• Food Science and Preservation
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• v.24 no.3
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• pp.394-405
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• 2017

This study was conducted to confirm the usefulness of essential oil components in yuzu and kumquat cultivated in Korea for comparison with those in lemon and lime. The volatile flavor compounds in citrus fruits (yuzu, kumquat, lemon and lime) were extracted for 3 h with 100 mL redistilled n-pentane/diethylether (1:1, v/v) mixture, using a simultaneous steam distillation and extraction apparatus (SDE). The volatile flavor compositions of the samples were analyzed by gas chromatography-mass spectrometry (GC-MS). The aroma compounds analyzed were 104 (3,713.02 mg/kg) in yuzu, 87 (621.71 mg/kg) in kumquat 103 (3,024.69 mg/kg) in lemon and 106 (2,209.16 mg/kg) in lime. Limonene was a major volatile flavor compound in four citrus fruits. The peak area of limonene was 35.03% in yuzu, 63.82% in kumquat, 40.35% in lemon, and 25.06% in lime. In addition to limonene, the major volatile flavor compounds were ${\gamma}$-terpinene, linalool, ${\beta}$-myrcene, (E)-${\beta}$-farnesene, ${\alpha}$-pinene and ${\beta}$-pinene in yuzu, and ${\beta}$-myrcene, ${\alpha}$-pinene, (Z)-limonene oxide, (E)-limonene oxide, geranyl acetate and limonen-10-yl acetate in kumquat. Furthermore, ${\gamma}$-terpinene, ${\beta}$-pinene, ${\beta}$-myrcene, geranyl acetate, neryl acetate and (Z)-${\beta}$-bisabolene in lemon and ${\gamma}$-terpinene, ${\beta}$-pinene, (Z)-${\beta}$-bisabolene, neral, geranial and neryl acetate in lime were also detected. As a result, it was confirmed that the composition of volatile flavor compounds in four citrus fruits was different. Also, yuzu and kumquat are judged to be worthy of use alternatives for lemon and lime widely used in the fragrance industry.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.359-365
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• 1985

The four rice varieties, Kwanak, Nongbaek, Pungsan and Nampung-byo were cultivated to examine the growth conditions and grain yield in a Gyuam SiL paddy field irrigated with cold water around $17^{\circ}C$. Water temperatures for various distances from the inlet were measured. The results were summerized as follows. 1. Culm length, panicle exertion, diameter of the 3rd internode stem, heading date, fertilization rate, ripeness rate, no. of grains per panicle and grain yield were sensitive to water temperature. Panicle length, flag-leaf length, diameter of spike-neck and no. of panicles, however, were negligibly sensitive and there were no differences among varieties. 2. Elongations of the 2nd and 3rd internode steam were unsensitive to water temperature. 1st internode elongation and 4th internode development, however, were sensitive which was major factor in the culm length. 3. Ratios of partial dry weight to total dry weight were closely correlated with water temperature, Therefore, dry weight of grain was increased with water temperature while that of plant and root decreased. 4. Chlorophyll contents were decreased with the increment of water temperature and the highest at $20^{\circ}C$. 5. There was no grain yield at $17^{\circ}C$, Increases of grain yield to water temperature per unit were order at Pungsan > Kwanak > Nongbaek > Nampung. 6. The critical temperature in grain yield was $21^{\circ}C$. Optimum temperatures of Japonica ${\times}$ Indica types were higher than those of Japonica types.

• Journal of vocational education research
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• v.36 no.1
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• pp.47-75
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• 2017

