Structural analyses of wooden chairs by finite element method (FEM) and assessment of the cyclic loading performance in comparison with allowable design loads

Tests were carried out to investigate the cyclic loading performance of chairs constructed of Scotch pine (Pinus sylvestris) and Oriental beech (Fagus orientalis). Totally, 30 real size chairs were constructed and assembled with polyvinyl acetate adhesive. Chairs were tested under 3 cyclic loading directions; namely, front to back, back to front, and backrest according to American Library Association specifications, and obtained loading performances of chairs were crosschecked with allowable design load levels that were specified in American Library Association. Additionally, specimens were analyzed  as structures by using finite element method in order to obtain axial, shear, and bending stresses acting on each member under loadings and compare to these values with design stresses. As a result, it was concluded that finite element method analyses achieves reasonable estimates for strength performances and failure behaviors of chairs.  Depending on allowable design loads by American Library Association; chairs constructed of beech could meet the medium service for front to back and back to front loading, while heavy service for backrest loading. In the case of pine chairs; they could meet the medium service for front to back and back to front loading, while light service for backrest loading

Untangling the Web of Historical Thinking: What the Structures of Student-Produced Wikis Reveal

During the past decade, most educators have focused on the collaborative aspects of wikis and how they enable us to collectively create web content. Our focus has been different.We are interested in the ways using wikis to structure information helps students learn the complex thinking skills necessary for understanding history as a web of knowledge rather than linear. We are also interested in the information about how and when students cross concept thresholds made visible by the interconnections of the different pages in a wiki. Using Luminotes, a rudimentary, yet elegant open-source wiki, students can represent--and, we theorize, better understand--the ways that knowledge in the discipline of history is constructed. By the end of the grant period we hope to demonstrate that wikis can be broadly used as a powerful tool for structuring the rich, relational character of knowledge in history (and, potentially, other humanities disciplines) and for better understanding student learning

Sentiment Analysis Using Averaged Weighted Word Vector Features

People use the world wide web heavily to share their experience with entities such as products, services, or travel destinations. Texts that provide online feedback in the form of reviews and comments are essential to make consumer decisions. These comments create a valuable source that may be used to measure satisfaction related to products or services. Sentiment analysis is the task of identifying opinions expressed in such text fragments. In this work, we develop two methods that combine different types of word vectors to learn and estimate polarity of reviews. We develop average review vectors from word vectors and add weights to this review vectors using word frequencies in positive and negative sensitivity-tagged reviews. We applied the methods to several datasets from different domains that are used as standard benchmarks for sentiment analysis. We ensemble the techniques with each other and existing methods, and we make a comparison with the approaches in the literature. The results show that the performances of our approaches outperform the state-of-the-art success rates

Değerleme ölçülerinin Türkiye muhasebe/finansal raporlama standartları, bobi frs ve vuk açısından karşılaştırılması: Finansal durum tablosu aktif yapısı üzerine bir çalışma

In this study, the valuation principles and measures in the Tax Procedure Law (VUK), Turkey Full Set Accounting / Financial Reporting Standards (TMS/TFRS) and Financial Reporting Standards for Large and Medium Enterprises (BOBİ FRS) are examined. The aim of this study is; it is the comparison of the valuation principles and measures in terms of TMS/TFRS, BOBI FRS and VUK on the elements of the asset structure of the statement of financial position and to demonstrate a common valuation basis and measure. The focus of the study is the approaches adopted by VUK, TMS/TFRS and BOBI FRS in terms of financial reporting. While the VUK focuses on the realization of financial reporting in terms of accurate calculation of the tax to be provided by the enterprises to the state, TMS/TFRS and BOBI FRS aim to provide financial information that is appropriate and truthful, understandable, comparable, verifiable and timely to those who need financial information. Valuation measures also differ due to the difference in the goals adopted

A Comparison of Ordered and Unordered Response Models for Analyzing Road Traffic Injury Severities in the North-Eastern Turkey

