• 한국인터넷방송통신학회논문지
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• 제9권5호
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• pp.191-197
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• 2009

본 논문에서는 쓰레기 소각로의 효율적인 연소 제어를 위해 쓰레기 소각 플랜트의 다변수 퍼지 모델을 구한다. 먼저 복잡하고 비선형 시스템인 소각로의 모델을 구하기 위해 다변수 퍼지 모델링을 수행한다. 얻어진 다변수 퍼지 모델은 주어지는 입력에 대해 소각로의 출력을 정확하게 예측한다. 그리고 얻어진 퍼지 모델은 시뮬레이터 구현에 사용되어 소각로의 출력예측에 의한 제어전략의 구축 및 운전자의 훈련 등에 사용되는 운전보조 시뮬레이션 시스템을 구현할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권7호
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• pp.1802-1814
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• 2012

In order to guide users to select the most optimal access network in heterogeneous wireless networks, a network selection algorithm is proposed which is designed based on multi-objective discrete particle swarm optimization (Multi-Objective Discrete Particle Swarm Optimization, MODPSO). The proposed algorithm keeps fast convergence speed and strong adaptability features of the particle swarm optimization. In addition, it updates an elite set to achieve multi-objective decision-making. Meanwhile, a mutation operator is adopted to make the algorithm converge to the global optimal. Simulation results show that compared to the single-objective algorithm, the proposed algorithm can obtain the optimal combination performance and take into account both the network state and the user preferences.

• Journal of information and communication convergence engineering
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• 제1권2호
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• pp.74-81
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• 2003

There are many researches on visual languages, but the most of them are difficult to support various collaborative interactions on a distributed multimedia environment. So, this paper suggests a collaborative visual language for interaction between multi-users. The visual language can describe a conceptual model for collaborative interactions between multi-users. Using the visual language, generated visual sentences consist of object icons and interaction operators. An object icon represents a user who is responsible for a collaborative activity, has dynamic attributes of a user, and supports flexible interaction between multi-users. An interaction operator represents an interactive relation between multi-users and supports various collaborative interactions. Merits of the visual language are as follows: supporting of both asynchronous interaction and synchronous interaction, supporting flexible interaction between multi-users according to participation or leave of users, supporting a user oriented modeling, etc. For example, an application to a workflow system for document approval is illustrated. So we could be found that the visual language shows a collaborative interaction.

• Computers and Concrete
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• 제16권2호
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• pp.329-342
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• 2015

The present paper aims at developing a method to accommodate multi-surface concrete plasticity from the point of view of a consistency concept applied to general tangent operators. The idea is based on a Taylor series expansion of the actual effective stress at the stress point corresponding to the previous accumulated true stresses plus the current increment values, initially taken to be elastic. The proposed algorithm can be generalized for any multi-surface criteria combination and has been tested here for typical cement-based materials. A few examples of application are presented to demonstrate the effectiveness of the multi-surface technique as used to a combination of Rankine and Drucker-Prager yield criteria.

• Journal of Welding and Joining
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• 제25권2호
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• pp.49-54
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• 2007

Since the wall thickness can be up to 6" or greater, welds must be made in many layers, each layer containing several passes. However, the welding time for the conventional welding processes such as SAW(Submerged Arc Welding) and FCAW(Flux Cored Arc Welding) can be required many hours. The aim of this paper is to develop a high speed welding system with multi-torch and laser vision sensor for increasing the production speed on the line and to remove the need for the operator so that the system can run automatically for the complete multi-torch multi-layer weld. It was shown that the developed laser vision sensor and analysis of arc blow for multi-torch were effective for multi-pass seam tracking and stable arc. A new automated multi-torch welding systems for thick wall applications has been proved in several production lines.

• 대한수학회논문집
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• 제33권4호
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• pp.1239-1248
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• 2018

Recently, many authors have obtained several hypergeometric identities involving hypergeometric functions of one and multi-variables such as the Appell's functions and Horn's functions. In this paper, we obtain several new transformations suitably by applying the fractional calculus operator to these hypergeometric identities, which was introduced recently by Tremblay.

• 대한수학회논문집
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• 제37권1호
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• pp.75-89
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• 2022

In this paper, we prove new fixed point theorems for single-valued and multi-valued weakly Picard operators in complete metric spaces and give several examples. As applications, we give several results to Fredholm integral equation.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.661-666
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• 2007

MMORPG, massively multi-players in online role-playing game, is the most popular genre in online games. Because large number of players interacts with each other, virtual worlds in MMORPG are alike communities of real worlds. Moreover, players in virtual worlds trade game items with real money. This paper is to find impacts of real-money trading into real worlds, and game operators, by using two-period model between players of the game and the game operator. It was found that real-money trading benefits game operators, and there exists optimal supply of game items to maximize the profit of game operator. Moreover we found that the income disparity in real worlds could be decreased when real-money trading is allowed To support the analytical model, we used an empirical analysis using real-money trading data, and find the relationship among play time of MMORPG, transaction volume of real-money trading, and price of game items. In empirical analysis, it was found that real-money trading benefits game operators. Moreover, it was found that play time and price have positive relationship.

• 대한산업공학회지
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• 제3권1호
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• pp.39-47
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• 1977

Most of the current literature on inventory theory has been devoted to the study of single stage models. A class of inventory problems which is of great interest is the multistage inventory system which involves a series and hierarchical sequence of stations. This study analyzes some aspect of the series type and multi-stage inventory system, using the fixed cycle ordering which bas a modificatory control function in the system equations. The objective of this study is to clarify the dynamic behavior of the system. The author has derived the theoretical formulas of variation of ordering quantity and stock fluctuation of each stage due to power spectral density function. Influence of parameters such as, (1) intensity of autocorrelation of demand sequence ($\lambda$), (2) forecasting exponential smoothing factors of each stage (${\alpha}_1,\;{\alpha}_2,\;{\alpha}_3$) and (3) production control factor of the 3rd stage ($\gamma$), as operators of the system on the variation of ordering quantity and stock fluctuation of the system. is also clarified. As a result of this study, the relations between the variation of ordering quantity, stock fluctuation and the parameters of the system, have been found. The principles and the theorical analysis presented here will be applicable to more complex type of discrete control systems in constructing the specific condition of the system to minimize inventory variances.

• 지식경영연구
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• 제20권3호
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• pp.39-47
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• 2019

Response surface methodology (RSM) is a group of statistical modeling and optimization methods to improve the quality of design systematically in the quality engineering field. Its final goal is to identify the optimal setting of input variables optimizing a response. RSM is a kind of knowledge management tool since it studies a manufacturing or service process and extracts an important knowledge about it. In a real problem of RSM, it is a quite frequent situation that considers multiple responses simultaneously. To date, many approaches are proposed for solving (i.e., optimizing) a multi-response problem: process capability function approach, desirability function approach, loss function approach, and so on. The process capability function approach first estimates the mean and standard deviation models of each response. Then, it derives an individual process capability function for each response. The overall process capability function is obtained by aggregating the individual process capability function. The optimal setting is given by maximizing the overall process capability function. The existing process capability function methods usually use the arithmetic mean or geometric mean as an aggregation operator. However, these operators do not guarantee the Pareto optimality of their solution. Moreover, they may bring out an unacceptable result in terms of individual process capability function values. In this paper, we propose a maximin-based process capability function method which uses a maximin criterion as an aggregation operator. The proposed method is illustrated through a well-known multiresponse problem.