bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of Infinite Height Levee in CaFunwave Using an Immersed Boundary Method
Authors: Oler Adam M. , Zhang Ning , Brandt Steven R.
Published: November 2015

Numerical simulations of storm-surge-wave actions on coastal highways and levees are very important research topics for coastal Louisiana. In a large scale region hydrodynamic model, highways and levees are often complicated in geometry and much smaller in size compared to the grid size. The immersed boundary method (IBM) allows for those complicated geometries to be modeled in a less expensive way. It can allow very small geometries to be modeled in a large scale simulation, without requiring them to be explicitly on the grid. It can also allow for complicated geometries not collocated on the grid points. CaFunwave is a project that uses the Cactus Framework for modeling a solitary coastal wave impinging on a coastline, and is the wave solver in this research. The IBM allows for a levee with different geometries to be implemented on a simple Cartesian grid in the CaFunwave package. The IBM has not been used previously for this type of application. Implementing an infinite height levee using the IBM in the Cactus CaFunwave code involves introducing IB forcing terms into the standard 2-D depth averaged shallow water equation set. These forcing terms cause the 2-D solitary wave to experience a virtual force at the grid points surrounding the immersed boundary levee. In this paper the levee was implemented and tested using two different immersed boundary methods. The first method was a feedback-force method, which proved to be more effective at modeling the levee than the second method, the direct-forcing method. In this study, the results of the two methods, as well as the shape effects on the flow, are presented and discussed.
High Efficiency and Low Pressure Fluctuation Redesign of a Centrifugal Pump Based on Unsteady CFD Analyses
Authors: Yan Peng , Wu Peng , Wu Dazhuan
Published: November 2015

In this study, a double volute centrifugal pump of relative low efficiency and high vibration was redesigned with the aid of unsteady CFD analyses. The local Euler head distribution (LEHD) representing the energy growth from the blade leading edge to trailing edge on s1 stream surface in a viscous flow field was introduced to evaluate the flow on s1 stream surfaces from hub to shroud. To investigate the unsteady internal flow of the centrifugal pump, the unsteady Reynolds-averaged Navier-Stokes equations (URANS) were solved with realizable k-ε turbulence model using the CFD code FLUENT. The impeller was redesigned with the same outlet diameter as prototype pump. A two-step-form LEHD was recommended to suppress flow separation and secondary flow encountered in the prototype impeller to improve the efficiency. The splitter was added to improve the hydraulic performance and reduce unsteady radial forces. The original double volute was substituted by a newly designed single volute. The hydraulic efficiency of the redesigned centrifugal pump is 89.2%, 3.2% higher than the prototype pump. The pressure fluctuation in volute is significantly reduced and the mean and max values of unsteady radial force are only 30% and 26.5% of the prototype pump.
Application of a Wall-Solar Chimney for Passive Cooling of Dwellings
Authors: Park David , Battaglia Francine
Published: November 2015

Energy consumption is an important issue and has become a great concern during last the few decades, where most energy consumption is utilized for conditioning buildings. The solar chimney is a natural ventilation technique that has the potential to save energy use in buildings as well as maintain comfortable indoor quality. The objective of the current study is to examine the effects of the wall-solar chimney on airflow distribution and thermal conditions in a room. In the current work, computational fluid dynamics was used to model a solar chimney. The time-dependent conservation equations for mass, momentum and energy were solved with the k-ε turbulence equations using ANSYS Fluent. Previous literature, that utilized numerical modeling to study the solar chimney for different dimensions of chimney geometry, only considered a two-dimensional solar chimney with one-directional heat transfer. In the current study, the solar chimney was modeled three-dimensionally for a more realistic simulation of actual flow and thermal condition of the room. Experimental and numerical data from literature were used to validate the current model, and the results agreed very well. The current study showed that the flow in the solar chimney system can be either laminar or turbulent depending on the parameters of the system, and that the effect of the chimney inlet is more significant than that of the air gap on the flow regime. This study also developed a new characteristic Rayleigh number Ra* relating the chimney inlet and the air gap, which showed good consistency with the prediction of the flow regime. The investigations on Ra* and the flow regime indicated that the flow becomes turbulent for Ra* ∼ 0.8 × 108. Lastly, the potential improvements of the designs were discussed by observing the flow and thermal condition of the room.
Effect of Biomass Inlet Concentration on Mixing in a Double Screw Pyrolyzer
Authors: Marmur Breanna L. , Heindel Theodore J.
Published: November 2015

