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[Author] Jun HAN(12hit)

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  • A Multicasting Scheme Using Multiple MCS for Reducing End-to-End Path Delay in ATM Networks

    Tae-Young BYUN  Ki-Jun HAN  

     
    PAPER-Network

      Vol:
    E84-B No:4
      Page(s):
    1020-1029

    In this paper, we proposed two models, the full multiple MCS (Multicast Server) model and the hybrid multiple MCS model to support multiple MCS over a single large cluster in ATM (Asynchronous Transfer Mode) networks. Also, we presented two methods for MCS assignment which are known as 2PSPMT (2 Phase Shortest Path based on Multicast tree) and hybrid-2PSPMT, and evaluated its performance by simulation. When an ATM host requests joining a specific multicast group, the MARS (Multicast Address Resolution Server) designates a proper MCS among the multiple MCSs for the group member to minimize the average path delay between the sender and the group members. Each method for MCS assignment construct a 2-phase partial multicast tree based on the shortest path algorithm. We reduced the average path delay in the multicast tree using these methods with various cluster topologies and MCS distribution scenarios in addition to distributing the load among multiple MCSs.

  • A Topology Control Scheme for Selecting Active Nodes in Wireless Sensor Networks

    Kyungjun KIM  Kijun HAN  

     
    LETTER-Network

      Vol:
    E92-B No:12
      Page(s):
    3915-3918

    Power consumption is one of the most important factors in successfully designing of wireless sensor networks since it directly affects network lifetime. We propose a topology control scheme that reduces power consumption by minimizing, as much as possible, the number of active nodes, in a highly dense region as well as to decrease packet transmission delay. Simulation results show that our scheme can effectively solve the energy inefficiency problem caused by unbalanced power consumption, and can significantly reduce packet transmission delay.

  • A 17-Inch WXGA Full-Color OLED Display Using the Polymer Ink-Jet Technology

    Makoto SHIBUSAWA  Michiya KOBAYASHI  Jun HANARI  Kazuyuki SUNOHARA  Nobuki IBARAKI  

     
    PAPER-OLED Technology

      Vol:
    E86-C No:11
      Page(s):
    2269-2274

    We have developed a 17-inch WXGA full-color polymer OLED display by using newly developed ink-jet printing method. On the ink-jet technology, both droplet volume and landing position were precisely controlled pixel by pixel in order to get luminance uniformity. A pixel circuit having Vth variation-cancellation was adopted and the circuit was modified to realize high uniformity and high gray scale reproduction under the short horizontal period operation. Correction on gamma profile difference among RGB OLEDs was achieved by optimizing on configuration between integrated source driver circuit and outer reference voltage circuit in spite of using a common source driver IC having only one gamma profile. Peak control system, that is important for the large size and high luminance display, was utilized and improved image quality on human feeling and actual power consumption. With these efforts a uniform picture with 260,000 colors and wide viewing angle was achieved. It was proved that the ink-jet method was the optimal manufacturing technology for large-size and high-resolution OLED displays. And we found there is no singular problem on the large size OLED display utilized the ink-jet technology.

  • A High Speed Reconfigurable Face Detection Architecture Based on AdaBoost Cascade Algorithm

    Weina ZHOU  Lin DAI  Yao ZOU  Xiaoyang ZENG  Jun HAN  

     
    PAPER-Application

      Vol:
    E95-D No:2
      Page(s):
    383-391

    Face detection has been an independent technology playing an important role in more and more fields, which makes it necessary and urgent to have its architecture reconfigurable to meet different demands on detection capabilities. This paper proposed a face detection architecture, which could be adjusted by the user according to the background, the sensor resolution, the detection accuracy and speed in different situations. This user adjustable mode makes the reconfiguration simple and efficient, and is especially suitable for portable mobile terminals whose working condition often changes frequently. In addition, this architecture could work as an accelerator to constitute a larger and more powerful system integrated with other functional modules. Experimental results show that the reconfiguration of the architecture is very reasonable in face detection and synthesized report also indicates its advantage on little consumption of area and power.

