基于区位差异的旅游季节性比较研究--以青岛、临沂、泰安为例

旅游季节性是旅游地及其旅游产业的重要特征之一。以青岛、临沂、泰安三地为例,从国内客流统计的角度,运用方差分析,分别对其旅游季节性强度指数进行计算,结果表明它们的旅游季节性特征有着显著不同,原因很大程度上可归结为三地旅游区位的差异。其中,资源条件、气候条件、客源市场和交通条件等旅游区位因子会对旅游资源、旅游需求产生不同的影响,并最终作用于旅游地客流的季节性波动。     

Comparative assessment of analytical approaches to quantify the risk for introduction of rare animal diseases: the example of avian influenza in Spain

Trade of animals and animal products imposes an uncertain and variable risk for exotic animal diseases introduction into importing countries. Risk analysis provides importing countries with an objective, transparent, and internationally accepted method for assessing that risk. Over the last decades, European Union countries have conducted probabilistic risk assessments quite frequently to quantify the risk for rare animal diseases introduction into their territories. Most probabilistic animal health risk assessments have been typically classified into one-level and multilevel binomial models. One-level models are more simple than multilevel models because they assume that animals or products originate from one single population. However, it is unknown whether such simplification may result in substantially different results compared to those obtained through the use of multilevel models. Here, data used on a probabilistic multilevel binomial model formulated to assess the risk for highly pathogenic avian influenza introduction into Spain were reanalyzed using a one-level binomial model and their outcomes were compared. An alternative ordinal model is also proposed here, which makes use of simpler assumptions and less information compared to those required by traditional one-level and multilevel approaches. Results suggest that, at least under certain circumstances, results of the one-level and ordinal approaches are similar to those obtained using multilevel models. Consequently, we argue that, when data are insufficient to run traditional probabilistic models, the ordinal approach presented here may be a suitable alternative to rank exporting countries in terms of the risk that they impose for the spread of rare animal diseases into disease-free countries.     

On consistent testing for serial correlation in seasonal time series models

The author considers serial correlation testing in seasonal time series models. He proposes a test statistic based on a spectral approach. Many tests of this type rely on kernel-based spectral density estimators that assign larger weights to low order lags than to high ones. Under seasonality, however, large autocorrelations may occur at seasonal lags that classical kernel estimators cannot take into account. The author thus proposes a test statistic that relies on the spectral density estimator of Shin (2004), whose weighting scheme is more adapted to this context. The distribution of his test statistic is derived under the null hypothesis and he studies its behaviour under fixed and local alternatives. He establishes the consistency of the test under a general fixed alternative. He also makes recommendations for the choice of the smoothing parameters. His simulation results suggest that his test is more powerful against seasonality than alternative procedures based on classical weighting schemes. He illustrates his procedure with monthly statistics on employment among young Americans.     

乌梢蛇某些器官生物量的季节变化

本文观测88条乌梢蛇((?)dhumnades)肥满度和5种器官与组织生物量的季节变化,以及蛇体9个部分含能量的比较。春季的肥满度最低,仅为年均值的87.8％,冬眠前夕或11月的水平最高,为年均值的114.5％。皮肤、肌肉生物量与体系的比重无明显的季节变化,二者的年均值,分别为体重的16.4％(SD=0.6)与59.4％(SD=3.2),其含水量为64.1％(SD=5.9)与70.3％(SD=1.7)。心脏、肝脏、体脂生物量的年均值为0.31％、2.2％与4.3％;三者生物量均以春季最低,分别为体重的0.25％,1.7％与2.1％。但生物量最高季节却不同,心脏在春季达体重的0.36％,肝脏在冬季占体重的2.8％。体脂在秋季占体重的5.8％。5月份,每条蛇体的能量为5.42Kcal/g(SD=0.08)。器官与组织含能值水平以体脂最高6.76Kcal/g(SD=0.31);蛇皮最低,仅5.12Kcal/g(SD=0.03)。     

Counting snowbirds: The importance of and the problems with estimating seasonal populations

Using the example of the seasonal population of ``snowbirds' that spend the winter in Arizona and other Sunbelt states, this paper examines the issues involved with estimating temporary populations. Specifically using the experience of ASU's ongoing research efforts on Arizona snowbirds, the paper discusses some of the problems associated with estimating a seasonal population – in particular: (1) defining the population under study and (2) developing effective procedures to collect information relating to the population. The concluding section emphasizes the growing national importance of temporary populations and the needs of both the public and private sector to have better information on both their size and characteristics.     

