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991.
基于自组织神经网络的实时统计特征抽取方法   总被引:3,自引:0,他引:3  
应用人工神经网络讨论统计了特征抽取的原理,提出了相应的抽取方法。该方法具有实时性,容错性,高数据压缩率和良好的特征分辨率。通过计算机仿真和桥梁索力状态的实例计算分析证实了该技术具有广泛的应用价值。  相似文献   
992.
This paper presents a fault-tolerant multicast scheme for hypercube multicomputers. The method is based on the routing capability information that is stored in each node. In comparison with the previous schemes, this information is able to capture the fault status more precisely. Two multicast algorithms are presented in the paper. These algorithms multicast messages in an attempt to minimize derouting so that time optimality can be achieved. Moreover, the routing capability information is used to guide derouting in an efficient manner when such needs arise. The amount of traffic incurred is addressed in the paper. The hardware design for the algorithms is also discussed. Extensive simulation has been conducted to evaluate the performance of the scheme. The results show the effectiveness of the proposed algorithms  相似文献   
993.
高韧性—70℃低温钢WHD4(09MnNiDR)的性能及应用   总被引:1,自引:0,他引:1  
陈晓  郭爱民 《宽厚板》1998,4(1):21-25
本文研究了武钢研制生产的高韧性—70℃低温钢WHD4(09MnNiDR)钢板的全面力学性能、焊接性能.介绍该钢在大型石油、化工设备中的应用实例.结果表明该钢具有优异的低温韧性和优良的焊接性能,是制造低温压力容器等设备的理想用材.  相似文献   
994.
OBJECTIVE: To examine the effect of cataract extraction (CE) after trabeculectomy on intraocular pressure (IOP) control. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: A total of 115 consecutive patients who underwent extracapsular CE (N = 58) or phacoemulsification (N = 57) with intraocular lens (IOL) placement after trabeculectomy were studied. INTERVENTION: Cataract extraction with IOL after trabeculectomy was performed. MAIN OUTCOME MEASURES: Preoperative, intraoperative, and postoperative factors were evaluated for association with loss of IOP control requiring additional medications, bleb needling, or further glaucoma surgery, using Kaplan-Meier survival analysis and Cox multivariate proportional hazards survival regression. RESULTS: After mean postoperative follow-up of 21.1 +/- 14.3 months, additional glaucoma medication or needling of the filtering bleb to maintain IOP control was required in 35 eyes (30.4%) and was significantly associated with intraoperative iris manipulation and early postoperative peak IOP greater than 25 mmHg. Additional glaucoma surgery was eventually required in 11 eyes (9.6%) and was significantly associated with age of 50 years or younger, preoperative IOP greater than 10 mmHg, and early postoperative peak IOP greater than 25 mmHg. The cumulative proportion of patients who did not require reoperation for glaucoma was 93% and 90% at 1 and 2 years, respectively. The mean IOP at last visit had increased 1.6 mmHg above the pre-CE level and did not vary significantly after the first postoperative month. The median interval from CE to the addition of glaucoma medication or bleb needling was 1.6 months (within 3 months in 20 of 33 eyes) and that from nonsurgical intervention to further glaucoma surgery was 3.6 months (before the 7th postoperative month in 6 of 11 eyes). Of 19 eyes with hypotony (IOP < or = 6 mmHg) before CE, 11 eyes remained hypotonous after CE despite an increase in the mean IOP from 4.6 to 7.5 mmHg. CONCLUSIONS: When CE is performed after trabeculectomy, age of 50 years or younger, preoperative IOP greater than 10 mmHg, intraoperative iris manipulation, and early postoperative IOP greater than 25 mmHg are associated with worsened postoperative IOP control. Most bleb failures occur soon after CE. Resolution of pre-existing hypotony after CE is unpredictable.  相似文献   
995.
本文介绍一种由机械装置,高精度圆光栅编码器,光栅位移传感器,微型计算机,接口控制电路等组成的多测头凸轮轴测量系统,该系统安装调整方便,定位准确,测量精度高,操作简单,工作可靠,能快速实现对凸轮轴的自动测量。  相似文献   
996.
997.
本文研究了在咪唑存在下 meso—四—(4—甲氧基—3—磺酸苯基)卟啉(TMPPS_4)与锌显色反应的最佳条件,建立了测定锌的新方法,灵敏度高,锌量在0—1.2μg/10mL 范围内遵守比耳定律,用于测定粮食中的锌时结果满意  相似文献   
998.
用KTP晶体研制成LD泵浦的YAG腔内倍频激光器,得到0.532μm连续绿色线偏振激光输出,阈值泵浦功率为41mW,输出功率为1.4mW,斜效率为1.7%。研究了泵浦光对倍频激光横模的影响。  相似文献   
999.
Relationship between mutagenic activity of drinking water and incidence of liver cancer was studied in Fusui County with micronucleus technique in the root tips of vicia faba. Results showed there existed substance that caused chromosome aberration in the drinking pond water of Fusui County. Micronucleus effects on the root tips of vicia faba induced by the substance in different kinds of drinking water coincided with the incidence of liver cancer (r = 0.86, P < 0.05). It suggested the existence of these chemical mutants in the water may be one of the important factors that caused high incidence of liver cancer. It provided experimental evidence for the etiological theory of liver cancer caused by the pollution of drinking water.  相似文献   
1000.
Before use of cardiovascular surgical techniques and procedures in humans, many experiments, e.g., hypothermic circulatory arrest and cardiopulmonary bypass using the heart-lung machine, have been performed in the dog. As a consequence experimental canine cardiovascular surgery is highly developed. This has not resulted in the routine performance of open heart surgery in veterinary medicine, probably because of the high costs. Cardiovascular surgery in the dog is generally limited to interventions not depending on hypothermic circulatory arrest or cardiopulmonary bypass. The clinical cardiovascular surgery in dogs can be divided into routine and more specialized interventions. The first category includes correction of peritoneopericardial diaphragmatic hernia, pericardial fenestration in dogs with pericardial effusion, treatment of persistent right aortic arch, and patent ductus closure. The specialized interventions include dilation of pulmonic and aortic stenoses and pacemaker implantation. The diagnosis and surgical treatment of such diseases is described. New developments in cardiovascular surgical treatment that can be expected include catheter techniques for occlusion of shunts and dilations using balloons, because the financial costs of these procedures are not prohibitive.  相似文献   
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