六月焦点：节电与安全——洛电“安全节”

6月1日开始，安徽淮南洛河发电厂的职工们实实在在地过上了为期一个月的“安全节”。

Review of Food Safety Supervision for the Wholesale Market of Chinese Agricultural Products

With the continuous improvement of living standards, there is an increasingly concerned about food quality and safety issues. Especially in recent years,food safety incidents, breaking out frequently, have become the focus of people＇s attention, putting forward new demands on the regulation of food safety. This paper reviewed the Food Safety Supervision in China from food safety supervision mode,regulatory system defects and circulation supervision system, and also proposed the future research trends of food safety regulations for the wholesale market of Chinese agricultural products.

An Authenticated Dynamic Key Management Scheme for Clustered Sensor Networks

Secure sensor networks has received much attention in the last few years.A sensor network always works unattended possibly in a hostile environment such as a battlefield.In such environments,sensor networks are subject to node capture.Constrained energy,memory,and computational capabilities of sensor nodes mandate a clever design of security solutions to minimize overhead while maintaining secure communication over the lifespan of the network.In this paper,an authenticated dynamic key management scheme,ADKM has been proposed.It provides efficient,scalable,and survivable dynamic keying in a clustered sensor network with a large number of sensor nodes.ADKM employs a combinatorial exclusion basis system (EBS) for efficiency and one-way hash chains for authentication.Analysis of security and performance demonstrate that ADKM is efficient in security of sensor networks.

Safety evaluation on the clinical application of Tenghuangjiangu tablet for osteoarthritis:a hospital registration study

To evaluate the treatment safety of Tenghuangjiangu tablet on osteoarthritis,3365 osteoarthritis patients whose prescription included Tenghuangjiangu tablet from 15 hospitals were involved in the prospective and multi-center clinical trial.Tenghuangjiangu tablet dosage was decided by instruction or doctors’experience.The course of treatment and observation was 4 weeks.The adverse drug reactions were observed in the treatment process.Results showed male and female patients were 1018(30.25%)and 2347(69.75%),respectively,and 528 patients had allergic history.The patients’average age was 58.30±8.99 years,and the average disease course was 33.29±37.40 months.The average score of WOMAC scale was 95.07±42.42,which indicated the light conditions.2275 patients were treated with combined drug regimen.There were two adverse drug reactions in this research.One reaction was skin rashes with itching and the interventions were stopped original drugs and give antianaphylactic treatment.The other reaction was stomach discomfort with disgusting and the intervention was stopped the original drugs temporarily,then continued to take two drugs after 3 days and the reaction didn’t appear.The accident rate of adverse drug reaction was 0.059%.The safety of Tenghuangjiangu tablet clinical application was good,and the mechanism of adverse drug reaction should be researched in-depth.

Node cooperation based location secure verification algorithm in wireless sensor networks localization

For the application of wireless sensor networks in the military field, one of the main challenges is security. To solve the problem of verifying the location claim for a node, a new location verifica- tion algorithm called node cooperation based location secure verification （NCBLSV） algorithm is proposed. NCBLSV could verify malicious nodes by contrasting neighbor nodes and nodes under beam width angle using an adaptive array antenna at a base point. Simulation experiments are con- ducted to evaluate the performance of this algorithm by varying the communication range and the an- tenna beam width angle. Results show that NCBLSV algorithm has high probability of successful ma- licious nodes detection and low probability of false nodes detection. Thus, it is proved that the NCBLSV algorithm is useful and necessary in the wireless sensor networks security.

Water Security-based Hydrological Regime Assessment Method for Lakes with Extreme Seasonal Water Level Fluctuations：A Case Study of Poyang Lake,China

Extreme seasonal water level fluctuations characterize natural floodplain lakes in monsoon regions, which are crucial for ensuring lake water security, including flood prevention water supply and health of aquatic ecosystem. In order to achieve this goal, we established a hydrological regime assessment method based on a set of hydrological indicators for lakes with heavy seasonal water level fluctuations. The results suggest that time-sensitive hydrological indicators and specific time scales for various water security aspects must be considered. We discovered that it is more practical and meaningful to combine the water level classification derived from statistical analyses with characteristic hydrological values linked to water security. The case study of Poyang Lake results show that there are no discernable trends of Poyang Lake water regime status over the last 35 years, and the two periods of poor status are in accordance with climate variation in the lake basin area. Scholars and policy makers should focus on both floods and droughts, which are the main water security problems for Poyang Lake. It is hoped that this multi-scale and multi-element hydrological regime assessment method will provide new guidelines and methods for other international scholars of river and lake water assessment.

