• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.147-153
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• 2012

Multi-view 3D displays based on a limited number of pixels have the problem that the stereo-scopic image has a low resolution because of increasing view number. To solve the problem of low resolution, we propose an optical approaching method that focuses the width of a unit pixel by using a commercial spherical shape lenticular lens sheet and increases the effective resolution by increasing the number of sources of light in the multi-view 3D display system based on projection type. The method was performed in such an order that several main derivable parameters were defined, and, through the theoretical and experimental result, the value of the contractible unit pixel width and the scalable effective resolution was derived in a given system environment. As a result, for the case that the ray of light from the projector transmitted the 25 LPI lenticular lens sheet which has the pitch size 1.016 mm, the focused unit pixel width was 0.19 mm and the scalable effective resolution was, at most, 5 times wider than the original one. In addition, the range of depth of focus was 1.496 mm, which shows us the range of thickness tolerances of commercial spherical shape lenticular lens sheet and sufficient optical alignment tolerances.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.816-819
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• 2005

This paper proposes a coordinate correction technique using the transformation of 3D parabolic coordinate function and BP(Back Propagation) neural network in order to solve space distortion problem caused by using catadioptric camera. Although Catadioptric camera can obtain omni-directional image at all directions of 360 degrees, it makes an image distorted because of an external form of lens itself. Accordingly, To obtain transformed ideal distance coordinate information from distorted image on 3 dimensional space, we use coordinate transformation function that uses coordinates of a focus at mirror in the shape of parabolic plane and another one which projected into the shape of parabolic from input image. An error of this course is modified by BP neural network algorithm.

• Smart Structures and Systems
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• v.31 no.2
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• pp.101-111
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• 2023

Structural health monitoring (SHM) covers a range of damage detection strategies for buildings. In real-time, SHM provides a basis for rapid decision making to optimise the speed and economic efficiency of post-event response. Previous work introduced an SHM method based on identifying structural nonlinear hysteretic parameters and their evolution from structural force-deformation hysteresis loops in real-time. This research extends and generalises this method to investigate the impact of a wide range of flag-shaped or pinching shape nonlinear hysteretic response and its impact on the SHM accuracy. A particular focus is plastic stiffness (K_p), where accurate identification of this parameter enables accurate identification of net and total plastic deformation and plastic energy dissipated, all of which are directly related to damage and infrequently assessed in SHM. A sensitivity study using a realistic seismic case study with known ground truth values investigates the impact of hysteresis loop shape, as well as added noise, on SHM accuracy using a suite of 20 ground motions from the PEER database. Monte Carlo analysis over 22,000 simulations with different hysteresis loops and added noise resulted in absolute percentage identification error (median, (IQR)) in K_p of 1.88% (0.79, 4.94)%. Errors were larger where five events (Earthquakes #1, 6, 9, 14) have very large errors over 100% for resulted K_p as an almost entirely linear response yielded only negligible plastic response, increasing identification error. The sensitivity analysis shows accuracy is reduces to within 3% when plastic drift is induced. This method shows clear potential to provide accurate, real-time metrics of non-linear stiffness and deformation to assist rapid damage assessment and decision making, utilising algorithms significantly simpler than previous non-linear structural model-based parameter identification SHM methods.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.4
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• pp.657-675
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• 2020

This study suggests a direction for design development through an analysis of the experiential rental Hanbok design in Jeonju Hanok Village. As a research method, 268 outfit photographs of tourists wearing experiential rental Hanbok for women were collected as design analysis data from Jeonju Hanok Village. Frequency analysis was then performed by dividing into form, color, material·pattern, and detail. The controversy over the design of experiential rental Hanbok revolves around how and how much tradition is reflected. This is a very important part of the design analysis and development direction. If necessary, traditionality was discussed using the Hanbok style of the Joseon Dynasty as a standard. Development directions derived from the analysis are summarized as follows. First, avoid the distorted shape of skirts. Second, develop underwear for traditional silhouettes. Third, expand traditional colorations and avoid the excessive use of accent colors. Fourth, it is necessary to develop rental Hanbok materials with decorative features. Fifth, there is a need to design flat pattern construction for rental Hanbok that reflects a standardized production method and a changed aesthetics.

• Knowledge Management Research
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• v.18 no.2
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• pp.85-102
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• 2017

With rapid development of information and communication technologies, open collaboration can be eased through the Internet. Open source software, as a representative area of open collaboration, is developed and adopted to various fields. In this research, based on organizational learning theory, we examine the impacts of exploration and exploitation on innovation performance in open source software development projects. We define knowledge exploration as a number of developers from outside organization and knowledge exploitation as the ratio of member of an organization who participated in an open source software project managed by the organization. For analysis, we collect data of 4794 projects from github which is a representative open source software development platform using Web crawler developed by Python. As a result, we find that excessive exploration has curvilinear (invers U-shape) relationship on project performance. On the other hand, exploitation with enough external developers will positively impact on project performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.696-700
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• 2007

