• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.216-239
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• 2021

The present work addresses the challenging problem of coordinating power allocation with interference management in multi-robot networks by applying the promising expansion capabilities of multiple-input multiple-output (MIMO) and full duplex systems, which achieves it for maximizing the throughput of networks under the impacts of Doppler frequency shifts and external jamming. The proposed power allocation with interference coordination formulation accounts for three types of the interference, including cross-tier, co-tier, and mixed-tier interference signals with cluster head nodes operating in different full-duplex modes, and their signal-to-noise-ratios are respectively derived under the impacts of Doppler frequency shifts and external jamming. In addition, various optimization algorithms, including two centralized iterative optimization algorithms and three decentralized optimization algorithms, are applied for solving the complex and non-convex combinatorial optimization problem associated with the power allocation and interference coordination. Simulation results demonstrate that the overall network throughput increases gradually to some degree with increasing numbers of MIMO antennas. In addition, increasing the number of clusters to a certain extent increases the overall network throughput, although internal interference becomes a severe problem for further increases in the number of clusters. Accordingly, applications of multi-robot networks require that a balance should be preserved between robot deployment density and communication capacity.

• Advances in Computational Design
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• v.7 no.1
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• pp.1-17
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• 2022

In this study, a new strategy is presented to transmit the fundamental elastic beam problem into the modern optimization platform and solve it by using artificial intelligence (AI) tools. As a practical example, deflection of Euler-Bernoulli beam is mathematically formulated by 2nd-order ordinary differential equations (ODEs) in accordance to the classical beam theory. This fundamental engineer problem is then transmitted from classic formulation to its artificial-intelligence presentation where the behavior of the beam is simulated by using neural networks (NNs). The supervised training strategy is employed in the developed NNs implemented in the heuristic optimization algorithms as the fitness function. Different evolutionary optimization tools such as genetic algorithm (GA) and particle swarm optimization (PSO) are used to solve this non-linear optimization problem. The step-by-step procedure of the proposed method is presented in the form of a practical flowchart. The results indicate that the proposed method of using AI toolsin solving beam ODEs can efficiently lead to accurate solutions with low computational costs, and should prove useful to solve more complex practical applications.

• Earthquakes and Structures
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• v.17 no.3
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• pp.307-315
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• 2019

Building prediction and control theory have been drawing the attention of many scientists over the past few years because design and control efficiency consumes the most financial and energy. In the literature, many methods have been proposed to achieve this goal by trying different control theorems, but all of these methods face some problems in correctly solving the problem. The Evolutionary Bat (EB) Algorithm is one of the recently introduced optimization methods and providing researchers to solve different types of optimization problems. This paper applies EB to the optimization of building control design. The optimized parameter is the input to the fuzzy controller, which gives the status response as an output, which in turn changes the state of the associated actuator. The novel control criterion for guarantee of the stability of the system is also derived for the demonstration in the analysis. This systematic and simplified controller design approach is the contribution for solving complex dynamic engineering system subjected to external disturbances. The experimental results show that the method achieves effective results in the design of closed-loop system. Therefore, by establishing the stability of the closed-loop system, the behavior of the closed-loop building system can be precisely predicted and stabilized.

• Structural Engineering and Mechanics
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• v.77 no.5
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• pp.613-626
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• 2021

In this paper, an enhanced Violation-based Sensitivity analysis and Border-Line Adaptive Sliding Technique (ViS-BLAST) will be utilized for optimization of some well-known structural and mechanical engineering problems. ViS-BLAST has already been introduced by the authors for solving truss optimization problems. For those problems, this method showed a satisfactory enactment both in speed and efficiency. The Enriched ViS-BLAST or EVB is introduced to be vastly applicable to any solvable constrained optimization problem without any specific initialization. It uses one-directional step-wise searching technique and mostly limits exploration to the vicinity of FNF border and does not explore the entire design space. It first enters the feasible region very quickly and keeps the feasibility of solutions. For doing this important, EVB groups variables for specifying the desired searching directions in order to moving toward best solutions out or inside feasible domains. EVB was employed for solving seven numerical engineering design problems. Results show that for problems with tiny or even complex feasible regions with a larger number of highly non-linear constraints, EVB has a better performance compared to some records in the literature. This dominance was evaluated in terms of the feasibility of solutions, the quality of optimum objective values found and the total number of function evaluations performed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.3
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• pp.22-28
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• 2010

