• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.235-241
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• 2004

Computations were performed to investigate the effects of air staging on combustion in three stage heavy-oil fired combustion burner. The burner was designed for 3 MW. Different amounts of air are introduced into each 3 three stages by means of each dampers. The goal of the study is to understand combustion phenomena according to each air stage mass ratios through CFD. Air flow rates at three inlets are adjusted by dampers inside a burner. Here, injection conditions of liquid fuel are kept constant throughout all simulations. This assumption is made in order to limit the complexity of oil combustion though it may cause some disagreement. In case of cold flows, only longitudinal velocities arc considered, On the other hand, flow, temperature and NOx generations are taken into account for reactive flows. Simple parametric study was conducted by setting 1'st air stage mass ratio as a parameter. And an optimal operation condition was found. The computational study is based on k-e model, P-1 radiation model(WSGGM) and PDF, and is implemented on a commercial code, FLUENT.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.7
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• pp.343-351
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• 2003

In this paper, interleaved boost converter is applied as a first-stage converter in switch mode power supply. The first-stage converter plays a role to improve power factor. Interleaved Boost Power Factor Corrector(IBPFC) can reduce input current ripple as a single voltage control loop only without inner current loop, because input current is divided each 50% by two switching devices. Each converter cell is also operated in discontinuous current mode and inductor current of each converter is discontinuous. Total input current which is composed by each converter cell is continuous current. Thus, IBPFC is able to improve input current ripple. IBPFC operating in discontinuous current mode can be classified as six modes from switching state and be carried out state space averaging small signal modeling. A control transfer function is obtained according to the modeling. Not only steady-state characteristics but also dynamic characteristics is considered. Single voltage control loop is also constructed by the control transfer function. From experimental result, improvement of power factor and input current ripple are verified.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.133-139
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• 2016

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.93-96
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• 1999

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.144-144
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• 2022

The amount of required forage is increasing by 20% every year in South Korea, but the cultivation area for forage production is limited. The yield ability of triticale forage is the highest among the winter forage crops including rye and the crop has cold tolerance within the average low temperature of -10℃ in January. Therefore, this study analyzed effects of sowing and harvesting times on feed value and quality for efficiently using and supplying triticale as livestock feed. Seed of the triticales, 'Joseong' was sown in 2021 fall (October) and 2022 spring (March). The triticales were harvested according to growth stages: seedling stage, booting stage, heading stage, 10 days after heading, and 20 days after heading. Moisture contents of each harvested triticales were adjusted to about 60%, and then the triticales were fermented for 40 days at room temperature under anaerobic conditions as silage. We have analyzed pH and organic acid to determine the feed value and quality of each silage. The contents of lactic acid in silage ofthe triticale harvested at the seedling stage of both fall and spring-sown (1.61%, 1.63%) were the highest among all of the silages; the booting stage (0.75%, 1.33%), the heading stage (0.50%, 0.69%), 10 days after the heading stage (0.31%, 0.42%), and 20 days after heading stage (0.22%, 0.40%). Such as the contents of lactic acid in the silages, and the pH value of the silages The pH value in both the fall- and spring-sown became lower as the triticale was grown up: seedling stage (7.05, 6.85), booting stage (6.21, 6.75), heading stage (6.18, 6.28), 10 days after heading stage (6.22, 6.17), and 20 days after heading stage (6.15, 5.81). Taken together, the results showed that the feed value and quality of triticale silage were more affected by harvesting time than sowing time.

• Journal of architectural history
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• v.15 no.1 s.45
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• pp.61-76
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• 2006

The stage is ceremonial and legendary space unlike the ordinary world. Performance is not simply scrip-staged, but spatial art based on tempo that transmits extreme condition. The stage art is a visual art combined with stage settings, lighting, customs and the like. I exemplify the stage of Middle Age and Renaissance in the history of the art of public performance and so I review that what meditative functions each stage perform and that as what pattern of media it can be conceptualized. In this thesis, I divide the places of public performance Into the spaces of proscenium and polygon and also set up the concepts of hot and cool that McLuhan presents for each space. So, the degree of participation could be different according to the distinction of quantity of information, which is communication following the patterns of spaces. The basis of public performance might be the communication between co-actors and audiences. Since the sense of the art of public performance is the art in the process of establishing the meaning based on the communication with co-actors, it is not a confirmed and fixed one, but rather a reflexive one that can be created and changed continuously. Therefore, audiences should be regarded as the subjects, who are making the art of public performance with co-actors.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E1
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• pp.9-16
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• 2001

To evaluate the correct separation capacity of cascade impactor for liquid aerosol, theoretical and experimental calculations of 50% cut-off diameter(ECOD(sub)50) were performed. A recalculation method of original diameter for hemispheric liquid aerosol collected on casecad impactor is also proposed newly using fixation technique. Calculated values for theoretical (ECOD(sub)50) of 40stage cascade impactor are 20, 6.4, 2.8, and 1.4$\mu\textrm{m}$ at 1st- ,2nd-, 3rd- and 4th-stage, respectively. A good agreement between the result of theoretical (ECOD(sub)50) and that og experimental ones was obtained at Stage 2 and 3. On the other hand, relatively large differences were found at Stage 1 and 4. Fixation for liquid aerosols using ${\alpha}$-cyanoacrylate monomer was performed successfully. The orignal diameter of liquid aerosols collected on each stage was calculated. The maximum levels of number size distribution curves at each stage are 19.8, 6.5, 3.1 and 1.5 $\mu\textrm{m}$ at 1st-, 2nd-, 3rd- and 4th-stage, respectively. The distortion of separation capacity of cascade impactor due to the split, merger, disappearance, and evaporation of liquid aerosols in the fluid did not occur.

