检索结果-南通市图书馆

A DEA MODEL FOR IDENTIFYING CRITICAL INPUT-OUTPUT PERFORMANCE MEASURES

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2012年第2期25卷 275-286页

作者： Jie WU liang liang School of Management University of Science and Technology of China

In this paper,the authors propose a new model for identifying the critical input-output combinations for each DMU.A real-world application case of 21 international tourist hotels(ITHs) is used to illustrate the propos... 详细信息

关键词： Data envelopment analysis (DEA) efficiency input-output combination performance.

Analysis and experimental study on resistance-increasing behavior of composite high efficiency autonomous inflow control device

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1290-1304页

作者： liang-liang Dong Yu-Lin Zhang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan ProvinceChengdu610500SichuanChina

Bottom water coning is the main reason to reduce the recovery of horizontal bottom water reservoir. By water coning, we mean the oil-water interface changes from a horizontal state to a mound-shaped cone and breaks through to the wellbore. Autonomous inflow control device(AICD) is an important instrument maintain normal production after bottom water coning, however, the resistance increasing ability of the swirl type AICD is insufficient at present, which seriously affects the water control effect. Aiming this problem, this paper designs a multi-stage resistance-increasing and composite type AICD. The separation mechanism of oil-water two phases in this structure, the resistance form of oil-water single phase and the resistance-increasing principle of water phase are analyzed. Establishing the dual-phase multi-stage separation and resistance-increasing model, and verified by measuring the throttling pressure drop and oil-water volume fraction of the AICD, it is found that the composite type AICD has the effect of ICD and AICD at the same time, which can balance the production rate of each well section at the initial stage of production, delay the occurrence of bottom water coning. In the middle and later stages of production, water-blocking can be effectively increased to achieve water control and stable *** structural sensitivity analysis, the influence law of various structural parameters on the water control performance of composite AICD was obtained. The simulation calculation results show that,compared with the existing swirl type AICD, composite AICD has higher sensitivity to moisture content,the water phase throttling pressure drop is increased by 4.5 times on average. The composite AICD is suitable for the entire stage of horizontal well production.

关键词： Water control Flow separation Flow resistance-increasing AICD device Simulation and experiment

Allocating Fixed Costs with Considering the Return to Scale: A DEA Approach

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2016年第5期29卷 1320-1341页

作者： DAI Qianzhi LI Yongjun liang liang School of Management University of Science and Technology of China Institute of Policy and Management Chinese Academy of Sciences

When the allocated fixed cost is treated as the complement of other costs, conventional data envelopment analysis （DEA） researches have ignored the effect of the return to scale （RTS） in fixed cost Mlocation problems. This paper first demonstrates why the RTS should be considered in fixed cost allocation problems. Then treating the fixed cost as a complementary input, the authors investigate the relationship between the allocated cost and the variable return to scale （VRS） efficiency based on the super BCC DEA model. However, the infeasibility problem may exist in this situation. To deal with it, the authors propose an algorithm. The authors find that the super BCC efficiency is a monotone non-increasing function of the allocated cost. Based on the relationship, the authors finMly propose a fixed cost allocation approach in terms of principles as：（i） The fixed cost proportion allocated to inelastic DMUs should be consistent with their consumed cost proportion, and （ii） the same efficiency satisfaction degree to the rest DMUs. The optimal allocation scheme is unique. A numerical example and a real example of allocating fixed costs among 13 subsidiaries are employed to illustrate the proposed approach.

关键词： Data envelopment analysis (DEA) fixed cost allocation infeasibility return to scale(RTS).

