Research on Economic Performance of Mining Enterprises Based on Stakeholders

Yunxiang Peng,Guixian Tian 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.6

Conventional mining enterprises, particularly coal-related ones, exhibit substantial environmental pollution andhigh energy consumption, while those involved in new energy resources, such as lithium and cobalt, face severeresource shortages. Consequently, the economic efficiency of China’s mining enterprises is significantlyconstrained. This study examines data from nine representative listed enterprises in China spanning 2016 to2021. Employing the DEA model—i.e., BCC (VRS) model, we analyze the economic efficiency of miningenterprises with a focus on stakeholders. The paper provides static and dynamic analyses, offering insights andrecommendations for enhancing technology, reducing costs, and fortifying social relationships.

Moral Hierarchy and Social Egoism in a Networked Society

Yunxiang Yan 한국사회학회 2015 韓國社會學 Vol.49 No.3

Unlike its many counterparts in Western social theories, the concept of chaxugeju--Fei Xiaotong’s ideal-type characterization of Chinese social structure-- leaves enough room for the soft factors of moral values, ranked differentiation, relational distance, and egoistic manipulation of both the soft factors and the hard factors such as social institutions and the law. The conceptual tool makes it possible to comprehend and unpack the entanglement of hierarchy and mutuality, morality and instrumentality, sociality and egoism, and the personal and collective in social actions. Focusing on the moralization of hierarchy and egotism, this article explores the inner connections of the various components of the notion of chaxugeju and discusses the wider implications of this indigenous theoretical thesis

Glucosinolate Enhancement in Leaves and Roots of Pak Choi (Brassica rapa ssp. chinensis) by Methyl Jasmonate

Yunxiang Zang,Hao Zhang,Linghui Huang,Fang Wang,Fei Gao,Xishan Lv,Jing Yang,Biao Zhu,홍승범,Zhujun Zhu 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.6

Glucosinolates have attracted considerable attention in the past several decades because of their involvement in pathogen and insect resistance of Brassicaceae as well as anti-inflammatory and anti-oxidation activity in humans. Methyl jasmonate (MeJA) treatment generally increases the levels of indole and aromatic glucosinolates; however, the time course of MeJA effects on the levels of individual glucosinolates in different pak choi cultivars has not been studied. Here, we found that foliar MeJA application increased accumulation of indole glucosinolates in both leaves and roots of four cultivars. However, roots accumulated much higher levels of indole glucosinolates and, compared to leaves, showed a delayed response to MeJA in terms of indole glucosinolate accumulation in all four cultivars. Individual indole glucosinolate levels in roots differed depending on the sampling time in different cultivars. The level of neoglucobrassicin steadily increased over 72 h. Glucobrassicin was induced in leaves of SHQ and HZYDE, and in roots of three cultivars, whereas 4-methoxyglucobrassicin was induced only in roots. Aromatic glucosinolate enrichment occurred only in roots. Aliphatic glucosinolates were detected only in the leaves but not in roots, accumulating to comparable levels as in untreated controls. These results suggest that exogenous MeJA-mediated signal transduction did not immediately lead to biosynthesis of aliphatic and aromatic glucosinolates but did induce increased accumulation of indole glucosinolates in pak choi. Individual glucosinolate accumulation profiles were different depending oncultivars.

Metabolic Engineering of Indole Glucosinolates in Chinese Cabbage Plants by Expression of Arabidopsis CYP79B2, CYP79B3, and CYP83B1

Zang, Yunxiang,Lim, Myungho,Park, Beomseok,Hong, Seungbeom,Kim, Doohwan Korean Society for Molecular Biology 2008 Molecules and cells Vol.25 No.2

