• Steel and Composite Structures
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• v.32 no.5
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• pp.571-582
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• 2019

This study aimed to assess the feasibility on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell. First, 5-m-wide and 15-m-long 9%Ni steel plates were test manufactured from a steel mill and specimens taken from the plates were tested for strength, toughness, and flatness to verify their performance based on international standards and design specifications. Second, plates with a thickness of 10 mm and 25 mm, a width of 4.8~5.0 m, and a length of 15 m were test fabricated by subjecting to pretreatment, beveling, and roll bending resulting in a final width of 4.5~4.8 m and a length of 14.8m with fabrication errors identical to conventional plates. Third, welded specimens obtained via shield metal arc welding used for vertical welding of inner tank shell and submerged arc welding used for horizontal welding were also tested for strength, toughness and ductility. Fourth, verification of shell plate material and fabrication was followed by test erection using two 25-mm-thick, 4.5-m-wide and 14.8-m-long 9%Ni steel plates. No undesirable welding failure or deformation was found. Finally, parametric design using wide and long 9%Ni steel plates was carried out, and a simplified design method to determine the plate thickness along the shell height was proposed. The cost analysis based on the parametric design resulted in about 2% increase of steel weight; however, the construction cost was reduced about 6% due to large reduction in welding work.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1352-1358
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• 2006

In this paper, we have fabricated and tested a broad band bow-tie slot antenna with dual reflector. If we put 1/2 length thin and long slot on a wide metal plate, the slot antenna radiates efficient and strong radio wave as same as 1/2 dipole antenna does. we made with bow-tie form slot which has wider broad band than normal rectangular slot. At first, we made and test a single reflector slot antenna. To enlarge the broad band, we inserted another reflection plate between the slot antenna and reflection plate. After the test, we could have known that the low band(VSWR<2.0) has about $22%(793MHz\sim992MHz)$, high band(VSWR<2.0) has about 61% (1626MHz\sim3064MHz).

• Journal of Korean Port Research
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• v.10 no.1
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• pp.53-61
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• 1996

This paper describes the effect of wave control using submerged flat plate by the numerical calculation and the hydraulic model test. The boundary element method is used to develop a numerical solution for the flow field caused by monochromatic oblique waves incident upon an infinitely long, sumerged flat plate situated in arbitrary water depth. The effect of wave blocking is examined according to the change of length, submerged depth of flat plate and incident angles. Numerical results show that longer length, shallower submergence of flat plate and larger incident angles enhance the effect of wave blocking. To validate numerical analysis method, hydraulic model test was conducted in 2-D wave flume with 60 cm metal sheet. Reflected waves are extracted from water surface elevation in front of the location of a submerged plate by least square method with 3 wave gages. From comparing experimental results with numerical results, efficiency of numerical analysis method by this study could be confirmed well within wide ranges of wave frequencies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1031-1038
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• 2001

In order to verify the analytical methods predicting failure behavior of cracked piping, full-scale pipe tests are crucial in nuclear power plant piping. For this reason, series of international test programs have been conducted. However, full-scale pipe tests require expensive testing equipment and long period of testing time. The objective of this paper is to develop a test system which can economically simulate the full-scale pipe test regarding the integrity evaluation. This system provides the failure behavior of cracked pipe by testing a wide-plate specimen. The system provides the failure behavior of cracked pipe by testing a wide-plate specimen. The system was developed for the integrity evaluation of nuclear piping based on the methodology of hardware-in-the-loop (HiL) simulation. Using this simulator, the piping integrity can be evaluated based on the elastic-plastic behavior of full-scale pipe, and the high cost full-scale pipe test may be replaced with this economical system.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.51-57
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• 1998

Comminuted fracture of the distal end of the humerus in adults is very rare and difficult to treat. In operative treatment, an implant which can achieve accurate anatoraical reduction and rigid fixation is needed. But the pre­existing Y -shaped plate had wide and thick limbs and some problems in fixation for most distal humeral fractures. So we devised a modified plate which is more narrow and th1n and has a different hole distance and wing length (long lateral wing). The aim of the study was to evaluate the clinical result of this modified anatomical Y -plate. From 1991 to 1997, we treated 23 cases of distal humeral fractures using modified anatomical plate and the results were as follows. 1. Fracture type in 18 patients(78%) was C-type(C1,C2,C3) which were intraarticular and mostly displaced or comminuted. 2. Bony union was obtained in 22 patients(96%) through rigid fixation and observed radiologically at 3.5 months(2-6months) on the average. 3. In 23 patients, 19 patients(82%) showed satisfactory results after 34 months(6-73months) follow-up. So if the modified anatomical Y-plate is used in the treatment of distal humeral fracture, a satisfactory result can be obtained through a more accurate, easy, and rigid fixation than preexisting plate.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3991-4000
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• 1975

