Table of Content

20 August 2006 Volume 33 Issue 4

  

Original Articles

Novel DWPM system based on fractionally spaced equalizers and the maximum likelihood algorithm

ZHOU Lei;LI Jian-dong;ZHANG Guang-hui

J4. 2006, 33(4):  509-513. 

Abstract ( 1921 )   PDF (218KB) ( 915 )   Save

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A novel Discrete Wavelet Packet Modulation(DWPM) system based on Fractionally Spaced Equalizers(FSE) and the Maximum Likelihood (ML) algorithm is studied for multipath fading channels. The proposed FSE based on the least mean square (LMS) algorithm can mitigate the detrimental effects of the inter-symbol interference (ISI) caused by the multipath fading channel. The demodulated symbols are detected by the maximum likelihood (ML) algorithm. The transmission performance is analyzed in the multipath fading channel and the Additive Gaussian White Noise (AWGN). Simulation results show that the proposed DWPM scheme can provide greater immunity to multipath fading channels and AWGN than the traditional orthogonal frequency division multiplexing (OFDM) scheme.

A parametric model based radar targets detection in the formation

JI Hong-bing;LI Lin;SHI Yin-shui

J4. 2006, 33(4):  514-519. 

Abstract ( 1985 )   PDF (294KB) ( 834 )   Save

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Based on the study of the time-varying autoregressive model (TVAR) and instantaneous frequency estimation of non-stationary signals, a TVAR model based radar targets detection in the formation is proposed, which takes the advantage of the TVAR model for the accurate description of a non-stationary signal and fuses the precise estimation of instantaneous frequency of the echoes and the resolution in range of targets in the formation, and hence the targets detection in both range and Doppler frequency dimensions. Experimental results on some actual echoes data illustrate the effectiveness of the method, and a reliable detection of a four-target formation is achieved with a series of 64 echoes.

Selective etching of GaN/ AlGaN by Inductively coupled plasma

WANG Chong;FENG Qian;HAO Yue;YANG Yan

J4. 2006, 33(4):  520-523. 

Abstract ( 1551 )   PDF (170KB) ( 878 )   Save

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A systematic study of etch rates and selectivities of GaN and Al_0.27Ga_0.73N at different processing terms is performed using Cl₂/Ar inductively coupled plasma. Selectivity between GaN and Al_0.27Ga_0.73N decreases with the increasing DC bias and changes a little with ICP power. Adding O2(10%) to Cl₂/Ar(3:1) gas mixture has little effect on etch rates of GaN, but leads to a great reduction in etch rates of Al_0.27Ga_0.73N, thus improving selectivity between GaN and Al_0.27Ga_0.73N. Schottky characteristics at different etching DC biases are contrasted, with the result that the leakage current increases with the enhanced DC bias.

Object based H.264 video coding for packet loss resilience

AI Da(1);CHANG Yi-lin(1);LUO Zhong(2);WANG Jing(2)

J4. 2006, 33(4):  524-528. 

Abstract ( 1643 )   PDF (177KB) ( 893 )   Save

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A novel method for video object segmentation is proposed for the purpose of packet loss resilience, which partitions a frame into foreground and background objects according to their Macroblock encoding mode. Combined with the new H.264 error resilience technique Flexible Macroblock Ordering, the two objects are put into different Slice groups that enable the independent packet loss resilience method for them. In the proposed joint source-channel coding method a more forced Intra update rate is applied on the foreground and different coding rates of channel encoding are used to the two objects with the packet loss rate. The technique presented in this paper is easily implemented and it improves the quality of video communications in the packet loss IP network effectively.

Modeling TCP performance in optical burst switching

LIU Jian-ping;LIU Zeng-ji;WEN Ai-jun

J4. 2006, 33(4):  529-534. 

Abstract ( 1945 )   PDF (218KB) ( 903 )   Save

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Optical burst switching (OBS) is a promising paradigm for the next-generation Internet infrastructure. This paper proposes a simple model of TCP performance in the OBS network. By analyzing the interaction between TCP congestion control mechanism and OBS-specific mechanisms such as burst assembly and buffer-less burst switching, our model quantitatively characterizes TCP throughput as a function of the number of TCP/IP packets assembled in one burst, the burst drop rate and the round-trip time. The model is validated through a number of simulations. Theoretical and simulation results show that there is an optimal number of TCP/IP packet assembled in one burst, which results in maximum throughout.

