In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains l qubits. In addition, a previously proposed quantumlogic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over l qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of l affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of l is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of 5 3 if the nearest neighbor interaction is applied.
Boolean reversible logic has applications in various research areas including quantum computing. ... more Boolean reversible logic has applications in various research areas including quantum computing. In this paper, a synthesis method for reversible logic is proposed which concentrates on two objectives, namely logical depth and quantum cost. To this end, the input specification is represented in a cycle form, and a set of three distinct subsets of input cycles are distinguished for parallel execution where the first set is executed on the first n input qubits and the remaining two sets are applied on the set of 2n ancillae. The final results are constructed on the main qubits. For each set, the cycle-based synthesis method is applied equipped with negative-control gates and parallel gate execution. Experimental results on the attempted benchmarks demonstrate more than 50% improvement in the logical depth with less than 2% increase in the quantum cost on average.
In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains l qubits. In addition, a previously proposed quantumlogic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over l qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of l affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of l is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of 5 3 if the nearest neighbor interaction is applied.
Recent advancements in deep reinforcement learning have brought forth an impressive display of hi... more Recent advancements in deep reinforcement learning have brought forth an impressive display of highly skilled artificial agents capable of complex intelligent behavior. In video games, these artificial agents are increasingly deployed as nonplayable characters (NPCs) designed to enhance the experience of human players. However, while it has been shown that the convincing human-like behavior of NPCs leads to increased engagement in video games, the believability of an artificial agent’s behavior is most often measured solely by its proficiency at a given task. Recent work has hinted that proficiency alone is not sufficient to discern human-like behavior. Motivated by this, we build a non-parametric two-sample hypothesis test designed to compare the behaviors of artificial agents to those of human players. We show that the resulting p-value not only aligns with anonymous human judgment of human-like behavior, but also that it can be used as a measure of similarity.
We design a circuit structure with linear depth to implement an n-qubit Toffoli gate. The propose... more We design a circuit structure with linear depth to implement an n-qubit Toffoli gate. The proposed construction uses a quadratic-size circuit consists of elementary 2-qubit controlled-rotation gates around the x axis and uses no ancilla qubit. Circuit depth remains linear in quantum technologies with finite-distance interactions between qubits. The suggested construction is related to the long-standing construction by Barenco et al. (Phys. Rev. A, 52: 3457-3467, 1995, arXiv:quant-ph/9503016), which uses a quadratic-size, quadratic-depth quantum circuit for an n-qubit Toffoli gate.
In this paper, a new non-search based synthesis algorithm for reversible circuits is proposed. Co... more In this paper, a new non-search based synthesis algorithm for reversible circuits is proposed. Compared with the widely used search-based methods, our algorithm is guarantied to produce a result and can lead to a solution with much fewer steps. To evaluate the proposed method, several circuits taken from the literature are used. The experimental results corroborate the expected findings.
While a couple of impressive quantum technologies have been proposed, they have several intrinsic... more While a couple of impressive quantum technologies have been proposed, they have several intrinsic limitations which must be considered by circuit designers to produce realizable circuits. Limited interaction distance between gate qubits is one of the most common limitations. In this paper, we suggest extensions of the existing synthesis flow aimed to realize circuits for quantum architectures with linear nearest neighbor (LNN) interaction. To this end, a template matching optimization, an exact synthesis approach, and two reordering strategies are introduced. The proposed methods are combined as an integrated synthesis flow. Experiments show that by using the suggested flow, quantum cost can be improved by more than 50% on average.
Reversible logic has applications in various research areas including signal processing, cryptogr... more Reversible logic has applications in various research areas including signal processing, cryptography and quantum computation. In this paper, direct NCT-based synthesis of a given k-cycle in a cycle-based synthesis scenario is examined. To this end, a set of seven building blocks is proposed that reveals the potential of direct synthesis of a given permutation to reduce both quantum cost and average runtime. To synthesize a given large cycle, we propose a decomposition algorithm to extract the suggested building blocks from the input specification. Then, a synthesis method is introduced which uses the building blocks and the decomposition algorithm. Finally, a hybrid synthesis framework is suggested which uses the proposed cycle-based synthesis method in conjunction with one of the recent NCT-based synthesis approaches which is based on Reed-Muller (RM) spectra. The time complexity and the effectiveness of the proposed synthesis approach are analyzed in detail. Our analyses show tha...
A major obstacle to implementing Shor's quantum number-factoring algorithm is the large size of m... more A major obstacle to implementing Shor's quantum number-factoring algorithm is the large size of modular-exponentiation circuits. We reduce this bottleneck by customizing reversible circuits for modular multiplication to individual runs of Shor's algorithm. Our circuit-synthesis procedure exploits spectral properties of multiplication operators and constructs optimized circuits from the traces of the execution of an appropriate GCD algorithm. Empirically, gate counts are reduced by 4-5 times, and circuit latency is reduced by larger factors.
