bluuebunny/crossref_metadata_2025 huggingface dataset:
Environment Based Design Approach to Integrating Enterprise Applications
Authors: Tan Suo , Zeng Yong , Chen Bo , Bani Milhim Hamzeh K. , Schiffauerova Andrea
Published: August 2012

Enterprises tend to depend on various legacy applications in supporting their business strategies and in achieving their goals. In order for an enterprise to be efficient and cost-effective, their legacy applications should be seamlessly integrated within and beyond the enterprise. Some research work in enterprise applications integrations (EAI) analyzed the problem, while others proposed solution models for the syntactic and semantic integration of business processes. In this paper, the EAI is considered as a design problem and is analyzed from design point of view. Environment based design (EBD) methodology is applied to handle the integration problem by analyzing and clarifying the design requirements to generate appropriate solutions. A framework is proposed for EAI problems based on the EBD approach. A case study is also provided to show how the approach can be applied within a company to generate satisfactory EAI solutions with low cost, high efficiency, and enhanced scalability.
The Asd
+
-DadB
+
Dual-Plasmid System Offers a Novel Means To Deliver Multiple Protective Antigens by a Recombinant Attenuated Salmonella Vaccine
Authors: Xin Wei , Wanda Soo-Young , Zhang Xiangmin , Santander Javier , Scarpellini Giorgio , Ellis Karen , Alamuri Praveen , Curtiss Roy
Published: August 2012

We developed means to deliver multiple heterologous antigens on dual plasmids with non-antibiotic-resistance markers in a single recombinant attenuated vaccine strain of
Salmonella enterica
serotype Typhimurium. The first component of this delivery system is a strain of
S
. Typhimurium carrying genomic deletions in
alr
,
dadB
, and
asd
, resulting in obligate requirements for diaminopimelic acid (DAP) and
d
-alanine for growth. The second component is the Asd
+
-DadB
+
plasmid pair carrying wild-type copies of
asdA
and
dadB
, respectively, to complement the mutations. To evaluate the protection efficacy of the dual-plasmid vaccine,
S
. Typhimurium strain χ9760 (a strain with multiple attenuating mutations: Δ
asd
Δ
alr
Δ
dadB
Δ
recF
) was transformed with Asd
+
and DadB
+
plasmids specifying pneumococcal antigens PspA and PspC, respectively. Both plasmids were stable in χ9760 for 50 generations when grown in nonselective medium. This was significantly (
P
< 0.05) greater than the stability seen in its
recF
+
counterpart χ9590 and could be attributed to reduced interplasmid recombination in χ9760. Oral immunization of BALB/c mice with 1 × 10
9
CFU of χ9760 (carrying Asd
+
-PspA and DadB
+
-PspC plasmids) elicited a dominant Th1-type serum IgG response against both antigens and protected mice against intraperitoneal challenge with 200 50% lethal doses (LD
50
s) of virulent
Streptococcus pneumoniae
strain WU2 or intravenous challenge with 100 LD
50
s of virulent
S. pneumoniae
strain L81905 or intranasal challenge with a lethal dose of
S. pneumoniae
A66.1 in a pneumonia model. Protection offered by χ9760 was superior to that offered by the mixture of two strains, χ9828 (Asd
+
-PspA) and χ11026 (DadB
+
-PspC). This novel dual-plasmid system marks a remarkable improvement in the development of live bacterial vaccines.
USING VARIABLE SPEED LIMITS TO ELIMINATE WIDE MOVING JAMS: A STUDY BASED ON THREE-PHASE TRAFFIC THEORY
Authors: WANG YIZHI , ZHANG YI , HU JIANMING , LI LI
Published: August 2012

One frequently observed congested traffic flow pattern is wide moving jam (WMJ), in which the average vehicle speed is very low and the density is very high. In some recent studies, variable speed limits (VSL) were proposed as effective measures to eliminate or abate the influence of jam waves. However, in most of these studies, the stochastic features of driving behaviors and the resulting uncertainty of traffic flow dynamics were not fully considered. In this paper, we use cellular automaton (CA) model-based simulations to test the performances of different VSL control strategies and apply the three-phase traffic theory to further analyze the obtained results. Based on the simulation results, we got two novel findings. Firstly, we observed seven, instead of the previously assumed six, states of traffic flow in the evolution process of WMJ, when VSL were applied. Secondly and more importantly, we found that inappropriate speed limit may induce new WMJ and exaggerate congestions in two ways: one way corresponds to an F → J transition and the other corresponds to an F → S → J transition. Based on these findings, the appropriate lower bound of VSL was finally discussed in this paper.
A DISCRETE MATHEMATICAL MODEL TO SIMULATE MALWARE SPREADING
Authors: DEL REY A. MARTIN , SÁNCHEZ G. RODRIGUEZ
Published: August 2012

With the advent and worldwide development of Internet, the study and control of malware spreading has become very important. In this sense, some mathematical models to simulate malware propagation have been proposed in the scientific literature, and usually they are based on differential equations exploiting the similarities with mathematical epidemiology. The great majority of these models study the behavior of a particular type of malware called computer worms; indeed, to the best of our knowledge, no model has been proposed to simulate the spreading of a computer virus (the traditional type of malware which differs from computer worms in several aspects). In this sense, the purpose of this work is to introduce a new mathematical model not based on continuous mathematics tools but on discrete ones, to analyze and study the epidemic behavior of computer virus. Specifically, cellular automata are used in order to design such model.
BRIEF REVIEW OF CHARM PHYSICS
Authors: GERSABECK MARCO
Published: August 2012

