• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.19-23
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• 2023

The Second-generation high-temperature superconducting (HTS) Rare-Earth Barium Copper Oxide (REBCO) wire is a composite laminate having a multi-layer structure (8 or more layers). HTS wires will undergo multiple loads including the bending-tension loads during winding, high current density, and high magnetic fields. In particular, the wires are subjected to bending stress and magnetic field stress because HTS wires are wound around a circular bobbin when making a high-field magnetic. Each of the different laminated wires inevitably exhibits damage and fracture behavior of wire due to stress deformation, mismatches in thermal, physical, electrical, and magnetic properties. Therefore, when manufacturing high-field magnets and other applications, it is necessary to calculate the stress-strain experienced by high-temperature superconducting wire to present stable operating conditions in the product's use environment. In this study, the finite element model (FEM) was used to simulate the strain-stress characteristics of the HTS wire under high current density and magnetic field, and bending loads. In addition, the result of obtaining the neutral axis of the wire and the simulation result was compared with the theoretical calculation value and reviewed. As a result of the simulation using COMSOL Multiphysics, when a current of 100 A was applied to the wire, the current value showed the difference of 10^-9. The stress received by the wire was 501.9 MPa, which showed a theoretically calculated value of 500 MPa and difference of 0.38% between simulation and theoretical method. In addition, the displacement resulted is 30.0012 ㎛, which is very similar to the theoretically calculated value of 30 ㎛. Later, the amount of bending stress by the circular mandrel was received for each layer and the difference with the theoretically obtained the neutral axis result was compared and reviewed. This result will be used as basic data for manufacturing high-field magnets because it can be expanded and analyzed even in the case of wire with magnetic flux pinning.

• Journal of Advanced Navigation Technology
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• v.26 no.2
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• pp.63-71
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• 2022

Barometers have been used to calculate altitude, and with the development of technology, barometer which had a large volume have now been reduced to about centimeter-level. The altitude calculation using barometer is proceeded using the relationship between reference sea level pressure and the pressure obtained by barometer, and for this, pre-calibration of the barometer is essential. In addition, the barometer has a certain level of bias from actual pressure due to production, and many smartphone manufacturers correct it during the manufacturing process, but it is difficult to correct errors caused by environmental variables. In this paper, we extended methodology of correcting barometer using static reference station to moving drone, and it was possible to calculate the altitude more accurately.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.663-670
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• 2018

H13 tool steels are widely used as metallic mold materials due to their high hardness and thermal stability. Recently, many studies are undertaken to satisfy the demands for manufacturing the complex shape of the mold using a 3D printing technique. It is reported that the mechanical properties of 3D printed materials are lower than those of commercial forged alloys owing to micropores. In this study, we investigate the effect of microstructures and defects on mechanical properties in the 3D printed H13 tool steels. H13 tool steel is fabricated using a selective laser melting(SLM) process with a scan speed of 200 mm/s and a layer thickness of $25{\mu}m$. Microstructures are observed and porosities are measured by optical and scanning electron microscopy in the X-, Y-, and Z-directions with various the build heights. Tiny keyhole type pores are observed with a porosity of 0.4 %, which shows the lowest porosity in the center region. The measured Vickers hardness is around 550 HV and the yield and tensile strength are 1400 and 1700 MPa, respectively. The tensile properties are predicted using two empirical equations through the measured values of the Vickers hardness. The prediction of tensile strength has high accuracy with the experimental data of the 3D printed H13 tool steel. The effects of porosities and unmelted powders on mechanical properties are also elucidated by the metallic fractography analysis to understand tensile and fracture behavior.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.255-261
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• 2015

This paper aimed to analyze the factors affecting on the implementation of supply chain management (SCM) system of manufacturing company in Korea. For preparation of the data for this research, the Internet-based questionnaires with 5 Likert's scale were performed to the 125 manufacturing companies in Korea. The affecting factors on the implementation of SCM system were crystallized through factor analysis methods. And the correlations between factors were analyzed with structural equation model (SEM). The factors affecting on the implementation of SCM system are company's IT-competence and relationship with supply chains. This paper could contribute to show the guideline for the successful implementation of SCM system to the korean manufacturing company.

