Localization of Subsurface Targets Based on Symmetric Sub-array MIMO Radar

Qinghua Liu,Yuanxin He,Chang Jiang 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.4

For the issue of subsurface target localization by reverse projection, a new approach of target localization with different distances based on symmetric subarray multipleinput multipleoutput (MIMO) radar is proposed in this paper. By utilizing the particularity of structure of the two symmetric subarrays, the received signals arejointly reconstructed to eliminate the distance information from the steering vectors. The distanceindependent direction of arrival (DOA) estimates are acquired, and the localizations of subsurface targets with different distances are realized by reverse projection. According to the localization mechanism and application characteristics of the proposed algorithm, the grid zooming method based on spatial segmentation is used to optimize the locaiton efficiency. Simulation results demonstrate the effectiveness of the proposed localization method and optimization scheme.

Hybridizing gaining–sharing knowledge and differential evolution for large-scale power system economic dispatch problems

Liu Qinghua,Xiong Guojiang,Fu Xiaofan,Mohamed Ali Wagdy,Zhang Jing,Al-Betar Mohammed Azmi,Chen Hao,Chen Jun,Xu Sheng 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.2

Economic dispatch (ED) of thermal power units is significant for optimal generation operation efficiency of power systems. It is a typical nonconvex and nonlinear optimization problem with many local extrema when considering the valve-point effects, especially for large-scale systems. Considering that differential evolution (DE) is efficient in locating global optimal region, while gain-sharing knowledge-based algorithm (GSK) is effective in refining local solutions, this study presents a new hybrid method, namely GSK-DE, to integrate the advantages of both algorithms for solving large-scale ED problems. We design a dual-population evolution framework in which the population is randomly divided into two equal subpopulations in each iteration. One subpopulation performs GSK, while the other executes DE. Then, the updated individuals of these two subpopulations are combined to generate a new population. In such a manner, the exploration and the exploitation are harmonized well to improve the searching efficiency. The proposed GSK-DE is applied to six ED cases, including 15, 38, 40, 110, 120, and 330 units. Simulation results demonstrate that GSK-DE gives full play to the superiorities of GSK and DE effectively. It possesses a quicker global convergence rate to obtain higher quality dispatch schemes with greater robustness. Moreover, the effect of population size is also examined.

A Joint Allocation Algorithm of Computing and Communication Resources Based on Reinforcement Learning in MEC System

( Qinghua Liu ),( Qingping Li ) 한국정보처리학회 2021 Journal of information processing systems Vol.17 No.4

For the mobile edge computing (MEC) system supporting dense network, a joint allocation algorithm of computing and communication resources based on reinforcement learning is proposed. The energy consumption of task execution is defined as the maximum energy consumption of each user's task execution in the system. Considering the constraints of task unloading, power allocation, transmission rate and calculation resource allocation, the problem of joint task unloading and resource allocation is modeled as a problem of maximum task execution energy consumption minimization. As a mixed integer nonlinear programming problem, it is difficult to be directly solve by traditional optimization methods. This paper uses reinforcement learning algorithm to solve this problem. Then, the Markov decision-making process and the theoretical basis of reinforcement learning are introduced to provide a theoretical basis for the algorithm simulation experiment. Based on the algorithm of reinforcement learning and joint allocation of communication resources, the joint optimization of data task unloading and power control strategy is carried out for each terminal device, and the local computing model and task unloading model are built. The simulation results show that the total task computation cost of the proposed algorithm is 5%-10% less than that of the two comparison algorithms under the same task input. At the same time, the total task computation cost of the proposed algorithm is more than 5% less than that of the two new comparison algorithms.

