• Structural Engineering and Mechanics
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• v.86 no.3
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• pp.291-309
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• 2023

This paper addresses the finite element modeling of functionally graded porous (FGP) beams for free vibration and buckling behaviour cases. The formulated finite element is based on simple and efficient higher order shear deformation theory. The key feature of this formulation is that it deals with Euler-Bernoulli beam theory with only three unknowns without requiring any shear correction factor. In fact, the presented two-noded beam element has three degrees of freedom per node, and the discrete model guarantees the interelement continuity by using both C⁰ and C¹ continuities for the displacement field and its first derivative shape functions, respectively. The weak form of the governing equations is obtained from the Hamilton principle of FGP beams to generate the elementary stiffness, geometric, and mass matrices. By deploying the isoparametric coordinate system, the derived elementary matrices are computed using the Gauss quadrature rule. To overcome the shear-locking phenomenon, the reduced integration technique is used for the shear strain energy. Furthermore, the effect of porosity distribution patterns on the free vibration and buckling behaviours of porous functionally graded beams in various parameters is investigated. The obtained results extend and improve those predicted previously by alternative existing theories, in which significant parameters such as material distribution, geometrical configuration, boundary conditions, and porosity distributions are considered and discussed in detailed numerical comparisons. Determining the impacts of these parameters on natural frequencies and critical buckling loads play an essential role in the manufacturing process of such materials and their related mechanical modeling in aerospace, nuclear, civil, and other structures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.68-77
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• 2007

In this paper, we address TPS (Triple Play Service) based on E-PON and also develop QoS control function for both directions, which is disadvantage of E-PON. E-PON technology has the configuration suitable for TPS, but relatively the large delay characteristics in upstream, so if QoS control function must be supported to transfer the real time traffic for both directions, E-PON technology can support TPS efficiently. Therefore, in this paper, we address the diverse requirements of quality for TPS, and then develop TPS platform to verify the quality characteristics according to QoS characteristics of each element in real environment based on this. This result will be used to improve the quality of TPS that become conventional in near future. ISP will use this result as the basis in establishing quality reference and as the guidance in developing new system.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.11
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• pp.235-244
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• 2017

This paper aims to design a system for psychological diagnosis in sandbox play by applying rule based expert system. Sandbox play is one of play therapy and it is a technique that can be combined with psychological diagnosis and treatment using sand and various kinds of figures. In this technique, we focus on psychological diagnostic factors and try to implement a system that automatically diagnoses psychological types when input values are given. Therefore, six kinds of language objects are set and the rules are created according to the types of figures, arrangement of figures, and production time in the sand box used as a reference element in the diagnosis method. In this system, it is assumed that the client recognizes the finished sandbox as a sensor device. Then, when the recognized state enters the input value, the rules based on the language object are ignited in order. Through this, the client is diagnosed with one of 26 types of psychology. As a result, the diagnostic process is simplified and automated. Accordingly, a more detailed psychological diagnosis and treatments are provided.

• Journal of Powder Materials
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• v.22 no.1
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• pp.6-9
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• 2015

In this study, the behavior of densification of copper powders during high-pressure torsion (HPT) at room temperature is investigated using the finite element method. The simulation results show that the center of the workpiece is the first to reach the true density of copper during the compressive stage because the pressure is higher at the center than the periphery. Subsequently, whole workpiece reaches true density after compression due to the high pressure. In addition, the effective strain is increased along the radius during torsional stage. After one rotation, the periphery shows that the effective strain is increased up to 25, which is extensive deformation. These high pressure and severe strain do not only play a key role in consolidation of copper powders but also make the matrix harder by grain refinement.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1469-1472
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• 2016

Cancer pathology reports play an important role in choice of patient care. They provide crucial information concerning diagnosis, therapy options, and prognosis. Professional pathology institutions, such as the College of American Pathologists (CAP), have developed checklists to ensure the presence of all the required elements in reports. In this study, 438 surgical pathology reports of patients with breast (148), colon (147), and stomach cancer (143) were evaluated with respect to the presence of mandated elements according to CAP checklists. The most common missing element in all the three types of cancer was 'staging' (73.6, 53.1, and 56.6% in breast, colon, and stomach cancer reports missed 'staging', respectively). The second most missing element was 'tumor site' in breast (64.2%) and stomach cancer (30.1%), and 'procedure' in colon cancer (29.3%). 'Perineural invasion' was the third most missing element in the three types of cancer (25.7, 17.0, and 22.4% in breast, colon, and stomach cancer, respectively). Only 11.4% of reports included all key elements required by CAP. The use of checklists was associated with higher rate of completeness. This study demonstrates that the key elements requiring the information on the requisition forms from the clinicians are commonly missed, leading to ambiguity.

