Privacy Protection Based Access Control Scheme in Cloud-Based Services

With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issue. In this paper, we present an access control system with privilege separation based on privacy protection(PS-ACS). In the PS-ACS scheme, we divide users into private domain(PRD) and public domain(PUD) logically. In PRD, to achieve read access permission and write access permission, we adopt the Key-Aggregate Encryption(KAE) and the Improved Attribute-based Signature(IABS) respectively. In PUD, we construct a new multi-authority ciphertext policy attribute-based encryption(CP-ABE) scheme with efficient decryption to avoid the issues of single point of failure and complicated key distribution, and design an efficient attribute revocation method for it. The analysis and simulation result show that our scheme is feasible and superior to protect users' privacy in cloud-based services.

Factors Affecting Community-Based Tourism Development and Environmental Protection: Practical Study in Vietnam

Community-based tourism (CBT) is considered as one of the typical types of tourism towards sustainable development with three important goals such as bringing back economic benefits, protecting natural environment and preserving indigenous cultural values. Therefore, this paper analyzes the factors that affect community ecotourism development associated with environmental protection in emerging economies, including Vietnam, by the method of key and community tourism potential value assessment with 721 sample surveys. In this paper, we have applied to assess the key factors of tourism in Vietnam and other key points to have more comprehensive solutions to promote the development of community-based tourism with environmental protection. The article has used guest-based approach and method of assessing the key success factors. The results of researching factors to develop community tourist (impacting tourist community needs of tourists) by running Logit function have shown the great influence of factors such as: environmental protection (influence factor +3.585780, with a statistical significance of 99%), security and safety (+3.024816—statistical significance 99%) followed by infrastructure conditions & facilities for the community based tourism, the level of information etc… for your community based tourism needs. From the research results, we propose the following policy groups: 1) Developing guidelines for CBT, the first step as a basis for the development of community based tourism laws later;2) Policies related to the implementation of planning, development of key community tourist areas and destinations;3) Policies related to the development of community-based tourism associated with the protection of natural and cultural environments;4) Policies related to tourism management;coordinating monitoring of community tourism resource points;policies related to the local community in community tourism development;5) Policies related to human resource development;promotion work;developing community based tourism products.

A Generalized Location Privacy Protection Scheme in Location Based Services

When the user getting location based services by the traditional technology,his location information of region is always be exposed.However,in modern mobile networks,even the current geographical region is a part of privacy information.To solve this problem,a new generalized k-anonymity location privacy protection scheme in location based services(LPPS-GKA)with the third trust servicer is proposed.And it can guarantee the users get good location-based services(LBS)without leaking the information of the geo-location region,which has protected the perfect privacy.Analysis shows that LPPS-GKA is more secure in protecting location privacy,including region information,and is more efficient than other similar schemes in computational and communicational aspects.It is suitable for dynamic environment for different user’s various privacy protection requests.

Design and implementation of self-protection agent for network-based intrusion detection system

Static secure techniques, such as firewall, hierarchy filtering, distributed disposing,layer management, autonomy agent, secure communication, were introduced in distributed intrusion detection. The self-protection agents were designed, which have the distributed architecture,cooperate with the agents in intrusion detection in a loose-coupled manner, protect the security of intrusion detection system, and respond to the intrusion actively. A prototype self-protection agent was implemented by using the packet filter in operation system kernel. The results show that all the hosts with the part of network-based intrusion detection system and the whole intrusion detection system are invisible from the outside and network scanning, and cannot apperceive the existence of network-based intrusion detection system. The communication between every part is secure. In the low layer, the packet streams are controlled to avoid the buffer leaks exist ing in some system service process and back-door programs, so as to prevent users from misusing and vicious attack like Trojan Horse effectively.

Research on market-based policy instruments for eco-environmental protection

The selection of policy instruments involves policy efficiency and policy effect.Effective settlement of eco-environment problems in the process of industrialization and implementation of active eco-environment protection depend on the innovation of policy instruments.In this paper,based on a descriptive analysis of the policy instruments for ecoenvironmental protection of our country,combined with the theoretical analysis and the empirical research on current marketization of eco-environmental protection,the authors indicate that eco-environmental problems originate fi'om the damage of eco-environment and the extemalities of eco-service,and that the market-based policy instruments which are helpful to balance the relationship between fight,responsibility and interest in the eco-service are effective measures to eliminate externalities and protect eco-environment.

