• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.25-34
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• 2002

The halophytes were investigated on Gyeonggi Bay from Aug. 1999 to Oct. 2001. The survey was conducted at 38 areas including natural salt marshes, dunes, abandoned salt farms and bank areas. During this study 46 species of halophytes were collected in the areas. Among the halophytes the following 7 species were found at natural salt marshes only; Triglochin maritimum L, Carex scabrifolia Steud., Salicornia herbacea L., Suaedu australis (R. Br.) Moq., S. martima Dum., S. japonica Makino, S. malacosperma Hara, on the other hand 8 species at dunes only; Glehnia littoralis Fr. Schm., Cnidium japonicum Miq., Messerschmidia sibirica L., Ixeris repens A. Gray, Corispermum stauntonii Miq., Vitex rotundifolia L. fil., Ischaemum anthephoroides Miq., Carex kobomugi Ohwi. The distributions of halophytes in each regions are as the followings : Isl. Gyodong-do 21 species, Isl. Seokmo-do 10 species, Isl. Ganghwa-do 28 species, Isl. Jangbong-do 16 species, Isl. Sin & Si-do 10 species, Isl. Daemuui-do 23 species, Isl. Deokjeok-do 23 species, Isl. Ijak-do 10 species, Isl. Yeongheung-do 29 species, Soyra 25 species, Isl. Daebu-do 15 species, Ssangsong-ri 6 species, Hogok-ri 16 species, Maehyang-ri 10 species.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.1
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• pp.47-62
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• 2001

An experimental study was peformed to provide the numerical models to predict the physical fate of marine debris with the key information concerning their trifling and sinkage on the sea. For hygroscopic materials their floating times in a pseudo ocean environment were measured, and for non-hygroscopic objects their drifting limes in a certain wave condition were measured. For sinking materials or objects became to be sinkable free falling experiment was performed to evaluate their falling speed. Summarized information was condensed into a numerical model to predict the most possible region of a significant marine debris accumulation, and the seas connected to the Han river and the Nak-Dong river were considered for the simulation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.4
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• pp.31-45
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• 2020

This study suggested the planting models of Carpinus turczaninowii community to make in Badahyanggi Arboretum and was carried out to the structure of C. turczaninowii commnity in Daebu-Yeongheung Islands. In order to identify the current ecological environment, this study set to 13 plots(i.e. 100㎡) for analysing detailed structure of plant communities. The research methodology was qualitative analysis. It used TWINSPAN, PCA and Indicator Species Analysis tools which are performed well in several comparisons of classification techniques and one of the ordination techniques showed that the plant communities. The results were classified into 3 communities that C. turczaninowii-Pinus densiflora community(I), C. turczaninowii-Quercus serrata community(II) and C. turczaninowii-Platycarya strobilacea community(III). In all of communities, C. turczaninowii was dominant species in canopy layer and understory layer, the degree of closure was high. Proposed the planting models that are I~II communities based on planting status in Badahyanggi Arboretum(Island Plant Botanical Garden), the structure of plant communities, indicator species and individual distribution by DBH classes. Also, The multi-layer planting plans are necessary, such as P. strobilacea, Lindera erythrocarpa, Viburnum carlesii, V. dilatatum, Ligustrum obtusifolium, Zanthoxylum schinifolium and so on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.239-250
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• 2022

LoRa is a physical layer technology designed to secure highly reliable long-range communication with introducing loco parentis tree network and chirp spreading spectrum. Since since a leaf can send message to more than one parents simultaneously with a single transmission in a region, packet delivery ratio increases logarithmically as the number of gateways increases. The delivery ratio, however, dramatically collapses even under loco parentis tree topology due to the limitations of ALOHA-like primitive MAC, . The proposed method is intended to exploit SDMA approach to reuse frequency in an area. With the view, TxPower of each sender for each message in a concurrent transmission is elaborately controlled to survive the collision at different gateway. Thus, the gain from the capture effect improves the capacity of resource-hungry Low Power and Wide Area Networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.194-198
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• 2021