Velocity control of Stewart platform with flexible supporting

BAO Hong;DUAN Bao-yan;MI Jian-wei

J4. 2006, 33(4):  535-538. 

Abstract ( 1577 )   PDF (175KB) ( 844 )   Save

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By considering the special characteristic of distinct dynamical couple between cabin-cable system and Stewart platform, the tracking control of the Stewart platform on the flexible supporting structure is studied. The dynamic coupling between the two comprised systems are considered as the unknown to the Stewart platform. A velocity controller is proposed for the Stewart platform with the flexible supporting based high gain feedback observer. Numerical simulation shows that the dynamic coupling is attenuated effectively and that trajectory tracking is improved.

An improved secure access control model in Operating System

QUAN Yi-ning(1;2);HU Yu-pu(1)

J4. 2006, 33(4):  539-542. 

Abstract ( 1697 )   PDF (149KB) ( 983 )   Save

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A mandatory secure access control model named SOSACM of Operating System that is based on the multi-level security policy is put forward. Its confidetiality inherits the BLP model, and its definition of integrity is on the basis of Biba model. But in fact, the simple conjunct of BLP and Biba models will make some legal object not accessible because the directions of information flow in the BLP model and integrity in the Biba model are opposite. In the model, a trusted level strategy that makes the combination of confidentiality and integrity property tight has been developed, which should ensure that subjects can access objects legally. The model will be beneficial to its application to constructing secure Operating Systems in future.

Application of AMMDFM in underwater low-light-level image enhancement

LIN Xiao-chun(1);LI Cun-zhi(2)

J4. 2006, 33(4):  543-546. 

Abstract ( 1840 )   PDF (126KB) ( 922 )   Save

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The imaging process and properties of underwater low-light-level image are discussed and the main reason that electrical and optical noises of the image enhancement device worsen image quality is proposed. A new disposing scheme aimed at the underwater low-light-level TV image is developed, on the basis of the Frame Integral method to eliminate the low-pass property of the image fluorescence screen and the optical noise of the enhancement device induced by the light source voltage ripple. By using the Arithmetics-Multi-Model-Data-Fusion-Method proposed by the author, the scenery’s edge becomes much clearer and the contrast degree of the image is improved. Experimental results show that the observation effect of the processed image is satisfactory.

Design of the ESD protection circuit with the gate-couple technique in CMOS technology

DU Ming;HAO Yue

J4. 2006, 33(4):  547-549. 

Abstract ( 1568 )   PDF (132KB) ( 828 )   Save

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An improved design method, the Gate-Couple technique, for the ESD protection circuit is presented for overcoming the asymmetrical turn-on of large dimension ESD protect devices. The gate-drain diffuse capacitance is used as the couple device. The capacitance couple effect can turn on the large dimension device uniformly when the ESD event occurs, and improve the performance of the ESD protection circuit. The testing of sample chips shows that the anticipated effect is achieved.

Aspect mining from the class diagram in program comprehension

HU Sheng-ming;LI Qing-shan;CHU Hua;CHEN Ping

J4. 2006, 33(4):  550-556. 

Abstract ( 1316 )   PDF (285KB) ( 883 )   Save

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The class diagram which is recovered from the large system’s source code is too complex to comprehend. This paper presents two kinds of TDG (Type Dependency Graph) abstracted from the class diagram, TDG without weight and TDG with weight. Then a mining algorithm is applied to the TDG to achieve the hierarchy abstraction and the system’s design aspects. The mining algorithms allote the TDG vertices into different subsets with each subset presenting one design aspect of the system. The complexity of the class diagram is reduced remarkably with design aspects obtained.

A New Directional Multi-resolution Ridgelet Network

YANG Shu-yuan;JIAO Li-cheng;WANG Min

J4. 2006, 33(4):  557-562. 

