Bilgisayar Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/253
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Article Topic Model Implementation To Find Related Documents In Corporate Archives In Real Life: “A Case Scenario On Knowledge Retrieval”(2013) Medeni, İhsan Tolga; Medeni, Tunç DurmuşToday’s organizations were mostly built over their documents. These documents are very crucial sources of knowledge. Even they know the existence of these documents, most of the time, it is nearly impossible to extract captive knowledge inside. In these conditions, organizations choose re-prepare same document again rather than finding proper documents in the archives. On the other hand, finding these documents would save precious time and decrease redundancy of the work. Topic model idea basically focuses on extraction of knowledge from these types of documents. In this study, our aim is to give a summary of Topic Model research and try to explain latest model concept over an imaginary case scenarioConference Object Multimodal Interaction Flow Representation for Ubiquitous Environments - Mif: a Case Study in Surgical Navigation Interface Design(Springer Verlag, 2015) Altun, G.; Cagiltay, N.E.; Maras, H.H.; Borcek, A.O.; Tokdemir, G.With the advent of technology, new interaction modalities became available which augmented the system interaction. Even though there are vast amount of applications for the ubiquitous devices like mobile agents, smart glasses and wearable technologies, many of them are hardly preferred by users. The success of those systems is highly dependent on the quality of the interaction design. Moreover, domain specific applications developed for these ubiquitous devices involve detailed domain knowledge which normally IT professionals do not have, which may involve a substantial lack of quality in the services provided. Hence, effective and high quality domain specific applications developed for these ubiquitous devices require significant collaboration of domain experts and IT professionals during the development process. Accordingly, tools to provide common communication medium between domain experts and IT professionals would provide necessary medium for communication. In this study, a new modelling tool for interaction design of ubiquitous devices like mobile agents, wearable devices is proposed which includes different interaction modalities. In order to better understand the effectiveness of this newly proposed design tool, an experimental study is conducted with 11 undergraduate students (novices) and 15 graduate students (experienced) of Computer Engineering Department for evaluating defect detection performance for the defects seeded into the interface design of a neuronavigation device. Results show that the defects were realized as more difficult for the novices and their performance was lower compared to experienced ones. Considering the defect types, wrong information and wrong button type of defects were recognized as more difficult. The results of this study aimed to provide insights for the system designers to better represent the interaction design details and to improve the communication level of IT professionals and the domain experts. © Springer International Publishing Switzerland 2015.Article Citation - WoS: 8Citation - Scopus: 8Localization of Metallicity and Magnetic Properties of Graphene and of Graphene Nanoribbons Doped With Boron Clusters(Taylor & Francis Ltd, 2014) Kunstmann, Jens; Quandt, Alexander; Ozdogan, CemAs a possible way of modifying the intrinsic properties of graphene, we study the doping of graphene by embedded boron clusters with density functional theory. Cluster doping is technologically relevant as the cluster implantation technique can be readily applied to graphene. We find that B-7 clusters embedded into graphene and graphene nanoribbons are structurally stable and locally metallize the system. This is done both by the reduction of the Fermi energy and by the introduction of boron states near the Fermi level. A linear chain of boron clusters forms a metallic "wire" inside the graphene matrix. In a zigzag edge graphene nanoribbon, the cluster-related states tend to hybridize with the edge and bulk states. The magnetism in boron-doped graphene systems is generally very weak. The presence of boron clusters weakens the edge magnetism in zigzag edge graphene nanoribbon, rather than making the system appropriate for spintronics. Thus, the doping of graphene with the cluster implantation technique might be a viable technique to locally metallize graphene without destroying its attractive bulk properties.Article Citation - WoS: 58Citation - Scopus: 66Molecular Dynamics Simulation of Sintering and Surface Premelting of Silver Nanoparticles(Japan inst Metals & Materials, 2013) Ozdogan, C.; Hu, A.; Yavuz, M.; Zhou, Y.; Atis, M.; Alarifi, H. A.Sintering of Ag nanoparticles (NPs) is increasingly being used as a driving mechanism for joining in the microelectronics industry. We therefore performed molecular dynamics simulations based on the embedded atom method (EAM) to study pressureless sintering kinetics of two Ag NPs in the size range of (4 to 20 nm), and sintering of three and four Ag NPs of 4 nm diameter. We found that the sintering process passed through three main stages. The first was the neck formation followed by a rapid increase of the neck radius at 50K for 20 nm particles and at 10 K for smaller NPs. The second was characterized by a gradual linear increase of the neck radius to particle radius ratio as the temperature of the sintered structure was increased to the surface premelting point. Different than previous sintering studies, a twin boundary was formed during the second stage that relaxed the sintered structure and decreased the average potential energy (PE). The third stage of sintering was a rapid shrinkage during surface premelting of the sintered structure. Based on pore geometry, densification occurred during the first stage for three 4 nm particles and during the second stage for four 4 nm particles. Sintering rates obtained by our simulation were higher than those obtained by theoretical models generally used for predicting sintering rates of microparticles.Conference Object A Mobile Application Flow Representation for Mutual Understanding of It and Healthcare Professionals(2013) Bilgen, S.; Tokdemir, G.; Cagiltay, N.E.; Yildiz, E.; Özcebe, E.; Erturan, Y.N.Ever since mobile applications were developed and became popular, they have started to take part in almost every field of our lives. Healthcare is one of the most popular fields that mobile applications have become a part of. However, development of mobile healthcare applications requires an inter-disciplinary work on which people from different domains should communicate. To do so efficiently, mobile application instructions should be provided as clearly as possible so that mutual understanding can be achieved. This study, aims to provide a methodology to provide the common grounds for healthcare and IT specialists so that to improve the satisfaction level of all the stakeholders of the system from the provided IT services and the end-user interfaces. In