The renewable energy industry relies on double screw pyrolyzers to convert cellulosic biomass into bio-oil. Bio-oil can then be converted into synthetic gasoline, diesel, and other transportation fuels, or can be converted into biobased chemicals for a wide range of applications. One of the processes by which bio-oil is produced in industry today is through fast pyrolysis, the fast thermal decomposition of organic material in the absence of oxygen. One type of pyrolyzer, a double screw pyrolyzer, features two intermeshing screws encased in a reactor which mechanically conveys and mixes the biomass and heat carrier media. The mixing effectiveness of the two materials in the pyrolyzer is directly correlated to the bio-oil yield — the better the mixing, the higher the yields. This study investigates the effects of varying biomass inlet concentrations on mixing effectiveness. Using 300–500 μm glass beads as simulated heat carrier media and 500–6350 μm red oak particles as biomass, a cold-flow double screw mixer with 360° of optical access and full sampling capabilities was used to collect mixing data. Advanced optical visualization and composition analysis paired with statistical analysis was used to evaluate the effects of varying the biomass inlet concentrations. Biomass inlet concentrations in terms of glass beads to red oak mass flow rate ratios (GB:RO) of 10:1, 20:1, 30:1, 40:1, and 50:1 were investigated, and correspond to biomass mass fractions of 9%, 4.7%, 3.2%, 2.4% and 1.9%. Both qualitative and quantitative analysis indicates that a counter rotating down pumping particle flow is best, and smaller biomass inlet concentrations noticeably reduce mixing effectiveness.
Effect of Initial Height on Drain Time of Water Drainage Through Cylindrical Tank
Authors: Nazir Kamran , Sohn C. H.
Published: November 2015

Draining of liquids through cylindrical tanks is very common phenomena. An interesting but undesirable Aircore is generated during draining process. Therefore understanding of air core formation and its growth is of quite interest in literature. In present study, water draining through cylindrical tanks is studied by experimental techniques. Rotational Froude number is varied based on different initial heights of water in the cylinder. Spatial and temporal variation of critical height and critical time against experiments performed is reported in paper. From comparison of critical height ratio against Froude numbers under consideration, it is found that air core generates slower for lower Froude numbers. Therefore, for higher initial heights of liquid column in the tank, the Aircore generates later as compared to lower initial liquid height case, and this seems to be the reason for the same drain time for all the initial water heights being used in the study. In order to validate the concept, further experiments are performed without initial swirl of tank. Thus causing no Aircore to generate during draining. It is found that with decreasing height the drain time decreases. This validate the concept that early Aircore generation was the major reason behind same drain times with different volumes of water in the cylinder.
Bubble Free High Efficiency Electroosmotic Pumps
Authors: Tawfik Mena E. , Hansen Thomas E. , Diez F. J.
Published: November 2015

In generating high electroosmotic flows for use in microfluidic pumps, a limiting factor is faradaic reactions which appear at high electric fields. These reactions lead to higher power consumption and bubble generation at the electrodes. We are proposing a novel technique that can limit and even prevent gas generation. This will extend the current range of operation of electroosmotic pumps. This is achieved by applying a unidirectional pulsed DC voltage waveform. The optimum pulse voltage waveform (OPW) tested is based on a theoretical model developed by the authors [1]. The power consumed and the efficiency of an electroosmotic pump under the pulsed DC voltage is measured experimentally and compared with the conventional bipolar rectangular voltage waveform (BRW). Results show an increase in the efficiency for the OPW when compared to the BRW. This increase in efficiency is obtained by preventing the reverse cycle in the BRW which flows against the pumping direction.
Bioinspired Dynamic Sensing of Acoustic Waves
Authors: Müller Rolf , Caspers Philip , Fu Yanqing , Gupta Anupam K.
Published: November 2015

Biosonar is one of the most capable active senses found in nature and in engineering. It enables certain bat species, such as the horseshoe bats (family Rhinolophidae) and the Old World leaf-nosed bats (family Hipposideridae) to navigate and pursue prey in dense natural environments. Bats from these families also stand out for the dynamics of their biosonar systems that is evident in shape-changing baffles that diffract the ultrasonic wave packets on emission as well as on reception. Some of the acoustic effects predicted for the dynamics in bats have been reproduced qualitatively with a simple biomimetic sonar head. Experimentation with this biomimetic system shows that the dynamic baffles are capable of creating time-variant signatures that could be employed to enhance the encoding of sensory information. Such time-variant sensing paradigms may not be unique to biosonar but may also play a role in the control of the bat’s time-variant flight.
Test Setup for Determination of Bat Flight Kinematics
Authors: Horton Brandon , Matta Alex , Battaglia Francine , Müller Rolf , Bayandor Javid
Published: November 2015

Bats can achieve great feats of agility by utilizing more than twenty degrees of freedom, however, this makes aerodynamic data extremely difficult to obtain, even for the simplest flight modes. Therefore, a test setup was developed to accurately map bat flight kinematics throughout the entire flap cycle with minimal occlusion using 3-D Stereo Triangulation. A controlled flight room was constructed in which the two bat species, Hipposideros Pratti and Hipposideros Armiger, could be safely monitored and directed. 3-D Stereo Triangulation was performed using three rings of ten high-speed cameras, as well as matte white markers on all of the major joint locations and scattered throughout the wing membrane. Flight direction was controlled by use of an elevated flight tunnel, ensuring that each bat would fly straight through all three camera rings. Obstacles were also incorporated to investigate the incredible banking and flight reversal that these bats are capable of. This research builds off of a previous study where markers were only placed on the major joint locations and Two-Camera Stereo Triangulation was used.
Experimental Study on Two-Oscillating Grid Turbulence With Polymer Additives
Authors: Wang Yue , Cai Wei-Hua , Wei Tong-Zhou , Wang Lu , Li Feng-Chen
Published: November 2015

