Negative working capital management

Dongmei Wang,Na Liu 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Working capital is the most liquid and dynamic component of total assets. Working capital management, as the core content of short-term corporate finance, is vital to enterprises" survival and development and plays an important roel in maximizing shareholders" wealth. In this paper, we test the differences in profitability and risk levels from 2002 to 2006 between Chinese listed companies which pursue positive and negative working capital policies with the method of One-Way ANOVA. Furthermore, the first sample is eventually subdivided according to net commercial credits into two sub-ones, namely positive and negative commercial credits. Same analyses are done on above two sub-samples again. To find out how and what factors influence enterprises" profitability through different working capital polices, we do linear regression analyses. The results show: the proportion of Chinese listed companies which adopt the policy of negative working capital is steadily rising year by year; they have gained greater improvement in performance; however, relatively higher risk can not be ignored; companies can improve their performance by increasing the ratio of current assets to total assets (CAAR), the ratio of net cash inflows from operating activities to current liabilities (COACL), growth rate of total assets (GRA). In this paper, net commercial credits are firstly introduced into working capital research and as much attention is paid to risk indicators as to profitability ones. Such a practice is absolutely a meaningful try in this type of study. The conclusion of this paper not only supports the concept of "negative working capital" and its technical application, butl also gives useful suggestions to listed companies both in China and other countries.

Characteristics of the aerodynamic interference between two high-rise buildings of different height and identical square cross-section

Dongmei, Huang,Xue, Zhu,Shiqing, He,Xuhui, He,Hua, He Techno-Press 2017 Wind and Structures, An International Journal (WAS Vol.24 No.5

In this work, wind tunnel tests of pressure measurements are carried out to assess the global aerodynamic interference factors, the local wind pressure interference factors, and the local lift spectra of an square high-rise building interfered by an identical cross-sections but lower height building arranged in various relative positions. The results show that, when the interfering building is located in an area of oblique upstream, the RMS of the along-wind, across-wind, and torsional aerodynamic forces on the test building increase significantly, and when it is located to a side, the mean across-wind and torsional aerodynamic forces increase; In addition, when the interfering building is located upstream or staggered upstream, the mean wind pressures on the sheltered windward side turn form positive to negative and with a maximum absolute value of up to 1.75 times, and the fluctuating wind pressures on the sheltered windward side and leading edge of the side increase significantly with decreasing spacing ratio (up to a maximum of 3.5 times). When it is located to a side, the mean and fluctuating wind pressures on the leading edge of inner side are significantly increased. The three-dimensional flow around a slightly-shorter disturbing building has a great effect on the average and fluctuating wind pressures on the windward or cross-wind faces. When the disturbing building is near to the test building, the vortex shedding peak in the lift spectra decreases and there are no obvious signs of periodicity, however, the energies of the high frequency components undergo an obvious increase.

Research Progress of Visual Inspection of Tray Seedling and the System of Automatic Transplanting

Dongmei Pei,Fanjun Meng,HaiLong Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.7

As a kind of modern technology of growing seedling, Tray seedling is efficient with little plant diseases and insect pests, and save labors, which make it develop rapidly in domestic. When growing seedlings, there are not only holes that are not germinant or missed, but also inferior seedlings, which lead to leakage of planting and empty of planting during follow-up mechanized transplanting. In order to utilize each area of holes and seedbeds, holes without seedlings need to be transplanted filling the gaps with seedlings. The paper introduces research of visual inspection of tray seedling and the system of automatic transplanting domestic and overseas, explores the research progress of automatic transplanting system from four aspects, which are technic of visual inspection, end effector, control system and route optimization. The paper proposes existing problems and development of domestic visual inspection and automatic transplanting system, which offers references for follow-up study and marketing application.

Genetic homogeneity between populations of cotton bollworm from Xinjiang, China

Dongmei Wang,Xianming Yang,Haiqiang Li,Akedan Wuwaishi,Ruifeng Ding,Haobin Li,Hongsheng Pan,Jian Liu,Yao Xu,Yan-Hui Lu 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

We studied the population structure of cotton bollworm (CBW), Helicoverpa armigera (Hübner) (Lepidoptera:Noctuidae), in Xinjiang, the largest cotton-growing region in China, using a fragment of cytochrome c oxidasesubunit I (COI) gene. Alignments of all 192 COI sequences revealed 28 haplotypes including 23 in southernXinjiang, 5 in eastern Xinjiang and 13 in northern Xinjiang. Negative and significant values of neutrality tests forthe Tajima's D and Fu's FS parameters, combined with the high values of haplotype diversity (Hd), low values ofnucleotide diversity (π) and a high number of low frequency haplotypes indicated a recent demographic expansionof Xinjiang CBW populations. Analysis of molecular variation (AMOVA) indicated low and non-significantgenetic structure, regardless of geographical scale or crop, with most of genetic variation occurringwithin local CBW populations. Pairwise FST analyses also indicated low genetic differentiation. This demographicevent and high gene flow could be responsible for the low genetic structure currently found. CBW populations inXinjiang need to be considered as one panmictic unit in its management, especially for the design of refuges todelay the development of resistance by this migratory pest to transgenic Bt (Bacillus thuringiensis) cotton.

