• Title/Summary/Keyword: DO3A

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Effects of DO concentration on Simultaneous Nitrification and Denitrification(SND) in a Membrane Bioreactor(MBR) (MBR 단일 반응조에서 용존산소 농도에 따른 동시 질산화-탈질반응(SND)의 영향)

  • Park, Noh-Back;Choi, Woo-Yung;Yoon, Ae-Hwa;Jun, Hang-Bae
    • Korean Journal of Environmental Agriculture
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    • v.28 no.4
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    • pp.371-377
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    • 2009
  • In this study, simultaneous nitrification and denitrification (SND) from synthetic wastewater were performed to evaluate dissolved oxygen(DO) effects on chemical oxygen demand(COD) and nitrogen removal in a single membarne bio-reactor(MBR). DO levels in MBR at Run 1, 2, and 3 were 1.9~2.2, 1.3~1.6, and 0.7~1.0 mg/L, respectively. Experimental results indicated that DO had an important factor to affect COD and total nitrogen(TN) removal. SND were able to be accomplished in the continuous-aeration MBR by controlling ambient DO concentration. It is postulated that, because of the oxygen diffusion limitation, an anoxic micro-zone was formed inside the flocs where the denitrification might occur. From the results of this study, 96% of COD could be removed at DO of 0.7mg/L. At run 2 72.92% of nitrogen was removed by the mechanisms of SND (7.75mg-TN/L in effluent). In this study, SND was successfully occurred in a MBR due to high MLSS that could help to form anoxic zone inside microbial floc at bulk DO concentrations of 1.3~1.6mg/L.

Building Local Digital Archives: The Case of "Gyeonggi-do Memory" (지역 디지털 아카이브 구축: '경기도메모리' 사례)

  • Shin, JeongA
    • Journal of Korean Society of Archives and Records Management
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    • v.20 no.3
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    • pp.161-166
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    • 2020
  • "Gyeonggi-do Memory," established and operated by Gyeonggi-do Cyber Library, is a local digital archive aiming to broaden the access to Gyeonggi-do's cultural resource records. Since 2014, the library has been expanding its digital information service, starting with the said archive. Through cooperation with various cultural institutions in the province, it builds the digital archive by collecting numerous records. In particular, the archive is expected to establish itself as a repository that stores records of production or dealing in Gyeonggi-do and a platform to share with researchers and citizens.

The Spider Fauna of Is. Dae Heucksan-do and Is. Hong-do, Korea (대흑산도와 홍도의 거미상)

  • Namkung Joon
    • Korean journal of applied entomology
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    • v.17 no.3 s.36
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    • pp.161-166
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    • 1978
  • Is. Dae Heucksan-do and Is. Heucksan-do and Is. Hong-do are located in the southwestern, apart 110km from Mockpo city, Korea., and the spider fauna of this area has never been explored. The author collected the spiders from these Islands in August 1974. Findings were; 1) 83 species of spiders belonging to 17 families, including 5 undetermined species. 2) Leptoneta sp., Carrhotus sp. (A), Marpissa sp. and Synagelides sp. are reserved for future study. 3) The materials were not sufficient for general discussion and conclusions of the spider fauna of these Islands. However, results can be summarized as follows: 7 northern species $8.9\%$ 9 southern species $11.5\%$, 4 cosmopolitan $5.1\%$ 4) The common species of mainland China were 41 $51.9\%$. 5) As the result of this survey, the spider fauna of this area is similar to that of the Is. Cheju-do and Is. Tsushima, in the south eastern area, and have much more common to China than any another area in Korea.

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A Method of Patch Merging for Atlas Construction in 3DoF+ Video Coding

  • Im, Sung-Gyune;Kim, Hyun-Ho;Lee, Gwangsoon;Kim, Jae-Gon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2019.11a
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    • pp.259-260
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    • 2019
  • MPEG-I Visual group is actively working on enhancing immersive experiences with up to six degree of freedom (6DoF). In virtual space of 3DoF+, which is defined as an extension of 360 video with limited changes of the view position in a sitting position, looking at the scene from another viewpoint (another position in space) requires rendering additional viewpoints using multiple videos taken at the different locations at the same time. In the MPEG-I Visual workgroup, methods of efficient coding and transmission of 3DoF+ video are being studied, and they released Test Model for Immersive Media (TMIV) recently. This paper presents the enhanced clustering method which can pack the patches into atlas efficiently in TMIV. The experimental results show that the proposed method achieves significant BD-rate reduction in terms of various end-to-end evaluation methods.

