Browsing by Subject "Computer programming"

Now showing 1 - 12 of 12

Open Access
Adaptive ensemble learning with confidence bounds for personalized diagnosis
(AAAI Press, 2016) Tekin, Cem; Yoon, J.; Van Der Schaar, M.
With the advances in the field of medical informatics, automated clinical decision support systems are becoming the de facto standard in personalized diagnosis. In order to establish high accuracy and confidence in personalized diagnosis, massive amounts of distributed, heterogeneous, correlated and high-dimensional patient data from different sources such as wearable sensors, mobile applications, Electronic Health Record (EHR) databases etc. need to be processed. This requires learning both locally and globally due to privacy constraints and/or distributed nature of the multimodal medical data. In the last decade, a large number of meta-learning techniques have been proposed in which local learners make online predictions based on their locally-collected data instances, and feed these predictions to an ensemble learner, which fuses them and issues a global prediction. However, most of these works do not provide performance guarantees or, when they do, these guarantees are asymptotic. None of these existing works provide confidence estimates about the issued predictions or rate of learning guarantees for the ensemble learner. In this paper, we provide a systematic ensemble learning method called Hedged Bandits, which comes with both long run (asymptotic) and short run (rate of learning) performance guarantees. Moreover, we show that our proposed method outperforms all existing ensemble learning techniques, even in the presence of concept drift.
Open Access
An automated system for design-rule-based visual inspection of printed circuit boards
(IEEE, 1991) Oğuz, Seyfullah Halit; Onural, Levent
The design and the implementation of an automated, design-rule-based, visual printed circuit board (PCB) inspection system are presented. The system employs mathematical-morphology-based image processing algorithms. This system detects PCB defects related to the conducting structures on PCBs by checking a set of geometric design rules. For this purpose, an image segmentation algorithm and a defect detection algorithm are designed. The defect detection algorithm is capable of verifying the minimum conductor spacing, minimum conductor trace width, and the minimum land width requirements on digital binary PCB images. Also, an existing defect detection algorithm is modified for its implementation in the system.
Open Access
AutopaR: An Automatic Parallelization Tool for Recursive Calls
(IEEE, 2014-09) Kalender, Mert Emin; Mergenci, Cem; Öztürk, Özcan
Manycore systems are becoming more and more powerful with the integration of hundreds of cores on a single chip. However, writing parallel programs on these manycore systems has become a problem since the amount of available parallel tools and applications are limited. Although exploiting parallelism in software is possible, it requires different design decisions, significant programmer effort and is error prone. Different libraries and tools try to make the transition to parallelism easier, however there is no concrete system to make it transparent to software developer. To this end, our proposed tool is a step forward to improve the current state. Our approach, Autopar, specifically aims at achieving automatic parallelization of recursive applications using static program analysis. It first decides on the recursive functions of a given program. Then, it performs analysis and collects information about these recursive functions. Our analysis module automatically collects program information without requiring any modification in the program design or developer involvement. Finally, it achieves automatic parallelization by introducing necessary OpenMP pragmas in appropriate places in the application. © 2014 IEEE.
Open Access
An extended user interface for CAL systems
(1990) Davenport, David
This paper examines the problems of complexity in human-computer interaction from the perspective of CAL systems. By considering the very special demands of young, pre-reading age children, it shows how pointing type interfaces can be extended in a simple and natural manner based on the notion that the position of, and spatial relationship between objects, is of significance. Various examples based on this extended interface concept are introduced to demonstrate its functionality.
Open Access
Induction of logical relations based on specific generalization of strings
(IEEE, 2007-11) Uzun, Yasin; Çiçekli, İlyas
Learning logical relations from examples expressed as first order facts has been studied extensively by the Inductive Logic Programming research. Learning with positive-only data may cause over generalization of examples leading to inconsistent resulting hypotheses. A learning heuristic inferring specific generalization of strings based on unique match sequences is shown to be capable of learning predicates with string arguments. This paper describes an inductive learner based on the idea of specific generalization of strings, and the given clauses are generalized by considering the background knowledge. ©2007 IEEE.
Open Access
Multi-item quick response system with budget constraint
(2012) Serel, D. A.
Quick response mechanisms based on effective use of up-to-date demand information help retailers to reduce their inventory management costs. We formulate a single-period inventory model for multiple products with dependent (multivariate normal) demand distributions and a given overall procurement budget. After placing orders based on an initial demand forecast, new market information is gathered and demand forecast is updated. Using this more accurate second forecast, the retailer decides the total stocking level for the selling season. The second order is based on an improved demand forecast, but it also involves a higher unit supply cost. To determine the optimal ordering policy, we use a computational procedure that entails solving capacitated multi-item newsboy problems embedded within a dynamic programming model. Various numerical examples illustrate the effects of demand variability and financial constraint on the optimal policy. It is found that existence of a budget constraint may lead to an increase in the initial order size. It is also observed that as the budget available decreases, the products with more predictable demand make up a larger share of the procurement expenditure.
Open Access
A novel algorithm for DC analysis of piecewise-linear circuits: popcorn
(IEEE, 1994) Topçu, S.; Ocalı, O.; Atalar, Abdullah; Tan, M. A.
