Observed Trends in Severe Weather Conditions Based on Humidex,Wind Chill,and Heavy Rainfall Events in Canada for 1953–2012     

Éva Mekis  Lucie A. Vincent  Mark W. Shephard  Xuebin Zhang 《大气与海洋》2015,53(4):383-397

Observed trends in severe weather conditions based on public alert statements issued by Environment Canada are examined for Canada. Changes in extreme heat and extreme cold events represented by various humidex and wind chill indices are analyzed for 1953–2012 at 126 climatological stations. Changes in heavy rainfall events based on rainfall amounts provided by tipping bucket rainfall gauges are analyzed for 1960–2012 at 285 stations. The results show that extreme heat events, defined as days with at least one hourly humidex value above 30, have increased significantly at more than 36% of the stations, most of which are located south of 55°N; days with nighttime hourly humidex values remaining above 20 have increased significantly at more than 52% of the stations, most of which are located south of 50°N. Extreme cold events represented by days with at least one hourly wind chill value below ?30 have decreased significantly at more than 76% of the stations across the country. No consistent changes were found in heavy rainfall events. Because city residents are very vulnerable to severe weather events, detailed results on changes in extreme heat, extreme cold, and heavy rainfall events are also provided for ten urban centres.  相似文献   

An Approach to Quantify the Heat Wave Strength and Price a Heat Derivative for Risk Hedging     

Samuel S. P. SHEN  Benedikt KRAMPS  Shirley X. SUN  Barbara BAILEY 《大气科学进展》2012,29(1):1-9

Mitigating the heat stress via a derivative policy is a vital financial option for agricultural producers and other business sectors to strategically adapt to the climate change scenario. This study has provided an approach to identifying heat stress events and pricing the heat stress weather derivative due to persistent days of high surface air temperature (SAT). Cooling degree days (CDD) are used as the weather index for trade. In this study, a call-option model was used as an example for calculating the price of the index. Two heat stress indices were developed to describe the severity and physical impact of heat waves. The daily Global Historical Climatology Network (GHCN-D) SAT data from 1901 to 2007 from the southern California, USA, were used. A major California heat wave that occurred 20-25 October 1965 was studied. The derivative price was calculated based on the call-option model for both long-term station data and the interpolated grid point data at a regular 0.1 ×0.1 latitude-longitude grid. The resulting comparison indicates that (a) the interpolated data can be used as reliable proxy to price the CDD and (b) a normal distribution model cannot always be used to reliably calculate the CDD price. In conclusion, the data, models, and procedures described in this study have potential application in hedging agricultural and other risks.  相似文献   

基于RouterOS技术的12322防震减灾电话呼叫系统双线路设计与实现     

兰陵  宋立军  哈斯高娃  陈勇  周文 《内陆地震》2010,24(4):370-374

根据12322电话呼叫系统的实际工作情况,提出了系统线路备份方案,设计了适合新疆维吾尔自治区地震局现状的12322电话呼叫系统双线路,并给出整体思路、实际配置及调试过程,该方案将会提高12322电话呼叫系统线路的稳定运行,同时也提高了系统的安全运行效率。  相似文献   

Maintaining a sustainable economic base in rural towns: a case study of Leeton     

David A. Chisholm 《The Australian geographer》1995,26(2):156-163

Leeton, a town of 6000 in the Murrumbidgee Irrigation Area, has in recent times suffered major economic upheaval. In 1993 the Letona Co‐operative stone fruit cannery, Leeton's masthead industry since 1921, was placed in receivership and closed after extensive search for a new investor in stone fruit processing failed. The removal of a substantial income stream from the local community has placed great stress on Leeton's economic and social fabric. However, the town in recent years has developed an economy that is no longer completely reliant on a narrow range of agricultural processing and service activities. Utilising factors of location, irrigation‐supported production flexibility and security, cheap land and utilities, and a stable and productive workforce, the combined efforts of the Leeton Shire Council, local community groups, the Riverina Development Board, and State Government departments have attracted a range of new industries to the town and shire over the past decade. It is these industries that will allow Leeton to survive the loss of Letona, sustain its economy and look to the future with confidence.  相似文献   

ESR dating of sedimentary quartz: Possibilities and limitations of the single-grain approach     

