• Title/Summary/Keyword: Hwang-to

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Organic Matter Cycle by Biogeochemical Indicator in Tidal Mud Flat, West Coast of Korea (생지화학적 지표를 이용한 서해안 갯벌 퇴적층에서의 유기물 순환에 관한 연구)

  • Lee, Dong-Hun;Lee, Jun-Ho;Jeong, Kap-Sik;Woo, Han Jun;Kang, Jeongwon;Shin, Kyung-Hoon;Ha, Sun-Yong
    • Ocean and Polar Research
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    • v.36 no.1
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    • pp.25-37
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    • 2014
  • To understand the degradation processes of organic matter related to sulfate reduction by Sulfate Reduction Bacteria (SRB) in the tidal flat sediments of Hwang-do and Sogeun-ri, Tae-an Peninsula in Chungnam-do, biogeochemical characteristics were analyzed and highlighted using specific microbial biomarkers. The organic geochemical parameters (TOC, ${\delta}^{13}C_{org}$, C/N ratio, long-chain-n-alkane) indicate that most of the organic matter has been derived from marine phytoplankton and bacteria in the fine-grained sediment of Sogeun-ri, although terrestrial plant components have occasionally been incorporated to a significant degree in the coarse-grained sediment of Hwang-do. The concentration of sulfate in pore water is a constant tendency with regard to depth profile, while methane concentration appears to be slightly different with regard to depth profile at the two sites. Especially, the sum of bacteria fatty acid (a-C15:0 + i-C15:0 + C16:1w5) confirms that the these concentrations in Sogeun-ri are related to the degradation of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) compounds from the crude oil retained in the sediments as a result of the Hebei Spirit oil-spill accident in 2007. The methane-related microbial communities as shown by lipid biomarkers (crocetane, PMI) are larger in some sedimentary sections of Hwang-do than in the Sogeunri tidal flat. These findings suggest that methane production by microbiological processes is clearly governed by SRB activity along the vertical succession in organic-enriched tidal flats.

A Investigation study on the evaluation of evacuation capacity for egress safety deign in Korea(III) (국내 PBD기반 피난안전설계를 위한 피난용량 산정에 관한 연구(III) - 수평적 군집피난속도식의 제안 -)

  • Seo, Dong-Goo;Hwang, Eun-Kyung;Hwang, Keum-Suk;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.334-339
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    • 2008
  • Recently the consideration for occupant's security has been raised as very important design element from the fire by building's large sized, higher storied, and its compounded. But the domestic laws regulated the predicative laws according to the technical standard which has no difference from the past domestic evacuation regulation. Therefore, regulation of escape code and developing technology for Korean conditions are needed to reduce victims during disaster by protecting occupant and guiding people to safe places.

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A Study on the Escape capacity for Evacuation safety Design of PBD foothold in Korea(I) (국내 PBD기반 피난안전설계를 위한 피난용량 산정에 관한 연구(I) - 국내외 피난용량 산정방안의 비교 -)

  • Seo, Dong-Goo;Hwang, Eun-Kyung;Hwang, Keum-Suk;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.340-347
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    • 2008
  • Recently the consideration for occupant's security has been raised as very important design element from the fire by building's large sized, higher storied, and its compounded. But the domestic laws regulated the predicative laws according to the technical standard which has no difference from the past domestic evacuation regulation. Therefore, regulation of escape code and developing technology for Korean conditions are needed to reduce victims during disaster by protecting occupant and guiding people to safe places.

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Autogenous tooth transplantation for replacing a lost tooth: case reports

  • Kang, Ji-Youn;Chang, Hoon-Sang;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann;Lee, Bin-Na
    • Restorative Dentistry and Endodontics
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    • v.38 no.1
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    • pp.48-51
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    • 2013
  • The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

Analysis of Noise Characteristic Considering Magnetic Force of IPM Motor (매입형 영구자석 전동기의 전자기력을 고려한 소음특성 분석)

  • Lee, Hong-Joo;Kwon, Joong-Hak;Lee, Chang-Min;Hwang, Gun-Yong;Hwang, Sang-Moon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.5
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    • pp.439-446
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    • 2009
  • Noise sources in electric machines are broadly categorized as magnetic, mechanical, electronic and aerodynamic. Especially, there are several kinds of noise sources due to the change of reluctance by rotor position in IPM motor. To separate acoustic noise by mechanical structure and electromagnetic sources, resonance frequency and the effect of vibration and acoustic noise by electromagnetic sources are analyzed. And then, the structural and electromagnetic designs to reduce acoustic noise are performed. The relevance about the study on noise reduction of IPM motor is verified by noise experiment, noise and vibration analysis.

