Efficient slope reliability analysis using a surrogate-assisted normal search particle swarm optimization algorithm

Yuan Yi-li,Hu Chang-ming,LI LIANG,Hou Xu-hui 한국CDE학회 2024 Journal of computational design and engineering Vol.11 No.1

Sampling of training data is the most important step in active learning slope reliability analysis, which controls the analysis accuracy. In this study, a novel surrogate-assisted normal search particle swarm optimization (SANSPSO) was proposed to enhance the accuracy and robustness of existing methodologies. In SANSPSO, the sampling process was considered a minimum problem with an objective function defined as the absolute value of the performance function. Initiated with a normal search paradigm and supplemented by three algorithm strategies, this approach seeks to preserve the continuity of the solution while refining the algorithm’s efficacy and efficiency. To reduce computation cost, surrogate-assistance was used, in which a surrogate model substitutes the objective function in most iterations. This surrogate model evolves during the iteration process and ultimately replaces the actual performance function within Monte Carlo simulation. Finally, this study presents a comparative study with five state-of-the-art methods across four explicit problems and three engineering cases, where test data suggest that the SANSPSO methodology yields a 20% improvement in accuracy and a 30% rise in stability under different dimensional problems relative to the most efficacious of the alternate methods assessed because of the improved and more consistent prediction of limit state function. These findings substantiate the validity and robustness of the SANSPSO approach.

Preparation, Characterization, and In Vivo Evaluation of Mitoxantrone- loaded, Folate-conjugated Albumin Nanoparticles

Liang-ke Zhang,Shi-xiang Hou,Jing-qin Zhang,Wen-jing Hu,Cheng-yuan Wang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.8

Folic acid was covalently conjugated to bovine serum albumin nanoparticles (BSANP) to target the nanoparticles to SKOV3 cells expressing folate receptors. Mitoxantrone was incorporated into the folate-conjugated albumin nanoparticles, and the final nanoparticle size was 68 nm, as measured by a laser light scattering particle analyzer. The cytotoxic activity of mitoxantrone-loaded, folate-conjugated albumin nanoparticles (MTO-BSANP-folate), which was quantitated by 3H-thymidine incorporation, was higher than mitoxantrone-loaded BSANP (MTO-BSANP) and MTO solution, and could be inhibited by free folic acid. MTO-BSANPfolate may be endocytosed via the folate receptor on the surface of SKOV3 cells. MTO-BSANPfolate also inhibited tumor growth better than the MTO-BSANP and MTO solution in vivo. These results indicate that folate-conjugated BSANP may have therapeutic potential as a vector for anticancer drugs in cancer chemotherapy.

Tip Position Control of a Flexible-Link Manipulator with Neural Networks

Yuan-Gang Tang,Fu-Chun Sun,Zeng-Qi Sun,Ting-Liang Hu 대한전기학회 2006 International Journal of Control, Automation, and Vol.4 No.3

To control the tip position of a flexible-link manipulator;a neural network (NN) controller is proposed in this paper. The dynamics error used to construct NN controller is derived based on output redefinition approach. Without the filtered tracking en-or;the proposed NN controller can still guarantee the closed-loop system uniformly asymptotically stable as well as NN weights bounded. Furthermore;the tracking error of desired trajectory can converge to zero with the proposed controller. For comparison an NN controller with filtered tracking en-or is also designed for the flexible-link manipulator. Finally;simulation studies are carried out to verify the theoretic results.

The Classic Security Application in M2M: the Authentication Scheme of Mobile Payment

( Liang Hu ),( Ling Chi ),( Hong-tu Li ),( Wei Yuan ),( Yu Yu Sun ),( Jian-feng Chu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

As one of the four basic technologies of IOT (Internet of Things), M2M technology whose advance could influence on the technology of Internet of Things has a rapid development. Mobile Payment is one of the most widespread applications in M2M. Due to applying wireless network in Mobile Payment, the security issues based on wireless network have to be solved. The technologies applied in solutions generally include two sorts, encryption mechanism and authentication mechanism, the focus in this paper is the authentication mechanism of Mobile Payment. In this paper, we consider that there are four vital things in the authentication mechanism of Mobile Payment: two-way authentication, re-authentication, roaming authentication and inside authentication. Two-way authentication is to make the mobile device and the center system trust each other, and two-way authentication is the foundation of the other three. Re-authentication is to re-establish the active communication after the mobile subscriber changes his point of attachment to the network. Inside authentication is to prevent the attacker from obtaining the privacy via attacking the mobile device if the attacker captures the mobile device. Roaming authentication is to prove the mobile subscriber`s legitimate identity to the foreign agency when he roams into a foreign place, and roaming authentication can be regarded as the integration of the above three. After making a simulation of our proposed authentication mechanism and analyzing the existed schemes, we summarize that the authentication mechanism based on the mentioned above in this paper and the encryption mechanism establish the integrate security framework of Mobile Payment together. This makes the parties of Mobile Payment apply the services which Mobile Payment provides credibly.

Improved Watkins–Johnson topology‑based photovoltaic MPPT converter

Liang Hu,Yuan Luo 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.12

A photovoltaic (PV) maximum power point tracking (MPPT) converter behaves as a decoupling stage that dynamically tracks the peak power of a PV generator with an output characteristic curve that is nonlinear and changes with respect to solar irradiation and cell temperature. Depending on diff erent voltage transfer functions and application requirements, the classical MPPT converter topologies include buck, boost, buck-boost, flyback, etc. In this paper, an improved Watkins–Johnson (WJ) topology is added to the family of MPPT converters. This improved topology has the merits of a simple circuit structure, power switches that are easy drive, synchronous mode capability, and high efficiency at a marginal duty cycle. To balance the tracking speed and tracking stability of the WJ topology, key issues including the perturbation period and perturbation amplitude have been resolved by means of small-signal modeling and an analysis according to the PV model parameters and converter electrical elements. An experimental prototype has been designed, constructed, and utilized to verify the feasibility of the proposed concept.

