• Title/Summary/Keyword: Secondary forest

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Landscape Structure and Relationship between Water Quality and Land Use Pattern in the Watershed of the Wangsuk River in Gyunggi-do Korea

  • Lee, Chang-Seok;Lee, An-Na;You, Young-Han
    • The Korean Journal of Ecology
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    • v.24 no.4
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    • pp.253-258
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    • 2001
  • Land use pattern in the Wangsuk river watershed was investigated on the bases of physiognomic vegetation maps made from the aerial photograph interpretation and field check. Landscape structure was analyzed using a GIS program supported by ArcView. Landscape structure depended on the geographical position of the river, such as the upper, middle and lower river. Watersheds of the upper and middle rivers were dominated by forests composed of secondary forest and plantation. But agricultural fields dominated that of the middle and lower river. Urban area and agricultural fields increased in from the upper toward the lower river watersheds. In addition to, a transformation of agricultural pattern into an institutional agriculture was characteristic in the middle and lower river basins. Water qualities of the Wangsuk river were usually better in the order of the upper, middle, and lower river, but they were fluctuated according to the site. Such fluctuation would due to self-purification of the river and land use pattern of the watershed as the non-point source. In this viewpoint, a strategy to manage the water quality in the level of watershed is urgently required.

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Creation and Maintenance of Woodland in the Revegetation Technology - History of Environmental Woodland and its Importance in Japan - (녹화분야(綠化分野)로부터 본 수림(樹林)의 조성(造成)과 보전(保全) - 일본(日本)에 있어서 환경림(環境林)의 역사(歷史)와 그 필요성(必要性) -)

  • Shibata, Shozo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.1 no.1
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    • pp.119-132
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    • 1998
  • In recent Japan, the demand for woodland creation on revegetation sites is increasing. In the forests and woodlands, we can find many functions of environmental conservation, in addition of biomaterial production, and all of these existences with such functions are defined as environmental woodlands. Many woodlands has been created from old times for the purpose of forest conservation and flood control, and most of these technology are handed down to present time. After Edo era (from the beginning of Meiji era, 1867), some valuable examples of woodlands were created, like Meiji shrine woodland in Tokyo. After the World War II, a lot of technology for woodland revegetation, such as ecological tree planting, have been developed. At present, many revegetation sites are aiming at woodland creation, like on man-made slope, etc.. In the great change of social structure, revegetation technology is also required to keep in close relationships to the restoration of devastated existing forests and woodlands, and to provide many technology for the restoration of secondary woodland, preservation of soil, mitigation, reclamation, etc.. Now in Japan, the improvement of environment including all the member of biosphere is demanded on a large scale. Therefore, revegetation technology should also try to make an activity taking a broad view of the restoration of natural vegetation in addition to the traditional and new woodland creation.

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Development of HDF Browser for the Utilization of EOC Imagery

  • Seo, Hee-Kyung;Ahn, Seok-Beom;Park, Eun-Chul;Hahn, Kwang-Soo;Choi, Joon-Soo;Kim, Choen
    • Korean Journal of Remote Sensing
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    • v.18 no.1
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    • pp.61-69
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    • 2002
  • The purpose of Electro-Optical Camera (EOC), the primary payload of KOMPSAT-1, is to collect high resolution visible imagery of the Earth including Korean Peninsula. EOC images will be distributed to the public or many user groups including government, public corporations, academic or research institutes. KARI will offer the online service to the users through internet. Some application, e.g., generation of Digital Elevation Model (DEM), needs a secondary data such as satellite ephemeris data, attitude data to process the EOC imagery. EOC imagery with these ancillary information will be distributed in a file of Hierarchical Data Format (HDF) file formal. HDF is a physical file format that allows storage of many different types of scientific data including images, multidimensional data arrays, record oriented data, and point data. By the lack of public domain softwares supporting HDF file format, many public users may not access EOC data without difficulty. The purpose of this research is to develop a browsing system of EOC data for the general users not only for scientists who are the main users of HDF. The system is PC-based and huts user-friendly interface.

Systematic Review of Reciprocal Changes after Spinal Reconstruction Surgery : Do Not Miss the Forest for the Trees

  • Kim, Chang-Wook;Hyun, Seung-Jae;Kim, Ki-Jeong
    • Journal of Korean Neurosurgical Society
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    • v.64 no.6
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    • pp.843-852
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    • 2021
  • The purpose of this review was to synthesize the research on global spinal alignment and reciprocal changes following cervical or thoracolumbar reconstruction surgery. We carried out a search of PubMed, EMBASE, and Cochrane Library for studies through May 2020, and ultimately included 11 articles. The optimal goal of a truly balanced spine is to maintain the head over the femoral heads. When spinal imbalance occurs, the human body reacts through various compensatory mechanisms to maintain the head over the pelvis and to retain a horizontal gaze. Historically, deformity correction has focused on correcting scoliosis and preventing scoliotic curve progression. Following substantial correction of a spinal deformity, reciprocal changes take place in the flexible segments proximal and distal to the area of correction. Restoration of lumbar lordosis following surgery to correct a thoracolumbar deformity induces reciprocal changes in T1 slope, cervical lordosis, pelvic shift, and lower extremity parameters. Patients with cervical kyphosis exhibit different patterns of reciprocal changes depending on whether they have head-balanced or trunk-balanced kyphosis. These reciprocal changes should be considered to in order to prevent secondary spine disorders. We emphasize the importance of evaluating the global spinal alignment to assess postoperative changes.

