A note on the departure process in an (S− 1, S) inventory system

Steady-state distribution functions are derived for interdeparture time (of filled requests) in an (S?1,S) inventory system in which (demand) arrival process is Poisson, replenishment times are independently and identically distributed negative exponential variates, and service is on a first-come-first-served basis. The departure process proves to be identical to the arrival process. Some implications of this property in the study of queueing networks with (S ? 1,S) inventory stations are discussed.     

A thermodynamic assessment of Ni–Sb system

The Ni–Sb system was critically assessed by means of the CALculation of PHAse Diagram (CALPHAD) technique. The solution phases, Liq and (αNi), were modelled as the substitutional solutions with the Redlich–Kister equation. The intermediate phases, (γNiSb) and (βNi₃Sb), with homogeneity ranges were described respectively using three-sublattices (Sb)_1/3(Ni%,V a)_1/3(V a%,Ni)_1/3 and (Sb)_1/4(Ni%,V a)_1/2(Ni%,V a)_1/4 based on their structure features. Corresponding to the phase (βNi₃Sb), the two low-temperature phases of (δNi₃Sb) and (θNi₅Sb₂) with narrow homogeneity ranges were modelled as two-sublattice, (Ni)_3/4(Sb,Ni)_1/4 and (Ni)_5/7(Sb,Ni)_2/7. The intermetallic compound ζNiSb₂ with no homogeneity ranges was treated as stoichiometric compound. The phase ε$\epsilon$Sb was considered as pure Sb for the solubility of Ni in ε$\epsilon$Sb is very low. A set of self-consistent thermodynamic parameters of the Ni–Sb system was obtained. The optimized phase diagram and thermodynamic properties were presented and compared with experimental data.     

A perishable inventory system with modified (S−1,S) policy and arbitrary processing times

In this article we analyze a lost sales (S−1,S) perishable system, under Poisson demands and exponential lifetimes, in which the reorders are placed at every demand epoch so as to take the inventory position back to its maximum level S. The items are replenished one at a time and the resupply time has arbitrary distribution. The various operating characteristics are obtained using Markov renewal techniques. A matrix recursive scheme is developed to determine the stationary distribution of the underlying Markov chain. The efficiency of this procedure in the determination of optimal S that minimizes the long run expected cost rate is discussed. Sensitivity analysis of various system parameters is also carried out.Scope and purposeThe analysis of perishable inventory systems, which has potential applications in various sectors of industry, is far more difficult than their infinite lifetime counterparts. In the study of perishable systems under traditional (S−1,S) policy, reorders for items are placed at demand as well as failure epochs. However, it will be more meaningful not to place orders at failure epochs, which is also practical and economical since it avoids continuous monitoring of items. This paper deals with a continuous review perishable system under a more realistic base stock policy, with variable ordering quantity and arbitrary unit resupply times. The operating characteristics of this complex model are derived using the techniques of semi-regenerative processes. A matrix recursive scheme developed to determine the stationary distribution has enabled us to code an efficient numerical program for cost optimization.     

Experimental study and thermodynamic re-assessment of the Co–Sb system

The Co–Sb system is of a special attention due to existence of CoSb₃ skutterudite structure which is the key structure for doped skutterudite based thermoelectric materials. A critical review of this system, performed recently, shows the published thermodynamic assessment may not be fully correct compared to existing studies. Especially, there is a contradiction in the position of the liquidus line on the Sb-rich side of the phase diagram and of the eutectic reaction, liquid ↔ CoSb₃ + (Sb). As these data are crucial for the study of thermal stability of skutterudite based thermoelectric materials, a good knowledge on phase relations in the Sb-rich part of the Co–Sb phase diagram is needed. To obtain reliable data, experimental alloys covering 80 to 100 at.% of Sb were prepared and investigated by differential thermal analysis and phase analysis. The data were compared with existing literature information and thermodynamic re-assessment of this binary system based on the CALPHAD approach was done.     

New stability analysis of T–S fuzzy system with robust approach

Based on the robustness criterion, this paper provides a new way to deal with the stability of T–S fuzzy system. A sufficient criterion is proposed to guarantee quadratic stability of the fuzzy model globally. The existence well-known problem of the common P for a set of Lyapunov equations in fuzzy control system design can be avoided here. An illustrative example is given to show the effectiveness of the proposed method.     

