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.

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.

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.

Upregulation of long non-coding RNA XIST has anticancer effects on epithelial ovarian cancer cells through inverse downregulation of hsa-miR-214-3p

Changhong Wang,Shan Qi,Cheng Xie,Chunfu Li,Pu Wang,Dongmei Liu 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.6

Objective: The present study is to evaluate the biological functions of long non-coding RNA (lncRNA), X-inactive specific transcript, X-inactive specific transcript (XIST) in human epithelial ovarian cancer (EOC). Methods: XIST was upregulated in EOC cell lines, CAOV3 and OVCAR3 cells by lentiviral transduction. The effects of XIST overexpression on cancer cell proliferation, invasion, chemosensitivity and in vivo tumor growth were investigated, respectively. Possible sponging interaction between XIST and human microRNA hsa-miR-214-3p was further evaluated. Furthermore, hsa-miR-214-3p was overexpressed in XIST-upregulated CAOV3 and OVCAR3 cells to evaluate its effect on XIST-mediated EOC regulation. Results: Lentivirus-mediated XIST upregulation had significant anticancer effects in CAOV3 and OVCAR3 cells by suppressing cancer cell proliferation, invasion, increasing cisplatin chemosensitivity and inhibiting in vivo tumor growth. Hsa-miR-214-3p was confirmed to directly bind XIST, and inversely downregulated in XIST-upregulated EOC cells. In EOC cells with XIST upregulation, secondary lentiviral transduction successfully upregulated hsa-miR-214-3p expression. Subsequently, hsa-miR-214-3p upregulation functionally reversed the anticancer effects of XIST-upregulation in EOC. Conclusion: Upregulation of lncRNA XIST may suppress EOC development, possibly through sponging effect to induce hsa-miR-214-3p downregulation.

Ginseng polysaccharides: A potential neuroprotective agent

Na Wang,Xianlei Wang,Mengjiao He,Wenxiu Zheng,Dongmei Qi,Yongqing Zhang,Chun-chao Han 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.2

The treatments of nervous system diseases (NSDs) have long been difficult issues for researchers because of their complexity of pathogenesis. With the advent of aging society, searching for effective treatments of NSDs has become a hot topic. Ginseng polysaccharides (GP), as the main biologically active substance in ginseng, has various biological properties in immune-regulation, anti-oxidant, anti-inflammation and etc. Considering the association between the effects of GP and the pathogenesis of neurological disorders, many related experiments have been conducted in recent years. In this paper, we reviewed previous studies about the effects and mechanisms of GP on diseases related to nervous system. We found GP play an ameliorative role on NSDs through the regulation of immune system, inflammatory response, oxidative damage and signaling pathway. Structure-activity relationship was also discussed and summarized. In addition, we provided new insights into GP as promising neuroprotective agent for its further development and utilization.

Emericella spp . in Soils of North China

( Li Dongmei,Wang Duanli,Li Ryoyu,Wang Xiaohong ) 한국균학회 1997 97 KOREA CHINA JOINT SYMPOSIUM Vol.- No.-

The Effects of Changes in Workplace Environment on Sedentary Behavior and Work Efficiency: A Natural Pre-Post Study

Jiameng Ma(Jiameng Ma),Dongmei Ma(Dongmei Ma),Qiang Wang(Qiang Wang),Hyunshik Kim(Hyunshik Kim) 사피엔시아 2020 Exercise Medicine Vol.4 No.-

Objectives: The workplace environment has an influence on the physical well-being of workers and their productivity. This study examined how sedentary time and work efficiency changed before and after an intervention to improve the ergonomics of a workplace environment. Methods: This study was designed as a natural pre-post study. Workers were evaluated 101 (77% men, mean [SD] age=44.6[9.8] years) after the intervention. The intervention included the addition of sit-stand desks, fitness rooms, and rest areas at the workplace. The effect of the intervention was assessed after a period of three months. Sedentary behavior and physical activities were evaluated using triaxial accelerometers, body fat percentage and fat-free mass were calculated from body composition, and work engagement and work performance were evaluated through questionnaires. T-tests were used to compare the differences. Results: The percentage of time spent sitting decreased post-intervention (-1.7, 95% CI: -0.4, -3.1). Work performance compared to either three months pre-survey increased significantly post-intervention (Most workers assessment: 0.4, 95% CI: 0.8, 0.3; Self-rated performance the past year or two: 0.4, 95% CI: 0.6, 0.4; Self-rated performance the past 4 weeks: 0.3, 95% CI: 0.6, 0.3). Work engagement improved significantly in terms of vigor at work (0.8, 95% CI: 1.1, 0.5), dedication to work (0.8, 95% CI: 1.1, 0.7), and absorption in work (0.7, 95% CI: 1.1, 0.5). Conclusions: Improving a workplace environment using existing facilities decreased sedentary time and enhanced work efficiency—these findings are useful for workplace health promotion and public health policies.