Charm physics has attracted increased attention after the first evidence for charm mixing was observed in 2007. The level of attention has risen sharply after LHCb reported first evidence for CP violation in the charm sector. Neither mixing nor CP violation have been established by a single unambiguous measurement to date. This review covers the status of mixing and CP violation measurements and comments on the challenges on the road ahead, both on the experimental and theoretical side, and on ways to tackle them.
ON THE DESIGN AND EVALUATION OF A PRECISE, ROBUST AND SCALABLE FIDUCIAL MARKER FRAMEWORK
Authors: DA CAMARA NETO VILAR FIUZA , DE MESQUITA DANIEL BALBINO , GARCIA RENATO FLORENTINO , CAMPOS MARIO MONTENEGRO
Published: August 2012

In this paper we present an improved color-based planar fiducial marker system. Our framework provides precise and robust full 3D pose estimation of markers with superior accuracy when compared with many fiducial systems in the literature, while color information encoding enables using over 65 000 distinct markers. Unlike most color-based fiducial frameworks, which requires prior classification training and color calibration, ours can perform reliably under illumination changes, requiring but a rough white balance adjustment. Our methodology provides good detection performance even under poor illumination conditions which typically compromise other marker identification techniques, thus avoiding the evaluation of otherwise falsely identified markers. Several experiments are presented and carefully analyzed, in order to validate our system and demonstrate the significant improvement in estimation accuracy of both position and orientation over traditional techniques.
EMBEDDED DISC-TYPE SURFACES WITH LARGE CONSTANT MEAN CURVATURE AND FREE BOUNDARIES
Authors: FALL MOUHAMED MOUSTAPHA
Published: August 2012

Given Ω ⊂ ℝ3an open bounded set with smooth boundary ∂Ω and H ∈ ℝ, we prove the existence of embedded H-surfaces supported by ∂Ω, that is regular surfaces in ℝ3with constant mean curvature H at every point, contained in Ω and with boundary intersecting ∂Ω orthogonally. More precisely, we prove that if Q ∈ ∂Ω is a stable stationary point for the mean curvature of ∂Ω, then there exists a family of embedded [Formula: see text]-surfaces near Q, ε > 0 small, which, once dilated by a factor [Formula: see text] and suitably translated, converges to a hemisphere of radius 1 as ε → 0.
INFINITELY MANY SOLUTIONS FOR HARDY–SOBOLEV–MAZ'YA EQUATION INVOLVING CRITICAL GROWTH
Authors: WANG CHUNHUA , WANG JIANGTAO
Published: August 2012

In this paper, by an approximating argument, we obtain infinitely many solutions for the following Hardy–Sobolev–Maz'ya equation with critical growth: [Formula: see text] provided N > 6 + t, where [Formula: see text] when k > 2, λ = 0 when k = 2, [Formula: see text] and Ω is an open bounded domain in ℝN, which contains some points x0= (0, z0).
FEATURE SELECTION APPLIED TO THE TIME-FREQUENCY REPRESENTATION OF MUSCLE NEAR-INFRARED SPECTROSCOPY (NIRS) SIGNALS: CHARACTERIZATION OF DIABETIC OXYGENATION PATTERNS
Authors: ROSATI SAMANTA , BALESTRA GABRIELLA , MOLINARI FILIPPO
Published: August 2012

Diabetic patients might present peripheral microcirculation impairment and might benefit from physical training. Thirty-nine diabetic patients underwent the monitoring of the tibialis anterior muscle oxygenation during a series of voluntary ankle flexo-extensions by near-infrared spectroscopy (NIRS). NIRS signals were acquired before and after training protocols. Sixteen control subjects were tested with the same protocol. Time-frequency distributions of the Cohen's class were used to process the NIRS signals relative to the concentration changes of oxygenated and reduced hemoglobin. A total of 24 variables were measured for each subject and the most discriminative were selected by using four feature selection algorithms: QuickReduct, Genetic Rough-Set Attribute Reduction, Ant Rough-Set Attribute Reduction, and traditional ANOVA. Artificial neural networks were used to validate the discriminative power of the selected features. Results showed that different algorithms extracted different sets of variables, but all the combinations were discriminative. The best classification accuracy was about 70%. The oxygenation variables were selected when comparing controls to diabetic patients or diabetic patients before and after training. This preliminary study showed the importance of feature selection techniques in NIRS assessment of diabetic peripheral vascular impairment.
CLASSIFICATION OF EEG SIGNALS IN NORMAL AND DEPRESSION CONDITIONS BY ANN USING RWE AND SIGNAL ENTROPY
Authors: PUTHANKATTIL SUBHA D. , JOSEPH PAUL K.
Published: August 2012

