• 센서학회지
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• 제5권4호
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• pp.47-56
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• 1996

속도제어루프내에서 외란의 각속도를 감지하여 짐발을 안정화시키기 위해 사용하는 동조자이로스코프에 대한 기본원리 및 특성을 분석하였다. 또한 비례모드 자이로스코프의 모델을 정확하게 제시하였으며, 제시된 모델은 공진 특성을 가지고 있기 때문에 기존에 사용하고 있는 2차 시스템 모델보다 실제 시스템의 특성과 유사하므로 일반적인 비례모드 자이로스코프에서도 적용 가능하다. 실제 시스템인 전자광학추적기에 사용할 경우 발생되는 문제점을 알아보고 그 해결 방안을 제시하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.930-937
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• 1994

Straodown intertial navigation system(SDINS) is a navigational instrument necessary to guide and control a free vehicle. Dynamically Tuned Gyroscope(DTG) which is widely applied to SDINS convers a wide dynamic range and is simple and small. In study, the analysis of mechanical parts or sensor parts and research of balancing is performed for manufacturing a DTG. In error analysis the criterion considered during designing and manufacturing is established by quantitatively anayzing the effect of DTG performance by tolerance. And the theory of dynamic balancing is derived and unbalance is reduced through experiment. And the stiffness of flexure is verified by tuning experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1146-1148
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• 1996

In this paper, uncertain parameters of the heat transfer model of a Dynamically Tuned Gyroscope (DTG) are estimated by the Recursive Least Squares (RLS) method. Also, using this model, a temperature controller for a DTG is designed. As the temperature controller, a PI controller is used. It is presented that a controller can be easily designed when the heat transfer model of a DTG is used. By simulations and experiments, it is shown that the estimated heat transfer model is appropriate and the desired performance of the temperature controller is satisfied.

• 대한물리의학회지
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• 제15권2호
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• pp.23-30
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• 2020

PURPOSE: The purpose of this study was to examine the effects of dual-task training with cognitive tasks on cognitive functions and β-amyloid levels in the elderly with mild dementia. METHODS: The subjects were 36 elderly inpatients diagnosed with mild dementia at S Hospital located in Gyeongsangbuk-do, South Korea. The patients were randomly divided into a dual-task training group (DTG; n = 18) or a single-task training group (STG; n = 18). DTG performed dual-task training with cognitive tasks while STG performed only exercise tasks. These groups performed their respective exercises during a 30-minute session occurring three times a week over an 8-week period. MMSE-K and GDS were used to measure the subjects' cognitive function. To assess the subjects' dementia-related factors, their β-amyloid levels were measured by blood analysis. RESULTS: The results of the experiment were as follows: DTG showed statistically significant differences between their MMSE-K scores and β-amyloid levels before and after training (p < .05), whereas they exhibited no statistically significant differences in their GDS scores. MMSE-K scores and β-amyloid levels were significantly different between DTG and STG after training. CONCLUSION: The present study's overall results indicate that dual-task training with cognitive tasks is more effective than single-task training in improving cognitive functions and β-amyloid levels in the elderly with mild dementia. In other words, regular dual-task training can be considered as effective in improving cognitive function and dementia-related factors in the elderly with mild dementia and thus may be suggested as an effective exercise method for the treatment and early prevention of dementia.

• 한국ITS학회 논문지
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• 제17권2호
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• pp.87-97
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• 2018

많은 승객들이 이용하는 대중교통수단인 버스의 위험운전을 체계적으로 평가 및 진단하기 위한 시스템은 현재까지 매우 미흡한 상황이다. 본 연구는 실제 고속버스 운행기록장치(DTG, Digital Tacho Graph) 자료를 활용하여 버스 위험운전의 특성과 패턴에 대해 분석하였다. 위험운전 8개 유형에 대해 시간대별, 요일별, 날씨별 분포를 분석한 결과, 급가속(61.3%), 급좌우회전(20.1%), 급감속(15.1%) 유형이 대부분을 차지하였으며, 새벽시간대, 금요일, 맑은 날에 각각 위험운전이 더 많이 발생하는 패턴을 보였다. 이어서 통계분석을 통해 위험운전 유형별 상관성과 시간대별 발생건수의 차이를 규명하였으며, 위험운전의 정도에 따라 3개 그룹을 제시하였다. 본 연구의 결과는 향후 안전운전 교육기관에서 운전 시뮬레이터를 통한 신뢰성 있는 진단 및 교육을 수행하기 위한 참고자료로 활용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.519-521
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• 1987

Among the gyroscopes used for SDINS, the dynamically turned gyroscope (DTG) covers a wide dynamic range while it is simple and small. In addition, it is a two-degree-of freedom gyro; it can detect two-axis input simultaneously. DTG, since its development in 1970's, is widely accepted for strapdown inertial systems. In the first year, we have concentrated on developing a two degree-of-freedom DIG. An interdisciplinary research team has been formed to accomplish the first year objective. Five departments in the College of Engineering, Seoul National University are involved. They are; 1) Department of Control and Instrumentation, 2) Department of Mechanical Design and Production, 3) Department of Electrical Engineering, 4) Department of Electronic Engineering, and 5) Department of Metallurgical Engineering. In addition, the Department of Precision Mechanical Engineering of Pusan National University is subcontracted to develop a test procedure for gyroscope and SDINS. Gyroscope is a key sensor for SDINS. Furthermore gyroscope itself is used as a. independent sensor for vehicle guidance and control and fire control system. Gyroscope and SDINS are an important for defense, aeronautical, and space industries that Korea is and will be actively involved. Upon the success of the project, they are expected to be manufactured in Korea under a cooperative effort between university and industry.