The Correlation between Sedentary Behavior by Time Period and Physical Activity and Health Indicators among Japanese Workers

Jiameng Ma(Jiameng Ma),Dongmei Ma(Dongmei Ma),Qiang Wang(Qiang Wang),Hyunshik Kim(Hyunshik Kim) 사피엔시아 2019 Exercise Medicine Vol.3 No.-

Objectives: In order to reduce the sedentary behavior of workers who remain seated for extended periods of time, the correlation between sedentary behavior by time period and health indicators must be investigated. Thus, the purpose of this study is to investigate the correlation between the sedentary behavior during work hours or per day and the amount of physical activity and health indicator. Methods: Based on an objective measurement method using an accelerometer and Inbody, the correlation among sedentary behavior, amount of physical activity, body fat percentage, muscle mass, and demographic variables in the survey of 101 Japanese workers was analyzed. For the amount of physical activity, a triaxial accelerometer was used to measure light-intensity lifestyle activity [1.6–2.9 metabolic equivalents (METs)], sedentary time (≤1.5 METs), and vigorous physical activity (3 METs or above), which was evaluated every 10 seconds. Results: The results reveal that the sedentary behavior by time period is related to gender, age, type of occupation, low-intensity physical activity, and walking time, in which low-intensity physical activity has a greater effect on the sedentary behavior than moderate-intensity or higher physical activity. Specifically, for the sedentary time during work hours, the subjects who perform more low-intensity physical activity had a shorter sedentary time than those who do not (OR = 0.41, 95 % CI = 0.17-0.97), and those who have longer walking times per day had a shorter sedentary time than those who do not (OR = 0.21,95 % CI = 0.62-0.72). Conclusions: In order to reduce the SB of workers in the future, research on developing a strategic intervention method based on the results of this study should be conducted.

Application of Data Mining Technology in the Screening for Gallbladder Stones: A Cross-Sectional Retrospective Study of Chinese Adults

Dongmei Pei,Shuang Wang,Chenhui Bao 연세대학교의과대학 2024 Yonsei medical journal Vol.65 No.4

Purpose: The purpose of this study was to use data mining methods to establish a simple and reliable predictive model based on the risk factors related to gallbladder stones (GS) to assist in their diagnosis and reduce medical costs. Materials and Methods: This was a retrospective cross-sectional study. A total of 4215 participants underwent annual health ex aminations between January 2019 and December 2019 at the Physical Examination Center of Shengjing Hospital Affiliated to Chi na Medical University. After rigorous data screening, the records of 2105 medical examiners were included for the construction of J48, multilayer perceptron (MLP), Bayes Net, and Naïve Bayes algorithms. A ten-fold cross-validation method was used to verify the recognition model and determine the best classification algorithm for GS. Results: The performance of these models was evaluated using metrics of accuracy, precision, recall, F-measure, and area under the receiver operating characteristic curve. Comparison of the F-measure for each algorithm revealed that the F-measure values for MLP and J48 (0.867 and 0.858, respectively) were not statistically significantly different (p>0.05), although they were significantly higher than the F-measure values for Bayes Net and Naïve Bayes (0.824 and 0.831, respectively; p<0.05). Conclusion: The results of this study showed that MLP and J48 algorithms are effective at screening individuals for the risk of GS. The key attributes of data mining can further promote the prevention of GS through targeted community intervention, improve the outcome of GS, and reduce the burden on the medical system.

An Improved Analytic Model for Power System Fault Diagnosis and its Optimal Solution Calculation

Wang, Shoupeng,Zhao, Dongmei The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

When a fault occurs in a power system, the existing analytic models for the power system fault diagnosis could generate multiple solutions under the condition of one or more protective relays (PRs) and/or circuit breakers (CBs) malfunctioning, and/or an alarm or alarms of these PRs and/or CBs failing. Therefore, this paper presents an improved analytic model addressing the above problem. It takes into account the interaction between the uncertainty involved with PR operation and CB tripping and the uncertainty of the alarm reception, which makes the analytic model more reasonable. In addition, the existing analytic models apply the penalty function method to deal with constraints, which is influenced by the artificial setting of the penalty factor. In order to avoid the penalty factor's effects, this paper transforms constraints into an objective function, and then puts forward an improved immune clonal multi-objective optimization algorithm to solve the optimal solution. Finally, the cases of the power system fault diagnosis are served for demonstrating the feasibility and efficiency of the proposed model and method.