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  • Optimization Algorithm with Automatic Adjustment of the Number of Switches in the Order/Radix Problem

    Masaki TSUKAMOTO  Yoshiko HANADA  Masahiro NAKAO  Keiji YAMAMOTO  

     
    PAPER

      Pubricized:
    2023/06/12
      Vol:
    E106-D No:12
      Page(s):
    1979-1987

    The Order/Radix Problem (ORP) is an optimization problem that can be solved to find an optimal network topology in distributed memory systems. It is important to find the optimum number of switches in the ORP. In the case of a regular graph, a good estimation of the preferred number of switches has been proposed, and it has been shown that simulated annealing (SA) finds a good solution given a fixed number of switches. However, generally the optimal graph does not necessarily satisfy the regular condition, which greatly increases the computational costs required to find a good solution with a suitable number of switches for each case. This study improved the new method based on SA to find a suitable number of switches. By introducing neighborhood searches in which the number of switches is increased or decreased, our method can optimize a graph by changing the number of switches adaptively during the search. In numerical experiments, we verified that our method shows a good approximation for the best setting for the number of switches, and can simultaneously generate a graph with a small host-to-host average shortest path length, using instances presented by Graph Golf, an international ORP competition.

  • Changes in Calling Parties' Behavior Caused by Settings for Indirect Control of Call Duration under Disaster Congestion Open Access

    Daisuke SATOH  Takemi MOCHIDA  

     
    PAPER-General Fundamentals and Boundaries

      Pubricized:
    2022/05/10
      Vol:
    E105-A No:9
      Page(s):
    1358-1371

    The road space rationing (RSR) method regulates a period in which a user group can make telephone calls in order to decrease the call attempt rate and induce calling parties to shorten their calls during disaster congestion. This paper investigates what settings of this indirect control induce more self-restraint and how the settings change calling parties' behavior using experimental psychology. Our experiments revealed that the length of the regulated period differently affected calling parties' behavior (call duration and call attempt rate) and indicated that the 60-min RSR method (i.e., 10 six-min periods) is the most effective setting against disaster congestion.

  • Strategy for Improving Target Selection Accuracy in Indirect Touch Input

    Yizhong XIN  Ruonan LIU  Yan LI  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2020/04/10
      Vol:
    E103-D No:7
      Page(s):
    1703-1709

    Aiming at the problem of low accuracy of target selection in indirect touch input, an indirect multi-touch input device was designed and built. We explored here four indirect touch input techniques which were TarConstant, TarEnlarge, TarAttract, TarEnlargeAttract, and investigated their performance when subjects completing the target selection tasks through comparative experiments. Results showed that TarEnlargeAttract enabled the shortest movement time along with the lowest error rate, 2349.9ms and 10.9% respectively. In terms of learning effect, both TarAttract and TarEnlargeAttract had learning effect on movement time, which indicated that the speed of these two techniques can be improved with training. Finally, the strategy of improving the accuracy of indirect touch input was given, which has reference significance for the interface design of indirect touch input.

  • Synchronized Tracking in Multiple Omnidirectional Cameras with Overlapping View

    Houari SABIRIN  Hitoshi NISHIMURA  Sei NAITO  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2019/07/24
      Vol:
    E102-D No:11
      Page(s):
    2221-2229

    A multi-camera setup for a surveillance system enables a larger coverage area, especially when a single camera has limited monitoring capability due to certain obstacles. Therefore, for large-scale coverage, multiple cameras are the best option. In this paper, we present a method for detecting multiple objects using several cameras with large overlapping views as this allows synchronization of object identification from a number of views. The proposed method uses a graph structure that is robust enough to represent any detected moving objects by defining their vertices and edges to determine their relationships. By evaluating these object features, represented as a set of attributes in a graph, we can perform lightweight multiple object detection using several cameras, as well as performing object tracking within each camera's field of view and between two cameras. By evaluating each vertex hierarchically as a subgraph, we can further observe the features of the detected object and perform automatic separation of occluding objects. Experimental results show that the proposed method would improve the accuracy of object tracking by reducing the occurrences of incorrect identification compared to individual camera-based tracking.

