1992년 겨울

구본주 민족미학회 2013 민족미학 Vol.12 No.2

위성본체용 무선 데이터 버스 시스템을 위한 IR-UWB 모듈의 개념 설계

구본주,지신애 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.11

인공위성 본체의 복잡한 유선 데이터 버스 시스템의 단점을 개선하기 위해 무선 데이터 버스 시스템의 구현을 위한 많은 연구가 진행되고 있으며, 적외선 및 지상에서 사용하는 다양한 무선 통신 기술들이 대안으로 제시되고 있다. 본 논문은 소비 전력과 전송 속도, 채널 특성 등에 있어 장점을 가진 IEEE 802.15.4a(IR-UWB)를 위성의 데이터 버스 시스템으로 사용하는 방안에 대해 제안하고, IR-UWB 모듈의 개발을 위한 베이스 밴드와 RF front end 스테이지의 개념 설계를 소개한다. 또한, 개발될 IR-UWB 모듈의 검증방안을 제안하고, IR-UWB 를 위성용 무선 데이터 버스 시스템에 성공적으로 이식하기 위해필요한 연구 방향에 대해 제시한다. To overcome the drawbacks of a complicated wired data bus system in satellites, much research on the implementation of wireless data bus system has been studying. To this end, infrared communication and various RF communications are suggested as the alternatives. This paper proposes the methodology to utilize IR-UWB system (IEEE 802.15.4a) with advantages in terms of power, data rate and channel characteristics as a feasible solution to wireless data bus system for intra-satellite communication. Also, a conceptual design of baseband and RF front end stage is introduced. Finally, a test method for the IR-UWB module is suggested and further studies needed to successfully transplant IR-UWB technique to wireless data bus system for satellite are mentioned.

위성영상 분석기술을 이용한 시흥갯벌의 지형 및 노출시간 분석

구본주,김민규 한국해양과학기술원 2013 Ocean and Polar Research Vol.35 No.4

In order to investigate the topography and exposure duration of the Siheung tidal flat, tidal ranges and DEM constructed by remote sensing techniques were analyzed. A cross-sectional diagram of the intertidal area reveals that it is relatively flat in the upper zone and then abruptly plunges into the bottom of the main channel where elevations increase in an upstream direction. The waterline during the Highest Low Water (HLW) is drawn back to the bottom of the channel at the middle part of the tidal flat and is formed along the slant of the channel during the Lowest High Water (LHW). The intertidal zone is located between −410 cm and 510 cm in terms of elevation and its total area is 0.65 km2. An area between the Highest High Water (HHW) and Lowest High Water (LHW), occupying about 80% of the total area, occupies 0.52 km2 of total area and accounts for 56% of the exposure duration. The boundary of wetland protection area in the Siheung tidal flat did not exactly coincide with the intertidal regime and differs by more than 15%. This study, which precisely analyzed the tidal flat area, tidal environment, and topography, would be useful in making a conservation plan and in learning how to use a wetland protection area in a sustainable manner.

A Preliminary Study on Changes in Macrobenthic Assemblages in the Fenced Experimental Plots for Restoring Tidal Marsh,Hogok-ri Tidal Flat, West Coast of Korea

구본주,제종길 한국해양과학기술원 2002 Ocean and Polar Research Vol.24 No.1

This preliminary study on the changes of macrobenthic assemblages in experimental sediment fences was conducted as a part of tidal marsh restoration project. Intertidal sediment fences were designed to increase the efficiency of trapping sediments on unvegetated tidal flats in order to raise sediment elevation and to allow colonization of intertidal vegetation. Although increment of soil surface level was not observed over the first three months of the study, it was possible to obtain some effects of the sediment fence. Three months later, the particle sizes of the surface sediment at experimental plots became much finer compared to unfenced areas on the natural mudflats located in the same tide level as that of the plots. The difference was much greater on the plot with drainage canals than on the plot without ones. Species diversity of the experimental plots became much higher than that of natural sites. Perinereis aibuhitensis and Glauconome chinensis which were absent from initial community appeared with high density in the plot with drainage canals. Those species were significantly different in abundance between the experimental plot and the natural mudflat. Changes in species composition were not detected in another experimental plot without drainage canals.

