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41.
以南京市城乡若干社区的实证调查为研究个案,深入探讨居民对街道办(乡镇)政府的信任度对居民参与社区志愿服务的意愿与居民的社区志愿精神究竟有何种程度的影响。通过Logistic回归分析,研究结果发现居民对街道办(乡镇)政府的信任度与居民的社区志愿精神之间存在着密切的关联性。对于各级政府而言,本研究的政策含义是需要特别关注影响居民对街道办(乡镇)政府信任的各种居民背景因素,培育居民对街道办(乡镇)政府的信任感和亲切感,不断促进居民社区志愿精神的孕育与成长,从而凝聚成社区草根民主成长的动力和纽带。  相似文献   
42.
目的研究广东省6~15周岁人群牙齿钙化的规律,建立根据牙齿钙化程度推断未成年人年龄的方法。方法观测2 710例(男性1 363例,女性1 347例)广东省6~15周岁汉族人全口曲面断层影像片,对其下颌牙齿钙化程度进行评分分级,所得数据经SPSS软件统计分析,建立根据牙齿钙化程度推断年龄的方程,并以100例(男60例、女40例)研究外样本进行盲测。结果数据统计显示,两侧同名牙钙化评分分级值的差异无显著性意义(P〉0.05),而性别间差异有显著性意义(P〈0.05);下颌单侧8颗牙齿的钙化评分分级值与年龄相关系数(r)女性为0.552~0.759,男性为0.672~0.838;所建回归模型拟合优度(R2)均在0.7以上,估计值标准误男性为0.91~1.11岁,女性为0.92~0.98岁;盲测推测年龄与真实年龄平均误差男性为0.429±0.282岁、女性为0.399±0.252岁。结论本研究所建方法推断结果准确可靠,可用于广东地区6~15周岁人群年龄推断。  相似文献   
43.
Text is still the most prevalent Internet media type. Examples of this include popular social networking applications such as Twitter, Craigslist, Facebook, etc. Other web applications such as e-mail, blog, chat rooms, etc. are also mostly text based. A question we address in this paper that deals with text based Internet forensics is the following: given a short text document, can we identify if the author is a man or a woman? This question is motivated by recent events where people faked their gender on the Internet. Note that this is different from the authorship attribution problem.In this paper we investigate author gender identification for short length, multi-genre, content-free text, such as the ones found in many Internet applications. Fundamental questions we ask are: do men and women inherently use different classes of language styles? If this is true, what are good linguistic features that indicate gender? Based on research in human psychology, we propose 545 psycho-linguistic and gender-preferential cues along with stylometric features to build the feature space for this identification problem. Note that identifying the correct set of features that indicate gender is an open research problem. Three machine learning algorithms (support vector machine, Bayesian logistic regression and AdaBoost decision tree) are then designed for gender identification based on the proposed features. Extensive experiments on large text corpora (Reuters Corpus Volume 1 newsgroup data and Enron e-mail data) indicate an accuracy up to 85.1% in identifying the gender. Experiments also indicate that function words, word-based features and structural features are significant gender discriminators.  相似文献   
44.
Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x(1)) and lower (x(2)) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x(1) and x(2) and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years.  相似文献   
45.
Changes in the size of the pulp canal, caused by apposition of secondary dentine, are the best morphometric parameters for estimating age by X-rays. The apposition of secondary dentine is the most frequently used method for age estimation in adult subjects. In two previous papers, we studied the application of the pulp/tooth area ratio by peri-apical X-rays as an indicator of age at death. The aim of the present study was to test the accuracy of age evaluation by combined analysis of labio-lingual and mesial peri-apical X-rays of lower and upper canines. A total of 200 such X-rays were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio according to labio-lingual and mesial X-rays on upper (x(1), x(2)) and lower (x(3), x(4)) canines. Very good agreement was found between intra-observer measurements. Statistical analysis showed that all variables x(1), x(2), x(3), and x(4) and the first-order interaction between x(1) and x(3) contributed significantly to the fit, so that they were included in the regression model, yielding the following regression formula: Age = 120.737 - 337.112x(1) - 79.709x(2) - 364.534x(3) - 65.655x(4) + 1531.918x(1)x(3) . The residual standard error of estimated ages was 3.62 years, with 94 degrees of freedom, and the median of the residuals was -0.155 years, with an interquartile range of 4.96 years. The accuracy of the method was ME = 2.8 years, where ME is the mean prediction error. The model also explained 94% of total variance (R(2) = 0.94).  相似文献   
46.
