Multi-lag Out of Sequence Measurement 환경에서의 IMM-MPDA 필터 성능 분석

徐日煥(Il-Hwan Seo),宋澤烈(Taek-Lyul Song) 대한전기학회 2007 전기학회논문지 Vol.56 No.8

In a multi-sensor target tracking systems, the local sensors have the role of tracking the target and transferring the measurements to the fusion center. The measurements from the same target can arrive out of sequence called, the out-of-sequence measurements(OOSMs). The OOSM can arise in a form of single-lag or multi-lag throughout the transfer at the fusion center. The recursive retrodiction step was proposed to update the current state estimates with the multi-lag OOSM from the several previous papers. The real world has the possible situations that the maneuvering target informations can arrive at the fusion center with the random clutter in the possible OOSMs. In this paper, we incorporate the IMM-MPDA(Interacting Multiple Model - Most Probable Data Association) into the multi-lag OOSM update. The performance of the IMM-MPDA filter with multi-lag OOSM update is analyzed for the various clutter densities, OOSM lag numbers, and target maneuvering indexes. Simulation results show that IMM-MPDA is sufficient to be used in out of sequence environment and it is necessary to correct the current state estimates with OOSM except a very old OOSM.

Shear Lag Effect in Welded Single Angle Tension Member

Jagdish R. Dhanuskar,Laxmikant M. Gupta 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.3

The typical failure of a welded single angle tension member is a gross section failure. The rupture strength of the single angle tension member is aff ected by the eff ect of shear lag. Full-scale tests on twenty-seven single angle specimens reported in this paper. Four diff erent angle sections with four diff erent section types were used in the test. The test parameter includes the steel’s grade, length of the connection, the eccentricity of the connection, and balanced and unbalanced weld arrangement. Twenty-three specimens failed by fracture of the gross section area, one failed in mixed mode (angle tear and the weld failure), and the remaining three failed in the weld. To interpret the experimental results, fi nite element analysis was performed on the specimen’s model. The fi nite element model well represents the welded single-angle tension member’s behaviour, and fi nite element results show exemplary test results. The ultimate strengths of the test specimens were also evaluated by using the current design standards (IS 800, AISC, CSA, AS 4100, and EC-3), the (1− x̅/L) rule, and Kulak and Wu’s equation. In general, IS 800 provides a good prediction of test results, AISC and AS 4100 provide a slightly conservative forecast; however, CSA and EC-3 provide a slightly un-conservative prediction. For a balanced weld arrangement, the specimen’s ultimate strength increased with an increase in connection length; however, an increase in connection length does not increase the specimen’s ultimate strength for an unbalanced weld arrangement. The angle specimen’s effi ciency decreased signifi cantly with an increase in eccentricity. The rupture strength predicted by assuming the ultimate strength of the connected leg and the strength contributed by the outstanding leg at the critical section shows a good prediction of the strength over the (1− x̅/L) rule.

Phase lag compensation for improving the stability of LCL‑type converters under weak grid condition

Jianfeng Wang,Guobing Pan,Jing Ouyang,Chengyao Liu,Yinghao Zhou,Gong Fei 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.5

LCL-type converters are widely used in the sustainable energy generation system due to their flexible current control strategies and high efficiency. The LCL filter has a resonance peak, which needs to be handled appropriately; otherwise, it causes system instability. Single-loop feedback control strategy is very popular at present; it does not require additional sensors to measure the state variables for active damping. Under weak grid condition, the resonance peak of LCL filter shifts to the left evidently and greatly reduces the stability margin; thus, maintaining the stability of single-loop control is a challenging task. This paper presents an improved grid current feedback (GCF) single-loop control strategy, which is designed to raise the stability margin of system to adapt weak grid condition. Low pass filter controller is used for phase lag compensation. A phase margin design method is proposed to ensure system stability, and the corresponding discrete method in z-domain has been proposed in detail. Experiments performed on a three-phase converter platform are finally presented to verify the effectiveness of the proposed phase lag compensation for GCF control strategy.

The Feasible Bias Set of BPNG Law for Single-Lag System

Sungjin Cho,Ick-Ho Whang,Young-In Lee,Dong-Kyun Choe,Dae-gyu Sang 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

In this paper, we suggest the feasible bias set of BPNG(Biased Proportional Navigation Guidance) law for single-lag strap-down imaging sensor homing loop design. The pitch angle is analytically derived from the turning rate dynamics based on analytic solution of the BPNG single-lag homing system. Moreover, the appropriate bias range which guarantees the FOV(Field-Of-View) limit of strap-down imaging sensor is obtained.

