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World Journal of Engineering and Technology 2023年第1期11卷 20-40页

作者： Kengne Chatue Charlène Steva Mengata Mengounou Ghislain Koko Koko Joseph Batassou Guilzia Jeannot Nneme Nneme Leandre Laboratory of Computer and Automatic Engineering UFD of Engineering Sciences ENSET University of Douala Douala Cameroon

This work is part of the resolution of problems encountered on a 225 KV MANGOMBE-OYOMABANG line. This line is characterized by important technical losses, so that the voltage injected in the busbar is always lower than 200kV. The main objective of this work is to show the new solutions that can provide a combined FACTS-STATCOM and IPC 240 dual system on this line. Then to show the limitation of STATCOM compared to RPI 240. The results obtained allowed us to observe that in symmetrical operation the STATCOM improves the voltage profile on the busbar and in asymmetrical operation we found that it continues to regulate the voltage of each phase despite the unbalance. But the system remains too unbalanced because of the sequence current flow. The IPC 240 corrects this limitation, allowing asymmetrical operation of the line in an emergency while providing continuous service to the load.

关键词： FACTS STATCOM IPC 240 Dual Symmetry asymmetry Contingency Voltage Profile

The Impacts of State Ownership on Information asymmetry:Evidence from an Emerging Market

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China Journal of Accounting Research 2010年第Z1期3卷 13-50页

作者： Jongmoo Jay Choi Heibatollah Sami Haiyan Zhou Department of Finance Fox School of BusinessTemple University Department of Accounting Lehigh University Department of Accounting and Business Law University of Texas-Pan American

This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask spread during the period 1995-2000, but disappears afterward during 2001-2003. The finding that state ownership raised bid-ask spread in the early period is consistent with recent studies on emerging markets including China, which indicate that firms with higher state ownership tend to have a greater deviation between cash flow rights and control rights(eg, Wei et al., 2005). This implies that lower state ownership is associated with lower information asymmetry in the market, an economic consequence of significant economic reform and privatization regarding the market microstructure. However, with more active control transfers andemergence of private controlling shareholders, regulatory changes in ownership structure and corporate governance mechanisms, and thus an improved legal and institutional environment, the link between the government ownership and information asymmetry turns to be insignificant in the later period. These results have important implications for transparency and information disclosure policies as well as privatization in emerging markets.

关键词： Bid-ask spread Information asymmetry Transparency

Nitrogen dilution effect for small angle GDH experiment in JLab Hall-A

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Chinese Physics C 2008年第8期32卷 653-656页

作者：吕海江叶云秀闫新虎程和平焦铮何聚刘仁臣 Department of Physics Huangshan University Department of Modern Physics University of Science and Technology of China

In the GDH sum rule measurement in JLab Hall-A, to obtain the cross section of electron scattering on polarized 3^He and its asymmetry in different helicity states, the dilution effect from unpolarized nitrogen mixed ... 详细信息

关键词： GDH sum rule dilution factor correction cross section asymmetry

An Optimality Theoretic Analysis of the Mid Tone in IsÊeÊkírì

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宏观语言学 2022年第1期10卷 132-150页

作者： Oludewa Roselyn Osewa Osaigbovo Obed Evbuomwan University of Benin Nigeria

The asymmetric behaviour of the mid tone has been reported in the Yoruboid literature and previous accounts of tone behaviour in Iṣẹkírìsuggest that a low tone is always deleted in favour of others at word boundary.However,synchronic data have shown that this is not the case.This paper investigates tonal asymmetry and the non-participation of the mid tone in some phonological processes in Iṣẹkírì.The study adopts an Optimality Theory(OT)version that incorporates the grounding conditions to develop constraints of implicational statements into faithfulness constraints.Data are elicited from eight speakers of the language,recordings are with the aid of a digital audio device and the tool used for our acoustic measurement is Praat 6.0.30.The analysis reveals that tonal asymmetry in this language always deletes the Mid-tone at word boundary and not the Low tone,also noting that the Low tone may be deleted in some cases.The lack of participation of the M tone in some phonological processes such as vowel elision,glide formation and vowel assimilation reveals the unstable nature of this tone in Iṣẹkírì.This paper concludes that the M tone is in asymmetry to the H and L tones in Iṣẹkírìand demonstrates the need for more perceptual and acoustic studies of tonal behaviour in Iṣẹkírì.

