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[Keyword] cost(184hit)

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  • Communication-Efficient Distributed Orthogonal Approximate Message Passing for Sparse Signal Recovery

    Ken HISANAGA  Motohiko ISAKA  

     
    PAPER-Signal Processing

      Pubricized:
    2023/08/30
      Vol:
    E107-A No:3
      Page(s):
    493-502

    In this paper, we introduce a framework of distributed orthogonal approximate message passing for recovering sparse vector based on sensing by multiple nodes. The iterative recovery process consists of local computation at each node, and global computation performed either by a particular node or joint computation on the overall network by exchanging messages. We then propose a method to reduce the communication cost between the nodes while maintaining the recovery performance.

  • Channel Capacity with Cost Constraint Allowing Cost Overrun

    Masaki HORI  Mikihiko NISHIARA  

     
    PAPER-Shannon Theory

      Pubricized:
    2023/10/10
      Vol:
    E107-A No:3
      Page(s):
    458-463

    A channel coding problem with cost constraint for general channels is considered. Verdú and Han derived ϵ-capacity for general channels. Following the same lines of its proof, we can also derive ϵ-capacity with cost constraint. In this paper, we derive a formula for ϵ-capacity with cost constraint allowing overrun. In order to prove this theorem, a new variation of Feinstein's lemma is applied to select codewords satisfying cost constraint and codewords not satisfying cost constraint.

  • Multi-Agent Surveillance Based on Travel Cost Minimization

    Kyohei MURAKATA  Koichi KOBAYASHI  Yuh YAMASHITA  

     
    PAPER

      Pubricized:
    2023/07/19
      Vol:
    E107-A No:1
      Page(s):
    25-30

    The multi-agent surveillance problem is to find optimal trajectories of multiple agents that patrol a given area as evenly as possible. In this paper, we consider the multi-agent surveillance problem based on travel cost minimization. The surveillance area is given by an undirected graph. The penalty for each agent is introduced to evaluate the surveillance performance. Through a mixed logical dynamical system model, the multi-agent surveillance problem is reduced to a mixed integer linear programming (MILP) problem. In model predictive control, trajectories of agents are generated by solving the MILP problem at each discrete time. Furthermore, a condition that the MILP problem is always feasible is derived based on the Chinese postman problem. Finally, the proposed method is demonstrated by a numerical example.

  • A New Transformation for Costas Arrays

    Ali ARDALANI  Alexander POTT  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2023/08/24
      Vol:
    E106-A No:12
      Page(s):
    1504-1510

    A Costas array of size n is an n × n binary matrix such that no two of the $inom{n}{2}$ line segments connecting 1s have the same length and slope. Costas arrays are found by finite-field-based construction methods and their manipulations (systematically constructed) and exhaustive search methods. The arrays found exhaustively, which are of completely unknown origin, are called sporadic. Most studies in Costas arrays have tended to focus on systematically constructed Costas arrays rather than sporadic ones, which reveals the hardness of examining a link between systematically constructed Costas arrays and sporadic ones. This paper introduces a new transformation that preserves the Costas property for some Costas arrays, but not all. We observed that this transformation could transform some systematically constructed Costas arrays to sporadic ones and vice versa. Moreover, we introduce a family of arrays with the property that the auto-correlation of each array and the cross-correlation between any two arrays in this family is bounded above by two.

  • A Low-Phase-Noise RF Up/Down-Converter for Cost-Effective 5G Millimeter-Wave Test Solutions

    Jaeyong KO  Namkyoung KIM  Kyungho YOO  Tongho CHUNG  

     
    BRIEF PAPER

      Pubricized:
    2023/04/19
      Vol:
    E106-C No:11
      Page(s):
    713-717

    The increasing demand for millimeter-wave (mmWave) frequencies with wider signal bandwidths, such as 5G NR, requires large investments on test equipment. This work presents a 5G mmWave up/down-converter with a 40 GHz LO, fabricated in custom PCBs with off-the-shelf components. The mmWave converter has broad IF and RF bandwidths of 1∼5 GHz and 21∼45 GHz, and the built-in LO generates 20∼29.5 GHz and 33.5∼40 GHz of output. To achieve high linearity of the converter simultaneously, the LO must produce low-phase-noise and be capable of high harmonics/spur rejection, and design techniques related to these features are demonstrated. Additionally, a reconfigurable IF amplifier for bi-directional conversion is included and demonstrates low gain variation to maintain the linearity of the wideband modulation signals. The final designed converter is tested with 5G OFDM 64-QAM 100 MHz 1-CC (4-CC) signals and shows RF/IF output power of -3/8 dBm with a linear range of 35 (30)/38 (33) dB at an EVM of 25 dB.

