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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korea Institute of Information and Communication Engineering
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The Korean Institute of Information and Commucation Engineering
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Volume & Issues
Volume 4, Issue 5 - Dec 2000
Volume 4, Issue 4 - Nov 2000
Volume 4, Issue 3 - Sep 2000
Volume 4, Issue 2 - Jun 2000
Volume 4, Issue 1 - Mar 2000
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Network Costing Model Alternatives for Reasonable Interconnection Charging Between Networks
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 907~917
In this paper the network costing model alternatives for reasonable interconnection charging are suggested. The current interconnection charge regimes is based on fully distributed costing method. Basically this method doesn't consider the common carrier's efficient network cost because it reflects the actual cost of network In this paper, 1 suggest the basic structure of the network costing model fur applications of incremental costing method that considers the efficient cost based on economics-prospective. And I classify network cost with capital cost and operating cost and analysis their reasonable costing methods.
A Computer Graphic Based Interactive Modeling System with Application to Ship Scheduling
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 919~930
This paper treats a development of visual interactive modeling(VIM) system for ship scheduling problem in integer formulation. The ship scheduling problem can be described as "A problem which assigns ships and cargos to achieve maximum revenue from transportation" in brief. Since late 1970s there has been rapid growth in development and use of VIM as MS10R technology due to the development of computer technology and now VIM has become a important discipline in MS/OR and MIS society. Visual Interactive Modeling is a process that decision maker takes part in modeling life cycle -data collection, formulation, derivation of optimal solution and representation of solution - and interacts with a modeling system to achieve a user-solution appropriate for his/her ultimate goal. This paper suggests the methodology how to collect data, build and modify model, and represent solution using computer graphics as a major driving tool and demonstrates effective performance of a prototype system.pe system.
A Novel Contour Path finite Difference Time Domain (CPFDTD) Algorithm for Modeling Objects with Curved Surfaces
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 931~936
A novel CPFDTD algorithm for modeling the smooth curved surfaces is presented. This scheme subdivides electric fields on the distorted grid into the extended contour field, the non-distorted field, and the quasi-available field to avoid the collinear borrowing approximation. Several preceding methods are applied to the I-plane sectoral horn antenna to get far-field patterns. The accuracy of the presented method is demonstrated by comparison with measured values.
A Modular Neural Network for The Arc Welding Process Modelling
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 937~942
This paper describes for applications of neural networks in the field of arc welding. Conventional, automated process generally involves sophisticated sensing and control techniques applied to various processing parameters. Welding parameters affecting quality include the arc voltage, the welding current and the torch travel speed. The relationship between the welding parameters and weld quality is not a direct one, and in addition, the effect of the weld parameter variables are not independent of the each other - changing the welding current will affect the arc voltage, and so on. Finally, a suitable proposal to improve the construction of the model has also been presented in the paper.
Detection of Ridges and Ravines using Fuzzy Logic Operations
Kim, Kyoung-Min ; Park, Joong-Jo ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 943~949
In object analysis, line and curve finding plays a universal role. And, it can be accomplished by detecting ridges and ravines in digital gray-scale images. In this paper, we present a new method of detecting ridges and ravines by using local min and max operations. This method uses erosion and dilation properties of these fuzzy logic operations and requires no information of ridge or ravine direction, so that the method is simple and easy in comparison with the conventional analytical methods. The experimental results show that the technique has a strong ability in finding ridges and ravines.
A Study on the Design of Fault-Diagnosis System for Healing Mill Bearing in Wavelet Transform
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 951~961
A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide early warnings in rolling mill. Because dynamics of rolling mill is non-linear. This Paper proposes a new method for diagnosis of rolling mill using wavelet transform(W) to solve this problem. Proposed method that measures the vibration signals of rolling mill on-line and analyze it using wavelet to acquire pattern data. And we design a fault-diagnosis system that diagnose a rolling mill using this data. Validity of the new method is asserted by real numerical data experiment.
Input-Output Gains of Linear Periodic Time-Varying Systems with Applications to Multirate Signal Processing
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 963~969
In this paper, we define two input-output gains of linear periodic time-varying systems. One is the ratio of output with worst-case l2-norm over all inputs with unit 12-norm. It denotes G(
.The other is the ratio of output with worst-case RMS value over all inputs with unit RMS value. It denotes G(RMS, RMS) .It is fact that these two gains are equivalent for linear time-invariant system. In this paper, we prove these two gains are also equivalent for linear periodic time-varying system. In addition, the relationship between two method of obtaining the generalized frequency responses for linear periodic time-varying system is derived. Finally, we apply the defined input-output gains to M-channel filter-bank which is multi-rate signal Processing system, used to speech coding. In the filter-bank, generally, aliasing distortion, magnitude distortion, and phase distortion are present. It is shown that these are kept small if the filter-bank is designed by a method that optimizes the gain G(
of an error system.
