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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Demographics and Cronartium appalachianum Rust Disease Assessments in Three Tennessee Populations of Buckleya distichophylla (Nutt.) Torr. (Santalaceae)

Ratliff, William S., Walker, Elaine S., Levy, Foster 01 December 2015 (has links)
A demographic census and disease assessment was conducted in 2007 and 2015 in three Tennessee populations of the dioecious shrub,;Buckleya distichophylla (Santalaceae). Population sizes were relatively stable over time and plant heights and numbers of stems per clump were similar among populations. Seedlings were present in all populations, where they represented 14–19% of individuals. Two populations had an equal male:female sex ratio, but a third population was male-biased. Nonflowering individuals comprised 33–41% of individuals in a population. The majority of plants in all populations had high vigor. Spatial analyses revealed clusters of seedlings in two populations and a cluster of low-vigor plants in one population. Cronartium appalachianum, a rust fungus dependent upon;Pinus virginiana and B. distichophylla as primary and alternate hosts, respectively, was present in all populations with prevalences on B. distichophylla of 19–29%, but there was no spatial clustering of disease in populations. The tree species nearest to B. distichophyllavaried among populations with Tsuga canadensis predominant in one population, T. caroliniana in another, and P. virginiana in the third. Buckleya distichophylla in proximity to P. virginiana had a higher than expected prevalence of C. appalachianum infection.
2

消費者行為與消費空間關係之研究-以台北市商圈為例

陳映如 Unknown Date (has links)
消費是現代人最常進行的日常行為之一,在追求淨利益最大化的前提下,廠商分析消費者行為,利用行銷概念探討並創造足以滿足消費者的行銷組合,檢視何時、何地、以何方式可滿足消費者最大需求。考慮到消費者行為特性,廠商選擇在商業、服務業發展繁盛地區提供服務,不同的廠商作出相同的商業區位選擇後,同質性(homogeneous)或是異質性(Heterogeneous)的商業設施不斷地群聚在一起,而群聚形成的商業核心區或是商圈,則又再度吸引消費者到此地進行消費行為。本文認為消費者行為與消費空間結構是互依的,對廠商而言,知覺並預測消費者的行為特性,並作出區位選擇行為是重要的。廠商藉此達成其區位決策,而重複性的區位決策造成空間上的聚集現象,又成為消費者再度前往該地的吸引力,從宏觀的角度同時分析「消費者行為、廠商區位與廠商空間聚集」之間的關係,不但使消費空間結構的解釋更為合理,對照消費者行為的變遷,便更能說明消費空間形式或其分佈上的改變。 本研究試圖從一個統整的分析角度探討需求面的消費者行為與供給面的廠商兩方,利用現況調查法、問卷調查法等研究方法,以台北市三大商圈作為實證範圍,對商業設施之經營者進行調查,以充分瞭解供給面廠商對於消費者行為與廠商區位決策之間關係的實際看法,並實證「消費者行為與廠商區位決策之關係」;另針對商圈內的消費者作消費者問卷調查,以瞭解需求面消費者的屬性與行為特性情形、消費行為的偏好分析,並分析廠商空間聚集與消費者行為兩類因素的關係,作為本文實證「消費者行為與廠商空間聚集現象二者關係」的依據。依上述的實證結果建構出「消費者行為、廠商區位與廠商空間聚集」之間影響關係的架構,所獲得的成果希望可為私部門廠商區位決策亦或是公部門制訂相關商業政策的參考。
3

疾病群聚檢測方法與檢定力比較 / Disease Cluster Detection Methods and Power Comparison

王泰期, Wang, Tai-Ci Unknown Date (has links)
空間群聚分析應用於流行病學已行之有年,但國內這方面的研究仍較缺乏,尤其在找出哪些地區有較高疾病發生率的群聚偵測。本文針對台灣鄉鎮市資料的特性,提出一套合適的群聚檢測方法,這個方法使用兩階段的電腦模擬,實證上更容易使用;這個方法除了可找出最大顯著群聚外,也能夠偵測出多個群聚的分佈。本文使用電腦模擬比較本文的方法與目前使用較為廣泛的方法(包括Kulldorff(1995)的spatial scan statistic和Tango(2005)的flexible scan statistic),以型一誤差、型二誤差及錯誤率三種標準衡量方法的優劣。最後套用台灣癌症死亡率與健保就診次數資料,探討台灣癌症空間群聚與就診情形的變化。 / Spatial cluster analyses have applied in epidemiology for many years. In this topic there still are few researches in Taiwan, especially in detecting the areas which have higher disease intensity. In this paper, we proposed a new cluster detection method which is aimed at Taiwan counties’ data. This method which uses two-stage computer simulation procedures is useful in practice. This method can find the most likely cluster. Besides, it can find multiple clusters. We use computer simulations to compare our method with others (Kulldorff’s spatial scan statistic& Tango’s flexible scan statistic). Type-I error, Type-II error and error rate are criterions of measurement. At last, we use Taiwan cancer mortality data and all the people health insurance data to discuss Taiwan cancer spatial clusters and the change of diagnoses.
4

