• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1834-1846
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• 2020

The SMART (System-integrated Modular Advanced ReacTor) is an integral-type small modular reactor developed by KAERI (Korea Atomic Energy Research Institute). This paper discusses the development of a dynamic equivalent model of the SMART control rod drive mechanism that can be efficiently utilized for complicated analysis during the design of the SMART. A semi-empirical approach is used to develop the equivalent model; that is, the equivalent model is defined analytically and verified empirically. Two types of tests, dynamic characteristics tests and seismic loading tests, are conducted for the development and verification of the dynamic equivalent model, respectively. Acceleration response spectra from the seismic analysis based on the developed equivalent model show good agreement with those from the seismic loading tests.

• Research in Mathematical Education
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• v.12 no.2
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• pp.143-149
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• 2008

Before the 14th century, China had been thought as one of the countries with the most developed mathematics all along. But after the 16th century, Chinese mathematics increasingly walked up to the eclipse. The main reasons include the following points. First, the development of neoteric mathematics was closely associated with the social industrialization, but the lags in feudal China seriously blocked the development of the capitalistic seed, and China was still in the agricultural society then and couldn't step into the industrial society, which impeded the development of mathematics concerned with the industry and commerce. Second. the increasingly carrion feudalization was one of the essential reasons to block the development of Chinese neoteric mathematics. Finally, seeing about the developing logics of Chinese neoteric mathematics, we can find it was a scattered and experiential mathematical knowledge without strict and rational self-organizing structure system, which had the limitations existing in its interior mechanism.

• Journal of Powder Materials
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• v.7 no.4
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• pp.237-243
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• 2000

The property and performance of the $Al_2O_3/Ni$ nanocomposites have been known to strongly depend on the structural feature of Ni nanodispersoids which affects considerably the structure of matrix. Such nanodispersoids undergo structural evolution in the process of consolidation. Thus, it is very important to understand the microstructural development of Ni nanodispersoids depending on the structure change of the matrix by consolidation. The present investigation has focused on the growth mechanism of Ni nanodispersoids in the initial stage of sintering. $Al_2O_3/Ni$ powder mixtures were prepared by wet ball milling and hydrogen reduction of $Al_2O_3$ and Ni oxide powders. Microstructural development and the growth mechanism of Ni dispersion during isothermal sintering were investigated depending on the porosity and structure of powder compacts. The growth mechanism of Ni was discussed based upon the reported kinetic mechanisms. It is found that the growth mechanism is closely related to the structural change of the compacts that affect material transport for coarsening. The result revealed that with decreasing porosity by consolidation the growth mechanism of Ni nanoparticles is changed from the migration-coalescence process to the interparticle transport mechanism.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.331-341
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• 2018

This study proposes an integrated serial spring-damper mechanism as a dual pulse generation system. Compared to the traditional dual pulse generation system, which used multiple springs and a damper to generate a dual pulse critical for impact testing of naval equipments, currently used separated serial spring-damper mechanism is comprised of two components: an air spring, and a damper. The proposed mechanism combines the two components into one integrated system with a unique design that lets simply changing the volume and the pressure of the air tank, and the length of the annular pipe adjust the stiffness and damping constants for testing, eliminating the need to have multiple sets of air springs and dampers. Simulations using MatLab and Simulink were conducted to verify the feasibility of this design. The results show the potential of an integrated serial spring-damper mechanism as a more convenient and flexible mechanism for dual pulse generation system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.296-305
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• 2017

This study aims to create a new urban space through mechanism structure and algorism analysis between IT and ET. The results are as follows. First, the development trends of ET IT are classified into 4 types, "Eco-Friendly Development", "Energy Production Technology Development", "Energy Saving Technology Development" and "Wide Area IT Network Development", which are found to be constantly evolving. Second, Sang-Am DMC developed through the environmentally protective and eco-friendly aspects of ET from the Korean War to 1978. Wide area IT networks developed rapidly from 1990 to 2000. However, in 2010, urban spaces began to develop by the fusion of the Environment and Information. The fusion of Environment and Information in the development trends in the past is referred to as "Individual Development", that in the present is referred to as "Semi-fusion Development" and that in the future will be referred to as "Total Fusion Development". Third, the mechanism structure of DMC has evolved through creation, extinction and fusion processes. The creation process will serve to supplement the insufficiencies of the existing systems, the extinction process will be the compactification of the fusion process, and the fusion process will be the standard for creation and extinction. Finally, the future of new innovative urban and architectural spaces will be forged by the mechanism symbolization patterns of IT ET.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.43-48
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• 2009

Generally, underwater vehicle type of propeller shows low efficiency about 50%-55%. However, the efficiency of swimming mechanism of a fish is 60%-70%, more efficient about 20% than screw propellers. Recently, research of underwater vehicle type of fish increase due to its good efficiency and is regarded as a typical bio-mimical robot. In this research, a new algorithm and mechanism that show low energy consumption imitating swimming mechanism of fish proposed increasing speed and running time in field trial.

