• The KIPS Transactions:PartD
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• v.18D no.2
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• pp.143-148
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• 2011

In this paper developed a wearable activity device and algorithm which can be converted into the real-time activity and monitoring by acquiring sensor row data to be occurred when a person is walking by using a tri-axial accelerometer. Test was proceeded at various step speeds such as slow walking, walking, fast walking, slow running, running and fast running, etc. for 36 minutes in accordance with the test protocol after wearing a metabolic test system(K4B2), Actical and the device developed in this study at the treadmill with 59 participants of subjects as its target. To measure the activity of human body, a regression equation estimating the Energy Expenditure(EE) was drawn by using data output from the accelerometer and information on subjects. As a result of experiment, the recognition rate of algorithm being proposed was shown the activity conversion algorithm was enhanced by 1.61% better than the performance of Actical.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1998.12a
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• pp.85-85
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• 1998

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2358-2367
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• 1994

This paper presents techniques for evaluation and compensation of total measuring errors in a commercial CMM. The probe errors as well as the machine geometric errors are assessed from probing of the mechanical artefacts such as shpere, step, and rings. For the error compensation, the integrated volumetric error equations are considered, including the probe error adn the machine geometric error. The error compensation is performed on the absolute scale coordinate system, in order to overcome the redundant degree of freedom in the CMM with multi-axis probe. A interface box and corresponding software driver are developed for data intercepting/correction between the machine controller and machine, thus the volumetric errors can be compensated in real time with minimum interference to the operating software and hardware of a commercial CMM. The developed system applied to a practical CMM installed on the shop floor, and demonstrated its performance.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.373-376
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• 2022

미세먼지 수집을 위하여 필요한 위치 선정 방안과 위치 선정시 중요한 바람길분석, 수요조사, 유동인구, 교통량 등의 중요 기준을 반영하여 최종 선정하여야 하며, 이에 따라 설치된 측정기로부터 데이터 수집을 위해 지역적, 환경적, 지형적 요소를 감안하여 수집 항목을 결정하여야 한다. 데이터 수집시 실시간 또는 배치(Batch)로 할 것인지 여부를 결정하여야 하며, 이 보고서에서는 실시간으로 데이터 수집하는 경우를 설명하였다. 데이터 수집시 정확도를 높이기 위해 결측값, 이상값인 전처리 단계를 거쳐서 분석과 Modeling 구축을 통하여 정확도가 높은 알고리즘을 선정하여야한다. 정확도가 높은 알고리즘은 검증용 데이터 셋으로 적합성을 검증하여, 측정기 설치 위치의 적합성, 데이터 수집의 적합성, Modeling 구축 및 평가가 적합함을 지표로서 제시하여 적합성 검증을 하고자 한다.

• Journal of Korean Association for Spatial Structures
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• v.8 no.6
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• pp.67-74
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• 2008

This paper is concerned with the development of a measurement system using field measuring device which will give the membrane stress of the membrane structures. Up to this point, several techniques on measurement of membrane stresses has been proposed and some have been used in the fields, but accuracy of the measured stresses to be far from reliable one. Such situation has not been changed until recent days, we do not have the measurement device on which we can depend. On top of that, due to the different properties in cross directions for material of the membrane, the stress in the warp direction is different from that in the fill one.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.58.2-58.2
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• 2009

금속 와이어를 전기폭발법에 의해 증기 상태로 만든 후 응축시킬 때 제조되는 금속나노분말의 크기특성을 파악하기 위하여 제조장치에 샘플링 포트를 삽입하여 실시간 입자 측정기(Scanning Mobility Particle Sizer; SMPS) 로 14~615 nm 범위의 크기분포를 측정하였다. SMPS는 입자의 크기에 따라 전기적 이동도가 달라지는 원리를 이용하여 공기 중에 부유된 나노입자의 크기분포를 수 분내에 측정하는 실시간 입자 측정기이다. 금속나노분말 제조장치 내부는 약 0.5 bar 수준으로 불활성가스로 채워져 있어서 대기압보다 높은 고압조건이므로 SMPS 전단에 작은 노즐이 삽입된 pressure reducer를 부착하여 적정한 압력 수준으로 낮춘 후 SMPS로 나노분말의 크기분포를 실시간으로 측정하였다. 제조공정이 진행되면서 전기폭발이 주기적으로 발생하는 동안에 SMPS로 측정한 14~615 nm 범위 입자의 총 수농도는 약 $10^7$ 개/$cm^3$ 수준으로 매우 높았고, 약 100 nm와 200 nm에서 고농도 피크를 나타내는 bimodal 분포를 나타냈다. 반면 전기폭발이 잠시 중단되는 경우 입자의 총 수 농도는 약 $10^4$ 개/$cm^3$ 수준으로 낮아지고, 약 20 nm 이하의 입자가 대부분을 차지하면서 입자의 크기가 커질수록 농도가 낮아지는 형태의 크기분포로 바뀌었다. 본 연구를 통해 얻어진 제조장치 내부의 나노분말 크기분포 자료는 고품질 제품을 생산하기 위해 나노분말의 크기분포를 제어하는 분급장치 개발에 활용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.462-465
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• 2011

A pulse oximeter is a device which provides non-invasive estimate of percentage oxygen saturation of haemoglobin (SpO2). Due to the limitations of resources of personal health devices (PHDs) including pulse oximeters, they generally transmit the estimated data to a remote monitoring server through a close manager (e.g. mobile device or PC). Therefore, communication protocols between PHDs and a manager is an important research topic in terms of interoperability. In this paper, we present design results of an SpO2 transmission agent based on the ISO/IEEE 11073 (X73) protocol. The protocol is an international standard for PHDs. The agent is an embedded program which generates X73 messages from the estimated pulse rates and SpO2, and transmits the messages to a close manager. The agent consists of a Session, Message and Memory Handler. The Session Handler manages a communication session with the manager, and the Message Handler generates and analyzes the exchanged messages according to the X73 protocol. The Memory Handler extracts pulse rates and SpO2s which are stored in a memory of the pulse oximeter. The SpO2 transmission agent allows pulse oximeters to communicate with managers based on x73 standard. Consequently, the interoperability between the pulse oximeters and the managers is guaranteed.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.424-425
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• 2005

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.59-59
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• 2004

최근에 발사되어 임무를 수행중인 GRACE(Gravity Recovery And Climate Experiment) 위성사업은 편대비행하는 두 개의 저궤도 위성 간 거리를 측정하여 지구중력장을 관측하는 연구인데, 여기에 사용되는 위성간 거리측정기 성능분석을 위한 기본연구단계로, 해석식을 이용하여 외력과 위성간 거리변화와의 관계를 연구하였다. 원궤도에 근접한 궤도를 비행하는 위성의 운동은 Hill's 방정식을 사용하여 나타낼 수 있는데, 이로부터 위성에 가해지는 외력에 의한 위성의 운동 관계식을 얻을 수 있다. (중략)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.140-145
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• 2022

In an advanced modern society, among air pollutants caused by urban industrialization and public transportation, fine dust flows into indoors from the outdoors. The fine dust meter used indoors provides limited information and measures the pollution level differently, so there is a problem that users cannot monitor and monitor the data they want. To solve this problem, in this paper, indoor air quality data fine dust and ultra-fine dust (PM1.0, PM2.5, PM10), VOC (Volatile Organic Compounds) and PIR (Passive Infrared Sensor) are used to measure fine dust. and a monitoring system were designed and implemented. We propose a fine dust meter and monitoring system that is installed in a designated area to measure fine dust in real time, collects, stores, and visualizes data through App Engine of Google Cloud Platform and provides it to users.