The aim of this work is to develop an efficient medical image segmentation technique by fitting a nonlinear shape model with pre-segmented images. In this technique, the kernel principle component analysis (KPCA) is used to capture the shape variations and to build the nonlinear shape model. The pre-segmentation is carried out by classifying the image pixels according to the high level texture features extracted using the over-complete wavelet packet decomposition. Additionally, the model fitting is completed using the particle swarm optimization technique (PSO) to adapt the model parameters. The proposed technique is fully automated, is talented to deal with complex shape variations, can efficiently optimize the model to fit the new cases, and is robust to noise and occlusion. In this paper, we demonstrate the proposed technique by implementing it to the liver segmentation from computed tomography (CT) scans and the obtained results are very hopeful.

In this paper, we propose a method for extracting an object boundary from a low-quality image such as an infrared one. To take full advantage of a training set, the overall shape is modeled by incorporating statistical characteristics of moments into the point distribution model (PDM). Furthermore, a differential equation for the moment of overall shape is derived for shape refinement, which leads to accurate and rapid deformation of a boundary template toward real object boundary. The simulation results show that the proposed method has better performance than conventional boundary extraction methods.

This paper addresses the problem of optimizing metalization patterns of back-end connections for the power-MOSFET based driver since the back-end connections tend to dominate the on-resistance Ron of the driver. We propose a heuristic algorithm to seek for better geometric shapes for the patterns targeting at minimizing Ron and at balancing the current distribution. In order to speed up the analysis, the equivalent resistance network of the driver is modified by inserting ideal switches to avoid repeatedly inverting the admittance matrix. With the behavioral model of the ideal switch, we can significantly accelerate the optimization. Simulation on three drivers from industrial TEG data demonstrates that our algorithm can reduce Ron effectively by shaping metals appropriately within a given routing area.

In this study, we introduce shift-invariant sparse image representations using tree-structured dictionaries. Sparse coding is a generative signal model that approximates signals by the linear combinations of atoms in a dictionary. Since a sparsity penalty is introduced during signal approximation and dictionary learning, the dictionary represents the primal structures of the signals. Under the shift-invariance constraint, the dictionary comprises translated structuring elements (SEs). The computational cost and number of atoms in the dictionary increase along with the increasing number of SEs. In this paper, we propose an algorithm for shift-invariant sparse image representation, in which SEs are learnt with a tree-structured approach. By using a tree-structured dictionary, we can reduce the computational cost of the image decomposition to the logarithmic order of the number of SEs. We also present the results of our experiments on the SE learning and the use of our algorithm in image recovery applications.

This letter proposes a new hybrid EM wave absorber with the crossed-wedge shape, which can be applied to 3 m semi anechoic chambers. In this study, we designed a new hybrid EM wave absorber with the crossed-wedge shape, which consisted of the inorganic and organic thin corrugated dielectric lossy sheet containing organic conductive fibers. Then the 3 m semi anechoic chamber is constructed in the size of 9.0 m6.0 m5.7 m (LWH) using these absorbers, and also the normalized site attenuation (NSA) is measured according to ANSI C63.4 in the frequency range of 30 MHz to 1 GHz. As a result, the measured NSA is obtained within 3 dB of the theoretical one.

This letter proposes a high-performance single-sided horn-shaped tapered bowtie antenna which is compact and covers more than the whole UWB frequency band. This design implements a bowtie radiating element and tapered strip-line feeder element on a single-sided dielectric substrate, which offers a measured return loss of less than -10 dB over the whole UWB frequency band of 3.0-10.8 GHz. The measured radiation pattern is bi-directional with consistent gain over the above frequency band. This compact-size design shows much enhanced performance, compared to the previously reported antenna, which is useful for UWB radar and communication applications.

To segment a shape into parts is an important problem in shape representation and analysis. We propose in this paper a novel framework of shape segmentation using deformation models learned from multiple shapes. The deformation model from the target image to every other image is then estimated. Finally, normalized-cut graph partition is applied to the graph constructed based on the similarity of local patches in the target image, and a segmentation of the shape is carried out. Experimental results for images from MPEG7 shape database show the effectiveness of the proposed method.

This letter proposes a new transceiver for OFDM systems based on Smooth Local Trigonometric Transform (LTT). In our transceiver, the transmitter is realized by first modulating the original serial data using a constellation mapper, then feeding the results into the inverse LTT modulator. Unlike the conventional DFT-OFDM system, which always uses the roll cosine function as its window function, the proposed system needs no additional window function for the reason that LTT transform includes a bell-shaped window function by itself. Moreover, each LTT-OFDM symbol has a much more rapid attenuation rate outside of the spectral bandwidth and better spectrum convergence. In the receiver, the original data is recovered by demodulating the received data using forward LTT. Comparative simulation results from the conventional DFT-OFDM system, the system we proposed, and the recently proposed DCT based OFDM system are discussed in terms of bit error rate (BER).

