汉任城武氏墓前石室测议

罗原觉先生(1891-1965年),原名罗泽堂,别字韬元、弢盒、恽卢等,号“道在瓦斋”、“菜园病叟”、“平宁瓷佛庵”等,广东南海人,著名文物鉴藏家兼学者。1928年,受聘为广州市市立博物院筹备委员会委员之一,是广州博物馆的创始人之一。1945年,被聘为广东省文献馆文物鉴定顾问。罗原觉收藏宏富,精鉴赏。他生前身后,多将藏品捐赠国家,广州博物馆即其捐赠受益者之一。本文是罗原觉先生晚年在香港完成的一篇力作,2005年由其子女罗思穆先生和罗德慈女士收集整理。今由广州博物馆程存洁、宋平、陈鸿钧编辑校对,并征得作者后人的同意,特刊于《广州文博》,以资纪念。为方便读者阅读,除将文稿繁体字改用简体字外,谨保存文稿原貌。

微波在线测湿仪的安装调试及应用

微波在线测湿仪在混凝土搅拌站中能对生产用砂进行连续在线测湿 ,从而实现生产中减水加砂的全自动控制 ,对稳定混凝土出厂坍落度效果理想 ,本文通过微波在线测湿仪的安装、调试及应用谈一点体会 ,以期提高测湿精度。

Improved Quantum ＂ Ping-Pong＂ Protocol Based on Extended Three-Particle GHZ State

In order to transmit secure messages, a quantum secure direct communication protocol based on extended three-particle GHZ state was presented, in which the extended three-particle GHZ state was used to detect eavesdroppers. In the security analysis, the method of the entropy theory is introduced, and three detection strategies are compared quantitatively by using the constraint between the information eavesdroppers can obtain and the interference introduced. If the eavesdroppers intend to obtain all inforrmtion, the detection rate of the original ＂Ping-pong＂ protocol is 50% ; the second protocol used two particles of EPR pair as detection particles is also 50%; while the presented protocol is 58%. At last, the security of the proposed protocol is discussed. The analysis results indicate that the protocol in this paper is more secure than the other two.

Formal analysis of robust email protocol based on authentication tests

Based on the authentication tests and the strand space model, the robust email protocol with perfect forward secrecy is formally analyzed, and the security shortcomings of the protocol is pointed out. Meanwhile, the man-in-the-middle attack to the protocol is given, where the attacker forges the messages in the receiving phase to cheat the two communication parties and makes them share the wrong session keys with him. Therefore, the protocol is not ensured to provide perfect forward secrecy. In order to overcome the above security shortcomings, an advanced email protocol is proposed, where the corresponding signatures in the receiving phase of the protocol are added to overcome the man-in-the-middle attack and ensure to provide perfect forward secrecy. Finally, the proposed advanced email protocol is formally analyzed with the authentication tests and the strand space model, and it is proved to be secure in authentication of the email sender, the recipient and the server. Therefore, the proposed advanced email protocol can really provide perfect forward secrecy.

Efficient Protocol-Proving Algorithm Based on Improved Authentication Tests

A new efficient protocol-proving algorithm was proposed for verifying security protocols. This algorithm is based on the improved authentication tests model, which enhances the original model by formalizing the message reply attack. With exact causal dependency relations between messages in this model, the protocol-proving algorithm can avoid the state explosion caused by asynchronous. In order to get the straight proof of security protocols, three authentication theorems are exploited for evaluating the agreement and distinction properties. When the algorithm terminates, it outputs either the proof results or the potential flaws of the security protocol. The experiment shows that the protocol-proving algorithm can detect the type flaw attack on Neuman-Stubblebine protocol, and prove the correctness of NSL protocol by exploring only 10 states.