Indole glucosinolates (IG) play important roles in plant defense, plant-insect interactions, and stress responses in plants. In an attempt to metabolically engineer the IG pathway flux in Chinese cabbage, three important Arabidopsis cDNAs, CYP79B2, CYP79B3, and CYP83B1, were introduced into Chinese cabbage by Agrobacterium-mediated transformation. Overexpression of CYP79B3 or CYP83B1 did not affect IG accumulation levels, and overexpression of CYP79B2 or CYP79B3 prevented the transformed callus from being regenerated, displaying the phenotype of indole-3-acetic acid (IAA) overproduction. However, when CYP83B1 was overexpressed together with CYP79B2 and/or CYP79B3, the transformed calli were regenerated into whole plants that accumulated higher levels of glucobrassicin, 4-hydroxy glucobrassicin, and 4-methoxy glu-cobrassicin than wild-type controls. This result suggests that the flux in Chinese cabbage is predominantly channeled into IAA biosynthesis so that coordinate expression of the two consecutive enzymes is needed to divert the flux into IG biosynthesis. With regard to IG accumulation, overexpression of all three cDNAs was no better than overexpression of the two cDNAs. The content of neoglucobrassicin remained unchanged in all transgenic plants. Although glucobrassicin was most directly affected by overexpression of the transgenes, elevated levels of the parent IG, glucobrassicin, were not always accompanied by increases in 4-hydroxy and 4-methoxy glucobrassicin. However, one transgenic line producing about 8-fold increased glucobrassicin also accumulated at least 2.5 fold more 4-hydroxy and 4-methoxy glucobrassicin. This implies that a large glucobrassicin pool exceeding some threshold level drives the flux into the side chain modification pathway. Aliphatic glucosinolate content was not affected in any of the transgenic plants.

An improved Rankine source panel method for three dimensional water wave problems

Aichun Feng,Yunxiang You,Huayang Cai 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

An improved three dimensional Rankine source method is developed to solve numerically water wave problems in time domain. The free surface and body surface are both represented by continuous panels rather than a discretization by isolated points. The integral of Rankine source 1=r on free surface panel is calculated analytically instead of numerical approximation. Due to the exact algorithm of Rankine source integral applied on the free surface and body surface, a space increment free surface source distribution method is developed and much smaller amount of source panels are required to cover the fluid domain surface than other numerical approximation methods. The proposed method shows a higher accuracy and efficiency compared to other numerical methods for various water wave problems.

First‑Principles Study of Black Phosphorus as Anode Material for Rechargeable Potassium‑Ion Batteries

Weiwei Yang,Yunxiang Lu,Chengxi Zhao,Honglai Liu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

In two-dimensional materials, black phosphorus has shown excellent performance as electrode materials for lithium- and sodium-ion batteries, due to its thermodynamic stability, layered anisotropic structure, and electrical conductivity. Recently, high capacity anodes based on black phosphorus as an active component for potassium-ion batteries (PIBs) have also been reported. However, in-depth studies are required to clarify the adsorption and difusion of K ions on black phosphorus and the K–P reaction mechanism. In this work, the surface adsorption, bulk difusion, and K–P binary phase formation were frstly investigated in detail using frst-principle calculations. We found that compared with Li and Na, K has the lowest difusion energy barrier in the bulk phase (0.182 eV for zigzag type and 2.013 eV for armchair type). Black phosphorus structure irreversibly collapses when the K ion concentration is up to 0.625, and no K3P phase is formed through the electrochemical profles obtained by calculation of the binary phase alloy structures. Furthermore, the maximum capacitance of black phosphorous for PIBs is calculated to be 864.8 mAh.g−1. This work will help in understanding the mechanism and further improving the performance of K-ion batteries.

A Novel Image Completion Algorithm Based on Planar Features

( Mang Xiao ),( Yunxiang Liu ),( Li Xie ),( Qiaochuan Chen ),( Guangyao Li ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.8

A novel image completion method is proposed that uses the advantage of planar structural information to fill corrupted portions of an image. First, in estimating parameters of the projection plane, the image is divided into several planes, and their planar structural information is analyzed. Second, in calculating the a priori probability of patch and patch offset regularity, this information is converted into a constraint condition to guide the process of filling the hole. Experimental results show that the proposed algorithm is fast and effective, and ensures the structure continuity of the damaged region and smoothness of the texture.