In order to investigate the polymer effect on grid turbulence, the experiments study on grid turbulence has been built based on Particle Image Velocimetry. The Newtonian fluid flow and 200ppm polymer solution flow in grid turbulence were carried out at different grid oscillating frequency, such as 5Hz, 7.5Hz, 10Hz and 12.5Hz. The experimental results show that the viscous dissipation rate and vortex vector ωz is smaller and more regular in space distribution in polymer solution case at grid oscillating frequency with 5Hz. It indicates that the existence of polymer additives inhibits enormously the viscous dissipation rate and vortex vector, but this phenomenon can be attenuated with the increase of grid oscillating frequency. From this result, it shows that there exists a critical Reynolds number for the inhibition of polymer effect, which is the same as that in turbulent channel flows with polymers. Then, proper orthogonal decomposition (POD) has been used to extract coherent structures in grid turbulence. It is found that it needs 24 and 4 POD eigenfunctions to examine coherent structure in the Newtonian fluid and the polymer solution cases respectively at grid oscillating frequency with 10Hz. It suggests that the coherent structures can be inhibited due to the existence of polymers so as to the flow field to be more regular. But, with the increase of grid oscillating frequency, the number of POD eigenfunctions for the Newtonian fluid case and the polymer solution case respectively are approaching the same. Through this analysis, it can be also seen that the inhibition effect of polymers is close relation with the grid oscillating frequency.
Direct Numerical Simulation of Turbulent Channel Flow With Heat Transfer for Low Prandtl and High Reynolds and Comparison With Algebraic Heat Flux Model
Authors: Yuan Haomin , Merzari Elia
Published: November 2015

The flow characteristic of fluid at low Prandtl number is of continued interest in the nuclear industry because liquid metals are to be used in the next-generation nuclear power reactors. In this work we performed direct numerical simulation (DNS) for turbulent channel flow with fluid of low Prandtl number. The Prandtl number was set to 0.025, which is representative of the behavior of liquid metals. Constant heat flux was imposed on the walls to study heat transfer behavior, with different boundary conditions for temperature fluctuation. The bulk Reynolds number was set as high as 50,000, with a corresponding friction Reynolds number of 1,200, which is closer to the situation in a reactor or a heat exchanger than used in normally available databases. Budgets for turbulent variables were computed and compared with predictions from several RANS turbulence models. In particular, the Algebraic Heat Flux Model (AHFM) has been the focus of this comparison with DNS data. The comparisons highlight some shortcomings of AHFM along with potential improvements.
CFD of Vortical Flows: Requirements and Mesh Adaption Techniques
Authors: Reclari Martino , Fukao Shinji , Iino Masamichi , Sano Takeshi , Nakamura Yuuki
Published: November 2015

In most hydraulic applications (turbines, pumps, water intakes, propellers) the appearance of gas filled vortices, either caused by cavitation or air entrainment from a free surface, is usually associated with increase of losses, vibrations, noise and erosion risk. However, a correct prediction of the vortex characteristics (most importantly, of the pressure at the core) by numerical simulations may be challenging. A common example is the over-prediction of the vortex dissipation, which leads to wrong estimation of the gas core collapse location.

In the present paper we assess the numerical requirements necessary to compute vortex characteristics comparable to experimental results. As a first step, we evaluate the influence of the mesh resolution for different turbulence models (SST, SAS and RMS), in the case of a vortex generated by an elliptical wing.

Secondly, we compare the efficiency of several popular vortex identification techniques (helicity, Q, λ, Δ, etc…) to designate the mesh refinement regions, thus adapting the mesh to successfully compute the vortex characteristics, in the case of a vortex created in a cylindrical container with tangential inflow and central outflow.

Therefore, we are able to present effective guidelines for the correct computation of the above mentioned two phase problems, that can also be applied to leakage flow in gas turbomachines, wing-tip vortices, and more generally all computations where a high quality resolution of the vortices is necessary.
Flow and Heat Transfer in an Air-Cooling Device for a Molten-Salt Pump
Authors: Kang Can , Zhang Guifeng , Li Liting , Li Yunxiao
Published: November 2015

Research emphasis is placed upon an air-cooling device that is introduced to ensure the stable operation of the upper bearings of a pump transporting high-temperature medium. Both the flow and heat transfer inside the air cooling device are simulated. The distributions of velocity, stress and temperature distributions related to the air-cooling device are obtained. The relationship between air flow rate and cooling effect is analyzed. A thermal fluid-solid coupling method is used to solve thermal stress and thermal deformation of solid parts associated with the air cooling device.
Deep germanium etching using time multiplexed plasma etching
Authors: Darnon Maxime , de Lafontaine Mathieu , Volatier Maïté , Fafard Simon , Arès Richard , Jaouad Abdelatif , Aimez Vincent
Published: November 2015

