• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.1
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• pp.11-16
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• 2014

When it comes to develop flight simulator, HAT (Height Above Terrain) is required to provide altitude information to the pilot who learns how to control an airplane in landing and takeoff situation. However, there might be inconsistent problem between real terrain and simulation information since current implementation of HAT simply depends on center of gravity point on the airplane. To overcome mentioned problem, in this paper, we propose how to obtain more accurate altitude information than existing scheme by making use of HAT and HOT (Height Of Terrain) information of landing equipments according to movement of the airplane. Moreover, we demonstrate the accuracy of the proposed scheme through new flight simulator developed through OSG(OpenSceneGraph) by taking example of terrain information for domestic airport.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.5
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• pp.713-722
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• 2004

This study examined the effects of two kinds of functional sun hats through a head-manikin test and a climatic chamber trial for farm workers in summer. Experiment was composed of four conditions. The first condition was the condition without any hat (Control). The second was the condition with a sun hat on the market (Hat A). The third was the condition with a functional sun hat made of reflective fabric (Hat B). The last was the condition with a functional sun hat having a ventilating structure as well as reflective fabric (Hat C). For the subjects in the climatic chamber trials, 12 healthy males volunteered. Air temperature, relative humidity and globe temperature in the chamber was maintained at $33{\pm}0.5^{\circ}C,\;65{\pm}5%RH\;and\;39{\pm}1^{\circ}C\;(WBGT\;33^{\circ}C)$. Subjects did a simulated red pepper-work (50-min work and 10-min rest, twice repetition) for 120 min. As the result of head-manikin test, the surface temperature on middle of back-neck was the lowest in Hat B of four conditions and the surface temperature on top of head was the lowest in Hat C. As the result of climatic chamber trials, there were apparent differences between with (Hat A, Hat B, Hat C) and without a sun hat (Control). In rectal temperature ($T_{re}$), mean skin temperature ($\={T}_{sk}$), heart rate (HR), total sweat rate (TSR), The physiological heat strain was less in the condition with hats than in the condition without a sun hat. As the increasing rate in Tre, Hat B is the most effective hat for alleviation heat strain. As the subjective responses, Hat B was the most effective hat for thermal comfort even though the difference was not significant. Hat C was less effective than Hat B and the reason might be the increase of weight due to inserting the ventilating structure.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.74-82
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• 2002

The present study is aimed to investigate the effect of the safety hat on the balance of body temperature by observation of the physiological response under hot working environment. The experiment was carried out in a climate chamber of 3$0^{\circ}C$, 50%RH for 70 minutes. To compare the two kinds of safety hat, 5 healthy male subjects worn safety hat without hole (called 'without hole') or safety hat with hole (called 'with hole') according to a randomized cross-over design. The main results of this study are as fellows: Rectal temperature and heart rate were significantly lower level in 'with hole'than in 'without hole'. The mean skin temperature was significantly higher in 'without hole'than in 'with hole'. Blood pressure were significantly low in 'with hole'. Sweat rate which was measured by weight loss before and after experiment was higher in 'without hole'. In subjective ratings, subjects replied more hot, more uncomfortable and more wet, they felt more fatigue in condition of 'without hole'. Work ability which was measured by a grip strength dynamometer was higher in 'with hole'. Safety hat which can be used for safety of the brain in work place is meaningful device of behavioral thermoregulatory response under the hot working environment. The safety hat which is designed for proper ventilation and hygiene can maintain the homeostasis of body temperature by releasing body temperature efficiently.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.297-306
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• 1994

This experiment was carried out to investigate the healing loss and the heavy metal residues such as copper, zinc, manganese, cadmium and lead In porcine visceras by inductively coupled argon plasma spectrometer(ICP), and to probe changes when porcine visceras were boiling In water treatment(BWT), heating in autoclave treatment (HAT) and heating In oil treatment (HOT) . The range of heating loss on porcine viscera were BWT(23.11∼34.53%) , HAT(18.48∼28.00%) and HOT(14.20∼25.22%)and the heart tissue were higher and liver were lower than those of the other tissues. The total value of heavy metal residues in large intestine, small intestine, heart, kidney, liver and stomach tissue were 11.298${\pm}$5.302 ppm, 27.825${\pm}$8. 177 ppm, 16.756${\pm}$6.334 ppm 21.107${\pm}$6.057 ppm, 25.369 ${\pm}$ 10.164 ppm and 12.611 ${\pm}$5.513 ppm, respectively. Heavy metal residues in porcine visceras tended to decrease according to heating methods and the variety viscera, and the change of total heavy metal residues on BWT, HAT and HOT were 4.16∼32.57%, 12.01∼28.09% and 9.60∼25.76%, respectively. The decrease of lead element of mean value were 21.76% and copper, zinc, manganese and cadmium element were 18.00∼ 18.16%. The change of heavy metal residues were not significant in the porcine visceras(P>0.05), and the these were significantly correlated among the three heating method(P < 0.05).