Adaboost is well known for a representative learner as one of the kernel methods. Adaboost which is based on the statistical learning theory shows good generalization performance and has been applied to various pattern recognition problems. However, Adaboost is basically to deal with a two-class classification problem, so we cannot solve directly a multi-class problem with Adaboost. One-Vs-All and Pair-Wise have been applied to solve the multi-class classification problem, which is one of the multi-class problems. The two methods above are ones of the output coding methods, a general approach for solving multi-class problem with multiple binary classifiers, which decomposes a complex multi-class problem into a set of binary problems and then reconstructs the outputs of binary classifiers for each binary problem. However, two methods cannot show good performance. In this paper, we propose the method to solve a multi-target classification problem by using radial basis function of Adaboost weak classifier.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.1
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• pp.43-49
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• 2015

The aim of this study was to model unusual association with declarative knowledge by positive affect using ACT-R cognitive architecture. Existing research related with cognitive modeling tends to pay a lot of attention to strong and negative cognitive moderator. Mild positive affect, however, has far-reaching effects on problem solving and decision making. Typically, subjects with positive affect were more likely to respond to unusual associates in a word association task than subjects with neutral affect. In this study, a cognitive model using ACT-R cognitive architecture was developed to show the effect of positive affect on the cognitive organization related with memory. First, we organized the memory structure of stimulus word 'palm' based on published results in a word association task. Then, we decreased an ACT-R parameter that reflects the amount of weighting given to the dissimilarity between the stimulus word and the associate word to represent reorganized memory structure of the model by positive affect. As a result, no significant associate probability difference between model prediction and existing empirical data was found. The ACT-R cognitive architecture could be used to model the effect of positive affect on the unusual association by decreasing (manipulating) the weight of the dissimilarity. This study is useful in conducting model-based evaluation of the effects of positive affect in complex tasks involving memory, such as creative problem solving.

• Journal of The Korean Association For Science Education
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• v.35 no.6
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• pp.1007-1018
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• 2015

In the 21st century, in a Knowledge-Based Information Society, systems thinking is a very important human resources skill in science and technology, which is required in STEAM education in order to understand and solve complex problems. The purposes of this study are: (1) to develop a STEAM education program based on systems thinking; (2) to investigate the effects of the program on students' systems thinking. The systems thinking-based STEAM education program was developed on the basis of 'ADBAS' model (Park & Lee, 2013), and focused on the theme of watermill. A total of 60 high school students participated in this study. The results of this study showed that quantitatively as well as qualitatively, systems thinking skills improved after the treatment. In conclusion, the program we developed in this study can contribute in improving high school students' systems thinking skills and creative problem-solving abilities. The findings of this study may provide useful insights into cultivating human resources with systems thinking skills and creative problem-solving abilities.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.99-106
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• 2014

Generation and analysis methods have been proposed in recent years, such as using a natural language and formal language processing, artificial intelligence algorithms based knowledge model is effective meaning. its semantic based knowledge model has been used effective decision making tree and problem solving about specific context. and it was based on static generation and regression analysis, trend analysis with behavioral model, simulation support for macroeconomic forecasting mode on especially in a variety of complex systems and social network analysis. In this study, in this sense, integrating knowledge-based models, This paper propose a text mining derived from the inter-Topic model Integrated formal methods and Algorithms. First, a method for converting automatically knowledge map is derived from text mining keyword map and integrate it into the semantic knowledge model for this purpose. This paper propose an algorithm to derive a method of projecting a significant topic map from the map and the keyword semantically equivalent model. Integrated semantic-based knowledge model is available.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.10-18
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• 2010

