• Steel and Composite Structures
• /
• v.25 no.5
• /
• pp.625-638
• /
• 2017

This paper presents a novel approach that describes the first-order (linear elastic) partial interaction analysis of members formed by multi-components based on the Generalised Beam Theory (GBT). The novelty relies on its ability to accurately model the partial interaction between the different components forming the cross-section in both longitudinal and transverse directions as well as to consider the cross-sectional deformability. The GBT deformations modes, that consist of the conventional, extensional and shear modes, are determined from the dynamic analyses of the cross-section represented by a planar frame. The partial interaction is specified at each connection interface between two adjacent elements by means of a shear deformable spring distributed along the length of the member. The ease of use of the model is outlined by an application performed on a multi-component member subjected to an eccentric load. The values calculated with an ABAQUS finite element model are used to validate the proposed method. The results of the numerical applications outline the influence of specifying different rigidities for the interface shear connection and in using different order of polynomials for the shape functions specified in the finite element cross-section analysis.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.33 no.8
• /
• pp.1262-1272
• /
• 2009

The study is classifies the figures of obese women aged 20-50 with an over 25 BMI from the data of the fifth Size Korea in 2005. As the result of conducting the factor analysis for segmenting the shape, Factor 1, Factor 2, Factor 3, and Factor 4 are respectively derived as the factor on a volume, the factor on the size of the vertical direction, the factor on the shoulder region, and the factor on the body length balance. As the result of conducting the cluster analysis using 4 factors (scores extracted from the analysis of factor analysis) the body type of obese women was classified into four types. The name of shape was specified by combining 'P' (an abbreviation of petite) that indicated the height (smaller than 155cm) among the height names of KS standard, 'R' (abbreviation of regular) that indicated the height (155cm-165cm) and the body characteristics. Type 1 had the longest length, and normal circumference, thickness, and width but with the developed shoulder. Type 1 was classified as a robust, 'Plus-RH'. Type 2 had the middle height, the shortest length of the upper part, a relatively-long length of the lower part of body. Type 2 shows the characteristics of a small body that was classified as 'Plus-PI'. The most obese body was Type 3 that had the normal length and shoulder size but showed the longest length of the upper part of the body; it was classified as 'Plus-PO'. Type 4 as the small shape had a potbelly and showed the characteristics of the shortest body classified as 'Plus-Pb'.

• Journal of the Korean Institute of Gas
• /
• v.14 no.1
• /
• pp.37-41
• /
• 2010

The most important element for improving the process safety that occurs from the flare system installed to convert into safe materials by burning the inflammable or toxic gases within the process and this is specified in the API 521 Code so that the radiation does not cause a risk factor. The flames that occur from the flare stack holds the shape of jet fire due to the pressure and flow velocity of discharge gas. This study has identified the shape of flames by using the Chamberlain Model rather than the API 521 Code method, analyzing the radiation due to this.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.2
• /
• pp.241-249
• /
• 1998

Somatotypes in the lower torso and legs of adult females were classified and discriminated. Then their distribution according to the age groups was studied. The subjects were 343 females of 18 to 49 year-old. 36 anthropometric and 21 photographic measurements were taken to each subject. The results were as follows: 1. The somatotypes in the lower torso and legs were classified into 4 types and their differences were shown by analysing factor scores and anthropometric values according to each somatotype. 2. The shape characteristic of tile classified somatotypes was represented by the rating scale of Heath-Carter. 3. The lateral silhouettes of 4 types were compared with balanced type which is type 3 in this study. 4. Individual somatotype in the lower torso and legs could be discriminated from the measured anthropometric data without modifying the data. Anthropometric data, which are needed for discriminating individual somatotype, are waist circumference, posterior waist height, and hip circumference. 5. The distribution of the somatotypes in each age group showed that the dominant somatotype of each age group was different and any somatotype was shown in a specified age group but rarely in other age group.

• Journal of Biosystems Engineering
• /
• v.33 no.3
• /
• pp.196-203
• /
• 2008

Hybrid robust image processing algorithm to extract visual features of melon during the cultivation was developed based on a wireless tele-operative interface. Features of a melon such as size and shape including position were crucial to successful task automation and future development of cultivation data base. An algorithm was developed based on the concept of hybrid decision-making which shares a task between the computer and the operator utilizing man-computer interactive interface. A hybrid decision-making system was composed of three modules such as wireless image transmission, task specification and identification, and man-computer interface modules. Computing burden and the instability of the image processing results caused by the variation of illumination and the complexity of the environment caused by the irregular stem and shapes of leaves and shades were overcome using the proposed algorithm. With utilizing operator's teaching via LCD touch screen of the display monitor, the complexity and instability of the melon identification process has been avoided. Hough transform was modified for the image obtained from the locally specified window to extract the geometric shape and position of the melon. It took less than 200 milliseconds processing time.