The purpose of this study was to provide basic data for policy making for secondary vocational education in each region and transformation in vocational high schools. To achieve this, the regional strategic industries in Daejeon and Jeonnam were selected, new demand for vocational high school graduates was forecasted in each industry and occupation. The results of the study are as follows. First, locational quotient analysis and regional shift-share analysis revealed that Daejon and Jeonnam have different strategic industries. Daejon, unlike Jeonnam strategically develops 'manufacturing food, beverage and tobacco', 'manufacturing timber and paper, printing and copying', 'public service and administration of national defense and social security' and 'manufacturing electrical devices, electronics and precision devices'. Jeonnam has specialized industries distinguished from Daejon's, which are 'manufacturing of machinery transportation equipments and etc', 'manufacturing of non-metallic minerals and metal products', 'electric, gas, steam and water supply systems/industries', 'manufacturing coal and chemical products, refining petroleum', 'mining' and 'agriculture, forestry and fishery'. Second, new demand for vocational high school graduates by occupations and industries showed regional differences(in Daejon and Jeonnam). According the forecast, Daejon will have many workforce demands based on manufacturing industries, on the other hand Jeonnam's focused on service industries. Analysis by occupations was also different, Daejon showed high demands on professional and related workers, while Jeonnam requested many new office and service workers. Third, new workforce demand by occupations in regional strategic industries is big part of overall new workforce demand both in Daejon and Jeonnam. Forth, according to the results of analyzing the new demand for vocational high school graduates in Daejeon and Jeonnam in terms of industry location quotient and change effect, there was high demand in industries with positive total change effects. In terms of location quotient, Daejeon and Jeonnam showed different results.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.985-994
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• 2018

Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

• Journal of agriculture & life science
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• v.53 no.5
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• pp.137-143
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• 2019

To manufacturing of solid fuel by reuse of the wastes, the drying unit which have 500 kg/hr of drying capacity was developed and experimentally evaluate the performance. The spinach grown in Nam-hae island were used for the experiments and investigated of the heated-air drying characteristics as the inlet amount of raw materials, raw material stirring status, conveying type and drying time. The drying air heated by the energy derived from the steam which is supplied from the incineration plant. The moisture contents of raw materials were measured 85.65%. The inlet flow rate of drying air made a difference as the depth of the raw materials loaded on the drying unit and temperature has showed 108~144℃. The drying speed of the mixed drying more than doubled as that of non mixed drying under the same drying type, inlet amount, drying time and drying air temperature. In each experiment, the drying capacity have showed over 500 kg/hr. A drying efficiency of the ratio of drying consumption energy to input energy was 33.46%, lower than the average of 57.76% for the 157 conventional dryers. Because developed dryer must have a drying time of less than one hour, it is considered that the dry efficiency has been reduced due to the loss of wind volume during drying. If waste heat from incineration plant is used as a direct heat source, the dry air temperature is expected to be at least 160℃, greatly improving the drying capacity.

• Journal of Popular Narrative
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• v.27 no.2
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• pp.107-142
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• 2021

Emergence of new media platform had changed relationship between the broadcaster and the viewer, which used to form 'performer-audience' structure. This research has focused on the transition of 'streamer-viewer' role in single-media broadcasting, such as Youtube or Twitch, and identify how they progress group storytelling as a team. Walter Benjam and Leslie Marmon Silko's notion of 'story and storyteller' and Erving Goffman's 'social role theory' was used to define participants' role in new media broadcasting. channel, on Youtube, was selected and analyzed as example case. The domain of 'front stage' was broadened in recorded contents comparing to live streaming. The audience of live streaming is included to the front stage during the expansion. The role of streamer, game participant, and live stream contents viewer is also adjusted during the change, which leads to group-creation of the contents. Streamer plays a role of main-storyteller and suggest identity of the community. Game participants work as sub-storyteller, filling in the blank space in game storytelling and making it sophisticated. They also perform based on community's identity, which streamer has built in advance. Lastly, live steam viewers are intermittent sub-storyteller, which seldom add up the narrative. Though, their main role is to preserve identity of game broadcasting community by reacting according to community's identity. As a result, the game broadcasting narrative is developed by combining and adding up pieces of story made in different level and role of participants. The research redefine the role of viewer and storytelling method in new media, especially in single-person broadcasting. Considering the rapid shift in recent media and contents, a new approach to the streamer-veiwer role and group storytelling of this research can be one of the new method to analyze contents produced in new media, such as Youtube.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.287-298
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• 2022

