• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.49-63
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• 2018

Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.4
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• pp.123-131
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• 2007

Purpose: To find the correlation between ambient temperature change and the efficacy of acupuncture on the postmenopausal hot flash. Methods: 52 patients entered a randomized clinical trial which was to verify the efficacy of acupuncture on postmenopausal hot flash. Participants were treated with optimal/minimal acupuncture in the course of 13 weeks. 34 of 52 visited for the temperature-rising period(Group 1), while 18 of 52 for the temperature-falling period(Group 2), 100mm hot flash VAS and average temperature were taken 18 times from each person. Linear mixed effects model was used to find the correlation between temperature and hot flash VAS score(p-value<0.05). Group1/2, optimal/minimal acupuncture, age, age of menarche, height, weight, percent body fat, BMI, waist-hip ratio, past history of hysterectomy and HRT were also examined. Results: Period of treatment had influence on the hot flash VAS. As time went by, hot flash decreased(p<.0000). Participants who underwent minimal acupuncture showed higher hot flash VAS(p=0.0479) and as waist-hip ratio rose, hot flash increased(p<.0000). As the temperature rose, hot flash VAS score became lower(p=0.0143) and it was because 34 of 52 participants were treated for the temperature-rising period. Group 1/2 had no interrelation with hot flash(p=0.5741). Conclusion: Hot flash diminished as participants were treated with acupuncture, independently of whether the ambient temperature rises or falls.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.273-280
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• 2012

Differences of gene expression between red flash peach cultivar and white flash peach cultivar were investigated by Nest-generation sequencing (NGS). EST from the red flash peach cultivar and white flash peach cultivar were selected for nucleotide sequence determination and homology searches. The levels of transcripts coding for proteins involved in pathogenesis related proteins, temperature stress, ethylene signal pathway were significantly higher in white flash peach cultivar than in red flash peach cultivar. On the other hand, the up-regulation of proteins involved in anthocyanin and flavonol biosynthesis and protein degradation and sorbitol metabolism were observed in red flash peach cultivar. Chalcone synthase was preferentially expressed in the red flesh peach cultivar, agreeing with the accumulation of anthocyanin and expression of other previously identified genes for anthocyanin biosynthesis. Anthocyanin pathway related genes CHS, F3H, DFR, LDOX, UFGT differentially expressed between red flash peach cultivar and white flash peach cultivar. These results suggest that red flash peach cultivar and white flash peach cultivar have different anthocyanin biosynthesis regulatory mechanisms.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.979-985
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• 2011

This paper includes that there are results of designing the flash hider and analyzing fluid dynamics of a front area of the barrel to shorten the length of small arms. Generally, the muzzle flash can be generated out of the barrel by the reaction between the oxygen in the air and unburned gunpowder contained in the propellant gas if a barrel is not long enough to burn gunpowder fully inside of the barrel. Though, the hugh muzzle flash, which is a characteristic of small arms with short barrel length, caused a soldier to aim at the target at night by making the soldier blind for a while and endangers his life by revealing firing position to enemies. Besides, the heat of muzzle flash can weaken the performance of thermal sights, which are attached to small arms for night battlefield. In this paper, flash hiders with several different shapes were designed for a newly developed 5.56mm caliber rifle with short barrel length. The performance of each flash hider to reduce the muzzle flash was compared theoretically and experimentally. Through the authorized test procedure, a highly efficient design of flash hider for reducing the muzzle flash was identified. The result of the paper can be helpful when designing flash hiders for small arms with short barrel length.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.11-17
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• 2020

In order to guarantee safe storage and transportation of a flammable liquid solution, it is very important to know its flash point information. In this paper, flash points of n-octane+n-nonane system and n-nonane+n-decane system were measured by Seta flash apparatus and an empirical equation is proposed for the accurate estimation of flash point. Empirical equation is used to predict flash point of n-octane+n-nonane system and n-nonane+n-decane system, which were also compared to Unifac-based model. Absolute average errors of flash point data predicted by Unifac-based model are 0.7℃ and 0.6℃ for n-octane+n-nonane system and n-nonane+n-decane system, respectively. Absolute average errors of flash point data predicted by empirical equation are 0.2℃ and 0.4℃ for n-octane+n-nonane system and n-nonane+n-decane system, respectively. In conclusion, empirical equation proposed in this paper, presented the most satisfactory.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.76-80
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• 2014

