Browsing by Subject "Assembly"

Now showing 1 - 12 of 12

Open Access
Analysis of assembly systems for interdeparture time variability and throughput
(Taylor & Francis, 2002) Sabuncuoğlu, İ.; Erel, E.; Kok, A. G.
This paper studies the effect of the number of component stations (parallelism), work transfer, processing time distributions, buffers and buffer allocation schemes on throughput and interdeparture time variability of assembly systems, As an alternative to work transfer, variability transfer is introduced and its effectiveness is assessed. Previous research has indicated that the optimal throughput displays an anomaly at certain processing time distributions and, this phenomenon is now thoroughly analyzed and the underlying details are uncovered. This study also yields several new findings that convey important practical implications.
Open Access
Annotated features of domestic cat-Felis catus genome
(BioMed Central Ltd., 2014) Tamaziani G.; Simonov, S.; Dobrynin, P.; Makunin, A.; Logachev, A.; Komissarov, A.; Shevchenko, A.; Brukhin, V.; Cherkasov, N.; Svitin, A.; Koepfli, Klaus-Peter; Pontius, J.; Driscoll, C. A.; Blackistone, K.; Barr, C.; Goldman, D.; Antunes, A.; Quilez, J.; Lorente-Galdos, B.; Alkan C.; Marques Bonet, T.; Menotti-Raymond, M.; David, V. A.; Narfström, K.; O'Brien, S. J.
Background: Domestic cats enjoy an extensive veterinary medical surveillance which has described nearly 250 genetic diseases analogous to human disorders. Feline infectious agents offer powerful natural models of deadly human diseases, which include feline immunodeficiency virus, feline sarcoma virus and feline leukemia virus. A rich veterinary literature of feline disease pathogenesis and the demonstration of a highly conserved ancestral mammal genome organization make the cat genome annotation a highly informative resource that facilitates multifaceted research endeavors.Findings: Here we report a preliminary annotation of the whole genome sequence of Cinnamon, a domestic cat living in Columbia (MO, USA), bisulfite sequencing of Boris, a male cat from St. Petersburg (Russia), and light 30× sequencing of Sylvester, a European wildcat progenitor of cat domestication. The annotation includes 21,865 protein-coding genes identified by a comparative approach, 217 loci of endogenous retrovirus-like elements, repetitive elements which comprise about 55.7% of the whole genome, 99,494 new SNVs, 8,355 new indels, 743,326 evolutionary constrained elements, and 3,182 microRNA homologues. The methylation sites study shows that 10.5% of cat genome cytosines are methylated. An assisted assembly of a European wildcat, Felis silvestris silvestris, was performed; variants between F. silvestris and F. catus genomes were derived and compared to F. catus.Conclusions: The presented genome annotation extends beyond earlier ones by closing gaps of sequence that were unavoidable with previous low-coverage shotgun genome sequencing. The assembly and its annotation offer an important resource for connecting the rich veterinary and natural history of cats to genome discovery. © 2014 Tamazian et al.; licensee BioMed Central Ltd.
Open Access
Balancing of U-type assembly systems using simulated annealing
(Taylor & Francis, 2001) Erel, E.; Sabuncuoğlu İ.; Aksu, B. A.
The paper presents a new simulated annealing (SA)-based algorithm for the assembly line-balancing problem with a U-type con®guration. The proposed algorithm employs an intelligent mechanism to search a large solution space. U-type assembly systems are becoming increasingly popular in today’s modern production environments since they are more general than the traditional assem- bly systems. In these systems, tasks are to be allocated into stations by moving forward and backward through the precedence diagram in contrast to a typical forward move in the traditional assembly systems. The performance of the algorithm is measured by solving a large number of benchmark problems available in the literature. The results of the computational experiments indicate that the proposed SA-based algorithm performs quite eŒectively. It also yields the optimal solution for most problem instances. Future research directions and a compre- hensive bibliography are also provided here.
Open Access
A goal programming approach to mixed-model assembly line balancing problem
(Elsevier, 1997) Gokcen, H.; Erel, E.
In this paper, a binary goal programming model for the mixed-model assembly line balancing (ALB) problem is developed. The model is based on the concepts developed by Patterson and Albracht [1] and the model of Deckro and Rangachari [2] developed for the single-model ALB problem. The proposed model provides a considerable amount of flexibility to the decision maker since several conflicting goals can be simultaneously considered.
