• Journal of IKEEE
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• v.18 no.4
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• pp.502-508
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• 2014

This paper has reviewed the performances of various AGCs which can be adopted in IEEE802.11p modems. IEEE802.11p, a high speed mobile communication standard for vehicles, requires high performance signal detector since the channel impulse responses are varied rapidly in time. In order to select the optimal signal detector, we simulated the performances of three detection methods. One is using RSSI signal, the other is using RSSI signal and I/Q signal, and the third is using I/Q signal through the Monte Carlo simulation. We evaluated the performances of the algorithms using our own system based on MAX 2829 transceiver(MAXIM $Integrated^{TM}$) in a real vehicular environment. As a result, the experiment using Fully I/Q signal derives the most excellent performance with the lowest minimum receiver sensitivity, packet error rate (PER) and false alarm rate (FAR).

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1159-1161
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• 2017

본 연구에서는 화장품, 세제, 쌀과 같은 생활용품들의 효율적인 관리를 위해 IoT 기기를 활용하여 무게를 감지하여 자동 주문을 하는 시스템을 제안한다. Hardware에서 생활용품의 무게를 지속적으로 sensing하고 BLE(Bluetooth Low Energy)를 통해 Android Application으로 데이터를 전송한다. Android Application에서 생활용품들의 상태를 저장하고 일정 무게 이하로 감소 시 Push Alarm으로 사용자에게 상품 재주문 제안 및 상품 추천을 한다. 이를 바탕으로 생활용품 관리의 번거로움을 줄이고 사용자의 생활물품의 소모 양상을 데이터화 할 수 있다.

• Fire Protection Technology
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• s.19
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• pp.9-16
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• 1995

The spot-type heat detector is a main component of the automatic fire alarm system intended to signal when heat energy is produced in protected area. The most of protected area in our country is installed spot-type heat detector. On this study, the responsiveness to the change of environmental temp. of spot-type heat detec-tor were obtained and analyzed under specified temp., velocity in accordance with the KOFEIS stan-dard. The experiment was carried under the condition with the change of environmental temp. Concluion of this study is as follows : 1. It was confirmed that the responsiveness of rate-of rise heat detector is sensitive to temp. below 10 degrees above zero. The malfunction appeared at 40 degrees above zero and intended performance is disqualified at 50 degrees above zero. 2. The intended performance of fixed-temp. detector which is maintained for the change of envi-ronmental temp. But the responsiveneness is confirmed instability for the change of environmental temp.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6018-6033
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• 2018

Fires are a common cause of catastrophic personal injuries and devastating property damage. Every year, many fires occur and threaten human lives and property around the world. Providing early important sign for early fire detection, and therefore the detection of smoke is always the first step in fire-alarm systems. In this paper we propose an automatic smoke detection system built on camera surveillance and image processing technologies. The key features used in our algorithm are to detect and track smoke as moving objects and distinguish smoke from non-smoke objects using a convolutional neural network (CNN) model for cascade classification. The results of our experiment, in comparison with those of some earlier studies, show that the proposed algorithm is very effective not only in detecting smoke, but also in reducing false positives.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.60-66
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• 1996

Precision of bearing race is very important to maintain the clearance between ball and inner race. In internal grinding of bearing race, its roundness is dependent on shoe wear, accuracy of jig, dressing method and grinding conditions. In this study, the characteristics of shoe wear and eccentricity of workpiece were investigated experimentally. When wear of fornt shoe wear reaches at 100.mu. m and that of rear shoe reaches at 114 .mu. m, eccentricity of inner race is increased to 1.4 .mu. m. Roundness of race is mainly related to wear of rear shoe and ring type shoe is recommended to improve roundness of race.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.890-892
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• 2022

스마트폰 모바일 앱을 이용한 범죄 예방 시스템은 다양하게 제안되고 개발되어 왔으나, 생활 안전의 유지를 위한 경찰 등 공공 서비스를 위한 인력은 매우 부족한 실정이다. 본 연구는 스마트폰 이용자가 "범죄예방 이론"에 따라 "범죄 취약환경에 및 감시 등 방어기제 부재" 상황에서 신속하게 벗어날 수 있도록 도움을 주는 앱 시스템 필요성 인식에 따라 "긴급 상황 인식 및 자동 알림 신고 앱 시스템"을 기획하여 개발한 결과를 기술하였다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.768-773
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• 2011

Today's urban transit system is regarded as the important public transportation service which saves passengers' time and provides the safety. Many researches focus on the rapid and protective responses that minimize the losses when dangerous situation occurs. In this paper we proposed the early fire detection and corresponding rapid response method in urban transit system by combining automatic fire detection for video input and the sensor system. The fire detection method consists of two parts, spark detection and smoke detection. At the spark detection, the RGB color of input video is converted into HSV color and the frame difference is obtained in temporal direction. The region with high R values is considered as fire region candidate and stepwise fire detection rule is applied to calculate its size. At the smoke detection stage, we used the smoke sensor network to secure the credibility of spark detection. The proposed system can be implemented at low prices. In the future work, we would improve the detection algorithm and the accuracy of sensor location in the network.

• Journal of Mechanical Science and Technology
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• v.18 no.7
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• pp.1055-1061
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• 2004

In this research, a vision system for detecting breakages of small-diameter taps, which are rarely detected by the indirect in-process monitoring methods such as acoustic emission, cutting torque and motor current, was developed. Two HMI (Human Machine Interface) programs to embed the developed vision system into a Siemens open architecture controller, 840D, were developed. They are placed in sub-windows of the main window of the 840D and can be activated or deactivated either by a softkey on the operating panel or the M code in the NC part program. In the event that any type of tool breakage is detected, the HMI program issues a command for an automatic tool change or sends an alarm signal to the NC kernel. An evaluation test in a high-speed tapping machine showed that the developed vision system was successful in detecting breakages of small-diameter taps up to M1.

• Land and Housing Review
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• v.13 no.4
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• pp.105-114
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• 2022

Non-fire activated fire alarms caused by such actions as cigarette smoke, cooking, and high humidity are fire safety risk factors. In such instances, it is important to quickly locate and replace the actuated detector. However, it is difficult to locate those detectors because most do not have an address function. While new apartments can incorporate addressable fire alarm detectors, in existing apartments there are limitations in converting over to addressable detectors due to cost and power line issues. This study developed an efficient address function for fire alarms in existing apartments. The newly developed system consists of the existing receiver, and a proposed addressable repeater and detector. Utilizing an experimental setup, the performance of the proposed address monitoring system was confirmed to be stable and compatible with the receiver and existing detectors.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.933-939
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• 2010

Gathering information and systemization of infrastructure disaster management is to reduce uncertainties in making decisions and maximize the number of alternations for reasonable decision making. The key object is the progress report & propagation automation system based on sensors, which is major for providing objective data to realize and support decision makings and delivering decision to a certain area, department, manager and other people rapidly. Collecting, reviewing and database of existing progress report & propagation manual in order to achieve networking of safety management on major social infrastructure of the nation, materialization of field-oriented intelligent business process by developing mobile safety management command transmission device and integrating it into facility safety management network.