• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.6
• /
• pp.1-6
• /
• 2020

Road movement pollutant air environment big data is a link between real-time traffic data such as vehicle type, speed, and load using AVC, VDS, WIM, and DTG, which are always traffic volume survey equipment, and road shape (uphill, downhill, turning section) data using GIS. It consists of traffic flow data. Also, unlike general data, a lot of data per unit time is generated and has various formats. In particular, since about 7.4 million cases/hour or more of large-scale real-time data collected as detailed traffic flow information are collected, stored and processed, a system that can efficiently process data is required. Therefore, in this study, an open source-based data parallel processing performance optimization study is conducted for the visualization of big data in the air environment of road transport pollution.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.4
• /
• pp.135-146
• /
• 2019

Deep beam has high section modules compared with shallow beam of the same weight. However, deep beam has low rotational capacity and high possibility of brittle failure so it is not possible to apply deep beams with a long span to intermediate moment frames, which should exhibit a ductility of 0.02rad of a story drift angle of steel moment frames. Accordingly, KBC and AISC limit the beam depth for intermediate and special moment frame to 750mm and 920mm respectively. The purpose of this paper is to improve the seismic performance of intermediate moment frame with 1200mm depth beam. In order to enhance vulnerability of plastic deformation capacity of deeper beam, Multi-Reduced Taper Beam(MRTB) shape that thickness of beam flange is reinforced and at the same time some part of the beam flange width is weakened are proposed. Based on concept of multiple plastic hinge, MRTB is intended to satisfy the rotation requirement for intermediate moment frame by dividing total story drift into each hinge and to prevent the collapse of the main members by inducing local buckling and fracture at the plastic hinge location far away from connection. The seismic performance of MRTB is evaluated by cyclic load test with conventional connections type WUF-W, RBS and Haunch. Some of the proposed MRTB connection satisfies connection requirements for intermediate moment frame and shows improved the seismic performance compared to conventional connections.

• Korean Journal of Metals and Materials
• /
• v.47 no.8
• /
• pp.494-499
• /
• 2009

As a novel method to produce a steel beam with 6mm thickness for buildings, a continuous roll forming process is reported. The roll shape is asymmetric and consists of 6 pairs of rollers to bend the steel plate from $0^{\circ}$ to $90^{\circ}$. Results obtained upon application of the roll forming process showed that the angle of the section plate is $90^{\circ}$. However, defects such as bowing and camber as high as 3.2 [$^{\circ}/m$] were observed. A FEM (Finite Element Method) analysis was applied to investigate the causes of the results for the region between rollers no. 5 and no. 6. The results of a FEM simulation of deformation and stress showed that there are some strong peak stresses on the upper surface and bottom surface of the material. The positions of the peak stresses did not show a correspondence between the upper and bottom surfaces. Thus, the defects in the process of roll forming with a 6 mm thick steel plate occur by the unbalanced stresses between the upper surface and bottom surface of the material in this study.

• Journal of the Korea Convergence Society
• /
• v.12 no.6
• /
• pp.33-38
• /
• 2021

In order to manufacture a lightweight medical radiation shielding sheet, a new shielding material was studied. We tried to verify the possibility of a shielding material by mixing egg shell powder, which is thrown away as food waste at home, with a polymer material. Existing lightweight materials satisfy eco-friendly conditions, but there are difficulties in the economics of shielding materials due to the cost of the material refining process. This study aims to solve this problem by using egg shells, which are household waste. A 3 mm-thick shielding sheet was fabricated using HDPE, a polymer material, and particle distribution within the cross-section of the shielding sheet was also verified. The shape of the particles was rough and there were voids between the particles, and the average weight per unit area was 1.5 g/cm². The shielding performance was around 20% in the low energy area and 10% in the high energy area, showing the possibility of a low-dose medical radiation shielding body.

• Journal of the Korean Wood Science and Technology
• /
• v.30 no.2
• /
• pp.79-86
• /
• 2002

Anatomical characteristics of Mulpurenamu (Korean ash, Praxmus rhynchopbylla), Deulmaenamu (Manshurican ash, Fraxinus mandsburica) and Sheamulpure (Sieboldiana ash, Fraxinus sieboldiana) grown in Korea were examined by an optical microscopy and an image analysis. Some characteristics such as boundary of annual rings, shape and size of vessel elements, arrangement of axial parenchyma cells in cross section, and cell volumetric composition showed significant differences between the sample species. In radial variation of elements, fiber length and vessel size increased from the pith for about 10 to 15 years and then reached a more or less constant. The results of this study can be used for identification of wood and indices of wood quality in Fraxinus spp.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.17-23
• /
• 2023

In this study, the thermoluminescence kinetics of electron trap in Li₆Y_0.5Gd_0.5(BO₃)₃ (LY_0.5G_0.5BO) scintillator for neutron detection composed of Li, Gd, and B with a high neutron response cross-section were investigated. The thermoluminescence glow curve of the LY_0.5G_0.5BO scintillation single crystal was measured and analyzed using the peak shape method, the initial rise method, and the machine learning algorithm to evaluate the physical parameters of the electron trap. The glow curve of the LY_0.5G_0.5BO scintillation single crystal consisted of a single peak. As a result of analyzing this peak, the activation energy, emission order, and frequency factor of the electron trap were 0.61 eV, 1.1, and 1.7×10⁷ s^-1, respectively. In addition, the possibility of thermoluminescence analysis of scintillators using machine learning was confirmed.