In case of dome-typed gymnastics training floor, since its form takes shape of the focus of sound, in the occasion when the finishing-material was used with the sandwich panel that prominent in reflexibility, and because the reverberation of sound in indoor is too loud, a smooth practice and teaching is very difficult. As this indoor gymnastics training floor, standing at its character, is required simultaneously the idea communication between the player and the coach, and the acoustic capability regarding to the clearness of music, besides the sport activity, the method to minimize the acoustic defect should be urgently contrived from the stages of design and beginning of construction. On this viewpoint, after investigation on the confidence of the surveyed value and the estimated value using acoustic simulation, and use of the changed finish-material, this thesis intends to design the dome-typed gymnastics training floor that secured the optimized acoustic condition. It is also considered that such result of the study could be utilized as the useful data that enables to improve the retrenchment effect of the construction cost as well as the acoustic performance, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• Journal of The Korean Digital Architecture Interior Association
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• v.13 no.4
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• pp.77-86
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• 2013

Uigwe is official reports of the Joseon dynasty. They published from early Joseon but remain from 17C. We can search many hidden informations in them. Ga-Jungjagak (temporary T-shaped house) is one of them. It is unique architecture of the Joseon dynasty but it doesn't exist now at all. We can see many drawings describing Ga-Jungjagak (temporary T-shaped house) located next to Jungjagak in Uigwe. Jungjagak (T-shaped house) was built in royal tombs for sacrifice. Ga-Jungjagak was built in royal tombs for sacrifice as Jungjagak but existed temporarily. In this study, I want to find the process of norms Ga-Jungjagak in old records, official reports and annals of the Joseon Dynasty. Results are as follows: Ga-Jungjagak is the sacrifice space for queens in royal tombs. It is need to avoid sacrifice of delight and sorrow at the same time. They sacrifice to represent sorrow after the death of kings and queens for three years. After three year, they sacrifice to represent delight for kings and queens became ancestral gods. Ga-Jungjagak was destroyed three years later to combined sacrifices. The shape of Ga-Jungjagak is similar to Jungjagak in the same tomb. But dimensions of Ga-Jungjagak are equal or smaller than Jungjagak and decorations are abstemious.

• Journal of Welding and Joining
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• v.11 no.1
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• pp.52-61
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• 1993

Laser welding of ASTM no. 1060 Al plate with a pulsed Nd: YAG laser of 200W average power was performed for end capping of KMRR nuclear fuel elements In this research, we performed basic welding experiments. Firstly, laser output parameters which affect laser welding parameters were studied by changing laser input parameters for effective welding of 1060 Al plates. We found that laser power density and pulse energy are important parameters for smooth bead shape. Secondly, welding parameters which affect weld width-to-depth ratio were studied by changing power density and pulse energy, shielding gas, and defocusing. We found that power density must be higher than 0.3 Mw/cm$^{2}$ pulse energy must be higer than 3 J. travel speed must not exceed 200mm/sec, laser focus must be existed beneath 2-3mm from plate surface and helium is proper shielding gas. Thirdly, we studied the weld defects of Al-1060 such as crack and porosity in lap-joint welding. We designed new welding geometry for crack free welding of Al-1060 plates, and obtained crack free weldment but with lack of fusion. However, with Ti, Zr grain refiner elements, we can weld Al plates without solidification hot crack. Finally, we studied the origin of porosity by changing shielding gas. And we found that porosity was resulted from entrapment of shielding gas by the collapsing keyhole.

• Journal of Fashion Business
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• v.19 no.4
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• pp.109-119
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• 2015

A wide variety of fashion materials focus on good drape property and softness. Among the recently emerging materials, Neoprene that consists of laminated knit on both sides of foamed neoprene sheet seeks a unique appearance that is considerably deviated from the current flow. Diverse processing methods for the newly released material heighten the value in function and beauty among trends of fashion materials by enhancing the appearance, touch and material property. Laser-cutting technique is one of the processing methods that is consistently used in the textile area. This study aimed to find the basic materials for applicability of laser-cutting technique to clothing goods after consideration of the changes in material property and drape shape, and to furthermore enforce different pattern conditions to Neoprene material, one of the newly attractive materials in the fashion area. In this study, we applied laser-cutting technique to Neoprene material sample under different conditions of pattern appearance, size and distance, based on current evaluation and theoretical background of Neoprene material, fashion trend and laser-cutting technique. Drape property can improve and the drape direction could also be controlled by a wide variety of laser-cutting techniques applied to Neoprene materials that have uniquely different appearances from most other textiles. This technique could be applied to the design for diversification of Neoprene clothing goods in the future.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.102-109
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• 2007

This is an analysis study about the pictorial frame of Georges Schwizgebel's animation "The Subject of Picture", focusing on Deleuze's frame theory. First of all, the shapes in the frame of the animation is the representation of the tactile sensation from the erased vestiges of the characters. It shows the metamorphosis of the erased vestiges of the shapes by Deleuze's sensibility theory. Besides, the layout of the animation's background has similar property with the aplat which was mentioned by Deleuze. It means that the background of the animation correspond to the aplat which is other boundary different from reality, and the character which has the minimum embodiment about the object makes the shape newly through the distortion of the shape. Secondly, as the problem of frames in terms of the continuity of time, the meaning in Schwizgebel's animation is created by the relation between each frame. It means that the depiction of the shape itself by the composition between each frame is composed of the frame. Eventually, Schwizgebel's work is the animation which has the characteristic of the modem cinema and is the crystal depiction that deviates from rules and logics of the object which was mentioned by Deleuze.