Number and distribution of cranes wintering at Poyang Lake,China during 2011-2012

Poyang Lake is a very important wintering place for cranes in China and East Asia.Two crane surveys were conducted at Poyang Lake during the 2011/2012 winter,the first on 18-19 December 2011 and the second on 18-19 February 2012.The survey covered the entire Poyang Lake basin,as well as two main lakes in Jiujiang (Saicheng Hu and Chi Hu),i.e.,a total of 85 sub-lakes were surveyed.Both surveys recorded four species of cranes.The first survey on 18-19 December 2011 recorded 4577 Siberian Cranes (Grus leucogeranus),mostly in Bang Hu,Sha Hu and Dahu Chi,302 Hooded Cranes (G.monacha),885 White-naped Cranes (G.vipio) and 8408 Eurasian Cranes (G.grus),for the most part in the center of the lake basin.The second survey on 18-19 February 2012 recorded 3335 Siberian Cranes (mostly in Poyang Lake National Nature Reserve (PLNR) and its surrounding areas),110 Hooded Cranes (largely in PLNR and its surrounding areas),283 White-naped Cranes (86％ in Bang Hu) and 2205 Eurasian Cranes (particularly in Duchang and Nanjishan NNR).The number of Siberian Cranes enumerated in December was 1000 more than the second count in February 2012.It is not possible to rule out double counting due to the close proximity of the main sites of the Siberian Cranes.During winters from 1998 to 2009,the average of the highest counts each winter was 3091,ranging from 2345 in 1996 to 4004 in 2002.By comparison with counts taken at other times,we therefore estimate a wintering population of Siberian Cranes of ～3800-4000 at Poyang Lake.Additional evidence will be needed to raise the world population estimate.Our more recent surveys indicate a continuing decline in the number of White-naped Cranes and an increase in Eurasian Cranes.

Evaluation of Driver-Induced Human Errors in Smart Construction Tower Crane Operations Based on DEMATEL-ISM-MICMAC

With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing factors, human unsafe behavior stands out as a primary cause for these incidents. This study aims to assess the human reliability of tower crane operations on smart construction sites. To proactively enhance safety measures, the research employs text mining techniques (TF-IDF-Truncated SVD-Complement NB) to identify patterns of human errors among tower crane operators. Building upon the SHEL model, the study categorizes behavioral factors affecting human reliability in the man-machine interface, leading to the establishment of the Performance Shaping Factors (PSFs) system. Furthermore, the research constructs an error impact indicator system for the intelligent construction site tower crane operator interface. Using the DEMATEL method, it analyzes the significance of various factors influencing human errors in tower crane operations. Additionally, the ISM-MICMAC method is applied to unveil the hierarchical relationships and driving-dependent connections among these influencing factors. The findings indicate that personal state, operating procedures, and physical environment directly impact human errors, while personal capability, technological environment, and one fundamental organizational management factor contribute indirectly. .

Impact of marsh changes on breeding cranes in Sanjiang Plain,northeastern China

In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the summers of 2007 and 2008,and obtained information on the changes in its marsh through interpretation of satellite images in 1986,1995,2000 and 2005.A comparison between the 1984 and 2008 census shows that:1) the number of Red-crowned Cranes remained stable at about 300 birds,while the number of White-naped Cranes increased markedly; 2) the estimates of nests of Red-crowned cranes are close to the numbers of 1984,while approximately 90％ of the nests of these two crane species were distributed over five national nature reserves (NNRs); 3) the two crane species became more concentrated in three regions,i.e.,the Fuyuan Delta,the middle reaches of the Naoli and Qixing rivers,and the Xingkai Lake wetlands,rather as formerly in six regions.The area of the marsh decreased by 45％ within the 20-year period from 1986 to 2005.The major loss of the marsh area was in the form of a conversion to paddy fields and dry land,which can be primarily attributed to direct human activity under various economic and policy drivers.The disappearance of cranes in the Dulu and Abuqin rivers was induced by large-scale agricultural development.The fragmentation into and isolation of small areas of the marsh became increasingly more serious,which resulted in unsuitable condtions for crane breeding in small patches of the marsh.The number of cranes declined from 1984-1995 but had recovered remarkably by 2008,which may be due to theestablishment of a system of nature reserves,in place since 2000.The land ownership of the reserve plays a key role in maintaining the integrity of the wetland ecosystem,especially in Sanjiang,Honghe,Naolihe and Qixinghe NNRs,which together accommodated approximately 80％ of the population of cranes.However,we did not discover any nests at all in the provincial and municipal reserves,which may be attributed to high human disturbances in these areas.In the end,we propose some recommendations on reserve management.

