A fuzzy rough copula Bayesian network model for solving complex hospital service quality assessment.

Healthcare tends to be one of the most complicated sectors, and hospitals exist at the core of healthcare activities. One of the most significant elements in hospitals is service quality level. Moreover, the dependency between factors, dynamic features, as well as objective and subjective uncertainties involved endure challenges to modern decision-making problems. Thus, in this paper, a decision-making approach is developed for hospital service quality assessment, using a Bayesian copula network based on a fuzzy rough set within neighborhood operators as a basis of that to deal with dynamic features as well as objective uncertainties. In the copula Bayesian network model, the Bayesian Network is utilized to illustrate the interrelationships between different factors graphically, while Copula is engaged in obtaining the joint probability distribution. Fuzzy rough set theory within neighborhood operators is employed for the subjective treatment of evidence from decision makers. The efficiency and practicality of the designed method are validated by an analysis of real hospital service quality in Iran. A novel framework for ranking a group of alternatives with consideration of different criteria is proposed by the combination of the Copula Bayesian Network and the extended fuzzy rough set technique. The subjective uncertainty of decision makers' opinions is dealt with in a novel extension of fuzzy Rough set theory. The results highlighted that the proposed method has merits in reducing uncertainty and assessing the dependency between factors of complicated decision-making problems.

Optimal Abort Rules for Multiattempt Missions.

Many real-world systems use mission aborts to enhance their survivability. Specifically, a mission can be aborted when a certain malfunction condition is met and a risk of a system loss in the case of a mission continuation becomes too high. Usually, the rescue or recovery procedure is initiated upon the mission abort. Previous works have discussed a setting when only one attempt to complete a mission is allowed and this attempt can be aborted. However, missions with a possibility of multiple attempts can occur in different real-world settings when accomplishing a mission is really important and the cost-related and the time-wise restrictions for this are not very severe. The probabilistic model for the multiattempt case is suggested and the tradeoff between the overall mission success probability (MSP) and a system loss probability is discussed. The corresponding optimization problems are formulated. For the considered illustrative example, a detailed sensitivity analysis is performed that shows specifically that even when the system's survival is not so important, mission aborting can be used to maximize the multiattempt MSP.

Security of Separated Data in Cloud Systems with Competing Attack Detection and Data Theft Processes.

Empowered by virtualization technology, service requests from cloud users can be honored through creating and running virtual machines. Virtual machines established for different users may be allocated to the same physical server, making the cloud vulnerable to co-residence attacks where a malicious attacker can steal a user's data through co-residing their virtual machines on the same server. For protecting data against the theft, the data partition technique is applied to divide the user's data into multiple blocks with each being handled by a separate virtual machine. Moreover, early warning agents (EWAs) are deployed to possibly detect and prevent co-residence attacks at a nascent stage. This article models and analyzes the attack success probability (complement of data security) in cloud systems subject to competing attack detection process (by EWAs) and data theft process (by co-residence attackers). Based on the suggested probabilistic model, the optimal data partition and protection policy is determined with the objective of minimizing the user's cost subject to providing a desired level of data security. Examples are presented to illustrate effects of different model parameters (attack rate, number of cloud servers, number of data blocks, attack detection time, and data theft time distribution parameters) on the attack success probability and optimization solutions.

Thermal cycling life prediction of Sn-3.0Ag-0.5Cu solder joint using type-I censored data.

Because solder joint interconnections are the weaknesses of microelectronic packaging, their reliability has great influence on the reliability of the entire packaging structure. Based on an accelerated life test the reliability assessment and life prediction of lead-free solder joints using Weibull distribution are investigated. The type-I interval censored lifetime data were collected from a thermal cycling test, which was implemented on microelectronic packaging with lead-free ball grid array (BGA) and fine-pitch ball grid array (FBGA) interconnection structures. The number of cycles to failure of lead-free solder joints is predicted by using a modified Engelmaier fatigue life model and a type-I censored data processing method. Then, the Pan model is employed to calculate the acceleration factor of this test. A comparison of life predictions between the proposed method and the ones calculated directly by Matlab and Minitab is conducted to demonstrate the practicability and effectiveness of the proposed method. At last, failure analysis and microstructure evolution of lead-free solders are carried out to provide useful guidance for the regular maintenance, replacement of substructure, and subsequent processing of electronic products.

Interaction prediction optimization in multidisciplinary design optimization problems.