DYNAMICS CHARACTERISTICS ANALYSIS AND CONTROL OF FWID EV

Dongmei Wu,Haitao Ding,Changqing Du 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

Compared with internal combustion engine (ICE) vehicles, four-wheel-independently-drive electric vehicles (FWID EV) have significant advantages, such as more controlled degree of freedom (DOF), higher energy efficiency and faster torque response of an electric motor. The influence of these advantages and other characteristics on vehicle dynamics control need to be evaluated in detail. This paper firstly analyzed the dynamics characteristics of FWID EV, including the feasible region of vehicle global force, the improvement of powertrain energy efficiency and the time-delays of electric motor torque in the direct yaw moment feedback control system. In this way, the influence of electric motor output power limit, road friction coefficient and the wheel torque response on the stability control, as well as the impact of motor idle loss on the torque distribution method were illustrated clearly. Then a vehicle dynamics control method based on the vehicle stability state was proposed. In normal driving condition, the powertrain energy efficiency can be improved by torque distribution between front and rear wheels. In extreme driving condition, the electric motors combined with the electro-hydraulic braking system were employed as actuators for direct yaw moment control. Simulation results show that dynamics control which take full advantages of the more controlled freedom and the motor torque response characteristics improve the vehicle stability better than the control based on the hydraulic braking system of conventional vehicle. Furthermore, some road tests in a real vehicle were conducted to evaluate the performance of proposed control method.

Automobile Optimal Driving Control Using Information of Traffic Jam and Signal based on Model Prediction Control

Dongmei Wu,Yang Xia,Masatoshi Ogawa,Yi-Chun Yeh,Harutoshi Ogai,Taketoshi Kawabe 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

As a basis of an intelligent driving assist system, an on-line calculation method calculating a desirable driving path based on information and prediction of surrounding traffic environment is developed. The problem is how to use information of traffic jam and signal. This paperreports an automobile optimal driving control system using information of traffic jam and signal based onthe model prediction control to support drivers. Moreover, physical models for information of traffic jam and signal are constructed.

Technical evaluation and optimization of biological aerated filter(BAF) treating micro-polluted source water at low temperature

Dongmei Liu,Xin Wang,Xiaobo Li,Aiwen Wang 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.4

In this study, polyethylene and zeolite, as media in two-stage biological aerated filters (BAF), were evaluated for simultaneous removal of ammonia nitrogen and organics in micro-polluted water under low temperature conditions. For specific source water, the contaminants removal characteristics are evaluated by single-factor experiment to determine the suitable pH, air-water ratio (AWR) and hydraulic load ratio (HLR). Ammonia nitrogen and permanganate index in BAFs were promoted effectively with pH = 7~8, AWR = 1.0:1.0~2.0:1.0, HLR = 1~4 m³/(m²·h), low pollution loads and a temperature of 10°C. Based on the response surface analysis, the optimum parameters were as follows: pH of 7.94, AWR of 1.41:1.0 and HLR of 1.39 m³/(m²·h), for simultaneous removal of ammonia nitrogen and permanganate index, their removal rates were respectively 59.76% and 18.16%. BAF has a great advantage in emergency treatment of low temperature micro-polluted water, and response surface analysis can be used to optimize operating parameters.

Experimental investigation of vortex-induced aeroelastic effects on a square cylinder in uniform flow

Dongmei Huang,Teng Wu,Shiqing He 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.1

To investigate the motion-induced aeroelastic effects (or aerodynamic feedback effects) on a square cylinder in uniform flow, a series of wind tunnel tests involving the pressure measurement of a rigid model (RM) and simultaneous measurement of the pressure and vibration of an aeroelastic model (AM) have been systematically carried out. More specifically, the aerodynamic feedback effects on the structural responses, on the mean and root-mean-square wind pressures, on the power spectra and coherence functions of wind pressures at selected locations, and on the aerodynamic forces were investigated. The results indicated the vibration in the lock-in range made the shedding vortex more coherent and better organized, and hence presented unfavorable wind-induced effects on the structure. Whereas the vibration in the non-lock-in range generally showed insignificant effects on the flow structures surrounding the square cylinder.

Drain Pipe Inspection Robot using Wireless Communication System

Dongmei Wu,Harutoshi Ogai,Yichun Yeh,Katsumi Hirai,Takahiko Abe,Gunkichi Sato 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Pipe lines of various materials need to be inspected after certain years. Therefore, it is necessary to develop a flexible pipe inspection robot using wireless communication system. In this research, wireless communication system istested, it is verified that the wireless communication system can steadily transmit image information at high speed. On the basis of wireless communication system, a new pipe inspection robot for drain pipe is developed. With this new system, movement of the robot can be controlled, defects or troubles inside pipe would be inspected and image inside pipe also can be transmitted in real time.

Financial ESG and Corporate Sustainable Development: the Moderating Effect of Attention

Dongmei Li 한국디지털정책학회 2023 디지털정책학회지 Vol.2 No.1

ESG는 기업 환경, 사회적 책임 및 기업 거버넌스에 더 많은 관심을 기울이는 재무 데이터이다.이 연구 는 실증 분석을 통해 ESG와 기업의 지속 가능한 발전 사이의 관계를 탐구한다.이 연구는 2015-2020년 중국 A주 상장 기업의 데이터에 대한 실증 연구를 수행하기 위해 고정 효과 회귀 방법을 사용한다.연구 결과에 따르 면 ESG가 잘 수행되면 기업의 지속 가능한 발전을 촉진할 수 있다.동시에 관심이 높을수록 ESG 성능이 우수할 수록 기업의 지속 가능한 발전 능력을 촉진할 수 있다.이 연구는 ESG에 대한 관련 연구를 풍부하게 하고 기업 의 지속 가능한 발전을 촉진하는 데 일정한 참고 가치가 있다. ESG is a kind of financial data that pays more attention to corporate environment, social responsibility and corporate governance. This study explores the relationship between ESG and corporate sustainable development through empirical analysis. This study uses the regression method of fixed effects to conduct empirical research on the data of China's A-share listed companies from 2015 to 2020. The research results show that: good ESG performance can promote the sustainable development of enterprises. At the same time, the higher the attention, the better the ESG performance can promote the sustainable development of enterprises. This study enriches the related research on ESG and has certain reference value for promoting the sustainable development of enterprises.