• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.6
• /
• pp.409-415
• /
• 2021

Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

• Korean Journal of Construction Engineering and Management
• /
• v.4 no.4 s.16
• /
• pp.173-181
• /
• 2003

During the last few years, the use of Pre-tensioned spun high strength concrete piles(PHC pile) has been gradually increased in many construction sites. Cutting work of the concrete pile is an important task to crush a part of pile head which is compressed with more than 800$\cal{kg}f/cm^2$. It is usually performed by a crusher and three to four skilled workers. Recent analysis results of the pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose conceptual designs for developing an automated pile cutting machine. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.531-534
• /
• 2004

Cutting work of the concrete pile is an important task to chsh a part of pile head which is compressed with more than $800kgf/cm^{2}$. It is usually performed by a crusher and three to four skilled workers. llecent analysis results of the pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose the end-effector which can effectively break PHC Pile without any longitudinal cracks before developing an automated pile cutting machine having unified grinder and crusher parts. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• Proceedings of the KSME Conference
• /
• 2001.06c
• /
• pp.116-121
• /
• 2001

Verification of tool collision is an important issue in die and mold machining. In this paper three functions of verification are schematically explained based on Z-Map model. The first function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision. The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Those functions can be easily implemented by using several basic operators of Z-Map model which are explained also. Proposed approaches have enough accuracy to verify collision in reasonable computing time.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.6
• /
• pp.35-42
• /
• 2002

Verification of tool collision Is an important issue in die and mold machining. In this paper three functions of verification for 3-axis milling machining are schematically explained. Operators of geometric models are explained at first, which will be used in the functions of verification. The first verification function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Proposed approaches can be easily implemented by using several basic operators of geometric model. An example to calculate collision-free region is presented also.

• Korean Journal of Head & Neck Oncology
• /
• v.26 no.1
• /
• pp.19-23
• /
• 2010

Objectives : In parotidectomy, facial nerve dissection technique had been evolved for its safety. Surgical landmarks are important and good guides to facial nerve detection. Conventional exposure and release of the nerve requires hemostat for elevation of parotid tissue from nerve and #11 blade for cutting the parotid away from the nerve. Material and Methods : The rolling the parotid tissue over the nerve after dissecting with Metzembaum scissors instead of knife, lessen pulling trauma and nerve cutting by knife. Eleven superficial parotidectomies since June 2009 were done with rolling technique and preliminary report is presented. Results : Total 11 parotidectomies were done using proposed technique with tolerable complications(temporary facial dysfunction in 4 cases). Conclusion : Rolling method using metzembaum scissors could be applied to parotid operation.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.956-961
• /
• 2003

Recently, environmental pollution has become a significant problem in industry and many researches have been investigated in order to preserve the environment. Environmentally conscious machining and technology have more and more important position in machining process. In the milling process, the cutting fluid has greatly bad influence on the environment. In this study, the machining of blade parts(12Cr steel) using the cutting fluid, compressed cold air and oil mist etc., also, the productivity and the surface topography was improved by using new end-mil tool considering tool material and shape.

• Journal of Biosystems Engineering
• /
• v.22 no.2
• /
• pp.199-209
• /
• 1997

A one-pass rice whitener with hard metal blades was developed to solve the problems of the existing one-pass rice whitener. The developed one-pass rice whitener was tested and improved through various milling experiments. It showed high performance such as the capacity of 3.5 t/h, the energy consumption of $1.0 kWh/100kg$, milled rice recovery of 91.6%, broken rice rate of 2.2%, the crack rate of 1.9% at the 750 rpm of the roller shaft, compared with those other domestic and foreign one-pass rice whiteners. Especially, it could whiten broun rice of high moisture (16～l7%) with water sprayed at low internal pressure of less than $0.2 kg/cm^2$ and low temperature due to the characteristics of the cutting part composed of 24 hard metal blades. The developed one-pass rice whitener was industrilized and distributed to some rice processing complexs in one fourth price compared with that of imported one-pass rice whiteners.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.1140-1141
• /
• 2006

Diamond tools with several layers of diamond grits through thickness direction were tested by sawing. The saw blades with evenly distributed grits showed better cutting performance compared to the random distributed saw. At a given concentration of grits, as the spacing between layers was increased, the cutting performance was improved, and as decreased, it showed more tool life

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.3
• /
• pp.83-90
• /
• 2004

This paper proposes a tool path generation method for machining impellers with 5-axis machining center. The shape of impeller is complex, being composed of pressure surface, suction surface and leading edge, and so on. The compound surface which is made of ruled surface such as pressure surface and suction surface and leading edge such as fillet surface, makes the tool path generation much complicated. To achieve efficient roughing, cutting area is divided into two region and then tool radius of maximum size that do not cause tool intereference is selected for shortening machining time. In finishing, accuracy is improved using side cutting for blade surface and point milling for leading edge.