Rain Cell Size Distribution Using Radar Data During Squall Line Episodes
Ricardo S. Tenorio ; Kwon, Byung-Hyuk ; Lee, Dong-In ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 971~976
The main objective of this paper is to present the rain cell size distribution observed during squall line episodes in the Sudano-Sahelian region. The used data were collected during the EPSAT Program [Etude des Precipitation par SATellite (Satellites Study of Precipitation)] which has been developed since 1958, on an experimental area located near Niamey, Niger (2 10′32"E, 13 28′38"N). The data were obtained with a C-band radar and a network composed of approximately 100 raingages over a 10,000
. In this work a culling of the squall line episodes was made for the 1992 rainy season. After radar data calibration using the raingage network a number of PPI (Plan Position Indicator) images were generated. Each image was then treated in order to obtain a series of radar reflectivity (Z) maps. To describe the cell distribution, a contouring program was used to analyze the areas with rain rate greater than or equal to the contour threshold (R
). 24700 contours were generated, where each iso-pleth belongs to a predefined threshold. Computing each cell surface and relating its area to an equi-circle (a circle having the same area as the cell), a statistical analysis was made. The results show that the number of rain cells having a given size is an inverse exponential function of the equivalent radius. The average and median equivalent radii ate 1.4 and 0.69 In respectively. Implications of these results for the precipitation estimation using threshold methods are discussed.
Maritime Atmospheric Boundary Layer Observed By L-band Doppler radar
Kwon, Byung-Hyuk ; Yoon, Hong-Joo ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 977~984
Atmospheric boundary layer over equatorial maritime continent was analyzed with Doppler radar. An L-band (1357.5 MHz) boundary layer radar (BLR) has been in continuous successful operation in Selpong, Indonesia(6.45, 106.7E), since November 1992. The performance of the BLR with respect to the observation height range and the wind measurement reliability has been examined on the basis of simultaneous meteorological observations. In the dry season (10-12 October 1993), we have found two types of strong echo structures appearing systematically in the equatorial planetary boundary layer with diurnal variations on clear days. The first type is the striking appearance of a strong echo layer ascending from below 300 m (in the morning) to above 3-5 km (in the afternoon), which is identified with a diurnal variation of the top of the mixing planetary boundary layer. As expected, it is higher in the Indonesian equatorial region than in midlatitudes. Another type is a layered echo appearing at 2-3 km heights from nighttime to morning, which seem to be coincident with humidity gaps. In the rainy season (20-21 February 1994), the height of the atmospheric mining was lower than that in the dry season.
Radar Data Correction for Long Distance Observation In Coastal Zone
Ricardo S. TENORIO ; Byung-Hyuk Kwon ; Hong-Joo Yoon ; Dong-In Lee ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 985~996
In the coastal zone, to draw up short and medium range weather forecasts, mesoscale pluviogenic systems coming from the sea have to be observed in real time. These observations use remote sensing. However, satellite remote sensing is not sufficient to describe pluviogenic systems; reference to radar long distance observations is indispensable. This paper deals with the corrections, which must be made to long distance radar data if the rainfall field is to be both accurately and quantitatively defined. The error due to vertical variation in the reflectivity factor can be corrected from estimation of the mean profiles or by a climatic adjustment method. Atten-uation in the propagation can be corrected by an iterative polarimetric method. These various correc-tions permit the distance validity limits of radar data to be extended.
Design of Boundary Filter in Subband Coding using M-band Orthogonal Wavelet Filter
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 997~1003
When finite length signal is the input of QMF banks which are composed of the M-band orthogonal wavelet filter, the boundaries of reconstructed signal are not reconstructed perfectly. For boundary signals to be reconstructed perfectly, different type filters or methods are applied to them. In this paper, the design method of boundary filters which can be reconstructed the boundary signal perfectly was proposed, in case the dimension of M-band decomposed signal is the same as that of input signal. The boundary filters were designed using the perfect reconstruction condition of paraunitary matrix. In an application of subband coding of still image, the proposed boundary filters achieve better PSNR about 5% in reconstructed image than reflected method at the same bit rate.
