ANOVA Research Papers - Academia.edu (original) (raw)

Pasos para realizar un Analisis de varianza con Excel

FDG-PET ([18F]fluorodeoxyglucose positron emission tomography) is frequently used to improve the differential diagnosis of dementia. However, a fundamental methodological issue of the reference area for the intensity normalization... more

FDG-PET ([18F]fluorodeoxyglucose positron emission tomography) is frequently used to improve the differential diagnosis of dementia. However, a fundamental methodological issue of the reference area for the intensity normalization procedure is still unsolved. Here, we systematically compared the two most commonly used normalization methods to the cerebral and to the cerebellar metabolic rate for glucose with regard to detection and differentiation of dementia syndromes. FDG-PET imaging was performed on 19 subjects with early Alzheimer's disease, 13 subjects with early frontotemporal lobar degeneration and 10 subjects complaining of memory impairment, which had not been confirmed by comprehensive clinical testing. Images were normalized to either the cerebral or the cerebellar metabolic rate for glucose. Differences in relative regional glucose metabolism were assessed by voxelwise comparison. Analysis using the two normalization procedures revealed remarkable differential effec...

Traditionally, the dried flower of Echium amoenum (Boraginaceae) has been used in Iran as an anxiolytic and mood enhancer. This study investigated the efficacy and safety of an aqueous extract of E. amoenum in treatment of... more

Traditionally, the dried flower of Echium amoenum (Boraginaceae) has been used in Iran as an anxiolytic and mood enhancer. This study investigated the efficacy and safety of an aqueous extract of E. amoenum in treatment of obsessive–compulsive disorder. Forty-four patients ...

Context: Jordan is looking for a cheap and locally affordable source for its cosmetics, fuel and medical applications. Jojoba offers one solution to such problems. It is considered as a good medicinal plant that can be used for several... more

Context: Jordan is looking for a cheap and locally affordable source for its cosmetics, fuel and medical applications. Jojoba offers one solution to such problems. It is considered as a good medicinal plant that can be used for several applications. Aims: To evaluate the effect of parameters as mixing speed, temperature, feedstock grain size, mixture ratio and mixing time on the jojoba yield. Methods: The mathematical model combining the effect of all the above variables was then used to find the optimum combination for maximum yield. Response Surface Methodology (RSM) technique was used for modeling and optimization. Based on the Pareto chart of parameters effect, the seed size was the most significant followed with temperature effect. Results: It was found that the optimum values obtained for best yield were seed size of about 0.48 mm, the temperature of about 65°C and mixing time of 2.8 hours maximum yield of about 56% wt can be obtained. Conclusions: A mathematical model was suc...

Optimization of process parameters in sheet metal forming is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the deformation behaviour... more

Optimization of process parameters in sheet metal forming is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the deformation behaviour of the sheet metal. The significance of three important process parameters namely, die radius, blank holder force and friction coefficient on the deep-drawing characteristics of a stainless steel axi-symmetric cup was determined. Finite element method combined with Taguchi technique form a refined predictive tool to determine the influence of forming process parameters. The Taguchi method was employed to identify the relative influence of each process parameter considered in this study. A reduced set of finite element simulations were carried out as per the Taguchi orthogonal array. Based on the predicted thickness distribution of the deep drawn circular cup and analysis of variance test, it is evident that die radius has the greatest influence on the deep drawing of stainless steel blank sheet followed by the blank holder force and the friction coefficient. Further, it is shown that a blank holder force application and local lubrication scheme improved the quality of the formed part.

This paper is based on an argument proposed by Salant (1969), who complained that on many occasions he found the writing of his colleagues “nearly incomprehensible,” and made suggestions to improve economists’ writing skills. Among other... more

This paper is based on an argument proposed by Salant (1969), who complained that on many occasions he found the writing of his colleagues “nearly incomprehensible,” and made suggestions to improve economists’ writing skills. Among other things, he argued that a “simple way of avoiding clumsiness is to prefer the short word to the long one and to avoid the unfamiliar word if a familiar one can be found that is equally correct, specific, and concrete” (p. 556). We call this “the Salant hypothesis,” and use ANOVA to test this hypothesis by comparing the average length of words used by Nobel laureates in their banquet speeches. We find that Literature laureates tend to use shorter words than laureates in other disciplines, and the difference is statistically significant. These results confirm Salant’s idea that words are a scarce resource and should be used efficiently. This includes using short words instead of longer ones whenever possible. In short, good writing is also “economical writing.”

