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.

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 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.

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.

Cluster-Based Design for Two-hop Cellular Networks

Optimal resource allocation with an objective of maximizing the system capacity is an NP-hard problem in multihop cellular networks. Hence, different heuristic algorithms have been developed over the years that would improve the network system capacity. In this paper, a novel cluster-based architecture is proposed for a two-hop cellular network whereby the transmission distance between any communicating pair is restricted to half the cell radius. In this design, a given radio resource is used by two simultaneously communicating pairs in every hexagonal cell, but for only half the time slot period. The characteristic feature of this cluster-based design is that it enables a frequency reuse ratio of one. The proposed hierarchical system is analyzed and tested under realistic propagation conditions including lognormal shadowing. It has been observed that the system capacity of a cluster-based design is 2.5 times that obtained from the single-hop cellular system with no relaying. In addition, the cluster-based design achieves higher capacity compared to state-of-the-art two-hop algorithms. This is an important finding since the hierarchical cluster-based approach has fewer degrees of freedom in the selection of the routing path for the end-to-end connection. Practical routing algorithms should be able to benefit from this.

Detection of the Hazards That Threaten Some Coastal Areas, and Ecosystem-Based Solution to Strengthen the Natural Defenses

The coastal strip of the Nile delta has been vulnerable to environmental hazards. Field surveys, interpretation of Landsat enhanced thematic mapper imageries (ETM), and hydrochemistry analysis of the water samples was used as methods and materials to detect the hazards associated with climate change which threaten some natural protection coastal areas of the central part of the Nile Delta and assess its magnitude. The invasion of seawaters is the main hazard due to the impacts of global warming phenomena. Elimination of the coastal dunes which act as natural defenses has been accelerating the negative impacts that have been appearing clearly on low-lying lands. Planting that protected areas of the coastal strip are considered the most suitable ecosystem-based and most beneficial solution should be authorized and adopted by the local administration to preserve those areas and adapt to these disasters.

基于Alt-Geohash编码的k-匿名位置隐私保护方案

在对享受基于位置服务(LBS)用户进行位置隐私保护时,传统k-匿名技术在执行匿名操作时没有全面考虑时间开销和位置背景信息。针对上述问题,提出了一种基于Alt-Geohash编码的k-匿名位置隐私保护方案(k-anonymous location privacy protection scheme based on Alt-Geohash coding,KLPPS-AGC)。首先,通过位置泛化和Alt-Geohash编码技术实现对历史数据的快速检索;其次,根据历史查询概率筛选出能与用户构建高位置熵的位置;再次,利用海伦公式改善匿名集的位置分散度;最后,构建安全匿名集实现对用户的位置隐私保护。实验证明,该方案拥有较低的时间开销和较高的隐私性。

强震下基础隔震结构软碰撞防护研究

针对基础隔震结构在超罕遇地震的强震作用下隔震层位移超限问题,采用已有弹性软碰撞防护装置和所研发的弹塑性软碰撞防护装置。考虑上部结构非线性,建立设置两类软碰撞防护装置的基础隔震结构模型,进行不同地震设防水准地震作用下设置两类软碰撞防护装置的基础隔震结构的非线性时程分析,研究不同防护距离、不同力学性能参数的弹性及弹塑性软碰撞防护装置对隔震层限位效果及上部结构地震响应的影响。结果表明:在超罕遇地震的强震作用下,两类软碰撞防护装置均可起到限制隔震层位移的作用;与仅能为隔震层附加刚度的弹性软碰撞装置相比较,能够为隔震层同时附加刚度和阻尼力的弹塑性软碰撞防护装置,隔震层限位效果和上部结构层间位移角响应控制效果均较优。合理设置弹性及弹塑性软碰撞防护装置,在将隔震层位移限制在规范限值以内的同时,上部结构最大加速度可限制在地震波输入峰值50%以下,确保基础隔震结构发挥正常的隔震功能。

改良Peyton四步教学在临床实习生个人防护培训中的应用及评价

目的探讨改良佩顿(Peyton)四步教学对临床实习生在医务人员分级防护和个人防护装备(PPE)穿脱培训中的应用和评价。方法采用实验对照方法,实验组采用改良Peyton四步教学,对照组采用传统方法培训。通过分级防护理论知识、PPE穿脱操作考核和问卷调查方式,比较实验组和对照组之间、不同专业和性别之间的培训效果差异。结果实验组理论知识考核成绩显著高于对照组(P<0.05),培训获益和总体满意度评价得分显著高于对照组(P<0.05),二级防护PPE穿脱操作考核成绩显著高于对照组(P<0.05)。临床医学专业实习生二级防护PPE穿脱操作考核成绩显著高于医学检验技术专业(P<0.05),女生理论知识考核成绩显著高于男生(P<0.05)。结论改良Peyton四步教学有助于提高临床实习生职业防护培训成效和满意度,对步骤流程更为复杂的二级防护PPE穿脱操作技能尤为显著,其教学效果在不同专业、不同性别之间存在一定差异。