• 한국가시화정보학회지
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• 제5권1호
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• pp.30-36
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• 2007

The global environment is deteriorating at an alarming rate, despite of enhanced international environmental regulation. Many studies have been performed to reduce toxic pollutants. Recently, plant-based phytoremediation technology for moving toxic contaminants from soil and water has been receiving large attention. Arsenic-contaminated soil is one of the major pollutant sources for drinking water. Pteris erotica has been known as a hyper-accumulator of arsenic from soils. In this study, we investigated the effect of arsenic absorption on sap flow inside xylem vessels of Pteris. The synchrotron X-ray micro-imaging technique was employed to monitor the refilling process of water containing arsenic inside the xylem vessels of Pteris's leaves and stems non-invasively. The captured phase-contrast X-ray images show both anatomy of internal structure and transport of water inside Pteris. The exposure of Pteris to arsenic solution was found to increase largely the water raise speed in xylem vessels. The present results would provide important information needed for understanding the mechanisms of accumulation and transportation of toxic materials in plants.

• 한국전자파학회논문지
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• 제16권2호
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• pp.174-181
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• 2005

이 논문에서는 숲 속에 숨어있는 타겟의 산란 특성을 계산할 수 있는 효율적인 모델을 계발한다. 이 산란모델은 숲의 산란 특성을 계산하기 위해 프랙탈 기하학과 single scattering 이론을 사용하는 channel model과 타겟 자체의 산란 특성을 계산하기 위해 physical optic(PO) 근사법을 사용하는 hybrid 모델이다. 그리고 전체 모델의 계산량을 줄이기 위해 가역정리를 사용하여 간단하게 타겟과 숲 사이의 상호 작용을 계산한다.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.248-253
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• 2005

The recording density of a hard disk drive is increasing so rapidly that the storage capacity of a commercial HDD in PC reaches several hundred giga bytes recently. Many technologies related to the HDD, such as servo, media, actuator dynamics, thermo and fluid dynamics, etc. must be developed together to realize high recording density. Especially, researches in the airflow inside the HDD cavity become important as the rotational speed of a disk increases. Typical problem due to the airflow is the vibration of an actuator as the airflow collides with an I-block, suspensions and sliders, that is, FIV(Flow Induced Vibration). This problem is one of the significant sources of increasing TMR so that it must be resolved. In this research, a disk damper shape has been modified to minimize the effects of airflow on the actuator. Modified disk dampers which change flow field inside HDD cavity show good effects not only on the disk (tufter but also on the vibration of an actuator. Vibrations of E- block and slider have been measured with LDV and the airflow field inside the HDD cavity has been analyzed using a commercial package to verify these effects.

• 정보처리학회논문지B
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• 제13B권2호
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• pp.83-88
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• 2006

일정한 형태의 물체를 분석하기 위해 사용되는 각-거리 그래프를 이용하여 임의의 물체의 경계선 내부 영역의 면적을 측정하는 디지털 영상처리 알고리듬을 제안한다. 물체의 경계선 내부의 한 점을 중심으로 1차 각-거리 그래프를 생성하고 이 그래프로부터 거리 값이 급격히 변화하는 위치를 추출하여 1차 그래프에서 접근하지 못한 영역을 인식하여 새 영역에서의 한 점을 중심으로 2차 각-거리 그래프를 생성한다. 물체의 형태가 복잡한 경우 차수가 증가하게 되며 이와 같이 계층적으로 구성된 각-거리 그래프 그룹에 대해 거리의 제곱을 각도 방향으로 적분하여 물체의 경계선 내부 영역의 면적을 측정한다.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.257-263
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• 2018

It is a small injection molding machine for table top considering the material heating mechanism and the design and structure stability by securing the mechanism that compresses the inside of the material heating tube by using the electric actuator and by providing space between the body and the material heating tube to reduce heat loss Develop body. An electric actuator suitable for applying pressure to the inside of a material heating tube is a mechanical system composed of a rigid structure. Since a large force is repeatedly applied to the electric actuator and the push rod, the interaction between the moving parts and the dynamic Maximum stress through analysis and prediction of fatigue life of critical parts The pushrod reflects the structural analysis results of the electric actuator and the push rod, and pushes the inside of the material heating tube by the push rod to inject the molten material from the nozzle into the mold. The pushrod operates by the operation of the electric actuator. The material heated by the coil heater is ejected through the nozzle by the pressure of the material heating tube, and the material heating tube and the nozzle are also lowered at the same time as the push rod is lowered, so that the material is closely adhered to the mold. We want to study the completion of the injection.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.511-517
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• 2022

