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JAQM Volume 10, Issue 3 - September 30, 2015
Contents
Test Statistics for Comparing Two proportions with Partially Overlapping Samples
Ben DERRICK, Anselma DOBSON-MCKITTRICK, Deirdre TOHER, Paul WHITE
Standard tests for comparing two sample proportions of a dichotomous dependent variable where there is a combination of paired and unpaired samples are considered. Four new tests are introduced and compared against standard tests and an alternative proposal by Choi and Stablein (1982). The Type I error robustness is considered for each of the test statistics. The results show that Type I error robust tests that make use of all the available data are more powerful than Type I error robust tests that do not. The Type I error robustness and the power among tests introduced in this paper using the phi correlation coefficient is comparable to that of Choi and Stablein (1982). The use of the test statistics to form confidence intervals is considered. A general recommendation of the best test statistic for practical use is made.
Comparison of Classification Success of Human Development Index by using Ordered Logistic Regression Analysis and Artificial Neural Network Methods
Emre YAKUT, Murat GUNDUZ, Ayhan DEMİRCİ
Economic development and growth are among the most important objectives for many countries. Not only economic development but also human development, which means enhancing and improving people’s quality of life, plays an important role for reaching this objective. In this way, it’s possible to take a more human oriented perspective by taking education, health and welfare dimensions of development into consideration by widening the perspective, which is focused narrowly on economic growth only. For this reason, human development index has become a widely preferred and recognized numerical indicator for comparison and classification of countries. Human Development Index (HDI) calculated by Human Development Report Office of United Nations Development Program (UNDP) measure people’s level of welfare every year. The purpose of this research is to compare the classification success of Human Development Index by using ordered logistic regression and artificial neural network. The data of 81 countries, which has United Nations Development Program’s Human Development Index, between the years of 2010-2012 were used in this study. Countries are classified for having very high, high and moderate levels of human development. The results of the ordered logistic regression model indicate that determinants including infant mortality rate, health expenses, number of internet users, import and export were observed as statistically significant. As a result of the analysis, Ordered Logistic Regression Analysis proved 88% success in classification while Elman’s back propagation learning algorithm showed 92% success.
Evaluating the Risk of Projects Implementation in Various Situations using Generalized TOPSIS Model and Business Plan
Gholamreza JANDAGHI, Mahbube HOSSEINI
Due to the growing acceptance of project management, the application of appropriate knowledge, processes, skills, tools and updated and new techniques can affect the success of project. Risk of project implementation has always been discussed in prosperity or not reaching the desired goal, and due to complex world, the updated techniques and tools must be used for measuring of this kind of risk. So the purpose of this paper is to evaluate this risk in various situations with the new models that its name is generalized TOPSIS and also used BP that it is one of the important tools before the implementation of the project. In this method the new concept is used; as peril, hazard and risk. A case study of the proposed model will be introduced in the MATLAB that the end method is modeled in it. The sensitivity analysis of the proposed method are discussed in the next and will be measured by using the Microsoft Excel.
SHA Family Functions
Stelian DUMITRA
This paper presents a general overview regarding SHA family functions. A lot of hash functions were proposed in the last three decades and most of them are based upon the MD construction, especially the MD4 family. The most popular hash functions that belong to the MD4 family are: MD5, the SHA family (SHA-0, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512) and the RIPEMD family (RIPEMD, RIPEMD-128, RIPEMD-160, RIPEMD-256, RIPEMD-320). In 2004, collision attacks against MD5 and SHA-0 were demonstrated by Xiaoyun Wang and one year later she extended a theoretical attack against SHA-1. NIST took the Wang attack into serious consideration and decided to open a competition to develop the next secure hash algorithm, named SHA-3. After five years of competition NIST selected Keccak as winner. Keccak is a family of sponge functions. Also, this paper describes the sponge construction and its security. Various comparisons between SHA-3, SHA-2 and SHA-1 regarding the security strengths, performances and construction details are summarized. The conclusions are presented at the end of the paper.
An Overview of Causal Directed Acyclic Graphs
Michael LEWIS
Given the mission of social work to improve people’s lives by intervening in ways to enhance their well-being, social work researchers are interested in the causal effects of various types of social interventions (de Anda, 2007; Ohmer, and Jorr, 2006; Hawkins, 2006). Statisticians, econometricians, and other experts in quantitative methods tend to view randomized controlled trials (RCTs) as the “gold standard” when it comes to estimating causal effects, and there’s a key reason for this--RCTs are based on randomly assigning units to at least two different intervention groups. Random assignment tends to result in the groups being balanced on variables that may have a causal relationship with the outcome of interest other than the intervention which is the focus of a given study. At least one of these “balanced variables” may also be causally related to the intervention itself. “Balanced” means that the average values of these other variables are equal across the different groups.
A Spreadsheet Solution to H. E. Dudeney’s Puzzle “Visiting the Towns”
Mike C. PATTERSON, Daniel FRIESEN, Bob HARMEL
The purpose of this paper is to present an optimization model approach to one of Dudeney’s puzzles, “Visiting the Towns,” which appears as puzzle number 243 in Amusements in Mathematics (Dudeney, 1917). Henry Ernest Dudeney (1857-1930) was one of the most prolific mathematical puzzle creators of the past two hundred years. His first collection of puzzles, The Canterbury Puzzles and Other Curious Problems, was published in 1907. This popular book is still in print today (Dudeney, 1907). Beginning in 1917, he created five other popular puzzle collections, three of which were published posthumously. In addition to prodigious quantities of puzzles, his range of puzzle-types was exceedingly large, including geometry-based, logic puzzles , combinatorics” (Bremner, 2011), “cryptarithmetic” (Kilpelainen, 2012), cross-number puzzles (Sit, 1991), and chess problems (Nowlan, n.d.). During his time, there were no calculators; his mathematical puzzles were approached through pencil and paper calculations.
Intellectual Capital Components as Drivers of Romanian SMEs Performance
Bogdan-Vasile ILEANU, Alexandru ISAIC-MANIU, Claudiu HERTELIU, Tudorel ANDREI
The paper studies the possibility of evaluation of the intellectual capital in Science, Information and Technology domain from Romania. The analysis is made starting from a base sample of 1400 SMEs. Quantitative methods such as Structural Equation Modelling method are used to determine the group of latent factors used to evaluate the IC components of SME. Due to the particularities of Romanian SMEs and of the indicators used, some findings such as reference age of manager, the role of strong internal organization and structural capital are revealing for the first time some aspects relating the intangible assets and their potential resource for companies’ performance. The results are similar to some particular studies made on SMEs from countries with economies in transition.
Sustainability Reporting and Consumers’ Protection
Ionel JIANU
The present article analyses the corporative practices and the consumers’ protection from the perspective of sustainability reporting, offering a fundamental theory for the sustainability reporting domain, which explains why a company is responsible for consumers’ protection. Based on the domain literature and on qualitative data from reports recommended by Global Reporting Initiative, within the article there is developed a conceptualization of corporate practice regarding consumers’ protection, the research having implications for the practice in the domain and for further researches.