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A. Yavuz Oruc

Publications and source records attributed to A. Yavuz Oruc.

8 recordsLinked to original sources

On the Reachability Problem in Quantum Petri Nets

In this paper, we propose a novel quantum solution to address the problem of reachability in bounded quantum Petri nets (QPNs), an advanced modeling framework that combines the classical Petri net model with quantum mechanical principles. The proposed approach exploits quantum parallelism to construct a superposition over all reachable markings from the initial marking. Grover's amplitude amplification algorithm is then applied to efficiently identify a desired target marking, while ancillary q-tokens used solely for transition control are excluded from the search space, significantly reducing its size. Theoretical analysis shows that our approach achieves a quadratic speed up over classical exhaustive algorithms. Experimental results also confirm the correctness and feasibility of the proposed quantum algorithm for solving the bounded reachability problem in Quantum Petri Nets.

quant-ph↗

On The Number Of Labeled Bipartite Graphs

Let $I$ and $O$ denote two sets of vertices, where $I\cap O =\emptyset$, $|I| = n$, $|O| = r$, and $B_u(n,r)$ denote the set of unlabeled graphs whose edges connect vertices in $I$ and $O$. Recently, it was established in\cite{atmacaoruc2018} that the following two-sided equality holds, \begin{equation} \label{mainResult} \displaystyle \frac{\binom{r+2^{n}-1}{r}}{n!}\, \le\, |B_u(n,r)|\, \le\, 2\frac{\binom{r+2^{n}-1}{r}}{n!},\, n < r.\nonumber \end{equation} and exact formulas were provided in~\cite{atmaca2017size} for $|B_u(2,r)|$ and $|B_u(3,r)|.$ In this paper, these results are extended to various families of labeled bipartite graphs.

math.CO↗

CodeAPeel: An Integrated and Layered Learning Technology For Computer Architecture Courses

This paper introduces a versatile, multi-layered technology to help support teaching and learning core computer architecture concepts. This technology, called CodeAPeel is already implemented in one particular form to describe instruction processing in compiler, assembly, and machine layers of a generic instruction set architecture by a comprehensive simulation of its fetch-decode-execute cycle as well as animation of the behavior of its CPU registers, RAM, VRAM, STACK memories, various control registers, and graphics screen. Unlike most educational CPU simulators that simulate a real processor such as MIPS or RISC-V, CodeAPeel is designed and implemented as a generic RISC instruction set architecture simulator with both scalar and vector instructions to provide a dual-mode processor simulator as described by Flynn's classification of SISD and SIMD processors. Vectorization of operations is built into the instruction repertoire of CodeAPeel, making it straightforward to simulate such processors with powerful vector instructions.

cs.AR↗

Faster Quantum Concentration via Grover's Search

We present quantum algorithms for routing concentration assignments on full capacity fat-and-slim concentrators, bounded fat-and-slim concentrators, and regular fat-and-slim concentrators. Classically, the concentration assignment takes $O(n)$ time on all these concentrators, where $n$ is the number of inputs. Powered by Grover's quantum search algorithm, our algorithms take $O(\sqrt{nc}\ln{c})$ time, where $c$ is the capacity of the concentrator. Thus, our quantum algorithms are asymptotically faster than their classical counterparts, when $c\ln^2{c}=o(n)$.In general, $c = n^μ,$ satisfies $c\ln^2{c}=o(n),$ implying a time complexity of $O(n^{0.5(1+ μ)} \ln n),$ for any $μ, 0 < μ< 1.$

quant-ph↗

Searching and Sorting with O(n^2) processors in O(1) time

The proliferation of number of processing elements (PEs) in parallel computer systems, along with the use of more extensive parallelization of algorithms causes the interprocessor communications dominate VLSI chip space. This paper proposes a new architecture to overcome this issue by using simple crosspoint switches to pair PEs instead of a complex interconnection network. Based on the cyclic permutation wiring idea described in \cite{oruc2016self}, this pairing leads to a linear crosspoint array of $n(n-1)/2$ processing elements and as many crosspoints. We demonstrate the versatility of this new parallel architecture by designing fast searching and sorting algorithms for it. In particular, we show that finding a minimum, maximum, and searching a list of $n$ elements can all be performed in $O(1)$ time with elementary logic gates with $O(n)$ fan-in, and in $O(\lg n)$ time with $O(1)$ fan-in. We further show that sorting a list of $n$ elements can also be carried out in $O(1)$ time using elementary logic gates with $O(n)$ fan-in and threshold logic gates. The sorting time increases to $O(\lg n\lg\lg n)$ if only elementary logic gates with $O(1)$ fan-in are used. The algorithm can find the maximum among $n$ elements in $O(1)$ time, and sort $n$ elements in $O(\lg n (\lg\lg n))$ time. In addition, we show how other fundamental queries can be handled within the same order of time complexities.

