• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권7호
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• pp.2420-2433
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• 2014

Fusing the scores of multibiometrics is a very promising approach to improve the overall system's accuracy and the verification performance. In recent years, there are several approaches towards studying score level fusion of several biometric systems. However, most of them does not consider the genuine and imposter score distributions and result in a higher equal error rate usually. In this paper, a novel score level fusion approach of different biometric systems (dual iris, thermal and visible face traits) based on $Acz{\acute{e}}l$-Alsina triangular norm is proposed. It achieves higher identification performance as well as acquires a closer genuine distance and larger imposter distance. The experimental tests are conducted on a virtual multibiometrics database, which merges the challenging CASIA-Iris-Thousand database with noisy samples and the NVIE face database with visible and thermal face images. The rigorous results suggest that significant performance improvement can be achieved after the implementation of multibiometrics. The comparative experiments also ascertain that the proposed fusion approach outperforms the state-of-art verification performance.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.25-25
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• 2005

• 한국초전도ㆍ저온공학회논문지
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• 제14권2호
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• pp.24-27
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• 2012

The superconducting coil system is one of the most important components in Korea Superconducting Tokamak Advanced Research (KSTAR), which has been operated since 2008. $Nb_3Sn$ and NbTi superconductors are being used for cable-in-conduit conductors (CICCs) of the KSTAR toroidal field (TF) and poloidal field (PF) coils. The CICCs are cooled by forced-flow supercritical helium about 4.5 K. The temperature, pressure and mass flow rate of the supercritical helium in the CICCs are interacting with each other during the operation of the coils. The complicate behaviors of the supercritical helium have an effect on the operation and the efficiency of the helium refrigeration system (HRS) by means of, for instance, pressure drop. The hydraulic characteristics of the supercritical helium have been monitored while the TF coils have stably achieved the full current of 35 kA. In other hands, the PF coils have been operated with various pulsed or bipolar mode, so the drastic changes happen in view of hydraulics. The heat load including AC loss on the coils has been analyzed according to the measurement. These activities are important to estimate the temperature margin in various PF operation conditions. In this paper, the latest hydraulic behaviors of PF coils during KSTAR operation are presented.

• 대한기계학회논문집
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• 제16권11호
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• pp.2021-2032
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• 1992

본 연구에서는 이동 로보트의 구동모터들의 회전수를 측정하는 두 개의 엔코 더와 로보트의 회전각 속도를 측정하는 자이로센서를 결합하여 주행중인 로보트의 자 세를 정확하게 추정할 수 있는 복수센서 시스템의 신호처리회로 및 알고리즘을 개발하 고 자이로센서의 측정방정식을 모델링하기 위하여 성능시험을 수행하였다. 그리고 확률이론을 유도된 측정방정식에 적용하여 본 복수센서 시스템의 출력 신호들을 효율 적으로 융합할 수 있는 센서데이터 융합알고리즘을 개발하여 사용된 측정센서들에 내 재하는 측정오차의 영향을 최소로 줄이고자 하였다. 제안된 융합알고리즘의 타당성 을 검증하기 위하여 주행실험을 수행하여 이동 로보트의 실제자세와 본 융합알고리즘 의 결과를 비교하였다.

• 한국산업정보학회논문지
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• 제20권6호
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• pp.47-56
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• 2015

다중센서 시스템에서 센서 바이어스를 제거하는 센서 등록 과정은 각각의 센서가 공통된 좌표를 갖게 하기 위해 반드시 필요하다. 만약 센서 등록 과정을 적절하게 처리하지 않는다면, 거대한 추적 에러 또는 같은 목표물을 향한 다수의 허수 트랙이 발생하게 되어 추적에 실패하게 된다. 특히, 발사체 추적에 있어서 각각의 추적 장비는 반드시 적절한 센서등록 과정을 거쳐야 하며, 이 후 다중센서 융합알고리즘을 활용하면 발사체 추적 성능을 높이고 다중 추적 시스템에 정확한 지향입력으로 활용 가능하게 된다. 본 논문에서는 실시간 바이어스 추정/제거 알고리즘과 비동기 다중 센서 융합 기법을 제안하였다. 제안된 바이어스 추정 알고리즘은 GPS와 다중 레이더 간의 의사 바이어스 측정치를 활용하였고, 비동기 센서 융합알고리즘 적용을 통해 추적 성능을 향상하였다.