Removal and transformation of dissolved organic matter in secondary effluent during granular activated carbon treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第7期9卷 994-1003页

作者： liang-liang WEI Qing-liang ZHAO Shuang XUE Ting JIA State Key Laboratory of Urban Water Resources and Environments （SKL UWRE） School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

This paper focused on the removal and transformation of the dissolved organic matter （DOM） in secondary effluent during the granular activated carbon （GAC） treatment. Using XAD-8/XAD-4 resins, DOM was fractionated into five classes： hydrophobic acid （HPO-A）, hydrophobic neutral （HPO-N）, transphilic acid （TPI-A）, transphilic neutral （TPI-N） and hydrophilic fraction （HPI）. Subsequently, the water quality parameters of dissolved organic carbon （DOC）, absorbance of ultraviolet light at 254 nm （UV-254）, specific ultraviolet light absorbance （SUVA） and trihalomethane formation potential （THMFP） were analyzed for the unfractionated and fractionated water samples. The results showed that the order of the DOC removal with respect to DOM fractions was observed to be HPI〉HPO-A〉HPO-N〉TPI-A〉TPI-N. During the GAC treatment, the THMFP of the unfractionated water samples decreased from 397.4 μg/L to 176.5 μg/L, resulting in a removal efficiency of 55.6%. The removal order of the trilaalomethanes （THMs） precursor was as follows： HPO-A〉TPI-A〉TPI-N〉HPO-N〉HPI. By the GAC treatment, the specific THMFP of HPO-A, TPI-A, TPI-N and the original unfractionated water samples had a noticeable decrease, while that of HPO-N and HPI showed a converse trend. The Fourier transform infrared （FTIR） results showed that the hydroxide groups, carboxylic acids, aliphatic C-H were significantly reduced by GAC treatment.

关键词： Dissolved organic matter (DOM) Fractionation Trihalomethane formation potential (THMFP) Specific THMFP Fourier-transform infrared (FTIR)

DEPENDENCE BETWEEN STOCK RETURNS AND INVESTOR SENTIMENT IN CHINESE MARKETS:A COPULA APPROACH

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2012年第3期25卷 529-548页

作者： Xunfa LU Kin Keung LAI liang liang Department of Management Sciences City University of Hong KongHong KongChina School of Business University of Science and Technology of China

Using data of newly opened stock trading accounts in China as a proxy of investor sentiment index, the authors employ the time-varying copula-GARCH model with Hansen＇s skewed Student-t innovations to investigate the dynamic dependence between investor sentiment and stock returns. The empirical findings show that shifts in investor sentiment are asymptotically positively correlated to stock returns in extreme value situations in both A shares market and B shares market in China, that is to say, stock prices will increase （decrease） more when investors become more bullish （bearish）. Also, results show that the dependence between investor sentiment and stock returns is time-varying, which means that the traditional Pearson＇s correlation based on normal distribution is not enough to describe the relationship between stock market behavior and investor behavior.

关键词： Behavioral finance copula GARCH investor sentiment newly opened stock trading accounts.

Oxygen Availability Affects Behavioural Thermoregulation of Turtle Embryos

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2023年第4期14卷 257-260页

作者： liang liang Weiguo DU Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China

Extending recent findings that reptile embryos seek optimal temperatures inside eggs for thermoregulation,our study demonstrates that this thermoregulatory behaviour can be affected by the amount of oxygen available to an *** exposed embryos of a freshwater turtle(Mauremys reevesii)to two heat sources(an optimal temperature of 30°C and a high temperature of 33°C)under three different oxygen levels–hypoxia(12%O2),normoxia(21%O2)and hyperoxia(30%O2)–and quantified the interactive effects of temperature and oxygen availability on embryonic thermoregulatory *** results demonstrated that,in both thermal treatments,embryos exposed to hypoxia did not move as close to the heat source and therefore selected lower temperatures than those exposed to normoxia or *** may select low temperatures under hypoxic conditions to decrease oxygen consumption and therefore alleviate the negative impact of hypoxic stress.

关键词： behavioural thermoregulation embryonic development heat tolerance hypoxia reptile

Measuring Environmental Performance of Provincial Thermal Power Plants in China:A Malmquist DEA Approach with Fixed-Sum Undesirable Outputs

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2022年第4期35卷 1201-1224页

作者： HOU Wenhui ZHENG Yunwen liang liang LI Yongjun School of Management University of Science and Technology of ChinaHefei230026China