Electronic Structure and Optical Properties of a Mn-Doped InSe/WSe2 van der Walls Heterostructure: First Principles Calculations

Liang Rundong,Zhao Xiuwen,Hu Guichao,Yue Weiwei,Yuan Xiaobo,Ren Junfeng 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.7

InSe-based van der Walls heterostructures (vdWHs) have attracted research interests recently because of their particular properties. In this work, the electronic structure and the optical properties of Mn-doped InSe/WSe2 vdWHs are investigated by using first-principles calculations. Mn doping in InSe/WSe2 vdWHs induces an increase in the system's band gap. The optical properties of the vdWHs are also studied, and the absorption intensity of Mn-doped InSe/WSe2 is found to be enhanced in the near-infrared and ultraviolet regions. In addition, built-in electric fields are generated in InSe/WSe2 and Mn-doped InSe/WSe2, which can inhibit recombination of photogenerated electron-hole pairs. This work predicates the feasibility of enhancing the optical properties in InSe/WSe2 vdWHs by introducing dopants, which extends the applications of InSe materials in the field of optoelectronics.

An Alkaline pH Control Strategy for Methionine Adenosyltransferase Production in Pichia pastoris Fermentation

Xiaoqing Hu,Ju Chu,Si-Liang Zhang,Ying-ping Zhuang,Xin Wu,Huaxin Chen,Zhongyuan Lv,Zhongyi Yuan 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.5

Pichia pastoris is a successful system forexpressing heterologous proteins and its fermentation pH isalways maintained below 7.0. However, particular proteinsare unstable under acidic conditions, such as methionineadenosyltransferase (MAT), and thus fermentation underacidic pH conditions is unsuitable because protein activityis lost owing to denaturation. Here, a strategy employingalkaline pH in the late fermentation period was developedto improve MAT production. Initially, P. pastoris KM71was transformed with the mat gene to overexpress MAT. After 72 h of in vitro incubation at different pH values, theexpressed MAT displayed highest stability at pH 8.0;however, pH 8.0 inhibited cell growth and induced cellrupture, thus affecting protein production. To balance MATstability and Pichia cell viability, different pH controlstrategies were compared. In strategy A (reference), theinduction pH was maintained at 6.0, whereas in strategy B,it was gradually elevated to 8.0 through a 25 h transitionperiod (80 ~ 105 h). MAT activity was 0.86 U/mg (twofoldhigher than the control). However, MAT content wasreduced by 50% when compared with strategy A, becauseof proteases released upon cell lysis. To improve cellviability under alkaline conditions, glycerol was added inaddition to methanol (strategy C). When compared withstrategy B, the MAT-specific activity remained nearlyconstant, whereas the expression level increased to 1.27 g/L. The alkaline pH control strategy presented herein for MATproduction represents an excellent alternative for expressingproteins that are stable only under alkaline conditions.

Expression and Characterization of RNA-dependent RNA Polymerase of Dendrolimus punctatus Tetravirus

( Zhou Liang ),( Jia Min Zhang ),( Xiao Chun Wang ),( Hong Jiang ),( Fu Ming Yi ),( Yuan Yang Hu ) 생화학분자생물학회 2006 BMB Reports Vol.39 No.5

Modeling and representation of a computer-aided conceptual design system

Bing Liang,Yuan Chen,Ju-Fan Zhang,Ying Hu 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.11

A novel hierarchical function action behavior mechanism (FABM) modeling framework is proposed to conduct intelligent mapping from the overall function to the principle solution, according to the requirements of customers. Based on the hierarchical modeling framework, an object-oriented representation method is developed to express the inheritance and the interconnecting characteristics between any two objects. In addition, the rules of expansion and modification in demand behavior are proposed to solve the combinational explosion problem, and the combinational rules in the mechanism behavior are developed to extend the innovation of the principle solution. A case study on the pan mechanism design for a cooking robot is presented to demonstrate the implementation of intelligent reasoning based on the FABM model.

MRI Findings of Primary CNS Lymphoma in 26 Immunocompetent Patients

Dong Zhang,Liang-Bo Hu,Tobias D Henning,Elisabeth M Ravarani,Li-Guang Zou,Xiao-Yuan Feng,Wen-Xian Wang,Li Wen 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.3

Objective: To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease. Materials and Methods: Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by nonenhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases. Results: The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and ‘open-ring-like’ enhancement (2). The ‘notch sign’ was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p < 0.01) and mildly or moderately enhanced lesions were more frequently found in the monofocal group (p < 0.05). There was no statistical difference between perifocal edema (p > 0.05) and the signal characteristics (p > 0.05) between the two groups. Conclusion: Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an ‘open-ring’ enhancement as well as four cases with a ‘notch sign’. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement. Objective: To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease. Materials and Methods: Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by nonenhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases. Results: The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and ‘open-ring-like’ enhancement (2). The ‘notch sign’ was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p < 0.01) and mildly or moderately enhanced lesions were more frequently found in the monofocal group (p < 0.05). There was no statistical difference between perifocal edema (p > 0.05) and the signal characteristics (p > 0.05) between the two groups. Conclusion: Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an ‘open-ring’ enhancement as well as four cases with a ‘notch sign’. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement.