Taking the time varying nature of wireless channels into account, two user selection schemes with lower complexity are developed for multiple-input multiple-output broadcast （MIMO BC）systems. According to the relati...Taking the time varying nature of wireless channels into account, two user selection schemes with lower complexity are developed for multiple-input multiple-output broadcast （MIMO BC）systems. According to the relationship between coherence time and Doppler frequency, an information frame is divided into several segments. At the beginning of each segment, the user selection is carded out with the greedy selection algorithm. In the simplified user selection algorithms employing the temporal correlation （SUSTC）, the selection results are applied for all the remaining slots in each segment. But in the improved simplified user selection algorithms employing the temporal correlation（ISUSTC）, at the remaining slots, users are kept with favorable channel conditions selected at the previous slot, and other users are updated from the candidate pool to communicate simultaneously. Simulations show that compared with the greedy user selection method, the proposed algorithms can reduce the selection complexity with a little sum capacity loss.展开更多
AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients w...AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients who had been admitted to the Division of Gastroenterology with gastrointestinal symptoms were enrolled from March to April 2005. Of those who had been diagnosed with clonorchiasis, epidemiology and correlation between infection and hepatobiliary diseases were surveyed by questionnaire. RESULTS： Of 3080 patients with gastrointestinal diseases, 396 （12.9%） had clonorchiasis and 1140 patients （37.2%） had a history of eating raw freshwater fish. Of those with a history of raw freshwater fish ingestion, 238 （20.9%） patients had clonorchiasis. Cholangiocarcinoma was more prevalent in C. sinensis-infected patients than nonnfected patients [34/396 （8.6%） vs 145/2684 （5.4%）, P = 0.015]. Cholangiocarcinoma and clonorchiasis showed statistically significant positive cross-relation （P = 0.008）. Choledocholithiasis, cholecystolithiasis, cholangitis, hepatocellular carcinoma, and biliary pancreatitis did not correlate with clonorchiasis. CONCLUSION： Infection rate of clonorchiasis was still high in patients with gastrointestinal diseases in Korea, and has not decreased very much during the last two decades. Cholangiocarcinoma was related to clonorchiasis, which suggested an etiological role for the parasite.展开更多
基金The National High Technology Research and Develop-ment Program of China(863 Program)(No.2006AA01Z268)the NationalNatural Science Foundation of China(No.60496311).
文摘Taking the time varying nature of wireless channels into account, two user selection schemes with lower complexity are developed for multiple-input multiple-output broadcast （MIMO BC）systems. According to the relationship between coherence time and Doppler frequency, an information frame is divided into several segments. At the beginning of each segment, the user selection is carded out with the greedy selection algorithm. In the simplified user selection algorithms employing the temporal correlation （SUSTC）, the selection results are applied for all the remaining slots in each segment. But in the improved simplified user selection algorithms employing the temporal correlation（ISUSTC）, at the remaining slots, users are kept with favorable channel conditions selected at the previous slot, and other users are updated from the candidate pool to communicate simultaneously. Simulations show that compared with the greedy user selection method, the proposed algorithms can reduce the selection complexity with a little sum capacity loss.
基金Supported by The Korean Society of Gastroenterology Research Fund, No. 2005-1
文摘AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients who had been admitted to the Division of Gastroenterology with gastrointestinal symptoms were enrolled from March to April 2005. Of those who had been diagnosed with clonorchiasis, epidemiology and correlation between infection and hepatobiliary diseases were surveyed by questionnaire. RESULTS： Of 3080 patients with gastrointestinal diseases, 396 （12.9%） had clonorchiasis and 1140 patients （37.2%） had a history of eating raw freshwater fish. Of those with a history of raw freshwater fish ingestion, 238 （20.9%） patients had clonorchiasis. Cholangiocarcinoma was more prevalent in C. sinensis-infected patients than nonnfected patients [34/396 （8.6%） vs 145/2684 （5.4%）, P = 0.015]. Cholangiocarcinoma and clonorchiasis showed statistically significant positive cross-relation （P = 0.008）. Choledocholithiasis, cholecystolithiasis, cholangitis, hepatocellular carcinoma, and biliary pancreatitis did not correlate with clonorchiasis. CONCLUSION： Infection rate of clonorchiasis was still high in patients with gastrointestinal diseases in Korea, and has not decreased very much during the last two decades. Cholangiocarcinoma was related to clonorchiasis, which suggested an etiological role for the parasite.
