• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.11-21
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• 2019

The purpose of this study is to evaluate the awareness and usability of descending life lines and simple descending life lines for fire situations in the accommodation of the public officials who are responsible for supervising the installation and maintenance of descending life lines and simple descending life lines. The main results of the study are summarized as follows. First, in comparison of the ability to distinguish between descending life lines and simple descending life lines, the majority of female public officers in general administrative services do not have the ability to distinguish between descending lifelines and simple descending life lines, so they should be able to improve their ability to distinguish descending life lines. Also, institutional strategies are needed to regularly receive education through the Safety Experience Center in order to prevent safety accidents such as falling in emergency situations. Second, as a result of verifying reusability of simple descending life lines by gender and occupation, most public officers with the exception of half of the firefighting officers were analyzed as having no ability to reuse the simple descending life lines. Therefore, it is necessary to change the relevant laws so that only the installation of descending life lines which can be used continuously is permitted, except for the simple descending life lines among the evacuation instruments to be additionally installed in each room of the accommodation. Third, in terms of the ability to perceive the maximum load of the descending life lines according to occupation, the perception ability of the rescuers was the highest and the perception ability of the fire service personnel was the lowest. In order to improve the perception abilities of the fire service personnel, it is necessary to strengthen the theoretical and practical education of descending life lines in collective education such as the command-enhancing training which is regularly carried out in fire service academy. Lastly, it is believed that it is more effective to conduct the experience training of the descending life lines by imagining the fire in accomodations rather than other facilities, because it is the location where fires are actually seen the most.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.1-2
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• 2011

Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.403-415
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• 2021

Seasonal development of Parthenolecanium corni was observed from 4 Jun. 2019 (nymph) - 25 Jun. 2020 (1^st Gen. nymph) in blueberry shrub in Sacheon city, Gyeongsangnam-do. To investigate their development, more than 5 twigs sprouted in 2018 were taken from the farm nearly weekly basis. The development of each scale were examined under the stereomicroscope and chemical control was conducted in the blueberry shrub with available three insecticides. The results on the development period and Centigrade Degree-Days accumulation (DDC) obtained are as follows: egg-laying period (peak): 12 -26 May 2020 (24 May)(DDC, 110.0-188.5 (173.6)); egg-hatching period (peak): 9 - 23 June 2020 (19 June)(DDC, 325.2-480.8(435.6); egg period: 26 days; nymph movement from overwintered adult to new leaves 16-25 June 2020 (DDC, 410,5-500.4); nymph movement from leaf to twig (peak) to become adult: 4-18 Feb. 2020 (8 Feb.). Eggs no. /adult (range): 956.8 ± 73.4 (13 - 3497). Size (mm) of egg, 0.29 ± 0.020(L), 0.15 ± 0.013(W); of egg-hatched nymph, 0.35 ± 0.018(L), 0.18 ± 0.007(W), 0.09 ± 0.007(eye distance); and of adult, 4.30 ± 0.893(L), 2.64 ± 0.520(W). The egg-hatched nymphs from the overwintered adult moved to the backside leaf of new shoot in which they found about 95% until leaf is falling by early February in next year. They overwintered as 2^nd instar and occurred univoltine. For the control of the 1^st instar crawler, three insecticides treated on 16 and 30 July at the registered dose for Ceroplastes japonicus. Acetamiprid 8WP showed 96.9% mortality at 21 days after 1^st treatment.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.120-145
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• 2018

This study intended to examine the drainage facility of Gyeongbokgung Palace based on the traces of the relic found during the excavation survey. Historical records indicate that various efforts have been made for smooth drainage facility for the palace since the foundation of the Joseon Dynasty. Although there are no drawings showing the image of early appearance of Gyeongbokgung Palace during the foundation, it is possible to estimate it through the drawings prepared after the King Yeongjo's reign. The image of the palace after reconstruction can be seen through the "Bukgwoldohyeong" and other relevant documents. At this present, since the survey intends to determine the image of Gyeongbokgung Palace during the reign of King Gojong based on the standard restoration plan of the Cultural Heritage Administration, this study also focused on the drainage facility of Gyeongbokgung Palace during King Gojong's reign, particularly on the collecting wells and culverts of six areas including "Chimjeon Hall", "Taewonjeon Hall", "Geoncheongung Hall", "Sojubang Hall", "Hamhwadang - Jipgyeongdang - Yeonghundang Hall", and "Heungbokjeon Hall". Gyeongbokgung Palace is divided into various zones composed of the central halls and surrounding corridors, and the drains also primarily start from each hall and later join the central drain of the zone. The central drain then leads to the "Eo-gu(御溝)" and the water led to the "Eo-gu" is finally discharged through the water gate. It appears that this series of processes were basically devised to coordinate artificial drain with the natural drain using the natural geographical features of the palace. Research showed that the collecting well where the draining begin was installed in the area where a large amount of household sewage was generated but mostly in the corners where corridors met or corridors and wall met. This appears to be an arrangement to handle the water falling from the roof and household sewage. Also, "Ju(廚)" was installed mainly at the end of the corridor to handle household sewage. The installation of these drainage facilities shows the possibility that the drainage of Gyeongbokgung was very compact under a series of plans.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.4-21
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• 2018

