• Proceedings of the Korean Environmental Sciences Society Conference
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• 1993.04a
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• pp.25-25
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• 1993

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.31-41
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• 2013

In this study, the properties of mudstone weathered soils related to landslides were analyzed at the area of landslide induced by heavy rainfall in Pohang. The soil tests were carried out to the soils obtained from landslide and non landslide sites, and the soil properties were investigated. The correlation between soil properties and landslides were analyzed using statistical technique, and then the soil factors were extracted from the correlation analysis. The correlation equation which can calculate the coefficient of permeability influenced on landslides was proposed using the soil factors. As the result of analysis, the porosity and unit weight of soils from the landslide area is smaller than those of soils from the non landslide area. The soils with poor grain size distribution and loose unit weight are prone to landslides because the soils have a large void ratio and a low unit weight. The permeability of soils from the landslide area is larger than that of soils from the non landslide area. According to the result of correlation analysis, the effective grain size, the saturated unit weight and silt and clay contents are evaluated as the influence factors. These factors were considered to estimate the coefficient of permeability of mudstone weathered soils.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.12-31
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• 1999

Topex/Poseidon satellite altimetric data are used to estimate characteristics on the oceanic and atmospheric correction factors, and the mean sea level and its variations in the Yellow Sea, the East China Sea and the East Sea from September 1992 through August 1994(70cycles). For the atmospheric correction factors, the variations of dry troposphere, humid troposphere, ionosphere and inverted barometer were very small as a few centimeters, but the variations of electromagnetic bias were higher than other factors. For the oceanic correction factors, the variations of ocean tide(35cm in track 127 and 60cm in track 214) showed high ranges compared to elastic tide(5cm in track 127 and 1cm in track 214) and loading tide(1.8cm in track 127 and 1cm in track 214). It should be understood that the variations of ocean free surface is mainly under the influence of, firstly, ocean tide and, secondly, electromagnetic bias. Mean sea level in the Yellow Sea are higher than in the rest of Seas. Then its range generally comprised between -60cm and 210cm with mean value of about 100cm. Also its variations showed high values in the Yellow Sea and East China Sea, especially 5.689cm in Youngampo. This result is mainly due to the effects of local topography and tidal current.

• Journal of agriculture & life science
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• v.44 no.4
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• pp.9-20
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• 2010

This study was carried out to analyze the landslide characteristics and forest environment factors on the landslide area of Jeonlabuk-do province in korea. The results obtained from this study were summarized as follows; The total number of landslide occurrence was 182 areas. The average area of landslide scar was $1,859m^2$, average length of the landslides was 139m, average width was 13m. The landslides were highly occurred in igneous rock and coniferous. And also, slope gradient was $21{\sim}30^{\circ}$, aspect was NE, altitude was 401~500m, vertical and cross slope was concave (凹),stream order was 1 order, soil depth was 15m below, landslide type was linear, forest type was artificial. The relationship between landslide area and environmental factors was a positive correlation with cross slope (convex), position (upper), altitude (501m), forest type (coniferous), parent rock (sedimentary rock), D.B.H. (over 17cm), but was negative correlation with slope gradient ($31{\sim}40^{\circ}$), parent rock (igneous rock), D.B.H. (6~16cm).

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.297-305
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• 2000

This research was conducted to analyze the factors influenced on stream water quality pollution in the northeastern part of Puk'ansan National Park from July, 1998 to November, 1999. The number of visitor and the percentage of the amount of $Cl^-$ resulted in the increase of electrical conductivity, which affected on pollution of the stream water quality. The relationships between those factors should be statistical significance at the 5% level in multiple regression. The multiple regression equations for the percentage of dissolved oxygen at the stream water quality showed that dissolved oxygen and water temperature had statistical significance at the 1% level. The multiple regression equations for the amount of $Cl^-$ at the stream water quality showed that electrical conductivity, the amount of cation($K^+$, $Na^+$), the amount of $SO_4{^{2-}}$, total amount of ion, the percentage of the amount of $Cl^-$, and the percentage of the amount of $SO_4{^{2-}}$ had statistical significance at the 5% and 1% level. Also, The multiple regression equations for the amount of $NO_3{^-}$ at the stream water quality showed that the amount of cation($Na^+$, $Ca^{2+}$), the amount of $SO_4{^{2-}}$, the percentage of the amount of $Cl^-$, and the percentage of the amount of $NO_3{^-}$ had statistical significance at the 5% and 1% level. The multiple regression equations for the amount of $SO_4{^{2-}}$ at the stream water quality showed that the amount of $NO_3{^-}$, total amount of ion had statistical significance at the 5% level.

