TEMPERATURE BEHAVIOR OF THE BLUESPOTTED SUNFISH ENNEACANTHUS GLORIOSUS (HOLBROOK), WITH AN EVALUATION OF THE INTERPRETATION OF THERMAL BEHAVIOR DATA1

The bluespotted sunfish, Enneacanthus gloriosus (Holbrook), had a final temperature preferendum of 31.5 C. Fish acclimated to 30 C avoided 36 C. The analysis of acute temperature preference data and the relationship between final temperature preferendum and upper avoidance temperatures are discussed.     

混沌理论在事故分析及预测中的应用

在对江苏常州市某公司安全事故资料进行大量调查与统计的基础上,应用混沌理论分析了该公司安全事故的混沌特征,指出了事故对初始条件的敏感依赖性和事故的长期不可预测性。应用重构相空间理论对安全事故次数的时间序列进行了分析和预测。同时,还对安全事故统计资料进行了R/S分析,得出该时间序列以2 0 0 1年6月为界限,存在两个Hurst指数,H1=1.6 82 8和H2 =0 .2 936 ,表明在以3个月为时间统计尺度的条件下,事故发生次数在前一时间段整体表现为持久相关性,而在后一时间段表现为反持久相关性。预测与分析结果与实际情况符合较好,表明应用混沌理论进行事故分析与预测是可行的,反映了事故的发展趋势。     

微重力波动与燃烧温度变化的研究

本文通过试验飞机抛物线飞行进行了微重力燃烧实验,采集得到微重力条件下一个采样点微重力波动和燃烧温度变化的数据,在此基础上将时间序列预测和神经网络相结合进行了微重力波动与燃烧温度变化的研究,揭示了试验飞机抛物线飞行中微策略波动和采样点燃烧温度变化的规律。     

我国潜在顾客对城市美食的偏好与影响因素研究--基于网络关注度视角

通过收集网络关注度等数据,利用赫芬达尔—赫希曼指数、皮尔逊相关系数、多元回归分析等方法分析了我国31个省份潜在顾客对10个典型城市美食的偏好与影响因素。结果发现:①同一性别、年龄和地区的潜在顾客对不同城市美食偏好程度均不同,男性潜在顾客对美食的偏好程度略高于女性潜在顾客,美食的潜在顾客以中青年为主。②不同性别、年龄和地区的潜在顾客对同一城市美食的偏好也存在明显差异。③人们对美食的偏好程度与可支配收入之间存在正相关关系,与空间距离之间存在负相关关系。④地域文化、宗教信仰、气候等因素也会对潜在顾客的美食偏好产生影响。     

Future prediction & estimation of faults occurrences in oil pipelines by using data clustering with time series forecasting

The world of oil pipelines is subjected to serious issues due to occurrences of toxic spills, explosions and deformations like particle deposition, corrosions and cracks due to the contact of oil particles with the pipeline surface. Hence, the structural integrity of these pipelines is of great interest due to the probable environmental, infrastructural and financial losses in case of structural failure. Based on the existing technology, it is difficult to analyze the risks at the initial stage, since traditional methods are only appropriate for static accident analyses. Nevertheless, most of these models have used corrosion features alone to assess the condition of pipelines. To sort out the above problem in the oil pipelines, fault identification and prediction methods based on K-means clustering and Time-series forecasting incorporated with linear regression algorithm using multiple pressure data are proposed in this paper. The real-time validation of the proposed technique is validated using a scaled-down experimental hardware lab setup resembling characteristics exhibited by onshore unburied pipeline in India. In the proposed work, crack and blockages are identified by taking pressure rise and pressure drop inferred from two cluster assignment. The obtained numerical results from K-means clustering unveils that maximum datasets accumulated range of multiple pressures are within 16.147–10.638 kg/cm², 14.922–12.1674 kg/cm², 2.7645–1.2063 kg/cm² correspondingly. Hence by this final cluster center data, inspection engineers able to estimate the normal and abnormal performance of oil transportation in a simple-robust manner. The developed forecast model successfully predicts future fault occurrences rate followed by dissimilarity rate from clustering results holds the validity of 91.9% when applied to the historical pressure datasets. The models are expected to help pipeline operators without complex computation processing to assess and predict the condition of existing oil pipelines and hence prioritize the planning of their inspection and rehabilitation.     