Atomization Characteristics of Cutting Fluids (절삭유의 미립화 특성)

  • Hwang, Joon;Chung, Eui-Sik;Joung, Jin-Yel;Hwang, Duck-Chul
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.943-946
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    • 2002
  • This paper presents atomization characteristics of cutting fluids. To analyze the behavior characteristics of cutting fluid, analytical approach and experimental measurement were performed to predict the aerosol size, velocity and concentration due to cutting fluid atomization mechanism in machining operation. The established analytical model which is based on atomization theory analyzes the cutting fluid motion and aerosol generation in machining process. The predictive models can be used as a basis for environmental impact analysis on the shop floor. It can be also facilitate the optimization of cutting fluid usage in achieving a balanced consideration of productivity and environmental consciousness.

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Occurrence of Pediatric Diseases in Relation to the Environment, Seasons and Atmospheric Phenomena(weather) (소아환자발생과 거주지역 환경, 계절 및 기상과의 관계)

  • Yun, Duk-Jin;Park, Kyung-Sook;Hwang, Han-Kee;Ahn, Chi-Ok;Yun, Do-Kwang;Kwon, Yung-Jo;Park, Dong-Chul;Yun, Yong-Hwang;Nam, Chung-Mo
    • Journal of Preventive Medicine and Public Health
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    • v.22 no.2 s.26
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    • pp.283-289
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    • 1989
  • This study was conducted to investigate the association of the occurrence of pediatric diseases with environmental, seasonal and atmospheric factors. The data were collected at 5 pediatric clinics in Seoul and the Department of Pediatrics of Yongin Severance Hospital from May 1986 to April 1987. The results were as follows: 1. Vacation periods had a great influence upon the occurrence of pediatric diseases. 2. The majority of pediatric diseases occurred mainly in spring and autumn, not in summer and winter. 3. The higher the average relative humidity was, the less diseases occurred : and the higher the maximum change of daily temperature, the more diseases occurred. 4. In summer, the pattern of diseases varied along with the environmental factors(eg., toilet).

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Multiplication and Transformation of Medicinal Plants for Production of Useful Secondary Metabolites II. Establishment of Hairy Root Cultures of Centella asiatica

  • Paek, Yun-Woong;Hwang, Sung-Jin;Park, Don-Hee;Hwang, Baik
    • Journal of Plant Biology
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    • v.39 no.3
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    • pp.161-166
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    • 1996
  • The hairy root cultures of Centella asiatica were established by infection leaf explants with Agrobacterium rhizogenes A4, 15834 in 1/2 Murashing and skoog liquid medium supplemented with 50 $\mu$M acetosyringone. The induced hairy roots were subjected to paper electrophoresis for the detection of opine and opine-positive clones which were considered to have been transformed. Five hairy root clones were selected according to the different bacterial strains used, growth rate and pattern. Among media tested, MS basal medium substituted phosphate concentration by 2.5mM K2HPO4 showed the highest growth rate in the dark condition.

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Made of temperature controlled coffee pot (온도 조절 커피포트 제작)

  • Hwang, Seung-jin;Jo, Su-jang;kwon, Se-hyun;Hwang, Ho-yeon;Yoo, Ji-yeon;Shin, Seong-Yoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.307-308
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    • 2018
  • Nowadays people often use coffee pots to boil water. The coffee pot is turned on and off at 100 degrees, but it is a technique that uses a temperature check sensor and algorithm to operate the coffee port to the desired temperature.

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Character Analysis of the Flora of Mt. Kumjung (금정산 식물상의 특성분석)

  • Kim, Maeng-Ki;Bae, Chun-Hwa;Kim, Jong-Won
    • Journal of Environmental Science International
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    • v.6 no.1
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    • pp.89-94
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    • 1997
  • The flora of Mt. Kum.lung(80 lm) was Investigated to compare the flora of Mt. Hwang-Ryung, Mt. Cheon-Hwang, Mt. Chulseo. The vascular plants, collected from March 1995 to Oct., 1996, were consisted of a total 564 taxa: 103 families, 312 genera, 493 species, 1 subspecies. 66 varieties and 4 forms. The Korean endemic plants of this area were 11 taxa, the alplan and endangered plants were 29 taxa, the special wild plants designatlrlg by Enoronmental Agency were 2 taxa and the alpian plants were 18 taxa. Because many plants, being necessary to conserve, are distributed Kumjung, but if development is indespensable. destruction of natural ecosystem must be minimized.

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