• Proceedings of the KWS Conference
• /
• 2005.11a
• /
• pp.105-107
• /
• 2005

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2000.11a
• /
• pp.163-167
• /
• 2000

The eligibility is used to solve the credit-assignment problem which is one of important problems in reinforcement learning. Conventional eligibilities which are accumulating eligibility and replacing eligibility make ineffective use of rewards acquired in learning process. Because only an executed action in a visited state is learned by these eligibilities. Thus, we propose a new eligibility, called the weighted eligibility with which not only an executed action but also neighboring actions in a visited state are to be learned. The fuzzy Q-learning algorithm using proposed eligibility is applied to a cart-pole balancing problem, which shows improvement of learning speed.

• Korean Journal of Mathematics
• /
• v.20 no.2
• /
• pp.225-237
• /
• 2012

In this paper, we introduce a new iterative scheme to investigate the problem of nding a common element of nonexpansive mappings and the set of solutions of generalized variational inequalities for a $k$-strict pseudo-contraction by relaxed extra-gradient methods. Strong convergence theorems are established in $q$-uniformly smooth Banach spaces.

• Journal of the Korea Society for Simulation
• /
• v.17 no.4
• /
• pp.249-257
• /
• 2008

This paper shows the Applied Q-learning Algorithm which supports selecting the waiting position of a robot and the part serviced next in the Flexible Manufacturing Cell (FMC) that consists of one robot and various types of facilities. To verify the performance of the suggested algorithm, we design the general FMC made up of single transfer robot and multiple machines with a simulation method, and then compare the output with other control methods. As a result of the analysis, the algorithm we use improve the average processing time and total throughputs as well by increasing robot utilization, reversely, by decreasing robot waiting time. Furthermore, because of ease of use compared with other complex ways and its adoptability to real world, we expect that this method contribute to advance total FMC efficiency as well.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.1
• /
• pp.334-349
• /
• 2022

The effectiveness of Wi-Fi networks is greatly influenced by the optimization of contention window (CW) parameters. Unfortunately, the conventional approach employed by IEEE 802.11 wireless networks is not scalable enough to sustain consistent performance for the increasing number of stations. Yet, it is still the default when accessing channels for single-users of 802.11 transmissions. Recently, there has been a spike in attempts to enhance network performance using a machine learning (ML) technique known as reinforcement learning (RL). Its advantage is interacting with the surrounding environment and making decisions based on its own experience. Deep RL (DRL) uses deep neural networks (DNN) to deal with more complex environments (such as continuous state spaces or actions spaces) and to get optimum rewards. As a result, we present a new approach of CW control mechanism, which is termed as contention window threshold (CW_Threshold). It uses the DRL principle to define the threshold value and learn optimal settings under various network scenarios. We demonstrate our proposed method, known as a smart exponential-threshold-linear backoff algorithm with a deep Q-learning network (SETL-DQN). The simulation results show that our proposed SETL-DQN algorithm can effectively improve the throughput and reduce the collision rates.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.6
• /
• pp.1324-1329
• /
• 2013

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, firstly, the fair SoQ-based Distributed Reservation Protocol (DRP) for D-MAC is analyzed. And a novel SoQ-based relay transmission protocol is proposed to overcome DRP conflicts fast. In the proposed protocol, each device executes the Satisfaction of QoS (SoQ) time slot allocation algorithm independently. And, in order to give the loser device due to DRP conflicts another chance to maintain QoS resources, the proposed relay transmission protocol helps the device reserve another indirect link maintaining the required QoS resources via a relay node.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.9A
• /
• pp.2197-2210
• /
• 1998

In the grand alliance (GA) HDTV receiver, a coherent detection is empolyed for coherent demodulation of vestigial side-band (VSB) signal by using frequency and phaselocked loop(FPLL) operating on the pilot carrier. Additional phase tracking loop (PTL) employed to track out phase noise that has not been removed by the FPLL in theGA system. In this paper, we propose an algorithm for phase detection which utilizes a weighting function. The simplest implementation of the proposed algorithm using te sign of the Q channel component can be tractable by imposing a phase detection gain to the loop gain. It is obserbed that the propsoed algorithm has a robust characteristic against the performance of the digital filters used for Q channel estimation. A second goal of this paper is to introduce a gain control algorithm for the PTL in order to provide an effective implementation of the proposed phase detection algorithm. And we design the PTL through the realization of the simplified digital filter for H/W reduction. The proposed algorithms and the designed PTL are evaluated by computer simulation. In spite of using the simplified H/W structure, simulation results show that the proposed algorithms outperform the coventional PTL algorithms in the phase detection and tracking performance.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.9 no.3
• /
• pp.3-12
• /
• 1999

The public key crytptosystem is represented by RSA based on the difficulty of integer factorization and ElGamal cryptosystem based on the intractability of the discrete logarithm problem in a cyclic group G. The index-calculus algorithm for discrete logarithms in GF${$q^n$}^+$ requires an polynomial factorization. The Niederreiter recently developed deterministic facorization algorithm for polynomial over GF$q^n$ In this paper we implemented the arithmetic of finite field with c-language and gibe an implementation of the Niederreiter's algorithm over GF$2^n$ using normal bases.

• Korean Journal of Mathematics
• /
• v.21 no.3
• /
• pp.223-236
• /
• 2013

Schensted algorithm was first described in 1938 by Robinson [5], in a paper dealing with an attempt to prove the correctness of the Littlewood-Richardson rule. Schensted [9] rediscovered Schensted algorithm independently in 1961 and Viennot [12] gave a geometric interpretation for Schensted algorithm in 1977. In this paper we describe some properties of Schensted algorithm using Viennot's geometric interpretation.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.11
• /
• pp.1604-1609
• /
• 2013

When the ground fault on the power side occurs on distribution system interconnected with distributed generations, the abnormal current is generated in the neutral conductor by the connection type and the iron core structure of transformers for the interconnection of distributed power supplies due to the unbalanced voltage of the system, and subsequently the false operation of the protective relay on the load side occurs. Herein, this paper proposes the method to correct errors in the phase current to prevent the false operation of the protective relay by applying p-q theory and presents the simulation result of the error correction algorithm using PSCAD/EMTDC.