• Journal of Magnetics
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• v.16 no.1
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• pp.74-76
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• 2011

Interior permanent-magnet synchronous motors (IPMSMs) produce both magnetic and reluctance torques. The reluctance torque is due to the difference between the d- and q-axis inductances based on the geometric rotor structure. The steady-state performance analysis and precise control of the IPMSMs greatly depend on the accurate determination of the parameters. The three essential parameters of the IPMSMs are the armature flux linkage of the permanent magnet, the d-axis inductance, and the q-axis inductance. In the basic design step of an IPMSM, the inductance parameters are very important for determining the motor characteristics, such as the input voltage, torque, and efficiency. Thus, it is very important to accurately estimate the values of the motor inductances. The inductance parameters of IPMSMs have nonlinear characteristics along the magnet size because the iron core is saturated by the magnet and armature reaction fluxes. In this study, the inductance parameters were calculated using both the magnetic-equivalent-circuit method and the finite-element method (FEM). Then the calculated parameters were compensated by the saturation coefficient function, which was also calculated via the magnetic-equivalent-circuit method and FEM.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.1-35
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• 2014

This study analyzed convergence status among input technologies used in technology development with Technology I-O analysis. It was another version of industry input-output analysis which is used in technology planning. This case is an analysis of association between technology an product. The subjects of analysis were 401 tasks that applied to '2012 Convergence Technology Development Project for Small and Medium Businesses' promoted by Korea Technology & Information Promotion Agency for Small and Medium Enterprises. The process of analysis is as followed. First step, we made a matrix table as an input of technology input-output analysis. Input was defined by technology and output was defined by the product. Input technology was defined in a 3-digit code under National Science Technology Classification and output products were defined in a 5-digit under National Standard Industry Code. Second, the Spillover ratio among technologies were calculated and was used to make a picture of technology linkage. As a result of analysis, technology spillover of embedded S/W was the highest in IT convergence, mold product in ET convergence, and functional cosmetics development technology in BT convergence. In general, IT convergence had many element technologies with high technology spillover, and ET had a small number of element technologies with high technology spillover. Therefore, investment effect of element technology is expected to be large if investment on element technologies with high technology spillover is important for vitalizing convergence.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.441-449
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• 2018

The knowledge and information processing competence is one of the essential competencies in an information-oriented society which is highly related to science education. The purpose of this study is to investigate middle school students' difficulties in science inquiry activity in view of the knowledge and information processing competence. Collection, processing, and application of information are extracted as common elements of the knowledge and information processing competence through literature search. Data were obtained from eight students of a middle school in Seoul for five months and were analyzed based on constant comparative method to extract students' difficulties. As a result, the element of information collection is observed through science inquiry and the element of information processing is observed in hypothesis setting step, inquiry result analysis step, and inquiry result sharing step. The element of information application is observed in the creation of posters for sharing and inquiry reports. Difficulties in information collection were found in lack of confidence in information gathering, systematic search strategy, and information reliability. Difficulties in information processing appeared in the inexperience of analysis program use, information transformation, and interpretation of linkage information. Difficulties in information application were caused by the lack of effective organization and effective expression of information. In this study, it is meaningful to provide a clue as to how the knowledge and information processing competence can be established in science education.

• Journal of the Korean Geographical Society
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• v.30 no.1
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• pp.35-56
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• 1995