other words, by providing a better communication medium for the stakeholders during the design phase, we believe that software development process will be improved, so do their satisfaction from the developed system. © 2013 Springer-Verlag.Article Citation - WoS: 23Citation - Scopus: 29Effective Social Productivity Measurements During Software Development: an Empirical Study(World Scientific Publ Co Pte Ltd, 2016) O'Connor, Rory V.; Clarke, Paul; Yilmaz, MuratMuch of contemporary scientific discussion regarding factors that influence software development productivity is undertaken in various domains where there is an insuflcient empirical basis for exploring socio-technical factors of productivity that are specific to a software development organization. The purpose of the study is to characterize the multidimensional nature of software development productivity and its social aspects as a set of latent constructs (i.e. variables that are not directly observed) for a medium-sized software company. To this end, we designed an exploratory in-depthfield study based on the hypothesized productivity constructs, which were modeled by a set of factors identified from literature reviews, and later refined by industrial focus groups. In order to demonstrate the applicability of our approach, we conducted confirmatory factor analysis with the data attained from a questionnaire with 216 participants. To investigate factors of influence further, we analyzed the impact of selected team-based variables over the latent constructs of productivity. Taken together, our findings confirm that such an approach can be used to explore the quantifiable influence of socio-technical factors that would affect productivity of a particular software development organization. Ultimately, the resulting model provides guidance to explore the comparative importance of a set of firm-specific factors that may help to improve the productivity of the organization.Article Citation - WoS: 49Citation - Scopus: 49Global Minima of Aln, Aun and Ptn, N≤80, Clusters Described by the Voter-Chen Version of Embedded-Atom Potentials(Iop Publishing Ltd, 2005) Sebetci, A; Güvenç, ZBWe report the global minima for aluminium, gold and platinum metal clusters modelled by the Voter-Chen version of the embedded-atom model potential containing up to 80 atoms using the basin-hopping Monte Carlo minimization approach. The results show that the global minima of the Al, Au and Pt clusters have structures based on either octahedral, decahedral, icosahedral or a mixture of decahedral and icosahedral packing. The 54-atom icosahedron without a central atom is found to be more stable than the 55-atom complete icosahedron for all of the elements considered in this work. Most of the Al global minima are identified as face-centred cubic structures and many of the An global minima are found to be low symmetric structures, both of which are in agreement with the previous theoretical and experimental Studies. Although many of the Pt global minima are identical with the global minima of the corresponding Au clusters, the most stable sizes of the Pt clusters correspond to the same sizes of the Al clusters.Article Citation - WoS: 2Citation - Scopus: 2Improvement of Dwt-Svd With Curve Fitting and Robust Regression: an Application To Astronomy Images(Kaunas Univ Technology, 2016) Elbasi, Ersin; Karadeniz, TalhaDWT-SVD is a frequency domain based eigenanalysis watermarking technique. In this work, we improve this method by exploring the relationship between the cover image's DWT singular values and those of the watermark. We show that, via the usage of curve fitting and robust regression, it is possible to achieve accurate results. We also demonstrate that the improved scheme is suitable for the watermarking of astronomy images. In addition to encoding and decoding examples, statistical results on stealth and robustness are deduced from the experiments so that the clear advance can be observed. Quality of the watermark is measured by testing against various attack types.Article Citation - WoS: 3Citation - Scopus: 4Automatic Coastline Detection Using Image Enhancement and Segmentation Algorithms(Hard, 2016) Caniberk, Mustafa; Maras, Hadi Hakan; Maras, Erdem EminCoastlines have hosted numerous civilizations since the earliest times of mankind due to the advantages they offer such as natural resources, transportation, arable areas, seafood, trade, and biodiversity. Coastal regions should be monitored vigilantly by planners and control mechanisms, and any changes in these regions should be detected with its human or natural origin, and future plans and possible interventions should be formed in these aspects to maintain ecological balance, sustainable development, and planned urbanization. Integrated coastal zone management (ICZM) provides an important tool to reach that goal. One of the important elements of ICZM is the detection of coastlines. While there are several methods to detect coastlines, remote sensing methods provide the fastest and the most efficient solutions. In this study, color infrared, grayscale, RGB, and fake infrared images were processed with the median filtering and segmentation software developed within the study, and coastal lines were detected by the edge detection method. The results show that segmentation with fake infrared images derived from RGB images give the best results.Article Analysing Iraqi Railways Network by Applying Specific Criteria Using the Gis Techniques(Coll Science Women, Univ Baghdad, 2019) Naji, Hayder Fans; Maras, H. Hakan; Hakan, H. MaraşThe railways network is one of the huge infrastructure projects. Therefore, dealing with these projects such as analyzing and developing should be done using appropriate tools, i.e. GIS tools. Because, traditional methods will consume resources, time, money and the results maybe not accurate. In this research, the train stations in all of Iraq's provinces were studied and analyzed using network analysis, which is one of the most powerful techniques within GIS. A free trial copy of ArcGIS (R) 10.2 software was used in this research in order to achieve the aim of this study. The analysis of current train stations has been done depending on the road network, because people used roads to reach those train stations. The data layers for this study were collected and prepared to meet the requirements of network analyses within GIS. In this study, the current train stations in Iraq were analyzed and studied depending on accessibility value for those stations. Also, to know the numbers of people who can reach those stations within a walking time of 20 minutes. So, this study aims to analyze the current train stations according to multiple criteria by using network analysis in order to find the serviced areas around those stations. Results will be presented as digital maps layers with their attribute tables that show the beneficiaries from those train stations and serviced areas around those stations depending on specific criteria, with a view to determine the size of this problem and to support the decision makers in case of locating new train stations within the best locations for it.