There is a growing need for patterning germanium for photonic and photovoltaics applications. In this paper, the authors use a time multiplexed plasma etch process (Bosch process) to deep etch a germanium substrate. They show that germanium etching presents a strong aspect ratio dependent etching and that patterns present scallops mostly on the upper part (aspect ratio below 0.8). Passivation layers are formed during the passivation step by neutrals' deposition and are reinforced during the etching step by the redeposition of sputtered fluorocarbon species from the etch front. When the sidewalls are passivated, reactive neutrals diffuse through Knudsen-like diffusion down to the bottom of the pattern to etch the germanium. The Knudsen-like diffusion is responsible for the aspect ratio dependent etching and makes difficult the etching of holes with aspect ratios above 10 while trenches with aspect ratio of 17 are still etched faster than 2 μm/min.
Substrate temperature influence on the properties of GaN thin films grown by hollow-cathode plasma-assisted atomic layer deposition
Authors: Alevli Mustafa , Gungor Neşe , Haider Ali , Kizir Seda , Leghari Shahid A. , Biyikli Necmi
Published: November 2015

Gallium nitride films were grown by hollow cathode plasma-assisted atomic layer deposition using triethylgallium and N2/H2 plasma. An optimized recipe for GaN film was developed, and the effect of substrate temperature was studied in both self-limiting growth window and thermal decomposition-limited growth region. With increased substrate temperature, film crystallinity improved, and the optical band edge decreased from 3.60 to 3.52 eV. The refractive index and reflectivity in Reststrahlen band increased with the substrate temperature. Compressive strain is observed for both samples, and the surface roughness is observed to increase with the substrate temperature. Despite these temperature dependent material properties, the chemical composition, E1(TO), phonon position, and crystalline phases present in the GaN film were relatively independent from growth temperature.
Investigation of interfacial stiffnesses of a tri-layer using Zero-Group Velocity Lamb modes
Authors: Mezil Sylvain , Bruno Francois , Raetz Samuel , Laurent Jérôme , Royer Daniel , Prada Claire
Published: November 2015

Zero-Group Velocity (ZGV) Lamb waves are studied in a structure composed of two plates bonded by an adhesive layer. The dispersion curves are calculated for a Duralumin/epoxy/Duralumin sample, where the adhesion is modeled by a normal and a tangential spring at both interfaces. Several ZGV modes are identified and their frequency dependence on interfacial stiffnesses and on the bonding layer thickness is numerically studied. Then, experiments achieved with laser ultrasonic techniques are presented. Local resonances are measured using a superimposed source and probe. Knowing the thicknesses and elastic constants of the Duralumin and epoxy layers, the comparison between theoretical and experimental ZGV resonances leads to an evaluation of the interfacial stiffnesses. A good agreement with theoretical dispersion curves confirms the identification of the resonances and the parameter estimations. This non-contact technique is promising for the local evaluation of bonded structures.
Interplay of lancet furrows and shape change in the horseshoe bat noseleaf
Authors: Gupta Anupam K. , Webster Dane , Müller Rolf
Published: November 2015

Horseshoe bats emit biosonar pulses through the nostrils and diffract the outgoing ultrasonic pulses with baffles, so-called “noseleaves,” that surround the nostrils. The noseleaves have complex static geometries and can furthermore undergo dynamic shape changes during emission of the biosonar pulses. The posterior noseleaf part, the lancet, has been shown to carry out anterior-posterior flicking motions during biosonar emissions with average lancet tip displacements of about 1 mm. Here, the acoustic effects of the interplay between the lancet furrows and shape change (lancet rotation) on the emission beam were investigated using the animated digital models obtained from the noseleaves of greater horseshoe bats (Rhinolophus ferrumequinum). It was found that forward lancet rotations increase the amount of sound energy allocated to secondary amplitude maxima (sidelobes) in the beampattern, but only in the presence of the furrows. The interaction between static and dynamic features can be readily quantified by roughness (standard deviation about local mean) of the amplitude distribution of the beampatterns. This effect goes beyond the static impact of the furrows on the width of the mainlobe. It could allow the bats to send out their pulses through a sequence of qualitatively different beampatterns.
A noise delivery system for multi-animal multi-level whole body ototoxicity studies
Authors: Stubbs John E. , Slagley Jeremy M. , Reboulet James E.
Published: November 2015

