• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.172-175
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• 2002

High speed machining is one of the most effective technologies to improve productivity. It can give great advantage for manufacture of die and Moulds. However, when machining of micro groove in high speed machining a severely thermal damage was generated on workpiece and cutting tool. Generally, the cutting fluid is used to improve penetration. lubrication. and cooling effect. In order to rise the performance of lubrication. it contains extreme pressure agents (Cl, S, P). But the environment of work room go bad by those additive. Therefore, the compressed chilly air with oil mist system was developed to replace the conventional cutting fluid system. This paper carried out the tests to evaluate the machinability by the cutting environment in high speed micro groove machining of NAK80 (HrC40). Compressed chilly air with oil mist was ejected on the contact area between cutting edge and workpiece. The effect of this developed compressed chilly air with oil mist system was evaluated in terms of tool life. The results showed that the tool lift of carbide tool coated TiAlN with compressed chilly air mist cooling was much longer than that of the dry and flood coolant when cutting the material.

• Journal of Powder Materials
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• v.24 no.5
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• pp.400-405
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• 2017

The addition of a large amount of alloying elements reduces the compactibility and increases the compacting pressure, thereby shortening the life of the compacting die and increasing the process cost of commercial PM steel. In this study, the characteristic changes of Fe-Mo-P, Fe-Mn-P, and Fe-Mo-Mn-P alloys are investigated according to the Si contents to replace the expensive elements, such as Ni. All compacts with different Si contents are fabricated with the same green densities of 7.0 and $7.2g/cm^3$. The transverse rupture strength (TRS) and sintered density are measured using the specimens obtained through the sintering process. The sintered density tends to decrease, whereas the TRS increases as the Si content increases. The TRS of the sintered specimen compacted with $7.2g/cm^3$ is twice as high as that compacted with $7.0g/cm^3$.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.203-208
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• 2008

Recently, the modern society in development and industrial growth is investing a lot of time and much effort to improvement and environment of life quality. Thus, the casting tape which uses environmentally friendly and human body friendly water hardening process Polymer is rapidly substituted for the gypsum cast product which has been plentifully used in medical treatment. Until currently, prior researches have a tendency to focusing the analysis about chemical creation expense and reaction quality rather than the issue about optimization of the process for this polymerization. In the polymerization process which has been accomplished with actual same chemical creation expense, there has been a problem which is the possibility of getting a different result. This is because the optimization of respectively control factors is not accomplished which affect at polymerization process. Therefore, this research sees the chemical qualities of casting tape Polymer, consequently selects the polymerization process which is suitable. And, by using a experimental design, this research will evaluate the affects which the respective factors have on remaining NCO and viscosity. futhermore, this research will carry out the process optimization which can get the above results.

• Transactions of Materials Processing
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• v.18 no.1
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• pp.26-38
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• 2009

It was reported that the semi-solid forming process has many advantages over the conventional forming process, such as a long die life, good mechanical properties and energy savings. It is very important, however, to control liquid segregation to gain mechanical property improvement of materials. During forming process, rheology material has complex characteristics, thixotropic behavior. Also, difference of velocity between solid and liquid in the semi-solid state material makes a liquid segregation and specific stress variation. Therefore, it is difficult for a numerical simulation of the rheology process to be performed. General plastic or fluid dynamic analysis is not suitable for the behavior of rheology material. The behavior and stress of solid particle in the rheology material during forging process is affected by viscosity, temperature and solid fraction. In this study, compression experiments of aluminum alloy were performed under each other tool shape which is rectangle shape(square array), rectangle shape(hexagonal array), and free shape tool. In addition, the dynamics behavior compare with Okano equation to power law model which is viscosity equation.

• Korean Journal of Hospice Care
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• v.7 no.2
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• pp.26-41
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• 2007

There are three things that are not known to the human being. That is when, where and how one will die. Most people live ignoring death. However, elements of death linger everywhere. The purpose of this treatise is investigates about justification Deciding for Other directions. First, I will investigate about Deciding for Other directions, when patient can not decide own, I will do investigate agent's decision's problem. Second, These four principles provide the common ground for biomedical ethics. Principlism argue that a method using four principles can resolve controversies in bioethics. The method holds that there are four principles-respect for autonomy, nonamleficence, beneficence, justice- that articulate the necessary conditions of common morality for health care and bioethics. Beauchamp and Childress respond by arguing that the two problems are nc the meaning or interpretation but the process of specification. Third, So, Supplement four principles' problem to Levinas concept of the Other theory. Levinas concept of the Other is very resemblant with 'Love your neighbour as yourself." Christians believe that Love is above all and they act accordingly. They base this faith mainly upon the motto of "love your neighbour as yourself." Fourth. difficult part of Levinas concept of the Other is that there is no human to equal infinite sense of responsibility. Can be supplemented about this through cooperation of community. Four principles can be brought to bear on moral choices. And they asserts that each principles has weigh but they do not assign a priority weighting of ranking. All the principles are equal in moral decision making.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.138-143
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• 2005