LoRa is a physical layer technology that is designed to provide a reliable long-range communication with introducing CSS and with introducing a loco parentis tree network. Since a leaf can utilize multiple parents at the same time with a single transmission, PDR increases logarithmically as the number of gateways increases. Because of the ALOHA-like MAC of LoRa, however, the PDR degrades even under the loco parentis tree topology similarly to the single-gateway environment. Our proposed method is aimed to achieve SDMA approach to reuse the same frequency in different areas. For that purpose, it elaborately controls each TxPower of the senders for each message in concurrent transmission to survive the collision at each different gateway. The gain from this so-called capture effect increases the capacity of resource-hungry LPWAN. Compared to a typical collision-free controlled-access scheme, our method outperforms by 10-35% from the perspective of the total count of the consumed time slots. Also, due to the power control mechanism in our method, the energy consumption reduced by 20-40%.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.129-138
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• 2024

This study examines the osteological development of the Pike gudgeon, Pseudogobio esocinus in the cranial, vertebral, caudal, pelvic and pectoral girdle for the purpose of taxonomic and aquacultural studies. Adult Pike gudgeon collected from the Boseonggang River were reared at 18.5~19.5℃ (average 19.0℃). At 5 days after hatching (total length (TL) 4.25 mm), the parasphenoid, dentary, centrum of vertebrae and clavicle began to ossify. At 22 days after hatching (TL 6.33 mm), 36 to 38 vertebrae had ossified. At 42 days after hatching (TL 16.71 mm), the majority of the skeleton had ossified. Pike gudgeon exhibited comparable characteristics to other fishes of Gobionidae throughout its development, although it displayed differences in some areas, such as the caudal skeleton and fin supports.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.68-80
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• 2021

This study aimed to provide basic data such as the structure of the Carpinus turczaninowii community and characteristics of the habitat environment for ex situ conservation by analyzing the plant community structure of Carpinus turczaninowii, an island plant resource. For the community structure analysis, this study established 29 plots, sized 100㎡ each, in Seokmo, Yeongjong, Yeongheung, and Daebu islands. TWINSPAN was used for the classification of communities. The classification identified six communities. Group I was the C. turczaninowii-Quercus serrata community, group II was the C. turczaninowii-Pinus densiflora community, group III was the C. turczaninowii-Quercus mongolica community, group IV was the C. turczaninowii-Sorbus alnifolia community, group V was the C. turczaninowii typical community, and group VI was the C. turczaninowii-Quercus variabilis community. The species diversity was 0.90008~1.12868, the dominance was 0.17536~0.25665, and the similarity index was 17.1429~38.2979%. The result of correlation analysis of 7 environmental factors for 6 communities by RDA ordination showed a positive correlation between the crown density and litter layer and a negative correlation between the bare rock, soil hardness, and altitude on the 1st axis. On the 2nd axis, the bare rock and crown density showed a positive correlation, and the slope showed a negative correlation. In the C. turczaninowii-Quercus serrata community (I), the crown density and the litter layer were the environmental factors affecting the vegetation distribution. In the C. turczaninowii-Pinus densiflora (II) and C. turczaninowii-Quercus mongolica (III) communities, the slope was the factor affecting vegetation distribution. In the C. turczaninowii-Sorbus alnifolia (IV), C. turczaninowii typical (V), and C. turczaninowii-Quercus variabilis (VI) communities, the bare rock, altitude, and soil hardness were the factors affecting vegetation distribution.

• KOMUNHWA
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• no.66
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• pp.5-35
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• 2005

