• Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.96-102
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• 2014

In the field of design and manufacturing, there are many problems with managing dynamic states of three-dimensional (3D) objects. In order to solve these problems, the four-dimensional (4D) mesh model and its modeling system have been proposed. The 4D mesh model is defined as a 4D object model that is bounded by tetrahedral cells, and can represent spatio-temporal changes of a 3D object continuously. The 4D mesh model helps to solve dynamic problems of 3D models as geometric problems. However, the construction of the 4D mesh model is limited on the time-series 3D voxel data based method. This method is memory-hogging and requires much computing time. In this research, we propose a new method of constructing the 4D mesh model that derives from the 3D mesh model with continuous rigid body movement. This method is realized by making a swept shape of a 3D mesh model in the fourth dimension and its tetrahedralization. Here, the rigid body movement is a screwed movement, which is a combination of translational and rotational movement.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.353-360
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• 2009

The principles for repair of bilateral cleft lip and nasal deformity are 1) symmetry, 2) primary muscular continuity, 3) proper philtral size and shape, 4) formation of the median tubercle and vermilion-cutaneous ridge from lateral labial elements, and 5) primary positioning of the alar cartilages to construct the nasal tip and columella. The authors underscore the essential role of preoperative premaxillary positioning for the synchronous closure of the cleft lip and primary palate, and describe Mulliken's operative technique. We discuss three-dimensional adjustments based on predicted fourth-dimensional changes. In a consecutive series of 50 patients, no revisions were necessary for philtral size or columellar length. Preoperative premaxillary positioning and primary repair of bilateral cleft lip and nasal deformity may impair maxillary growth. Nevertheless, a symmetric nasolabial appearance, rather than emphasis on maxillary growth, is the priority for the child with bilateral cleft lip.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.109-118
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• 2021

Due to changes such as those stemming from the onset of the fourth industrial revolution, it is expected that industrial complexes will transform from being spacious structures into smaller, integrated complexes. Green parks, which are also a type of infrastructure within industrial complexes, also require planned direction suited to the changing environment. The planned directions of green parks in new industrial complexes were examined and surveys were conducted on industrial complex workers. Preferred functional arrangement, importance, and satisfaction levels of green ratios, preference of compound facilities linked to parks, appropriate dimensional greening methods were all surveyed across 1,035 businesses. Results of the survey exhibited that there was high awareness on the importance of building green areas, but it was found that current greenery levels were insufficient. There was a high rate of responses indicated that dimensional greening is required in building-type industrial spaces, and preferences for rooftop greenery, stair-type greenery, and atrium greenery were also high. There were many opinions that it is necessary to integrate cultural facilities, exhibition and educational facilities, commercial facilities, parking lots in parks. Furthermore, it was found that it is necessary to provide pathways for bikes and pedestrians, rather than those for vehicles, and to connect them with the green parks. This study stopped short of exploring the directions for which green parks should aim in new industrial complexes with changes in the industrial environment. In the future, more concrete plans on green park planning techniques according to the spatial characteristics and structures of new industrial complexes will be necessary.

• Journal of the Korean Society of Costume
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• v.39
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• pp.99-111
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• 1998

Cubism has played a great role to change traditional concept of art and visual of people as developed into one of new art stlyes. It has avoided three dimensional perspectives and reformed the concept of time and space. It expresses objects with geometric shape by simplifying and reconstructing the objects after taking them apart. This has the effect of simultaneous vision and transparency and brings in collage by combining geometric image and visual elements. The results of the study as follows: First, the geometric shape expresses straight lines, curves, faces, and cubics by simplifying the objects. In fashion, it expresses circles, triangles, squares with a cloth. This shows visual changes as three dimensional space moves. Second, simultaneity disassembles and recontructs the objects. It tries to understand the internal shape with method of disassembling and makes visions coexist. In so doing, cubists adopt simultaneity for expressing shapes. In fashion, it expresses new items through disassembling or combining with other items. Third, transparency simplifies cubics by duplicating with transparent flats and crosses contour lines for reconstructing the simplified objects. This implies broader spatial order. It allows people to perceive penetration of layed clothes. Fourth, collage expresses geometric shape by adding visual elements(concrete image and color). It uses concrete image with paper, letters, cloth, etcs, which is not related to painting, and introduces various colors. In fashion, it uses dolls, postcards, feathers, metals, plastics, for patchwork.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.58-66
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• 2020

