• Journal of the Korean Geotechnical Society
• /
• v.28 no.11
• /
• pp.5-16
• /
• 2012

Since geologic data are often sampled at sparse locations, it is important not only to predict attribute values at unsampled locations, but also to assess the uncertainty attached to the prediction. In this paper, the assessment of the local uncertainty of prediction for the depth to weathered soil was performed by using the indicator kriging. A conditional cumulative distribution function (ccdf) was first modeled, and then E-type estimate was computed for the spatial distribution of the depth to the weathered soil. Also, optimal estimate of spatial distribution for the depth to weathered soil was determined by using ccdf and loss function. The design procedure and method considering the minimum expected loss presented in this paper can be used in the decision-making process for geotechnical engineering design.

• Journal of Sericultural and Entomological Science
• /
• v.22 no.1
• /
• pp.52-58
• /
• 1980

Root system and distribution of soil components (pH, available P, K, Ca and Mg) were studied in a 20-year old, low-cutting mulberry field. The variety, kairyonezumigaeshi (Morus alba L.), was planted in a spacing of 1.8m${\times}$0.6m(740 tiess/10a). Roots and soil samples were taken from each of 196 blocks in a demension of 26${\times}$17${\times}$10cm(as shown in Fig. 1) from the soil between rows. 1. Whereas root system concentrated towards the stock, chemical components, pH, available P, Ca and Mg, were increasing toward the center of the row spacing. 2. Root system and distribution of chemical components between trees were not significantly different among blocks. 3. Roots were distributed most densely in a depth of 10∼20, intermediate 20∼30 and 30∼40, and least 0∼10cm. However, the concentrbtion of chemical components was the highest in a depth of 0∼10cm and decreased with soil depth. The soil. a depth of 0∼10cm on the center of row spacing, was the lowest in the root system and the richest in a chemical components. The results indicate that special fertilizinng management is required for the efficient absorption of nutrients.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.17 no.1
• /
• pp.45-56
• /
• 2015

The distribution of seaweed was examined in Jeonnam archipelago marine ranching area, the coastal of geumo-do, Yosu. Abundance and distribution of seaweed in dropping site of artificial reef were sampled at 6 station at October 2007. Seaweed community were investigated with quadrat method at line-transect by scientific SCUBA divers. as a result, 30 species in total, 4 green, 9 brown and 15 red seaweed were identified. Range of seaweed biomass in all sampling stations were about 1,600~4,000 g/m². At intertidal zone, appearance of individuals and dominance rate were showed higher than below the subtidal line and at depth from 4m to 6m, individuals, dominance rate and biomass were represented low level. characteristic of water in marine ranching area is turbidity and also compensation depth is low. For that reason, individuals of seaweed community were smaller from depth of 4 meters. Therefore, when equip the artificial reef for preparation of seaweed beds need consider that equipment periods(early spring; before releasing marine seaweed spore) and suitable water depth(3~6m).

• Journal of Korean Society on Water Environment
• /
• v.39 no.5
• /
• pp.396-412
• /
• 2023

Species from the mayfly genus Ephemera (Order Ephemeroptera) was assessed for their physical microhabitat suitability (namely E. strigata, E. separigata, and E. orientalis-sachalinensis). Probability distribution models (Exponential, Normal, Lognormal, Logistic, Weibull, Gamma, Beta, and Gumbel) based on the data collected from 23,957 sampling units of 6,787 sites in Korea from 2010 to 2021 were used. Mode and standard deviation calculated from the best-fitting models to species distribution along a water depth gradient were 265 cm and 159 cm in E. orientalis-sachalinensis; 10 cm and 83 cm in E. strigata; 20 cm and 15 cm in E. separigata, respectively. The current velocity gradient was 22 cm/s and 40 cm/s in E. orientalis-sachalinensis; 60 cm/s and 53 cm/s in E. strigata; 82 cm/s and 25 cm/s in E. separigata, respectively. The mean diameter (phi scale) of substrate grains were -3.6 and 2.2 in E. orientalis-sachalinensis; -7.4 and 1.5 in E. strigata; -5.8 and 0.9 in E. separigata, respectively. Habitat suitability range of E. orientalis-sachalinensis was estimated to be 161~369 cm (water depth), 5~44 cm/s (current velocity), -5.2~-2.0 (mean diameter); 3~34 cm (water depth), 36~94 cm/s (current velocity), -8.1~-6.3 (mean diameter) for E. strigata; 12~32 cm (water depth), 63~96 cm/s (current velocity), -6.3~-5.2 (mean diameter) for E. separigata. In relative comparison, E. orientalis-sachalinensis was estimated to be rheophobic, eurybathophilic, and eurypsephophilic; E. strigata to be euryrheophilic, bathophobic, and lithophilic; E. separigata to be stenomesorheophilic, stenobathophobic, stenolithophilic.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.1
• /
• pp.108-117
• /
• 1998

This study was performed to analyze the fluid flow characteristics and the temperature distribution of the aquarium for fish breeding. In this study, the finite volume method and turbulence k-$\varepsilon$ model with the SIMPLE computational algorithm are used to study the water flow in the aquarium. The calculation parameters are the circulating flow rate and the basin depth, and the experiments were carried out for the water flow visualization This numerical analysis gives reasonable velocity distributions in good agreement with the experimental data. As the results of the three dimmentional simulations, the sectional mean velocity increased as the sectional mean temperature increases for constant basin depth, and the mean velocity increased more rapidly for small basin depth than that of large basin depth, The mean velocity and temperature can be expressed as the function of the circulating flow rates and the basin depth.

