• Journal of Industrial Technology
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• v.22 no.B
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• pp.133-139
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• 2002

In precision instrumentation system, an A/D conversion of signal conditioning has been always suffered from some problems ; offset and drift voltage with environmental situation. This paper suggests a method of reducing the offset voltage and the drift error from the A/D conversion hardware using analog signal switching technique with specific operational amplifier circuits. Also, we have designed a hardware active filter and a software digital filter with Auto Zero Tracking algorithm for better dignal process of the our proposed weighing system. Software technique was performed to obtain the stable data from A/D converter. As a result of our experimental works, the proposed system is expected to be used in the industrial field where a high precision measurement is required.

• Journal of computational fluids engineering
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• v.11 no.2 s.33
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• pp.56-61
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• 2006

As the size and dimension of target problems in the field of computational engineering including CFD gets bigger and higher, it is needed to have more efficient and flexible data visualization environment in terms of software and hardware. Even though it is still manageable to use a mouse in controlling 3-dimensional data visualization, it would be beneficial to use 3-D input device for 3-D visualization. 'Data Glove' is one of the best 3-D input devices, because human hands are best tools for understanding 3-D space and manipulating 3-D objects. Signals coming from 'Data Glove' are analog and very sensitive to finger motions, therefore signal filtering using a digital filter is applied. This paper describes our experience and benefits of using data gloves in controlling 3-dimensional postprocessing softwares.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.4
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• pp.620-627
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• 1990

A software tool implementing cascaded SCF (Switched Capacitor Filter) is developed. A comprehensive procedure is described for the design of cascaded SCF, and some design considerations are discussed. In program several user-selectable filter approximation techniques, and two optimising methods which reduce the total capacitance are included. Analysis of the partial positive feedback and the effect of clock frequency to total capacitance are presented in detail. Two pratical examples are given to prove its validity in reducing the total capacitance. Developed tool can be used for general SCF generator.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.672-675
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• 2012

SMART Highway 사업은 첨단 IT통신과 자동차 및 도로 기술이 접목된 세계 최고수준의 빠르고 편안한 지능형 녹색도로 실현을 목표로 하고 있다. SMART Highway의 도로-자동차 기반 교통운영에서 핵심기술인 VANET(Vehicular Ad-hoc Network)은 다수의 차량들이 무선통신을 이용하여 차량 간 통신 또는 차량과 RSU(Road Side Unit)사이의 통신을 제공하는 차세대 네트워킹 기술이다. 특히, 운전자의 안전에 직접적인 영향을 끼칠 수 있는 V2V 통신의 경우 차량 간의 안전한 통신을 위해 차량 간 상호인증이 반드시 고려되어야 한다. 이처럼 빠른 속도로 이동하는 차량 간 인증이 원활이 이루어지기 위해서는 기존의 네트워크에서 사용된 인증방식은 그대로 적용시키기 어렵다. 따라서 본 논문에서는 다수의 차량 간 통신 시에 보다 효율적인 차량 인증을 위해 카운팅 블룸필터를 이용한 차량 인증 기법을 제안한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1250-1256
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• 2017

In this research, a high-performance ultrasonic positioning system is proposed to track the positions of an indoor mobile object. Composed of an ultrasonic sender (mobile object) and a receiver (anchor), the system employs three ultrasonic time-off-flights (TOFs) and trilateration to estimate the positions of the object with an accuracy of sub-centimeter. On the other hand, because ultrasonic waves are interfered by temperature, wind and various obstacles obstructing the propagation while propagating in air, ultrasonic pulse debounce technique and Kalman filter were applied to TOF and position calculation, respectively, to compensate for the interference and to obtain more accurate moving object position. To perform tasks in real time, ultrasonic signals are processed full-digitally with a Zynq SoC, and as a software design tool, Vivado IDE(integrated design environment) is used to design the whole signal processing system in hierarchical block diagrams. And, a hardware/software co-design is implemented, where the digital circuit portion is designed in the Zynq's fpga and the software portion is c-coded in the Zynq's processors by using the baremetal multiprocessing scheme in which the c-codes are distributed to dual-core processors, cpu0 and cpu1. To verify the usefulness of the proposed system, experiments were performed and the results were analyzed, and it was confirmed that the moving object could be tracked with accuracy of sub-cm.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.188-196
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• 2003