Biological Status of Captive Crane in Southern Districts of Northern Pakistan

A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Northern Pakistan. Field survey, questionnaire and interview with communities were the major tools for the data collection. Total 165 and 85 camps were visited, respectively, in fall, 2008 and spring, 2009. These camps were established in Baran dam, Kurram, Kashu, Kethu and Dowa in Bannu; and Gambilla, Lunder and Chall rivers in Lakki. The numbers of 1,650 hunters have 6,600 demoiselle and 3,300 common captive cranes in Bannu and Lakki, respectively. From 920 breeding pairs, 900 eggs were obtained, from which only 640 were hatched. Among natural foods of the cranes, snails, grasshoppers and earthworms, the pebbles were the most favorite foods. The young ones of cranes were fed on maize bread, eggs of insects and other small animals like wasp＇s larvae and grasshoppers by hunters. They faced the problems of development of feathers, trapping in mud and parasitic attack during their development. The cranes suffered from many diseases; head tumor, influenza and stomach blockage were the most common in the adults and young ones. The hunters used traditional things, garlic, coriander and brown sugar with antibiotics for treatments of diseases. Migratory cranes were found to be declining viewed by hunters in southern districts of Northern Pakistan. Knowledge about egg hatching, foods and diseases of common and demoiselle captive cranes, might be assisted in their conservation.

Habitat utilization and resource partitioning of wintering Hooded Cranes and three goose species at Shengjin Lake

The loss and degradation of wetlands have adversely affected waterbirds, which depend on wetland habitats. Interspecific competition has an important effect on habitat utilization of wintering waterbirds. Resource utilization, including partitioning, in degraded wetlands has become a hot issue in ecological studies of wintering waterbirds. In order to have an insight into the habitat utilization and resource partitioning between a Hooded Crane(Grus monacha) population and the guild of three goose species, i.e., Anser fabalis, A. albifrons and A. erythropus wintering in lake wetlands, we carried out a study at Shengjin Lake National Nature Reserve from November 2011 to April 2012. We surveyed the Hooded Cranes and goose guild foraging in various habitats during the wintering periods with a combined method of fixed route searching and fixed site observations. Resource partitioning was studied by means of calculating habitat utilization rates and the width and overlap of spatial niches. The results showed that the habitat utilization rate and the width of spatial niches of the Hooded Crane population and goose guild shifted with the season. The habitat utilization rates of the cranes in grasslands were high at all three wintering stages. The habitat utilization rates were 0.454, 0.435 and 0.959 respectively for the Hooded Cranes and 0.627, 0.491 and 0.616 for the goose guild. This suggests that the overlap in grasslands was higher between cranes and goose guild. Most habitats were accessible at the middle stage, so the width of the spatial niche of the cranes(1.099) and goose guild(1.133) both reached their peak at this stage. The greatest niche overlap was 0.914 for these two groups at the late stage, followed by 0.906 at the middle stage and the smallest was 0.854 at the early stage. Ecological response to the changes in habitats of wintering waterbirds was clearly shown in the dynamic variations of the niche of both the Hooded Cranes and the three goose species. Coexistence among waterbirds was achieved by regulation of niche width to reduce niche overlap and relieve interspecific resource partitioning.

Fatigue behavior of crane beam strengthened with CFRP

In order to study the fatigue behavior of the damaged reinforced concrete （RC） beams strengthened by carbon fiber reinforced polymer （CFRP） laminate, three T-shaped beams strengthened by CFRP and one contrasting beam are tested under fatigue loading, with the parameters of different modes of strengthening and different fatigue load levels considered. The main results obtained from the tests are： the width of the crack decreases 50. 2% to 66%, and the development of the crack is limited; the stress of steel decreases 24. 1% to 28. 2%, and the stiffness increases 14.9% to 16. 1% after being strengthened. Based on the technical specification for strengthening concrete structures with CFRP and the conclusions from the tests, a calculating scheme of the flexure stiffness is given, which can be used for reference in engineering design. Finally, some suggestions are given for design in fatigue strengthening.

