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.
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.
205485574
Assessing term effectiveness in the interactive information access process
This study addresses the question of whether the way in which sets of query terms are identified has an impact on the effectiveness of users' information seeking efforts. Query terms are text strings used as input to an information access system; they are products of a method or grammar that identifies a set of query terms. We conducted an experiment that compared the effectiveness of sets of query terms identified for a single book by three different methods. One had been previously prepared by a human indexer for a back-of-the-book index. The other two were identified by computer programs that used a combination of linguistic and statistical criteria to extract terms from full text. Effectiveness was measured by (1) whether selected query terms led participants to correct answers and (2) how long it took participants to obtain correct answers. Our results show that two sets of terms - the human terms and the set selected according to the linguistically more sophisticated criteria - were significantly more effective than the third set of terms. This single case demonstrates that query languages do have a measurable impact on the effectiveness of query term languages in the interactive information access process. The procedure described in this paper can be used to assess the effectiveness for information seekers of query terms identified by any query language.
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.
18303917
Asymmetric Demand Information and Channel Profits When Retailers Compete
We consider a supply chain with a single manufacturer selling a single product through two competing retailers. The manufacturer sets the wholesale price, and the retailers set the retail margin, simultaneously. The demand information among the members is asymmetric. The main contribution of this paper is extended the results of [5] with two competing retailers under asymmetric demand information. We consider six cases with the manufacturer or the retailers whether owning the information or not, and analyze these six cases in turn solve for a Bayesian equilibrium. Some results are obtained finally.
17111160
Video Histogram: A Novel Video Signature for Efficient Web Video Duplicate Detection
The explosive growth of information technology and digital content industry stimulates various video applications over the Internet. Since it is quite easy to copy, reformat, modify and republish video files on the websites, similarity/duplicate detection and measurement is essential to identify the excessive content duplication, so as to facilitate effective video search and intelligence propriety protection as well. In this paper, we propose a novel signature-based approach for duplicate video comparison. The so-called video histogram scheme counts the numbers of video’s frames that are closest to a set of representative seed vectors chosen from the feature space of the training data set in advance. Then all the numbers are normalized to generate the signature of the video for further comparison. As our signature is a compact fixed-size vector with low dimension for each video, it requires less storage and computation cost than previous methods. The experiments show that our approach is both efficient and effective for web video duplicate detection.
6386219
The Separation of Duty with Privilege Calculus
This paper presents Privilege Calculus (PC) as a new approach of knowledge representation for Separation of Duty (SD) in the view of process and intents to improve the reconfigurability and traceability of SD. PC presumes that the structure of SD should be reduced to the structure of privilege and then the regulation of system should be analyzed with the help of forms of privilege.