• Title/Summary/Keyword: Discrete-time system

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An Object Oriented Data Model of a Spatiotemporal Geographic-Object Based on Attribute Versioning (속성 버전화에 기반한 시공간 지리-객체의 객체 지향 데이터 모델)

  • Lee, Hong-Ro
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.6
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    • pp.1-17
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    • 2001
  • Nowadays, spatiotemporal data models deal with objects which can be potentially useful for wide range applications in order to describe complex objects with spatial and/or temporal facilities. However, the information needed by each application usually varies, specially in the geographic information which depends on the kind of time oriented views, as defined in the modeling phase of the spatiotemporal geographic data design. To be able to deal with such diverse needs, geographic information systems must offer features that manipulate geometric, space-dependent(i.e, thematic), and spatial relationship positions with multiple time oriented views. This paper addresses problems of the formal definition of relationships among spatiotemporal objects and their properties on geographic information systems. The geographical data are divided in two main classes : geo-objects and geo-fields, which describe discrete and continuous representations of the spatial reality. I study semantics and syntax about the temporal changes of attributes and the relationship roles on geo-objects and non-geo-objects, This result will contribute on the design of object oriented spatiotemporal data model which is distinguishied from the recent geographic information system of the homogeneously anchored spatial objects

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A Simulator for Integrated Voice/Data Packet Communication Networks (음성과 데이터가 집적된 패킷통신망을 위한 시뮬레이터 개발)

  • Park, Soon;Un, Chong-Kwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.11 no.2
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    • pp.108-121
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    • 1986
  • In this paper, the development of a simulator for the performance estimation and parameter optimization of an integrates voice/data packet communication network is described. The simulator implemented is capable of simulating the integrated voice/data network that handles packet voice terminals as well as data terminals and hosts operating under standard CCITT protocols. Of the three descrete event simulation approaches presently known, the process interaction method has been chose. With this approach one can implement a simulator that is related most Closely with the real system. The simulator has been implemented in PL/I and GPSS simulation languages, resulting in a software package of about 4,000 lines. To reduce the computer run time of the simulator, we have used a method of reducing conditional events based on a GPSS LINK block. We describe various aspects of the simulation model developed. We then investigate the performance of a 7-node network using the simulator, and present the results. For validation of the simulator developed, we construct a simulation model for a simple voice/ data multiplexer, and compare the results of simulation with those of an analytical model.

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Design of Computer Access Devices for Severly Motor-disability Using Bio-potentials (생체전위를 이용한 중증 운동장애자들을 위한 컴퓨터 접근제어장치 설계)

  • Jung, Sung-Jae;Kim, Myung-Dong;Park, Chan-Won;Kim, Il-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.11
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    • pp.502-510
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    • 2006
  • In this paper, we describe implementation of a computer access device for the severly motor-disability. Many people with severe motor disabilities need an augmentative communication technology. Those who are totally paralyzed, or 'locked-in' cannot use conventional augmentative technologies, all of which require some measure of muscle control. The forehead is often the last site to suffer degradation in cases of severe disability and degenerative disease. For example, In ALS(Amyotrophic Lateral Sclerosis) and MD(Muscular dystrophy) the ocular motorneurons and ocular muscles are usually spared permitting at least gross eye movements, but not precise eye pointing. We use brain and body forehead bio-potentials in a novel way to generate multiple signals for computer control inputs. A bio-amplifier within this device separates the forehead signal into three frequency channels. The lowest channel is responsive to bio-potentials resulting from an eye motion, and second channel is the band pass derived between 0.5 and 45Hz, falling within the accepted Electroencephalographic(EEG) range. A digital processing station subdivides this region into eleven components frequency bands using FFT algorithm. The third channel is defined as an Electromyographic(EMG) signal. It responds to contractions of facial muscles and is well suited to discrete on/off switch closures, keyboard commands. These signals are transmitted to a PC that analyzes in a time series and a frequency region and discriminates user's intentions. That software graphically displays user's bio-potential signals in the real time, therefore user can see their own bio-potentials and control their physiological signals little by little after some training sessions. As a result, we confirmed the performance and availability of the developed system with experimental user's bio-potentials.