EEG is useful for the analysis of the functional activity of the brain and a detailed assessment of this non-stationary waveform can provide crucial parameters indicative of the mental state of patients. The complex nature of EEG signals calls for automated analysis using various signal processing methods. This paper attempts to classify the EEG signals of normal and depression patients using well-established signal processing techniques involving relative wavelet energy (RWE) and artificial feedForward neural network. High frequency noise present in the recorded signal is removed using total variation filtering (TVF). Classification of the frequency bands of EEG signals into appropriate detail levels and approximation level is carried out using an eight-level multiresolution decomposition method of discrete wavelet transform (DWT). Parseval's theorem is used for calculating the energy at different resolution levels. RWE analysis gives information about the signal energy distribution at different decomposition levels. Both RWE and feedforward Network are used to classify the signals from normal controls and depression patients. The performance of the artificial neural network was evaluated using the classification accuracy and its value of 98.11% indicates a great potential for classifying normal and depression signals.
AUTOMATED DETECTION OF ATRIAL FLUTTER AND FIBRILLATION USING ECG SIGNALS IN WAVELET FRAMEWORK
Authors: MARTIS ROSHAN JOY , PRASAD HARI , CHAKRABORTY CHANDAN , RAY AJOY KUMAR
Published: August 2012

In this paper, an electrocardiogram (ECG)-based pattern analysis methodology is presented for the detection of artrial flutter and atrial fibrillation using fractal dimension (FD) of continuous wavelet transform (CWT) coefficients of raw ECG signals, sample entropy of heart beat interval time series, and mean heart beat interval features. Accurate diagnosis of atrial tachyarrhythmias is important, as they have different therapeutic options and clinical decisions. In view of this, we have made an attempt to develop a discrimination mechanism between artrial flutter and atrial fibrillation. The methodology consists of mean heart beat interval detection using Pan Tompkins algorithm, calculation of sample entropy of heart beat interval time series, computation of box counting FD from CWT coefficients of raw ECG, statistical significance test, and subsequent pattern classification using different classifiers. Different wavelet basis functions like Daubechies-4, Daubechies-6, Symlet-2, Symlet-4, Symlet-6, Symlet-8, Coiflet-2, Coiflet-5, Biorthogonal-1.3, Biorthogonal-3.1, and Mayer wavelet have been used to compute CWT coefficients. Features are evaluated using statistical analysis and subsequently two-class pattern classification is done using unsupervised (k-means, fuzzy c-means, and Gaussian mixture model) and supervised (error back propagation neural network and support vector machine) techniques. In order to reduce the bias in choosing the training and testing set, k-fold cross validation is used. The obtained results are compared and discussed. It is found that the supervised classifiers provide higher accuracy in comparison to the set of unsupervised classifiers.
BASIC HANDWRITTEN CHARACTER RECOGNITION FROM MULTI-LINGUAL IMAGE DATASET USING MULTI-RESOLUTION AND MULTI-DIRECTIONAL TRANSFORM
Authors: PRASAD SHITALA , VERMA GYANENDRA K. , SINGH BHUPESH KUMAR , KUMAR PIYUSH
Published: August 2012

This paper, proposes a novel approach for feature extraction based on the segmentation and morphological alteration of handwritten multi-lingual characters. We explored multi-resolution and multi-directional transforms such as wavelet, curvelet and ridgelet transform to extract classifying features of handwritten multi-lingual images. Evaluating the pros and cons of each multi-resolution algorithm has been discussed and resolved that Curvelet-based features extraction is most promising for multi-lingual character recognition. We have also applied some morphological operation such as thinning and thickening then feature level fusion is performed in order to create robust feature vector for classification. The classification is performed with K-nearest neighbor (K-NN) and support vector machine (SVM) classifier with their relative performance. We experiment with our in-house dataset, compiled in our lab by more than 50 personnel.
GENERAL LAW OF GROWTH AND REPLICATION, GROWTH EQUATION AND ITS APPLICATIONS
Authors: SHESTOPALOFF YURI K.
Published: August 2012

We present significantly advanced studies of the previously introduced physical growth mechanism and unite it with biochemical growth factors. Obtained results allowed formulation of the general growth law which governs growth and evolutional development of all living organisms, their organs and systems. It was discovered that the growth cycle is predefined by the distribution of nutritional resources between maintenance needs and biomass production. This distribution is quantitatively defined by the growth ratio parameter, which depends on the geometry of an organism, phase of growth and, indirectly, the organism's biochemical machinery. The amount of produced biomass, in turn, defines the composition of biochemical reactions. Changing amount of nutrients diverted to biomass production is what forces organisms to proceed through the whole growth and replication cycle. The growth law can be formulated as follows: the rate of growth is proportional to influx of nutrients and growth ratio. Considering specific biochemical components of different organisms, we find influxes of required nutrients and substitute them into the growth equation; then, we compute growth curves for amoeba, wild type fission yeast, and fission yeast's mutant. In all cases, predicted growth curves correspond very well to experimental data. Obtained results prove validity and fundamental scientific value of the discovery.
DUAL PIVOT QUICKSORT
Authors: ILIOPOULOS VASILEIOS , PENMAN DAVID B.
Published: August 2012

