• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.60-65
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• 2008

For autumn field cutting of Sedum sarmentosum, the effects of cutting site (distal, middle, and proximal) and planting method (space drill seeding, drill seeding, and broadcast seeding) on survival rate and growth characteristics were investigated at pre- and post-winter season. Plant height root length, stem number per plant, number of branch per plant, fresh weight of shoot, and dry weight of shoot were significantly superior in distal site at pre-wintering (40 days after cutting). At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in cutting of distal site showed a significant increasement compared to the cutting of proximal site. At pre-wintering (40 days after cutting), the growth in space drill seeding was well than that in drill seeding and broadcast seeding, and fresh weight and dry weight per $m^2$ in space drill seeding were high in order of space drill seeding, broadcast seeding, and drill seeding. At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in space drill seeding were significantly increased than those in drill seeding. Accordingly, the cutting using distal site of stem in autumn field cutting was desirable for the growth and shoot yield. The space drill seeding showed the highest yield potential among three seeding methods, but broadcast seeding was favorable in saving of labor, because the fresh weight of shoot in broadcast seeding was similar in the space drill seeding at post-wintering.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.12
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• pp.1140-1145
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• 2008

In conventional cutting system of Heat-Shrink-Tube, workers operate cutting system after considering about length and quantity of heat-shrink-tube. So, not only work time and production cost is increased but also material is wasted because the data that workers have to consider is so much. In this paper, an effective cutting system of heat-shrink-tube was developed to reduce production cost, work time and waste of material. The cutting system consists of a supervisory computer installed inside a control room, a on-site computer installed on the work area, and a PLC system. In the developed system, a supervisory computer send work order to the on-site computer using LAN and the on-site computer operates the cutting system of the heatshrink-tube after it makes an array production order. Also, the on-site computer reports information to the supervisory computer when an accident happened.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.811-818
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• 2018

A fire and explosion accident caused by a liquefied petroleum gas (LPG) welding and cutting torch gas leak occurred 10 m underground at the site of reinforcement work for bridge columns, killing four people and seriously injuring ten. We conducted a comprehensive investigation into the accident to identify the fundamental causes of the explosion by analyzing the structure of the construction site and the properties of propane, which was the main component of LPG welding and cutting work used at the site. The range between the lower and upper explosion limits of leaking LPG for welding and cutting work was examined using Le Chatelier's formula; the behavior of LPG concentration change, which included dispersion and concentration change, was analyzed using the fire dynamic simulator (FDS). We concluded that the primary cause of the accident was combustible LPG that leaked from a welding and cutting torch and formed a explosion range between the lower and upper limits. When the LPG contacted the flame of the welding and cutting torch, LPG explosion occurred. The LPG explosion power calculation was verified by the blast effect computation program developed by the Department of Defense Explosive Safety Board (DDESB). According to the fire simulation results, we concluded that the welding and cutting torch LPG leak caused the gas explosion. This study is useful for safety management to prevent accidents caused by LPG welding and cutting work at construction sites.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.243-244
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• 2023

Noise, dust, etc. caused by road pavement cutting work, which frequently occurs in new construction or reconstruction of buildings, construction of complexes, etc., are environmental hazards and cause civil complaints. Recently, an eco-friendly pavement cutter is being developed to make the work low in noise and dust, however, the on-site cutting performance of the equipment has not been quantified. In this study, in order to derive a standard value for comparing the cutting performance of the eco-friendly cutter under development, a conventional pavement cutter was applied to four residential sites in Seoul and Gyeonggi-do, and the cutting data was collected. As a result of analyzing the collected data, the conventional pavement cutter showed a cutting performance of 12.3 to 20.2 sec/m, and the average was 27.2 sec/m. In the future, additional cutting experiments with various mixing ratios, materials, and depths are planned to confirm the performance of conventional pavement cutter in more detail.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.120-130
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• 1994

The leadwire cutting machine that has been used recently cuts leadwires by putting one-side force with the same priciple as a saw, and applies a stress at soldered part of PCB. Because the stress becomes one cause of contact-defect, a leadwire cutting robot that cuts leadwire-site with nipper and does not apply stress is considered, In this paper a technique of detecting leadwire-site is studied for the purpose of using on automatic leadwire cutting robots. A technique deriving 2-dimensional site-information with many I-dimensional binary data of perspective front-view of PCB taken from various direction was proposed. Simulation and experiments were done under the same condition each other and a small universal PCB was choosen as an experimental object. As a result of simulations and experiments, the proposed technique turns out to be very useful for automatic leadwire cutting robots.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.179-184
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• 1999