Hyperparameter Tuning Based Machine Learning classifier for Breast Cancer Prediction

  • Md. Mijanur Rahman;Asikur Rahman Raju;Sumiea Akter Pinky;Swarnali Akter
    • International Journal of Computer Science & Network Security
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    • v.24 no.2
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    • pp.196-202
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    • 2024
  • Currently, the second most devastating form of cancer in people, particularly in women, is Breast Cancer (BC). In the healthcare industry, Machine Learning (ML) is commonly employed in fatal disease prediction. Due to breast cancer's favorable prognosis at an early stage, a model is created to utilize the Dataset on Wisconsin Diagnostic Breast Cancer (WDBC). Conversely, this model's overarching axiom is to compare the effectiveness of five well-known ML classifiers, including Logistic Regression (LR), Decision Tree (DT), Random Forest (RF), K-Nearest Neighbor (KNN), and Naive Bayes (NB) with the conventional method. To counterbalance the effect with conventional methods, the overarching tactic we utilized was hyperparameter tuning utilizing the grid search method, which improved accuracy, secondary precision, third recall, and finally the F1 score. In this study hyperparameter tuning model, the rate of accuracy increased from 94.15% to 98.83% whereas the accuracy of the conventional method increased from 93.56% to 97.08%. According to this investigation, KNN outperformed all other classifiers in terms of accuracy, achieving a score of 98.83%. In conclusion, our study shows that KNN works well with the hyper-tuning method. These analyses show that this study prediction approach is useful in prognosticating women with breast cancer with a viable performance and more accurate findings when compared to the conventional approach.

Pedogenesis of Forest Soils(Kandiustalfs) Derived from Granite Gneiss in Southern Part of Korea (우리나라 남부지역(南部地域) 화강편마암질(花崗片麻巖質) 삼림토양(森林土壤)의 토양생성(土壤生成))

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
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    • v.86 no.2
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    • pp.186-199
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    • 1997
  • The soils derived from granite gneiss occupy almost one third of the land area in Korea. The soils under forest vegetation, formed on granite gneiss, in Sun chon-shi, Chollanam-do in southern part of Korea, were studied to evaluate the weathering and the transformation of primary minerals into secondary minerals, clay minerals. The studied soils contained large amounts of ferromagnesian minerals, weathered biotites and were well weathered, strongly acid and low in organic matters and in ration exchange capacity. The clay contents in the Bt horizon were almost two times higher than those in the C horizon. The O horizon had a thin layer which consisted of a little decomposed plant components with a granic fabric and high porosity, and showed the micromorphological characteristics of moder humus. The related distribution pattern of the E horizon were enaulic and large amounts of silts and small amounts of sand grains were another characteristics of the E horizon. The most striking micromorphological features were multilaminated clay coating and infillings in the voids in the Bt and C horizons, and generally limpid ferriargillans ejected from the biotites and imparted red color to the soils in the Bt horizon. High clay contents in the Bt horizon was not only due to clay translocation, but also due to intensive in situ mineral weathering in this horizon. The most significant pedogenic process, revealed by the petrographic microscope and SEM, was the formation of iron oxides from biotites, the formation of tubular halloysites and the weathering models of biotites; wedge weathering and layer weathering. The thick coating on the weathering biotites showed the characteristics of the weathering process and the synthetic hematites were revealed in clays by TEM. Total chemical analysis of clays revealed extensive loss of Ca, and Na and the concentration of Fe and Al. Mineralogical studies of clays by XRD showed that micas were almost completely weathered to kaolinite, vermiculite-kaolinite intergrade, hematite, gibbsite, while halloysites from other primary minerals. Some dioctahedral mica appeared to be resistant in the soils. Parent rock of the soils contained a considerable amounts of biotites and this forest soils showed especially a dominant characteristics of biotite weathering.