Plastic Injection molding industry has been playing a major role in the mass production of plastic products for various industries; here a product from electrical industry is taken and studied for its quality improvement. This Study deals... more

Plastic Injection molding industry has been playing a major role in the mass production of plastic products for various industries; here a product from electrical industry is taken and studied for its quality improvement. This Study deals with the application of Computer-aided Engineering integrating with statistical technique to develop an injection molded Electrical Product with a reduced warpage and shrinkage which is considered as serious quality defects. For this purpose, the optimum injection molding processing parameters were found by conducting number of flow analyses using Moldex 3D software. The various combination of parameters were selected by following the L27 orthogonal array, the optimization methodology of Taguchi, experimental design and analysis of variance (ANOVA) were used to predict the optimum and significant process parameters inducing the warpage and shrinkage. Statically it is concluded that Packing Pressure and Melt temperature were found to be the most significant parameters, while the mold temperature had the least effect on the warpage and shrinkage for this product. Furthermore effect of variation of significant parameters on the warpage and shrinkage are also studied.

Microplastics are causing serious environmental threats worldwide. To evaluate the current state of microplastics pollution, 28 sediment samples were examined for microplastics and plastic debris contamination along Silver Beach, Southern... more

Microplastics are causing serious environmental threats worldwide. To evaluate the current state of microplastics pollution, 28 sediment samples were examined for microplastics and plastic debris contamination along
Silver Beach, Southern India. Visual identification followed by FT-IR spectroscopy was used to estimate the overall distribution and characterization of plastic debris. The results reveal that white-colored (44%) and irregularly-shaped (82%) plastics are prevalent in the study area. Moreover, the dominant polymer in the study
area is polyvinyl chloride (79%) followed by polyethylene (14%) and nylon (7%). Based on size fractions, mesoplastics are widely distributed in the beach sediments (65%), followed by microplastics (18%) and macroplastics (17%). The regional sources of plastic debris are tourism and fishing activities followed by storm water
runoff through the Gadilam river and wave-induced deposition through high tides. Strict policy measures need to be implemented in recreational beaches like Silver beach to reduce plastic pollution.

The accuracy of achieving required surface finish or surface roughness is of great importance in case of any mass production environment. Thus, understanding and recognizing the optimal process parameters for machining is the key to... more

The accuracy of achieving required surface finish or surface roughness is of great importance in case of any mass production environment. Thus, understanding and recognizing the optimal process parameters for machining is the key to achieving the required surface roughness and gaining competitive advantage. This research is concerned with obtaining the optimal machining process parameters (cutting
speed, depth of cut, feed) which will in turn effect in optimizing the surface roughness in turning glass fiber reinforced polymer (GFRP) matrix composite using coated carbide insert. To find the optimal machining process parameters Taguchi design method has been implemented. An L-16 orthogonal array, signal to noise ratio and ANOVA have been implemented to analyze and understand various process parameters in determining possible relationship with surface roughness. The optimum surface roughness value for this experiment is (3.664µm) which is obtained from Taguchi design method. The results from ANOVA conclude that feed is the most influential factor affecting the outcome having a contribution of (56.04%). And the contributions of depth of cut and cutting speed are separately in order of (17.94%) and (16.42%) respectively. This research provides optimal process parameters for any desired value of surface roughness which results in gaining a competitive edge over others in any mass production environment.

DMAIC one of the Six Sigma methodologies used to improve quality by reducing defects through its several techniques. In this paper Six Sigma and DMAIC used as a defect reduction technique to reduce defects happening during the casting... more

DMAIC one of the Six Sigma methodologies used to improve quality by reducing defects through its several techniques. In this paper Six Sigma and DMAIC used as a defect reduction technique to reduce defects happening during the casting process. For this different type defects are identified, root causes are found and provide a way for minimizing the defects according to the DMAIC phases. Through DMAIC phases from many defects surface roughness is found as main defect and its root causes are found as pouring temperature too high and too coarse the molding sand grain size. For improving the condition, combination of design of experiments (DOE), and two way analysis of variance (ANOVA) are accomplished by Vassar Stats online two way ANOVA solver to find the significance of pouring temperature and grain size on surface roughness. With the help of IBM SPSS Software, boxplot is performed and through trial and error process an optimum solution is gained. At about 50% surface roughness defects are concentrated after performing DMAIC methodology which helped to reduce its defects per million opportunities (DPMO) from 609,302 to 304,651 and improve its Sigma level from 1.2 to 2.

In two studies, this thesis depicts the relationship between minority group status in the United States, perceived discrimination, and coping with stress. Past literature on coping and its types – problem-focused versus emotion-focused –... more

In two studies, this thesis depicts the relationship between minority group status in the United States, perceived discrimination, and coping with stress. Past literature on coping and its types – problem-focused versus emotion-focused – is inconsistent in terms of differences between minority status groups and majority groups. It remains unknown whether or why Black Americans and lesbian or gay Americans may demonstrate coping patterns that differ from White Americans and heterosexual Americans, respectively. What is altogether absent from the literature is the possible mediating factor of perceived discrimination experienced by these minority groups. That is, differences in internal, stable coping processes that manage stress may have been molded by one’s experience with discrimination. Study 1 examines the relationship between race (Black versus White) and coping, mediated by perceived discrimination. Study 2 examines the relationship between sexual orientation (lesbian or gay versus heterosexual) and coping, mediated by perceived discrimination. Both studies confirm the thesis that minority group members exhibit maladaptive, emotion-focused coping more than majority group
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members – but that this difference is explained by the minority group members’ perceived discrimination. Historical and political relevance, social implications, and possible limitations in design and interpretation are discussed.

