基于射频指纹技术的卫星信号个体识别方法

现有射频指纹识别研究主要集中于射频指纹产生及提取的通信机理,忽略了实际应用中信号采集数据的清洗筛分、识别算法模型的效率等工程性问题。为此,分析了卫星通信号的载波信息提取的原理与方法,并针对现有射频指纹方法的不足,围绕卫星信号识别领域,利用海量采集的射频指纹数据,深入研究基于自组织神经网络的射频指纹识别算法,提出了对应的算法模型,并与现有常见的无监督算法进行了比较。结果表明,所提方法可以取得更优的算法聚类效果和时间开销,可作为设计实现卫星频谱管理系统的基础。     

TEST OF THE CONVERGENCE HYPOTHESIS ALLOWING FOR CROSS‐SECTIONAL DEPENDENCE

A large empirical literature has investigated whether per capita output converges around a common trend across national and regional economies. The methods used in this literature assume no cross‐sectional dependence even though it is likely to be present and might be important in practice. Chang has devised a promising method of testing for unit roots in heterogeneous panels with cross‐sectional dependence. We apply her method to test whether convergence takes place across three samples of economies: 15 advanced industrial countries; a broader group of 57 countries; and the 48 contiguous US states. We find evidence of convergence for the 15 advanced industrial economies but no evidence of convergence across either the broad group of countries or the US states.     

Tariff and Quota Equivalence in Vertically Related Markets

This paper re‐examines the issue of tariff and quota equivalence by introducing an upstream market into the Hwang and Mai (1988 ) model, and then allowing the two downstream firms to cross‐haul within each other's market. We assume the upstream monopolist can select either a two‐part or a one‐part tariff pricing strategy. It is found that if the upstream firm adopts a two‐part (one‐part) tariff pricing strategy, then the market price of the final good under a tariff will be higher (lower) than that under an equivalent quota; that is, the quota is set at the import level under the tariff regime. This result stands in stark contrast to the prior findings of both Hwang and Mai (1988 ) and Fung (1989 ). Moreover, if the quota rent is set as being equal to the tariff revenue, the social welfare under a tariff will necessarily be lower than that under an equivalent quota.     

基于钱纳里模型的中国经济结构研究——来自1978～2009年的经验证据

自20世纪80年代以来,中国经济一直处于高速增长态势,即使2008年席卷全球经济的国际金融危机也没有阻碍其增长步伐。研究经济增长对经济结构优化的影响具有重要意义0以钱纳里的经济结构分析模型为出发点,运用中国1978～2009年的真实数据实证分析了经济增长和就业人数两大因素对经济结构的影响,并使用弹性系数指标对影响程度进行细致刻画。从实证结论中得到如下启示：一是应继续解放和发展生产力,以经济的高速增长带动经济结构升级和优化;二是保持产业结构按“二、三、一”顺序发展,加强对第三产业的投入;三是通过发展第二、三产业来解决就业压力问题;四是促进经济和谐增长,积极转变经济增长方式。     

QUALITY AND ECONOMIES OF SCALE IN HIGHER EDUCATION: A SEMIPARAMETRIC SMOOTH COEFFICIENT ESTIMATION

This paper proposes a semiparametric smooth coefficient cost model to study the university cost structure where coefficients are an unknown function of the university's overall quality. A local least square method with a kernel weight function is used to estimate the cost function, and a simple statistic for testing a parametric model of the additive quality versus the semiparametric smooth coefficient model is applied. Empirical results from 56 universities in Taiwan show that, taking quality into account, higher education is subject to diseconomies of scale. In all categories—comprehensive and science/technology and public and private universities—the current university scale in Taiwan is too big to be cost efficient. (JEL I21, H52, 9120)     

Taxes,Tuition Fees,and Education for Pleasure

The fact that education provides both a productive and a consumptive (nonproductive) return has important and, in some cases, dramatic implications for optimal taxes and tuition fees. Using a simple model, we show that when the consumption share in education is endogenous and tuition fees are unconstrained, the optimal tax/fee system involves regressive income taxes and high tuition fees. A progressive labor income tax system may, on the other hand, be a second‐best response to politically constrained, low tuition fees. Finally, the existence of individuals with different abilities will also move the optimal income tax system toward progressivity.     

