• Title/Summary/Keyword: Natural stand

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Design of the Stand-alone Autothermal Reformer for Natural Gas (자체 기동형 천연가스 자열개질기 설계)

  • Koo, Jeongboon;Kim, Youngae;Kwon, Hyunji;Kwak, Inseob;Sin, Jangsik
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.113.1-113.1
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    • 2010
  • 본 연구에서는 중 소형 SOFC에 적용할 수 있는 연료 변환 시스템으로 자체 기동 및 독립운전이 가능한 천연가스 자열개질(ATR) 반응기를 $10Nm^3/hr$급으로 개발하고자한다. 설계된 천연가스 자열개질기는 자열개질 촉매를 코팅한 금속 모노리스형 촉매체를 반응기 내에 장착함으로써 반응열을 신속하게 제거 또는 공급할 수 있는 시스템으로 구성되었다. 이는 금속 모노리스의 뛰어난 열전도 능력에 의해 반응기 내의 촉매층 전체 온도 분포를 균일하게 유지할 수 있는 저에너지형 자열개질 반응기이다. 또한 빠른 기동 특성을 실현하기 위하여 전기 발열식 촉매체(EHC ; Electically Heated Catalyst)를 장착한 start-up 시스템을 적용하여 천연가스 자열개질 반응기의 신속한 기동과 장치 간편화를 실현하였으며, 합성 syngas의 배열 회수를 위한 최적 열교환 시스템을 설계/적용함으로써 에너지 효율 향상을 도모하였다. 이와 같은 촉매 및 구조 시스템을 가지는 천연가스 자열개질 반응용 소형 연료변환 시스템을 원통형의 이중관 구조로 구성하고, 독립운전 모드로 개발함으로써 소형 SOFC의 연료 변환장치의 적용에 용이하게 하고자 한다.

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Development of a Human Motion Analyzer (인체 동작 분석기의 개발)

  • 김민기;김성호
    • Journal of Biomedical Engineering Research
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    • v.16 no.2
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    • pp.217-222
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    • 1995
  • We propose some applications of image processing techniques to extract quantitative measurements by using a camera system developed in Korea university and Catholic Medical School. From now on the system will be called as KCMOTION. The purpose of this study is to provide basic kinematic and kinetic data for the analysis of human movements and to find the clinical usefulness and reliability of the proposed motion analysis system. Two tests, sit-to-stand (STS) movements and pendulum test, are conducted by the system. The aims of the tests are to identify variability and reliability of KCMOTION to give some quantitative comparisons to the other systems. The result of STS movement are compared to the LOCUS IIID motion analyzer by the ratio of maximum flexion movement per body weight to the actual maximum flexion extension torque per body weight. That result in 29 % and 33 % for hip and knee joint, respectively in KCMOTION and 27 % and 30 % in LOCUS IIID System. The results of the pendulum movements are compared to that of using Cybex and Electrogoniometer with relaxation index, amplitude ratio, swing number and swing time. The results of relaxation index and amplitude ratio of the KCMOTION are between those of the Cybex and Electrogoniometer. We also observed that the KCMOTION detect more natural movement, from the results of swing number and time.

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Regional and Environmental Status of Upper Basin of Daechung Reservoir to Predict Nitrogen and Phosphorus Loads from Aerable Land and Forest Stand

  • Kim, Hye-Jin;Lim, You-Jin;Song, Jin-A;Park, Misuk;Chung, Doug-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.5
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    • pp.690-697
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    • 2012
  • Approximately 67% of the total land area of the Korea is covered by forest. Eutrophication, defined as the enrichment of waters beyond natural levels, principally by the nutrient phosphorus (P), is a serious cause of concern at the present time. The contribution of forestry to P loading in catchment waters has not been intensively studied in Korea, but is potentially important because forests are often located in near-pristine environments. Phosphorus is retained by most mineral soils and, as a consequence, losses are usually negligible. However, it is much more mobile in organic soils where it can be relatively easily leached or lost through surface runoff, as these soils have a low capacity to retain free phosphate. This report has been prepared to study the influence of arable land used for paddy, upland, and forestry on water quality in the basin of Daechung reservoir.