Annual Burden of Occupationally‐Acquired Influenza Infections in Hospitals and Emergency Departments in the United States

Infections among health‐care personnel (HCP) occur as a result of providing care to patients with infectious diseases, but surveillance is limited to a few diseases. The objective of this study is to determine the annual number of influenza infections acquired by HCP as a result of occupational exposures to influenza patients in hospitals and emergency departments (EDs) in the United States. A risk analysis approach was taken. A compartmental model was used to estimate the influenza dose received in a single exposure, and a dose–response function applied to calculate the probability of infection. A three‐step algorithm tabulated the total number of influenza infections based on: the total number of occupational exposures (tabulated in previous work), the total number of HCP with occupational exposures, and the probability of infection in an occupational exposure. Estimated influenza infections were highly dependent upon the dose–response function. Given current compliance with infection control precautions, we estimated 151,300 and 34,150 influenza infections annually with two dose–response functions (annual incidence proportions of 9.3% and 2.1%, respectively). Greater reductions in infectious were achieved by full compliance with vaccination and IC precautions than with patient isolation. The burden of occupationally‐acquired influenza among HCP in hospitals and EDs in the United States is not trivial, and can be reduced through improved compliance with vaccination and preventive measures, including engineering and administrative controls.     

The impact of avian influenza on the Korean egg market: Who benefited?

The historical decomposition and directed acyclic graph methods are employed to estimate the effect of avian influenza in Korea on egg price transmission between the farm, wholesale, and retail levels. Our findings suggest that farm and retail egg prices are connected by the wholesale price. We also find that the farm-wholesale and the wholesale-retail margins increase during the avian influenza period. Our results imply that the retailer and wholesaler use their market power to increase their price during the food safety crisis. Therefore, the Korean government should control market power by allowing more emergency egg imports.     

“甲型H1N1流感”之语言生成

语言静态是相对的,动态是绝对的。当下“猪流感”到“甲型H1N1流感”术语变更的实际情形表明,语言生成会经过“基础、修正、生成”的直线过程,经受从言语到语言的心理认知过程。     

基于状态空间模型的中国消费率变动趋势

中国消费率长期偏低且近年有持续下降的趋势,在中国消费社会处于转型升级的重要时期,投资和消费的失衡是当前宏观经济中最严重的问题之一。在对中国消费率偏低原因的静态分析和评价的基础上,首先从消费结构的视角构建了中国1992年1季度至2010年4季度的商品货物消费率。其次,在状态空间季节调整模型中引入均方根信息滤波方法,对原有Kalman滤波模型予以改进,用R软件中DECOMP程序将中国商品货物消费率非平稳序列进行分解,得到变动趋势。再将其与总消费率的走势进行比较发现两者之间的走势存在明显差异。通过建立总消费率与商品货物消费率及消费结构之间的合理函数关系,对前两者差异以及近年中国消费率持续走低进行了合理解释,并从消费结构视角提出提高中国消费率推动消费结构升级的对策。     

Decomposition of Seasonality and Long‐term Trend in Seismological Data: A Bayesian Modelling of Earthquake Detection Capability

This study demonstrates the decomposition of seasonality and long‐term trend in seismological data observed at irregular time intervals. The decomposition was applied to the estimation of earthquake detection capability using cubic B‐splines and a Bayesian approach, which is similar to the seasonal adjustment model frequently used to analyse economic time‐series data. We employed numerical simulation to verify the method and then applied it to real earthquake datasets obtained in and around the northern Honshu island, Japan. With this approach, we obtained the seasonality of the detection capability related to the annual variation of wind speed and the long‐term trend corresponding to the recent improvement of the seismic network in the studied region.