  • Architecture and Physical Implementation of Reconfigurable Multi-Port Physical Unclonable Functions in 65 nm CMOS

    Pengjun WANG  Yuejun ZHANG  Jun HAN  Zhiyi YU  Yibo FAN  Zhang ZHANG  

     
    PAPER-Cryptography and Information Security

      Vol:
    E96-A No:5
      Page(s):
    963-970

    In modern cryptographic systems, physical unclonable functions (PUFs) are efficient mechanisms for many security applications, which extract intrinsic random physical variations to generate secret keys. The classical PUFs mainly exhibit static challenge-response behaviors and generate static keys, while many practical cryptographic systems need reconfigurable PUFs which allow dynamic keys derived from the same circuit. In this paper, the concept of reconfigurable multi-port PUFs (RM-PUFs) is proposed. RM-PUFs not only allow updating the keys without physically replacement, but also generate multiple keys from different ports in one clock cycle. A practical RM-PUFs construction is designed based on asynchronous clock and fabricated in TSMC low-power 65 nm CMOS process. The area of test chip is 1.1 mm2, and the maximum clock frequency is 0.8 GHz at 1.2 V. The average power consumption is 27.6 mW at 27. Finally, test results show that the RM-PUFs generate four reconfigurable 128-bit secret keys, and the keys are secure and reliable over a range of environmental variations such as supply voltage and temperature.

  • Executable Code Recognition in Network Flows Using Instruction Transition Probabilities

    Ikkyun KIM  Koohong KANG  Yangseo CHOI  Daewon KIM  Jintae OH  Jongsoo JANG  Kijun HAN  

     
    LETTER-Application Information Security

      Vol:
    E91-D No:7
      Page(s):
    2076-2078

    The ability to recognize quickly inside network flows to be executable is prerequisite for malware detection. For this purpose, we introduce an instruction transition probability matrix (ITPX) which is comprised of the IA-32 instruction sets and reveals the characteristics of executable code's instruction transition patterns. And then, we propose a simple algorithm to detect executable code inside network flows using a reference ITPX which is learned from the known Windows Portable Executable files. We have tested the algorithm with more than thousands of executable and non-executable codes. The results show that it is very promising enough to use in real world.

  • GroupScan: Group-Based Fast Handoff Scheme for Wireless LAN

    Jangkyu YUN  Mahnsuk YOON  Byunghwa LEE  Kijun HAN  

     
    LETTER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E94-B No:10
      Page(s):
    2929-2932

    Handoff is a critical issue for stations in IEEE 802.11-based wireless networks. In order to provide Voice-over IP (VoIP) and real-time streaming applications to stations, a handoff mechanism is needed that can reduce latency and provide seamless communication. However, the IEEE802.11 handoff scheme is not appropriate to supply their quality of service (QoS), because it is based on a full-scanning approach. Full-scanning spends too much time searching for access points (APs). Therefore, various pre-scan handoff protocols such as SyncScan and DeuceScan have been proposed. They scan to find nearby APs before the station loses contact with its current AP, but the pre-scanning overhead is considerable. Our handoff mechanism reduces the delay and overhead associated with the link layer handoff by periodically scanning the channel groups.

  • Self-Adjustable Rate Control for Congestion Avoidance in Wireless Mesh Networks

    Youngmi BAEK  Kijun HAN  

     
    PAPER-Network

      Vol:
    E97-B No:11
      Page(s):
    2368-2377

    In this paper, we investigate the problems of the established congestion solution and then introduce a self-adjustable rate control that supports quality of service assurances over multi-hop wireless mesh networks. This scheme eliminates two phases of the established congestion solution and works on the MAC layer for congestion control. Each node performs rate control by itself so network congestion is eliminated after it independently collects its vector parameters and network status parameters for rate control. It decides its transmission rate based on a predication model which uses a rate function including a congestion risk level and a passing function. We prove that our scheme works efficiently without any negative effects between the network layer and the data link layer. Simulation results show that the proposed scheme is more effective and has better performance than the existing method.

