• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.62-65
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• 2003

VLM-ST process requires an additional human interaction due to the manual stacking and bonding. Hence, building time, building cost and the part quality are dependent on the skill of labor. In this present work, a novel rapid prototyping (RP) process, as an automatic VLM-ST (VLM-STA), has been proposed to improve building efficiency of VLM-ST process and reliability of products. The apparatus of VLM-STA is designed to embody the process. Several characteristics of the proposed process and the apparatus are discussed. In order to examine the efficiency and the applicability of the proposed process, various three-dimensional shapes, such as a piston and a human head shape, are fabricated on the apparatus.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.861_862
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• 2009

본 논문은 LCD 생산라인의 물류 자동화 시스템 중 OHS(Over Head Shuttle)을 분기가 되도록 하여, 이송 효율을 높이고, 이송거리를 단축시키기 위한 선형 이송시스템에 적용이 가능한 영구자석 여자 횡자속 선형 전동기 개발에 관한 내용이다. 3차원 FEM 해석과정특성 실험을 통해 전동기의 특성을 분석하여, 직선-곡선 레일과 분기구간에서 이송 가능한 횡자속 선형전동기 추진모듈의 사양을 결정하고 시작품을 설계, 제작하여 OHS 시스템 등의 이송시스템에 적용 가능한지 그 타당성을 검토하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1065-1066
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• 2007

본 논문은 LCD 생산라인의 물류 자동화 시스템 중 OHS와 같은 선형 이송시스템에 적용이 가능한 영구자석 여자 횡자속 선형 전동기 개발에 관한 내용이다. 3차원 등가 자기 회로망법을 이용한 해석과 정특성 실험을 통해 전동기의 특성을 분석하여, 직선-곡선부에서 이송 가능한 횡자속 선형전동기 추진모듈의 사양을 결정하고 시작품을 설계, 제작하여 OHS 시스템 등의 이송시스템에 적용 가능한지 그 타당성을 검토하였다.

• Geophysics and Geophysical Exploration
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• v.16 no.1
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• pp.27-35
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• 2013

In this study, we developed the trial product on 3D magnetic inversion tentatively named 'KMag3D'. Also, we briefly introduced its own function and graphic user interface on which especially focused through the development in the form of user manual. KMag3D is consisted of two fundamental frame for the 3D magnetic inversion. First, algebraic reconstruction technique was selected as a 3D inversion algorithm instead of least square method conventionally used in various magnetic inversion. By comparison, it was turned out that algebraic reconstruction algorithm was more effective and economic than that of least squares in aspect of both computation time and memory. Second, for the effective determination of the 3D initial and a-priori information model required in the execution of our algorithm, we proposed the practical technique based on the assemblage of 2D forward modeling and inversion results for individual user-selected 2D profiles. And in succession, initial and a-priori information model were constructed by appropriate interpolation along the strke direction. From this, we concluded that our technique is both suitable and very practical for the application of 3D magentic inversion problem.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.471-476
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• 2021

Soft magnetic composite (SMC) materials based on powder metallurgy have a number of advantages over the conventional electrical steel sheets commonly used in electric machines. Thus, technologies related to these materials have shown significant improvement in recent years. In general, SMCs are magnetically isotropic owing to the shape of the powder, which makes them suitable for the construction of electric machines with three-dimensional flux and complex structures. However, the materials with isotropic magnetic properties (such as SMCs) have complex vector hysteresis; thus, it is very difficult to predict accurate loss properties. Therefore, we manufactured ring-type specimens of electrical steel sheets and SMC, which analyzed their magnetic properties according to the specimen size, and performed the electromagnetic field analysis of a high-speed permanent magnet (PM) motor driven at 800 Hz or higher using the measured magnetic information to compare the core loss of the motor. The reliability of this paper has been verified by measuring the efficiency after manufacturing the motor.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.760-765
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• 2001

A new rapid prototyping process, as a transfer type of Variable Lamination Manufacturing by using expandable polystyrene foam (VLM-ST), has been developed to reduce building time, apparatus cost including the introduction and the maintenance and additional post-processing. The objective of this study is to propose a VLM-ST process and to develop an apparatus for implementation of the process. Design criteria of the apparatus were defined and the techniques were proposed to satisfy the design criterion. In order to examine the efficiency and applicability of the developed process, various three-dimensional shapes, such as a world-cup logo, a knob shape and a character, Son-o-kong, were fabricated on the apparatus in which unit shape layer (USL) was generated to build up each layer.