In this paper, we analyze the dual pivot Quicksort, a variant of the standard Quicksort algorithm, in which two pivots are used for the partitioning of the array. We are solving recurrences of the expected number of key comparisons and exchanges performed by the algorithm, obtaining the exact and asymptotic total average values contributing to its time complexity. Further, we compute the average number of partitioning stages and the variance of the number of key comparisons. In terms of mean values, dual pivot Quicksort does not appear to be faster than ordinary algorithm.
COMPLEXITY OF CERTAIN FUNCTIONAL VARIANTS OF TOTAL DOMINATION IN CHORDAL BIPARTITE GRAPHS
Authors: PRADHAN D.
Published: August 2012

In this paper, we consider minimum total domination problem along with two of its variations namely, minimum signed total domination problem and minimum minus total domination problem for chordal bipartite graphs. In the minimum total domination problem, the objective is to find a smallest size subset TD ⊆ V of a given graph G = (V, E) such that |TD∩NG(v)| ≥ 1 for every v ∈ V. In the minimum signed (minus) total domination problem for a graph G = (V, E), it is required to find a function f : V → {-1, 1} ({-1, 0, 1}) such that f(NG(v)) = ∑u∈NG(v)f(u) ≥ 1 for each v ∈ V, and the cost f(V) = ∑v∈V f(v) is minimized. We first show that for a given chordal bipartite graph G = (V, E) with a weak elimination ordering, a minimum total dominating set can be computed in O(n + m) time, where n = |V| and m = |E|. This improves the complexity of the minimum total domination problem for chordal bipartite graphs from O(n2) time to O(n + m) time. We then adopt a unified approach to solve the minimum signed (minus) total domination problem for chordal bipartite graphs in O(n + m) time. The method is also able to solve the minimum k-tuple total domination problem for chordal bipartite graphs in O(n + m) time. For a fixed integer k ≥ 1 and a graph G = (V, E), the minimum k-tuple total domination problem is to find a smallest subset TDk ⊆ V such that |TDk ∩ NG(v)| ≥ k for every v ∈ V.
HOW LARGE ARE THE IMPACTS OF CARBON MOTIVATED BORDER TAX ADJUSTMENTS?
Authors: DONG YAN , WALLEY JOHN
Published: August 2012

This paper discusses the size of impact of carbon motivated border tax adjustments on world trade and welfare. We report numerical simulation results which suggest that impacts on welfare, trade, and emissions will likely be small. This is because proposed measures use carbon emissions in the importing country in producing goods similar to imports rather than carbon content in calculating the size of barriers. Moreover, because border adjustments involve both tariffs and export rebates, it is the differences in emissions intensity across sector rather than emissions level which matters. Where there is no difference in emissions intensities across sectors, Lerner symmetry holds for the border adjustment and no relative effects occur.
A COMPUTABLE GENERAL EQUILIBRIUM ANALYSIS OF BORDER ADJUSTMENTS UNDER THE CAP-AND-TRADE SYSTEM: A CASE STUDY OF THE JAPANESE ECONOMY
Authors: TAKEDA SHIRO , TETSUYA HORIE , ARIMURA TOSHI H.
Published: August 2012

Using a multi-region and multi-sector computable general equilibrium model, this paper evaluates the border adjustment policies of carbon regulations in Japan. We consider five types of border adjustments and examine their effects on the welfare, carbon leakage, and competitiveness of the Japanese energy-intensive trade-exposed (EITE) sectors.

Our analysis shows that no single border adjustment policy is superior to the other policies in terms of simultaneously solving three primary issues: Welfare degradation, carbon leakage, and a loss of competitiveness in the EITE sectors. In addition, we show that export border adjustments are effective at restoring the competitiveness of Japanese exporters and reducing leakage. Our analysis also reveals that border adjustment in Japan significantly affects carbon leakage to China and the competitiveness of the iron and steel sectors. Finally, we show that border adjustments with and without consideration of indirect emissions have similar impacts, which indicates that the information regarding direct emissions is sufficient for implementing border adjustment in Japan.
Relating petroleum system and play development to basin evolution: Brazilian South Atlantic margin
Authors: Beglinger Suzanne E. , Doust Harry , Cloetingh Sierd
Published: August 2012

We review the structural genesis and evolutionary history of basins along the Brazilian South Atlantic margin from the Sergipe-Alagoas (north) to the Pelotas basin (south), and demonstrate the links with petroleum system and play development. In our approach, we first break basins down into their tectonostratigraphic megasequences and define their characteristics, particularly focused on the development of characteristic source- and reservoir-rock intervals. We then compare these megasequences with similar types of megasequences in other basins, thereby providing a means to learn through a greater population of analogues. We demonstrate, using trajectory plots, that these basins experienced a similar tectonostratigraphic basin evolution, resulting in the deposition of many analogue potential source- and reservoir-rock intervals. These give rise to the development of similar types of potential petroleum systems and play (level)s. Although the area is currently being actively explored, large areas remain poorly understood, with unknown source-rock maturity distributions and many unknown/untested reservoirs/plays. This approach allows us to make analogue comparisons between the Brazilian marginal basins in order to evaluate and predict the presence of potential, yet undiscovered or under-explored, hydrocarbon accumulations.