The Naval Medical Research Unit Dayton (NAMRU-D) at Wright-Patterson Air Force Base, Ohio, in conjunction with the U.S. Air Force, studied ototoxic effects of JP-8 in rats. NAMRU-D used a multi-chamber whole body exposure facility for up to 96 test animals and 32 control animals at different exposure levels. The objective was to design a noise delivery system that could provide a white noise source one octave band wide, centered at 8 kHz frequency, delivered from outside the exposure chambers. Sound pressure levels were required to be within ±2 dB at all exposure points within each chamber and within ±2 dB over a 6-h run. Electrodynamic shakers were used to produce input noise in exposure chambers by inducing vibration in chamber plenums. Distribution of sound pressure levels across exposure points was controlled within a ±1.5dB prediction interval (α = 0.05) or better. Stability at a central reference point was controlled over 6-h runs within a ±1 dB prediction interval (α = 0.05) or better. The final system allowed NAMRU-D to deliver noise and whole-body aerosol exposures to multiple animals at different levels simultaneously and study the effects that ototoxins may have on hearing loss.
Reacting With or Without Detecting
Authors: Smeets Jeroen B.J. , Wijdenes Leonie Oostwoud , Brenner Eli
Published: November 2015

We begin our response by clarifying the concept of detection, and explaining why this is needed for initiating, but not for adjusting a movement. We present a simulation to illustrate this difference. Several commentators referred to studies with results that might seem in conflict with our proposal that movement adjustments have short latencies because there is no need to detect anything. In the last part of our response, we discuss how we interpret these studies as being in line with our proposal.
Depth-independent cone penetration mechanism by a discrete element method (DEM)-based stress normalization approach
Authors: Liu Su , Wang Jianfeng
Published: November 2015

A two-dimensional discrete element model of driven piles in crushable sand was developed and validated against laboratory data. Numerical experiments were conducted to investigate the effects on the pile penetration behavior of initial sample porosity, particle crushability, initial stress state, ratio of pile diameter to median particle diameter, and ratio of model width to pile diameter. A new stress normalization method is adopted to synthesize the data at different driven depths from the simulations. The normalized vertical and horizontal stress fields surrounding the pile show an invariable pattern of stress distribution, suggesting a unique penetration mechanism independent of the penetration depth. The validity of the discrete element method (DEM) simulation results is verified by comparing the stress distributions to those observed from calibration chamber tests on model pile installation in sands.
THE STRESS-DEPENDENT RANDOM WALK
Authors: GREMM MARTIN
Published: November 2015

A log-normal random walk with parameters that are functions of market stress naturally accounts for volatility clustering and fat-tailed return distributions. Fitting this model to a stock and a bond index we find no evidence of significant misspecification despite the fact that the model has no adjustable parameters. This model can be interpreted as a stochastic volatility model without latent variables. We obtain a closed-form expression for the Value at Risk (VaR) that accommodates returns of any magnitude and discuss several other applications.
Geological and Geomorphological Tsunami Hazard Analysis for the Maldives Using an Integrated WE Method and a LR Model
Authors: Riyaz Mahmood , Suppasri Anawat
Published: November 2015

This study presents a tsunami hazard analysis for the Maldives using integrated statistical approaches, such as the WE (weight of evidence) method and a LR (logistic regression) model, using historical flooding records from the Maldives following the 2004 Indian Ocean Tsunami. The data with respect to the geological and geomorphological parameters of the islands and reefs, which were collected from 202 inhabited islands and seven resorts in the Maldives, were weighted by the presence/absence of evidence from the impacted islands. The tsunami hazard and risk were evaluated using spatial weights calculated for each variable. The predicted tsunami risk was compared with the impact of the 2004 Indian Ocean Tsunami.

The results show that for the three cases, the success rate of the estimated hazard and risk prediction ranged between 74% and 90% for the low and high impact islands, respectively. However, the predictability for medium impact islands in the three cases was within the range of 52–58%. The results of this study can be applied to hazard and risk assessments, are useful for tsunami behavior model development for coral islands and can be used to identify islands that are naturally protected, sheltered or resilient against natural disasters, such as tsunamis.
Guiding Novice Web Workers in Making Image Descriptions Using Templates
Authors: Morash Valerie S. , Siu Yue-Ting , Miele Joshua A. , Hasty Lucia , Landau Steven
Published: November 2015

This article compares two methods of employing novice Web workers to author descriptions of science, technology, engineering, and mathematics images to make them accessible to individuals with visual and print-reading disabilities. The goal is to identify methods of creating image descriptions that are inexpensive, effective, and follow established accessibility guidelines. The first method explicitly presented the guidelines to the worker, then the worker constructed the image description in an empty text box and table. The second method queried the worker for image information and then used responses to construct a template-based description according to established guidelines. The descriptions generated through queried image description (QID) were more likely to include information on the image category, title, caption, and units. They were also more similar to one another, based on Jaccard distances of q-grams, indicating that their word usage and structure were more standardized. Last, the workers preferred describing images using QID and found the task easier. Therefore, explicit instruction on image-description guidelines is not sufficient to produce quality image descriptions when using novice Web workers. Instead, it is better to provide information about images, then generate descriptions from responses using templates.
A Performance Comparison of On-Hand versus On-Phone Nonvisual Input by Blind and Sighted Users
Authors: Oh Uran , Findlater Leah
Published: November 2015

