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      • KCI등재

        Psychosis, Treatment Emergent Extrapyramidal Events, and Subsequent Onset of Huntington’s Disease: A Case Report and Review of the Literature

        Changqing Xu,Jegan Yogaratnam,Nigel Tan,Kang Sim 대한정신약물학회 2016 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.14 No.3

        Huntington’s disease (HD) is an autosomal dominant neurodegenerative disease characterized by a triad of progressive motor dysfunction, cognitive decline and psychiatric disturbances. The hallmark of HD is the distinctive choreiform movement disorder that typically has a subtle, insidious onset in the fourth to fifth decade of life and gradually worsens over 10 to 20 years until death. Notably, two-thirds of HD patients present with chorea and one third with mental changes. The prevalence of psychiatric symptoms is significantly higher than in the general population, and is estimated to be around 66-73%. Here, we report a unique case of subsequent onset of HD in a patient previously treated for schizophrenia and complicated by the extrapyramidal side effects to antipsychotics.

      • KCI등재

        THE LOWER BOUND OF THE NUMBER OF NON-OVERLAPPING TRIANGLES

        Xu, Changqing,Ding, Ren 한국전산응용수학회 2003 Journal of applied mathematics & informatics Vol.11 No.1

        Andras Bezdek proved that if a convex n-gon and n points are given, then the points and the sides of the polygon can be renumbered so that at least[${\frac{n}{3}}$] triangles spanned by the ith point and the ith side (i = 1,2,...n) are mutually non-overlapping. In this paper, we show that at least [${\frac{n}{2}}$] mutually non-overlapping triangles can be constructed. This lower bound is best possible.

      • KCI등재
      • KCI등재
      • KCI등재

        Comparison of overfed Xupu and Landes geese in performance, fatty acid composition, enzymes and gene expression related to lipid metabolism

        Liu Xu,Li Peng,He Changqing,Qu Xiangyong,Guo Songchang 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.12

        Objective: The aim of this study was to compare overfeeding performance, fatty acid composition, blood chemistry, enzymes and genes expression overfed Xupu and Landes geese. Methods: Sixty male Xupu geese (80 d) and Landes geese (80 d) were selected. After a period of one-week of pre-overfeeding, Xupu and Landes geese were overfed three meals of 550 and 350 g/d, respectively, of a high-carbohydrate diet in the first week of the overfeeding period. The next week, geese were given four meals of 1,200 and 850 g/d, respectively, over 8 to 14 d. Finally, geese were given five meals of 1,600 and 1,350 g/d, respectively, for the last two weeks. Results: After overfeeding for 28 d: Compared with Landes geese, Xupu geese liver weight and liver-to-body weight ratio decreased (p<0.05), while final weight, slaughter weight, total weight gain, abdominal fat weight, and feed-to-liver weight ratio increased (p<0.05). The levels of elaidic acid (C18:1t9), oleic acid (C18:1n-9), eicosenoic acid, and arachidonic acid in the liver of Xupu geese significantly increased (p<0.05), and the levels of myristic acid and stearic acid significantly decreased (p<0.05), while methyleicosanoate acid significantly increased (p<0.05). Xupu geese had higher plasma concentrations of triglyceride and very low density lipoprotein cholesterol (p<0.05), and decreased activities of alanine aminotransferase, aspartate aminotransferase, and lipase (LPS) (p<0.05). Landes geese had higher LPS activity (p<0.05), but lower cholinesterase activity (p<0.05) when compared with Xupu geese. The mRNA expression levels of fatty acid dehydrogenase (FADS) gene, elongase of long-chain fatty acid 1 (ELOVL1) gene, ELOVL5, and acyl-Co A: cholesterol acyltransferase 2 (ACAT2) gene were significantly upregulated (p<0.05) in Landes goose when compared with Xupu geese. Conclusion: This study demonstrates that the liver production performance of Landes geese was better than that of Xupu geese to some extent, which may be closely related to LPS activity, as well as the expression of FADS, ELOVL1, ELOVL5, and ACAT2.

      • KCI등재

        INTEGRATED STEADY-STATE AND DYNAMIC SIMULATION OF MULTI-UNIT AIR CONDITIONERS BASED ON TWO-PHASE FLUID NETWORK MODEL

        HONGBO XU,SHUANGQUAN SHAO,Huiming Zou,Changqing Tian 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.4

        An integrated simulation model is developed to investigate the steady-state and dynamic performance of multi-unit air conditioners (MUACs). It is built as two-phase fluid network which is able to describe different systems by incidence matrixes. And the submodels are embedded in the system framework, where the submodels can be either steady-state or dynamic model, distributed parameter or lumped parameter model. For this case, the numerical submodels are employed with moving-boundary models of condenser and evaporator, steady-state models of compressor and electronic expansion valve. The comparison with experimental data shows that it cannot only predict the steady-state performance, but also catch dynamic trends with high accuracy, for example, the differences of evaporating pressure < ${\pm}4%$, condensing pressure < ${\pm}3%$, compressor discharge temperature < ${\pm}4^{\circ}C$, superheating degree < ${\pm}2^{\circ}C$ and subcooling degree < ${\pm}1^{\circ}C$. Therefore, the simulation model is confirmed as an effective tool to analyze the steady and transient characteristics and optimize the design and control algorithm of MUACs.

