• 한국정밀공학회지
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• 제21권3호
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• pp.38-43
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• 2004

This paper describes the construction of a circular polariscope. Generally, a circular polariscope contains four optical elements and a light source. The first element following the light source is called the linear polarizer. It converts the ordinary light into plane-polarized light. The second element is a quarter wave plate which converts the plane-polarized light into circularly polarized light. Following the quarter wave plate, a specimen made of transparent photoelastic material is located in a loading device. The second quarter wave plate is set and the last element is the analyzer. These polarizing elements, two quarter wave plates and two linear polarizing filters, were purchased from the USA. Frames and other structures for holding polarizing filters were machined and assembled to be rotated. Light box, which includes four incandescent lamps and two sodium-vapor lamps, was made. In order to proof the function of the newly built polariscope, Tardy compensation test was applied to a rectangular shaped specimen made of poly-carbonate material (PSM 1). The error of the fringe constant, which was measured by the newly built polariscope, was within 4.4 percent compared to the standard value of this material. It is possible to make a good quality of polariscope if accurate polarizing filters will be used.

• 한국임상수의학회지
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• 제39권2호
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• pp.65-69
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• 2022

A 5 day-old Warmblood foal was presented with a quarter crack due to the dam accidentally stepping on his left hind foot. Physical examination revealed the vertical crack included the coronary band of the medial side of the left hind hoof (quarter crack) with the lower pastern avulsion wound. Different from adult horses, the foot of the 5 day-old foal lacked adequate hoof wall thickness for stainless steel wire insertion and hoof size for a reinforcing fabric to be applied. Therefore, the authors decided to stabilize the edges of the cracked wall only by the polymethyl methacrylate (PMMA) composites without wiring and a reinforcing fabric application; and gluing a plastic shoe that was reshaped to protect the lower pastern and to spread pressure to other parts of the hoof when bearing weight. Disinfection and a supportive bandage were applied daily for 2 weeks. A month after the hoof crack accident, lameness had diminished. The quarter crack in this foal was treated successfully by the application of the composites three times with a reshaped gluing shoe, with approximately a month interval over the 4 months. After 4 months, it presented a successful functional recovery and needed no further treatment. When followed up 8 months after the accident, it revealed successful outcomes without hoof shape distortion and unbalanced hoof/limb growth.

• Structural Engineering and Mechanics
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• 제48권2호
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• pp.241-255
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• 2013

The receding contact problem for two elastic layers whose elastic constants and heights are different supported by two elastic quarter planes is considered. The lower layer is supported by two elastic quarter planes and the upper elastic layer is subjected to symmetrical distributed load whose heights are 2a on its top surface. It is assumed that the contact between all surfaces is frictionless and the effect of gravity force is neglected. The problem is formulated and solved by using Theory of Elasticity and Integral Transform Technique. The problem is reduced to a system of singular integral equations in which contact pressures are the unknown functions by using integral transform technique and boundary conditions of the problem. Stresses and displacements are expressed depending on the contact pressures using Fourier and Mellin formula technique. The singular integral equation is solved numerically by using Gauss-Jacobi integration formulation. Numerical results are obtained for various dimensionless quantities for the contact pressures and the contact areas are presented in graphics and tables.

• 아태비즈니스연구
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• 제7권1호
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• pp.31-42
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• 2016

Small and Medium Enterprises (SMEs) are suitable to provide employment with lower investment in densely populated countries like Bangladesh. A stochastic frontier model is used to evaluate performance of SME Banking of the commercial banks in Bangladesh. Input (Total Deposit, Cost of Fund and Salary Expenditure) and output (Finance to SME) data are collected on 45 banks which are dealt with SME for 13 quarters from $1^{st}$quarter of 2010 to $2^{nd}$quarter of 2013. Average performance of the SME banking is 0.716 in Bangladesh. That is, banks have opportunity to increase 30% performance in SME banking from the same inputs. Bangladesh Development Bank has lowest performance (0.540) while Eastern bank has the highest performance (0.753). Highest (0.743) and lowest (0.662) performance is observed during the second quarter of 2013 and fourth quarter of 2010 respectively. Inefficient Bank might be benefited by following the rules of efficient banks.