This paper reviewed the legitimacy of the name of those sixteen pieces of hat artifacts known in Korean as pyeongjeongmo and currently housed by the National Palace Museum. This was undertaken in order to rectify the error of calling them pyeongjeongmo. Also, the paper suggested pyeongjeongmo's production method to apply representation of the artifacts or production of Joseon officials' hats as representation of ritual costumes in the royal court. The name pyeongjeongmo originated from pyeongjeonggeon. Gyeongguk Daejeon recorded that noksas wore yugak-pyeongjeonggeon and seoris wore mugak-pyeongjeonggeon, but the pyeongjeongmo artifacts housed in the National Palace Museum have been found irrelevant to those pyeongjeonggeons put on by both noksas and seoris. Rather, they has been confirmed as corresponding to dugeon or jogeon worn by byeolgams or suboks who served at the palace of the crown prince or princess. Through the investigation of the artifacts, the researchers could find out the tailoring and sewing methods, the finished look, and the folding manner of pyeongjeonggeon. Although the structure of pyeongjeonggeon was generally consistent, the frontal look was slightly different depending on the folding manner, resulting in three distinguished types of pyeongjeonggeon. Regardless, the pyeongjeongmo was made with one piece of fabric by a flat tailoring and folding method to create a three-dimensional hat. The finished shape appeared low in the front and high in the back side structure. The head girth was 55~59 cm, and the height was 19.4~21.5 cm. To make it with one piece of fabric, the head girth part was tailored in the same direction as the strands. Based on the artifact Changdeok 23820, this paper has also suggested a finished reproduction through the processes of preparing the materials, mounting, making the center ornaments, sewing and folding. The tailoring was completed with black silk fabric which was cut in a unique shape designed in advance, and hemp fabric which was mounted to the former. The top part of the head was finished with black threads, and the center line at the back was fixed with decolored cotton threads by blanket stitches with 3.5~4 cm intervals. Bamboo strands were inserted in the inside of the front-folded part, which then was fixed by patterned stitches with white cotton thread. At the back, a small bamboo clasp was attached so that one can lock it to the headband and prevent it from falling off.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.47-58
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• 2019

This paper is brought to analyze an impact of coaching activities over entrepreneur with respect to entrepreneurs' personal characteristics on the performance of Startups focusing on entrepreneur's awareness conversion effect. In particular, the situation of falling focus of serious startup failure on uncoachable obstinate entrepreneur among the several causes of startup failures, this paper define the research mission of reducing this risk by inducing coaching types of cooperations between senior entrepreneur having serial successful startup experiences and beginning entrepreneur. This paper carry out literature reviews chiefly on startup coaching researches rather than mentoring studies because coaching stressing on self-oriented problem defining and solving by entrepreneur actively tend to be more effective than mentoring relying on mentor's guideline passively as solving startup's main upcoming problems. This paper implement four related researches. First, the impact analysis of entrepreneur's personal characteristics on coaching activities, second, influences of entrepreneurs environmental factors on them, Third, impact of coaching activities on entrepreneur's awareness conversion effect, Fourth, how strongly this conversion effect contributing on the performance of startup. As results of empirical research, first, this paper prove that entrepreneur's environmental factors impact positively on coaching activities over entrepreneur although failing on validating on significant impact of entrepreneur's personal characteristics on coaching activities. Second, this paper prove that coaching activities positively influence on entrepreneur's awareness conversion, hence ultimately positively on the performance of startups. As conclusion, this paper validate that coaching activities over entrepreneur through inducing on the conversion of entrepreneur's awareness lead entrepreneur to setting the bar high and accountable planning of business milestone. This paper contribute on delivering policy implication that government initiatin action-oriented training program for entrepreneurs should accept the module of coaching session to produce more effective results.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.182-195
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• 2011

