• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.457-470
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• 2019

This study aims to present the characteristics of marine physics, water quality, and sediment quality around offshore wind farm near the Gochang and Buan sea areas through the analysis of monitoring data. The relationships between suspended solid and wave height as well as suspended solid and flow velocity were analyzed. We found that Correlation Coefficient values of 0.61~0.69 between wave height and suspended solid, and suspended solid concentration reaches 75 mg/L or higher when wave height of more than 1m occurred in the spring (1 month). The water quality index (WQI) was used to identify the status of the water quality in the study area. Most of the measured points were rated first grade (very good). The variation of chlorophyll-a was relatively hight compared to the other criteria, indicating that it is a major factor affecting the quality index. In the sediment column, all heavy metals were detected below the Threshold Effects Level(TEL), and ignition loss and grain size show a positive correlation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.334-339
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• 1997

The feasibility of foam separation to remove solid produced from fish culture water was investigated. Performance characteristics of foam separator were highly dependent upon the operating parameters which were superficial air velocity, Hydraulic retention time (HRT), and foam height. About $50\%$ of the total protein contained in a sample of fish culture water could be removed by foam separator. The removal efficiencies of protein, T-N, TA, and solid components were increased with increasing superficial air velocity and HRT. The combined effects of these operational variables show that removal rates of TVS increase with increasing superficial air velocity and HRT, and decrease as foam height goes up. It could be confirmed that foam separator might offer good perspective for removal of harmful components such as TA and TVS in aquacultural recirculating water.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.178-181
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• 2005

The positioning accuracy of the Global Positioning System (GPS) has been improved considerably during the past two decades. The main error sources such as ionospheric refraction, orbital uncertainty, antenna phase center variation, signal multipath, and tropospheric delay have been reduced substantially, if not eliminated. In this study, the GPS data collected by the GPS receivers that were established as continuously operating reference stations by International GNSS Service (IGS), Ministry of the Interior (MOl), Central Weather Bureau (CWB), and Industrial Technology Research Institute (ITRI) Of Taiwan are utilized to investigate the impact of atmospheric water vapor on GPS positioning determination. The surface meteorological measurements that were concurrently acquired by instruments co-located with the GPS receivers include temperature, pressure and humidity data. To obtain the influence of the GPS height on the proposed impact study. A hydrodynamic ocean tide model (GOTOO.2 model) and solid earth tide were used to improve the GPS height. The surface meteorological data (pressure, temperature and humidity) were introduced to the data processing with 24 troposphere parameters. The results from the studies associated with different GPS height were compared for the cases with and without a priori knowledge of surface meteorological measurements. The finding based on the measurements in 2003 is that the surface meteorological measurements have an impact on the GPS height. The associated daily maximum of the differences is 1.07 cm for the KDNM station. The impact is reduced due to smoothing when the average of the GPS height for the whole year is considered.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.141-159
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• 2011

The purpose of the present research is to suggest implications on guidance of height concept understanding of figures by investigating concept understanding how sixth grade's elementary school students understand a height concept of figures. In order to achieve this research purpose, a height concept understanding test of figures was carried out with the target of 54 sixth grade students who already learned a height concept of plane figures and three-dimensional solid figures and thus this research analyzed characteristics and errors appeared there. When analyzing its characteristics and errors interviews with students were carried out for in-depth analysis. And as a result the following implications could be obtained. First, students felt more difficulty in measuring height in a figure that its lower base is not horizontal in questions measuring height of a plane figure. Second, there were cases that students associate a height concept of figures with experience of height experienced in daily life. Third, students were feeling difficulty in linguistically expressing a concept called height that oneself has. Expressing a concept linguistically plays an important role in understanding a concept clearly. Accordingly activities for raising this mathematical communication ability are required, Fourth, the present research can suggest implications in designing classes that students can clearly understand the height concept of figures.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.256-265
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• 1997