关键词： tone asymmetry vowel elision vowel assimilation tone behaviour

Asymmetric Environmental Regulation:Mechanism and a Yardstick Phenomenon

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China Economist 2023年第1期18卷 87-107页

作者： Yu Yazhuo Zhang Huilin Zhang Pingdan Business School Renmin University of ChinaBeijingChina School of Economics and Business Administration Beijing Normal UniversityBeijing

In discussing the policy effects of environmental regulation,we should focus not only on whether environmental regulation helps improve the environmental and economic performance of firms,but also on how such improvement is materialized,i.***.whether the obsolete mode of production is reversed.After matching the database of China’s industrial enterprises with that of pollution emissions from these industrial enterprises,this paper identifies the asymmetric scope of clean production standards to test the effect of environmental regulation on the total factor productivity(TFP)of the industrial enterprises.Our empirical research finds that the implementation of clean production standards may induce TFP improvement.However,such improvement only occurs for polluters who cannot or who barely meet clean production standards and does little to improve the production standards of polluters with low pollution emission,reflecting the yardstick phenomenon of the asymmetric environmental regulation policy effect:While polluters are forced to improve,clean enterprises that pollute less are more likely to take no action.Further research finds that such TFP improvement is materialized primarily by means of overall firm optimization;the compensation effect is insignificant and does not reverse the backward mode of production.Polluters cope with the implementation of clean production standards by purchasing more equipment and expanding capacity,which adds to the tension between the expansion of capacity and the abatement of pollution emission.

关键词： Environmental regulation clean production standards TFP asymmetry yardstick phenomenon

A study on vestibular-evoked myogenic potentials via galvanic vestibular stimulation in normal people

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Journal of Otology 2018年第1期13卷 16-19页

作者： Ying Cheng Yusuke Kimura Kimitaka Kaga National Institute of Sensory Organs Tokyo Medical Center Japan The Department of Otolaryngology Head and Neck Surgery in the Second Affiliated Hospital of Xi 'an Jiaotong University Shaanxi Province PR China

Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.Methods: We enrolled sixteen healthy subjects to record the average responses of SCM to galvanic vestibular stimulation(GVS) [current 3 mA;duration 1 ms] by electromyography(EMG). SPSS 18.0 software was used to analyze the obtained data for mean and standard deviation.Results: In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was 11.7 ± 3.0 ms. The latency of n23 was 17.8 ± 3.4 ms. The amplitude of p13-n23 was147.0 ± 69.0 μV. The interaural asymmetry ratio(AR) of p13, n23 latency and the amplitude was respectively 0.12 ± 0.09, 0.08 ± 0.08 and0.16 ± 0.10.Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound(ACS) or bone conducted vibration(BCV) can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.

关键词： Galvanic vestibular stimulation Vestibular nerve Vestibular-evoked myogenic potentials Sternocleidomastoid muscle Interaural asymmetry ratio (AR)

Application of Equivalent Black Body Temperature in the Forecast of Tropical Cyclone Intensity

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Acta meteorologica Sinica 2007年第4期21卷 465-475页

作者：陈佩燕端义宏余晖胡春梅 Shanghai Typhoon Institute of China Meteorological Administration Chongqing Meteorological Bureau

Using equivalent black body temperature （TBB） data retrieved from meteorological satellite GMS-5 during 1996-2002, the correlation between the circular symmetric/asymmetric component of TBB and the intensity of tropical cyclone （TC） at various time lags from 0 to 48 h is analyzed for the Northwest Pacific （0^-50~N, 120%155~E）, excluding landed and near-coast samples. It is found that the total TBB near southeast of the eyewall, the circular symmetric component, and the sum of the amplitudes of tangential wave numbers 1-10 （SA10） of the TBB between the radii of 0.8^o and 1.7^o are significantly and negatively correlated with the TC intensity at various time lags from 0 to 48 h. Especially, the maximum 24-h lag correlation coefficients reach -0.52, -0.58, and -0.625, respectively. A statistical prediction scheme for TC intensity is developed based on climatic persistent, synoptic, and TBB factors by stepwise regression technique. It is found that the variance contribution of the averaged TBB over the ring between 1.0^o and 1.5^o from the TC center ranks the fourth in the equation for 12-h TC intensity prediction, and those of the total TBB near southeast of the eyewall and the difference between maximum and minimum TBB between 1.1^o and 1.5^o rank the third and fifth respectively in the 24-h forecast equation. It is also shown that, with TBB factors, the following predictions are improved compared to the scheme without TBB factors： 48-h prediction for severe tropical storm （STS）, 12-h prediction for TC with a weakening rate greater than 15 m s-1/12 h, 24-h intensity prediction for TC with almost no intensity change, and 48-h prediction for TC intensifying faster than 10 m s^-1/48 h.