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Characteristics of Reverse Flux by using Direct Omosis in RO Membrane Process (역삼투막 공정에서 Direct Osmosis의 역방향 Flux 기초특성)

  • Kang, Il-Mo;Dock-Ko, Seok
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.3
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    • pp.399-405
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    • 2011
  • In a desalination technology using RO membranes, chemical cleaning makes damage for membrane surface and membrane life be shortened. In this research cleaning technology using direct osmosis (DO) was introduced to apply it under the condition of high pH and high concentration of feed. When the high concentration of feed is injected to the concentrate side after release of operating pressure, then backward flow occurred from treated water toward concentrated for osmotic pressure. This flow reduces fouling on the membrane surface. Namely, flux of DO was monitored under pH 3, 5, 10 and 12 conditions at feed concentrations of NaCl 40,000 mg/L, 120,000 mg/L and 160,000 mg/L. As a result, DO flux in pH 12 increased about 21% than pH 3. DO cleaning was performed under the concentrate NaCl 160,000 mg/L of pH 12 during 20 minutes. Three kinds of synthetic feed water were used as concentrates. They consisted of organic, inorganic and seawater; chemicals of SiO2 (200 mg/L), humic acid (50 mg/L) sodium alginate (50 mg/L) and seawater. As a result, fluxes were recovered to 17% in organic fouling, 15% in inorganic fouling and 14% of seawater fouling after cleaning using DO under the condition of concentrate NaCl 160,000 mg/L of pH 12.

Developing Object Library Browser for Reclamation Based BIM (BIM 기반의 준설매립전용 Library Browser 개발)

  • Lee, Dongyun;Lee, Junho;Lee, Sangwoong;Choi, Chaseok;Gu, Bonhyo
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.3
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    • pp.57-63
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    • 2014
  • This study has been conducted to building a library intended for structures considered in the design of reclamation for design automation and developing browser for integrated management system. The library has been developed using a parametric modeling method capable of changing section shape, also classifying standard crossing and family library, has been developed according to the working environment. Classified library by the characteristics manages objects and working modeling on based BIM has been developed browser using the C# program for objects to use conveniently. By interworking between developed Browser and 3D Autocad based BIM, it is possible to use easily at design drafting, calculating quantities, developing a new library, and managing a library. The browser using effectively exclusive library to reclamation is developed in this study.

Characteristics of Precipitation and Temperature at Ulleung-do and Dok-do, Korea for Recent Four Years(2005~2008) (최근 4년간(2005~2008) 울릉도와 독도의 강수 및 기온 특성)

  • Lee, Young-Gon;Kim, Baek-Jo;Park, Gil-Un;Ahn, Bo-Young
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1109-1118
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    • 2010
  • Characteristics of precipitation and temperature in Ulleung-do and Dok-do were analyzed with hourly accumulated precipitation and mean temperature data obtained from Automatic Weather System(AWS) for latest four years(2005~2008). In Ulleung-do, total annual mean precipitation for this period is 1,574.4 mm, which shows larger amount than 1434.2 mm of whole Korean peninsula for latest 10 years(1999~2008) and 1,236.2 mm at Ulleung-do on common years(1971~2000), shows that the trend of precipitation gradually increases during the recent years. This amount is also 1.4 times larger than the total annual mean precipitation of 660.1 mm in Dok-do. Mean precipitation intensity(mm $h^{-1}$) at each time of a day in each month at Ulleung-do represents that the maximum values larger than $3.0\;mm\;h^{-1}$ were shown in May and on 0200 LST, whereas these were found in August and 0700 LST with $3.1\;mm\;h^{-1}$ in Dok-do. The difference of the precipitation amount and its intensity between Uleung-do and Dok-do is explained by the topological effect came from each covering area, and this fact is also identified from similar comparison of the precipitation characteristics for the islands in West Sea. The annual mean temperature of $14.0^{\circ}C$ in Dok-do is $1.2^{\circ}C$ higher than that of $12.8^{\circ}C$ in Ulleung-do. Trends of monthly mean temperature in both islands are shown to increase for the observed period.

