• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.2
• /
• pp.28-33
• /
• 2007

In this paper, we are studied on the direction and formation of carbonized conductive path according to surface leakage current between electrodes. The characteristics of the tracking as surface is broken down between exposed live parts. Using the HSIS(high speed imaging system. 100,000[fps], redlake ltd., USA), it took photographs by arc growth mechanism occurred in on/off surge, ground fault and discharge between electrodes. Then the results was analyzed. Hereafter, it expected effects that application of energy utility technology through the arc control.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1525-1526
• /
• 2006

Electrical current always travels through the minimum resistance path. In this paper, we are studied on the direction and formation of carbonized conductive path according to surface leakage between electrodes. The analysis of characteristics of the arc discharge as surface is broken down between exposed live parts. Using the HSIS(high speed imaging system, 100,000fps, redlake ltd., USA), it took photographs by arc growth mechanism occurred in on/off surge, ground fault and discharge between electrodes. Therefore, it recommended for results of technology development and application such as theoretic verification of an arc direction and economic security according to a technology about connecting arc generation in surfaces of insulators. Hereafter, it expected effects that application of energy utility technology through the arc control.

• 한국연소학회:학술대회논문집
• /
• 2015.12a
• /
• pp.209-211
• /
• 2015

Evaporation characteristics of a single droplet of carbon nanofluids were investigated in a rapid compression machine(RCM). n-Heptane and carbon black N990 were used to synthesize the carbon nanofluids. RCM is an experimental set-up to simulate a single compression stroke of reciprocating engine. Temperature and pressure in a reaction chamber were measured during the compression stroke. After the piston reaches top dead center(TDC), temperature and pressure decreased due to the heat loss at wall. In that process, a single droplet of carbon nanofluids underwent unsteady condition. A single droplet was put at the center of reaction chamber. Thermocouple whose tip is $50{\mu}m$ was used not only to measure transient bulk temperature, but also to suspend the droplet. The picture of single droplet was taken using high speed camera with a frame rate of 500 fps. From those pictures, the droplet diameter was measured by visual basic program.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2019.05a
• /
• pp.593-595
• /
• 2019

원격지의 로봇을 조작함에 있어, 원격지의 상황을 정확히 인식하는 것이 우선적으로 필요하다. 본 연구에서는 로봇에 설치된 스테레오 카메라를 통해 입력된 비디오를 네트워크를 통해 전달하고, 조작 공간에 있는 사용자가 Head Mounted Display(HMD) 기기를 통해 원격지의 상황을 현장감 있게 파악할 수 있는 비전 시스템을 구현했다. 로봇 내 S/W의 효과적인 통합을 위해 카메라 입력 처리 및 비디오 스트리밍은 Ubuntu의 ROS를 이용하여 구현됐으며, 조작 공간의 HMD 기기 및 관련 조작 센서 통합은 Windows 상에 구현하여, 실험을 통해 원격지의 상황을 25fps 수준의 HD 해상도 비디오로 확인할 수 있었다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.03a
• /
• pp.465-472
• /
• 2003

The main concept of base isolation system is to reduce the member forces by decreasing the earthquake forces transmitted to superstructure instead of the conventional techniques of strengthening the structural members. There are two important advantages in friction pendulum systems. The functions of carrying the vertical load and of providing horizontal stiffness are effectively separated. This results in a more stable system that eliminates the need of a fail-safe mechanism. Friction pendulum systems are less sensitive to variations in the frequency content of ground excitation and tend to limit the intensity of the farce imparted to the superstructure. This study investigates the friction coefficients on the FPS test specimens according to the velocity, bearing pressure and test waveform.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.339-342
• /
• 2010

최근 프로세서가 클럭 향상의 한계에 부딪힘에 따라, 프로세서의 성능을 향상시키기 위해 멀티 코어 기반의 병렬처리를 이용한 방법들이 제안 되고 있다. 본 논문은 여러개의 연산기를 한 명령어 사이클에 동시에 사용할 수 있는 MIMD(Multiple Instruction, Multiple Data) 구조를 가지며, Scratch Counter를 이용해 멀티 코어와 멀티 스레드의 작업을 할당하는 구조의 GP-GPU(General Purpose - Graphics Processing Unit)를 활용해 멀티 코어, 멀티 스레드 환경에서의 효율적인 픽셀 셰이딩 방법을 설계 하였다. 선형 안개 픽셀 셰이딩의 경우 싱글코어에서 18.3 FPS이며 4개의 멀티코어 GP-GPU에서는 4배가 증가한 73.2 FPS 결과를 얻었다.

