• Advances in concrete construction
• /
• v.11 no.4
• /
• pp.271-284
• /
• 2021

This study aims to trace the response of twelve one-way sustainable concrete hollow-core slabs made by reducing cement content and using replacement of coarse aggregate by plastic aggregate. The trial mixes comprise the 25, 50, 75, and 100% replacement of natural coarse aggregate. The compressive strength of the resulting lightweight concrete with full replacement of coarse aggregate by plastic aggregate was 28 MPa. These slabs are considered to have a reduced dead weight due to using lightweight aggregate and due to reducing cross-section through using voids. The samples are tested under two verticals line loads. Several parameters are varied in this study such as; nature of coarse aggregate (natural or recycled), slab line load location, the shape of the core, core diameter, flexural reinforcement ratio, and thickness of the slab. Strain gauges are used in the present study to measure the strain of steel in each slab. The test samples were fourteen one-way reinforced concrete slabs. The slab's dimensions are (1000 mm), (600 mm), (200 mm), (length, width, and thickness). The change in the shape of the core from circular to square and the use of (100 mm) side length led to reducing the weight by about (46%). The cracking and ultimate strength is reduced by about (5%-6%) respectively. With similar values of deflection. The mode of failure will remain flexural. It is recognized that when the thickness of the slab changed from (200 mm to 175 mm) the result shows a reduction in cracking and ultimate strength by about (6% and 7%) respectively.

• Steel and Composite Structures
• /
• v.13 no.5
• /
• pp.409-421
• /
• 2012

Recently, as the height of building is getting higher, the applications of CFST column for high-rise buildings have been increased. In structural system of high-rise building, The RC core and exterior concrete-filled tubular (CFST) column-beam pinned connection is one of the structural systems that support lateral load. If this structural system is used, due to the minimal CFST column thickness compared to that of the CFST column width, the local moment occurred by the eccentric distance between the column flange surface from shear bolts joints degrades the shear strength of the CFST column-beam pinned connections. This study performed a finite element analysis to investigate the shear strength under eccentric moment of the CFST column-beam pinned connections. The column's width and thickness were used as variables for the analysis. To guarantee the reliability of the finite element analysis, an actual-size specimens were fabricated and tested. The yield line theory was used to formulate an shear strength formula for the CFT column-beam pinned connection. the shear strength formula was suggested through comparison on the results of FEM analysis, test and yield lime theory, the shear strength formula was suggested.

• Corrosion Science and Technology
• /
• v.23 no.3
• /
• pp.215-220
• /
• 2024

Recently, the demand for Zn-Ni electrogalvanized steel sheets for home appliances and automobiles is increasing. Products should have a thick plating (30 to 40 g/m²) on both side with a thin thickness (≤ 0.8 mm) and the highest surface quality. By a high current density operation, current is concentrated in the edge part of the steel sheet, resulting in large surface dent defects due to dendritic plating. This can lead to a low productivity due to low line speed operation. To solve this problem, this study aimed to identify factors influencing dendritic plating. A cylindrical electroplating device was manufactured. Effects of cut edge shape and thickness of steel plate, current density, temperature, flow rate, electrolyte concentration, and pH on dendrite generation of Zn-Ni electroplating were examined. To investigate effect of edge shape of the steel sheet, the steel sheet was manufactured using three processing methods: shearing, polishing after shearing, and laser. Relative effects thickness and cut edge processing methods of the steel plate, current density, temperature, flow rate, electrolyte concentration, and pH of plating solution on dendrite plating were investigated. To prevent dendrite plating, an edge mask was manufactured and its application effect was investigated.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.2 no.2
• /
• pp.1-8
• /
• 1999

Information representing the thickness of the original lines from the thinning results can be used efficiently in order to implement the automated vectorizing system. This paper proposes a preprocessing scheme of thinning which can show the information of the original lines' thickness from the thinning result. In the proposed scheme, the depth of each pixel constructing the lines was calculated, which was represented by the number of layers composed of neighboring pixels surrounding the original pixel. And then the original lines' thickness could be recognized through the depth information of the skeleton from the thinning results. We implemented the proposed scheme and experimented on a contour map. Using the depth information of the skeleton, we could easily distinguish each line of the contour either an intermediate or an index contour.

