• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.261-266
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• 2017

This study describes the design and implementation of SHF band Upconverter Digital Satellite Communication. The SHF band Upconverter unit consists of PLDROand frequency converter. In frequency converter, microstripBPF and LPF designed through the pre EMsimulation are implemented to minimize the unwanted spurious in frequency converter. Through the pre-simulation analysis ofspace environment, the possibility of and minimized about the malfunction of equipment and we designed a reliable SHF band Upconverter through simulation for a TID according to the vibration generated during the launch and space radiation environment, and compared pre-simulation of main performance results to test results about main performances of SHF band Upconverter after production.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.764-767
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• 2010

The high enthalpy plasma research center in Chonbuk national university is under construction for MW class plasma wind tunnel. Four types of plasma equipment will be installed in the research center. The equipments are 1set of 0.4 MW class enhanced Huels type plasma equipment, 1 set of 2.4 MW class enhanced Huels type plasma equipment, 1 set of 60 kW RF plasma equipment and 1 set of 200 kW RF plasma equipment. And electrical, water and gas utilities to assistant plasma equipments are under construction. The research center consists of experiment building, research building, power supply building, air supply building, cooling tower foundation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.45-50
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• 2005

최근 복원된 청계천의 야간경간조명은 야간에 도심의 새로운 미관을 창출함으로써, 5.8Km에 이르는 체계적인 야간경관을 시각적으로 체험할 수 있는 공간의 역할을 하고 있다. 그러나 야간에 청계천의 수변산책로를 이용하는 사람에게는 문화유산, 휴식공간, 22개의 교량, 자연환경뿐만 아니라 지상건물이 시야 내에 존재한다. 특히 청계천 지상도로의 남북측면에 위치한 기존의 건물들은 청계천 복원과 관계없이 대부분 기존에 설치된 옥외조명을 사용하고 있다. 이에 본 연구는 청계천 수변공간 산책시 사람의 시야내에 나타나는 지상건물의 조명환경특성을 분석하여 청계천변 조명과의 통합된 이미지가 연출되는지의 여부를 분석하는 것이 연구목적이다. 이를 위하여 지상에 위치하고 있는 건물을 대체적인 용도에 따라 오피스지역, 상업지역, 주거지역 등 3개 지역으로 구분하여 이 지역에 쥐치한 대표적인 지상건물 표면의 휘도, 색온도, 색도를 측정하여 분석하였다. 조명학적 물리량을 분석한 결과, 지상에 위치한 건물들이 산책로를 이용하는 사람들의 시각환경에 영향을 미치는 것으로 나타났고 경관조명요소로서 지상건물의 조명환경을 적절히 보완해야 할 필요성이 나타났다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1009-1014
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• 2012

This paper has proposed a 2,500 MHz ~ 2,570 MHz 0.13-${\mu}m$ CMOS RF front-end transmitter for LTE-Advanced systems. The proposed RF front-end transmitter is composed of a quadrature up-conversion mixer and a driver amplifier. The measurement results show the maximum output power level is +6 dBm and the suppression ratio for the image sideband and LO leakage are better than -40 dBc respectively. The fabricated chip consumes 36 mA from a 1.2 V supply voltage.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.141-152
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• 1999

This study aims at advancing waterfront planning and development of North Harbor of Pusan and attempting to establish an identity through the analysis and case studies of waterfront development of foreign countries. This study is based on Pusan urban harbor plan and the case study which was investigated the relational port with an urban area to find a model of development method and procedure of urban waterfront renewal, The approach of this study is to classify diversified cases and to suggest elements after reviewing successful cases. The point in the waterfront development plan of North Harbor of Pusan is how to secure an amenity on the edge and provides a comprehensive theoretical base such as skyline, coastline, green area, accessibility, scenery, landmark, open space, and so on. The result of this study is useful for the planner to develop more and systematic approaches which could utilize waterfront. Waterfront development will be a new chance of urban development for Pusan.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.4
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• pp.113-122
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• 2018

Residentialization is in progress in the coastal areas of the cities as the number of apartment houses rapidly increase with the simultaneous provision-centered development. It would be necessary to provide quality residential environments which would not deteriorate and would be chosen by many people as a sustainable residence in the future through the demand-centered development, considering the residents' consciousness. To do so, it is necessary to understand the residents' consciousness about the residential environment in the coastal area that has differentiated characteristics as a waterfront space through an evaluation of the residential environment, different from the existing residences. This study understands the significance of the waterfront space in the residential environment through people's consciousness when they choose a residence before they reside and people's consciousness when they evaluate the residence after they reside, concerning how the environment of the waterfront space is recognized as compared to other elements of the residential environment according to the geographic characteristics of the coastal area. In addition, this study analyzes the significance of people's consciousness before and after their residence through a comparison according to the change of distance to the waterfront from the perspective of access to the waterfront, the characteristic as a residential environment in the coastal area.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.16-24
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• 2015

