• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.17-24
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• 2019

The combustion properties of the flammable substance used in industrial fields include lower/upper flash point, lower/upper explosion limit, autoignition temperature(AIT), fire point, and minimum oxygen concentration(MOC) etc.. The accurate assessment of these characteristics should be made for process and worker safety. In this study, tert-amylalcohol(TAA), which is widely used as a solvent for epoxy resins, oxidizers of olefins, fuel oils and biomass, was selected. The reason is that there are few researches on the reliability of combustion characteristics compared to other flammable materials. The flash point of the TAA was measured by Setaflash, Pensky-Martens, Tag, and Cleveland testers. And the AIT of the TAA was measured by ASTM 659E. The lower/upper explosion limits of the TAA was estimated using the measured lower/upper flash points by Setaflash tester. The flash point of the TAA by using Setaflash and Pensky-Martens closed-cup testers were experimented at 19 ℃ and 21 ℃, respectively. The flash points of the TAA by Tag and Cleveland open cup testers were experimented at 28 ℃ and 34 ℃, respectively. The AIT of the TAA was experimented at 437 ℃. The LEL and UEL calculated by using lower and upper flash point of Setaflash were calculated at 1.10 vol% and 11.95 vol%, respectively.

• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.64-70
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• 2013

To examine the proportion of secondary seed dispersion by wildlife and to identify the related wildlife, We measured seed removal rates and related wildlife at the natural mixed broadleaved forest in mountain Jungwang, Pyeungchang-gun in middle part of Korean peninsula, seed-tray contained four kind of tree seeds were setted from mid-september to late-October for three years. Mean seed removal rates(MSRR) of acorn(Q. mongolica)is shown the highest values 87.2%, next MSRR of samara(A. pseudosieboldianum) does 33.1%, MSRR of samara(A. pictum subsp. mono) does 29.2%. and then SRR of samara(A. mandshuricum) does only 13.6%. Acorns are removed more faster than samaras. Among the related wildlife, Siberian chipmunks most freqently visit seed tray, and ordered Korean squirrel, Wild boar, and Yellow-throated marten. Most secondary dispersed acorns might be consumed by Wild boar, and small portions does comsumed or scatter-hoarded by rodents. Most secondary dispersed samaras might be consumed by rodents, and small portions does scatter-hoarded by rodents. A few sound seeds are remained on the forest floor in late October owing to the seed consunption and seed hoarding by wildlife. We observe seedling establishment of four broadleaved tree species. From these results, We proved Wild boar is seed comsummer, and rodents are seed consummer and seed disperser. Further studies on secondary seed dispersion, seed consumption and hoarding and related wildlife should be needed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.125-132
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• 2016

The European Telecommunication Standards Institute (ETSI) Technical Committee (TC) Reconfigurable Radio Systems (RRS) is standardizing the multi-mode Mobile Device (MD). The configuration of multi-mode MD is determined by the downloaded mobile communication standard software. In this paper, we introduce the Radio Library concept for multi-mode MD which is one of the key components of RRS standard. This paper also introduces the Standard Functional Block which is a part of Radio Library. A method for selecting efficiency SFBs for multi-mode MD is presented and a Radio Library is generated based on the selected SFBs. This paper also shows sample Standard Functional Block Set which included in Radio Library. In order to verify the compatibility of the generated Radio Library which was made by C language, we implement the LTE Rel-10 and Wi-Fi(802.11b) to show the efficiency of generating a mobile communication standard software based on the Radio Library. Then using the Prograph Visual Programming MartenTM 1.6.4, we compiled our LTE Rel-10 and Wi-Fi(802.11b) source code.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.7
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• pp.850-856
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• 2004

When a shock wave arrives at the open end of a tube, an impulsive wave is discharged from the tube exit and causes serious noise and vibration problems. In the current study, the effect of the cross-sectional area of a circular tube on the impulsive wave is investigated using computational methods. Marten-Yee's TVD scheme was employed to solve axisymmetric, unsteady, compressible Euler equations. With a change in the cross-sectional area of the tube, the Mach number of an incident shock wave is varied between 1.01 and 1.50. The results obtained show that the magnitude of the impulsive wave strongly depends upon the Mach number of the incident shock wave and the cross-sectional area of the tube. It is also found that for a given cross-sectional area of the tube, the impulse wave has strong directivity to the tube axis.

• Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.224-233
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• 2023

This research was conducted at Langgur City, Southeast Maluku Regency, Maluku Province, Eastern Indonesia from November 2020 to February 2021 to study biological aspects of roundscads (Decapterus spp.) which consist of species composition, sex ratio, gonad maturation level, size distribution, length-weight relationship and condition factor. Samples were collected at traditional fish market in Langgur City. Fish samples collected at the market were put into cool box and then brought to the laboratory for further examination. Fish samples were identified, separated based on species, dissected to determine their sex and gonad maturation stage and then measured. Totally, there were 290 specimen collected which consist of five species namely Decapterus kurroides, D. macarellus, D. macrosoma, D. muroadsi and D. russelli. Sex ratio between male and female for all species showed 1:1. Gonad maturation level showed that stage I and II have higher percentage than stage III and IV indicates immature fish more dominant compare to mature one. Among five species found, D. macarellus has larger size while the smaller belongs to D. muroadsi. Results of length-weight relationship analysis showed that roundscads inhabiting Southeast Maluku waters have isometric and negative allometric growth pattern with relative condition factor around 1.00.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.75-81
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• 2014

