Determinants of the components of bid-ask spreads on stocks

In this paper we show that George et al. (GKN, 1991) estimators of the adverse selection and order processing cost components of the bid-ask spread are biased due to intertemporal variations in the bid-ask spread. We use alternative estimators that correct this bias and that are applicable to individual securities, and estimate these cost components empirically using data on NYSE/AMEX stocks. As expected, our results indicate that on average adverse selection costs account for approximately 50% of the bid-ask spread, sharply higher than the estimates of 8-10% obtained by GKN for NASDAQ stocks and 21% that we obtain for NYSE/AMEX stocks using GKN's estimators. We then conduct cross-sectional regressions designed primarily to determine whether adverse selection costs vary across specialists after controlling for firm size and other factors. Consistent with previously established hypotheses, we find that adverse-selection costs vary across specialists, and that this variation is related to the number of securities that the specialist handles.     

Automatically extracting tourism-related opinion from Chinese social media

Existing tourism-destination investigations of Chinese texts remain weak, and no approach is available to realize Chinese context semantically and automatically. To resolve this, we provide a novel method based on qualitative analysis for studying the online opinions of Chinese tourists regarding the destinations to which they travel. Both traditional and simplified Chinese forums were chosen as the object of study. Spain was selected as a travel destination to evaluate the proposed method. After processing the natural language, unstructured Chinese content is analysed to derive the general sentiment and relevant topics regarding the destination through user comments on social media. The proposed method allows us to understand what tourists are interested in and how they form opinions about tourist destinations.     

我国政府审计存在的问题,原因及制度对策

我国现行政府审计体制存在着一些缺陷和弊端,不利于审计机关独立行使审计监督权,应适时建立直接隶属于最高权力机关的政府审计监督系统;实行高级审计管理人员和高级审计人员轮换制度;实行独立于本级政府控制的经费预算。     

乳及乳制品加工的技术优化

将国外乳制品加工业的先进技术和设备与我国乳及乳制品加工的实际情况相结合,通过对乳及乳制品特性的认真分析和相关指标的精心比选,从而实现了工艺流程、工艺设备及工艺管道的优化。     

基于邻域信息的噪声图像的恢复

噪声图像的恢复是影响图像信息提取的一个重要因素。主要针对现存的噪声图像恢复算法在消除细线及椒盐噪声方面的困难,基于待检像素的邻域信息提出了一种针对细线和椒盐噪声感染的图像的恢复算法。实验结果表明,文中所提算法不仅具有很好的抑制细线及椒盐噪声的效果,而且有效地保存了图像的细节与结构信息,同时对其它的噪声也有一定的抑制作用。     

混叠通信信号的盲分离处理

同频混叠信号的处理一直是通信信号处理中的难点,常规的信号处理方法难以对其进行有效分析。本文运用最新的盲源分离理论,实现了混叠通信信号的盲分离。仿真结果表明,本文采用的算法分离效果好,运算速度快,可移植性强,基本实现了对混叠通信信号的实时盲分离。     

Discovering latent commercial networks from online financial news articles

Unlike most online social networks where explicit links among individual users are defined, the relations among commercial entities (e.g. firms) may not be explicitly declared in commercial Web sites. One main contribution of this article is the development of a novel computational model for the discovery of the latent relations among commercial entities from online financial news. More specifically, a CRF model which can exploit both structural and contextual features is applied to commercial entity recognition. In addition, a point-wise mutual information (PMI)-based unsupervised learning method is developed for commercial relation identification. To evaluate the effectiveness of the proposed computational methods, a prototype system called CoNet has been developed. Based on the financial news articles crawled from Google finance, the CoNet system achieves average F-scores of 0.681 and 0.754 in commercial entity recognition and commercial relation identification, respectively. Our experimental results confirm that the proposed shallow natural language processing methods are effective for the discovery of latent commercial networks from online financial news.     

利用逐步判别分析方法识别碳酸盐岩地层岩性的方法探讨——以川东上余家坝构造石炭系地层为例

碳酸盐岩储层岩性组成复杂,仅仅依靠少量的岩心、岩屑和几条常规的测井曲线资料很难准确地展现储层岩性的纵向及横向分布特征,从而影响对储层空间分布的预测。本文以上余家坝石炭系石炭系地层的岩心、岩屑录井资料为分析样本,结合对应的常规测井资料并对其进行数学处理,处理后共有12个参数供逐步判别函数筛选,经过多次的引入与剔除,建立了各类岩石的判别函数。其中灰岩、灰质云岩、云岩选择了9个参数;云质灰岩选择了10个参数。将岩性判别结果与取心井段的岩性对照,每类岩性的判别符合率都在85.39%以上,综合符合率为91.49%。说明本方法对目的层段碳酸盐岩储层岩性的识别是可行的。     

Marketing Dynamics and Management Excellence: The Sources of Successful Internationalization of a Food Processing Company from a Transition Economy (Case: MASPEX—Poland)

The article presents a case story of the fall and rise of the food industry in Poland's transition economy, illustrated with the example of one of its most successful companies. The author distinguishes 3 stages of the economic transition of Poland: Stage 1, in which the Polish food processing industry collapsed, faced with fierce foreign competition after the implementation of a strategy of liberalization and privatization; Stage 2 (since the late 1990s), when young, dynamic, and relatively well-educated Polish entrepreneurs and managers not only started to regain the local market but also began international expansion, intensifying exports, primarily to EU markets; Stage 3, during which the internationalization took the form of foreign direct investment outward into the former neighboring socialist/communist countries.

The MASPEX Group provides an excellent example of successful revival and expansion achieved thanks to the company's dynamic marketing strategy, executed by a young, dynamic, and highly professional management team.     

MATLAB在工程测试信号平滑处理中的应用

工程测试信号或数据都混杂着各种干扰成分,给后续的信号分析和处理带来了误差甚至错误,为了能够从测试信号或数据中快速、高效地提取有用的特征信息,必须对测试数据样本进行信号预处理,即消除或者抑制干扰成分的影响。结合压力自动控制系统,利用MATLAB软件中smooth函数对测试样本进行平滑处理,比较了smooth函数中各种平滑方法对测试数据的处理效果,确定了适用于自动压力控制系统测试数据平滑处理的METHOD类型,为测试数据的后续分析奠定了基础。