Accounting for the Distribution of Adverse Birth Outcomes in Ontario: A Hierarchical Analysis of Provincial and Local Outcomes

Williams, David Neil 29 April 2013 (has links)
Background: Adverse birth outcomes present a difficult and chronic challenge in Ontario, in Canada and in developed countries in general. Increasing proportions of preterm births, significant regional disparities and the high cost of treating all adverse birth outcomes have focused attention on explaining them and developing effective treatments. Methods: Birth outcomes and maternal characteristics for approximately 626,000 births, about 90% of births in 2005–2009, were linked to small geographic areas throughout Ontario. For each of four adverse outcomes: late preterm, moderate to very preterm, small for gestation age and still births, proportions of total births were calculated for the full province and for each small geographic area. Geographic hotspots of elevated rates were identified for each of the different adverse birth outcomes using the local Moran’s I statistic. Data for nine known ecologic and individual risk factors were then linked to the areas. Hierarchical regression analysis was used to model each of the outcomes for the full province and for dispersed local areas. The resulting models for the different outcomes were contrasted. Results: Significant geographic hotspots exist for each of the four outcomes. Hotspots for the different outcomes were found to be largely spatially exclusive. For like outcomes, predictive models differed markedly between local areas (i.e. local groups of hotspots) as well as between full-province and local areas. Ecologic level variables played a strong role in all models; the influence of individual level risk factors was consistently modified by ecologic risk factors except for small for gestational births. Conclusions: The finding of significant hotspots for different adverse birth outcomes indicates that certain geographic areas have aetiologies or patterns of predictors sufficient to create significantly elevated levels of particular outcomes. The finding that hotspots for the different adverse outcomes are largely exclusive implies that the aetiologies are specific; i.e., those that are sufficient to create significantly higher levels for one outcome do not also create significantly higher levels of others. The consistently strong role of ecologic level risk factors in modifying individual level risk factors implies that contextual characteristics are an important part of the aetiology of adverse birth outcomes. Differences in local area models suggest the existence of location-specific (rather than universal) aetiologies. The findings support the need for more careful attention to local context when explaining birth outcomes.
5

都市內部建築物重開發之影響因素-以臺北市為例 / The elements of building redevelopment in Taipei city

蔡友翔 Unknown Date (has links)
藉由建築物之改變,可以觀察都市發展轉變之過程。在一個都市經過完全開發之後,都市內部就會開始出現建築物重開發。林享博(1993)與俞國華(2010)的研究指出,建築物之重開發並非是因為建築物損壞至無法使用,而另有原因存在。本研究藉由過去之相關文獻觀察各都市建築物重開發之情形,歸納出建築物重開發可能影響因素。 本研究選取臺北市為研究範圍,使用臺北市建築管理處核發之建築物使用執照及拆除執照計算建築物之重開發程度,以里為最小空間單元,運用空間分析方法觀察臺北市建築物重開發之空間分佈模式,並運用迴歸分析方法觀察各種因素對於臺北市建築物重開發之影響。經實證研究發現,臺北市之建築重開發會受到地區之戶口數變動率、所得水準、平均屋齡、捷運站、政府主導土地開發等因素影響;戶口數變動率與政府主導之土地開發分別代表了市場力量以及政府力量,則為影響建築物重開發最主要的兩個因素。曾經發生過區段徵收或市地重劃等政府主導土地開發計畫之地區,將形成建築物重開發之高-高空間聚集,而捷運規劃這類重大交通建設則會加速此情形之發生。 / Urban development can be exemplified by means of replacement of old buildings by new ones. Once sites in a city are fully developed, the old buildings will need to be demolished for vacant sites to be supplied. It is not just the physical obsolescence that leads to teardowns of buildings, a number of other factors are also at play. In this study, we select the occupancy permits and demolition permits of buildings issued by Taipei city government to calculate net supply of floor spaces. This net supply serves as a proxy variable of building replacement in regression models. We also employ spatial analysis to measure local spatial clustering of building activities. Our empirical results show that building replacement is affected by changes in households, income level, building ages, access to metro stations and government-led land development projects. Amongst them, changes in households and government-led land development projects are two primary contributing factors. Building activities tend to cluster in areas where government-led land development projects are located, and public transport (metro lines) intensifies this tendency.
6

