The conservatism is an important indicator for measuring a robust approach. In the process of our previous research for the conservatism of robust linear programming problems, we have found that k is a critical parameter to depict the conservatism of robust linear programming problems, where k is the number of nonzero components in optimal solution of the extremely conservative robust linear programming problems. In this paper we give the distribution and expectation of k through analyzing the probability that any basic solutions are the optimal solutions of the extremely conservative robust linear programming problems.

Let F_q be a finite field with q=p^s (s≥1) elements, where p is an odd prime number. In this paper, we present formulas for the number of solutions of the following equations defined over F_q
x₁^m₁+…+x_n^m_n=cx₁…x_t
and
(x₁+…+x_n)²=cx₁…x_t
under some certain restrictions, where m_j|q-1,n≥2,c∈F_q^*,t > n. When m₁=…=m_n=m, an explicit formula for the number of solutions of the equation x₁^m+…+x_n^m=cx₁…x_t is presented.

Due to the time-varying characteristics of length-of-day (LOD), it is difficult to model LOD variations with a deterministic model. We employ a new type of artificial neural networks (ANN)-extreme learning machine (ELM) to predict LOD variations. In order to solve the problems of embedding dimension selection and network topology design, a training algorithm for ELM based on grey relational analysis (GRA) is first proposed. It optimizes the input and hidden layers simultaneously. Secondly, the values of LOD variation are preprocessed and a GRA-ELM model is then set up to accurately forecast LOD variation in near real-time. Finally, the prediction results are analyzed and compared with those obtained by the back propagation neural networks, generalization regression neural networks and Earth orientation parameters prediction comparison campaign. The results show that the prediction accuracy of our method is equal to or even better than those of the other prediction methods. The developed method is easy to use.

The redox property of palladium nanoparticles (NPs) is pivotal to CeO₂ supported Pd catalysts in oxidation reactions and is closely related to the structure of Pd-CeO₂ interface. Herein, we report that low-temperature CO oxidation activity of Pd/CeO₂ highly depends on the shape and crystal plane of CeO₂ supports. Pd/CeO₂ catalysts with CeO₂ nanoocthedrons (NOCs) and nanocubes (NCs) as supports were prepared by colloidal-deposition method. Results show that Pd/CeO₂ NOCs with ceria {111} facets enclosed exhibited much higher catalytic activity than Pd/CeO₂NCs with ceria {100} facets exposed. DFT calculations revealed that the redox property of surface Pd species may play important roles in determining the reducibility and activity of catalysts. The PdO_x to Pd cycle is more facile on Pd₄@CeO₂(111) than on Pd₄@CeO₂(100), which is dictated by the Pd-ceria interaction in the end. Our results show that the redox property of surface Pd is pivotal to the reducibility and activity of Pd/ceria catalysts, which could be tuned by manipulation of the Pd-CeO₂ interaction via tuning the exposed facets of ceria support.

About 80% of ammonia in municipal wastewater comes from urine. In the present study, Ti/RuO₂-TiO₂ anode and stainless steel cathode were used in the nitrogen removal process of stored urine. The operating variables in the electrochemical nitrogen removal including the current density (20-100 mA/cm²), initial pH (9-12), and sodium chloride dosage (4-16 g/L) were considered to be the influence factors on the nitrogen removal. The the most effective electrochemical process was observed when utilizing a current density at about 80 mA/cm², initial pH at about 11, and sodium chloride dosage at about 8 g/L. Under the optimum conditions the removal rates of ammonia and total nitrogen were 91.83% and 88.34%,erspectively, and the reaction time was 270 min. A total of 0.311 kW·h energy was consumed for treating 1 L of stored urine. This process was rapid and efficient with low cost, and it would have promising applications in removal of nitrogen in stored urine.

This work takes Xiji as a typical area to investigate the development trend and its influence factors in the ecological fragile areas and poor areas from county level to farmer level. Under the background of economic and social development, the number and size of villages significantly increased and concentrated on good ecological environment and traffic convenient areas. The influencing factors are analyzed. At the macro level, population and economic growth are the main driving forces. The government immigration and structure upgrade also significantly contribute to the space evolution of rural settlements. Under the background of population pressure and ecological degradation, rural development in Xiji has entered a vicious cycle: relocation-ecological deterioration-increasing poverty, which is the result of fragile ecology, extensive development mode, and lagging economy. At the micro level (from farmer's respect), the core reasons of spatial variation of rural settlements are found to be the family separation, working outside, and other social factors rather than revenue growth, based on Logistic regress analysis.