Do People Always Pay Less Than They Say? Testbed Laboratory Experiments with IV and HG Values

Hypothetical bias is a long‐standing issue in stated preference and contingent valuation studies—people tend to overstate their preferences when they do not experience the real monetary consequences of their decision. This view, however, has been challenged by recent evidence based on the elicitation of induced values (IV) in the lab and homegrown (HG) demand function from different countries. This paper uses an experimental design to assess the extent and relevance of hypothetical bias in demand elicitation exercises for both induced (IV) and homegrown (HG) values. For testbed purpose, we use a classic second‐price auction to elicit preferences. Comparing the demand curve we elicit in both, hypothetical bias unambiguously (i) vanishes in an IV, private good context and (ii) persists in HG values elicitation context. This suggests hypothetical bias in preference elicitation appears to be driven by “preference formation” rather than “preference elicitation.” In addition, companion treatments highlight two sources of the discrepancy observed in the HG setting: the hypothetical context leads bidders to underestimate the constraints imposed by their budget limitations, whereas the real context creates pressure leading them to bid “zero” to opt out from the elicitation mechanism. As a result, there is a need for a demand elicitation procedure that helps subjects take the valuation exercise sincerely, but without putting extra pressure on them.     

An exploratory study of organizational politics in Kuwait

Because politics is a way of life in organizations, organizational politics has been studied by several scholars over the past 40 years. Few studies, though, have examined organizational politics outside of the United States and Europe. This study is a further step toward closing that gap. In particular, we (1) examined the applicability of the Perceptions of Organizational Politics Scale (POPS) instrument in Kuwait, (2) examined the perceived existence of organizational politics in a public organization in Kuwait, and (3) sought to determine if perceptions of organizational politics seemed to be influenced by the same variables in Kuwait as in Western societies. The study found that the perception of organizational politics is relatively strong and that the POPS instrument was applicable in the Kuwaiti culture and could lead to an expanded understanding of organizational politics. The gender of the respondents, their tenure, and their current positions had some influence on perceptions of organizational politics. © 2011 Wiley Periodicals, Inc.     

Chinese dietary culture influences consumers' intention to use imported soy‐based dietary supplements: an application of the theory of planned behaviour

The over‐saturated dietary supplement (DS) market in developed countries such as the US spurs the need for foreign market expansion, and the Chinese market provides a great potential for the foreign soy‐based DS industry. This study examined Chinese consumers' intention to use imported (US‐made US‐brand) soy‐based DS based on the Theory of Planned Behavior (TPB). Two alternative models were also examined in which Chinese dietary culture variables, including soyfoods favourability and dining‐out sociability, as well as their interactions with attitudes, were integrated into the TPB model. A cross‐sectional, self‐administered survey was conducted with a sample of 215 subjects (137 females; 78 males) in Shanghai, China. The TPB variables attitude, subjective norm, perceived behaviour control and behavioural intention, as well as the Chinese dietary culture variables: soyfoods favourability and dine‐out sociability were measured. Multiple linear regressions were used to analyze the three models. The statistical results indicated that all three models were statistically significant to predict intention (Model 1: R² = 0.473, P < 0.001; Model 2: R² = 0.505, P < 0.001; Model 3: R² = 0.525, P < 0.001). The results also showed that attitude, perceived behavioural control, and dine‐out sociability were significant (positive) determinants of intention. Soyfoods favourability acted a significant (negative) moderator of the relationship between attitude and intention. Subjective norm had no significant impact on intention. In conclusion, the TPB model was useful to predict Chinese consumers' intention to use imported soy‐based DS, but not all the TPB components weighed significantly in exploring DS consumption in China. The selected Chinese dietary culture variables were much more important predictors than subjective norm. This study makes a significant contribution in the application of the TPB model and in market strategy development for imported dietary supplements in China.     

Clothing as an environment for older adults' successful ageing

This research tested a conceptual model for proximity of clothing to self (PCS) in relation to age identity, self‐actualization, psychological well‐being, self‐assessed health, sex and chronological age among older adults, aged 65 and over, within the human ecological perspective. A mail survey was sent to a national random sample of 1700 older adults in the US resulting in 195 usable respondents in the final sample. The respondents returned two completed questionnaires, which were (1) Clothing: A Resource for Successful Aging? (to measure PCS, age identity and demographic variables) and (2) Personal Orientation Inventory (to measure self‐actualization). The results indicated that older adults' psychological well‐being, one component of successful ageing, was directly affected by their self‐assessed health, age identity and self‐actualization. PCS indirectly influenced individuals' psychological well‐being in a slightly negative way in later life. In sum, clothing may be used as a needs satisfier for different levels of needs or related more closely with needs in addition to self‐actualization needs for older adults. Further research should be conducted to explore relationships among PCS, different levels of human needs, clothing‐related variables and psychological well‐being for this age group. In practice, the effort should be given to teach the use of clothing (or other human‐built objects) as a tool or need satisfier to contribute to success in a person's later life by offering some educational or training programmes through local senior community centres or universities.