Ran LI Hongbing LIU Jie CHEN Zongliang GAN
The conventional bilateral motion estimation (BME) for motion-compensated frame rate up-conversion (MC-FRUC) can avoid the problem of overlapped areas and holes but usually results in lots of inaccurate motion vectors (MVs) since 1) the MV of an object between the previous and following frames is more likely to have no temporal symmetry with respect to the target block of the interpolated frame and 2) the repetitive patterns existing in video frame lead to the problem of mismatch due to the lack of the interpolated block. In this paper, a new BME algorithm with a low computational complexity is proposed to resolve the above problems. The proposed algorithm incorporates multi-resolution search into BME, since it can easily utilize the MV consistency between two adjacent pyramid levels and spatial neighboring MVs to correct the inaccurate MVs resulting from no temporal symmetry while guaranteeing low computational cost. Besides, the multi-resolution search uses the fast wavelet transform to construct the wavelet pyramid, which not only can guarantee low computational complexity but also can reserve the high-frequency components of image at each level while sub-sampling. The high-frequency components are used to regularize the traditional block matching criterion for reducing the probability of mismatch in BME. Experiments show that the proposed algorithm can significantly improve both the objective and subjective quality of the interpolated frame with low computational complexity, and provide the better performance than the existing BME algorithms.
Tai TANAKA Yoshio INASAWA Yasuhiro NISHIOKA Hiroaki MIYASHITA
The characteristic basis function method using improved primary characteristic basis functions (IP-CBFM) has been proposed as a technique for high-precision analysis of monostatic radar cross section (RCS) of a scattering field in a specific coordinate plane. IP-CBFM is a method which reduces the number of CBF necessary to express a current distribution by combining secondary CBF calculated for each block of the scatterer with the primary CBF to form a single improved primary CBF (IP-CBF). When the proposed technique was evaluated by calculating the monostatic RCS of a perfect electric conductor plate and cylinder, it was found that solutions corresponding well with analysis results from conventional CBFM can be obtained from small-scale matrix equations.
Hideyuki NAKAJIMA Tatsuhiro TSUTSUI Hiroyuki URABAYASHI Miki YAMAMOTO Elisha ROSENSWEIG James F. KUROSE
In recent years, much work has been devoted to developing protocols and architectures for supporting the growing trend of data-oriented services. One drawback of many of these proposals is the need to upgrade or replace all the routers in order for the new systems to work. Among the few systems that allow for gradual deployment is the recently-proposed Breadcrumbs technique for distributed coordination among caches in a cache network. Breadcrumbs uses information collected locally at each cache during past downloads to support in-network guiding of current requests to desired content. Specifically, during content download a series of short-term pointers, called breadcrumbs, is set up along the download path. Future requests for this content are initially routed towards the server which holds (a copy of) this content. However, if this route leads the request to a Breadcrumbs-supporting router, this router re-directs the request in the direction of the latest downloaded, using the aforementioned pointers. Thus, content requests are initially forwarded by a location ID (e.g., IP address), but encountering a breadcrumb entry can cause a shift over to content-based routing. This property enables the Breadcrumbs system to be deployed gradually, since it only enhances the existing location-based routing mechanism (i.e. IP-based routing). In this paper we evaluate the performance of a network where Breadcrumbs is only partially deployed. Our simulation results show Breadcrumbs performs poorly when sparsely deployed. However, if an overlay of Breadcrumbs-supporting routers is set-up, system performance is greatly improved. We believe that the reduced load on servers achieved with even a limited deployment of Breadcrumbs-supporting routers, combined with the flexibility of being able to deploy the system gradually, should motivate further investigation and eventual deployment of Breadcrumbs. In the paper, we also evaluate more coarse level than router level, i.e. ISP-level Breadcrumbs deployment issues. Our evaluation results show that Higher-layer first deployment approach obtains great improvement caused by Breadcrumbs redirections because of traffic aggregation in higher layer ISP.