With the development of China’s economy,environmental pollution has become cumulatively *** primary source of environmental pollution is thermal power generation,which has attracted the attention of governments and academia in recent *** effectively reduce environmental pollution,research should study how to constrain the undesirable output of thermal power plants,that is,to limit the total undesirable output of the plants to a certain fixed ***,few studies have suggested that these undesirable outputs should be fixed-sum ***,no previous research publication about thermal power plants has analyzed their environmental performance *** address these gaps,a novel Malmquist-DEA approach is proposed for evaluate the environmental performance of thermal power plants in this *** approach generalizes the equilibrium efficient frontier DEA model with fixed-sum undesirable outputs and incorporates the model into the Malmquist productivity index(MPI).The authors apply this approach to the analysis of provincial thermal power plant environmental performance in China and analyze such plants’trends based on panel data from2011 to *** empirical research shows that the environmental performance of regional thermal power plants was positively affected by efficiency change and negatively affected by technical ***,the authors provide policy suggestions based on our findings.

关键词： Data envelopment analysis environmental performance fixed-sum undesirable outputs Malmquist productivity index thermal power plants

Effects of Pesticide Exposure on Embryonic Development and Hatchling Traits of Turtles

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2016年第1期7卷 28-33页

作者： Baofeng WU liang liang liang MA Weiguo DU Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of Sciences

Deltamethrin is a widespread environmental hormone with endocrine-disrupting properties, but its effect on embryonic development of reptiles is largely unexplored. We investigated the effects of deltamethrin on embryonic development and offspring traits in two turtle species, one with parchment-shelled eggs and the other with rigidshelled eggs. Deltamethrin exposure during egg incubation did not affect hatching success and hatchling body size in either species. However, embryonic exposure to deltamethrin resulted in reduced hatchling locomotor performance in the red-eared slider turtle（Trachemys scripta） with parchment-shelled eggs, but not in the Chinese three-keeled pond turtle（Chinemys reevesii） with rigid-shelled eggs. These results suggest that parchment-shelled eggs are likely more vulnerable to deltamethrin than rigid-shelled eggs.

关键词： Parchment-shelled eggs Rigid-shelled eggs Red-eared slider turtle Trachemys scripta Chinese threekeeled pond turtle Chinemys reevesii Embryo Environmental hormone

A clinical trial of combined use of rosiglitazone and 5-aminosalicylate for ulcerative colitis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第1期14卷 114-119页

作者： Hong-liang liang Qin Ouyang Department of Gastroen-terology West China Hospital Sichuan University Chengdu610041 Sichuan Province China

AIM: To investigate the therapeutic effects of the combined use of rosiglitazone and aminosalicylate on mild or moderately active ulcerative colitis (UC).METHODS: According to the national guideline for diagnosis and treatment of inflammatory bowel disease (IBD) in China, patients with mild or moderately active UC in our hospital were selected from July to November, 2004. Patients with infectious colitis, amoebiasis, or cardiac, renal or hepatic failure and those who had received corticosteroid or immunosuppressant treatment within the last month were excluded. Following a quasi-randomization principle, patients were allocated alternatively into the treatment group (TG) with rosiglitazone 4 mg/d plus 5-ASA 2 g/d daily or the control group (CG) with 5-ASA 2 g/d alone, respectively, for 4 wk. Clinical changes were evaluated by Mayo scoring system and histological changes by Truelove-Richards' grading system at initial and final point of ***: Forty-two patients completed the trial, 21 each in TG and CG. The Mayo scores in TG at initial and final points were 5.87 (range: 4.29-7.43) and 1.86 (range: 1.03-2.69) and those in CG were 6.05 (range: 4.97-7.13) and 2.57 (range: 1.92-3.22) respectively. The decrements of Mayo scores were 4.01 in TG and 3.48 in CG, with a remission rate of 71.4% in TG and 57.1% in CG, respectively. Along with the improvement of disease activity index (DAI), the histological grade improvement was more significant in TG than in CG (P < 0.05).CONCLUSION: Combined treatment with rosiglitazone and 5-ASA achieved better therapeutic effect than 5-ASA alone without any side effects. Rosiglitazone can alleviate colonic inflammation which hopefully becomes a novel agent for UC treatment.

关键词： Peroxisome proliferators-activated receptor γ Rosiglitazone Ulcerative colitis