The purpose of this paper deals with direct multiple-shooting method (DMS) to resolve helicopter maneuver problems of helicopters. The maneuver problem is transformed into nonlinear problems and solved DMS technique. The DMS method is easy in handling constraints and it has large convergence radius compared to other strategies. When parameterized with piecewise constant controls, the problems become most effectively tractable because the search direction is easily estimated by solving the structured Karush-Kuhn-Tucker (KKT) system. However, generally the computation of function, gradients and Hessian matrices has considerably time-consuming for complex system such as helicopter. This study focused on the approximation of the KKT system using the matrix exponential and its integrals. The propose method is validated by solving optimal control problems for the linear system where the KKT system is exactly expressed with the matrix exponential and its integrals. The trajectory tracking problem of various maneuvers like bob up, sidestep near hovering flight speed and hurdle hop, slalom, transient turn, acceleration and deceleration are analyzed to investigate the effects of algorithmic details. The results show the matrix exponential approach to compute gradients and the Hessian matrix is most efficient among the implemented methods when combined with the mixed time integration method for the system dynamics. The analyses with the proposed method show good convergence and capability of tracking the prescribed trajectory. Therefore, it can be used to solve critical areas of helicopter flight dynamic problems.

• Journal of Korean Academy of Nursing
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• v.4 no.3
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• pp.105-116
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• 1974

This study was made on patients who were Hospitalized due to sickness caused by the abuse of marihuana at the Psychiatric Section of a hospital during the period from Feb. to Oct., 1974. The following conclusion was obtained by reviewing the literature with respect to the nursing, and problem solving of those patients. 1. It appears that marihuana is a comparatively mild intoxicant in ordinary preparation without causing physical dependence or tolerance. 2. According to the status of men who are marihuana smokers, approximately 20% of them were college students, those preparing to retake college entrance examinations, non-employed and pharmacists. The men belong mostly to the middle foreigner′s mistress of higher, income bracket, and in the case of women, most of the smokers were US. servicemen entertainers. 3. Dynamic developmental factors: Case 1. : The patient had a characteristic, hysterical and emotionally unitable character, and was of low intelligence, In addition, to this already existing problem, the added uses of marihuana caused a mental illness to develope. Case 2 : The character, was reserved and introspective, her creative power and sentiment was fading and his ability of self-control was weakened. She used the smoking of marihuana to get rid of her own feeling of inferiority complex and tensions coming from interpersonal relationships. Case 3 : The patient was unconditionally resistive to the authoritativeness of superiors and irresponsible in his relationship with women, in his attitude concerning sex in general. He smoked marihuana because he felt become peace-loving and get enchanted experience through smoking it. 4. The points of issue appearing from the above case; (1) Movement of anti-social feelings against the "established system" by the youngsters. (2) Family problem. (3) Shamelessness, loss of motivation, disorderly attitude toward the sex, (4) Worries concerning the future. (5) Lack of knowledge concerning smoking of cigarette and marihuana. Chronic use of marihuana made, those youngman who had originally been ambitions to achieve something in life, lazy, inefficient, unable to make long-term plans, are such weak mined persons that they did not try to overcome problems when encountered. This will pose a great and important question in the mental health of the society, 5. Treatment and Problem sieving According to the literature, we will have to place importance upon hospitalized treatment The phases of treatment were divided into five parts. (1) Prehospital phase (2) Withdrawal Phase (3) Rehabilitation phase (4) Transitional phase (5) After-care phase The experiments have proved that there was much progress in the recovery of patients through environment therapy, supportive therapy and group psychotherapy. This was the above mentioned 5 phases of treating process in accordance with the weekly schedule of the hospital. It was thought that the patients would require prolonged after care management even after they were released from the hospital and that they will also require periodic visit, to the hospital and doctor′s interview with their family. In conclusion, the question of the young generation and marihuana smoking is becoming a great social problem in which their resistances to the "established system" and society is growing in the from of antiestablishment movements. In our country, the smoking of marihuana is gradually developing, therefore, I think, that it would be a very fortunate thing for us, if this report could be helpful for the motivation of further study on the questions of the young generation and its problems.