Ecosystem-Based and Community-Based Model Integration to Designate Coral Reef No-Take Marine Protected Areas: A Case Study from Puerto Rico

Ecosystem-based management and community-based participation in governance of Marine Protected Areas (MPAs) have been identified as key elements to improve management success, local stakeholder support, and compliance with regulations. However, both are often rarely achieved, resulting in poor MPA governance, support and success. A quantitative assessment of the spatio- temporal change (1997-2012) of coral reef fish communities within Arrecifes La Cordillera Natural Reserve in northeastern Puerto Rico was carried out. We also identified community expectations of and support for the designation of a network of small no-take MPAs within the reserve’s boundaries. A holistic approach employing biophysical and socioeconomic methods was used as part of a participatory model to identify priorities for the designation of candidate no-take MPAs. Populations of the most important fishery-targeted species showed a significant temporal decline, particularly in areas subjected to intense recreational activities and spearfishing. Most groupers (Serranidae), snappers (Lutjanidae), barracudas (Sphyraenidae), and some parrotfishes (Scaridae) were nearly absent at most sites. Most individuals belonged to smaller size categories. Herbivores represented the majority of the total fish biomass, suggesting strong fishing impacts on apex predators. Fish declines also occurred after two massive coral bleaching events in 1998 and 2005 that were followed by mass coral mortalities, suggesting combined negative impacts of fishing and climate change. A no-take MPA designation was supported by 80% of the artisanal fishermen, 73% of the concessionaires (i.e., SCUBA diving, charter boats), and 52% of registered vessel operators. Stakeholders agreed that coral reef conditions in the reserve had declined over time, as well as water quality which affected reef health and fisheries. Stakeholders did not recognize climate change and sea surface warming as threats to coral reefs and fisheries. Nonetheless, stakeholder perceptions of candidate no-take MPA sites remarkably matched those identified through fish counts. This study also highlighted the pervasive views held by many stake-holders concerning MPA management and enforcement, and recommended that any no-take MPA designation process considers improving stakeholder participation, understanding of management objectives, actions, and accomplishments, and building stakeholders trust. The integration of ecosystem-based and community-based participatory models may be critical to foster improved support of no-take MPAs and foster a long-term community-based integration to develop and implement mitigation strategies for climate change impacts in novel future scenarios.

Main issues in research and practice of environmental protection for water conservancy and hydropower projects in China

In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades.First,the adverse impacts of these projects since the technical guidelines were proposed in 2006 are analyzed.Then,combined with projects and experience from 2006 to 2014,the four main issues are summarized:(1) There exist many questions in the design and construction of fishways,which are useful for fish migration,and the migration effects are not as expected.(2) Temperature stratification affecting the downstream fish is the major impact of temperature,and alters fish spawning in the reproduction season.(3)Ecological base flow has been one of the primary questions of the last 30 years in China,the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history.(4) Fish habitat protection and restoration are popular topics in recent years with the development of river ecosystem restoration.Fish habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more serious.These four issues are now the main difficulties in water project management,and interact with one another to bear combined effects on river ecosystems.The issues of eco-hydraulic consideration in the design period are the key factors.Finally,future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are proposed.The main purpose of this paper is to enhance the scientific research,monitoring,and assessment of operating effectiveness.

Protection of Low Voltage CIGRE Distribution Network

High quality electricity services are the prime objectives in the modern power systems around the world. One of the main players to achieve this is the protection of the system which needs to be fast, reliable and cost effective. The study about the protection of the Low Voltage (LV) CIGRE distribution grid and networks like this has been proposed in this paper. The main objective of this paper is to develop protection against short circuit faults which might appear anywhere in the network. The protection of the power networks that comprises of renewable energy generation units is complicated because of the bidirectional flow of the current and is a challenge for the protection engineers. The selection of the protection devices in this paper is made to protect the network against faults in grid connected and island mode of operation. Ultra-fast fuses are proposed in order to protect the inverters used for Photovoltaic (PV) and battery applications. The disconnection of the PV solar panels when in island mode is made by proposing switch disconnecting devices. ABB is currently using these kinds of disconnection devices for the purpose of protecting solar panels against over voltages in the case of islanding. The over speed protection of the existing Wind Turbine Generator (WTG) in the CIGRE network in case of grid loss is also proposed in this paper.