On-body interaction, in which the user employs one's own body as an input surface, has the potential to provide efficient mobile computing access for blind users. It offers increased tactile and proprioceptive feedback compared to a phone and, because it is always available, it should allow for quick audio output control without having to retrieve the phone from a pocket or bag. Despite this potential, there has been little investigation of on-body input for users with visual impairments. To assess blind users’ performance with on-body input versus touchscreen input, we conducted a controlled lab study with 12 sighted and 11 blind participants. Study tasks included basic pointing and drawing more complex shape gestures. Our findings confirm past work with sighted users showing that the hand results in faster pointing than the phone. Most important, we also show that: (1) the performance gain of the hand applies to blind users as well, (2) the accuracy of where the pointing finger first lands is higher with the hand than the phone, (3) on-hand pointing performance is affected by the location of targets, and (4) shape gestures drawn on the hand result in higher gesture recognition rates than those on the phone. Our findings highlight the potential of on-body input to support accessible nonvisual mobile computing.
Technologies from Classroom to e-learning
Authors: Carr-Chellman Alison
Published: November 2015

Many new technology devices hit the market each year. Most of them are targeted at traditional, face-to-face settings. This article takes a look at recent technologies that might be adapted in the future for an e-learning setting.
A Predictive Control Approach for Fault Management of Computing Systems
Authors: Jia Rui , Abdelwahed Sherif , Erradi Abdelkarim
Published: November 2015

In this paper, a model-based predictive control approach for fault management in computing systems is presented. The proposed approach can incorporate existing fault diagnosis methods and fault recovery actions to facilitate the recovery process. When a fault is identified, the proposed algorithm uses utility cost functions to compute the optimal recovery solution that minimizes fault impacts on the system's Quality of Service. The proposed approach has been demonstrated on a Web service testbed under various faults.
Admit or Reject? Preserve or Drop?
Authors: Lavi Nadav , Levy Hanoch
Published: November 2015

Server failures on the cloud introduce acute operational dilemmas as now the cloud management entity needs to handle existing task preservations in addition to new task admissions. These admission and preservation decisions have significant impact on the cloud performance and operational cost, as they impact future system decisions. Should a cloud manager prefer to use resources for new task admissions and increase the risk of dropping an already admitted task in the future? Or should he/she prefer to maintain resources for potential future task preservations at the expense of new task admissions? These dilemmas are even more critical in Distributed Cloud Computing (DCC) due to the small scale of the micro Cloud Computing Center (mCCC). In this paper we will address these questions through the use of Markov Decision Process (MDP) analysis. We will show that even though the problem appears to be rather complicated (as the two decision rules are coupled), our analysis reveals that it can be significantly simplified (as one of the rules is of a trivial form). These results enables us to compose a holistic framework for cloud computing task management.
Coordinated Colocation Datacenters for Economic Demand Responce
Authors: Tran Nguyen H. , Do Cuong T. , Hong Choong Seon , Ren Shaolei , Han Zhu
Published: November 2015

Demand response of datacenters recently has received increasing efforts due to huge demands and flexible power control knobs. However, very few works focus on a critical segment of datacenter business: multi-tenant colocation. In colocation datacenters, while there exist multiple tenants who manger their own servers, the colocation operator only provides other facilities such as cooling, reliable power, and network connectivity. Therefore, colocation has a unique challenge for the demand response: uncoordinated power management among tenants. To tackle this challenge, we study how to coordinate tentants for economic demand response. We show that there is an interaction between the operator and tenants' strategies, where each side maximizes its own benefit. Hence, we apply a two-stage Stackelberg game to analyze this scenario and derive this game's equilibria. Finally, trace-based simulations are also provided to illustrate the efficacy of our proposed incentive schemes.
Abstract A1-04: The role of chromatin remodeler CHD1 in genomic alterations and prostate cancer progression
Authors: Liu Wennuan , Rodrigues Lindsey Ulkus , Li Tao , Zhang Zheng , Rider Leah , Romero Lina , Zheng Lilly S. , Isaacs William B. , Cramer Scott , Xu Jianfeng
Published: November 2015

The chromodomain helicase DNA (CHD) binding proteins have been implicated to play a role in genome stability. CHD1 is second only to PTEN as the most frequent homozygously deleted gene in the tumor genome of prostate cancer (PCa). To assess the role of CHD1 in genomic integrity and PCa progression, we performed a comprehensive survey of DNA copy number alterations (CNAs) in the tumor genome among a total of 611 patients from 5 independent cohorts and an association analysis of CHD1 deletion with cancer progression from low (Gleason 6) to high (Gleason ≥ 8) grade tumors. Our data revealed that the frequency of CHD1 deletion significantly increased as cancer progressing from low to intermediate and to high grades, suggesting a role of this CNA in cancer progression. Loss of CHD1 was significantly associated with homozygous deletions at other genomic locations in the tumor genome, and with deletion of MAP3K7. We next evaluated the in vitro and in vivo joint effects of knockdown of CHD1 and the collaborative gene MAP3K7 on tumorigenesis, cell proliferation (Ki67), tumor size, histopathological characteristics, and cancer progression, using shRNA and tissue recombination with rat urogenital mesenchyme and mouse prostate epithelial stem/progenitor cells grafted under the renal capsule and subcutaneous xenografts in nude mice. While suppressing CHD1 expression, in general, resulted in deceased growth of tumor cells vs. shControl cells, concurrently suppressing expression of both CHD1 and MAP3K7 promoted aggressive tumor growth and reduced survival. We finally explored the effect of knockdown of CHD1/MAP3K7 expression in stable cell lines derived human normal prostate epithelial cells and cancer cells on genomic rearrangement via CNA analysis. Although a wide range of CNAs was observed in different cell lines, some of them recapitulated the CNAs that were commonly observed in the tumors of human PCa. Collectively, these data suggest that loss of CHD1 leads to further evolution of cancer cells via genomic instability and combined loss of CHD1 and MAP3K7 drives the progression of PCa.

