Quantitative Comparative Study of the Performance of Lossless Compression Methods Based on a Text Data Model

Data compression plays a key role in optimizing the use of memory storage space and also reducing latency in data transmission. In this paper, we are interested in lossless compression techniques because their performance is exploited with lossy compression techniques for images and videos generally using a mixed approach. To achieve our intended objective, which is to study the performance of lossless compression methods, we first carried out a literature review, a summary of which enabled us to select the most relevant, namely the following: arithmetic coding, LZW, Tunstall’s algorithm, RLE, BWT, Huffman coding and Shannon-Fano. Secondly, we designed a purposive text dataset with a repeating pattern in order to test the behavior and effectiveness of the selected compression techniques. Thirdly, we designed the compression algorithms and developed the programs (scripts) in Matlab in order to test their performance. Finally, following the tests conducted on relevant data that we constructed according to a deliberate model, the results show that these methods presented in order of performance are very satisfactory:- LZW- Arithmetic coding- Tunstall algorithm- BWT + RLELikewise, it appears that on the one hand, the performance of certain techniques relative to others is strongly linked to the sequencing and/or recurrence of symbols that make up the message, and on the other hand, to the cumulative time of encoding and decoding.

Effects of Different Protein Energy Ratios on Fattening Performance,Slaughter Performance and Meat Quality of Pigs

[Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generally expressed as CP:ME or CP:DE.This study was conducted to investigate the effects of different diets on fattening and slaughter performance and meat quality traits for"L(Large Yorkshire)×L(Landrace)"crossbred pigs.[Methods]Eighteen piglets of L×L crossbred with similar body weights about 51 kg were selected.The piglets were divided into 3 groups randomly and each group was assigned to 3 replicates with 2 piglets in a replicate.Group A was fed diet Ⅰ (control diet),group B was fed the same diet of group A in the first month of the trial but fed diet Ⅱ in second month,and group C consumed diet Ⅲ.All the pigs were fed in the same feeding condition for two months except the different diets during the trial.One pig in similar body weight from each replicate was slaughtered for the determination of slaughter performance and meat quality traits in the end of the trial.[Results]The average daily feed intake(ADFI)of pigs from group B was only(2.32±0.52)kg and significantly lower than those from group A and group C(P<0.05),but no difference was found in average daily gain(ADG) and feed/gain(P>0.05).Also,no differences occurred in the carcass length,back fat thickness,longissimus muscle (LM) area and dressing percentage(P>0.05).In addition,no differences were found in the meat quality traits of shear force,meat color,pH_(45 min),pH_(24 h) and cooking loss(P>0.05).However,the water-holding capacity of meat from group C was(2.58±0.02)ms and significantly lower than that of(2.80±0.20)ms from group A(P<0.05).Although the contents of glutamic acid and cystine in LM from group B was significantly lower than those from group A and group C(P<0.05),no differences occurred in the contents of other amino acids,the total amino acid and total flavor amino acid among the three groups(P>0.05).However,the inosine monophosphate content of LM from group C was only(331.80±11.53)mg/100 g and significantly lower than those of(361.00±6.36)and(366.37±4.80)mg/100 g from group A and B(P<0.05).Even though no differences were found in the contents of DM and CP in LM among the three groups of pigs,the content of intramuscular fat(IMF)in LM from group B and group C was increased by 45.6%and 46.58%respectively from that of group A(P<0.05),but no difference occurred between group B and C(P>0.05).[Conclusions]DietsⅡ and Ⅲ in this study caused no differences in fattening and slaughter performance of L×L crossbred pigs,but the effects on some meat traits were still significant,especially on the improvement of intramuscular fat in experimental pigs.Therefore,they could improve the meat quality of crossbred pigs to a certain extent.

