• Journal of the Korean Society for Precision Engineering
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• v.12 no.10
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• pp.149-156
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• 1995

This paper presents a method of detecting chatter vibration in end-mill process. The detecting system consists of an adaptive signal processing scheme which uses an autore- gressive time-series model and a neural network is proposed and is verified its effectiveness by using acceleration and cutting force signals recorded during slotting in end-mill operations. Expeerimental results indicate that the proposed system provides excellent detection when chatter is occured within the ranges of cutting conditions considered in this study and an effectiveness of the integration of signals is confirmed.

• East Asian mathematical journal
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• v.39 no.4
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• pp.419-436
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• 2023

In this study, we aimed to develop a teacher-adaptive platform model that enhances teachers' instructional activities and teaching capabilities, allowing them to conduct intended lessons effectively. The platform is designed to support various teaching and learning activities based on the instructional situation, and additionally provides teaching and learning materials, assessment questions, and results. The developed teaching and learning platform utilized Moodle, an open-source-based LMS solution that provides various tools for online learning. The platform was specifically designed for teaching conic sections in high school geometry, and it was constructed to enable teachers to deliver their intended lessons effectively.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.4_1
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• pp.753-758
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• 2024

Trajectory tracking of the AMR robot is one research for the AMR robot navigation. For the control system of the Autonomous mobile robot(AMR) being in non-honolomic system and the complex relations among the control parameters, it is d ifficult to solve the problem based on traditional mathematics model. In this paper, we presents a simple and effective way of implementing an adaptive tracking controller based on the PID for AMR robot trajectory tracking. The method uses a non-linear model of AMR robot kinematics and thus allows an accurate prediction of the future trajectories. The proposed controller has a parallel structure that consists of PID controller with a fixed gain. The control law is constructed on the basis of Lyapunov stability theory. Computer simulation for a differentially driven non-holonomic AMR robot is carried out in the velocity and orientation tracking control of the non-holonomic AMR. The simulation results of wheel type AMR robot platform show that the proposed controller is more robust than the conventional back-stepping controller to show the effectiveness of the proposed algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1107-1109
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• 2007

Context-based access control is an emerging approach for modeling adaptive solution, making access control management more flexible and powerful. However, these strategies are inadequate for the increased flexibility and performance that ubiquitous computing environment requires because such systems can not utilize effectively all benefit from this environment. In this paper, we propose a solution based on risk to make use of many context parameters in order to provide good decisions for a safety environment. We design a new model for risk assessment in ubiquitous computing environment and use risk as a key component in decision-making process in our access control model.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.457-458
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• 2007

Clustering plays an indispensable role for data analysis. Many clustering algorithms have been developed. However, most of them suffer poor performance of learning. To archive good clustering performance, we develop a hybrid neural network model. It is the combination of Multi-Layer Perceptron (MLP) and Adaptive Resonance Theory 2 (ART2). It inherits two distinct advantages of stability and plasticity from ART2. Meanwhile, by combining the merits of MLP, it improves the performance for clustering. Experiment results show that our model can be used for clustering with promising performance.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.4
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• pp.499-505
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• 2015

Trend Impact Analysis(: TIA) is an advanced forecasting tool used in futures studies for identifying, understanding and analyzing the consequences of unprecedented events on future trends. An adaptive neuro-fuzzy inference system is a kind of artificial neural network that integrates both neural networks and fuzzy logic principles, It is considered to be a universal estimator. In this paper, we propose an advanced mechanism to generate more justifiable estimates to the probability of occurrence of an unprecedented event as a function of time with different degrees of severity using Adaptive Neuro-Fuzzy Inference System(: ANFIS). The key idea of the paper is to enhance the generic process of reasoning with fuzzy logic and neural network by adding the additional step of attributes simulation, as unprecedented events do not occur all of a sudden but rather their occurrence is affected by change in the values of a set of attributes. An ANFIS approach is used to identify the occurrence and severity of an event, depending on the values of its trigger attributes. The trigger attributes can be calculated by a stochastic dynamic model; then different scenarios are generated using Monte-Carlo simulation. To compare the proposed method, a simple simulation is provided concerning the impact of river basin drought on the annual flow of water into a lake.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.159-169
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• 2012

The purpose of this study was to assess the vulnerability of forest ecosystem to climate change in South Korea using socio-environmental indicators and the results of two vegetation models named as Hydrological and Thermal Analogy Group(HyTAG), and MAPSS-Century 1(MC1). The changing frequency and direction of biome types estimated by HyTAG model was used for quantifying sensitivity and adaptive capacity of forest distribution. Similarly, the variation and changing tendency of net primary production and soil carbon storage estimated by MC1 model was used for quantifying sensitivity and adaptive capacity of forest function. As socio-environmental indicators, many statistical data such as financial autonomy rate and the number of forestry officer was prepared. All indicators were standardized, and then calculated using the vulnerability assessment equation. The period of vulnerability assessment was divided into the past(1971-2000) and the future(2021-2050). To understand what policy has a priority to climate change, distribution maps of each indicators was depicted and the vulnerability results were compared among administrative districts. Evident differences could be found in entire study area. These differences were mostly derived from regionalspecific adaptive capacity. The result and methodology of this study would be helpful for the development of decision-making supporting system and policy making in forest management with respect to climate change.

