17430531
Interactive Separation of Segmented Bones in CT Volumes Using Graph Cut
We present a fast, interactive method for separating bones that have been collectively segmented from a CT volume. Given user-provided seed points, the method computes the separation as a multi-way cut on a weighted graph constructed from the binary, segmented volume. By properly designing and weighting the graph, we show that the resulting cut can accurately be placed at bone-interfaces using only a small number of seed points even when the data is noisy. The method has been implemented with an interactive graphical interface, and used to separate the 12 human foot bones in 10 CT volumes. The interactive tool produced compatible result with a ground-truth separation, generated by a completely manual labelling procedure, while reducing the human interaction time from a mean of 2.4 hours per volume in manual labelling down to approximately 18 minutes.
1115065
An interactive tool for fitting surfaces to volume data
MRI and CT scanners have long been used to produce threeWe begin with a volume dataset. In this example, we have a CT scan of a human prostate. There are 256 slices. The figure to the right shows one input slice, along with rectangles that outline the locations of every 10th slice. We perform linear interpolation between each slice in the input dataset, and now we can render arbitrarily oriented image planes. The figure to the right shows one such plane.
27964880
Surface reconstruction from point set using projection operator
Step 1: Lay a grid over the input point set. Step 3: Mark all grid edges with projection vectors at their two ends pointing in opposite directions. Approximate the intersection points between the surface and these edges based on the magnitudes of their projection vectors. Step 4: For each grid cell, calculate a grid center as the average of all intersection points. For each marked edge, connect the centers of its incident cells to make a piece of the surface.
13366067
Tarsal and Metatarsal Bone Mineral Density Measurement Using Volumetric Quantitative Computed Tomography
A new method for measuring bone mineral density (BMD) of the tarsal and metatarsals is described using volumetric quantitative computed tomography (VQCT) in subjects with diabetes mellitus and peripheral neuropathy. VQCT images of a single foot were acquired twice from eight subjects (mean age 51 [11 SD], seven males, one female). The cortical shells of the seven tarsal and five metatarsal bones were identified and semiautomatically segmented from adjacent bones. Volume and BMD of each bone were measured separately from the two acquired scans for each subject. Whole-bone semiautomatic segmentation measurement errors were determined as the root mean square coefficient of variation for the volume and BMD of 0.8% and 0.9%, respectively. In addition to the whole-bone segmentation methods, we performed atlas-based partitioning of subregions within the second metatarsal for all subjects, from which the volumes and BMDs were obtained for each subregion. The subregion measurement BMD errors (root mean square coefficient of variation) within the shaft, proximal end, and distal end were shown to vary by approximately 1% between the two scans of each subject. The new methods demonstrated large variations in BMDs between the 12 bones of the foot within a subject and between subjects, and between subregions within the second metatarsal. These methods can provide an important outcome measure for clinical research trials investigating the effects of interventions, aging, or disease progression on bone loss, or gain, in individual foot bones.
42568731
Defining and computing multi-dimensional skeletons
Describing shapes is an important task in graphics and vision. A simple, concise descriptor that captures the essential shape properties of an object would greatly facilitate computer-based understanding of the object and applications such as matching and segmentation. For this reason, medial axes (MA) has become a popular shape descriptor since its introduction by Blum [Blum 1967]. The MA of an N-D object is an (N -- 1)-D geometry centered within the object. For example, the MA of a 2D object consists of medial curves at elongated parts, whereas the MA of a 3D object consists of medial surfaces describing the protrusions on the object.
5384230
A Simulation Platform for Intelligent Scheduling In Automated Container Terminal
The present invention relates generally to a method and apparatus for evaluating the resistivity of invaded formations at high apparent dip angle. A multi-array induction tool having a plurality of arrays is disposed in a borehole. Signals from a subset of coils of the array are selected to probe different volumes of the formation surrounding the borehole. The maximum entropy method is used to process data from the subset of coils to effectively remove distortions produced by shoulder and dip effect in the presence of shallow, moderate, or deep invasion. An advantage of the invention is a computer program that accurately predicts the response of induction arrays in an assumed layered formation with dip. After processing the data, the resulting multi-array induction log will indicate a conductivity profile for the subset of coils which is substantially identical to that of an array in a thick bed, without dip or layering, with the same invasion profile. A 1D radial inversion of the resulting logs at each point in depth will give a closer estimate of the actual formation parameters, Rxo, Rt, and the invasion radius.
41392373
Small-World Peer-to-Peer for Resource Discovery
Small-world phenomenon is potentially useful to improve the performance of resource discovery in decentralized peer-to-peer (P2P) networks. The theory of small-world networks can be adopted in the design of P2P networks: each peer node is connected to some neighbouring nodes, and a group of peer nodes keep a small number of long links to randomly chosen distant peer nodes. However, current unstructured search algorithms have difficulty distinguishing among these random long-range shortcuts and efficiently finding a set of proper long-range links located in itself or its local group for a specific resource search. This paper presents a semi-structured P2P model to efficiently create and find long-range shortcuts toward remote peer groups.
42190506
Three-objective fuzzy chance-constrained programming model for multiproject and multi-item investment combination
This paper presents a new fuzzy chance-constrained programming model to find the solution for multiproject and multi-item investment combination in investment combination problems. The proposed 0-1 integer programming model has three objectives with fuzzy constraints, and NSGA-II is applied to solve the optimization model with a small modification of the constraint-handling rule. A simulation experiment illustrating the application of the proposed model is presented and Pareto-optimal solutions are obtained through a modified NSGA-II algorithm. A comparison among NSGA-II, PSO, and DE shows that modified NSGA-II has some advantages over PSO and DE.
15166655
The Vector Data Management of GIS Based on PDA
Traditionally, vector data of GIS based on PDA is managed with a traditional pyramid model to promote displaying speed. However, this pyramid model does not flexible or practical enough to solve many problems, neither the data file designing and data processing method are discussed before. Therefore, in this paper, an improved pyramid model is proposed and a new data format for the model is designed, also, the data processing method is discussed. The experimental results show that, this solution is practical and efficient.
11138089
Research on System Architecture and Interfaces in Heterogeneous Network Platform
The paper proposes an architecture for heterogeneous network platform based on adaptation layer according to service capability requirements and characteristics of modern service industry. In order to shield the diversity of heterogeneous networks to provide open interfaces in the adaptation layer, an abstract method of service capability is proposed to get a set of SCF components and sub-platforms. The basic service capabilities can be also integrated to generate new services by the service integration method. Some interfaces and service applications illustrate that the abstract method and interfaces are reasonably effective on the platform for the applications of modern service industry.