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PurposeTo overcome the severe intensity inhomogeneity and blurry boundaries in HIFU (High Intensity Focused Ultrasound) ultrasound images, an accurate and efficient multi-scale and shape constrained localized region-based active contour model (MSLCV), was developed to accurately and efficiently segment the target region in HIFU ultrasound images of uterine fibroids.MethodsWe incorporated a new shape constraint into the localized region-based active contour, which constrained the active contour to obtain the desired, accurate segmentation, avoiding boundary leakage and excessive contraction. Localized region-based active contour modeling is suitable for ultrasound images, but it still cannot acquire satisfactory segmentation for HIFU ultrasound images of uterine fibroids. We improved the localized region-based active contour model by incorporating a shape constraint into region-based level set framework to increase segmentation accuracy. Some improvement measures were proposed to overcome the sensitivity of initialization, and a multi-scale segmentation method was proposed to improve segmentation efficiency. We also designed an adaptive localizing radius size selection function to acquire better segmentation results.ResultsExperimental results demonstrated that the MSLCV model was significantly more accurate and efficient than conventional methods. The MSLCV model has been quantitatively validated via experiments, obtaining an average of 0.94 for the DSC (Dice similarity coefficient) and 25.16 for the MSSD (mean sum of square distance). Moreover, by using the multi-scale segmentation method, the MSLCV model’s average segmentation time was decreased to approximately 1/8 that of the localized region-based active contour model (the LCV model).ConclusionsAn accurate and efficient multi-scale and shape constrained localized region-based active contour model was designed for the semi-automatic segmentation of uterine fibroid ultrasound (UFUS) images in HIFU therapy. Compared with other methods, it provided more accurate and more efficient segmentation results that are very close to those obtained from manual segmentation by a specialist.

A highly efficient Ruddlesden‐Popper structure anode material with a formula of Sr3Fe1.3Mo0.5Ni0.2O7‐δ (RP‐SFMN) has been developed for hydrocarbon fueled solid oxide fuel cells (HF‐SOFC) application. It is demonstrated that a nanostructured RP‐SFMN anode decorated with in‐situ exsolved Ni nanoparticles (Ni@RP‐SFMN) has been successfully prepared by annealing the anode in reducing atmosphere similar to the operating conditions. The phase compositions, valence states, morphologies, and electrocatalytic activities of RP‐SFMN material have been characterized in detail. In addition, the in‐situ exsolution mechanism of the metallic Ni phase from the parent oxide is clearly explained by using density function theory calculation. The peak output power density at 800°C is significantly enhanced from 0.163 to 0.409 W/cm2 while the electrode polarization resistance is effectively lowered from 0.96 to 0.30 Ω cm2 by the substitution of B‐site Fe by Ni, which is attributed to the improved electrocatalytic activities induced by the in‐situ exsolved Ni nanocatalysts. Moreover, the single cell with RP‐SFMN anode exhibits good stability in 3% H2O humidified H2 and syngas for 110 and 60 h at 800°C, respectively. Our findings indicate that RP‐SFMN is a greatly promising anode candidate of HF‐SOFCs due to its good electrochemical performance and stability during the operation.

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The required total gain control range of TD-SCDMA transmitter is 74dB, which is challenging. ABB IC provides 12dB of digital Comlent Communication, Shanghai, China gain control and leave 62dB gain control in analog domain. To 'UrangverCosityof Semrico,Gaind vine, CA achieve this, two or more VGA stages are commonly utilized. 3University otFlorida, Gainesville, FLAdditional VGA stages degrade linearity performance and con-Time-division synchronous code-division multiple access (TD-sume more power making the practice less favorable for achiev-SCDMA) technology, initiated by the China Wireless ing a high adjacent channel leakage ratio (ACLR). As illustrated Telecommunications Standard Group (CWTS), was adopted as in Fig. 19.5.2, the VGA employs a gain control circuit to achieve one of the 3G standards by International Telecommunication more than 40dB of gain control range. High and low gain switch-Union (ITU) in 2000. Though the main structure of TD-SCDMA ing is achieved by switching between G,, 1 (M1, M2, R1) and Gm2 (M3, core network is similar to that of WCDMA and CDMA2000, it M4, H2). The fine gain step is realized by the switch transistor offers unique features such as asymmetric up/down link, smart array. Two identical switching arrays are controlled by a pair of antenna, joint detection and baton handover to improve the spec-complimentary digital signals, one array is connected to VDD and trum efficiency and system capability [1]. In this paper, a dual-the other is connected to VGA output. As shown in Fig. 19.5.2, by band TD-SCDMA RF transceiver compliant to its specifications is turning on and off transistors K1 to K51, the gain can be stepped by reported. This device integrates a VCO, a fractional-N PLL, a 6dB. DA circuit also provides gain control. When the input is receive channel-select filter, and a transmit driver amplifier into changed from G,,,, (M7, M) to G, (M, M10), the gain of the DA is a single chip. The transceiver is fabricated in a 0.18im CMOS changed from high to low. The degeneration inductors L3 and L4 process.