• Transactions of Materials Processing
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• v.24 no.2
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• pp.115-120
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• 2015

Deep drawing of cylindrical cups is one of the most fundamental and important processes in sheet metal forming. Circular cups are widely used in industrial fields such as automobile and electronic appliances. Some of these cups are formed by a one-stage process, others such as battery cases and beverage cans are made by a multi-stage process. In the current study the multi-stage deep drawing of aluminum sheet metal is examined. The process consists of two deep drawing operations followed by two ironing operations. The press die, which can be used for the four-stage forming process, was manufactured allowing punch and die components to be easily changed for various experiments. The rolling direction of both the sheet and the drawn cups was always positioned toward the horizontal x-direction on the die face to minimize experimental errors during the progressive forming. The dimensional accuracy of the cylindrical cups formed at each stage and the earing defect due to the anisotropy of sheet were investigated. The influence of anisotropy on the thickness distribution was also examined. Both the thickness and the outer diameter of the cups were measured and compared for each set of experimental conditions. It was found that the dimensional accuracy of cups rapidly improves by employing the ironing process and also by increasing the amount of ironing.

• Journal of Korean Medical classics
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• v.20 no.3
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• pp.57-65
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• 2007

This present study tried to observe an each feature that the difference of Neijing(內經) and Nanjing(難經) descriptions about the three-portion and nine-position pulse taking(三部九候脈). It was interpreted and contradistinguished that discrimination of position, diagnosis object, and the perceptions of Earth of the center among the Five Phase of each literature were described in Neijing and Nanjing for the three-portion and nine-position(三部九候). In Neijing, the three-portion and nine-position method divided three parts the whole body. Then the each three parts again divided with Heaven, Earth and Man(天地人). About the corresponding parts of pulse diagnosis, there mentioned for the head and the Zang-Fu organs(臟腑), but not mentioned for the hand and foot. In addition, Earth is assigned to the Earth(土), an each Earth accounted for the source of life. In Nanjing, three-portion divided Chon, Gwan, and Cheok(寸關尺) and each spots separated three stage of pulse taking. For the pulse taking spots and diagnosis, there mentioned the hand and foot instead of the unclear mention of Zang-Fu organs. Then Gwan spot and middle stage of pulse taking were assigned to the Earth, respectively. It was emphasized stomach Qi(胃氣) that the region of Earth, Gwan spot and middle stage among the pulse taking spots each literature were described in Neijing, Nanjing.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.455-462
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• 1999

This study was designed to investigate the number of the growing and mature follicles in each stage of estrus cycle in mature rats. Eighteen mature rats(Sprague-Dawley, initially 190~230gm) were randomly alloted into 4 groups(proestrus, estrus, metestrus, and diestrus) according to estrus cycles. The uteri and ovaries of rats were collected and then alternative sections of paraffin embedding ovaries were stained with H-E. Numbers of large, middle and small follicles or only large and middle follicles from secondary and tertiary follicles were investigated by LM photography of preparations. Small follicles were defined as secondary follicles with 2~5 cell layers of granulosa cells surrounding the oocyte, and middle follicles were defined as secondary follicles with more than 5 cell layers or with early signs of antral cavity or with more than one small cleft on either side of the oocytes and large follicles were defined as tertiary follicles with a single medium or large antral cavity. The number of follicles in a pair ovary per rat was appeared to be ranged from 207 to 370 and the mean number of these follicles was $270.4{\pm}52.6$ and the mean number of follicles per ovary was $134.9{\pm}32.0$. The mean number of large, middle and small follicles per ovary was appeared to be $16.4{\pm}4.4$($12.2{\pm}3.3%$), $36.2{\pm}8.6$($26.8{\pm}6.4%$), and $82.7{\pm}24.0$($61.3{\pm}17.8%$), respectively. The mean number of large and middle follicles in each stage group of estrus cycle was appeared to be $17.8{\pm}2.1$ and $38.3{\pm}7.4$ at proestrus stage group, $15.7{\pm}5.2$ and $38.0{\pm}10.0$ at estrus stage group, $16.5{\pm}3.5$ and $33.8{\pm}7.0$ at metestrus stage group, $16.7{\pm}5.8$ and $29.7{\pm}5.5$ at diestrus group, respectively. In histological findings of large follicles during each estrus cycle, the large follicles in proestrus group contain single small antrum, thick granulosa cell layers, and were $300{\sim}500{\mu}m$ in diameter and were growing follicles with PCNA-positive cells in the granulosa cell layers, and other luteinizing follicles of proestrus cycle stage were decreased in size and were thicker in wall thickness and more luteinized than those in metestrus and diestrus stage groups. The large follicles in estrus stage group contain thick granulosa cell layers and nonprominent cumulus-oocyte complexes in antrum, and were $400{\sim}700{\mu}m$ in diameter and were growing follicles with PCNA-positive cells in the granulosa cell layers. The large follicles in metestrus and diestrus stage groups contain enlarged antrums, thinner layers of walls and prominent cumulus-oocyte complexes, and were $700-950{\mu}m$ in diameter, and were nongrowing follicles without PCNA-positive cells or another large follicles contain cells with dark stainability and distinct boundary.