  • Digital Packet Video Link for Super High Resolution Display

    Naruhiko KASAI  Toshio FUTAMI  Johji MAMIYA  Kazushi YAMAUCHI  Atsuo OKAZAKI  Jun HANARI  

     
    PAPER-Passive Matrix LCDs

      Vol:
    E84-C No:11
      Page(s):
    1630-1636

    We have manufactured a trial 'Digital Packet Video (PV) Link' system for super high-resolution display. 'Digital PV Link' is a new data transmission protocol where the host transfers video data with attributes for only a selected area such as a motion picture window. This protocol handles the video data with an ID, which can be used for handling between plural hosts and plural displays such as multi display. This ID also makes the display to handle plural windows in accordance with different parameter such as scaling factor, color-adjust, and so on. In this protocol, error handling is a key because the video data is transferred only when the host wants to change display data. So, we have examined transmission errors and capability for motion pictures by using this trial system. In this report, we will introduce the concept and the characteristics of 'Digital PV Link,' and the result of examination.

  • Design Approach and Implementation of Application Specific Instruction Set Processor for SHA-3 BLAKE Algorithm

    Yuli ZHANG  Jun HAN  Xinqian WENG  Zhongzhu HE  Xiaoyang ZENG  

     
    PAPER-Electronic Circuits

      Vol:
    E95-C No:8
      Page(s):
    1415-1426

    This paper presents an Application Specific Instruction-set Processor (ASIP) for the SHA-3 BLAKE algorithm family by instruction set extensions (ISE) from an RISC (reduced instruction set computer) processor. With a design space exploration for this ASIP to increase the performance and reduce the area cost, we accomplish an efficient hardware and software implementation of BLAKE algorithm. The special instructions and their well-matched hardware function unit improve the calculation of the key section of the algorithm, namely G-functions. Also, relaxing the time constraint of the special function unit can decrease its hardware cost, while keeping the high data throughput of the processor. Evaluation results reveal the ASIP achieves 335 Mbps and 176 Mbps for BLAKE-256 and BLAKE-512. The extra area cost is only 8.06k equivalent gates. The proposed ASIP outperforms several software approaches on various platforms in cycle per byte. In fact, both high throughput and low hardware cost achieved by this programmable processor are comparable to that of ASIC implementations.

  • A New Hybrid Scheme for Preventing Channel Interference and Collision in Mobile Networks

    Kyungjun KIM  Kijun HAN  

     
    LETTER-Network

      Vol:
    E93-B No:2
      Page(s):
    385-388

    This paper proposes a new hybrid scheme based on a given set of channels for preventing channel interference and collision in mobile networks. The proposed scheme is designed for improving system performance, focusing on enhancement of performance related to path breakage and channel interference. The objective of this scheme is to improve the performance of inter-node communication. Simulation results from this paper show that the new hybrid scheme can reduce a more control message overhead than a conventional random scheme.

  • A Channel Allocation Scheme Using Channel Reservation, Carrying and Sub-Rating for Handoff in Wireless Networks

    Kil-Woong JANG  Ki-Jun HAN  

     
    PAPER-Wireless Communication Technology

      Vol:
    E85-B No:11
      Page(s):
    2387-2394

    In this paper, we propose a new channel allocation scheme, which is designed to efficiently carry out handoffs in wireless networks. Our scheme is based on conventional handoff methods, which include the channel reservation, carrying and sub-rating methods to assign channels for handoffs. First, we reserve a number of channels only for handoffs. Second, if there is no available channel in the next cell during handoff, the mobile station is allowed to carry a movable channel into the next cell. Finally, in order to avoid co-channel interference due to channel mobility, we adopt the sub-rating method for its carried channel. We evaluated our scheme using both Markov analysis and computer simulation. The analytical and simulation results indicate that our scheme may offer better performance than conventional handoff schemes in terms of handoff blocking probability and channel utilization.