Effects of human disturbance on the Hooded Crane (Grus monacha) at stopover sites in northeastern China

There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200％ in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p ＜ 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species.

Population sizes and group characteristics of Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) in Poyang Lake Wetland

Both the Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies.To document the current size of their respective populations and characterize their groups,between October 2012 and April 2013 we undertook fieldwork at four nature reserve areas within the Poyang Lake wetlands.We divided Poyanghu National Nature Reserve(PYH) into the Wucheng(PWC) and Hengfeng areas(PHF),because each are each located in different counties.Our fieldwork showed that the Siberian Crane occurred mainly in PYH(364 in the PHF,158 in the PWC) and the Nanjishan Wetland National Nature Reserve(NJS,with 200 individuals).The Hooded Crane was mainly distributed in PYH(302 in the PHF and 154 in the PWC).Family groups accounted for more than 50% of the total number of groups among both species,with Hooded Cranes forming more family groups than Siberian Cranes.Typically,these groups were formed of two adults with one offspring(Siberian Crane),and two adults with two offspring(Hooded Crane),with the mean family group size of the Siberian Crane and Hooded Crane being respectively 2.65±0.53(n=43) and 3.09±0.86(n=47) individuals per group.The mean collective group size of the Siberian Crane and Hooded Crane included 28.09±24.94(n=23) and 28.94±27.97(n=16) individuals per group,respectively,with the proportion of juveniles among Hooded Cranes being more than double that seen among the Siberian Cranes.

ROBOTIC DYNAMIC MODEL ON LOAD SWING OF SLEWING CRANE

This paper sets up a robotic manipulator model on slewing crane. The model can synthetically describe the dynamic behavior of the load of slewing crane in rotating, elevating and hoisting motions. The dynamic equations of the system are recursively derived by a Newton Euler method. The dynamic behavior of the load of slewing crane in rotating motion is simulated on a computer. The method of robotic dynamics to derive the dynamic equations of the swing of load is accurate and convenient and it has good regularity. The result of the study provides a base in theory on design of crane and an accurate mathematical model for controlling the swing of load.

Suitable distance to observe Red-crowned Cranes:a note on the observer effect

In order to assess the effect of the observer distance on the behavior of Red-crowned Cranes (Grus japonensis),we studied their time budgets with a gradient of observer distances in Yancheng,China from December 2008 to March 2009.Observer distance was classified into four levels,i.e.,＜ 200 m,200-300 m,300-400 m and ＞ 400 m.The results indicated that cranes increased their vigilance when the observer was less than 300 m away.A safe distance for the observer was often as far as or more than 300 m.Cranes increased scan frequency when observers were within 200 m,whereas they prolonged the duration of their scan when observers were between 200 m and 300 m away,indicating two distinct vigilant strategies,given the observer distance.We suggest an observer distance of at least 300 m,in order to minimize the observer effect.

海洋平台吊机iCrane自动控制模型

为了促进海洋平台吊机产品系列化、自动化及信息化发展进程,针对多样化的海洋平台吊机产品,提出一种iCrane控制系统模型。描述了模型组成、功能和应用方法。介绍了载荷力矩指示、运动及调速、安全保护及报警等关键技术,并以一种常用的海洋钻井平台配套吊机为控制对象设计开发了一套应用样机。样机在模拟试验和应用实例中取得了良好的效果。最后指出,在此模型下的各个层面和单元都集中体现海洋平台吊机系列化产品的自动化和信息化水平,并可积累大量宝贵的信息和数据资源,为将来实现油气装备大数据库管理打下坚实基础。

Status and behavior of the Black-necked Crane (Grus nigricollis) in the Altun Mountain Reserve,Xinjiang