• Journal of Powder Materials
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• v.10 no.6
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• pp.422-429
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• 2003

The reduction mechanism of the composite powders mixed with $WO_3$ and CuO has been studied by using thermogravimetry (TG), X-ray diffraction, and microstructure analyses. The composite powders were made by simple Turbula mixing, spray drying, and ball-milling in a stainless steel jar with the ball to powder ratio of 32 to 1 at 80 rpm for 1 h without process controlling agents. It is observed that all the oxide composite powders are converted to W-coated Cu composite powder after reducing treatment under hydrogen atmosphere. For the formation mechanism of W-coated Cu composite powder, the sequential reduction steps are proposed as follows: CuO contained in the ball-milled composite powder is initially reduced to Cu at the temperature range from 20$0^{\circ}C$ to 30$0^{\circ}C$. Then, $WO_3$ powder is reduced to W $O_2$ via W $O_{2.9}$ and W $O_{2.72}$ at higher temperature region. Finally, the gaseous phase of $WO_3(OH)_2$ formed by reaction of $WO_2$ with water vapour migrates to previously reduced Cu and deposits on it as W reduced by hydrogen. The proposed mechanism has been proved through the model experiment which was performed by using Cu plate and $WO_3$ powder.

• International Journal of Computer Science & Network Security
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• v.22 no.11
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• pp.141-148
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• 2022

The development of the education system and the labor market today requires new conditions for unification and functioning, the introduction of an innovative culture in the field of Education. The construction of modern management of innovative development of a higher education institution requires consideration of the existing theoretical, methodological and practical planes on which its formation is based. The purpose of the article is to substantiate the modern paradigm of organizing the mechanism of managing the innovative development of higher education institutions. Innovation in education is represented not only by the final product of applying novelty in educational and managerial processes in order to qualitatively improve the subject and objects of management and obtain economic, social, scientific, technical, environmental and other effects, but also by the procedure for their constant updating. The classification of innovations in education is presented. Despite the positive developments in the development of Education, numerous problems remain in this area, which is discussed in the article. The concept of innovative development of higher education institutions is described, which defines the prerequisites, goals, principles, tasks and mechanisms of university development for a long-term period and should be based on the following principles: scientific, flexible, efficient and comprehensive. The role of the motivational component of the mechanism of innovative development of higher education institutions is clarified, which allows at the strategic level to create an innovative culture and motivation of innovative activity of each individual, to make a choice of rational directions for solving problems, at the tactical level - to form motives for innovative activity in the most effective directions, at the operational level - to monitor the formation of a system of motives and incentives, to adjust the directions of motivation. The necessity of the functional component of the mechanism, which consists in determining a set of steps and management decisions aimed at achieving certain goals of innovative development of higher education institutions, is proved. The monitoring component of the mechanism is aimed at developing a special system for collecting, processing, storing and distributing information about the stages of development of higher education institutions, prediction based on the objective data on the dynamics and main trends of its development, and elaboration of recommendations.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.324-333
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• 2012

The conventional medium and large caliber gun, in general, utilize the hydro-pneumatic recoil mechanism to control the firing impulse and to return to the battery position. However, this kind of mechanism may cause the problems like the leakages and the property changes in oil and gas due to the temperature variations between low and high temperatures. Accordingly, the friction spring mechanism has recently been researched as an alternative system. The friction spring mechanism consists of a set of closed inner and outer rings with the concentric tapered contact surfaces assembled in the columnar form, and can only be used under the compression load. When the spring column is axially loaded, the tapered surfaces become overlapped, causing the outer rings to expand while the inner rings are being contracted in diameter allowing an axial displacement. Because of friction between tapered contact surfaces, much higher spring stiffness is obtained on the stroke at the increase in load than the stroke at the decrease. In this paper, the dynamic equations regarding the friction spring system and the design approach have been investigated. It is also tried for a dynamic model representing the recoil motion and the friction spring forces. And the model has been proved from firing test using a gun system with friction springs. All the results show that the recoil mechanism using friction springs can substitute for the classic hydro-pneumatic recoil system.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.287-289
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• 1999

This paper proposes mechanism analysis in thermal overload relay. Overload protection performance is closely connected with mechanism of thermal overload relay. In shortage of analytical technique, we have experienced many difficulties in development of thermal overload relay. We applied analytical results to develop optimum thermal overload relay.