Pipeline leakage detection and isolation: An integrated approach of statistical and wavelet feature extraction with multi-layer perceptron neural network (MLPNN)

Leakage diagnosis of hydrocarbon pipelines can prevent environmental and financial losses. This work proposes a novel method that not only detects the occurrence of a leakage fault, but also suggests its location and severity. The OLGA software is employed to provide the pipeline inlet pressure and outlet flow rates as the training data for the Fault Detection and Isolation (FDI) system. The FDI system is comprised of a Multi-Layer Perceptron Neural Network (MLPNN) classifier with various feature extraction methods including the statistical techniques, wavelet transform, and a fusion of both methods. Once different leakage scenarios are considered and the preprocessing methods are done, the proposed FDI system is applied to a 20-km pipeline in southern Iran (Goldkari-Binak pipeline) and a promising severity and location detectability (a correct classification rate of 92%) and a low False Alarm Rate (FAR) were achieved.     

长江上游泥石流灾害的特征

长江上游地区地质条件复杂、新构造运动强烈、地震活跃、地形起伏巨大、降水丰沛而集中,对泥石流发育极为有利;而长期不合理的人类经济活动(如过度采伐森林、毁林开荒、陡坡耕作、建设和采矿不合理弃渣等)则对生态环境造成强烈破坏,加剧了泥石流灾害的发生,使长江上游成为我国泥石流活动最强烈及灾害最严重的地区。据统计,1753~2002年的200多年中,区内仅一场泥石流致死百人以上的特大灾害点就达17个,累计死亡近6 000人;致死百人以下的灾害点更多,致死十人以下的灾害点不计其数,死亡人数总和远远大于上列数字;有60余个市县政府驻地城镇受泥石流危害或威胁,乡镇则多达上百个。由泥石流造成的人员伤亡每年数十到数百人,经济损失10~15(亿元／a)。其灾害的严重性由此可见一斑。泥石流灾害已成为制约长江上游地区经济发展的重要因素之一。研究泥石流灾害,掌握其特征,是长江上游防灾减灾所必需,对促进长江上游地区社会经济发展和西部大开发具有重要意义。长江上游己查明的泥石流沟6 800余条。其特殊的地理位置和巨大的地形高差及岩性差异,使区内发育的泥石流不仅数量众多,而且类型石相当齐全,除无火山泥石流外,几乎 包含了世界上目前己发现的其他各种类型的泥石流。在青藏高原边缘等岭谷高差变化大的地貌过渡带,泥石流极为发育;沿深大断裂带和强烈地震带泥石流集中分布;泥石流主要出现在流域面积小于10 km\+2的小流域内,分布呈非地带性特征。泥石流活动频率高,每年都有成百上千处发生,导致了泥石流灾害频繁。如云南东川的蒋家沟,从1965~2001年的37年中,共发生泥石流459次,平均12．4次／a;甘肃武都柳弯沟平均每年暴发泥石流11次。此外,泥石流搬运泥沙石块的能力惊人,搬运物以粗粒物质为主,据干流和支流的69个泥石流堆积物样品分析,堆积物中粒径大于20 mm 的石块占43.%~64.8%,平均50．4％;由此,常常造成其汇入的主河被堵塞而形成淹没和溃决后水毁等次生灾害。泥石流冲刷与淤积能力极强,运动中可将基岩下切10余m,金沙江、雅砻江、大渡河、岷江及其支流被泥石流堵塞成湖,形成淹没灾害,溃决后对下游造成严重的水毁灾害,均屡见不鲜。     

基于事故深度调查的城市交通事故特征分析

为探索适合我国的事故数据深度采集标准,并分析城市道路交通事故特征及致因,基于《道路交通事故深度调查信息采集表》(简称采集表),调查人员随交警赴事故现场随机详细调查87起城市道路交通事故。借鉴"Haddon Matrix"思想建立致因分析矩阵系统,分析事故的致因。发现采集表对事故地点、事故形态及原因项分类更加具体、明确,女性驾驶员的事故发生率略低于男性驾驶员,驾驶员年龄超过60岁后,发生事故的危险性显著提高,"交叉口影响区"事故50%由变更车道引起,非机动车驾驶员未戴安全头盔是造成严重伤害的重要原因。     

Improving pedestrian safety using combined HOG and Haar partial detection in mobile systems

Objective: The objective of this study is to develop a novel algorithm on a mobile system that can warn drivers about the possibility of a collision with a pedestrian. The constraints of the algorithm are near-real-time detection speed and a good detection rate.

Method: Histogram of gradients (HOG)-based detection is widely used in pedestrian safety applications; however, it has low detection speed for real-time systems. Hence, it has no direct usage for mobile systems. In order to achieve near-real-time detection speed, partial Haar transform predetections are applied to an image before HOG detection. The partial and HOG detections are merged and a score-based confidence level is defined for the final detection phase. In this way, the outcome is prioritized and different warning levels can be issued to warn the driver before a possible pedestrian collision.

Results: The proposed algorithm provides an increase in detection speed (from 46 to 76 fps) and detection rate (from 80 to 91%) with respect to HOG-based pedestrian detection. It also improves confidence of the results by multidetection merging and score assignment to detections.

Conclusions: Performance improvement of the algorithm is compared with respect to state-of-the-art detectors/algorithms. Based on the detection rate and detection speed performance, it can be concluded that the proposed algorithm is suitable to be used for mobile systems to warn drivers about the possibility of collision with a pedestrian.     

