基于相干对消的噪声子空间自适应估计

MUSIC算法的运算量主要集中在特征值分解和空间谱的搜索两部分,为避免进行特征 值分解,将相干信号自适应对消的思想用于噪声子空间的估计。由于阵元输出信号完全相干 ,视一个阵元输出为参考信号,其它阵元输出能够完全对其进行对消,得到的系数矩阵作为 噪声子空间的估计。基于LMS算法,给出了算法的矩阵形式,得到的噪声子空间估计算法的 运算量大大降低,且以迭代的方式进行,适合应用于运动信号源的跟踪,在阵元数较大时能 很好地逼近MUSIC算法性能。为减少空间谱搜索过程的计算量,对搜索过程先用系数矩阵的 一列进行搜索,然后采用其它列对搜索峰值进行验证。仿真结果显示算法具有很好的空间谱 估计性能和DOA跟踪性能。     

Halifax Henna: The Art of Manageable Growth*

This case explores the dilemma many young women face when they begin a family: juggling a full‐time job as a young Chartered Professional Accountant (CPA) with a government job, continuing to grow a small business as a henna artist, and caring for a new baby. Even before the arrival of the first child, the combination of continuing to do both jobs was not sustainable. The case provides information to enable students to assess the financial health of a small business and provides a recommendation to the owner. In addition, information regarding paying childcare costs while continuing with a government job provides a realistic comparison for students. Often students jump to the money, which is currently in her accounting job, and forget that passion, dreams, and objectives for work–life balance, although earning less at the moment due to the part‐time nature, may be the best way forward.     

Privacy in Doubt: An Empirical Investigation of Canadians' Knowledge of Corporate Data Collection and Usage Practices

We investigate Canadians' level of awareness of the ways in which businesses collect and use their data via existing and emerging technologies, including facial and voice recognition, mobile location tracking and the Internet of Things. In a survey of 1,005 Canadians, we found that many respondents are ill informed about how their data are being collected and used. Such low awareness of data practices is partially explained by the shortcomings of the “privacy notice.” We suggest further research into alternative methods of informing Canadians about corporate data practices and of enhancing individuals' control of private data in today's increasingly connected and mobile world. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.     

Voluntary Disclosure and Informed Trading*

This study analyzes the impact of informed trading on voluntary corporate disclosure in the presence of two factors: the cost of disclosure and the value of a manager's informedness. In the absence of both factors, informed trading has no impact on disclosure even when traders are not certain whether the manager has information. When disclosure is costly, informed trading serves as a free substitute for the disclosure of favorable information, and reduces disclosure. Surprisingly, when the manager's informedness is valuable for the firm, informed trading can also increase disclosure. Traders can discover unfavorable information about the firm, so managers with such information have less incentive to pool with uninformed managers and disclose to show that they are informed. The study also demonstrates that informed trading can have either a positive or a negative effect on firm value by crowding in or crowding out information production in the firm. These results hold for general information structures and are robust if traders can choose how much information can be acquired.     

Managing critical success factors for IS implementation: A stakeholder engagement and control perspective

Enterprise information systems (IS) implementation is often part of an organization's strategic IT initiatives and requires a large investment of organizational resources, yet may fail due to inadequate management of critical success factors (CSF). Using a revelatory case study of a multi‐partner COTS implementation process by a large Canadian government organization, this research investigates successful management of CSF through optimal stakeholder engagement and a balancing of control configurations. This research identifies four distinct project orientations related to stakeholder engagements—strategic, responsibility, harmony, and persuasion—that can be of significant value in managing CSF and other challenges during implementation and post‐implementation phases. In addition to the identification of a need for control balancing in a multi‐partner IS implementation, three key drivers responsible for triggering control balancing are identified: (a) shared understanding, (b) negative anticipation, and (c) deviation of expectations. Copyright © 2017 ASAC. Published by John Wiley & Sons, Ltd.     

Les effets du gel d'une caisse de retraite sur la performance et le risque des entreprises

This study considers the effect of freezing defined benefit pension funds on shareholder risk and returns. The conditional models used in this study directly assess the effects of a pension fund freeze on returns and on systematic and residual risk. While pension fund freezes do not significantly affect performance or systematic risk, they do significantly reduce short‐term residual risk. Pension fund freezes therefore do not generally present significant financial advantages to shareholders. Only shareholders of funds in crisis would benefit from significant systematic risk reductions. Copyright © 2015 ASAC. Published by John Wiley & Sons, Ltd.     

一种单天线同频混合信号幅度的估计算法

针对非协作通信中平坦衰落条件下单天线接收两路MSK混合信号分量的幅度估计问 题,提出了一种基于max-min思想的幅度盲估计算法。该算法采用混合信号幅值序 列中多个极大极小幅值的估计值来进行混合信号分量的幅度估计,并采用加窗局部极值平均 的方法来获得多个极大极小幅值的估计值。仿真结果表明：在信噪比大于10 dB条件下 ,该 算法 对MSK混合信号幅度估计较为准确,并且该算法对混合信号分量功率比和相对时延差的变化 具有较强的鲁棒性,具有不需要数据辅助、计算量较小的优点,能够满足后续盲信号处理的 需要。     

Differential multipliers

A modified version of the Archer tourism multiplier model is used to derive differential multipliers, at both the sectoral and firm scale, for the Cook Islands tourist industry and ancillary sectors. Firm level analysis is shown to be necessary if factors of industrial organization, such as size and ownership characteristics, are not to be overlooked. The results reveal that smaller, locally owned establishments generate more local income, employment, and gross government revenue than their larger, overseas controlled counterparts. The model is shown to be a highly suitable surrogate for conventional input-output models, which, due to factors such as cost and lack of data, cannot always be used in small nations or regions to develop a data base suitable for the planning of tourist development.     

Tourism data processing: Elementary methodology

The aim of this paper is to give a method of rationally analyzing touristic data. The development of this method is a parallel of the solution of a survey on tourism promotion in a French region which uses concrete support for the various theoretical elements presented. The proposed proceeding can be applied to every touristic problem in which data are very numerous and are, in fact, impossible to interpret. The aim is to distill from a mass of information the most striking tendencies, the most evident propositions, and briefly, the greatest number of relationships possible. Toward these purposes, the following techniques apply: organizing the data by following criterions and structuring data in hierarchical or non-hierarchical groups; data visualization by the statistical scatter; and data reduction. Linear factorial analysis has been applied in the solution of the concrete case presented at the beginning of this paper.     

Implementing Big Data Analytics in Small Firms: A Situated Human Practice Approach

This study identifies and addresses an important gap in the nascent literature on big data analytics, using a longitudinal case study to investigate the implementation and application of big data analytics into a small firm specialized in transport logistics. Our research is rooted in Practice Theory, considering the implementation of new technologies in organizations as a result of multiple social negotiations, interpretations, and interactions. Our findings indicate the importance and centrality of human factors in decision-making and operational implementation, technology representing only a means to a clearly specified and collectively assumed objective. Big data analytics adoption and use in the case-study firm represents a gradual process, with each stage justified by the need to solve the problems caused by heavy and unpredictable road traffic. This approach validates the entrepreneurial effectuation model, which defines a firm's strategy as a fragmented but continuous effort to find and implement effective solutions to the market challenges encountered.