Key-insulated encryption based group key management for wireless sensor network

The key exposure problem is a practical threat for many security applications. In wireless sensor networks (WSNs), keys could be compromised easily due to its limited hardware protections. A secure group key management scheme is responsible for secure distributing group keys among valid nodes of the group. Based on the key-insulated encryption (KIE), we propose a group key management scheme (KIE-GKMS), which integrates the pair-wise key pre-distribution for WSN. The KIE-GKMS scheme updates group keys dynamically when adding or removing nodes. Moreover, the security analysis proves that the KIE-GKMS scheme not only obtains the semantic security, but also provides the forward and backward security. Finally, the theoretical analysis shows that the KIE-GKMS scheme has constant performance on both communication and storage costs in sensor nodes.

Physical-layer security enhancement method for wireless HetNets via transmission pair scheduling

In order to enhance the physical-layer security of wireless transmission in a wireless heterogeneous network (HetNet), a two-stage-based cooperative framework is advocated. To be specific, a source-destination (SD) pair is opportunistically chosen at the beginning of the transmission slot, which can be used to assist the transmissions of other SD pairs. Under this framework, a transmit antenna selection assisted opportunistic SD pair scheduling (TAS-OSDS) scheme is proposed, and the intercept probability (IP) of the proposed TAS-OSDS, the conventional round-robin source-destination pair scheduling (RSDS) and the conventional non-cooperation (non-coop) schemes is also analyzed, where the RSDS and non-coop schemes are used for comparison with the proposed TAS-OSDS. Numerical results show that increasing the number of the SD pairs can effectively reduce the IP of the TAS-OSDS scheme, whereas the IP of the RSDS and the non-coop remain unchanged with an increasing number of the SD pairs. Furthermore, the TAS-OSDS scheme achieves a lower IP than that of the RSDS and the non-coop schemes, showing the superiority of the proposed TAS-OSDS.

ENERGY EFFICIENT DISTRIBUTED STEGANOGRAPHY FOR SECURE COMMUNICATION IN WIRELESS MULTIMEDIA SENSOR NETWORKS

A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs), which is more vulnerable to security attacks due to the presence of multimedia data. Additionally, given the limited technological resources (in term of energy, computation, bandwidth, and storage) of sensor nodes, security and privacy policies have to be combined with energy-aware algorithms and distributed processing of multimedia contents in WMSNs. To solve these problems in this paper, an energy efficient distributed steganography scheme, which combines steganography technique with the concept of distributed computing, is proposed for secure communication in WMSNs. The simulation results show that the proposed method can achieve considerable energy efficiency while assuring the communication security simultaneously.

Cluster Based Secure Dynamic Keying Technique for Heterogeneous Mobile Wireless Sensor Networks

In Heterogeneous Wireless Sensor Networks, the mobility of the sensor nodes becomes essential in various applications. During node mobility, there are possibilities for the malicious node to become the cluster head or cluster member. This causes the cluster or the whole network to be controlled by the malicious nodes. To offer high level of security, the mobile sensor nodes need to be authenticated. Further, clustering of nodes improves scalability, energy efficient routing and data delivery. In this paper, we propose a cluster based secure dynamic keying technique to authenticate the nodes during mobility. The nodes with high configuration are chosen as cluster heads based on the weight value which is estimated using parameters such as the node degree, average distance, node's average speed, and virtual battery power. The keys are dynamically generated and used for providing security. Even the keys are compromised by the attackers, they are not able to use the previous keys to cheat or disuse the authenticated nodes. In addition, a bidirectional malicious node detection technique is employed which eliminates the malicious node from the network. By simulation, it is proved that the proposed technique provides efficient security with reduced energy consumption during node mobility.

Optimized Algorithms for Flexible Length-Based Authenticated Skip List

With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.