Performance Analysis of Hybrid CDMA Systems in Impulsive Noise and Nakagami Fading of Wireless Radio Communication
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1005~1015
In this paper, the performance of Hybrid CDU MFSK system has been analyzed in the environment that narrowband Class-A impulsive noise include Gaussian noise in wireless communication channel and Nakagami fading. The performance of system improved to adopting both of technique MRC diversity and BCH channel coding. The results show that there is substantial degraded in Hybrid CDMA system performance by impulse index is stronger and the fading index is smaller. But also improvement can be obtained when BCH coding techniques are adopted. Additional MRC diversity techniques is more improvement than BCH coding techniques when degraded environment with the low fading index. But BCH coding techniques is more improvement than MRC diversity techniques when fading index has been increased. The Hybrid CDMA MFSK system is incomplete to voice communication standard BER
in Rayleigh fading by independent each adopting techniques BCH coding and MRC diversity. But it's satisfy(improvement can be obtained) to voice communication standard BER in strong impulse noise(24dB over) by adopting techniques BCH coding and MRC diversity at a time. Additional it's a substantial enhancement
satisfaction) in fading index (m=3, 22dB) in addition to strong impulse noise and 24dB over with data service standard
BER satisfaction. This result show that there is error performance improved by diversity branch and coding advantage.
Implementation of Sound Source Location Detector
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1017~1025
The human auditory system has been shown to posses remarkable abilities in the localization and tracking of sound sources. The localization is the result of processing two primary acoustics cues. These are the interaural time difference(ITD) cues and interaural intensity difference(IID) cues at the two ears. In this paper, we propose TEPILD(Time Energy Previous Integration Location Detector) model. TEPILD model is constructed with time function generator, energy function generator, previous location generator and azimuth detector. Time function generator is to process ITD and energy function generator is to process IID. Total average accuracy rate is 99.2%. These result are encouraging and show that proposed model can be applied to the sound source location detector.
Optimum Technique for WATM Error Control in Indoor Environment
Kang, Young-Heung ; Shin, Song-Sup ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1027~1035
In this paper, we have proposed the optimum technique for wireless ATM (WATM) error control in indoor environment. As the optimum technique, the conventional concatenated FEC only is regarded as the efficient error control method for time-critical ATM traffic in AWGN, and the pilot symbol-added fading compensation with the concatenated FEC is required to optimize the WATM performance in fading environment. Also, the truncated Type- H hybrid ARQ technique will be developed for quality-critical ATM traffic in order to improve its throughput. Therefore, this paper presents the optimization of WATM performance in indoor environment by means of evaluating above techniques using theoretical analysis and simulation.
The study on Multicast Cell Scheduling for Parallel Multicast packet switch with Ring Network
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1037~1050
A goal of a BISDN network is to provided integrated transport for a wide range of applications such as teleconferencing, Video On Demand etc. There require multipoint communications in addition to conventional point-to-point connections. Therefore multicast capabilities are very essential in multimedia communications. In this paper, we propose a new multicast cell scheduling method on the Parallel Multicast Packet Switch with Ring network: PMRN which are based on separated HOL. In this method, we place two different HOLs, one for unicast cells and the other for multicast cells. Then using non-FIFO scheduling, we can schedule both unicast cells and multicast cells which are available at the time in the input buffer. The simulation result shows that this method reduces the delay in the input buffer and increases the efficiency of both point-to-point network and ring network and finally enhances the bandwidth of the overall packet switch. A goal of a BISDN network is to provided integrated transport for a wide range of applications such as teleconferencing, Video On Demand etc. There require multipoint communications in addition to conventional point-to-point connections. Therefore multicast capabilities are very essential in multimedia communications. In this paper, we propose a new multicast cell scheduling method on the Parallel Multicast Packet Switch with Ring network: PMRN which are based on separated HOL. In this method, we place two different HOLs, one for unicast cells and the other for multicast cells. Then using non-FIFO scheduling, we can schedule both unicast cells and multicast cells which are available at the time in the input buffer. The simulation result shows that this method reduces the delay in the input buffer and increases the efficiency of both point-to-point network and ring network and finally enhances the bandwidth of the overall packet switch.
A Study on Contents-based Retrieval using Wavelet
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1051~1066
According to the recent advances of digital encoding technologies and computing power, large amounts of multimedia informations such as image, graphic, audio and video are fully used in multimedia systems through Internet. By this, diverse retrieval mechanisms are required for users to search dedicated informations stored in multimedia systems, and especially it is preferred to use contents-based retrieval method rather than text-type keyword retrieval method. In this paper, we propose a new contents-based indexing and searching algorithm which aims to get both high efficiency and high retrieval performance. To achieve these objectives, firstly the proposed algorithm classifies images by a pre-processing process of edge extraction, range division, and multiple filtering, and secondly it searches the target images using spatial and textural characteristics of colors, which are extracted from the previous process, in a image. In addition, we describe the simulation results of search requests and retrieval outputs for several images of company's trade-mark using the proposed contents-based retrieval algorithm based on wavelet.