Naoya OIKAWA Jiro HIROKAWA Hiroshi NAKANO Yasutake HIRACHI Hiroshi ISONO Atsushi ISHII Makoto ANDO
For the realization of a high-efficiency antenna for 60GHz-band wireless personal area network, we propose placing a CMOS RF circuit and an antenna on opposing sides of a silicon chip. They are connected with low loss by a coaxial-line structure using a hole opening in the chip. Since the CMOS circuit is driven differentially, a differential-feed antenna is used. In this paper, we design and measure a differential-feed square patch antenna on a silicon chip. To enhance the radiation efficiency, it is placed on a 200µm thick resin layer. The calculated radiation efficiency of 79% includes the connection loss. A prototype antenna is measured in a reverberation chamber, and its radiation efficiency is estimated to be about 81±3%.
Broadcasting and communications networks can be used together to offer hybrid broadcasting services that incorporate a variety of personalized information from communications networks in TV programs. To enable these services, many different applications have to be run on a user terminal, and it is necessary to establish an environment where any service provider can create applications and distribute them to users. The danger is that malicious service providers might distribute applications which may cause user terminals to take undesirable actions. To prevent such applications from being distributed, we propose an application authentication protocol for hybrid broadcasting and communications services. Concretely, we modify a key-insulated signature scheme and apply it to this protocol. In the protocol, a broadcaster distributes a distinct signing key to each service provider that the broadcaster trusts. As a result, users can verify that an application is reliable. If a signed application causes an undesirable action, a broadcaster can revoke the privileges and permissions of the service provider. In addition, the broadcaster can update the signing key. That is, our protocol is secure against leakage of the signing key by the broadcaster and service providers. Moreover, a user terminal uses only one verification key for verifying a signature, so the memory needed for storing the verification key in the user terminal is very small. With our protocol, users can securely receive hybrid services from broadcasting and communications networks.
Face verification in the presence of age progression is an important problem that has not been widely addressed. Despite appearance changes for same person due to aging, they are more similar compared to facial images from different individuals. Hence, we design common and adapted vocabularies, where common vocabulary describes contents of general population and adapted vocabulary represents specific characteristics of one of image facial pairs. And the other image is characterized with a concatenation histogram of common and adapted visual words counts, termed as “age-invariant distinctive representation”. The representation describes whether the image content is best modeled by the common vocabulary or the corresponding adapted vocabulary, which is further used to accomplish the face verification. The proposed approach is tested on the FGnet dataset and a collection of real-world facial images from identification card. The experimental results demonstrate the effectiveness of the proposed method for verification of identity at a modest computational cost.
Keisuke OKUNO Shintaro IZUMI Kana MASAKI Hiroshi KAWAGUCHI Masahiko YOSHIMOTO
This report describes an all-digital phase-locked loop (ADPLL) using a temperature compensated settling time reduction technique. The novelty of this work is autonomous oscillation control word estimation without a look-up table or memory circuits. The proposed ADPLL employs a multi-phase digitally controlled oscillator (DCO). In the proposed estimation method, the optimum oscillator tuning word (OTW) is estimated from the DCO frequency characteristic in the setup phase of ADPLL. The proposed ADPLL, which occupies 0.27×0.36mm2, is fabricated by a 65 nm CMOS process. The temperature compensation PLL controller (TCPC) is implemented using an FPGA. Although the proposed method has 20% area overhead, measurement results show that the 47% settling time is reduced. The average settling time at 25°C is 3µs. The average reduction energy is at least 42% from 0°C to 100°C.
Li-Chung HSU Junichiro KADOMOTO So HASEGAWA Atsutake KOSUGE Yasuhiro TAKE Tadahiro KURODA
ThruChip interface (TCI) is an emerging wireless interface in three-dimensional (3-D) integrated circuit (IC) technology. However, the TCI physical design guidelines remain unclear. In this paper, a ThruChip test chip is designed and fabricated for design guidelines exploration. Three inductive coupling interface physical design scenarios, baseline, power mesh, and dummy metal fill, are deployed in the test chip. In the baseline scenario, the test chip measurement results show that thinning chip or enlarging coil dimension can further reduce TCI power. The power mesh scenario shows that the eddy current on power mesh can dramatically reduce magnetic pulse signal and thus possibly cause TCI to fail. A power mesh splitting method is proposed to effectively suppress eddy current impact while minimizing power mesh structure impact. The simulation results show that the proposed method can recover 77% coupling coefficient loss while only introducing additional 0.5% IR-drop. In dummy metal fill case, dummy metal fill enclosed within TCI coils have no impact on TCI transmission and thus are ignorable.