During the last two decades, Korea has achieved remarkable economic growth. In this process the nation has become urbanized and industrialized. But we have also encountered widening regional disparity, housing shortage of larger cities, transportation congestion, environmental pollution and many other problems. Rapid increasing urbanization and continuous migration toward Seoul since the late 1960s have been one of the major concerns of government. Government has sought ways to moderate the population increase in Seoul. The regulation which include new town development near Seoul and dispersion strategies of higher education and other administration and living facilities outside of Seoul havemade a great expansion of the spatial influence of Seoul city. Seoul metropolitan reaion has evolved as the most powerful center of political and economical spaces. Generally within a metropolitan region, there exists a growing mutual interdependence economically, as well as socially between a central city and its surrounding area. Seoul metropolitan region manifests itself not only as a coherent system of urbanized regions, but also as an integral part of the daily urban system. The surrounding Gyunggi province and Seoul city become closely linked both economically and functionally, constituting true functlonai urban system. This study is primarily undertaken with the purpose of delineation of the sphere of influence of Seoul city in 1990. At the time of 1985, Seoul metropolitan region was delineated according to the result of the study which was performed by Korea Research Institute for Human Settlements. Afterward, the rapid speed of metropolitanization process with dramatic increase in mobility through the provision of wider transportation system across the Capital region have evolved, resulting in the great expansion of the spatial influence of Seoul city. So this study examines the expanded area of Seoul metropolitan regin during the period of 1985-90. In order to delineate Seoul metropolitan region, the indices of urbanization and functional linkage are selected. Variables included in the measurement of the urbanization level are agricultural structure, population characteristics, manufacturing and service industries, and cultural aspects such as newspaper circulation, the ratio of car ownership and piped water supply. Variables included in the measurement of functional linkage are commuting, shopping pattern, centralized service such as medical facilities and trade of agricultural products. The standardization method and factor analysis are employed in making the delineation of Seoul metropolitan region. According to the result of this study, 2 cities, 8 Eups and 46 Myuns are included Seoul metropolitan region in 1990. If we compare this delineated area in 1990 to that of 1985, we can find the distinctive pattern of expanded axes according to the main transportation routes such as Seoul-Suweon, Seoul-Gwangju, Seoul-Incheon. In 199O, all the Gyunggi province, except a few Myuns located at the north and northwest part of Gyunggi province, are included in Seoul metropolitan region. Furthermore, this study attempts to the analysis of regional structure of Seoul metropolitan region according to the functional characteristics of each city and Gun. Variables included in this analysis are the new residential function, manufacturing function, service function, education and infermation function, public facility function and agricultural function. Factor analysis and cluster analysis are employed in making regionalization. Seoul metropolitan reaion is subdivided into four subregions which reflect different functional specialization. The first group is the specialized region of newly formed residential function. The second group is the specialized reaion of manufacturing function. The third group is the specialized region of service function. And the fourth group has little specialized in terms of manufacturing, service, and residential function. But this region has some potentiality of development when Seoul metropolitan region grow continuously. Seoul metropolitan region accounted for 43% of national population, despite 11.8% of national land size in 1990. Although Seoul metropolitan region enjoys important agglomeration economies, it also has huge social cost in the form of transportation congestion, housing shortage, rapid increase of land value, environment pollution, and etc. Efficient metropolitan plan making is a vital element in promoting Seoul's economic development and providing high quality living environment at low cost. In the light of the result of this study, the outer ring of Seoul metropolitan region, especially northeastern part, are underdeveloped compared to overdeveloped southwestern area. It is needed to develop the guidelines for the implement of the growth control and management plan, inducing more balanced development for whole Seoul metropolitan reaion.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.26-33
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• 2017

We propose a variable frame structure connected with telescopic mast-shaped shaft for a robot displaying outstanding ability to cross obstacles, and for effective traction control. The wireless control system was built to extend and contract a deployable mechanism, which is shaped into a hoberman sphere assembled with frame structures. In order to develop important parameters for efficient locomotion, we derived an Euler-Lagrange equation for the spherical robot. According to the equation, the DC motor was selected. A prototype mechanism was tested and a Finite-Element Analysis (FEA) was conducted in parallel. Using these data, we constructed a deployable spherical robot with structural stability. The deployable robot moved at a speed of 0.85 m/s from 520 mm to 650 mm.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.3-11
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• 2012