5G-based HMD technology grew rapidly in the context of the environment change of convergence technology media and mobile networks in the fourth industrial era. It has also grown into a core technology that transforms our digital visual system. However, there is no research or system that can understand and verify radical visual system changes. Therefore, it is necessary to have an engineering understanding and verification of the diffusion of HMD media imaging devices. Beyond the distinction between virtual and real, research is urgently needed on the new three-dimensional interface of the 21st century through viewer participation. For this reason, research on the algorithm structure of interactive video media using L-System is an essential process and will be a guide to understanding the virtual reality interactive environment.

• Structural Engineering and Mechanics
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• v.66 no.2
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• pp.249-262
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• 2018

In this paper, reaction of functionally graded (FG) thick nanoplates resting on a viscoelastic foundation to a moving nanoparticle/load is investigated. Nanoplate is assumed to be thick by using second order shear deformation theory and small-scale effects are taken into account in the framework of Eringen's nonlocal theory. Material properties are varied through the thickness using FG models by having power-law, sigmoid and exponential functions for material changes. FG nanoplate is assumed to be on a viscoelastic medium which is modeled using Kelvin-Voight viscoelastic model. Galerkin, state space and fourth-order Runge-Kutta methods are employed to solve the governing equations. A comprehensive parametric study is presetned to show the influence of different parameters on mechanical behavior of the system. It is shown that material variation in conjunction with nonlocal term have a significant effect on the dynamic deformation of nanoplate which could be used in comprehending and designing more efficient nanostructures. Moreover, it is shown that having a viscoelastic medium could play an important role in decreasing these dynamic deformations. With respect to the fresh studies on moving atoms, molecules, cells, nanocars, nanotrims and point loads on different nanosctructures using scanning tunneling microscopes (STM) and atomic force microscopes (AFM), this study could be a step forward in understanding, predicting and controlling such kind of behaviors by showing the influence of the moving path, velocity etc. on dynamic reaction of the plate.

• Journal of the Korean Society of Costume
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• v.64 no.3
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• pp.77-92
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• 2014

The purpose of this research is to examine the expression methods of Haute Couture designers' high value-added jacket designs, In order to achieve this, the positions and sizes of the design component items of tailored jackets designed by Haute Couture designers from the 1940s to the 1970s were analyzed. The results of the analysis are as follows. First, the silhouette changed while leading the contemporaneous fashions, and such changes could be confirmed by the width and length of the jacket's shoulder, chest, waist, and hem that determine the silhouette. Particularly, the length of the chest changed which signifies that the depth of the armhole was playing an important role in the production of high value-added jackets in relation to the sleeves and the fit of jackets. Second, the position and the size of the dart are the components that can express the fit of a jacket and the designer's creativity, The starting point position of the dart and the position passing by waist, and the position of the end of the dart were placed in the position beyond B.P. depending on the designer's creativity and techniques, deriving the changes of the silhouette and creating high value-added jackets. Third, the tailored collar, which was a three-dimensional component made up of the upper collar, gorge line, lapel, and break line, was an important component that could express high value-added jackets. Changes in the width and the height of the break line position of the sides of the neck were represented as changes in the neck size of the collar, and changes in the vertex locations of the upper collar corner-point, the gorge line (the corner-point of the lapel and V zone) were also represented as diverse tailored collar designs. And the differences in the width and the length of each component of the collar were related to each other and represented as changes in the slope and angle of the collar outline. Fourth, the changes in sleeve designs of the jacket were in such items as the width of the sleeve opening, the width of the sleeve hem, and the length of the sleeve, and were represented as diverse sleeve designs such as widened sleeve opening types, and straight line types.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.943-961
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• 2020