Species Diversity and Niche Breadth of the Herb Layer Communities in Young Open Natural Pinus densiflora Stands (자연생유령 소나무림내 초본층의 종다양도와 생태적지위량에 대하여)

  • 오규칠
    • Journal of Plant Biology
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    • v.17 no.4
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    • pp.18-22
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    • 1974
  • Counts of herb stems were made with each systematic grid sized 10cm by 1300cm within six apparently homogeneous herb layers under the open young Japanese red pine, Pinus densiflora, stands. The stands had often been subjected to strong human interferences such as burning, cutting, grazing, and denuding since human settlement until the conservation scheme practiced in these stands for last decade. In addition, amounts of loss of ignition and field capacity were determined to detect soil heterogeneity among and within the stands. The values of information measure of diversity(H), and Hurlbert's probability of interspecfic encounter(Δ), obtained here do not show any consistent correlation. The amount of interspecific competetion(Δ1), the ratio of interspecific to intraspecific competetion(Δ4), Levin's niche breadth(Sh), and species evenness(V), increase, while the amount of intraspecific competetion decrease, as the soil factors become favorable. One stand examined does not follow the above trends, which is more young and shows strong within site heterogeneity of the soil factors. The stand includes pioneer species which is not detectable without detailed observation. It is argued that in stable or favorable environment more intense interspecific competetion and less intraspecific competetion might occur, but this situation does not necessarily always bring smaller niche breadth. In this connection, the results support Hurlbert's contention that the two components of diversity should be analyzed separately.

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The Effects of Lateral Wedged Insole to the Shoe of the Affected Side on Weight Bearing, Balance and Gait with Stroke (마비측에 적용한 외측 쐐기 깔창이 뇌졸증 환자의 체중부하율과 균형, 보행에 미치는 영향)

  • Kim, Hye-Lim;Shin, Won-Seob
    • PNF and Movement
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    • v.11 no.2
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    • pp.21-29
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    • 2013
  • Purpose : The study was to evaluate the weight distribution, balance and gait function of stroke patients wearing lateral wedged insole to the shoe of the affected side. Methods : 27 patients with stroke (15 men, 12 women) participated in this study. Participants performed weight distribution, dynamic balance and gait ability with or without wedged insole on affected side in a random order. The balancia was used to evaluate the weight distribution. Deviation from the center line was analyzed by Dartfish during sit to stand to evaluate dynamic balance. The functional walk ability evaluated by 10 m walking velocity. Results : The asymmetry index of weight bearing improved significantly with wedged insole of affected side(p<.05). During sit to stand, center of gravity significantly moved from non-affected side to more mid line of body(p<.05). Improvement were shown in walking speed after wearing the wedged insole(p<.05). Conclusion : Wedged insole applied on affected side have a beneficial effect on weight distribution, dynamic balance and walking speed with stroke.

Differences of Nutrient Input by Throughfall, Stemflow and Litterfall between Deciduous Forest and Larix kaempferi Plantation in Mt. Joonwang, Kangwon-do (강원도 중왕산 지역 낙엽활엽수림과 낙엽송 조림지에서 수관통과우와 수간류 및 낙엽낙지에 의한 양분 유입의 차이)

