• The Journal of Korean Physical Therapy
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• 제32권3호
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• pp.152-156
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• 2020

Purpose: The subjective visual vertical (SVV) test is used to evaluate the otolith function in the inner ear. This study compared the different balance ability according to the results of the SVV in healthy adults. Methods: This study recruited 30 normal healthy subjects who did not have neurological and musculoskeletal disorders. The subjects were divided into experimental and control groups based on the results of SVV: experimental group, >2°; control group, <2°. The static balance ability was evaluated using the Fourier Index, which could evaluate the balance capacity objectively and quantitatively. Results: The mean angle of the SVV in the experimental and control groups was 4.44° and 0.59°, respectively. In the result of the Fourier series, the F1 frequency band in the experimental group showed a significantly higher value under one condition compared to the control group (p<0.05). In the F2-4 and F5-6 frequency bands, the experimental group showed a significant increase in the Fourier series value under the four conditions compared to the control group (p<0.05). In the F7-8 frequency band, significantly higher values of the Fourier series were observed in the experimental group under the three different conditions (p<0.05). Conclusion: These results showed increased trunk sway while maintaining static balance in the experimental group who showed a larger SVV angle compared to the control group. The SVV can be applied to evaluate the vestibular system and balance ability in normal adults.

• Membrane and Water Treatment
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• 제9권5호
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• pp.309-315
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• 2018

The applicability of the ultrafiltration process for color removal from dye-containing water has been examined in this study. The optimization of major process variables, such as dye concentration, chitosan concentration and transmembrane pressure on permeate flux and color removal efficiency was investigated. To find the most appropriate results for the experiment, the Box-Wilson experimental design method was employed. The results were correlated by a response function and the coefficients were determined by regression analysis. Permeate flux variation and color removal efficiency determined from the response functions were in good agreement with the experimental results. The optimum conditions of chitosan concentration, dye concentration and pressure were 50 mg/l, 50 mg/l and 3 bars, respectively for the highest permeate flux. On the other hand, optimum conditions for color removal efficiency were determined as 50 mg/l of dye concentration, 50 mg/l of chitosan concentration and 1 bar of pressure.

• Computers and Concrete
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• 제14권4호
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• pp.419-444
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• 2014

In this study experimental result of a total of eight SCC and FRSCC slabs with the same cross-section were monitored for up to 240 days to measure the time-dependent development of cracking and deformations under service loads are presented. For this purpose, four SCC mixes are considered in the test program. This study aimed to compare SCC and FRSCC experimental results with conventional concrete experimental results. The steel strains within the high moment regions, the concrete surface strains at the tensile steel level, deflection at the mid-span, crack widths and crack spacing were recorded throughout the testing period. Experimental results show that hybrid fibre reinforced SCC slabs demonstrated minimum instantaneous and time-dependent crack widths and steel fibre reinforced SCC slabs presented minimum final deflection.

• Structural Monitoring and Maintenance
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• 제7권2호
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• pp.149-166
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• 2020

This paper presents the results of an experimental investigation on a vibration-based damage identification framework for a steel girder type and a truss bridge based on acceleration responses to operational loading. The method relies on sensor clustering-based time-series analysis of the operational acceleration response of the bridge to the passage of a moving vehicle. The results are presented in terms of Damage Features from each sensor, which are obtained by comparing the actual acceleration response from the sensors to the predicted response from the time-series model. The damage in the bridge is detected by observing the change in damage features of the bridge as structural changes occur in the bridge. The relative severity of the damage can also be quantitatively assessed by observing the magnitude of the changes in the damage features. The experimental results show the potential usefulness of the proposed method for future applications on condition assessment of real-life bridge infrastructures.

• 설비공학논문집
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• 제15권6호
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• pp.461-470
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• 2003

The purpose of this study is to investigate the performance of a transcritical cycle for hot water heating using $CO_2$ as a working fluid. Some of the main parameters that affect the practical performance of the $CO_2$ system are discussed; the performance on the variation of refrigerant charge, changes in flow conditions of secondary fluids, and that with or without internal heat exchanger, The experimental results show that the optimum charge is approximately the same for various mass flow rates of the secondary fluid at gas cooler. The experimental results on the effect of secondary fluids are in general agreement with the experimental results of transcritical cycle in the open literature and show similar trend for conventional subcritical vapor compression cycles. The heat exchanger effectiveness increases with an increase of the heat exchange area of the internal heat exchanger regardless of the mass flow rate at the gas cooler.

• Journal of Advanced Marine Engineering and Technology
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• 제10권4호
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• pp.67-77
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• 1986

The information on the heat transfer characteristics, flow pattern and pressure drop, are very important for the desing of general heat exchanger, refrigerating system, air conditioning system and energy recovery system. In these systems, water or lubricating oil contained in working fluid affects greatly the flow and heat transfer condition and this phenomena must be considered in the practical design. An experiment has been performed for studying the flow and heat transfer characteristics of the forced convective horizontal flow of R-113 under the range of the liquid single phase state to the boiling flow state. Basic experimental results are obtained in the case that water or lubricating oil does not contaminate in the test fluid. Experimental results are as follows; (1) The local heat transfer coefficients in the nucleate boiling region and transition boiling region are almostly ten times as large as that of liquid single phase flow. (2) The measured heat transfer coefficient in the present experimental range is relatively agreed well with the predicted value from the various experimental results for the boiling flow.

• 한국전산유체공학회지
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• 제6권1호
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• pp.14-20
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• 2001

The CFD analysis of the three-dimensional turbulent flow in the impeller and diffuser of an axial flow pump was performed. Not only the design point but also the off-design points were computed. The results were compared with available experimental data in terms of head generated. At the design point, the analysis accurately predicted the experimental head value. In the range of the higher flow rates, the results were also in very good agreement with the experimental data, not only in absolute value but also in term of slope. Although experimental data to be compared were not available in the range of the lower flow rates, the results well described the S-shape performance curve of the axial pump characteristic.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
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• pp.117-121
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• 2000

We developed a general purpose program for the analysis of flows in a gas turbine combustor. The program uses non-staggered grids based on finite volume method and the cartesian velocities as primitive variables. We calculated a flow inside the C-type diffuser to check the boundary fitted coordinate. The velocity profiles at cross section agree well with experimental results. We calculated turbulent diffusion flame behind a bluff body for the combustion simulation. Simulation shows two recirculating region like experimental results. Simulated velocity, turbulent kinetic energy, temperature and concentration distribution agree well with experimental data. Finally, simulation of axisymmetric flows with swirl shows two recirculating region like experimental results.

• Steel and Composite Structures
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• 제2권5호
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• pp.397-410
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• 2002

The main aim of the present paper is to present the results of a full-scale experimental investigation to study the structural behaviour of composite steel beams. The composite beam was made of cold-formed steel section shapes filled with reinforced concrete. First a comprehensive description of the experimental results in terms of: deflections, deformations, slippage and stress levels on critical steps of the load path is presented. The experimental results were then compared to theoretical values obtained by the use of an analytical model based on ultimate limit state stress blocks. Finally, a practical application of the use of this structural solution is depicted.

• 대한기계학회논문집
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• 제19권8호
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• pp.1844-1853
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• 1995

Theoretical and experimental drawing characteristics for the single circular and square drawbeads are discussed. During the blank holding process, the strain distributions of upper and lower skins of specimens, and the die reactional forces are analysed by F. E. M., and they are compared with the experimental results. The drawbead restraining forces and strain distributions for the drawn specimens by the various drawing length are also analysed and compared with the experimental results. It is concluded that the theoretical simulations and results could be very useful for the prediction of real cases.