We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

IoT security: Review, blockchain solutions, and open challenges

The problem of error control and concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the techniques that have been developed for error control and concealment. These techniques are described in three categories according to the roles that the encoder and decoder play in the underlying approaches. Forward error concealment includes methods that add redundancy at the source end to enhance error resilience of the coded bit streams. Error concealment by postprocessing refers to operations at the decoder to recover the damaged areas based on characteristics of image and video signals. Last, interactive error concealment covers techniques that are dependent on a dialogue between the source and destination. Both current research activities and practice in international standards are covered.

/pdf/error-control-and-concealment-for-video-communication-a-3tm7c48xjc.pdf

Error control and concealment for video communication: a review

A wearable sensor system enables continuous and remote health monitoring and is widely considered as the next generation of healthcare technology. The performance, the packet error rate (PER) in particular, of a wearable sensor system may deteriorate due to a number of factors, particularly the interference from the other wearable sensor systems in the vicinity. We systematically evaluate the performance of the wearable sensor system in terms of PER in the presence of such interference in this paper. The factors that affect the performance of the wearable sensor system, such as density, traffic load, and transmission power in a realistic moderate-scale deployment case in hospital are all considered. Simulation results show that with 20% duty cycle, only 68.5% of data transmission can achieve the targeted reliability requirement (PER is less than 0.05) even in the off-peak period in hospital. We then suggest some interference mitigation schemes based on the performance evaluation results in the case study.

https://www.mdpi.com/1424-8220/15/10/24977/pdf

Performance Evaluation of Wearable Sensor Systems: A Case Study in Moderate-Scale Deployment in Hospital Environment.

There have been researchers working on the design of coding-aware routing protocols to exploit the power
of network coding in static wireless ad hoc networks. However, most of them have overlooked the fact that routing decisions for multiple flows need to be coordinated in order to achieve maximum throughput. A mechanism to alter prior routing decisions is mandatory for this purpose. In this paper, we propose Self-recommendation coding-aware routing (SCAR), to provide such a mechanism. With intermediate nodes sensing the arrival of new flows, they can send self-recommendations to source nodes, triggering a route-change procedure. In the route-change procedure, adjustments are applied to the route metrics so that the newly recommended route can be fairly weighed without bias. A thorough analysis of coding structures is carried out, and a series of indicators are devised to predict how much throughput benefits we can gain from the mere knowledge of the topology. The rationale behind the protocol design and the effectiveness of the indicators are further justified by a series of simulations. Results show that SCAR can exploit coding opportunities better and provide higher throughput than other coding-aware routing protocols. It is also
shown that the opportunity of throughput gain is ubiquitous and it is tested on many typical topologies.

/pdf/scar-a-coding-aware-routing-protocol-with-self-1d4wm5ybri.pdf

SCAR: A Coding-Aware Routing Protocol with Self-Recommendation in Static Wireless Ad Hoc Networks

This paper provides an overview of blood flow in the arterial system and aims to estimate the blood velocity from cerebral angiography scans without having acquired data on velocity by using Murray's Law. The estimation technique post-processes the scan and provides crucial 3D visual data for the development of a visualization program of the blood flow in the human brain.

Estimation and presentation of blood flow and velocity from angiographic scans in the human cerebral arterial system

Recently there has been increasing interest in building networks with Ambient Intelligence (AmI), which incorporates the user-centricity and context awareness. However, both the Internet TCP/IP protocol stack and the seven-layer OSI reference model are not suitable for AmI networks, because they do not specifically take the end-user requirements into consideration in their architecture design. Under the client-server architecture, we propose to explicitly take the end-user into account by defining a new layer called User Layer above the traditional application layer. The User Layer empowers the end-users to influence network performance based on their interaction activities with the networks. We adopt the Model Human Processor (MHP) approach for building the User Model. After that we present an exemplary User Layer implementation to illustrate how the User Layer interacts with the underlying protocol stack and improves end-user's satisfaction with network performance.

Wai-Choong Wong

Papers

Performance Evaluation of Wearable Sensor Systems: A Case Study in Moderate-Scale Deployment in Hospital Environment.

SCAR: A Coding-Aware Routing Protocol with Self-Recommendation in Static Wireless Ad Hoc Networks

Estimation and presentation of blood flow and velocity from angiographic scans in the human cerebral arterial system

When Ambient Intelligence Meets Internet Protocol Stack: User Layer Design

Context-Aware Service Discovery in Ubiquitous Computing