Recently, due to rapid climate change, the population of honey bees has decreased, posing a great threat to the existence of the Earth's ecosystem. In particular, the colony collapse phenomenon in which bees disappeared nationwide in early 2022 had devastating consequences for beekeepers. In order to solve the problems of beekeeping due to climate change, it is urgent to develop a system that can monitor the situation inside the hive through various IoT sensors. This paper develops a system that can measure the activity of bees inside the hive and uses it to measure the number of times of entry and exit of the hive. The data measured by the developed system can be monitored in real time on a smartphone through the cloud server. The system developed in this paper can monitor the ecology of bees according to climate change and measure internal and external bee activities. Using this method, it is possible to check in advance for the colony collapse phenomenon in which bees disappeared in early 2022. This is very meaningful in that it presents an alternative that can identify the cause of the problem through early detection.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.77-82
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• 2001

An intelligent road transport management system focused on microscopic, real-time traffic signal control is proposed. Referring to the development of those systems in Japan, extensive use of image traffic detectors observing the movement of vehicles inside intersections, and direct data exchange between the signal controllers of neighboring intersections are newly assumed. On site investigation of five intersections in Japan or in Malaysia shows the possibility of effective information provision and simple algorithm for solving heavy congestion, as well as easy installation.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.170-175
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• 2009

This paper introduces Zigbee based ubiquitous service. Most of ubiquitous services require the position information. Positioning algorithms utilize the transmission characteristics of the signal. Zigbee based positioning researches have been conducted mainly for the spatial factors inside the building. This paper proposes the possibility to consider the temporal factors of Zigbee signal and analyzes empirically the signal characteristics influenced according to the temporal factors as well as the spatial factors for ubiquitous services based on Zigbee sensor network.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 춘계학술발표대회
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• pp.480-481
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• 2015

온라인 게임에서 핵 프로그램을 탐지하는 방식 중 하나인 시그니처 탐지 방식의 문제점을 제시와 제시된 문제점을 보완하기 위한 발전된 시그니처 탐지 방식을 적용하므로 인하여 기존의 가지고 있던 문제를 개선할 수 있는 방법이다. 이 방식을 기존에 탐지하고 있는 방식과 병행할 경우 핵 프로그램을 수집해야하는 번거로움과 미 탐지로 인한 게임내의 핵 프로그램을 탐지하는데 일조할 것으로 보인다.

• 한국문헌정보학회지
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• 제50권4호
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• pp.121-142
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• 2016

본 연구는 국회도서관 서비스의 경제적 이용가치를 측정하고 평가함으로써 국회도서관이 제공하는 서비스에 대한 경제적 타당성을 확보하고 이용자의 인식을 제고하여 국회도서관 이해관계자들의 지지를 확인하는 것을 목적으로 하였다. 이를 위해 국회도서관 이용자를 국회의 내부 이용자와 외부 이용자, 협정기관 이용자로 구분하였고, 가치측정을 위한 방법으로 시간가치 및 대체서비스가치, WTP 가치측정 방법을 적용하였다. 이용자들이 국회도서관이 없어 다른 대체서비스를 이용할 경우 연간 추가로 더 필요한 시간의 가치는 내부 이용자가 1,948.2백만 원, 외부 이용자가 417,057.5백만 원으로 이는 국회도서관 1년 예산 대비 약 10배에 해당하는 금액이다. WTP로 측정된 총 가치를 이용자별로 보면 내부 이용자의 총 가치는 8,528.3백만 원이고 외부 이용자의 총 가치는 33,272.4백만원, 협정기관 이용자의 총 가치는 924백만 원으로 산출되었다. 이용자별 WTP 가치는 내부 이용자에 비해 외부 이용자가 전체 가치의 77%를 차지해 외부 이용자 가치가 큰 비중을 차지하였다. 국회도서관 2015년 예산 대비 BC ratio는 1:1.04로 나타났다.