Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

SEI/dead Li-turning capacity loss for high-performance anode-free solid-state lithium batteries

Anode-free solid-state lithium metal batteries(AF-SSLBs)have the potential to deliver higher energy density and improved safety beyond lithium-metal batteries.However,the unclear mechanism for the fast capacity decay in AF-SSLBs,either determined by dead Li or solid electrolyte interface(SEI),limits the proposal of effective strategies to prolong cycling life.To clarify the underlying mechanism,herein,the evolution of SEI and dead Li is quantitatively analyzed by a solid-state nuclear magnetic resonance(ss-NMR)technology in a typical LiPF6-based polymer electrolyte.The results show that the initial capacity loss is attributed to the formation of SEI,while the dead Li dominates the following capacity loss and the growth rate is 0.141 mA h cm^(−2)cycle−1.To reduce the active Li loss,the combination of inorganic-rich SEI and self-healing electrostatic shield effect is proposed to improve the reversibility of Li deposition/dissolution behavior,which reduces the capacity loss rate for the initial SEI and following dead Li generation by 2.3 and 20.1 folds,respectively.As a result,the initial Coulombic efficiency(ICE)and stable CE increase by 15.1%and 15.3%in Li-Cu cells,which guides the rational design of high-performance AF-SSLBs.

Improved model on asynchronous measurement-device-independent quantum key distribution with realistic devices

In principle,the asynchronous measurement-device-independent quantum key distribution(AMDI-QKD)can surpass the key rate capacity without phase tracking and phase locking.However,practical imperfections in sources or detections would dramatically depress its performance.Here,we present an improved model on AMDI-QKD to reduce the influence of these imperfections,including intensity fluctuation,the afterpulse effect,and the dead time of detectors.Furthermore,we carry out corresponding numerical simulations.Simulation results show that,by implementing our present work,it can have more than 100 km longer secure transmission distance and one order of magnitude enhancement in the key generation rate after 320 km compared with the standard method.Moreover,our model can still break the Pirandola–Laurenza–Ottaviani–Banchi(PLOB)bound even under realistic experimental conditions.

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter method.This study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction curve.The uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of uncertainty.The MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical model.The results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)<0.070 for the comparison of each source,and the uncertainty results of the GUM were all lower than those of the MCM.However,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

肝细胞肝癌中DDX24、TRIP12表达与上皮间质转化及临床预后的关系

目的探讨肝细胞肝癌(HCC)中DEAD盒解旋酶24(DDX24)、甲状腺激素受体相互作用因子12(TRIP12)表达,分析两者与上皮间质转化(EMT)及临床预后的关系。方法回顾性选取2019年2月—2021年1月中国人民解放军联勤保障部队第九四〇医院肝胆外科手术治疗的HCC患者96例。免疫组化检测癌组织和癌旁组织DDX24、TRIP12蛋白表达;采用实时荧光定量PCR检测DDX24、TRIP12和EMT指标[E-钙黏素(E-cad)、N-钙黏素(N-cad)及TWIST]表达;Pearson相关分析DDX24 mRNA、TRIP12 mRNA和EMT指标的相关性;绘制Kaplan-Meier曲线,Log-Rank检验分析DDX24 mRNA、TRIP12 mRNA高表达组和低表达组HCC患者预后的差异;多因素Cox比例风险模型分析影响HCC患者死亡预后的独立因素。结果HCC癌组织中DDX24、TRIP12阳性率显著高于癌旁组织(χ^(2)/P=109.714/<0.001,108.755/<0.001);与癌旁组织比较,HCC癌组织中DDX24、TRIP12、N-cad、TWIST mRNA表达较高,E-cad mRNA表达较低,差异均有统计学意义(t/P=35.810/<0.001,48.036/<0.001,25.015/<0.001,48.482/<0.001,38.069/<0.001)。HCC癌组织中DDX24 mRNA与TRIP12 mRNA表达呈正相关(r=0.701,P<0.001);DDX24 mRNA、TRIP12 mRNA均与N-cad mRNA、TWIST mRNA呈正相关,与E-cad mRNA呈负相关(r/P=0.723/<0.001,0.661/<0.001,0.706/<0.001,0.745/<0.001,-0.694/<0.001,-0.609/<0.001)。低分化程度、CNLC分期Ⅱ~Ⅲ期和有血管侵犯HCC患者癌组织中DDX24、TRIP12 mRNA高于高中分化程度、CNLC分期Ⅰ期和无血管侵犯者(DDX24:t/P=10.348/<0.001,18.474/<0.001,6.302/<0.001;TRIP12:t/P=25.661/<0.001,36.396/<0.001,14.928/<0.001)。DDX24 mRNA高表达组和低表达组3年总生存率分别为39.13%(18/46)、64.00%(32/50),2组生存曲线总体比较,差异具有统计学意义(Log rankχ^(2)=7.491,P=0.006);TRIP12 mRNA高表达组和低表达组3年总生存率分别为36.17%(17/47)、67.35%(33/49),2组生存曲线总体比较,差异有统计学意义(Log rankχ^(2)=8.146,P=0.004)。CNLC分期Ⅱ~Ⅲ期、低分化程度、血管侵犯、DDX24 mRNA高表达、TRIP12 mRNA高表达是影响HCC患者死亡预后的危险因素[HR(95%CI)=1.611(1.175~2.209),1.768(1.238~2.526),1.464(1.089~1.968),1.859(1.330~2.599),1.775(1.275~2.473)]。结论HCC癌组织中DDX24、TRIP12表达上调,与N-cad、TWIST呈正相关,与E-cad呈负相关,DDX24、TRIP12可能通过促进HCC肿瘤EMT的发生,促进HCC肿瘤的恶性进展,两者是影响HCC患者死亡预后的独立危险因素。

