滴灌棉田节水灌溉系统控制策略研究

针对传统棉田节水灌溉系统灌溉精度低、运行稳定性差的问题,设计了一种基于Fuzzy-PID控制的棉田节水灌溉控制系统。系统通过土壤湿度传感器采集棉田的实时土壤湿度作为控制决策依据,结合专家经验制定模糊控制规则,设计了Fuzzy-PID控制器,并在Simulink中对系统进行建模与仿真试验,对Fuzzy-PID控制方法和常规的PID控制方法进行仿真分析。仿真曲线表明:与传统PID控制器相比,Fuzzy-PID控制的稳态时间减少了约7.3 s,超调量减少了5.65%。试验结果表明:模糊PID控制方式调节精度和稳态性能更好,可及时调整土壤湿度,进行适时、适量的灌溉,一定程度上提高了系统灌溉精度,可以满足大田棉花灌溉需求。

Freezing on demand: A new concept for mine safety and energy savings in wet underground mines

The artificial ground freezing(AGF)systems are designed to operate continuously for an extended period of time to control the groundwater seepage and to strengthen the groundwater structure surrounding excavation areas.This mode of operation requires a massive amount of energy to sustain the thickness of the frozen body.Therefore,it is of great interest to propose new concepts to reduce energy consumption while providing sufficient structural stability and safe operation.This paper discusses the principle of the freezing on demand(FoD)by means of experiment and mathematical model.A lab-scale rig that mimics the AGF process is conceived and developed.The setup is equipped with more than 80 thermocouples,flow-meters,and advanced instrumentation system to analyze the performance of the AGF process under the FoD concept.A mathematical model has been derived,validated,and utilized to simulate the transient FoD concept.The results suggest that the overall energy saving notably depends on the coolant’s temperature;the energy saving increases while decreasing the coolant inlet temperature.Moreover,applying the FoD concept in an AGF system leads to a significant drop in energy consumption.

RESIDENTS' ATTITUDES TO TOURISM DEVELOPMENT IN ANCIENT VILLAGE RESORTS——Case Study of World Cultural Heritage of Xidi and Hong Villages

Tourism development surely has social, economic and environmental impacts on tourist destinations.The study on resorts residents' attitudes can help understand the nature of tourism development and the extent to which it may influence on tourist destinations. By now, researches on residents' perception and attitudes are plenteous in the international circle and achievements are great, yet few are found in developing countries. As a most representative cultural tourist destination, World Cultural Heritage-Xidi and Hong villages in Yi County of Anhui Province, are drawing the attention of both tourists and academic circles. This article, taking Xidi and Hong villages as examples, seeks to analyze ancient village residents' attitudes towards tourism impacts and then tries further to explore the connection between tourism development and residents' attitudes. Both qualitative and quantitative surveys are applied in the exploratory investigation into local residents' attitudes of tourism impacts. Based on abundant face-to-face interviews with the local households, tourism enterprises concerned, local government and tourists from July to August of 2002, we are able to have a better understanding of local residents' attitudes to community life, and perception of tourism impacts on society, economy and environment. By this we can promote domestic study on resorts residents' attitudes, and provide some theoretical grounds for establishing tourism development planning and perfect community participation system at tourist destinations.

Thermodynamic Analysis,Simulation and Optimization on Energy Savings of Ideal Internal Thermally Coupled Distillation Columns

Internal thermally coupled distillation columns (ITCDIC) are the frontier of distillation energy saving research. In this paper, a novel energy saving model of ideal ITCDIC and a simulation algorithm are presented,upon which a series of comparative studies on energy savings with conventional distillation columns are carried out. Furthermore, we present an optimization model of ideal ITCDIC, which can be used to achieve the maximum energy saving and find the optimal design parameters directly. The binary system of benzene-toluene is adopted for the illustrative example of simulation and optimization. The results show that the maximum energy saving of ITCDIC is 52.25% (compared with energy consumption of conventional distillation under the minimum reflux ratio operation); the optimal design parameters are obtained, where the rectifying section pressure and the feed thermal condition are Pr=0.3006 MPa and q=0.5107 respectively.

Analysis of Power Matching on Energy Savings of a Pneumatic Rotary Actuator Servo-Control System

When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic system,and the energy-saving effect is verified by experiments.First,the experimental platform of a pneumatic rotary actuator servo-control system is built,and the mechanism of the valve-controlled cylinder system is analyzed.Then,the output power characteristics and load characteristics of the system are derived,and their characteristic curves are drawn.The employed air compressor is considered as a constant-pressure source of a quantitative pump,and the power characteristic of the system is matched.The power source characteristic curve should envelope the output characteristic curve and load characteristic curve.The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure.The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.