급격한 조석 감소에 의한 새만금 갯벌 대형저서동물 변화

구본주,신상호,이석 한국해양과학기술원 2008 Ocean and Polar Research Vol.30 No.4

Tidal ranges of inner Saemangeum were largely reduced after the final dyke enclosure, resulting in the former tidal flats becoming either permanently exposed, still influenced by changing tide, or permanently submerged. The effect of reduced tidal range on survival and population stability of tidal flat macrofauna were investigated at three shifted habitats after the dyke completion. At the exposed area, several species survived for 80 days after the dyke enclosure. However, within 120 days, all macrofauna died off due to the elevated temperature during summer. At the intertidal area, some species were maintained until 170 days after the dyke enclosure with a large decrease of the faunal abundance. Species of the submerged area were seen to be more tolerant of the changed environments. The opportunistic species, such as Sinocorophium sinensis, Theora fragilis and Pseudopolydora Kempi, were massively introduced into the submerged area after the dyke enclosure, in which the benthic ecosystem was severely disturbed. Tidal ranges of inner Saemangeum were largely reduced after the final dyke enclosure, resulting in the former tidal flats becoming either permanently exposed, still influenced by changing tide, or permanently submerged. The effect of reduced tidal range on survival and population stability of tidal flat macrofauna were investigated at three shifted habitats after the dyke completion. At the exposed area, several species survived for 80 days after the dyke enclosure. However, within 120 days, all macrofauna died off due to the elevated temperature during summer. At the intertidal area, some species were maintained until 170 days after the dyke enclosure with a large decrease of the faunal abundance. Species of the submerged area were seen to be more tolerant of the changed environments. The opportunistic species, such as Sinocorophium sinensis, Theora fragilis and Pseudopolydora Kempi, were massively introduced into the submerged area after the dyke enclosure, in which the benthic ecosystem was severely disturbed.

The Sediment-Water Interface Increment due to the Complex Burrows of Macrofauna in a Tidal Flat

구본주,권개경,Jung-Ho Hyun 한국해양과학기술원 2005 Ocean science journal Vol.40 No.4

The architecture of macrofaunal burrows and the total area of the sediment-water interface created by biogenic structure were investigated in the Donggeomdo tidal flat on the west coast of Korea. Resin casting methods were applied to recover burrows of four dominant species, Macrophthalmus japonicus, Cleistostoma dilatatum, Perinereis aibuhitensis, and Periserrula leucophryna, and whole burrows within the casting area at three sites in different tidal levels. P. leucophryna excavated the largest burrow in terms of a surface area among them. In the case of whole burrow casting, the space occupied by the biogenic structure was extended into deeper and expanded more greatly at the higher tidal level. In the upper-most flat, the burrow wall surface area within sediment was more extensive than the sediment surface area. Increased oxygen supply through the extended interface could enhance the degradation rates of organic carbon and also change the pathways of degradation. Quantifying the relationship between the extended interface and mineralization rate and pathway requires more extensive study.

Experimental Restoration of a Salt Marsh with Some Comments on Ecological Restoration of Coastal Vegetated Ecosystems in Korea

구본주,제종길,우한준 한국해양과학기술원 2011 Ocean science journal Vol.46 No.1

Since the 1980s, the coastal wetlands in Korea have been rapidly degraded and destroyed mainly due to reclamation and landfills for coastal development. In order to recover damaged coastal environments and to develop wetland restoration technologies, a 4-year study on ecological the restoration of coastal vegetated ecosystems was started in 1998. As one of a series of studies, a small-scale experiment on salt marsh restoration was carried out from April 2000 to August 2001. The experiment was designed to find effective means of ecological restoration through a comparison of the changes in environmental components and species structure between two different experimental plots created using sediment fences, one with and one without small canals. Temporal variation in surface elevation, sedimentary facies, and benthic species were measured seasonally in each plot and in the adjacent natural reference sites. Monthly exposure occurred from 330 cm to mean sea level, which represents the critical tidal level (CTL) at which salt marsh plants colonize. Vegetation, especially Suaeda japonica, colonized the site the following spring and recovered to a similar extent in the natural marshes 16 months later. The sedimentary results indicated that the sediment fences had effects on particle size and sediment accumulation, especially in the plot with small canals. This experiment also showed that tidal height, especially that exceeding the CTL, is an important factor in the recovery of the benthic fauna of salt marshes. From these results, we suggested that designs for the restoration of salt marsh ecosystems must consider the inclusion of a tidal height exceeding CTL, as this may allow reconstruction of the previous natural ecosystem without artificial transplanting.