Abstract ( 1370 )   PDF (214KB) ( 737 )   Save

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A new directional multi-resolution ridgelet network (DMRN) is proposed based on the ridgelets frame theory, which uses the ridgelet as the activation function of the hidden layer. For some multi-resolution properties of the ridgelet in the direction besides the scale and the position, the DMRN has great capabilities to catch essential features of “direction-rich” data. It proves to be able to approximate any multivariate function in a more stable and efficient way, and it is optimal in approximating functions with spatial inhomogeneities. On the other hand, by using the binary ridgelet frame as the mathematical foundation in its construction, the DMRN is more flexible and simple structure. The construction and the learning algorithm for the proposed DMRN are given, with its approximation property also analyzed in detail. Possibilities of applications to regression and pattern recognition are included to demonstrate its superiority to other methods and its feasibility in practice. Both theoretical analysis and simulation results prove its efficiency.

Ergodic capacity formula for MIMO-OFDM systems under correlated fading channels

PANG Ji-yong(1);LI Jian-dong(1);YANG Ke-hu(2)

J4. 2006, 33(4):  563-567. 

Abstract ( 2676 )   PDF (191KB) ( 986 )   Save

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An explicit formula for the ergodic capacity of orthogonal frequency division multiplexing (OFDM)-based multiple-input multiple-output(MIMO) systems under correlated frequency selective Rayleigh fading channels is derived, by simplifying the channel response matrix in the frequency domain into the so-called “Kronecker” model composed of three kinds of correlations, i.e., multipath tap gain correlation and spatial fading correlations at both the transmitter and the receiver. The derived formula is very simple and convenient for one to estimate the effects of all three kinds of correlations on MIMO-OFDM capacity. If taps are independent, there exists a simple expression for the ergodic capacity. In the case of tap correlation, the capacity formula could be further given in an integral expression. Both the validity of the new formula is verified and the effects of correlations, delay spread as well as the number of subcarriers on the ergodic capacity are evaluated via Monte Carlo simulations.

A routing algorithm in an unsymmetrical optical burst switching network

QIN Hao;ZHANG Shi;LIU Zeng-ji

J4. 2006, 33(4):  568-571. 

Abstract ( 1820 )   PDF (163KB) ( 850 )   Save

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This paper studies the routing algorithm in an Optical Burst Switching(OBS) network. Generally, the shortest path between the source-destination paris is used as the route of the bursts, which may lead to unbalanced link load in an unsymmetrical network and deteriorate the network performance dramatically in the context of one-way reservation protocol adopted by OBS. A probability based routing algorithm is proposed. For every source-destination pair, different weights are assigned to the links. The switching node will select the output link of the coming bursts proportional to their weights. The weights of different source-destination pairs at different links are decided by a non-linear programming. Simulation results show that our routing algorithm can obviously decrease the burst blocking probability in an unsymmetrical network compared with the shortest-path routing algorithms.

Threshold secret sharing scheme based on ECC and its security

PANG Liao-jun;ZHAN Yang;WANG Yu-min

J4. 2006, 33(4):  572-575. 

Abstract ( 1697 )   PDF (129KB) ( 814 )   Save

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Based on elliptic curve cryptography, a novel (t,n) threshold secret sharing scheme is proposed. Each participant’s private-key is used as his secret shadow and the secret dealer does not have to distribute each participant’s secret shadow. In the secret distribution phase, the dealer only needs to compute some public values without sending any information to each participant. And in the secret recovery phase, each cooperative participant only needs to submit a verifiable pseudo-shadow instead of his secret shadow. The trusted center to manage participants’ keys is eliminated and no secret communication is required in the secret distribution phase, so the scheme is characterized by excellent security as well as high efficiency.

A new scattered-feature-points-based algorithm for generating the terrain

LI Guang-xin;WU Zi-li;DING Zhen-guo;ZHOU Li-hua

J4. 2006, 33(4):  576-579. 