The objectives of this study were to examine the ability to predict soluble solid and firmness in intact apples based on the visible/near-infrared spectroscopic technique. Two cultivars of apples, Delicious and Gala, were handled, tested and analyzed separately. Reflectance spectra, Magness-Tayor (MT) firmness, and soluble solids in apples were measured sequentially. Maximum and minimum diameters, height, and weight of apples were recorded before the MT firmness tests. A spectrophotometer was used to collect reflectance spectra of intact apples over a wavelength range of 400 to 2, 498 nm. The W firmness tests were conducted using a standard 11.1mm (7/16 in.) MT probe mounted in an Instron universal testing machine. A digital refractormeter was used to measure soluble solid contents in the apples. Apple samples were divided into a calibration set and a prediction set. The calibration set was used during model development, and the prediction set was used to predict soluble solids and firmness from unknown spectra. The method of partial least square (PLS) analysis was used. An unique set of PLS loading vectors (factors) was developed for soluble solid content and firmness. The PLS model showed good correlations between predicted and measured soluble solids of intact apples in 860～1078 nm of the wavelengths. However, the PLS analysis was not good enough to predict the apple firmness.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.312-321
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• 2023

Fluidized beds have been widely used in industrial applications, which in most of them, the operating fluid is non-Newtonian. In this study, the combination of the lattice Boltzmann method (LBM) and the smoothed profile method has been developed for non-Newtonian power-law fluids. The validation of the obtained model were investigated by experimental correlations. This model has been used for numerical studying of changing the operating fluid and geometrical parameters on the expansion behavior in liquid-solid beds with both Newtonian and non-Newtonian fluids. Investigations were performed for seven different geometries, one Newtonian, and two non-Newtonian fluids. The power-law index was in the range of 0.8 to 1, and the results for the Newtonian fluidized beds show more porosity than the non-Newtonian ones. Furthermore, increasing the power-law index resulted in enhancing the bed porosity. On the other hand, bed porosity was decreased by increasing the initial bed height and the density of the solid particles. Finally, the porosity ratio in the bed was decreased by increasing the solid particle diameter.

• Education of Primary School Mathematics
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• v.19 no.2
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• pp.113-125
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• 2016

The concept and measuring activities of the height of figures are essential to find the areas or volumes of the corresponding figures. For plane figures, the height of a triangle is defined to be the line segment from a vertex that is perpendicular to the opposite side of the triangle, whereas the height of a parallelogram(trapezoid) is defined to be the distance between two parallel sides. For the solid figures, the height of a prism is defined to be the distance of two parallel bases, whereas the height of a pyramid is defined to be the perpendicular distance from the apex to the base. In addition, the height of a cone is defined to be the length of the line segment from the apex that is perpendicular to the base and the height of a cylinder is defined to be the length of the line segment that is perpendicular to two parallel bases. In this study, we discuss some pedagogical problems on the concepts and measuring activities of the height of figures to provide alternative activities and suggest their educational implications from a teaching and learning point of view.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1624-1626
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• 1999

PD in defect of solid insulation system is very harmful since It often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge. PD can indicate incipient failure, so it has been used to determine degradation of insulation. In this paper. we investigated PD in defects of solid insulation by using statical method and classified PD patterns with surface discharge, electrical tree and void discharge by using Kohonen network. we used peak charge, average discharge power, average discharge current, repetition rate, skewness, kurtosis, QN of the max pulse height vs. repetition rate $H_q(n)$ for analysis and classification.

• Ocean and Polar Research
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• v.26 no.4
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• pp.647-653
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• 2004

Experimental studies with 4.3m and enlarged 30m in height have been conducted to investigate the flow characteristics of solid-liquid mixture in a lifting pipe and to acquire the design data for sea tests that will be performed in the future. From the results, it was observed that the more the discharged volume fraction and the solid diameter increase, the more the hydraulic gradient increases. Also, the more the diameter of the lifting pipe increases, the smaller the friction loss, and consequently, the less pressure drop and hydraulic gradient. From the enlarged hydraulic pumping experiments, it was shown that the results of the experiments were matched with those of the numerical model previously developed. On the bases of these studies, we plan to conduct further experiments and validate the hydraulic pumping model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.226-230
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• 1997

A plasticity theory applicable to powdered metal compaction is briefly summarized and its variational form for the finite element analysis is described. The compaction processes of axisymmetric solid cylinder are simulated. For the analysis of the friction effect of solid cylinder, the investigations were performed for different compact geometries. Highlights of the results for given geometries are reported in terms of transmitted pressure on the lower punch from the upper punch through the compact and maximum density variation within the compacts. General conclusions from these simulation results are : (1) the friction coefficient could be selected from the transmitted force data during the single acting compaction test with the simulated results ; and (2) density variatioins within the compacts are very much dependent of the compact geometry such as the height to diameter ratio and the frictional condition between compact and dies.