Integration of wastewater treatment units and optimization of waste residue pyrolysis conditions in the brominated phenol flame retardant industry

Shiqi Liu,Xiangting Hou,Chengze Yu,Xiangrui Pan,Junhao Ma,Guocheng Liu,Chengzhi Zhou,Yanjun Xin,Qinghua Yan 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

Among the bromine flame retardants, tetrabromobisphenol A (TBBPA) is a highly effective flame retardantthat can be used as both reactive and additive. However, the synthesis reaction of TBBPA has alow conversion rate and many brominated phenolic organics. Therefore, there is an urgent need toremove brominated organic pollutants produced in the process of producing flame retardants to reducethe harm to the environment and human beings and to reduce production costs. In this study, an efficientprocess was developed to treat the wastewater and waste residue generated in TBBPA production process,realizing its harmless and resource utilization. In the resource utilization system, through the ingeniousdesign of solution mixing, precipitation separation, three-effect evaporation and concentration,valuable substances were extracted to realize the recovery and reuse of wastewater. In the harmless utilizationprocess of hazardous waste residue, through high-temperature pyrolysis at 500 C for 2 h afteroptimization with hypoxia-hyperoxia atmosphere modulation, it can avoid the production of dioxinsand carbon black, effectively remove the organic impurities, realize the harmlessness and obtain highqualitysodium sulfate. This paper aims to propose a simple, efficient and feasible utilization system,including the three major technological processes of TBBPA production, integrated wastewater treatmentand optimized the harmless treatment of waste residue to obtain sodium sulfate, so as to realize TBBPAgreen production. Compared with the traditional TBBPA synthesis system, wastewater and waste residuetreatment processes, the TBBPA quality is increased by 2 % and the economic cost is reduced by 10 %,which is of great significance to the development of the industry.

한국어 보조사 ‘만’에 대응하는 중국어 표현 연구

유경화 ( Liu Qinghua ) 중국한국(조선)어교육연구학회 2020 한국(조선)어교육연구 Vol.15 No.-

Because of the differences in grammatical structure, the Korean auxiliary particle correspond to the Chinese adverbs. This study researched the semantic functions of Korean auxiliary particle ‘man’ firstly. And then studied each function of the corresponding Chinese expressions. Usually Korean auxiliary particle ‘man’ means single-limitation. When it connects with an adverb, adverbial ending, or quantifier, ‘man’ plays as a emphasis. The single-limitation of ‘man’ in Chinese corresponding expression is ‘只, 只有, 只是, 光’. There is no Chinese corresponding expression when ‘man’ connects with an adverb, adverbial ending and ‘-ya(야)’. When ‘man’ connects with a quantifier gives a meaning of minimal limitation. Therefore corresponding expression in Chinese will be ‘只, 只有, 就’. Moreover, Chinese corresponding expressions were defined when ‘man’ used as an idiom. Finally, this paper checked the teaching methods of Korean auxiliary particle for Chinese learners.

Emerging roles of centromeric RNAs in centromere formation and function

Qian Liu,Yang Liu,Qinghua Shi,Handong Su,Chunhui Wang,James A. Birchler,Fangpu Han 한국유전학회 2021 Genes & Genomics Vol.43 No.3

Background Centromeres are specialized chromosomal domains involved in kinetochore formation and faithful chromosome segregation. Despite a high level of functional conservation, centromeres are not identifed by DNA sequences, but by epigenetic means. Universally, centromeres are typically formed on highly repetitive DNA, which were previously considered to be silent. However, recent studies have shown that transcription occurs in this region, known as centromeric-derived RNAs (cenRNAs). CenRNAs that contribute to fundamental aspects of centromere function have been recently investigated in detail. However, the distribution, behavior and contributions of centromeric transcripts are still poorly understood. Objective The aim of this article is to provide an overview of the roles of cenRNAs in centromere formation and function. Methods We describe the structure and DNA sequence of centromere from yeast to human. In addition, we briefy introduce the roles of cenRNAs in centromere formation and function, kinetochore structure, accurate chromosome segregation, and pericentromeric heterochromatin assembly. Centromeric circular RNAs (circRNAs) and R-loops are rising stars in centromere function. CircRNAs have been successfully identifed in various species with the assistance of high-throughput sequencing and novel computational approaches for non-polyadenylated RNA transcripts. Centromeric R-loops can be identifed by the single-strand DNA ligation-based library preparation technique. But the molecular features and function of these centromeric R-loops and circRNAs are still being investigated. Conclusion In this review, we summarize recent fndings on the epigenetic regulation of cenRNAs across species, which would provide useful information about cenRNAs and interesting hints for further studies.