  • Analysis of DNS TXT Record Usage and Consideration of Botnet Communication Detection

    Hikaru ICHISE  Yong JIN  Katsuyoshi IIDA  

     
    PAPER

      Pubricized:
    2017/07/05
      Vol:
    E101-B No:1
      Page(s):
    70-79

    There have been several recent reports that botnet communication between bot-infected computers and Command and Control servers (C&C servers) using the Domain Name System (DNS) protocol has been used by many cyber attackers. In particular, botnet communication based on the DNS TXT record type has been observed in several kinds of botnet attack. Unfortunately, the DNS TXT record type has many forms of legitimate usage, such as hostname description. In this paper, in order to detect and block out botnet communication based on the DNS TXT record type, we first differentiate between legitimate and suspicious usages of the DNS TXT record type and then analyze real DNS TXT query data obtained from our campus network. We divide DNS queries sent out from an organization into three types — via-resolver, and indirect and direct outbound queries — and analyze the DNS TXT query data separately. We use a 99-day dataset for via-resolver DNS TXT queries and an 87-day dataset for indirect and direct outbound DNS TXT queries. The results of our analysis show that about 30%, 8% and 19% of DNS TXT queries in via-resolver, indirect and direct outbound queries, respectively, could be identified as suspicious DNS traffic. Based on our analysis, we also consider a comprehensive botnet detection system and have designed a prototype system.

  • Entity Identification on Microblogs by CRF Model with Adaptive Dependency

    Jun-Li LU  Makoto P. KATO  Takehiro YAMAMOTO  Katsumi TANAKA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2016/06/20
      Vol:
    E99-D No:9
      Page(s):
    2295-2305

    We address the problem of entity identification on a microblog with special attention to indirect reference cases in which entities are not referred to by their names. Most studies on identifying entities referred to them by their full/partial name or abbreviation, while there are many indirectly mentioned entities in microblogs, which are difficult to identify in short text such as microblogs. We therefore tackled indirect reference cases by developing features that are particularly important for certain types of indirect references and modeling dependency among referred entities by a Conditional Random Field (CRF) model. In addition, we model non-sequential order dependency while keeping the inference tractable by dynamically building dependency among entities. The experimental results suggest that our features were effective for indirect references, and our CRF model with adaptive dependency was robust even when there were multiple mentions in a microblog and achieved the same high performance as that with the fully connected CRF model.

  • An Improved Indirect Attribute Weighted Prediction Model for Zero-Shot Image Classification

    Yuhu CHENG  Xue QIAO  Xuesong WANG  

     
    PAPER-Pattern Recognition

      Pubricized:
    2015/11/20
      Vol:
    E99-D No:2
      Page(s):
    435-442

    Zero-shot learning refers to the object classification problem where no training samples are available for testing classes. For zero-shot learning, attribute transfer plays an important role in recognizing testing classes. One popular method is the indirect attribute prediction (IAP) model, which assumes that all attributes are independent and equally important for learning the zero-shot image classifier. However, a more practical assumption is that different attributes contribute unequally to the classifier learning. We therefore propose assigning different weights for the attributes based on the relevance probabilities between the attributes and the classes. We incorporate such weighed attributes to IAP and propose a relevance probability-based indirect attribute weighted prediction (RP-IAWP) model. Experiments on four popular attributed-based learning datasets show that, when compared with IAP and RFUA, the proposed RP-IAWP yields more accurate attribute prediction and zero-shot image classification.

  • Foreground Segmentation via Dynamic Programming

    Bing LUO  Chao HUANG  Lei MA  Wei LI  Qingbo WU  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E97-D No:10
      Page(s):
    2818-2822

    This paper proposes a novel method to segment the object of a specific class based on a rough detection window (such as Deformable Part Model (DPM) in this paper), which is robust to the positions of the bounding boxes. In our method, the DPM is first used to generate the root and part windows of the object. Then a set of object part candidates are generated by randomly sampling windows around the root window. Furthermore, an undirected graph (the minimum spanning tree) is constructed to describe the spatial relationships between the part windows. Finally, the object is segmented by grouping the part proposals on the undirected graph, which is formulated as an energy function minimization problem. A novel energy function consisting of the data term and the smoothness term is designed to characterize the combination of the part proposals, which is globally minimized by the dynamic programming on a tree. Our experimental results on challenging dataset demonstrate the effectiveness of the proposed method.