Pick sequencing optimization problem in the rotary rack S／R system

The problem of pick sequencing in the rotary, rack S/R system (PPS-RRS) is investigated with the objective of mininizing the execution rime. The rotary rack S/R system consists of one S/R machine and multiple levels of carousals that can rotate independently in bi-directions. The routing policy, namely the decision on the storage or retrieval sequence, donfinates the efficiency and the throughput for such S/R systems, due to the complicated relationship between all levels of carousels and the S/R machine. For the purpose of optimizing the PPS-RRS, a computational model is developed in temps of execution time for picking multiple items in one trip. Characteristics of the PPS-RRS are analyzed and a local search heuristic based on a newly proposed neighborhood is presented. Integrated with the proposed local search procedure a new hybrid genetic algorithm is developed. Experimental results demonstrate the structure characteristics of good sequence and the efficiency and effectiveness of the proposed sequencing algorithms.     

系统system

找回硬盘丢失的空间,总是显示有文件需要写入CD，手工免疫流氓软件，文件夹选项丢失，正确地删除双系统中的一个系统，任务管理器的CPU面板显示红色曲线。[编者按]     

system系统

Ghost备份后的文件变小了；Vista关闭升级后无法重新开启；关闭系统升级后重启的提示；无法看到闪盘盘符；如何修复双系统引导菜单。     

Symbol-display system

1<美国专利> llll6,499,103 。。。Tsuria,et a1.。。。 。 -Decelnbe≯24’i2002 0 i l”<发明人>。。 。TsuL ri。a Yossef(、Shoham,IL)々Itkis~Gerle(NMaaleAdumim.IL);seua;Yairon(:Jerusalem,IL);Sered{Yishai一(Jerusal—em,IL)。j j i i ll<代理人>NDS Limited(Mi(州[1esex,GB)<公开号> j341075 。 j<公开日》October 2民1999 。<美国分类> j j7乃/153;7i3,/168;713/200;713/201 一i?<国际分类> _G06F¨_001。/24l 。0 i j。0 0<检索号> 、713/i.53,168,200,201<摘要>: This inventi、on disclp8eS a symbol-display…     

Tropospheric aerosol observations in São Paulo,Brazil using a compact lidar system

A backscattering light detection and ranging (lidar) system, the first of this kind in the country, has been set up in a suburban area in the city of São Paulo, Brazil (23°33′?S, 46°44′?W) to provide the vertical profile of the aerosol backscatter and extinction coefficients at 532?nm and up to 4–5?km height above sea level (asl). The measurements have been carried out during the second half of the so‐called Brazilian dry season, September and October in the year of 2001. When possible, the lidar measurements were complemented with aerosol optical thickness measurements obtained by a CIMEL Sun‐tracking photometer in the visible spectral region, not only to validate the lidar data, but also to provide an input value of the so‐called extinction‐to‐backscatter ratio (lidar ratio). The lidar data were also used to retrieve the Planetary Boundary Layer (PBL) height and low troposphere structural features over the city of São Paulo. Three‐dimensional air mass back trajectory analysis was also conducted to determine the source regions of aerosols observed during this study. These first lidar measurements over the city of São Paulo during the second half of the dry season showed a significant variability of the aerosol optical thickness (AOT) in the lower troposphere (0.5–5?km) at 532?nm. It was also found that the aerosol load is maximized in the 1–3?km height region and this load represents about 20–25% of the lower tropospheric aerosol.     

Electronic payment system

Equipment and method for acknowledging a trans- action in an electronic payment system, comprising first processing means for providing electronic receipts corresponding to payments, second processing means for receiving said receipts, and transfer means for transferring said receipts between the first and second processing means. Said electronic receipt or part of it is encrypted with a public-key algorithm by using the payee's private key as an encryption key, and a receipt is decrypted with a public-key algorithm by using the payee's public key as s decryption key. If a recipient of the receipt wants to be convinced of the authenticity of the receipt, he decrypts the encryption by means of the payee's public key. Digital encryption with the payee's private key certifies the origin of the receipt undeniably. As long as the receipt is in encrypted form, it cannot be read without exactly knowing the payee, and counterfeiting of the receipt is impossible. An electronic receipt can be easily read and tran     

Research of internet worm warning system based on system identification

In this paper, by analyzing the worm’s propagation model, we propose a new worm warning system based on the method of system identification, and use recursive least squares algorithm to estimate the worm’s infection rate. The simulation result shows the method we adopted is an efficient way to conduct Internet worm warning.     

简简单单提升system权限

大家都知道在Windows中的管理员用户Administrator吧？Administrator的权限确实很大,但它也不是万能的,例如有些注册表操作就需要system权限。Administrator就不行。下面我们就来看看如何把Administrator权限提升为system权限。