• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.489-496
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• 1988

This paper is studied to know wear mechanism in variation of austempering temperature and holding time of austempered ductile cast iron against mating material SM45C hardened by heat treatment. The wear tests were carried out by rubbing the annular surface of two test pieces in dry sliding friction. The wear mechanism was investigated by scanning electron microscopy and the retained austenite volume fraction was investigated by X-ray diffractometer. The experimental results show that the wear characteristics depend largely on the oxidation of the testing materials which is influenced by the sliding velocity and distance. The retained austenite has a negative effect during frictional contact because it has increased severe wear by softened surface layer. It is shown experimentally that hard metals have lower frictional resistance and hence the resistance to adhesion is increased due to stronger interatomic linking bonds and increase in the surface energy.

• Journal of Korea Foundry Society
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• v.10 no.3
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• pp.235-246
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• 1990

This study has been carried out to investigate into the rolling wear characteristics of austempered ductile iron under unlubricated dry rolling condition by Amsler type test with 9.09% sliding ratio. Wear amount is increased with increasing of ferrite and retained austenite and it has been found that the amount of rolling wear is decreased when the hardness of matrix are higher. The rolling life up to generation of abnormal condition is conspicusly increased and amount of rolling wear is increased asrolling revolutionis increased and wear of austempered ductile ironunder dry rolling condition. Matrix has been obtained to upper bainite, low bainite at heat treatment, obtained to bull`s eye structure at as cast. It has been found that the amount of rolling wear is decreased when the tensile strength of the casting are increased and then the rolling life up to generation of abnormal wear in conspicuously increased and amount of wear was intend to graphite content.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.1
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• pp.77-86
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• 2000

Purposes of this study were firstly to refine the measurement technique of tactile sensation and sensibility induced by touching the fabrics and secondly to investigate the differences of tactile sensibility depending on environmental conditions and the type of polyester fabrics. The environmental conditions were controlled at 20$\pm$1$^{\circ}C$, 65$\pm$3%RH(standard) and at 29$\pm$1$^{\circ}C$, 75$\pm$3%RH(warm & humid). As results, three factors were extracted from factor analysis of sensory assessment scale. The first factor was thickness and weight, the second one was surface-related property and the third one was stiffness in both environments. Depending on the environmental conditions, heat and moisture-related sensations such as [cold], [damp] and [dry & drapable] were affected significantly. Regression equations with the sensation descriptors were developed for the prediction of tactile sensibility(R2>.89). While the most efficient descriptor was [thin & flexible] in the standard environmental conditions, that was [dry & drapable] in the warm & humid environmental condition.

• Journal of the Korean Society of Food Culture
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• v.35 no.1
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• pp.28-54
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• 2020

This study aims to investigate the food preservation methods adopted by the Joseon Dynasty, which existed before the 17^th century. A total of 232 food preservation methods were discovered in 25 books, and could be classified by their targeted food types: vegetables (84), sea foods (60), meats (41), fruits (37), and others (10). Depending on the preservation method applied, they are classified as food drying, soaking, mud cellar preservation, and other preservation. Food drying is further classified into 8 sub-types: drying, sun-drying, shadow-drying, wind-drying, dry heat, combined drying, smoking, and others. Soaking could be sub-divided into using salt, ash, dry sand, bran, fermented paste, wet distillers grains, oil, and others. Mud cellar preservation is sub-classified into installing shelf inside the mud cellar, making the mud cellar for food preservation, and making hole or underground tunnel for food preservation. Other food preservation methods include minimizing moisture loss by applying beeswax on a section of the vegetable stem, and cutting the vegetables or fruits with their branches and leaves for food preservation.

• Advances in materials Research
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• v.9 no.3
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• pp.189-202
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• 2020

The objective of the present work is to investigate the effect of cutting parameters (Vc, fz and ap) on tool life and the level of vibrations velocity in the machined part during face milling operation of hardened AISI 52100 steel. Dry-face milling has been achieved in the annealed (28 HRc) and quenched (55 HRc) conditions using multi-layer coating micro-grain carbide inserts. Statistical analysis based on the Response surface methodology (RSM) and ANOVA analysis have been conducted through a plan of experiments methodology using a reduced Taguchi table (L9) in order to obtain engineering models for tool life and vibration velocity in the workpiece for both heat treatment conditions. The results show that the cutting speed has a dominant influence on tool life for both soft and hard part. Cutting speed and feed per tooth is the most significant parameters for vibration levels. Comparing the experimental values with those predicted by the developed engineering models of tool life and levels of vibrations velocity, a good correlation has been obtained (between 97% and 99%) in annealed and hard conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.330-337
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• 2001

