2011

We give an efficient method based on minimal deterministic finite automata for computing the exact distribution of the number of occurrences and coverage of clumps (maximal sets of overlapping words) of a collection of words. In addition, we compute probabilities for the number of h-clumps, word groupings where gaps of a maximal length h between occurrences of words are allowed. The method facilitates the computation of p-values for testing procedures. A word is allowed to contain other words of the collection, making the computation more general, but also more difficult. The underlying sequence is assumed to be Markovian of an arbitrary order.
Moments of Random Sums and Robbins' Problem of Optimal Stopping
Authors: Gnedin Alexander , Iksanov Alexander
Published: December 2011

Robbins' problem of optimal stopping is that of minimising the expected rank of an observation chosen by some nonanticipating stopping rule. We settle a conjecture regarding the value of the stopped variable under the rule that yields the minimal expected rank, by embedding the problem in a much more general context of selection problems with the nonanticipation constraint lifted, and with the payoff growing like a power function of the rank.
‘M?lama the '?ina, M?lama the people on the '?ina’
Authors: Gould Rachelle K , Ardoin Nicole M , Hashimoto Jennifer Kamakanipakolonahe`okekai
Published: December 2011

We explore perceptions of the film Avatar in Kona, Hawai`i using a mixed-methods study that included surveys (n = 146) and semi-structured interviews (n = 15). Quantitative analyses indicated that Native Hawaiians were more likely than Caucasians to express a sense of cultural pride related to messages in the film. Analyses of the qualitative data revealed four central concepts addressed in surveys and interviews: (1) the need for preservation of land and culture; (2) the Native Hawaiian link to land, and its similarity with the Na`vi link; (3) the diversity of perspectives on the land, but the underlying human tendency to be greedy; and (4) the plight of native peoples in the world, and particularly in Hawai`i. We briefly discuss how these perceptions relate to the emerging field of Cultural Ecosystem Services, and potential implications of these findings for understanding how popular media can impact societal beliefs and practices.
Climate variations in greenhouse cultivated with gerbera and relationship with external conditions
Authors: Andrade Júnior Aderson S. de , Damasceno Lisânea M. O. , Dias Nildo da S. , Gheyi Hans R. , Guiselini Cristiane
Published: December 2011

Black meshes used in greenhouses provide shade to plants, affecting photosynthesis and presenting certain properties that change the microclimatic conditions in these environments. The objective of this study was to evaluate the variation in climate elements in greenhouse cultivated with gerbera (Gerbera jamesonii, Vr. Rambo) in relation to external conditions and the reference evapotranspiration (ETo) at Teresina, State of Piauí, Brazil. The measurements were obtained from July to October 2007 by an automatic data acquisition system installed inside and outside the greenhouse. The global solar radiation, evapotranspiration, precipitation, temperature, relative humidity, and wind speed were estimated. The results showed that major effect of the shading occurred on the mean air temperature during the 120 days, making it higher than the external environment. Inside the greenhouse, mean values of relative air humidity, reference evapotranspiração, global solar radiation and wind speed were lower compared to those outside the greenhouse.
Viabilidade econômica do sistema de adubação diferenciado comparado ao sistema de adubação convencional em lavoura cafeeira: um estudo de caso
Authors: Ferraz Gabriel A. E S. , Silva Fábio M. da , Carvalho Francisval de M. , Costa Pedro A. N. da , Carvalho Luis C. C.
Published: December 2011