  • ZGridBC: Zero-Knowledge Proof Based Scalable and Privacy-Enhanced Blockchain Platform for Electricity Tracking

    Takeshi MIYAMAE  Fumihiko KOZAKURA  Makoto NAKAMURA  Masanobu MORINAGA  

     
    PAPER-Information Network

      Pubricized:
    2023/04/14
      Vol:
    E106-D No:7
      Page(s):
    1219-1229

    The total number of solar power-producing facilities whose Feed-in Tariff (FIT) Program-based ten-year contracts will expire by 2023 is expected to reach approximately 1.65 million in Japan. If the facilities that produce or consume renewable energy would increase to reach a large number, e.g., two million, blockchain would not be capable of processing all the transactions. In this work, we propose a blockchain-based electricity-tracking platform for renewable energy, called ‘ZGridBC,’ which consists of mutually cooperative two novel decentralized schemes to solve scalability, storage cost, and privacy issues at the same time. One is the electricity production resource management, which is an efficient data management scheme that manages electricity production resources (EPRs) on the blockchain by using UTXO tokens extended to two-dimension (period and electricity amount) to prevent double-spending. The other is the electricity-tracking proof, which is a massive data aggregation scheme that significantly reduces the amount of data managed on the blockchain by using zero-knowledge proof (ZKP). Thereafter, we illustrate the architecture of ZGridBC, consider its scalability, security, and privacy, and illustrate the implementation of ZGridBC. Finally, we evaluate the scalability of ZGridBC, which handles two million electricity facilities with far less cost per environmental value compared with the price of the environmental value proposed by METI (=0.3 yen/kWh).

  • CAMRI Loss: Improving the Recall of a Specific Class without Sacrificing Accuracy

    Daiki NISHIYAMA  Kazuto FUKUCHI  Youhei AKIMOTO  Jun SAKUMA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2023/01/23
      Vol:
    E106-D No:4
      Page(s):
    523-537

    In real world applications of multiclass classification models, misclassification in an important class (e.g., stop sign) can be significantly more harmful than in other classes (e.g., no parking). Thus, it is crucial to improve the recall of an important class while maintaining overall accuracy. For this problem, we found that improving the separation of important classes relative to other classes in the feature space is effective. Existing methods that give a class-sensitive penalty for cross-entropy loss do not improve the separation. Moreover, the methods designed to improve separations between all classes are unsuitable for our purpose because they do not consider the important classes. To achieve the separation, we propose a loss function that explicitly gives loss for the feature space, called class-sensitive additive angular margin (CAMRI) loss. CAMRI loss is expected to reduce the variance of an important class due to the addition of a penalty to the angle between the important class features and the corresponding weight vectors in the feature space. In addition, concentrating the penalty on only the important class hardly sacrifices separating the other classes. Experiments on CIFAR-10, GTSRB, and AwA2 showed that CAMRI loss could improve the recall of a specific class without sacrificing accuracy. In particular, compared with GTSRB's second-worst class recall when trained with cross-entropy loss, CAMRI loss improved recall by 9%.

  • Variable Tap-Length Algorithm Based on a Mixed Error Cost Function

    Yufei HAN  Yibo LI  Yao LI  

     
    LETTER-Digital Signal Processing

      Pubricized:
    2021/12/17
      Vol:
    E105-A No:6
      Page(s):
    1006-1009

    Numerous variable tap-length algorithms can be found in some literature and few strategies are derived from a basic theoretical formula. Thus, some algorithms lack of theoretical depth and their performance are unstable. In view of this point, the novel variable tap-length algorithm which is based on the mixed error cost function is presented in this letter. By analyzing the mixed expectation of the prior and the posterior error, the novel variable tap-length strategy is derived. The proposed algorithm has a more valid proximity to the optimal tap-length and a good convergence ability by the performance analysis. It can solve many deficiencies comprising large fluctuations of the tap-length, the high complexity and the weak steady-state ability. Simulation results demonstrate that the proposed algorithm equips good performance.