  • Register Indirect Jump Target Forwarding

    Ryota SHIOYA  Naruki KURATA  Takashi TOYOSHIMA  Masahiro GOSHIMA  Shuichi SAKAI  

     
    PAPER-Computer System

      Vol:
    E96-D No:2
      Page(s):
    278-288

    Object-oriented languages have recently become common, making register indirect jumps more important than ever. In object-oriented languages, virtual functions are heavily used because they improve programming productivity greatly. Virtual function calls usually consist of register indirect jumps, and consequently, programs written in object-oriented languages contain many register indirect jumps. The prediction of the targets of register indirect jumps is more difficult than the prediction of the direction of conditional branches. Many predictors have been proposed for register indirect jumps, but they cannot predict the jump targets with high accuracy or require very complex hardware. We propose a method that resolves jump targets by forwarding execution results. Our proposal dynamically finds the producers of register indirect jumps in virtual function calls. After the execution of the producers, the execution results are forwarded to the processor's front-end. The jump targets can be resolved by the forwarded execution results without requiring prediction. Our proposal improves the performance of programs that include unpredictable register indirect jumps, because it does not rely on prediction but instead uses actual execution results. Our evaluation shows that the IPC improvement using our proposal is as high as 5.4% on average and 9.8% at maximum.

  • Multimedia Multicast Based on Multiterminal Source Coding

    Ali AGHAGOLZADEH  Mahdi NOOSHYAR  Hamid R. RABIEE  Elhameh MIKAILI  

     
    PAPER-Information Theory

      Vol:
    E93-A No:9
      Page(s):
    1639-1649

    Multimedia multicast with two servers based on the multiterminal source coding is studied in some previous researches. Due to the possibility of providing an approach for practical code design for more than two correlated sources in IMTSC/CEO setup, in this paper, the framework of Slepian-Wolf coded quantization is extended and a practical code design is presented for IMTSC/CEO with the number of encoders greater than two. Then the multicast system based on the IMTSC/CEO is applied to the cases with three, four and five servers. Since the underlying code design approach for the IMTSC/CEO problem has the capability of applying to an arbitrary number of active encoders, the proposed MMBMSC method can also be used with an arbitrary number of servers easily. Also, explicit expressions of the expected distortion with an arbitrary number of servers in the MMBMSC system are presented. Experimental results with data, image and video signals show the superiority of our proposed method over the conventional solutions and over the MMBMSC system with two servers.

  • Indirectly Reactive Sputtering Coater for High Quality Optical Coatings

    Kei-ichi C. NAMIKI  Xinbin CHENG  Haruo TAKAHASHI  

     
    LETTER

      Vol:
    E91-C No:10
      Page(s):
    1673-1674

    An indirectly reactive sputtering coater has been developed to deposit various high quality metallic and metal oxide films at high deposition rate. In this letter, several kinds of filters such as antireflection (AR) coating, IR-cut filter, and Rugate filter were deposited for the benchmark test of implemental capabilities. Our coater was established to be a powerful tool for both discrete multilayer and Rugate filters due to high stability and reproducibility of the refractive index and the deposition rate.

  • Indirect Calculation Methods for Open Circuit Voltages

    Naoki INAGAKI  Katsuyuki FUJII  

     
    PAPER-Electromagnetics

      Vol:
    E91-B No:6
      Page(s):
    1825-1830

    Open circuit voltage (OCV) of electrical devices is an issue in various fields, whose numerical evaluation needs careful treatment. The open-circuited structure is ill-conditioned because of the singular electric field at the corners, and the TEM component of the electric field has to be extracted before integrated to give the voltage in the direct method of obtaining the OCV. This paper introduces the indirect methods to calculate the OCV, the admittance matrix method and the Norton theorem method. Both methods are based on the short-circuited structure which is well-conditioned. The explicit expressions of the OCV are derived in terms of the admittance matrix elements in the admittance matrix method, and in terms of the short circuit current and the antenna impedance of the electrical device under consideration in the Norton theorem method. These two methods are equivalent in theory, but the admittance matrix method is suitable for the nearby transmitter cases while the Norton theorem method is suitable for the distant transmitter cases. Several examples are given to show the usefulness of the present theory.

