• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2624-2633
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• 1993

Mass transfer experiment by naphthalene sublimation method has great advantages in measurement of local transfer coefficients in the region of a three dimensional flow or for a model of complex geometry, which is considered to be very difficult with conventional heat transfer measurements. Mass transfer data obtained by naphthalene sublimation technique are converted to the heat transfer data through heat/mass transfer analogy. This analogy is valid for a simple or laminar flow, but new insight is needed when applying to a turbulent flow or complex flow such as separation, reattachment and recirculation, The purpose of this research is to investigate how geometries and flow conditions incorporate heat/mass transfer analogy. Mass transfer experiments are performed using naphthalene sublimation technique for a flat plate, a circular cylinder, and rectangular cylinders. And mass transfer data are compared with earlier heat transfer measurements for the same geometries. Usefulness of analogy relation between heat and mass transfer is examined with these results.

• Journal of the Korean Society of Costume
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• v.52 no.6
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• pp.85-102
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• 2002

The research has the aim of defining the special characteristics of the functionalist fashion design in the 20th century by understanding the essence of functionalism in the sociocultural contexts and studying functionalism in fashion design and architectural and product design by the comparative. Giving careful consideration to functionalist fashion design in the 20th century makes it possible to foresee the way of fashion design to meet the needs of the moderns and men of the future world. To obtain the purposes, documentary study and comparative study have been executed. Main results are as follows. Functionalism stressed in the beginning of the 20th century can be defined and categorized using three analogies, mechanical analogy of futuristic quality based on mechanical aesthetics and standardization by mass production, organic analogy in which the perfect beauty of nature is stressed on, moral analogy of fitness for purpose and absence of ornament based on integrity and sincerity. In while, functionalism in 1990s has been developed in different ways from those analogies. In comparative studies, functionalist fashion design and architectural and product design have the dissimilarity as well as the similarity of formative features. Since fashion design has much closer relation to human body and movements. it has been expressed considering a division of men and women and the places and times for the designs more than other designs.

• Transactions of the Korean Society of Mechanical Engineers
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• v.6 no.4
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• pp.315-322
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• 1982

The slab analogy method was introduced in the 1920's for the first time as a new experimental stress analysis method. Notwithstanding its theoretical propriety, this method has not been recognized as efficient one because of its difficulty in practical measurement of the slab curvature. In this paper, aiming at experimental determination of two-dimensional stress intensity factors(S. I. F) of arbitrarily shaped cracks which had been regarded as almost impossible by conventional method, the slab analogy was reevaluated. Measuring of slab curvature was replaced by three simple measuring factors to overcome vital slab-analogy's shortcoming by joint use of the shadow-moire method. A determination formula was also derived from the theory of fracture mechanics. By this newly exploited method, it was found that the slab analogy still has its great advantage in determination of S.I.F. of arbitrarily shaped cracks with considerable accuracy compared with existent experimental methods.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.611-617
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• 1991

Effective stiffness of short fiber composite with a three-dimensional random orientation of fibers is derived theoretically and compared with available experimental data. The laminate analogy and transformed laminate analogy are used for modulus prediction of 2-D and 3-D random composites, respectively. The effective stiffness of random oriented fiber composite can be expressed in terms of longitudinal and transverse stiffnesses of unidirectional composites. The result of transformed laminate analogy is more accurate than other approaches such as, Christensen-Waals equational and Lavengood-Goettler equation, etc. Also the effective properties of random oriented fiber composite can be expressed in terms of fiber and matrix properties such as elastic modulus, shear modulus and Poisson's ratio.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3105-3114
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• 1993

previously, several basic studies in the experimental analysis of stress intensity factors of cracks by slab analogy have been presented by authors. But, for the application of above mentioned method to the analysis of the arbitrarily distributed cracks, there still is several bottlenecks to be overcome in terms of its experimental process and data treatment. Moreover, authors recently proposed an improved experimental method to use the fixed slab analogy device which has promised more accurate measurement of S.I.F. of small cracks. In this paper, for the completion of slab analogy analysis of distributed cracks, a grating imaginary rotation method is introduced. And, to prove its validity, this combined method is applied to the determination of stress intensity factors of theoretically known distributed cracks. The results show good agreement with the existing theoretical solutions and physical crack propagation tendencies.