Flora and Life-form of the Uninhabited Islets, in Jeju-do (제주도 무인도서의 식물상과 생활형)

  • Song, Kuk-Man;Hyun, Hwa-Ja;Kang, Chang-Hun;Kim, Moon-Hong
    • Journal of Environmental Science International
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    • v.18 no.11
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    • pp.1309-1324
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    • 2009
  • This study was survey a flora and life form spectrum of 11 uninhabited islets, in jeju-do. The vascular plants of each uninhabited islets were summarized as Beomseom 159 taxa, Chagwi-do 136 taxa, Daryeo-do 81 taxa, Hyeongje-do 61 taxa, Jigwi-do 39 taxa, Munseom 147 taxa, Ran-do 58 taxa, Saeseom 65 taxa, Seogeondo 60 taxa, Seopseom 183 taxa and Wa-do 46 taxa. Floristic richness was in order analyzed to be Seogeon-do 28.62, Ran-do 19.24, Daryeo-do 18.53, Wa-do 16.42, Munseom 16.14, Hyeongje-do 14.76, Seopseom 13.32, Beomseom 13.24, Chagwi-do 6.15, Saeseom 5.86 and Jigwi-do 2.51. Life form spectrum was surveyed to H-$D_5$-$R_4$-e; hemieryptophyte(H) 26.8%, not production seeds($D_5$) 54.4%, clonal growth by stolons and struck roots($R_4$) 46.9% and erect form(e) 30.3%. According to the life form spectrum hemieryptophyte dominated high portions, which suggests islet in jeju-do has hemieryptophytic climate and similar to middle parts in Korean Peninsular. However, were noticed by that it has more therophytes. As a result, Partially shows the characteristics change from the temperate climate to the warm temperate climate or a semitropical climate by a climatic change.

A Study on Projection Conversion for Efficient 3DoF+ 360-Degree Video Streaming

  • Jeong, Jong-Beom;Lee, Soonbin;Jang, Dongmin;Kim, Sungbin;Lee, Sangsoon;Ryu, Eun-Seok
    • Journal of Broadcast Engineering
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    • v.24 no.7
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    • pp.1209-1220
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    • 2019
  • The demand for virtual reality (VR) is rapidly increasing. Providing the immersive experience requires much operation and many data to transmit. For example, a 360-degree video (360 video) with at least 4K resolution is needed to offer an immersive experience to users. Moreover, the MPEG-I group defined three degrees of freedom plus (3DoF+), and it requires the transmission of multiview 360 videos simultaneoulsy. This could be a burden for the VR streaming system. Accordingly, in this work, a bitrate-saving method using projection conversion is introduced, along with experimental results for streaming 3DoF+ 360 video. The results show that projection conversion of 360 video with 360lib shows a Bjontegaard delta bitrate gain of as much as 11.4%.

Quantitative Analysis of Contents of Vegetable Oils in Sesame Oils by NIRS (근적외선분광광도법을 이용한 참기름중 이종식용유지 정량법에 관한 연구)

  • Kim, Jae-Kwan;Kim, Jong-Chan;Ko, Hoan-Uck;Lee, Jung-Bock;Kim, Young-Sug;Park, Yong-Bae;Lee, Myung-Jin;Kim, Myung-Gil;Kim, Kyung-A;Park, Eun-Mi
    • Journal of Food Hygiene and Safety
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    • v.22 no.4
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    • pp.257-267
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    • 2007
  • The possibility of rapid non-destructive qualitative and quantitative analysis of vegetable oils such as perilla, com, soybean and rapaseed oils in sesame oils was evaluated. A calibration equation calculated by MPLS(Modified Partial Least Squares) regression technique was developed and coefficients of determination for perilla oil, com oil, soybean oil and rapaseed oil contents were 0.9992, 0.9694, 0.9795 and 0.9790 respectively. According to the data obtained from validation study, $R^2$ of contents of perilla, com, soybean, rapaseed oils were 0.997, 0.848, 0.957 and 0.968, and SEP of content of them 0.747, 5.069, 3.063 and 3.000 by MPLS respectively. The results indicate that the NIRS procedure can potentially be used as a non-destructive analysis method for the rapid and simple measurement of sesame oil mixed with other vegetable oils. The detection limits of the NIRS for perilla oil, com oil, soybean oil and rapaseed oil were presumed as 2%, $15{\sim}20%,\;15{\sim}20%$ and 10%, respectively.