Two Degree-of-Freedom Dynamic Theoretical Model on Tile Thermal Protection System

In order to study the dynamic behaviors of the thermal protection system(TPS)and dynamic strength of the strain-isolation-pad(SIP),a two degree-of-freedom dynamic theoretical model is presented under the acoustic excitation and base excitation. The tile and SIP are both considered as the elastic body and simplified as a mass point,a linear spring and a damping element. The theoretical solutions are derived,and the reasonability of theoretical model is verified by comparing the theoretical results with the numerical results. Finally,the influences on the dynamic responses of TPS by the structural damping coefficient of TPS,elasticity modulus and thickness of SIP are analyzed.The results show that the material with higher damping,and SIP with thicker size and lower elastic modulus should be considered to reduce the dynamic responses and intensify the security of TPS. The researches provide a theoretical reference for studying the dynamic behaviors of TPS and the dynamic strength of SIP. Besides,the dynamic theoretical model can be used as a quick analysis tool for analyzing the dynamic responses of TPS during the initial design phase.

Integrated Protection Scheme for Power Line

This paper presents an integrated relay and its associated protection scheme for power transmission lines.The concept of integrated protection is firstly introduced,in which a centralized protection system or relay provides the protection for multiple power plants or a substation.A novel integrated protection relay based on the combination of a number of protection principles is described.In the proposed scheme,the specially designed protection relays are installed at each substation of a network and are responsible for the protection of every line section connected to the substation busbar.The combined algorithms with multiple settings are implemented into the relay to cover all the protected line sections.Simulation studies show that the proposed protection scheme is able to produce desirable performance and may offer many advantages over the existing one and great potential for future applications.

Identification of Lightning Stroke and Fault in the Travelling Wave Protection

To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.

Research on Hidden Failure Reliability Modeling of Electric Power System Protection

Aiming at digital relay protection system, a novel hidden failure Markov reliability model is presented for a single main protection and double main protection systems according to hidden failure and protection function under Condition-Based Maintenance (CBM) circumstance and reliability indices such as probability of protection system hidden failure state are calculated. Impacts of different parameters (containing impacts of human errors) to hidden failure state probability and the optimal measures to improve reliability by variable parameter method are also analyzed. It’s demonstrated here that: Compared to a single main protection, double main protection system has an increased hidden failure probability, thus the real good state probability decreases, two main protections’ reliability must be improved at the same time, so configuration of the whole protection system for the component being protected can’t be complicated. Through improving means of on-line self-checking and monitoring system in digital protection system and human reliability, the real application of CBM can decrease hidden failure state probability. Only through this way can we assure that the protection systems work in good state. It has a certain reference value to protection system reliability engineering.

A Similarity Comparison Based Pilot Protection Scheme for VSC-HVDC Grids Considering Fault Current Limiting Strategy

In the voltage source converter based high-voltage direct current(VSC-HVDC)grids,fast and reliable protections are the key technologies.The traditional protection schemes are easily affected by fault resistance,line distributed capacitance,etc.Meanwhile,the influence of fault current limiting strategy(FCLS)has not been fully considered.In this paper,the fault characteristics under FCLS and the feasibility of traditional travelling wave protections are analyzed.To improve the reliability and sensibility,a similarity comparison based pilot protection scheme is proposed,which focuses on the relationship between the fault characteristics and the state of the protected transmission line,with the establishment of a precise frequencydependent transmission line model.The criteria based on the similarity comparison calculated by cross-wavelet can identify the fault effectively.Meanwhile,the protection scheme can also endure the influence of error synchronization.Finally,the protection performance is verified in the PSCAD/EMTDC under different fault conditions.

A DoS Attacks Detection Aglorithm Based on Snort-BASE for Robotic Arm Control Systems

In response to the frequent safety accidents of industrial robots, this paper designs and implements a safety detection system for robot control. It can perform real-time security detection of robot operations on industrial production lines to improve the security and reliability of robot control systems. This paper designs and implements a robot control system based Snort-BASE for real-time online detection of DoS attacks. The system uses a six-degree-of-freedom robotic arm as an example, uses Snort to record the network communication data of the robot arm control system in real time, and filters the network traffic through self-defined rules, and then uses the BASE analysis platform to achieve security analysis of the network traffic. The solution verifies the effectiveness of online real-time detection of attacks and visualisation of attack records by designing simulated robotic arm and real robotic arm attack experiments respectively, thus achieving the security of network communication of the robot remote control system.

