• Education of Primary School Mathematics
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• v.6 no.1
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• pp.11-28
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• 2002

The purposes of this study were to analyze elementary school mathematics textbooks developed in accordance with the 7th national amended curriculum and to find implications for the development of a new revised curriculum to meet the needs of the knowledge-based society. Elementary school mathematics textbooks and accompanying practice books were analyzed. Teacher's manuals were also studied to examine the intentions of the textbook developers. The two major questions were sought. First, to what degree do elementary school mathematics textbooks and practice books match with the intentions of the national curriculum\ulcorner Second, how do elementary school mathematics textbooks and practice books facilitate student's learning for understanding mathematics\ulcorner The findings were as follows. First textbooks, practice books, and teacher's manuals appeared not to reflect the intentions of the 7th amended curriculum to the full extent. Second, characteristics and roles of textbooks, practice books, and teacher's manuals were not clearly defined and therefore, they were not very feasible for teaming for understanding mathematics. The recommendations for a new revised curriculum were suggested. First, regarding the contents presented in the textbooks, the idea of structure of subject matter need to be considered in order to help students to understand connections of concepts and relationships between concepts and functions in mathematics. Second, more ill defined problems should be presented to develop problem solving ability in real life contexts in students. Third, contents for relearning and enrichment need to be reorganized to reflect students' real ability. Fourth, uses of the concrete and the manipulative need to be more realistically suggested. Fifth, more prototypes of performance assessment tasks, scoring rubrics, and portfolios need to be presented in a more teacher-friendly manner. Sixth, characteristics and roles of textbooks and practice books need to be more discernible.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.591-599
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• 2021

Rail transit agencies in Korea have been struggling to set up a performance-based rail facility maintenance plan because there are no formal definition and decision criteria for aging infrastructure. This study investigates the definition of aging infrastructure through extensive literature review and identifies benchmarking criteria through comparison with rail transit facility management systems in Korea and United States. As results, an aging infrastructure should be defined considering both service age and performance level of a facility. The priority of repair/replacement should be also determined with reasonable criteria based on relationship between service age and performance level. To determine the definition and decision criteria, a practicable classification system for aging rail transit needs to be established in accordance with classification system for performance assessment. Furthermore, a comprehensive database needs to be built including useful life, performance level, and maintenance cost of each component of rail transit. It will allow establishing an efficient budget execution plan for aging infrastructure.

• Asia Marketing Journal
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• v.16 no.1
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• pp.215-228
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• 2014

The automotive industry plays a significant role in the global economy. One of the reasons is that this industry compasses every aspects of the value chain - from raw materials to design and development, manufacturing, sales and services, and even disposal. Thus, the industry needs significant upfront capital investment and requires years of R&D and market development. As a result, this industry is dominated by a handful of global players and it is not easy for a new entrant to enter this industry. Furthermore, success is even more difficult to achieve. How did Hyundai Motor make it in this tough marketplace? Can it continue against all odds? The CAGR for last 5 years is 12% and it stands at 6th in the world. Compared to other global brands, Hyundai has geographically well-balanced sales portfolio. The quality improvement is outstanding. The brand performance follows these quality and sales improvements. Yet, the global competition is ever intensifying. Now, it is the time to step up once more. The next strategic goal needs fundamental shift toward brand and marketing-focus. In constructing global marketing strategy, Hyundai Motor's vision is "Lifetime partner in mobility and beyond" and its goal is global top 3 brand by year 2015 through modern premium brand image and selling 5 million vehicles. The target brand positioning of Hyundai Motor is the leading position in premium dimension and stylish/modern dimension. The global brand strategy framework is based on the brand direction of "Modern Premium" and is designed to deliver core brand identity (i.e., Simple, Creative, Caring) to customers. In order to manage brand performance, Hyundai's marketing platformalso includes marketing performance management, brand performance management, and market driven organization. From this diagnosis, Hyundai Motor is well posed to build a strong brand. Nevertheless, there are still challenges ahead from consumer, technology, competitor, and macro-environment perspectives. To overcome these threats, the bases of competition for all successful automotive brands are various differentiation factors, including technology, performance, value proposition, or heritage. Hyundai Motor is well prepared so far. However, it is not tested against time yet whether Hyundai can overcome these unforeseeable major threats. Hyundai is trying to find the solution from a strong brand, while believing in "New Thinking. New Possibilities."

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.10
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• pp.1427-1434
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• 2003

Turbo- or Super-charging has been used to boost engine power for Gasoline- and Diesel Engine since beginning of 20th century. So far turbo-charger has enjoyed a high reputation in the charging field for its technical advantages such as no demand of operation power from engine and an excellent charging effect in a static operation at mid- and high engine speed. A mechanically driven super-charger, however, is now popular due to the high engine power at quick change of the driving mode - high engine torque even at low engine speed. Since super-charger needs operation power from engine, it is difficult to improve its relatively higher fuel consumption than that of turbo-charger. This negative point is still an obstacle to the wide use of supercharger. Super-charger using screw-type compressor will fulfill the purpose to reduce fuel consumption by minimizing operation power owing to no charge at idling or part load driving condition. This study aims to develop power control concept to achieve the minimization of operation power. A screw type super-charger was modified in design partially and installed with an internal bypass valve and a bypass tube to control charging pressure at part load. The various control concepts show a possibility to reduce operation power of super-charger.

