• Journal of Communications and Networks
• /
• 제15권3호
• /
• pp.245-251
• /
• 2013

This paper addresses the issue of time-difference-of-arrival (TDOA) estimation for complex noncircular signals. First, under the wide-sense stationary assumption, we derive the maximum likelihood (ML) estimator and the Cramer-Rao lower bound for Gaussian noncircular signals in Gaussian circular noise. The ML estimator uses the second-order statistics information of a noncircular signal more comprehensively when compared with the cross-correlation (CC) and the conjugate CC estimators. Further, we present a scheme to modify the traditional signal-selective TDOA methods for noncircular signals on the basis of the cyclostationarity of man-made signals. This scheme simultaneously exploits the information contained in both the cyclic cross-correlation (CCC) and the conjugate CCC of a noncircular signal.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제11권4호
• /
• pp.344-350
• /
• 2011

Higher integrated density in 3D ICs also brings the difficulties of routing, which can cause the routing failure or re-design from beginning. Hence, precise congestion estimation at the early physical design stage such as floorplan is beneficial to reduce the total design time cost. In this paper, an effective estimation method of routing congestion is proposed for 3D ICs at floorplan stage. This method uses synthesized virtual signal nets, power/ground network and clock network to achieve the estimation. During the synthesis, the TSV location is also under consideration. The experiments indicate that our proposed method had small difference with the estimation result got at the post-placement stage. Furthermore, the comparison of congestion maps obtained with our method and global router demonstrates that our estimation method is able to predict the congestion hot spots accurately.

• 전기학회논문지
• /
• 제62권3호
• /
• pp.387-394
• /
• 2013

A travel aid system for the visually impaired person is proposed by providing the position and heading information. The position and heading information is obtained from range difference localization estimator, and the information is notified to the visually impaired person by using braille display system. For the precise estimation of the position and heading information, we apply recently developed linear localization estimator which utilizes the instrumental variable method and the state augmentation method. The estimation results are compared with well-known Kalman filter through experiment.

• Journal of Magnetics
• /
• 제19권2호
• /
• pp.174-180
• /
• 2014

In this paper, a new and simple method is proposed to quickly estimate the induced electric field in the human child exposed to a 100 kHz-10 MHz magnetic field, for the sake of electromagnetic field (EMF) safety assessment. The quasi-static finite-difference time-domain (FDTD) method is used to calculate the induced electric fields in high resolution 3D human child models with various body size parameters, in order to derive the correction factor for the estimation equation. The calculations are repeated for various frequencies and incident angles of the magnetic field. Based on these calculation results, a new and simple estimation equation for the 99th percentile value of the body electric field is derived that depends on the body size parameters, and the incident magnetic field. The estimation errors were equal to or less than 5.1%, for all cases considered.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제18권2호
• /
• pp.438-455
• /
• 2024

Recently, many unsupervised learning-based models have emerged for Just Noticeable Difference (JND) estimation, demonstrating remarkable improvements in accuracy. However, these models suffer from a significant drawback is that their heavy reliance on handcrafted priors for guidance. This restricts the information for estimating JND simply extracted from regions that are highly related to handcrafted priors, while information from the rest of the regions is disregarded, thus limiting the accuracy of JND estimation. To address such issue, on the one hand, we extract the information for estimating JND in an Adversarial Complementary Learning (ACoL) way and propose an ACoL-JND network to estimate the JND by comprehensively considering the handcrafted priors-related regions and non-related regions. On the other hand, to make the handcrafted priors richer, we take two additional priors that are highly related to JND modeling into account, i.e., Patterned Masking (PM) and Contrast Masking (CM). Experimental results demonstrate that our proposed model outperforms the existing JND models and achieves state-of-the-art performance in both subjective viewing tests and objective metrics assessments.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제31권2호
• /
• pp.173-181
• /
• 2004

본 논문에서는 움직이는 카메라로부터 획득한 연속영상에서 이동물체를 자동으로 검출하고 추적하는 시스템을 제안한다. 제안된 방법은 크게 이동물체 검출과 추적과정으로 나뉘어진다. 이동물체는 BBME(block-based motion estimation)와 DD(double difference)를 통합한 방법을 이용하여 검출된다. 검출된 이동물체는 히스토그램 백 프로젝션을 통하여 분할되며, 히스토그램 인터섹션과 XY-프로젝션을 사용하여 대상물체를 정합하고 추적된다. 본 논문에서는 컴퓨터 모의실험을 통하여 제안된 방법이 움직이는 카메라로부터 획득된 영상에서 이동물체를 검출하고 큰 오차 없이 추적함을 보였다.

