• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권8호
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• pp.2170-2187
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• 2023

The general interference is the imperative trouble for simultaneous wireless information and power transfer (SWIPT) system. Although interference has bad influences on the performance of the system, it carries energy simultaneously. In this paper, the energy-constrained relay of the SWIPT system needs to spend much time on energy collecting (EC) in the information transmission (IT) period. Therefore, we propose the scheme of interference signal energy collecting (ISEC) when the interference is strong, and the SWIPT system does not carry out IT. The relay of the system continues to collect energy and stores it until the interference has minimal impact on IT. Then the system performs IT. We divide the collected interference energy equally into several parts, and each IT block receives one part. The proposed scheme is appealing because it can reduce the time of EC in IT period to make the relay spends more time forwarding the received signal in order to improve the performance of the system throughput. Furthermore, we propose a time-switching (TS) protocol based on EC at the relay. And it allows the relay forwarding signal at an appropriate power. Under the protocol, the time of EC can be flexible according to the forwarding power that we give so that the collected energy can be used more efficiently. We give the expressions of the system throughput according to the proposed scheme and protocol. Moreover, the influence of the interference power on the system throughput is also studied.

• Journal of Mechanical Science and Technology
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• 제18권11호
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• pp.2058-2065
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• 2004

A light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames to obtain the flame propagation speed in freely falling droplet suspension produced by an ultrasonic atomizer. Two MICRO probes are used to monitor time-series signals of OH chemiluminescence from two different locations in the flame. By detecting the arrival time difference of the propagating flame front, the flame propagation speed is calculated with a two-point delay-time method. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the two-point delay-time method by the MICRO system. Furthermore, the relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with three different experimental conditions by changing the fuel injection rate. It was confirmed that the two-point delay-time method with two MICRO probes is useful and convenient to obtain the flame propagation speed and that the flame propagation speed depends on the spray properties.

• Journal of Advanced Marine Engineering and Technology
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• 제20권1호
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• pp.56-66
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• 1996

In this study, the characteristics of generation and propagarion of transient wave induced in the assembly of four collecting plate upon the propagation of waves are analyzed. Also double exposure holographic inteferometry using ruby pulse laser is built in order to investigate the propagation of transient waves generated by impact load. When impact load was applied at edge of connecting band, the vibration of collecting plates was generated from the contact points between collecting plate and band which connects four collecting plates. Waves generated from the lower part and those reflected from the upper part were mixed as time went on and then formed very complex shapes. Also, when impact load was aplied at center of collecting plate, the waves propagating across the convexo-concave plane were reflected partly at curved section. Therefore the vibration amplitude was decreased as the transiet waves were propagated through the convexo-concave plane.

• 한국응용곤충학회지
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• 제46권3호
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• pp.375-383
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• 2007

곤충의 채집방법, 횟수 및 시기와 채집된 곤충의 종류 및 개체수에 대한 상관관계를 조사하기 위하여 충북대학교 내 4곳을 선정, 일 년간 봄부터 가을까지 매 2주마다 채집을 실시, 총 16회 조사를 하였다. 각 장소마다 light trap, net sweeping, pitfall trap, window trap의 4가지 채집방법을 병행 실시하여 결과를 비교분석하였다. 모두 14목 672종이 조사되었으며, 전체 종수의 75%인 501종이 채집된 유아등 채집(light trap)방법이 18% 또는 그 이하의 종수를 기록한 타 채집방법들에 비해 보다 효과적인 것으로 나타났다. 또한 각 채집시기에서 채집된 종이 2주 후의 채집에서 다시 채집되는 비율이 평균 30% 정도 밖에 되지 않았다. 결과적으로 곤충다양성 조사에 있어서 보다 의미 있는 결과를 확보하기 위해서는 다양한 채집방법과 함께 채집의 빈도(sampling window)를 높이는 것이 특히 중요한 것으로 나타났다.

• 한국안전학회지
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• 제19권3호
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• pp.20-25
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• 2004

In order to obtain the flame Propagation speed in freely falling droplet suspension Produced by an ultrasonic atomizer, a light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames. Two MICRO probes are used to monitor time-series signals of OH chemilumine-scence from two different locations in the flame. The flame propagation speed is calculated by detecting the arrival time difference of the propagating flame front. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the MICRO system. Furthermore, relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with k different experimental conditions by changing the fuel injection rate. It was confirmed that the MICRO probe system was very useful and convenient to obtain the flame propagation speed and that the flame propagation speed was different depending on the spray properties.