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with O(n n) depth with O(n) ancillae. Prior circuit construction needs O(n^2) running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains O(n^2), as in traditional circuits.
Synthesis of reversible logic has received significant attention in the recent years and many syn... more Synthesis of reversible logic has received significant attention in the recent years and many synthesis approaches for reversible logic have been proposed so far. In this paper, a librarybased synthesis approach for reversible circuits is proposed where an input specification is considered as a permutation comprising a set of cycles. In order to synthesize a given permutation, a library which contains seven building blocks is used where each building block is a cycle of length less than 6. We also propose a decomposition algorithm which produces all possible minimal and inequivalent factorizations for a given cycle of length greater than 5. All decompositions contain the maximum number of disjoint cycles. The generated decompositions are used in conjunction with a cycle assignment algorithm which is proposed based on the graph matching problem to select the best possible cycle pairs. Then, each pair is synthesized by using the available components of the library. The decomposition a...
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with O(n log n) depth with O(n) ancillae. Prior circuit construction needs O(n 2) running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains O(n 2), as in traditional circuits.
Reversible computing plays an important role in various research areas including quantum computin... more Reversible computing plays an important role in various research areas including quantum computing. Among open research problems, reversible circuit synthesis has recently received significant attention. In this paper, we propose a new non-search based forward-looking synthesis (FLS) algorithm for reversible circuits. Compared with the widely used search-based methods, FLS is guaranteed to produce a result and can lead to a solution with much fewer steps. Next, a forward-looking order independent synthesis (FLOPS) algorithm is introduced which uses several novel criteria to improve the FLS resulted cost. To evaluate the proposed algorithms, different circuits taken from the literature are used. The experimental results corroborate the expected findings.
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with $O(n \log n)$ depth with O(n) ancillae. Prior circuit construction needs $O(n^2)$ running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains $O(n^2)$, as in traditional circuits.
Many synthesis approaches for reversible and quantum logic have been proposed so far. However, mo... more Many synthesis approaches for reversible and quantum logic have been proposed so far. However, most of them generate circuits with respect to simple metrics, i.e. gate count or quantum cost. On the other hand, to physically realize reversible and quantum hardware, additional constraints exist. In this paper, we describe cost metrics beyond gate count and quantum cost that should be considered while synthesizing reversible and quantum logic for the respective target technologies. We show that the evaluation of a synthesis approach may differ if additional costs are applied. In addition, a new cost metric, namely Nearest Neighbor Cost (NNC) which is imposed by realistic physical quantum architectures, is considered in detail. We discuss how existing synthesis flows can be extended to generate optimal circuits with respect to NNC while still keeping the quantum cost small.
Proceedings of the 10th ACM Multimedia Systems Conference
Cloud gaming allows users with thin-clients to play complex games on their end devices as the bul... more Cloud gaming allows users with thin-clients to play complex games on their end devices as the bulk of processing is offloaded to remote servers. A thin-client is only required to have basic decoding capabilities which exist on most modern devices. The result of the remote processing is an encoded video that gets streamed to the client. As modern games are complex in terms of graphics and motion, the encoded video requires high bandwidth to provide acceptable Quality of Experience (QoE) to end users. The cost incurred by the cloud gaming service provider to stream the encoded video at such high bandwidth grows rapidly with the increase in the number of users. In this paper, we present a content-aware video encoding method for cloud gaming (referred to as CAVE) to improve the perceptual quality of the streamed video frames with comparable bandwidth requirements. This is a challenging task because of the stringent requirements on latency in cloud gaming, which impose additional restrictions on frame sizes as well as processing time to limit the total latency perceived by clients. Unlike many of the previous works, the proposed method is suitable for the state-ofthe-art High Efficiency Video Coding (HEVC) encoder, which by itself offers substantial bitrate savings compared to prior encoders. The proposed method leverages information from the game such as the Regions-of-Interest (ROIs), and optimizes the quality by allocating different amounts of bits to various areas in the video frames. Through actual implementation in an open-source cloud gaming platform, we show that the proposed method achieves quality gains in ROIs that can be translated to bitrate savings between 21% and 46% against the baseline HEVC encoder and between 12% and 89% against the closest work in the literature. CCS CONCEPTS • Information systems → Multimedia streaming.
In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains $l$ qubits. In addition, a previously proposed quantum-logic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over $l$ qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of $l$ affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of $l$ is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of $\frac{5}{3}$ if the nea...
In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains l qubits. In addition, a previously proposed quantumlogic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over l qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of l affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of l is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of 5 3 if the nearest neighbor interaction is applied.
