• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.880-883
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• 2006

The reduction of tool vibration has been a serious issue for both employers and workers because of the risks of vibration transmitted to the workers. In this study a hand-arm vibration measurement and evaluation system was developed based on ISO 5349:2001 and used for analyzing relation of vibration level and components of tools. This system consists of a notebook PC installed a LabVIEW program and the data acquisition system including two 3-axial accelerometers and a NI-DAQ card. Vibration measurement tests were conducted for eight angle grinders and four impact wrenches where 3 subjects were used for each of the tools. The relation between different components of each tool and its vibration total value made it possible to set-up a guideline of tool design. In the past engineers developed tools by using their experience and intuition, but by using this system it became possible to design tool components so as to minimize the risks of hand-transmitted vibration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.585-587
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• 1999

The rotorbody and rotor winding of generator are isolated by an insulator and the output characteristic of the generator is maintained in the best states. Only when an insulation resistance between them is over a certain extent. The aim of this research is to develop the simulator for rotor earth fault detection circuits. It is composed of the power resource which is to control the virtual field voltage, stepping motor which is to give virtual ground. It is possible to inspect with the device and program developed in this study in the same as real operating condition and evaluate the integrity of generator rotor through the function of data acquisition and graphic output. If these technologies will be applied to the inspection, prevent a damage of the generator and contribute to improve maintenance reliance.

• 한국치위생학회지
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• 제14권5호
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• pp.681-687
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• 2014

Objectives : The purpose of the study is to investigate the recognition of the single tied system in dental hygiene education. Methods : A self-reported questionnaire was filled out by 302 dental hygienists in Seoul and Gyeonggi Province from May 1 to 30, 2013. The questionnaire included general characteristics, recognition of single tied education system, and duration of the bachelor course. The data were analyzed using SPSS(PASW statistics) 18.0 program for frequency analysis, t-test, and ANOVA. Results : The majority of the respondents agreed the necessity of the single tied system of curricula. The expectation of acquisition of bachelor and continuous education showed 3.23 points of 5 points. Pros and cons for the single tied curriculum system accounted for 50 percents respectively. The majority of the respondents(74.3%) agreed that there was no difference between the 3 year curricula and 4 year curricula. Conclusions : It is necessary to unite the opinion debate for the single tied curriculum system in the dental hygiene department through analysis and review for the curricula.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.199-210
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• 2008

Acoustic emission(AE)/Microseimsic(MS) activities are low-energy seismic events associated with a sudden inelastic deformation such as the sudden movement of existing fractures, the generation of new fractures or the propagation of fractures. These events rapidly increase before major failure and happen within a given rock volume and radiate detectable seismic waves. The main difference between AE and MS signals is that the seismic motion frequencies of AE signals are higher than those of MS signals. As the failure of geotechnical structures usually happens as a high velocity and small displacement, it is not easy to determine the precursor and initiation stress level of failure in displacement detection method. To overcome this problem, AE/MS techniques for detection of structure failure and damage have recently adopt in civil engineering. In this study, AE/MS monitoring system, which consist of sensor, data acquisition and operation program, is constructed with domestic technology. To verify and optimize the developed system, we are now carrying out the field application at an underground research laboratory and the developed AE/MS monitoring will be used in detecting of seismic events with various scales.

• 한국추진공학회지
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• 제14권1호
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• pp.40-47
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• 2010

본 연구에서는 하이브리드 로켓의 산화제 유량 제어를 통한 추력제어를 위한 기초 연구를 진행하였다. 실험을 위해 하이브리드 로켓 모터와 산화제 유량 조절장치 그리고 데이터 획득을 위한 전체 시스템을 설계, 제작하였다. 산화제 유량 제어를 하기 위해서 니들밸브와 스텝모터를 결합하여 스텝모터의 구동에 의해 니들밸브의 개폐량을 조절할 수 있도록 설계하였고 LabVIEW프로그램을 이용하여 스텝모터를 컨트롤 하였다. 또한 기체산소($GO_2$)와 고체연료(Polyethylene)를 이용한 하이브리드 로켓의 연소실험을 통해 산화제 유량 제어를 통한 하이브리드 로켓의 추력제어 가능성을 확인하였다.