A agricultura de precisão surge como uma importante ferramenta para maximizar o gerenciamento da atividade cafeeira, principalmente para esta cultura, que possui elevado custo de produção. O presente trabalho teve por objetivo fazer um estudo comparativo da viabilidade econômica de dois sistemas de adubação na lavoura cafeeira: o sistema utilizando as técnicas da agricultura de precisão e o sistema de aplicação convencional. Os dados utilizados foram extraídos dos custos de produção da fazenda Brejão, no sul de Minas Gerais, em três áreas (22 ha, 10,52 ha e 6,23 ha), onde foram realizadas aplicações de adubos de forma diferenciada nas safras de 2007/2008 e 2008/2009. O sistema de adubação em agricultura de precisão caracterizou-se por coleta de amostras de solo, georreferenciadas, e aplicação diferenciada de fósforo e potássio. Os custos da adubação convencional foram obtidos por meio de simulações, considerando a amostragem convencional do solo realizada nas glebas. Para efeito comparativo entre os sistemas de adubação, foram consideradas as operações e as quantidades de adubos necessárias em cada sistema. Entre os dois sistemas, observou-se diferenças de aplicação dos elementos fósforo e potássio, e também nas quantidades aplicadas. A adubação diferenciada foi vantajosa para as áreas de 22 ha e 10,52 ha, nas duas safras em estudo, e para a área de 6,23 ha só foi vantajosa (menor prejuízo) na safra de 2008/09.
Não-linearidades: da dinâmica do simples à dinâmica do complexo
Authors: Piqueira José Roberto Castilho
Published: December 2011

Foram apresentados alguns conceitos relativos à utilização da Teoria dos Sistemas Dinâmicos em problemas de sistemas complexos. A apresentação destes conceitos centra-se no estabelecimento de duas dinâmicas: uma de curto termo e outra de longo termo, relacionando-as com os processos de organização dos sistemas.
Improving Horizontal Completions on Heterogeneous Tight Shales
Authors: Suarez-Rivera Roberto , Deenadayalu Chaitanya , Chertov Maxim , Hartanto Ricardo Novalo , Gathogo Patrick , Kunjir Rahul
Published: December 2011

Production from nanodarcy-range permeability shale formations requires extensive hydraulic fracturing, large volumes of water, and close-spaced wells. The current trend, which includes increasing lateral lengths, increasing the number of perforation stages, and increasing the volume of water and proppants pumped, is unsustainable. Comparing calculations of the possible surface area created during fracturing versus production results indicate that a large portion of the surface area is ineffective to production, resulting in ineffective use of resources and increased costs. This paper describes the fundamental understanding required to improve the efficiency of horizontal completions in oil- and gas-producing shales. Using extensive laboratory characterization of mechanical properties on core, core/log integration, and continuous mapping of these properties by logging-while-drilling (LWD) methods along the horizontal wellbore, appropriate guidelines are defined for effective perforation and fracturing to improve the efficiency and sustainability of horizontal completions. The objective of the study is to improve completion design and horizontal well completions efficiency. This objective is achieved by adequate selection of perforation intervals based on understanding the relevant physical processes and adequate rock characterization. Two reservoir regions, the near-wellbore and the far-wellbore, are defined and essential to completion design. Conditions at the far-wellbore region, which define the extent of the surface area in contact with the reservoir, are fundamental to well productivity. However, these conditions are often poorly understood. The near-wellbore region is the choking point to production, provided that ideal far-wellbore conditions exist. Properties along the near-wellbore region can be measured and are better understood. In this paper, these properties are used to minimize the near-wellbore choking effect by evaluating rock types that maximize near-wellbore fracture width, minimize breakdown pressures, and reduce the potential of solids production during the initial drawdown. The result is a nonsubjective and consistent methodology that defines the variability in near-well fracture performance along wellbores and allows selecting perforation stages based on measured or inferred rock properties (from LWD or drill cuttings analysis). Finally, the method that will be described provides a means for monitoring and comparing consistency between the predicted values and measured results by comparing the results to actual production data. The results of this study show the need to better understand the far-wellbore conditions as well as the near-wellbore conditions when making inferences about well production.
Defining Reservoir Quality for Successful Shale Gas Play Development and Exploitation
Authors: Han Shim Yen , Atwood Keith , Kok Jeffrey , Baihly Jason , Ingraham David
Published: December 2011

For any resource play, quantifying production potential is key when transiting from exploration phase to development phase. In a self-sourcing environment, a host of reservoir properties such as clay type, mineral content, organic content, fluid saturations, pore pressure, texture, source, storage, mobility, natural fractures and structural features, defines the quality of the reservoir. Recently several published articles alluded to this fact and the term reservoir quality is loosely defined, vague or contradicting.

