绿道地图设计与编制

绿道包括生态型绿道、郊野型绿道和都市型绿道,是新出现的一种城市环保建设产物。目前广州市三年绿道建设目标已经基本完成,因此制作一份既能展现绿道建设成果又能指引市民出行的地图是地图工作者新的任务。本文从绿道的分类和功能出发,研究绿道地图设计的一般性原则与符号设计特点,在此基础上以《广州绿道攻略》地图集的编制为例进行验证,达到了绿道地图设计制作科学性与艺术性的统一。

Fast and secure elliptic curve scalar multiplication algorithm based on special addition chains

To resist the side chaimel attacks of elliptic curve cryptography, a new fast and secure point multiplication algorithm is proposed. The algorithm is based on a particular kind of addition chains involving only additions, providing a natural protection against side channel attacks. Moreover, the new addition formulae that take into account the specific structure of those chains making point multiplication very efficient are proposed. The point multiplication algorithm only needs 1 719 multiplications for the SAC260 of 160-bit integers. For chains of length from 280 to 260, the proposed method outperforms all the previous methods with a gain of 26% to 31% over double-and add, 16% to22% over NAF, 7% to 13% over4-NAF and 1% to 8% over the present best algorithm--double-base chain.

Channel Selection Information Hiding Scheme for Tracking User Attack in Cognitive Radio Networks

For the discontinuous occupancy of primary users in cognitive radio networks(CRN),the time-varying of spectrum holes becomes more and more highlighted.In the dynamic environment,cognitive users can access channels that are not occupied by primary users,but they have to hand off to other spectrum holes to continue communication when primary users come back,which brings new security problems.Tracking user attack(TUA) is a typical attack during spectrum handoff,which will invalidate handoff by preventing user accessing,and break down the whole network.In this paper,we propose a Channel Selection Information Hiding scheme(CSIH) to defense TUA.With the proposed scheme,we can destroy the routes to the root node of the attack tree by hiding the information of channel selection and enhance the security of cognitive radio networks.

The Diplomatic Offensive of the DPRK and Challenges Faced

Actively taking the opportunity of participating in the Pyeongchang Winter Olympic Games held last February, the Democratic People's Republic of Korea(DPRK) launched a fierce diplomatic offensive: in March, Kim Jong-un, Chairman of the Korean Workers' Party, paid a visit to China; in April, the DPRK-ROK summit was held;and the DPRK and the US also announced that they would hold a summit in early June. Kim Jong-un has made positive moves, particularly on the nuclear issue: when visiting China, he affirmed that the DPRK would remain committed to denuclearization of the peninsula; at the Third Plenary Session of the 7 th National Congress of the Korean Workers' Party, he announced the termination of nuclear testing and the intercontinental ballistic missile(ICBM) test launches, as well as the abjuration of the nuclear testing site in the north; and later on, he affirmed with Moon Jae-in, President of the Republic of Korea(ROK), that the common goal of a nuclear free peninsula would be realized through denuclearization. This series of diplomatic moves by the DPRK has taken the world by surprise. The DPRK government's motivations are both internal and external. In their attempts to preserve and deepen the hard-won peace, and make it a true turning point in their history, the DPRK is obviously faced with multiple challenges, and a lot of work has to be done on the nuclear issue in particular.

Discussion about cultural commonalities of Chinese martial arts and kickboxing in a developing perspective

With five thousand years of civilization, the profound traditional culture of China has cultivated generations of Chinese people to possess the spirit of manner, patience, humility, perseverance and self-improvement, which especially are expressed in the sports industry, let alone in taekwondo. Taekwondo emphasizes morality and respect for teachers. It requires practices to love the motherland, love the people, respect opponents and abide by good faith; to emphasis on inner training and spiritual cultivation; to develop noble moral characters like courtesy, patience, self-denial, humility and tolerance. Because taekwondo take footwork as the main means of attack, the atmosphere of competition will be intense and the two sides battle with wits and physical fighting with amazing destructive power and lethality. So practitioner＇ s inner practice and morality is particularly emphasized. Chinese traditional culture plays a vital role among it.