A fast and convergent iteration method for piecewise-linear analysis of nonlinear resistive circuits is presented. Most of the existing algorithms are applicable only to a limited class of circuits. In general, they are either not convergent or too slow for large circuits. The new algorithm presented in the paper is much more efficient than the existing ones and can be applied to any piecewise-linear circuit. It is based on the piecewise-linear version of the Newton-Raphson algorithm. As opposed to the Newton-Raphson method, the new algorithm is globally convergent from an arbitrary starting point. It is simple to understand and it can be easily programmed. Some numerical examples are given in order to demonstrate the effectiveness of the proposed algorithm in terms of the amount of computation. © 1994 IEEE
Open Access
Scheduling beams with different priorities on a military surveillance radar
(Institute of Electrical and Electronics Engineers, 2012) Taner, M. R.; Karasan O. E.; Yavuzturk, E.
The problem of scheduling the searching, verification, and tracking tasks of a ground based, three-dimensional military surveillance radar is studied. Although the radar is mechanically steered in the sense that a servomechanism rotates the antenna at a constant turn rate, it has limited electronic steering capability in azimuth. The scheduling problem arises within a planning period during which the antenna scans a given physical range. A task/job corresponds to sending a transmission beam to hit a particular target. Targets are allowed to be hit with an angular deviation up to a predetermined magnitude. The steering mechanism of the radar helps alter these deviations by imposing a scan-off angle from broadside on the transmission beam. A list of jobs along with their priority weights, processing times, and ideal beam positions are given during a predetermined planning period. The ideal beam position for a given job allows hitting the corresponding target with zero deviation. Each job also has a set of available scan-off angles. It is possible to map the antennas physical position, beam positions, scan-off angles, and angular deviations to a time scale. The goal is to select the subset of jobs to be processed during the given planning period and determining the starting time and scan-off angle for each selected job. The objectives are to simultaneously minimize the weighted number of unprocessed jobs and the total weighted deviation. An integer programming model and two versions of a heuristic mechanism that relies on the exact solution of a special case are proposed. Results of a computational study are presented.
Open Access
Schema changes in an object-oriented database system
(ASME, 1992) Alhajj, Reda; Arkun, M. Erol
Proper and efficient handling of schema changes is an important aspect of any object-oriented database management system. Clearly, it is desirable for an object-oriented database management system to satisfy as many schema operations as possible. This paper deals with schema changes in ODS; an object-oriented database management system prototype. A brief description of the basic features of ODS along with its storage and indexing models are included to facilitate the treatment. The invariants of the class hierarchy/lattice as well as the rules for resolving ambiguities due to schema changes are discussed. In addition, schema changes handled by ODS are described. Schema modifications are done through the user interface of ODS that provides both a class browser and a programming shell. Versions are supported by ODS in handling both methods and messages. For composite objects name conflicts are handled by considering both superclasses and nesting classes.
Open Access
SIMARD: a simulated annealing based RNA design algorithm with quality pre-selection strategies
(IEEE, 2017-12) Sav, Sinem; Hampson, D. J. D.; Tsang, H. H.
Most of the biological processes including expression levels of genes and translation of DNA to produce proteins within cells depend on RNA sequences, and the structure of the RNA plays vital role for its function. RNA design problem refers to the design of an RNA sequence that folds into given secondary structure. However, vast number of possible nucleotide combinations make this an NP-Hard problem. To solve the RNA design problem, a number of researchers have tried to implement algorithms using local stochastic search, context-free grammars, global sampling or evolutionary programming approaches. In this paper, we examine SIMARD, an RNA design algorithm that implements simulated annealing techniques. We also propose QPS, a mutation operator for SIMARD that pre-selects high quality sequences. Furthermore, we present experiment results of SIMARD compared to eight other RNA design algorithms using the Rfam datset. The experiment results indicate that SIMARD shows promising results in terms of Hamming distance between designed sequence and the target structure, and outperforms ERD in terms of free energy. © 2016 IEEE.
Open Access
V. Lifschitz, ed., formalizing common sense: papers by John McCarthy
(Elsevier BV, 1995) Akman, V.
A review is presented of Lifschitz's collection of seventeen papers written by McCarthy on the subject of common sense. The book opens with a fine overview of McCarthy's research in artificial intelligence (AI). Lifschitz offers an admirably succinct account of the development of McCarthy's ideas on common sense from the early days of AI to his current work. Lifschitz's introduction is especially useful in appreciating the dramatically original and permanently influential nature of McCarthy's work. While McCarthy's papers collected in this volume were written over the span of almost three decades, Lifschitz correctly observes that the underlying concern has always been the same: to understand and model the intellectual ability realized by human common sense.
Open Access
Voltage island based heterogeneous NoC design through constraint programming
(Pergamon Press, 2014) Demiriz, A.; Bagherzadeh, N.; Ozturk, O.
This paper discusses heterogeneous Network-on-Chip (NoC) design from a Constraint Programming (CP) perspective and extends the formulation to solving Voltage-Frequency Island (VFI) problem. In general, VFI is a superior design alternative in terms of thermal constraints, power consumption as well as performance considerations. Given a Communication Task Graph (CTG) and subsequent task assignments for cores, cores are allocated to the best possible places on the chip in the first stage to minimize the overall communication cost among cores. We then solve the application scheduling problem to determine the optimum core types from a list of technological alternatives and to minimize the makespan. Moreover, an elegant CP model is proposed to solve VFI problem by mapping and grouping cores at the same time with scheduling the computation tasks as a limited capacity resource allocation model. The paper reports results based on real benchmark datasets from the literature.