• Computational Structural Engineering : An International Journal
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• v.1 no.1
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• pp.1-9
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• 2001

Collapse behavior of Mission-Gothic Undercrossing under Northridge earthquake is studied by performing nonlinear time-history analysis and three-dimensional nonlinear finite element method for flared columns. Bridge structural model is characterized as three-dimensional with consideration of columns, superstructures, and abutment conditions. Three components of ground motion, corresponding to bridge's longitudinal, transverse, and vertical direction and their combinations are used to investigate bridge collapse. Studies indicate that bridge collapse is dominantly caused by transverse ground motion and the consideration of three-dimensional ground motion leads to a more accurate assessment. Failure mechanism of flared columns is analyzed applying nonlinear finite element method. Reduction of column capacity is observed due to orientation of flare. Further investigation demonstrates that the effects of flare play an important role in predicting of bridge failure mechanism. Suggestions are offered to improve the performance of bridges during severe earthquake.

• Transactions of Materials Processing
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• v.17 no.1
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• pp.52-58
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• 2008

Tube hydroforming process is generally consisted with pre-bending, preforming and hydroforming processes. Among forming defects which may occur in tube hydroforming such as buckling, wrinkling and bursting, the wrinkling and bursting by local instability under excessive tensile stress mode were mainly caused by thinning phenomenon in the manufacturing process. Thus the accurate prediction and suitable evaluation of the thinning phenomenon play an important role in designing and producing the successfully hydroformed parts without any failures. In this work, the formability on hydroformed part for automobile, i.e. engine cradle, was evaluated using finite element analysis. The initial tube radius, loading path with axial feeding force and internal pressure, and preformed configuration after preforming process were considered as the dominant process parameters in total tube hydroforming process. The effects on these process parameters could be confirmed through the numerical experiments with respect to several kinds of finite element simulation conditions. The degree of enhancement on formability with each process parameters such as initial tube radius, loading path and preform configuration were also compared. Therefore, it is noted that the evaluation approach of the formability on hydroformed parts for lots of industrial fields proposed in this study will provide one of feasible methods to satisfy the increasing practical demands for the improvement of the formability in tube hydroforming processes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.215-219
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• 2010

The evaluation of the mechanical properties and behavior is very important for the design of embankment using granular materials. In this research, the lab. tests with Nak-dong river sand were conducted to find out mechanical properties related to stress-strain behavior. Also, numerical simulations which can express the behavior of granular material were conducted by distinct element method. Distinct element method can play a import role to predict stress-strain behavior for different confining stress and loading condition if micro-parameters can be estimated in specific condition.

• Journal of Korea Game Society
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• v.17 no.5
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• pp.113-122
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• 2017

The location of the objects that make up a game can be an element of immersion for players. repeatedly appearing at the same position, the fun may be reduced, and as the play time elapses, the players will feel the game's fun as they appear in a larger area than at the beginning of the game play. This paper is a study to find out the location of objects according to the passage of time and to see how players controlled these objects. First, foreground images are extracted and accumulated using OpenCV programming language. The accumulated result is displayed as a heat map image. Second, the mouse movement area is detected using the mouse tracking program and compared with the heat map image, so that the screen area in which the player is interested can be known.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.304-311
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• 1995

To determine whether chitinolytic enzymes from Chromobacterium violaceum C-61 play an important role in the suppression of Rhizoctonia damping-off, Tn5 insertion mutants deficient in chitinolytic activity (Chi a- mutants) were selected and their chitinolytic and disease suppression were compared with those of the parental strain. Four Chi a- mutants selected from about 2,000 transconjugants did not inhibit mycelial growth of Rhizoctonia solani on nutrient agar-potato dextrose agar (BA-PDA) and their abilities to suppress Rhizoctonia damping-off were much lower than the parental strain. However, population density in the eggplant rhizosphere did not differ significantly between the parental strain and four Chi a- mutants. The crude enzyme of the parental strain inhibited growth of R. solani on NA-PDA and its chitinase activity was much higher than that of Chi a- mutants. But the N,N' -diacetylchitobiase activity between these isolates were not significantly different. The chitinase of Chi a- mutants was defective in 2 isoforms of 52- and 37-kDa among four isoforms of 54-, 52-, 50- and 37-kDa. A Tn5 element was inserted into one site of 10 kb EcoRI fragment of chromosomal DNA in three Chi- mutants, C61-C1, -C2, and -C3. In C61-C4 mutant, a Tn5 element was inserted into two sites of 10 kb and 4.4 kb EcoRI fragments. These results suggest that the chitinase of C. violaceum C-61 play an important role in the suppression of Rhizoctonia damping-off of cucumber and eggplant.