Öz: Giriş: Kitap tüketim açısından bakıldığında özel bir yere sahiptir yani özellikli bir üründür. Dolayısıyla kitap okuma eylemi de tüketicilerin yaptığı özel bir tüketim türüdür. Bireyler kitapları bilgi edinmek, araştırma yapmak, hoşça... more

Öz: Giriş: Kitap tüketim açısından bakıldığında özel bir yere sahiptir yani özellikli bir üründür. Dolayısıyla kitap okuma eylemi de tüketicilerin yaptığı özel bir tüketim türüdür. Bireyler kitapları bilgi edinmek, araştırma yapmak, hoşça vakit geçirmek, boş vaktini değerlendirmek vb. amaçlarla okumaktadırlar. Okuyucuların bu belirtilen farklı amaçlarla kitap okumaları onların, kitapları satın alırken farklı özelliklerine bakmalarına sebep olmaktadır. Yayınevleri de bireylerin kitap satın almalarını arttırabilmek için kitapların biçimsel özellikleri ve tasarımlarına büyük önem vermektedirler. Ürünlerin tasarımlarının satın alma tercihleri üzerinde etkili oldukları pazarlama literatüründe kabul edilmiş bir durumdur. Dolayısıyla kitapların, türü fark etmeksizin, sahip olduğu tasarımı, boyutu, sayfa sayısı, sayfasının yapısı, kapak tasarımında kullanılan renkler ve şekiller vb. özellikleri, onların okuyucuların tarafından tercih edilme durumlarını etkilemektedir. Amaç: Araştırma kapsamında " Kitap Kapak Tasarımının " ve " Kitabın Biçimsel Özelliklerinin " okuyucuların " Kitap Satınalma Tercihi " üzerindeki etkisi incelenmeye çalışılmıştır. Yöntem: Bu amaçla kolayda örnekleme metoduyla belirlenen ve Sivas ilinde yaşayan 289 kişi ile yüz yüze anket yöntemi kullanılarak veri toplanmıştır. Söz konusu anket Likert tipi maddeler ve demografik ifadelerden oluşmaktadır. Likert tipi maddeler ise kapak tasarımı ile ilgili 9 ifade; biçimsel tasarımla ilgili 5 ifade ve son olarak satın alma tercihini gösteren 3 ifadeden olmak üzere toplamda 17 ifadeden oluşmaktadır. Kapak tasarımı, biçimsel özellikler ve satın alma tercihi değişkenlerinin cinsiyet, yaş, gelir durumu, kitaba ayrılan bütçe, kitap okuma süresi ve akademik birim gibi bazı demografik faktörler açısından incelenmesinde öncelikle Kolmogorov-Smirnov testi ile normallik sınaması yapılmıştır. Değişkenlerin her üçünün normal dağıldığı (p>0,05) görülmüş ve bu doğrultuda parametrik teknikler olan bağımsız gruplar için t testi ve tek yönlü varyans analizi (ANOVA) kullanılmıştır. Ayrıca kapak tasarımı ve biçimsel özelliklerin kitap satın alma tercihi üzerinde etkisinin olup olmadığı ise Pearson korelasyon katsayısı ve basit doğrusal regresyon analizi ile incelenmiştir. Bulgular ve Sonuç: Yapılan T testi ve ANOVA analizleri sonucunda her üç değişken için de bazı demografik faktörlerin geneli açısından anlamlı farklılıklar olmadığı tespit edilmiştir. Sadece " Biçimsel Özellikler " değişkeni " Cinsiyet " faktörüne göre anlamlı bir farklılık

Selfies have become means of self-expression and validation. Posting selfies on social networking sites have become a global phenomenon. By uploading selfies to social media, users seek to gratify their needs. However, there are... more

Selfies have become means of self-expression and validation. Posting selfies on social networking sites have become a global phenomenon. By uploading selfies to social media, users seek to gratify their needs. However, there are psychologists that point out that the trend of taking and posting selfies is related to self-esteem values. This research examined the most sought and least sought gratifications in posting selfies on Facebook, and the relationship between gratifications and self-esteem levels of the users. Social-connection was identified as the most sought gratification and attention-seeking as the least sought gratification. Also, it was found that attention seeking was positively associated with low self-esteem level, social-influence was positively associated with high self-esteem level, and habitual was positively associated with low self-esteem level.