Experimental study on the shear performance of quasi-NPR steel bolted rock joints

Quasi-NPR(negative Poisson’s ratio)steel is a new type of super bolt material with high strength,high ductility,and a micro-negative Poisson’s effect.This material overcomes the contrasting characteristics of the high strength and high ductility of steel and it has significant energy-absorbing characteristics,which is of high value in deep rock and soil support engineering.However,research on the shear resistance of quasi-NPR steel has not been carried out.To study the shear performance of quasi-NPR steel bolted rock joints,indoor shear tests of bolted rock joints under different normal stress conditions were carried out.Q235 steel and#45 steel,two representative ordinary bolt steels,were set up as a control group for comparative tests to compare and analyze the shear strength,deformation and instability mode,shear energy absorption characteristics,and bolting contribution of different types of bolts.The results show that the jointed rock masses without bolt reinforcement undergo brittle failure under shear load,while the bolted jointed rock masses show obvious ductile failure characteristics.The shear deformation ca-pacity of quasi-NPR steel is more than 3.5 times that of Q235 steel and#45 steel.No fracture occurs in the quasi-NPR steel during large shear deformation and it can provide stable shear resistance.However,the other two types of control bolts become fractured under the same conditions.Quasi-NPR steel has significant energy-absorbing characteristics under shear load and has obvious advantages in terms of absorbing the energy released by shear deformation of jointed rock masses as compared with ordinary steel.In particular,the shear force plays a major role in resisting the shear deformation of Q235 steel and#45 steel,therefore,fracture failure occurs under small bolt deformation.However,the axial force of quasi-NPR steel can be fully exerted when resisting joint shear deformation;the steel itself does not break when large shear deformation occurs,and the supporting effect of the jointed rock mass is effectively guaranteed.

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.

Performance Framework for Virtual Machine Migration in Cloud Computing

In the cloud environment,the transfer of data from one cloud server to another cloud server is called migration.Data can be delivered in various ways,from one data centre to another.This research aims to increase the migration performance of the virtual machine(VM)in the cloud environment.VMs allow cloud customers to store essential data and resources.However,server usage has grown dramatically due to the virtualization of computer systems,resulting in higher data centre power consumption,storage needs,and operating expenses.Multiple VMs on one data centre manage share resources like central processing unit(CPU)cache,network bandwidth,memory,and application bandwidth.Inmulti-cloud,VMmigration addresses the performance degradation due to cloud server configuration,unbalanced traffic load,resource load management,and fault situations during data transfer.VMmigration speed is influenced by the size of the VM,the dirty rate of the running application,and the latency ofmigration iterations.As a result,evaluating VM migration performance while considering all of these factors becomes a difficult task.Themain effort of this research is to assess migration problems on performance.The simulation results in Matlab show that if the VMsize grows,themigration time of VMs and the downtime can be impacted by three orders ofmagnitude.The dirty page rate decreases,themigration time and the downtime grow,and the latency time decreases as network bandwidth increases during the migration time and post-migration overhead calculation when the VMtransfer is completed.All the simulated cases of VMs migration were performed in a fuzzy inference system with performance graphs.

Effects of Filler-Asphalt Ratio on the Properties of Lignin and Polyester Fiber Reinforced SMPU/SBS Modified Asphalt Mortar

To understand the effects offiller-asphalt ratio on different properties of lignin and polyesterfiber reinforced shape memory polyurethane(SMPU)/styrene butadiene styrene(SBS)composite modified asphalt mortar(PSAM),as well as to reveal the reinforcing and toughening mechanisms of lignin and polyesterfibers on PSAM,SMPU,SBS and mineral powder werefirst utilized to prepare PSAM.Then the conventional,rheological and anti-cracking properties of ligninfiber reinforced PSAM(LFAM)and polyesterfiber reinforced PSAM(PFAM)at dif-ferentfiller-asphalt ratios were characterized.Test results indicate that the shear strength,deformation resistance and viscosity are increased after adding 0.8wt%ligninfiber or polyesterfiber and increasing thefiller-asphalt ratio from 0.8 to 1.2.The optimalfiller-asphalt ratio of 1.0 is proposed after comprehensive performance assessments of PSAM.Polyesterfiber shows a better reinforcing effect than ligninfiber,but its improvement in the thermal stability of PSAM is not significant at high temperatures.Additionally,the complex modulus,storage modulus,loss modulus and rutting resistance factor of PSAM are improved after adding ligninfiber and polyesterfiber,as well as show an increasing trend as thefiller-asphalt ratio is raised,but the phase angle is gradually decreased.Further,the increase of elastic components in PSAM effectively enhances the anti-deformation ability of PSAM at high temperatures,and polyesterfiber more obviously improves the high-temperature deformation resistance of PSAM than ligninfiber.Finally,the anti-cracking performance of PFAM and LFAM at low temperatures is reduced by 74.2%and 46.7%,respectively,as thefiller-asphalt ratio is raised from 0.8 to 1.2.The low-temperature anti-cracking performance of LFAM is lower than that of PFAM at the samefiller-asphalt ratio,even lower than that of PSA.Compared with ligninfiber,the anti-cracking performance and deformation resistance of PSAM at low temperature is more greatly enhanced by polyester fiber.