Energy ecological footprint method is a new and important approach for evaluating regional sustainable development. We use energy ecological footprint model, GM(1,1)model, index prediction model, and STIRPAT model to analyze energy footprint in Yangtze River Delta region from 1990 to 2012. The results are given below. 1) The annual growth rate of EEF had reached 7.70% in the past 23 years, and the national energy footprint per capita was less than those of Yangtze River Delta region and the three provinces. As the change rates, the fastest-growing segment was the provincial zone, and the nation was low. 2) VEF appeared the growth trend while EFI showed the decreased trend, and the annual rates were 8.42% and 8.37%, respectively. Yangtze River Delta region and the three provinces were mainly implemented by industrial transformation and upgrade, the nation mainly relied on policy development and technical innovation. 3)EEF and VEF would continue to grow in Yangtze River Delta region but EEI would decline, which shows the harmonious trends. 4) Population, GDP per capita, industrial structure, and technology had great impacts on EEF, and the corresponding coefficients were 0.596,0.073,0.18, and -0.123, respectively.

In this work, we used DEA model and Malmquist index method to evaluate the efficiency of input-output and the TFP(total factor productivity) change of the equipment manufacturing industries in Northeast China in the years of 2006 and 2012. The results show that the advantages of the equipment manufacturing industries in Northeast China present a mutually complementary state. Seven industries in Liaoning province are in the stage of the decreasing returns to scale, while six industries in Jilin province and three industries in Heilongjiang province achieve the best returns to scale. During the six years, the TFP changes of the electric equipment manufacturing industries and the special purpose machinery manufacturing industries in Northeast China are the biggest. In addition, the TFP change of the computer, the telecommunication, and other electronic equipment manufacturing industries in Heilongjiang province and the transport equipment manufacturing and general purpose machinery manufacturing industries in Jilin province are significantly higher than the national average. On the basis of the analysis, we give the adjustment values for achieving the best index of input-output level of the equipment manufacturing industries in Northeast China.

The oasis urbanization characteristics were studied by using a comprehensive index evaluation system,which included "water penetration", "over-exploitation of water resources", and some basic index. The quality and scale of urbanization of oasis cities was evaluated by entropy method. The couplings between the quality and scale of urbanization of 14 states in Xinjiang were considered through the coupling coordination degree model.The results showed that: 1)the urbanization comprehensive level was rising in the past years with quality of urbanization lagged behind the scale of urbanization in oasis cities; and 2)the coupling coordination degrees of the quality and scale of urbanization were obviously spatially different in oasis cities. Therefore, some measures were put forward to coordinate the quality and scale of urbanization in oasis.

More and more researchers focus on the relationship between satellite infrared anomaly and seismic activity. Some researchers did some rock experiments to observe the thermal evolution of rock specimen during loading and deformation. The results for the rock experiments match well with the classical thermodynamics theory. Based on the experimental data, we used finite element model to simulate temperature evolution of the rock specimen during the loading process. Thermal-elastic effect of both homogeneous specimen and heterogeneous specimen with en-echelon cracks is simulated under the elastic loading condition. The simulated results are well consistent with the data of experiments and thermodynamics theory. This study may provide a theoretic foundation for the relationship between satellite infrared anomaly and seismic activity.

The M_w7.8 Kunlunshan earthquake of November 14,2001, which ruptured over a total distance of about 400 km, was characterized by a 350-km-long main fault with an east-ward-propagating pulse of left-lateral slip. The field observations of coseismic displacement along the main fault provide us a good opportunity to study the earthquake source mechanism and fault geometry inside the earth. In this paper, based on Freund's III-dislocation model and constrained by two groups of surface rupture data from field investigation and geodetic measurement, we invert the slip distribution, the variation of static stress drop on the fault surface, and the fault width extending at depth along the fault strike-slip direction. The pattern of slip distribution on the fault surface deduced from the III-dislocation model is very similar to the result of the finite-fault solution based on the teleseismic body-wave inversion, showing that both slip distributions appear intensively heterogeneous in the special domain. The fault rupture width is much less than 20 km. These results also imply that the coseismic displacement along the fault strike direction on the earth surface is proportional to the fault width. In addition we also calculate the static stress change on the fault based on the III-dislocation model and slip distribution by teleseismic inversion. The analytical and numerical results show that they have high-level consistency.

