• Transactions of the Korean Society of Mechanical Engineers A
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• 제28권8호
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• pp.1075-1086
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• 2004

In this paper, Time Delay Control(TDC) for robot manipulators is analyzed and its problems are founded. In order to remedy the problems, the enhanced controller is proposed and analyzed. The effect of friction associated with TDC is reported and its cause is presented. Through the analysis, simulation and experiment, it is shown that the friction effect causes serious degradation in control performance and that it is a result of the error of Time Delay Estimation(TDE) in TDC. In order to remedy the problems, TDC combined with Internal Model Control(IMC) concept is proposed. The proposed compensator is effective enough to handle the bad effect of friction, and is so simple and efficient as to match positive attribute of TDC. The simulation and experimental results show the effectiveness of proposed controller against the friction of the robot manipulators.

• Journal of Educational Research in Mathematics
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• 제19권4호
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• pp.531-543
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• 2009

This study identified what cognitive attributes are required of eighth graders to solve geometrical problems such as 'Recall,' 'Analyze,' 'Justify,' 'Synthesize/Integrate,' and 'Solve Non-routine Problems' by using the cognitive diagnostic theory. The five attributes are proved as the skills for solving the geometric problems. Many students have not fully mastered the attributes of 'Justify' and 'Synthesize/Integrate'. There was high correlation between these attributes. 'Analyze' best predicted the changes in the geometric achievement. And while students with high levels of geometrical achievement have mastered all the five attributes, those in the mid- and low-level range of performance have mastered fewer attributes.

• Journal of the Korea Institute of Military Science and Technology
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• 제19권1호
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• pp.57-65
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• 2016

Threat evaluation is a process to estimate the threat score which enemy aerial threat poses to defended assets. The objective of threat evaluation is concerned with making an engagement priority list for optimal weapon allocation. Traditionally, the threat evaluation of massive air threats has been carried out by air defence experts, but the human decision making is less effective in real aerial attack situations with massive enemy fighters. Therefore, automation to enhance the speed and efficiency of the human operation is required. The automatic threat evaluation by air defense experts who will perform multi-variable judgment needs formal models to accurately quantify their linguistic evaluation of threat level. In this paper we propose a threat evaluation model by using a fuzzy rule-based inference method. Fuzzy inference is an appropriate method for quantifying threat level and integrating various threat attribute information. The performance of the model has been tested with a simulation that reflected real air threat situation and it has been verified that the proposed model was better than two conventional threat evaluation models.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.379-384
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• 2011

The scope of the problems that could be solved by monitoring and the improvement of the recognition time is directly correlated to the performance of the management function of the business process. However, the current monitoring process of business activities decides whether to apply warnings or not by assuming a fixed environment and showing expressions based on the design rules. Also, warnings are applied by carrying out the measuring process when the event attribute values are inserted at every point. Therefore, there is a limit for distinguishing the range of occurrence and the level of severity in regard to the new external problems occurring in a complicated environment. Such problems cannot be ed. Also, since it is difficult to expand the range of problems which can be possibly evaluated, it is impossible to evaluate any unexpected situation which could occur in the execution period. In this paper, a process-evaluating model based on the goal scenario is suggested to provide constant services through the current monitoring process in regard to the service demands of the new scenario which occurs outside. The new demands based on the outside situation are analyzed according to the goal scenario for the process activities. Also, by using the meta-heuristic algorithm, a similar process model is found and identified by combining similarity and interrelationship. The process can be stopped in advance or adjusted to the wanted direction.

• KIPS Transactions on Software and Data Engineering
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• 제2권4호
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• pp.219-226
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• 2013

Feature selection is the one of important issues in the field of machine learning and pattern recognition. It is the technique to find a subset from the source data and can give the best classification performance. Ie, it is the technique to extract the subset closely related to the purpose of the classification. In this paper, we experimented to select the best feature subset for improving classification accuracy when classify success and failure factors in software reuse. And we compared with existing studies. As a result, we found that a feature subset was selected in this study showed the better classification accuracy.