Effect of Refrigerant on the Performance of a C3/MRC Liquefaction Process

The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.

Effects of Dietary Concentrate to Forage Ratios on Production Performance and Serum Biochemical Indicators in Post-fattening Hainan Yellow Cattle

[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(242.22 ±0.71 kg) were randomly divided into four treatments.Cattles were fed with diets of different concentrate to forage ratios(20:80, group Ⅰ;30:70, Group Ⅱ;40:60, group Ⅲ;50:50, group Ⅳ).The trial lasted 62 d.[Result]The daily gain in experimental group Ⅳ was significantly higher than that in experimental group Ⅱ(P<0.05), but the feed gain ratio in experimental group Ⅳ was lower than those in other ex-perimental groups(P>0.05).The feed intake in experimental group Ⅳ was also markedly higher than those in experimental groups Ⅰ and Ⅱ(P<0.05).Compared with the experimental group Ⅱ, the gross profit of experimental group Ⅳ was significantly promoted(P<0.05).The alanine aminotransferase and aspartate aminotransferase activities in experimental group Ⅱ were markedly higher than those in experimental groups Ⅰ, Ⅲ and Ⅳ.[Conclusion]When the dietary concentrate to forage ratios was 50∶50, the production performance of post-fattening Hainan Yellow Cattle was better.

Different dietary methionine to lysine ratios in the lactation diet:effects on the performance of sows and their offspring and methionine metabolism in lactating sows

Background:Over the last decade,the nutritional requirements of lactating modern genotype sows have increased.The current nutritional recommendations might be unable to meet the needs of increased litter size and milk production,and thus the nutritional requirements need to be re-evaluated.The current study was conducted to investigate the effects of dietary methionine to lysine(Met:Lys)ratios on the performance of and methionine metabolism in lactating sows.Results:During the 1st week of lactation,piglets reared on sows in the 0.37 to 0.57 Met:Lys ratio groups grew faster than those reared on sows in the control group(0.27)(P<0.01).The 0.37-ratio group showed increased levels of GSHPx in plasma during lactation(P<0.01)and decreased concentrations of urea nitrogen in the plasma of sows(P<0.05).Compared with the 0.27-ratio group,the levels of T-AOC and GSH-Px in the plasma and homocysteine in the milk of lactating sows were significantly increased in sows in the 0.47-ratio group(P<0.01).In sows fed a 0.57-ratio diet,the levels of glutathione and taurine in the plasma and milk were improved significantly during lactation.However,the content of TBARS in the blood(P<0.05 at day 7 and P=0.06 at weaning day)was increased(P<0.01).Moreover,there were linear increases in the levels of homocysteine in the blood and milk of sows during the lactation period(P<0.01)with increased dietary Met:Lys ratios in the lactation diet.Conclusions:The current study indicated that increasing the dietary Met:Lys ratio(0.37~0.57)in the lactation diet had no significant effect on the overall performance of sows or the colostrum and milk composition,but it increased piglet mean BW and piglet ADG during the first week of lactation.Increasing dietary methionine levels had no significant effect on antioxidant function in lactation sows,even though it increased levels of GSH and GSH-Px in the plasma of sows during lactation.However,the content of homocysteine in the plasma and milk increased during lactation due to a high level of dietary methionine.