• The Korean Journal of Ecology
• /
• v.17 no.4
• /
• pp.435-442
• /
• 1994

In the littoral zone of Lake Paltangho, a vegetation map of aquatic macrophytes was constructed to estimate their occupied area, and the change of abundance of submersed macrophytes was examined along water depth to elucidate niche perferences on the depth gradient. Total area of the littoral zone was 267 ha, of which submersed, emergent and floating-leaved macrophytes covered 155ha, 103 ha and 10ha, respectively. Submersed macrophytes were distributed within a water-depth of 2.5m, with an apparent pattern of zonation: Vallisnaria gigantea and Ceratophyllum demersum at the deeper water depth of 1.5~2.5m.

• Structural Engineering and Mechanics
• /
• v.18 no.2
• /
• pp.263-276
• /
• 2004

The purpose of this paper is to determine the subsoil depth affected from the load on the plate resting on elastic foundation using stress distribution within the subsoil that will be occurred depending on the loading and dimension of the plate. An iterative method is developed in order to determine the effective depth of the subsoil under the plate. Numerical examples from the technical literature are solved by means of the method suggested herein and displacements, bending moments and shear forces are presented in graphical and tabular forms to evaluate the effects of the limit depth considered in the study. Results showed the efficiency and simplicity of the present approach for the plate resting on an elastic foundation.

• Journal of the Korea Concrete Institute
• /
• v.28 no.3
• /
• pp.257-265
• /
• 2016

The failure behavior of reinforced concrete beams is governed by the mechanical relationships between the shear span-to-effective depth ratio, flexural reinforcement ratio, load and support conditions, and material properties. In this study, two simple indeterminate strut-tie models which can reflect all characteristics of the failure behavior of reinforced concrete beams were proposed. The proposed models are effective for the beams with shear span-to-effective depth ratio of less than 3. For each model, a load distribution ratio, defined as the fraction of load transferred by a truss mechanism, is also proposed to help structural designers perform the rational design of the beams by using the strut-tie model approaches of current design codes. In the determination of the load distribution ratios, the effect of the primary design variables including shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete was reflected through numerous material nonlinear analysis of the proposed indeterminate strut-tie models. In the companion paper, the validity of the proposed models and load distribution ratios was examined by applying them to the evaluation of the failure strength of 335 reinforced concrete beams tested to failure by others.

• Korean Journal of Ichthyology
• /
• v.7 no.1
• /
• pp.64-70
• /
• 1995

Vertical distribution of eggs and larvae of Maurolicus muelleri were studied in the south-eastern waters of Korea during 1985 and 1986. Samples were collected vertically at three different layers, 0~30 m, 30~50m and 50~100m. The densities of egg and larva were high in August. Eggs and zooplankton were abundant around the thermocline in the temperature range of $10{\sim}15^{\circ}C$ at the layers of 50 m depth in 1985, and 30~100m depth in 1986. Eggs in the cleavage stage were abundant at the layer of 50~100m depth, while those of processing embryonic body formation were tended to concentrate at the layer of 30~50m depth. The vertical distribution of each developmental stage differed according to sampling time. They were distributed uniformly at water column from 30 m to 100m depth in the midnight, but concentrated at the layer from 30 m to 50 m from dawn to sunset. Before and after midnight, eggs in the cleavage stage were most abundant. It was assumed that M. muelleri spawned at the layer of 50~100m depth around the midnight, and the eggs ascended to the layer of 30~50m depth with development.

• Analytical Science and Technology
• /
• v.15 no.4
• /
• pp.373-380
• /
• 2002

Humic and fulvic acids present in soil of different depth were extracted and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of radioactive elements deposited on soil. Molecular size distribution of the humic and fulvic acids was measured by stirred cell ultrafiltration technique and the structural informations were obtained from their UV-Vis., IR and synchronous fluorescence (SyF) spectral analysis. Main molecular size ranges of the soil 1) humic and fulvic acids were 30~100 kDa (46~56%) and 10~30 kDa (33~43%) respectively, and their overall molecular sizes were found to became smaller with increasing the soil depth. Absorptivities measured at 280 nm in the UV-Visible spectra of humic acids were 1.4~1.5 times higher than those of fulvic acids, and increased with increasing the soil depth. SyF spectral data showed two distinct peak components having maximum peak positions of 428 nm (type I) and 498 nm (type II) for the soil humic and fulvic acids. From the analysis of the peak components, it was found that humic molecules are mainly made up of aromatic compounds corresponding to longer wavelength (type II), and the molecular components increased with increasing the soil depth. Analysis of IR spectral data indicated that the humic molecules contain a higher relative concentration of carboxylic groups than those of fulvic molecules, and the carboxylic group contents are seen to increase as the soil depth increase.