• International Journal of Aeronautical and Space Sciences
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• v.3 no.1
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• pp.39-49
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• 2002

This paper presents a robust tracker design method that is specific to the trajectories of target aircraft. This method assumes that representative trajectories of the target aircraft are available. The exact trajectories known to the tracker enables the incorporation of the exact data in the tracker design instead of the measurement data. An estimator is designed to have acceptable performance in tracking a finite number of different target trajectories with a capability to trade off the mean and maximum errors between the exact trajectories and the estimated or predicted trajectories. Constant estimator gains that minimize the cost functions related to the estimation or prediction error are computed off-line from an iterative algorithm. This tracker design method is applied to the longitudinal motion tracking of target aircraft.

• The Journal of Information Technology
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• v.3 no.3
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• pp.67-76
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• 2000

Internet user are very important target market in off-line. Also as being activated e-business, they become core target market in on-line. It comes the present question to the business that marketer has to develop the most suitable marketing method by analysis of consumer's purchasing behavior In this study, we analysis internet user's purchasing behavior and consider the way which is the most suitable internet advertisement using an analysis of census.

• Journal of KIISE
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• v.45 no.1
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• pp.86-93
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• 2018

When multiple clients share bandwidth and receive a streaming service, HTTP Adaptive Streaming has a problem in that the bandwidth is measured inaccurately due to the ON-OFF pattern of the segment request. To solve the problem caused by the ON-OFF pattern, the proposed PANDA (Probe AND Adapt) determines the quality of the segment to be requested while increasing the target bandwidth. However, since the target bandwidth is increased by a fixed amount, there is a problem in low bandwidth utilization and a slow response to changes in bandwidth. In this paper, we propose a video quality control scheme that improves the low bandwidth utilization and slow responsiveness of PANDA. The proposed scheme adjusts the amount of increase in the target bandwidth according to the bandwidth utilization after judging the bandwidth utilization by comparing the segment download time and the request interval. Experimental results show that the proposed scheme can fully utilize the bandwidth and can quickly respond to changes in bandwidth.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.323-330
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• 2018

In this paper, design and fabrication of a MSP(Multiple Scattering Points) discriminator for a simulated target measurement using a HRR(High Range Resolution) RADAR are described. The MSP discriminator is designed to provide a reference signal at the installed point on the simulated target in an outdoor test. The MSP discriminator is designed to have a remote control function that can turn the MSP discriminator on and off when the target moves to a remote location. While the MSP discriminator is off, the MSP discriminator is designed to be small enough not to spoil the target's unique RCS. The MSP discriminator consists of RF components in the Ku-band. In order to prevent spreading of the signal, a cable were added to the MSP discriminator to have an appropriate feedback loop delay considering the resolution of the RADAR. The fabricated MSP discriminator provided a reference scattering point as an RCS of approximately 1 dBsm. As a result, by using the MSP discriminator, the physical scattering points of the target were clearly identified in the measured signals with the RADAR.

• Progress in Medical Physics
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• v.27 no.4
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• pp.272-276
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• 2016

To investigate the optimum x-ray tube design for the dental radiology, factors affecting x-ray beam characteristics such as tungsten target thickness and anode angle were evaluated. Another goal of the study was to addresses the anode heel effect and off-axis spectra for different target angles. MCNPX has been utilized to simulate the diagnostic x-ray tube with the aim of predicting optimum target angle and angular distribution of x-ray intensity around the x-ray target. For simulation of x-ray spectra, MCNPX was run in photon and electron using default values for PHYS:P and PHYS:E cards to enable full electron and photon transport. The x-ray tube consists of an evacuated 1 mm alumina envelope containing a tungsten anode embedded in a copper part. The envelope is encased in lead shield with an opening window. MCNPX simulations were run for x-ray tube potentials of 70 kV. A monoenergetic electron source at the distance of 2 cm from the anode surface was considered. The electron beam diameter was 0.3 mm striking on the focal spot. In this work, the optimum thickness of tungsten target was $3{\mu}m$ for the 70 kV electron potential. To determine the angle with the highest photon intensity per initial electron striking on the target, the x-ray intensity per initial electron was calculated for different tungsten target angles. The optimum anode angle based only on x-ray beam flatness was 35 degree. It should be mentioned that there is a considerable trade-off between anode angle which determines the focal spot size and geometric penumbra. The optimized thickness of a target material was calculated to maximize the x-ray intensity produced from a tungsten target materials for a 70 keV electron energy. Our results also showed that the anode angle has an influencing effect on heel effect and beam intensity across the beam.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.45-52
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• 2021