• Transactions of Materials Processing
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• v.20 no.6
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• pp.427-431
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• 2011

In general, hot stamped component is trimmed by costly and time consuming laser cutting when the material strength is over 1,500MPa. The aim of this work was to demonstrate that the trimming die life is improved and the trimming load is decreased by lowering the strength of the region to be trimmed. The model employed in this study was a hat shape, similar to the cross section of many hot stamped products. FE-analysis of hot stamping process was performed to evaluate the effect of tool shape on cooling rate at the area to be trimmed. The best tool shape was thus identified, which created slower cooling and lower hardness at the region to be trimmed. The wear at the cutting tool edge was also reduced.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.160-165
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• 2023

As the supply of eco-friendly vehicles increases, the application rate of hot stamping components is rising to reduce vehicle weight and improve safety. Although Al-Si coated steel sheets are commonly used in hot stamping processes, their manufacturing costs are elevated due to process patents and royalties. Various hot stamping studies have been conducted to reduce these production costs. In this study, we derived a process control method for suppressing the oxide layer of hot stamping parts using uncoated boron steel sheets. Firstly, hat-shaped parts were hot stamped under atmospheric conditions to analyze the tendency of oxide layer formation by location. Then, the Gleeble system was used to observe oxide layer formation based on oxygen content under various atmospheric conditions. Finally, the oxide layer thickness was quantitatively measured using SEM images.

• Transactions of Materials Processing
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• v.26 no.2
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• pp.101-107
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• 2017

Aluminum alloys are widely used in automotive industry because of their high strength-to-density ratio and excellent corrosion resistance. However, conventional cold stamping of aluminum alloys leads to low formability and excessive spring-back. To overcome these problems, Hot Forming Quenching (HFQ) is applied to manufacture automotive part using aluminum alloy. The purpose of this study is to investigate effect of forming temperature on spring-back in HFQ of T6 heat treated AA6061 sheet. In this study, hat shape forming test was adopted to evaluate spring-back characteristics according to various forming temperatures. In additions, the test was also performed with warm forming conditions in comparison with dimensional accuracy of HFQed part. The experimental results showed that dimensional accuracy of HFQed part was superior to warm formed part and amount of spring-back was decreased as forming temperature rise.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.2
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• pp.73-77
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• 2004

The efforts which increase the strength of the auto-body structure and decrease its weight lead to develop a new concept of part production systems, such as Post-Form Strengthening by induction heat treatment. In this study, several cold and hot-rolled sheet steels were used to find out optimum induction heat treatment conditions. After induction heat treatment, strength of heat-treated sheet steels was increased significantly compared with that of as-rolled steels. From these results, auto-body structure which has more light and safe has been made by using this induction hardening method.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.255-261
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• 1995

This paper presents results from a study of the effects of age and sex on body and carcass composition of different goat genotypes. A completely randomized $3{\times}3{\times}2$ factorial design was used. Factors were genotype (Thai Native; TN, $50%TN{\times}50%$ Anglo-Nubian (AN) and $25%TN{\times}75%AN$ goats), age ($206{\pm}8$, $349{\pm}9$ and $428{\pm}8days$ or 6.9, 11.6 and 14.3 months, respectively) and sex (male and female). It was shown that TN kids had significantly higher (p < 0.05) hind percentage (7.9%) compared with $50%TN{\times}50% AN$ (7.2%) and $25%TN{\times}75%AN$ (7.1 %) kids. TN kids had a significantly (p < 0.05) higher heart percentage (0.44%) than that of $25%TN{\times}75%AN$ kids (0.38%). However, there was no significant difference in heart percentage between TN and $50%TN{\times}50%AN$ and between $50% TN{\times}50%AN$ and $25%TN{\times}75%AN$ kids. TN and $50%TN{\times}50%AN$ kids had significantly higher (p < 0.05) carcass muscle content (63.1 and 63.7%, respectively) than did $25%TN{\times}75%AN$ kids (59.9%). Kids at 6.9 months of age had significantly higher percentages of hide, feet, intestinal tract, liver, heart, kidneys and carcass bone than those of kids at 11.6 and 14.3 months of age. There were no significant differences in these characteristics between kids at 11.6 and 14.3 months of age. However, kids at 11.6 and 14.3 months of age had significantly higher percentages of omental fat, dressing carcass, muscle, total fat (subcutaneous + intermuscular + kidney and pelvic fat), muscle to bone ratios (MBR), and muscle plus fat to bone ratios (MFBR) than those of kids at 6.9 months. Males had significantly higher gut contents, but lower percentages of liver, omental fat and heart. Prediction equations were developed relating empty body weight (EBW) to hot carcass weight and some dissectible carcass fractions.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.11
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• pp.1520-1529
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• 2007

Workers on construction sites are exposed to multiple and varied threats. Of those, climatic factors such as high/low air temperatures and high/low humidity have a bad mental and physical health effect on workers. Especially, work in hot environment has a tendency to cause fatigue, reduce productivity and increase the incidence of accident. So, the purpose of this research was to understand working clothes and working environment of workers at a construction site in summer. The depth interview was performed by 45 workers of 4 different construction sites and the results were as follows. Workers wore average 4 items as clothing(upper, lower) and average 5 items as personal protective equipments(PPEs). They answered "head" is the hottest body area and must be protected during working. This means the necessity of development in safety hat. In addition, it should be developed working clothes and gaiters for alleviating heat stress and safety shoes for diminishing weight. It is expected that this research plays basic and important rolls to develop PPEs for reducing the heat stress of construction workers.