• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.484-489
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• 2003

It is well known that root distribution of rice is a crucial factor for nutrient absorbtion and affect by soil fertility management. However, the findings on root distribution are limited due to laborious and tedious work. The characteristics of root distribution were investigated in long-term fertilizer experiment plots that were established in paddy soil, a fine silty family of typic Hal-paqueps (Pyeongtaeg series) in 1967. fertilizer experiment plots of no fertilizer, compost, NPK and NPK+compost plot have been maintained consistently for the past thirty six year and Npk+silicate plot for the past twenty two years. In NPK plot, 150kg N (urea), 100kg -$\textrm{P}_2\textrm{O}_5$ (fused phosphate) and 100kg $\textrm{K}_2\textrm{O}$(potassium chloride) per hectare have been applied. For NPK+silicate plot, 500kg $\textrm{Si}\textrm{O}_2$ (silicate) was applied in addition to fertilizer in NPK plot. For the compost plot, 10,000kg rice straw compost per hectare were applied. Root samples were taken from the positions of hill-center (below hill) and mid-point of four adjacent rice hills at heading stage by cylinder monolith (CM) method. The soil cores were sampled 20cm depth from the soil surface and partitioned four into layers at an interval of 5cm. The soil particles surrounding roots were washed out with tap water, Length and weight of the roots in each soil layer were measured and root length density (RLD), root weight density (RWD), specific root length(SRL) and rooting depth index (RDI) were calculated. Total root length was measured by intersection method. Plant height, tiller and shoot dry weight were the highest in NPK+compost plot. But RLD of hill-center soil cores was the highest in no-fertilizer plots. In the soil cores from mid-point position of four adjacent hills, RLD at 15-20cm soil depth was higher in compost plot than NPK plot. RLD in compost plots showed even distribution compared to those in chemical- fertilizer plots. RWD was the highest in the NPK+compost plot. SRL was the lowest in the NPK+silicate plot. RDI was the highest in the compost plot. Also, in this experiment it was found that the distribution of roots was closely related to the physical properties of the soil as affected by fertilization management.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.165-175
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• 2009

Fatty liver-hemorrhagic syndrome (FLHS) is a common nutritional disease in commercial layers and breeders. The most important clinical sign of FLHS is a sudden drop in egg production and increased mortality which causes significant economic loss in the poultry industry. However, the current diagnostic method for FLHS is based on the gross findings at necropsy which is not helpful to reduce the economic loss because of lateness of diagnosis. Therefore, we need early diagnosis and diagnostic methods before chickens were affected by FLHS. In this study we tried to evaluate the effectiveness of clinical pathology including blood chemistry as an early diagnostic method for FLHS in commercial chickens. Profiles of blood biochemistry were compared between two flocks selected in the same commercial layer farm based on the presence of FLHS clinical sings. A flock with clinical signs of FLHS was designated as FLHS and other flock without clinical signs of FLHS as Non-FLHS. Several parameters of blood biochemistry were selected and compared between FLHS and Non-FLHS to evaluate the possibility of early diagnosis. Average concentrations of serum cholesterol, serum calcium, aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) were $139.4\;{\pm}\;87.2$ (mg/dL), $24.5\;{\pm}\;5.4$ (mg/dL), $153.6\;{\pm}\;23.1$ (IU/L), $1238.3\;{\pm}\;475.2$ (IU/L) and $1107.3\;{\pm}\;422.8$ (IU/L) in Non-FLHS flock, respectively, and $210.2\;{\pm}\;173.2$ (mg/dL), $25.2\;{\pm}\;4.1$ (mg/dL), $174.3\;{\pm}\;53.5$ (IU/L), $1694.9\;{\pm}\;691.3$ (IU/L) and $1104.9\;{\pm}\;472.9$ (IU/L) in FLHS flock, respectively. The activities of serum cholesterol, AST and LDH except CK, were significantly higher in FLHS than those in Non-FLHS flock (p<0.05). Some birds of FLHS flock showed 2~17 times greater than in Non-FLHS flock. For the definitive diagnosis of FLHS in the flocks tested for blood chemistry, we analyzed fat content and histological lesion score in the liver sampled from both FLHS and Non-FLHS flock. Average liver fat contents based on dry weight were $16.1\;{\pm}\;0.4$ (%) in Non-FLHS flock and were $21.6\;{\pm}\;16.0$ (%) in FLHS flock. These result confirmed that FLHS flock was definitely affected by FLHS. The above results suggest that selected parameters of blood biochemistry, particularly AST, could be useful to diagnose FLHS before significant liver damage occurred in commercial layers.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.17-31
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• 2006