Old big tree transcends the simple meaning of trees as they are the natural monuments that embody the people's history and culture of this land. The Cultural Heritage Administration of Korea (CHA) defines and protects old big tree based not only on the size of the tree but also on its definitive cultural and natural factors such as value, implications, and originality. This research aims to identify and analyze the habitation and measurements, the soil conditions, as well as the protective facilities of 14 old big tree spread throughout the Gangwondo. The research examined the soundness of the arboreal form, the degree of damage on the bark, as well as the quantity of leafs levels to evaluate the overall condition of growth and development. Then, the tree height, the eastwest and south-north width of the crown, the sternum circumference, and the root circumference were recorded to identify the measurements of the selected old big tree. Also, the research analyzed 9 elements such as soil texture, pH levels, and organic contents in order to determine the scientific characteristics of soil upon which the trees draw nutrition. Finally, the research evaluated supporting pillars, lightning rods, iron pulling-facilities, as well as notice boards to study the protective facilities of old big tree. The research procedures revealed that 78.57% of the old big tree identified as natural monuments in the Gangwondo have average to above average habitation conditions. Also, the average tree height reaches 18.80m above ground while the average root circumference measures 7.34m. Moreover, the results of the scientific analyses conducted on the soil elements determined that most chemical values were within the defined levels, with the exception of phosphoric acid levels falling within the hyper-nutritious range. Finally, although most of the protective facilities did support the habitation of the Old big tree, there were some supporting pillars and iron pulling-facilities that actually damaged the trees. This research means to provide foundational reference data for the analysis of the habitation and management conditions of natural monument old big tree within the Gangwondo. A follow-up topic led by the results of this research is the identification and analysis of correlating environmental elements that affect the habitation of the old big tree.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.208-220
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• 2019

The seasonality of leaf fall has important implications for understanding the response of trees' phenology to climate change. In this study, we quantified the leaf fall pattern with a model to estimate the timing and speed of leaf litter according to species and considered the nutrient use strategy of canopy species. In the autumns of 2015 and 2016, leaf litter was collected periodically using 36 litter-traps from the deciduous forests in Gwangneung and sorted by species. The seasonal leaf fall pattern was estimated using the non-linear regression model of Dixon. Additionally, the resorption rate was calculated by analyzing the nitrogen concentration of the leaf litter at each collection time. The leaf litter generally began in early October and ended in mid-November depending on the species. At the peak time (T50) of leaf fall, on average, Carpinus laxiflora was first, and Quercus serrata was last. The rate of leaf fall was fastest (18.6 days) for Sorbus alnifolia in 2016 and slowest (40.8 days) for C. cordata in 2015. The nitrogen resorption rates at T50 were 0.45% for Q. serrata and 0.48% for C. laxiflora, and the resorption rate in 2015 with less precipitation was higher than in 2016. Since falling of leaf litter is affected by environmental factors such as temperature, precipitation, photoperiod, and $CO_2$ during the period attached foliage, the leaf fall pattern and nitrogen resorption differed year by year depending on the species. If we quantify the fall phenomena of deciduous trees and analyze them according to various conditions, we can predict whether the changes in leaf fall timing and speed due to climate change will prolong or shorten the growth period of trees. In addition, it may be possible to consider how this affects their nutrient use strategy.

• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.21-33
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• 2019

This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.143-149
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• 2019

This study was conducted to investigate the graft-taking and growth of grafted cucumber seedlings as affected by light quality and blink cycle of LED modules. Four light quality treatments, namely blue, red, blue+red, white LED and four blink cycle levels of 5s/5s, 7s/3s, 9s/1s and control were provided to investigate the effect of lighting quality and blink cycle on the graft-taking and growth of grafted cucumber seedlings. Photoperiod for the control was 12/12 h. Photosynthetic photon flux, air temperature, and relative humidity for healing were maintained at $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $25^{\circ}C$, and 90%, respectively. There was no significant difference in graft-taking of grafted cucumber seedlings according to light quality except the blue LED with the blink cycle of 5s/5s. Regardless of the blink cycle, there was no significant difference in graft-taking of cucumber seedlings healed under red, blue+red, and white LED modules. These results implied that the effects of light quality and blink cycle on the graft-taking were not significant. Differences in the leaf length, leaf area, and fresh weight of cucumber seedlings healed blue or red LED with the blink cycle of 9s/1s were found to be significant. There was no significant effect of the blink cycle on the growth of cucumber seedlings healed under white LED modules. The prices of white LED are gradually falling due to increased demand. Considering the manufacturing unit price of white LED modules, the cost savings of 10-15% are expected as compared to the conventional blue/red LED modules. Therefore, it was concluded that the use of white LED modules will be economical as an artificial lighting sources for healing of grafted seedlings.