• 대한인간공학회지
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• 제30권1호
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• pp.195-202
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• 2011

Objective: The aim of this study is to investigate and review the previous researches about objective measuring fatigue caused by visual stimuli. Also, we analyze possibility of alternative visual fatigue measurement methods using facial expression recognition and gesture recognition. Background: In most previous researches, visual fatigue is commonly measured by survey or interview based subjective method. However, the subjective evaluation methods can be affected by individual feeling's variation or other kinds of stimuli. To solve these problems, signal and image processing based visual fatigue measurement methods have been widely researched. Method: To analyze the signal and image processing based methods, we categorized previous works into three groups such as bio-signal, brainwave, and eye image based methods. Also, the possibility of adopting facial expression or gesture recognition to measure visual fatigue is analyzed. Results: Bio-signal and brainwave based methods have problems because they can be degraded by not only visual stimuli but also the other kinds of external stimuli caused by other sense organs. In eye image based methods, using only single feature such as blink frequency or pupil size also has problem because the single feature can be easily degraded by other kinds of emotions. Conclusion: Multi-modal measurement method is required by fusing several features which are extracted from the bio-signal and image. Also, alternative method using facial expression or gesture recognition can be considered. Application: The objective visual fatigue measurement method can be applied into the fields of quantitative and comparative measurement of visual fatigue of next generation display devices in terms of human factor.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.173-180
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• 2000

During the last decade many researches have been working on multiple target tracking problem in the area of radar application, Various approaches have been proposed to solve the tracking problem and the concept of sensor fusion was established as an effort. In this paper utilization of geographic information for ground target tracking is investigated and performance comparison with the results of applying sensor fusion is described. Geographic information is used in three aspects: association masking target measurement and re-striction of removing true target. Simulation results indicate that using two sensors shows better performance with respect to tracking but a single with geographic information is a winner in reducing the number of false tracks.

• 한국철도학회논문집
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• 제8권2호
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• pp.155-160
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• 2005

We propose a tram position estimation method for automatic train control system. The accurate train position should be continuously feedback to control system for safe and efficient operation of trains in railway. In this paper, we propose the sensor fusion method integrating a tachometer, a transponder, and a doppler sensor far estimation of train position. The external sensors(transponder, doppler sensor) are used to compensate for the error of internal sensor (tachometer). The Kalman filter is also applied to reduce the measurement error of the sensors. Simulation results are then presented to verify the usefulness of the proposed method.

• 한국항행학회논문지
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• 제27권6호
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• pp.884-887
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• 2023

Recently, research has been actively conducted to overcome the limitations of high-priced single sensors and reduce costs through the convergence of low-cost multi-variable sensors. This paper estimates state variables through asynchronous Kalman filters constructed using CVXPY and uses Cvxpylayers to compare and learn state variables estimated from CVXPY with true value data to estimate filter parameters of low-cost sensors fusion.

• Journal of Korean Neurosurgical Society
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• 제63권2호
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• pp.228-236
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• 2020

Objective : It can be assumed that the progression of scoliosis in the juvenile period will increase the asymmetry in the rib cage, and thus will contribute to an increase in the breast asymmetry (BA) in the future. We are looking for answers to the questions; "How will the breasts look with respect to each other and what is the possibility of developing BA in the early follow-up period following the early surgical treatment and final fusion surgery of juvenile idiopathic scoliosis (JIS)?" For this reason, in this study, we aimed to evaluate the breast asymmetries of patients in the period after the final fusion. Methods : Following growing rod treatment, final fusion was achieved in 12 females with JIS. We used the anthropomorphic measurement of the modified BREAST-V formula to assess whether there was an asymmetry between the breasts after an average of 4.8 years (2-11) following final fusion. Results : In comparison, the mean volume of the left breast (222.4 mL [range, 104.1-330.2]) was larger than the mean volume of the right breast volume (214.5 mL [range, 95.2-326.7]) (p=0.034). The left breast was larger in 75% of the patients. BA was observed in 50% of the patients. No correlation was detected between the Cobb angle of the patient after final fusion and BA (p=0.688). Conclusion : In the late follow-up period, BA was detected in 50% of the patients with JIS who achieved final fusion after treatment with growing rod. In majority of the patients, left breast was larger. The patients with JIS and their families can be informed prior to the operation about the probability of BA seen in the follow-up period after fusion.