Systematic approach for validating the ubiquitinated proteome

Protein ubiquitination plays an essential regulatory role within all eukaryotes. Large-scale analyses of ubiquitinated proteins are usually performed by combining affinity purification strategies with mass spectrometry. However, there is no reliable method to systematically differentiate ubiquitinated species from copurified unmodified components. Here we report a simple strategy for the large-scale validation of ubiquitination by reconstructing virtual Western blots for proteins analyzed by gel electrophoresis and mass spectrometry. Because protein ubiquitination, especially polyubiquitination, causes a dramatic shift of molecular weight, the difference between experimental and expected molecular weight was used to confirm the status of ubiquitination. Experimental molecular weight of putative yeast ubiquitin-conjugates was computed from the value and distribution of spectral counts in the gel using a Gaussian curve fitting approach. Unmodified proteins in yeast cell lysate were also analyzed as a control to assess the accuracy of the method. Multiple thresholds that incorporated the mass of ubiquitin and/or experimental variations were evaluated with respect to sensitivity and specificity. Ultimately, only approximately 30% of the candidate ubiquitin-conjugates were accepted based on the stringent filtering criteria, although they were purified under denaturing conditions. These accepted conjugates had an estimated false discovery rate of approximately 8% and primarily consisted of proteins larger than 100 kDa. Compared with another validation method (i.e., identification of ubiquitinated lysine sites), approximately 95% of the proteins with defined modification sites showed a convincing increase in molecular weight on the virtual Western blots. A second independent analysis indicated that the method can be simplified by excising fewer than ten gel bands. Therefore, this strategy establishes criteria necessary for the interpretation of ubiquitinated proteins.     

Investigating the role of business processes and knowledge management systems on performance: A multi-case study approach

In the ever-changing and competitive market place, organisations continuously need to improve their competitive advantage. One method to accomplish this is to form collaborative networks. Both knowledge management (KM) and KM systems play a pivotal role in the success of collaborative networks since information sharing and knowledge assets are so critical to the network. There has been a vast amount of research on KM systems but very little is known about how it affects individual and organisational performance. Drawing on the task–technology fit theory, in this study, we explore the fit or alignment between business process (task) and KM systems (technology) and its impact on KM systems utilisation based on multiple case studies. Subsequently, we investigate the impacts of both the task–technology fit and KM systems utilisation on individual and business performance. This paper contributes to the collaborative network/KM literature in several ways. First, it extends the task–technology fit theory to an important context of collaborative network/KM. Second, it replaces task with business process, which has the potential to help explain KM systems’ success on business performance. Third, the paper explores the positive impact of task–technology fit on KM system utilisation and business performance. Fourth and finally, the study provides insight into the future development of KM systems and how to better align them with managerial purposes.     

BPMN-based business process model feasibility analysis: a petri net approach

Business process modelling has been widely applied by many companies to support the projects such as BPR or enterprize integration. In general, business modelling technique plays the role of pre-designing and evaluating the business flow before the final implementation. However, due to certain improper situations, the developed model might not be appropriate for the final analysis and evaluation. Therefore, model feasibility should be confirmed before the formal evaluation. This research proposed a Petri-net-based approach to evaluate the feasibility of a model defined by BPMN (business process modelling notation). Two kinds of invalid situations, deadlock and infinite loops, will be defined and analysed. There are four phases in the proposed approach. In problem analysis phase, a modified business process development approach would be proposed first. Then, the invalid model would be defined and classification. In the design stage, the developed BPMN model will be transferred to Modified BPEL4WS, which is an XML based language. By applying XSLT and Java, the transferred BPEL4WS will be translated to a Petri-net model specified as CPNXML (Colored Petri-net XML). In the simulation phase, the CPNXML file can be imported into a graphical simulation package CPN Tools for further analysis. Finally, in the implementation phase, the three kinds of property analysis (deadlock, infinite loops and execution time) will be evaluated in terms of the ‘liveness’, ‘reachability’ and ‘consumed time’ of the converted Petri net model.     

Bayesian prediction for business mortality analysis

Summary This paper is concerned with business mortality analysis in a Bayesian setting. We assume that a businessman startsN businesses at different points of time and at a certain epoch referred to as the ‘present’, the failure times of the failed businesses and the survival times of the still surviving businesses are recorded. Bayesian prediction for business mortality or survival up to a future time pointt ₀ is made under the assumptions of a Weibull business survival distribution (WBSD) and the squared error loss function (SELF). The results are extended to the situation where one of the observed times of business failure may possibly be an outlier.     

