By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is p...By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is proposed. Initialization, member adding and member evicting operations are introduced. The new scheme is compared with three other group key management schemes which are based on the keys tree： SKDC, LKH, and OFF. As far as transmission, computation and storage costs are concerned, the performance of the new group key management scheme is the best. The security problem of the new scheme is analyzed. This new scheme provides backward and forward security, i.e.. newly admitted group members cannot read previous multicast messages and evicted members cannot read future multicast messages, even with collusion by many arbitrarily evicted members.展开更多
Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed. The corresponding BER formulas and computer aided numeric r...Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed. The corresponding BER formulas and computer aided numeric results are also given. Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.展开更多
A reduced-complexity detection algorithm is proposed, which is applied to iterative receivers for multiple-input multiple-output （MIMO） systems. Unlike the exhaustive search over all the possible trans-mitted symbol...A reduced-complexity detection algorithm is proposed, which is applied to iterative receivers for multiple-input multiple-output （MIMO） systems. Unlike the exhaustive search over all the possible trans-mitted symbol vectors of the optimum maximum a posteriori probability （MAP） detector, the new algo-rithm evaluates only the symbol vectors that contribute significantly to the soft output of the detector. The algorithm is facilitated by carrying out the breadth-first search on a reconfigurable tree, constructed by computing the symbol reliability of each layer based on zero-forcing criterion and reordering the symbols according to the symbol reliabilities. Simulations are presented and the good performance of the new algo-rithm over a quasi-static Rayleigh channel even for relatively small list sizes are proved.展开更多
The progression through which a person acquires ,;kills, understanding, and opinions regarding a particular organization or company is called organizational learning （OL）. In this study, the connection between organ...The progression through which a person acquires ,;kills, understanding, and opinions regarding a particular organization or company is called organizational learning （OL）. In this study, the connection between organizational innovation （OI） and OL within the inf3rmation and communication technology （ICT） industry in Malaysia is surveyed. These relationships are examined, because various previous inquiries have shown that an imperative precursor to firm performance is OL. Two hundred and seventy-eight surveys were completed by small and medium organizations across Malaysia. The connections existing between the causes of OL and the causes of OI were ascertained by using structural equation modeling （SEM）. Amongst the Malaysian small- and medium-sized enterprises （SMEs） that participated in fire study, OI and OL are considerably linked.展开更多
the transmission error coed performance of square MQAM and starMQAM modulation schemes for the AGWN Rayleigh fading channel isanalyzed. The corresponding EBR formulas and computer aided numericresults are given. There...the transmission error coed performance of square MQAM and starMQAM modulation schemes for the AGWN Rayleigh fading channel isanalyzed. The corresponding EBR formulas and computer aided numericresults are given. Therefore it provides a Theoretical basis forchoosing MQAM modulation schemes in mobile communications.展开更多
Objective： The aim of the study was to explore the role of Wnt βcatenin signalling pathway in the maintenance, invasion and metastasis of colorectal cancer stem cells. Methods： Double immunohistochemical staining w...Objective： The aim of the study was to explore the role of Wnt βcatenin signalling pathway in the maintenance, invasion and metastasis of colorectal cancer stem cells. Methods： Double immunohistochemical staining was used to detect the expression of EpCAMhigh/CD44~ which is regarded as the marker of colorectal cancer stem cells in 80 cases of colorectal cancer and their corresponding liver metastases. The SP method of immunohistochemistry was used to detect the expression of the key protein βcatenin in the Wnt pathway in these tissue. The expression and correlation of ^-catenin and EpCAMh^gh/ CD44＋ in colorectal cancer were analyzed and their role on the biological behavior of colorectal cancer was explored. Results： The abnormal expression of βcatenin was significantly higher in colorectal cancer than in the paraneoplastic normal intes- tinal mucosa [55% （44/80） vs 10% （2/20）, P 〈 0.05]. The positive expression of EpCAMhigh/CD44＋ was significantly higher in colorectal cancer than in the paraneoplastic normal intestinal mucosa [66.25% （53/80） vs 0% （0/20）, P 〈 0.05]. In the 80 cases of colorectal cancer, the abnormal expression of ^-catenin has no correlation with gender （P = 0.079）, age （P = 0.416） and the magnitude （P = 0.816） of the tumor （P 〉 0.05）, but it was significantly correlated with degree of differentiation （P = 0.001）, depth of invasion （P = 0.001）, clinical stage （P = 0.000） and metastasis （P = 0.000）. In the colorectal cancer, the expression of EpCAMhi^h/CD44~ cells has no correlation with gender （P = 0.934） and the magnitude （P = 0.160） of the tumor （P 〉 0.05）, but was significantly correlated with age （P = 0.021）, degree of differentiation （P = 0.013）, depth of invasion （P = 0.000）, clinical stage （P = 0.000） and metastasis （P = 0.000）. In the corresponding liver metastases, we could also detecte EpCAMhih/CD44＋ cells. In cases with abnormal expression of βcatenin, the positive expression rate of EpCAMhigh/CD44＋ was significantly higher than those with normal expression of β-catenin （84.1% vs 44.4%）, and the difference was statistically significant （P 〈 0.05）. Conclusion： The abnormal activation of Wnt β-catenin signalling pathway may prompt the abnormal proliferation of the colorectal cancer stem cells, which leads to the recurrence and metastasis of the cancer.展开更多