Finite Element analysis is widely applied to elevated temperature forging processes and shows a lot of information of plastic deformation such as strain, stress, defects, damages and temperature distributions. In highly elevated temperature deformation processes, temperature of material and tool have significant influence on tool life, deformation conditions and productivities. To predict temperature related properties accurately, adequate coefficients of not only contact heat transfer between material and dies but also convection heat transfer due to coolants are required. In most F.E analysis, too higher value of contact heat transfer coefficient is usually applied to get acceptable temperature distribution of tool. For contact heat transfer coefficients between die and workpiece, accurate values were evaluated with different pressure and lubricants conditions. But convection heat transfer coefficients have not been investigated for forging lubricants. In this research, convection heat transfer coefficients for cooling by emulsion lubricants are suggested by experiment and Inverse method. To verify acquired convection and contact heat transfer coefficients, tool temperature was measured for the comparison between measured tool temperature and analysis results. To increase analysis accuracy, repeated analysis scheme was applied till temperature of the tool got to be in the steady-state conditions. Verification of heat transfer coefficients both contact and convection heat transfer coefficients was proven with good accordance between measurement and analysis.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.3 no.1
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• pp.4-14
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• 2003

Maple syrup urine disease or branched chain ketoacidurias caused by a deficiency in activity of the branched-chain ${\alpha}$-keto acid dehydrogenase(BCKD) complex. This metabolic block results in the accumulation of the branched-chain amino acids(BCAAs) leucine, isoleucine and valine, and the corresponding branched chain ${\alpha}$-keto acids (BCKAs). Based on the clinical presentation and biochemical responses to thiamine administration, MSUD patients can be divided into five phenotypes : classic, intermediate, intermittent, thiamine responsive and dihydrolipoyl dehydrogenase(E3)-deficient. Classic MSUD has a neonatal onset of encephalopathy, and is the most severe ad most common form. Variant forms of MSUD generally have the initial symptoms by 2 years of age. The majority of untreated classic patients die within the early months of life from recurrent metabolic crisis and neurologic deterioration. Treatment involves both longterm dietary management and aggressive intervention during acute metabolic decompensation. We report here our experience of longterm diet therapy and treatment of acute metabolic decompensation of a case of classic MSUD.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.5
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• pp.224-229
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• 2019

PVD coating is a technology that can be applied to various industries, and is widely used for processing molds and machinery, improving performance of core parts, and extending the life. Therefore, there is a need for a research on a device and a process technology that can adjust the performance to suit each application. In this study, a PVD coating device with ion density control was used to deposit a coating layer on SKD 11, a cold die steel, with magnetron currents of 1 A, 2 A, 3 A at arc currents of 80 A, 100 A, 130 A. It examined the mechanical properties for each condition. Increasing the arc current and magnetron current could improve the thickness, adhesion, and hardness of the coating layer. Especially, When the magnetron current was high, it suppressed the droplets that could be generated by the high arc current, showing excellent surface uniformity and adhesion of the coating layer.

• The Korean Journal of Emergency Medical Services
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• v.23 no.1
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• pp.165-178
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• 2019

Purpose: This study examined medical college students' perception of euthanasia and analyzed whether there were significant differences in their perceptions based on their grade, religion, and economic situation. Methods: A questionnaire comprising items relating to students' knowledge about euthanasia, their economic situation relationships with patients, and the extent to which euthanasia would be allowed depending on the patient's condition. Results: Results by age and school year revealed there were no statistically significant differences concerning permissible levels of euthanasia. However, differences were found in the permissible levels of euthanasia according to changes in the patients' condition. Conclusion: It can be interpreted that students' personal values and religion had a great effect on the perception of euthanasia than the process of acquiring medical knowledge. The religion or values they have in your life affect your perception of euthanasia more than the process of acquiring and learning medical knowledge. The suffering of patients is the most important priority and it supports euthanasia on the grounds of relieving psychological distress for patients' families and the right of every patient to die gracefully. Nevertheless, considering the possibility of patient survival and euthanasia being used for murder, it is necessary to legislate the use of euthanasia and have the appropriate qualifications for its administration on patients.

• Korean Journal of Materials Research
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• v.31 no.11
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• pp.601-607
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• 2021

Laser cladding a surface treatment process that grants superior characteristics such as toughness, hardness, and corrosion resistance to the surface, and rebuilds cracked molds; as such, it can be a strong tool to prolong service life of mold steel. Furthermore, compared with the other similar coating processes - thermal spray, etc., laser cladding provides superior bonding strength and precision coating on a local area. In this study, surface characteristics are studied after laser cladding of low carbon steel using 18%Cr-2.5%Ni-Fe powder (Rockit404), known for its high hardness and excellent corrosion resistance. A diode laser with wavelength of 900-1070 nm is adopted as laser source under argon atmosphere; electrical power for the laser cladding process is 5, 6, and 10 kW. Fundamental surface characteristics such as crossectional microstructure and hardness profile are observed and measured, and special evaluation, such as a soldering test with molten ALDC12 alloy, is conducted to investigate the corrosion resistance characteristics. As a result of the die-soldering test by immersion of low carbon alloy steel in ALDC12 molten metal, the clad layer's soldering thickness decreases.