• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.320-326
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• 1994

The KITSAT-1 (Auguse, 1992) and the KITSAT-2(September, 1993) were successfully launched and operated by the SatRec(Satellite Research Center). Both carry the CCD cameras to monitor the image of the earth. We used the camera bench type automatic equipment in the KSRI(Korea Standards Research Institute) to measure the MTF(Modulation Transfer Function) value of the lens attached to the CCD camera. We measured the tangential MTF and the sagital MTF by varing the f-number and the field angle. According to the result, the light from a point source is focused within one pixel of the CCD chip when the f-number is smaller than 4.0, and the MTF value becomes smaller as the field angle increases.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.25 no.2
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• pp.47-56
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• 2019

Background: The purpose of this study was compare and analyze the Cobb's angle, core muscle strengthening in adolescents with idiopathic scoliosis and provide scientific basis for effectively treating idiopathic scoliosis in the future. Methods: The subjects of this study were 20 members of adolescent girls. Measurement tools were comprised Cobb's angle test, core muscle strengthening test. After 8 weeks of program, both groups had the same measurements as before program start. Results: The results of the study are as follows. First, the experimental group was decreased statistically significantly in Cobb's angle than the control group. Second, Both groups were increased statistically significantly in core muscle strengthening. The experimental group was increased statistically significantly direction in front, back l than the control group. Conclusion: Sling exercise with core exercise was effective in the decrease of Cobb's angle and core muscle strength than general scoliosis exercise in adolescents with idiopathic scoliosis.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.35-40
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• 2000

Teflon-like fluorocarbon thin film was deposited on various substrates by vapor deposition using PFDA (perfluorodecanoic acid). The fluorocarbon films were characterized by static/dynamic contact angle analysis, VASE (Variable-angle Spectroscopic Ellipsometry) and AFM/LFM (Atomic/Lateral Force Microscopy). Based on Lewis Acid/Base theory, the surface energy ($S_{E}$) of the films was calculated by the static contact angle measurement. The work of adhesion (WA) between de-ionized water and substrates was calculated by using the static contact data. The fluorocarbon films showed very similar values of the surface energy and work of adhesion to Teflon. All films showed larger hysteresis than that of Teflon. The roughness and relative friction force of films were measured by AFM and LFM. Even though the small reduction of surface roughness was found on film on $SiO_2$surface, the large reduction of relative friction farce was observed on all films. Especially the relative friction force on TEOS was decreased a quarter after film deposition. LFM images showed the formation of "strand-like"spheres on films that might be the reason far the large contact angle hysteresis.

• The Journal of Korea CHUNA Manual Medicine
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• v.2 no.1
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• pp.121-132
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• 2001

Objectives The present study retrospectively investigated clinical outcome of patients with structual scoliosis during Chuna treatment. Methods : The study population consisted of 34 patients(14 patients of adolescent and 20 patients of adult) who were diagnosised as scoliosis with radiological finding. All patients were treated with Chuna treatment, and after treatment, evaluated with radiological measurement by calculating the scoliosis correction angle from the Initial and follow-up spine AP and lateral views. Also the evaluation of clinical outcome was done twice pre and post treatment during this study. Results : The results were summarized as follows ; 1) The 85.3 percent of patients complained physical pain. and adult group had various painful lesion compared with adolescent group. 2) Adult group had treated $18.0{\pm}7.2$ times and adolescent group treated $13.5{\pm}5.7$ times with Chuna treatment. 3) Scoliotic angle is reduced in 92.9 percent of adolescent group and had all of adult group after Chuna treatment, especially, statistically significance appeared in adult group. 4) Adult group was superior to adolescent group in correctability and scoliotic angle change. 5) Correction effect was better in the group which initial scoliotic angle was lessor, or had more time of treatment. 6) According to grade of vertebral body rotation, scoliotic angle is larger and correctability was lower. Conclusions : Chuna treatment was efficacious against scoliosis. And it is necessary for adolescent scoliosis patient to be more carefully treated and observed.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.69-73
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• 2016

In order to derive reliable propagation models for future millimeter-wave frequency indoor pico-cellular communications systems, accurate reflectivity data of building materials is necessary. The broad variety of building materials and construction codes makes accurate attenuation prediction very difficult without the support of specific construction data or measurements. This paper derives a transmission and reflection coefficient based on 13 GHz to 28 GHz measurement data. Transmission and reflection is measured by applying change in the reception angle of each building material, such as plasterboard. The transmission and reflection coefficient derived shows a correlation between frequency dependence and angle. As a result, as the reception angle is reduced, the reflected angle from the transmitter that could be received increases, showing that there is a correlation. In addition, the fundamental investigations carried out lay the foundation for radio channel-related research, which is essential for the development of future millimeter-wave communications systems.

