• 제목/요약/키워드: U-do

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Seasonal Characteristics of Phytoplankton Dynamics and Environmental Factors in the Coast of Mara-do and U-do, Jeju Island, Korea

  • Affan, Abu;Lee, Joon-Baek
    • ALGAE
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    • 제19권3호
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    • pp.235-245
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    • 2004
  • A study on seasonal characteristics of phytoplankton dynamics and environmental factors was carried out at four stations including Mara-do and U-do located in the western and eastern coast of Jeju Island in southern Korea from April 2003 to March 2004. Out of 101 phytoplankton species identified, 84 belong to Bacillariophyceae, 9 Dinophyceae, 6 phytoflagellates and 2 coccolithophorids, and the highest value of species diversity was observed in April. Phytoplankton was more abundant at the western coast than at the eastern coast from March to September and its highest abundance was 49.24 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July. The pennate diatoms were more abundant at the western coast than at the eastern coast with the highest abundance of 38.75 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July, and during this period Nitzschia longissima contributed 68.5% of the total phytoplankton abundance. Naviculaceae was more abundant at Gosan (western coast) in November when Stauroneis membranacea represented 80.1% of the abundance. Leptocylindrus dances contributed 49.4% of the abundance at U-do in November. Dinophyceae was more abundant at U-do in August. Water temperature and pH fluctuated from 11.7${^{\circ}C}$ to 27.1${^{\circ}C}$ and from 7.31 to 8.70, respectively. Water temperature of Mara-do was about 1-2${^{\circ}C}$ higher than the other stations. Salinity varied from 30.4 to 35.0 psu with the minimum in rainy season and the maximum at the end of winter. The concentration of NH$_4$-N, NO$_3$-N, NO$_2$-N, PO$_4$-P and SiO$_2$-Si ranged 0.07-6.79, 1.0-62.0, 1.0-8.0, 1.0-7.0 and 7.0-191.0 $\mu$g-at L$^{-1}$, respectively. Chlorophyll a concentrations varied from 0.10 to 1.17 $\mu$g L$^{-1}$. NH$_4$-N concentrations were high at U-do from May to December, and at Mara-do from January to February. The high concentrations of NO$_3$-N were found at Mara-do from June to September and at U-do from January to May. The effects of various physicochemical parameters on the seasonal distribution and succession of phytoplankton population suggest that there is a classical pattern of phytoplankton dynamics in Jeju coastal waters.

NCW 구현을 위한 한국군 GIG 구축 방향에 관한 연구 (A Study on the Way of ROK's GIG Construction to enable NCW)

  • 김혜령;최상영
    • 한국국방경영분석학회지
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    • 제34권3호
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    • pp.53-66
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    • 2008
  • NCW 개념을 구현하기 위해서는 센서격자망(Sensor Grid)과 타격격자망(Shooter Grid)을 네트워크로 연결하는 정보격자망 구축이 핵심이다. 미 국방부는 정보격자망 개념을 국방 전 임무영역을 연결하는 GIG(Global Information Grid, 범세계 정보격자망)개념으로 발전시켰고, 이를 점진적으로 구축하고 있다. 이러한 관점에서 미 국방부 GIG구축 사례는 한국적 GIG 개념을 정립하는데 있어서 참고할 수 있다. 따라서 본 논문에서는 미 국방부 GIG 구축 동향과 한국군의 GIG 구축 현황을 분석하였고, 이를 근간으로 한국군의 GIG 구축 방향을 제시하였다.

REGULARITY OF NONLINEAR VECTOR VALUED VARIATIONAL INEQUALITIES

  • Kim, Do-Wan
    • 대한수학회지
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    • 제37권4호
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    • pp.565-577
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    • 2000
  • We consider regularity questions arising in the degenerate elliptic vector valued variational inequalities -div(|▽u|p-2∇u)$\geq$b(x, u, ∇u) with p$\in$(1, $\infty$). It is a generalization of the scalar valued inequalities, i.e., the obstacle problem. We obtain the C1,$\alpha$loc regularity for the solution u under a controllable growth condition of b(x, u, ∇u).