  • Channel Coding with Cost Paid on Delivery

    Mikihiko NISHIARA  

     
    PAPER-Information Theory

      Pubricized:
    2021/07/27
      Vol:
    E105-A No:3
      Page(s):
    345-352

    In the source coding problem with cost constraint, a cost function is defined over the code alphabet. This can be regarded as a noiseless channel coding problem with cost constraint. In this case, we will not distinguish between the input alphabet and the output alphabet of the channel. However, we must distinguish them for a noisy channel. In the channel coding problem with cost constraint so far, the cost function is defined over the input alphabet of the noisy channel. In this paper, we define the cost function over the output alphabet of the channel. And, the cost is paid only after the received word is observed. Note that the cost is a random variable even if the codeword is fixed. We show the channel capacity with cost constraint defined over the output alphabet. Moreover, we generalize it to tolerate some decoding error and some cost overrun. Finally, we show that the cost constraint can be described on a subset of arbitrary set which may have no structure.

  • Generation of Surface Wave in C-Band Automotive On-Glass Antenna and an Easily Realizable Suppression Method for Improving Antenna Characteristics

    Osamu KAGAYA  Keisuke ARAI  Takato WATANABE  Takuji ARIMA  Toru UNO  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2021/08/02
      Vol:
    E105-B No:1
      Page(s):
    51-57

    In this paper, the influence of surface waves on the characteristics of on-glass antennas is clarified to enable appropriates design of C-band automotive on-glass antennas. Composite glasses are used in automotive windshields. These automotive composite glasses are composed of three layers. First, the surface wave properties of composite glass are investigated. Next, the effects of surface waves on the reflection coefficient characteristics of on-glass antennas are investigated. Finally, the antenna placement to reduce surface wave effect will be presented. Electromagnetic field analysis of a dipole antenna placed at the center of a 300mm × 300mm square flat composite glass showed that the electric field strength in the glass had ripples with the half wavelength period of the surface waves. Therefore, it was confirmed that standing waves are generated because of these surface waves. In addition, it is confirmed that ripples occur in the reflection coefficient at frequencies. Glass size is divisible by each of those guide wavelengths. Furthermore, it was clarified that the reflection coefficient fluctuates with respect to the distance between the antenna and a metal frame, which is attached to the end face in the direction perpendicular to the thickness of the glass because of the influence of standing waves caused by the surface waves; additionally, the reflection coefficient gets worse when the distance between the antenna and the metal frame is an integral multiple of one half wavelength. A similar tendency was observed in an electric field analysis using a model that was shaped like the actual windshield shape. Because radiation patterns also change as a result of the influence of surface waves and metal frames, the results imply that it is necessary to consider the actual device size and the metal frames when designing automotive on-glass antennas.

  • Enhancing the Business Model: Automating the Recommended Retail Price Calculation of Products

    Bahjat FAKIEH  

     
    PAPER-Office Information Systems, e-Business Modeling

      Pubricized:
    2021/04/15
      Vol:
    E104-D No:7
      Page(s):
    970-980

    The purpose of this paper is to find an automated pricing algorithm to calculate the real cost of each product by considering the associate costs of the business. The methodology consists of two main stages. A brief semi-structured survey and a mathematical calculation the expenses and adding them to the original cost of the offered products and services. The output of this process obtains the minimum recommended selling price (MRSP) that the business should not go below, to increase the likelihood of generating profit and avoiding the unexpected loss. The contribution of this study appears in filling the gap by calculating the minimum recommended price automatically and assisting businesses to foresee future budgets. This contribution has a certain limitation, where it is unable to calculate the MRSP of the in-house created products from raw materials. It calculates the MRSP only for the products bought from the wholesaler to be sold by the retailer.

  • An Experimental Study across GPU DBMSes toward Cost-Effective Analytical Processing

    Young-Kyoon SUH  Seounghyeon KIM  Joo-Young LEE  Hawon CHU  Junyoung AN  Kyong-Ha LEE  

     
    LETTER

      Pubricized:
    2020/11/06
      Vol:
    E104-D No:5
      Page(s):
    551-555

    In this letter we analyze the economic worth of GPU on analytical processing of GPU-accelerated database management systems (DBMSes). To this end, we conducted rigorous experiments with TPC-H across three popular GPU DBMSes. Consequently, we show that co-processing with CPU and GPU in the GPU DBMSes was cost-effective despite exposed concerns.