In evaluating the success of an unconventional reservoir, this paper segregates the reservoir properties into two main categories. Reservoir quality (RQ) is defined by the combination of rock properties leading to hydrocarbon storage and producibility, including hydrocarbon-filled porosity, effective permeability, organic content, and pore pressure. Completion quality (CQ) is defined by the combination of rock properties leading to fracture surface area contacting the reservoir during production, including rock mechanical properties that will impact fracture containment, fracture complexity, retention of fracture area, and retention of fracture conductivity.

This paper assesses each parameter thoroughly and rationalizes their impact and importance. A case study using a comprehensive data set is published here to support and understand the importance of reservoir quality, along with its utilization for selective grading of prospective locations. This paper concludes a detailed workflow for determining key parameters in defining reservoir quality towards a successful shale gas play development and its exploitation.
Propagation of Nanocatalyst Particles Through Athabasca Sands
Authors: Zamani Amir , Maini Brij , Almao Pedro Pereira
Published: December 2011

This paper presents results of an experimental study that systematically examined the propagation of nanodispersed catalyst suspension in sand packs at Athabasca reservoir conditions. The concentration and size distribution of the particles at the injection and production end were measured. The pressure drops in different segments along length of the sand pack were monitored continuously. The retention behavior of particles at the end of each experiment was examined by measuring the catalyst concentration in the bed as a function of the distance from injection end of the sand pack and also by analysis of extracted samples using scanning electron microscopy.

This research is a part of a large multidisciplinary effort aimed at developing a nanoparticles based process for in situ upgrading of heavy oil by catalytic hydrogenation during thermal recovery processes. An essential element of such in situ upgrading is the placement of nanodispersed catalyst particles deep into the formation where it can accelerate the high temperature upgrading reactions. Therefore, an understanding of the propagation behavior of nanoparticles in reservoir sand is essential for developing such technology. The results of this work would also be useful for modeling any other process involving transport of nanoparticles through porous media.

The results show that it is possible to propagate the nanodispersed catalyst suspension through sand beds without causing permeability damage but a small fraction of the injected particles are retained in the sand. It was found that much higher retention occurs in the entrance region of the bed and such retention was higher in the Athabasca sand beds than in clean silica sand with the same flow and suspension properties. A modified deep bed filtration model was developed to history match the macroscopic propagation behavior of suspended particles in sand beds.

To best of our knowledge, this is the first experimental study on transport of nanoparticles dispersed in viscous oil through sand beds. It provides valuable information on propagation and retention behavior of nanoparticles. Considering the rapidly rising use of nanoparticles in industry, such transport will be encountered in many industrial applications and environmental problems.
Using Stochastic Simulation To Quantify Risk and Uncertainty in Shale Gas Prospecting and Development
Authors: Williams-Kovacs J. D. , Clarkson C. R.
Published: December 2011

Ultra-low permeability shale gas reservoirs have emerged as a significant source of natural gas in North America. Improved drilling, completion and stimulation techniques combined with declining conventional gas reserves have made shale gas a desirable commodity with significant long-term production potential.

Despite extensive development and production (particularly in North America), minimal work has been done to develop tools and methodologies for shale gas prospect analysis. Due to the complexity and large extent of unconventional natural gas resources, it is crucial to be able to investigate potential prospects in a methodical manner to determine whether a given prospect has commercial potential and to compare it to other potential prospects. Experience has shown that conventional exploration techniques using deterministic solutions are not suitable for unconventional prospects due to the unique nature of each prospect and the complexity of each reservoir.

The most common method for exploiting shale gas reservoirs is through the use of multi-fractured horizontal wells; the resulting well performance, influenced by both the stimulation treatment and complex reservoir attributes, precludes the use of traditional techniques for production data analysis and forecasting. Several new techniques have been developed to improve the quality and efficiency of analysis while accounting for properties that are unique to shale gas (i.e. adsorbed gas in self-sourced reservoirs and nanodarcy level permeability). Also, due to the complexity of shale gas reservoirs, many authors have suggested that deterministic analysis is unsuitable and that probabilistic analysis should be used to quantify the risk and uncertainty associated with shale gas prospects and the associated data.