In this paper, a demultiplexer for MPEG-2 Transport Stream which can be applied to terrestrial digital broadcast is developed. The demultiplexer separates video, audio, and data from MPEG-2 multimedia stream and transports them to each decoders respectively. While most existing demultiplexers of MPEG-2 transport stream have been developed as hardware systems, but the fast increment of computer's performance enables a software demultiplexer to be worked in realtime. The developed demultiplexer is implemented as a software module called a filter using DirectShow of Microsoft which is based on COM(Component Object Model)and works on the Windows system. The operation of the demultiplexer is verified by using the GraphEdit tool and rendering a test file formatted as MPEG-2 transport stream.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.2824-2837
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• 2019

Container technologies are widely used in infrastructures to deploy and manage applications in cloud computing environment. As containers are light-weight software, the cluster of cloud applications can easily scale up or down to provide Internet-based services. Container-based applications can well deal with fluctuate workloads by dynamically adjusting physical resources. Current works of scheduling applications often construct applications' performance models with collected historical training data, but these works with static models cannot self-adjust physical resources to meet the dynamic requirements of cloud computing. Thus, we propose a self-adaptive automatic container scheduling framework AutoScale for cloud applications, which uses a feedback-based approach to adjust physical resources by extending, contracting and migrating containers. First, a queue-based performance model for cloud applications is proposed to correlate performance and workloads. Second, a fuzzy Kalman filter is used to adjust the performance model's parameters to accurately predict applications' response time. Third, extension, contraction and migration strategies based on predicted response time are designed to schedule containers at runtime. Furthermore, we have implemented a framework AutoScale with container scheduling strategies. By comparing with current approaches in an experiment environment deployed with typical applications, we observe that AutoScale has advantages in predicting response time, and scheduling containers to guarantee that response time keeps stable in fluctuant workloads.

• ETRI Journal
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• v.46 no.3
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• pp.538-549
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• 2024

A conventional codec aims to increase the compression efficiency for transmission and storage while maintaining video quality. However, as the number of platforms using machine vision rapidly increases, a codec that increases the compression efficiency and maintains the accuracy of machine vision tasks must be devised. Hence, the Moving Picture Experts Group created a standardization process for video coding for machines (VCM) to reduce bitrates while maintaining the accuracy of machine vision tasks. In particular, in-loop filters have been developed for improving the subjective quality and machine vision task accuracy. However, the high computational complexity of in-loop filters limits the development of a high-performance VCM architecture. We analyze the effect of an in-loop filter on the VCM performance and propose a suboptimal VCM method based on the selective activation of in-loop filters. The proposed method reduces the computation time for video coding by approximately 5% when using the enhanced compression model and 2% when employing a Versatile Video Coding test model while maintaining the machine vision accuracy and compression efficiency of the VCM architecture.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.78-81
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• 2002

We propose a current-mode analog programmable finite-impulse-response (FIR) filter with variable tap circuits. From the circuit simulation, the operation of the 7- tap FIR filter is confirmed. We design and fabricate the 0.0625-step tap circuit using 0.8$\mu\textrm{m}$ CMOS technology. The proposed FIR filter has a variable length of taps and variable coefficients, so it has a potential for being used to software defined radio (SDR) terminals.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.93-101
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• 2017

This paper proposes an algorithm for adaptive loop filter (ALF) complexity reduction in the decoding process. In the original ALF algorithm, filtering for I frames is performed in the frame unit, and thus, all of the pixels in a frame are filtered if the current frame is an I frame. The proposed algorithm is designed on top of the local gradient calculation. On both the encoder side and the decoder side, homogeneous areas are checked and skipped in the filtering process, and the filter coefficient calculation is only performed in the inhomogeneous areas. The proposed algorithm is implemented in Joint Exploration Model (JEM) version 3.0 future video coding reference software. The proposed algorithm is applied for frame-level filtering and intra configuration. Compared with the JEM 3.0 anchor, the proposed algorithm has 0.31%, 0.76% and 0.73% bit rate loss for luma (Y) and chroma (U and V), respectively, with about an 8% decrease in decoding time.