Character projection (CP) lithography is utilized for maskless lithography and is a potential for the future photomask manufacture because it can project ICs much faster than point beam projection or variable-shaped beam (VSB) projection. In this paper, we first present a projection mask set development methodology for multi-column-cell (MCC) systems, in which column-cells can project patterns in parallel with the CP and VSB lithographies. Next, we present an INLP (integer nonlinear programming) model as well as an ILP (integer linear programming) model for optimizing a CP mask set of an MCC projection system so that projection time is reduced. The experimental results show that our optimization has achieved 33.4% less projection time in the best case than a naive CP mask development approach. The experimental results indicate that our CP mask set optimization method has virtually increased cell pattern objects on CP masks and has decreased VSB projection so that it has achieved higher projection throughput than just parallelizing two column-cells with conventional CP masks.

In this paper, a new lifting-based shape-direction-adaptive discrete wavelet transform (SDA-DWT) which can be used for arbitrarily shaped segments is proposed. The SDA-DWT contains three major techniques: the lifting-based DWT, the adaptive directional technique, and the concept of object-based compression in MPEG-4. With SDA-DWT, the number of transformed coefficients is equal to the number of pixels in the arbitrarily shaped segment image, and the spatial correlation across subbands is well preserved. SDA-DWT also can locally adapt its filtering directions according to the texture orientations to improve energy compaction for images containing non-horizontal or non-vertical edge textures. SDA-DWT can be applied to any application that is wavelet based and the lifting technique provides much flexibility for hardware implementation. Experimental results show that, for still object images with rich orientation textures, SDA-DWT outperforms SA-DWT up to 5.88 dB in PSNR under 2.15-bpp (bit / object pixel) condition, and reduces the bit-budget up to 28.5% for lossless compression. SDA-DWT also outperforms DA-DWT up to 5.44 dB in PSNR under 3.28-bpp condition, and reduces the bit-budget up to 14.0%.

A multiband T-shaped monopole antenna for WLAN/WiMAX applications is presented. The T-shaped monopole is comprised of two horizontal arms of different lengths, which generate two separate resonant modes for 2.5/5.5 GHz WLAN/WiMAX bands, and with a shortened parasitic element, which generates a middle resonant mode for 3.5 GHz WiMAX band, for seamless wireless network access applications. The proposed antenna has been successfully simulated and implemented. Both results of simulation and measurement show good agreement. For the lower band from 2.3 to 2.7 GHz, the gain varies in the range of 2.5-3.3 dB, while the radiation efficiency is from 72% to 85% over the band. As for the middle band from 3.3 to 3.7 GHz, the gain varies from 1.5 to 2.0 dB, and the radiation efficiency is from 62% to 70%. As for the upper band from 5.2 to 5.8 GHz, the antenna gain varies from 5.4 to 5.9 dB, and the radiation efficiency is from 63% to 66%.

A design method is proposed for a low-profile dual-shaped reflector antenna for the mobile satellite communications. The antenna is required to be low-profile because of mount restrictions. However, reduction of its height generally causes degradation of antenna performance. Firstly, an initial low-profile reflector antenna with an elliptical aperture is designed by using Geometrical Optics (GO) shaping. Then a Physical Optics (PO) shaping technique is applied to optimize the gain and sidelobes including mitigation of undesired scattering. The developed design method provides highly accurate design procedure for electrically small reflector antennas. Fabrication and measurement of a prototype antenna support the theory.

This paper proposes a novel technique in designing the optimum pulse shape for ultra wideband (UWB) systems under the presence of timing jitter. In the UWB systems, pulse transmission power and timing jitter tolerance are crucial keys to communications success. While there is a strong desire to maximize both of them, one must be traded off against the other. In the literature, much effort has been devoted to separately optimize each of them without considering the drawback to the other. In this paper, both factors are jointly considered. The proposed pulse attains the adequate power to survive the noise floor and at the same time provides good resistance to the timing jitter. The proposed pulse also meets the power spectral mask restriction as prescribed by the Federal Communications Commission (FCC) for indoor UWB systems. Simulation results confirm the advantages of the proposed pulse over other previously known UWB pulses. Parameters of the proposed optimization algorithm are also investigated in this paper.

Burn-in is a widely used method to improve the quality of products or systems after they have been produced. In this paper, optimal burn-in procedures for a system with two types of failures (i.e., minor and catastrophic failures) are investigated. A new system surviving burn-in time b is put into field operation and the system is used under a warranty policy under which the manufacturer agrees to provide a replacement system for any system that fails to achieve a lifetime of at least w. Upper bounds for optimal burn-in time minimizing the total expected warranty cost are obtained under a more general assumption on the shape of the failure rate function which includes the bathtub shaped failure rate function as a special case.