Performance Analysis of Turbo code using Semi Random Interleaver over the Radio Communication Channel
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1067~1075
In this paper, the performance of turbo code using semi random interleaver over the radio communication channel was analyzed. In the result, we proved that the performance of decoder was excellent as increase the interleaver size, constraint length, and iteration number. When the constraint length of turbo code using seim random interleaver and convolutional code is constant, and BER
each value of
was 6.4(DB) and 1.7(dB). There(ore, when the constraint length was constant, we proved that the performance of turbo code using semi random interleaver is superior to convolutional code about 4.7(dB) in the case of BER=
A Study on ADSL transmission speed enhancement in High-speed Internet
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1077~1083
With rising demand of Internet Service, the existing communication for users (aced the restricted capability and speed, and also failed to satisfy consumer's desire for providing service-quality to them. It can be accomplished the broad-band on subscribe-line to offer various multimedia service to subscriber. But it takes a lot of times and costs. Consequently, it stands out the most economic subscribe-line for acheving a broadband scheme that new transmission technology can be realized the high-speed data communication as the present telephone-line and telephone by the general public of FTTH(Fiber To The Home). As using the pseudo line, this paper have the result that the mesured speed was improved by connecting a variable resistor on the line.
Distribution of Target Bits based on Size, Motion and Distortion
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1085~1093
An efficient bit rate distribution technique that distributes available bits for multiple objects based on motion vector magnitude, size of object shape, and coding distortion is presented. This coding concept using the three parameters was exploited in MPEG-4 multiple object coding. But the scheme is likely to produce poor results such as allocating more bits to less important objects and degrading picture quality, due to the lack of analysis and research in view of human visual aspect. In this paper importance of each object is represented by the three parameters and visually analyzed. Target bits are distributed according to coding distortion using the pre-assigned shape and motion information.
Design and Implementation of Web-Based MINI-PACS using the DICOM
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1095~1104
In recent years, medical procedures have become more complex, while financial pressures for shortened hospital stays and increased efficiency in patient care have increased. As a result, several shortcomings of present film-based systems for managing medical images have become apparent. Maintaining film space is labor intensive and consumes valuable space. Because only single copies of radiological examinations exist, they are prone to being lost or misplaced, thereby consuming additional valuable time and expense. In this paper, mini-PACS for image archiving, transmission, and viewing offers a solution to these problems. Proposed mini-PACS consists of mainly four parts such as web module, client-server module, internal module, acquisition module. In addition, mini-PACS system includes DICOM converter that non-DICOM file format converts standard file format. In client-server module case, proposed system is combined both SCU (service class user: client) part and SCP(service class provider: sewer)part therefore this system provides the high resolution image processing techniques based on windows platform. Because general PACS system is too expensive for medium and small hospitals to install and operate the full-PACS. Also, we constructed web module for database connection through the WWW.
Implementation of Web Based Teleradiology Internet PACS
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1105~1110
In the past high cost and complex system configuration often discouraged hospitals from building teleradiology system or PACS(Picture Archiving and Communication System). But new standard platforms enable us to construct the same system with very low cost and simple configurations. internet as a communication channel made us overcome the regional limit and communication cost, and WWW technologies simplified the complex problems on the software developments, configurations and installations. So whoever has a Web browser to access internet can review medical images at anywhere. And we adopted DICOM technology which is a standard for medical imaging, thus we could resolve the interface problems among medical imaging systems such as modalities or archives. The implementation is comprised of three part DICOM/WWW interface subsystem, image format conversion subsystem and viewing applets which are displayed on users WWW browsers. In addition, Teleradiology intrenet PACS system includes DICOM converter that non-DICOM file format converts standard file format.
digital control of Inverted pendulum system
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1111~1116
control method is one of positive approaches to design a controller having both the
-performance and the
-robust stability. In this paper, Firstly, The tracking Performance to be designed has been represented as
-norms for the plants with uncertainties. Secondly,
-norm have been set up in order to ensure the robust stabilities. The mixed digital controllers have been designed for an inverted system. The mixed
digital controller for the inverted pendulum system was intended to stabilize the unstability of the plant together with the good tracking Performance.