The flash point is one of the most important physical properties used to determine the fire hazard of flammable liquid mixture and defined as the lowest temperature at which a liquid produces sufficient vapor to form a combustible mixture with air. The main purpose of this paper is to measure and predict the flash point of binary flammable miscible mixtures. The flash points for n-hexanol+n-butyric acid and n-butanol+propionic acid, were measured by using Seta-flash closed cup method. The experimentally derived data were correlated with the binary interaction parameters of the van Laar and NRTL equations through the optimization method. The flash points estimated by these correlations were compared with those calculated by the method based on Raoult's law. The optimization method were found to be better than the method based on the Raoult's law.

• The KIPS Transactions:PartA
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• v.12A no.7 s.97
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• pp.621-626
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• 2005

Recently, flash memory is widely used in various embedded applications since it has many advantages in terms of non-volatility, fast access speed, shock resistance, and low power consumption. However, it requires a software layer called FTL(Flash Translation Layer) due to its hardware characteristics. We present a new FTL algorithm named LSTAFF(Large State Transition Applied Fast flash Translation Layer) which is designed for large block flash memory The presented LSTAFF is adjusted to flash memory with pages which are larger than operating system data sector sizes and we provide performance results based on our implementation of LSTAFF and previous FTL algorithms using a flash simulator.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.826-830
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• 2002

In the civil engineering and architecture fields, welding for large sectional members, such as I section steel and H section steel, are usually performed. a flash welding system, by which large I section steel or H section steel can be welded for a short time, was newly developed. In order to know the basic characteristics of welded joints, the specimens were cut out from flash welded joints, and tensile and fatigue experiments were carried out. The joint efficiency of welded joints by flash welding is 100% for the specimens with reinforcements and 93% for without reinforcements. The fatigue strength of welded joints with reinforcement was about 50% of that of the base metal. Removing the reinforcement generated by flash welding, fatigue strength of flash welded joints became 75% of that of the base metal. In case of flash welded joints with reinforcements, after a couple of fatigue cracks had propagated, ductile fracture occurred at the toe. In flash welded joints without reinforcements, fracture occurred at the bond or at HAZ (Heat Affected Zone). In case of fracture at the bond, fracture was brittle, and in case at HAZ, fracture was ductile.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.12-24
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• 2016

Recently, as the price per bit is decreasing at a fast rate, flash memory is considered to be used as primary storage of large-scale database systems. Although flash memory shows off its high speeds of page reads, however, it has a problem of noticeable performance degradation in the presence of increasing update workloads. When updates are requested for pages with random page IDs, in particular, the shortcoming of flash tends to impair significantly the overall performance of a flash-based database system. Therefore, it is important to have a way to efficiently update the B+-tree, when it is stored in flash storage. This is because most of updates in the B+-tree arise at leaf nodes, whose page IDs are in random. In this light, we propose a new flash B+-tree that stores up-to-date versions of leaf nodes in sibling-leaf blocks (SLBs), while updating them. The use of SLBs improves the update performance of B-trees and provides the mechanism for fast key range searches. To verify the performance advantages of the proposed flash B+-tree, we developed a mathematical performance evaluation model that is suited for assessing B-tree operations. The performance comparisons from it show that the proposed flash B+-tree provides faster range searches and reduces more than 50% of update costs.

• Fire Science and Engineering
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• v.27 no.5
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• pp.70-74
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• 2013

The flash point is one of the most important physical properties to charaterize fire and explosion hazard of liquid solutions. The maximum flash point of liquid mixture is larger than those of the individual components. In this study, the flash points of 2-pentanol+acetic acid system were measured by Seta flash closed cup tester. This system exhibited the maximum flash point behavior. The flash points were estimated by the Raoult's law and the optimization methods using the van Laar and Wilson equations. The calculated values by optimization methods were found to be better than those based on the Raoult's law.