The capital structure is one of the hot financial topics among researchers and scholars. Its importance comes from the fact that capital structure is closely related to companies' ability to meet different stakeholders' needs. A suitable capital structure will boost the business and create a competitive advantage in the context of fierce competition. Many companies choose an optimal debt level based on the trade-off between interest and debt costs. This study aimed to test the existence of trade-off theory in capital structure, the case of Vietnam's real estate companies, which are growing very fast recently. Instead of considering constant optimal leverage to test the trade-off model, we take advantage of the dynamic capital structure determined by growth opportunities, profitability, tax incentives, tangibility, liquidity, and firm size. The dynamic panel data regression was estimated by the system Generalized Method of Moment (Sys-GMM). The empirical evidence showed that real estate companies listed in the Vietnamese stock market might change their leverage toward a target capital structure determined by influential factors in a long-term perspective. In particular, the debt-to-asset ratio will change by approximately 14 percent, positively, in response to the difference between the current debt-to-asset ratio and the dynamic target debt-to-asset ratio.

• Journal of the Korean Ceramic Society
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• v.28 no.3
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• pp.243-251
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• 1991

High-Tc YBa2Cu3O7-x superconducting thin films have been prepared by single-target off-axis RF magnetron sputtering. Optimal ratio of Y : Ba : Cu of the single-target was determined as 1 : 1.65 : 3.35 in order to obtain the stoichiometric films. Tc, crystalline phase, and microstructures of the surface and cross-section of the ex-situ YBa2Cu3O7-x thin films on MgO(100) had a Tc, zero of 80K, and the films on LaAlO3/Si had a Tc, on-set of 90 K and a Tc, zero of 70 K.

• The Journal of Fisheries Business Administration
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• v.34 no.1
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• pp.45-67
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• 2003

Main target of fishing policy was enlargement of fishing catches in Korea after 1960s. This has caused sustainable decrease of the amount on the fisheries resource. In the result, fishing managements in Korea have suffered from aggravation of management. In this research, it is estimated the technical efficiency on Korean Off-shore Stow Nets Fishery that was made publication by Farrel in 1957. According to the analysis, Its were excessive to the gap of technical efficiency among Korean Off-shore Stow Nets Fishing boats. The gaps were excessive not only among each fishing managements but also by tonnage class and by region. Then we can recognize we need the change of Fishing Policy. That is, we should change for main target of fishing policy from enlargement of fishing catches to the policy of Price. And we should consider the supply of standard tonnage boats and specialization of fisheries by regions.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.582-590
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• 2020

This paper presents the results of new error analysis on the veering of marine target with the concept of frequency of occurrence, and shows how to apply the midcourse guidance errors of anti-ship missile. The veering error would be a dominant factor in the midcourse guidance errors with flight time increase. This study suggests the reasonable application method of the veering error based on the characteristics of abnormal error, and describes the tailoring method including trade-off between the midcourse guidance range of veering target and the value of frequency of occurrence on veering error.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.73-74
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• 2023

The purpose of this study is to derive the cause of the quantity difference and present the considerations when take-off rebar quantity based on BIM model by comparing the quantity of rebar based on BIM model with 2D drawing. This research was limited to take-off the quantity of rebars in the building frame work, and after take-off the quantity of rebars by 3D modeling the 2D drawing of the target building with Revit, the quantity difference was compared with 2D-based software. Therefore, when take-off the quantity of rebars based on the BIM model, instead of take-off the existing 2D-based quantity premium proportion, according to general structural consider development length, lap splice length, covering thickness, reinforcing bars and spacing. In the future, this study is expected to contribute to improving the accuracy of BIM-based frame construction quantity take-off.