  • Jung, Mun-Ho;Lee, Don-Koo;Um, Tae-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.2
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    • pp.136-144
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    • 2007
  • The objectives of this study were to compare nutrient input by throughfall, stemflow and litterfall and concentration of nutrient in soil water between deciduous forest stand and Larix kaempferi plantation at Mt. Joongwang, Pyongchang-gun, Gangwon-do. The amount of rainfall interception during study period in deciduous forest stand and L. kaempferi plantation was 12% and 36%, respectively. Concentrations of cation ($Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$) in throughfall were not different, while concentration of $Cl^-$ in stemflow was higher in L. kaempferi plantation. The results indicated that annual nutrient inputs by rainfall with the exception of $Cl^-$ were significantly greater in deciduous forest stand. In soil water, concentrations of anion ($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) in A-layer, and $Ca^{2+}$ and $Cl^-$ in B-layer were higher in L. kaempferi plantation. Litterfall input during study period was $2,589kg\;ha^{-1}$ in deciduous forest stand and $1,046kg\;ha^{-1}$ in L. kaempferi plantation. Concentration of N was higher in L. kaempferi plantation, while N input from litterfall was greater in the deciduous forest stand ($36.81kg\;ha^{-1}yr^{-1}$) than L. kaempferi plantation ($16.16kg\;ha^{-1}yr^{-1}$). $Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$ in litterfall collected from deciduous forest stand were found to be higher than those from the L. kaempferi plantation. Also, input of those were greater in deciduous forest stand. Thus, total nutrient input by throughfall, stemflow and litterfall was greater in deciduous forest stand than L. kaempferi plantation, significantly.

Plant Distributions and Physicochemical Characteristics of Topsoil on the Reclaimed Dredging Area (임해준설매립지 식물분포와 표층토양의 이화학적 특성)

  • Nam, Woong;Kwak, Young-Se;Jeong, In-Ho;Lee, Deok-Beom;Lee, Sang-Suk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.3
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    • pp.52-62
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    • 2008
  • By analyzing specific plant distributions and physicochemical characteristics of topsoil in a reclaimed dredging area, baseline data was found of natural landscape planting sites, and developing dredged fill ground. The reclaimed dredging area is five different stands (1, 2, 3, 4 and 5) which were examined in this research. They are located from sea level to 15 meters in altitude and exhibited typical characteristics of the salt marsh in Gwangyang Bay. Species with high constancy in the vegetation on the reclaimed soil were classified into four stages. A total of 12, 15, 22, 27 and 35 different plant species were found and also increased in stands 1, 2, 3, 4 and 5, respectively. Moving from stand 1 to 5, halophytes decreased and non-halophytes increased. Desalination at each stage of the reclaimed dredging area was a driving force affecting the performance and distribution of halophytes and non-halophytes. Overall, 35 quadrats of soil were selected and analyzed for specific physicochemical characteristics of topsoil between O${\sim}$20cm. Results of the physicochemical analysis such as altitude, slope, vegetation and kind of reclaimed dredging soil, exhibited irregular increases or decreases. As survey areas moved from stand 1 to 4, desalination areas, soil acidity, electric conductions, content of salinity, available phosphorus, potassium, chlorine, calcium, and magnesium indicated decreasing patterns; however, total nitrogen, silt, and clay content increased. Cluster analysis and PCA by environmental data within the stands clearly showed five distinct vegetation patterns on the tested reclaimed area. These results indicate that the differences of performance and distribution of vegetation are due to the SAR in the reclaimed soil and related to the natural survival strategy at the given hostile habitat.

Construction of BLAST Server for Mollusks (연체동물 전용 서열 블라스트 서버구축)

