• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.63-71
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• 2005

e-VLBI was invented to enhance the efficiency of VLBI (Very-Long-Baseline Interferometry) system by transmitting the data via high speed network. Korean VLBI Network (KVN) has a plan to construct e-VLBI system named e-KVN. High speed backbone network and efficient network model are essential to implement successful e-VLBI system. This paper introduces a network model based on PC cluster technology. The present status of high speed backbone network in Korea is overviewed. We suggest that the network link via Korea Advanced Research Network (KOREN) is one of feasible way for e-KVN. We also describe the principles of e-VLBI and protocol for network transmission such as VSI-E (VLBI Standard Interface - Electronic), RTP (Real-Time Transport Protocol) and RTCP (Real-Time Transport Control protocol).

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.131-136
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• 2021

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, a real-time EtherCAT master is implemented on Linux operating systems and its performances are evaluated. To enhance the real-time capability of mainline Linux kernel, Xenomai is applied as a real-time framework and an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on it. Unlike other studies, the real-time performance of the EtherCAT master is evaluated at the output of the network interface card, so that the evaluation results include all possible effects from the EtherCAT master system. The implemented EtherCAT master can send and receive packets up to 20KHz control frequency with low jitter, even in stressed condition.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.273-281
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• 2022

In this paper, we propose a robot sound recognition system that detects various sound events. The proposed system is designed to detect various sound events in real-time by using a microphone on a robot. To get real-time performance, we use a VGG11 model which includes several convolutional neural networks with real-time normalization scheme. The VGG11 model is trained on augmented DB through 24 kinds of various environments (12 reverberation times and 2 signal to noise ratios). Additionally, based on random forest algorithm, a decision logic is also designed to generate event signals for robot applications. This logic can be used for specific classes of acoustic events with better performance than just using outputs of network model. With some experimental results, the performance of proposed sound recognition system is shown on real-time device for robots.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.109-118
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• 1999

A graphic software is one of the most important components of the vehicle simulator. To increase a visual reality of the simulator, the graphic software should require several technologies such as three-dimensional graphics, graphic modeling of the vehicle and the environment, drivers biomechanical models, and real-time data processing. This study presents a real time graphic driving simulator of a construction vehicle. The graphic simulator contains the three models of the construction vehicle, the human, and the environment, and employes a neural network approach to decrease an on-line dynamic computation. An excavator model is represented using an object-oriented paradigm and contains the detailed information about a real-size vehicle. The human model is introduced for objective visual evaluations of the developed excavator model. Since the environment model plays an important role in a real-time simulator, a block-based approach is implemented and a text format is utilized for easier construction of environment. The simulation results are illustrated in order to demonstrate the applicability of developed models and the neural network approach.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.463-468
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• 2003

The Internet, especially the mobile Internet influences enormously in many areas in human societym espeially in terms of the exchanging speed of knowledge and information. This new society of knowledge and information will introduce many new types of services based on valuable knowlwdge and information. Among many new services in this mobile computing environment, the real-time worldwide korean information networking service using the Korean characters invented by the mobile computing environment, the real-time worldwide Korean information networking service using the Koean characters invented by the King Sejong is possible ubiquitously with wired and mobile Internet. We studied the user interface with Korean characters in the mobile computing environment, and introduce the useful results with new metrics of performance analysis after real implementation for real-time Korean information networking using Korean domain names.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.237-252
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• 2017

In recent years, data centers have become the core infrastructure to deal with big data processing. For these big data applications, network transmission has become one of the most important factors affecting the performance. In order to improve network utilization and reduce job completion time, in this paper, by real-time monitoring from the application layer, we propose job-aware priority scheduling. Our approach takes the correlations of flows in the same job into account, and flows in the same job are assigned the same priority. Therefore, we expect that flows in the same job finish their transmissions at about the same time, avoiding lagging flows. To achieve load balancing, two approaches (Flow-based and Spray) using ECMP (Equal-Cost multi-path routing) are presented. We implemented our scheme using NS-2 simulator. In our evaluations, we emulate real network environment by setting background traffic, scheduling delay and link failures. The experimental results show that our approach can enhance the Hadoop job execution efficiency of the shuffle stage, significantly reduce the network transmission time of the highest priority job.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.207-215
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• 2014

In this paper, we propose a Micro Real-Time Control System (MRTCS) for decreasing the delay during interrupts processing and data transfer on sensor nodes. The MRTCS consists of a control, sensor nodes based on Controller Area Network (CAN) device. The control node was designed with Real Time Operating System (RTOS) on top of the small Micro Control Unit (sMCU). Sensor nodes have the CAN device without sMCU, which have multiple Digital Inputs, Outputs (DI/DO) and the CAN controller. We have evaluated with OCTAVE v3.6.4 from open source for system performance. Simulation results show that the system performance was increased through the delay reducing for interrupt processing and internal data transfer. We verify that a proposed MRTCS approach will be adapted to various real-time control system.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.331-338
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• 2016

In this paper, we propose a GRNN(: Generalized Regression Neural Network) algorithms for new eyes and face recognition identification system to solve the points that need corrective action in accordance with the existing problems of facial movements gaze upon it difficult to identify the user and. Using a Kalman filter structural information elements of a face feature to determine the authenticity of the face was estimated future location using the location information of the current head and the treatment time is relatively fast horizontal and vertical elements of the face using a histogram analysis the detected. And the light obtained by configuring the infrared illuminator pupil effects in real-time detection of the pupil, the pupil tracking was - to extract the text print vector.

• The Journal of Korean Association of Computer Education
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• v.14 no.5
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• pp.71-79
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• 2011

We designed and implemented a cooperative learning system using social network service which can be utilized on a smart phone for users to read each other's posting once they upload posting and to give feedback concerning the posting in real time without the need for accessing a relevant website, through the installation of a necessary application which makes it possible for learners to interact at any time in any place on a smart phone. The developed program is used as an intermediate tool for real-time communications so as to aid in solving the task of learners, and it was made to boost academic achievement as well as interest in learning through real-time interactions and feedback. Furthermore, the program was designed in such a way that an instructor actually helps learners by closely identifying their levels based on accumulated data.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.19-28
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• 2005

Recently, it has been sharply increased the interests to detect the network traffic anomalies to help protect the computer network from unknown attacks. In this paper, we propose a new anomaly detection scheme using the simple linear regression analysis for the exported LetFlow data, such as bits per second and flows per second, from a border router at a campus network. In order to verify the proposed scheme, we apply it to a real campus network and compare the results with the Holt-Winters seasonal algorithm. In particular, we integrate it into the RRDtooi for detecting the anomalies in real time.