Real-time resolution of self-intersection in dynamic cylindrical free-form deformation

This paper presents a method of self-intersection detection and resolution for dynamic cylindrical-lattice-based free-form deformation (FFD). The lattice-based approach allows efficient computation of deformation of complex geometries. But excessive deformation can cause visual anomalies such as surface infiltration and distortion. This paper derives a geometrically intuitive sufficient condition to guarantee that the FFD function is a homeomorphism and there is no self-intersection. The FFD function is defined by linear and quadratic B-Spline functions with the control points of the cylindrical lattice cell. The sufficient condition is satisfied if each trilinear function of the nine prism-shaped pentahedrons derived from the cell has a positive Jacobian determinant. The positivity is satisfied if the 12 tetrahedrons derived from the pentahedron have positive volumes. Based on the sufficient condition, the proposed method converts the self-intersection problem into a point-face collision detection and response problem suitable for dynamic simulation. The efficiency and accuracy of the self-intersection detection algorithm is analyzed and compared with a previous method. The results show that the proposed technique allows simulation of excessive deformation of tubular objects in an efficient and realistic manner.     

A dual‐polarized cylindrical conformal array antenna suitable for unmanned aerial vehicles

A dual‐polarized X‐band conformal array antenna is presented for unmanned aerial vehicles with polarimetric radars/sensors. Starting from the planar structure, the array antenna consisted of sixteen 2 × 2 subarrays is conformal to the cylinders with various curvature radii to fit the payload box of the airborne vehicle. The return losses are almost constant even if the curvature radius changes. Measured radiation patterns are compared with various curvatures at the same frequencies. The array can be easily placed on the aircraft payload or fuselage due to its ultra thin thickness, ultra lightweight, and conformal structure, which has potential airborne applications in polarimetric radar surveillance, remote sensing, and wireless communications. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

A playmate robot system for playing the rock-paper-scissors game with humans

We have developed a playmate robot system for playing the rock-paper-scissors game with humans. The playmate robot recognizes the hand motions of a human using image processing without attaching any additional units to the human. The playmate robot system consists of three parts: a game management part, a hand motion recognition part, and a robot hand control part. The system functions as follows. (1) Before the game is played, the game management part decides on the motion of the robot hand from amongst rock, paper, and scissors. After the game is played, the robot develops a reaction using speech and facial expressions depending on the result of the game. (2) The hand motion recognition part recognizes the hand motion of the human. It does not use any additional units on the human’s body, only a camera on the robot. (3) The robot hand control part shows the motion of the robot hand. A robot hand has four fingers that are controlled independently. We have played the rock-paper-scissors game with this playmate robot.     

Laser marking system for light guide panel using design of experiment and web-based prototyping

A light guide panel (LGP) is an element of the liquid crystal display (LCD) back light unit (BLU), which is used for display devices. In this study, the laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected. A web-based design tool was developed to generate patterns of light guide panel via the network, and the tool may assist the designer to develop various prototype patterns. Topcon-BM7 was used for luminance measurement of each specimen with 100 mm×100 mm area. By Taguchi method, optimized levels of each parameter were found, and luminance of 3523 cd/cm² and uniformity of 92% were achieved using the laser machined BLU.     

Impact of a simple load balancing approach and an incentive-based scheme on MANET performance

Most reactive mobile ad hoc network (MANET) routing protocols such as AODV and DSR do not perform search for new routes until the network topology changes. But, low node mobility does not affect the MANET connectivity and the same routes may be used for a long time. This may cause concentration of traffic on few mobile stations (MSs), which results in congestion and hence longer end-to-end delay. In addition, continuous use of MSs may cause their battery power to get exhausted rapidly. Expiration of MS energy causes disruption of connections traversing through the MSs and could generate many simultaneous new routing requests. Therefore, we propose a load balancing approach called Simple Load Balancing Approach (SLBA), which can be transparently added to any current reactive routing protocol such as AODV and DSR. SLBA minimizes the traffic concentration by allowing each MS to drop RREQ or to give up packet forwarding depending on its own traffic load. Meanwhile, MSs may deliberately give up forwarding packets to save their own energy. For encouraging MSs to volunteer in forwarding packets, we introduce a reward scheme for packet forwarding, named Protocol-Independent Fairness Algorithm (PIFA). We compare the performance of AODV and DSR with and without SLBA and PIFA. Simulation results indicate that SLBA can distribute traffic very well and improve the MANET performance. PIFA is also observed to prevent MANET partitioning and any performance degradation due to selfish nodes.     