  • Lee, Yong-Seok;Jo, Yong-Hun;Kim, Dae-Soo;Kim, Dae-Won;Kim, Min-Young;Choi, Sang-Haeng;Yon, Jei-Oh;Byun, In-Sun;Kang, Bo-Ra;Jeong, Kye-Heon;Park, Hong-Seog
    • The Korean Journal of Malacology
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    • v.20 no.2
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    • pp.165-169
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    • 2004
  • The BLAST server for the mollusk was constructed on the basis of the Intel Server Platform SC-5250 dual Xeon 2.8 GHz cpu and Linux operating system. After establishing the operating system, we installed NCBI (National Center for Biotechnology Information) WebBLAST package after web server configuration for cgi (common gate interface) (http://chimp.kribb.re.kr/mollusks). To build up the stand alone blast, we conducted as follows: First, we downloaded the genome information (mitochondria genome information), DNA sequences, amino acid sequences related with mollusk available at NCBI. Second, it was translated into the multifasta format that was stored as database by using the formatdb program provided by NCBI. Finally, the cgi was used for the Stand Alone Blast server. In addition, we have added the vector, Escherichia coli, and repeat sequences into the server to confirm a potential contamination. Finally, primer3 program is also installed for the users to design the primer. The stand alone BLAST gave us several advantages: (1) we can get only the data that agree with the nucleotide sequence directly related with the mollusks when we are searching BLAST; (2) it will be very convenient to confirm contamination when we made the cDNA or genomic library from mollusks; (3) Compared to the current NSBI, we can quickly get the BLAST results on the mollusks sequence information.

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Development of Simulation for Estimating Growth Changes of Locally Managed European Beech Forests in the Eifel Region of Germany (독일 아이펠의 지역적 관리에 따른 유럽너도밤나무 숲의 생장변화 추정을 위한 시뮬레이션 개발)

  • Jae-gyun Byun;Martina Ross-Nickoll;Richard Ottermanns
    • Journal of the Korea Society for Simulation
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    • v.33 no.1
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    • pp.1-17
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    • 2024
  • Forest management is known to beneficially influence stand structure and wood production, yet quantitative understanding as well as an illustrative depiction of the effects of different management approaches on tree growth and stand dynamics are still scarce. Long-term management of beech forests must balance public interests with ecological aspects. Efficient forest management requires the reliable prediction of tree growth change. We aimed to develop a novel hybrid simulation approach, which realistically simulates short- as well as long-term effects of different forest management regimes commonly applied, but not limited, to German low mountain ranges, including near-natural forest management based on single-tree selection harvesting. The model basically consists of three modules for (a) natural seedling regeneration, (b) mortality adjustment, and (c) tree growth simulation. In our approach, an existing validated growth model was used to calculate single year tree growth, and expanded on by including in a newly developed simulation process using calibrated modules based on practical experience in forest management and advice from the local forest. We included the following different beech forest-management scenarios that are representative for German low mountain ranges to our simulation tool: (1) plantation, (2) continuous cover forestry, and (3) reserved forest. The simulation results show a robust consistency with expert knowledge as well as a great comparability with mid-term monitoring data, indicating a strong model performance. We successfully developed a hybrid simulation that realistically reflects different management strategies and tree growth in low mountain range. This study represents a basis for a new model calibration method, which has translational potential for further studies to develop reliable tailor-made models adjusted to local situations in beech forest management.

A Study on the Forest Classification for Ecosystem Services Valuation - Focused on Forest Type Map and Landcover Map - (생태계 서비스 가치평가를 위한 산림 유형 분류 방안 - 임상도와 토지피복지도 활용을 중심으로 -)

  • Jeon, Seong Woo;Kim, Jaeuk;Jung, Huicheul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.3
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    • pp.31-39
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    • 2013
  • Some researcher started studies of natural capital from 1980's. But many researches are going along with the theme lately. Most assessment of ecosystem services are approaching a general assessment using a land-cover map. Therefore they have some problems such as overestimate, underestimate, and double counting, and so on. This study suggested a detailed typology for quantitative assessment about ecosystem services. It compared land-cover map and forest type map to select a based map and made criteria with reference to the literature and field survey. It subdivided a forest typology using ecological feature (natural forest, artifical forest), forest type (coniferous forest, mixed forest, hardwood forest) and age of stand in forest type map. Each forest type is widely distributed 21~40 ages of forests and biggest area is 21~40 ages of mixed forest in all forest typology. Further researches have to progress consistently assessment using detailed typology and function of forest ecosystem services.