Experimental Investigation on Combustion Performance of Solid Propellant Subjected to Erosion of Particles with Different Concentrations

A test device with rectangular channel is developed to study the combustion performance of solid propellant in high temperature particles erosion.The flowfields in this newdevice and a test device with circular channels are simulated numerically.The particle erosion experiments in these two devices are carried out under different particle concentrations.The results showthat the test device with rectangular channel can effectively improve the clarity and precision of combustion diagnosis image and can be used for research on combustion performance of solid propellant under lowconcentration particle erosion;the circular channel device has good particle convergent effect,provides high concentration particle erosion,and can be used for research on the combustion performance of solid propellant under high concentration particle erosion.The experiment data indicates that the propellant burning rate does not change obviously in lower particle concentration;the propellant with lower static burning rate increases remarkably under particle erosion,while the propellant with high static burning rate is not sensitive to the particle erosion.

Effect of Pelleted Total Mixed Ration with Different Concentrate-roughage Ratios on Production Performance and Serum Biochemical Parameters of Fattening Hainan Black Goats

[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved.

Study on Filtration Performance of Silica/ Alumina Slurry in the Process of Recycling Mother Liquor of NaY Zeolite

In order to recover the SiO2 contained in the mother liquor in the course of NaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on the filtering velocity of gel slurry was studied using the SiO2/Al2O3 gel recovered from the NaY mother liquor in the laboratory. The results of study had shown that at a SiO2/A12O3 ratio in the feed equating to 9:1 the SiO2 recovery rate and Al2O3utilization rate were high with a faster flow velocity of the filtrate. The pH value of the system had great impact on the flow velocity of filtrate. Between the two methods for regulating the pH value, the one for formation of silica/alumina gel slurry by addition of sulfuric acid prior to adding aluminium sulfate in the solution could secure a faster filtration velocity. The filtration velocity was decreased in tandem with increasing SiO2 concentration in mother liquor, meanwhile an increase in dry filter cake yield.

Study for the Forming Principle of Logix Gear Tooth Profile and Its Mesh Performance

In recent years, a new type of gear named Logix gea r was developed. Actually, the tooth profile of this new type of gear is composed of lots of micro-segment involute curves, and on the profile, there exist lots of points, which their relative curvatures are equal to zero. This can result in the sliding coefficient smaller between two meshed Logix gears, and the mesh ch aracteristic becomes almost rolling transmission from sliding transmission accor dingly. So, this new type of gear has lots of advantages such as higher contact intensity, longer useful life and can easily realize power transfer of bigger tr ansmission ratio than standard involute gear. Study results showed that the cont act fatigue strength is 3 times larger, the bend fatigue strength is 2.5 times l arger, and the minimum tooth number can be decreased to 3, much smaller than tha t of standard involute gear. In this paper, following studies had been done: 1) The formation principle of Logix gear tooth profile was studied. The theoreti cal models describing the geometrical formations of this type of gear and its re lative Logix rack had been deduced. 2) While cutting a Logix gear, its tooth profile is decided by its normal tooth profile of Logix rack. Besides the basic parameters of standard involute gear, L ogix rack has its own specific parameters such as preliminary pressure angle, re lative pressure angle, and preliminary referential circle radius etc. So, the in fluence of connatural parameters of Logix rack on the tooth profile of Logix gea r had been farther studied. Reasonable selection for these parameters had been d iscussed. 3) Several kinds of transition curves for gear’s tooth profile had been introdu ced, its selection used by Logix gear had been described, and also its mathemati cal description model had been deduced. 4) The mesh theories of Logix gears had been developed. It had been proved that the transmission performance between Logix gears coincides with E-W theorem as that of ordinary standard involute gears. The formula calculating superposition coefficient was deduced according to its definition. Different from standard inv olute gears, the parameter of gear number has no effect on the superposition coe fficient of the Logix gears. Accordingly, bigger ratio transmission can be acqui red by means of decreasing the gear number, and its minimum gear number can be r eached to 3, much smaller than the minimum gear number of ordinary standard invo lute gear: 14～17. This is very important to realize the miniaturization of prod uction design. 5) The CAD special software was developed to design all kinds of Logix gears, an d a solid design example was offered. To sum up, by means of above study, the system info about Logix gear had been de veloped and enriched. This has most significant impact on its widely promotion a nd practical application, on the improvement of carrying capacity, miniaturizati on, and life of kinetic transmission products.