Learning Multiple-Gait Quadrupedal Locomotion via Hierarchical Reinforcement Learning

Lang Wei,Yunxiang Li,Yunfei Ai,Yuze Wu,Hao Xu,Wei Wang,Guoming Hu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.9

Over long periods of evolution, legged animals have developed the capability to use a variety of gaits to move efficiently and flexibly at different speeds. To enable quadruped robots to acquire this ability, this study proposes a two-stage training hierarchical framework that can have quadruped robots generate energy-efficient multiple-gait locomotion, consisting of a gait selection policy module and a react controller module. The parameters of both modules are optimized using reinforcement learning. The experimental results in the simulation demonstrate that the proposed method can generate energy-efficient multiple-gait quadrupedal locomotion compared to previous methods. To validate the robustness and effectiveness of the method, we constructed a closed-chain quadruped robot and deployed the controller trained by the method to the robot. The experimental results in the real world suggest that the controller can enable the robot to move stably and efficiently in different gaits. The main contribution of this paper is that the authors propose a novel hierarchical framework, which makes quadruped robots use an optimal gait at a specific speed and smoothly switch to another one after getting a different speed command. These behaviors are automatically produced through simulation training, eliminating the need for the tedious work of designing gaits and modulating controllers. Experimental results showcase that the proposed method has significant advantages compared to previous methods.

Modeling and Direct Power Control Method of Vienna Rectifiers Using the Sliding Mode Control Approach

Hui Ma,Yunxiang Xie,Biaoguang Sun,Lingjun Mo 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper uses the switching function approach to present a simple state model of the Vienna-type rectifier. The approach introduces the relationship between the DC-link neutral point voltage and the AC side phase currents. A novel direct power control (DPC) strategy, which is based on the sliding mode control (SMC) for Vienna I rectifiers, is developed using the proposed power model in the stationary α-β reference frames. The SMC-based DPC methodology directly regulates instantaneous active and reactive powers without transforming to a synchronous rotating coordinate reference frame or a tracking phase angle of grid voltage. Moreover, the required rectifier control voltages are directly calculated by utilizing the non-linear SMC scheme. Theoretically, active and reactive power flows are controlled without ripple or cross coupling. Furthermore, the fixed-switching frequency is obtained by employing the simplified space vector modulation (SVM). SVM solves the complicated designing problem of the AC harmonic filter. The simplified SVM is based on the simplification of the space vector diagram of a three-level converter into that of a two-level converter. The dwelling time calculation and switching sequence selection are easily implemented like those in the conventional two-level rectifier. Replacing the current control loops with power control loops simplifies the system design and enhances the transient performance. The simulation models in MATLAB/Simulink and the digital signal processor-controlled 1.5 kW Vienna-type rectifier are used to verify the fast responses and robustness of the proposed control scheme.

Analysis and Application of Repetitive Control Scheme for Three-Phase Active Power Filter with Frequency Adaptive Capability

Biaoguang Sun,Yunxiang Xie,Hui Ma,Li Cheng 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Active power filter (APF) has been proved as a flexible solution for compensating the harmonic distortion caused by nonlinear loads in power distribution power systems. Digital repetitive control can achieve zero steady-state error tracking of any periodic signal while the sampling points within one repetitive cycle must be a known integer. However, the compensation performance of the APF would be degradation when the grid frequency varies. In this paper, an improved repetitive control scheme with frequency adaptive capability is presented to track any periodic signal with variable grid frequency, where the variable delay items caused by time-varying grid frequency are approximated with Pade approximants. Additionally, the stability criterion of proposed repetitive control scheme is given. A three-phase shunt APF experimental platform with proposed repetitive control scheme is built in our laboratory. Simulation and experimental results demonstrate the effectiveness of the proposed repetitive control scheme.