This paper discusses a new tool that was developed specifically for shale gas prospect screening. This tool combines the latest production data analysis and forecasting techniques with a simple, yet rigorous method for stochastically comparing shale gas prospects. The paper discusses the production analysis and rate forecasting techniques used in the tool, as well as the tool development and application. A sample case using simulated data is presented for proof of concept and a discussion is given for extension of the tool for comparison of several potential prospects.
Investigation of Geomechanical Responses of Reservoirs Induced by Carbon Dioxide Storage
Authors: Eshiet Kenneth I. , Sheng Yong
Published: December 2011

Assessment of the suitability of potential sub-surface storage sites for CO2 storage cuts across several issues, a dominant part being the sustainability in terms of the retention capacity of prospective reservoirs. Questions often raised but not properly investigated border on the stability of underground reservoirs during the injection process and the protracted effect after injection is fully completed. A review of studies on CO2 sequestration reveal several uncovered areas with one significant aspect being the geo-mechanical effect of CO2 injection and storage within the underground formation. A computational framework has been built as part of a series of ongoing investigations to ascertain the susceptibility of underground formations during and after CO2 is introduced. This is made possible by adopting a discrete element modelling (DEM) methodology as a first step in the sequence of a designed procedure. By applying this technique the formation materials are idealized as an assembly of discrete particles interacting in a manner which allow for specific descriptions of the morphology and fracturing events. Computational tests conducted on several types of models representative of reservoir formations reveal reservoir geomechanical responses highly dependent on factors such as material property of rocks, pressure build-up, and injection pressure. An example of this is observed in the mode of fracturing events which is significantly influenced by the rate of fluid injection. The outcome of this study forms a strong basis towards a better understanding of behaviour of reservoir formations subjected to CO2 injection and storage. In addition, information from these studies could serve as a reference for Enhanced Oil Recovery processes (EOR) and Enhanced Coal Bed Methane (ECBM) productions.
Prediction Performance of Permeability Models in Gas Hydrate Bearing Sands
Authors: Delli Mohana L. , Grozic Jocelyn L.
Published: December 2011

A major factor affecting the hydrate formation and that of gas dissociation is the variation of permeability of the porous media in the presence of gas hydrates. In the absence of reliable experimental data, theoretical and empirical models have been proposed to establish the relationship between gas hydrate saturation and permeability. The effectiveness of a particular permeability model in fitting the measured data has largely been qualitative through graphical analysis. In contrast, this paper introduces a quantitative performance measure to evaluate the effectiveness of a specific model in predicting the measured permeability. Secondly, a novel hybrid model based on the weighted combination of pore-filling and grain coating model is proposed. Permeability measurements from laboratory and field data were used to assess the prediction performance of various permeability models and the proposed hybrid model.
Community Engagement
Authors: Mascarenhas Audrey
Published: December 2011

Oil and gas development in the proximity of landowners is most often met with opposition either at the application stage or after the operation begins. The publicity from recent documentaries has only added fuel to the fire. Issues with water, air and footprint top the list of environmental concerns. Stringent regulation is being enacted to attempt to address these fears. Technology will play an increasingly key role in the solutions.

Incineration technology is being used throughout the oil and gas industry worldwide to address the regulatory and landowner emission and air quality requirements. Many jurisdictions have already demanded high efficiency combustion of waste gas hydrocarbon streams. This technology delivers measurable 99.99% combustion efficiency with no visible flame, black smoke or detectable odor while reducing greenhouse gas emissions, and therefore an improvement in overall air quality, over a conventional flaring and venting. Incineration technology has applicability in well workovers, testing, gas processing and transmission. The benefits are significant and quantifiable. Landowners become potential allies for future development and the benefits and savings continue to accumulate. Having a positive relationship with the community for the life of the reserves yields immeasurable payback for all.