The distributed strategy of Collaborative Optimization (CO) is suitable for large-scale engineering systems. However, it is hard for CO to converge when there is a high level coupled dimension. Furthermore, the discipline objectives cannot be considered in each discipline optimization problem. In this paper, one large-scale systems control strategy, the interaction prediction method (IPM), is introduced to enhance CO. IPM is utilized for controlling subsystems and coordinating the produce process in large-scale systems originally. We combine the strategy of IPM with CO and propose the Interaction Prediction Optimization (IPO) method to solve MDO problems. As a hierarchical strategy, there are a system level and a subsystem level in IPO. The interaction design variables (including shared design variables and linking design variables) are operated at the system level and assigned to the subsystem level as design parameters. Each discipline objective is considered and optimized at the subsystem level simultaneously. The values of design variables are transported between system level and subsystem level. The compatibility constraints are replaced with the enhanced compatibility constraints to reduce the dimension of design variables in compatibility constraints. Two examples are presented to show the potential application of IPO for MDO.

A modified nonlinear damage accumulation model for fatigue life prediction considering load interaction effects.

Many structures are subjected to variable amplitude loading in engineering practice. The foundation of fatigue life prediction under variable amplitude loading is how to deal with the fatigue damage accumulation. A nonlinear fatigue damage accumulation model to consider the effects of load sequences was proposed in earlier literature, but the model cannot consider the load interaction effects, and sometimes it makes a major error. A modified nonlinear damage accumulation model is proposed in this paper to account for the load interaction effects. Experimental data of two metallic materials are used to validate the proposed model. The agreement between the model prediction and experimental data is observed, and the predictions by proposed model are more possibly in accordance with experimental data than that by primary model and Miner's rule. Comparison between the predicted cumulative damage by the proposed model and an existing model shows that the proposed model predictions can meet the accuracy requirement of the engineering project and it can be used to predict the fatigue life of welded aluminum alloy joint of Electric Multiple Units (EMU); meanwhile, the accuracy of approximation can be obtained from the proposed model though more simple computing process and less material parameters calling for extensive testing than the existing model.

Identification of characteristic components in frequency domain from signal singularities.

In rotating machinery condition monitoring, identification of characteristic components is fundamental in many engineering applications so as to obtain fault sensitive features for fault detection and diagnosis. This paper proposed a novel method for the identification of characteristic components in frequency domain based on singularity analysis. In this process, Lipschitz exponent function is constructed from the signal through wavelet-based singularity analysis. In order to highlight the periodic phenomena, autocorrelation transform is employed to extract the periodic exponents and Fourier transform is used to map the time-domain information into frequency domain. Case study with rolling element bearing vibration data shows that the proposed has very excellent capability for the identification of characteristic components compared with traditional methods.

Expression of phosphatase and tensin homolog deleted on chromosome ten in liver of athymic mice with hepatocellular carcinoma and the effect of Fuzheng Jiedu Decoction.

AIM: To explore the expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN) in liver of athymic mice with hepatocellular carcinoma (HCC) and the effect of Fuzheng Jiedu Decoction (FJD). METHODS: Forty eight male BALB/c athymic mice models were built by Bel-7402 with an indirect method. After 24 h of postoperation, the 48 athymic mice were distributed randomly into 4 groups: A, B, C, D, each group had 12 athymic mice. Group A were were treated by intragastric administration with FT207 (Tegafur) for 4 wk. Group B, C and D were treated by intragastric administration with FJD (complex prescription of Chinese crude drug) that had been delegated into 3 kinds of density as the low, middle, and high for 4 wk. At last, athymic mice were put to death, live time, volume of tumors, exponent of tumors and the tumor metastasis in livers were observed; and PTEN was detected in hepatic tissue, latero-cancer tissue and cancer tissue by immunohistochemistry. RESULTS: Four weeks later, the total survival rate in treatment group (A + B + C) was 50% and higher than the control group (0%) treated by FT207, (P < 0.01). The survival rate in group A, B, C was higher than in group D, and except group A with D, there was significant differences (Fisher's Exact Test P = 0.05 or 0.01). And no differences were observed between the treatment groups and the control group in volume of tumors and exponent of tumors (P > 0.05). Tumor metastasis in livers of the treatment group was less than the controls (Fisher's Exact Test, P = 0.021). The result of immunohistochemistry showed that the intensity of PTEN in latero-cancer tissue was the highest, and then the hepatic tissue, the lowest was cancer tissue (Kruskal-Wallis test, chi2 = 60.67, P = 0.000). It also showed that the intensity of PTEN in treatment groups (A, B, C) was higher than the control group (D) (F = 5.90, P = 0.002 in hepatic tissue and F = 15.99, P = 0.000 in latero-cancer tissue and chi2 = 26.08, P = 0.000 in cancer tissue), and group B is the highest in the treatment groups (P < 0.05, r = 0.01. respectively). However, there was no significant statistic difference between group A and group C (P > 0.05). CONCLUSION: FJD can prolong the survival time and decrease tumor metastasis in livers of these experimental mice. Mechanisms of FJD healing HCC may partially be explained by enhancing the expression of PTEN in liver.