关键词： TBB （black body temperature） asymmetry intensity prediction tropical cyclone

Decadal Anomalies of Winter Precipitation over Southern China in Association with El Nio and La Nia

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Journal of Meteorological Research 2014年第1期28卷 91-110页

作者：袁媛李崇银杨崧 Laboratory of Climate Studies of CMA National Climate Center LASG Institute of Atmospheric PhysicsChinese Academy of Sciences Institute of Meteorology PLA University of Science and Technology School of Environmental Science and Engineering Sun Yat-Sen University

Using multiple datasets, this paper analyzes the characteristics of winter precipitation over southern China and its association with warm and cold phases of E1 Nifio-Southern Oscillation during 1948 2011. The study proves that E1 Nifio is an important external forcing factor resulting in above-normal winter precipitation in southern China. The study also reveals that the impact ofLa Nifia on the winter precipitation in southern China has a decadal variability. During the winter of La Nifia before 1980, the East Asian winter monsoon is stronger than normal with a deeper trough over East Asia, and the western Pacific subtropical high weakens with its high ridge retreating more eastward. Therefore, anomalous northerly winds dominate over southern China, leading to a cold and dry winter. During La Nifia winter after 1980, however, the East Asian trough is weaker than normal, unfavorable for the southward invasion of the winter monsoon. The India-Burma trough is intensified, and the anomalous low-level cyclone excited by La Nifia is located to the west of the Philippines. Therefore, anomalous easterly winds prevail over southern China, which increases moisture flux from the tropical oceans to southern China. Meanwhile, La Nifia after 1980 may lead to an enhanced and more northward subtropical westerly jet over East Asia in winter. Since southern China is rightly located on the right side of the jet entrance region, anomalous ascending motion dominates there through the secondary vertical circulation, favoring more winter precipitation in southern China. Therefore, a cold and wet winter, sometimes with snowy and icy weathers, would occur in southern China during La Nifia winter after 1980. Further analyses indicate that the change in the spatial distribution of sea surface temperature anomaly during the La Nifia mature phase, as well as the decadal variation of the Northern Hemisphere atmospheric circulation, would be the important reasons for the decadal variability of the La Nifia impact on the atmospheric circulat

关键词： East Asian winter monsoon winter precipitation E1 Nifio and La Nifia asymmetry decadalvariability

The resilience of pollination interactions: importance of temporal phases

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Journal of Plant Ecology 2019年第1期12卷 157-162页

作者： Edy Fantinato Silvia Del Vecchio Carlo Gaetan Gabriella Buffa Department of Environmental Sciences Informatics and StatisticsCa’Foscari University of VeniceVia Torino 15530172 VeniceItaly

Aims The loss of species that engage in close ecological interactions,such as pollination,has been shown to lead to secondary extinctions,ultimately threatening the overall ecosystem stability and function-ing.Pollination studies are currently flourishing at all possible levels of interaction organization(i.e.,species,guild,group and network),and different methodological protocols aimed to define the resil-ience of pollination interactions have been proposed.However,the temporal dimension of the resilience of pollination interactions has been often overlooked.In the light of these considerations,we addressed the following questions:does a temporal approach help to reveal critical moments during the flowering season,when polli-nation interactions are less resilient to perturbations?Do pollination interactions evaluated at species,guild,group and network level show different patterns when assessed through time?Methods We monitored contacts between plant and pollinator species in dry grassland communities every 15 days during the overall community flowering season(12 surveys).For each survey,we built a quantita-tive plant-pollinator interaction matrix and we calculated two sets of metrics characterizing,respectively,the diversity and the distribution of interactions across hierarchical levels.To describe the diversity of interactions,we calculated partner diversity(PD)at the species level,vulnerability/generality(V/G)at the guild level,and interaction diver-sity and evenness at the network level.The distribution of interactions was characterized by calculating selectiveness at the species and the network level,and modularity at the group level.We assessed the temporal variation of PD,V/G at the level of plants and pollinators,and species selectiveness,by means of Linear Mixed Models(LMMs).To investigate the temporal variation of indexes calculated at group and network level,we applied simple linear and quadratic regres-sions after checking for temporal autocorrelation in residuals.Important Findings When taking into

关键词： asymmetry complementarity ecosystems’resilience redundancy species-rich ecosystems

Influence of RMB exchange rate fluctuation on urban-rural income from the perspective of transmission asymmetry

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Ecological Economy 2017年第2期10卷 181-189页

作者： CHANG Yuan School of Public Finance & Taxation Guangdong University of Finance & Economics

Based on time series data of RMB exchange rate and urban-rural income, this paper makes an empirical study for the influence of RMB exchange rate fluctuation on urban-rural income by utilizing rolling regression model through direct and indirect transmission mechanisms. According to the results, the transmission effect of RMB exchange rate fluctuation on urban-rural income has features of incompleteness and asymmetry. Moreover, RMB appreciation will help to reduce the urban-rural income gap. Therefore, this paper suggests that the Chinese economy should accelerate the course of transforming mode, adjusting structure and promoting development under the new normal. Meanwhile, reform of RMB exchange rate mechanism should be promoted, living standard of residents must be improved, and the urban-rural income gap should be reduced.

关键词： RMB exchange rate urban-rural income transmission effect asymmetry