• Structural Engineering and Mechanics
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• 제82권1호
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• pp.69-79
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• 2022

This paper discusses the field testing of two single-span double-tee girder (DTG) bridges in South Dakota to determine live load distribution factors (LLDFs) and the dynamic load allowance (IM). One bridge had seven girders and another had eight girders. The longitudinal girder-to-girder joints of both bridges were deteriorated in a way that water could penetrate and the joint steel members were corroded. A truck traveled across each of the two bridges at five transverse paths. The paths were tested twice with a crawl speed load test and twice with a dynamic load. The LLDFs and IM were determined using strain data measured during the field tests. These results were compared with those determined according to the AASHTO Standard and the AASHTO LRFD specifications. Nearly all the measured LLDFs were below the AASHTO LRFD design LLDFs, with the exception of two instances: 1) An exterior DTG on the seven-girder bridge and 2) An interior DTG on the eight-girder bridge. The LLDFs specified in the AASHTO Standard were conservative compared with the measured LLDFs. It was also found that both AASHTO LRFD and AASHTO Standard specifications were conservative when estimating IM, compared to the field test results for both bridges.

• 한국건설순환자원학회논문집
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• 제12권1호
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• pp.8-16
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• 2024

포틀랜드 시멘트, 철강 산업 등에서 원료로 사용되는 석회석(CaCO₃, calcium carbonate)은 고온에서 탈탄산 분해 반응에 의해 CO₂를 배출한다. 석회석 사용에 의한 CO₂ 배출을 저감하기 위해 CO₂ 배출의 원인이 되는 carbonate 광물을 함유하지 않거나 함유량이 적으면서도 CaO를 함유한 산업부산물로 석회석을 대체하려는 기술이 제안되었다. 이들 산업부산물에 함유된 CO₂를 정량 측정하는 방법으로 Loss of Ignition(LOI), Thermo-Gravimetric Analysis(TG), Infrared Spectroscopy(IR) 등이 사용되나, 산업부산물의 특성에 따라 CO₂ 배출량을 과대 또는 과소 평가할 우려가 있다. 본 연구에서는 CaCO₃ 시료와 고온에서 산화반응에 의해 중량이 증가하는 시료 각각에 carbonate 형태로 함유된 CO₂의 함량을 측정하는 방법으로 LOI, TG, IR 및 DTG(Differential Thermo-Gravimetric Analysis) 방법의 신뢰도와 시험방법별 측정결과를 비교 검토하였다. CaCO₃ 시료에 대해서는 검토한 모든 시험결과는 충분한 수준의 신뢰도를 나타내었다. 반면, 고온에서 중량이 증가하는 시료의 CO₂ 함량에 대해서는 LOI와 TG는 시료의 CO₂ 함량을 제대로 평가하지 못했으며, IR은 예측값에 비해 CO₂ 함량을 과대평가하는 경향을 나타내었으나, DTG에 의한 평가 결과는 예측값에 근사하였다. 이로부터 수 % 미만 수준의 미량의 CO₂를 함유하고, carbonate 광물의 분해 배출 온도에서 CO₂ 배출에 의한 중량 감소 외에도 중량이 변화하는 시료의 경우 DTG를 이용하여 CO₂ 함량을 구하는 것이 LOI나 TG, IR을 이용한 평가보다 합리적이라고 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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• pp.27-30
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• 2003

In this paper, the new dual trench gate Emitter Switched Thyristor (DTG-EST) is proposed for improving snap-back effect which leads to a lot of serious problems of device applications. And the parasitic thyristor that is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and $35A/cm^2$, respectively. But the proposed DTG-EST exhibits snap-back with the anode voltage and current density 0.96V and $100A/cm^2$, respectively.

• 대한전기학회논문지
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• 제38권2호
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• pp.119-126
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• 1989

In this paper, a new technique, which uses an "input compensator", is proposed to design a controller for the rebalance loop of a Dynamically Tuned Gyroscope (DTG) and the performance of this new controller is compared with that of a Proportional and Integral (PI) controller through simulation. The rebalance loop is an essential part of a DTG` it is composed of a controller, low-pass filters, notch filters and torque drivers. Among them, the controller is the main attributor to determine the performance of the rebalance loop. Through simulation, it is concluded that the performance of the newly designed controller is better than that of a PI controller in the point of (1) low maximum overshoot, (2) short settling time and (3) small steady state error.