Objective: To study the altering rule of coagulation function at molecular level in patients with secondary brain injury (SBI). Methods: Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were studied in 32...Objective: To study the altering rule of coagulation function at molecular level in patients with secondary brain injury (SBI). Methods: Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were studied in 32 patients 1, 2, 3 and 7 days after craniocerebral injury. Repeated cranial CT scans and platelet counts were made simultaneously. Same measurements were done in 30 normal adults except CT scan. Results: No obvious difference was found in age, sex and platelet count between the injured and the normal groups. TFPI/TF decreased markedly in the first week after injury in patients with SBI, but only decreased on the 7th day in the patients without obvious SBI. For the patients who developed delayed intracranial hematoma (DIH) or hematoma enlargement, TF rose only 1 and 2 days after injury, but TFPI had a tendency to rise again after a fall on the 3rd day. For those patients who developed no DIH, TF rose all the time within the 1st week. Conclusions: Decrease of TFPI/TF for a long time, especially within 3 days after injury, may be one of the most important reasons for SBI. High expression of TF for a relative short time and increase of TFPI after a fall within 3 days may be one of the important reasons for DIH or hematoma enlargement.展开更多
Traditional 802.11 power saving mechanism (PSM) treats multicast and broadcast traffic equally, and suffers sig-nificant performance degradation with multicast background traffic. This paper proposes an enhanced PSM t...Traditional 802.11 power saving mechanism (PSM) treats multicast and broadcast traffic equally, and suffers sig-nificant performance degradation with multicast background traffic. This paper proposes an enhanced PSM that effectively dif-ferentiates multicast streams. It re-arranges the virtual bitmap of the traffic indication map (TIM) to carry traffic status for mul-ticast groups and introduces a concept of sequential transmission of multi-addressed data to facilitate differentiation among mul-ticast groups. Our analysis shows that the enhanced PSM can effectively save power in mixed traffic environments.展开更多
文摘By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is proposed. Initialization, member adding and member evicting operations are introduced. The new scheme is compared with three other group key management schemes which are based on the keys tree： SKDC, LKH, and OFF. As far as transmission, computation and storage costs are concerned, the performance of the new group key management scheme is the best. The security problem of the new scheme is analyzed. This new scheme provides backward and forward security, i.e.. newly admitted group members cannot read previous multicast messages and evicted members cannot read future multicast messages, even with collusion by many arbitrarily evicted members.
文摘Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed. The corresponding BER formulas and computer aided numeric results are also given. Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.
基金Supported by the National Natural Science Foundation of China （No.60332030, 60572157） and the High Technology Research and Development Pro-gramme of China （No.2003AA123310）.
文摘A reduced-complexity detection algorithm is proposed, which is applied to iterative receivers for multiple-input multiple-output （MIMO） systems. Unlike the exhaustive search over all the possible trans-mitted symbol vectors of the optimum maximum a posteriori probability （MAP） detector, the new algo-rithm evaluates only the symbol vectors that contribute significantly to the soft output of the detector. The algorithm is facilitated by carrying out the breadth-first search on a reconfigurable tree, constructed by computing the symbol reliability of each layer based on zero-forcing criterion and reordering the symbols according to the symbol reliabilities. Simulations are presented and the good performance of the new algo-rithm over a quasi-static Rayleigh channel even for relatively small list sizes are proved.
文摘The progression through which a person acquires ,;kills, understanding, and opinions regarding a particular organization or company is called organizational learning （OL）. In this study, the connection between organizational innovation （OI） and OL within the inf3rmation and communication technology （ICT） industry in Malaysia is surveyed. These relationships are examined, because various previous inquiries have shown that an imperative precursor to firm performance is OL. Two hundred and seventy-eight surveys were completed by small and medium organizations across Malaysia. The connections existing between the causes of OL and the causes of OI were ascertained by using structural equation modeling （SEM）. Amongst the Malaysian small- and medium-sized enterprises （SMEs） that participated in fire study, OI and OL are considerably linked.