• Clean Technology
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• v.26 no.2
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• pp.102-108
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• 2020

In recent years, packed column has been widely used in separation processes, such as absorption, desorption, distillation, and extraction, in the petrochemical, fine chemistry, and environmental industries. Packed column is used as a contacting facility for gas-liquid and liquid-liquid systems filled with random packed materials in the column. Packed column has various advantages such as low pressure drop, economical efficiency, thermally sensitive liquids, easy repairing restoration, and noxious gas treatment. The performance of a packed column is highly dependent on the maintenance of good gas and liquid distribution throughout a packed bed; thus, this is an important consideration in a design of packed column. In this study, hydraulic pressure drop, hold-up as a function of liquid load, and mass transfer in the air, air/water, and air-NH₃/water systems were studied to find the geometrical characteristic for raschig super-ring experiment dry pressure drop. Based on the results, design factors and operating conditions to handle noxious gases were obtained. The dry pressure drop of the random packing raschig super-ring was linearly increased as a function of gas capacity factor with various liquid loads in the Air/Water system. This result is lower than that of 35 mm Pall-ring, which is most commonly used in the industrial field. Also, it can be found that the hydraulic pressure drop of raschig super-ring is consistently increased by gas capacity factor with various liquid loads. When gas capacity factor with various liquid loads is increased from 1.855 to 2.323 kg^-1/2 m^-1/2 S^-1, hydraulic pressure drop increases around 17%. Finally, the liquid hold-up related to packing volume, which is a parameter of specific liquid load depending on gas capacity factor, shows consistent increase by around 3.84 kg^-1/2 m^-1/2 S^-1 of the gas capacity factor. However, liquid hold-up significantly increases above it.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.338-347
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• 1987

The research was carried out to investigate the related phenomena, the latent structures and synthetical characteristics in various growth factors of Phyllostachys bambusoides Sieb. et Zucc. growing at Damyang gun, Chollanamdo, using multivariate analysis. 1. By synthetical characteristics in canonical correlation between height-growth factor group and diameter-growth factor group, the former was determined by the culm height ($x_1$), and the latter by the. diameter of the largest internode($x_7$). And for those between quantitative growth factor group and qualitative growth factor group, the former was determined by the surface area($x_{10}$), and the latter by the diameter of the largest internode ($x_7$). 2. The ten growth factors of bamboo culm were simplified by two principal components on the basis of accumulated proportion aimed at 90%. The first principal component($Z_1$) as a "size factor" showed high correlation with growth factors except eye-height diameter($x_5$). The second principal component($Z_2$) as a "shape factor" showed high correlation only with $x_5$. 3. The bamboo culm, and the latent phenomenon between their growth factors could be determined by two common factors showing high communality(94.16%). The ten growth factors can be grouped into two attribute factors: quantity and quality. 4. The bamboo culms can be classified into five types: total, volume, shape-quality, inferior and middle.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1059-1075
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• 1997

The transprot layer protocol for distrubuted multimedia applications in high speed network should gurantee the Quality of Serivce(QoS)requested by uwer.,The QoS Parmenters can be divied into two calssifications:those depend on the speed of a network such as bandiwidth,end-to-end transmission delay and throughput;and net- woek independent parameters such as various typed of group communications, retransmission method based on multimeda characteristic,acceptable packet wrror rate and transmission priority.In this proposed protocol,we divided user's QoS into performance redated parmeters and non-performance related parameters.The perform- ance-related paramenters are mapped into ATM traddic paramenters by the Distributed QoS Manger(DQM),the QoS manager,and the non-performance redlted paramenters are supported by the Distributed Multimedia Trans-port protocol(DMTP),a high-performance group transport protocol.Especially,becaues the DMTP is designed with considering the IP protocol,it can be efficiently used as an underlying protocol not onlu in ATM,but also in Ethernet,Token ring and FDDI LAN.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.677-682
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• 2014

In the present study, a decision tree and artificial neural network were used to determine critical design parameters for lithium ion batteries and compare their performances. First, a design method that used a decision tree-artificial neural network model was used to determine the major design factors among early pole plate design factors that showed nonlinearity. Then, the artificial neural network was used to implement a weighted value analysis of the importance of the design factors and their effect on the current density. The second method involved the use of an artificial neural network model to construct artificial networks without separate determinations of the major early design factors to analyze the connections and weighted values related to the current density.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.38-44
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• 2006

Using GJS and fuzzy sets, a model was developed for evaluating the site-suitability of forest stands for extracting sap of Acer pictum Thunb. var. mono in Mt. Baekun area. In the model, the productivity of sap extraction was expressed as the function of biotic and abiotic site factors. Among the factors, the topographic terrain conditions and accessibility of forest stands were chosen to consider working environment of the sap extraction. The difference in measurements of the factors between sap-extraction and non-sap-extraction forest stands was used in determining the weight of the relative importance for sap extraction productivity. The weight for distance-to-stream, vegetation type and shading condition turned out relatively higher than those for tree age, distance-to-road and DBH. Based on the results, a site-suitability map in Mt. Baekun area for sap extraction was built.