In this paper, passport recognition and face verification methods which can automatically recognize passport codes and discriminate forgery passports to improve efficiency and systematic control of immigration management are proposed. Adjusting the slant is very important for recognition of characters and face verification since slanted passport images can bring various unwanted effects to the recognition of individual codes and faces. Therefore, after smearing the passport image, the longest extracted string of characters is selected. The angle adjustment can be conducted by using the slant of the straight and horizontal line that connects the center of thickness between left and right parts of the string. Extracting passport codes is done by Sobel operator, horizontal smearing, and 8-neighborhood contour tracking algorithm. The string of codes can be transformed into binary format by applying repeating binary method to the area of the extracted passport code strings. The string codes are restored by applying CDM mask to the binary string area and individual codes are extracted by 8-neighborhood contour tracking algerian. The proposed RBF network is applied to the middle layer of RBF network by using the fuzzy logic connection operator and proposing the enhanced fuzzy ART algorithm that dynamically controls the vigilance parameter. The face is authenticated by measuring the similarity between the feature vector of the facial image from the passport and feature vector of the facial image from the database that is constructed with PCA algorithm. After several tests using a forged passport and the passport with slanted images, the proposed method was proven to be effective in recognizing passport codes and verifying facial images.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.704-710
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• 2012

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. This study was conducted to evaluate soil physical characteristics by drainage improvement in poorly drained sloping paddy field. The results showed that subsurface drainage by Pipe Drainage improves the productivity of poorly drained soils by lowering the water table and improving root zone soil layer condition. In an Pipe drainage plot, soil moisture drained faster as compared to the other drainage methods. Infiltration rate showed high tendency to Piper Drainage method about $20.87mm\;hr^{-1}$ than in Open Ditch method $0.15mm\;hr^{-1}$. And Similarly soil water and degree of hardness and shear strength phase of soil profile showed a tendency to decrease. From the above results, we found that when an subsurface drainage was established with at 1m position from the lower edge paddy levee of the upper field in sloping poorly drained paddy fields Pipe Drainage was the most effective drainage system for multiple land use.

• Geophysics and Geophysical Exploration
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• v.17 no.1
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• pp.1-10
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• 2014

To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity ($v_s$) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks ($D_b$), shear wave velocities of these basement rocks ($v_s^b$), average velocities of the overburden layer ($\bar{v}_s^s$), and the average velocity to a depth of 30 m ($v_s30$), were then derived from those models. The estimated values of $D_b$, $v_s^b$, $\bar{v}_s^s$, and $v_s30$ for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated $v_s30$ indicates that the lower altitude areas in Chuncheon are classified as $S_C$ (very dense soil and soft rock) or $S_D$ (stiff soil). To determine adequate proxies for $v_s30$, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between $v_s30$ and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.

• Biomedical Science Letters
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• v.2 no.2
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• pp.167-174
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• 1996

Alcoholics increased susceptibility to microbial infection that is associated with decreased immunity. but there has been little experimental evidence to support alcoholics-induced increase of microbial infection directly in non-specific immunity. Therefore, we were used the method of phagocytic-plaque including all the stimulating factors for the phagocytosis, subtypes of lymphocytes and T-lymphocyte proliferation. The experimental groups were divided into 3 groups: (1) alcoholics who were hospitalized less than 1 week (newly hospitalized alcoholics), (2) alcoholics who were hospitalized more than 2 weeks (old hospitalized alcoholics), (3) healthy blood donors. We have studied 98 alcoholics and 35 healthy blood donors and control groups. A physician has checked the biological markers and diagnosed the body-condition alcoholics. The immunity and non-specific immunity on the alcoholics were analyzed by using the simultest kit and flow cytometry. Proliferation of the lymphocytes was analyzed by the phytohemmagglutinine mitogen. Phagocytosis and migration properties of leukocytes were identified on the layer formed by Staphylococcus aureus Cowan I strain. Biological markers of alcoholics and control groups, by such as blood glucose, ${\gamma}$-glutamyl transpeptidase and mean corpuscular volumes of red blood cells, were determined by biochemical and hematological methods. Compared with control groups, cluster of differentiation (CD)3+, CD8+ and CD19+ in alcoholic were more decreased except CD4+/CD8+ ratio. Proliferation of the T-lymphocytes, phagocytosis and migration properties of the leukocytes in alcoholics were decreased compared with those of control groups. According to the results observed in our experiment, they can be summerized as follows: 1, Cellular, humoral and non-specific immunities, are markedly decreased in alcoholics than those in control groups. 2. It is inferred that Phagocytic plaque formation is a very useful method to evaluate phagocytosis and migration properties of the alcoholic leukocytes 3. It is thought that the subtypes of lymphocytes, especially CD4+/CD8+ ratio, are essential methods to analyzed the alcoholic immunity. 4. Specific and non-specific immunity on the old hospitalized alcoholics was slightly increased, which depends upon the alcoholic medication.