The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,population dynamics,flock size and behavior was conducted in Altun Mountain National Natural Reserve from September to November 2011.We investigated the size and distribution of its population in this area with a sample spot survey and by direct counting.We found Black-necked Cranes on the wetlands of Wuzunxiaoer,Yusup Aleksei,Yaziquan,Qimantag,Tula Ranch and elsewhere,where we recorded 126 individual birds of the species in Yixiekepati (37° 15′-37°23′N,90°11′-90°20′E,elevation 3903 m),the largest population we have observed in this area.In the reserve,the population consists of about 180-200 birds.Combined with previous records,we conclude that more than 260 Black-necked Cranes live in Xinjiang.Cranes gathered conspicuously in the middle of October where the highest number of birds appeared on 29 October.All of the cranes had migrated out of this area by 6 November.Time budgets and diurnal behavior rhythms of Blacknecked Cranes were observed in the Yixiekepati wetland at daylight (from 06:00 to 18:00).Foraging was the most prevalent type of behavior during the autumn period,accounting for 58.9％ of the diurnal time budget,followed by preening (13.2％),vigilance (9.5％),walking (8.2％),flying (3.5％),resting (3.4％),chirping (2.7％) and other types of behavior (0.6％).

On Naturalism in Stephen Crane's The Open Boat

Stephen Crane is one of the greatest figures in the history of American literature and his novella The Open Boat is widely known by people all over the world as a representative work of Naturalism. This paper aims at exploring Naturalism in Stephen Crane's The Open Boat,which will guide the readers to understand American Naturalism accurately and thoroughly. It firstly introduces the author and his novel The Open Boat. Secondly,it progressively dissects Naturalism. It not only analyses the general characteristics of Naturalism with details in The Open Boat,but also interprets the distinguishing features of American Naturalism so that readers can better understand the features of American Naturalism. Through textual perusal,it further studies the unique characteristics of Stephen Crane's Naturalism and lays particular emphasis on Crane's special concern on the awakening of humanity. It is hoped that this thesis can help readers get an in-depth comprehension of Naturalism and gain some inspiration from TheOpenBoat.

Detection of mechanical stress in the steel structure of a bridge crane

A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing include unevenness of the crane track,unequal loading of the traction drives depending on the position of the crane trolley,slips and different sizes of travel wheels and combinations of these causes.Firstly,this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane,caused by the effects of skewing.The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge.The resulting electrical signal from element mechanical voltage detectors,loaded by axial forces,can be used for feedback control of separate crane travel drives controlled by frequency converters.Secondly,this paper presents the calculation of the lateral transverse forces according to CSN 270103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019.Finally,this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment.At the same time,it presents records of the measured axial forces acting in the mechanical stress detectors,arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes.

Pressure from hunting on crane species in southern districts of northern Pakistan

This study was carried out to assess the biological status of two crane species, the Common Crane (Grus grus L.) and the Demoiselle Crane (Anthropoides virgo L.), with respect to the hunting pressure in two southern districts of northern Pakistan, Bannu and Lakki. Field surveys, interviews and questionnaires were the major tools for data collection. We visited 165 hunting camps in the fall of 2008 and 85 in the spring of 2009 in the two districts. Of the hunters, most possessed wildlife permits for hunting and most people hunted for recreation. According to our survey, the population of two crane species is declining due to overhunting, destruction of natural habitats, anthropogenic activities and geographical factors. Suggestions for protection of the cranes are proposed.

Pendulation reduction on ship-mounted container crane via T-S fuzzy model

Ship-mounted container cranes are challenging industrial applications of nonlinear pendulum-like systems with oscillating disturbance which can cause them unstable.Since wave-induced ship motion causes the hoisted container to swing during the transfer operation,the swing motion may be dangerously large and the operation must be stopped.In order to reduce payload pendulation of ship-mounted crane,nonlinear dynamics of ship-mounted crane is derived and a control method using T-S fuzzy model is proposed.Simulation results are given to illustrate the validity of the proposed design method and pendulation of ship-mounted crane is reduced significantly.

