Browsing by Subject "Applications"

Now showing 1 - 5 of 5

Open Access
Access pattern-based code compression for memory-constrained systems
(Association for Computing Machinery, 2008-09) Ozturk, O.; Kandemir, M.; Chen, G.
As compared to a large spectrum of performance optimizations, relatively less effort has been dedicated to optimize other aspects of embedded applications such as memory space requirements, power, real-time predictability, and reliability. In particular, many modern embedded systems operate under tight memory space constraints. One way of addressing this constraint is to compress executable code and data as much as possible. While researchers on code compression have studied efficient hardware and software based code compression strategies, many of these techniques do not take application behavior into account; that is, the same compression/decompression strategy is used irrespective of the application being optimized. This article presents an application-sensitive code compression strategy based on control flow graph (CFG) representation of the embedded program. The idea is to start with a memory image wherein all basic blocks of the application are compressed, and decompress only the blocks that are predicted to be needed in the near future. When the current access to a basic block is over, our approach also decides the point at which the block could be compressed. We propose and evaluate several compression and decompression strategies that try to reduce memory requirements without excessively increasing the original instruction cycle counts. Some of our strategies make use of profile data, whereas others are fully automatic. Our experimental evaluation using seven applications from the MediaBench suite and three large embedded applications reveals that the proposed code compression strategy is very successful in practice. Our results also indicate that working at a basic block granularity, as opposed to a procedure granularity, is important for maximizing memory space savings. © 2008 ACM.
Open Access
İnsan hareketlerinin PIR-sensör tabanlı bir sistemle sınıflandırılması
(IEEE, 2008-04) Urfalıoğlu, Onay; Soyer, Emin B.; Töreyin, B. Uğur; Çetin, A. Enis
Bu bildiride, tek bir pasif kızılberisi sensörü (PIR) kullanarak beş farklı insan hareketi ve bir hareketsiz arkaplan gürültüsünden oluşan toplam 6 çeşit olay için bir sınıflandırma yöntemi önerilmiştir. Otomatik olay sınıflandırma sistemleri, dinamik süreçler barındıran ortamlar için yeni uygulamalara fırsat vermektedir. Olay sınıflandırması, herhangi bir sensör ya da sensör dizisinden gelen işaretlerin analiz edilerek, belirli bir olaya ait dinamik süreçle eşleştirilmesi olarak tanımlanabilir. Genelde, insan etkinliklerinin izlenmesi uygulamalarında kamera ve mikrofonlar kullanılmaktadır. Bir alternatif veya bir tümleyici yaklaşım olarak, bahsi geçen uygulamalarda PIR sensörleri de kullanılabilir. Bu bildiride, olay sınıflandırılması için Bayes yaklaşımına dayalı olan şartlı Gauss karışım modeli (CGMM) kullanımı önerilmektedir. Deneysel çalışmalarda, bu yaklaşımın başarılı olduğu görülmüştür.
Open Access
Location and logistics
(Springer, 2014) Alumur, Sibel A.; Kara, Bahar Y.; Melo, M. T.; Laporte, G.; Nickel, S.; Saldanha da Gama, F.
Facility location decisions play a critical role in designing logistics networks. This chapter provides some guidelines on how location decisions and logistics functions can be integrated into a single mathematical model to optimize the configuration of a logistics network. This will be illustrated by two generic models, one supporting the design of a forward logistics network and the other addressing the specific requirements of a reverse logistics network. Several special cases and extensions of the two models are discussed and their relation with the scientific literature is described. In addition, some interesting applications are outlined that demonstrate the interaction of location and logistics decisions. Finally, new research directions and emerging trends in logistics network design are provided.
Open Access
Nesne tanımada bağlam ve anlambilimsel sınıflandırmanın önemi: Bilgisayarla görme ve insanda görme alanlarındaki çalışmalar
(IEEE, 2008-04) Aksoy, Selim; Boyacı, Hüseyin; Gökçay, D.
Sahne sınıflandırması ve nesne tanıma, bilgisayarla görme alanında fok uzun yıllardır üzerinde çalışılan temel problemlerdir. Bilgisayarlara kazandırılmaya çalışılan, sahnelerin ve içerdikleri nesnelerin otomatik olarak tanınması ve etiketlendirilmesi yeteneği, yapay zeka konusunda önemli bir adım olma potansiyeli taşımaktadır. Bu yetenek, her geçen gün artan hesaplama kapasitesi ile birleştirildiğinde de henüz çözümü mümüun olmayan birçok uygulamanın da gerçekleştirilmesi mümkün olacaktır. Yazımızda nesne tanımayı kolaylaştıran anlambilimseI sınıflandırma yaklaşımları, hem bilgisayarda hem de insanda görme alanlarındaki literatür üzerinden özetlenmektedir. Object recognition and scene classification are among the main interests in computer vision which have been investigated for long. Automatic recognition and classification ofobjects and scenes is an important skill to be gained by computers, especially in the field of artificial intelligence. Merging this skill with the ever increasing computing power of the computers will help in the development ofmany applications that are yet to be resolved. In this article, we present a survey on contextual and semantic approaches for object recognition by reviewing both computer vision and human vision literatures. ©2008 IEEE.
Open Access
Optimization and tunability of deep subwavelength resonators for metamaterial applications: complete enhanced transmission through a subwavelength aperture
(Optical Society of American (OSA), 2009) Alici, K.B.; Bilotti F.; Vegni L.; Özbay, Ekmel
In the present work, we studied particle candidates for metamaterial applications, especially in terms of their electrical size and resonance strength. The analyzed particles can be easily produced via planar fabrication techniques. The electrical size of multi-split ring resonators, spiral resonators, and multi-spiral resonators are reported as a function of the particle side length and substrate permittivity. The study is continued by demonstrating the scalability of the particles to higher frequencies and the proposition of the optimized particle for antenna, absorber, and superlens applications: a multi-spiral resonator with ë/30 electrical size operating at 0.810 GHz. We explain a method for tuning the resonance frequency of the multi-split structures. Finally, we demonstrate that by inserting deep subwavelength resonators into periodically arranged subwavelength apertures, complete transmission enhancement can be obtained at the magnetic resonance frequency. © 2009 Optical Society of America.