Supplementary material:

Published source-rock and play properties used in this analysis are available at
http://www.geolsoc.org.uk/SUP18536
Controls on improved sub-salt reservoir imaging at the giant Karachaganak Field, Kazakhstan
Authors: Eales Martin , Daley Timothy , Morosini Michele , Marples Timothy , Sim Lee King
Published: August 2012

In western Kazakhstan there are several world class hydrocarbon fields, including the onshore Karachaganak Field. The geological setting is very challenging for the seismic imaging techniques where deep carbonate platform targets underlie a complex overburden including diapiric and detached salt structures. Furthermore, the extensive oil field infrastructure generates a noisy environment for seismic acquisition and reduced access for vibroseis trucks.

KPO conducted an extensive integrated feasibility study for a new survey, complemented by a seismic acquisition test in 2008 which confirmed the need for dense source and receiver coverage, long offsets and wide azimuths to optimize imaging of the pre-salt targets. The survey was acquired in 2009 and survey execution exceeded local and international standards. It was the highest channel survey acquired in Kazakhstan and when fully depth image processed it will yield a high spatially sampled seismic volume, with improved resolution and structural definition. The application of the latest technology and techniques will enable better characterization of this complex carbonate reservoir, adding future value by better placement of wells and reducing overall costs for the ongoing development of the field.
Continuous deep microseismic monitoring of the Karachaganak Field, Kazakhstan: integrating reservoir geoscience, drilling and engineering
Authors: Morosini M. , Daley T. , Eales M. , Boivineau A. S. , Nicou C. , Jupe A.
Published: August 2012

The Karachaganak Field is an oil and gas condensate supergiant field located in the western Kazakhstan Pricaspian Basin. As part of the challenge to improve reservoir knowledge, KPO has been continuously monitoring the reservoir using a microseismic array deployed downhole since February 2009. Continuous deep recording of microseismic activity is an innovative technique for reservoir monitoring; progressive refinements were made to fine-tune the acquisition and processing techniques. By December 2010, 8074 events had been detected and, from this group, 2556 events have been located. Events within the reservoir were recorded up to 8 km from the array to a depth of 5 km with moment magnitudes (Mw) ranging from −2.4 to +1. Microseismic events are continuously located and their spatial and temporal distribution analysed. This basic analysis is the input to an integrated study that considers the static model for the reservoir, in addition to dynamic and operational aspects such as production and injection rates, pressure baffles, drilling behaviour and casing perforations. The results to date indicate valuable reservoir information concerning the location of lateral and vertical reservoir pressure baffles and delineation of zones of instability at the reservoir–seal interface, important for well integrity issues. This new information is helping to improve dynamic and geomechanical reservoir models and also wellbore stability predictions.

This article presents the details of the Karachaganak microseismic array and how microseismic events were located. Discussion follows on the interpretation and the possible impact on reservoir monitoring and drilling. The Karachaganak array is one of the deepest installations of a passive microseismic monitoring system and also represents one of the longer periods of continuous monitoring, with two years of data available.
New insights into hydrocarbon plays in the Caspian Sea, Kazakhstan
Authors: Okere Davies , Toothill Steve
Published: August 2012

New exploration opportunities and improved imaging of already known prospects in the Caspian Sea, Kazakhstan, are presented, based on the acquisition, processing and interpretation of long-offset 2D seismic data acquired by CGGVeritas from 2006–2009. We have identified further examples of three already successful plays in the Caspian Sea and onshore, within open blocks in the North Caspian and North Ustyurt basins and a fourth, relatively unknown play, in the North Ustyurt basin. The already known plays include Devono-Carboniferous carbonate reefs and clastics, Triassic–Tertiary post-salt clastics and carbonates in the North Caspian basin and Jurassic–Cretaceous post-thrust clastics and carbonates in the North Ustyurt basin. The fourth play that we have identified comprises thrust faults, anticlinal structures with Late Palaeozoic–Early Mesozoic clastic and carbonate reservoirs in the North Ustyurt basin which, to our knowledge, has not been tested elsewhere in the region.
Appraisal of reservoir compartmentalization using fluid mixing time-scales: Horn Mountain Field, Gulf of Mexico
Authors: Go Jason , Smalley P. Craig , Muggeridge Ann
Published: August 2012

Reservoir compartmentalization can seriously compromise a project’s economics if left undetected during appraisal. Its early identification is made more likely if maximum use is made of available fluid appraisal data. This involves making a critical comparison of time-scales for various fluid properties to equilibrate compared with the actual time since those properties were initially disturbed. Spatially varying fluid properties indicate compartmentalization if they have existed for longer than the time needed for them to equilibrate.