Two versions of architectures for dynamic implied addressing mode

The complexity of today’s embedded applications increases with various requirements such as execution time, code size or power consumption. To satisfy these requirements for performance, efficient instruction set design is one of the important issues because an instruction customized for specific applications can make better performance than multiple instructions in aspect of fast execution time, decrease of code size, and low power consumption. Limited encoding space, however, does not allow adding application specific and complex instructions freely to the instruction set architecture. To resolve this problem, conventional architectures increases free space for encoding by trimming excessive bits required beyond the fixed word length. This approach however shows severe weakness in terms of the complexity of compiler, code size and execution time. In this paper, we propose a new instruction encoding scheme based on the dynamic implied addressing mode (DIAM) to resolve limited encoding space and side-effect by trimming. We report our two versions of architectures to support our DIAM-based approach. In the first version, we use a special on-chip memory to store extra encoding information. In the second version, we replace the memory by a small on-chip buffer along with a special instruction. We also suggest a code generation algorithm to fully utilize DIAM. In our experiment, the architecture augmented with DIAM shows about 8% code size reduction and 18% speed up on average, as compared to the basic architecture without DIAM.     

Pattern recognition using feature feedback: Application to face recognition

In this paper, we propose a new pattern recognition method using feature feedback and present its application to face recognition. Conventional pattern recognition methods extract the features employed for classification using PCA, LDA and so on. On the other hand, in the proposed method, the extracted features are analyzed in the original space using feature feedback. Using reverse mapping from the extracted features to the original space, we can identify the important part of the original data that affects the classification. In this way, we can modify the data to obtain a higher classification rate, make it more compact or abbreviate the required sensors. To verify the applicability of the proposed method, we apply it to face recognition using the Yale Face Database. Each face image is divided into two parts, the important part and unimportant part, using feature feedback, and the classification performed using the feature mask obtained from feature feedback. Also, we combine face recognition with image compression. The experimental results show that the proposed method works well.     

Efficient RNTS system for privacy of banking off-line customer

With the development in IT technology and with growing demands of users, a ubiquitous environment is being made. Because individual identification is important in ubiquitous environment, RFID technology would be used frequently. RFID is a radio frequency identification technology to replace bar code. The reader transmits query (request of user information) and tag-provides user information. RFID has various advantages, such as high speed identification rates, mass memory storages. However, eavesdropping is possible as well as a problem that user information is exposed (Juels et al. in Conference on Computer and Communications Security—ACM CCS, pp. 103–111, 2003; Ohkubo et al. in RFID Privacy Workshop 2003; Weis et al. in International Conference on Security in Pervasive Computing, pp. 201–212, 2003; Weis et al. in Cryptographic Hardware and Embedded Systems—CHES, pp. 454–469, 2002). Therefore, when off-line customer had visited bank for banking service, RNTS (RFID number ticket service) system provides both anonymity in customer identification and efficiency of banking service. In addition, RNTS system protects privacy of an off-line user visiting the bank and it is an efficient method offering service in order of arriving in the bank.     

Global optimization of case-based reasoning for breast cytology diagnosis

Case-based reasoning (CBR) is one of the most popular prediction techniques in medical domains because it is easy to apply, has no possibility of overfitting, and provides a good explanation for the output. However, it has a critical limitation – its prediction performance is generally lower than other AI techniques like artificial neural networks (ANN). In order to obtain accurate results from CBR, effective retrieval and matching of useful prior cases for the problem is essential, but it is still a controversial issue to design a good matching and retrieval mechanism for CBR systems. In this study, we propose a novel approach to enhance the prediction performance of CBR. Our suggestion is the simultaneous optimization of feature weights, instance selection, and the number of neighbors that combine using genetic algorithms (GA). Our model improves the prediction performance in three ways – (1) measuring similarity between cases more accurately by considering relative importance of each feature, (2) eliminating useless or erroneous reference cases, and (3) combining several similar cases represent significant patterns. To validate the usefulness of our model, this study applied it to a real-world case for evaluating cytological features derived directly from a digital scan of breast fine needle aspirate (FNA) slides. Experimental results showed that the prediction accuracy of conventional CBR may be improved significantly by using our model. We also found that our proposed model outperformed all the other optimized models for CBR using GA.     

Cloud motion in the GOCI/COMS ocean colour data

The Geostationary Ocean Colour Imager (GOCI) instrument, on Korea’s Communications, Oceans, and Meteorological Satellite (COMS), can produce a spectral artefact arising from the motion of clouds – the cloud is spatially shifted and the amount of shift varies by spectral band. The length of time it takes to acquire all eight GOCI bands for a given slot (portion of a scene) is sufficient to require that cloud motion be taken into account to fully mask or correct the effects of clouds in all bands. Inter-band correlations can be used to measure the amount of cloud shift, which can then be used to adjust the cloud mask so that the union of all shifted masks can act as a mask for all bands. This approach reduces the amount of masking required versus a simple expansion of the mask in all directions away from clouds. Cloud motion can also affect regions with unidentified clouds – thin or fractional clouds that evade the cloud identification process – yielding degraded quality in retrieved ocean colour parameters. Areas with moving and unidentified clouds require more elaborate masking algorithms to remove these degraded retrievals. Correction for the effects of moving fractional clouds may also be possible. The cloud shift information can be used to determine cloud motion and thus wind at the cloud levels on sub-minute timescales. The beneficial and negative effects of moving clouds should be considered for any ocean colour instrument design and associated data processing plans.