Modified Sub-aperture Stitching Algorithm using Image Sharpening and Particle Swarm Optimization

Yiwei Chen,Erlong Miao,Yongxin Sui,Huaijiang Yang 한국광학회 2014 Current Optics and Photonics Vol.18 No.4

This study proposes a modified sub-aperture stitching algorithm, which uses an image sharpening algorithm and particle swarm optimization to improve the stitching accuracy. In sub-aperture stitching interferometers with high positional accuracy, the high-frequency components of measurements are more important than the low-frequency components when compensating for position errors using a sub-aperture stitching algorithm. Thus we use image sharpening algorithms to strengthen the high-frequency components of measurements. When using image sharpening algorithms, sub-aperture stitching algorithms based on the least-squares method easily become trapped at locally optimal solutions. However, particle swarm optimization is less likely to become trapped at a locally optimal solution, thus we utilized this method to develop a more robust algorithm. The results of simulations showed that our algorithm compensated for position errors more effectively than the existing algorithm. An experimental comparison with full aperture-testing results demonstrated the validity of the new algorithm.

Data-driven estimation of change-points with mean shift

Yang Wenzhi,Liu Huanshuo,Wang Yiwei,Wang Xuejun 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.1

Asymptotically linear negative quadrant dependent (ALNQD) sequence is more general than negatively associated (NA) sequence and \rho∗-mixing sequence. Based on ALNQD errors, the CUSUM estimator of mean change-point is studied with common conditions. We obtain a limiting distribution of CUSUM estimator, which can be used to judge the existence of mean change-point. Meanwhile, some weak and strong convergence rates are established for the CUSUM estimator of change-point. In addition, a data-driven algorithm of multiple change-point detection is given, which performs better than Lasso algorithm. Last, multiple change-point detection simulations and real data analysis illustrate the accuracy of our results.

Polymorphism of Estrogen Receptor Genes and Its Interactions With Neurodevelopmental Genes in Attention Deficit Hyperactivity Disorder Among Chinese Han Descent

Yiwei Lin,Haimei Li,Jing Zhang,Ziqi Yang,Yi Zhou,Lu Liu,Qiujin Qian 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.8

Objective Attention deficit hyperactivity disorder (ADHD) is a polygenic neurodevelopmental disorder with significant gender differences. The sexual dimorphism of ADHD may be associated with estrogen acting through estrogen receptors (ESR). This study investigates the impact of <i>ESR</i> gene polymorphism and its interactions with neurodevelopmental genes on ADHD susceptibility.Methods The study compared genotyping data of single nucleotide polymorphisms in <i>ESR1</i> and <i>ESR2</i> in 1,035 ADHD cases and 962 controls. The gene-gene interactions between <i>ESR</i> genes and three neurodevelopmental genes (brain-derived neurotrophic factor [<i>BDNF</i>], synaptosomal-associated protein of 25 kDa gene [<i>SNAP25</i>], and cadherin-13 [<i>CDH13<i></i></i>]) in ADHD were investigated using generalized multifactor dimensionality reduction and verified by logistic regression analysis.Results The G allele of rs960070/<i>ESR2</i> (empirical p=0.0076) and the A allele of rs8017441/<i>ESR2</i> (empirical p=0.0426) were found significantly higher in ADHD cases than in the controls but not in male or female subgroups. Though no difference was found in all subjects or females, the A allele of rs9340817/<i>ESR1</i> (empirical p=0.0344) was found significantly higher in ADHD cases than controls in males. We also found genetic interaction models between <i>ESR2</i> gene, neurodevelopmental genes and ADHD susceptibility in males (<i>ESR2</i> rs960070/<i>BDNF</i> rs6265/<i>BDNF</i> rs2049046/<i>SNAP25</i> rs362987/<i>CDH13</i> rs6565113) and females (<i>ESR2<i></i></i> rs960070/<i>BDNF<i></i></i> rs6265/<i>BDNF</i> rs2049046) separately, though it was negative in overall subjects.Conclusion The <i>ESR</i> gene polymorphism associates with ADHD among Chinese Han children, with interactions between <i>ESR<i></i></i> genes and neurodevelopmental genes potentially influencing the susceptibility of ADHD.