Road traffic injuries are estimated to be one of the major causes of death worldwide and a majority of them occur in low- and middle income countries. In that respect, further studies that address to determine risk factors that may influence road traffic injury severities in the corresponding countries may contribute the existing road safety literature. This paper determines possible risk factors influencing road traffic injury severity in north-eastern Turkey. For this purpose, a retrospective cross-sectional study is conducted analysing 11,771 traffic accidents reported by the police during the sample period of 2008-2013. As the accident severity is inherently ordered, the data are analysed using both ordered and unordered response models. The estimation results reveal that several driver (age and education level), accident (speeding violation, avoiding manoeuvre and right-of-way rule), vehicle (bus/minivan, single-unit truck/heavy truck, private and single vehicles), temporal (time of day, morning peak, evening peak), environmental (summer and cloudy or rainy weather), geometry (asphalt road and road class type), and control characteristics (presence of crosswalk and traffic lights) were found to have an impact on injury severity. This paper is most probably the first attempt to analyse possible risk factors of road traffic injury severities in Turkey using both ordered and unordered response models. The evidence of this study may be valuable for future road safety policies in emerging countries

Weight–strength optimization of wooden household chairs based on member section size

Weight-strength optimization of wooden household chairs was performed based on the member section size in this study. Member section sizes of the Scotch pine (Pinus sylvestris) and Oriental beech (Fagus orientalis) chairs were optimized and resulting re-manufactured optimized chairs were tested under the cyclic “front to back”, “back to front” and “backrest” loads according to American Library Association (ALA) specification. Finite element method (FEM) and MATLAB nonlinear programming were utilized for the optimization. Firstly, the internal forces and moments acting on each member were analyzed by FEM in order to obtain the maximum critical stresses in each type of member; then, optimized cross-sectional sizes of the members were determined by Gradient Descent method, and all constraints were treated with Logarithmic Barrier Functioning. As a result, the minimum section sizes of members were determined, and cyclic performance tests were performed to determine whether the optimized chairs were strong enough to carry the acceptable loads. According to the results, member section size of both beech and pine chairs could be significantly reduced. The reduction was 32 % in the total weight and volume for beech chairs while 16 % for pine chairs without sacrificing the performance required for domestic usage by ALA. In conclusion, the method used is suitable for the optimization of furniture frames, making it lighter and reducing the material costs.&nbsp

An Analysis of the Education System in Turkey: Supervision Policies Between the Years 1980 – 2021

This article intends to delineate the policy of the supervision system, which is a sub-system of the Turkish education system, for the years 1980-2021, through policy analysis. A systematic literature review (SLR) analyzed the research findings of 44 studies. The findings of the study were categorized according to four main themes that Eranıl (2021) pinpointed as the critical periods in the history of the Turkish education system. Critical periods were classified as a post-coup period: (1980-1997), compulsory eight-year education period: (1997-2005), constructivist period: (2005-2012), 4 + 4 + 4 education system period: (2012 and later). The results of the research indicate that the supervision system in Turkey struggled with organizational structuring problems for more than 40 years. It is also revealed that the supervision system does not have a developed philosophy or applicable principles. Due to these issues raised pertaining to supervision processes, supervisor competencies and personnel are analyzed and discussed

Analysis Of Concentrated Fruit Juice Demand Using The Tobit Model

The purpose of this study was to evaluate the comsumption of concertrated fruit juice by household, and determine the socio-economic factors that affect the level of comsumption. For this purpose, data was collected from a survey of 225 households in Adana in February 1997. A Tobit model was used in the analysis to determine the effects of various socio-economic variables on consumption. It was concluded that four variables are significant on househod fruit juice purchase. These are: the mothers’ status, household income, the number of teenagers in the household, and the mother’s education level. Two of these factors were found to strongly influence comsumption: the number of teenagers in the household (a positive effect) and the mother’s level of education (negative effect).Concentrated Fruit Juice, Demand Analyses,Tobit Model, Turkey