Boolean reversible logic has applications in various research areas including quantum computing. ... more Boolean reversible logic has applications in various research areas including quantum computing. In this paper, a synthesis method for reversible logic is proposed which concentrates on two objectives, namely logical depth and quantum cost. To this end, the input specification is represented in a cycle form, and a set of three distinct subsets of input cycles are distinguished for parallel execution where the first set is executed on the first n input qubits and the remaining two sets are applied on the set of 2n ancillae. The final results are constructed on the main qubits. For each set, the cycle-based synthesis method is applied equipped with negative-control gates and parallel gate execution. Experimental results on the attempted benchmarks demonstrate more than 50% improvement in the logical depth with less than 2% increase in the quantum cost on average.
In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains l qubits. In addition, a previously proposed quantumlogic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over l qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of l affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of l is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of 5 3 if the nearest neighbor interaction is applied.
Recent advancements in deep reinforcement learning have brought forth an impressive display of hi... more Recent advancements in deep reinforcement learning have brought forth an impressive display of highly skilled artificial agents capable of complex intelligent behavior. In video games, these artificial agents are increasingly deployed as nonplayable characters (NPCs) designed to enhance the experience of human players. However, while it has been shown that the convincing human-like behavior of NPCs leads to increased engagement in video games, the believability of an artificial agent’s behavior is most often measured solely by its proficiency at a given task. Recent work has hinted that proficiency alone is not sufficient to discern human-like behavior. Motivated by this, we build a non-parametric two-sample hypothesis test designed to compare the behaviors of artificial agents to those of human players. We show that the resulting p-value not only aligns with anonymous human judgment of human-like behavior, but also that it can be used as a measure of similarity.
We design a circuit structure with linear depth to implement an n-qubit Toffoli gate. The propose... more We design a circuit structure with linear depth to implement an n-qubit Toffoli gate. The proposed construction uses a quadratic-size circuit consists of elementary 2-qubit controlled-rotation gates around the x axis and uses no ancilla qubit. Circuit depth remains linear in quantum technologies with finite-distance interactions between qubits. The suggested construction is related to the long-standing construction by Barenco et al. (Phys. Rev. A, 52: 3457-3467, 1995, arXiv:quant-ph/9503016), which uses a quadratic-size, quadratic-depth quantum circuit for an n-qubit Toffoli gate.
In this paper, a new non-search based synthesis algorithm for reversible circuits is proposed. Co... more In this paper, a new non-search based synthesis algorithm for reversible circuits is proposed. Compared with the widely used search-based methods, our algorithm is guarantied to produce a result and can lead to a solution with much fewer steps. To evaluate the proposed method, several circuits taken from the literature are used. The experimental results corroborate the expected findings.
While a couple of impressive quantum technologies have been proposed, they have several intrinsic... more While a couple of impressive quantum technologies have been proposed, they have several intrinsic limitations which must be considered by circuit designers to produce realizable circuits. Limited interaction distance between gate qubits is one of the most common limitations. In this paper, we suggest extensions of the existing synthesis flow aimed to realize circuits for quantum architectures with linear nearest neighbor (LNN) interaction. To this end, a template matching optimization, an exact synthesis approach, and two reordering strategies are introduced. The proposed methods are combined as an integrated synthesis flow. Experiments show that by using the suggested flow, quantum cost can be improved by more than 50% on average.
Reversible logic has applications in various research areas including signal processing, cryptogr... more Reversible logic has applications in various research areas including signal processing, cryptography and quantum computation. In this paper, direct NCT-based synthesis of a given k-cycle in a cycle-based synthesis scenario is examined. To this end, a set of seven building blocks is proposed that reveals the potential of direct synthesis of a given permutation to reduce both quantum cost and average runtime. To synthesize a given large cycle, we propose a decomposition algorithm to extract the suggested building blocks from the input specification. Then, a synthesis method is introduced which uses the building blocks and the decomposition algorithm. Finally, a hybrid synthesis framework is suggested which uses the proposed cycle-based synthesis method in conjunction with one of the recent NCT-based synthesis approaches which is based on Reed-Muller (RM) spectra. The time complexity and the effectiveness of the proposed synthesis approach are analyzed in detail. Our analyses show tha...
A major obstacle to implementing Shor's quantum number-factoring algorithm is the large size of m... more A major obstacle to implementing Shor's quantum number-factoring algorithm is the large size of modular-exponentiation circuits. We reduce this bottleneck by customizing reversible circuits for modular multiplication to individual runs of Shor's algorithm. Our circuit-synthesis procedure exploits spectral properties of multiplication operators and constructs optimized circuits from the traces of the execution of an appropriate GCD algorithm. Empirically, gate counts are reduced by 4-5 times, and circuit latency is reduced by larger factors.
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with O(n n) depth with O(n) ancillae. Prior circuit construction needs O(n^2) running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains O(n^2), as in traditional circuits.