      • KCI등재

        The fuzzy comprehensive evaluation (FCE) and the principal component analysis (PCA) model simulation and its applications in water quality assessment of Nansi Lake Basin, China

        Shiguo Xu,Yixiao Cui,Chuanxi Yang,Shujing Wei,Wenping Dong,Lihui Huang,Changqing Liu,Zongming Ren,Weiliang Wang 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.2

        The Fuzzy Comprehensive Evaluation (FCE) and the Principal Component Analysis (PCA) were simulated to assess water quality of the Nansi Lake Basin, China. The membership functions were established via the Nor-Half Sinusoidal Distribution Method, and the weight was calculated via the Exceeding Standard Multiple Method. To enhance the efficiency of extracting principal pollutant, the eigenequation was solved through the Jacobi Method, and the principal components were extracted based on eigenvalue, contribution ratio, accumulating contribution ratio, principal component loading and score. Water quality classification based on “National Surface Water Environmental Quality Standards of China (GB3838-2002) was used to assess the water quality. Considering the difference of the temporal and spatial distribution in average, water quality of Level I was 28.9%, 28.1%, 25.1%, 25.6%, respectively in spring, summer, autumn, and winter, which suggested that water quality in spring and summer was better than in autumn and winter. The order of water quality was Zhaoyang Lake (Level I) > Nanyang Lake (Level I) > Dushan Lake (Level III) > Weishan Lake (Level III and IV). There were four extracted principal components that can replace the fourteen pollutant indexes for assessing water quality. According to the annual mean data of the 1<SUP>st</SUP> principal components, the most important pollutions were heavy metals, including As (0.933), Hg (0.931), Cd (0.929), Cr(VI) (0.926), Pb (0.925), and Cu (0.534). It is proved that the combined FCE-PCA model could provide valuable information in the water quality assessment for the Nansi Lake Basin.

      • SCIESCOPUS

        Earthquake response analysis of series reactor

        Bai, Changqing,Xu, Qingyu,Zhang, Hongyan Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.6

        A direct transfer substructure method is presented in this paper for analyzing the dynamic characteristics and the seismic random responses of a series reactor. This method combines the concept of FRF (frequency response function) and the transfer matrix algorithm with the substructure approach. The inner degrees of freedom of each substructure are eliminated in the process of reconstruction and the computation cost is reduced greatly. With the convenient solution procedure, the dynamic characteristics analysis of the structure is valid and efficient. Associated with the pseudo excitation algorithm, the direct transfer substructure method is applied to investigating the seismic random responses of the series reactor. The numerical results demonstrate that the presented method is efficient and practicable in engineering. Finally, a precise time integration method is employed in performing a time-history analysis on the series reactor under El Centro and Taft earthquake waves.

      • KCI등재

        Control Method of Self-Frequency Recovery and Active Power Sharing for an Isolated Microgrid Based on VSGs

        Pengxiang Xing,Fan Ma,Chunzheng Tian,Changqing Xu,Lili Wang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

        The concept of virtual synchronous generator (VSG) is emerging as an attractive solution for renewable energies to enhance the microgrid inertia and damping property by emulating the essential behaviors of conventional synchronous generators. However, in the isolated microgrid based on VSGs, there will be a frequency deviation when the power demand varies because of the droop characteristic of the VSG in active power–frequency regulation. In this paper, a control method for VSGs to implement self-frequency recovery and active power sharing in isolated microgrid is proposed. With this method, the VSGs regulate their power baseline values over multiple iterations through local-feedback of the frequency deviation until the microgrid frequency restores to normal value, and simultaneously share the power demand variation according to the ratio of their power baseline values. Compared to the previous studies, the proposed method can eliminate the output power and frequency oscillations in secondary control, and additionally, reduce the dependence of the microgrid on communication system, which is beneficial to enhance the robustness of the microgrid operation. Simulation results proved the proposed method to be effective.

      • KCI등재

        Performance characteristics around the TDC of linear compressor based on whole-process simulation

        Huiming Zou,Mingsheng Tang,HONGBO XU,SHUANGQUAN SHAO,Changqing Tian 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

        A whole-process simulation platform is established for linear compressor to analyze the performance characteristics on different pistondisplacement conditions from small oscillation without pumping till to rushing out of the top dead center (TDC). The measuring methodsof the related parameters in the model are presented and the values of these parameters are obtained from an actual test. The simulatedresults agreed well with the experimental results under the same working conditions. The errors of the effective voltage, the effectivecurrent, the compression efficiency and the phase angle between the current and the displacement were within ±6.9%,±8.5%,±6.2%and±13.4%, respectively. Based on this simulation platform, the performance characteristic around the TDC of the linear compressor ondifferent working conditions is analyzed. The performance comparison on 60 Hz shows that the compression efficiency near to the TDCon 0.7 MPa is higher than that on 0.5 MPa because the phase angle α under that condition is around 90°, but the operation reliability on0.7 MPa is worse than that on 0.5 MPa because the jump phenomenon happens when the piston displacement goes near to the TDC. Thejump phenomenon results in unstable operation as the piston displacement jumps from the position before the TDC to the position afterthe TDC. According to the simulation on different power frequency, two important performance characteristics are inferred. One is thatthere is an inflection point in the curve of the phase angle α versus the displacement at the TDC. This characteristic is a good choice forthe TDC detection. The other is that the jump phenomenon is prone to happening when there exist different displacement responses onthe same voltage value, becoming inconspicuous when the power frequency is decreased and disappearing when the power frequency isincreased. Based on this characteristic, the jump phenomenon can be avoided through suitable system configuration and frequency adjustment.

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