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[Keyword] swap(16hit)

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  • Joint User Grouping and Resource Allocation for NOMA Enhanced D2D Communications Open Access

    Jin XIE  Fangmin XU  

     
    PAPER-Communication Theory and Signals

      Pubricized:
    2023/09/20
      Vol:
    E107-A No:6
      Page(s):
    864-872

    To mitigate the interference caused by frequency reuse between inter-layer and intra-layer users for Non-Orthogonal Multiple Access (NOMA) based device-to-device (D2D) communication underlaying cellular systems, this paper proposes a joint optimization strategy that combines user grouping and resource allocation. Specifically, the optimization problem is formulated to maximize the sum rate while ensuring the minimum rate of cellular users, considering three optimization parameters: user grouping, sub channel allocation and power allocation. However, this problem is a mixed integer nonlinear programming (MINLP) problem and is hard to solve directly. To address this issue, we divide the problem into two sub-problems: user grouping and resource allocation. First, we classify D2D users into D2D pairs or D2D NOMA groups based on the greedy algorithm. Then, in terms of resource allocation, we allocate the sub-channel to D2D users by swap matching algorithm to reduce the co-channel interference, and optimize the transmission power of D2D by the local search algorithm. Simulation results show that, compared to other schemes, the proposed algorithm significantly improves the system sum rate and spectral utilization.

  • A SAT Approach to the Initial Mapping Problem in SWAP Gate Insertion for Commuting Gates

    Atsushi MATSUO  Shigeru YAMASHITA  Daniel J. EGGER  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2023/05/17
      Vol:
    E106-A No:11
      Page(s):
    1424-1431

    Most quantum circuits require SWAP gate insertion to run on quantum hardware with limited qubit connectivity. A promising SWAP gate insertion method for blocks of commuting two-qubit gates is a predetermined swap strategy which applies layers of SWAP gates simultaneously executable on the coupling map. A good initial mapping for the swap strategy reduces the number of required swap gates. However, even when a circuit consists of commuting gates, e.g., as in the Quantum Approximate Optimization Algorithm (QAOA) or trotterized simulations of Ising Hamiltonians, finding a good initial mapping is a hard problem. We present a SAT-based approach to find good initial mappings for circuits with commuting gates transpiled to the hardware with swap strategies. Our method achieves a 65% reduction in gate count for random three-regular graphs with 500 nodes. In addition, we present a heuristic approach that combines the SAT formulation with a clustering algorithm to reduce large problems to a manageable size. This approach reduces the number of swap layers by 25% compared to both a trivial and random initial mapping for a random three-regular graph with 1000 nodes. Good initial mappings will therefore enable the study of quantum algorithms, such as QAOA and Ising Hamiltonian simulation applied to sparse problems, on noisy quantum hardware with several hundreds of qubits.

  • Efficient Algorithms for Sorting k-Sets in Bins

    Atsuki NAGAO  Kazuhisa SETO  Junichi TERUYAMA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E98-D No:10
      Page(s):
    1736-1743

    We propose efficient algorithms for Sorting k-Sets in Bins. The Sorting k-Sets in Bins problem can be described as follows. We are given numbered n bins with k balls in each bin. Balls in the i-th bin are numbered n-i+1. We can only swap balls between adjacent bins. Our task is to move all of the balls to the same numbered bins. For this problem, we give an efficient greedy algorithm with $ rac{k+1}{4}n^2+O(k+n)$ swaps and provide a detailed analysis for k=3. In addition, we give a more efficient recursive algorithm using $ rac{15}{16}n^2+O(n)$ swaps for k=3.

  • Pose-Free Face Swapping Based on a Deformable 3D Shape Morphable Model

    Yuan LIN  Shengjin WANG  

     
    PAPER-Computer Graphics

      Vol:
    E97-D No:2
      Page(s):
    305-314

    Traditional face swapping technologies require that the faces of source images and target images have similar pose and appearance (usually frontal). For overcoming this limit in applications this paper presents a pose-free face swapping method based on personalized 3D face modeling. By using a deformable 3D shape morphable model, a photo-realistic 3D face is reconstructed from a single frontal view image. With the aid of the generated 3D face, a virtual source image of the person with the same pose as the target face can be rendered, which is used as a source image for face swapping. To solve the problem of illumination difference between the target face and the source face, a color transfer merging method is proposed. It outperforms the original color transfer method in dealing with the illumination gap problem. An experiment shows that the proposed face reconstruction method is fast and efficient. In addition, we have conducted experiments of face swapping in a variety of scenarios such as children's story book, role play, and face de-identification stripping facial information used for identification, and promising results have been obtained.