Window Approach for Cosine-Modulated Filter Bank Design for Multitone Data Communication (윈도우를 이용한 멀티톤 데이터 통신용 코사인 변조 필터뱅크 디자인)

  • 김정학;신승철;정진균;송상섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8B
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    • pp.1586-1592
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    • 1999
  • In DWMT, CMFB is employed in the synthesis/analysis part. The CMFB uses filters of greater length than the DFT, resulting in reduced interference between the carriers. In addition, the CMFB system is computationally efficient and fast algorithms are available for their implementation. Traditional designs for the prototype filters of CMFB usually involve nonlinear optimizations. Thus the required design time is considerably large even for small filter orders. In this paper, a prototype filter design method for CMFB is presented using optimal window method. The design process is reduced to the optimization of a single parameter and consequently the required design time is much less than those of the existing methods. It is shown that the stopband performance of the proposed method is better than that of the Kaiser window method.

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Complexity Estimation Based Work Load Balancing for a Parallel Lidar Waveform Decomposition Algorithm

  • Jung, Jin-Ha;Crawford, Melba M.;Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.25 no.6
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    • pp.547-557
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    • 2009
  • LIDAR (LIght Detection And Ranging) is an active remote sensing technology which provides 3D coordinates of the Earth's surface by performing range measurements from the sensor. Early small footprint LIDAR systems recorded multiple discrete returns from the back-scattered energy. Recent advances in LIDAR hardware now make it possible to record full digital waveforms of the returned energy. LIDAR waveform decomposition involves separating the return waveform into a mixture of components which are then used to characterize the original data. The most common statistical mixture model used for this process is the Gaussian mixture. Waveform decomposition plays an important role in LIDAR waveform processing, since the resulting components are expected to represent reflection surfaces within waveform footprints. Hence the decomposition results ultimately affect the interpretation of LIDAR waveform data. Computational requirements in the waveform decomposition process result from two factors; (1) estimation of the number of components in a mixture and the resulting parameter estimates, which are inter-related and cannot be solved separately, and (2) parameter optimization does not have a closed form solution, and thus needs to be solved iteratively. The current state-of-the-art airborne LIDAR system acquires more than 50,000 waveforms per second, so decomposing the enormous number of waveforms is challenging using traditional single processor architecture. To tackle this issue, four parallel LIDAR waveform decomposition algorithms with different work load balancing schemes - (1) no weighting, (2) a decomposition results-based linear weighting, (3) a decomposition results-based squared weighting, and (4) a decomposition time-based linear weighting - were developed and tested with varying number of processors (8-256). The results were compared in terms of efficiency. Overall, the decomposition time-based linear weighting work load balancing approach yielded the best performance among four approaches.

Two-Level Hierarchical Production Planning for a Semiconductor Probing Facility (반도체 프로브 공정에서의 2단계 계층적 생산 계획 방법 연구)

  • Bang, June-Young
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.159-167
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    • 2015
  • We consider a wafer lot transfer/release planning problem from semiconductor wafer fabrication facilities to probing facilities with the objective of minimizing the deviation of workload and total tardiness of customers' orders. Due to the complexity of the considered problem, we propose a two-level hierarchical production planning method for the lot transfer problem between two parallel facilities to obtain an executable production plan and schedule. In the higher level, the solution for the reduced mathematical model with Lagrangian relaxation method can be regarded as a coarse good lot transfer/release plan with daily time bucket, and discrete-event simulation is performed to obtain detailed lot processing schedules at the machines with a priority-rule-based scheduling method and the lot transfer/release plan is evaluated in the lower level. To evaluate the performance of the suggested planning method, we provide computational tests on the problems obtained from a set of real data and additional test scenarios in which the several levels of variations are added in the customers' demands. Results of computational tests showed that the proposed lot transfer/planning architecture generates executable plans within acceptable computational time in the real factories and the total tardiness of orders can be reduced more effectively by using more sophisticated lot transfer methods, such as considering the due date and ready times of lots associated the same order with the mathematical formulation. The proposed method may be implemented for the problem of job assignment in back-end process such as the assignment of chips to be tested from assembly facilities to final test facilities. Also, the proposed method can be improved by considering the sequence dependent setup in the probing facilities.