• 산업경영시스템학회지
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• 제25권4호
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• pp.22-31
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• 2002

A high-speed rail system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as train, electrical hardware, electronics, control, information, communication, civil technology etc. The system design and acquisition data of the large-scale system must be the subject under strict configuration control and management. Not only the requirements of the large-scale system dictate the contracts with the suppliers but also become the basis for the development process, project execution, system integration, and testing. The requirements database provide the system design specification of all development activities. Using the RDD-100, a systems engineering tool, the Korea next-generation high-speed rail program can establish requirements traceability and development process management in performing the enabling train technology development projects. This paper presents the results from a computer-aided systems engineering application to the Korea next-generation high-speed railway project. Especially, the focus of the study was on requirement management and PBS(Product Breakdown Structure) management.

• 동력기계공학회지
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• 제17권2호
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• pp.38-45
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• 2013

In this study, for carrying out the spray and combustion experiment using a Common Rail Direct Injection(CRDI) system, the controller was fabricated to drive a high speed camera, a injector and a laser beam sequentially at a low cost. CB280 module of one-chip micro processer was used for the controller. In order to confirm responsibility and utility of the controller, the current drive performance, the spray behavior and the injection rate were tested and analyzed under various experimental conditions. As this research results, we found that the fabricated controller was able to control the devices for the spray experiment precisely with the input value in program and it had the dynamic load responsibility and repetition. Also, we found that the injection rates of our experimental results were higher than those of others at the same injection pressure and the controller connected with the laser system and the data acquisition system had validity for carrying out the spray visualization experiment.

• 한국소음진동공학회논문집
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• 제15권4호
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• pp.404-411
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• 2005

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure the grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with a data acquisition system and the corresponding software. Strain gauges and an accelerometer were mounted on the handle surface for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root-mean-square accelerations at the handle, obtained in repetition for each power tool with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce random error of the measured vibration.

• 천문학회보
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• 제43권1호
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• pp.67.3-68
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• 2018

We plan to automatize the operation of Kyung Hee Astronomical Observatory (KHAO) 76 cm Telescope by adapting KAOS30 (KHU Automatic Observing Software for McDonald 30 inch Telescope). The software is developed to improve the efficiency of the observation system for monitoring transients and variable sources. It has installed and operated at McDonald 30 inch telescope since 2017 August. KAOS76 (KHU Automatic Observing Software for KHAO 76 cm Telescope) consists of four packages: Telescope Control Package (TCP), Data Acquisition Package (DAP), Auto Focus Package (AFP), and Script Mode Package (SMP). Most of the packages can be configured by minimized modifications of the codes because it includes common libraries for FLI instruments and also ASCOM standard. TCP, DAP, and AFP control astronomical devices. SMP supports automatic observing in a script mode. TCP of KAOS76 can communicate with the TCS via ASCOM. Also, KAOS76 has an extra function to compensate the misalignment of the polar axis. In this poster, we show the current status of the observing system with KAOS76.

• 전기학회논문지
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• 제59권10호
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• pp.1776-1786
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• 2010

Intelligent distribution automation system have total monitoring and control capability. The system covers substation, distribution network, distributed generations and customers at HV system. Various intelligent distribution facilities installed at distribution systems have voltage sensor, current sensor, aging monitoring sensor. Intelligent Feeder Remote Terminal Unit (IFRTU) tied to intelligent distribution facilities process information from facilities and it checks information of fault, power quality and aging of distribution facilities. The information is transmitted to master station through communication line. The master station have remote monitoring system covers substation, distribution network, distributed generations and customers. It also have various application programs that maintain optimal network operation by using information from on-site devices.