Note: This abstract was not presented at the conference.

Citation Format: Wennuan Liu, Lindsey Ulkus Rodrigues, Tao Li, Zheng Zhang, Leah Rider, Lina Romero, Lilly S. Zheng, William B. Isaacs, Scott Cramer, Jianfeng Xu. The role of chromatin remodeler CHD1 in genomic alterations and prostate cancer progression. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-04.
Abstract A1-08: Comparative genomics study of FOXA/ER dual regulation in breast cancer and liver cancer
Authors: Li Zhaoyu
Published: November 2015

Estrogen, the female dominant hormone, has been found to play critical roles in cancers for over 100 years. In 1896, estrogen was found to promote the tumor growth of breast cancer; and in 1937, estrogen was found to prevent the tumor growth of liver cancer. After the estrogen receptor alpha (ERα) was identified in 1958, ERα-mediated estrogen signaling was found to promote or prevent the growth of breast cancer cells or liver cancer cells, respectively. Recent studies showed that ERα-mediated estrogen signaling in promoting the growth of breast cancer cells was dependent of forkhead box protein A1 (FOXA1). Our recent study showed that ERα-mediated estrogen signaling in preventing the growth of liver cancer cells also depended on FOXA factors (FOXA1 and FOXA2). Thus, FOXA-dependent ERα-mediated estrogen signaling plays opposite roles in the growth of breast cancer and liver cancer cells. Here, we applied genomic approaches to identify 184 FOXA/ER dual target genes that showed opposite expression in response to estrogen-mediated stimulation or suppression of cell growth in breast or liver cancer cells. Gene ontology analysis showed that the majority of these FOXA/ER dual target genes were involved in the processes of cell proliferation and growth, cell death, tissue development, and cancer. Manipulations of the expression of these target genes were able to reverse the growth of breast and liver cancer cells. Thus, these 184 FOXA/ER dual target genes provide us a novel set of potential biomarkers and therapeutic targets for both breast cancer and liver cancer.

Note: This abstract was not presented at the conference.

Citation Format: Zhaoyu Li. Comparative genomics study of FOXA/ER dual regulation in breast cancer and liver cancer. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-08.
Abstract A1-09: Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression with prognostic implications
Authors: Hoskins Jason W. , Ibrahim Abdisamad , Emmanuel Mickey , Manmiller Sarah , Jia Jinping , Parikh Hemang , Collins Irene , Ylaya Kris , Altekruse Sean F. , Hewitt Stephen M. , Petersen Gloria M. , Amundadottir Laufey T.
Published: November 2015

A genome-wide association study (GWAS) of pancreatic cancer conducted within the NCI Cohort Consortium (PanScan I and II) identified pancreatic cancer susceptibility loci on chromosomes 1q32.1/NR5A2, 5p15.33/CLPTM1L/TERT, 9q34.2/ABO, and 13q22.1. The most significant single-nucleotide polymorphism (SNP) identified on 13q22.1, rs9543325, lies in a ~600 kb gene desert; the nearest genes are KLF5, KLF12, PIBF1, DIS3, and BORA (265–586 kb away). Imputation using the 1000 Genomes and DCEG reference datasets did not improve the GWAS signal, but produced a set of highly correlated SNPs for functional follow-up. We performed eQTL analysis to test for association between the genotypes of these functional candidate variants and expression of nearby genes. Among 64 normal derived pancreatic tissue samples, DIS3 expression showed the strongest association with a 30 bp indel variant in the risk locus (P = 4.8 × 10-4), indicating risk alleles associate with reduced DIS3 expression. Mutations in DIS3 have previously been identified in acute myeloid leukemia and multiple myeloma, and its expression has been correlated with metastatic potential in colorectal cancer, suggesting DIS3 is relevant to cancer biology. Chromosome conformation capture identified a physical interaction between the indel-containing locus and a region near the DIS3 promoter. Luciferase assay for regulatory function of this indel-containing locus revealed allele-specific silencer activity for the insertion allele. Supershift electromobility shift assay (EMSA) demonstrated binding of LEF1 specifically to the insertion allele of the indel, which contains two in silico predicted LEF1 binding elements. Finally, through immunohistochemical analysis, high DIS3 protein levels associated with better survival for pancreatic cancer patients (hazard ratio = 2.87, 95% CI = 1.49–5.53, P = 0.001). Our results suggest that at least one target gene for the pancreatic cancer risk variants on chr13q22.1 may be DIS3, and that the underlying biology may be mediated by the novel indel through a long-range repressive effect on DIS3 expression.

