• Structural Engineering and Mechanics
• /
• v.44 no.1
• /
• pp.61-72
• /
• 2012

The paper is on contact analysis of a spherical ball with a deformable flat, considering the effect of tangent modulus on the contact parameters of a non-adhesive frictionless elastic-plastic contact. The contact analysis of this model has been carried out using analysis software Ansys and Abaqus. The contact parameters such as area of contact between two consecutive steps, volume of bulged material are evaluated from the formulated equations. The effect of the tangent modulus is considered for determining these parameters. The tangent modulus are accounted between 0.1E and 0.5E of materials E/Y value greater than 500 and less than 1750. Result shows that upto an optimal tangent modulus values the elastic core push up to the free surface in the flat. The simulation is also carried out in Abaqus and result provide evidence for the volume of bulged material in the contact region move up and flow into the free surface of the flat from the contact edge between the ball and flat. The strain energy of the whole model is varied between 20 to 40 percentage of the stipulated time for analysis.

• Health Policy and Management
• /
• v.6 no.2
• /
• pp.58-90
• /
• 1996

This study provides an empirical analysis of location competition for demand maximization by central place theory among physicians in nonmetropolitan areas of Korea. The results show that the primary care physicians distribute themselves evenly from urban communities to rural communities. The subspecialists, however, cluster together in major cities rather than decentralize themselves in rural counties. This study establishes the three statistical models : Primary care physicians, subspecialist physicians, and total physicians. Two models of primary care physicians and total physicians have a strong significance in multiple regression analysis (p=-.0001). The primary care model explains approximately 45% of the variation and the total physicians model explains approximately 70% of the variation in physician/1,000 population ratios across national counties. The subspecialist physicians model analysze the tobit regreassion because of the left consored and truncated values(57 cases = 0). In all three models, analysis of the coefficiencts for physician centralization degrees in the 0- to 5- and 5- to 10-km rings around the core county reveals each a positive and negative association betwee these degrees and the physician/1,000 population ratios in the core county. Also, the results provide moderate evidence that the relationship between clinic physicians and community hospitals is competitive, and the relationship between clinic physicians and pharmaceutists is synergistic. This suggests that public policy makers and local self-governing bodies must take an active role to ensure procider availability and the regional health planning in all nonmetropolitan areas of Korea.

• Nuclear Engineering and Technology
• /
• v.37 no.4
• /
• pp.363-374
• /
• 2005

A heterogeneous thorium-based Kyung Hee Thorium Fuel (KTF) assembly design was assessed for application in the APR-1400 to study the feasibility of using thorium fuel in a conventional pressurized water reactor (PWR). Thermal hydraulic safety was examined for the thorium-based APR-1400 core, focusing on the Departure from Nucleate Boiling Ratio (DNBR) and Large Break Loss of Coolant Accident (LBLOCA) analysis. To satisfy the minimum DNBR (MDNBR) safety limit condition, MDNBR>1.3, a new grid design was adopted, that enabled grids in the seed and blanket assemblies to have different loss coefficients to the coolant flow. The fuel radius of the blanket was enlarged to increase the mass flow rate in the seed channel. Under transient conditions, the MDNBR values for the Beginning of Cycle (BOC), Middle of Cycle (MOC), and End of Cycle (EOC) were 1.367, 1.465, and 1.554, respectively, despite the high power tilt across the seed and blanket. Anticipated transient for the DNBR analysis were simulated at conditions of $112\%$ over-power, $95\%$ flow rate, and $2^{\circ}C$ higher inlet temperature. The maximum peak cladding temperature (PCT) was 1,173K for the severe accident condition of the LBLOCA, while the limit condition was 1,477K. The proliferation resistance potential of the thorium-based core was found to be much higher than that of the conventional $UO_2$ fuel core, $25\%$ larger in Bare Critical Mass (BCM), $60\%$ larger in Spontaneous Neutron Source (SNS), and $155\%$ larger in Thermal Generation (TG) rate; however, the radio-toxicity of the spent fuel was higher than that of $UO_2$ fuel, making it more environmentally unfriendly due to its high burnup rate.

• Journal of Elementary Mathematics Education in Korea
• /
• v.23 no.4
• /
• pp.405-435
• /
• 2019

Despite the recent emphasis on value research in mathematics education along with the significance of values from a new perspective, there has been a lack of research on the values perceived by teachers and students in Korea. This paper analyzes how fifth-grade students would perceive the values of a master teacher with expertise in elementary mathematics education after her teaching of mathematics and whether their values on mathematics learning would change. According to the study, the students recognized that the master teacher valued understanding, preview-review, picture, problem, and reason in mathematics learning. Among these, the value of understanding was perceived as the core value. An analysis of the students' values on general mathematics learning and personal mathematics learning showed that preview and review were the most important before and after the master teachers' teaching. An analysis of the changes in the values of students showed the greatest change in the value of understanding. Instead of accepting the values of the master teacher as it were, students actively reconstructed and maintained them. Based on these results, this paper has drawn implications regarding the consideration of students' values in mathematics learning.

• Structural Engineering and Mechanics
• /
• v.77 no.1
• /
• pp.57-74
• /
• 2021

The thermal eigenvalue responses of the graded sandwich shell structure are evaluated numerically under the variable thermal loadings considering the temperature-dependent properties. The polynomial type rule-based sandwich panel model is derived using higher-order type kinematics considering the shear deformation in the framework of the equivalent single-layer theory. The frequency values are computed through an own home-made computer code (MATLAB environment) prepared using the finite element type higher-order formulation. The sandwich face-sheets and the metal core are discretized via isoparametric quadrilateral Lagrangian element. The model convergence is checked by solving the similar type published numerical examples in the open domain and extended for the comparison of natural frequencies to have the final confirmation of the model accuracy. Also, the influence of each variable structural parameter, i.e. the curvature ratios, core-face thickness ratios, end-support conditions, the power-law indices and sandwich types (symmetrical and unsymmetrical) on the thermal frequencies of FG sandwich curved shell panel model. The solutions are helping to bring out the necessary influence of one or more parameters on the frequencies. The effects of individual and the combined parameters as well as the temperature profiles (uniform, linear and nonlinear) are examined through several numerical examples, which affect the structural strength/stiffness values. The present study may help in designing the future graded structures which are under the influence of the variable temperature loading.