• Journal of Drive and Control
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• v.13 no.4
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• pp.23-30
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• 2016

This paper presents a control-oriented dynamical model of a towing rope system with variable-length. In this system, a winch driven by a motor's torque uses the towing rope to pull a cart. In general, it is a difficult and complicated process to obtain an accurate mathematical model for this system. In particular, if the rope length is varied by operating the winch, the varying rope dynamics needs to be considered, and the key physical parameters need to be re-identified... However, real time parameter identification requires long computation time for the control scheme, and hence undesirable control performance. Therefore, in this article, the rope is modeled as a straight massless segment, with the mass of rope being considered partly with that of the cart, and partly as halfway to the winch. In addition, the changing spring constant and damping constant of the towing rope are accounted for as part of the dynamics of the winch. Finally, a reduced-order observer-based servomechanism controller is designed for the system, and the performance is evaluated by computer simulation.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.247-254
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• 2020

The socio-cultural and economic changes following the Fourth Revolution are driving the growth of the food tech industry. Korea's food tech industry is still focused on delivery apps and the smart farms, robot market including artificial intelligence are in its infancy. In the United States, alternative meat companies are already included in unicorn companies, while Korea, the fourth largest importer of beef, lacks alternative meat development. France, Europe's largest agricultural country, is focusing on Agtech. China has developed the Internet and online e-commerce market with the world's number one population. Korea also needs to change regulations that focus on the past industry and various food tech industries should be developed through political and business-driven research and investment.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.915-920
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• 2001

A spent fuel problem has prevented the nuclear power from claiming to be a completely clean energy source. The nuclear transmutation technology to incinerate the long lived radioactive nuclides and produce energy during the incineration process is believed to be one or the best solutions. HYPER(Hybrid Power Extraction Reactor) is the accelerator driven transmutation system which is being developed by KAERI(Korea Atomic Energy Research Institute). Some major feature of HYPER have been developed and employed. On-power fueling concepts are employed to keep system power constant with minimum variation of accelerator power. A hollow cylinder-type metal fuel is designed for the on-line refueling concept. Lead-bismuth(Pb-Bi) is adopted as a coolant and Spallation target material. HYPER is a subcritical reactor which needs an external neutron source. 1GeV proton beam is irradiated to Lead-bismuth(Pb-Bi) target inside HYPER, and spallation neutrons are produced. When proton beams are irradiated, much heat is also deposited in the Pb-Bi target and beam window which separates Pb-Bi and accelerator vacuum. Therfore, an effective cooling is needed for HYPER target. In this paper, we performed the thermal-hydraulic analysis of HYPER target using FLUENT code, and also calculated thermal and mechanical stress of the beam window using ANSYS code.

• Archives of design research
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• v.13
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• pp.67-80
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• 1996

The textile industry, accounting nearly 25% of total industrial output, has progressed steadily in the last 30 years contributing greatly to the export driven economic development of Korea. Althought the textile industry has some competitiveness in the international market in terms of production capability through the ongoing restructuring effort, the area of textile design lags far behind compared to that of advanced industrial countries. This is believesd mainly due to the inadequate college education in addition to the social indifference toward the design. The current curriculum of textile design in most universities put more emphasis on the artistic aspects of design, rather than preparing the students as design specialists as required by the industries. The education system for textile design should, therfore, be restructured for the purpose of producing professional designers integrating the needs of sosiety, culture, art, economy, and advancing technology.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.39-46
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• 1998

In this paper, we present a neural network identification and a control of highly complicated nonlinear left ventricular assist device(LVAD) system with a pneumatically driven mock circulation system. Generally, the LVAD system needs to compensate for nonlinearities. It is necessary to apply high performance control techniques. Fortunately, the neural network can be applied to control of a nonlinear dynamic system by learning capability. In this study, we identify the LVAD system with neural network identification(NNI). Once the NNI has learned the dynamic model of the LVAD system, the other network, called neural network controller(NNC), is designed for a control of the LVAD system. The ability and effectiveness of identifying and controlling the LVAD system using the proposed algorithm will be demonstrated by computer simulation.

• Journal of Gifted/Talented Education
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• v.21 no.4
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• pp.1011-1032
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• 2011

For recently training the creative convergence talents, 'art education' is being greatly noted at home and abroad. In the meantime, this art education, which is being paid attention now as the educational trend of 'new alternative' in international society, has great difference in the aspect of objective, contents, and an operating method from the traditional art education in the past. Accordingly, this study analyzed and introduced the international art-education trend in a new concept, pointed out problems of art education as a part of activating the art education at elementary and middle schools, which is being driven now by the government, and of the integrated art education in the science technology field like STEAM, and suggested the desirable art-education orientation direction of satisfying the historical and social needs hereafter.