This study quantified storage and annual uptake of carbon for riparian greenspaces established in watersheds of four major rivers in South Korea and explored desirable strategies to improve carbon reduction effects of riparian greenspaces. Greenspace structure and planting technique in the 40 study sites sampled were represented by single-layered planting of small trees in low density, with stem diameter at breast height of $6.9{\pm}0.2cm$ and planting density of $10.4{\pm}0.8trees/100m^2$ on average. Storage and annual uptake of carbon per unit area by planted trees averaged $8.2{\pm}0.5t/ha$ and $1.7{\pm}0.1t/ha/yr$, respectively, increasing as planting density got higher. Mean organic matter and carbon storage in soils were $1.4{\pm}0.1%$ and $26.4{\pm}1.5t/ha$, respectively. Planted trees and soils per ha stored the amount of carbon emitted from gasoline consumption of about 61 kL, and the trees per ha annually offset carbon emissions from gasoline use of about 3 kL. These carbon reduction effects are associated with tree growth over five years to fewer than 10 years after planting, and predicted to become much greater as the planted trees grow. This study simulated changes in annual carbon uptake by tree growth over future 30 years for typical planting models selected as different from the planting technique in the study sites. The simulation revealed that cumulative annual carbon uptake for a multilayered and grouped ecological planting model with both larger tree size and higher planting density was approximately 1.9 times greater 10 years after planting and 1.5 times greater 30 years after than that in the study sites. Strategies to improve carbon reduction effects of riparian greenspaces suggest multilayered and grouped planting mixed with relatively large trees, middle/high density planting of native species mixed with fast-growing trees, and securing the soil environment favorable for normal growth of planting tree species. The research findings are expected to be useful as practical guidelines to improve the role of a carbon uptake source, in addition to water quality conservation and wildlife inhabitation, in implementing riparian greenspace projects under the beginning stage.

• Journal of Environmental Policy
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• v.4 no.2
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• pp.31-55
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• 2005

Dangsan forests and Rural Community Forests(RCF) have been historical assets for the rural communities of more than 40,000 in Korea and they have provided an identity through the cultural heritage. The Dangsan forests and the RCF are parts of a unique cultural landscape in the rural areas as components of stream landscape. In many cases, the Dangsan forests and the RCF are located close to stream corridors. The objective of this study was to understand the function of the Dangsan forests and the RCF on stream water quality and to evaluate its ecological landscape values. Through the consideration of international concensus and domestic government policy for close-to-nature stream, we could find out that Dangsan forests and RCF's have close relationship with the close-to-nature streams. The water quality of the streams close to the Dangsan forests and the RCF are maintained with local culture. It is also compared to the streams located where Dangsan forests and the RCF are absent. Eight study sites were selected. Water samples were collected at three different locations at each study site. Water samples were analyzed for temperature, pH, total P, total N, dissolved oxygen, EC, BOD, COD and SS. Aquatic invertebrates were observed as water quality indicator species. The results showed that the number of aquatic invertebrate species, GPI, DO, EC, BOD, and SS were significantly improved in stream water due to the presence of the Dangsan forests and the RCF. The role of Dangsan forests and the RCF was evident in the conservation of stream landscape and rural culture as well as in maintaining stream water quality. The management schemes of the streams with Dangsan forests and the RCF's are also suggested.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.332-342
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• 2013

We collected zooplankton from May to October, 2011, with the aim of understanding the zooplankton community distribution and food web interaction between the open water and littoral (aquatic plants) zones in two small reservoirs with different land covers (Sobudang, Myeongdong). Small-sized reservoirs are more abundant in South Korea, and a total of 51 and 65 species of zooplankton were identified at the two small reservoir (Sobudang and Myeongdong), where zooplankton densities were more abundant in the littoral zone than in the open water zone. Cladocerans and copepods densities were also higher in the littoral zone, in contrast, rotifers showed higher densities in the open water zone (t-test, P/0.05). Epiphytic zooplankton dominated at the littoral zone (Lecane, Monostyla, Alona and Chydorus) because aquatic plants provided refuge spaces for attachment. Some rotifers (e.g. Brachionus, Keratella and Polyarthra) were more abundant in the open water zone because of their small size, which might help them to go unnoticed by predators. In two-way ANOVA, rotifers related to two reservoirs or habitat space (littoral zone and open water zone), but cladocerans and copepods showed a statistically significant relationship on only two reservoirs. The results of stable isotope analysis showed that zooplankton in the littoral zone tended to depend on organic matter attached to aquatic plants as a food source, which indicates the avoidance of competition of zooplankton with other macro-invertebrates (e.g. Damselfly larva, Cybister brevis and Neocardina denticulate). As a result, zooplankton community distribution is determined by not only habitat space (aquatic plant zone and open water zone) but also by food source (phytoplankton).

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.105-117
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• 2018

This study conducted health assessment and multivariate vegetation analysis using the riparian vegetation index in 30 sites of the Geumgang mainstream and Mihocheon to obtain practical data on the river management of the Geumgang. The result showed that the number of plant communities was 54. The flora was 75 families, 185 genera, 243 species, 2 subspecies, 21 varieties, 2 varieties, and 268 taxa. The riparian vegetation index was 38.3 (3.3; G-D1 ~ 66.7; G-U2, G-U4, and G-M3), and the health of the rivers in this area was evaluated as normal (grade C). The health of rivers was the highest in the upper stream of Geumgang mainstream and lowest in the downstream of Geumgang mainstream. The relationship between riparian vegetation index and chlorophyll-a content was low. The riparian vegetation was divided into five groups of Digitaria ciliaris colony group, Salix gracilistyla colony group, Erigeron annuus colony group, the group dominated by Humulus japonicus, Salix koreensis, Miscanthus sacchariflorus, and Phragmites japonica colonies, and the group dominated by Conyza canadensis and Echinochloa crusgalli var. echinata colonies. They had the similar health conditions. The CCA analysis showed that the environmental factors affecting the distribution of vegetation were physical factors such as vegetation area, artificial structure area, waterway area, branch width, channel width, and bank height and the biological factors such as the number of species. As such, it is necessary to maintain the health condition through continuous monitoring where the health condition is high and to apply active measures such as ecological restoration where the health condition is low.