Development and Performance Evaluation of a Deep Water Synthetic Based Drilling Fluid System

With the enhancement of environmental protection awareness, the requirements on drilling fluid are increasingly strict, and the use of ordinary oil-based drilling fluid has been strictly restricted. In order to solve the environmental protection and oil-gas reservoir protection problems of offshore oil drilling, a new synthetic basic drilling fluid system is developed. The basic formula is as follows: a basic fluid (80% Linear a-olefin + 20% Simulated seawater) + 2.5% nano organobentonite + 3.5% emulsifier RHJ-5# + 2.5% fluid loss agent SDJ-1 + 1.5% CaO + the right amount of oil wetting barite to adjust the density, and a multifunctional oil and gas formation protective agent YRZ has been developed. The performance was evaluated using a high-low-high-temperature rheometer, a high-temperature and high-pressure demulsification voltage tester, and a high-temperature and high-pressure dynamic fluid loss meter. The results show that the developed synthetic based drilling fluid has good rheological property, demulsification voltage ≥ 500 V, temperature resistance up to 160°C, high temperature and high pressure filtration loss < 3.5 mL. After adding 2% - 5% YRZ into the basic formula of synthetic based drilling fluid, the permeability recovery value exceeds 90% and the reservoir protection effect is excellent. The new synthetic deepwater drilling fluid is expected to have a good application prospect in offshore deepwater drilling.

Direction Protection Based on Time-domain Travelling Wave for Flexible MTDC Grid

Fault direction identification is important for dc protection,which cannot only be used in directional pilot pro-tection,but also plays an important role in non-unit protection(for excluding backward faults).Direction criteria based on i and di/dt have been utilized in LCC-HVDC system extensively.However,the reliability and sensitivity of the protection are significantly influenced by fault transition resistance and line distribution capacitors.In a flexible MTDC grid,boundary char-acteristics of the DC inductor can be utilized to judge the fault direction.But when the DC inductor is only installed at converter outlet,this kind of direction protection cannot work.Therefore,this paper analyzes the frequency characteristic of the fault traveling wave(TW)first.On this basis,the direction protection based on the time-domain TW is proposed,which is immune from frequency-dependence line parameters.Compared with existing direction protection,it has higher operation reliability and sensitivity,and is independent of the line boundary.Finally,the feasibility and superiority of the designed direction protection are verified by simulation cases based on PSCAD/EMTDC.Index Terms-Frequency-dependent characteristic,operation sensitivity,operation reliability,traveling-wave based direction protection.

Development of key additives for organoclay-free oil-based drilling mud and system performance evaluation

Traditional oil-based drilling muds(OBMs) have a relatively high solid content, which is detrimental to penetration rate increase and reservoir protection. Aimed at solving this problem, an organoclay-free OBM system was studied, the synthesis methods and functioning mechanism of key additives were introduced, and performance evaluation of the system was performed. The rheology modifier was prepared by reacting a dimer fatty acid with diethanolamine, the primary emulsifier was made by oxidation and addition reaction of fatty acids, the secondary emulsifier was made by amidation of a fatty acid, and finally the fluid loss additive of water-soluble acrylic resin was synthesized by introducing acrylic acid into styrene/butyl acrylate polymerization. The rheology modifier could enhance the attraction between droplets, particles in the emulsion via intermolecular hydrogen bonding and improve the shear stress by forming a three-dimensional network structure in the emulsion. Lab experimental results show that the organoclay-free OBM could tolerate temperatures up to 220 ?C and HTHP filtration is less than 5 m L. Compared with the traditional OBMs, the organoclay-free OBM has low plastic viscosity, high shear stress, high ratio of dynamic shear force to plastic viscosity and high permeability recovery, which are beneficial to penetration rate increase, hole cleaning and reservoir protection.

Measured Impedance and Threshold Value of Electrode Line Impedance Supervision Based Protection in HVDC Transmission System

At present,electrode line impedance supervision(ELIS)based protection is widely used to detect faults on grounding electrode lines,which are indispensable elements of high-voltage direct current(HVDC)systems.The existing theoretical analysis of measured impedance is based on lumped line model and the threshold value is generally set according to engineering experience,which have caused the dead zone problem and even accidents.Therefore,a study on measured impedance of ELIS-based protection and its threshold value selection method is carried out to solve this problem.In this study,the expressions of measured impedance under normal operation and fault conditions are deduced based on rigorous and accurate line model.Based on the expressions,the characteristics of the measured impedance are calculated and analyzed.With the characteristics of the measured impedance,the applicability of the protection with the traditional threshold value is further discussed and the distribution of the dead zone can be located.Then,the method to calculate the threshold value of ELIS-based protection is proposed.With a proper threshold value selected by the proposed method,the dead zone of ELIS-based protection is effectively eliminated,and the protection can identify all types of faults even with large transition resistances.Case studies on PSCAD/EMTDC have been conducted to verify the conclusion.