Predictability of healing of ischemic leg ulcers by radioisotopic and Doppler ultrasonic examination

In a prospective study of twenty-six patients with ischemic ulcerations of the lower extremity, the predictive reliability with regard to spontaneous wound healing of diabetes, pedal pulses, ankle blood pressure (ABP) as measured by doppler ultrasound, and "leg ulcer scan" as performed by the intra-arterial injection of radioactive albumin was evaluated. The results suggest that only the leg ulcer scan is significantly reliable in predicting the likelihood of spontaneous healing. The following format for the evaluation of the ischemic leg ulcer is therefore suggested: (1) If pedal pulses are present, a three week trial of conservative therapy is indicated before further evaluation. (2) If the doppler ABP is 50 mm Hg or less, the ulcer will not heal spontaneously. (3) Leg ulcer scan is indicated: (a) in the absence of pedal pulses if ABP is less than 50 mm Hg; (b) in the presence of pedal pulses if there is no evidence of spontaneous healing after three weeks of conservative therapy.     

Improving Water Supply Outlook in Korea with Ensemble Streamflow Prediction

Abstract

The purpose of this study is to propose an alternative forecasting approach for improving the current water supply outlook in Korea. Using a rainfall-runoff model, the existing technique for the water supply outlook in Korea produces monthly low, average, and high runoff forecasts. The proposed technique is called Ensemble Streamflow Prediction (ESP), and is currently implemented by the National Weather Service in the U.S.A. ESP appears particularly valid in Korea where the historical rainfall record is much more comprehensive than the historical streamflow record. This study applies ESP to runoff forecasting for a river basin in Korea to examine its applicability. An ensemble of one-month ahead runoff forecasts at the Gongju gauging station in the Keum River basin, Korea, was generated for each month. The resulting ESP forecasts were compared with the corresponding observed runoff data as well as the existing forecasts. Although this study is limited to one case study, the following conclusions can be made: (1) the ESP technique dominates the existing forecasting techniques in terms of both systematic and random errors; and (2) ESP is more accurate when high flows occur.     

Part-based spatio-temporal model for multi-person re-identification

In this paper we propose an adaptive part-based spatio-temporal model that characterizes person’s appearance using color and facial features. Face image selection based on low level cues is used to select usable face images to build a face model. Color features that capture the distribution of colors as well as the representative colors are used to build the color model. The model is built over a sequence of frames of an individual and hence captures the characteristic appearance as well as its variations over time. We also address the problem of multiple person re-identification in the absence of calibration data or prior knowledge about the camera layout. Multiple person re-identification is a open set matching problem with a dynamically evolving and open gallery set and an open probe set. Re-identification is posed as a rectangular assignment problem and is solved to find a bijection that minimizes the overall assignment cost. Open and closed set re-identification is tested on 30 videos collected with nine non-overlapping cameras spanning outdoor and indoor areas, with 40 subjects under observation. A false acceptance reduction scheme based on the developed model is also proposed.     

Electron Acoustic Solitons

Electron acoustic solitons in collisionless and weakly relativistic plasmas are studied. The Krylov–Bogoliubov–Mitropolsky perturbative technique is employed to obtain the nonlinear Schrodinger wave equation. We have numerically investigated modulational instability for different values of the streaming velocity. Graphs have been plotted to see the change in amplitude and inverse width by varying different plasma parameters.     

Determining driver visual attention with one camera

This paper presents a system for analyzing human driver visual attention. The system relies on estimation of global motion and color statistics to robustly track a person's head and facial features. The system is fully automatic, it can initialize automatically, and reinitialize when necessary. The system classifies rotation in all viewing directions, detects eye/mouth occlusion, detects eye blinking and eye closure, and recovers the three dimensional gaze of the eyes. In addition, the system is able to track both through occlusion due to eye blinking, and eye closure, large mouth movement, and also through occlusion due to rotation. Even when the face is fully occluded due to rotation, the system does not break down. Further the system is able to track through yawning, which is a large local mouth motion. Finally, results are presented, and future work on how this system can be used for more advanced driver visual attention monitoring is discussed.     