  • Overhead Reduction of Internet Indirection Infrastructure (i3) for Future Mobile and Wireless Communications

    Takayuki WARABINO  Keizou SUGIYAMA  

     
    PAPER

      Vol:
    E90-B No:4
      Page(s):
    761-768

    This paper proposes a new identifier scheme for Internet Indirection Infrastructure (i3). i3 is an overlay network on top of IP, and realizes rendezvous-based communications. It provides a general solution to deal with communication primitives such as host mobility, multicast and anycast. Although i3 provides flexible communication mechanisms, it is not optimized for mobile and wireless communications. Thus, three key problems still remain to be addressed: header overhead, multiple trigger updates and detection of a close i3 server after handover. The proposed identifier scheme, called local ID, significantly reduces the overhead without sacrificing the flexibility of i3. In a typical case, the local ID makes the total header size nearly half that of the original protocol. This paper also discusses how to adapt the local ID to various types of i3 primitives, so that a mobile host can receive all the benefits of i3 communications.

  • Using Topic Keyword Clusters for Automatic Document Clustering

    Hsi-Cheng CHANG  Chiun-Chieh HSU  

     
    PAPER-Document Clustering

      Vol:
    E88-D No:8
      Page(s):
    1852-1860

    Data clustering is a technique for grouping similar data items together for convenient understanding. Conventional data clustering methods, including agglomerative hierarchical clustering and partitional clustering algorithms, frequently perform unsatisfactorily for large text collections, since the computation complexities of the conventional data clustering methods increase very quickly with the number of data items. Poor clustering results degrade intelligent applications such as event tracking and information extraction. This paper presents an unsupervised document clustering method which identifies topic keyword clusters of the text corpus. The proposed method adopts a multi-stage process. First, an aggressive data cleaning approach is employed to reduce the noise in the free text and further identify the topic keywords in the documents. All extracted keywords are then grouped into topic keyword clusters using the k-nearest neighbor approach and the keyword clustering technique. Finally, all documents in the corpus are clustered based on the topic keyword clusters. The proposed method is assessed against conventional data clustering methods on a web news corpus. The experimental results show that the proposed method is an efficient and effective clustering approach.

  • Memory Allocation and Code Optimization Methods for DSPs with Indexed Auto-Modification

    Yuhei KANEKO  Nobuhiko SUGINO  Akinori NISHIHARA  

     
    PAPER

      Vol:
    E88-A No:4
      Page(s):
    846-854

    A memory address allocation method for digital signal processors of indirect addressing with indexed auto-modification is proposed. At first, address auto-modification amounts for a given program are analyzed. And then, address allocation of program variables are moved and shifted so that both indexed and simple auto-modifications are effectively exploited. For further reduction in overhead codes, a memory address allocation method coupled with computational reordering is proposed. The proposed methods are applied to the existing compiler, and generated codes prove their effectiveness.

  • Multiagent Cooperating Learning Methods by Indirect Media Communication

    Ruoying SUN  Shoji TATSUMI  Gang ZHAO  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E86-A No:11
      Page(s):
    2868-2878

    Reinforcement Learning (RL) is an efficient learning method for solving problems that learning agents have no knowledge about the environment a priori. Ant Colony System (ACS) provides an indirect communication method among cooperating agents, which is an efficient method for solving combinatorial optimization problems. Based on the cooperating method of the indirect communication in ACS and the update policy of reinforcement values in RL, this paper proposes the Q-ACS multiagent cooperating learning method that can be applied to both Markov Decision Processes (MDPs) and combinatorial optimization problems. The advantage of the Q-ACS method is for the learning agents to share episodes beneficial to the exploitation of the accumulated knowledge and utilize the learned reinforcement values efficiently. Further, taking the visited times into account, this paper proposes the T-ACS multiagent learning method. The merit of the T-ACS method is that the learning agents share better policies beneficial to the exploration during agent's learning processes. Meanwhile, considering the Q-ACS and the T-ACS as homogeneous multiagent learning methods, in the light of indirect media communication among heterogeneous multiagent, this paper presents a heterogeneous multiagent RL method, the D-ACS that composites the learning policy of the Q-ACS and the T-ACS, and takes different updating policies of reinforcement values. The agents in our methods are given a simply cooperating way exchanging information in the form of reinforcement values updated in the common model of all agents. Owning the advantages of exploring the unknown environment actively and exploiting learned knowledge effectively, the proposed methods are able to solve both problems with MDPs and combinatorial optimization problems effectively. The results of experiments on hunter game and traveling salesman problem demonstrate that our methods perform competitively with representative methods on each domain respectively.