• Fashion & Textile Research Journal
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• v.19 no.3
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• pp.259-266
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• 2017

In a contemporary fashion along with the advance of high technology, development of a new material is being increasingly emphasized and the need of creative convergence using a computer is being expanded. As a global designer who appeared through association between Japan and the West, Issey Miyake has been continually pursuing a new challenge and a solution using high technology, leading the globalization of Japanese fashion. This research aims at examining design characteristics of Issey Miyake collection's A-POC showing a new paradigm, that is, an innovative clothing manufacture system to input information on materials, colors and shapes into a textile machine based on the computer program and manufacture a cylindrical fabric for completion of seamless clothing without sewing or cutting. A-POC is evolving continually through the development of new materials including recycled fibers and organics together with diversification of processing technology. Besides, it shows design characteristics including an integrated manufacturing method, autonomy for customers' selection, practicality for comfortable wearing by the majority, environment friendly idea to reduce waste of fabrics and materials and a new presentation through convergence of exhibition concepts of modern art. This research on Issey Miyake's A-POC characteristics is expected to present a role of fashion designers in a new design idea and paradigm of contemporary clothing using high technology.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.4
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• pp.250-258
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• 2015

In this research, we proposed a new approach to implement the real-time motion control of biped robot based on voice command for unmanned FA. Voice is one of convenient methods to communicate between human and robots. To command a lot of robot task by voice, voice of the same number have to be able to be recognition voice is, the higher the time of recognition is. In this paper, a practical voice recognition system which can recognition a lot of task commands is proposed. The proposed system consists of a general purpose microprocessor and a useful voice recognition processor which can recognize a limited number of voice patterns. Given biped robots, each robot task is, classified and organized such that the number of robot tasks under each directory is net more than the maximum recognition number of the voice recognition processor so that robot tasks under each directory can be distinguished by the voice recognition command. By simulation and experiment, it was illustrated the reliability of voice recognition rates for application of the manufacturing process.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.148-153
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• 2021

During the manufacture of a ZnS lens with excellent transmittance in the mid-infrared region (3-5 ㎛) by the hot-press process, a single-layer sintering method is used in which one lens is manufactured in one process. Additional research is required to improve this single-layer sintering method because of its low manufacturing efficiency. To solve this problem, the variation in optical properties of ZnS lenses with change in sintering temperature was investigated by introducing a Stack sintering method that can sinter multiple lenses simultaneously. A carbon paper was placed between the molded lenses and sintered into five layers. The average permeability of 67% at medium infrared wavelengths of 3-5 ㎛ was excellent under the following sintering conditions: pressure of 50 MPa and temperature of 850℃. This value is 1% less than the average permeability in the case of single-layer sintering of the ZnS lens. It was confirmed that the stack sintering method developed in this study can be used to manufacture a large number of lenses with excellent characteristics in a single process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.1
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• pp.7-14
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• 2023

Forty Viscosity data of glass bottles fabricated in a glass bottle manufacturing plant for 4 years were calculated using Lakatos model. The relationship between the glass bottle compositions and viscosities at log η of 3, 6.6, 10 and 12.3 Pa·s was analyzed. MgO that was a component of the glass bottle showed the maximum coefficient of variation of 0.89, but it gave a very small change in the viscosity. CaO that was another component of the glass bottle lowered the isokom temperature because it tended to reduce the number of non-bridging oxygen at temperature below a softening point.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.175-184
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• 2021

The purpose of this study is to investigate the effect of the strategic role of the human resources department in the manufacturing industry on organizational effectiveness through education and training satisfaction. Among the data from the 7th human capital company panel survey, data from the manufacturing industry were used and analyzed through a structural equation model. The results of this study are as follows: First, the strategic role of the HR department has a positive effect on satisfaction with education and training. Second, satisfaction with education and training and the strategic role of HR departments have a positive effect on job satisfaction among organizational effectiveness. Third, it was confirmed that education and training satisfaction has a mediating effect on the relationship between the HR department's strategic role and job satisfaction. The results of this study are expected to become the basis for expanding the authority and responsibilities of the HR department, which is an important factor in overcoming the crisis faced by SMEs as well as innovation, and redefining their role.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.1-9
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• 2020

In highly complex EPC(engineering, procurement, construction)-based manufacturing processes such as shipbuilding and marine plants, it is essential to prepare a way to enable organic working at the site referring to each other's detailed working data for collaboration between partner companies. However, companies cannot share the progress of the sites including working information in real-time due to the use of SW unique to each company and the complex site management system. As a result, the construction process is delayed, and resources are used inefficiently. This study developed a neutral data generation algorithm that can apply the working information in various file formats to a collaborative manufacturing process. In addition, this study verified the accuracy of the algorithm by applying the developed algorithm to the manufacturing process of piping in shipbuilding and marine plants, developing the SW for visualization of working information using the generated neutral data, and comparing the coordinate, shape & dimension and the kind, number, and spec. of BOM. The result confirmed that the accuracy of the coordinate of the neutral data was 99%, and that of the shape & dimension of the neutral data and BOM Spec. was both 100%. It is thought that this study can be used for overcoming the restrictions in information sharing due to the development of informatization at companies and maximizing the share of working file information in a complex manufacturing process.