• International Journal of Advanced Culture Technology
• /
• v.11 no.2
• /
• pp.238-248
• /
• 2023

This study aims to examine the symbolism of the emblems of World Expositions by using Victor Turner's symbolic theory as a research method, and to reveal the symbolic types behind them by classifying the emblem designs of different periods and themes. The research object is 12 comprehensive World's Fair emblems from the 1939 New York World's Fair in the United States to the 2025 Osaka World's Fair in Japan, as identified by Bureau International des Expositions. The research method mainly adopts documentary research to collect historical information and theoretical frameworks related to the design of World's Fair emblems. In the analysis process, Victor Turner's symbolic sign theory is used as the main analytical framework to link the design elements of emblems to their relevance to specific societies and cultures in order to reveal the themes, values and ideas represented by the emblem symbolism. The results of the study show that the design of the Expo emblem uses different symbols, including material symbols, behavioral symbols, sensory symbols, natural symbols, social symbols and virtual symbols, to convey the core concepts, themes and values of the Expo. Through different types of symbols, the Expo emblem shows a wide range of concerns about technology and the future, mankind and the world, nature and ecology, and society and innovation. The symbolic design of the emblem plays an important role in conveying the core concept and theme of the Expo.

• Journal of Korean Academy of Nursing Administration
• /
• v.17 no.3
• /
• pp.301-314
• /
• 2011

Purpose: This study was a methodological research conducted to develop a clinical ladder system for operating nurses. Methods: Participants were 20 OR nurses, working in C Hospital, who had a mean tenure of 6 years and 10 months. Data collection consisted of 4 focus group interviews during May and June 2009. The content analysis method of Kim and Lee (1986) was used to analyze the data. Two clinical expert groups consisting of 16 nurses verified the content validity of the preliminary system from September 16 to 26, 2009 using Kim's tool (1999). Results: The final clinical ladder system consisted of goals, core values, and 4 domains of practice related to core values, which were defined as professional value, perioperative nursing practice, education/research, and collaboration/leadership. Eleven nursing competencies and 44 behavior indicators were included in accordance with the 4-step ladder. The 4 operation systems for the clinical ladder system were the promotion system, continuous learning system, reward system, and support system. Conclusion: The results indicate that nursing managers need to pay more attention to developing a clinical ladder system for nurses.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.5
• /
• pp.338-343
• /
• 2004

In general, the insulation and protective sheaths on electrical conductors are made of combustible substances like PVC, natural or synthetic rubbers, and other organic or synthetic materials. When an electrical fire starts due to overheating of conductors/joints or sparking/arcing, the first thing to ignite is usually the insulation on the cables. When the insulation bums, the produced fumes are very toxic. To solve the problem, we have surely need the fire resistance cable that doesn't bum in a high temperature and emit toxic fume for operating a disaster prevention installation. In this paper, we have simulated the thermal analysis for the fire resistance cable according to the values of current in a overload and a short, and the values of outside flame with the fire resistance cable of the L's company product(600 V, FR-8 : Four Core) using the finite element method(Flux2D).

• Journal of the Korean Society for information Management
• /
• v.40 no.3
• /
• pp.163-196
• /
• 2023

The academic library development plan has external importance as it explicitly declares the library's role and development direction. Internally, it is also a library service guideline. To develop the development plan, libraries must understand the trends and needs of international, national, and affiliating universities and their constituents. Accordingly, this research includes case, content, and network analyses of foreign academic libraries' development plans to identify the trends. The analysis results show most foreign academic libraries employed various strategies and plans, which can be characterized as 'collaboration,' 'collection development,' and 'research support.' Consequently, we propose the following factors to consider when developing an academic library development plan: specification of mission, vision, and core values; recognition of core values such as diversity, equity, and inclusion; awareness of the significance of collaboration and partnership with other units within the universities and external organizations; and utilization of university library development plans as tools for achieving management objectives.

• Structural Engineering and Mechanics
• /
• v.77 no.2
• /
• pp.293-304
• /
• 2021

Structural failure due to seismic pounding between two adjacent buildings is one of the major concerns in the context of structural damage. Pounding between adjacent structures is a commonly observed phenomenon during major earthquakes. When modelling the structural response, stiffness of impact spring elements is considered to be one of the most important parameters when the impact force during collision of adjacent buildings is calculated. Determining valid and realistic stiffness values is essential in numerical simulations of pounding forces between adjacent buildings in order to achieve reasonable results. Several impact model stiffness values have been presented by various researchers to simulate pounding forces between adjacent structures. These values were mathematically calculated or estimated. In this study, a linear spring impact element model is used to simulate the pounding forces between two adjacent structures. An experimental model reported in literature was adopted to investigate the effect of different impact element stiffness k on the force intensity and number of impacts simulated by Finite Element (FE) analysis. Several numerical analyses have been conducted using SAP2000 and the collected results were used for further mathematical evaluations. The results of this study concluded the major factors that may actualise the stiffness value for impact element models. The number of impacts and the maximum impact force were found to be the core concept for finding the optimal range of stiffness values. For the experimental model investigated, the range of optimal stiffness values has also been presented and discussed.