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진해만의 수괴구조와 용존산소 분포 (Water Mass Structure and Dissolved Oxygen Distribution in Chinhae Bay)

  • 김차겸;이필용
    • 한국수산과학회지
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    • 제27권5호
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    • pp.572-582
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    • 1994
  • To investigate water mass structure and DO(Dissolved Oxygen) distribution in Chinhae Bay, temperature, salinity and DO were observed in the bay in summer and winter from 1990 to 1993, and two-dimensional tidal current and parameter log($H/U^3$) were computed. Shallow water fronts in the bay were formed in summer in Kaduk channel and the central part of the bay having log($H/U^3$) values of $2.0{\sim}2.5$. Oxygen deficiency at the bottom layer in summer occurred in the western and northern part of the bay with weak tidal current, where the value of log($H/U^3$) was more than about 3.5 and $M_2$ tidal current was less than about 20 cm/s. DO concentration at the bottom layer of Kaduk channel and the central channel of the bay having the strong tidal current was more than about 3.5 mg/l. The isolines of DO concentration were nearly parallel to the isovelocity, and the concentrations correlated with the frontal location. The frontal location and DO distribution were influenced by tidal range, river inflow and meteorological conditions, and also correlated with bottom slope characteristics.

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제주도 동부연안역의 생물생태학적 기초연구 - 조간대 암반역에 분포하는 저서무척추동물의 계절적 군집변동 - (Bioecological Studies of the Eastern Coastal Area in Cheju Island - Seasonal Changes of Macroinvertebrate Commuity on the Intertidal Rocky Shores -)

  • 이정재;현재민
    • 한국패류학회지
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    • 제8권1호
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    • pp.1-20
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    • 1992
  • A study on the seasonal changes of the benthic macroinvertebrate community was performed on the intertidal rocky shores ao eastern coast of Cheju island and U-do throughout four seasons from october 1991 to August 1992. The macroinvertebrates were composed of 10 phyla, 18 classes, 39 orders, 94 families and 201 species. the number of speecies were 183 in summer, 147 in autumn, 138 in spring and 94 in winter, respectively. The total wpecies collected throuhout the study period were 193 species in U-do and 151 species in the eastern coast of Cheju Island. Nodilittorina exigua was the most dominant species in all seasons, followed by Monodonta neritoides in spring, autumn and winter, and pollicipes mitella in summer. U-do was higher in species diversity and richness and lower in evenness than the eastern coast. Species diversity and richness were higher in summer than any other seasons in lower intertidal zones. Community dominance indices, however, were significantly higher in upper intertidal zones than in lower intertidal zones.

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U-Healthcare 기기에서 DRDoS공격 보안위협과 Big Data를 융합한 대응방안 연구 (A Study on Countermeasures of Convergence for Big Data and Security Threats to Attack DRDoS in U-Healthcare Device)

  • 허윤아;이근호
    • 한국융합학회논문지
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    • 제6권4호
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    • pp.243-248
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    • 2015
  • U-Healthcare는 언제, 어디서나 환자의 건강을 검사하고 관리하며 유지할 수 있도록 하는 의료와 IT가 융합된 서비스이다. U-Healthcare 서비스에서 이루어지는 통신은 검진한 분석 결과나 긴급 데이터를 무선 통신방식을 이용하여 병원 서버에 전송하는 방식이 활용되고 있다. 이 때 악의적인 접근을 수행하는 자(공격자)가 U-Healthcare기기나 BS(Base Station)에 DRDoS(Distributed Reflection DoS)공격을 하면 위급한 환자의 상황 정보가 병원 서버까지 전송되지 않는 다양한 피해가 예상된다. 이를 대응하기 위해 DRDoS 공격 시나리오와 DRDoS에 대한 대응방안을 제안하고 대량의 패킷을 처리할 수 있는 빅데이터와 융합한다. 공격자가 U-Healthcare 기기나 BS(Base Station)를 공격 시 DB와 연동하여 일치하면 공격을 막는다. 본 논문은 원격의료 서비스인 U-Healthcare기기나 BS에서 나타날 수 있는 공격방법을 분석하고, 빅데이터를 활용하여 보안 위협에서의 대응방안을 제안한다.