With the advent of IoT technology and Big Data computing, the importance of WSNs (Wireless Sensor Networks) has been on the rise. For energy-efficient and collection-efficient delivery of any sensed data, lots of novel wireless medium access control (MAC) protocols have been proposed and these MAC schemes are the basis of many IoT systems that leads the upcoming fourth industrial revolution. WSNs play a very important role in collecting Big Data from various IoT sensors. Also, due to the limited amount of battery driving the sensors, energy-saving MAC technologies have been recently studied. In addition, as new IoT technologies for Big Data computing emerge to meet different needs, both sensors and sinks need to be mobile. To guarantee stability of WSNs with dynamic topologies as well as frequent physical changes, the existing MAC schemes must be tuned for better adapting to the new WSN environment which includes energy-efficiency and collection-efficiency of sensors, coverage of WSNs and data collecting methods of sinks. To address these issues, in this paper, a self-organization scheme for mobile sensor networks with mobile multiple sinks has been proposed and verified to adapt both mobile sensors and multiple sinks to 3-dimensional group management MAC protocol. Performance evaluations show that the proposed scheme outperforms the previous schemes in terms of the various usage cases. Therefore, the proposed self-organization scheme might be adaptable for various computing and networking environments with big data.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.157-169
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• 2020

Objective: The aim of this retrospective study was to evaluate the pre- and postsurgical bone densities at alveolar and extra-alveolar sites following two-jaw orthognathic surgery. Methods: The sample consisted of 10 patients (mean age, 23.2 years; range, 18.0-27.8 years; 8 males, 2 females) who underwent two-jaw orthognathic surgery. A three-dimensional imaging program (Invivo 5) was used with multidetector computed tomography images taken pre- and postoperatively (obtained 32.3 ± 6.0 days before surgery and 5.8 ± 2.6 days after surgery, respectively) for the measurement of bone densities at the following sites: (1) alveolar bone in the maxilla and mandible, (2) extra-alveolar sites, such as the top of the head, menton (Me), condyle, and the fourth cervical vertebrae (C4). Results: When pre- and postsurgical bone densities were compared, an overall tendency of decrease in bone density was noted. Statistically significant reductions were observed in the densities of cancellous bone at several areas of the maxillary alveolar bone; cortical and cancellous bone in most areas of the mandibular alveolar bone; cortical bone in Me; and cancellous bone in C4. There was no statistically significant difference in bone density in relation to the depth of the alveolar bone. In a comparison of the bone densities between groups with and without genioplasty, there was almost no statistically significant difference. Conclusions: Accelerated tooth movement following orthognathic surgery may be confirmed with reduced bone density. In addition, this study could offer insights into bone metabolism changes following orthognathic surgery, providing direction for further investigations in this field.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.1
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• pp.68-75
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• 2019

This study aims to look at the application methods of landscape architecture in response to the 4th Industrial Revolution. The results of the analysis of trends in the 4th Industrial Revolution and the subsequent search for application methods to the field of landscape architecture are as follows. First, the 4th Industrial Revolution means innovative change based on digital technology and seeks to create value based on intelligent information technology, and continuous growth is being made through innovation. This requires expertise to collect large amounts of information and creatively rework it, and a strategy to flexibly cope with changes in the times. Second, the status of technological use in response to the 4th Industrial Revolution in the field of landscape architecture is generalizing the establishment of precise analysis results such as survey technology and global mapping using drones, three-dimensional design simulation, and VR. In the field of traditional landscape architecture, efforts are made to obtain accurate fact-finding data on landscape site components. Third, the application methods in the field of landscape science according to the 4th Industrial Revolution in the future are required to supply precision technology and supply programs in the technology sector, and to provide a shared platform. In addition, a systemically standardized process will need to be established for this. In addition, educational efforts should be continued to professional manpower training and provide economic support for the development of technologies.