Synthesis of reversible logic has received significant attention in the recent years and many syn... more Synthesis of reversible logic has received significant attention in the recent years and many synthesis approaches for reversible logic have been proposed so far. In this paper, a librarybased synthesis approach for reversible circuits is proposed where an input specification is considered as a permutation comprising a set of cycles. In order to synthesize a given permutation, a library which contains seven building blocks is used where each building block is a cycle of length less than 6. We also propose a decomposition algorithm which produces all possible minimal and inequivalent factorizations for a given cycle of length greater than 5. All decompositions contain the maximum number of disjoint cycles. The generated decompositions are used in conjunction with a cycle assignment algorithm which is proposed based on the graph matching problem to select the best possible cycle pairs. Then, each pair is synthesized by using the available components of the library. The decomposition a...
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with O(n log n) depth with O(n) ancillae. Prior circuit construction needs O(n 2) running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains O(n 2), as in traditional circuits.
Reversible computing plays an important role in various research areas including quantum computin... more Reversible computing plays an important role in various research areas including quantum computing. Among open research problems, reversible circuit synthesis has recently received significant attention. In this paper, we propose a new non-search based forward-looking synthesis (FLS) algorithm for reversible circuits. Compared with the widely used search-based methods, FLS is guaranteed to produce a result and can lead to a solution with much fewer steps. Next, a forward-looking order independent synthesis (FLOPS) algorithm is introduced which uses several novel criteria to improve the FLS resulted cost. To evaluate the proposed algorithms, different circuits taken from the literature are used. The experimental results corroborate the expected findings.
GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and q... more GCD computations and variants of the Euclidean algorithm enjoy broad uses in both classical and quantum algorithms. In this paper, we propose quantum circuits for GCD computation with $O(n \log n)$ depth with O(n) ancillae. Prior circuit construction needs $O(n^2)$ running time with O(n) ancillae. The proposed construction is based on the binary GCD algorithm and it benefits from log-depth circuits for 1-bit shift, comparison/subtraction, and managing ancillae. The worst-case gate count remains $O(n^2)$, as in traditional circuits.
Many synthesis approaches for reversible and quantum logic have been proposed so far. However, mo... more Many synthesis approaches for reversible and quantum logic have been proposed so far. However, most of them generate circuits with respect to simple metrics, i.e. gate count or quantum cost. On the other hand, to physically realize reversible and quantum hardware, additional constraints exist. In this paper, we describe cost metrics beyond gate count and quantum cost that should be considered while synthesizing reversible and quantum logic for the respective target technologies. We show that the evaluation of a synthesis approach may differ if additional costs are applied. In addition, a new cost metric, namely Nearest Neighbor Cost (NNC) which is imposed by realistic physical quantum architectures, is considered in detail. We discuss how existing synthesis flows can be extended to generate optimal circuits with respect to NNC while still keeping the quantum cost small.
Proceedings of the 10th ACM Multimedia Systems Conference
Cloud gaming allows users with thin-clients to play complex games on their end devices as the bul... more Cloud gaming allows users with thin-clients to play complex games on their end devices as the bulk of processing is offloaded to remote servers. A thin-client is only required to have basic decoding capabilities which exist on most modern devices. The result of the remote processing is an encoded video that gets streamed to the client. As modern games are complex in terms of graphics and motion, the encoded video requires high bandwidth to provide acceptable Quality of Experience (QoE) to end users. The cost incurred by the cloud gaming service provider to stream the encoded video at such high bandwidth grows rapidly with the increase in the number of users. In this paper, we present a content-aware video encoding method for cloud gaming (referred to as CAVE) to improve the perceptual quality of the streamed video frames with comparable bandwidth requirements. This is a challenging task because of the stringent requirements on latency in cloud gaming, which impose additional restrictions on frame sizes as well as processing time to limit the total latency perceived by clients. Unlike many of the previous works, the proposed method is suitable for the state-ofthe-art High Efficiency Video Coding (HEVC) encoder, which by itself offers substantial bitrate savings compared to prior encoders. The proposed method leverages information from the game such as the Regions-of-Interest (ROIs), and optimizes the quality by allocating different amounts of bits to various areas in the video frames. Through actual implementation in an open-source cloud gaming platform, we show that the proposed method achieves quality gains in ROIs that can be translated to bitrate savings between 21% and 46% against the baseline HEVC encoder and between 12% and 89% against the closest work in the literature. CCS CONCEPTS • Information systems → Multimedia streaming.
In this paper, the problem of constructing an efficient quantum circuit for the implementation of... more In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains $l$ qubits. In addition, a previously proposed quantum-logic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over $l$ qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of $l$ affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of $l$ is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of $\frac{5}{3}$ if the nea...
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Papers by Mehdi Saeedi