모정훈 교수

In this paper, we demonstrate the existence of fair end-to-end window-based congestion control protocols for packet-switched networks with first come-first served routers. Our definition of fairness generalizes proportional fairness and includes arbitrarily close approximations of max-min fairness. The protocols use only information that is available to end hosts and are designed to converge reasonably fast. Our study is based on a multiclass fluid model of the network. The convergence of the pr

We propose some improvements of TCP Vegas and compare its performance characteristics with TCP Reno. We argue through analysis that TCP Vegas, with its better bandwidth estimation scheme, uses the network resources more efficiently and fairly than TCP Reno. Simulation results are given that support the results of the analysis.

This paper compares, analytically and through simulations, a number of multichannel MAC protocols. We first classify these protocols into four categories based on their principles of operation: Dedicated Control Channel, Common Hopping, split phase, and parallel rendezvous protocols. We then examine the effects of the number of channels and devices, channel switching times, and traffic patterns on the throughput and delay of the protocols. Here are some of the conclusions of our study: 1) Parall

This paper compares, through analysis and simulation, a number of multichannel MAC protocols for wireless networks. We first classify these protocols into 4 categories based on their principles of operation. We then examine the effects of the number of channels and devices, channel switching times, and traffic patterns on throughput and delay. Our study focuses on a single collision domain.

The past oil crises have caused dramatic improvements in fuel efficiency in all industrial sectors. The aviation sector-aircraft manufacturers and airlines-has also made significant efforts to improve the fuel efficiency through more advanced jet engines, high-lift wing designs, and lighter airframe materials. However, the innovations in energy-saving aircraft technologies do not coincide with the oil crisis periods. The largest improvement in aircraft fuel efficiency took place in the 1960s whi

In this paper, we demonstrate the existence of fair end-to- end window-based congestion control protocols for packet- switched networks with FCFS routers. Our definition of fairness generalizes proportional fairness and includes arbitrarily close approximations of max-min fairness. The protocols use only information that is available to end hosts and are designed to converge reasonably fast. Our study is based on a multiclass fluid model of the network. The convergence of the protocols is proved

The extensive utilization of electronic health records (EHRs) and the growth of enormous open biomedical datasets has readied the area for applications of computational and machine learning techniques to reveal fundamental patterns. This study's goal is to develop a medical treatment recommendation system using Korean EHRs along with the Markov decision process (MDP). The sharing of EHRs by the National Health Insurance Sharing Service (NHISS) of Korea has made it possible to analyze Koreans' me

Media publishers that have commonly relied on profits from advertisements and content sales to fund their operations are not only content providers (manufacturers) to media aggregator platforms (retailers) but are also competing service providers (rival retailers) in the digital video supply chain. Different from a traditional media supply chain, they can easily operate their own direct distribution channels in the Internet era. In the digital video supply chain, it is not clear whether commerci

In this paper, we revisit the optimization based control problem of wireless ad-hoc networks. Even though much work has been done so far, they are limited either in their practicality or in their efficiency. We develop another framework based on independent set and propose an implementable heuristic algorithm. Our heuristic is based on the longest queue first (LQF) policy and the neighborhood price.

Abstract In this article, we propose a novel loss recovery algorithm of transmission control protocol (TCP) using packet transmission order, which shows a steady loss recovery ability even though packet loss rate increases. This leads to a significant throughput increase of TCP with heavy packet loss. We have verified the performance increase of the new TCP under various environments such as a wireless network, and multimedia transmission through simulation. Moreover, we implemented the proposed