This study was conducted to clarify the differences in small mammal populations due to habitat structure caused by different forest practices within natural deciduous forests at National Forest, Pyoungchang, Kangwon Province, Korea from May to November, 1996. Three sites, 1ha each, were selected as cutting, thinning, and control for live trapping of small mammals. Total captures of small mammals in all sites were combined Apodemus peninsulae(45.1%, n=64) and Eothenomys regulus(54.9%, n=78). A. peninsulae was captured in the cutting and the control site. And E. regulus was captured in the thinning and the control site. The number of captured small mammals in a month were the highest in the control site and the lowest in the cutting site. A. peninsulae's mean body weight of adult individuals was more higher in the control site than in the cutting site. And E. regulus's mean body weight of adult individuals was more higher in the control site than in the thinning site. Habitat structure seems to be an important factor in abundance and species composition of small mammals.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.231-232
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• 2022

Pavement cutting work frequently occurs in new building construction, reconstruction, and complex construction, and this work causes a lot of noise and dust. Eco-friendly pavement cutters are being developed to reduce noise and dust in this work, however the on-site cutting performance of the equipment under development has not been quantified. In this study, the eco-friendly pavement cutter was applied to four residential areas in Seoul and Gyeonggi-do, and its cutting performance was quantified. As a result of the analysis, the eco-friendly pavement cutter showed cutting performance of 20.1~46.9sec/m, and the average was 33.5sec/m. In the future, we plan to conduct additional cutting experiments with various mixing ratios, materials, and depths to confirm the performance of eco-friendly road cutters in more detail.

• The KSFM Journal of Fluid Machinery
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• v.11 no.5
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• pp.50-56
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• 2008

Metal cutting operations involve generation of heat due to friction between the tool and the pieces. This heat needs to be carried away otherwise it creates white spots. To reduce this abnormal heat cutting fluid is used. Cutting fluid also has an important role in the lubrication of the cutting edges of machine tools and the pieces they are shaping, and in sluicing away the resulting swarf. As a cutting fluid, water is a great conductor of heat but is not stable at high temperatures, so to improve stability an emulsion type mixed fluid with water and oil is often used. It is pumped over the cutting site of cutting machines as a state of atomized water droplet coated with oil by using jet. In this paper, to develop cutting fluid supplying nozzle to obtain ultra thin oil film for coating water droplet, a numerical analysis of three dimensional mixed fluid Jet through multi-stage nozzle was carried out by using a finite volume method. Jet flow characteristics such as nozzle exit velocity, development of mixing region, re-entrance and jet intensity were analyzed. Detailed mixing process of fluids such as air, water and oil in the nozzle were also investigated. It is easy to understand complex flow pattern in multi-stage nozzle. Important flow Information for advance design of cutting fluid supplying nozzle was drawn.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.3
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• pp.95-102
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• 2013

It is indispensable to modern society metal processing since the industrialized rapidly, but it is a metalworking cutting fluid immediately. In addition, this means selecting a emulsion on the basis of quality criteria processing method, the material of the material, cutting depth, cutting speed, Djourou fence Liang, and surface roughness, cutting oil, the shape of the device based on the emulsion, I will be the structure of the tank, filtration equipment also changes. In particular, acting bacteria is now breeding in response to the passage of time due to metal ion degradation due to heat generated hydraulic fluid leakage, humidity tung, during processing, seep from processing material at the time of processing the water-soluble cutting oil for generating the malodor by dropping significantly the performance of the cutting oil to corruption from, sometimes by introducing various additives to suppress spoilage in advance. In this study, we expect the effect of the cost reduction in the extension of fluid replacement cycle through the application of the management apparatus and deep understanding in the management of cutting fluid, the working environment through the understanding and interest of workers in the production site more than anything I try to become useful for the improvement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.387-388
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• 2023

PHC pile head cutting is an essential work in pile foundation construction. However, since the work has labor-intensive characteristics, there are problems such as productivity and safety. So in previous study PHC pile one-cutting head cutting automation equipment was developed to solve this problem. However, it has been investigated as a limitation that checking the cutting position of the PHC pile can be challenging in place where a rotary laser leveler cannot irradiate cutting position, as the sensing unit of the developed automated equipment utilizes an optical method. Therefore, the objective of this study is to delvelop a GNSS-based methodology for sensing the cutting position of PHC piles to overcome the limitations of the optical method and to examine its feasibility for field application. If the proposed methodology is applied to the construction site, it is expected that the convenience and productivity of the PHC pile cutting position sensing work will be improved.