We present a problem for benchmarking the robustness of cellular up-links, in an automatic weather station (AWS) testbed. Based on the problem, we conduct a small-scale measurement study of robustness, where the AWS i...We present a problem for benchmarking the robustness of cellular up-links, in an automatic weather station (AWS) testbed. Based on the problem, we conduct a small-scale measurement study of robustness, where the AWS is equipped with four (4) cellular modems for weather data delivery. The effectiveness of up-links is challenging because of overlapping spatial-temporal factors such as the presence of good reflectors that lead to multi-path effects, interference, network load or other reasons. We argue that, there is a strong need for independent assessments of their robustness, to perform end-to-end network measurement. However, it is yet difficult to go from a particular measurement to an assessment of the entire network. We extensively measure the variability of Radio Signal Strength (RSSI) as link metric on the cellular modems. The RSSI is one of the important link metrics that can determine the robustness of received RF signals, and explore how they differed from one another at a particular location and instant time. We also apply the statistical analysis that quantifies the level of stability by considering the robustness, referring short-term variation, and determines good up-link in comparison to weak one. The results show that the robustness of cellular up-links exists for an unpredictable period of time and lower than one could hope. More than 50% of up-links are intermittent. Therefore, we plan to extend our work by exploring RSSI thresholds, to develop a classification scheme supporting a decision whether a link is either intermittent or not. This will help in normalizing the level of stability, to design the RSSI estimation metric for the robust routing protocol in weather data networks.展开更多
目的:探讨梗阻性胆管炎大鼠细胞免疫功能降低的发生机制及清热通下中药锦红片的影响.方法:♂SD大鼠24只建立急性梗阻性胆管炎模型,随机分为模型组(n=8)、锦红片治疗组(n=8)和单纯胆管梗阻组(n=8),检测血浆IL-2,CD_3^+,CD_4^+,CD_8^+,内...目的:探讨梗阻性胆管炎大鼠细胞免疫功能降低的发生机制及清热通下中药锦红片的影响.方法:♂SD大鼠24只建立急性梗阻性胆管炎模型,随机分为模型组(n=8)、锦红片治疗组(n=8)和单纯胆管梗阻组(n=8),检测血浆IL-2,CD_3^+,CD_4^+,CD_8^+,内毒素,胸腺指数,胸腺细胞凋亡指数及电镜下观察胸腺的超微结构及凋亡.结果:模型组IL-2,CD_3^+,CD_4^+和胸腺指数显著低于治疗组和单纯胆管梗阻组(IL-2:28.5±3.0 ng/L vs 33.9±3.6 ng/L,39.6±2.2 ng/L,P<0.05,P<0.01;CD_3^+:54.5%±5.5% vs 70.7%±4.8%,66.3%±7.1%,均P<0.01;CD_4^+:34.5%±8.3% vs 44.2%±3.3%,44.5%±4.2%,均P<0.01:胸腺指数:0.89±0.18 vs 1.10±0.13.1.12±0.24,均P<0.05),CD_8^+3组间没有统计学差异,血浆内毒素和凋亡指数明显高于治疗组和梗阻组(内毒素:0.85±0.14 Eu/mL vs 0.53±0.10 EU/mL,0.49±0.11 EU/mL,均P<0.01;凋亡指数:25.7±5.1 vs 15.8±5.5.9.0±3.1.P<0.05,P<0.01),模型组胸腺可见较多典型的凋亡细胞,结果显示经中药干预治疗后,免疫功能、内毒素血症和胸腺细胞凋亡有所改善,接近单纯胆管梗阻组水平.结论:梗阻性胆管炎大鼠存在免疫功能降低,胸腺细胞异常凋亡.锦红片对维持免疫机能的稳定有积极的意义.展开更多
文摘We present a problem for benchmarking the robustness of cellular up-links, in an automatic weather station (AWS) testbed. Based on the problem, we conduct a small-scale measurement study of robustness, where the AWS is equipped with four (4) cellular modems for weather data delivery. The effectiveness of up-links is challenging because of overlapping spatial-temporal factors such as the presence of good reflectors that lead to multi-path effects, interference, network load or other reasons. We argue that, there is a strong need for independent assessments of their robustness, to perform end-to-end network measurement. However, it is yet difficult to go from a particular measurement to an assessment of the entire network. We extensively measure the variability of Radio Signal Strength (RSSI) as link metric on the cellular modems. The RSSI is one of the important link metrics that can determine the robustness of received RF signals, and explore how they differed from one another at a particular location and instant time. We also apply the statistical analysis that quantifies the level of stability by considering the robustness, referring short-term variation, and determines good up-link in comparison to weak one. The results show that the robustness of cellular up-links exists for an unpredictable period of time and lower than one could hope. More than 50% of up-links are intermittent. Therefore, we plan to extend our work by exploring RSSI thresholds, to develop a classification scheme supporting a decision whether a link is either intermittent or not. This will help in normalizing the level of stability, to design the RSSI estimation metric for the robust routing protocol in weather data networks.
文摘目的:探讨梗阻性胆管炎大鼠细胞免疫功能降低的发生机制及清热通下中药锦红片的影响.方法:♂SD大鼠24只建立急性梗阻性胆管炎模型,随机分为模型组(n=8)、锦红片治疗组(n=8)和单纯胆管梗阻组(n=8),检测血浆IL-2,CD_3^+,CD_4^+,CD_8^+,内毒素,胸腺指数,胸腺细胞凋亡指数及电镜下观察胸腺的超微结构及凋亡.结果:模型组IL-2,CD_3^+,CD_4^+和胸腺指数显著低于治疗组和单纯胆管梗阻组(IL-2:28.5±3.0 ng/L vs 33.9±3.6 ng/L,39.6±2.2 ng/L,P<0.05,P<0.01;CD_3^+:54.5%±5.5% vs 70.7%±4.8%,66.3%±7.1%,均P<0.01;CD_4^+:34.5%±8.3% vs 44.2%±3.3%,44.5%±4.2%,均P<0.01:胸腺指数:0.89±0.18 vs 1.10±0.13.1.12±0.24,均P<0.05),CD_8^+3组间没有统计学差异,血浆内毒素和凋亡指数明显高于治疗组和梗阻组(内毒素:0.85±0.14 Eu/mL vs 0.53±0.10 EU/mL,0.49±0.11 EU/mL,均P<0.01;凋亡指数:25.7±5.1 vs 15.8±5.5.9.0±3.1.P<0.05,P<0.01),模型组胸腺可见较多典型的凋亡细胞,结果显示经中药干预治疗后,免疫功能、内毒素血症和胸腺细胞凋亡有所改善,接近单纯胆管梗阻组水平.结论:梗阻性胆管炎大鼠存在免疫功能降低,胸腺细胞异常凋亡.锦红片对维持免疫机能的稳定有积极的意义.