For the safe handling of isobutylalcohol(IBA), this study was investigated the explosion limits of isobutylalcohol in the reference data. And the lower flash points, upper flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. By using the literatures data, the lower and upper explosion limits of isobutylalcohol recommended 1.7 Vol% and 10.9 Vol.%, respectively. The lower flash point of isobutylalcohol by using Setaflash and Penski-Martens closed-cup testers were experimented $25^{\circ}C$ and $30^{\circ}C$, respectively. The lower flash point isobutylalcohol by using Tag and Cleveland open cup testers were experimented $36^{\circ}C$ and $39^{\circ}C$, respectively. Also, this study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for isobutylalcohol. The experimental AIT of isobutylalcohol was $400^{\circ}C$.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.9-10
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• 2015

Purpose : The purpose of this study was to report the incidence of drowning accident in order to prevent and decrease the accidents of drowning. Methods : Data were obtained on all accidents of drowning accidents occurred were identified by using the Emergency Activity Daily Report Data from the National Emergency Management Agency (NEMA). Results : The age, location, days, season of the drowning accident were examined. The Chi-square test was used to compare each group. All comparisons were made at the p<0.05 level of significance. The result show that the age of drowning accidents for victims aged 20-29 was 27.9%, and for victims aged 30-39 years, 18.7%. In reguard to the age group, drowning accidents was age 20-39; 51(44.8%). In reguard to the locations, the number of drowning accidents in a lake or reservoir was 62(53.4%). The number of drowning accidents in a lake or reservoir during etc was 51(58%). In reguard to the days, the number of drowning accidents on Saturday was 30(25.8%), on Sunday 32(27.6%). The weather of drowning accidents was sunny 60(51.8%), rainy 40(34.4%), cloudy 16(13.8%). The season of drowning accidents was summer 53(45.7%). In reguard to season, two groups are significantly different. Conclusion : Drowning is a leading cause of injury related accidents. Understanding the characteristics of drowning is the first step to developing prevention strategies that may be beneficial for people of all ages and under nearly all circumstances are increased swimming ability, lifeguard staffing, providing life jackets, and public education activities.

• Journal of Forest and Environmental Science
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• v.31 no.3
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• pp.207-213
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• 2015

It is estimated that there is a total of approximately 100,000 species in Korea. However, the number is currently about 30,000 and only 16,027 species are listed in the 'Species Korea' (as of December, 2014). Of the listed species, 51 species are designated as the Endangered Species Class I while 195 species are in the Class II, totaling 246 endangered species including 20 mammals. Under the circumstances that development (e.g., roads) is increasingly threatening the persistence of endangered mammals, it is significant to identify and preserve suitable habitats for them. In this context, evaluating the values of the suitable habitat environment would serve as essential information for development decision making. This study estimated the values of endangered mammals' forest habitats through spatialization of habitat services. In doing so, a species distribution model, Maximum Entropy Model (MaxEnt) was utilized for a group of endangered mammals including, mountain goat, wildcat, marten cat, and flying squirrel. To calculate the values per unit area, a benefit transfer method was used based on the point-estimate technique with the best available values estimated previously. The range of discount rate of 3.0 to 5.5 percent was applied taking the notion of social discount rate into account. As a result, the province with the highest values for endangered mammal habitats appeared to be Gangwon, followed by Gyeongbuk and Gyeongnam. The monetary values of the endangered mammal habitats were estimated to be 330 billion to 421 billion won per year.

• Structural Engineering and Mechanics
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• v.57 no.3
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• pp.569-585
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• 2016

This paper highlights a case study that investigates the behaviour of existing bridge, West Terrace Bridge, induced by horizontal seismic loading. Unfortunately the lack of past information related to seismic activity within the NSW region has made it difficult to understand better the capacity of the structure if Earthquake occurs. The research was conducted through the University of Western Sydney in conjunction with Railcorp Australia, as part of disaster reduction preparedness program. The focus of seismic analyses was on the assessment of stress behaviour, induced by cyclic horizontal/vertical displacements, within the concrete slab and steel truss of the bridge under various Earthquake Year Return Intervals (YRI) of 1-100, 1-200, 1-250, 1-500, 1-800, 1-1000, 1-1500, 1-2000 and 1-2500. Furthermore the stresses and displacements were rigorously analysed through a parametric study conducted using different boundary conditions. The numerical analysis of the concrete slab and steel truss were performed through the finite element software, ABAQUS. The field measurements and observation had been used to validate the results drawn from the finite element simulation. It was illustrated that under a YRI of 1/1000 the bottom chord of the steel truss failed as the stress induced surpassed the ultimate stress capacity and the horizontal displacement exceeded the allowable displacement measured in the field observations whereas the vertical displacement remained within the previously observed limitations. Furthermore the parametric studies in this paper demonstrate that a change in boundary conditions alleviated the stress distribution throughout the structure allowing it to withstand a greater load induced by the earthquake YRI but ultimately failed when the maximum earthquake loading was applied. Therefore it was recommended to provide a gap of 50mm on the end of the concrete slab to allow the structure to displace without increasing the stress in the structure. Finally, this study has proposed a design chart to showcase the failure mode of the bridge when subjected to seismic loading.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.169-175
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• 2014

For the safe handling of ethylbenzene, this study was investigated the explosion limits of ethylbenzene in the reference data. And the lower flash points, upper flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower flash points of ethylbenzene by using Setaflash closed-cup and Pensky-Martens closed-cup testers were experimented $20^{\circ}C$ and $22^{\circ}C$, respectively. The lower flash points ethylbenzene by using Tag and Cleveland open cup testers were experimented $25^{\circ}C$ and $28^{\circ}C$, respectively. Also, this study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for ethylbnezene. The experimental AIT of ethylbenzene was $430^{\circ}C$. The calculated LEL and UEL by using the measured lower flash point and upper flash point were 0.93 Vol.% and 7.96 Vol.%, respectively.