《国际相互影响》2012,38(1):84-128
Given both corruption's and bureaucratic inefficiency's importance for development and good governance, understanding their causes is paramount. This paper argues that majority state ownership of most the most important economic sectors of a country results in higher levels of corruption and inefficiency. When political and managerial elites both own and manage the country's most important economic resources, they have greater incentives for corrupt or inefficient behavior. These elites use national resources at their disposal more for short-term personal and political goals than for long-term economic ones. This paper tests this hypothesis on a relatively underused, but often cited, data set from the 1980s. Using a cross-national, regression analysis, this paper finds that the best predictors a country's level of corruption or bureaucratic inefficiency are these: majority state ownership of significant economic sectors, levels of GDP per capita, levels of government spending, and levels of democracy. Other factors, such as common law heritage, percent of population that is Protestant, federalism, economic freedoms, or mineral/ oil exporting, were not consistent, significant predictors of either bureaucratic inefficiency or corruption. We also argue that Tobit may be the best estimation procedure for these data.  相似文献   
47.
Classification of particles as gunshot residues (GSRs) is conducted using a semiautomatic approach in which the system first classifies particles based on an automatic elemental analysis, and then, examiners manually analyze particles having compositions which are characteristic of or consistent with GSRs. Analyzing all the particles in the second stage is time consuming with many particles classified by the initial automated system as being potentially GSRs excluded as such by the forensic examiner. In this paper, a new algorithm is developed to improve the initial classification step. The algorithm is based on a binary tree that was trained on almost 16,000 particles from 43 stubs used to sample hands of suspects. The classification algorithm was tested on 5,900 particles from 23 independent stubs and performed very well in terms of false positive and false negative rates. A routine use of the new algorithm can reduce significantly the analysis time of GSRs.  相似文献   
48.
We examine how parents have made decisions about the number of children they have, given their social status in accordance with residential location (either urban or rural areas) and time (either the pre-modern or modern periods). We use two sets of microdata – Jokbo and Jejeokbu – spanning the early nineteenth to mid-twentieth centuries in Korea. Combining the two data-sets, we use multiple imputation to fill the missing entries of some observations and apply a Poisson regression model on the augmented data. Our empirical results reveal statistically significant evidence that higher socioeconomic status is related to having more children. Additionally, our findings indicate that: (1) all else being constant, among high-status people, rural residents had more children than urban families; (2) for people born between 1800 and 1945, those born closer to the 1940s tended to have fewer children; and (3) during modernization, there was still a significant trend for high-status families to have more children.  相似文献   
49.
The purpose of this study is to compare a specialized community-oriented policing (COP) unit to a reactive unit on officer perceptions of public contact and officer perceptions of job performance. We also compare bicycle patrol officers to motor vehicle patrol officers within these units. Using a static group comparison design, questionnaires were distributed to officers within the Toronto Police Service (n = 178). Bicycle patrol is associated with more contacts with the public and higher rates of proactive policing when compared to motor vehicle patrol and bicycle officers are more likely to rate higher on several measures of crime control. Officers with a COP mandate engage with the public for a wider variety of reasons compared to those with a reactive mandate, and are more likely to rate higher on perceptions of performing job duties in a procedurally just manner. This study demonstrates the value of a specialized COP unit that includes bicycle patrol in achieving tenets of COP. It contributes to the literature on COP and the use of bicycle patrol in law enforcement by presenting the perspective of the police officer.  相似文献   
50.
The increasing governmental spending and simultaneously declining income of municipality are two of the most significant challenges of the 21st century. The introduction of the Internet and innovative information and communication tools over the last few decades have led to a cost saving and efficiency advantage in many areas. By far, public administration has not fully profited from these opportunities and advantages. This article seeks to understand the underlying barriers of technology implementation, namely e-procurement, within the public administration area by analyzing the key barriers of central decision makers within the organization. The empirical findings of 289 respondents from the German public administration show that the barrier typologies are identified and that they have a strong impact on the resistance of implementation. However, the collected data could not verify the theoretically postulated relationship between high resistance and low implementation of the new technology.  相似文献   
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