• Journal of Distribution Science
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• v.12 no.10
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• pp.109-121
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• 2014

Purpose - Most studies related to emotional labor have been conducted in the low-contact service industry rather than the high-contact service industry. Since the subjects of this study were golf service assistants, working in an industry in which the interaction and contact between customers and employees are considerable and the degree of customization is high, this study is significant. Thus, we would like to focus on the relationship between the humor style of golf service assistants and emotional labor. Humor style was divided into two styles-adaptive humor and maladaptive humor. Emotional labor was divided into two dimensions-surface acting and deep acting. In addition, we identify the relationship between emotional labor, job satisfaction, and turnover intention. Research design, data, & methodology - This study focuses on the humor styles in the golf service industry, among golf service assistants, on their emotion labor, and verifies the relationship between emotion labor and work satisfaction or job turnover intention. Based on the outcome, a total of four hypotheses were set up. To verify the hypotheses, surveys were conducted on the golf service assistants working in two golf fields in the region of Busan as well as its neighboring area. A total of 250 copies of the questionnaire were distributed. Subsequently, a total of 227 valid questionnaire copies, after excluding improper responses, were used in the analysis. After verifying the reliability and feasibility of variances, Amos 18.0 was used to implement the structure method so as to verify the study hypotheses. As a result of this analysis, the suitability of the entire model was considerably appropriate to the standard value, and the level is adequate to accommodate the study model completely. Results - First, it was found that the adaptive humor of golf service assistants had a positive effect on deep acting and maladaptive humor had a positive effect on surface acting. Second, It was found that employees' satisfaction with their job was reduced through surface acting, and those employees who experienced positive emotional labor in the form of deep acting were more satisfied with their job. Third, surface acting among employees increased turnover intention, but deep acting reduced it. Finally, the relationship between job satisfaction and the turnover intention of golf service assistants in the golf service industry was examined. Conclusions - First, the adaptive humor of the golf assistants in the golf service industry had a positive effect on their expression behavior. Second, deep acting increased their job satisfaction while their surface acting had a noticeably negative effect on their job satisfaction. Third, the surface acting of the emotion labor dimensions that the golf service assistants experience increases their turnover intention while their deep acting decreases their turnover intention. Finally, when analyzing the relationship between job satisfaction and turnover intention of the golf service assistants, it was found that the turnover intention decreased when their job satisfaction is increased.

• Journal of Korea Technology Innovation Society
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• v.10 no.4
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• pp.755-788
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• 2007

This study investigates the effects of individual and group level factors on the use of GSS (Group Support System) and task performance from GSS use. GSS facilitates the group work, so that GSS adoption is not necessarily influenced only by individual perceptions on information systems. Adaptive Structuration Theory (AST) in our study to explain the adoption and success from GSS use. AST contends that the success of IS is not necessarily the technical fit between tasks and technology, instead the political outcome among user socializations. We have the following two research inquires: Are the IS use and performance maximized when information technologies are provided properly?; and, Does TTF always influence positively on IS use (or performance)? To research these issues, we investigate the influence of TTF (Task-Technology Fit) on use and performance of GSS, which is introduced to foster collaboration among organizational members. Drawing insights from the AST, we examine if COA (Consensus on Appropriation) among group members and FOA (Faithfulness of Appropriation) between those who use technology and who design it show any moderating effect. A questionnaire survey was conducted on firms using the GSS for one month from June 2 to June 27 2005 and a sample of 303 responses was used for a statistical analysis. The result demonstrates that TTF exerts a positive influence on use and performance of GSS. We find that the stronger the COA, the greater the effect of W on use of GSS and performance. FOA likewise has a positive effect on both use of GSS and performance. The TTF model has been widely applied to studies on individual performance of information system, whereas the AST theory specifically explains members' adaptation process to information system. By integrating the AST theory with the TTF model, the study contributes to heightening our understanding on if and how individual performance varies with the use of GSS.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.671-678
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• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.