Open Access
The impact of reengineering in manufacturing companies: a methodology for operations improvement and manufacturing productivity
(1993) Atceter, Muzaffer
Many manufacturing companies today are facing the problem of loosing their competitive edge in international markets. This is partly due to the outdated manufacturing processes. This study is examining the improvement methods and suggesting a methodology whose scope is wider than small changes. This type of improvements requires a radical change in the manufacturing processes. The word reengineering, meaning process redesign, is used to describe this method for achieving the manufacturing productivity considering the cost, quality, customer service, time and management issues. First chapter is defining reengineering. The techniques, methods and a step-bystep approach for productivity projects are explained in the second chapter. Chapter three includes an analysis of a Turkish case company with the methods given in chapter 2. The thesis questioning the applicability of reengineering projects for manufacturing companies in Turkey in chapter 4. It is examining the difficulties that the project teams would face.
Open Access
Inquiring the main assumption of the assembly line balancing problem : solution procedures using and/or graph
(2005) Koç, Ali
In this thesis, we consider the assembly/disassembly line balancing (ADLB) problem. The studies in the literature consider assembly and disassembly problems separately and use task precedence diagram (TPD) and AND/OR Graph (AOG) in assembly and disassembly line balancing problems, respectively. In contrast to these studies, we use AOG for both assembly and disassembly line balancing problems, considering these two problems as complementary of each other. Hence, we call the complementary problem as ADLB-AOG. We show theoretically that AOG is a more general version of the TPD. We also develop integer programming (IP) and dynamic programming (DP) formulations to solve the ADLB-AOG problem. Our analysis indicates that the DP formulation performs much better than the IP formulation in terms of the problem sizes that can be optimally solved. We also develop a DP-based heuristic to solve large-size instances of the ADLB-AOG problem. An experimentation of the procedures on some sample problems and the implementation of the heuristic on a sample problem are also given.
Open Access
A methodology for solving single-model, stochastic assembly line balancing problem
(Pergamon Press, 1999) Sarin, S. C.; Erel, E.; Dar-El, E. M.
In this paper, a methodology is developed to solve the single-model, stochastic assembly line balancing problem for the objective of minimizing the total labor cost and the expected incompletion cost arising from tasks not completed within the prescribed cycle time. The methodology is based on determining an initial DP based solution and its improvement using a branch-and-bound procedure which uses an approximate solution instead of a lower bound for fathoming nodes. Detailed experimentation shows the superiority of this method over the most promising one from the literature.
Open Access
Multi-material specific, targeted self-assembly of nanocrystal emitters using genetically engineered peptides on optoelectronic microchips
(IEEE, 2008-11) Zengin, Güliş; Şeker, U. O. S.; Koç, Aslı; Mutlugün, Evren; Akyüz, Özgün; Sarı, Emre; Sarıkaya, M.; Tamerler, C.; Demir, Hilmi Volkan
We demonstrated material-specific binding of the quantum dot emitters hybridized with GEPI on multi-material patterned microchips. These proof-of-concept results open up new opportunities in nanophotonics, allowing for more specific and controlled assembly of quantum dots in optoelectronic devices and building of novel molecular organic-inorganic hybrid devices
Open Access
Nanopore sequencing technology and tools for genome assembly: computational analysis of the current state, bottlenecks and future directions
(Oxford University Press, 2018-04) Cali, D. S.; Kim, J. S.; Ghose, S.; Alkan, Can; Mutlu, O.
Nanopore sequencing technology has the potential to render other sequencing technologies obsolete with its ability to generate long reads and provide portability. However, high error rates of the technology pose a challenge while generating accurate genome assemblies. The tools used for nanopore sequence analysis are of critical importance, as they should overcome the high error rates of the technology. Our goal in this work is to comprehensively analyze current publicly available tools for nanopore sequence analysis to understand their advantages, disadvantages and performance bottlenecks. It is important to understand where the current tools do not perform well to develop better tools. To this end, we (1) analyze the multiple steps and the associated tools in the genome assembly pipeline using nanopore sequence data, and (2) provide guidelines for determining the appropriate tools for each step. Based on our analyses, we make four key observations: (1) the choice of the tool for basecalling plays a critical role in overcoming the high error rates of nanopore sequencing technology. (2) Read-to-read overlap finding tools, GraphMap and Minimap, perform similarly in terms of accuracy. However, Minimap has a lower memory usage, and it is faster than GraphMap. (3) There is a trade-off between accuracy and performance when deciding on the appropriate tool for the assembly step. The fast but less accurate assembler Miniasm can be used for quick initial assembly, and further polishing can be applied on top of it to increase the accuracy, which leads to faster overall assembly. (4) The state-of-the-art polishing tool, Racon, generates high-quality consensus sequences while providing a significant speedup over another polishing tool, Nanopolish. We analyze various combinations of different tools and expose the trade-offs between accuracy, performance, memory usage and scalability. We conclude that our observations can guide researchers and practitioners in making conscious and effective choices for each step of the genome assembly pipeline using nanopore sequence data. Also, with the help of bottlenecks we have found, developers can improve the current tools or build new ones that are both accurate and fast, to overcome the high error rates of the nanopore sequencing technology.