• Journal of the Korean Society for Precision Engineering
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• 제18권12호
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• pp.116-123
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• 2001

An automated injection molding design methodology has been developed to optimize multiple quality attributes, which are usually in conflict with each other, in injection molded parts. For the optimization, commercial CAE simulation tools and optimization techniques are integrated into the methodology. To decal with the multiple objective problem the relative closeness computed in TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) is used as a performance measurement index for optimization multiple part defects. To attain robustness against process variation, Taguchi's quadratic loss function is introduced in the TOPSIS. Also, the modified complex method is used as an optimization tool to optimize objective function. The verification of the developed design methodology was carried out on simulation software with an actual model. Applied to production this methodology will be useful to companies in reducing their product development time and enhancing their product quality.

• Journal of Magnetics
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• 제21권4호
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• pp.544-553
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• 2016

Torque ripple minimization without decrease in average torque is a vital attribute in the design of Synchronous Reluctance (SynRel) motor. As the design of SynRel motor is an arduous task, which encompasses many design variables, this work first analyses the significance of the effect of varying the geometrical parameters on average torque and torque ripple and then proposes an extensive optimization procedure to obtain configurations with improved average torque and minimized torque ripple. A hardware prototype is fabricated and tested. The Finite Element Analysis (FEA) software tool used for validating the test results is MagNet 7.6.0.8. Multi Objective Particle Swarm Optimization (MOPSO) is used to determine the various designs meeting the requirements of reduced torque ripple and improved torque performance. The results indicate the efficacy of the proposed methodology and substantiate the utilization of MOPSO as a significant tool for solving design problems related to SynRel motor.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.985-996
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• 2021

While green packaging related concerns are mainly studied in developed countries, there is a lack of knowledge to observe purchase behavior toward green packaging in developing countries, especially in Vietnam. Buying green packaged products in FMCG is not required to trade-off between sustainability and product performance. Hence, this present research aims to understand the gap attitude - behavior existing on FMCG green packaged products among Vietnamese young consumers with psychosocial factors (environmental concern, environmental knowledge of green packaging and green trust) and contextual factors (availability of desired green packaging and product attributes). With a sample size of 396 respondents, data was collected by convenient sampling method and then was analyzed using structural equation modeling. The results reveal that all psychosocial factors are positive related to attitudes while purchase behavior is positively influenced. The findings also report that contextual factors have positive impacts on purchase behavior, which proves the important role of contextual factors in influencing consumer choices. It suggests that green packaging is receptive to Vietnamese young consumers but it should be considered within product-related context to enhance the difference in sustainability among similar FMCG products. Practical implications for marketers and future researches have also been discussed at the end of study.

• Journal of the Korea Institute of Military Science and Technology
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• 제25권5호
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• pp.530-538
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• 2022

Recently, the R&D of weapon systems has been strengthened in terms of economic cost management throughout the entire life cycle from performance. This study proposes the method for setting the optimal maintenance concept based on RAM-C in weapon system acquisition stage by calculating the operation & maintenance cost as well as reliability, availability, and maintainability. First, we design a simulation model for analysis of weapon system logistic supportability. In addition, information such as weapon system Part Breakdown Structure, operation & maintenance system, cost, and etc for simulation analysis, is applied. Based on the obtained simulation results, the optimal plan is selected among alternatives designed with various maintenance concepts through normalization and weight setting. It is expected to be of technical help in the application of RAM-C in the weapon system acquisition stage.

• Korean Journal of Organic Agriculture
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• 제31권1호
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• pp.29-44
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• 2023

The activation of consumption of environment-friendly agricultural processed foods means not only the growth of environment-friendly agriculture, but also the development of related industries. Therefore, it is necessary to identify and apply the needs and purchasing attributes of environment-friendly agricultural processed food consumers. For this, survey was conducted to adult men and women in their 20s and 60s and a total of 200 copies were used for empirical analysis. In this study, the average difference between importance-satisfaction for purchase attributes of environment-friendly agricultural processed food was verified, and the IPA Matrix was prepared based on this. As a result, in terms of purchasing importance and satisfaction, it was found that those with no experience in purchasing environment-friendly agricultural processed foods regarded product, price, place, promotion as more important than those with experience in purchasing. In case of IPA, product and price factors were all important and satisfactory regardless of purchasing experience. On the other hand, it was found that the key factors for promotion were neither important nor satisfied with consumers regardless of their purchasing experience. Therefore, it is mainly necessary to focus on marketing and mass media promotion. At the same time, various domestic and foreign best practices should be benchmarked and a 4P marketing strategy should be established and promoted.