5129503
Detailed layer assignment for MCM routing
A new routing environment model, called the k-MCM model, is developed to take into account the unique features of a multilayer MCM, such as the availability of “segmented vias” , and the presence of two “active” or terminal-bearing layers. A detailed layer assignment problem is formulated on the k-MCM model. A fast heuristic algorithm for the layer assignment problem is proposed. and experimental results on twelve test examples with net counts up to 842 are presented.
36602039
A low-power 1.85 GHz 32-bit carry lookahead adder using Dual Path All-N-Logic
We have developed Dual Path All-N-logic (DPANL) and applied to 32-bit adder design for higher performance. The speed enhancement is mainly due to reduced capacitance at each evaluation node of dynamic circuits. Post-layout simulation results show that this adder can operate at frequencies up to 1.85 GHz for 0.35 /spl mu/m 1P4M CMOS technology and is 32.4% faster than the adder using all-N-transistor (ANT). It also consumes 29.2% less power than the ANT adder. A 0.35 /spl mu/m CMOS chip has been fabricated and tested to verify the functionality and performance of the DPANL adder on silicon.
24075467
Analytic transient solution of general MOS circuit primitives
The exact analytic transient solution is presented for a general MOS circuit primitive. In the circuit primitive, I-V characteristics of transistors are modeled by quadratic equations and node voltages by piecewise-linear waveforms. The proposed MOS circuit primitive, of which an inverter is a special case, is shown to be more suitable for switch level and fast timing simulations than the commonly used inverter. For circuit simulation of medium-size digital circuits containing a few hundred transistors, the application of this analytic solution has resulted in two to three orders of speed improvement over the conventional circuit simulator. The speed improvement factor is expected to grow with the circuit size. It is also shown that the exact transient solution of a macromodel which models the charge sharing can be obtained in the same way. >
1671645
Domino logic synthesis minimizing crosstalk
Based on the new concept of crosstalk immunity set (CIS), procedures to minimize capacitive cross-coupling effects are developed for domino logic circuit. The nets in a crosstalk immunity set are free from crosstalk effects for any combination of input vectors. New algorithms for CIS identification and minimization are proposed to maximize the chance of crosstalk minimization in routing step. Our routing algorithm augmented with CIS information searches for optimal solution to minimize maximum crosstalk the circuit would experience. Experimental results show that the reduction of maximum crosstalk is up to 30% with CIS-augmented routing.
36636082
An accurate analytical delay model for BiCMOS driver circuits
An analytical delay model for BiCMOS driver circuits is presented. The model is based on physical device parameters and can be used to estimate both the pull-up and the pull-down times for a variety of circuit configurations. The intrinsic delay associated with the bipolar transistors is taken into consideration by using a charge control model that incorporates the high-injection effects upon the current gain and the base transport factor. Separate sets of delay equations are derived for the pull-up and pull-down transient responses to account for significant differences between the two cases. The comparison with SPICE circuit simulation results shows that the new model predicts the respective delay times with less than 10% error in most cases. The influence of device dimensions upon the driver delay time is also investigated. The model has been applied to find an optimal area allocation between the CMOS and bipolar parts of the driver circuit when the total available area is limited as in the standard cell configuration. >
17977437
Technology independent arbitrary device extractor
This paper presents the technology independent arbitrary device specification language and device extraction algorithm used in our layout extractor iLEX. Device models specified in the device specification language are converted to graphs, and subgraph isomorphism is used to extract device instances in given layouts. Finally, experimental data are provided to show the capability of our device extraction algorithms.
40534720
A robot system that observes and replicates grasping tasks
To alleviate the problem of overwhelming complexity in grasp synthesis and path planning associated with robot task planning, we adopt the approach of teaching the robot by demonstrating in front of it. The system has four components: the observation system, the grasping task recognition module, the task translator and the robot system. The observation system comprises an active multibaseline stereo system and a dataglove. The data stream recorded is then used to track object motion; this paper illustrates how complimentary sensory data can be used for this purpose. The data stream is also interpreted by the grasping task recognition module, which produces higher levels of abstraction to describe both the motion and actions taken in the task. The resulting information are provided to the task translator which creates commands for the robot system to replicate the observed task. In this paper we describe how these components work with special emphasis on the observation system. The robot system that we use to perform the grasping tasks comprises the PUMA 560 arm and the Utah/MIT hand.<<ETX>>
5718915
Determination of motion breakpoints in a task sequence from human hand motion
This paper describes the authors' work on the temporal segmentation of grasping task sequences based on human hand motion. The segmentation process results in the identification of motion breakpoints separating the different constituent phases of the grasping task. A grasping task is composed of three basic phases: pregrasp phase, static grasp phase, and manipulation phase. The authors show that by analyzing the fingertip polygon (preshape) area and the speed of hand movement, they can divide a task into meaningful action segments such as approach object, grasp object, manipulate object, place object, and depart. The authors introduce a measure called the volume sweep rate, which is the product of the fingertip polygon area and the hand speed. The profile of this measure is also used in the determination of the task breakpoints. The temporal task segmentation process is important as it serves as a preprocessing step to the characterization of the task phases. Once the breakpoints have been identified, further analyses such as grasp recognition and object motion extraction can then be carried out.<<ETX>>
956323
Estimating Intrinsic Images from Image Sequences with Biased Illumination
We present a method for estimating intrinsic images from a fixed-viewpoint image sequence captured under changing illumination directions. Previous work on this problem reduces the influence of shadows on reflectance images, but does not address shading effects which can significantly degrade reflectance image estimation under the typically biased sampling of illumination directions. In this paper, we describe how biased illumination sampling leads to biased estimates of reflectance image derivatives. To avoid the effects of illumination bias, we propose a solution that explicitly models spatial and temporal constraints over the image sequence. With this constraint network, our technique minimizes a regularization function that takes advantage of the biased image derivatives to yield reflectance images less influenced by shading.
8347342
Keyword-based document clustering
Document clustering is an aggregation of related documents to a cluster based on the similarity evaluation task between documents and the representatives of clusters. Terms and their discriminating features of terms are the clue to the clustering and the discriminating features are based on the term and document frequencies. Feature selection method on the basis of frequency statistics has a limitation to the enhancement of the clustering algorithm because it does not consider the contents of the cluster objects. In this paper, we adopt a content-based analytic approach to refine the similarity computation and propose a keyword-based clustering algorithm. Experimental results show that content-based keyword weighting outperforms frequency-based weighting method.
18320279
Stereo matching with reflections and translucency
In this paper, we address the stereo matching problem in the presence of reflections and translucency, where image formation can be modeled as the additive superposition of layers at different depth. The presence of such effects violates the Lambertian assumption underlying traditional stereo vision algorithms, making it impossible to recover component depths using direct color matching based methods. We develop several techniques to estimate both depths and colors of the component layers. Depth hypotheses are enumerated in pairs, one from each layer, in a nested plane sweep. For each pair of depth hypotheses, we compute a component-color-independent matching error per pixel, using a spatial-temporal differencing technique. We then use graph cut optimization to solve for the depths of both layers. This is followed by an iterative color update algorithm whose convergence is proven in our paper. We show convincing results of depth and color estimates for both synthetic and real image sequences.