Xiaoli GONG Yanjun LIU Yang JIAO Baoji WANG Jianchao ZHOU Haiyang YU
An earthquake is a destructive natural disaster, which cannot be predicted accurately and causes devastating damage and losses. In fact, many of the damages can be prevented if people know what to do during and after earthquakes. Earthquake education is the most important method to raise public awareness and mitigate the damage caused by earthquakes. Generally, earthquake education consists of conducting traditional earthquake drills in schools or communities and experiencing an earthquake through the use of an earthquake simulator. However, these approaches are unrealistic or expensive to apply, especially in underdeveloped areas where earthquakes occur frequently. In this paper, an earthquake drill simulation system based on virtual reality (VR) technology is proposed. A User is immersed in a 3D virtual earthquake environment through a head mounted display and is able to control the avatar in a virtual scene via Kinect to respond to the simulated earthquake environment generated by SIGVerse, a simulation platform. It is a cost effective solution and is easy to deploy. The design and implementation of this VR system is proposed and a dormitory earthquake simulation is conducted. Results show that powerful earthquakes can be simulated successfully and the VR technology can be applied in the earthquake drills.
Qing YANG Jiancheng LI Hongyi WANG
In many radio frequency identification (RFID) applications, the reader identifies the tags in its scope repeatedly. For these applications, many algorithms, such as an adaptive binary splitting algorithm (ABS), a single resolution blocking ABS (SRB), a pair resolution blocking ABS (PRB) and a dynamic blocking ABS (DBA) have been proposed. All these algorithms require the staying tags to reply with their IDs to be recognized by the reader. However, the IDs of the staying tags are stored in the reader in the last identification round. The reader can verify the existence of these tags when identifying them. Thus, we propose an anti-collision algorithm with short reply for RFID tag identification (ACSR). In ACSR, each staying tag emits a short reply to indicate its continued existence. Therefore, the data amount transmitted by staying tags is reduced significantly. The identification rate of ACSR is analyzed in this paper. Finally, simulation and analysis results show that ACSR greatly outperforms ABS, SRB and DBA in terms of the identification rate and average amount of data transmitted by a tag.
Masoud REYHANI HAMEDANI Sang-Wook KIM
In this paper, we propose SimCS (similarity based on contribution scores) to compute the similarity of scientific papers. For similarity computation, we exploit a notion of a contribution score that indicates how much a paper contributes to another paper citing it. Also, we consider the author dominance of papers in computing contribution scores. We perform extensive experiments with a real-world dataset to show the superiority of SimCS. In comparison with SimCC, the-state-of-the-art method, SimCS not only requires no extra parameter tuning but also shows higher accuracy in similarity computation.
The authors proposed an algorithm for calculation of new lower bound (rank bounded distance) using the discrete Fourier transform in 2010. Afterward, we considered some algorithms to improve the original algorithm with moving the row or column. In this paper, we discuss the calculation method of the rank bounded distance by conjugate elements for cyclic codes.
Gang DENG Hong WANG Zhenghu GONG Lin CHEN Xu ZHOU
Address configuration is a key problem in data center networks. The core issue of automatic address configuration is assigning logical addresses to the physical network according to a blueprint, namely logical-to-device ID mapping, which can be formulated as a graph isomorphic problem and is hard. Recently years, some work has been proposed for this problem, such as DAC and ETAC. DAC adopts a sub-graph isomorphic algorithm. By leveraging the structure characteristic of data center network, DAC can finish the mapping process quickly when there is no malfunction. However, in the presence of any malfunctions, DAC need human effort to correct these malfunctions and thus is time-consuming. ETAC improves on DAC and can finish mapping even in the presence of malfunctions. However, ETAC also suffers from some robustness and efficiency problems. In this paper, we present GA-MAP, a data center networks address mapping algorithm based on genetic algorithm. By intelligently leveraging the structure characteristic of data center networks and the global search characteristic of genetic algorithm, GA-MAP can solve the address mapping problem quickly. Moreover, GA-MAP can even finish address mapping when physical network involved in malfunctions, making it more robust than ETAC. We evaluate GA-MAP via extensive simulation in several of aspects, including computation time, error-tolerance, convergence characteristic and the influence of population size. The simulation results demonstrate that GA-MAP is effective for data center addresses mapping.