Quasidiffusion model of transfer processes in a gap

The problem of free-molecular flow in the gap between two plane parallel walls is reduced to solving the Poisson equation with an anisotropic tensor of transmission coefficients.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 46, No. 3, pp. 406–414, March, 1984.     

Systematic design approach for capacitively coupled microelectromechanical filters

A design procedure for microelectromechanical (MEMS) band-pass filters is formulated that takes into account specifications set for carrier-to-interference ratio (C/I) and insertion loss. Since suppressing intermodulation distortion to maximize C/I in MEMS filter design typically leads to increased loss and vice versa, it is necessary to aim at a feasible compromise in filter performance that meets all of the requirements. In order to meet specifications that are typical for a handheld communication terminal, an integrated receiver architecture, where filter input and output impedances other than 50 omega can be used, is found to be more feasible than resistively terminating the front-end filter at source and load to 50 omega.     

An Eulerian approach for die compaction processes

For the analysis of deformation processes the Eulerian approach is usually formulated in material velocities. To describe the die compaction of compressible media, this paper presents an Eulerian simulation method, basically expressed in displacements. The material behaviour is modelled by the theory of elastoplasticity. Frictional interaction with the surroundings is included. As a spatially fixed finite element mesh is applied, rezoning is governed by the process specification and not, as in the Lagrangian approach, by the mesh distortion. The solution scheme, using a Newton-Raphson algorithm, is considered in detail. A consistent iteration procedure is derived. Examples demonstrate the merits of the method developed.     

The design of business processes within manufacturing systems management

Manufacturing organizations are currently being subjected to increased business, regulatory and legislative pressures that require them to regularly re-engineer themselves. To be able to effectively manage such activities, a manufacturing systems management (MSM) framework is required, which helps to define the necessary activities needed to regulate and optimize a manufacturing system as it progresses through its life cycle. The current merging of automotive manufacturers highlights the need for such a framework. Maximizing the benefits of such mergers requires the effective convergence of the organizations' processes, which is a complex undertaking that requires a structured approach. Through an approach known as Business Process Development (BPD), as used in the case of the design of BMW's new UK engine factory, this paper describes how a MSM framework can be applied in practice to deal with a range of issues related to the analysis, design and implementation of a new manufacturing system.     

An empirical mode decomposition‐based frequency‐domain approach for the fatigue analysis of nonstationary processes

Mechanical structures in service are often subjected to irregular loads, which are typically idealized as stationary random processes. However, the service loads in real applications are often nonstationary ones, in which case conventional frequency‐domain methods are no longer applicable. Here, a novel frequency‐domain approach based on empirical mode decomposition is developed for the fatigue analysis of nonstationary processes. A simplified approach is introduced to calculate the rainflow cycle distributions of non‐Gaussian intrinsic mode functions. Two typical nonstationary processes in engineering practice are simulated numerically to validate the proposed method. The proposed method is applied to fatigue life estimation of a dynamical structure under nonstationary excitations. Reliable life estimations are obtained within much less computation time than the time‐domain method. The results verify the applicability and effectiveness of the proposed method for the fatigue analysis of nonstationary processes.     

Systematic approach for conceptual design of an integrated biorefinery with uncertainties

The objective of this work is to present a systematic approach for conceptual design of an integrated biorefinery with maximum economic potential accounting for the predefined uncertainties in energy economics. Various parameters commencing from raw biomass feedstock, desired end products, to market price trend, technological constraints and system uncertainties at multi-periods are to be considered. A structural framework, integrated biorefinery pathway map which embeds and interconnects the latest processing technologies is first developed. Then, a robust optimisation model is adopted to determine the optimum network which handles the predefined sets of uncertainties in energy economics. To illustrate the proposed approach, a case study with two different scenarios of uncertainties is solved. Furthermore, a sensitivity analysis is also performed to identify the critical parameters of an integrated biorefinery.     

