Browsing by Author "Wu, Meng-Huan"

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Novel corrugated coupled-line stage with ideal frequency response and its application to bandpass filter design with multi-harinonic suppression
(2007)
Kuo, Jen-Tsai
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Lok, U-Hou
;
Wu, Meng-Huan
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電信工程研究所
;
Institute of Communications Engineering
Coupled-line stages are designed with corrugated periods to accurately allocate inherent transmission zeros at three leading even harmonics of design frequency, f(0). The corrugation pattern is finely trimmed so that phase velocities of the two eigenmodes can be simultaneously equalized at these frequencies. By decreasing munber of coupled periods in a stage, frequencies of the zeros can be arbitrarily scaled up to a certain extent In this way, a parallel-coupled line bandpass filter with a cascade of several such stages cant be synthesized to be free of spurious harmonics up to at least 10f(0,) with aid of tapped input/output coupling scheme. The measured data of the fabricated bandpass filter show a rejection level of better than 30 dB in the upper stopband up to 18f(0).
Periodic stepped-impedance resonator (PSIR) bandpass filters with multispurious suppression
(2006)
Chiou, Yi-Chyun
;
Wu, Meng-Huan
;
Kuo, Jen-Tsai
;
電信工程研究所
;
Institute of Communications Engineering
Periodic stepped-impedance resonators (PSIRs) are proposed to design bandpass filters for multi-spurious suppression. Denoted as PSIRN, a PSIR of lambda/2 long at design frequency f(0) consists of N periods of hi-Z and low-Z sections. A PSIRN coupled section shows transmission zeros at various frequencies. The zeros can be tuned by changing the impedance ratio of the hi-Z and low-Z sections, and can be adopted to suppress the spurious peaks. Responses of the PSIR filters show good rejection in the upper stopband.
Significant predictive factors of the severity and outcomes of the first attack of acute angioedema in children
(2019-11-11)
Syue, Yuan-Jhen
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Li, Chao-Jui
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Chen, Wen-Liang
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Lee, Tsung-Han
;
Huang, Cheng-Chieh
Background The initial episode of angioedema in children can be potential life-threatening due to the lack of prompt identification and treatment. We aimed to analyze the factors predicting the severity and outcomes of the first attack of acute angioedema in children. Methods This was a retrospective study with 406 children (< 18 years) who presented in the emergency department (ED) with an initial episode of acute angioedema and who had subsequent follow-up visits in the out-patient department from January 2008 to December 2014. The severity of the acute angioedema was categorized as severe (requiring hospital admission), moderate (requiring a stay in the short-term pediatric observation unit [POU]), or mild (discharged directly from the ED). The associations among the disease severity, patient demographics and clinical presentation were analyzed. Result In total, 109 (26.8%) children had severe angioedema, and the majority of those children were male (65.1%). Most of the children were of preschool age (56.4%), and only 6.4% were adolescents. The co-occurrence of pyrexia or urticaria, etiologies of the angioedema related to medications or infections, the presence of respiratory symptoms, and a history of allergies (asthma, allergic rhinitis) were predictors of severe angioedema (all p < 0.05). Finally, the duration of angioedema was significantly shorter in children who had received short-term POU treatment (2.1 +/- 1.1 days) than in those who discharged from ED directly (2.3 +/- 1.4 days) and admitted to the hospital (3.5 +/- 2.0 days) (p < 0.001). Conclusion The co-occurrence of pyrexia or urticaria, etiologies related to medications or infections, the presence of respiratory symptoms, and a history of allergies were predictors of severe angioedema. More importantly, short-term POU observation and prompt treatment might be benefit for patients who did not require hospital admission.