Research on Evaluating Index of Lightning Protection Safety Performance of High Voltage Overhead Transmission Line

In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.

The Corrosion Fatigue Properties of High Performance Concrete

With the loading test equipment of corrosion fatigue specially designed, the corrosion fatigue characteristics of high performance concrete (HPC) withstanding the interaction of third point fatigue loading and Na_2SO_4 solution were investigated and analyzed. The experimental results indicate that water-binder ratio evidently influences the corrosion fatigue characteristics of HPC, and a moderate quantitative fine mineral admixture enhances the corrosion fatigue resistance of HPC. The effect is more significant when fly ash and silica fume are added.

Dimensional Synthesis for 3-PRS Mechanism Based on Identifiability Performance

Many performance indices for parallel mechanism are put forward in the phase of dimensional synthesis,except for identifiability index,which determines the difficulty of kinematical calibration.If the dimensional parameters are inappropriately selected,the existing methods for optimizing identifiability will not effectively work.Thus,with the aim of studying identifiability optimization in dimensional synthesis for 3-PRS mechanism,kinematics with structural errors is analyzed to provide theoretical bases for kinematical model.Then through a comparison of two 3-PRS mechanisms with different dimensional parameters,identifiability performance is proved to be necessary and feasible for optimization in the phase of dimensional design.Finally,an index δ is proposed to scale the identifiability performance.With the index,identifiability analysis and dimensional synthesis simulation in the whole workspace is completed.The index is verified to be correct and feasible,and based on the index,a procedure of dimensional synthesis,as well as an example set of non-dimensional parameters of 3-PRS mechanism,is proposed.The proposed identifiability index and design method can effectively introduce identifiability optimization into dimensional synthesis,and will obviously benefit later kinematical calibration.

Investigation of short-channel design on performance optimization effect of Hall thruster with large height–radius ratio

In this study,the neutral gas distribution and steady-state discharge under different discharge channel lengths were studied via numerical simulations.The results show that the channel with a length of 22 mm has the advantage of comprehensive discharge performance.At this time,the magnetic field intensity at the anode surface is 10%of the peak magnetic field intensity.Further analysis shows that the high-gas-density zone moves outward due to the shortening of the channel length,which optimizes the matching between the gas flow field and the magnetic field,and thus increases the ionization rate.The outward movement of the main ionization zone also reduces the ion loss on the wall surface.Thus,the propellant utilization efficiency can reach a maximum of 96.8%.Moreover,the plasma potential in the main ionization zone will decrease with the shortening of the channel.The excessively short-channel will greatly reduce the voltage utilization efficiency.The thrust is reduced to a minimum of 46.1 m N.Meanwhile,because the anode surface is excessively close to the main ionization zone,the discharge reliability is also difficult to guarantee.It was proved that the performance of Hall thrusters can be optimized by shortening the discharge channel appropriately,and the specific design scheme of short-channel of HEP-1350 PM was defined,which serves as a reference for the optimization design of Hall thruster with large height–radius ratio.The shortchannel design also helps to reduce the thruster axial dimension,further consolidating the advantages of lightweight and large thrust-to-weight ratio of the Hall thruster with large height–radius ratio.