In heterogeneous networks, Macro eNodeBs reduce transmit power on almost blank subframe (ABS) so that Pico cell range expansion(CRE) users could be protected from cross-layer interference. However, few focus on power reduction and user QoS constraints. In this paper, a joint resource allocation and ABS power control algorithm(RA-APC) is proposed. The algorithm is carried out by iterating between RA and APC under user QoS constraints. Simulation results show that the proposed algorithm converges fast and improves overall network utility.

About 500 million of smart mobile devices have been sold in China because of the new architecture, secure mechanism, rich sensors, and applications. However, the new features cause a new secure problem named smart mobile device covert channel, which is more dangerous than the traditional attacks and leaks users' privacy. At the present stage there are no elimination and mitigation methods. In this work, the Android covert channels are classified into two models including the shared resource-based Android covert channel and the sensor-based covert channel. The latter one has been carefully studied in this work. The new secure features of permission mechanisms is analyzed and extended to protect the sensors. A new mitigation approach for sensor-based channel is designed and implemented, and the experiments show that the covert channel can be mitigated perfectly.

Nowadays, AD(active directory) is usually used to carry out the unified identity management and achieve access control systems of most enterprises, but many cloud storage devices do not support connection to the AD directly. We propose a scheme to connect cloud storage device and AD. The scheme uses the Samba file access control server to communicate with the AD server and the cloud storage device, and user achieves single sign-on and access control through the AD domain accounts, which greatly improves the work efficiency and enhances the overall security of the system.

We study the technology of unified identity management and the user authentication & authorization in the cloud storage environment. We propose a cloud service scheme for the unified authentication and identity management, which provides the security assurance when users enjoy the cloud storage and application services in the cloud environment.

Malicious applications pose tremendous threats to Android platform. More than 90% of malicious codes are introduced in the form of Android apps. Hence, behavior monitoring scheme for Android applications are required in order to resolve the problem. However, most of the schemes are based on system customization and hard to deploy on devices for Android's fragmentation problem. In this paper, an easy-to-deploy Android application monitoring method on the basis of process hijacking is proposed after analysis of Android process model and code execution details. The method depends on Dalvik interpreter entry point and system call interception. The authors created a fully usable prototype of the system, and the evaluation results show that the system is easy to deploy, provides a whole-scale behavior of Android applications, and incurs little performance overhead.

More and more consumer electronic devices are equipped with Nand Flash as nonvolatile memory device. Unique digital fingerprint information can be extracted from each Nand Flash chip by using the physical properties of Nand Flash, which are determined in the production process. We propose a new method, based on the physical properties of Nand Flash, to produce private keys for SM2 signature scheme, which is verifiably tight coupled to the Nand Flash device. Notably, this method is irrelevant to the specific digital signature schemes, and it is applicable to any occasion where digital signature scheme is used for identification of the storage devices or electronic devices.

Currently desktop virtualization technology has become a focal point of the cloud computing technology and we analyze the main virtual desktop systems. Considering the legal requirement in communication security, we summarize the characteristics of the virtual desktop transmission protocols and choose the SPICE protocol, based on KVM, to improve the transmission security. In SPICE, the communication between the client and server can be secured by using OpenSSL. We propose to support the China standard cryptographic algorithms including SM3 and SM4 in the open-source project OpenSSL to ensure the security of virtual desktop system. The experimental results show that our scheme can not only ensure the safety of the transmission, but also keep good performance.

As a new cryptographic tool, attribute-based signature(ABS) allows user to sign messages using his attributes. The signature could be verified to satisfy some predicate without exposing any particular attributes or identity information of the signer. These properties effectively protect user's privacy while achieving attribute-based access control. In this paper, we propose an efficient threshold attribute-based signature scheme with constant signature size and constant pairing computation during verification. The scheme has been proved to be unforgeable and unconditionally anonymous. Compared with other existing constant-size ABS schemes, our scheme is short in signature size while keeps the secret key size acceptable.

This paper analyzes the security threats of software and the confidential file, provides an overview of software dynamic measure technology in trusted computing and digital watermarking technology for confidential files, and proposes an anti-lost scheme for confidential files by combining software dynamic measurement and digital watermarking technique. Finally, the technical characteristics of the model are summarized.