Fast Sub-aperture Stitching Algorithm Using Partial Derivatives

Yiwei Chen,Erlong Miao,Yongxin Sui,Huaijiang Yang 한국광학회 2015 Current Optics and Photonics Vol.19 No.1

For large optical elements which are tested by many sub-apertures, it takes too much time for asub-aperture stitching algorithm to get the stitching result. To solve this problem, we propose a fastsub-aperture stitching algorithm to quickly compensate for piston, tilt, and defocus errors. Moreover, thenew algorithm is easy to understand and program. We use partial derivatives of measurement data toseparately solve piston, tilt, and defocus errors. First, we show that the new algorithm has a lower timecomplexity than the currently used algorithm. Although simulation results indicate that the accuracy ofthe new algorithm is lower than the current algorithm in all 20 simulations, our experimental results validatethe algorithm and show it is sufficiently accurate for general use

Dynamic Economic Dispatch and Control of a Stand-alone Microgrid in DongAo Island

Yiwei Ma,Ping Yang,Hongxia Guo,Yuewu Wang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

A dynamic economic dispatch and control method is proposed to minimize the overall generating cost for a stand-alone microgrid in DongAo Island, which is integrated with wind turbine generator, solar PV, diesel generator, battery storage, the seawater desalination system and the conventional loads. A new dispatching strategy is presented based on the ranking of component generation costs and two different control modes, in which diesel generator and battery storage alternate to act as the master power source to follow system power fluctuation. The optimal models and GA-based optimization process are given to minimize the overall system generating cost subject to the corresponding constraints and the proposed dispatch strategy. The effectiveness of the proposed method is verified in the stand-alone microgrid in DongAo Island, and the results provide a feasible theoretical and technical basis for optimal energy management and operation control of stand-alone microgrid.

Strength, deformation and failure behavior of bolted rock-like specimen with multiple cracks under uniaxial compression by particle flow simulation

Wendong Yang,Yiwei Li,Ling Wang,Kaicheng Zhang,Zhicheng Gong 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.6

Most of the rock mass in nature contains a large number of joints, faults and other defects, which make the rock mass have the characteristics of discontinuity and anisotropy, and easily lead to instability and failure of rock engineering. A great quantity of engineering practices show that the bolt has a significant supporting effect on jointed rock mass. Therefore, it is of great significance to study the deformation and failure characteristics of jointed rock mass and the crack arrest effect of bolt for the safety and stability of engineering. A reasonable numerical model of bolted rock samples with non-persistent joints is established by using a three-dimensional Particle Flow Code (PFC) based on the laboratory rock specimens, and the uniaxial compression numerical test is carried out. The results indicate that (1) the numerical simulation results are in good agreement with the laboratory test results, and the variation trend of strength is basically consistent; (2) the different joint angles and anchorage angles result in variations in the mechanical properties of bolted specimens with non-persistent joints; (3) the joint angle has a significant effect on the failure mode of the specimen; (4) the existence of bolts can effectively limit the initiation and propagation process of micro-cracks, and greatly improve the mechanical properties of the specimen containing non-persistent joints.

Dynamic Economic Dispatch and Control of a Stand-alone Microgrid in DongAo Island

Ma, Yiwei,Yang, Ping,Guo, Hongxia,Wang, Yuewu The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

A dynamic economic dispatch and control method is proposed to minimize the overall generating cost for a stand-alone microgrid in DongAo Island, which is integrated with wind turbine generator, solar PV, diesel generator, battery storage, the seawater desalination system and the conventional loads. A new dispatching strategy is presented based on the ranking of component generation costs and two different control modes, in which diesel generator and battery storage alternate to act as the master power source to follow system power fluctuation. The optimal models and GA-based optimization process are given to minimize the overall system generating cost subject to the corresponding constraints and the proposed dispatch strategy. The effectiveness of the proposed method is verified in the stand-alone microgrid in DongAo Island, and the results provide a feasible theoretical and technical basis for optimal energy management and operation control of stand-alone microgrid.