文摘the transmission error coed performance of square MQAM and starMQAM modulation schemes for the AGWN Rayleigh fading channel isanalyzed. The corresponding EBR formulas and computer aided numericresults are given. Therefore it provides a Theoretical basis forchoosing MQAM modulation schemes in mobile communications.
文摘Objective： The aim of the study was to explore the role of Wnt βcatenin signalling pathway in the maintenance, invasion and metastasis of colorectal cancer stem cells. Methods： Double immunohistochemical staining was used to detect the expression of EpCAMhigh/CD44~ which is regarded as the marker of colorectal cancer stem cells in 80 cases of colorectal cancer and their corresponding liver metastases. The SP method of immunohistochemistry was used to detect the expression of the key protein βcatenin in the Wnt pathway in these tissue. The expression and correlation of ^-catenin and EpCAMh^gh/ CD44＋ in colorectal cancer were analyzed and their role on the biological behavior of colorectal cancer was explored. Results： The abnormal expression of βcatenin was significantly higher in colorectal cancer than in the paraneoplastic normal intes- tinal mucosa [55% （44/80） vs 10% （2/20）, P 〈 0.05]. The positive expression of EpCAMhigh/CD44＋ was significantly higher in colorectal cancer than in the paraneoplastic normal intestinal mucosa [66.25% （53/80） vs 0% （0/20）, P 〈 0.05]. In the 80 cases of colorectal cancer, the abnormal expression of ^-catenin has no correlation with gender （P = 0.079）, age （P = 0.416） and the magnitude （P = 0.816） of the tumor （P 〉 0.05）, but it was significantly correlated with degree of differentiation （P = 0.001）, depth of invasion （P = 0.001）, clinical stage （P = 0.000） and metastasis （P = 0.000）. In the colorectal cancer, the expression of EpCAMhi^h/CD44~ cells has no correlation with gender （P = 0.934） and the magnitude （P = 0.160） of the tumor （P 〉 0.05）, but was significantly correlated with age （P = 0.021）, degree of differentiation （P = 0.013）, depth of invasion （P = 0.000）, clinical stage （P = 0.000） and metastasis （P = 0.000）. In the corresponding liver metastases, we could also detecte EpCAMhih/CD44＋ cells. In cases with abnormal expression of βcatenin, the positive expression rate of EpCAMhigh/CD44＋ was significantly higher than those with normal expression of β-catenin （84.1% vs 44.4%）, and the difference was statistically significant （P 〈 0.05）. Conclusion： The abnormal activation of Wnt β-catenin signalling pathway may prompt the abnormal proliferation of the colorectal cancer stem cells, which leads to the recurrence and metastasis of the cancer.
文摘Objective: To study the altering rule of coagulation function at molecular level in patients with secondary brain injury (SBI). Methods: Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were studied in 32 patients 1, 2, 3 and 7 days after craniocerebral injury. Repeated cranial CT scans and platelet counts were made simultaneously. Same measurements were done in 30 normal adults except CT scan. Results: No obvious difference was found in age, sex and platelet count between the injured and the normal groups. TFPI/TF decreased markedly in the first week after injury in patients with SBI, but only decreased on the 7th day in the patients without obvious SBI. For the patients who developed delayed intracranial hematoma (DIH) or hematoma enlargement, TF rose only 1 and 2 days after injury, but TFPI had a tendency to rise again after a fall on the 3rd day. For those patients who developed no DIH, TF rose all the time within the 1st week. Conclusions: Decrease of TFPI/TF for a long time, especially within 3 days after injury, may be one of the most important reasons for SBI. High expression of TF for a relative short time and increase of TFPI after a fall within 3 days may be one of the important reasons for DIH or hematoma enlargement.
基金Project (Nos. 60574087 and 60721003) supported by the National Natural Science Foundation of China
文摘Traditional 802.11 power saving mechanism (PSM) treats multicast and broadcast traffic equally, and suffers sig-nificant performance degradation with multicast background traffic. This paper proposes an enhanced PSM that effectively dif-ferentiates multicast streams. It re-arranges the virtual bitmap of the traffic indication map (TIM) to carry traffic status for mul-ticast groups and introduces a concept of sequential transmission of multi-addressed data to facilitate differentiation among mul-ticast groups. Our analysis shows that the enhanced PSM can effectively save power in mixed traffic environments.