Wire drawing process of the high carbon steel with a high speed is usually conducted at room temperature using a number of passes or reductions through consequently located dies. In multi-stage drawing process, temperature rise in each pass affects the mechanical properties of final product such as bend, twist and tensile strength. Also, this temperature rise during the deformation is the reason that the wire in drawing process is broken by the embrittlement due to rapid strain aging effect. This paper presents the estimation of the wire temperature for the multi-stage wire drawing process. Using the proposed calculation method of wire temperature, temperature rise at deformation zone as well as temperature drop in block considering the heat transfer between the block and wire were calculated. As these calculated wire temperatures were applied to the real industrial fields, it was known that the calculated results were in a good agreement with the measured wire temperature.

• The Journal of Internal Korean Medicine
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• v.39 no.5
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• pp.914-928
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• 2018

Objectives: This case report examines the effects of traditional Korean medicine for unspecified tremor with xerostomia caused by psychometric drug intake. Methods: A patient who suffered from unspecified tremor with xerostomia caused by psychometric drug intake was treated with acupuncture, pharmacopuncture, and traditional Korean medicine for 30 days. We provided the patient with herbal medicines including Ondam-tang-gagam (溫膽湯加減), Pumsimgieum-gagam (忿心氣陰加減), and Hoichunyanggyeok-san-gami (回春凉隔散加味). Symptoms were charted and evaluated using the Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale. Results: After treatment with Korean Medicine and pharmacopuncture, the frequency and degree of tremor has decreased, and degree of Xerostomia also improved. The Scores of Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale were also improved. And we could see reduction in the level of distribution of gastrointestinal heat at Digital Infrared Thermal Imaging test. The patient's Symtoms (Xerostomia as well as unspecified tremor) were improved after treated with Korean Medicine and pharmacopuncture. Conclusion: Korean medicine treatments may be valuable for xerostomia caused by psychometric drug intake.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.530-532
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• 1990

The moisture sorption behaviors of dry corn(DC). dry-corn (DCC) and soaked-rooked corn(SCC) at $25^{\circ}C$ were analyzed. The corn was soaked in water at $26^{\circ}C$ for 8hr. The cooking times for DCC and SCC were 30 and 20min. respectively, at $80^{\circ}C$. Desorption occurred for DC and DCC at RH below 23% and SCC at RH below 33% during storage. Moldiness was observed in all samples at RH 97%, after 192hr for DC and 288 hr for both DCC and SCC. At the same water activity. SCC sample had the highest moisture content, followed by DC. The SCC sample had the highest monolaver value and sorption heat. Stability isotherms indicated that DC and SCC had better storability than DCC.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.104-106
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• 1998

For the development of the 0.7 MJ small-sized superconducting magnetic energy storage (${\mu}$SMES) device, quench currents of a kA class superconducting cable were tested for various winding tensions because a dry superconducting coil is usually quenched by an abrupt heat pulse due to strand motions. The test coil similar to parameters of the optimally designed 0.7 MJ ${\mu}$SMES except a stored energy and a size was fabricated based on the test results of the kA class superconducting cable and tested. These experimental results show that the highly prestressed test coil has an excellent DC performance in spite of a dry type coil but its quench current is much degraded even at the low field ramping rate of about 0.4 T/s.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.8
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• pp.432-439
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• 2015

Current building procedures seek to minimize external air supplies to reduce the energy consumption of air conditioning, resulting in a high dependency on mechanical ventilation. We therefore studied an economizer-cycle system, whereby the introduction of external air saves energy. We analyzed different economizer-control methods, addressing mixed-air temperatures and outdoor-air fractions according to outdoor-air temperatures; also, we analyzed the energy consumption of the three economizer-cycle control types using detailed EnergyPlus simulation modeling. A differential enthalpy control method showed a lower energy consumption range from 5.8% to 6.2% than that of other methods during the simulated period. A differential dry-bulb control method showed a 12.7% lower energy consumption than the no-economizer method in the intermediate period, but also showed 7.1% more energy consumption during the summer period. When latent heat was not removed due to high summer humidity, we found a significant level of resultant energy consumption.