일인가구의 우울과 사회적 관계의 종단적 상호인과관계

유지애 ( Yu Ji Ae ) 한국가족사회복지학회 2020 한국가족복지학 Vol.67 No.1

The purpose of this study is to verify the Reciprocal Longitudinal Relationship between depression and social relationships of single households. To this end, the 1st, 4th, 7th and 10th data of the Korea Welfare Panel were merged and analyzed through the Autoregressive Cross-lagged Modeling(ARCL). The results of this study are as follows. First, the Autoregressive coefficients of single-person households remained stable at a statistically significant level over 10 years in both depression and social relationships. This means that the depression of single-person households predicts their depression in the future, and the satisfaction of social relationships can also predict the satisfaction of social relationships in the future. Second, the Cross-lagged coefficient was different between depression and social relationship variables. Specifically, the depression of single-person households did not affect the satisfaction of social relationships at a later point in time, whereas the satisfaction of social relationship of single-person households had an influence on later depression. Third, as a result of multi-group analysis by dividing the group into the young and the old, there was no significant difference between the two groups. Based on this, suggestions were made to promote mental health and social relations of single-person households.

교차지연 모형을 통한 비혼 아버지의 양육참여와 아동의 문제행동간의 인과관계 검증

최정균(Choi, Jeong-Kyun) 한국아동복지학회 2017 한국아동복지학 Vol.- No.59

본 연구는 교차지연 모형을 사용하여 비혼 아버지(unmarried fathers)의 양육참여와 아동의 문제행동 간에 인과관계를 분석하였다. 분석을 위해 미국 취약가구 및 아동복지연구자료(Fragile Families and Child Wellbeing Study)를 사용하였으며, 아버지가 자녀와 동거하지 않는 비혼여성 한부모가구만 선별하여 총 3,409가구를 연구대상으로 설정하였다. 비혼 아버지의 양육참여는 아동방문빈도와 도구적 양육지원, 지지적 양육태도의 세 가지 하위변수로 측정하였으며, 아버지의 양육참여와 아동의 문제행동을 각각 아동의 3세와 5세, 9세 시점에서 반복측정한 변수를 사용하여 시간의 흐름에 따른 각 변수의 변화를 고려하였다. 연구결과, 비혼 아버지의 양육참여는 아동의 문제행동을 결정하는 유의미한 요인인 것으로 검증되었다. 전반적으로 아동연령 3-5세 시점에서 비혼 아버지의 적극적인 양육참여는 5-9세 시점에서의 아동문제행동을 감소시키는 것으로 분석되었다. 연구결과를 기초로 비혼 아버지의 지속적인 양육참여를 유도하기 위한 정책적⋅실천적 전략에 대해 논의하였으며, 동시에 보다 효과적으로 아버지의 역할과 책임을 이해하고 관련 기술을 습득할 수 있도록 자녀양육, 관계형성기술, 갈등해결기술 등의 구체적인 서비스 제공 및 프로그램 개발과 지원방안을 제시하였다. Using a subsample of 3,409 unmarried smothers and their children from the Fragile Families and Child Wellbeing study, the present study examined the cross-lagged effects of unmarried fathers’ involvement on their children’s behavior problems. Father involvement was used as a latent variable to measure the frequency of fathers’ visits to the child, fathers’ instrumental support, and their supportive parenting. Both variables of father involvement and child behavior problems were repeatedly measured at child ages 3, 5, and 9 to estimate their trends over time. The results indicated that fathers’ more active engagement in parenting at child ages 3 to 5 reduced behavior problems in children at ages 5 to 9. Further discussions include programs and services to support unmarried fathers through education and training opportunities for effective parenting, relationship skills, and conflict resolutions as well as policy strategies to encourage their continuous involvement in the lives of their children.

Heterogeneous Sensor-Based Target Tracking With Constant Time Delay

Qilong Wang,Yu Zhang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.1

Aiming to address the problem of constant-step-lag in-sequence measurements (CISM) in the process of heterogeneous sensor tracking, an Unscented Transformation-based CISM indirect update algorithm is proposed in this paper. First, based on the classical A1 algorithm, Unscented Transformation is applied to the nonlinear measurement equation to solve the computation of nonlinear systems. This method does not need to solve the Jacobian matrix or Hessian matrix of nonlinear equations. Second, combined with the complementarity of information from heterogeneous sensor systems, CISM is further analyzed, and an indirect update algorithm is proposed to obtain the approximate estimate of the current time of the delay information, which is substituted into UT-A1 to complete a delay information update algorithm that is suitable for the heterogeneous sensor system in this paper. Finally, the experimental results show that the UT-CISM indirect update algorithm can effectively improve the real-time capability and accuracy of the time-delay sensor system in this paper.