Citation Format: Jason W. Hoskins, Abdisamad Ibrahim, Mickey Emmanuel, Sarah Manmiller, Jinping Jia, Hemang Parikh, Irene Collins, Kris Ylaya, Sean F. Altekruse, Stephen M. Hewitt, Gloria M. Petersen, Laufey T. Amundadottir. Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression with prognostic implications. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-09.
Abstract A1-15: Systematic genomic characterization of uveal melanoma
Authors: Place Chelsea S. , Kim Ivana K. , Esmaeli Bita , Amin-Mansour Ali , Treacy Daniel J. , Carter Scott L. , Hodis Eran , Wagle Nikhil , Seepo Sara , Yu Xiaoxing , Vazquez Francisca , Nickerson Elizabeth , Cibulskis Kristian , McKenna Aaron , Gabriel Stacey B. , Getz Gad , Allen Eliezer M. Van , Garraway Levi A. , Woodman Scott E.
Published: November 2015

Uveal melanoma (UM) is a rare type of melanoma that occurs in the iris, ciliary body, and choroid of the eye. Metastatic disease is typically found in the liver and has no effective therapeutic options. To improve our understanding of the genetic drivers of UM, we sequenced the exome of 61 primary tumors and 3 liver metastases, each with matched normal DNA. Consistent with prior studies, the majority of UM tumors harbored mutually exclusive mutations in GNAQ and GNA11. Co-occurring with GNAQ and GNA11 mutations were inactivating mutations throughout the BAP1 coding region as well as recurrent mutations in the splicing factor SF3B1 and the translation initiation factor EIF1AX. Somatic mutations found only in metastatic tumor samples were also identified. The function of mutant EIF1AX was probed using loss of function experiments. Reduction of EIF1AX expression impaired the growth of both wild type and mutant cells. To identify transcripts regulated by EIF1AX at the level of translation, RNA sequencing of polysome-associated mRNAs was performed. Knockdown of wild type, but not mutant EIF1AX reduced the efficiency of ribosomal protein translation. Cancer cells expressing mutant EIF1AX may harbor changes in protein translation, which may be important for tumorigenesis.

Citation Format: Chelsea S. Place, Ivana K. Kim, Bita Esmaeli, Ali Amin-Mansour, Daniel J. Treacy, Scott L. Carter, Eran Hodis, Nikhil Wagle, Sara Seepo, Xiaoxing Yu, Francisca Vazquez, Elizabeth Nickerson, Kristian Cibulskis, Aaron McKenna, Stacey B. Gabriel, Gad Getz, Eliezer M. Van Allen, Levi A. Garraway, Scott E. Woodman. Systematic genomic characterization of uveal melanoma. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-15.
Abstract A1-26: Inhibiting stemness and invasion property of glioma stem cells by biguanide compound
Authors: Choi Junjeong , Lee Ji-Hyun , Shim Jin-Kyoung , Pilnam Kim , Kang Seok-Gu
Published: November 2015

Introduction: Ever since pharmacoepidemiologic clues of antineoplastic actions of metformin were reported in 2005, potential application of biguanide for the treatment of several types of cancer has been evaluated. To overcome limited pharmacokinetic properties of prototype biguanides such as metformin and penformin, a newly developed biguanide compound HL156A was developed. In the present, we assessed the potential biologic effect of HL156A on the glioma stemness and invasion properties.

Methods: Using patient derived glioma cancer stem cells (gCSCs), we assessed cell viability, AMPK-mTOR pathway, stemness, differentiation, tumor invasion and epithelial-mesenchymal properties of gCSCs. In addition, expression profiles with drug treatment were obtained using Illumina HumanHT-12 v4 Expression BeadChip and gene set enrichment analysis (GSEA) was performed with GSEA application. Orthotopic tumor model was generated and assessed for tumor margin.

Results: The compound activated p-AMPK and reduced phosphorylation of mTORC-1-regulated proteins. It decreased stemness of gCSCs, proved by sphere formation assay and decreased expression of stemness markers. The invasive properties of gCSCs were inhibited on 3D invasion assay and the expression of proteins related with epithelial-mesenchymal transition was inhibited by the compound. GSEA revealed cell adhesion related gene set was altered in the compound treated groups. Orthotopic model of the tumor showed less invasive tumor margin on the treatment of the compound.

Citation Format: Junjeong Choi, Ji-Hyun Lee, Jin-Kyoung Shim, Kim Pilnam, Seok-Gu Kang. Inhibiting stemness and invasion property of glioma stem cells by biguanide compound. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-26.