• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.125-134
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• 1989

This study was conducted to investigate the flexural behaviour of sandwich constructions with cement concrete core and polymer concrete facings. Six different cross-sectional shapes using epoxy based polymer concrete facings were investigated. Some of the results from the static tests are given including the load-deflection responses, load-strain relationships, ultimate moment, and mode of failure. From the. results the following conclusions can be made. 1. The various strengths of polymer concrete were very high compared to the strengths for portland cement concrete, while modulus of elasticity assumed an aspect of contrast. 2. The thickness of core and facing exerted a great influence on the deflection and ultimate strenght of polymer concrete sandwich constructions. 3. The variation shape of deflection and strain depend on loading were a very close approximation to the straight line. The ultimate strain of polymer concrete at the end of tensile side were ranged from 625x10-6 to 766x10-6 and these values increased in proportion to the decrease of thickness of core and facings. 4. The ultimate moments of polymer sandwich constructions were 3 to 4 times that of cement concrete constructions which was transformed same section. It should he noted that polymer concrete have an effect on the reinforcement of weak constructions. 5. Further tests are neede to investigate the shear strain of constructions, and thermal expansion, shrinkage and creep of cement and polymer concrete which were composite materials of sandwich constructions.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.9
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• pp.840-845
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• 2010

This paper proposes the method indirectly measuring the operating force of the end-effect tip of surgical robot instrument which conducts the surgical operation in the body on behalf of the surgeon's hand. Due to the size and safety obligation to the surgical robot instrument, it is difficult to measure the operation force of its tip like grasping force. However the instrument is driven by cable-pulley torque transmission mechanism and when some force is occurred at the tip, then the reaction force appears on the cable as additional tension. Based on this phenomenon, this paper proposes a method to estimate the operating force from measuring reaction force against the driving motor by using a loadcell. And it induces mathematical equation to calculate the force from loadcell by approaching the modulus of elasticity to high order polynomial. And this paper proves the validity of proposed mechanism by experimental test.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.211-216
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• 1994

This study dealt with the properties for fly ash of conbined heat power plant and application for concrete industry. For this purpose, fly ash sampled Ulsan conbined heat power plant and analyzed for physical and chemical properties. As analyzed results of fly ash, contents of $SiO_ and Al_O_ $in the fly ash of Ulsan were less than those of Thermo-electric power plant(Boryuing), but contents of CaO were tem times as much as those of Boryung, because of these differences, it is expected that pozzolanic activity of concrete using fly ash of Ulsan will be different from another fly ash. Concrete specimens were tested to evaluate concrete preformance when 10 to 50 percent of the portland cement by weight in the concrete mix was replaced with fly ash of conbined heat power plant. As test results, workability and consideration in the fresh concrete were increased and concrete strength was showed more than 400kg/$\textrm{cm}^2$ for the required age. This study would be provided valuable data for the practical utilization of fly ash(conbined heat power plant). In the future, properties of fly ash concrete including long term strength, elapsed time, pozzolanic activity, modulus of elasticity, sulfate resistance, shrinkage, freeze-thaw durability and so on will be studied.

• Korea-Australia Rheology Journal
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• v.16 no.3
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• pp.117-128
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• 2004

The effect of molecular parameters on the steady vortex behaviors in the inertial viscoelastic flow past a cylinder has been investigated. FENE-CR model was considered as a constitutive equation. A recently developed iterative solution method (Kim et al., (in press)) was found to be successfully applicable to the computation of inertial viscoelastic flows. The high-resolution computations were carried out to understand the detailed flow behaviors based on the efficient iterative solution method armed with ILU(0) type pre-conditioner and BiCGSTAB method. The discrete elastic viscous split stress-G/streamline upwind Petrov Galerkin (DEVSS-G/SUPG) formulation was adopted as a stabilization method. The vortex size decreased as elasticity increases. However, the vortex enhancement was also observed in the case of large extensibility, which means that the vortex behavior is strongly dependent upon the material parameters. The longitudinal gradient of normal stress was found to retard the formation of vortex, whereas the extensional viscosity played a role in the vortex enhancement. The present results are expected to be helpful for understanding the inertial vortex dynamics of viscoelastic fluids in the flow past a confined cylinder.

• Fashion & Textile Research Journal
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• v.19 no.3
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• pp.302-311
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• 2017

The purpose of this study is to develop an aesthetic and functional bicycle wear for new senior women in their 50s and 60s. We developed bicycle wear that is friendly to bicycling posture and reflects the preference of new senior women. Both the expert group and the subject group evaluated the appearance, completeness of clothing and motion functionality. The results are as followed: First, in the evaluation result of the expert group regarding the appearance and completeness of clothing, high scores are given to design, materials, color scheme, the trends suitability as well as the appearance with regard to clothing fitness. Second, in the results of the evaluation of the appearance and movement functionality targeting the subject groups, movement functionality was rated higher than appearance. In the case of the appearance evaluation, adhesion of both jacket and pants was rated very highly, which is considered to come from the elasticity of the material. In the functionality evaluation, what were pointed out as inconvenient details in the prior studies were found to be all improved and the sleeves and armpit parts were rated highly. Therefore, the pattern design and the usage of the materials suggested in this study were found to be very suitable in the movement on the ride of bicycle.