The first visual contact in architecture happens in surface, and it could be significant object as well as the starting point to recognize the essence and perceive the buildings. Architecture surface could not get out of the restriction of structures and materials that support buildings for a long time in the past. Architecture surface in the past should fulfill the structural role to form are appearance of buildings and support buildings at the same time, so it was difficult to get out of logic for material and thickness of walls, arrangements and sizes of windows. However, since the modern age, architecture surface came to be freer according to the development of building technology, and development of technology changes shows tendencies to express role of new design factor as an architectural element emphasized expression and autonomy,s which was escaped from the subordinate relationship that the surface of building must do the structural function. In this study, it would be examined the expressive characteristics of various epidermis that are expressed in architecture of Herzog & de Meuron since the end of 20thcentury focused on comprehended and analyzed results of changes and characteristics of contemporary society. Through this, it would be comprehended the epidermis of architecture that has particular character expressed in modern buildings of Herzog & de Meuron, and it would be composed a certain linkage between this and characteristics of contemporary society and it would be investigated that the establishing process of inner spaces. Identification through case analysis for this would perform a role of catalyst for the new possibility and development of contemporary architecture's surface expression in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1077-1082
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• 2011

Ball joint is a rotating and swiveling element that is typically the interface between two parts. In an automobile, the ball joint is the component that connects the control arms to the steering knuckles by playing a role of bearing. The ball joint can also be installed in linkage systems for motion control applications. This paper describes the simulation strategy for a ball joint analysis, considering manufacturing process. Its manufacturing process can be divided into plugging and spinning. Then, the interested response is selected as the stress distribution generated between its ball and bearing. In this paper, a commercial code of NX DAFUL 2.0 using an implicit integration method is introduced to calculate the response. In addition, the gap analysis is performed to investigate the fitness. Also, the optimum design is suggested through case studies.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.765-773
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• 2022

This study is a study on the application of a horizontal excavation machine system to improve constructability. In this study, the structural stability of non-covered temporary facilities was evaluated by comparing field measurements and numerical analysis. In addition, the appropriateness of the measurement results was analyzed by comparing and analyzing the results of numerical analysis with the analysis results applying the Gaussian probability density function to the measurement results. In this study, structural safety and long-term durability of the linkage were analyzed based on numerical analysis. As a result of the study, it was analyzed that the non-open cut method (H.A.S. method) of this study secures structural safety and constructability as the behavior in the actual construction process is more safe than the numerical analysis results, even if the uncertainty of the ground condition is taken into account.

• Coupled systems mechanics
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• v.11 no.6
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• pp.557-586
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• 2022

In spite of extensive testing of the individual shear wall and the coupling beam (CB), numerical and experimental researches on the seismic behavior of CSW are insufficient. As far as we know, no previous research has investigated the affectations of position of CB regarding to the slab level (SL). So, the investigation aims to enhance an overarching framework to examine the consequence of connection positions between CB and SL. And, three cases have been created. One is composed of the floor slab (FS) at the top of the CB (FSTCB); the second is created with the FS within the panel depth (FSWCB), and the third is employed with the FS at the bottom of the CB (FSLCB). And, FEA is used to demonstrate the consequences of various CB positions with regard to the SL. Furthermore, the main measurements of structure response that have been investigated are deformation, shear, and moment in a coupled beam. Additionally, wall elements are used to simulate CB. In addition, ABAQUS software was used to figure out the strain distribution, shear stress for four stories to further understand the implications of slab position cases on the coupled beam rigidity. Overall, the findings show that the position of the rigid linkage among the CB and the FS can affect the behavior of the structures under seismic loads. For all structural heights (4, 8, 12 stories), the straining actions in FSWCB and FSLCB were less than those in FSTCB. And, the increases in displacement time history response for FSWCB are around 16.1-81.8%, 31.4-34.7%, and 17.5% of FSTCB.

