• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1100-1106
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• 2012

This paper has presented the analysis of the micro-Doppler signatures scattered from the blades of the rotating propeller using the modified HHT method, one of the joint time-frequency analysis methods. The field scattered from the blade edge of the propeller was calculated using equivalent current method(ECM). After the acquisition of the scattered field data in the time domain, the modified HHT method was applied to analyze the micro-Doppler signature. The analysis results showed not only a good agreement with the realistic dynamic characteristic of the blade but also sinusoidally varing characteristics of the micro-Doppler signatures generated from rotating objects. It could be concluded that the joint time-frequency analysis via the modified HHT provided the discriminative characteristics for recognizing a small aircraft target with small RCS value.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.443-446
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• 2005

The shear strength equations of the joint with RC column and steel beam are used the proposed equations of ASCE, Kanno and AIJ but there are not applied variable joint details. Until now the variable experimental studies are practiced but the studies of predicted shear strength equation are not integrated and only the applicable equations to each case are proposed. The purpose of this study is statistical analysis for the proposed equations applied existing experiments. The proposed equations are ASCE, Kanno, M-Kanno, AIJ and M-AIJ. The 47 of shear failure experiments are used in this study The consequence is that the Kanno's equation is very analogized with the experimental result but ASCE equation underestimates about 42$\%$. AIJ and M-AIJ are not proper equations for estimating the shear strength of RCS joint.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.3
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• pp.204-212
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• 2020

For general target tracking works by receiving a set of measurements from sensor. However, if the SNR(Signal to Noise Ratio) is low due to small RCS(Radar Cross Section), caused by remote small targets, the target's information can be lost during signal processing. TBD(Track Before Detect) is an algorithm that performs target tracking without threshold for detection. That is, all sensor data is sent to the tracking system, which prevents the loss of the target's information by thresholding the signal intensity. On the other hand, using all sensor data inevitably leads to computational problems that can severely limit the application. In this paper, we propose an iterative Joint Integrated Probabilistic Data Association as a practical target tracking technique suitable for a low SNR multi-target environment with real time operation capability, and verify its performance through simulation studies.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.232-236
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• 2001

In this paper, we consider the problem of estimation of average radar cross section (RCS) for Swerling 1 fluctuation model, based on the maximum likelihood (ML) estimation method. In a mathematical development we take into account the event that target strength is lower than detection threshold, or the target is not detected. Our ML estimation for the SWR uses the score function that is the joint probability-pdf of the events and random variables. The solution to the ML estimation reduces to an expression in the from of a contraction mapping. The computational efficiency of the contraction mapping theorem is significant in computing the ML estimation as compared with other root-finding algorithms fur most radar tracking conditions.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.474-481
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• 2017

This paper presents a multiple target tracking system using Normalized Rayleigh likelihood of amplitude information of target. Although many studies of Radar systems using amplitude information have been studied, they are focused on single target tracking. This paper proposes the multiple target tracking using amplitude information as well as kinematic information from Radar sensor. The amplitude information are applied in generating the association probability of joint probabilistic data association(JPDA) algorithm through the normalized Rayleigh likelihood. It is verified that the proposed system can enhance the track maintenance and tracking accuracy, especially, in the target crossing case.

• Clinical Pain
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• v.20 no.2
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• pp.99-104
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• 2021

Objective: To confirm the safety of Intra-articular (IA) injection on the ipsilateral adhesive capsulitis (AC) after breast cancer surgery. Methods: Between January 2017 and May 2020, we retrospectively studied 29 patients after breast cancer surgery who underwent IA injection in the glenohumeral joint for AC in aseptic procedure. Results: There were no side effects or complications such as lymphedema or cellulitis in the patients. There was a significant improvement in pain score and range of motion (ROM) at the 1st, 3rd, and 6th months visits compared to the baseline (p<0.05). The presence or absence of axillary lymph node dissection and radiation therapy had no significant difference in improvement of ROM. But, in rotator cuff syndrome (RCS) group, there was a significant difference in improvement of shoulder IR in patients without RCS. Conclusion: IA Injection on the ipsilateral AC after breast cancer surgery was safe and even effective to improve pain and shoulder ROM. Ipsilateral IA injection can be a good treatment for breast cancer surgery patients suffering from AC.

• Steel and Composite Structures
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• v.45 no.1
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• pp.101-118
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• 2022

The seismic performance of the reinforced concrete (RC) special-shaped column to steel beam connections with steel jacket used in the RC column to steel beam fabricated frame structures was investigated in this study. The three full-scale specimens were subjected to cyclic loading. The failure mode, ultimate bearing capacity, shear strength capacity, stiffness degradation, energy dissipation capacity, and strain distribution of the specimens were studied by varying the steel jacket thickness parameters. Test results indicate that the RC special-shaped column to steel beam connection with steel jacket is reliable and has excellent seismic performance. The hysteresis curve is full and has excellent energy dissipation capacity. The thickness of the steel jacket is an important parameter affecting the seismic performance of the proposed connections, and the shear strength capacity, ductility, and initial stiffness of the specimens improve with the increase in the thickness of the steel jacket. The calculation formula for the shear strength capacity of RC special-shaped column to steel beam connections with steel jacket is proposed on the basis of the experimental results and numerical simulation analysis. The theoretical values of the formula are in good agreement with the experimental values.