Abstract ( 1671 )   PDF (191KB) ( 928 )   Save

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The paper presents a new algorithm for generating the terrains with a small number of scattered feature points. The feature point, which has a position vector and four incidence vectors and which can describe the position and form of a mountain, is defined. An interpolation algorithm, called Ellipse Terrain Interpolation, is proposed for calculating the height of vertices within the incidence of the feature point. The terrain area is divided into the quasi-uniform grid and the interpolation results in the terrain template. The fractal method is used to iterate the terrain template to get multilayer terrain details. The algorithm has the advantage over real-terrain-data-based algorithms that it needs fewer input data and that the local characteristic of the terrain can be changed arbitrarily and the advantage over simple fractal-based methods that it overcomes the difficulty of controlling the position and the form of the terrain. Our experiment proves that using a small number of scattered feature points, the form of the terrain can be controlled and realistic terrain can be obtained.

Broadcast scheduling algorithms in multihop Ad Hoc networks with MIMO links

LI Jian-dong;ZHANG Guang-hui;CHEN Yan-yu;LI Chang-le;ZHANG Wen-zhu

J4. 2006, 33(4):  580-583. 

Abstract ( 2229 )   PDF (144KB) ( 960 )   Save

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As the current medium access control (MAC) protocols with multiple input multiple output (MIMO) links only bear point to point service, a broadcast scheduling algorithm in multihop Ad Hoc networks with MIMO links is proposed. The key to the algorithm is the time slot scheduling which guarantees collision-free transmissions for every node and minimum frame length. The algorithm increases the simultaneous broadcast transmissions of MIMO links efficiently. Due to the interference null capacity of MIMO links, the interference node set of each node can decrease from two hop neighbors to one hop neighbors. Results show that our algorithm can greatly improve network capacity and decrease average packet delay.

Target’s matching method for the remote sensing image based on the histogram invariant moments

JIAN Jian-feng(1;2);YIN Zhong-hai(1);ZHOU Li-hua(1);WANG Ren-xiang(2)

J4. 2006, 33(4):  584-587. 

Abstract ( 1852 )   PDF (227KB) ( 1172 )   Save

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The existing methods of the target searching in remote sensing image database are discussed, with their defect in mind, and a target’s matching method, from “roughness” to “fine” is presented. The primary target location is found by the use of direct two values correlation method based on edge features, and with the invariant moments and statistical features of the image histogram, combined with similarity measurement, the target can be found quickly. Experimental results show that with high matching precision and rapid matching speed, this method can meet the need of rapid target searching in remote sensing image database.

Orbit design for the space station adjoint satellite cluster considering the impact of perturbation

WEI Juan(1);NING Fang-li(2)

J4. 2006, 33(4):  588-592. 

Abstract ( 1394 )   PDF (183KB) ( 809 )   Save

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By considering the impact of perturbation, theoretical conditions are derived for long term adjoint flying based on the equation of relative motion based on kinematics. Using various celestial mechanics properties, a direct relation between the relative parameters and the orbit elements is developed, so relative orbit elements can be connected with the force of perturbation directly. Analysis shows that the impact of the earth oblate can be eliminated partly by the restrictions of orbit elements, but the decrease in the impact of atmosphere resistance is difficult due to the large difference for the ballistic coefficient. The impact of atmosphere resistance on orbit can be amended by the thrust equipment or by the method of callback and release.

New Compact Enhanced-Bandwidth Hybrid Ring

ZHANG Peng-fei;GONG Shu-xi

J4. 2006, 33(4):  593-597. 

Abstract ( 1316 )   PDF (220KB) ( 888 )   Save

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Two new compact enhanced-bandwidth hybrid rings using composite right/left-handed transmission lines are designed. The replacement of the 270° branch by ±90° ones results in at least 75% reduction in size of the hybrid ring compared with the conventional one. At the same time, the bandwidths of the first hybrid ring operating at 2GHz are enhanced by 50% in the in-phase operation, and 49% in the 180°-out-of-phase operation. The introduction of the 0° transmission line branches makes it possible that the second new hybrid ring be used as a mixer of two signals with -90°, 0°, 90° or 180° phase difference. The bandwidth is enhanced by 38% in the in-phase operation.

A new method for impossible differential cryptanalysis of the 6-round advanced encryption standard

CHEN Jie;ZHANG Yue-yu;HU Yu-pu

J4. 2006, 33(4):  598-601. 