This paper describes a modified ICP registration system of facial point data with range-scanning equipment for medical Augmented Reality applications. The reference facial point data are extracted from the pre-stored CT images; the floating facial point data are captured from range-scanning equipment. A modified soft-shape-context ICP including an adaptive dual AK-D tree for searching the closest point and a modified shape-context objective function is used to register the floating data to reference data to provide the geometric relationship for a medical assistant system and pre-operative training. The adaptive dual AK-D tree searches the closest-point pair and discards insignificant control coupling points by an adaptive distance threshold on the distance between the two returned closest neighbor points which are searched by using AK-D tree search algorithm in two different partition orders. In the objective function of ICP, we utilize the modified soft-shape-context information which is one kind of projection information to enhance the robustness of the objective function. Experiment results of using touch and non-touch capture equipment to capture floating point data are performed to show the superiority of the proposed system.

This paper presents design of an alternating-phase fed single-layer slotted waveguide array for a sector shaped beam in the E-plane radiation pattern. A sector beam pattern is very effective for radar applications for detecting obstacles in a certain angular range without mechanical or electronic scanning. The sector shaped beam with 13 degree beam width is synthesized by a cascade of T-junctions in the feed waveguide which excite the radiating waveguides with a longitudinal shunt slot array. In order to realize the required excitation distribution of the radiating waveguides for the sector shaped beam, 30 T-junctions with symmetrical arrangement are designed by tuning a width of the coupling window, an offset of the window, and a width of the feed waveguide cascaded to the subsequent T-junction, respectively. Design and measurement are performed in 60 GHz band. The prototype antenna assembles easily; the slotted plate is just tacked on the groove feed structure and is fixed by screws at the periphery, which is the key advantage of the alternating-phase fed arrays. The measured sector pattern with low sidelobe level agrees well with the predicted one. Validity of the sector beam design as well as the performance of the alternating-phase fed array is confirmed by the measurement.

The electric fields inside and outside a car must be carefully determined when designing a wireless communication system to be employed in the car. This paper introduces an effective simulation method and a precise measurement method of electric field distributions in a cabin of a simplified scale car model. A 1/3 car model is employed for ease of measurement. The scaled frequency of 2859 MHz, 3 times 953 MHz, is employed. The use of a moment method simulator utilizing the multilevel fast multipole method allows calculations to be performed on a personal computer. In order to judge the accuracy of simulation results, convergence of simulation output in accordance with segment size (triangle edge length) changes is ensured. Simulation loads in the case of metallic body only and a metallic body with window glass are also shown. In the measurements, an optical electric field probe is employed so as to minimize the disturbances that would otherwise be caused by metallic feed cable; precise measurement results are obtained. Comparisons of measured and simulated results demonstrate very good agreement which confirms the accuracy of the calculated results. 3-dimensional electric field distributions in the car model are shown and 3-dimensional standing wave shapes are clarified. Moreover, calculated and measured radiation patterns of the car model are shown so the total electric field distributions around a car are clarified.

A fully integrated 5.8 GHz ETC transceiver LSI has been developed. The transceiver consists of LNA, down-conversion MIX, ASK detector, ASK modulator, DA VCO, and ΔΣ-fractional-N PLL. The features of the transceiver are integrated matching circuitry for LNA input and for DA output, ASK modulator with VGA for local signal control to avoid local leakage and to keep suitable modulation index, and LO circuitry consisting of ΔΣ-fractional-N PLL and interference-robust ∞-shape inductor VCO to diminish magnetic coupling from any other circuitry. Use of these techniques enabled realization of the input and output VSWR of less than 1.25, modulation index of over 95%, and enough qualified TX signals. This transceiver was manufactured by 1P3M SiGe-BiCMOS process with 47 GHz cut-off frequency.

The character projection (CP) lithography is utilized for maskless lithography and is a potential for the future photomask fabrication. The drawback of the CP lithography is its low throughput and leads to a price rise of IC devices. This paper discusses a technology mapping technique for enhancing the throughput of the CP lithography. The number of electron beam (EB) shots to project an entire chip directly determines the fabrication time for the chip as well as the throughput of CP equipment. Our technology mapping technique maps EB shot count-effective cells to a circuit in order to increase the throughput of CP equipment. Our technique treats the number of EB shots as an objective to minimize. Comparing with a conventional technology mapping, our technology mapping technique has achieved 26.6% reduction of the number of EB shots for the front-end-of-the-line (FEOL) process without any performance degradation of ICs. Moreover, our technology mapping technique has achieved a 54.6% less number of EB shots under no performance constraints. It is easy for both IC designers and equipment developers to adopt our technique because our technique is a software approach with no additional modification on CP equipment.

A normal-distribution-function-shaped superconducting tunnel junction (NDF-STJ) which consists of Nb/Al-AlOx/Al/Nb has been fabricated as an X-ray detector. Current - voltage characteristics were measured at 0.4 K using three kinds of STJs, which have the dispersion parameters σ of 0.25, 0.45 and 0.75. These STJs showed very low subgap leakage current of about 5 nA. By irradiating with 5.9 keV X-rays, we obtained the spectrum of these NDF-STJs. They showed good energy resolution with small magnetic fields of below 3 mT, which is about one-tenth of those for conventional-shaped STJs.