Reducing the Effects of Driving Fatigue with Magnetic Stimulation

The purpose of this study was to assess the effects of reducing driving fatigue with magnitopuncture stimuli on Dazhui (DU14) point and Neiguan (PC6) points using heart rate (HR), reaction time (RT) testing, critical flicker fusion frequency (CFF) and subjective evaluation. Twenty healthy subjects were randomly divided into two groups: A-group (study group) and B-group (control group). All subjects were required to be well rested before the experiment. The subjects were engaged in high speed driving at a constant vehicle velocity of 80 km/h continuously for three hours on a test course simulating an expressway. During the driving magnitopunctures were applied to the Dazhui (DU14) point and Neiguan (PC6) points for the A-group when the subject performed the task for two and half hours, and for the B-group magnitopunctures were applied to non-acupuncture points at the same time session. In this study RT exbited a significant delay in B-group (P<0.01) but no found in A-group after the driving task. CFF and subjective evaluation also exhibited significant differences between the two groups after the driving task (P<0.05). The findings showed that magnitopuncture stimuli on Dazhui (DU14) point and Neiguan (PC6) points could reduce the effects of driving fatigue.

Postpartum intrauterine device contraception: A review

AIM： To review the safety （infection, perforation） and efficacy （expulsion, continuation rates, pregnancy） of intrauterine device （IUD） insertion in the postpartum period. METHODS： MEDLINE, PubMed and Google Scholar were searched for randomized controlled trials and prospective cohort studies of IUD insertions at different times during the postpartum period. Time of insertion during the postpartum period was documented speci-fically, immediate post placenta period （within 10 min）, early post placenta period （10 min to 72 h）, and de-layed/interval period （greater than 6 wk）. Other study variables included mode of delivery, vaginal vs cesarean, manual vs use of ring forceps to insert the IUD. RESULTS： IUD insertion in the immediate postpartum （within 10 min of placental delivery）, early postpartum （10 min up to 72 h） and Interval/Delayed （6 wk onward） were found to be safe and effcacious. Expulsion rates were found to be highest in the immediate postpartum groups ranging from 14% to 27%. Immediate post placental insertion found to have expulsion rates that ranged from 3.6% to 16.2%. Expulsion rate was significantly higher after insertion following vaginal vs cesarean delivery. The rates of infection, perforation and unplanned pregnancy following postpartum IUD insertion are low. Method of insertion such as with ring forceps, by hand, or another placement method unique to the type of IUD did not show any signifcant difference in expulsion rates. Uterine perforations are highest in the delayed/interval IUD insertion groups.Breastfeeding duration and infant development are not affected by delayed/interval insertion of the non-hormonal （copper） IUD or the Levonorgestrel IUD. Timing of the Levonorgestrel IUD insertion may affect breastfeeding. CONCLUSION： IUD insertion is safe and efficacious during the immediate postpartum, early postpartum and delayed postpartum periods. Expulsion rates are highest after vaginal delivery and when inserted during the immediate postpartum period. IUD associated infection rates were not increased by insertion during the postpartum period over interval insertion rates. There is no evidence that breastfeeding is negatively affected by postpartum insertion of copper or hormone-secreting IUD. Although perforation rates were higher when inserted after lactation was initiated. Randomized controlled trials are needed to further elucidate the consequence of lactation on postpartum insertion. Despite the concerns regarding expulsion, perforation and breastfeeding, current evidence indicates that a favorable risk beneft ratio in support of postpartum IUD insertion. This may be particularly relevant for women for whom barriers exist in achieving desired pregnancy spacing.

Toward Energy-Efficient and Trustworthy eHealth Monitoring System

The rapid technological convergence between Internet of Things （loT）, Wireless Body Area Networks （WBANs） and cloud computing has made e-healthcare emerge as a promising application domain, which has significant potential to improve the quality of medical care. In particular, patient-centric health monitoring plays a vital role in e-healthcare service, involving a set of important operations ranging from medical data collection and aggregation, data transmission and segregation, to data analytics. This survey paper firstly presents an architectural framework to describe the entire monitoring life cycle and highlight the essential service components. More detailed discussions are then devoted to {／em data collection} at patient side, which we argue that it serves as fundamental basis in achieving robust, efficient, and secure health monitoring. Subsequently, a profound discussion of the security threats targeting eHealth monitoring systems is presented, and the major limitations of the existing solutions are analyzed and extensively discussed. Finally, a set of design challenges is identified in order to achieve high quality and secure patient-centric monitoring schemes, along with some potential solutions.

