Exact bootstrap confidence intervals for regression coefficients in small samples

ABSTRACT

Regression analysis is one of the important tools in statistics to investigate the relationships among variables. When the sample size is small, however, the assumptions for regression analysis can be violated. This research focuses on using the exact bootstrap to construct confidence intervals for regression parameters in small samples. The comparison of the exact bootstrap method with the basic bootstrap method was carried out by a simulation study. It was found that on a very small sample (n ≈ 5) under Laplace distribution with the independent variable treated as random, the exact bootstrap was more effective than the standard bootstrap confidence interval.     

The Appropriateness of Some Common Procedures for Testing the Equality of Two Independent Binomial Populations

For testing the equality of two independent binomial populations the Fisher exact test and the chi-squared test with Yates's continuity correction are often suggested for small and intermediate size samples. The use of these tests is inappropriate in that they are extremely conservative. In this article we demonstrate that, even for small samples, the uncorrected chi-squared test (i.e., the Pearson chi-squared test) and the two-independent-sample t test are robust in that their actual significance levels are usually close to or smaller than the nominal levels. We encourage the use of these latter two tests.     

Efficiency and effectiveness of knowledge management systems in SMEs

This paper proposes a 3D fuzzy logic methodology to assess the efficiency and effectiveness of knowledge management systems (KMSs) adopted by small and medium enterprises (SMEs) and identifies a classification bringing together the behaviour of SMEs when adopting KMSs. The proposed methodology was previously tested on an individual SME and then implemented on a sample of SMEs. The results highlight that there is an ample variety of behaviours related to the nature of knowledge and the KMSs used. Specifically, four typologies of behaviour are identified: the efficient and effective SME, the effective but inefficient SME, the efficient but ineffective SME, and the inefficient and ineffective SME. The results show that only 18% of surveyed SMEs are efficient and effective for both KM-Tools and KM-Practices, the remaining 82% are inefficient or ineffective for KM-Tools and/or KM-Practices. Lastly, the paper shows how this methodology may be used by an SME as a managerial tool to suggest appropriate changes to improve the efficient and effective adoption of KMSs supporting SMEs in the knowledge management processes.     

Signed likelihood ratio tests in the Birnbaum-Saunders regression model

The Birnbaum-Saunders regression model is becoming increasingly popular in lifetime analyses and reliability studies. In this model, the signed likelihood ratio statistic provides the basis for testing inference and construction of confidence limits for a single parameter of interest. We focus on the small sample case, where the standard normal distribution gives a poor approximation to the true distribution of the statistic. We derive three adjusted signed likelihood ratio statistics that lead to very accurate inference even for very small samples. Two empirical applications are presented.     

The moderating effects of home region orientation on R&D investment and international SME performance: Lessons from Korea

Drawing from the resource-based view, we investigate how firm and country combinations affect international SME performance. Using a sample of 2676 international Korean SMEs, we explore the relationships among SME R&D investment, home region orientation and financial performance. Results show that R&D investment has a horizontally inverted S-shaped relationship with performance reflecting cost leadership, stuck in the middle, and differentiation strategies. We also find that a home region orientation moderates the relationship between R&D investment and performance. Home region orientation positively moderates the relationship when R&D investment reflects cost leadership or differentiation but negatively moderates a stuck in the middle strategy.     

洪武永乐时期明朝与西域诸“地面”的关系

明初西域除东察合台汗国和帖木儿帝国两个势力强大的帝国外,还有一些大小不等的“地面”,学界对诸“地面”则鲜有涉猎.洪武永乐时期,与明朝关系相对密切的当是在东察合台汗国控制下的土鲁番、哈刺火州、柳城和于阗等.这一时期,瓦刺进入西域,并与东察合台汗国展开了角逐,瓦剌在西域地区的兴衰变化不仅对当时西域局势产生重要影响,而且对以后西域历史的发展影响深远.     

小人物悲剧命运的必然性——论舍伍德·安德森小说《鸡蛋》中“父亲”的悲剧命运

《鸡蛋》是美国作家舍伍德.安德森最著名的短篇小说之一。它讲述了＂父亲＂两次奋斗却都惨遭失败的悲惨命运。从小人物角度入手,探讨了＂父亲＂的小人物典型性,从＂父亲＂小人物性格、西西弗斯神话与存在主义对小人物命运的影射,剖析了＂父亲＂这一小人物悲剧命运的必然性。希望可以提供一个不同的角度来理解这篇优秀的短片小说。     

苍凉残缺的团圆——解读张爱玲的《小团圆》

张爱玲的遗作《小团圆》描述了她的家族和爱情,叙述了令她重度缺乏爱的一生境况。从母爱的回归与家族的团圆、爱情的失落与宽容、自我生命与情感的超越三个方面剖析了张爱玲创作《小团圆》的真正动因——爱恨的宽容与生命的回归、实现自己一生无奈而又凄艳的＂小团圆＂,而这也正是张爱玲心中所期盼的苍凉残缺的团圆。     

基于关系型贷款的城市商业银行小企业贷款定价研究

城市商业银行与小企业有着天然的、共生共荣的联系。如何制定一个科学合理的小企业贷款利率定价机制,是城市商业银行经营决策中的重要课题。通过对某城市商业银行的小企业贷款定价现状进行的实证分析,发现银行主要侧重于风险的考虑,忽略了银企之间的“关系”因素,没有借助“关系”收集并利用“软”信息进行准确定价。在此基础上,以关系型贷款作为小企业贷款定价的指导思想,研究设计了基于关系型贷款的定价思路。