In addition, the waste heat generated can be recovered converted to useful heat or power, hence unlocking the value in the waste gas stream. The focus in the future will be on energy efficiency as a means to reduce the environmental footprint. Incineration is an established innovative technology that can cost effectively significantly reduce the greenhouse gas emissions with environmental and sustainability benefits by improving air quality, minimizing footprint and hence addressing the public concerns.
Pelvic Leiomyosarcoma obstructing vaginal opening — case report
Authors: Terzic Milan , Aksam Slavica , Bila Jovan , Maricic Sanja , Arsenovic Nebojsa
Published: December 2011

We present a 42-year-old female admitted for a 4 month history of increasing pelvic discomfort and pain. Clinical examination revealed a large tumor obstructing the vagina. Tumor markers (CA 125, CEA, AFP and CA 19-9), white blood cells and biochemical tests were all within the normal limits. Pelvic ultrasound and magnetic resonance imaging scan confirmed the presence of a large retroperitoneal/pelvic mass. The tumor was surgically excised and pathohistologically diagnosed as a well differentiated leiomyosarcoma, staged IB. Six years after surgery the patient is well and disease free.
Impact of Jobs–Housing Balance on Average Jurisdiction Commuting Times
Authors: Miller John S.
Published: December 2011

The Code of Virginia requires that goals relating to jobs-to-housing ratios be considered when projects are selected for the state's transportation program. Because the code does not specify the relative importance of the jobs–housing balance, this paper examines its influence on average jurisdiction commuting times. After regional differences were controlled for, the correlations between shorter commuting times and higher jobs–labor force ratios were from -.71 to -.76 for 1980, 1990, 2000, and 2006 data sets. A 20% increase in the 2000 ratio led to travel times being decreased by 5.3 min (about 18.5% of the statewide average). However, higher ratios may be associated with better transit service or other variables. Correlations alone do not prove causality and are potentially misleading. Consequently, a longitudinal model was developed that predicted changes in commuting time from 1990 to 2000 for each urban Virginia jurisdiction examined. This model estimated that the average impact of a given urban jurisdiction improving its balance by 20% was a reduction in commuting time of 2.2 min (7% of the average urban value). This effect is evident only if several factors, such as the manner in which the region is defined, are carefully controlled for. Otherwise, commuting time is not significantly affected by a change in balance. This finding suggests that the jobs–housing balance has a statistically significant impact on commute-related travel, but that the impact is more modest than a correlation-only analysis would suggest. Modifications necessary to apply this approach at a census tract level of analysis are discussed.
Lessons Learned from Four Alternative Transportation System Partnership Endeavors in Public Lands
Authors: Eidswick Jaime , Steinholtz Patricia
Published: December 2011

Land managers can benefit from each other's successes and lessons learned through existing alternative transportation system (ATS) deployment efforts. For this reason, the Paul S. Sarbanes Transit in Parks Technical Assistance Center assembled a set of four case studies to document those successes and examine those lessons. The case studies focused on the partnerships that allowed the ATS to be implemented, integrated with other ATSs, and operated and, in some cases, to remain financially sustainable. The four partnership case studies were the Santa Ana National Wildlife Refuge, the North Moab Recreation Area, the Cape Cod National Seashore, and the Grand Island National Recreation Area. The objective of this study was to share the ATS model and partnership lessons learned from each of the four partnering endeavors. Although each of the four case studies had its own unique ATS and set of partners, the partnership lessons learned had some major common themes, including choosing partners carefully, clearly identifying partners’ roles and responsibilities, meeting with partners on a regular basis, and making ongoing communication a priority. The ATS lessons learned also had some major common themes, including identifying support for the ATS both in the community and with national land management agency leaders and creating detailed financial plans and vehicle specifications.
Modeling the Effects of Shuttle Service on Transportation System Performance and Quality of Visitor Experience in Rocky Mountain National Park
Authors: Lawson Steve , Chamberlin Robert , Choi Janet , Swanson Ben , Kiser Brett , Newman Peter , Monz Chris , Pettebone David , Gamble Larry
Published: December 2011