  • Bee Colony Algorithm Optimization Based on Link Cost for Routing and Wavelength Assignment in Satellite Optical Networks Open Access

    Yeqi LIU  Qi ZHANG  Xiangjun XIN  Qinghua TIAN  Ying TAO  Naijin LIU  Kai LV  

     
    PAPER-Internet

      Pubricized:
    2019/12/18
      Vol:
    E103-B No:6
      Page(s):
    690-702

    Rapid development of modern communications has initiated essential requirements for providing efficient algorithms that can solve the routing and wavelength assignment (RWA) problem in satellite optical networks. In this paper, the bee colony algorithm optimization based on link cost for RWA (BCO-LCRWA) is tailored for satellite networks composed of intersatellite laser links. In BCO-LCRWA, a cost model of intersatellite laser links is established based on metrics of network transmission performance namely delay and wavelengths utilization, with constraints of Doppler wavelength drift, transmission delay, wavelength consistency and continuity. Specifically, the fitness function of bee colony exploited in the proposed algorithm takes wavelength resources utilization and communication hops into account to implement effective utilization of wavelengths, to avoid unnecessary over-detouring and ensure bit error rate (BER) performance of the system. The simulation results corroborate the improved performance of the proposed algorithm compared with the existing alternatives.

  • Cost-Sensitive and Sparse Ladder Network for Software Defect Prediction

    Jing SUN  Yi-mu JI  Shangdong LIU  Fei WU  

     
    LETTER-Software Engineering

      Pubricized:
    2020/01/29
      Vol:
    E103-D No:5
      Page(s):
    1177-1180

    Software defect prediction (SDP) plays a vital role in allocating testing resources reasonably and ensuring software quality. When there are not enough labeled historical modules, considerable semi-supervised SDP methods have been proposed, and these methods utilize limited labeled modules and abundant unlabeled modules simultaneously. Nevertheless, most of them make use of traditional features rather than the powerful deep feature representations. Besides, the cost of the misclassification of the defective modules is higher than that of defect-free ones, and the number of the defective modules for training is small. Taking the above issues into account, we propose a cost-sensitive and sparse ladder network (CSLN) for SDP. We firstly introduce the semi-supervised ladder network to extract the deep feature representations. Besides, we introduce the cost-sensitive learning to set different misclassification costs for defective-prone and defect-free-prone instances to alleviate the class imbalance problem. A sparse constraint is added on the hidden nodes in ladder network when the number of hidden nodes is large, which enables the model to find robust structures of the data. Extensive experiments on the AEEEM dataset show that the CSLN outperforms several state-of-the-art semi-supervised SDP methods.

  • An Evolutionary Game for Analyzing Switching Behavior of Consumers in Electricity Retail Markets

    Ryo HASE  Norihiko SHINOMIYA  

     
    PAPER

      Vol:
    E103-A No:2
      Page(s):
    407-416

    Many countries have deregulated their electricity retail markets to offer lower electricity charges to consumers. However, many consumers have not switched their suppliers after the deregulation, and electricity suppliers do not tend to reduce their charges intensely. This paper proposes an electricity market model and evolutionary game to analyze the behavior of consumers in electricity retail markets. Our model focuses on switching costs such as an effort at switching, costs in searching for other alternatives, and so on. The evolutionary game examines whether consumers choose a strategy involving exploration of new alternatives with the searching costs as “cooperators” or not. Simulation results demonstrate that the share of cooperators was not improved by simply giving rewards for cooperators as compensation for searching costs. Furthermore, the results also suggest that the degree of cooperators in a network among consumers has a vital role in increasing the share of cooperators and switching rate.