Accounting for the Distribution of Adverse Birth Outcomes in Ontario: A Hierarchical Analysis of Provincial and Local Outcomes

Williams, David Neil January 2013 (has links)
Background: Adverse birth outcomes present a difficult and chronic challenge in Ontario, in Canada and in developed countries in general. Increasing proportions of preterm births, significant regional disparities and the high cost of treating all adverse birth outcomes have focused attention on explaining them and developing effective treatments. Methods: Birth outcomes and maternal characteristics for approximately 626,000 births, about 90% of births in 2005–2009, were linked to small geographic areas throughout Ontario. For each of four adverse outcomes: late preterm, moderate to very preterm, small for gestation age and still births, proportions of total births were calculated for the full province and for each small geographic area. Geographic hotspots of elevated rates were identified for each of the different adverse birth outcomes using the local Moran’s I statistic. Data for nine known ecologic and individual risk factors were then linked to the areas. Hierarchical regression analysis was used to model each of the outcomes for the full province and for dispersed local areas. The resulting models for the different outcomes were contrasted. Results: Significant geographic hotspots exist for each of the four outcomes. Hotspots for the different outcomes were found to be largely spatially exclusive. For like outcomes, predictive models differed markedly between local areas (i.e. local groups of hotspots) as well as between full-province and local areas. Ecologic level variables played a strong role in all models; the influence of individual level risk factors was consistently modified by ecologic risk factors except for small for gestational births. Conclusions: The finding of significant hotspots for different adverse birth outcomes indicates that certain geographic areas have aetiologies or patterns of predictors sufficient to create significantly elevated levels of particular outcomes. The finding that hotspots for the different adverse outcomes are largely exclusive implies that the aetiologies are specific; i.e., those that are sufficient to create significantly higher levels for one outcome do not also create significantly higher levels of others. The consistently strong role of ecologic level risk factors in modifying individual level risk factors implies that contextual characteristics are an important part of the aetiology of adverse birth outcomes. Differences in local area models suggest the existence of location-specific (rather than universal) aetiologies. The findings support the need for more careful attention to local context when explaining birth outcomes.
7

ANTIMICROBIAL RESISTANCE OF HUMAN CAMPYLOBACTER JEJUNI INFECTIONS FROM SASKATCHEWAN

Otto, Simon James Garfield 29 April 2011 (has links)
Saskatchewan is the only province in Canada to have routinely tested the antimicrobial susceptibility of all provincially reported human cases of campylobacteriosis. From 1999 to 2006, 1378 human Campylobacter species infections were tested for susceptibility at the Saskatchewan Disease Control Laboratory using the Canadian Integrated Program for Antimicrobial Resistance Surveillance panel and minimum inhibitory concentration (MIC) breakpoints. Of these, 1200 were C. jejuni, 129 were C. coli, with the remaining made up of C. lari, C. laridis, C. upsaliensis and undifferentiated Campylobacter species. Campylobacter coli had significantly higher prevalences of ciprofloxacin resistance (CIPr), erythromycin resistance (ERYr), combined CIPr-ERYr resistance and multidrug resistance (to three or greater drug classes) than C. jejuni. Logistic regression models indicated that CIPr in C. jejuni decreased from 1999 to 2004 and subsequently increased in 2005 and 2006. The risk of CIPr was significantly increased in the winter months (January to March) compared to other seasons. A comparison of logistic regression and Cox proportional hazard survival models found that the latter were better able to detect significant temporal trends in CIPr and tetracycline resistance by directly modeling MICs, but that these trends were more difficult to interpret. Scan statistics detected significant spatial clusters of CIPr C. jejuni infections in urban centers (Saskatoon and Regina) and temporal clusters in the winter months; the space-time permutation model did not detect any space-time clusters. Bernoulli scan tests were computationally the fastest for cluster detection, compared to ordinal MIC and multinomial antibiogram models. eBURST analysis of antibiogram patterns showed a marked distinction between case and non-case isolates from the scan statistic clusters. Multilevel logistic regression models detected significant individual and regional contextual risk factors for infection with CIPr C. jejuni. Patients infected in the winter, that were between the ages of 40-45 years of age, that lived in urban regions and that lived in regions of moderately high poultry density had higher risks of a resistant infection. These results advance the epidemiologic knowledge of CIPr C. jejuni in Saskatchewan and provide novel analytical methods for antimicrobial resistance surveillance data in Canada. / Saskatchewan Disease Control Laboratory (Saskatchewan Ministry of Health); Laboratory for Foodborne Zoonoses (Public Health Agency of Canada); Centre for Foodborne, Environmental and Zoonotic Infectious Diseases (Public Health Agency of Canada); Ontario Veterinary College Blake Graham Fellowship

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