薄壁结构件铣削加工振动稳定性分析

针对如何考虑刀具与工件相互耦合作用及加工位置对系统稳定性影响,通过对切屑厚度、铣削力建模,建立薄壁件铣削系统动力学模型,考虑薄壁件铣削稳定性受铣削位置影响,获得以轴向铣削深度、转速、铣削加工位置为参数的三维稳定性图。通过对曲面图分析,可确定在不同主轴转速、不同铣削区域内薄壁件各模态对铣削稳定性影响。通过时域模拟分析加工位置对系统失稳机制影响,揭示稳定铣削与不稳定铣削、不同模态在不稳定铣削时铣削力、铣削位移的变化规律。     

On pressurized feeding approach for effective control on working gap in ECDM

Electrochemical discharge machining (ECDM) process is promising for machining of micro features on glass and ceramic materials. ECDM requires an effective control on process parameters for high productivity and accuracy with an increase in the depth of penetration. Among all parameter settings, the most important requirement is the effective control on working gap. The present article reports the development of pressurized feeding system for effective control on working gap during ECDM. In pressurized feeding system, the exerted pressure maintains constant working gap (almost zero) during machining, and that was provided by the development of a workpiece holding fixture. The existence of micro cavities between abrasive coated tool and work material generates thin and stable gas films underneath the tool electrode. The breakdown of these films results in high-frequency and low-intensity discharges with reduced critical voltage (V_c), and these discharges seem to be responsible for the machining of deep holes even with the use of high applied voltage. The developed pressurized feeding system exhibits 207.4% improvement in machining depth while compared to the other feeding systems. The effect of exerted pressure along with applied voltage, pulse on time, and electrolyte concentration on material removal rate, hole over cut, and taper was also investigated.     

Quasimode theory of quantum optical processes in photonic band gap materials

This paper deals with atomic systems coupled to a structured reservoir of quantum EM field modes, with particular relevance to atoms interacting with the field in photonic band gap materials. The case of high Q cavities has been treated elsewhere using Fano diagonalization based on a quasimode approach, showing that the cavity quasimodes are responsible for pseudomodes introduced to treat non-Markovian behaviour. The paper considers a simple model of a photonic band gap case, where the spatially dependent permittivity consists of a constant term plus a small spatially periodic term that leads to a narrow band gap in the spectrum of mode frequencies. Most treatments of photonic band gap materials are based on the true modes, obtained numerically by solving the Helmholtz equation for the actual spatially periodic permittivity. Here the field modes are first treated in terms of a simpler quasimode approach, in which the quasimodes are plane waves associated with the constant permittivity term. Couplings between the quasimodes occur owing to the small periodic term in the permittivity, with selection rules for the coupled modes being related to the reciprocal lattice vectors. This produces a field Hamiltonian in quasimode form. A matrix diagonalization method may be applied to relate true mode annihilation operators to those for quasimodes. The atomic transitions are coupled to all the quasimodes, and the true mode atom-EM field coupling constants (one-photon Rabi frequencies) are related to those for the quasimodes and also expressions are obtained for the true mode density. The results for the one-photon Rabi frequencies differ from those assumed in other work. Expressions for atomic decay rates are obtained using the Fermi Golden rule, although these are valid only well away from the band gaps.     

A reinforcement learning approach to stochastic business games

The Internet revolution has resulted in increased competition among providers of goods and services to lure customers by tearing down the barriers of time and distance. For example, a home buyer shopping for a mortgage loan through the Internet is now a potential customer for a large number of lending institutions throughout the world. The lenders (players, in generic game theory nomenclature) seeking to capture this customer are involved in a nonzero-sum stochastic game. Stochastic games are among the least studied and understood of the management science problems, and no computationally tractable solution technique is available for multi-player nonzero-sum stochastic games. We now develop a computer-simulation-based machine learning algorithm that can be used to solve nonzero-sum stochastic game problems that are modeled as competitive Markov decision processes. The methodology based on this algorithm is implemented on a supply chain inventory planning problem with a limited state space. The equilibrium reward obtained from the stochastic game problem is compared with a logical upper bound obtained from the corresponding Markov decision problem in which a single decision maker (player) is substituted for all the competing players in the game. Several numerical versions of the problem are studied to assess the performance of the methodology. The results obtained from our methodology for the inventory planning problems are within 0.8% of the upper bound.     

Systematic approach to manage hazardous chemicals safely

正To thoroughly implement the deployment of the Central Party Commit tee and the State Council on safety management of hazardous chemicals,according to the requirements stipulated in the State Council’s Notification on Issuing the Regulations on the Safe Management of Hazardous Chemicals in China,SAC and State     

An economic off-line quality control approach for unstable production processes

An economic off-line inspection/disposition approach is proposed, which incorporates manufacturing variation. This approach includes a new inspection algorithm for inspections based on cost minimization and utilizing a specified confidence level for identifying in-control items. This approach addresses two situations not addressed in previous papers: (i) the last unit in the batch is conforming; (ii) inspection time is non-negligible. Advantages are that there is no need to record the original position of each unit, the impact of manufacturing variation is reduced and non-negligible inspection times can be easily incorporated. Comparisons of this approach to other approaches are provided.