COMPARATIVE STUDY ON RESIDENTS′ PERCEPTION OF TOURISM IMPACT AT TOURIST PLACES——A Case Study of Xidi, Zhouzhuang and Jiuhua Mountain

Based on the questionnaire investigation, the authors make a comparative study on local residents′ perception of tourism impacts in Xidi, Zhouzhuang and Jiuhua Mountain. The result shows that residents of the three places tend to have strong and consistent perception of its positive economic, socio-cultural and environmental impacts, but distinctly diverse ones of its negative impacts. Residents in Xidi and Zhouzhuang also have noticeable perception of its negative environmental impacts while those in Jiuhua Mountain have weaker perception of them. The research confirms the fact that residents are more liable to have positive perceptions at the early stage of the life cycle of the tourist places. The authors conclude that there exists a nonlinear relationship between residents′ perception and tourism development stages, and that tourism socio-cultural impact may appear at an early stage of tourism development instead of being no universal.

Residents'Satisfaction with Public Services in Mountainous Areas:An Empirical Study of Southwestern Sichuan Province,China

Abstract： Enhancing the efficiency of public services is essential to residents in mountainous areas. It is also important to promote sus- tainable development of these regions. Analysing residents＇ satisfaction with public services in mountainous areas can help in evaluating outcomes of fiscal investment and identifying potential coping approaches for improving public service efficiencies. The residents＇ satisfaction with public services and the factors that influence such satisfaction were examined in this study. A study of 12 towns located in the southwestern Sichuan Province was performed using an entropy-weighted analytic hierarchy process （EWAHP）, the technique for order preference by similarity to ideal solution （TOPSIS） and Tobit regression methods. The results indicate that： 1） the spatial distribu- tion of satisfaction with public services is non-uniform, and the spatial distribution structure varies for different types of public services. 2） Residents＇ satisfaction with public services is influenced by both objective and subjective factors. Population density, economic dis- tance, social and cultural divisions and elevation are the major objective factors, whereas bounded rationality, the hierarchy of needs and service expectations are the main subjective factors. The most effective strategies for enhancing residents＇ satisfaction with public ser- vices are likely to be clustering the population, choosing supply centres with different public services, regulating the cultural division in ethnic minority towns, selecting supply priorities in accordance with residents＇ needs, implementing targeted intervention policies and establishing ＇bottom-up＇ and ＇top-down＇ integrated decision-making mechanisms. Keywords： mountainous areas; public services; residents＇ satisfaction; entropy-weighted analytic hierarchy process （EWAHP）; technique for order preference by similarity to ideal solution （TOPSIS）; Tobit regression; southwestern Sichuan Province

Use of Diesel Engine and Surface-Piercing Propeller to Achieve Fuel Savings for Inshore Fishing Boats

Fishing is a major local industry in Malaysia, particularly in rural areas. However, the rapidly increasing price of fuel is seriously affecting the industry＇s viability. At present, outboard petrol engines are the preferred choice for use in small-scale fishing boats because they deliver the advantages of high speed and low weight, they are easy to install, and they use minimal space. Petrol outboard engines are known to consume a greater amount of fuel than inboard diesel engines, but installing diesel engines with conventional submerged propellers in existing small-scale fishing boats is not economically viable because major hullform modifications and extra expenditure are required to achieve this. This study describes a proposal to enable reductions in fuel consumption by introducing the combined use of a diesel engine and Surface-Piercing Propeller （SPP）. An analysis of fuel consumption reduction is presented, together with an economic feasibility study. Resulting data reveal that the use of the proposed modifications would save 23.31 liters of fuel per trip （40.75%） compared to outboard motors, equaling annual savings of RM 3962 per year.

Savings,investment,and growth in Nepal:an empirical analysis

This study analyzes the relationship between savings,investment,and economic growth in Nepal over 1975–2016.The structural breaks in the variables have been accounted for using the(Zivot and Andrews’s,J Bus Econ Stat 10:251–2701992)unit root test along with(Gregory and Hansen’s,Oxf Bull Econ Stat 58:555–560,1996)cointegration approach.The ARDL approach to cointegration in the presence of structural breaks has also been utilized to analyze the long-and short-run dynamics of savings,investment,and growth in Nepal.The results show structural breaks in the real GDP per capita during 2001 when the Royal Massacre and a state of emergency have taken place in Nepal.After allowing for this structural break,evidence of a cointegration relationship amongst savings,investment,and economic growth was identified.The estimates of the ARDL approach suggest that investment has a significant and positive impact on economic growth.However,gross domestic savings have a negative impact on growth in the long run.These results clearly show weaknesses of the economy in mobilizing savings into productive sectors.