• 반도체디스플레이기술학회지
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• 제14권2호
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• pp.23-27
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• 2015

In this paper, eco-friendly paper strain gauge was fabricated in the way of printing strain gauge on paper substrate, using PEDOT:PSS ink and inkjet printer technology. As a p-type conductive high polymer, PEDOT:PSS is known to be piezoresistive effect. I formed a strain gauge by connecting in parallel 5 lines of $60{\mu}m$ width printed with PEDOT:PSS. To minimize surrounding influence such as temperature, I formed wheat-stone bridge by combining 4 strain gauges (quarter-bridge strain gauge) which were made up of PEDOT:PSS 5 lines and measured. In quarter-bridge strain gauge, only two strain gauges, facing each other, arranged in strain and horizontal direction were deformed while the other two strain gauge of vertical direction were not. Therefore, quarter-bridge strain gauge showed the output of half bridge. The fabricated quarter-bridge strain gauge had output sensitivity of $105.6{\mu}V/V{\cdot}mm$ and its output linearity was relatively good.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.343-348
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• 2011

This paper presents ride comfort characteristics of a quarter-vehicle magneto-rheological (MR) suspension system with respect to different tire pressure. As a first step, controllable MR damper is designed and modeled based on both the optimized damping force levels and mechanical dimensions required for a commercial full-size passenger vehicle. Then, a quarter-vehicle suspension system consisting of sprung mass, spring, tire and the MR damper is constructed. After deriving the equations of the motion for the proposed quarter-vehicle MR suspension system, vertical tire stiffness with respect to different tire pressure is experimentally identified. The skyhook controller is then implemented for the realization of the quarter-vehicle MR suspension system. Finally, the ride comfort analysis with respect to different tire pressure is undertaken in time domain. In addition, a comparative result between controlled and uncontrolled is provided by presenting vertical RMS displacement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.644-649
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• 2006

This paper presents a robust and superior control performance of a quarter-vehicle electrorheological (ER) suspension system. In order to achieve this goal, a moving sliding mode control algorithm is adopted, and its moving strategy is tuned by fuzzy logic. As a first step, ER damper is designed and manufactured for a passenger vehicle suspension system, and its field-dependent damping force is experimentally evaluated. After formulating the governing equation of motion for the quarter-vehicle ER suspension system, a stable sliding surface and moving algorithm based on fuzzy logic are formulated. The fuzzy moving sliding mode controller is then constructed and experimentally implemented. Control performances of the ER suspension system are evaluated in both time and frequency domains.

• 한국소음진동공학회논문집
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• 제16권8호
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• pp.822-829
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• 2006

This paper presents a robust and superior control performance of a quarter-vehicle electrorheological (ER) suspension system. In order to achieve this goal, a moving sliding mode control algorithm is adopted, and its moving strategy is tuned by fuzzy logic. As a first step, ER damper is designed and manufactured for a passenger vehicle suspension system, and its field-dependent damping force is experimentally evaluated. After formulating the governing equation of motion for the quarter-vehicle ER suspension system, a stable sliding surface and moving algorithm based on fuzzy logic are formulated. The fuzzy moving sliding mode controller is then constructed and experimentally implemented. Control performances of the ER suspension system are evaluated in both time and frequency domains.

• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.96-99
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• 2015

Norwegian Continental Shelf(NCS) is known as rich oil & gas reservoir and takes one third(1/3) of total continental shelf of Europe.(As of year 2013, Norway ranked third in the world in terms of exporting natural gas.) Until recent low oil price stream, development of oil & gas in NCS was active and perceived as profitable business. This paper describes study of living quarter fire protection for PSA AoC to prepare for likely increasing demands of offshore projects in NCS field.

• 한국기계가공학회지
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• 제17권6호
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• pp.111-116
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• 2018

Recently, shape manufacturing method has been changed to a 3D printer. Since lamination type manufacturing method is the basis for forming a three-dimensional shape by repeated lamination, the horizontal accuracy of the lamination layer is very important. In the current paper, we have proposed a new leveling system to be installed in a large 3D printer. The light source was reflected from the water surface contained in the measuring device, and the inclination of the measuring device was measured from the light that entered into four regions of a quarter photodetector. The electrical signals generated differently according to the position of the beam spot incident on the quarter photodetector was acquired and compensated to be horizontal by using a motor mounted at the corner. Compared to a digital leveler, the newly developed leveling system gave errors of only 2 to 3%. This new device can be applied to various fields including the 3D printer in future.