Abstract ( 1467 )   PDF (160KB) ( 826 )   Save

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This paper first presents an impossible differential property of the 4-round AES-if only one S-box of the input plaintext pair is different, and it is impossible that there be three different S-boxes in the same column for the corresponding cipher-text pair after 4-round encryption. Based on this property, a new method is proposed for cryptanalyzing the 6-round AES, which is to add one round to each end of the impossible differential cryptanalysis for the 4-round AES. This attack on the reduced 6-round AES requires about 2^99.5 chosen plaintexts, demands 2⁵⁷ words of memory, and performs 2⁸⁶ 6-round AES encryptions. Furthermore, there is only 2^-66.5 of the probability to fail to recover the secret key.

Study of blind detection techniques in adaptive OFDM

HAN Gang(1;2);LI Jian-dong(1);LI Chang-le(1)

J4. 2006, 33(4):  602-606. 

Abstract ( 1928 )   PDF (181KB) ( 940 )   Save

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A blind detection algorithm based on Higher-order cumulants(HOC) is proposed to detect the modulation scheme for the OFDM subcarriers. Its detection feature is robust to the Gaussian noise and is invariant with respect to the attenuation and the phase rotation induced by subchannels. The invariant property is theorectically proved. The high performance and robustness of the blind detection algorithms are proved by simulation.

Application of the optimal set of elementary siphons in FMS for deadlock control

HU He-suan;LI Zhi-wu;WANG An-rong

J4. 2006, 33(4):  607-611. 

Abstract ( 2329 )   PDF (233KB) ( 905 )   Save

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Petri nets are used to model the concurrent execution and the deadlock problem in a flexible manufacturing system(FMS). With the number of reachable states in the controlled system being the criterion, an idea of the optimal set of elementary siphons is illustrated. A set of siphons can be used to optimize the dynamical behavior of the resultant system if their corresponding dependant siphons are all strictly dependant ones. Furthermore, the integer programming method is exploited as the mathematical tool for the generation of a polynomial algorithm producing the optimal set elementary siphons. Experimental results show that the optimal set of elementary siphons ensures more permissive behavior with fewer controlling places in the controlled net system when the same deadlock control policy is applied.

V-BLAST detection based on nulling vector set searching

ZHENG Jian-ping;BAI Bao-ming;WANG Xin-mei

J4. 2006, 33(4):  612-616. 

Abstract ( 1842 )   PDF (185KB) ( 859 )   Save

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A new combined maximum likelihood (ML) and decision feedback equalization (DFE) detection algorithm for the V-BLAST system is proposed based on nulling vector set searching. First the nulling vector set and corresponding signals of l levels are found with ML detection. Then the remnant signals of successive levels are gained level by level after removing the effect of first l levels. The analysis and simulation results show that, compared with the known combined ML and DFE detection based on the QR decomposition of the channel transmit matrix, this proposed algorithm can achieve the same detection performance but lower the computational complexity if the receive antennas number is smaller than the square of the maximum degree.

Linear complexity of binary whiteman generalized cyclotomic sequences

YAN Tong-jiang(1;2);FAN Kai(1);DU Xiao-ni(1;3);XIAO Guo-zhen(1)

J4. 2006, 33(4):  617-621. 

Abstract ( 1969 )   PDF (173KB) ( 973 )   Save

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Based on the polynomial theory on a Galois field, the author presents linear complexity and minimal polynomials of all binary Whiteman generalized cyclotomic sequences with the period pq. The results obtained show that the upper bound and the lower bound of their linear complexity are pq-1 and (p-1)(q-1)/2 respectively. From the viewpoint of stream cipher cryptosystems, almost all these sequences have good linear complexity. They can resist the attacks from the application of the Berlekamp-Massey algorithm.

The generalization and application of ray optical systems

TAN Kang-bo;LIANG Chang-hong;YUAN Hao-bo

J4. 2006, 33(4):  622-625. 