• Computers and Concrete
• /
• v.3 no.6
• /
• pp.375-388
• /
• 2006

Poor strength test results are sometimes not an indication of low concrete quality, but rather inferior testing quality. In a compression test, the strain distribution over the ends of the specimen is a critical factor for the test results. Non-uniform straining of a concrete specimen leads to locally different compressive stresses on the cross-section, and eventual premature breaking of the specimen. Its effect on a specimen can be quantified by comparing the compressive strength results of two specimens, one subjected to uniform strain and another to a specified strain gradient. This can be done with the help of a function that relates two parameters, the strain ratio and the test efficiency. Such a function depends on the concrete strength and cross-sectional shape of the specimen. In this study, theoretical relationships between the strain ratio and test efficiency are developed using a concrete stress-strain model. The results show that for the same strain ratio, the test efficiency is larger for normal strength concrete than for high strength concrete. Further, the effect of the strain gradient on the test result depends on the cross-sectional shape of the specimen. Implementation of the results is demonstrated with the aid of two examples.

• Transactions of Materials Processing
• /
• v.17 no.8
• /
• pp.570-578
• /
• 2008

A flexible forming apparatus is composed a number of punches which have spherical pin tip shape instead of conventional solid die. The flexible forming tool consisted of punch array in a matrix form was proposed as an alternative forming method to substitute the conventional line heating method which use heat source to induce residual stress along specified heating lines. In this study, application of the flexible forming process to the small scale curved plate forming was conducted. Numerical simulations for both solid and flexible die forming process were carried out to compare the shape of the products between flexible and conventional die forming process. In addition, spring-back analysis was conducted to figure out the feasibility of the flexible forming process comparing with the die forming process in view of final configuration of the specimens. Moreover, experiment was also carried out to confirm the formability of the process. Consequently, it was confirmed that the flexible die forming method has capability and feasibility to manufacture the curved plates for shipbuilding.

• Korean Journal of Computational Design and Engineering
• /
• v.18 no.3
• /
• pp.234-242
• /
• 2013

Different CAD systems are used in ship outfitting design on different usage and purpose. Therefore, data exchanges between CAD systems are required from different formats. For data exchange, boundary representation standard formats such as IGES and ISO 10303 (STEP) are widely used. However, they present only B-rep representation. Because of different CAD systems have their own geometry format, data exchanges with design intend are difficult. Especially, Tribon and PDMS use primitives for express their geometry in ship outfitting design. However, Tribon primitives are represented their parameter by values that are non-parametric. Therefore, data size of catalogue library is bigger than different CAD system using parametric primitive representation. And that system has difficulty on data reprocessing. To solve that problem, we discuss about shape DB which contains design parameters of primitive for exchange Tribon primitives. And geometry data exchange between Tribon and Shape Database that defines based on PDMS scheme are specified using primitive mapping that can represent design intend.

• International Journal of Aeronautical and Space Sciences
• /
• v.18 no.3
• /
• pp.403-413
• /
• 2017

Dual-point aerodynamic design optimization is conducted for DLR-F6 wing-body-nacelle-pylon configuration adopting an efficient surface mesh movement method for complex junction geometries. A three-dimensional unstructured Euler solver and its discrete adjoint code are utilized for flow and sensitivity analysis, respectively. Considered design conditions are a low-lift condition and a cruise condition in a transonic regime. Design objective is to minimize drag and reduce shock strength at both flow conditions. Shape deformation is made by variation of the section shapes of inboard wing and pylon, nacelle vertical location and nacelle pitch angle. Hicks-Henne shape functions are employed for deformation of the section shapes of wing and pylon. By the design optimization, drag coefficients were remarkably reduced at both design conditions retaining specified lift coefficient and satisfying other constraints. Two-point design results show mixed features of the one-point design results at low-lift condition and cruise conditions.

• Journal of Korean Society of Steel Construction
• /
• v.20 no.1
• /
• pp.195-203
• /
• 2008

This paper aims to evaluate the yield stress of SM570TMC concrete-filed H-shape steel columns subjected to axial force. These columns were evaluated and compared using quasi-static tests. The displacements and the axial loads column specimens were measured during the tests, and test results showed that the yield stress of concrete-filed H-shape steel columns subjected to axial load could be predicted using the previously proposed yield stress of steel columns.