Design for a Crane Metallic Structure Based on Imperialist Competitive Algorithm and Inverse Reliability Strategy

Uncertainties in parameters such as materials, loading, and geometry are inevitable in designing metallic structures for cranes. When considering these uncertainty factors, reliability-based design optimization （RBDO） offers a more reasonable design approach. However, existing RBDO methods for crane metallic structures are prone to low convergence speed and high computational cost. A unilevel RBDO method, combining a discrete imperialist competitive algorithm with an inverse reliabil- ity strategy based on the performance measure approach, is developed. Application of the imperialist competitive algorithm at the optimization level significantly improves the convergence speed of this RBDO method. At the reli- ability analysis level, the inverse reliability strategy is used to determine the feasibility of each probabilistic constraint at each design point by calculating its a-percentile per- formance, thereby avoiding convergence failure, calcula- tion error, and disproportionate computational effort encountered using conventional moment and simulation methods. Application of the RBDO method to an actual crane structure shows that the developed RBDO realizes a design with the best tradeoff between economy and safety together with about one-third of the convergence speed and the computational cost of the existing method. This paper provides a scientific and effective design approach for the design of metallic structures of cranes.

Intelligent Optimization Methods for the Design of an Overhead Travelling Crane

In design optimization of crane metal structures, present approaches are based on simple models and mixed variables, which are difficult to use in practice and usually lead to failure of optimized results for rounding variables. Crane metal structure optimal design（CMSOD） belongs to a constrained nonlinear optimization problem with discrete variables. A novel algorithm combining ant colony algorithm with a mutation-based local search（ACAM） is developed and used for a real CMSOD for the first time. In the algorithm model, the encoded mode of continuous array elements is introduced. This not only avoids the need to round optimization design variables during mixed variable optimization, but also facilitates the construction of heuristic information, and the storage and update of the ant colony pheromone. Together with the proposed ACAM, a genetic algorithm（GA） and particle swarm optimization（PSO） are used to optimize the metal structure of a crane. The optimization results show that the convergence speed of ACAM is approximately 20% of that of the GA and around 11% of that of the PSO. The objective function value given by ACAM is 22.23% less than the practical design value, a reduction of 16.42% over the GA and 3.27% over the PSO. The developed ACAM is an effective intelligent method for CMSOD and superior to other methods.

The effects of food abundance and disturbance on foraging flock patterns of the wintering Hooded Crane(Grus monacha)

Background:Food abundance and availability affect flock patterns of foraging birds.Cost and risk tradeoffs are especially critical for flocks of wintering waterbirds foraging in lake wetlands.Waterbirds losing suitable habitats face insufficient food supplies and high levels of disturbance,affecting their foraging activities.Our objective was to study the effects of food abundance and disturbances on flock size and the structure of Hooded Crane flocks wintering at Shengjin Lake and,as well,to understand the response of wintering waterbirds to habitat degradation for future management decisions and protection of the population.Methods:We investigated food abundance,disturbances and flock foraging activities of the wintering Hooded Crane in several foraging habitats of Shengjin Lake from November 2013 to April 2014.Flock size and structure were observed by scan sampling.Data on food abundance and disturbances were collected by sampling.Flock size and structure were compared among three wintering stages.The relationship between food resources,disturbances and flock size were illustrated using a generalized linear model.Results:In the early and middle wintering periods,the Hooded Crane used paddy fields as its major foraging habitat,where the number of foraging birds and flocks were the highest.During the late period,the cranes took to meadows as their major foraging habitat.The variation among foraging flock was mainly embodied in the size of the flocks,while the age composition of these flocks did not change perceptibly.Family flocks were notably different from flock groups in size and age composition.The results of a generalized linear model showed that the food abundance had a marked effect on foraging flock size and age composition,while disturbances had a significant effect only on flock size.From our analysis,it appeared that the combined effect of the two variables was significant on the size of the foraging flock,but had less impact on age composition.Conclusions:Food abundance and disturbances affected the flock size of the Hooded Crane.With abundant food and high disturbances,flock sizes increased owing to cooperation in foraging.To avoid competition and maximize foraging benefits,flock size reduces with an abundance of food but low disturbance.By trading off risks and costs,the cranes showed flexible flock distributions and a variety of foraging strategies to maximize benefits and to improve their fitness.

Adaptive Proportional-Derivative Sliding Mode Control Law With Improved Transient Performance for Underactuated Overhead Crane Systems

In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.