Correlation of fatty liver and abdominal fat distribution using a simple fat computed tomography protocol

AIM: To evaluate the relationship between hepatic fat infiltration and abdominal fat volume by using computed tomography (CT).METHODS: Three hundred and six patients who visited our obesity clinic between November 2007 and April 2008 underwent fat protocol CT scans.The age range of the patients was 19 to 79 years and the mean age was 49 years.The male to female ratio was 116:190.Liver and spleen attenuation measurements were taken with three regions of interests (ROIs) from the liver and two ROIs from the spleen.Hepatic attenuation indices (HAIs) were measured as follows: (1) hepatic parenchymal attenuation (CTLP);(2) liver to spleen attenuation ratio (LS ratio);and (3) difference between hepatic and splenic attenuation (LSdif).Abdominal fat volume was measured using a 3 mm slice CT scan starting at the level of the umbilicus and was automatically calculated by a workstation.Abdominal fat was classified into total fat (TF),visceral fat (VF),and subcutaneous fat (SF).We used a bivariate correlation method to assess the relationship between the three HAIs and TF,VF,and SF.RESULTS: There were significant negative correlations between CTLP,LS ratio,and LSdif with TF,VF,and SF,respectively.The CTLP showed a strong negative correlation with TF and VF (r = -0.415 and -0.434,respectively,P < 0.001).The correlation between CTLP and SF was less significant (r = -0.313,P < 0.001).CONCLUSION: Fatty infiltration of the liver was correlated with amount of abdominal fat and VF was more strongly associated with fatty liver than SF.

A New Solution to Detectable Byzantine Agreement Problem

We present a new quantum protocol for solving detectable Byzantine agreement problem between threeparties by employing one quantum key distribution protocol.The protocol is suggested by a special four-qubit entangledstate instead of singlet states,which shows that singlet states are not necessary to achieve detectable Byzantine agreement.

Prediction-based energy-efficient target tracking protocol in wireless sensor networks

A prediction based energy-efficient target tracking protocol in wireless sensor networks(PET) was proposed for tracking a mobile target in terms of sensing and communication energy consumption.In order to maximize the lifetime of a wireless sensor network(WSN),the volume of messages and the time for neighbor discovery operations were minimized.The target was followed in a special region known as a face obtained by planarization technique in face-aware routing.An election process was conducted to choose a minimal number of appropriate sensors that are the nearest to the target and a wakeup strategy was proposed to wakeup the appropriate sensors in advance to track the target.In addition,a tracking algorithm to track a target step by step was introduced.Performance analysis and simulation results show that the proposed protocol efficiently tracks a target in WSNs and outperforms some existing protocols of target tracking with energy saving under certain ideal situations.

Experimental Evaluation of TCP and ICMP in Network Measurement

Network measurement is an important approach to understand network behaviors, which has been widely studied. Both Transfer Control Protocol （TCP） and Interact Control Messages Protocol （ICMP） are applied in network measurement, while investigating the differences between the measured results of these two protocols is an important topic that has been less investigated. In this paper, to compare the differences between TCP and ICMP when they are used in measuring host connectivity, RTT, and packet loss rate, two groups of comparison programs have been designed, and after careful evaluation of the program parameters, a lot of comparison experiments are executed on the Internet. The experimental results show that, there are significant differences between the host connectivity measured using TCP or ICMP; in general, the accuracy of connectivity measured using TCP is 20%- 30% higher than that measured using ICMP. The case of RTT and packet loss rate is complicated, which are related to path loads and destination host loads. While commonly, the RTF and packet loss rate＂ measured using TCP or ICMP are very close. According to the experimental results, some advices are also given on protocol selection for conducting accurate connectivity, RTF and packet loss rate measurements.

An efficient two-step quantum key distribution protocol with orthogonal product states

An efficient two-step quantum key distribution （QKD） protocol with orthogonal product states in the （×）（n ≥3） Hilbert space is presented. In this protocol, the particles in the orthogonal product states form two particle sequences. The sender, Alice, first sends one sequence to the receiver, Bob. After Bob receives the first particle sequence, Alice and Bob check eavesdropping by measuring a fraction of particles randomly chosen. After ensuring the security of the quantum channel, Alice sends the other particle sequence to Bob. By making an orthogonal measurement on the two particle sequences, Bob can obtain the information of the orthogonal product states sent by Alice. This protocol has many distinct features such as great capacity, high efficiency in that it uses all orthogonal product states in distributing the key except those chosen for checking eavesdroppers.

