Design of Control IC for Multiphase Interleaved Buck Converter with Alternate Phase-Shedding

Ji-Shiang Lee,Chun-Yu Huang,Tsorng-Juu Liang,Kai-Hui Chen 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, a controller for a multiphase interleaved buck converter with alternate phase-shedding is realized. With phase-shedding control, the efficiency at low load condition is improved by turning-on appropriate number of phase(s), but the temperature on the active phase(s) is higher than the off phase(s) that cause the temperature unevenly distribution. To solve this problem, the alternate phase-shedding is implemented in the proposed controller. The phases take turns to provide the load current at low load condition to distribute power to each phase and share the same load as well as improve reliability. The proposed controller would implement interleaved control regardless the number of active phases. In addition, taking advantage of the application of high step-down ratio, the proposed control structure that input current is sensed to control each phase is adopted. The number of components and pins of controller can be reduced. This chip is fabricated with TSMC 0.25um CMOS high voltage mixed signal general purpose process and is tested with an input voltage of 12 V, output voltage of 1.2 V, and output power of 72 W three-phase buck converter to verify the feasibility.

Magnetization Reversal of Co/Pd Multilayers on Si Substrates and AAO Membranes

Chin-Chung Yu,Yung-Shiang Teng,Yu-Kuan Huang,Shih-Yuan Chen,Yeong-Der Yao 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Reversible and High-Capacity Data Hiding in High Quality Medical Images

( Li-chin Huang ),( Min-shiang Hwang ),( Lin-yu Tseng ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.1

Via the Internet, the information infrastructure of modern health care has already established medical information systems to share electronic health records among patients and health care providers. Data hiding plays an important role to protect medical images. Because modern medical devices have improved, high resolutions of medical images are provided to detect early diseases. The high quality medical images are used to recognize complicated anatomical structures such as soft tissues, muscles, and internal organs to support diagnosis of diseases. For instance, 16-bit depth medical images will provide 65,536 discrete levels to show more details of anatomical structures. In general, the feature of low utilization rate of intensity in 16-bit depth will be utilized to handle overflow/underflow problem. Nowadays, most of data hiding algorithms are still experimenting on 8-bit depth medical images. We proposed a novel reversible data hiding scheme testing on 16-bit depth CT and MRI medical image. And the peak point and zero point of a histogram are applied to embed secret message k bits without salt-and-pepper.

Comparing the performance of two hybrid deterministic/Monte Carlo transport codes in shielding calculations of a spent fuel storage cask

Po-Chen Lai,Yu-Shiang Huang,Rong-Jiun Sheu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.8

This study systematically compared two hybrid deterministic/Monte Carlo transport codes, ADVANTG/MCNP and MAVRIC, in solving a difficult shielding problem for a real-world spent fuel storage cask. Both hybrid codes were developed based on the consistent adjoint driven importance sampling (CADIS) methodology but with different implementations. The dose rate distributions on the cask surface were of primary interest and their predicted results were compared with each other and with a straightforward MCNP calculation as a baseline case. Forward-Weighted CADIS was applied for optimization toward uniform statistical uncertainties for all tallies on the cask surface. Both ADVANTG/MCNP and MAVRIC achieved substantial improvements in overall computational efficiencies, especially for gamma-ray transport. Compared with the continuous-energy ADVANTG/MCNP calculations, the coarse-group MAVRIC calculations underestimated the neutron dose rates on the cask's side surface by an approxi-mate factor of two and slightly overestimated the dose rates on the cask's top and side surfaces for fuel gamma and hardware gamma sources because of the impact of multigroup approximation. The fine-group MAVRIC calculations improved to a certain extent and the addition of continuous-energy treat-ment to the Monte Carlo code in the latest MAVRIC sequence greatly reduced these discrepancies. For the two continuous-energy calculations of ADVANTG/MCNP and MAVRIC, a remaining difference of approximately 30% between the neutron dose rates on the cask's side surface resulted from inconsistent use of thermal scattering treatment of hydrogen in concrete.

Incidentally Detected Enhancing Breast Lesions on Chest Computed Tomography

Wen-Chiung Lin,Hsian-He Hsu,Chao-Shiang Li,Jyh-Cherng Yu,Giu-Cheng Hsu,Cheng-Ping Yu,Tsun-Hou Chang,Guo-Shu Huang 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.1

Objective: To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. Materials and Methods: Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. Results: Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fi broglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-signifi cant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. Conclusion: Routine contrast-enhanced chest CT can reveal suffi cient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy. Objective: To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. Materials and Methods: Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. Results: Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fi broglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-signifi cant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. Conclusion: Routine contrast-enhanced chest CT can reveal suffi cient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy.

Transitional Percentage of Minute Volume as a Novel Predictor of Weaning from Mechanical Ventilation in Patients with Chronic Respiratory Failure

Ya-Ru Liang,Mei-Chen Yang,Yao-Kuang Wu,I-Shiang Tzeng,Pei-Yi Wu,Shiang-Yu Huang,Chou-Chin Lan,Chin-Pyng Wu 한국간호과학회 2020 Asian Nursing Research Vol.14 No.1

Purpose: Some patients with respiratory failure fail initial weaning attempts and need prolonged mechanical ventilation (MV). Prolonged MV is associated with many complications and consumption of heathcare resources. Objective weaning indices help staffs to identify high-potential patients for weaning from the MV. Traditional weaning indices are not reliable in clinical practice. Transitional percentage of minute volume (TMV%) is a new index of the work of breathing. This study aimed to investigate the utility of TMV% in the prediction of weaning potential. Methods: This study was prospectively performed including all patients with prolonged MV. Researchers recorded their demographics, TMV%, respiratory parameters, Acute Physiology and Chronic Health Evaluation II score, and laboratory data upon arrival at the respiratory care center. The factors associated with successful weaning were analyzed. Results: Out of the 120 patients included, 84 (70.0%) were successfully weaned from MV. Traditional weaning indices such as rapid shallow breathing index could not predict the weaning outcome. TMV% was a valuable parameter as patients with a lower TMV%, higher tidal volume, higher hemoglobin, lower blood urea nitrogen, and lower Acute Physiology and Chronic Health Evaluation II scores had a higher rate of successful weaning. TMV%, tidal volume, and HCO3- levels were independent predictors of successful weaning, and the area under the curve was .79 in the logistic regression model. Conclusion: TMV% is a novel and effective predictor of successful weaning. Patients with lower TMV% had a higher MV weaning outcome. Once patients with a high potential for successful weaning are identified, they should be aggressively weaned from MV as soon as possible.