Experimental study on aerodynamic characteristics of a high-speed train on viaducts in turbulent crosswinds

In this study, experiments were carried out to investigate aerodynamic characteristics of a high-speed train on viaducts in turbulent crosswinds using a 1:25 scaled sectional model wind-tunnel testing. Pressure measurements of two typical sections, one train-head section and one train-body section, at the windward and leeward tracks were conducted under the smooth and turbulence flows with wind attack angles between-6° and 6°, and the corresponding aerodynamic force coefficients were also calculated using the integral method. The experimental results indicate that the track position affects the mean aerodynamic characteristics of the vehicle, especially for the train-body section. The fluctuating pressure coefficients at the leeward track are more significantly affected by the bridge interference compared to those at the windward track. The effect of turbulence on the train-head section is less than that on the train-body section. Additionally, the mean aerodynamic force coefficients are almost negatively correlated to wind attack angles, which is more prominent for vehicles at the leeward track. Moreover, the lateral force plays a critical role in determining the corresponding overturning moment, especially on the train-body section.

Two-Phased Method for Detecting Evasive Network Attack Channels

With the rapid developments of information technology,various industries become much more dependent on networks.Driven by economic interests and the game between countries reflected by growing cyberspace confrontations,evasive network attacks on information infrastructures with high-tech,high concealment and longterm sustainability become severe threats to national security.In this paper,we propose a novel two-phased method for the detection of evasive network attacks which exploit or pretend to be common legal encryption services in order to escape security inspection.Malicious communications which camouflage themselves as legal encryption application are identified in the SSL'session structure verification phase firstly,and then by serverside X.509 certificate based anomaly detection,suspicious attack behaviors are further distinguished effectively.Experiment results show that our method is very useful for detecting the network activities of certain unknown threats or new malwares.Besides,the proposed method can be applied to other similar services easily.

大洪山民兵义务保护国防通讯线路30余载畅通无事故

湖北随州市地处大洪山脚下,是中南地区的重要通讯枢纽之下。地上银线纵横,地下电缆环绕。民兵把国防通讯线看成是自己的生命线,为通讯畅通作贡献。一次,护线联防领导小组去检查线路安全时,发现一条新架的高压线与国防通讯线路相距太近,对通讯有妨害,决定攻道高压线。大洪山百名民兵义务投工,移杆20根,改道5公里,消除了事故隐患。又有一次,三里岗镇一带遭受龙卷风袭击,经过这里的线路遭到毁坏,武装部长立即组织民兵400余人抢险,4小时就恢复了通讯畅通。

英国历代王室的饮食

王室饮食一向为人津津乐道。但过去,一提及“吃起来像个国王”,这一说法总是意味着那种绝非有益的嗜好,甚至被当作“暴饮暴食”的同义语,亦即放纵沉溺于12道大菜的宴会中,狼吞虎咽大量的黄鳗。

Side-channel attacks and learning-vector quantization

The security of cryptographic systems is a major concern for cryptosystem designers, even though cryptography algorithms have been improved. Side-channel attacks, by taking advantage of physical vulnerabilities of cryptosystems, aim to gain secret information. Several approaches have been proposed to analyze side-channel information, among which machine learning is known as a promising method. Machine learning in terms of neural networks learns the signature （power consumption and electromagnetic emission） of an instruction, and then recognizes it automatically. In this paper, a novel experimental investigation was conducted on field-programmable gate array （FPGA） implementation of elliptic curve cryptography （ECC）, to explore the efficiency of side-channel information characterization based on a learning vector quantization （LVQ） neural network. The main characteristics of LVQ as a multi-class classifier are that it has the ability to learn complex non-linear input-output relationships, use sequential training procedures, and adapt to the data. Experimental results show the performance of multi-class classification based on LVQ as a powerful and promising approach of side-channel data characterization.

Correlation power attack on a message authentication code based on SM3

Hash-based message authentication code(HMAC)is widely used in authentication and message integrity.As a Chinese hash algorithm,the SM3 algorithm is gradually winning domestic market value in China.The side channel security of HMAC based on SM3(HMAC-SM3)is still to be evaluated,especially in hardware implementation,where only intermediate values stored in registers have apparent Hamming distance leakage.In addition,the algorithm structure of SM3 determines the difficulty in HMAC-SM3 side channel analysis.In this paper,a skillful bit-wise chosen-plaintext correlation power attack procedure is proposed for HMAC-SM3 hardware implementation.Real attack experiments on a field programmable gate array(FPGA)board have been performed.Experimental results show that we can recover the key from the hypothesis space of 2256 based on the proposed procedure.