• Fashion & Textile Research Journal
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• v.23 no.2
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• pp.237-246
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• 2021

This study aims to analyze short sleeve cycling tops from three brands for a change in garment fit and pressure depending on the static and cycling postures. To this end, it used a 3D virtual garment system to virtualize the garments. Further, a cross-section of the 3D virtual garment data was obtained, and the space length was measured in the design-X program to prove the objectivity of the 3D virtual garment. The results indicated that three brands had a large space length at the front than the back because of the bent posture in cycling. Therefore, appropriate ease was required for the waist and abdomen. Although there were various cutting lines of the bodice panel by brand, the design of the cutting lines should consider the changes in the surface to reflect the bent posture in cycling. The results of this experiment confirmed that the wrinkles present in the 3D virtual garment were reflected in the cross-section and that the space length was small in the high-stress area, as shown in red. Therefore, it was proven the stress of the 3D virtual garment could be used for 3D virtual garment evaluation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.393-396
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• 2000

Spent fuel rod cutting device should cut a spent fuel rod to an optimal size in order to fast decladding operation. In this paper, for developing spent fuel rod cutting device with cutter blade, rod properties such as dimension and material of zircaloy tube and fuel pellet are investigated at first and then, various methods of existing cutting devices used commercially are investigated and their performance are analyzed and compared. This device is designed to be operated automatically via remote control system considering later use in Hot-Cell (radioactive area) and the mdularization in the structure of this device makes maintenance easy. SUS and Zircaloy-4 are selected as cut material used in the test of spent fuel rod cutting device by cutter blade. In order for constructing the high durable cutter blade, various materials are analyzed in terms of quality, shape, characteristic, and heat treatment, etc. and from these results, spent fuel rod cutting device is designed and manufactured based on the considerations of durability, round shape sustainability of rod cross-section, debris generation, and fire risk, etc.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.20-24
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• 2010

High speed cutting processes of rigid flexible printed circuit board by making use of high power UV laser with nano-second pulse width have been proposed and investigated experimentally. Also robust laser cutting system has been designed and developed in order to obtain a good cutting quality of rigid and flexible PCB with multi-layers (2-6 layers). Power controller module developed for ourselves is adapted to control the laser output power in the range less than 1%. The systems show the good performance of cutting speed, cutting width and cutting accuracy, respectively. Especially we have confirmed that the short circuit problem due to the carbonized contamination occurred in cross section of multi-layers by thermal effect of high power laser has been improved largely by using multi-pass cutting process with low power and high speed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.119-127
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• 2000

This paper describes the database for wire cutting electrodischarge conditions and variable taper wire-cut Machining. Electodischarge wire-cut machining is applicable to all materials that are fairly good electrical conductors, including metals, alloys, and most carbides. Thus it provides a relatively simple method for making holes of any desired cross section in materials that are too hard or brittle to be machined by most other methods. In conventional wire cutting CAM systems usually generate the NC code omitting electrodischarge conditions, so operator edits the NC code manually. But it is very inefficient. Therefore in this paper we propose a wire cutting CAM system including database for electrodischarge conditions. Proposed system consists of three steps: 1) Development of database for electrodischarge conditions 2) Development of CAM functions, Including 2D CAD modeling tools, file I/O functions, wire path genera tion functions and postprocessor. 3) Development of variable taper wire-cut machining module. The proposed system has been tested in the JinYoung precision Machine Co.,LTD. and found to be working satisfactorily.

• Journal of the Korean institute of surface engineering
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• v.35 no.2
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• pp.122-128
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• 2002

This study was conducted to synthesize the diamond like carbon films by plasma enhanced chemical vapor deposition (PECVD). The effects of gas composition on growth and mechanical properties of the films were investigated. A little amount of hydrogen or oxygen were added to base gas mixture of methane and argon. Methane dissociation and diamond like carbon nucleation were enhanced by installing negatively bias grid near substrate. The deposited films were indentified as hard diamond like carbon films by micro-Raman spectroscopy. The surface and fractured cross section of the films which were observed by scanning electron microscopy showed that film growth is very slow as about 0.3$\mu\textrm{m}$/hour, and relatively uniform with hydrogen addition. Vickers hardness of tungsten carbide (WC) cutting tool increased from about 1000 to 1600~1800 by deposition of DLC film, that of commercial TiN coated tool was about 1270. In cutting test of aluminum 6061 alloy, DLC coated cutting tool showed 1/3 or lower crater and flank wear than TiN coated or non-coated WC cutting tools.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.9-14
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• 1996

The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of radial cross sections of tile helical end mill is calculated for the determination of the relation between cross section and rigidity of tile tools. Using tile Bernoulli-Euler beam and and the concept of equivalent diameter, a deflection model is established, which includes most influence from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.2
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• pp.3-9
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• 2005

In this study, the chip breaking characteristics of S, PbS and BiS free machining steels have been assessed. PbS free machining steel shows the lowest value of chip thickness ($t_c$) under the same cutting conditions. SM10C steel has the largest value of the chip cross-section area ratio ($R_{CA}$). As the feed rate becomes larger the chip breaking cycle time ($T_B$) decreases and the chip breaking index ($C_B$) increases. The properly controlled-C type chip has been obtained with the value of $C_B$ between 0.05 and 0.2. Free machining steel, PbS produces the properly controlled-C type chip in a wider feed rate range than other steels.

• Composites Research
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• v.28 no.4
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• pp.204-211
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• 2015

This paper presents a theory related to a two-dimensional linear cross-sectional analysis, recovery relationship and a one-dimensional nonlinear beam analysis for composite wing structure with initial twist. Using VABS including a related theory, the design process of the composite rotor blade has been described. Cross-sectional analysis was performed at cutting point including all the details of geometry and material. Stiffness matrix and mass matrix were linked to each section to make 1D beam model. The 3D strain distributions within the structure were recovered based on the global behavior of the 1D beam analysis and visualize numerical results.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.104-109
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• 1988

A field experiment was conducted in order to investigate the seasonal changes of leaf grwoth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased in a nearly linear phase during first and third cutting stages. It was increased slowly in early 10 days to 15 days after cutting and increased rapidly there-after during the rest cutting stages. In cultivars, Potomac was showed higher leaf elongation than other cultivars during all cutting stages. There was no difference of leaf width within cutting stages, but the leaf width of fall regrwoth was narrow. Sumas had relatively short and wide leaves. 2. Leaf dry weight and leaf area in first cutting stage were larger than others. Leaf area was increased rapidly form 15 days after cutting and leaf weight was increased rapidly from 20 days over all cutting stages. The increase in leaf area and dry weight were slow down after 30 days. 3. Number of epidermal cells was increased rapidly after cutting and the rate of increase was slow down after 30 days. In a cross section of leaf tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissues. Leaf tissue had a large vacancy at early growth period after harvest and was filled gradually with mesophyll. This result was related to the increase of leaf dry matter.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.213-223
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• 2011

Recent cross-country competition and Chinese steel industry because of the emerging steel industry in Korea is a very difficult situation. Therefore, the steel industry in order to overcome this difficult market environment, the quality, cost competitiveness, enhance customer service levels and enhance international competitiveness through is needed. In this study, the purpose of strengthening the competitiveness of steel companies in order and hit the recovery of raw materials have been developed to optimize the model, developed before and after the results were analyzed. In addition, when applied to other products in order to minimize risk and optimize cutting trial stage of development details of the model is presented in detail. Therefore, the developed model was applied to order the recovery of raw materials hits and significantly improved production planning time has been shortened dramatically. In the present study the contents of other products when properly applied and the competitiveness of companies to improve customer service levels are expected to be helpful.