转录因子HNF1A、HNF4A和FOXA2调节肝细胞蛋白质N-糖基化

Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells.

The “Dead Universe” Theory: Natural Separation of Galaxies Driven by the Remnants of a Supermassive Dead Universe

This article explores the dead universe theory as a novel interpretation for the origin and evolution of the universe, suggesting that our cosmos may have originated from the remnants of a preceding universe. This perspective challenges the conventional Big Bang theory, particularly concerning dark matter, the expansion of the universe, and the interpretation of phenomena such as gravitational waves.

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

Research Background: The marketing of cosmetic products derived from Dead Sea (DS) mud has undergone significant evolution, transforming from simple souvenirs into a large-scale cosmetic industry offering a diverse array of products. DS mud is utilized both as pure mud for home spa treatments and as an active ingredient in cosmetic and cosmeceutical formulations. Its global appeal is largely due to its natural, health-oriented image, which aligns with consumer preferences and provides assurance regarding its use in skincare. Research Objectives: This review examines the published data related to the rationale for formulating DS mud in cosmetics, the biological and cosmetic effects of DS mud on the skin, and the speculated bio-mechanisms underlying these effects. Methods: We screened relevant literature on DS mud collected from the shores of the Dead Sea in Jordan and Israel. Publications on mineral muds excavated in different locations around the globe, as well as studies on the biological mechanisms of other DS minerals, were also reviewed as indications and supportive recommendations. Summarizing the vast collected data into a comprehensive review was undertaken to expose readers to the various aspects of DS mud in cosmetics. Results: The primary reason for formulating DS mud in skincare products is its deep cleansing and skin detoxification properties. Consequently, it is often incorporated into rinse-off masks, soaps, and scrubbing products. Additionally, DS mud is used in leave-on products and sheet masks. Cosmeceutical applications of DS mud, recommended for various skin conditions, offer complementary treatments to improve the quality of life for people with skin diseases. The physicochemical and biological effects of DS mud are driven by its rich mineral ion composition, including magnesium, calcium, sodium, potassium, zinc, and strontium—elements known to improve skin barrier function, enhance hydration, and reduce inflammation. The high salt concentration induces moderate ionic osmotic stress, stimulating cellular growth and hydration pathways. Moreover, DS mud’s anti-microbial properties further contribute to its therapeutic potential. Ongoing innovations in formulation techniques continue to expand the applications of DS mud, including blending it with other active ingredients, developing novel application methods, and refining manufacturing processes to improve product quality and efficacy. Conclusions: DS mud remains a valuable ingredient in modern skincare due to its rich mineral content and therapeutic properties. Ongoing research and technological advancements promise further innovations, reinforcing its status as a natural and effective component in the global cosmetics industry.