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On the Milled Wood Lignins Isolated from Hardwood by Progressive Milling (단계적(段階的) 분쇄법(粉碎法)에 의해 조제(調製)된 활엽수(闊葉樹) MWL에 관한 연구(硏究))

  • Cho, Nam Seok
    • Journal of Korean Society of Forest Science
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    • v.45 no.1
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    • pp.62-67
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    • 1979
  • Ultraviolet microscopy of ultrathin sections of wood has proved to be one of the useful means for determining the lignin distribution in the various regions of the cell wall. Also, spectral approach and quantitative analysis of isolated compound middle lamella fraction from birch xylem have revealed that the lignin associated with the vessel secondary wall and middle lamella is composed predominantly of gualacylpropane units. Lignin deposited in the fiber and ray parenchyma secondary walls is composed mostly of syringylpropane units. The middle lamella lignin around fibers and ray cells contains both guaiacyl and syringyl propane quits. On the basis of the results above, this research was carried out to clarify the origin of milled wood lignin (MWL) by analysing the chemical characteristics of ML MWLs extracted at various milling stages. The amount of phenolic hydroxyl-, ${\alpha}$-carbonyl-, and methoxyl-group in the MWL's increases the milling time. And progressive mining contributes to the merease of ratio of syringylaldehyde to vanillin(S/V ratio) after nitrobenzene oxidation of MWL. Accordingly, It could be concluded that milled wood lignin extracted at the initial milling stage derives from compound middle lamella region of cell wall, whereas, with progressive milling, lignin of secondary wall of fiber is introduced gradually to milled wood lignin. These results are suggesting that heterogeneous chemical structure of lignins in hardwood exists. Although milled wood lignin at the initial stage seems to have lower molecular weight in comparison with milled wood lignin extracted at final milling stage from the result of Gel-filtration curves, further study would be required on molecular weight distribution of milled wood lignin in future.

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Effects of Fire on Forest Vegetation in Mt. Samma (산불이 삼마산의 삼림식생에 미치는 영향)

  • Kim, Woen;Park, Jung-Hye;Cho, Young-Ho
    • The Korean Journal of Ecology
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    • v.22 no.3
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    • pp.145-153
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    • 1999
  • Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

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The Characteristics of Bird Community at Hannam Area of Jeju Experimental Forests (제주시험림 한남 지역의 조류 군집 특성)

  • Park, Chan-Ryul;Kim, Eun-Mi;Kang, Chang-Wan
    • Korean Journal of Environment and Ecology
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    • v.25 no.6
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    • pp.828-835
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    • 2011
  • This study was conducted to understand the characteristics of bird community, migration, nesting guild, ordination analysis of observed frequency of birds at Jeju Experimental Forests (JEFs) from November 2006 to September 2007 with surveys of two areas by line transect methods and point-count methods at five areas for three consecutive days in each month. Among observed 58 species could be classified into the 24 residents, 9 summer visitors, 9 winter visitors and 16 passage migrants according to migration habit. In species composition, passage migrants are dominant birds at study areas whereas summer and winter visitors are most dominant birds at mainland's forests. We could divide two groups of bird community in the view of monthly species composition, one is November to February group, the other March to July group by ordination analysis. Number of species did not show seasonal fluctuation which is common pattern of bird community in mainland. This pattern reflects that species composition can change during breeding and non-breeding periods, but overall number of species did not change. This can be related with the high use of passage migrants at study area, also suggests that the JEFs can be highly utilized as stopover sites during migration. At mainland's forests, we can observe about five species of woodpeckers, however we just observed the only one species of White-backed Woodpeckers (Dendrocopos leucotos) at study areas. In the view of nesting guild, breeding birds can be grouped into the 9 bush-& ground nesters, 8 canopy nesters, 7 hole nesters and one house nesters. Among hole nesters, we can observe only one species of primary cavity nesters White-backed woodpecker, and the five secondary cavity nesters, that is three species of tits, tricolor flycatchers (Ficedula zanthopygia) and ruddy kingfishers (Halcyon coromanda). Therefore, White-backed woodpeckers can be regarded as a keystone species and forest practice should consider the careful conservation of this species.

The Assessment of pH Variation for Neutralized Acidic Areas using Lysimeters by Seasons (라이시미터를 이용한 중화처리된 산성화경사지의 계절별 pH 용탈특성 평가)

  • Oh, Seungjin;Oh, Minah;Park, Chan-O;Jung, Munho;Lee, Jai-Young
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.79-86
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    • 2015
  • Korean territories has formed about 70% of mountainous areas that have acidified serious level to average pH 4-5. There are a number of abandoned metal mines about 1,000 in Korea. However, mine tailings and waste rock included heavy metals are exposed to long-term environment without prevention facility or treatment system. Thus, ongoing management and monitoring of soil environment are required. Most of abandoned mine scattered in forest areas of slopes. Soil erosion due to continuous rainfall in the slopy areas can cause the secondary pollution by the influence eutrophication of water system and the productivity loss of the plant. Therefore, this study would like to estimate pH leaching rate by artificial rainfall using waste neutralization-agent in lysimeter. Moreover, the potentially of secondary pollution related to precipitation is figured out through the experiments, and the optimal planting methods would examinate after neutralizing treatment in soil. Experiments composed three kinds of lysimeter; lysimeter 1 had filled only acidic soil, lysimeter 2 had neutralized soil, and lysimeter 3 had planting plants after neutralized soil. In the results, lysimeter 2 showed the lowest pH leaching, and there is not specific relativity with pH leaching of the seasonal characteristics.