1,720,959 research outputs found
An Empirical Assessment of Customer Lifetime Value Models within Data Mining
Get PDFCustomer lifetime value has been of significant importance to marketing researchers and practitioners in specifying the importance level of each customer. By means of segmentation which could be carried out using value-based characteristics it is indeed possible to develop tailored strategies for customers. In fact, approaches like data mining can facilitate extraction of critical customer knowledge for enhanced decision making. Although the literature has several analytical lifetime value models, comparative assessment of the existing models especially within the context of data mining seems a missing component. The aim of this paper is to compare two different customer lifetime value models within data mining. The evaluation was carried out within the context of customer segmentation using a database of a company operating in retail sector. The results indicated that two models yield the same segmentation structure and no statistical differences detected on the select control variables. However, the remaining model produced rather different segmentation results than their peers and it was possible to identify the most lucrative model according to the statistical analyses that were carried out on the select control variables
A Novel Agent-Supported Academic Online Examination System
No full textProper execution of exams aimed at assessment & evaluation is of critical importance in Learning Management Systems (LMS). Problems arising from human-centered errors or technical difficulties may lead to questioning of exams, and thus of reliability and efficiency of the distance education systems. Online examination system architecture proposed in this paper provides for integrated management of main functions such as question pool creation and update, exam authoring, execution and evaluation, and management of the feedbacks from students, along with ensuring use of analysis reports related to the questions and exams created by an intelligent agent in the decision-making processes. After conducting analyses on the distance education (DE) system of Sakarya University, it was found that the proposed intelligent agent supported online exam system detects the problems that arise to a large extent and enables the instructors to decide more easily in a shorter time. This system, which is possible to expand with its flexible structure to include additional intelligent features with the aim of resolving different problems, can also be adapted to different institutions that use online examination systems
Çok kademeli tedarik zincirlerinde kamçı etkisinin azaltılması için yeni bir model önerisi : genişletilmiş satıcı yönetimli envanter modeli
Get PDF06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Tedarik zincirlerinde, küreselleşen pazarlar ile talepteki belirsizliğin artması sonucunda ortaya çıkan kamçı etkisi önemli bir problemdir. Bu olumsuz etkinin üstesinden gelebilmek için firmalar, bilgi paylaşımı temelli yeni yönetim yaklaşımlarını tercih etmektedirler. Satıcı yönetimli envanter; üst kademenin alt kademe stok yönetimi sürecinin kontrolünü ele aldığı, bilgi paylaşımı temelli bir yönetim felsefesidir. Aynı zamanda tedarik ağı boyunca kamçı etkisi değerlerinin azaltılmasında önemli faydalar sağlamaktadır.Bu çalışma da; satıcı yönetimli envanter yaklaşımlarının sağladığı faydaların çok kademeli tedarik ağlarına genişletilmesi amacıyla yeni bir ?genişletilmiş satıcı yönetimli envanter? modeli önerilmiştir. Genişletilmiş modelde, değişken talep ve değişken teslim süreleri koşulları ile çalışan talep tahmini tabanlı dinamik stok kontrol politikası ele alınmıştır. Önerilen yeni modelin klasik tedarik zinciri yönetimi ve satıcı yönetimli envanter yaklaşımları ile karşılaştırılması için benzetim uygulaması gerçekleştirilmiştir. Karşılaştırılan modellerin sonuçları toplam zincir maliyeti, kamçı etkisi, sipariş erteleme oranı ve stok miktarı performans ölçütleri açısından tek yönlü varyans analizi (ANOVA) testi ile değerlendirilmiştir. Genişletilmiş satıcı yönetimli envanter modeli ile kamçı etkisi değerlerinde önemli düşüşler sağlanmıştır. Ayrıca toplam zincir maliyetleri ve stok miktarlarını düşürülürken, sipariş erteleme oranlarında müşteri hizmet seviyesi hedeflerinden sapmanın olmadığı sonucuna ulaşılmıştır.Geliştirilen modelin, üretici odaklı yapısından dolayı farklı sektörlerde kullanım alanı (beyaz eşya, otomotiv ve benzeri) bulunabileceği düşünülmektedir. Ayrıca genişletilmiş model kullanımıyla üreticilerin elde etikleri faydaların, dağıtıcı ve perakendecilerine, miktar, fiyat veya maliyet indirimleri şeklinde dağıtılması sonucunda, kullanılabilecek sektörlerin sayısında artış sağlanabileceği öngörülmektedir.In supply chains, bullwhip effect, which was emerged due to raising demand uncertainties in global markets, has been considered as an essential problem in the current body of the literature and causes negative financial impact on companies. Firms prefer adopting new management approaches that are based on information sharing in order to overcome this negative effect. Vendor managed inventory is one of the information based management approaches that suggests upstream supply chain member takes control of the inventory management processes of the downstream member. Also it provides important benefits on reducing the bullwhip effect values along with the supply chain network.In this thesis, a new model that is called ?extended vendor managed inventory? was proposed with purpose of extending the benefits of the vendor managed inventory to multi echelon supply network. In the extended inventory model, a dynamic inventory control policy based on demand forecasting was followed in which demand and lead time variables may vary during the process. A simulation study was developed and conducted in order to compare the proposed model with traditional supply chain