[Expression of PTEN in athymic mice with HCC treated by complex prescription of Chinese crude drug].

OBJECTIVE: To research the treatment effect of complex prescription of Chinese crude drug in BALB/c athymic mice with human liver cancer, which were built by Bel-7402. METHOD: 48 male BALB/c athymic mouse models were built by Bel-7402 with an indirect method. After 24 hours of postoperation, the 48 athymic mice were distributed randomly into 4 groups which were treated by intragastric administration with complex prescription of Chinese crude drug that had been deliquated into 3 groups by the different density as the low, middle, and high and FT207 (Tegafur) for 4 weeks. At last, athymic mice were put to death and PTEN was detected in hepatic tissue, latero-cancer tissue and cancer tissue by immunohistochemistry (PowerVision Two-Step Histostaining Reagent). RESULT: All of the 48 athymic mice survived 12 to 28 days (Ms 24 days) and every mouse with liver cancer demonstrated by dissection. The result of immunohistochemistry represents that the intensity of PTEN in latero-cancer tissue is the highest, and then the hepatic tissue, the lowest is cancer tissue, P < 0.01. It also represents that the intensity of PTEN in treatment groups (A, B, C) is more higher than the control group (D), P < 0.05 or P < 0.01, and group B is the highest in the treatment groups, P < 0.05 or P < 0.01. However, there is no significant statistic difference between group A and group C. CONCLUSION: The higher expression of PTEN in the laterocancer tissue can represent the protective reaction of stress of the organism. And anticancer effect of this complex prescription of Chinese crude drug relates to an eligible density of it. Mechanisms of this complex prescription of Chinese crude drug healing HCC may partially be explained by enhancing the expression of PTEN in liver.

[Study of antitumous effect of the complex prescription of Chinese crude drug in athymic mice with HCC].

OBJECTIVE: To research the treatment effect of a complex prescription of Chinese crude drug in BALB/c athymic mice. METHODS: 48 male BALB/c athymic mouse models were built by Bel-7402 with an indirect method. After 24 hours of postoperation, they were distributed randomly into 4 groups which were treated by intragastric administration with complex prescription of Chinese crude drug of different density as the low, middle, high and FF207 (Tegafur) for 4 weeks. At last, athymic mice were put to death and survial time, volume of tumors, exponent of tumors and the tumor metastasis in livers were observed; and PTEN was detected in hepatic tissue, latero-cancer tissue and cancer tissue by immunohistochemistry. RESULTS: 4 weeks later, the total survival rate in treatment group (A + B + C) was 50% and more higher than the control group (0%) treated by FT207, P < 0.01. The survival rate in group A, B, C was higher than group D, except group A, there was significant differences, P < 0.05 or 0.01. And no differences were observed between the treatment groups and the control group in volume of tumors and exponent of tumors, P > 0.05. Tumor metastasis in livers of the treatment group is less than the control's, P < 0.05. Negative correlation between volume of tumors and survival time, positive correlation between tumors volume and spleen exponent were observed, P < 0.01. The result of immunohistochemistry represented that the intensity of PTEN in latero-cancer tissue was the highest, and then the hepatic tissue, the lowest was cancer tissue, P < 0.01. It also represented that the intensity of PTEN in treatment groups (A, B, C) was more higher than the control group (D), and group B was the highest in the treatment groups, P < 0.05 or P < 0.01. However, there was no significant statistic difference between group A and group C, P > 0.05. CONCLUSION: This complex prescription of Chinese crude drug can prolong the survival time and decrease tumor metastasis in livers of these experimental mice. Too large tumor volume is an main death cause of model. Mechanisms of this complex prescription of Chinese crude drug healing HCC may partially be explained by enhancing the expression of PTEN in liver.