‘인들’의 문법적 특성

유경화(Liu, Qinghua) 한국어문학회 2015 語文學 Vol.0 No.128

‘Indeul’ can be used as an conjugation form of ‘ida’ and as an auxiliary particle in modern Korean language. This study researched grammatical characteristics of ‘indeual’ when it is used as an auxiliary particle. As Korean language changes, the ‘indeul’ is on the process of grammaticalization from the conjugation form of ‘ida’ to an auxiliary particle. So, as for morphological characteristic of ‘indeual’, it indicates both part of speech as the conjugation form of ‘ida’ and auxiliary particle. And sometimes the letter ‘i’ of ‘indeual’ can not be deleted even if it followed with a word ending with a vowel. The syntactic characteristic of ‘indeul’ is that there are some restrictions when it combines with prefinal endings of aspect and final endings of the sentence types.

Progressive Collapse Analysis of Large-span Reticulated Domes

Qinghua Han,Mingjie Liu,Yan Lu,Chenxu Wang 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2

The paper presents the progressive collapse analysis of large-span reticulated domes based on Alternate path (AP) method. Nonlinear buckling analysis is conducted on a large span roof with two different structural layouts. The results show that although large-span single-layer reticulated dome has a certain redundancy. When 10 key elements or 3 key nodes were removed, the single-layer reticulated dome under the service load would cause progressive collapse. Therefore the protection of key nodes of this structure should be strengthened. However, the redundancy of large-span double-layer reticulated dome is 7 to 13 times that of single-layer reticulated dome. When 10 key elements or 3 key nodes were removed, the double-layer reticulated dome under the service load would not cause progressive collapse. Hence, the resistance to progressive collapse of large-span double-layer reticulated dome is better than that of large-span single-layer reticulated dome.

Experimental research on load-bearing capacity of cast steel joints for beam-to-column

Qinghua Han,Mingjie Liu,Yan Lu 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.56 No.1

The load transfer mechanism and load-bearing capacity of cast steel joints for H-shaped beam to square tube column connection are studied based on the deformation compatibility theory. Then the monotonic tensile experiments are conducted for 12 specimens about the cast steel joints for H-shaped beam to square tube column connection. The findings are that the tensile bearing capacity of the cast steel joints for beam-column connection depends on the ring of cast steel stiffener. The tensile fracture happens at the ring of the cast steel stiffener when the joint fails. The thickness of square tube column has little influence on the bearing capacity of the joint. The square tube column buckles while the joint without concrete filled, but the strength failure happens for the joint with concrete filled column. And the length of welding connection between square tube column and cast steel stiffener has little influence on the load-bearing capacity of the cast steel joint. Finally it is shown that the load-bearing capacity of the joints for H-shaped beam to concrete filled square tube column connection is larger than that of the joints for H-shaped beam to square tube column connection by 10% to 15%.

Effects of Alkyl Chain Length on the Optoelectronic Properties and Performance of Pyrrolo-Perylene Solar Cells

Liu, Xianqing,Kim, Yu Jin,Ha, Yeon Hee,Zhao, Qinghua,Park, Chan Eon,Kim, Yun-Hi American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.16

<P>While the impact of alkyl side-chain length on the photovoltaic properties of conjugated polymers and their performance in bulk heterojunction (BHJ) solar cells has been studied extensively, analogous studies on pyrrolo-perylene-based polymers have not received adequate attention. To explore these effects, we synthesized two copolymers based on <I>N</I>-annulated pyrrolo-perylene and consisting of cyano group substituents on thiophene vinylene thiophene units with two different alkyl groups of 2-decyltetradecyl and 7-decylnonadecyl, and we studied them with regard to chemical structure and photovoltaic performance. UV–vis spectroscopy and cyclic voltammetry studies showed that variations in alkyl chain length affect crystallization, light absorption, and the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. These factors have a pronounced impact on the morphology of BHJ thin films and their charge carrier separation and transportation characteristics, which, in turn, influences photovoltaic properties.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-16/acsami.5b01444/production/images/medium/am-2015-01444m_0008.gif'></P>