Open Access
Reconstructing complex regions of genomes using long-read sequencing technology
(Cold Spring Harbor Laboratory Press, 2014) Huddleston, J.; Ranade, S.; Malig, M.; Antonacci, F.; Chaisson, M.; Hon, L.; Sudmant, P. H.; Alkan C.; Eichler, E. E.; Graves, T. A.; Dennis, M. Y.; Wilson, R. K.; Turner, S. W.; Korlach, J.
Obtaining high-quality sequence continuity of complex regions of recent segmental duplication remains one of the major challenges of finishing genome assemblies. In the human and mouse genomes, this was achieved by targeting large-insert clones using costly and laborious capillary-based sequencing approaches. Sanger shotgun sequencing of clone inserts, however, has now been largely abandoned, leaving most of these regions unresolved in newer genome assemblies generated primarily by next-generation sequencing hybrid approaches. Here we show that it is possible to resolve regions that are complex in a genome-wide context but simple in isolation for a fraction of the time and cost of traditional methods using long-read single molecule, real-time (SMRT) sequencing and assembly technology from Pacific Biosciences (PacBio). We sequenced and assembled BAC clones corresponding to a 1.3-Mbp complex region of chromosome 17q21.31, demonstrating 99.994% identity to Sanger assemblies of the same clones. We targeted 44 differences using Illumina sequencing and find that PacBio and Sanger assemblies share a comparable number of validated variants, albeit with different sequence context biases. Finally, we targeted a poorly assembled 766-kbp duplicated region of the chimpanzee genome and resolved the structure and organization for a fraction of the cost and time of traditional finishing approaches. Our data suggest a straightforward path for upgrading genomes to a higher quality finished state.
Open Access
Synthesis of mesoporous lithium titanate thin films and monoliths as an anode material for high-rate lithium-ion batteries
(Wiley-VCH Verlag, 2016) Balcı, F. M.; Kudu, Ö. U.; Yılmaz, E.; Dag, Ö.
Mesoporous Li4Ti5O12 (LTO) thin film is an important anode material for lithium-ion batteries (LIBs). Mesoporous films could be prepared by self-assembly processes. A molten-salt-assisted self-assembly (MASA) process is used to prepare mesoporous thin films of LTOs. Clear solutions of CTAB, P123, LiNO3, HNO3, and Ti(OC4H9)4 in ethanol form gel-like meso-ordered films upon either spin or spray coating. In the assembly process, the CTAB/P123 molar ratio of 14 is required to accommodate enough salt species in the mesophase, in which the LiI/P123 ratio can be varied between molar ratios of 28 and 72. Calcination of the meso-ordered films produces transparent mesoporous spinel LTO films that are abbreviated as Cxx-yyy-zzz or CAxx-yyy-zzz (C=calcined, CA=calcined–annealed, xx=LiI/P123 molar ratio, and yyy=calcination and zzz=annealing temperatures in Celsius) herein. All samples were characterized by using XRD, TEM, N2-sorption, and Raman techniques and it was found that, at all compositions, the LTO spinel phase formed with or without an anatase phase as an impurity. Electrochemical characterization of the films shows excellent performance at different current rates. The CA40-350-450 sample performs best among all samples tested, yielding an average discharge capacity of (176±1) mA h g−1 at C/2 and (139±4) mA h g−1 at 50 C and keeping 92 % of its initial discharge capacity upon 50 cycles at C/2.
Restricted
Türkiye Büyük Millet Meclisi Kütüphanesi’nin tarihi
(Bilkent University, 2019) Tezcanolur, Hilal; Yazar, Şeyma; İlhan, Zeynep; Çakır, Doğa
Bu projede tarihi I. Meşrutiyet dönemine dayanan ve Türkiye Cumhuriyeti’nin kurulması ile Türkiye Büyük Millet Meclisi’ne devredilen Meclis Kütüphanesi’nin tarihi incelenecektir. Osmanlı döneminde Ayan ve Meclis-i Mebusan Kütüphanesi olarak görev yapan bu kütüphanenin hem Osmanlı hem de Cumhuriyet dönemlerindeki tarihi araştırılacaktır. Cumhuriyet dönemi Meclis Kütüphanesi’nin binasının mimari özellikleri ve kütüphanenin yönetmeliği de araştırma kapsamına alınmıştır.