Editorial

Machine Vision and Applications -     

Tri-view morphing

This paper presents an efficient image-based approach to navigate a scene based on only three wide-baseline uncalibrated images without the explicit use of a 3D model. After automatically recovering corresponding points between each pair of images, an accurate trifocal plane is extracted from the trifocal tensor of these three images. Next, based on a small number of feature marks using a friendly GUI, the correct dense disparity maps are obtained by using our trinocular-stereo algorithm. Employing the barycentric warping scheme with the computed disparity, we can generate an arbitrary novel view within a triangle spanned by three camera centers. Furthermore, after self-calibration of the cameras, 3D objects can be correctly augmented into the virtual environment synthesized by the tri-view morphing algorithm. Three applications of the tri-view morphing algorithm are demonstrated. The first one is 4D video synthesis, which can be used to fill in the gap between a few sparsely located video cameras to synthetically generate a video from a virtual moving camera. This synthetic camera can be used to view the dynamic scene from a novel view instead of the original static camera views. The second application is multiple view morphing, where we can seamlessly fly through the scene over a 2D space constructed by more than three cameras. The last one is dynamic scene synthesis using three still images, where several rigid objects may move in any orientation or direction. After segmenting three reference frames into several layers, the novel views in the dynamic scene can be generated by applying our algorithm. Finally, the experiments are presented to illustrate that a series of photo-realistic virtual views can be generated to fly through a virtual environment covered by several static cameras.     

Assembly modeling as an extension of feature-based design

The advantages and limitations of procedural and declarative approaches for product modeling are discussed. Concepts are developed for modeling all levels of product relations with a uniform set of structures and relationships. It is shown that five basic structures,Part-of, Structuring relation, Degrees of freedom, Motion limits, andFit can be used to define relationships between assemblies, parts, features, feature volume primitives, and evaluated boundaries. Generic relations which facilitate constraint specification between target and reference entities are also presented. Methods for the derivation of the location of an assembly unit from high level constraint specifications, such as mating conditions, and techniques for determining the degrees of freedom, motion limits, and assemblability are required. This can be done by uni-directional parameter derivation in the procedural approach, or by symbolic geometric reasoning or numerical equation solution in the declarative approach. The former is less expensive, easy to implement, avoids conflicts, but leads to combinatorial explosion. The latter is general, flexible, decouples constraint specification from validation, but is expensive, and may require conflict resolution.     

Aging effects on the structure and properties of recycled wastepaper fiber cement composites

Dry-processed wastepaper (magazine) fibers possess desirable mechanical characteristics as reinforcing fibers in cement-based matrices; up to 50% of virgin wood fibers have been replaced with wastepaper fibers in cement composites without any significant change in short-term performance characteristics. The large volumes of fibrous cement board used in building construction promise to provide wastepaper with a large-volume and high-value application. In this study, the effects of weathering on the performance of recycled wastepaper fiber-cement composites were investigated through accelerated aging tests simulating natural aging conditions. Microstructural studies were conducted in order to establish the mechanisms of aging in the composite material. These mechanisms provided the basis for the selection of certain refinements in the matrix composition, which were successfully evaluated for the control of weathering effects on the composite material structure and properties. The effects of aging and moisture on composites were best controlled by measures which reduced the calcium hydroxide content of hydration products and improved the watertightness and the structure of interface zones; these refinements were made using relatively high levels of cement replacement with silica fume or through full substitution of Portland cement with a special cement.     

Synthesis, structure and properties of a novel hybrid bimodal network elastomer with inorganic cross-links: The case of silicone–nanocrystalline titania

We describe an innovative concept of synthesizing a novel hybrid bimodal network elastomer with high strength–high ductility combination involving utilization of functionalized nanocrystalline titania as short-chain cross-links between neighboring elastomer chains. This subject is germane both fundamentally and from an application viewpoint. Silicone rubber is selected as the model elastomer. The short-chain cross-links are acrylic acid functionalized nanocrystalline titania that are an integral component of bimodal network structure of the elastomer. To delineate and separate the effects of functionalization from nanoparticle effects, a relative comparison is made between silicone rubber–titania nanocomposite (i.e. containing dispersion of titania as a reinforcement filler) and silicone rubber–titania hybrid network elastomer (i.e. titania as short chain cross-links). An important finding is that the effect of functionalized titania present as short chain cross-links is far more significant than non-functionalized titania present as reinforcement filler, on mechanical behavior. This is presently ascribed to the double bonds introduced to nanocrystalline titania via functionalization with acrylic acid that provide active sites for the cross-linking reaction resulting in inorganic bridging chains. The basic physical mechanisms that govern elastic recovery in hybrid bimodal network elastomer with short chain cross-links of functionalized nanocrystalline inorganic particles are discussed. The hypothesis of the study described here is that the hybrid bimodal network elastomer with short chain cross-links of functionalized nanocrystalline inorganic particles modifies the unimodal long chain network elastomer with consequent increase in modulus and high strength–ductility combination.