• The Korea Journal of Herbology
• /
• v.33 no.3
• /
• pp.11-18
• /
• 2018

Objectives : Saururus chinensis and Houttuynia cordata (Saururaceae) are perennial herbs using for medicinal purposes in Korea. The objectives of this study are to compare anatomical key characters between two medicinal plants and to provide fundamental information for the identification of two herbal medicines by using anatomical features. Methods : Cross-sections of root, rhizome, stem, petiole, and leaf for each species were observed in this study. Materials were analyzed through dehydration, paraffin embedding and micro-sectioning, and double staining with Safranin O and Fast-Green FCF. Observations of permanent preparation were conducted using light microscope. Results : S. chinensis and H. cordata were distinguished with anatomical differentiations; Idioblasts with essential oil were scattered in the parenchyma cell of cortex, pith, and phloem of S. chinensis, on the other hand, in H. cordata, idioblasts were distributed ring-shaped in the cortex of the root. S. chinensis had two cycles of vascular bundles in the stem while H. cordata had one cycle. Hypodermis layer was conspicuous in a stem of H. cordata, crystals were observed the only parenchyma in a stem of S. chinensis, and epidermal oil cells were developed in the epidermis of H. cordata. S. chinensis had air cavity at the cortex and pith of the stem. The shape of cross-section was polygonal in the stem of S. chinensis and was circular in the stem of H. cordata. Conclusions : We investigated anatomical study of Korean S. chinensis and H. cordata. To identify two herbal medicines, we considered main anatomical features and provided identification key here.

• The Korea Journal of Herbology
• /
• v.34 no.5
• /
• pp.1-12
• /
• 2019

Objectives : The consumption of licorice is large in Korea, but domestic production is insufficient due to the lack of adaptability. This study aimed to provide a morphological basis for adding interspecific hybrid licorice with improved adaptability to pharmacopoeia. Methods : This study was to establish identification criteria for the original plants, external and internal morphology of the authentic herbal medicines (Glycyrrhiza uralensis, G. glabra and G. inflata), market products and artificially interspecific hybrid forms of licorice. For this purpose, previous studies were investigated and visual and histological observations were carried out. We focused on the internal morphology by microscopic observation for securing objectivity. Finally, we proposed the identification keys for precise classification of each part. Results : 1) Original plant : Licorice species in the compendium were distinguished by the number of leaflets, presence of hair on the fruit, curvature and swelling of the fruit. 2) External morphology : Licorice species were distinguished by degree of powderiness, tearing gap, radial structure in the cross section and existence of protrusion of outer epidermis. 3) Internal morphology : Licorice species were distinguished by the degree of development of phloem fiber bundle, development of obliterated sieve, whether the secondary medullary ray are branched. In the case of interspecific hybrids, the characteristics of both species used for hybridization were mixed in all observation methods. Conclusions : These results suggest that the interspecific crossbred licorice is suitable for the pharmacopoeial standard. Therefore, it can be applied as a herbal medicine through additional supplementary study.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.4_2
• /
• pp.699-706
• /
• 2022

In this study, Directed energy deposition (DED) among additive manufacturing is applied to repair damaged spindle key parts of planner miller. The material of the spindle key is SCM415, and the P21 Powder is used. In order to find the optimal deposition conditions for DED equipment, a single-line deposition experiment is conducted to analysis five parameters. The laser power affects the width, and the height is a parameter affected by coaxial gas and powder gas. In addition, laser power, powder feed rate, coaxial gas, and powder gas are parameters that affect dilution. Otimal deposition is that 400 W of laser power, 4.0 g/min of powder feed rate, 6.5 L/min of coaxial gas, 3.0 L/min of powder gas and 4.5 L/min of shield gas. By setting the optimum conditions, a uniform deposition cross section in the form of an ellipse can be obtained. Damage recovery process of spindle key consists of 3D shape design of the base and deposition parts, deposition path creation and deposition process, and post-processing. The hardness of deposited area with P21 powder on the SCM415 spindle key is 336 HV for the surface of the deposition, 260 HV for the boundary area, and 165 HV for the base material.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.2
• /
• pp.1-10
• /
• 2022

Exhaust gases emitted from internal combustion engines contain nitrogen oxides (NOx) and sulfur oxides (SOx), which are major air pollutants causing acid rain, respiratory diseases, and photochemical smog. As a countermeasure, scrubber systems are being studied extensively. In this study, the pressure drop characteristics were analyzed by changing the exhaust gas inflow velocity using a scrubber for a 700 kW engine as a model. In addition, the fluid flow inside the scrubber and the behavioral characteristics of the droplets were studied using CFD, and the design compatibility of the cleaning device was verified. Flow analysis was performed using inertial and viscous resistances by applying porous media to the complex shape of the scrubber. The speed of the exhaust passing through the outlet nozzle from the inlet was determined through the droplet behavior analysis by spraying, and the flow characteristics for the pressure drop were studied. In addition, it was confirmed through computational analysis whether there was a stagnation section in the exhaust gas flow in the scrubber or the sprayed droplets were in good contact with the exhaust gas.