From Finnish Assortment Pricing to Market Economy Using Prices for Sawn Wood and Chips in Reference Bucking

Dominant Finnish assortment pricing gives prices for sawlog and pulp wood volumes. Buyers buck stems to sawlogs using secret price matrices. Agreed dimensions allow wide range of sawlog volumes. Forest owners cannot objectively compare biddings: timber trade is a lottery game. Bucking is analyzed in terms of sawlog, pulp wood, log cylinder, sawn wood, value-weighted sawn wood, and chips. Sawn wood and its value are computed from top diameter of the sawlog. Profit maximization requires buyers to buck logs producing smaller than maximal value, causing dead weight loss. Nominal assortment prices have unpredictable relation to effective stumpage price. Assortment pricing does not meet requirements of market economy. If sawmills linked to pulp mills buck smaller sawlog percentages than independent sawmills, as generally believed, they use higher price for chips in their own harvests than they pay for independent sawmills, indicating imperfect competition for chips. Sawn wood potential pricing is suggested which gives prices for sawn wood and chips coming both from sawlogs and pulp wood in reference bucking which maximizes sawn wood for given minimum and maximum log length and minimum top diameter. Simple algorithm generates feasible bucking schedules from which optimum can be selected using any objective. Pricing produces unit price for all commercial wood utilizing ratio of theoretical sawn wood and commercial volume in stand. Unit price can be compared to stem pricing and could be compared to assortment pricing if assortment pricing would produce predictable sawlog percentages. Sawn wood potential pricing is concrete, transparent, easy to compute, considers stem size and tapering, reduces trading cost and is less risky to buyers than stem pricing. It meets requirements of market economy. Readers can repeat computations using open-source software Jlp22.

The Need for International Cooperation between Israel and Other Middle East Nations to Protect the Jordan River Landscape

The Jordan River, also referred to as Nahr Al Sharieat in Arabic, is a long river in the Middle East that flows from north to south through the Sea of Galilee to the Dead Sea. The Jordan River is bordered by the Golan Heights and the Hashemite Kingdom of Jordan in the east and by Israel and the Palestinian West Bank (Judea and Samaria) in the west. Soil tunnels, including those in the Jordan River watershed and on the Israel, Syria, and Lebanon borders, have a long history of use for warfare, as invasion pathways, smuggling, and storage of rockets, missiles and ordnance and are causes of serious political tension between the countries. Soil tunnel construction and destruction often has adverse environmental and human health impacts in the Jordan River landscape. Due to agricultural wastes, the discharge of untreated sewage, and diversion of saline springs into the river water there has been serious deterioration in the water quality in the lower courses of the Jordan River. The primary objective of this research is to encourage the development of a multi-country clean-up, mitigation, and protection plan for the Jordan River.

Strong Tracking Particle Filter Based on the Chi-Square Test for Indoor Positioning

In recent years,a number of wireless indoor positioning(WIP),such as Bluetooth,Wi-Fi,and Ultra-Wideband(UWB)technologies,are emerging.However,the indoor environment is complex and changeable.Walls,pillars,and even pedestrians may block wireless signals and produce non-line-of-sight(NLOS)deviations,resulting in decreased positioning accuracy and the inability to provide people with real-time continuous indoor positioning.This work proposed a strong tracking particle filter based on the chi-square test(SPFC)for indoor positioning.SPFC can fuse indoor wireless signals and the information of the inertial sensing unit(IMU)in the smartphone and detect the NLOS deviation through the chi-square test to avoid the influence of the NLOS deviation on the final positioning result.Simulation experiment results show that the proposed SPFC can reduce the positioning error by 15.1%and 12.3% compared with existing fusion positioning systems in the LOS and NLOS environment.