Oxygen Penetration through Invertebrate Burrow Walls in Korean Tidal Flat

구본주,고철환 한국해양과학기술원 2013 Ocean science journal Vol.48 No.4

Macrofaunal burrows increase the surface area of the sediment-water interface, which has a great impact on the metabolism of aerobic microbes and the oscillation of reduced metabolites within the sediment. Given the importance of macrofauna in surficial sediments, the aim of this study is to examine the effects of burrow architectures on dissolved oxygen diffusion rates in comparison with unburrowed sediment, and thereby to evaluate the theoretical assumption used for modeling solute distribution in the burrow system using field samples. Employing microsensors, horizontal oxygen profiles were measured on a micrometer scale around burrows of seven invertebrates in tidal flats of the west coast of Korea. Oxygen diffusion distance through the burrow walls of seven invertebrates showed spatio-temporal variation with a range of 0.6 to 2.9 mm. Two groups of burrows were identified based on their oxygen diffusive properties relative to unburrowed sediments: 1) oxygen penetration similar to that of ambient sediments and 2) clearly enhanced oxygen penetration. Differences in the diffusive properties of the burrow wall were related to the burrow depth and diameter, existence of mucus lining on the wall, sediment grain size, and tidal phases. Also inhabitant activity was an important factor affecting oxygen penetration, which is discussed in the paper. These results further demonstrate that simplified assumptions (i.e. burrow structures are viewed as direct biogeochemical extensions of the sediment-water interface) may not be exact representation of the nature.

세가시육질꼬리옆새우(단각류)의 생물교란이 시화호 퇴적물 내 황화합물과 산소 농도의 수직적 분포에 미치는 영향

구본주,권개경,신상호,제종길 한국습지학회 2006 한국습지학회지 Vol.8 No.3

시화호의 우점종 중의 하나인 세가시육질꼬리옆새우의 염분구배 (1, 5, 10, 15, 20, 25, 30, 35, 40‰)에 따른 생존율 및 튜브형성 개수 실험을 하였다. 그리고 수층 내 산소농도가 충분할 경우 황화합물 농도가 높은 퇴적물 속에서 대상 종의 생존율과 이들의 생물교란 활동이 퇴적물 내 산소농도와 황화합물의 수직구배에 미치는 영향을 실험하였다. 대상 종은 20~30‰ 염분 조건에서 생존율이 높았으며 튜브형성 개수 또한 많았다. 수층 내 산소 농도가 충분할 경우, 대상 종은 황화합물 퇴적물에서 높은 생존율을 나타내었다. M. uenoi의 생물교란 활동은 퇴적물 내로 산소를 확산시킴으로써 황화합물을 제거하였다. 산소 확산과 황화합물이 제거되는 깊이는 대상 종의 서식밀도가 높을수록 증가하였다. 시화호 퇴적물에는 황화합물의 농도가 높게 나타나며, 특히 여름철에는 밀도성층의 강화로 저층수에 빈산소층이 형성되어 저서동물이 서식하지 못하는 무생물대가 형성된다. 가을 무렵에는 성층의 약화로 저층수에도 산소가 충분히 공급되며 M. uenoi가 높은 밀도로 출현한다. M. uenoi의 생물교란 활동은 저서동물 군집이 재형성될 수 있는 서식지를 조성하는데 중요한 역할을 하는 것으로 판단되었다.

Sediment Reworking by a Polychaete, Perinereis aibuhitensis, in the Intertidal Sediments of the Gomso Bay, Korea

구본주,서재환 한국해양과학기술원 2017 Ocean science journal Vol.52 No.4

Bioturbation, especially sediment reworking by the activities of macroinvertebrates, such as feeding and burrowing, is one of the major processes that affect the physical, chemical, and biological characteristics of marine sediments. Given the importance of sediment reworking, this study was designed to evaluate the sediment reworking rate of a polychaete, Perinereis aibuhitensis, which is dominant in the upper tidal flats on the west coast of Korea, based on quantification of pellet production during spring and fall surveys. The density of individuals was higher in fall than in spring, whereas, due to a difference in the proportion of adults between the two seasons, the morphometric dimensions of the worm and its pellets were significantly longer and heavier in the spring. Hourly pellet production per inhabitant and density were closely related, with pellet production gradually decreasing as density increased. Daily pellet production was much higher in spring than in fall, mostly due to an increase in daytime production. The sediment reworking rate of Perinereis was similar in the two seasons in which observations were made and depended on its density and the sediment reworking rate per individual. The overall sediment reworking rate of Perinereis was 31 mm yr−1 based on its density in the study area.