Abstract ( 1698 )   PDF (141KB) ( 811 )   Save

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Refraction of electromagnetic or optical waves on the interface of LHMs and RHMs is studied by the uniform approach on the basis of the high frequency ray theory through the application of Fermat’s principle. And then the matrix optics is generalized through the combination of the refraction law gained and sympletic coordinates with phase items. The relevant expression for ray transmission can maintain the essence of the symplectic formulation and have the application in the RHMs and LHMs mixing optical systems.

A study of the dynamic optimal inventory/pricing policies in a homogeneous inventory system

YANG Tao(1);WEI Yi-hua(2);WANG Jin-ling(3)

J4. 2006, 33(4):  626-629. 

Abstract ( 1535 )   PDF (139KB) ( 788 )   Save

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For the inventory and pricing decision problems, a finite version of the joint dynamic inventory/pricing decision model in a continuous homogeneous deterministic inventory system is formulated and the relationship between the adjacent order periods under the optimal conditions is analyzed. Further, it is proved that the equal-interval-ordering policy is optimal and that the price in each period should be equal. Then, a method for computing the optimal inventory/pricing polices is obtained. Finally, some numerical analyses are made.

Analysis of the inductive iris in rectangular waveguide with the conservation of the complex power technique

ZHAI Yang-wen;ZHAO Yong-jiu

J4. 2006, 33(4):  630-634. 

Abstract ( 1644 )   PDF (203KB) ( 972 )   Save

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The generalized S-parameter matrices of rectangular inductive irises are calculated based on a rigorous mixed method of the Mode Matching Method and the Conservation of the Complex Power Technique (CCPT). The influence of the thickness and length of the irises upon the transmission characteristic is analyzed, which includes the influence of higher order modes. Finally a seven-cavity band-pass filter of unilateral inductive irises is designed. The curve results agree well and the calculation time is greatly shortened compared with the HFSS, which verifies the validity of this technique.

An optimal software release management model under imperfect debugging

LIU Yun(1);TIAN Bin(2);WEN Xiao-ni(1)

J4. 2006, 33(4):  635-639. 

Abstract ( 1379 )   PDF (156KB) ( 724 )   Save

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This paper presents an optimal software release policy model under imperfect debugging, in which the software imperfect debugging, the new faults introduced during debugging as well as the situation that the probability of perfect debugging will be increased due to the experience gained in the process of software testing are taken into account. This model makes the total average cost minimized under the constraint of a given software reliability. This paper also gives the optimal software release time when the parameters take different values.

A dynamic threshold and varying rate TCP slow-start algorithm

LI Shi-ning(1;2);FANG Ji-ping(3);QIN Zheng(2)

J4. 2006, 33(4):  640-645. 

Abstract ( 1727 )   PDF (204KB) ( 804 )   Save

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DSVR, a dynamic threshold and verying rate TCP Slow-Start algorithm, is proposed. The key technologies of Vegas and TCP Westwood are applied to the first slow start process in DSVR, which dynamically configures the TCP Slow-Start threshold and adaptively adjusts the increasing rate of TCP transmitting windows. DSVR can reach the steady state rapidly because its configuration of the slow-start threshold is based on the bandwidth estimation, and thus the lost packages will be limited and the entrance of congestion avoidance stage will not be too early. Simulation result proves that this alogrithm can avoid the loss of data packets, reach the steady state quickly, and improve TCP throughput in the complex network. This algorithm is robust to the bottleneck buffer, adaptable to WEB service, and compatible with the present TCP protocol. It is simple and practical in that it only modifies the sender of TCP.

Study of the performance of the high-pressure resistant FBG pressure sensor with the exterally pressurized type elastic cylinder

ZHOU Hong;QIAO Xue-guang;SHAO Jun;WANG Hong-liang;LI Lan

J4. 2006, 33(4):  646-649. 

Abstract ( 1736 )   PDF (150KB) ( 882 )   Save

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A high-pressure resistant fiber Bragg grating(FBG) pressure sensor using a metallic elastic cylinder as the substrate is designed, the properties of the said sensor are tested in the temperature range of 16~60℃ and the pressure range of 0~52MPa, and its performance parameters and the temperature revise factor are calculated. Results show that the performance of the said sensor is stable, with its repeatability being good, the tuning range of linearity being 4.066nm, the pressure sensitivity being 0.0782nm/MPa, and the wavelength resolving capability for pressure demodulation being 1.56pm. After the temperature is revised, the opposite error margin of the pressure measure is reduced from 5.2% to 0.25%. Double sealing design has been adopted, thus avoiding fluid or gas leakage. By selecting the materials of different elastic moduli, the inner diameter and thickness, the measuring range and sensitivity of the said sensor can be adjusted.