Research and improvement on the limitation of authentication test

This paper elaborated on the limitation of authentication test theorem, illustrated the fundamental cause of that limitation through examples, then enhanced authentication test to solve this problem, and also proved the soundness of that improvement with formal method. The enhanced theory can deal with protocols with test component as proper subterm of other regular node＇ s component under certain conditions, and extend the application scope of authentication test. With enhanced authentication test, the automatic protocol verification tools will be more efficient and convenient.

V-BLAST-based demodulate-and-forward two-way relaying:protocol design and the detection

We propose a novel vertical Bell Laboratories layered space-time （V-BLAST） based two-way relaying protocol that comprises two user terminals and one multi-antenna demodulate-and-forward （DMF） relay station. We consider the situation when these two user temainals employ different modulation types and investigate its detection techniques. The key feature of the detection techniques is that we quantify decision reliability at the relay station by introducing a so-called normalized correlation coefficient （CORR）, rather than having full confidence in demodulation at the relay station. With the assistance of the normalized correlation coefficient, we develop detection methods at both the relay station and user terminals. In particular, we propose a CORR-based ordering algorithm at the relay station which can be applied to detection for general V-BLAST architectures. Simulation results demonstrate the superiority of the CORR- based ordering algorithm over the conventional signal-to-noise based ordering algorithm. Finally, we demonstrate overall error-performance of the V-BLAST-based DMF two-way relaying protocol via simulations.

Research on Stress Testing of OSPF Protocol Implementation

The stability and robustness of routing protocol implementations (RPI) in a router are becoming more and more important with the growth of Internet scale. A novel approach named stress testing is proposed to test the properties of RPI. Compared with some traditional test techniques, stress testing is remarkably necessary to inspect and analyze RPI. The test environment is proposed and the test process of OSPF RPI is illustrated by a stochastic Petri Net model with large-scale route simulation and OSPF protocol emulation. Based on this model, the integrated performance tester (IP-TEST) is designed and developed, with which we test a CISCO2600 router. With mathematical methods, we find that the computational complexity of OSPF implementation in this router is O((lnN) 4)to the number of its routing table entries. This experiment shows that this technique can inspect the stability, the computational complexity and the scalability of RPI. Furthermore, it can also be widely used with other routing protocols, such as RIP and BGP.

Cognitive MAC Protocol with Minimum Sampling Time and Cross-Layer Cooperation for Low Signal-to-Noise Ratio Environments

The previous Decentralised Cognitive Medium Access Control(DC-MAC) protocol allows Secondary Users(SUs) to independently search for spectrum access opportunities without the need for a central coordinator.DC-MAC assumes that the detection scheme is ideal at the Physical(PHY) layer.In fact,a more complex detection algorithm is impractical in distributed spectrum sharing scenarios.Energy Detection(ED) at the PHY layer has become the most common method because of its low computational and implementation complexities.Thus,it is essential to integrate the DC-MAC with ED at the PHY layer.However,ED requires the Minimum Sampling Time(MST)duration to achieve the target detection probability in low Signal-to-Noise Ratio(SNR)environments.Otherwise,it cannot achieve the expected detection performance.In this paper,we derive an accurate expression of MST for ED in low SNR environments.Then,we propose an Optimised DC-MAC(ODC-MAC) protocol which is based on MST,and which amends the aforementioned problems of DC-MAC with ED.Moreover,the closed-form expressions for the unreliable data transmission probability are derived for both DC-MAC and ODC-MAC.We show that the simulation results agree well with the theoretical analyses.The proposed ODC-MAC can improve the data transmission reliability and enhance the throughput compared to the performance of the traditional DC-MAC.