几株光合细菌的表型特征及DNA－NDA同源性分析

对５株新分离的光合细菌从形态、生理生化及ＤＮＡ－ＤＮＡ同源性等方面进行了研究．结果表明，菌株８与深红红螺菌（Ｐｈｏｄｏｓｐｉｒｉｌｌｕｍｒｕｂｒｕｍ）的模式菌株ＡＴＣＣ１１１７０的ＤＮＡ－ＤＮＡ同源性为９７％，菌株３７与沼泽红假单胞菌（Ｒｈｏｄｏｐｓｅｕｄｏｍｏｎａｓｐａｌｕｓｔｒｉｓ）的模式菌株ＡＴＣＣ１７００１的ＤＮＡ－ＤＮＡ同源性为８０％；菌株５５与球形红杆菌（Ｒｈｏｄｏｂａｃｔｅｒｓｐｈａｅｒｏｉｄｅｓ）的模式菌株ＡＴＣＣ１７０２３的ＤＮＡ－ＤＮＡ同源性为７１％；菌株４０和５２分别为另外两个ＤＮＡ同源群．根据各菌株形态、生理生化等表型特征以及ＤＮＡＧ＋Ｃｍｏｌ％和ＤＮＡ－ＤＮＡ同源性分析结果，确定了几株光合细菌的分类地位．     

我国城市地价评估模型及其空间分布规律研究

本文以城市地价产生地区差异的理论分析为依据,提出了城市地价的主要影响因素、因子,并以城市土地批租资料为基础运用逐步回归分析方法建立城市地价评估模型。根据模型估测了我国５１７个城市１９９２年的地价水平,最后分析了我国城市地价空间分布的规律及其未来走势展望。     

浙江省海岸带优势资源及其组合特点

浙江省海岸带以自然资源集聚、种类众多为其特色，它为振兴浙江经济提供了极为有利的条件。浙江海岸带有六项优势资源，即港口航道资源、水产资源、滩涂土地资源、海洋能资源、旅游资源以及岛屿资源。本文分析了这些优势资源的组合特点，并指出优势资源存在着多宜性、动态性，在开发利用过程中要加以综合规划，统一协调，目的是以期引起有关方面注意，采纳或参考。     

Clinical and pathological factors in spontaneous abortion following chorionic villus sampling

Twenty-nine cases of spontaneous abortion following first-trimester chorionic villus sampling (CVS) were reviewed out of a series of 722 patients. Of the 29 cases, there were only four abnormal CVS results. Pathological examination was performed in 79 per cent of cases, and this did not identify any characteristic pathological feature associated with spontaneous abortion after CVS. There was no obvious difference in the pathological features following the transabdominal (TA) or the transcervical (TC) methods. The majority of miscarriages occurred within 4 weeks of the procedure, but 38 per cent of cases aborted between 7 and 14 weeks after CVS. The TC method was used in 22 patients; the TA in 6; and both methods in 1 patient. The TA method was associated with a significantly lower fetal loss rate than the TC method (TA 2 per cent, TC 9 per cent, p < 0.001).     

太湖藻型湖区CH4冒泡通量

冒泡是甲烷排放的主要途径之一,为量化太湖藻型湖区CH₄冒泡通量及其占总通量的比例,本研究采用静态箱-便携式温室气体自动分析仪方法对春、夏季太湖梅梁湾进行了多日连续观测.结果表明,太湖藻型湖区春、夏季CH₄冒泡通量均存在白天高于夜间的日变化特征.春、夏季CH₄冒泡通量分别为1.843、104.497nmol/（m²·s）,占总通量的比例分别为31.2%和68.6%,即冒泡是夏季CH₄排放的主要方式,而春季CH₄排放则以扩散为主.在小时及日尺度上,CH₄冒泡通量与温度（气温、表面水温和底泥温度）和气压显著相关,且随着温度升高、气压降低,CH₄冒泡排放分别呈指数增加和线性增加趋势.本研究可为准确估算太湖流域CH₄总排放量及明确我国湖泊对全球碳循环的贡献提供重要的基础数据.     

环境条件对遵义市呼吸系统疾病的影响及预测研究

为探究气象和空气污染等环境条件对呼吸系统疾病发病的影响,为遵义地区相关疾病预防提供科学依据,采用分布滞后非线性模型和广义线性、相加模型,利用当地气象和污染资料,分析了2012~2016年遵义市气象环境要素对呼吸系统疾病发病的影响.结果显示,遵义市呼吸系统疾病发病状况与当地长期气候状态基本保持一致,气候效应对其的影响占主导作用,其中,冬季为呼吸系统疾病高发期,立秋至处暑前后其发病人数最少,表明此时间段内当地气候条件对呼吸系统疾病患者有气候疗养效应.气温对呼吸系统疾病发病的影响以低温滞后效应为主,在其敏感阈值附近气温每变化1℃,发病人数将累积增加31.6%（95% CI：4.4%~65.8%）;气压以高压滞后效应为主,相对湿度则在低湿部分同时有即时和滞后效应.舒适度对呼吸系统疾病的影响,在冷、热斜胁迫下其发病人数明显多于舒适状况时.PM_2.5、SO₂和NO₂三种污染物的影响都以即时效应为主,而CO则在累积滞后lag04时相对危险度最高,PM_2.5与呼吸系统疾病发病人数的暴露-反应曲线呈单调线性分布,SO₂、NO₂和CO均为“J”型分布.低温与高浓度NO₂或者低湿与高浓度SO₂的协同作用对呼吸系统疾病的影响较大.建立的全年和季节多元逐步回归方程的试预报准确率在75%以上（夏季除外）,其中分季节建模预测效果显著优于全年预测效果.