Image-based Soft Drink Type Classification and Dietary Assessment System Using Deep Convolutional Neural Network with Transfer Learning

  • Rubaiya Hafiz;Mohammad Reduanul Haque;Aniruddha Rakshit;Amina khatun;Mohammad Shorif Uddin
    • International Journal of Computer Science & Network Security
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    • v.24 no.2
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    • pp.158-168
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    • 2024
  • There is hardly any person in modern times who has not taken soft drinks instead of drinking water. The rate of people taking soft drinks being surprisingly high, researchers around the world have cautioned from time to time that these drinks lead to weight gain, raise the risk of non-communicable diseases and so on. Therefore, in this work an image-based tool is developed to monitor the nutritional information of soft drinks by using deep convolutional neural network with transfer learning. At first, visual saliency, mean shift segmentation, thresholding and noise reduction technique, collectively known as 'pre-processing' are adopted to extract the location of drinks region. After removing backgrounds and segment out only the desired area from image, we impose Discrete Wavelength Transform (DWT) based resolution enhancement technique is applied to improve the quality of image. After that, transfer learning model is employed for the classification of drinks. Finally, nutrition value of each drink is estimated using Bag-of-Feature (BoF) based classification and Euclidean distance-based ratio calculation technique. To achieve this, a dataset is built with ten most consumed soft drinks in Bangladesh. These images were collected from imageNet dataset as well as internet and proposed method confirms that it has the ability to detect and recognize different types of drinks with an accuracy of 98.51%.

Simulation of Efficient Flow Control for FAB of Semiconductor Manufacturing (반도체 FAB 공정에서의 효율적 흐름제어를 위한 시뮬레이션)

  • 한영신;전동훈
    • Journal of Korea Multimedia Society
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    • v.3 no.4
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    • pp.407-415
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    • 2000
  • The ultimate goal of flow control in the semiconductor fabrication process, one of the most equipment-intensive and complex manufacturing process, is to reduce lead time and work in process. In this paper, we propose stand alone layout in the form of job shop using group technology to improve the Productivity and eliminate the inefficiency in FMS (flexible manufacture system). The performance of stand alone layout and in-line layout are analyzed and compared while varying number of device variable chanties. The analysis of in-line layout is obtained by examining its adoption in the memory products of semiconductor factory. The comparison is performed through simulation using ProSys; a window 95 based discrete system simulation software, as a tool for comparing performance of two proposed layouts. The comparison demonstrates that when the number of device variable change is small, in-line layout is more efficient in terms of production Quantity. However, as the number of device variable change is more than 14 times, stand alone layout prevails over in-line layout.

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A full-Hardwired Low-Power MPEG4@SP Video Encoder for Mobile Applications (모바일 향 저전력 동영상 압축을 위한 고집적 MPEG4@SP 동영상 압축기)

  • Shin, Sun Young;Park, Hyun Sang
    • Journal of Broadcast Engineering
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    • v.10 no.3
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    • pp.392-400
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    • 2005
  • Highly integrated MPEG-4@SP video compression engine, VideoCore, is proposed for mobile application. The primary components of video compression require the high memory bandwidth since they access the external memory frequently. They include motion estimation, motion compensation, quantization, discrete cosine transform, variable length coding, and so on. The motion estimation processor adopted in VideoCore utilizes the small-size local memories such that the video compression system accesses external memory as less frequently as possible. The entire video compression system is divided into two distinct sub-systems: the integer-unit motion estimation part and the others, and both operate concurrently in a pipelined architecture. Thus the VideoCore enables the real-time high-quality video compression with a relatively low operation frequency.

PSPICE analysis of the Lorenz circuit using the MOS resistor (MOS 가변저항을 이용한 로렌츠 회로의 PSPICE 해석)

  • Ji, Sung-Hyun;Kim, Boo-Kang;Nam, Sang-Guk;Nguyen, Van Ha;Park, Yong Su;Song, Han Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1348-1354
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    • 2015
  • In this paper, chaotic circuit of the voltage controlled Lorentz system for engineering applications has been designed and implemented in an electronic circuit. The proposed circuit consists of MOS variable resistor, multipliers, capacitors, fixed resistors and operational amplifiers. The circuit was analysed by PSPICE program. PSPICE simulation results show that chaotic dynamics of the circuit can be controlled by the MOS variable resistor through time series analysis, frequency analysis and phase diagrams. Also, we implemented the proposed circuit in an electronic hardware system with discrete elements. Measured results of the circuit showed controllability of the circuit using the MOS resistor.