Deterministic Quantum Key Distribution with Pulsed Homodyne Detection

In this paper, we propose a deterministic quantum communication protocol using weak coherent states and pulsed homodyne detection. In this protocol, the communication parties exchange their secret information deterministicaJly in two rounds. The devices and efficiency of the protocol are discussed respectively. We also show the security of the protocol against intercept-resend and Trojan-Horse eavesdropping attacks.

A multipath routing protocol for wireless sensor network for mine security monitoring

Underground mining is a hazardous industrial activity. In order to provide a safe working environment for miners, a Wireless Sensor Network (WSN) technology has been used for security monitoring. It can provide a wide range of surveillance with a relatively low cost. In this study, an Energy-Based Multipath Routing (EBMR) protocol is proposed, which considers residual energy capacity and link quality in choosing hops and routing paths. Hops and paths with a high residual energy capacity and link quality will have the best chance to be selected to transmit data packages. Since the EBMR stores several routes in the routing table, when the current path fails, another path will be chosen to fulfill the task immediately. In this way, EBMR improves reliability and decrease time latency. Compared to AOMDV and REAR, EBMR decreases time latency by 51% and 12%.

Research on Network Security Algorithm based on ZigBee Technology

Paper study the MAC layer security mechanism and data frame structure in ZigBee protocol, improve the algorithm for random Fuzzing test technology, and test method of attack fusion boundary, structure of Fuzzing and the node clone, proposed a ZigBee routing protocol for the MAC layer security comprehensive detection algorithm. Fuzzing test show that the testing algorithm can not only greatly improve the test efficiency in Fuzzing, more than the structure of Fuzzing is increased by 50% in path coverage.

Design and Implementation of Remote Health Monitoring Sensor Network Based on the Internet of Things

From the view of practical application, this paper designs the human body physiology information collection nodes, the coordinator node, wireless transmission system using CC2430 microcontroller, and detailed design information of human body sensor （temperature, heart rate, ECG / pulse） circuit diagram. This paper set up software of a wireless network （ZigBee protocol）, sensor signal acquisition, wireless transmitting and receiving, and communicate with PC machine by serial communication coordinator node. Experiments show that the network node data transmission accurate, reliable work, basically reached the requirements of the design issues.

Research on the Computer Network Protocol Test Model based on Genetic and Random Walk Algorithm

In this paper, we conduct research on the computer network protocol test model based on genetic and random walk algorithm.Network protocol is the abstract concept, is important in the process of the development of network system. Fully understand and grasp of thenetwork protocols for managers is there is a big diffi cult. Network covert channel is the evaluation of intrusion detection system and fi rewallsecurity performance of an important means, the paper will start from the angle of the attacker, the fl aws of the research, and use this kind ofdefect to realize network covert channel, the random walk algorithm will be feasible for dealing with this issue. For achieving this, we integratethe genetic and random walk algorithm for systematic optimization.

Three-step semiquantum secure direct communication protocol

Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first.In the existing schemes,quantum secure direct communication is possible only when both parties are quantum.In this paper,we construct a three-step semiquantum secure direct communication(SQSDC)protocol based on single photon sources in which the sender Alice is classical.In a semiquantum protocol,a person is termed classical if he(she)can measure,prepare and send quantum states only with the fixed orthogonal quantum basis{|0,|1}.The security of the proposed SQSDC protocol is guaranteed by the complete robustness of semiquantum key distribution protocols and the unconditional security of classical one-time pad encryption.Therefore,the proposed SQSDC protocol is also completely robust.Complete robustness indicates that nonzero information acquired by an eavesdropper Eve on the secret message implies the nonzero probability that the legitimate participants can find errors on the bits tested by this protocol.In the proposed protocol,we suggest a method to check Eves disturbing in the doves returning phase such that Alice does not need to announce publicly any position or their coded bits value after the photons transmission is completed.Moreover,the proposed SQSDC protocol can be implemented with the existing techniques.Compared with many quantum secure direct communication protocols,the proposed SQSDC protocol has two merits:firstly the sender only needs classical capabilities;secondly to check Eves disturbing after the transmission of quantum states,no additional classical information is needed.