Here we use data from appraisal wells and reservoir mixing time-scales to investigate vertical and horizontal compartmentalization in the Horn Mountain Field (Gulf of Mexico) and to quantify the properties of the baffles/barriers identified. We compare our results with earlier work using time-lapse geochemistry and mud gas isotope logging. Present fluid compositional variations in the field are shown not to be diagnostic of horizontal compartmentalization as the mixing time-scales by molecular diffusion are longer than the time since the reservoir filled. In contrast, pressure shifts and density differences are diagnostic. They indicate that faults within the Horn Mountain Field are relatively impermeable and would act as barriers during oil production. They also confirm that a shale-filled channel acts as a barrier to vertical flow.
Optimizing locomotion controllers using biologically-based actuators and objectives
Authors: Wang Jack M. , Hamner Samuel R. , Delp Scott L. , Koltun Vladlen
Published: August 2012

We present a technique for automatically synthesizing walking and running controllers for physically-simulated 3D humanoid characters. The sagittal hip, knee, and ankle degrees-of-freedom are actuated using a set of eight Hill-type musculotendon models in each leg, with biologically-motivated control laws. The parameters of these control laws are set by an optimization procedure that satisfies a number of locomotion task terms while minimizing a biological model of metabolic energy expenditure. We show that the use of biologically-based actuators and objectives measurably increases the realism of gaits generated by locomotion controllers that operate without the use of motion capture data, and that metabolic energy expenditure provides a simple and unifying measurement of effort that can be used for both walking and running control optimization.
Soft body locomotion
Authors: Tan Jie , Turk Greg , Liu C. Karen
Published: August 2012

We present a physically-based system to simulate and control the locomotion of soft body characters without skeletons. We use the finite element method to simulate the deformation of the soft body, and we instrument a character with muscle fibers to allow it to actively control its shape. To perform locomotion, we use a variety of intuitive controls such as moving a point on the character, specifying the center of mass or the angular momentum, and maintaining balance. These controllers yield an objective function that is passed to our optimization solver, which handles convex quadratic program with linear complementarity constraints. This solver determines the new muscle fiber lengths, and moreover it determines whether each point of contact should remain static, slide, or lift away from the floor. Our system can automatically find an appropriate combination of muscle contractions that enables a soft character to fulfill various locomotion tasks, including walking, jumping, crawling, rolling and balancing.
Video-based 3D motion capture through biped control
Authors: Vondrak Marek , Sigal Leonid , Hodgins Jessica , Jenkins Odest
Published: August 2012

Marker-less motion capture is a challenging problem, particularly when only monocular video is available. We estimate human motion from monocular video by recovering three-dimensional controllers capable of implicitly simulating the observed human behavior and replaying this behavior in other environments and under physical perturbations. Our approach employs a state-space biped controller with a balance feedback mechanism that encodes control as a sequence of simple control tasks. Transitions among these tasks are triggered on time and on proprioceptive events (
e.g
., contact). Inference takes the form of optimal control where we optimize a high-dimensional vector of control parameters and the structure of the controller based on an objective function that compares the resulting simulated motion with input observations. We illustrate our approach by automatically estimating controllers for a variety of motions directly from monocular video. We show that the estimation of controller structure through incremental optimization and refinement leads to controllers that are more stable and that better approximate the reference motion. We demonstrate our approach by capturing sequences of walking, jumping, and gymnastics.
Schelling points on 3D surface meshes
Authors: Chen Xiaobai , Saparov Abulhair , Pang Bill , Funkhouser Thomas
Published: August 2012

This paper investigates "Schelling points" on 3D meshes, feature points selected by people in a pure coordination game due to their salience. To collect data for this investigation, we designed an online experiment that asked people to select points on 3D surfaces that they expect will be selected by other people. We then analyzed properties of the selected points, finding that: 1) Schelling point sets are usually highly symmetric, and 2) local curvature properties (e.g., Gauss curvature) are most helpful for identifying obvious Schelling points (tips of protrusions), but 3) global properties (e.g., segment centeredness, proximity to a symmetry axis, etc.) are required to explain more subtle features. Based on these observations, we use regression analysis to combine multiple properties into an analytical model that predicts where Schelling points are likely to be on new meshes. We find that this model benefits from a variety of surface properties, particularly when training data comes from examples in the same object class.
Sketch-based shape retrieval
Authors: Eitz Mathias , Richter Ronald , Boubekeur Tamy , Hildebrand Kristian , Alexa Marc
Published: August 2012

We develop a system for 3D object retrieval based on sketched feature lines as input. For objective evaluation, we collect a large number of query sketches from human users that are related to an existing data base of objects. The sketches turn out to be generally quite abstract with large local and global deviations from the original shape. Based on this observation, we decide to use a bag-of-features approach over computer generated line drawings of the objects. We develop a targeted feature transform based on Gabor filters for this system. We can show objectively that this transform is better suited than other approaches from the literature developed for similar tasks. Moreover, we demonstrate how to optimize the parameters of our, as well as other approaches, based on the gathered sketches. In the resulting comparison, our approach is significantly better than any other system described so far.
Practical temporal consistency for image-based graphics applications
Authors: Lang Manuel , Wang Oliver , Aydin Tunc , Smolic Aljoscha , Gross Markus
Published: August 2012

We present an efficient and simple method for introducing temporal consistency to a large class of optimization driven image-based computer graphics problems. Our method extends recent work in edge-aware filtering, approximating costly global regularization with a fast iterative joint filtering operation. Using this representation, we can achieve tremendous efficiency gains both in terms of memory requirements and running time. This enables us to process entire shots at once, taking advantage of supporting information that exists across far away frames, something that is difficult with existing approaches due to the computational burden of video data. Our method is able to filter along motion paths using an iterative approach that simultaneously uses and estimates per-pixel optical flow vectors. We demonstrate its utility by creating temporally consistent results for a number of applications including optical flow, disparity estimation, colorization, scribble propagation, sparse data up-sampling, and visual saliency computation.
DRAPE
Authors: Guan Peng , Reiss Loretta , Hirshberg David A. , Weiss Alexander , Black Michael J.
Published: August 2012