• Journal of the Korean Statistical Society
• /
• 제25권4호
• /
• pp.603-611
• /
• 1996

In this article we consider a sequential procedure for the fixed width interval estimation of the means of two mutually independent linear processes. It is shown that the proposed stopping rule is asymptotically efficient as in iid samples (cf. Robbins, Simons and Starr(l967)).

• 한국군사과학기술학회지
• /
• 제14권4호
• /
• pp.590-597
• /
• 2011

The IDRS provides detection, classification and bearing/range estimation by performing wavefront curvature analysis on an intercepted active transmission from target. Especially, a estimate of the target bearing/range that significantly affects the optimal operation of own submarine is required. Target bearing/range can be estimated by wavefront curvature ranging which use the difference of time arrival at sensors. But estimation ambiguity occur in bearing/range estimation due to a number of peaks caused by high center frequency and limited bandwidth of the intercepted active transmission and distortion caused by noise. As a result the bearing/range estimation performance is degraded. To estimate target bearing/range correctly, bearing/range estimation method that eliminate estimation ambiguity is required. In this paper, therefore, for wavefront curvature ranging, NLS cost function with curve fitting method is proposed, which provide robust bearing/range estimation performance by eliminating estimation ambiguity. Through simulation the performance of the proposed bearing/range estimation methods are verified.

• 한국음향학회지
• /
• 제28권5호
• /
• pp.461-470
• /
• 2009

본 연구에서는 CPSP (Cross Power Spectrum Phase) 함수를 이용한 프레임 기반의 TDOA (Time Difference of Arrival) 추정시 나타나는 문제점들을 분석하고 연구하였다. 구형 윈도우함수를 이용해서 음성신호의 프레임을 추출할 때 나타나는 스펙트럼 누설현상은 CPSP 스펙트럼의 추정을 부정확하게 한다. 또한 스펙트럼 누설을 줄이기 위하여 구형이 아닌 다른 윈도우함수를 사용하여 프레임을 추출하면 프레임의 끝부분에서 발생하는 윈도우함수 가중치의 불일치 때문에 신호를 왜곡시킨다. 이 문제점들은 CPSP 기반의 TDOA 추정성능을 감소시킨다. 본 논문에서는 음성신호의 프리엠퍼시스를 이용하여 이러한 문제점들을 완화시키는 방법을 제안한다. 프리엠퍼시스된 음성신호의 다이나믹 레인지를 줄여줌으로써 스펙트럼 누설을 감소 시킨다. 제안한 프리엠퍼시스 방법을 검증하기 위하여, 다양한 잡음 및 잔향환경에서 TDOA 추정실험을 수행하였다. 실험결과 프라엠퍼시스된 마이크 출력에 구형 윈도우함수를 적용시켜 CPSP를 구할 경우 프리엠퍼시스를 하지 않거나 다른 윈도우를 사용하는 경우에 비해 TDOA 추정성능이 향상됨을 확인하였다.

• 대한한방소아과학회지
• /
• 제37권2호
• /
• pp.1-11
• /
• 2023

Objectives We aimed to compare the bone age (BA) estimation by a deep learning-based program and by a specialist in pediatrics of Korean medicine using the Tanner-Whitehouse 3 (TW3) technique for the cases of children who visited a Korean medicine hospital for growth, and to report the effect of Korean medicine treatment. Methods For three children who visited the Korean medicine hospital for growth, BA estimation by the deep learning program and by the specialist in pediatrics of Korean medicine using the TW3 technique was compared, and the time required for estimation was investigated. The change of height, BA, and predicted adult height (PAH) using deep learning program after Korean medicine treatment was observed. Results BA estimation of the left hand bone X-ray by the specialist using the TW3 technique showed a difference of -0.03 to +0.15 years from the estimation by the deep learning program. The mean estimation time was 5 minutes and 49 seconds per one for the specialist and 48 seconds for the deep learning program. During the treatment period, the height percentile and PAH estimated by deep learning program were increased after Korean medicine treatment compared to baseline while acceleration of BA was suppressed compared to chronological age. Conclusions BA estimation using the deep learning program and the TW3 technique showed a difference of less than 0.15 years, and in three cases of patients with growth as the chief complaint, Korean medicine treatment increased height percentile and PAH without accelerating BA maturation.