• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.201-205
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• 2007

This paper proposes a link model that can provide the spacial position along the surface of the earth as an information or data using ePosition ID through the Internet. Moreover, to support the information service of maritime position, it needs the ENC linked technique based on S-57 that is an IHO transfer standard for digital hydrographic data. Therefore, it designs the linked model for applying and utilizing the ePosition technology with ENC data, as well as supplementing the base technology in applying them to marine related fields. As a study method, this paper first analyses ENC data model and structure, and converses for processing of ENC file to ePosition data. Finally, it derives the interconnection method with ePosition database and shows the ePosition service application based on the linked ENC data and its validity.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.697-702
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• 2022

For imaging in positron emission tomography(PET), it is necessary to measure the position of the scintillation pixel interacting with the gamma rays incident on the detector. To this end, in the conventional system, a flood image of the scintillation pixel is obtained, the imaged area of each scintillation pixel is separated, and the position of the scintillation pixel is specified and acquired as a digital signal. In this study, a deep learning method was applied based on the signal formed by the photosensor of the detector, and a method was developed to directly acquire a digital signal without going through various procedures. DETECT2000 simulation was performed to verify this and evaluate the accuracy of position measurement. A detector was constructed using a 6 × 6 scintillation pixel array and a 4 × 4 photosensor, and a gamma ray event was generated at the center of the scintillation pixel and summed into four channels of signals through the Anger equation. After training the deep learning model using the acquired signal, the positions of gamma-ray events that occurred in different depth directions of the scintillation pixel were measured. The results showed accurate results at every scintillation pixel and position. When the method developed in this study is applied to the PET detector, it will be possible to measure the position of the scintillation pixel with a digital signal more conveniently.

• PNF and Movement
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• v.19 no.2
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• pp.279-285
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• 2021

Purpose: This study aimed to develop new digital navicular drop test (ND-NDT) equipment and to determine its validity and reliability. Methods: A total of 24 healthy male and female adults, who fully understood the purpose of the study and gave consent to participate in the study, were selected as participants. The NDT and ND-NDT were conducted in the dominant foot of the participants in a random order. For the NDT, the position of the navicular bone was marked with a pen first; then, the height of the navicular bone from the ground was measured in both sitting and standing positions. For the ND-NDT, after the sticker-type reflection markers were attached to the position of the navicular bone, the height of the navicular bone from the ground was measured in both sitting and standing positions. To assess the validity of the diagnostic tests, the same examiner measured the height of the medial longitudinal arch (MLA) three times in both the sitting and standing positions. To assess the inter-rater reliability of the ND-NDT, three examiners, in a random order, attached the sticker-type reflection markers to the position of the navicular bone and then measured the height of the MLA in both positions. Results: In the sitting position, the Pearson correlation coefficient (r) between the two diagnostic tests was very high (r = 0.97) and statistically significant. In the standing position, the Pearson correlation coefficient (r) between the two tests was 0.95, which was also statistically significant. The ICC_2,1 values in the sitting and standing positions were 0.93 and 0.95, respectively, indicating significantly high inter-rater reliability. Conclusion: The ND-NDT equipment showed very high diagnostic validity, as well as excellent inter-rater reliability, indicating the clinical usefulness of the equipment as a diagnostic system for confirming pes planus.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.2
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• pp.1-9
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• 2008

The objective of the study is 10 know the relation of landslide occurrence with using TPI (Topographic Position Index) in the Pyungchang County. Total 659 landslide scars were detected from aerial photographs. To analyze TPI, 100m SN (Small-Neighborhood) TPI map, 500m LN (Large-Neighborhood) TPI map, and slope map were generated from the DEM (Digital Elevation Model) data which are made from 1 : 5,000 digital topographic map. 10 classes clustered by regular condition after overlapping each TPI maps and slope map. Through this process, we could make landform classification map. Because it is only to classify landform, 7 classes were finally regrouped by the slope angle information of landslide occurrence detected from aerial photography analysis. The accuracy of reclassified map is about 46%.

• Journal of the Korean Society of Visualization
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• v.10 no.3
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• pp.11-15
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• 2012

Inertial migration phenomena of phytoplankton in pipe flows were investigated using a digital holography technique. As the Reynolds number increases, the microorganisms suspended in a pipe flow are focused at a certain radial position which is called equilibrium position or pinch point. In this study, the effects of the size of microorganism and Reynolds number in the range of 1 < Re < 78 on the inertial migration were investigated and the results are compared with those for solid particles under similar experimental conditions. As a result, the equilibrium position for the elastic microorganisms is not so distinct, compared to the solid particles. This results from deformation of elastic body shape caused by shear-gradient of surrounding flow.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.148-150
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• 1988

The output characteristics of VSI by transistor depend upon bias signal with drive circuit. As the CTI is one of the VSI, takes case PWM output voltage. This Inverter operation is based upon position and negative of sinusoldal PWM signal by carrier triangular wave and compared sine one. Besides, the Inverter operation system required digital signal for microprocessor, sampling method of Inverter driver signals study for get rid of generated signal is error. In the paper, the method of 3 level PWM signal for CTI was studied. This method of signals depend upon caculated switching position of natural sampling with $10^{-6}$ modulation error for time flowchart programs.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.121-130
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• 2000

A practical method is proposed to improve hit probability of the digital gun fire control system, when the measured rate of the tracking sensor becomes biased under some operational situation. For ground moving target it is shown that the well-known Kalman filter which uses position measurement only can be optimally used to eliminate the rate bias error. On the other hand, for 3D moving aircraft we present a new algorithm which incorporate FIR-type filter, which uses position and rate measurement at the same time, and the fixed-lag smoother using position measurement only, and show that it has the optimal performance in terms of both estimation accuracy and response time.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.433-434
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• 2012

In this paper, we developed the algorithm which tracking the vehicle and deciding the moment of dumping in landfills. We first trace the position of vehicle using the difference image between current image and background image and then we decide the stop point from the shape of vehicle route and detect the dumping point by comparing the dumping image with the image that vehicle is stopping.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.3
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• pp.251-259
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• 2005

A discrete time model reference adaptive control has been applied in order to compensate the nonlinear friction characteristics in a hydraulic proportional position control system. As nonlinear friction, static and coulomb friction forces are considered and modeled as dead zone and external disturbance respectively. The model reference adaptive control system consists of a cascade combination of the dead zone. external disturbance and linear dynamic block. For adaptive control experiment. the DSP(Digital Signal Processor) board has been interfaced the hydraulic proportional position control system. The experimental results show that the MRAC(Model Reference Adaptive Control) for compensation of static and coulomb friction are very effective.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.266-275
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• 2008

The sensorless speed control technique for BLDC motor using digital IP control is proposed in this paper for advanced speed characteristic which is robust to motor parameters and load variations. The sensorless drive of BLDC motor using terminal voltages is affected by load or speed because it uses analog filters to estimate the rotor position. For this reason, the robust speed controller with the accurate rotor position estimator is needed for sensorless control which is robust to load and insensitive to motor parameters. The constant speed robust to load variation and the stable sensorless control of BLDC motor robust to the increase or decrease of speed with constant load is implemented using digital IP control in this paper. The validity to these is established with experimentation.