• Korean Journal of Environment and Ecology
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• v.1 no.1
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• pp.1-23
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• 1987

To investigate the forest structure of Mt. Bukhan. ranging from Seoul to Kyongkido, twenty plots were set up by the vegetation physiognomy and vegetation analysis was carried out. According to the leading dominant tree species in canopy stratum, forest communities were classified into three large groups of natural forest communities, semi-natural forest communities and artificial forest communities, and each of them covered 82.64, 7.03, and 5.71% of Mt. Bukhan area, respectively. Pure or mixed natural forest communities of Pinus densiflora and Quercus mongolica were major forest communities and covered 70.8% of Mt. Bukhan area. The important planted tree species were Robinia pseudoacacia, Pinus rigida, and Alnus birsuta and they were mainly planted at the southern slope and roadside. The degree of human disturbance of vegetation of 8, 7, and 6 area covered 82.64, 0, and 12.74%, respectively. According to forest dimensions, most of forest communities were young aged forests of which mean DBH was 20cm and canopy height below 10m. However, a few mature forest communities of Pinus densiflora or Quercus mongolica were found in the small area. The range of Shannon's species diversity of major natural forest communities, pure or mixed forest communities of Pinus densiflora and Quercus mongolica was 1.085~1.242. According to stand dynamic analysis by DBH class distribution, the present Quercus mongolica communities arid Robinia pseudoacacia communities may last long their present forest structure and most of other communities may be succeeded to Quercus mongolica communities, however, a few communities invaded by Robinia pseudoacacia and Quercus aliena-Quercus acutissima communities may be succeeded to Robinia pseudoacacia communities and Quercus aliena communities, respectively. DCA was the most effective method of this study. DCA ordination were showed that successional trends of tree species seem to be from Pinus densiflora through Quercus serrata. Prunus sargrntii. Sorbus alnifolia to Q. mongolica. Fraxinus mandsburica, F. rhynchophylla in the upper layer and from Zanthoxylum schinifolium, Lespedeza crytobotrya trough Rhus trichocarpa. Rh. verniciflua. Rhododendron mucronulatum. Rh. schlippenbachii to Acer pseudo-sieboldianus. Magnolia sieboldii, Euonymus sieboldianus.

• Economic and Environmental Geology
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• v.30 no.2
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• pp.137-142
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• 1997

At the tailings dam of the disused Brukunga pyrite mine in South Australia, reaction of groundwater with the tailings causes the formation and discharge of sulphuric acid. There is a need to improve remediation efforts by decreasing groundwater flow through the tailings dam. Geophysical methods have been investigated to determine whether they can be used to characterise variations in depth to watertable and map preferred groundwater flow paths. Three methods were used: transient electromagnetic (TEM) soundings, direct current (DC) soundings and profiling, and self potential (SP) profiling. The profiling methods were used to map the areal extent of a given response, while soundings was used to determine the variation in response with depth. The results of the geophysical surveys show that the voltages measured with SP profiling are small and it is hard to determine any preferred channels of groundwater flow from SP data alone. Results obtained from TEM and DC soundings, show that the DC method is useful for determining layer boundaries at shallow depths (less than about 10 m), while the TEM method can resolve deeper structures. Joint use of TEM and DC data gives a more complete and accurate geoelectric section. The TEM and DC measurements have enabled accurate determination of depth to groundwater. For soundings centred at piezometers, this depth is consistent with the measured watertable level in the corresponding piezometer. A map of the watertable level produced from all the TEM and DC soundings at the site shows that the shallowest level is at a depth of about 1 m, and occurs at the southeast of the site, while the deepest watertable level (about 17 m) occurs at the northwest part of the site. The results indicate that a possible source of groundwater occurs at the southeast area of the dam, and the aquifer thickness varies between 6 and 13 m. A map of the variation of resistivity of the aquifer has also been produced from the TEM and DC data. This map shows that the least resistive (i.e., most conductive) section of the aquifer occurs in the northeast of the site, while the most resistive part of the aquifer occurs in the southeast. These results are interpreted to indicate a source of fresh (resistive) groundwater in the southeast of the site, with a possible further source of conductive groundwater in the northeast.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.130-149
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• 2017