Junjun ZHENG Hiroyuki OKAMURA Tadashi DOHI
Survivability is the capability of a system to provide its services in a timely manner even after intrusion and compromise occur. In this paper, we focus on the quantitative analysis of survivability of virtual machine (VM) based intrusion tolerant system in the presence of Byzantine failures due to malicious attacks. Intrusion tolerant system has the ability of a system to continuously provide correct services even if the system is intruded. This paper introduces a scheme of the intrusion tolerant system with virtualization, and derives the success probability for one request by a Markov chain under the environment where VMs have been intruded due to a security hole by malicious attacks. Finally, in numerical experiments, we evaluate the performance of VM-based intrusion tolerant system from the viewpoint of survivability.
Peer-to-peer (P2P)-Grid systems are being investigated as a platform for converging the Grid and P2P network in the construction of large-scale distributed applications. The highly dynamic nature of P2P-Grid systems greatly affects the execution of the distributed program. Uncertainty caused by arbitrary node failure and departure significantly affects the availability of computing resources and system performance. Checkpoint-and-restart is the most common scheme for fault tolerance because it periodically saves the execution progress onto stable storage. In this paper, we suggest a checkpoint-and-restart mechanism as a fault-tolerant method for applications on P2P-Grid systems. Failure detection mechanism is a necessary prerequisite to fault tolerance and fault recovery in general. Given the highly dynamic nature of nodes within P2P-Grid systems, any failure should be detected to ensure effective task execution. Therefore, failure detection mechanism as an integral part of P2P-Grid systems was studied. We discussed how the design of various failure detection algorithms affects their performance in average failure detection time of nodes. Numerical analysis results and implementation evaluation are also provided to show different average failure detection times in real systems for various failure detection algorithms. The comparison shows the shortest average failure detection time by 8.8s on basis of the WP failure detector. Our lowest mean time to recovery (MTTR) is also proven to have a distinct advantage with a time consumption reduction of about 5.5s over its counterparts.
Dae-Chul KIM Wang-Jun KYUNG Ho-Gun HA Yeong-Ho HA
The role of an optical low-pass filter (OLPF) in a digital still camera is to remove the high spatial frequencies that cause aliasing, thereby enhancing the image quality. However, this also causes some loss of detail. Yet, when an image is captured without the OLPF, moiré generally appears in the high spatial frequency region of the image. Accordingly, this paper presents a moiré reduction method that allows omission of the OLPF. Since most digital still cameras use a CCD or a CMOS with a Bayer pattern, moiré patterns and color artifacts are simultaneously induced by aliasing at high spatial frequencies. Therefore, in this study, moiré reduction is performed in both the luminance channel to remove the moiré patterns and the color channel to reduce color smearing. To detect the moiré patterns, the spatial frequency response (SFR) of the camera is first analyzed. The moiré regions are identified using patterns related to the SFR of the camera and then analyzed in the frequency domain. The moiré patterns are reduced by removing their frequency components, represented by the inflection point between the high-frequency and DC components in the moiré region. To reduce the color smearing, color changing regions are detected using the color variation ratios for the RGB channels and then corrected by multiplying with the average surrounding colors. Experiments confirm that the proposed method is able to reduce the moiré in both the luminance and color channels, while also preserving the detail.