• Journal of Information Processing Systems
• /
• v.17 no.2
• /
• pp.227-241
• /
• 2021

Object detection techniques based on deep learning such as YOLO have high detection performance and precision in a single channel video stream. In order to expand to multiple channel object detection in real-time, however, high-performance hardware is required. In this paper, we propose a novel back-end server framework, a real-time AI vision platform (RAVIP), which can extend the object detection function from single channel to simultaneous multi-channels, which can work well even in low-end server hardware. RAVIP assembles appropriate component modules from the RODEM (real-time object detection module) Base to create per-channel instances for each channel, enabling efficient parallelization of object detection instances on limited hardware resources through continuous monitoring with respect to resource utilization. Through practical experiments, RAVIP shows that it is possible to optimize CPU, GPU, and memory utilization while performing object detection service in a multi-channel situation. In addition, it has been proven that RAVIP can provide object detection services with 25 FPS for all 16 channels at the same time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.11a
• /
• pp.117-118
• /
• 2018

본 논문에서는 작은 객체를 검출하기 위한 수정 된 YOLOv3-tiny 를 제안한다. 컴퓨터 비전에서 작은 객체 검출은 제한된 해상도와 정보로 검출하기 어렵다. 이 문제를 해결하기 위해 기존 방법의 대부분은 높은 정확도 향상을 위해 속도를 희생한다. 본 논문은 정확도와 속도가 균형적인 성능을 통해 빠른 속도로 작은 객체를 검출하는 것을 목표로 한다. 실험은 WIDER FACE 와 자체 수집한 데이터베이스에서 기존 YOLOv3-tiny 보다 높은 87.48% mAP 를 얻었으며, 속도는 각각 100.5FPS 로 YOLOv3-tiny 보다는 느리지만 높은 정확도와 YOLOv3 보다는 빠르지만 낮은 정확도를 통해 균형적인 성능을 얻을 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.06a
• /
• pp.326-328
• /
• 2018

최근 4K/8K 급 초고품질 콘텐츠의 서비스에 관심이 집중되는 만큼 스트리밍 서비스에 대한 연구도 활발히 이루어지고 있다. 하지만 단일 PC 성능의 한계로 인해 SW 기반 영상 처리에 어려움을 겪고 있다. 본 논문에서는 분산 처리를 통해 실시간 영상 처리가 가능하도록 시스템을 제안한다. 제안한 시스템은 영상 패킷 분석 및 분할, 분산 트랜스코딩, 패킷 통합 단계로 이루어지며 Hadoop 과 Spark 를 이용하여 실시간 분산 처리를 지원한다. 실험 결과는 초고품질 입력 영상($3840{\times}2160@60Hz$, YCbCr 4:2:2, 10-bit)에 대해 평균 74.47fps 의 트랜스코딩 속도를 보인다.

• Journal of Information Processing Systems
• /
• v.18 no.1
• /
• pp.12-25
• /
• 2022

In recent years, deep convolutional neural networks have made significant progress in the research of single image super-resolution. However, it is difficult to be applied in practical computing terminals or embedded devices due to a large number of parameters and computational effort. To balance these problems, we propose CSRNet, a lightweight neural network based on channel split residual learning structure, to reconstruct highresolution images from low-resolution images. Lightweight refers to designing a neural network with fewer parameters and a simplified structure for lower memory consumption and faster inference speed. At the same time, it is ensured that the performance of recovering high-resolution images is not degraded. In CSRNet, we reduce the parameters and computation by channel split residual learning. Simultaneously, we propose a double-upsampling network structure to improve the performance of the lightweight super-resolution network and make it easy to train. Finally, we propose a new evaluation metric for the lightweight approaches named 100_FPS. Experiments show that our proposed CSRNet not only speeds up the inference of the neural network and reduces memory consumption, but also performs well on single image super-resolution.