  • Fault Diagnosis and Reconfiguration Method for Network-on-Chip Based Multiple Processor Systems with Restricted Private Memories

    Masashi IMAI  Tomohiro YONEDA  

     
    PAPER

      Vol:
    E96-D No:9
      Page(s):
    1914-1925

    We propose a fault diagnosis and reconfiguration method based on the Pair and Swap scheme to improve the reliability and the MTTF (Mean Time To Failure) of network-on-chip based multiple processor systems where each processor core has its private memory. In the proposed scheme, two identical copies of a given task are executed on a pair of processor cores and the results are compared repeatedly in order to detect processor faults. If a fault is detected by mismatches, the fault is identified and isolated using a TMR (Triple Module Redundancy) and the system is reconfigured by the redundant processor cores. We propose that each task is quadruplicated and statically assigned to private memories so that each memory has only two different tasks. We evaluate the reliability of the proposed quadruplicated task allocation scheme in the viewpoint of MTTF. As a result, the MTTF of the proposed scheme is over 4.3 times longer than that of the duplicated task allocation scheme.

  • Scalable Cache-Optimized Concurrent FIFO Queue for Multicore Architectures

    Changwoo MIN  Hyung Kook JUN  Won Tae KIM  Young Ik EOM  

     
    LETTER

      Vol:
    E95-D No:12
      Page(s):
    2956-2957

    A concurrent FIFO queue is a widely used fundamental data structure for parallelizing software. In this letter, we introduce a novel concurrent FIFO queue algorithm for multicore architecture. We achieve better scalability by reducing contention among concurrent threads, and improve performance by optimizing cache-line usage. Experimental results on a server with eight cores show that our algorithm outperforms state-of-the-art algorithms by a factor of two.

  • Improving the Efficiency in Halftone Image Generation Based on Structure Similarity Index Measurement

    Aroba KHAN  Hernan AGUIRRE  Kiyoshi TANAKA  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E95-D No:10
      Page(s):
    2495-2504

    This paper presents two halftoning methods to improve efficiency in generating structurally similar halftone images using Structure Similarity Index Measurement (SSIM). Proposed Method I reduces the pixel evaluation area by applying pixel-swapping algorithm within inter-correlated blocks followed by phase block-shifting. The effect of various initial pixel arrangements is also investigated. Proposed Method II further improves efficiency by applying bit-climbing algorithm within inter-correlated blocks of the image. Simulation results show that proposed Method I improves efficiency as well as image quality by using an appropriate initial pixel arrangement. Proposed Method II reaches a better image quality with fewer evaluations than pixel-swapping algorithm used in Method I and the conventional structure aware halftone methods.

  • Indexed Swap Matching for Short Patterns

    Hua ZHAO  Songfeng LU  

     
    PAPER-Algorithms and Data Structures

      Vol:
    E95-A No:1
      Page(s):
    362-366

    Let T be a text of length n and P be a pattern of length m, both strings over a fixed finite alphabet. The Pattern Matching with Swaps problem is to find all occurrences of P in T if adjacent pattern characters can be swapped. In the Approximate Pattern Matching problem with Swaps, one seeks for every text location with a swapped match of P, the number of swaps necessary to obtain a match at the location. In this paper we provide the first off-line solution for the swap matching problem and the approximate pattern matching problem with swaps. We present a new data-structure called a Swap-transforming Tree. And we give a precise upper-bond of the number of the swapped versions of a pattern. By using the swap-transforming tree, we can solve both problems in time O(λmlog2 n) on an O(nHk) bits indexing data structure. Here λ is a constant. Our solution is more effective when the pattern is short.

  • Quantum Communication Experiments Using Telecom-Band Entangled Photons

    Hiroki TAKESUE  Toshimori HONJO  Kenichi HARADA  Benjamin MIQUEL  

     
    INVITED PAPER

      Vol:
    E93-A No:5
      Page(s):
    903-909

    Entanglement is expected to play a crucial role in the next-generation quantum communication systems. This paper reviews recent quantum communication experiments over optical fiber using 1.5-µm telecom-band entangled photon pairs. After describing the telecom-band entanglement sources based on spontaneous parametric processes, we review three quantum communication experiments using entangled photons: a long-distance entanglement distribution, an entanglement-based quantum key distribution, and an entanglement swapping.

  • Interoperability Experiment of VLAN Tag Swapped Ethernet and Transmitting High Definition Video through the Layer-2 LSP between Japan and Belgium Open Access

    Sho SHIMIZU  Wouter TAVERNIER  Kou KIKUTA  Masahiro NISHIDA  Daisuke ISHII  Satoru OKAMOTO  Didier COLLE  Mario PICKAVET  Piet DEMEESTER  Naoaki YAMANAKA  

     
    LETTER-Network

      Vol:
    E93-B No:3
      Page(s):
    736-740

    The first global interoperability experiment of GMPLS controlled Ethernet with VLAN tag swapping between two different implementations is successfully demonstrated. High definition video streaming is realized through a newly established Layer 2 Label Switched Path (L2-LSP). The results of this experiment can be applied to designing reliable Layer 2 networks.