This study investigated the changes in the physiochemical property, phytochemical content, nutritional content and antioxidant activity of Polygoni multiflori Radix by steam, aging, and fermentation. After processing Polygoni multiflori Radix (PMR), pH slightly decreased, while acidity increased (pH 5.70→4.78, acidity 0.23→0.29%). The reducing sugar content increased after aging and fermentation from 1.19 mg/g (PMR) to 1.40 (fermented PMR, FPMR), 1.30 (red PMR, RPMR), 1.53 (fermented red PMR, FRPMR), 1.99 (black PMR, BPMR), and 2.33 mg/g (fermented black PMR, FBPMR). Total phenolic content was highest in PMR (6.05 mg/g) and total flavonoids and maillard product were increased after aging and fermentation of PMR, and were the highest in BPMR (1.60 mg/g) and FBPMR (2.76 O.D.), respectively. The major phytochemical was 2,3,5,4'-tetrahydroxystilbene-2-0-α-glucoside, which were highest in PMR (64.9 mg/g) with 46.47 mg/g at FPMR, 33.94 mg/g at RPMR, 48.76 mg/g at FRPMR, 36.68 mg/g at BPMR and 34.35 mg/g at FBPMR. The main fatty acids and free amino acids were detected as palmitic acid (C16:0) and proline, respectively. Generally, 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activities and FRAP reducing powers were shown high in PMR (39.06%, 98.32%, and 2.61 O.D. in extracts concentration 1.0 mg/mL), then were decreased after aging and fermentation.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.603-614
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• 2022

This study investigated the characteristics of fish communities in the Bangtaecheon Stream in Korea from April to October 2020. The survey collected 4,640 fish of 26 species in 9 families from 11 survey stations. The dominant and subdominant species were Rhynchocypris kumgangensis(relative abundance at 31.5%) and Zacco koreanus(27.8%), respectively. The next most abundant species were Ladislavia taczanowskii(15.9%), Pungtungia herzi(4.0%), Brachymystax lenok tsinlingensis(3.7%), Microphysogobio longidorsalis(2.4%), and Zacco platypus(2.3%). Among the collected fish species, 17 (65.4%) were Korean endemic species, 4 (15.4%), including Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, and B. l. tsinlingensis,were class II endangered wildlife as designated by the Ministry of Environment, and 1 species, Hemibarbus mylodon, was a natural monument. Moreover, two landlocked species (B. l. tsinlingensisand C. koreanus) were also collected. Additionally, four cold-water species (R. kumgangensis, L. taczanowskii, B. l. tsinlingensis,and Cottus koreanus) were collected, and all of them mainly inhabited the upper and middle streams. Fish community analysis showed a tendency for dominance and uniformity to decrease and abundance and diversity to increase from upstream to downstream and that the community structure was divided into upstream and downstream groups. The river health was rated as excellent (9 stations) and good (2 stations). Compared to the previous studies, three species (Carassius auratus, Leiocassis ussuriensis,and Siniperca scherzeri) appeared in the past but did not appear in this survey, and three species (Opsariichthys uncirostris amurensis, Microphysogobio yaluensis,and Orthrias nudus) that did not appear in the past appeared in this survey. Bangtaecheon Steam is well-preserved, and climate-sensitive species, endangered wildlife, and natural monuments inhabit the stream. Therefore, continuous attention and systematic conservation measures are required.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.715-728
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• 2023

Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

• The Journal of the Acoustical Society of Korea
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• v.28 no.4
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• pp.343-355
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• 2009

In order to restore the identity of sound environment and expand the sound culture of a region, the purpose of this study are to excavate the resources of soundscape and find out the plans for the preservation and promotion of soundscape resources peculiar to the region. For this purpose, this research is conducted through an interview survey of residents and an observation survey using listening walk in Hongdo, one of the southwesten island of Korea. The results of survey confirm that there are so many sounds to hear around Hongdo island, those are, natural sounds such as the song of the birds, the roar of the waves, the whistling sounds, the shriek of the seagulls, and the pebbles sounds washed away by the waves, and artificial sounds such as the steam-whistle signals, the ship's broadcasts, the voice of tourists, the sounds of church bells, lighthouse sirens etc. The results suggest that it is necessary to consider several ways for restoration of an unique soundscape in Hongdo island, those are, improvement for efficient management of a ship's broadcasts in public areas, removal of a ferry in Hongdo swimming beach, management of Dangsanje (a religious service), preservation of a lighthouse siren and a foghorn, restoration and improvement of underground stream, management and control of public fish market, restoration of brooklet, management of cooperative system for a fish market, restoration of PoongO-Gut (a ritual for a large harvest) and a skate festival, management of a Hongdo sports meeting, sound quality modification of a boat whistle, restoration of orientalia such as a funeral bier, ecosystem preservation activity of the shore and ocean, and promotion of amenity for fascination and vitality in a rural community. Also, a sound map is drawn up for many tourists so as to realize the importance of sound environment and identity of soundscape and to gain their experience at first hand in Hongdo island.