• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1558-1559
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• 2007

This study is an application field by using optical fiber. The system to measure sBs from optical fiber is designed, So it can be used as a temperature sensor. by using frequency shift, resulting from temperature changes. the frequency shift is checked by changing temperature from $25^{\circ}C$ to $69^{\circ}C$ with chamber in the laboratory and using 40Km optical fiber. It's also measured by varying the length of optical fiber The program to do the real-time monitoring and analyze the measured data is created to find accurate frequency. It can be used as an optical fiber sensor, which is capable of measuring temperature and distance by using sBs.

• 항공우주의학회지
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• 제30권2호
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• pp.54-60
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• 2020

Pilot fatigue is a great hazard to aviation safety. In recent years, long-distance fights have been increasing and flight hours have been increasing, which has made fatigue issues important. International organizations in the aviation sectors (ICAO, FAA, IATA etc.) recommend management of fatigue within the SMS (Safety Management System) framework. A scientific and systematic approach to measuring fatigue is required as a prerequisite to preparing safety management measures for pilot's fatigue. Therefore, in this study, I would like to consider recent trends and implications for fatigue measurement. First, I aimed to consider recent the accident cases related to fatigue. Second, I also considered how to measure the pilot's fatigue. Finally, the direction of the countermeasures against fatigue through fatigue measurement was developed and suggested.

• Journal of information and communication convergence engineering
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• 제22권1호
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• pp.23-32
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• 2024

This study aims to improve the quality of distance learning by developing webcast-based e-learning media and integrating it into an e-learning platform for functional job training purposes at the National Research and Innovation Agency, Indonesia. This study uses a Technology Acceptance Model (TAM) to assess and predict user perceptions of information systems using webcast platforms as an alternative to conventional applications. The research method was an online survey using Google Forms. Data collected from 136 respondents involved in practical job training were analyzed using structural equation modeling to test the technology acceptance model. The results showed that the proposed model effectively explained the variables associated with the adoption of web-based e-learning during the COVID-19 pandemic in Indonesia for participants engaged in functional job training. These findings suggest that users' perceptions of ease of use, usefulness, benefits, attitudes, intentions, and webcast usage significantly contribute to the acceptance and use of a more effective and efficient webcast-based e-learning platform.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.538-561
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• 2020

Recommender Systems (RecSys) have a major role in e-commerce for recommending products, which they may like for every user and thus improve their business aspects. Although many types of RecSyss are there in the research field, the state of the art RecSys has focused on finding the user similarity based on sequence (e.g. purchase history, movie-watching history) analyzing and prediction techniques like Recurrent Neural Network in Deep learning. That is RecSys has considered as a sequence prediction problem. However, evaluation of similarities among the customers is challenging while considering temporal aspects, context and multi-component ratings of the item-records in the customer sequences. For addressing this issue, we are proposing a Deep Learning based model which learns customer similarity directly from the sequence to sequence similarity as well as item to item similarity by considering all features of the item, contexts, and rating components using Dynamic Temporal Warping(DTW) distance measure for dynamic temporal matching and 2D-GRU (Two Dimensional-Gated Recurrent Unit) architecture. This will overcome the limitation of non-linearity in the time dimension while measuring the similarity, and the find patterns more accurately and speedily from temporal and spatial contexts. Experiment on the real world movie data set LDOS-CoMoDa demonstrates the efficacy and promising utility of the proposed personalized RecSys architecture.

• 한국정보통신학회논문지
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• 제10권9호
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• pp.1671-1678
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• 2006

본 논문은 컴퓨터 모니터 거리 30-40cm에서 실시간 쌍안 눈동자 추적 마우스 시스템 구현에 관한 연구이다. 눈동자 탐색과 커서 의 추적과정은 소형 CCD카메라에서 받은 안면영상은 2진영상으로 변환되고 눈 주위의 5영역 매스크 방법으로 눈을 찾고 측4점 대각선위치 지 정 방법으로 각 홍채를 탐색한다. 커서추적은 홍채중심좌표의 이동위치를 측정하여 이루어진다. 화면커서 제어는 홍채의 최대 이동거리를 측정하여 화면커서최대 이동거리와 비교하고 홍채의 움직임에 비례해서 커서가 이동해야 하는 거리를 계산하여 화면커서를 화면의 바라보는 지점에 위치시킴으로써 화면커서가 제어된다. 실험 결과 구현시스템은 비교적 간단하고 실시간으로 동작속도가 빠름을 보였다.