Runtime Energy Savings Based on Machine Learning Models for Multicore Applications

To improve the power consumption of parallel applications at the runtime, modern processors provide frequency scaling and power limiting capabilities. In this work, a runtime strategy is proposed to maximize energy savings under a given performance degradation. Machine learning techniques were utilized to develop performance models which would provide accurate performance prediction with change in operating core-uncore frequency. Experiments, performed on a node (28 cores) of a modern computing platform showed significant energy savings of as much as 26% with performance degradation of as low as 5% under the proposed strategy compared with the execution in the unlimited power case.

City Size,Commuting Cost and Household Savings Rate:Evidence from China

Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.

Factors associated with financial support in old age for young and middle-aged rural residents in China

This study examined the factors associated with financial support in old age from three primary mechanisms-personal savings,family support,and social insurance-to explore the implications for the future development of China's rural social welfare system.Cross-sectional surveys of 1392 young and middle-aged rural residents were conducted in July and August2012.The results showed that while social insurance was increasingly acceptable,personal savings and family support still had fundamental value.Combining the three mechanisms,the rural old-age welfare system presented nontraditional features.China's new rural endowment insurance is discussed as a means to address the need for financial support among the rural aging population.

RELATIONSHIP BETWEEN RESORT LIFE CYCLE AND RESIDENTS' PERCEPTION AND ATTITUDE——A Case Study of Putuo Mountain

The change in residents′ perception and attitude and resort life cycle are the basic problems in the course of resort evolution. This thesis sets up the dynamic model of residents′perception and attitude, analyzes the linkage between residents′ perception and attitude and the influential factors of resort life cycle, and finally, with a case study of Putuo Mountain, preliminarily discusses the relationship between resort life cycle and residents′perception and attitude. The research findings show that, although within development stage of life cycle, Putuo Mountain has already presented some signs of mature stage. The on-the-spot survey also indicates that, the local residents′ positive perception is stronger than their negative perception. But compared with residents in some other coastal resorts such as Haikou and Sanya, negative perception of residents in Putuo Mountain is more evident, as the result of the smaller tourism carrying capacity in Putuo Mountain. There are some influential factors that have great impact on tourism carrying capacity in Putuo Mountain: tourist-resident number ratio, residents′ benefit-cost ratio and characteristics of tourism resources. And the less influential factors are residents′ demographic character, tourist behavioral character and cultural differences between local residents and tourists. Therefore, effective measures should be taken to adjust the structure of tourism product for the purpose of expanding tourism carrying capacity, lowering its pressure, lessening residents′ environmental cost and enhancing their positive perception, which is the most essential prerequisite for the maturation of life cycle in Putuo Mountain.

Process Adaption of a Small WWTP Operated at Low Loading Conditions for Substantial Energy Savings

The very long tradition of the activated sludge treatment model within the water industry has demonstrated very versatile possibilities to adopt the operation mode for different enhancements. By looking into other treatment models within the activated sludge family it is possible to find alternatives for the operation. This paper concentrates on the possibilities to improve even small WWTP with respect to energy savings. The small plant in Northern Sweden, called Rosvik WWTP, is given as an example. Some important findings related to the intermittent aeration mode may be summarized as follows: 1) An energy savings for the operation of the small WWTP with respect to aeration needs that resulted in a decrease of the energy power supply by more than 35%, as compared with the previous operation based on continuous aeration;2) The up to date effluent levels with respect to the main pollutants have remained at very good levels in 2020, P-level averages 0.16 mg P/l versus consent level < 0.5 mg P/l;COD-level 40 versus < 70 mg/l and BOD7 9 versus < 15 mg/l;3) Sometimes, also improved sludge settling characteristics have been observed, thus providing improved discharge figures;4) The potential to develop an enhanced biological phosphorus removal. There are however some needed conditions to accomplish these improvements: 1) Reliable on-line probes for both oxygen control, SS-concentration control and optionally also for nitrogen control;2) A flexible automation system that allows the needed process modifications to take place;3) And finally, very important dedicated and competent plant operators, with the needed curiosity for operation improvements.

