• 대한방사선치료학회지
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• 제21권2호
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• pp.83-88
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• 2009

목 적: 온 보드영상(OBI)장치를 이용한 콘빔CT는 환자 치료 중 실시간으로 전산화모의치료 영상과 비교하여 환자의 자세 및 표적용적의 움직임과 셋업오차를 확인 할 수 있다. IMRT 시 콘빔CT를 이용해 환자의 자세 및 표적용적의 변화와 움직임을 확인하여 치료계획과의 오차정도를 산출하고, Automatic Match System을 이용하여 위치 보정을 한 후 전자포털영상 장치를 통하여 위치보정의 정확성을 검증하고, IMRT에서 콘빔CT의 유용성과 Automatic Match System의 정확성에 대하여 알아보고 자 한다. 대상 및 방법: 본원에서 치료받은 IMRT 환자 중 두 경부 치료환자 3명, 골반부 치료환자 1명을 대상으로 치료 자세의 변동과 그에 따른 조사용적의 위치변동을 알아보기 위해 선형가속기에 장착된 온 보드 영상 장치를 이용해 콘빔 CT를 촬영하였다. IMRT 전 매 치료 시 마다 콘빔CT를 촬영하여 전산화단층모의치료 영상과 비교하여 좌표별로 치료계획과의 오차값을 확인하고 3D/3D Match의 Automatic Match System을 통하여 치료계획과 일치하도록 이동 보정한 후 전자포털영상 장치를 이용하여 검증, 평가하였다. 결 과: 치료 전 콘빔 CT와 전산화단층모의치료 영상 비교 시 두 경부에서 좌표별 평균오차는 Vertical 0.99 mm, Longitudinal 1.14 mm, Lateral 0.84 mm, Rotation $0.49^o$이고, 골반부의 평균오차는 Vertical 2.78 mm, Longitudinal 2.04 mm, Lateral 4.91 mm, Rotation $1.07^o$로 부위별로 다소 근소한 차이를 보였다. 보정 후 검증에서는 전자포털영상 장치에 의한 영상과 DRR 영상 비교 결과 0.5 mm 이내의 오차로 정확한 보정이 이루어졌음을 알 수 있었다. 결 론: 치료 전 콘빔CT 영상은 환자의 셋업오차와 장기 및 표적의 위치변화를 2차원적 영상의 비교와 달리 하나의 체적으로 재구성된 3차원적 영상으로 비교함으로써 보다 정확하게 위치변화와 표적용적의 변동 등을 측정, 보정하여 정확한 치료를 할 수 있으며, 그 오차 값을 산출하여 비교할 수 있다. 이상의 연구로 보아 콘빔CT는 치료계획과 일치하는 정확한 치료전달과 반복적인 치료재현성에 유용하였으며, 만족스러운 결과를 얻을 수 있었다. 콘빔CT에 의해 향상된 정확도는 복잡한 모양의 표적용적과 급격한 선량분포의 변화가 나타나는 IMRT에서 더욱 필요하며 각 치료 부위별, 치료 목적별로 Match focus에 대한 기준을 연구해야 될 것으로 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.465-467
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• 1998

A lane change maneuver is a part of lateral control of an automated highway system. Assuming no direct measurement of its position during transition from one lane to another. A vehicle is controlled to follow the virtual desired trajectory using only on-board sensors. This paper investigates the development of a fuzzy controller for automated lateral control during emergencies. The performance of the fuzzy controller is presented at 20m/s for a step lane change and a double lane change. The robustness of fuzzy controller is investigated with respect to change in tire parameters and the number of passengers.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• Journal of Oral Medicine and Pain
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• 제25권2호
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• pp.191-203
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• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.92-99
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• 2002

To obtain visual information of a target object, a camera should be placed within the visibility region. As the visibility region is dependent on the relative position of the target object and the surrounding object, the position change of the surrounding object during a task requires recalculation of the visibility region. For a fast computation of the visibility region so as to modify the camera position to be located within the visibility region, we propose a spherical projection method. After being projected onto the sphere the visibility region is represented in $\theta$-$\psi$ spaces of the spherical coordinates. The reduction of calculation space enables a fast modification of the camera location according to the motion of the surrounding objects so that the continuous observation of the target object during the task is possible.

• 치과방사선
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• 제22권1호
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• pp.67-75
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• 1992

Transcranial radiograph is widely used in the diagnosis of craniomandibular disorder because it can be used by the dentist with relative ease in spite of image distortion. But correct information can be obtained only when one know the image change by projection angulation. The author compared the condyle position in the 3 groups of transcranial radiographs (horizontal angulation - 0°, 5°, individualized) with that in the individualized corrected lateral tomogram by objective and subjective evaluation methods. The results were as follows: 1. Among 3 transcranial groups, the condyle position in individualized group showed the highest concordance rate with that in the tomogram group in objective and subjective evaluation methods. 2. Correlation coefficient between individualized transcranial group and tomogram group in objective evaluation method was highest (P≤0.01). 3. Image clarity in individualized transcranial group was worse than that of the other two transcranial groups.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1092-1099
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• 2011

This paper is concerned with the ATO speed profile generation method in the moving block system. The ATO speed profile is calculated using the acceleration limit and the jerk limit to improve ride comfort. In addition, the speed limit and stop distance provided from ATP profile should be considered to ensure safety. In the moving block system, the speed limit and the stop position are frequently changed in real-time. Therefore, the ATO speed profile should be regenerated immediately according to change of the speed limit and the stop position, within the acceleration limit and the jerk limit. In this paper, the ATO speed profile generation method is proposed, which considers not only frequent changes of the speed limit and the stop position but also acceleration limit and jerk limit. Futhermore the simulation result is presented to verify usefulness of this method.

• 한국소음진동공학회논문집
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• 제20권8호
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• pp.761-766
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• 2010

The goal of this study is to analysis natural frequency for different static postures of human leg. To perform this research human leg is modeled by multi-body modeling for the musculoskeletal system. This leg model has biarticular muscles which acting on two joints and the muscles represents some of the major muscles, such as hamstring, of the upper and lower limbs. To obtain each static equilibrium position energy method is employed and to analysis natural frequency linearization method for constrained mechanical system is employed. Static equilibrium position depends on some parameter or condition such as hamstring stiffness or external force. Making a change these parameter the aim of this research can be performed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.141-143
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• 2003

This paper proposes a new sensorless drive system for the trapezoidal Brushless Direct Current (BLDC) motor requiring mechanical position or speed sensor. The proposed method is using only one current sensor For this an indirect rotor position sensing method from the periodically variation DC Link current waveform. DC Link current waveform change from high to low when BLDC commutate status. This algorithm was verified by simulations using MATLAB SIMULINK and experiment.

• Journal of Advanced Marine Engineering and Technology
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• 제29권1호
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• pp.132-139
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• 2005

This paper describes the application of sliding mode control based on the variable structure control(VSC) concept for high-performance position control of an induction servo motor A design method based on external load parameters has been developed for the robust control of AC induction servo drive. Also, a slip frequency vector control with software current control technique has been adopted to achieve fast response of an induction motor drive The position control scheme is comprised of a variable structure controller and slip frequency vector control for inverter fed induction servo motor. Simulated results are given to verify the proposed design method by adoption of sliding mode and show robust control for a change of shaft inertia, viscous friction and torque disturbance.