We describe a complete system for animating realistic clothing on synthetic bodies of any shape and pose without manual intervention. The key component of the method is a model of clothing called DRAPE (DRessing Any PErson) that is learned from a physics-based simulation of clothing on bodies of different shapes and poses. The DRAPE model has the desirable property of "factoring" clothing deformations due to body shape from those due to pose variation. This factorization provides an approximation to the physical clothing deformation and greatly simplifies clothing synthesis. Given a parameterized model of the human body with known shape and pose parameters, we describe an algorithm that dresses the body with a garment that is customized to fit and possesses realistic wrinkles. DRAPE can be used to dress static bodies or animated sequences with a learned model of the cloth dynamics. Since the method is fully automated, it is appropriate for dressing large numbers of virtual characters of varying shape. The method is significantly more efficient than physical simulation.
3D imaging spectroscopy for measuring hyperspectral patterns on solid objects
Authors: Kim Min H. , Harvey Todd Alan , Kittle David S. , Rushmeier Holly , Dorsey Julie , Prum Richard O. , Brady David J.
Published: August 2012

Sophisticated methods for true spectral rendering have been developed in computer graphics to produce highly accurate images. In addition to traditional applications in visualizing appearance, such methods have potential applications in many areas of scientific study. In particular, we are motivated by the application of studying avian vision and appearance. An obstacle to using graphics in this application is the lack of reliable input data. We introduce an end-to-end measurement system for capturing spectral data on 3D objects. We present the modification of a recently developed hyperspectral imager to make it suitable for acquiring such data in a wide spectral range at high spectral and spatial resolution. We capture four megapixel images, with data at each pixel from the near-ultraviolet (359 nm) to near-infrared (1,003 nm) at 12 nm spectral resolution. We fully characterize the imaging system, and document its accuracy. This imager is integrated into a 3D scanning system to enable the measurement of the diffuse spectral reflectance and fluorescence of specimens. We demonstrate the use of this measurement system in the study of the interplay between the visual capabilities and appearance of birds. We show further the use of the system in gaining insight into artifacts from geology and cultural heritage.
Primal-dual coding to probe light transport
Authors: O'Toole Matthew , Raskar Ramesh , Kutulakos Kiriakos N.
Published: August 2012

We present
primal-dual coding
, a photography technique that enables direct fine-grain control over which light paths contribute to a photo. We achieve this by projecting a sequence of patterns onto the scene while the sensor is exposed to light. At the same time, a second sequence of patterns, derived from the first and applied in lockstep, modulates the light received at individual sensor pixels. We show that photography in this regime is equivalent to a
matrix probing
operation in which the elements of the scene's transport matrix are individually re-scaled and then mapped to the photo. This makes it possible to directly acquire photos in which specific light transport paths have been blocked, attenuated or enhanced. We show captured photos for several scenes with challenging light transport effects, including specular inter-reflections, caustics, diffuse inter-reflections and volumetric scattering. A key feature of primal-dual coding is that it operates almost exclusively in the optical domain: our results consist of directly-acquired, unprocessed RAW photos or differences between them.
Discovery of complex behaviors through contact-invariant optimization
Authors: Mordatch Igor , Todorov Emanuel , Popović Zoran
Published: August 2012

We present a motion synthesis framework capable of producing a wide variety of important human behaviors that have rarely been studied, including getting up from the ground, crawling, climbing, moving heavy objects, acrobatics (hand-stands in particular), and various cooperative actions involving two characters and their manipulation of the environment. Our framework is not specific to humans, but applies to characters of arbitrary morphology and limb configuration. The approach is fully automatic and does not require domain knowledge specific to each behavior. It also does not require pre-existing examples or motion capture data.

At the core of our framework is the contact-invariant optimization (CIO) method we introduce here. It enables simultaneous optimization of contact and behavior. This is done by augmenting the search space with scalar variables that indicate whether a potential contact should be active in a given phase of the movement. These auxiliary variables affect not only the cost function but also the dynamics (by enabling and disabling contact forces), and are optimized together with the movement trajectory. Additional innovations include a continuation scheme allowing helper forces at the potential contacts rather than the torso, as well as a feature-based model of physics which is particularly well-suited to the CIO framework. We expect that CIO can also be used with a full physics model, but leave that extension for future work.
How do humans sketch objects?
Authors: Eitz Mathias , Hays James , Alexa Marc
Published: August 2012

Humans have used sketching to depict our visual world since prehistoric times. Even today, sketching is possibly the only rendering technique readily available to all humans. This paper is the first large scale exploration of human sketches. We analyze the distribution of non-expert sketches of everyday objects such as 'teapot' or 'car'. We ask humans to sketch objects of a given category and gather 20,000 unique sketches evenly distributed over 250 object categories. With this dataset we perform a perceptual study and find that humans can correctly identify the object category of a sketch 73% of the time. We compare human performance against computational recognition methods. We develop a bag-of-features sketch representation and use multi-class support vector machines, trained on our sketch dataset, to classify sketches. The resulting recognition method is able to identify unknown sketches with 56% accuracy (chance is 0.4%). Based on the computational model, we demonstrate an interactive sketch recognition system. We release the complete crowd-sourced dataset of sketches to the community.
CrossShade
Authors: Shao Cloud , Bousseau Adrien , Sheffer Alla , Singh Karan
Published: August 2012

