• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.275-282
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• 2024

Lead bismuth eutectic (LBE) is used as coolant for MicroURANUS, a small marine nuclear power plant, and this coolant is transported in the plant by an electromagnetic pump. Given the considerable heat generated by the electromagnetic pump, the cooling of the pump is essential. This study compared air cooling and water-cooling methods and found that the maximum temperatures during air and water cooling were 640 K and 372 K, respectively. These findings were utilized to design an electromagnetic pump with water-cooling. The maximum temperature of the pump was lower than the boiling point of water; thus, the pump did not require a separate pressurization. Consequently, the resistance problem of the coil and the deformation problem of the material caused by generated heat can be solved through water-cooling.

• Nonlinear Functional Analysis and Applications
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• v.29 no.3
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• pp.673-710
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• 2024

In this paper, we propose a modified Halpern's iterative scheme developed from a sequence of a new class of enriched nonspreading mappings and an enriched nonexpansive mapping in the setup of a real Hilbert space. Moreover, we prove strong convergence theorem of the proposed method under mild conditions on the control parameters. Also, we obtain some basic properties of our new class of enriched nonspreading mappings.

• Journal of Web Engineering
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• v.20 no.3
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• pp.795-816
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• 2021

The existing industry evaluation method utilizes the method of collecting the structured information such as the financial information of the companies included in the relevant industry and deriving the industrial evaluation index through the statistical analysis model. This method takes a long time to calculate the structured data and cause the time delay problem. In this paper, to solve this time delay problem, we derive monthly industry-specific interest and likability as a time series data type, which is a new industry evaluation indicator based on unstructured data. In addition, we propose a method to predict the industrial risk index, which is used as an important factor in industrial evaluation, based on derived industry-specific interest and likability time series data.

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.493-506
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• 2000

Recently the first author and his coworker report a new finite element method for the Poisson equations with homogeneous Dirichlet boundary conditions on a polygonal domain with one re-entrant angle [7], They use the well-known fact that the solution of such problem has a singular representation, deduced a well-posed new variational problem for a regular part of solution and an extraction formula for the so-called stress intensity factor using tow cut-off functions. They use Fredholm alternative an Garding's inequality to establish the well-posedness of the variational problem and finite element approximation, so there is a maximum bound for mesh h theoretically. although the numerical experiments shows the convergence for every reasonable h with reasonable size y imposing a restriction to the support of the extra cut-off function without using Garding's inequality. We also give error analysis with similar results.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.48-56
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• 2000

The bifurcation problem of thin walled structures in contact with rigid surfaces is formulated by adopting the multiple scales asymptotic technique. The general theory developed in this paper is very useful for the bifurcation analysis of waviness instabilities in the sheet metal forming. The formulation is presented in a full Lagrangian formulation. Through this general formulation, the bifurcation functional is derived within an error of O($(E^4)$) (E: shell's thickness parameter). This functional can be used in numerical solutions to sheet metal forming instability problem.

• Journal of Families and Better Life
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• v.25 no.6
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• pp.83-94
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• 2007

The purpose of this study was to examine the relationships between ego- resilience and stress coping styles of adolescents. The study also tried to identify differences on stress coping styles based on the level of ego- resilience of adolescents. Ego-resilience showed positive correlations with problem-focused and social support seeking coping styles and a negative correlation with an emotion-focused coping style. Canonical Correlation analysis revealed that self-confidence among four sub-domains of ego-resilience made the most outstanding contributions in predicting stress coping styles of adolescents. The problem-focused coping style had the highest correlation with ego-resilience among the four coping styles. The group of adolescents who had a higher level of ego-resilience reported more problem-focused and social support-seeking coping styles in stressful situations. The results of this study suggested that development of ego-resilience of adolescents who were in the midst of transitions and adjustment problems was important for effective coping strategies.

• Korean Management Science Review
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• v.28 no.3
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• pp.15-29
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• 2011

In this paper, we consider a system working at both primary service and secondary service. A server can switch between the primary service and the secondary service or it can be assigned to secondary service as a dedicated server. A service policy is characterized by the number of servers dedicated to the secondary service and a rule for switching the remaining servers between two services. The primary service system is modelled as a Markovian queueing system and the throughput is a function of the number of servers, buffer capacity, and service policy. And the secondary service system has a service level requirement strategically determined to perform the service assigned. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simultaneously determining the optimal total number of servers, buffers, and service policy to maximize profit of the system subject to both an expected customer waiting time constraint of the primary service and a service level constraint of the secondary service and develop an algorithm which can be successfully applied with the small number of computations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.291-297
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• 2012

In this paper, potential field algorithm was used for path planning in dynamic environment. This algorithm is used to plan a robot path because of its elegant mathematical analysis and simplicity. However, there are some problems. The problems are problem of collision risk, problem of avoidance path, problem of time consumption. In order to solve these problems, we fused potential field with fuzzy system. The input of the fuzzy system is set using relative velocity and location of robot and obstacle. The output of the fuzzy system is set using the weighting factor of repulsive potential function. The potential field algorithm is improved by using fuzzy potential field algorithm and, path planning in various environment has been done.

• ETRI Journal
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• v.20 no.3
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• pp.251-271
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• 1998

It is well known that if usage parameter control/network parameter control (UPC/NPC) functions are used together with a cell loss priority control scheme in ATM networks, the measurement phasing problem can occur. This makes it difficult for a network provider to define and commit the cell loss ratio as a QoS parameter. To solve the problem, we propose a new UPC/NPC algorithm. By using the proposed UPC/NPC algorithm, we can define the cell loss ratios for CLP = 0 and CLP = 0+1 cell streams without the measurement phasing problem under any conditions. We analyzed the performance of the proposed UPC/NPC algorithm. Using a discrete time model for the UPC/NPC architecture with a discrete-time semi-Markov process (DSMP) input model, we obtained the cell discarding probabilities of CLP = 0 and CLP = 0+1 cells streams and showed that more CLP = 0 cells are accepted compared to what was proposed in ITU-T.

• Journal of Engineering Education Research
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• v.18 no.2
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• pp.65-76
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• 2015

Despite its ineffectiveness, the dominant pedagogy for engineering education is still "chalk & talk". Meanwhile, student-centered learning models have been highlighted for strong communication, teamwork skills, deep understanding and analysis on social, environmental and economic issues as well as application of their engineering knowledge in practice. Among others, on problem- and project-based learning, this article examines theoretical background and detailed features and a comparison between both learning models including common and different features from the previous theoretical and empirical studies. It reviews some cases of where they have been practiced successfully in engineering, and further, applied strategies for engineering education are suggested.