• Journal of the Optical Society of Korea
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• v.20 no.3
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• pp.381-388
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• 2016

The performance of a staring infrared imaging system can be characterized based on estimating the modulation transfer function (MTF). The slant edge method is a widely used MTF estimation method, which can effectively solve the aliasing problem caused by the discrete undersampling of the infrared focal plane array. However, the traditional slant edge method has some limitations such as the low precision of the edge angle extraction and using the approximate function to fit the edge spread function (ESF), which affects the accuracy of the MTF estimation. In this paper, we propose a modified slant edge method, including an edge angle extraction method that can improve the precision of the edge angle extraction and an ESF fitting algorithm which is based on the transfer function model of the imaging system, to enhance the accuracy of the MTF estimation. This modified slant edge method presents higher estimation accuracy and better immunity to noise and edge angle than other traditional methods, which is demonstrated by the simulation and application experiments operated in our study.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1802-1807
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• 2004

When a construction company builds a high structure, many piles should be driven into the ground by a hammer whose weight is 7,000 Kg in order to make the ground under the structure safe and strong. So, it is essential to determine whether a pile is penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a visual measurement system for pile rebound and penetration movement including vibration using a high-speed line-scan camera and a specially designed mark to recognize two-dimensional motion parameters of the mark using only a line-scan camera. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously

• Journal of KSNVE
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• v.4 no.3
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• pp.295-305
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• 1994

The reflection coefficient of a material at oblique incidence is measured in a free field. The sound pressure distributions are measured at discrete points on two measurement lines and then decomposed into plane wave components by using spatial Fourier transform. The inciedent and reflected plane wave components are obtained from a set of "decomposition equations" of which uses the plane wave propagation theory. Numerical simulations and experiments have been performed to see the effect of finite size of measurement area. To reduce this effect, a window fuction has been performed to see the effects of finite size of mesurement area. To reduce this effect, a window function has been proposed and its effect on the measurement of sound absorbing material property has been studied as well. The reflection coefficient obtained by this method is compared with those obtained from other methods; 2-microphone method in a duct and an expirical equation of which determines the characteristic impedance .rho.c and propagation constant k of a material from flow resistance information.formation.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.3
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• pp.234-239
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• 2010

The utilization of micro-electro-mechanical system (MEMS) gyros and accelerometers in low-level inertial measurement unit (IMU) influences cost effectiveness in a positive way under the condition that device error characteristics are fully calibrated. The conventional calibration process utilizes a rate table; however, this paper proposes a new method for achieving reference calibration data from the natural motion of pendulum to which the IMU undergoing calibration is attached. This concept was validated with experimental data. The pendulum angle measurements correlate extremely well with the solutions acquired from the pendulum equation of motion. The calibration data were computed using the regression method. The whole process was validated by comparing the measurement from the 6 sensor components with the measurements reconstructed using the identified calibration data.

• Bulletin of the Korean Space Science Society
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• 1993.04a
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• pp.18-18
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• 1993

The first sounding rocket in Korea, KSR-4205 has been under the development at Korea Aerospace Research Institute (KARI), and is expected to be launched in 1993 to measure the vertical ozone profile over the Korean Peninsula. The KSR-4205 is expected to provide the first in situ meastulement of ozone concentrations over the Korean Peninsula. An optical ozone detector has been developed at Korea Research Institute of Standards and Science (KRISS), and its calibration has been completed recently. Also, sun-sensor has been developed for measurement of the angle between the sun and the KSR-4205. In this paper, measurement principles of the ozone detector in KSR-4205, its calibration data, ozone measurement procedure and data reduction algoriHun are presented with sample calculations.