management and vendor managed inventory approaches. The comparison results were evaluated using one way analysis of variance (ANOVA) based on the following performance criteria; total supply chain costs, bullwhip effect, backorder rate and inventory level. Through utilizing the proposed extended vendor managed inventory model, a significant reduction was achieved in bullwhip effect values. Also, the results showed that there was no deviation on customer service level targets in backorder rate amongst the comparative models while the proposed model produced better outcomes by achieving decreased values on total supply chain costs and inventory levels.The proposed model may be applicable on different industrial application domain areas eg., home appliances and automotive due to its producer-driven structure. Furthermore, expanding the benefits obtained by the producers using the proposed model to its distributors and retailers in the forms of quantity, price and cost discounts may facilitate further applicability of the model in different application domains
İnternet destekli öğretimde öğrencilerin başarısını etkileyen faktörlerin istatistiksel yöntemler ve yapay sinir ağları ile analizi
No full textBu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır.ÖZET Anahtar Kelimeler: Uzaktan Öğretim, İnternet Destekli Öğretim, istatistiksel Analiz, Yapay Sinir Ağlan Internet destekli öğretim sistemlerinde öğrenci başarısını etkileyen faktörler kişisel ve demografik karakteristikler, öğretim yönetim sistemi ve öğretimsel ortam tasarımı şeklinde dört grupta sınıflandırılır. Kesin sınırların ve standartların belli olması yüzünden öğretim yönetim sistemlerinin basan üzerindeki etkisi sınırlı sayılabilir. Kişisel değişkenler ise tahmin edilmesi ve nümerikleştirilmesi zor değerlerdir. Bu yüzden demografik değişkenlerin ve öğretimsel ortam tasarımı faktörlerinin basan üzerindeki etkisinin araştınlmasmda fayda vardır. Çalışama, internet destekli öğretim öğrencilerinin başanlanmn demografik ve öğretimsel ortam tasarımı faktörleri ile ne ölçüde değiştiğinin belirlenmesi amacıyla hazırlanılmıştır. Çalışmaya genel bir giriş yapıldıktan sonra ikinci bölümde literatürde bu alanda yapılan çalışmalar hakkında kısa bilgiler verilmiştir. Üçüncü bölümde uzaktan öğretim ve internet destekli öğretim kavramları tanıtılmıştır. Dördüncü bölümde istatistiksel analiz yöntemleri ve yapay sinir ağlan hakkında teorik bilgi sunulmuştur. Beşinci bölümde ise istatistiksel analizler ve yapa sinir ağlan ile öğrenme uygulamaları anlatılmıştır. Son bölümde sonuçlar tartışılmış ve öneriler sunulmuştur. Yapılan istatistiksel testler sonucunda demografik etkenlerden yaş, aile reisinin meslek kategorisi, mezun olunan lisenin bulunduğu bölge ve liseden mezuniyet yılı değerleri ile basan düzeyleri arasında anlamlı bir ilişki bulunmuş, kardeş sayısı ile basan düzeyi arasında anlamlı bir ilişkiye rastlanmamıştır. Yapılan regresyon analizi sonucunda öğretimsel ortam tasanmı faktörleri olarak belirlenen, metin uzunluğu, örnek ve uygulama kullanımı, çalışma sorulan, kısa sınav ve ödevler, çoklu ortam uygulamalan ve görsel bütünlük ile basan düzeyleri arasında anlamlı bir ilişki bulunmuştur. Aynca aym değerle yapay sinir ağı modellerinden çok katmanlı algılayıcı modeli ile tekrar işlenmiş. Ağa öğretilen değerler sonucunda tahmin sonuçları elde edilmiştir. Bu kısımda regresyon sonuçlan ile yapay sinir ağının ürettiği değerler arasında karşılaştırmalı bir analiz yapılmış, yapılan test sonucunda iki farklı yöntemin benzer sonuçlar ürettiği sonucuna ulaşılmıştır.ANALYZING FACTORS EFFECT ON THE SUCCESS OF WEB BASED LEARNING STUDENTS' WITH STATISTICAL METHODS AND NEURAL NETWORKS SUMMARY Key words : Distant Learning, Internet Based Learning, Statistical Analysis, Neural Networks The factors which effect to student's success on Internet Based Learning can be classified in four group as personal characteristics, demographic characteristics, learning management system and instructional design. With explicit limits and standards of learning management systems' effects on student's success can be respected as finite. Personal variables are hard values to predict and to be numerical. So, researching the effects of demographic variables and instructional desing would be more effective. This study was prepared to determine how the demographic and instructional design factors change the internet based learning students' successes. After a general introduction, in second chapter short briefings was presented about this literature. In third chapter, distant learning and internet based learning concepts are explained. In fourth chapter, teorical information about statistical analysis methods and neural networks are given. In fifth chapter, learning applications about statistical analysis and neural networks were presented. In last chapter, consequences were discussed and suggestions were presented. After making statistical tests, a meaningful relationship was found between success factors and demographic factors such as age, profession of family man, distinct of the graduation of high school and high school graduation year. A meaningful relationship between success factors and number of brothers/sisters could'nt found. After a regression analysing, a meaningful relationship was found between success factors and instructional design factors before such as length of text, sample and application usage, study questions, short exams and studies, multimedia applications and visual entirety. Furthermore, same values will be processed with multi layer perception model from neural network models. After teaching these values to the network, prediction values were found. In this chapter, a comparative analysis made between regression consequences and values produced by neural network, so two different methods were produced same consequences. X
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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