结直肠癌组织和细胞中DEAD盒解旋酶10和Bystin样蛋白的表达及其临床意义

目的:探讨结直肠癌(CRC)组织及结肠癌细胞DLD-1中DEAD盒解旋酶10(DDX10)与Bystin-like(BYSL)的关系及其临床意义。方法:收集2017年3月至2018年3月间福建医科大学附属第二医院手术切除的78例CRC组织和配对癌旁组织,采用免疫组织化学Envision法检测癌组织和癌旁组织中DDX10和BYSL的表达水平,采用卡方检验、Pearson相关性分析和Kaplan-Meier法分别分析CRC组织中DDX10、BYSL蛋白表达与其患者的临床病例特征的关系,两者表达的相关性,以及与患者PFS和OS的关系。利用瞬时转染技术在DLD-1细胞中分别转染siDDX10和siNC,用qPCR法检测DLD-1细胞中敲减DDX10的表达对BYSL表达的影响,用CCK-8及Transwell实验验证DDX10及BYSL表达对结肠癌细胞增殖迁移及侵袭的影响。结果:免疫组织化学Envision法检测显示,与癌旁组织相比,DDX10和BYSL在CRC组织中呈高表达(73.08%和74.36%)。CRC组织中DDX10与BY肿瘤分期、是否发生淋巴结转移及复发等临床病例特征均有关联(均P<0.05)。Pearson相关分析结果显示,DDX10与BYSL的表达呈正相关(r=0.636,P<0.001)。Kaplan-Meier生存分析结果显示,DDX10与BYSL的高表达与患者更差的预后相关。Logistic回归分析发现,DDX10与BYSL均是CRC复发的独立风险因素。CCK-8法及Transwell实验检测结果显示,敲降DDX10的表达可使BYSL表达降低,且可抑制DLD-1细胞的增殖、迁移、侵袭能力(均P<0.05)。结论:DDX10和BYSL在CRC组织中呈高表达,两者表达水平呈正相关,且与患者更差的预后相关,是CRC复发的独立风险因素。可调控结直肠癌DLD-1细胞的增殖、迁移、侵袭能力。

Modelling the dead fuel moisture content in a grassland of Ergun City,China

The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression resources.In this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in 2021.We chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data collected.To ensure accuracy,we added time-lag variables of 3 d to the models.The results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three models.The accuracies of the models in spring and autumn were higher than those in the other two seasons.In addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time lags.Moreover,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the DFMC.This study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention.

Evaluation of Nutritional Value and Safety of Black Soldier Flies Fed on Dead Pig Meat and Bone Meal

[Objectives]This study was conducted to evaluate the nutritional value and safety of black soldier flies fed with dead pig meat and bone meal(DPMBM)and to explore the resource utilization of DPMBM.[Methods]The general nutrient composition,amino acids,fatty acids and mineral elements of black soldier fly meal(BSLM)were detected and analyzed.[Results]The results showed that the contents of moisture,crude protein,crude fat and ash in BSLM were 3.42%,42.31%,34.04%and 5.40%,respectively.The contents of total amino acids(TAA),essential amino acids(∑EAA)and non-essential amino acids(∑NEAA)and umami amino acids(∑DAA),the EAA/TAA value and the EAA/NEAA value were 37.93%,13.08%,24.85%,13.43%,34.47%,52.61%,respectively.A total of eight kinds of saturated fatty acids and seven kinds of unsaturated fatty acids were detected,accounting for 63.65%and 32.67%of the total fatty acids.Among the major mineral elements,the content of Ca was the highest,followed by K,Mg and Na.Among the trace mineral elements,the content of Mn was the highest,followed by Fe,Zn,Cu,Ni,Cr,Cd,As,Pb,Se,Sn,Ti,Sb and Hg.The contents of heavy metal mineral elements in BSLM were far lower than the limits specified in Hygienical Standard for Feeds.[Conclusions]In conclusion,BSLM has high nutritional value and good safety of heavy metals,and thus great potential for development and utilization as a high quality dietary protein,fat and mineral elements source.

