• 대한기계학회논문집A
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• 제26권9호
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• pp.1882-1887
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• 2002

This study is to develop a automatic design program of mechanical elements as the integrated system which can create automatically 3-dimensional solid and surface model using visualLISP. By the applying developed system to CAE system, the following objects are realized. At first, constructing the library of automatic design program for unexperienced design engineer, the 3-dimensional modeling of mechanical elements can be obtained easily. at second, the 3-dimensional model for ratchet wheel design is created by finete element model of CAE system and the optimal design condition of key way.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.486-493
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• 2007

In the field of maintenance of domestic high-speed railroad which has cost a great deal more than any other fields since it was opened; 1) We found out the conditions of current domestic railroad by understanding the status of track maintenance and analyzing operative processes of track maintenance. 2) The main factors in track maintenance of high-speed railroad, that is, the elements for success to help decision-support in track maintenance were derived from a research on literature about the condition of railroad R&D in these days and about the prediction of the irregular progresses of track. 3) We derived the order of priority and weights from AHP analysis which was based on the survey regarding elements for success.

• 대한수학회보
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• 제48권1호
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• pp.115-127
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• 2011

We study the structure of the set of nilpotent elements in various kinds of ring and introduce the concept of NR ring as a generalization of Armendariz rings and NI rings. We determine the precise relationships between NR rings and related ring-theoretic conditions. The Kothe's conjecture is true for the class of NR rings. We examined whether several kinds of extensions preserve the NR condition. The classical right quotient ring of an NR ring is also studied under some conditions on the subset of nilpotent elements.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.218-218
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• 2000

Advanced Vehicle Control Systems(AVCS) is one of the key elements in Intelligent Transportation Systems(ITS). This paper considers the problem of longitudinal control in vehicle platoon on a straight lane of a highway. In a very simplified situation, longitudinal vehicle dynamics contains many nonlinear elements. The nonlinear characteristics are mainly composed of an engine, a torque converter, and a drag force. In this paper, sliding control, one of nonlinear control methods, is applied to longitudinal automated vehicle control for platooning. Output feedback linearization is also simulated for comparison with the sliding control. Simulations for comparative study for the adopted controllers such as sliding control and output feedback linearization are peformed under the same conditions. This Paper aims at clarifying the characteristics of sliding control and output feedback linearization.

• 대한한의학원전학회지
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• 제20권1호
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• pp.85-102
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• 2007

Zhang thinks human life consists of body(形) and Shen(神 spirit). Body comes from Jing(精), Shen comes from Qi(氣). The common basic of body and Shen is Qi. Thus the elements of human life are Jing, Qi and Shen. Among the three life elements, Jing is the lowest level. To preserve Jing is the key to Life Care. To preserve Jing, we should rest body and Shen, and Shen rules body, so to rest Shen is necessary to preserve Jing. When Jing is full, it converts to Qi, and Qi converts to Shen. Shen is ruled by mind(心), so mind sould be quiet. There is a gate through which Jing and Qi pass. It is called Mingmen(命門), and it sould be closed tight to preserve Jing.

• Coupled systems mechanics
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• 제6권1호
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• pp.1-15
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• 2017

Despite the exceptional mechanical properties of individual carbon nanotubes (CNTs), the effective properties of CNT-reinforced composites remain below expectations. The composite's microstructure has been identified as a key factor in explaining this discrepancy. In this contribution, a method for generating representative volume elements of aligned CNT sheets is presented. The model captures material characteristics such as random waviness and entanglement of individual nanotubes. Thus it allows studying microstructural effects on the composite's effective properties. Simulations investigating the strengthening effect of the application of a pre-stretch on the CNTs are carried out and found to be in very good agreement with experimental values. They highlight the importance of the nanotube's waviness and entanglement for the mechanical behavior of the composite. The presented representative volume elements are the first to accurately capture the waviness and entanglement of CNT sheets for realistically high volume fractions.

• 산업경영시스템학회지
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• 제23권54호
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• pp.65-75
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• 2000

Cellular manufacturing(CM) is a philosophy and innovation to improve manufacturing productivity and flexibility. Cell formation(CF), the first and key problem faced in designing an effective CM system, is a process whereby parts with similar design features or Processing requirements are grouped into part families, and the corresponding machines into machine cells. Cell formation solutions often contain exceptional elements(EEs). EE create interactions between two manufacturing cells. A policy dealing with EEs considers minimizing the total costs of three important costs; (1)intercellular transfer (2)machine duplication and (3)subcontracting. This paper presents an effective cell formation method with fuzzy nonlinear mixed-integer programming simultaneously to form manufacturing cells and to minimize the total costs of eliminating exceptional elements.

• Asian Journal of Innovation and Policy
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• 제10권1호
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• pp.155-158
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• 2021

Entrepreneurial ecosystem is a very active area of research both conceptually and empirically, yet most literature that emerged over the last two decades predominantly pertain to developed economies. At the same time, transitioning and emerging economies have continued to grow rapidly, making a strong case to study entrepreneurial ecosystems in emerging economies (Bruton et al., 2018). Ecosystems are broad constructs and the constitutive elements of an ecosystem are themselves complex (Stam, 2015). Hence exploring key elements of the ecosystem in depth to understand the mechanisms of how entrepreneurship is supported through intermediary organizations like incubators is a fruitful exercise. In this context, we review the book "Technology Business Incubators in India Structure, Role and Performance" which is a timely synthesis for academic researchers and practitioners, looking to explore the topic as it pertains to emerging economies. The book is part of the De Gruyter Studies in Knowledge Management and Entrepreneurial Ecosystems series, that covers pertinent ecosystems issues around universities, and sustainability by leading authors.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1124-1128
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• 2005

The duration of a construction project is not only a key element for taking a new order, but also a strict yardstick to determine certain project successful or not. However, since construction project is basically outdoor job and most of the activities are proceeded out-air, no matter how the schedule plan has been established accurately, actual project proceeds due to the weather condition, beyond anyone's control. In this paper, the functional relationship between work productivity rate and weather elements is suggested by regression analysis. Difference of the relationship and influence of weather due to the seasonal group are also revealed. With these results, by simulating actual weather data and generating weather forecast through historical data, more accurate schedule would be obtained.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제21권2호
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• pp.25-33
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• 2015

Purpose: This study is to suggest a direction for comprehensive planning of educational environment in which children's cognitive development and emotional needs are achieved in childcare facilities. The importance of educational environment in childcare facilities has increased since it was discovered that high quality educational environment can not be guaranteed in current childcare facilities while the number of women participating in labor force, hence the number of children spending most of their time in these facilities is rapidly increasing. Methods: Correlation analysis on Reggio Emilia Approach to education environment and Max Luscher's psychological healing theory, and case study. Results: The result of the correlation analysis, the 4 key elements of educational environment and the 4 emotional status have significant relationship. Based on the elements of educational environment in Reggio Emilia Approach, case studies were pursued in 3 different childcare facilities in Korea. Implications: Evaluation of these case studies addresses the important elements to be considered in comprehensive planning of the educational environment in childcare facilities.