Analysis of Waste-Rock Transportation Process Performance in an Open-Pit Mine Based on Statistical Analysis of Cycle Times Data

In this paper, the performance of a waste rock transportation process in an open pit mine was assessed by using cycle time data. A computerized truck-excavator dispatch system was used to record the cycle times. The process was broken into seven steps (or components of the total cycle), durations of which were recorded for a period of 1 month, leading to N = 60,690 data points or dispatches. The open pit mine studied consisted of 12 waste types loaded by 14 excavators and hauled by 49 trucks (at a trucks-to-excavator ratio of 3.5:1) in 75 changing locations. The string-type data was coded using integers to allow a FORTRAN code to extract process performance parameters using statistical analysis. The study established a wide range of parameters including: the waste material generation rate (about 1.73 million t/month, 81% comprising waste rock), truck fill factor, f, total cycle time (Tct), production capacity, theoretical cycle time, non-productive cycle time Tnp, and cycle time performance ratio (CTPR), denoted as Tpr. The factors affecting the process performance include: truck model, excavator model, location (haul distance and road conditions) and material type. For a fixed material type and tonnage, the PDFs of the cycle time components were logarithmic in nature, capable of differentiating performance variations under different factors. It was concluded that the performance of the waste material transportation system in this mine was determined to be acceptable due to mean value of Tpr = 2.432 being closer to unity. Reduction measures were suggested to minimize the cycle time for the process bottlenecks determined from Pareto analysis (that is, full haul, empty haul and loading processes).

Effects of Feeding Time on the Growth Performance and Variation of RNA/DNA Ratio of the Chinese Soft-shelled Turtle, Pelodiscus sinensis

The present study was to investigate the effects of feeding time on growth of the Chinese soft-shelled turtle. The experiment was carried out with a photoperiod of 12L （light）： 12D （dark） with lights on at 06：00 and off at 18：00. Turtles were maintained at a temperature of 32 - 0.2 ℃ in tanks throughout the length of the experiment. The turtles in group 1 to group 6 were fed respectively at 00：00, 04：00, 08：00, 12：00, 16：00 and 20：00 with 60 turtles each （Initial body weight 88.27 - 0.09 g）. Acrophases of postprandial RNA/DNA ratio in liver in each group was shown between 5h and 7h after feeding. A positive linear correlation could be seen between specific growth rate （SGR） and RNA/ DNA：SGR=t.1586RNA/DNA-0.7097 （r = 0.9328, P = 0.0066）. The results indicated that the values at the acrophases of about 6h after feeding might be used as an instantaneous growth index in the Chinese soft-shelled turtle. The turtles in group 1 grew better than group 3, group 4, group 5, group 6, because they ate more, but they ate more and grew slower than group 2, whose feed conversion rate was also higher. Meanwhile, the SGR and feeding rate of turtles fed at 12：00 were the lowest from the six groups （P 〈 0.05）. Turtles fed in group 1, group 2 and group 6 developed more heavy final body weight （FBW）, higher feeding rate and SGR than the other three groups. This probably suggested that turtles fed in scotophase grew better than that fed at photophase in total.

Effects of Different Breeds,Number of Squabs and Temperature on Production Performance of Pigeons

To explore the effects of breeds,number of nurturing squabs,and temperature on nest feed conversion ratio and analyze the effects of number of nurturing squabs on parent pigeon body mass,fertility rate,and laying intervals,5 widely used breeds of pigeon were nurtured under the condition of natural laying and hatching in this research.In each breed,24 pair pigeons nurturing 1,2,3,and 4 squabs were chosen to measure the production performance,respectively.The results indicated that different numbers of nurturing squabs had a significant effect on parent pigeon body mass changes and survival rate of 28-d old squabs(P<0.05);the nest feed conversion ratio of breeds nurturing 1 squab(7.58)was extremely significantly higher than those of nurturing 2,3,and 4 squabs(P<0.01);the nest feed conversion ratio of breeds nurturing 2 squabs(4.75)was extremely significantly higher than those of nurturing 3(3.95)and 4 squabs(3.75)(P<0.01);there was no significant difference between breeds nurturing 3 and 4 squabs(P>0.05).Laying intervals of breeds nurturing 4 squabs(43.8 d)were significantly higher than those of nurturing 3(37.4 d),2(35.4 d),and 1(33.8 d)squabs(P<0.05).Nest feed conversion ratio significantly increased with the decrease of environment temperature(P<0.05).The breed showed no effect on the nest feed conversion ratio.In production,nurturing 3 squabs of parent pigeons is appropriate.In some cold areas in winter,cold protection measures should be taken.