基于MNL的高速公路施工区合流选择意愿研究

为分析驾驶人高速公路施工区合流选择意愿的影响因素,基于非集计理论构建多属性施工区驾驶人合流选择意愿模型.利用SP调查法自主设计调查问卷,获得328份有效施工区驾驶人合流选择数据;利用Pearson相关系数分析施工区合流选择意愿与驾驶人因素和道路交通环境因素的相关性;以上游过渡区、警告区Ⅰ和警告区Ⅱ 3个合流区域作为选择...     

Optimized quantity-within-distance models of spatial welfare heterogeneity

Spatial welfare heterogeneity is frequently modeled within stated preference analysis as a function of discrete or continuous distance between households and affected resources. A common example is distance-decay analysis. Although distance-based models such as these are easily estimated, the ubiquity of this paradigm can lead to analyses that overlook other forms of analysis with equal or greater relevance. This paper develops an alternative approach to spatial heterogeneity in stated preference willingness to pay (WTP) based on the quantity or area of an affected resource surrounding each respondent at an optimized distance band or radius, with distance bands optimized using a grid-search algorithm that maximizes model likelihood. Methods and results are illustrated using a choice experiment on riparian land restoration in Maine, USA. The resulting quantity-within-distance model identifies systematic spatial patterns that are undetectable using distance-based analysis and directly relevant for welfare analysis.     

The use of proactive risk management to reduce emergency service vehicle crashes among firefighters

IntroductionEmergency service vehicle crashes (ESVCs), including rollovers and collisions with other vehicles and fixed objects, are a leading cause of death among U.S. firefighters. Risk management (RM) is a proactive intervention to identifying and mitigating occupational risks and hazards. The goal of this study was to assess the effect of RM in reducing ESVCs. Methods: Three fire departments (A, B and C), representing urban and suburban geographies, and serving medium to large populations, participated in facilitated RM programs to reduce their ESVCs. Interventions were chosen by each department to address their department-specific circumstances and highest risks. Monthly crash rates per 10,000 calls were calculated for each department an average of 28 months before and 23 months after the start of the RM programs. Interrupted time series analysis was used to assess the effect of the RM programs on monthly crash rates. Poisson regression was used to estimate the number of crashes avoided. Economic data from Department A were analyzed to estimate cost savings. Results: Department A had a 15.4% (P = 0.30) reduction in the overall monthly crash rate immediately post-RM and a 1% (P = 0.18) decline per month thereafter. The estimated two-year average cost savings due to 167 crashes avoided was $253,100 (95%CI= $192,355 – $313,885). Department B had a 9.7% (P = 0.70) increase in the overall monthly crash rate immediately post-RM and showed no significant changes in their monthly crash rate. Department C had a 28.4% (P = 0.001) reduction in overall monthly crash rate immediately post-RM and a 1.2% (P = 0.09) increase per month thereafter, with an estimated 122 crashes avoided. Conclusions: RM programs have the potential to reduce ESVCs in the fire service and their associated costs; results may vary based on the interventions chosen and how they are implemented. Practical applications: Risk management may be an effective and broadly implemented intervention to reduce ESVCs in the US fire service.     

成都入境旅游客源市场时空演变规律研究

入境旅游客源市场时空演变规律的研究是入境旅游市场研究的一个热点.依据成都市2000-2008年入境旅游市场的相关统计数据,通过分析亲景度和竞争态在时间和空间上的演变,揭示了成都入境旅游客源市场的时空演变规律.研究发现,泰国是成都最重要的入境客源市场,但自从2004年以来亲蓉度有所下降.面对入境客源市场空间分布比较均匀的状况,市场关注的重点应放在市场竞争态有所衰退的市场,以确保整体市场的稳步攀升.