Takatsugu ONO Yotaro KONISHI Teruo TANIMOTO Noboru IWAMATSU Takashi MIYOSHI Jun TANAKA
Big data analysis and a data storing applications require a huge volume of storage and a high I/O performance. Applications can achieve high level of performance and cost efficiency by exploiting the high I/O performance of direct attached storages (DAS) such as internal HDDs. With the size of stored data ever increasing, it will be difficult to replace servers since internal HDDs contain huge amounts of data. Generally, the data is copied via Ethernet when transferring the data from the internal HDDs to the new server. However, the amount of data will continue to rapidly increase, and thus, it will be hard to make these types of transfers through the Ethernet since it will take a long time. A storage area network such as iSCSI can be used to avoid this problem because the data can be shared with the servers. However, this decreases the level of performance and increases the costs. Improving the flexibility without incurring I/O performance degradation is required in order to improve the DAS architecture. In response to this issue, we propose FlexDAS, which improves the flexibility of direct attached storage by using a disk area network (DAN) without degradation the I/O performance. A resource manager connects or disconnects the computation nodes to the HDDs via the FlexDAS switch, which supports the SAS or SATA protocols. This function enables for the servers to be replaced in a short period of time. We developed a prototype FlexDAS switch and quantitatively evaluated the architecture. Results show that the FlexDAS switch can disconnect and connect the HDD to the server in just 1.16 seconds. We also confirmed that the FlexDAS improves the performance of the data intensive applications by up to 2.84 times compared with the iSCSI.
Shinya TAKAMAEDA-YAMAZAKI Hiroshi NAKATSUKA Yuichiro TANAKA Kenji KISE
Soft processors are widely used in FPGA-based embedded computing systems. For such purposes, efficiency in resource utilization is as important as high performance. This paper proposes Ultrasmall, a new soft processor architecture for FPGAs. Ultrasmall supports a subset of the MIPS-I instruction set architecture and employs an area efficient microarchitecture to reduce the use of FPGA resources. While supporting the original 32-bit ISA, Ultrasmall uses a 2-bit serial ALU for all of its operations. This approach significantly reduces the resource utilization instead of increasing the performance overheads. In addition to these device-independent optimizations, we applied several device-dependent optimizations for Xilinx Spartan-3E FPGAs using 4-input lookup tables (LUTs). Optimizations using specific primitives aggressively reduce the number of occupied slices. Our evaluation result shows that Ultrasmall occupies only 84% of the previous small soft processor. In addition to the utilized resource reduction, Ultrasmall achieves 2.9 times higher performance than the previous approach.
Takafumi HAYASHI Yodai WATANABE Anh T. PHAM Toshiaki MIYAZAKI Shinya MATSUFUJI Takao MAEDA
The present paper introduces a novel method for the construction of a class of sequences that have a zero-correlation zone. For the proposed sequence set, both the cross-correlation function and the side lobe of the auto-correlation function are zero for phase shifts within the zero-correlation zone. The proposed scheme can generate a set of sequences of length 8n2 from an arbitrary Hadamard matrix of order n and a set of 2n trigonometric-like function sequences of length 4n. The proposed sequence construction can generate an optimal zero-correlation zone sequence set that satisfies the theoretical bound on the number of members for the given zero-correlation zone and sequence period. The auto-correlation function of the proposed sequence is equal to zero for all nonzero phase shifts. The peak factor of the proposed sequence set is √2, and the peak factor of a single trigonometric function is equal to √2. Assigning the sequences of the proposed set to a synthetic aperture ultrasonic imaging system would improve the S/N of the obtained image. The proposed sequence set can also improve the performance of radar systems. The performance of the applications of the proposed sequence sets are evaluated.
Su-Jin CHOI Jeong-Yong BOO Ki-Jun KIM Hochong PARK
We propose a method of enhancing the performance of a cross-talk canceller for a four-speaker system with respect to sweet spot size and ringing effect. For the large sweet spot of a cross-talk canceller, the speaker layout needs to be symmetrical to the listener's position. In addition, a ringing effect of the cross-talk canceller is reduced when many speakers are located close to each other. Based on these properties, the proposed method first selects the two speakers in a four-speaker system that are most symmetrical to the target listener's position and then adds the remaining speakers between these two to the final selection. By operating only these selected speakers, the proposed method enlarges the sweet spot size and reduces the ringing effect. We conducted objective and subjective evaluations and verified that the proposed method improves the performance of the cross-talk canceller compared to the conventional method.