Rocky Mountain National Park (RMNP) was one of the first national parks to adopt an alternative transportation system: a shuttle bus system initiated in 1978. To address parking lot shortages while accommodating growing numbers of park visitors, RMNP expanded its shuttle bus service in 2001. Although the expanded shuttle service has helped to alleviate parking congestion at popular trailheads, expansion may also be enabling levels of visitation that cause or exacerbate visitor crowding. Thus, there is a need to evaluate and potentially refine RMNP's shuttle service according to the amount of visitor use that can be accommodated at popular destinations in the park without unacceptable effects on the quality of visitors’ experiences. This study evaluated and quantified transportation system performance and visitor crowding at popular recreation sites in the Bear Lake Road corridor resulting from RMNP's shuttle service operations. The study used integrated transportation and visitor use modeling to provide quantitative estimates of the extent of parking congestion, transportation-related greenhouse gas emissions, transit operating costs per passenger, and visitor crowding associated with existing and alternative transit service operations scenarios. The National Park Service will use information from the study to refine the operation of shuttle service in RMNP in a manner that both optimizes transportation system performance and protects the quality of visitors’ experiences. Further, the study framework can be generalized to other public lands units to design and operate transit service in accordance with transportation, resource, and visitor experience objectives.
Adjacency Modeling for Coordination of Investments in Infrastructure Asset Management
Authors: Amador Luis Esteban , Magnuson Sherry
Published: December 2011

Departments of transportation and municipalities are expected to implement infrastructure management systems powered by analytical tools. The tools perform long-term strategic analysis capable of identifying alternatives that achieve the most cost-effective solution and that provide sustainability to networks of infrastructure assets. However, results from such analyses reflect uncoordinated programs of works represented by actions scattered across time and space. The implementation of strategic analysis results as they emerge from life-cycle optimization bring about many small contracts, which translate into constant disruption of services for users and higher costs to the government. In addition, uncoordinated actions may result in utility cuts or premature damage to recently rehabilitated assets. This paper adapts classical time–space adjacency modeling to translate results from strategic analysis into coordinated tactical and operational plans addressing the aforementioned drawbacks. A case study of Kindersley, Saskatchewan, Canada, is used to illustrate the proposed approach for coordinating the program of works of pavements, sanitary and storm sewers, and water mains for one of the scenarios of the original strategic analysis. The approach can incorporate time and space considerations among neighboring assets for selected compatible actions (investments) guided by a heuristic simulation that follows the guiding objectives of the original optimization. The results from coordinated actions are compared with results from classical life-cycle optimization to determine the degree of optimality.
Innovative Methods for Collecting Data and for Modeling Travel Related to Special Events
Authors: Kuppam Arun , Copperman Rachel , Rossi Thomas , Livshits Vladimir , Vallabhaneni Lavanya , Brown Ted , DeBoer Kathy
Published: December 2011

The Maricopa Association of Governments (MAG) is the designated metropolitan planning organization for the Phoenix, Arizona, metropolitan area. In collaboration with local transit agencies and local jurisdictions, MAG developed a successful proposal to compete for FTA Alternatives Analysis Discretionary Program Section 5339 funds. The proposal included development of the special events model and special events data collection. The importance of this task was highlighted by the success of the introduction of light rail transit in the region. The need for better understanding and forecasting of transit markets required in-depth study and modeling of planned special events in the region. Special events patrons constituted a significant portion of light rail ridership and overall regional travel demand. This paper focuses on the first results of this effort, including the completed special events data collection and some preliminary data analysis results. The special events surveys used advanced data collection techniques that allowed better data expansion and processing and ultimately will facilitate development of advanced special events travel demand forecasting models. The paper discusses survey design, survey instruments, counting and interviewing processes, organizational issues, and data expansion procedures.
In-Depth Comparison of Global Positioning System and Diary Records
Authors: Stopher Peter , Shen Li
Published: December 2011

Many studies have compared Global Positioning System (GPS) and diary records to estimate the amount of misreporting of travel that occurs in self-report diaries. This paper examines the comparison of GPS and diary records in detail to further the understanding of what leads to misreporting in diary surveys. The research is based on a recent comparative survey undertaken in the area of Melbourne, Victoria, Australia. The survey is analyzed in depth, and diary records are compared in detail with GPS records to check whether the two groups of data match. Departure and arrival times, trip lengths, and trip times are compared. Reasons for mismatches are suggested. The paper proposes some values as standards for similar analyses in the future.
Bayesian Approach for Identifying Efficient Stated-Choice Survey Designs with Reduced Prior Information
Authors: Cavalcante Rinaldo , Roorda Matthew J.
Published: December 2011

