• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.175-182
• /
• 2018

As Internet of things with a large number of nodes emerges, wireless-power communication networks (WPCN) based on a random access protocol needs to be investigated. In the random access-based WPCN, a terminal accessing later in given random access (RA) slots can harvest more energy before transmission and thus can transmit data with higher power and achieve higher throughput if the access is successful. On the basis of this property, the proposed random access control protocol gives the terminals priority and distinguishes the RA slots according to the priority level, so that a near terminal with access point allows to access preferentially other than a remote terminal. This operation decreases the throughput of near terminal and increases the throughput of remote terminal, and then, the doubly near-far problem in WPCN is resolved and the user fairness is improved. Results show that the proposed random access control improves both channel throughput and user fairness according to the priority level.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.12
• /
• pp.1632-1638
• /
• 2020

In this paper, we investigate a multi-beam satellite communication system where multiple terminals transmit information signals to the gateway via a satellite. The satellite is equipped with phased array antennas to form multiple spot beams of which bandwidths are not identically allocated. We formulate an optimization problem to maximize fairness of beam bandwidth allocation. In order to solve the problem, we propose two heuristic algorithms; iterative beam bandwidth allocation (IBBA) and request ratio-based beam bandwidth allocation (RRBBA) algorithms. The IBBA algorithm iteratively equalizes the ratio of allocated bandwidth of each beam to their resource request while the RRBBA algorithm allocates beam bandwidth calculated from the ratio. Simulation results show that the IBBA algorithm has close fairness performance to the optimum while the RRBBA algorithm has less performance than the IBBA algorithm at the price of reduced computational complexity.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.6
• /
• pp.1496-1501
• /
• 2013

IEEE 802.11 has become the main technology in wireless network. However, performance anomalies, especially in terms of fairness, arise in its use in ad hoc networks. Two independent emitters nodes can easily monopolize the medium, preventing other nodes to send packets. This paper proposes the modified (m,k)-firm scheme which is based on T-MAC to improve fairness. The basic idea is to assign higher priorities to nodes that are closer to a dynamic failure so as to improve their chances of meeting their deadlines. The simulation result shows that the proposed scheduling scheme helps improve the fairness of the DCF.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.649-652
• /
• 2015

Previous marking policy for the AF service of TCP traffic in the Diffserv network have no sufficient consideration on the effect of RTT and target rate. In this paper, in order to improve fairness Index by the effect RTT difference of TCP traffic, we propose the modified TSW3CDM(Time Sliding Window Three Color Dynamic Marker) based on average transfer rate estimation and the flow state. The proposed algorithm is dynamic marking policy that do allocate band width in proportion to transmission rate. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed TSW3CDM algorithm improves fairness index by comparison with TSW3CM.

• The Journal of Korean Association of Computer Education
• /
• v.11 no.2
• /
• pp.99-106
• /
• 2008

In this paper, we have proposed a novel re-marking strategy at tbe ingressive edge router to improve TCP fairness of DiffServ Assured Services. Our re-marking strategy introduces a configuration method of the Temporary Permitted Rate (TPR). By using this new configuration method of TPR, IN packets of greedy TCP flows are re-marked to OUT packets pertinently and constantly whenever the network traffic changes. Simulation Results show that this novel re-marking strategy can regulate the packet transmission rate of each TCP flow to the contract rate without a decrease in the link utilization.

• Journal of Families and Better Life
• /
• v.19 no.2
• /
• pp.23-30
• /
• 2001

The purpose of this study was to examine the effect of the traditional fairy tales based program on the improvement of preschoolers level of distributive justice reasoning. The program was developed on the six Korean fairy tales which deal with the sharing problem among the friends and the families. The subjects were seventy-six, 4- and 5-year-old children selected from two kindergartens in Seoul and Ichon. Solomon 4-group experimental design was used. Each children were assigned for 2 experimental groups and for 2 control groups. Before the intervention, the subjects in experimental group 1 and control group 1 were interviewed individually with story dilemmas for their distributive justice reasoning. For eight-week period, the program based on six Korean traditional fairy tales were used as an intervention. After the intervention, all the subjects were interviewed individually with another story dilemmas. The data were analyzed in SPSS Win 10.0 program, by frequency, percentile, mean, standard deviation, paired t-test and independent t-test. As a result, the children in experimental groups had higher level of distributive justice reasoning than those in control groups. That is, program based on the traditional fairy tales gave positive effect on preschoolers distributive justice reasoning.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.05a
• /
• pp.147-151
• /
• 2002

One of the main issues in Diffserv AS architecture is guaranteeing fairness among the flows which have their own QoS requirements. Because the methodology of resource allocation and traffic conditioning would affect the end-to-end QoS and backbone link utilization. In this paper, we propose a variant of TSW algorithm for enhancing fair bandwidth allocation and link utilization and presents performance evaluation between TSW & TS2W3C through NS-2 Simulations.

• The KIPS Transactions:PartC
• /
• v.9C no.5
• /
• pp.743-748
• /
• 2002

In recent research for the Internet, many studies have investigated the Diffserv AS architecture that can provide Quality of Service. However, this architecture still lacks the qualification to provide full use of the bandwidth to the customer In this paper, we propose the TS2W3C (Time Sliding Two Window Three Color) marking algorithm to improve the fair share of bandwidth by enhancing the TSW (Time Sliding Window) marking algorithm. Our proposed mechanism provides the bandwidth relatively more fairly than the TSW mechanism.

• The Korean Journal of Applied Statistics
• /
• v.28 no.4
• /
• pp.807-826
• /
• 2015

Generational contracts are specified into public pensions based on generational solidarity. The Korean National Pension has been reformed with a focus on generational equity with a narrow meaning related to contribution rate and benefit level. As a result, the Korean National Pension has only emphasized generational equity and not contributed to generational solidarity. We investigate changes in the content of the generational contract and propose to reconstruct generational contract to contribute to solidarity with a more comprehensive perspective. A new social contract by reformed pension system should not concentrate on narrowed generational equity. It should be reconstructed in the direction of enhancing efficacy and the stability of generational solidarity with an emphasis on social sustainability. Investment into the next generation would be one of many policy measures to decrease conflicts around intergenerational redistribution and improve the financial stability of the public pension by creating population structure and labor market changes.

• Journal of KIISE:Information Networking
• /
• v.31 no.5
• /
• pp.469-481
• /
• 2004

Previous works for the AF(Assured Forwarding) service in the Diffserv network have no sufficient consideration on the fairness of bandwidth share based on RTTs, the target rates, and the impact of UDP against TCP. In this paper, in order to solve these problems, we propose a FDSA(Fair Differentiated Service Architecture) composed of TRA3CM(Target rate and RTT Aware 3 Color Marking) and TRBD(Target Rate Based Dropping) mechanisms. The TRA3CM and TRBD mechanisms provide three color marking and fair transmission rates among aggregate flows by considering RTT, target rate, and UDP flows simultaneously. In the results of comparing the performance among existing mechanisms and the TRA3CM-TRBD, the TRA3CM-TRBD mechanism was able to mitigate the RTT and UDP effect better than the former. The TRA3CM-TRBD is shown to provide good performance for transmission rates proportional to various target rates.