We facilitate the creation of 3D-looking shaded production drawings from concept sketches. The key to our approach is a class of commonly used construction curves known as
cross-sections
, that function as an aid to both sketch creation and viewer understanding of the depicted 3D shape. In particular, intersections of these curves, or
cross-hairs
, convey valuable 3D information, that viewers compose into a mental model of the overall sketch. We use the artist-drawn cross-sections to automatically infer the 3D normals across the sketch, enabling 3D-like rendering.

The technical contribution of our work is twofold. First, we distill artistic guidelines for drawing cross-sections and insights from perception literature to introduce an explicit mathematical formulation of the relationships between cross-section curves and the geometry they aim to convey. We then use these relationships to develop an algorithm for estimating a normal field from cross-section curve networks and other curves present in concept sketches. We validate our formulation and algorithm through a user study and a ground truth normal comparison. As demonstrated by the examples throughout the paper, these contributions enable us to shade a wide range of concept sketches with a variety of rendering styles.
HelpingHand
Authors: Lu Jingwan , Yu Fisher , Finkelstein Adam , DiVerdi Stephen
Published: August 2012

Digital painters commonly use a tablet and stylus to drive software like Adobe Photoshop. A high quality stylus with 6 degrees of freedom (DOFs: 2D position, pressure, 2D tilt, and 1D rotation) coupled to a virtual brush simulation engine allows skilled users to produce expressive strokes in their own style. However, such devices are difficult for novices to control, and many people draw with less expensive (lower DOF) input devices. This paper presents a data-driven approach for synthesizing the 6D hand gesture data for users of low-quality input devices. Offline, we collect a library of strokes with 6D data created by trained artists. Online, given a query stroke as a series of 2D positions, we synthesize the 4D hand pose data at each sample based on samples from the library that locally match the query. This framework optionally can also modify the stroke trajectory to match characteristic shapes in the style of the library. Our algorithm outputs a 6D trajectory that can be fed into any virtual brush stroke engine to make expressive strokes for novices or users of limited hardware.
Fabricating articulated characters from skinned meshes
Authors: Bächer Moritz , Bickel Bernd , James Doug L. , Pfister Hanspeter
Published: August 2012

Articulated deformable characters are widespread in computer animation. Unfortunately, we lack methods for their automatic fabrication using modern additive manufacturing (AM) technologies. We propose a method that takes a skinned mesh as input, then estimates a fabricatable single-material model that approximates the 3D kinematics of the corresponding virtual articulated character in a piecewise linear manner. We first extract a set of potential joint locations. From this set, together with optional, user-specified range constraints, we then estimate mechanical friction joints that satisfy inter-joint non-penetration and other fabrication constraints. To avoid brittle joint designs, we place joint centers on an approximate medial axis representation of the input geometry, and maximize each joint's minimal cross-sectional area. We provide several demonstrations, manufactured as single, assembled pieces using 3D printers.
Stress relief
Authors: Stava Ondrej , Vanek Juraj , Benes Bedrich , Carr Nathan , Měch Radomír
Published: August 2012

The use of 3D printing has rapidly expanded in the past couple of years. It is now possible to produce 3D-printed objects with exceptionally high fidelity and precision. However, although the quality of 3D printing has improved, both the time to print and the material costs have remained high. Moreover, there is no guarantee that a printed model is structurally sound. The printed product often does not survive cleaning, transportation, or handling, or it may even collapse under its own weight. We present a system that addresses this issue by providing automatic detection and correction of the problematic cases. The structural problems are detected by combining a lightweight structural analysis solver with 3D medial axis approximations. After areas with high structural stress are found, the model is corrected by combining three approaches: hollowing, thickening, and strut insertion. Both detection and correction steps are repeated until the problems have been eliminated. Our process is designed to create a model that is visually similar to the original model but possessing greater structural integrity.
Beady
Authors: Igarashi Yuki , Igarashi Takeo , Mitani Jun
Published: August 2012

We introduce the interactive system "Beady" to assist the design and construction of customized 3D beadwork. The user first creates a polygonal mesh model called the design model that represents the overall structure of the beadwork. Each edge of the mesh model corresponds to a bead in the beadwork. We provide two methods to create the design model. One is interactive modeling from scratch. The user defines the mesh topology with gestural interaction and the system continuously adjusts edge lengths by considering the physical constraints among neighboring beads. The other is automatic conversion that takes an existing polygonal model as input and generates a near-hexagonal mesh model with a near-uniform edge length as output. The system then converts the design model into a beadwork model with the appropriate wiring. Computation of an appropriate wiring path requires careful consideration, and we present an algorithm based on face stripification of the mesh. The system also provides a visual step-by-step guide to assist the manual beadwork construction process. We show several beadwork designs constructed by the authors and by test users using the system.