The subalpine zone which is vulnerable to climate change could be functioning as a habitat for northern plant species especially in the Korean peninsula. In this study, classification of phytosociological community type and investigation on flora of vascular plants of Daecheongbong area in Mt. Seorak were carried out in order to provide a basic information for an ecological restoration and management of the vegetation through community ecological approach. Vegetation data were collected from 31 of quadrates from May to October, 2016. We analyzed vegetation types with phytosociological method, importance value with Curtis & McIntosh method, CCA using PC-ORD program tool, and flora of vascular plants. As a result, the forest vegetation was classified into Abies nephrolepis community. The community was divided 3 groups such as Pinus pumila group, Rhododendron brachycarpum group and Angelica decursiva group. Therefore, the vegetation had 3 kinds of units. The differential species group, it was classified into total of 7 species group units including Thuja koraiensis and Smilacina bicolor differential species group. The mean importance percentage (MIP) in VU 1 was shown Pinus koraiensis (24.1), A. nephrolepis (23.6) and Betula ermanii (10.5), and in VU 2, it was P. koraiensis (26.2), A. nephrolepis (20.8) and B. ermanii (10.5), and in VU 3, it was P. koraiensis (22.2), A. nephrolepis (16.4), B. ermanii (13.5) in the order, respectively. As for importance values of P. koraiensis and A. nephrolepis representative competition species, were different at each layers. The former (46.7) was higher than the latter (26.1) in tree layer, but the latter was higher than the former in subtree and, shrub and herb layers of VU 1. VU 2 and VU 3 also indicated the same tendency. P. pumila group and A. decursiva group were shown to have positive correlation with altitude and present species, respectively. The designated as the endemic plant was 11 taxa and, as the rare plant 24 taxa and 62.5% of vascular plant was northern plant species. It is necessary to continue further long-term monitoring of 3 vegetation units, IV of main competition species (P. koraiensis and A. nephrolepis) with stratum and main specific species (rare plants and endemic plants) considering vegetation science and, population and community ecology approaches.

• Asia pacific journal of information systems
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• v.19 no.2
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• pp.157-178
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• 2009

Corporate credit rating is a very important factor in the market for corporate debt. Information concerning corporate operations is often disseminated to market participants through the changes in credit ratings that are published by professional rating agencies, such as Standard and Poor's (S&P) and Moody's Investor Service. Since these agencies generally require a large fee for the service, and the periodically provided ratings sometimes do not reflect the default risk of the company at the time, it may be advantageous for bond-market participants to be able to classify credit ratings before the agencies actually publish them. As a result, it is very important for companies (especially, financial companies) to develop a proper model of credit rating. From a technical perspective, the credit rating constitutes a typical, multiclass, classification problem because rating agencies generally have ten or more categories of ratings. For example, S&P's ratings range from AAA for the highest-quality bonds to D for the lowest-quality bonds. The professional rating agencies emphasize the importance of analysts' subjective judgments in the determination of credit ratings. However, in practice, a mathematical model that uses the financial variables of companies plays an important role in determining credit ratings, since it is convenient to apply and cost efficient. These financial variables include the ratios that represent a company's leverage status, liquidity status, and profitability status. Several statistical and artificial intelligence (AI) techniques have been applied as tools for predicting credit ratings. Among them, artificial neural networks are most prevalent in the area of finance because of their broad applicability to many business problems and their preeminent ability to adapt. However, artificial neural networks also have many defects, including the difficulty in determining the values of the control parameters and the number of processing elements in the layer as well as the risk of over-fitting. Of late, because of their robustness and high accuracy, support vector machines (SVMs) have become popular as a solution for problems with generating accurate prediction. An SVM's solution may be globally optimal because SVMs seek to minimize structural risk. On the other hand, artificial neural network models may tend to find locally optimal solutions because they seek to minimize empirical risk. In addition, no parameters need to be tuned in SVMs, barring the upper bound for non-separable cases in linear SVMs. Since SVMs were originally devised for binary classification, however they are not intrinsically geared for multiclass classifications as in credit ratings. Thus, researchers have tried to extend the original SVM to multiclass classification. Hitherto, a variety of techniques to extend standard SVMs to multiclass SVMs (MSVMs) has been proposed in the literature Only a few types of MSVM are, however, tested using prior studies that apply MSVMs to credit ratings studies. In this study, we examined six different techniques of MSVMs: (1) One-Against-One, (2) One-Against-AIL (3) DAGSVM, (4) ECOC, (5) Method of Weston and Watkins, and (6) Method of Crammer and Singer. In addition, we examined the prediction accuracy of some modified version of conventional MSVM techniques. To find the most appropriate technique of MSVMs for corporate bond rating, we applied all the techniques of MSVMs to a real-world case of credit rating in Korea. The best application is in corporate bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. For our study the research data were collected from National Information and Credit Evaluation, Inc., a major bond-rating company in Korea. The data set is comprised of the bond-ratings for the year 2002 and various financial variables for 1,295 companies from the manufacturing industry in Korea. We compared the results of these techniques with one another, and with those of traditional methods for credit ratings, such as multiple discriminant analysis (MDA), multinomial logistic regression (MLOGIT), and artificial neural networks (ANNs). As a result, we found that DAGSVM with an ordered list was the best approach for the prediction of bond rating. In addition, we found that the modified version of ECOC approach can yield higher prediction accuracy for the cases showing clear patterns.