• Journal of Mechanical Science and Technology
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• v.18 no.7
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• pp.1258-1266
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• 2004

It is important to completely understand heat/mass transfer from a flat plate because it is a basic element of heat/mass transfer. In the present study, local heat/mass transfer coefficient is obtained for two flow conditions to investigate the effect of boundary layer using the naphthalene sublimation technique. Obtained local heat/mass transfer coefficient is converted to dimensionless parameters such as Sherwood number, Stanton number and Colburn j-factor. These also are compared with correlations of laminar and turbulent heat/mass transfer from a flat plate. According to experimental results, local Sherwood number and local Stanton number are in much better agreement with the correlation of turbulent region rather than laminar region, which means analogy between heat/mass transfer and momentum transfer is more suitable for turbulent boundary layer. But average Sherwood number and average Colburn j-factor representing analogy between heat/mass transfer and momentum transfer are consistent with the correlation of laminar boundary layer as well as turbulent boundary layer.

• Journal of the Korean Society of Costume
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• v.52 no.5
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• pp.155-172
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• 2002

The research has the aim of defining the special characteristics of the functionalist fashion design in the 1900s by understanding the essence of functionalism in the sociocultural contexts. Giving careful consideration to functionalist fashion design in the 1990s makes it possible to foresee the way of fashion design to meet the needs of the modems and men of the future world. To obtain the purposes, documentary study and demonstrative study with fashion photographs have been executed. Main results are as follows. Functionalism in the 1990s has been developed in different ways from the analogies in the beginning of the 20th century. It doesn't belong to an analogy but has the fused characteristics. It can be classified into techno functionalism influenced by new technology Pure functionalism related to minimalism. casual functionalism for those who are crazy about the speed and sports and enjoy the freedom and comfort and symbolic functionalism. Mechanical analogy has been developed into techno functionalism. Pure functionalism has come from the blend of mechanical and moral analogy, casual functionalism from mechanical. organic and moral analogy. and symbolic functionalism from organic and moral analogy. Since fashion design has much closer relation to human body and movements. it has been expressed considering a division of men and women and the places and times for the designs more than other designs. More casual manners of formal wear are distinct elements in functionalist fashion design in the 1990s. The 20th century general cultural phenomena including post modernism can be explained by eclectic functionalism. Functionalism considering Practical and conceptional functions ill continue and techno functionalism and casual functionalism in future fashion design will be expressed more strongly with new technology and casual trends of life style.

• The International Journal of Costume Culture
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• v.5 no.2
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• pp.1-14
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• 2002

The first purpose of this research is to investigate the functionalistic concept through the general consideration of Functionalism, and to study the art's aesthetic value of functionalistic expressionist artists implication and form in terms of architecture and product design. Secondly, it analyzes the implication and shape of Functionalism towards 'Art to Wear', which can be explained as a mixture of fashion and art. The results are as follows; First, functionalistic 'Art to Wear' of Mechanical Analogy appears to have futuristic inclination stressing the significance of geometric shapes and machine aesthetics. It uses new materials, and reduce an unnecessary work of art to convey more accurate, concrete and effective character of form. Secondly, functionalistic 'Art to Wear' of Organic Analogy regards natural elements as important to pursue the warm human nature. Also, it appears to be free and comforting forms of Functionalism through an organic silhouette. Thirdly, functionalistic 'Art to Wear' of Moral Analogy excludes excessive ornaments, and includes the implication of appropriate and purposive purity which serves for practical function.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.4
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• pp.306-314
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• 2012

Several numerical or analytical models have been proposed to analyze the thermal response of vertical ground heat exchangers (GHEX). However, most models are valid only after several hours of operation since they neglect the heat capacity of the borehole. Recently, the short time response of the GHEX became important in system simulation to improve efficiency. In this paper, a simple new method to evaluate the short time response of the GHEX by using an analogy model of electric circuit transient analysis was presented. The new transient heat exchanger model adopting the concept of thermal capacitance of the borehole as well as the steady-state thermal resistance showed the transient thermal resistance of the borehole. The model was validated by in-situ thermal response test and then compared with the DST model of the TRNSYS program.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.409-419
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• 2006

The actuating performance of plate-type unimorph piezoelectric composite actuators having various stacking sequences was evaluated by three dimensional finite element analysis on the basis of thermal analogy model. Thermal residual stress distribution at each layer in an asymmetrically laminated plate with PZT ceramic layer and thermally induced dome height were predicted using classical laminated plate theory. Thermal analogy model was applied to a bimorph cantilever beam and LIPCA-C2 actuator in order to confirm its validity. Finite element analysis considering thermal residual deformation showed that the bending behavior of piezoelectric composite actuator subjected to electric loads was significantly different according to the stacking sequence, thickness of constituent PZT ceramic and boundary conditions. In particular, the increase of thickness of PZT ceramic led to the increase of the bending stiffness of piezoelectric composite actuator but it did not always lead to the decrease of actuation distance according to the stacking sequences of piezoelectric composite actuator. Therefore, it is noted that the actuating performance of unimorph piezoelectric composite actuator is rather affected by bending stiffness than actuation distance.