• Journal of The Korean Association of Information Education
• /
• v.17 no.1
• /
• pp.23-31
• /
• 2013

Elementary students can easy access to the smartphones and also can have been interested with them. Elementary learning tools to use smartphones are effective at the learning. So, Smartphones learning tools used in scientific experiments, the learning effect would be nice. Elementary school students to learn speed learning areas is a difficult concept. Therefore, the speed of learning application for smartphones is required. In this study, we develop a module for learning speed. This module that use the acceleration sensors of smart phones extract data from a given point in time, calculated by integrating speed. In addition, the distance is calculated. Students experiment at speed so that you can immediately see the changes in the module proposed in this study has the advantage. Measure the speed of the existing tools students again need to calculate the speed of a hassle to experiment and measured data values are separated. That the module proposed in this study is expected to be able to overcome the disadvantage.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.3
• /
• pp.281-290
• /
• 2007

In this paper, the dynamic behavior of a 12m plate girder railway bridge is analyzed using the commercial FEM program. A time history load is applied to a standard train load via the shape function ofthe beam element. In addition, lateral behavior characteristics were simulated using the Klingel sine movement. A feasibility study of the FEM program and an analysis were performed by comparing the displacement and the acceleration, from the experimental data and the results of the FEM analysis. the time history of the lateral and vertical displacements are reflected in the experimental results. Six kinds of reinforcements were studied from the effects of the displacement and the acceleration. The RF-1 model that was applied to the upper lateral bracing system, and the RF-3 model that reinforced the plate, turned out to be the most effective reinforcement methods with respect to weight limits and construction simplification.

• Journal of Yeungnam Medical Science
• /
• v.7 no.2
• /
• pp.115-120
• /
• 1990

Scatter-air ratios are used for the purpose of calculating scattered dose in the medium. The computation of the primary and the scattered dose separately is particularly useful in the dosimetry of irregular fields with shielding block in radiation field, dose distribution of scattered radiation using 18MeV Linear accelerator and Co-50 teletherapy measured. The effect of scattered radiation dose by protecting block was been ignored in radiation therapy, 2-3% of scattered radiation may be 90-200 cGy which could be influence vitial complications such as cataract, oligospermia or sterility. So that exect calculation of such scattered radiation especially for large field $\bar{c}$ small protection of vitial organ is very important. The purpose of this article is to calculate scattered radiation by protecting block exactly for irregular field $\bar{c}$ Linac or Co-60 irradiation and to applicate these data in clinical radiation field. Authors could obtain following results. 1. The lesser angle between shielding block showed more scattered radiation. 2. With decreasing distance between shielding blocks, the dependent of scattered radiation were increased. 3. Output of 18MeV Linear accelerator and Co-60 was related linear proportion on field size, but independent according to the size of shielding block in 18MeV Linear accelerator.

• Journal of Korea Multimedia Society
• /
• v.16 no.1
• /
• pp.67-74
• /
• 2013

In this paper, we propose the pointing and correction algorithm for optimized performance based on Bluetooth communication. The error from the accelerometer sensor's output must be carefully managed as the accelerometer sensor is more sensitive to data change compared to that of the gyroscope sensor. Thus, we minimize the noise by applying the Kalman filter to data for each axis from the accelerometer. In addition, we can also obtain effect compensating the hand tremor by applying the Kalman filter to the data variation for x and y. In this study, we extract data through the Quaternion mapping process on data from the accelerometer and gyroscope. In turn, we can obtain a tilt compensation by applying a compensation algorithm with acceleration of the gravity of the extracted data. Moreover, in order to correct the inaccuracy on smart sensor due to the rapid movement of a device, we propose a adaptive pointing and correction algorithm using the genetic approach to generate the initial population depending on the user.

• Journal of the Korean Society of Radiology
• /
• v.5 no.5
• /
• pp.223-229
• /
• 2011

When negative electron in x-ray tube is accelerated in to a high speed and then the currency of the electron is blocked by the target, x-ray happens by the conversion of the energy. The real area where the fast accelerated electron collides to a target area is called actual focal spot. When the string focused size is observed at the central ray side, where the direction x-ray comes out, the size seems to be reduced. This focus is called effective focal spot. According to radiation angle of x-rays tube, the degree of the negative pole side presents higher value than inclination, the amount of exposed radiation that patient receives differs by the angle of positive pole, which means effective focal spot is the variable. This paper presents the correlation between size of effective focal spot and amount of exposed radiation to the patient by it, and effective research for homogenized dose dispersion by the size of effective focal spot. In conclusion, following the focal size, effective range which was -8cm ~ 0 cm on average, was found and average dose rate was 0.019 R/min. Through this range, for patients with small radiation exposure, image with good density and resolution in aspect of diagnosing will be able to be obtained.

• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.33-38
• /
• 2008

본 논문은 핀홀 카메라 모델에 의해 렌더링한 컬러와 깊이 이미지의 후처리에 의한 실시간 필드심도 렌더링 방법을 제안한다. 필드심도 렌더링은 최근의 향상에도, 큰 스케일의 블러링에 필요한 계산 때문에 실용적으로 사용되지 못해 왔다. 본 방법은 이방성 가우시안 필터로 생성된 밉맵 이미지들을 비선형으로 보간하여 필드심도 효과에 필요한 블러링을 수행한다. 모든 계산 과정은 GPU로 가속되어, 안정적이고 확장 가능한 실시간 수행 성능을 확보한다. 또한, 후처리 방식의 두 가지 결점인 강도 누출과 블러링 불연속성을 이방성 가우시안 필터와 블러링 정도를 부드럽게 하여 제거한다. 본 방법은 뛰어난 실시간 성능과 함께 고품질의 필드심도 효과를 생성한다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.473-476
• /
• 2011

본 논문에서는 열차와 교량의 상호작용과 주행속도에 의해 결정되어지는 진동지속시간과 차체연직가속도 증폭효과를 고려하여 철도교량의 진동사용성 허용처짐을 제시하고자 하였다. 열차가 교량을 통과할 때의 처짐 형상을 사인파로 가정하고 열차와 교량의 상호작용을 진동전달함수로 표현하여 철도교량의 진동 사용성 허용처짐을 유도하였다. 그리고 진동지속시간을 고려하기 위해 연직가속도 허용기준으로서 진동지속시간을 고려한 교량구조물의 진동사용성기준을 사용하였다. 매개변수연구를 통하여 열차 주행속도의 증가에 비례하여 차체연직가속도는 증가하지만 교량최대변위의 변화는 미미함이 확인됨으로 인하여 차체연직가속도 증가와 동반하여 연직가속도 허용기준역시 증가하는 것을 보정할 필요가 있을 것으로 판단하였다. 따라서 전개된 철도교량의 진동사용성 허용처짐식에 매개변수연구를 통하여 가정한 가속도 증폭계수를 적용하여 열차의 증속에 의한 가속도증폭효과를 고려하였다.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.11 no.3
• /
• pp.231-238
• /
• 2017

In this paper, we propose a method of analyzing exercise behavior to increase health care and exercise effect in personal fitness. In this study, a user wears a band-shaped acceleration sensor, an angular velocity sensor, and a motion sensor equipped with a geomagnetic module. Using the technique presented in this paper, we analyzed the motion of three resistive exercises which is consistent with previous studies. We have acquired a technique for processing personalized exercise information from the data generated in the resistive exercise situation.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.331-334
• /
• 2010

본 논문에서는 준능동 TMD가 설치된 고층건물의 풍응답을 효과적으로 저감시키기 위하여 다목적 유전자알고리즘(MOGA)을 이용한 퍼지관리제어기를 개발하였다. 퍼지관리제어기는 하위제어기인 그라운드훅(groundhook) 제어알고리즘과 스카이훅(skyhook) 제어알고리즘에 의해서 결정된 제어명령을 적절하게 하나로 합치는 역할을 한다. 다목적 유전자알고리즘의 최적화 과정에서 75층의 가속도 응답과 준능동 TMD의 변위응답을 목적함수로 사용하였다. 다목적 유전자알고리즘 최적화과정을 통하여 퍼지관리제어기의 파레토 최적해집합을 효과적으로 얻을 수 있었다. 다목적 유전자알고리즘에 의하여 개발된 퍼지관리제어기는 가중합방법의 제어기보다 매우 우수한 성능을 나타내었다.

• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.537-540
• /
• 2016

유체역학적 추력 방향 제어(Fluidic Thrust Vector Control) 방법 중 하나인 동축류 제어 유동 분사를 이용한 추력 방향 제어(Co-flow Thrust Vector Control)의 작동 특성에 대해서 연구하였다. 이 제어 방법은 점성 유동이 벽면에 부착되어 흐르는 코안다 효과(Coanda Effect)를 이용하여 주 유동을 편향 시키는 방법으로서 그 편향각은 이러한 제어 유동 노즐 출구의 플랩 형상에 영향을 받는 것으로 알려져 있다. 이 연구에서는 출구 플랩 형상을 여러 가지로 바꾸어 가며 주 유동의 전압력 300kPa일 때 제어 유동의 편향각이 포화되는 제어유동의 전압력을 측정하였다. 그 결과 쐐기형 플랩의 각도가 증가할수록 포화 영역에서의 편향각은 증가하며 그 각은 플랩의 각도와 일치한다. 그러나 각도가 증가할수록 제어 유동이 플랩의 벽면을 지나면서 팽창파에 의해 가속되어 충격파을 발생시키게 되고 이 충격파는 주 유동에게까지 전파되어 주 유동 제트의 속도를 감소시킨다.