Chung Him Yuen

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Prior to the discovery of the celebrated orthogonal frequency division multiplexing (OFDM), multicarrier techniques that use analog filter banks were introduced in the 1960s. Moreover, advancements in the design of perfect reconstruction filter banks have led to a number developments in the design of prototype digital filters and polyphase structures for(More)
In regard to the causes of simple rectovaginal fistulas (RVF) we examined the methods of diagnosis and the efficacy and outcome of surgical procedures. The study included all of our patients diagnosed with simple RVF between December 1988 and July 1998 (n=19). Medical charts of these patients were reviewed regarding diagnostic investigations, operative(More)
Although orthogonal frequency division multiplexing (OFDM) has been the dominant technology for broadband communications in the past, a number of researchers have noted the shortcomings of OFDM in frequency-selective fast-fading channels, e.g., underwater acoustic channels. Hence, alternative systems that use filter banks for multicarrier (FBMC) modulation(More)
Endoscopic retrograde cholangiopancreatography has been part of clinical practice for over 35 years. The procedure itself carries risks. Most complications associated with the procedure have been described in the literature. Splenic injury is an extremely rare complication after endoscopic retrograde cholangiopancreatography and only nine such cases have(More)
The Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) radio standard has adopted a special form of orthogonal frequency division multiplexing (OFDM) method for the uplink of multiple access networks. This method which is called single carrier frequency division multiple access (SC-FDMA) applies a precoding to each user data set in each(More)
A growing number of research projects have been devoted to the study of needs, burdens and intervention programmes of families of psychiatric patients due to the emphasis on deinstitutionalization and community integration. Although it is noted that burdens for families when looking after a patient with a criminal history are even heavier and more(More)
The development and persistence of personality in nature are counterintuitive because, in heterogeneous environments, personality is expected to limit the degree of behavioural flexibility. Recent work has shown that personality and behavioural flexibility might be linked, but their interaction is not well understood and could be elucidated by studying a(More)
A continuous audit is required to ensure laparoscopic cholecystectomy (LC) is performed safely in the surgical community in general. A retrospective review of all LC done in a single center was performed. A total of 1,244 LC were attempted. The conversion rate was 12.4%, the complication rate 3.5%, and the bile duct injury rate 0.4%. Forty percent of bile(More)