• Journal of the Korean Home Economics Association
• /
• v.36 no.5
• /
• pp.17-27
• /
• 1998

The need for periodic investigation on human growth rate and somatotypes has been increased because the scientific development and environmental factors have effected a lot on them recently. This study aimed to investigate the changes of the 638 female somatotypes in the age of 18-54 obtained by direct and indirect measurement. The measurement data were divided into 4 groups early young women age group (18-54), late young women age group (25-34), early middle age group (35-44), late middle age group (45-54) and compared each other based on each group by age. The results obtained from this study were as follows: 1. According to Mollison Curve based on the early young women, items of depth decreased overall and pp.P. length & shoulder length increased as the age increased. The circumference, breadth and thickness tended to increase, especially waist girth and thickness of waist increased markedly. The data showed that the increase rate of thickness was higher than that of breadth. 2. Gradual somatotype changes were observed by overlapping projection drawings obtained by direct measurement. Compared with the young women, the middle aged showed lower should point depth and hip line & crotch depth line were lengthened significantly. No significant difference was observed in overlapping of the early young women and the late young women' figure, neither was in early middle aged and the late middle aged. 3. By overlapping the side view of the young women group (18-37) and middle aged group (35-54), no significant postural characteristics were found, while the back tended to bend forward and the abdomen and hip appeared to get fat.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.12
• /
• pp.17-23
• /
• 1997

A 3-D vision system is developed to evaluate blanks' line up and monitor gap and thickness difference between blanks in tailored blank welding system. A structured lighting method is used for 3-D vision recognition. Images of sheared portion in blanks are irregular according to roughness of blank surface, shape of sheared geometry and blurring. It is difficult to get accurate and reliable informations in the case of using binary image processing or contour detection techniques in real time for such images. We propoe a new energy integration method robust to blurring and changes of illumination. The method is computationally simple, and uses feature restoration concept, different to another digital image restoration methods which aim image itself restoration and may be used in conventional applications using structured line lighting technique. Experimental results show this system measuring repeatability is .+-. pixel for gap and thickness difference in static and dynamic tests. The data are expected to be useful for preview gap control.

• Steel and Composite Structures
• /
• v.22 no.2
• /
• pp.411-427
• /
• 2016

In this study, by using finite element non-linear static analysis and comparing it with experimental models, the buckling and post-buckling behavior of bracing gusset plates has been investigated. The effects of such parameters as dimension and thickness of the gusset plate and the influence of position of the bracing member on the behavior of gusset plate have been examined. The results of the analyses clearly suggest that capacity, buckling and post-buckling behaviors of gusset plates depend on the position of the bracing splice plate with respect to the free bending line as well as on the size and thickness of the gusset plate. Also, with respect to numerical analysis results, some practical graphs for the calculation of buckling capacity of gusset plate connections are presented. For steel structures, the proposed method is apparently more accurate than available code procedures.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.73.4-73
• /
• 2001

We suggest a system to detection whether material picked up is double or single when the robot feeds them in automation line. This system measures thickness of metal plate and alarms when they are double sheet measuring boundary lines of metal sheet. This system calculates the minimum distance of straight boundary lines by eliminating noise in the edge regions. In the experimental system, double or single is determined by calculating implemented the thickness in the image where the distance of pixels are retrieved by the hash table. In this paper, the algorithm of histogram is adapted to experiment in the implement, thus proved as double sheet detection system.

• Journal of Mechanical Science and Technology
• /
• v.20 no.12
• /
• pp.2242-2249
• /
• 2006

The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor being used for refrigeration and air-conditioning systems was investigated. The Newton-Raphson method was used for a partial elastohydrodynamic lubrication analysis between the vane and the rolling piston of a rotary compressor. The results demonstrated that the vane thickness and the center line position of the vane significantly influenced the friction force and the energy loss between the vane and the rolling piston.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.9 no.2
• /
• pp.73-80
• /
• 1991

Identifying linear form of the parts of precision machine, precise monitoring is indispensable. Therefore, in this study, close-range photogrammetry being tried to screw one of the parts of precision machine, using non-metric camera that is calibrated by plumb line method. Also, it is analyzed three dimensional values of tortien, offset, section and thickness. From results of this study, monitoring of the parts of precision machine was conducted efficiently using non-metric camera and possibility of this application was proved.