It is the aim of this study to investigate the influence of the factors in the sprayer nozzle for the travelling distance and to get nozzle design data in relation to the nozz1e with and without swirl plate. The factors of sprayer nozzle are composed of the spraying pressure, the helical angle of swirl plate, the helical groove depth of swirl plate, the distance of vortex chamber the slope of nozz1e cap, the curvature of nozzle cap and the hole diameter of nozz1e cap. The travelling distance and the size of sprayed particle are experimeted indoors by the factorial arrange-ment according to the 5 each level of the above factors. The results of this stupy are summarized as follows; 1. In the nozzle with swirl p1ate there were remarkable significance among factors each other, while without swirl plate were no significance. 2. The helical angle and groove depth in the nozzle with swirl plate were the highest effective factors. The effect of helical angle was very remarked in the quadratic curve with minium value. 3. The correlation betweenthe travelling distance and the sprayed particle size was no high and under 250 micron in the case with swirl plate, and there was higher correlation in the case without swirl plate. 4. The new ideal development of the swirl plate using of the most effective helical angle and groove depth will probably show the possiblities to make effective travelling distance over 8 meters and more over and to make average particle diameter under 300 micron.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.3
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• pp.411-436
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• 1992

The purpose of this study was to assess the adhesion of resilient denture liners (such as, heat-cured silicone molloplast B,cold- cured silicone Mollosil) to polymethyl metacrylate (K-33) and metal (Megalloy) in the laboratory by peel test. The resilient denture lines were processed according to manufactures instruction, onto prepared specimens(original resin base plate, rough resin base plate, stippled metal plate, mesh metal plate ) 75mm long and 25m wide. And then, the peel test was performed by instron. The results were as follows : 1. The bonding strength of Mollosil was stronger than that of Molloplast B except the specimen of stippled metal plate. 2. The tensile strength of Mollosil was weaker than that of Molloplast Bas tearing of Mollosil was occured in the peel test. 3. Mesh metal plate had the highest bonding strength in the case of Molloplast B and Mollosil. But stippled metal plate have high bonding strength in the case of Molloplast B and have the lowest bonding strength in the case of Mollosil. 4. The bonding strength of rough resin base plate was stronger than that of original resin base plate in the case of Molloplast B and Mollosil. 5. The bonding strength of metal plates was stronger than that of resin base plates in the case of Molloplast B and Mollosil except the case of bonding strength between the stippled metal plate and Mollosil. 6. It seems that the Increase of surface and retention form of metal plate and resin base plate produces higher physical bonding strength.

• Journal of the Korean institute of surface engineering
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• v.54 no.5
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• pp.278-284
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• 2021

Corrosion of steel plate is common phenomenon which results in the gradual destruction caused by a wide variety of environments. Corrosion monitoring is the tracking of the degradation progress for a long period of time. Corrosion on steel plate appears as a discoloration and any irregularities on the surface. In this study, we developed a quantitative evaluation method of the rust formed on steel plate by using k-means clustering from the corroded area in a given image. The k-means clustering for automated corrosion detection was based on the GrabCut segmentation and Gaussian mixture model(GMM). Image color of the corroded surface at cut-edge area was analyzed quantitatively based on HSV(Hue, Saturation, Value) color space.

• Structural Engineering and Mechanics
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• v.90 no.3
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• pp.273-285
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• 2024

Tapered girders emerged as an economical remedy for the challenges associated with constructing long-span buildings. From an economic standpoint, these systems offer significant advantages, such as wide spans, quick assembly, and convenient access to utilities between the beam's shallow sections and the ceiling below. Elastic-local buckling is among the various failure modes that structural designers must account for during the design process. Despite decades of study, there remains a demand for efficient and comprehensive procedures to streamline product design. One of the most pressing requirements is a better understanding of the tapered web plate girder's local buckling behavior. This paper conducts a comprehensive numerical analysis to estimate the critical buckling coefficient for simply supported tapered steel web plates, considering loading conditions involving compression and bending stresses. An eigenvalue analysis was carried out to determine the natural frequencies and corresponding mode shapes of tapered web plates with varying geometric parameters. Additionally, the study highlights the relative significance of various parameters affecting the local buckling phenomenon, including the tapering ratio of the panel, normalized plate length, and ratio of minimum to maximum compressive stresses. The regression analysis and optimization techniques were performed using MATLAB software for the results of the finite element models to propose a separate formula for each load case and a unified formula covering different compression and bending cases of the elastic local buckling coefficient. The results indicate that the proposed formulas are applicable for estimating the critical buckling coefficient for simply supported tapered steel web plates.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.147-152
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• 2017

In the present study, we used a loop thermosyphon heat exchanger consisting of condensers with internal fins and external plate fins which are 480 mm wide, 68 mm long, and 1,000 mm high. The heat transfer pipes in the heat exchanger were 15 mm in diameter and 1,000 mm in length, and 98 heat transfer pipes were installed in the heat exchanger. According to the experimental results, as the spaces between the internal discontinuous pins decreased, the frequency of pressure drops increased and changes in temperature at the outlet of the condenser were shown to be a little smaller. Therefore, we can see that as the spaces between internal discontinuous pins decreased, the heat transfer performance increased. For the loop heat pipe heat exchanger consisting of a condenser with internal and plate fins, as the temperature of the air flowing into the condenser increased, the condensation heat transfer rate also increased, and as the condenser refrigerant inflow temperature increased, the condensation heat transfer rate increased as well.