• Tunnel and Underground Space
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• v.26 no.3
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• pp.220-234
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• 2016

Sprayable waterproofing membrane has been considered as a substitute for a sheet waterproofing membrane in a variety of underground excavation works. However, fundamental properties of sprayble waterproofing membrane have not been fully given yet. In this study, a new two-component sprayable waterproofing membrane prototype was developed. In addition, its physico-mechanical properties were measured and compared with those of two kinds of thin spray-on liners where constitutive materials and construction methods are very close to each other. From direct tensile tests, the sprayable waterproofing membrane with elongations at break between 250% and 300% showed much higher ductility than TSLs. However, the sprayable waterproofing membrane had a limitation as a support member since its bond strength and loading capacity was lower than those of TSLs. From three-dimensional X-ray CT images, the porosity of the sprayable waterproofing membrane was estimated to be 26.13%. However, most of pores which might have been generated during membrane curing were not observed to be interconnected but isolated.

• (The)Study of the Eastern Classic
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• no.32
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• pp.311-362
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• 2008

This study aimed to make clear the education process, from antenatal training to early childhood education, of Joseon Royal Family. Centered on the successors to the throne and reviewed also the education of other Royal Family members, this study carried out comparative analysis on them. Antenatal training is pregnant woman's essential physical and mental attitude. It is indispensable to the health and good nature of unborn baby. Antenatal training had been based on the theory of Oriental medical science that fetus can sympathize what mother see and feel. Such theory, combined with Confucian self-culture theory, had taken very important position in Confucianism. Not to speak of Royal Family, noble family regarded antenatal training very essential as beginning of education and root of nature formation. For firstborn son and firstborn grandson, Boyangcheong (輔養廳, special nursery agency) was set up before their age became three, but not for other sons and grandsons of Royal Family. When firstborn son or firstborn grandson grew up to read letters, Ganghakcheong (講學廳) was set up for their early education. Other sons of king also learned in their early ages at Ganghakcheong while other grandsons of king learned at Gyohakcheong (敎學廳). Education courses were almost same between successors and non-successors but there were wide difference in the ranks of their tutors; firstborn son's tutor marked 2nd Jeong(正) class, firstborn grandson's tutor marked 2nd Jong(從) class and other royal sons' tutors were just 9th Jong(從) class.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.10-15
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• 2017

Research interest has strongly focused on developing a method for effectively transmitting bio-signals over a distance using a wireless wearable device. In this paper, we describe a procedure for the design and fabrication of a wearable antenna based on embroidering conductive threads to clothing capable of transmitting electrocardiogram signals. 3D electromagnetic simulation software and embroidery software were used to design and fabricate the conductive thread-based antenna, respectively. The measurement results show that the reflection coefficient of the fabricated antenna prototype exhibits excellent antenna impedance matching characteristics of less than -10dB in the Zigbee 2.4GHz frequency band. We also verified that the electrocardiogram data could be effectively received and monitored in real-time by a receiver 220m away from the transmitter.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.109-119
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• 2004

Rapid prototyping (RP) technologies have been widely used to reduce the lead-time and development cost of new products. $VLM-_{ST}$ process has been developed to overcome the currently developed RP technologies such as a large building time, a high building cost, an additional post-processing and a large apparatus cost. $VLM-_{ST}$ process requires an additional human interaction due to the manual stacking and bonding. Hence, building time, building cost and the part quality are dependent on the skill of labor. A novel RP process, fully automated $VLM-_{ST}$ process ($VLM-_{ST}$), has been developed to improve building efficiency of the process and the human dependency of the part. The objective of this work is to propose a $VLM-_{ST}$ process and to develop an apparatus for implementation of the process. $VLM-_{ST}$ process and its apparatus have various technical novelties such as two step cutting using a rotating table, an automatic stacking method using two pilot holes and two reference shapes, a concept of automatic unit shape layer (AUSL), and an automatic bonding using the bonding roller and building magazine. In order to examine the efficiency and the applicability of the proposed process, various three-dimensional shapes, such as a piston, a human head shape and a human bust shape, were fabricated on the apparatus.