• Journal of the Korean Society of Costume
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• v.30
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• pp.261-274
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• 1996

In the present age dominate by both cer-taingty of 1% and uncertainty of 99% 'Fuzzy thinking' of Bart Kosko that is the way to solve the problems by the scientific way through a worldview of Buddhism or Taoism greatly prevails around the world over 'Lateral greatly prevails around the world over 'Lateral thinking' and the authenticity or the right and-wrong of the uncertainty which is the thinking way to find the answer of the problems of illogical way of Edward de Beno against the western vertical thinking were Concurrently fashion designers over the world also adopt the oriental elements. But there exist differences of thoughts between the orient and the occident. And they have dif-ferent thinking way of aestheticism and references of the value on the beauty. Not only beauty but the view through the mind as intuitional thought in which not only the rec-ognition of sense but also the rationalism and the naturalness play key role. The aesthetic sense in the orient contains both the truth and virtue. 2) The beauty of the mean It's from the thought of neutralization of Confucius. The mean or moderation state which in harmony with ethical virtue and aes-thetic beauty is the ideal and is the ultimate. Therefore the thought of Confucian is the creativity in which the balance and the har-mony is most important. Fashion design is also one of the representation of the mean because the spirit of the designer is harmonized for-mlessly with the object of the model of the fashion design. 2) The beauty of skillfulness It indicates the Taoism of Lao-tzu and Chuangtzu. It takes a super-artistic declar-ation that human can feel and recognize the color of colorlessness the sound of sound-lessness and the taste of tastelessness. The thought of arts affected by Taoism is 'ad-vanced age' called the beauty of skillfulness. The view of arts of lao-tzu takes the beauty of cosmos and the nature as a standard. Es-pecially the beauty of inactivity is recognized by the linkage between the beauty and the ugliness. And these things appear in fashion design as a design element such as humor or exaggeration. 3) The beauty of non-dualism It is thought of Buddhism that all evil passions of worry occur form the opposition in dualism. Finally this thought leads to that everything is consistent and truth is only one from the point of view that virtue and vice has on linkage that is 'no virtues no vices' and 'one with two, two, with one, one is not two' A big tendency like this became the root forma-tion of the thought of the oriental arts. 3. Characteristics of the oriental aesthetic sense on the present fashion design 1) The formation of the fashion design on the oriental elements In the picture-incantation which was a representation of an era when the thought of 'cosmic dual forces' dominated the basic polygons of 'a circle square triangle' means both 'one two three' and 'the negative positive mean' of cosmic elements. From this point of view the was of planner cutting in the Orient is dif-ferent from that of the Occidental which is in three-dimensional. The planner polygon type of the cut-pieces comes to have the meaning of the three-dimension when they consist of a suit that has the combination of each cut-piece. This shows the consistency with the principle of cosmos creation of Taoism that one is two two is three and three is every-thing. 2) The coloring and the symbolic represen-tation of the fashion design on the orien-tal elements The sense on the colors in the Orient from the thought of 'the cosmic dual forces and the five elements' is not the experi-enced from the knowledge but contains the consideration of philosophy Five-primary-color representing compass directions Blue(East) Red(South) Yellow(Center) White (West) and Black (North) is called ' the posi-tive' for this five-primary-color secondary-color which comes from the compound of the primary colors is called 'the negative' The thought of 'the cosmic dual forces and the five elements' is also an theory containing the natural order of the cos-mos and this shows the perceptional differ-ence that they are not conceptual but to be recognized and fell directly. A thought of Buddhism which is 'Colors are colorlessness and Clolorlessness are color's proves that. 3) The pattern and symbolic representation of the fashion design on the oriental elements The pattern as a visual style is a figure of symbolic representation which adopt the mental and physical world of human and are the compo-sition of artistic revelation of the human nature and the religous thought of incantation. Es-pecially the symbolic representation of the oriental thought of Confusion. Buddhism and Taoism There are patterns such as plants aminals the oriental four gods and geometry. From the above it's the time toward the 21'th century when the world is constructing one global area and one historical zone. And the exotic mood of the Orient represented in the fashion which doesn't make the common feeling in general does not cease to develop only to express the visual modeling but also adopts the thought religion and the art which are the root of the Orientail and contains inherent willing of modeling.