cs.DS↗

On The Number Of Unlabeled Bipartite Graphs

This paper solves a problem that was stated by M. A. Harrison in 1973~\cite{harrison1973number}. This problem, that has remained open since then is concerned with counting equivalence classes of $n\times r$ binary matrices under row and column permutations. Let $I$ and $O$ denote two sets of vertices, where $I\cap O =Φ$, $|I| = n$, $|O| = r$, and $B_u(n,r)$ denote the set of unlabeled graphs whose edges connect vertices in $I$ and $O$. Harrison established that the number of equivalence classes of $n\times r$ binary matrices is equal to the number of unlabeled graphs in $B_u(n,r).$ He also computed the number of such matrices (hence such graphs) for small values of $n$ and $r$ without providing an asymptotic formula $|B_u(n,r)|.$ Here, such an asymptotic formula is provided by proving the following two-sided equality using Polya's Counting Theorem.

math.CO↗

On Ordinal Covering of Proposals Using Balanced Incomplete Block Designs

A frequently encountered problem in peer review systems is to facilitate pairwise comparisons of a given set of proposals by as few as referees as possible. In [8], it was shown that, if each referee is assigned to review k proposals then ceil{n(n-1)/k(k-1)} referees are necessary and ceil{n(2n-k)/k^2} referees are sufficient to cover all n(n-1)/2 pairs of n proposals. While the upper bound remains within a factor of 2 of the lower bound, it becomes relatively large for small values of k and the ratio of the upper bound to the lower bound is not less than 3/2 when 2 <= k <= n/2. In this paper, we show that, if sqrt(n) <= k <= n/2 then the upper and lower bounds can be made closer in that their ratio never exceeds 3/2. This is accomplished by a new method that assigns proposals to referees using a particular family of balanced incomplete block designs. Specifically, the new method uses ceil{n(n+k)/k^2} referees when n/k is a prime power, n divides k^2, and sqrt(n) <= k <= n/2. Comparing this new upper bound to the one given in [8] shows that the new upper bound approaches the lower bound as k tends to sqrt(n) whereas the upper bound in [8] approaches the lower bound as k tends to n. Therefore, the new method given here when combined together with the one in [8] provides an assignment whose upper bound referee complexity always remains within a factor of 3/2 of the lower bound when sqrt(n) <= k <= n, thereby improving upon the assignment described in [8]. Furthermore, the new method provides a minimal covering, i.e., it uses the minimum number of referees possible when k = sqrt(n) and k is a prime power.

cs.DM↗

Asymptotically Optimal Assignments In Ordinal Evaluations of Proposals

In ordinal evaluations of proposals in peer review systems, a set of proposals is assigned to a fixed set of referees so as to maximize the number of pairwise comparisons of proposals under certain referee capacity and proposal subject constraints. In this paper, the following two related problems are considered: (1) Assuming that each referee has a capacity to review k out of n proposals, 2 < k < n, determine the minimum number of referees needed to ensure that each pair of proposals is reviewed by at least one referee, (2) Find an assignment that meets the lower bound determined in (1). It is easy to see that one referee is both necessary and sufficient when k = n, and n(n-1)/2 referees are both necessary and sufficient when k = 2. We show that 6 referees are both necessary and sufficient when k = n/2. We further show that 11 referees are necessary and 12 are sufficient when k = n/3, and 18 referees are necessary and 20 referees are sufficient when k = n/4. A more general lower bound of n(n-1)/k(k-1) referees is also given for any k, 2 < k < n, and an assignment asymptotically matching this lower bound within a factor of 2 is presented. These results are not only theoretically interesting but they also provide practical methods for efficient assignments of proposals to referees.

cs.DM↗