• The Korean Journal of Health Service Management
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• v.7 no.3
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• pp.45-55
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• 2013

Cosmetic products are high value-added ones, and characterized by short life-cycles and income elasticity. Since most cosmetic products are procured through consults with salespersons, it is necessary to have detailed knowledge about basic cosmetics. In this paper, a possible relationship marketing strategy is suggested using the results of examining the effects of relationship marketing factors and relationship quality in cosmetics industry. The findings of this research can be summarized as follows. In order to examine the effects of relationship marketing factors and relationship quality on satisfaction which is a relationship performance, and the willingness to procure it again, this paper executed multiple regression analysis. The typical findings of this paper are as follows. The higher the specialty is, the better the brand image is, the higher customization and trust with customer are, the higher satisfaction and willingness to buy it again get. The analysis of relative influences of sub-factors revealed that trust was the strongest factor. In this paper, by revealing the effects of relationship marketing factors and relationship quality on relationship performance, empirically suggested the results which show the same findings as those of previous researches. This result can be a method to establish systematic education systems in places selling basic cosmetic products and in cosmetics companies.

• Structural Engineering and Mechanics
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• v.40 no.4
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• pp.563-581
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• 2011

Many novel materials, developed in recent years, have obvious properties with different modulus of elasticity in tension and compression. The ratio of their tensile modulus to compressive modulus is as high as five times. Nowadays, it has become a new trend to study the mechanical properties of these bimodular materials. At the present stage, there are extensive studies related to the strength analysis of bimodular structures, but the investigation of the buckling stability problem of bimodular rods seems to cover new ground. In this article, a semi-analytical method is proposed to acquire the buckling critical load of bimodular slender rod. By introducing non-dimensional parameters, the position of neutral axis of the bimodular rod in the critical state can be determined. Then by combining the phased integration method, the deflection differential equation of bimodular pin-ended slender rod is deduced. In addition, the buckling critical load is obtained by solving this equation. An example, which is conducted by comparing the calculation results between the three of the methods including the laboratory tests, numerical simulation method and the method we developed here, shows that the method proposed in the present work is reliable to use. Furthermore, the influence of bimodular characteristics on the stability is discussed and analyzed.

• Computers and Concrete
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• v.9 no.5
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• pp.389-402
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• 2012

In this study, the modulus of elasticity of low, normal and high strength steel fiber reinforced concrete has been predicted by developing a fuzzy logic model. The fuzzy models were formed as simple rules using only linguistic variables. A fuzzy logic algorithm was devised for estimating the elastic modulus of SFRC from compressive strength. Fibers used in all of the mixes were made of steel, and they were in different volume fractions and aspect ratios. Fiber volume fractions of the concrete mixtures have changed between 0.25%-6%. The results of the proposed approach in this study were compared with the results of equations in standards and codes for elastic modulus of SFRC. Error estimation was also carried out for each approach. In the study, the lowest error deviation was obtained in proposed fuzzy logic approach. The fuzzy logic approach was rather useful to quickly and easily predict the elastic modulus of SFRC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3232-3236
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• 2012

Consolidation and remedies for slope stability were considered for the slope with additional embankment. Transferred stresses due to additional embankment were assessed by the derived formula based on elasticity theory. Available remedies for slope stability with additional embankment including JSP method, stone column method and EPS method were studied. Caution needed for using JSP method is high pressure which can result in heaving of adjacent soils. Shortages of used case and noise of construction of stone column method are also considered for the safe remedy for slope stability.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.61-64
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• 2015

A number of dynamic stabilization systems have been used to overcome the problems associated with spinal fusion with rigid fixation recently and the demand for an ideal dynamic stabilization system is greater for younger patients with multisegment disc degeneration. Nitinol, a shape memory alloy of nickel and titanium, is flexible at low temperatures and regains its original shape when heated, and the Nitinol shape memory loop (SML) implant has been used as a posterior tension band mostly in decompressive laminectomy cases because the Nitinol implant has various characteristics such as high elasticity and a tensile force, flexibility, and biological compatibility. The reported short-term outcomes of the application of SMLs as posterior column supporters in cervical and lumbar decompressive laminectomies seem to be positive, and complications are minimal except for the rare occurrence of pullout and fracture of the SML. However, there was no report of neurological complications related to neural compression in spite of the use of the loop of SML in the epidural space. The authors report a case of delayed development of radiating pain caused by subsidence of the SML resulting epidural compression.