본 고는 매우 복잡 다양하게 출토되고 있는 선사시대 토기 중 굽다리토기에 대한 연구이다. 특수한 기형의 이 토기는 분류조차 제대로 이루어지지 않은 채 의례용으로 인식되어져 왔으며, 그 명칭 또한 무분별하게 사용되어져 왔다. 따라서 충분히 객관적이고도 적절한 정립이 필요한 상황이다. 이 토기는 저부와 신부의 상대크기에 따라 대부형(Ⅰ형)과 대각형(Ⅱ)으로의 세부기종 설정이 가능하고 세부기종별 속성분석을 통하여 6형식의 형식분류가 이루어졌다. 무문토기시대 전기 주거지유적에서 공렬 및 각형토기와 공반하는 1·2·3·4형식의 토기(북한→강원영동→경기중부·충청서해안지역)는 점토대토기문화가 도래하면서 생활, 분묘, 생산, 폐기 그리고 의례관련유구에서 출토되는 5·6형식 토기(경기중부·충청서해안→호남·영남지역)로의 변화를 보이면서 전개된다. 즉 점토대토기문화가 도래하는 시점에서 굽다리토기의 형식도 변화·확대되고 있다. 또한 출토맥락, 형식조합, 제작기술 등의 관점에서 공렬 및 각형토기와 공반하는 1·2·3·4형식은 일상 생활용기로의 상정이 가능한 반면 점토대토기와 조합을 이루는 5·6형식 토기는 의례관련유구와 분묘유구에서 다량 출토되고 있어 기원이나 소원과 관련된 의례용기, 그리고 부장용으로의 기능분화가 관찰된다. 〔주제어〕: 굽다리토기, 공렬토기, 각형토기, 점토대토기문화, 기술유형, 시공적 전개, 기능분화

• 한국경영정보학회:학술대회논문집
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• 2007.11a
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• pp.429-434
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• 2007

이 연구는 공공부문이 구축/관리중인 지식정보자원의 시민활용 실태를 점검하고 유비쿼터스 기술을 활용한 지식정보자원의 시민활용성 제고방안 모색을 목적으로 한다. 이를 위하여 부산광역시의 시민 200 명을 대상으로 설문조사를 실시하여 지식정보자원에 대한 인지도/활용도/활용장애요인과 유비쿼터스 기술에 대한 인지도/활용도/유용성을 조사하였고, 향후 유비쿼터스 기술을 활용한 공공행정, 교육학술, 사회문화/복지, 생활경제 등 4 대부문 16 개분야 32 개의 지식정보자원에 대한 시민활용 의향을 분석하였다. 분석결과 지식정보자원에 대한 인지도와 활용도는 보통보다 낮은 수준에 있으며, 그 이유로는 개인정보유출에 대한 불안, 지식정보자원 소재에 대한 정보부족, 지식정보자원 활용 비용의 부담 및 활용의 불편 등으로 나타났다. 향후 유비쿼터스 기술을 활용한 지식정보자원 활용의향에 대해서는 실생활과 밀접한 관련을 갖고 있는 교통/기상정보, U-Care 및 U-Health 정보, 금융, 공연예술, 관광여가 등의 정보에 대해서는 높은 의향을 보이나, 실생활과 직접 관련이 적고 전문적인 능력이나 관심이 요구되는 행정정보공개, 정책참여, U-학술연구 등에 대해서는 낮은 의향을 보이는 것으로 나타났다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.268-270
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• 2001

현재 ad hoc의 연구 방향은 무천 기반의 패킷 라우팅에 관련된 것이 대부뿐 이러 네트워크 토폴로지 생성에 대한 연구는 거의 진행된 것이 없다. 현재 대부분의 ad hoc 네트워크는 대표적인 싱글 채널 방식인 broadcast 기반의 무선 미디어 방식을 물리적 계층을 사용하며, 이를 기반으로 이동 노드의 무선 범위 제한을 극복하기 위한 형태로 네트워크 토폴로지를 형성한다. 블루투스(B1uetooth)는 frequency hopping(FH) 방식을 사용하므로 연결 설정 과정에서 동기화 과정이 반드시 요구되며, ad hoc 네트워크을 형성을 위해 다중 채널을 사용한다. 따라서 블루투스와 같이 다중 채널을 물리적 계층으로 사용하는 네트워크에서는 싱글 채널 방식과 달리 명시적으로 토폴로지를 형성하기 위한 메커니즘이 요구된다. 본 논문에서는 다중 채널과 블루투스가 탑재된 노드의 이질적 특성을 고려한 스캐터넷(Scatternet) 구성 메커니즘을 제안한다. 본 메커니즘은 칵 노드의 전력 상태와 이동성 정보를 바탕으로 스캐터넷의 마스터와 브리지 노드틀 선택 함으로서 효율적인 네트워크 토플로지를 구성한다.