Experimental Study on the Behavior of Fire Resistance of Welded Hollow Spherical Joint under Compression

Bingsheng Huang,Yiwei Zhang,Ranyang Zhang,Fang Yang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.12

Through the transient test on two welded hollow spherical joints subjected to compression under fire, the temperature distribution, displacement characteristics, failure mode and ultimate fire resistance time of the joint under different load ratios were obtained under standard fire. The three-dimensional finite element model of welded hollow spherical joints was established, and the performance of the joints subjected to compression under fire was analyzed. Compared with the test results, the correctness of finite element simulation analysis was verified. The results showed that during the heating process, the surface temperature of the sphere inside the steel pipe is the lowest. The surface temperature of the sphere is low at the intersection with the steel tube and is highest at the middle-latitude of the sphere. The surface temperature of sphere is lower than ISO-834 standard heating curve. Failure mode of axially compressed welded hollow spherical joints under fire is concave failure. Failure position is at the sphere connected with the steel pipe. Failure process is short. Fire resistance time of load-ratio 0.35 specimen is more than 20% longer than that of load-ratio 0.6 specimen. The critical temperature of the current fire protection code is smaller than the results of the finite element.

Traditional Dual Growing Rods With 2 Different Apical Control Techniques in the Treatment of Early-Onset Scoliosis

Shengru Wang,Yiwei Zhao,Guanfeng Lin,You Du,Yang Yang,Jianguo Zhang 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: Based on traditional dual growing rods (TDGR), apical control techniques (ACTs) were introduced as adjuvant procedures to improve deformity correction at the apex segment in the treatment of early-onset scoliosis (EOS). We aimed to explore whether TDGR+ ACTs have different indications, attain more deformity correction, have negative effects on spinal growth, and have different complications. Methods: Between 2004 and 2019, a retrospective study of EOS patients treated with TDGR with or without ACTs was conducted and divided into 3 groups: TDGR group; hybrid technique (HT) group: Vertebrectomy/hemivertebrectomy with short fusion and TDGR; ACPS group: apical convex control pedicle screws (ACPS) and TDGR. Demographic, radiographic parameters, clinical outcomes, complications, and revisions were analyzed and compared. Results: Seventy-eight EOS patients were enrolled. The preoperative main curve was the largest in the HT group. ACPS group had the smallest residual curve (19° ± 8.9°) and apical vertebral translation (12.0 ± 9.0 mm) at the latest follow-up, followed by the HT group (30° ± 17.4°, 22.1 ± 13.4 mm) and TDGR group (30° ± 13.2°, 32.8 ± 17.1 mm). ACPS group had the largest T1–12 height and T1–S1 height after index surgery. Complications and revisions in the ACTs groups was lower than the TDGR group. Scoliosis Research Society-22 self-image questionnaire was superior in the ACPS group. Conclusion: According to our intermediate results, TDGR+ACTs could improve correction ability of apex deformity. ACTs had little deleterious effects on spinal height during the lengthening procedures, with a lower complication rate than TDGR. TDGR+ACTs might be a supplemental option for suitable EOS patients.

Lowest Instrumented Vertebra at L3 Versus L4 in Posterior Fusion for Moderate Lenke 5C Type Adolescent Idiopathic Scoliosis: A Case-Match Radiological Study

Zhiyi Li,You Du,Yiwei Zhao,Guanfeng Lin,Haoran Zhang,Chenkai Li,Xiaohan Ye,Yang Yang,Shengru Wang,Jianguo Zhang 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: To compare the radiological outcomes in Lenke 5C type patients whose lowest instrumented vertebra (LIV) was L3 or L4 in a case-match study. Methods: We conducted a retrospective case-match study and included 82 patients in the study. Radiological results before surgery, after surgery, and at last follow-up were recorded and analyzed in the L3 and L4 groups. Results: After matching the age, Risser’s sign, sex, and main Cobb, 41 pairs of patients were enrolled in our study. The total fusion segments in the L3 group (median [interquartile range]: 5.0 [6.0–5.0]) were shorter than those in the L4 group (6.0 [6.5–6.0]). The main curve was significantly corrected after surgery in both groups, and was comparable at the last followup between groups. In addition, according to the results of Fisher precision probability test, there was no significant difference of coronal or sagittal imbalance between the 2 groups at the 2-year follow-up. Conclusion: The correction in coronal and sagittal planes in L3 group and L4 group remains similar. On account of more motion segments, L3 could be an ideal choice as LIV in moderate Lenke 5C type AIS. Long-term follow-up is needed to evaluate the effect of larger compensatory lumbar-sacral curve when stopping at L3.