Current Mode PWM Control for the Buck Converter Using One Cycle Response
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1117~1125
A current mode PWM method applied one cycle response to averaging circuit model Buck converters is presented. The controller nonlinear PWM implement is based on the error between the switched variable and the response reference to zero each cycle. As the result, the system transfer function is derived as a function of the desired close loop poles, simplifying the design procedure and bringing forward all the important characteristics of the close loop system. The proposed controller has significant advantages over conventional current mode control methods in noise susceptibility, dynamic response and without inductor current sensing, Finally, the simulation and experiment results confirm the proposed PWM control techniques.
Thin Films for Bottom Electrode in Ferroelectric Memory by Using the RF Sputtering
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1127~1134
thin films are prepared by RP magnetron reactive sputtering and their characteristics of crystalliBation,microstructure, surface roughness and resistivity are studied with various O2/(Ar+O2)ratios and substrate temperatures. As O2/(Ar+O2) ratio decreases and substrate temperature increases, the preferred growing plane of
thin films are changed from (110) to (101) plane. With increase of the 021(Ar+O2) ratio from 2075 to 50%, the surface roughness and the resistivity of
thin films increase from 2.38nm to 7.81nm, and from
, respectively, but the deposition rate decreases from 47nm/min to 17nm/min. On the other hand, as the substrate temperature increases from room temperature to
, resistivity decreases from
thin film deposited at
shows a excellent surface roughness of 2.38 m. As the annealing temperature increases in the range between
, the resistivity decreases because of the improvement of crystallinity. We find that RuO
thin film deposited at 20% of 02/(Ar+O2) ratio and
of substrate temperature shows excellent combination of surface smoothness and low resistivity so that it is well qualified for bottom electrode for ferroelectric thin films.
A study on the fabrication of the polarization-insensitive semiconductor optical amplifier
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1135~1142
In this study, we fabricated a 1.55um polarization-insensitive semiconductor optical amplifier(SOA) with rectangular buried heterostructure using a InGaAsP/InP double heterostructure wafer. Measured characteristics of the fabricated SOA are that 3dR bandwidth is 35nm and 3dB saturation output power is 4dBm. Maximum gain under the 150mA CW driving condition is 19.4dB. We measured the ASE(amplified spontanouse emission) Power spectrum or n and TM mode in the fabricated SOA using ASE measurement system and knew that distributions of the TE and TM mode about the maxinum region are nearly coincident. this shows the fabricated SOA is a polarization-insensitive.
A 200-MHZ@2.5-V Dual-Mode Multiplier for Single / Double -Precision Multiplications
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1143~1150
A dual-mode multiplier (DMM) that performs single- and double-precision multiplications has been designed using a
5-metal CMOS technology. An algorithm for efficiently implementing double-precision multiplication with a single-precision multiplier was proposed, which is based on partitioning double-precision multiplication into four single-precision sub-multiplications and computing them with sequential accumulations. When compared with conventional double-precision multipliers, our approach reduces the hardware complexity by about one third resulting in small silicon area and low-power dissipation at the expense of increased latency and throughput cycles. The DMM consists of a
single-precision multiplier designed using radix-4 Booth receding and redundant binary (RB) arithmetic, an accumulator and a simple control logic for mode selection. It contains about 25,000 transistors on the area of about
. The HSPICE simulation results show that the DMM core can safely operate with 200-MHZ clock at 2.5-V, and its estimated power dissipation is about 130-㎽ at double-precision mode.
Fabrication of InP-Based Microstructures for III- V Compound Semiconductor Micromachining
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1151~1156
In this paper, we report a fabrication of InP-based microstructurs for III-V compound semiconductor micromachining. Vertical liquid phase epitaxy(LPE) system was used in order to grow the InP/lnGaAsP/InP layers. The thicknesses of InP top-layer and InGaAsP were
, respectively. The fabrication of InGaAsP microstructures involves front-side bulk micromachining. The experimental result showed the beams must be carefully aligned in the <100> direction since the etching of the beam in the <100> direction is more faster than that of the beam in the <110> and <110> direction.
Depth Map Using New Single Lens Stereo
Changwun Ku ; Junghee Jeon ; Kim, Choongwon ;
Journal of the Korea Institute of Information and Communication Engineering, volume 4, issue 5, 2000, Pages 1157~1163
In this paper, we present a novel and practical stereo vision system that uses only one camera and four mirrors placed in front of the camera. The equivalent of a stereo pair of images are formed as left and right halves of a single CCD image by using four mirrors placed in front of the ten of a CCD camera. An object arbitrary point in 3D space is transformed into two virtual points by the four mirrors. As in the conventional stereo system, the displacement between the two conjugate image points of the two virtual points is directly related to the depth of the object point. This system has the following advantages over traditional two camera stereo that identical system parameters, easy calibration and easy acquisition of stereo data.