This paper presents the results of a stated-choice survey design in which reduced information is available about the values of the parameters. The main objective of the survey is to develop discrete choice models to analyze the carrier selection process by shippers. The only information available is the expected sign of the parameter in the utility function. Therefore, the use of a Bayesian approach is necessary in analyzing the efficiency of potential survey designs. The measure of efficiency adopted is the 95th percentile value of the D-error, the determinant of the asymptotic variance–covariance matrix, obtained via Monte Carlo simulation. This measure would maximize the expected gain of information with the experiment. In the survey, the respondents (shippers) will be asked to provide the main carrier's attributes used in the selection process. On the basis of the answers, the survey will be customized to each respondent (situation). In this paper, only the results of the design for situations in which shippers select continuous attributes are presented. An algorithm is developed in a statistical package to search and evaluate the efficiency of 1,000 randomly selected potential survey designs. The algorithm maintains the 10 most efficient designs to be evaluated and uses box plots to identify the most suitable design. The results show that the approach adopted improves the efficiency of the design substantially, which would result in more accurate models from the survey data.
Effect of Onboard Survey Sample Size on Estimation of Transit Bus Route Passenger Origin–Destination Flow Matrix Using Automatic Passenger Counter Data
Authors: Mishalani Rabi G. , Ji Yuxiong , McCord Mark R.
Published: December 2011

Origin–destination (O-D) flows at the bus passenger route level have traditionally been estimated from costly and labor-intensive onboard surveys. The availability of automatic passenger counter (APC) data on many bus transit systems offers the possibility of enhancing the quality of the onboard survey data at little marginal cost. This paper investigates the value of estimating route-level passenger O-D flows from APC data and onboard O-D survey data with a focus on the effect of onboard O-D survey sample size. An empirical study using field data collected on three bus routes investigates and quantifies the value of combining APC counts with onboard O-D survey data as a function of survey sample size. Encouraging estimation performance obtained in using APC data with no onboard O-D survey data, previously seen in a smaller study, is confirmed in this more extensive study. In addition, incorporating onboard O-D survey data with APC data produces O-D flow estimates that are better than those produced by using only the APC data, and increasing the sample size of the onboard O-D survey improves the quality of these estimates. However, the magnitude of the improvement depends on the O-D flow structure of the given bus route; increasing sample size results in less appreciable improvement for routes with more concentrated O-D flows than for routes with more evenly distributed O-D flows.
Processing Commercial Global Positioning System Data to Develop a Web-Based Truck Performance Measures Program
Authors: Ma Xiaolei , McCormack Edward D. , Wang Yinhai
Published: December 2011

Although trucks move larger volumes of goods than other modes of transportation, public agencies know little about their travel patterns and how the roadway network performs for trucks. Trucking companies use data from the Global Positioning System (GPS) provided by commercial vendors to dispatch and track their equipment. This research collected GPS data from approximately 2,500 trucks in the Puget Sound, Washington, region and evaluated the feasibility of processing these data to support a statewide network performance measures program. The program monitors truck travel time and system reliability and will guide freight investment decisions by public agencies. While other studies have used a limited number of project-specific GPS devices to collect frequent location readings, which permit a fine-grained analysis of specific roadway segments, this study used data that involved less frequent readings but that were collected from a larger number of trucks for more than a year. Automated processing was used to clean and format the data, which encompassed millions of data points. Because a performance measurement program ultimately monitored trips generated by trucks as they travel between origins and destinations, an algorithm was developed to extract this information and geocode each truck's location to the roadway network and to traffic analysis zones. Measures were developed to quantify truck travel characteristics and performance between zones. To simplify the process and provide a better communications platform for the analysis, the researchers developed a Google Maps–based online system to compute the measures and show the trucks’ routes graphically.