Examining Potential Travel Time Savings Benefits Due to Toll Rates That Vary by Lane

By assigning different toll rates to different lanes during peak traffic hours, the demand for each lane of a road can be optimized. Lanes with lower travel times charge higher toll rates which are paid by those drivers who have higher values of travel time (VTT) and who want to avoid congestion in the other lanes. Conversely, travel time for those drivers with lower values of travel times will increase as they select the lower priced and slower lanes. This research examines toll rates that minimize the total value of travel time spent on the road under such a scenario. The optimum toll rates are dependent on the total road volume and distribution of VTT. The results show that total saved value of travel time can easily reach 11% of the total value of time spent traveling on the lanes when compared to a toll road with a uniform toll rate for all lanes. These savings vary based on many factors including the number of travelers on urgent trips.

Optimization of Finishing Process and Energy Savings in Denim Textile Facility

Denim is widely accepted among exported textile products due to its aesthetics, appearance, and fashion. Practitioners employed several physical or chemical treatments to improve denim qualities in denim finishing operations. So, several treatment processes, including enzymatic, bleaching, singeing, heat set, and ozone finish, are used, which made this processing more energy consumption and time-consuming. Therefore, it is significant to investigate how changing the chemicals and raw ingredients could improve the finishing process, which is environmentally and economically beneficial for sustainable production practices in the denim finishing process. This study’s research design comprises an experimental investigation in a denim plant in Bangladesh. Two different fabrics were chosen to analyze, determining the potential savings of finishing on the denim fabrics’ performance characteristics. By deducting singeing and heat-set processes, the researchers ran an experimental process by maintaining the same length of fabric. Then, the impacts of finishing process optimization on the mechanical, thermal, and comfort parameters of drape, stiffness, and tear strength were examined. The study’s findings demonstrated that this experiment increased productivity and reduced the finishing unit’s energy consumption without compromising the denim fabrics’ quality. This study significantly impacts environmental sustainability by preserving limited energy resources and manufacturing denim finishing processes.

The Optical Properties of Black Coatings and Their Estimated Cooling Effect and Cooling Energy Savings Potential

The optical properties of coatings pigmented with different black colorants were systematically investigated and their surface temperatures and cooling energy savings were estimated. The black coatings pigmented with chromite iron nickel black and manganese ferrite black spinel colorants are not cool enough to be energy efficient cool black coatings. The cool black coatings pigmented with NIR-transmitting perylene black and dioxazine purple colorants possess a green shade and a violet shade, respectively. The estimated surface temperature reduction values and annual cooling energy savings in Beijing range from 3.0&deg;C and 1.21 kWhm-2yr-1 for the black coating pigmented with chromite iron nickel colorant to 13.8&deg;C and 5.52 kWhm-2yr-1 for the black coating pigmented with dioxazine purple colorant, respectively.

China’s High Savings Rate Puzzle:Role of Precautionary Saving

Academics have yet to agree on the effectiveness of the precautionary saving theory in explaining Chinese households’saving behavior.With the Wenchuan megaearthquake of 2008 as an uncertain event to overcome the endogeneity problem of income volatility,this paper puts forward a brand-new hypothesis that"an earthquake influences household saving rate through its effects on expected income and the variance of expected income."Then,we employ propensity score matching-difference-in-differences(PSMDID)method,the systematic GMM methods,the synthetic control method,together with instrumental variable method,for an analysis of Chinese Household Income Project(CHIP)and inter-provincial data at the micro and macro levels,respectively.We find that the Wenchuan mega-earthquake was followed by an increase in the variance of household expected income in Sichuan and a significant rise in the household saving rate.Second,social protection is negatively correlated with expected income,and has a significant substitutive relationship with saving rate.This finding indirectly proves that the earthquake’s impact on the household saving rate is subject to the variance of expected income,shedding light on how the precautionary saving motivation works in the real world.

Daylight Savings Calculation Technique for Smart Buildings

This publication presents a technique of quantifying energy savings due to daylight. The technique is designated to be used in smart buildings or similar applications where daylight harvesting is welcomed. The technique is divided into three stages. In the first stage an optical sensor is evaluated for its P (power)-E (illumination) response characteristics. In the second stage the calibration of room properties is carried out. In the final stage photometric calculations are performed, and energy savings are calculated. The major advantage of the proposed approach is to determine energy savings during the design stage of a building, not after the building construction or retrofitting. The information obtained from the calculations is useful for investors, future tenants and environmentalists.