  • A Study on the Next Generation HomeRF System

    Jeung-Hwa CHO  Hyoung-Kyu SONG  Young-Hwan YOU  Jin-Woong CHO  

     
    LETTER-Multimedia Systems

      Vol:
    E85-B No:12
      Page(s):
    2971-2975

    Among the wireless personal area networks, much attention has been placed on the HomeRF system due to the simple hardware complexity. In this letter, we propose several techniques for the HomeRF system. First, a DC-offset compensation technique is considered for HomeRF system. In addition, a decision directed channel estimation technique is proposed. The proposed techniques require no additional training sequence and a little additional hardware. And finally, a turbo coding technique is considered as a improved coding scheme. It is shown that the performance of the proposed algorithm is significantly improved in comparison with the conventional HomeRF system.

  • Optical Code Based Label Swapping for Photonic Routing

    Hideyuki SOTOBAYASHI  Ken-ichi KITAYAMA  

     
    PAPER

      Vol:
    E83-B No:10
      Page(s):
    2341-2347

    This paper describes an all-optical label swapping for the photonic label switching router (LSR). The optical code routing photonic LSR in which label is mapped onto an optical code is one of the most promising photonic network technologies. It utilizes such unique features of optical code division multiplexing (OCDM) as asynchronous transmission, tell-and-go access protocol, and high degree of scalability. In practical photonic LSRs, all optical code conversion will play an important role. All-optical code conversion of 10 Gbit/s binary phase-shift keying (BPSK) codes by use of cross-phase modulation (XPM) in an optical fiber without wavelength-shift is proposed for the photonic LSR and experimentally demonstrated.

  • The Next-Generation ATM Switching Architecture for Multimedia Communications

    Zenichi YASHIRO  Toshiro TANAKA  Yukihiro DOI  

     
    PAPER-ATM switching architecture

      Vol:
    E81-B No:2
      Page(s):
    209-214

    The Internet is expected to see a rapid growth in multimedia services in the next few years. Network traffic will increase dramatically for many different services, so it will be necessary to have high-speed broadband backbone networks capable of supporting wide-area coverage. Such networks are expected to be built on ATM technology. This paper describes the next-generation ATM switching node architecture for multimedia communications, the enhancement of system capability and functions, and improved system maintainability. The goal is an ATM switching system for Multimedia Communications switching systems; we call it a Multimedia Handling Node for ATM (MHN-A). MHN-A is based on the concept of a unified architecture for circuit switching, packet switching, and ATM switching. Various functions are provided as options that can be economically added or deleted according to customers' requirements.

  • The Security of an RDES Cryptosystem against Linear Cryptanalysis

    Yasushi NAKAO  Toshinobu KANEKO  Kenji KOYAMA  Routo TERADA  

     
    PAPER

      Vol:
    E79-A No:1
      Page(s):
    12-19

    RDES cryptosystem is an n-round DES in which an probabilistic swapping is added onto the right half of the input in each round. It is more effective than a simple increase of DES rounds for a countermeasure against differential attack. In this paper, we show that the RDES is also effective against linear cryptanalysis. We applied Matsui's search algorithm to find the best expression for RDES-1 and RDES-2. The results are as follows: (a) The 16-round RDES-1 is approximately as strong as a 22-round DES, and the 16-round RDES-2 is approximately as strong as a 29-round DES. (b) Linear cryptanalysis for a 16-round RDES-1 and a 16-round RDES-2 requires more than 264 known-plaintexts.

  • Dynamic Swapping Schemes and Differential Cryptanalysis

    Toshinobu KANEKO  Kenji KOYAMA  Routo TERADA  

     
    PAPER

      Vol:
    E77-A No:8
      Page(s):
    1328-1336

    This paper proposes a dynamically randomized version of DES (called RDES) in which a input-dependent swapping Sk(X) is added onto the right half of the input in each round of DES. This new scheme decreases the probability of success in differential cryptanalysis because it decreases the characteristic probability. Each "best" two-round characteristic probability is analyzed for typical schemes of the RDES: (i) RDES-1 with a simple one-level swapping, (ii) RDES-1' with an optimal one-level swapping, (iii) RDES-2 with a simple two-level swapping, and (iv) RDES-2' with an optimal two-level swapping. The main results are as follows. (a) The differential attacks on the 16-round RDES-1' and the 16-round RDES-2 require more computational time than the exhaustive search. (b) A differential attack is substantially inapplicable to the 16-round RDES-2' because more than 263 chosen plaintext pairs are required. (c) The encryption/decryption speed of the n-round RDES is almost the same as that of the n-round DES.

  • How to Strengthen DES-like Cryptosystems against Differential Cryptanalysis

    Kenji KOYAMA  Routo TERADA  

     
    PAPER

      Vol:
    E76-A No:1
      Page(s):
    63-69

    We propose a new randomized version of DES in which a key-dependent swapping is used to strengthen DES and DES-like cryptosystems against differential cryptanalysis. This new scheme, called RDES, decreases the probability of success in differential attack by decreasing the characteristic probability. The characteristic is the effect of particular differences in plaintext pairs on the differences in the resultant ciphertext pairs. The characteristic probability for the n-round RDES is 2-n+1 times that for the n-round DES. As for the differential cryptanalysis based on characteristics, the 16-round RDES is as strong as the about 20-round DES. Encryption/decryption speed of n-round RDES is almost the same as that of the n-round DES.