电影《Dead Poets Society》中对教育共情力的思考

共情力是个体在观察和理解他人情感的基础上,产生与观察对象相似的情感体验并表现出相应行为反应的一种能力。在教育过程中,家庭和学校对个体的教育最为直接,学生阶段是个体人生成长的重要时期,好的教育是需要共情力的。本文以美国影片《Dead Poets Society》为例,针对“共情教育”,启发家长、教师在教育过程中的共情能力对个体心理发展所具有的积极作用。提出加强教育者共情意识,家校合力,建立轻松和谐的交往氛围,促进教育者与受教育者之间关系融洽。

An Improved Particle Filter Map Matching Algorithm for Personal Inertial Positioning

The current particle filtering map matching algorithm has problems such as low map utilization and poor accuracy of turnoff positioning, etc. This paper proposed an improved particle filtering-based map-matching algorithm for the inertial positioning of personnel. The historical moment position constraint and feasible region constraint of particles were introduced in this paper. A resampling method based on multi-stage backtracking of particles was proposed. Therefore, the effectiveness of newly generated particles could be guaranteed. The utilization rate of map information could be improved, thus enhancing the accuracy of personnel localization. The walking experiment results showed that, compared with the traditional PDR algorithm, the proposed method had higher localization accuracy and better repeatability of the localization trajectory for multi-turn paths. Under the total travel of 480 meters, the deviation of the starting end point was less than 2 meters, which was about 0.4% of the total travel.

Chimeric ALT Perforator-Free Flap with Vastus Lateralis Muscle for the Obliteration of the Intrathoracic Dead Space Post-Pneumonectomy: A Case Report

Chest wall reconstruction is a surgical procedure aimed at restoring the integrity and function of the chest wall, which may be damaged due to trauma, cancer, infection, or congenital defects. The chest wall plays a vital role in protecting the thoracic organs, supporting the respiratory system, and maintaining the shape of the chest. Therefore, any defect or deformity of the chest wall can have significant functional and aesthetic consequences for the patient. The authors present a case report at Kenyatta National Hospital (KNH) of a dyspneic 47-year-old male patient with a right anterolateral chest wall defect post-pneumonectomy previously complicated by bronchopleural fistula. Past attempts at the chest wall reconstruction had utilized the ipsilateral latissimus dorsi muscle, pectoralis major muscle, and the omental pedicled flaps with limited success. A chimeric anterolateral thigh (ALT) perforator-free flap with vastus lateralis (VL) muscle was used to obliterate the post-pneumonectomy intrathoracic dead space and to provide a cutaneous paddle. This case report aims to show the versatility of the ALT flap for chest wall reconstruction to prevent the post-pneumonectomy syndrome associated with tracheal deviation, inspiratory stridor, and exertional dyspnea. In conclusion, chest wall reconstruction with obliteration of intrathoracic dead space post-pneumonectomy is challenging and needs careful planning and execution.

不同温度及厌氧/好氧运行条件对聚磷菌衰减特性的影响

以富含90%±2%纯度聚磷菌(PAOs)的强化生物除磷系统(EBPR)为研究对象,考察了10℃厌氧、10℃好氧、20℃厌氧、20℃好氧4种运行条件下PAOs的衰减特征。结果表明:温度越高对应衰减速率越快,4个系统在1～9d里衰减速率的平均值分别为:10℃厌氧:0.053/d;10℃好氧:0.050/d;20℃厌氧:0.072/d;20℃好氧:0.145/d。其中4个系统由于细胞死亡引起的活性衰减速率分别为:10℃厌氧:0.019/d;10℃好氧:0.017/d;20℃厌氧:0.019/d;20℃好氧:0.03/d,占总活性衰减的比例分别为:35.8%、34%、26.4%、20.7%。在9d饥饿衰减期间,污泥中所含PHA与糖原的量总体呈下降趋势。相同温度下,糖原在厌氧衰减过程中降解速率大于好氧;在同样的厌氧、好氧衰减条件下,温度越高糖原降解速率越快。

污水生物处理系统细菌衰减特征的实验研究

通过衰减速率测定实验和LIVE/DEAD细胞活性染色实验,分析了污水生物处理系统中细菌在好氧环境下的衰减状态.研究发现,细菌的衰减实质上是由生物量减少引起的数量衰减和由细胞活性降低引起的活性衰减两部分构成的.结果表明,硝化系统细菌在衰减过程中由细胞活性降低引起的衰减约占60%,由细胞死亡引起的衰减约占40%;而在异养系统中由活性降低引起的衰减和由细胞死亡引起的衰减分别为80%和20%.

Dead Reckoning技术在网络游戏中的应用

介绍了基于物理运动学算法的预测技术以及基于Cubic Splines算法的平滑处理技术,并给出了Dead Reckoning在网络游戏中应用的具体算法以及该算法的相应实例。