A one time password generation algorithm suitable for HOTP

LIU Jian-wei(1;2);LI Hui(2);MA Jian-feng(3)

J4. 2006, 33(4):  650-654. 

Abstract ( 2066 )   PDF (171KB) ( 1014 )   Save

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A one time password algorithm HTOPC is proposed based on HMAC SHA-1 and a dynamic truncating function. The algorithm has a fast computing speed and high security, and it is easy to implement by using Token or IC card hardware. Therefore, the algorithm is suitable for the HTOP authentication framework. Besides, three basic conditions are proposed for the token-based authentication protocol, and an authentication protocol based on counter synchronization is designed. At the server side, the protocol sets up a maximum trying number to prevent the brute-force attack, and a look-ahead parameter to realize counter resynchronization. Finally, the security of the protocol is analyzed. Results show that the protocol can resist normal attacks, such as brute-force attack and interception/replay attack effectively, and is highly secure.

An immune algorithm for load balancing of hybrid flow shop scheduling

LIU Jian-guo(1;2);ZHU Heng-min(1);WANG Ning-sheng(1)

J4. 2006, 33(4):  655-659. 

Abstract ( 2022 )   PDF (160KB) ( 837 )   Save

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In hybrid flow shop scheduling, generally, the object of optimization is to get the makespan minimized, not considering differences of the same facilities’ processing time during the same stage, which is disadvantageous for machines’ maintenance and management and is unfair for manipulators. This paper formulates a load balancing model, sets forth a new immune algorithm for solving it, and compares two results for subjection and non-subjection to load balancing, and the computed result shows that the algorithm is an effective tool for such problems.

Development of the digital DC-speed controller of the pulse load

LI Lin;SHI Fu-bin;ZHANG Qi-zhi

J4. 2006, 33(4):  660-664. 

Abstract ( 1352 )   PDF (179KB) ( 870 )   Save

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With the pulse load, the digital DC-speed controller which is used in electric running-rigs by a 1~2kW DC motor. Full use is made of the P87LPC768 MPU and the FUZZY-PID algorithm. The digital DC-speed controller can automatically adjust the PID parameter and generate the PWM pulse that can accurately control the electrically driven running-rigs’ velocity. It has a simple structure and a high performance-to-price ratio, and at the same time it can be applied to other small power DC speed governing systems of the same load types.

An efficient way for wavelet tight frames construction

LI Wan-she;LIU Zhi-guo

J4. 2006, 33(4):  665-669. 

Abstract ( 1578 )   PDF (181KB) ( 932 )   Save

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Using the demonstration about the interpolation of W.Swelden and M.J.Shensa , we prove that the interpolated wavelet tight frame generated by three generators does not exist. Under satisfying nearly interpolation and higher vanishing moment, we design a low-pass filter, and then using an inequality giving by Ron, we will get three high-pass filters. Therefore we can get the wavelet tight frames that satisfy our properties. Two of those high-pass filters satisfy symmetry or antisymmetry, and all of them have a free parameter. The greater freedom will widen the selection of both low-pass and high-pass filters. Finally, we give the algorithm for filters and some concrete examples of wavelet tight frames.

A generating approach to the guided electromagnetic wave propagation regularity with time in waveguides

WANG Xin-wen(1;2);LIANG Chang-hong(1);XING Rui-na(2)

J4. 2006, 33(4):  670-672. 

Abstract ( 1337 )   PDF (108KB) ( 894 )   Save

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A generating approach to the guided electromagnetic wave propagation regularity with time in waveguides based on 3DS MAX is proposed. The space vector lines moving with time in wave guides are designed. The complicated and abstract TE10 mode electromagnetic field chart and current distribution chard are created using these space vector lines moving with time. Other mode charts can be created using this design.