• 한국컴퓨터정보학회논문지
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• 제24권3호
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• pp.87-93
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• 2019

In this paper, we propose a real-time drone-based violent protest detection system. Our proposed system uses drones to detect scenes of violent protest in real-time. The important problem is that the victims and violent actions have to be manually searched in videos when the evidence has been collected. Firstly, we focused to solve the limitations of existing collecting evidence devices by using drone to collect evidence live and upload in AWS(Amazon Web Service)[1]. Secondly, we built a Deep Learning based violence detection model from the videos using Yolov3 Feature Pyramid Network for human activity recognition, in order to detect three types of violent action. The built model classifies people with possession of gun, swinging pipe, and violent activity with the accuracy of 92, 91 and 80.5% respectively. This system is expected to significantly save time and human resource of the existing collecting evidence.

• 한국콘텐츠학회논문지
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• 제18권7호
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• pp.459-469
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• 2018

본 연구는 폐지수집 여성노인이 경험하는 일상생활에서의 삶의 의미와 본질을 탐색하기 위한 질적 연구이다. 연구 참여자는 장기간 폐지수집 생활을 지속하는 여성노인 7명이며, 예비조사와 심층면접을 통해 자료를 수집하였고, Colaizzi(1978)의 현상학적 분석방법에 따라 분석한 결과 18개의 주제와 5개의 주제모음을 도출하였다. 폐지수집 여성노인의 경험에 대한 5개의 주제모음은 '힘들었던 지난시간-지나온 나', '힘겨운 생활의 연속', '계속 지탱하기', '거리 환경변화에 적응하기', '능동적이고 적극적인 내인생-지금의 나'로 나타났다. 이를 통해 종합해 볼 때 폐지수집 여성노인의 삶의 본질은 '수용'으로 해석되었다. 따라서 이러한 폐지수집 여성노인을 위한 사회복지에서의 제도적 실천적 개입 방안을 제시하였다.

• 분석과학
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• 제15권2호
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• pp.157-162
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• 2002

전통한지 섬유질 슬러지 및 기계한지 섬유질 슬러지를 양이온 계면활성제 cetyltrimethylammonium chloride(CTAC)를 이용하여 효과적으로 제거하는 방법에 대해 연구하였다. 전통한지 슬러지 시료일 경우 고형분의 양이 약 0.08 g/L 일 때 CTAC의 농도가 $1{\mu}g/mL$ 되면 제거율이 95% 이상 되었으며, 이 때 걸리는 시간은 30초 이내이었다. 기계한지 슬러지에 대해 CTAC만을 이용하여 슬러지를 제거하였을 때 $15{\mu}g/mL$ 이상에서 90% 정도의 제거효율을 보였으나 슬러지 층이 안정하지 못하고, 부상시간이 비교적 오래 걸렸다. $5{\mu}g/mL$의 CTAC에 PAMID$^{(R)}$를 첨가하여 부상시켰을 때는 CTAC만을 이용하였을 때 보다 제거율이 증가하였으며 슬러지 층도 또한 안정하였다. 기계한지 슬러지보다 전통한지 슬러지를 제거할 때 더 효율적이었다.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 춘계학술발표회
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• pp.273-274
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• 2008

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.411-418
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• 2007

To analyze dynamic and long-term behavior of high speed rail system, and seismic measurements been installed at the various locations in the high speed rail system. Among these, 76 measurements were installed Chunan and Deajeon, and 80 measurements between Kwangmyung and Chunan. From these 156 measurements, real time data are continuously corrected and be sent to the main monitoring system to be used further analysis. These two systems were installed by different institution, and so there are not only basic differences in the system itself, but system running methods and data collecting/transferring methodology. There has been systematic difficulties due to these differences. This study shows the whole steps of high speed rail data monitoring systems include measurement equipment itself and data collecting/transferring system. study will proposed a more effective methods for collecting. This study also discuss the real time analysis method which can be used for future high speed rail monitoring system.