A Secure-Efficient Data Collection Algorithm Based on Self-Adaptive Sensing Model in Mobile Internet of Vehicles

Existing research on data collection using wireless mobile vehicle network emphasizes the reliable delivery of information.However,other performance requirements such as life cycle of nodes,stability and security are not set as primary design objectives.This makes data collection ability of vehicular nodes in real application environment inferior.By considering the features of nodes in wireless IoV,such as large scales of deployment,volatility and low time delay,an efficient data collection algorithm is proposed for mobile vehicle network environment.An adaptive sensing model is designed to establish vehicular data collection protocol.The protocol adopts group management in model communication.The vehicular sensing node in group can adjust network sensing chain according to sensing distance threshold with surrounding nodes.It will dynamically choose a combination of network sensing chains on basis of remaining energy and location characteristics of surrounding nodes.In addition,secure data collection between sensing nodes is undertaken as well.The simulation and experiments show that the vehicular node can realize secure and real-time data collection.Moreover,the proposed algorithm is superior in vehicular network life cycle,power consumption and reliability of data collection by comparing to other algorithms.

Analysis and Countermeasures Research of Beijing Country Fair

Organic vegetables, does not use pesticides, synthetic fertilizers, herbicides, growth regulators in production process and refers to organisms and products got from genetic engineering. It follows the laws of nature and ecological principles, adopts a series of sustainable development of agricultural technology, to coordinate planting balanced, and stable agricultural ecosystems, and through the identification of organic certification, it will be recognized and awarded organic certification. Beijing Country Fair launched by a group of consumer volunteers concerned about ecological agriculture and rural issues, aiming to build a platform for farmers engaged in organic agriculture and consumers can communicate directly, exchange. It can help consumers find safe, assured products, but also help farmers to broaden market channels and encourage more farmers to engage in organic farming, thereby reducing environmental pollution produced by fertilizer and pesticide, safeguarding food security, and practicing fair trade.

Secure Data Aggregation Approach Based on Monitoring in Wireless Sensor Networks

In order to avoid internal attacks during data aggregation in wireless sensor networks, a grid-based network architecture fit for monitoring is designed and the algorithms for network division, initialization and grid tree construction are presented. The characteristics of on-off attacks are first studied and monitoring mechanisms are then designed for sensor nodes. A Fast Detection and Slow Recovery (FDSR) algorithm is proposed to prevent on-off attacks by observing the behaviors of the nodes and computing reputations. A recovery mechanism is designed to isolate malicious nodes by identifying the new roles of nodes and updating the grid tree. In the experiments, some situations of on-off attacks are simulated and the results are compared with other approaches. The experimental results indicate that our approach can detect malicious nodes effectively and guarantee secure data aggregation with acceptable energy consumption.

A Reliable and Secure Smart Grid Communication Network Using a Comprehensive Cost Function

SG （smart grids） is an intelligent power grid in which the diverse nodes should communicate different types of information which have different communication requirements with CS （control stations）. There exist several RATs （radio access technologies）, with diversification in quality of service character which respect to the SG nodes communication requirements. On the other side, spectrum is becoming a rare source and its demands request is increasing exponentially. Therefore, resource allocation to support different types of SG nodes should be elaborated so that the resource efficiency is maximized while the SG communication requirements are respected. Using a CF （cost function） based on the SG node requirements and RATs characteristics to find the desirability value of every RATs for a certain node type accomplish this goal in combination with prioritizing the different SG nodes types based on SG goals by creating a priority table for RATs and different SG node types. The main node communication requirements are formulized to be used in the CF in this paper. The numerical results show that the proposed method defines the desirability value of each RAT for a certain SG node type that helps to make a priority table by using the SG node prioritization table.

Seismic analysis of a long-span continuous steel truss-arch bridge across the Yangtze River

In this paper, an FEM （Finite Element Method） model is established for the main span of the bridge, with the main box arch and suspender members modeled by beam elements, truss members by truss elements, and the orthotropic steel deck by plate elements. The natural frequencies and mode shapes are acquired by the eigen-parameter analysis. By input of a typical earthquake excitation to the bridge system, the dynamic responses of the bridge, including the displacement and accelerations of the main joints of the structure, and the seismic forces and stresses of the key members, are calculated by the structural analysis program, based on which the main laws of the seismic responses of the bridge are summarized, and the safety of the structure is evaluated.

Construction of Agricultural Circular Economy and Standard System in China

Under the new situation of advocating the development of circular economy and low-carbon economy in the world, the agriculture is facing all the challenges to ensure food safety, dealing with climate change, promote energy conservation and pollution reduction, protect resources and environment, and increase the income of farmers. Moreover, developing circular agriculture is in the direction that the international challenges can be dealt with and the development of agriculture in China can be accelerated. This paper has reported current situation of agricultural circular economy, keep energy conservation and pollution reduction, and analyzed the basic thought of developing agricultural circular economy.