• International Journal of Precision Engineering and Manufacturing
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• 제8권3호
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• pp.20-23
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• 2007

To calibrate precision autocollimators, the Korean Research Institute of Standards and Science (KRISS) has built a small angle generator using a laser interferometer. The system is based on a sine bar mechanism in which the angle is determined from the ratio of two lengths. The rotational angle is measured by the angle interferometer and the heterodyne laser interferometer detects the relative displacement of two retro-reflectors attached to the rotating arm. The distance between the two retro-reflectors of the laser angle interferometer is self-calibrated by an index table positioned on the rotating arm. The resolution of the system is 0.002 seconds, and the accuracy is better than 0.04 seconds within a measuring range of $\pm$1 degree. The small angle generator can also be used with an index table that can divide one circle into 1440 angles. The combined system can generate any angle over 360 degrees to an accuracy of 0.11 seconds.

• 수산해양기술연구
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• 제24권1호
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• pp.7-11
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• 1988

수산, 해양자원을 개발함에 있어 가장 중요한 요소중의 하나인 해양환경요소를 효과적으로 측정하기 위해 원격제어장치를 제작하여 수온에 대한 원격제어실험을 행한 결과, 수은온도계로 직접 측정한 측정치와 원격제어 시스템에 의한 측정치는 수온 $12^{\circ}C~37^{\circ}C$ 범위에서는 완전정상관을 이루어, 본 원격계측 시스템은 수온의 원격제어에 효과적으로 사용할 수 있음을 확인할 수 있으며, 다른 수중정보의 원격제어에도 크게 활용될 수 있으리라 생각된다.

• 제어로봇시스템학회논문지
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• 제12권9호
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• pp.883-890
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• 2006

Nowadays, CPS is used widely, especially in cases which need more precise position information, such as car navigation systems and even in the mobile robot for position measuring in the outdoor environment. RTK (Real-Time Kinematics) and DGPS (Differential Global Positioning System) have more precise accuracy than the general-purposed GPS. However can't easily use them because of high prices and large size of equipments. In order fur the mobile robot to obtain precise position information it is important that CPS receiver has portability and low price. In this study, we introduce a new GPS data acquisition system that offers the precise position data using the DGPS mechanism and satisfying low cost and portability. In addition to this, we propose an improved data compensation algorithm that offers more accurate position information to the outdoor mobile robot by compensating the error rate of CPS data measured from the three points with geometrical rotation and distance formula. Proposed method is verified by comparing with the precise real position data obtained by RTK. Proposed method has more than 70% performance enhancement.

• 한국지능시스템학회논문지
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• 제16권5호
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• pp.581-586
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• 2006

본 논문에서는 무인주행 차량의 자율주행에 사용되는 자계안내시스템에서 지자계를 제거하기 위한 새로운 방법으로 Ground 검출법을 제안한다. 자계안내시스템은 도로에 일정한 간격으로 자계표식을 매설하고 차량이 자계표식으로부터 떨어진 거리를 인식하여 주행하는 방법이다. 차량이 주행 중 측면이탈거리를 알기 위해서는 지자계가 제거된 자계표식의 자계만을 이용해야 한다. 그러나 자계센서는 자계를 검출할 때 자계표식의 자계와 지자계를 함께 계측한다. 지자계는 차량의 주행방향과 경사에 따라 다르게 검출되기 때문에 자계표식의 자계와 더해질 경우 측면이탈거리를 인식하는데 오차를 발생한다. 따라서 본 논문에서는 지자계를 제거하는 새로운 방법을 제안하고, 이를 검증하기 위한 실험 장치를 구성하였다. 그리고 실험을 통하여 제안한 방법의 타당성과 유용성을 입증한다.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.50-56
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• 2013

Optical-fiber electronic speckle pattern interferometry (ESPI) is a non-contact, non-destructive examination technique with the advantages of rapid measurement, high accuracy, and full-field measurement. The optical-fiber ESPI system used in this study was compact and portable with the advantages of easy set-up and signal acquisition. By suitably configuring the optical-fiber ESPI system, producing an image signal in a charge-coupled device camera, and periodically modulating beam phases, we obtained phase information from the speckle pattern using a four-step phase shifting algorithm. Moreover, we compared the actual defect size with that of interference fringes which appeared on a screen after calculating the pixel value according to the distance between the object and the CCD camera. Conventional methods of measuring defects are time-consuming and resource-intensive because the estimated values are relative. However, our simple method could quantitatively estimate the defect length by carrying out numerical analysis for obtaining values on the X-axis in a line profile. The results showed reliable values for average error rates and a decrease in the error rate with increasing defect length or pressure.