Koen Beerten  Andre Stesmans 《Quaternary Geochronology》2007,2(1-4):373-380

Usually, multiple-grain aliquots are used for electron spin resonance (ESR) dating of sediments. However, this approach excludes the ability of detecting insufficient bleaching, as would be the case when measuring several single aliquots or single grains. In this paper, we present preliminary results of single-grain ESR dating experiments on three different sedimentary deposits (fluvial, fluvio-aeolian and desert aeolian), ranging in age between 100 ka and 2 Ma. Titanium-related impurity centres (Ti–Li and Ti–H) were measured in a Q-band ESR spectrometer for estimating equivalent doses (D_e) of individual quartz grains (0.5–1 mm). Both additive and regenerative dose methods were used. The resulting D_e plots show a large scatter in D_e—from 100 Gy to more than 600 Gy—for the fluvial sample, probably reflecting different bleaching histories of the grains. On the contrary, a clear plateau can be observed in D_e for sands with a strong aeolian component. Preliminary single-grain ESR ages are in relatively good agreement with independent estimates, the best results being obtained for the desert aeolian sample (200 ka). It is concluded that ESR has a promising potential for estimating large naturally accumulated doses of well-bleached sediments. Nevertheless, the method is challenged by several experimental difficulties, such as long measurement times, excessive errors, and presumably a complex interrelationship between Ti–Li and Ti–H components.  相似文献   

基于负顾客M/M/s/k＋M重试、反馈排队的呼叫中心性能分析     

鲍媛媛  朱翼隽 《成都信息工程学院学报》2008,23(6):692-697

针对顾客到达时遇忙音重试、服务结束后以一定概率重新请求服务、顾客在排队中因不耐烦而放弃等待,以及负顾客等因素对系统产生的影响,研究了一类具有负顾客到达的,且顾客在ACD中排队中会因不耐烦而放弃等待的M/M/s/k＋M重试、反馈排队模型.运用矩阵几何方法求解,给出了解析解和系统的稳态性能指标,并给出数值计算实例以及适当提高服务率能降低总的顾客损失率等结论.  相似文献   

呼叫中心在安全监控系统中运用的研究   总被引：1，自引：0，他引：1  

张望  郭培峰  古钟璧 《成都信息工程学院学报》2004,19(1):72-75

介绍了将呼叫中心技术应用于基于H.263( )的使用公众电话网(PSTN)传输视频图像的安全监控系统.该呼叫中心采用自动语音应答(IVR)技术实现无人值守时的事故举报,与该安全监控系统进行互动,实现灾情的自动上报和应急方案的调用.详细给出了该系统的设计与实现.  相似文献   

Changing retail structure in Southern Sydney     

《The Australian geographer》1991,22(1):57-66

Analysis of the retail structure in three local government areas in southern Sydney revealed many changes over the period 1969–1989: the number of establishments grew by more than 20 per cent despite a significant population decline; there was considerable evidence of the suburbanisation of the professions; and the composition of shopping centres reflected changing suburban lifestyles, notably as regards an increased concern for eating out, fitness and health, and personal services. Over time, the hierarchy of shopping centres became less clear‐cut and more attenuated. The geographical pattern of growth and decline suggests that the retail structure of the area is becoming increasingly complex.  相似文献   

忻州市“12121”气象声讯服务发展状况分析     

刘丽英  杨勇  王文祥  郭定选  蒋云盛  康晋伟 《山西气象》2009,(2):44-46

山西省结合忻州市“12121”发展状况,通过分析提高拨打率的三大因素,明确了如何充分地利用气象声讯服务平台的优势,向广大用户及时提供内容丰富、专业性强、贴近百姓生活的气象信息,使“12121”气象声讯服务项目具有较强的市场竞争能力和持续发展能力,产生显著的社会效益和经济效益。  相似文献   

"校园一卡通"系统中呼叫中心的设计与实现     

王强  汤彬 《华东地质学院学报》2006,29(2):192-196

呼叫中心(Call Center)系统是综合利用先进的通信及计算机技术,对信息和物资的流程进行优化处理和管理,集中实现沟通、服务和生产指挥的系统。详细介绍了小型呼叫中心系统的实现及在校园一卡通系统中的应用。本系统结合实际需求,采用板卡实现方案,有效地提高了系统的性能价格比,解决了呼叫中心在客户服务系统应用中所涉及的相关问题。  相似文献