  • A Hypergraph Matching Labeled Multi-Bernoulli Filter for Group Targets Tracking Open Access

    Haoyang YU  Wei AN  Ran ZHU  Ruibin GUO  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2019/07/01
      Vol:
    E102-D No:10
      Page(s):
    2077-2081

    This paper addresses the association problem of tracking closely spaced targets in group or formation. In the Labeled Multi-Bernoulli Filter (LMB), the weight of a hypothesis is directly affected by the distance between prediction and measurement. This may generate false associations when dealing with the closely spaced multiple targets. Thus we consider utilizing structure information among the group or formation. Since, the relative position relation of the targets in group or formation varies slightly within a short time, the targets are considered as nodes of a topological structure. Then the position relation among the targets is modeled as a hypergraph. The hypergraph matching method is used to resolve the association matrix. At last, with the structure prior information introduced, the new joint cost matrix is re-derived to generate hypotheses, and the filtering recursion is implemented in a Gaussian mixture way. The simulation results show that the proposed algorithm can effectively deal with group targets and is superior to the LMB filter in tracking precision and accuracy.

  • Fast Visual Odometry Based Sparse Geometric Constraint for RGB-D Camera Open Access

    Ruibin GUO  Dongxiang ZHOU  Keju PENG  Yunhui LIU  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2018/10/09
      Vol:
    E102-D No:1
      Page(s):
    214-218

    Pose estimation is a basic requirement for the autonomous behavior of robots. In this article we present a robust and fast visual odometry method to obtain camera poses by using RGB-D images. We first propose a motion estimation method based on sparse geometric constraint and derive the analytic Jacobian of the geometric cost function to improve the convergence performance, then we use our motion estimation method to replace the tracking thread in ORB-SLAM for improving its runtime performance. Experimental results show that our method is twice faster than ORB-SLAM while keeping the similar accuracy.

  • Function Design for Minimum Multiple-Control Toffoli Circuits of Reversible Adder/Subtractor Blocks and Arithmetic Logic Units

    Md Belayet ALI  Takashi HIRAYAMA  Katsuhisa YAMANAKA  Yasuaki NISHITANI  

     
    PAPER

      Vol:
    E101-A No:12
      Page(s):
    2231-2243

    In this paper, we propose a design of reversible adder/subtractor blocks and arithmetic logic units (ALUs). The main concept of our approach is different from that of the existing related studies; we emphasize the function design. Our approach of investigating the reversible functions includes (a) the embedding of irreversible functions into incompletely-specified reversible functions, (b) the operation assignment, and (c) the permutation of function outputs. We give some extensions of these techniques for further improvements in the design of reversible functions. The resulting reversible circuits are smaller than that of the existing design in terms of the number of multiple-control Toffoli gates. To evaluate the quantum cost of the obtained circuits, we convert the circuits to reduced quantum circuits for experiments. The results also show the superiority of our realization of adder/subtractor blocks and ALUs in quantum cost.

  • A New Semi-Blind Method for Spatial Equalization in MIMO Systems

    Liu YANG  Hang ZHANG  Yang CAI  Qiao SU  

     
    LETTER-Digital Signal Processing

      Vol:
    E101-A No:10
      Page(s):
    1693-1697

    In this letter, a new semi-blind approach incorporating the bounded nature of communication sources with the distance between the equalizer outputs and the training sequence is proposed. By utilizing the sparsity property of l1-norm cost function, the proposed algorithm can outperform the semi-blind method based on higher-order statistics (HOS) criterion especially for transmitting sources with non-constant modulus. Experimental results demonstrate that the proposed method shows superior performance over the HOS based semi-blind method and the classical training-based method for QPSK and 16QAM sources equalization. While for 64QAM signal inputs, the proposed algorithm exhibits its superiority in low signal-to-noise-ratio (SNR) conditions compared with the training-based method.

  • Block-Matching-Based Implementation of Affine Motion Estimation for HEVC

    Chihiro TSUTAKE  Toshiyuki YOSHIDA  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2018/01/15
      Vol:
    E101-D No:4
      Page(s):
    1151-1158

    Many of affine motion compensation techniques proposed thus far employ least-square-based techniques in estimating affine parameters, which requires a hardware structure different from conventional block-matching-based one. This paper proposes a new affine motion estimation/compensation framework friendly to block-matching-based parameter estimation, and applies it to an HEVC encoder to demonstrate its coding efficiency and computation cost. To avoid a nest of search loops, a new affine motion model is first introduced by decomposing the conventional 4-parameter affine model into two 3-parameter ones. Then, a block-matching-based fast parameter estimation technique is proposed for the models. The experimental results given in this paper show that our approach is advantageous over conventional techniques.

1-20hit(184hit)