  • A Proposal of Effective Compensation Method for IR Lamp Deterioration in NDIR Type Capnograph Systems

    Il-Yong PARK  Hee-Joon PARK  Jeong-Woo LEE  Shin-Won KANG  Jin-Ho CHO  

     
    LETTER

      Vol:
    E86-A No:6
      Page(s):
    1513-1516

    An effective compensation method for the IR lamp deterioration in NDIR (non-dispersive infrared) capnograph system is proposed. The optical chamber with two IR (infrared) lamps has been designed newly and an electronic hardware for the control of lamp intensity has been implemented. After applying the proposed optical chamber and the reference lamp control circuit to the NDIR type capnograph system, it is identified that the proposed method can compensate the lamp deterioration effectively.

  • Code Optimization Technique for Indirect Addressing DSPs with Consideration in Local Computational Order and Memory Allocation

    Nobuhiko SUGINO  Akinori NISHIHARA  

     
    PAPER-Implementations of Signal Processing Systems

      Vol:
    E84-A No:8
      Page(s):
    1960-1968

    Digital signal processors (DSPs) usually employ indirect addressing using address registers (ARs) to indicate their memory addresses, which often introduces overhead codes in AR updates for next memory accesses. Reduction of such overhead code is one of the important issues in automatic generation of highly-efficient DSP codes. In this paper, a new automatic address allocation method incorpolated with computational order rearrangement at local commutative parts is proposed. The method formulates a given memory access sequence by a graph representation, where several strategies to handle freedom in memory access orders at the computational commutative parts are introduced and examined. A compiler scheme is also extended such that computational order at the commutative parts is rearranged according to the derived memory allocation. The proposed methods are applied to an existing DSP compiler for µPD77230(NEC), and codes generated for several examples are compared with memory allocations by the conventional methods.

  • A 7/3-Approximation for the Minimum Weight 3-Connected Spanning Subgraph Problem

    Hiroshi NAGAMOCHI  Katsuhiro SEKI  Toshihide IBARAKI  

     
    PAPER

      Vol:
    E83-A No:4
      Page(s):
    687-691

    We consider the problem of finding a minimum weight k-connected spanning subgraph of a given edge-weighted graph G for k=3. The problem is known to be NP-hard for k 2, and there are an O(n2m) time 3-approximation algorithm due to Nutov and Penn and an O(n8) time 2-approximation algorithm due to Dinitz and Nutov, where n and m are the numbers of vertices and edges in G, respectively. In this paper, we present a 7/3-approximation algorithm which runs in O(n2m) time.

  • Performance Comparisons of Approaches for Providing Connectionless Service over ATM Networks

    Doo Seop EOM  Masayuki MURATA  Hideo MIYAHARA  

     
    PAPER-Communication protocol

      Vol:
    E80-B No:10
      Page(s):
    1454-1465

    Connectionless data from existing network applications compose a large portion of the workload during an early ATM deployment, and are likely to make up an important portion of ATM's workload even in the long term. For providing a connectionless service over the ATM network, we compare two approaches; an indirect and a direct approaches, which are adopted by International Telecommunication Union-Telecommunication (ITU-T) as generic approaches. Our main subject of this paper is to compare network costs of two approaches by taking into account several cost factors such as transmission links, buffers, and connectionless servers in the case of the direct approach. Since the cost of the direct approach heavily depends on the configuration of a virtual connectionless overlay network, we propose a new heuristic algorithm to construct an effective connectionless overlay network topology. The proposed algorithm determines an optimal number of connectionless servers and their locations to minimize the network cost while satisfying QoS requirements such as maximum delay time and packet loss probability. Through numerical examples, we compare the indirect and direct approaches, the latter of which is constructed by means of our proposed algorithm.

1-20hit(25hit)