• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.659-670
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• 2012

The purpose of this study is to formulate the local displacement and moments of a plate stiffened with open ribs according to the dimensions of stiffened plates. Analyzed results of various plates stiffened with rectangular and reverse T ribs show that the effect of the lower flange to the local behavior is very small, so the local behavior can be expressed by ratio functions of the rib space, web thickness, web height and plate thickness and the ratio functions of rectangular and reverse T ribs can be unioned. The application of ratio functions to other types of stiffened plates shows that the increment of the error ratio is so small compared with examples of this study that the applicability of this study is proved.

• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.23-32
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• 2005

In this paper, the modified coefficient of the orthotropic rigidity for stiffened plates with open ribs is proposed to improve the inaccurate results of the orthotropic plate analysis. For stiffened plates with rectangular and angle ribs having various aspect ratios and boundary conditions, the aspect ratio and the rigidity ratio are selected as parameters and the parametric study on the modified coefficient is performed. Analyzed results of stiffened plates modeling with the isotropic and orthotropic plate element show that the modified coefficient can be expressed as a function of the rigidity ratio for each rib space regardless of the aspect ratio in case of the aspect ratio under 1 and can be represented as a single union function without regard to rib spaces and aspect ratios in the other case. The results also shows that the effects of the boundary condition on the modified coefficient is small and coefficient functions have different values according to rib shapes. The application to examples shows that the modified coefficient of the orthotropic rigidity improves accuracy. Therefore, the orthotropic plate analysis of stiffened plates with open ribs can easily achieve more accurate results using the coefficient function proposed in this study

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.171-179
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• 2014

The purpose of this study is to evaluate the structural performance of DH beams. DH beam construction method uses thin steel plates as form-works and structural elements. The prefabricated plates and rebars of DH beams were transported to a construction site and erected for casting concrete at the site. In this study, the contribution of steel plates to the flexural strength was evaluated since the plates were expected to play a role as reinforcements. Five test specimens were made for experimental and analytical studies. They consisted of two DH beams for the positive moment test and two DH beams for the negative moment test and a RC beam for the comparison purpose. Test results on DH beams were compared with design equations and the RC beam test result. It was proven that DH beams demonstrated the good flexural behavior showing sufficient strengths and deformation capacities. Flexural strengths, principal strains of concrete, and rebar stresses were evaluated through nonlinear finite element analyses for two test beams. The analyses also showed that steel plates can contribute to the enhancement of flexural strength of DH beams. Based on experimental and analytical studies, it was concluded that steel plates of DH beams can be used as good flexural reinforcements.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.175-191
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• 2002

The equations of a polar fluid of hydromagnetic fluctuating through a porous medium axe cast into matrix form using the state space and Laplace transform techniques the resulting formulation is applied to a variety of problems. The solution to a problem of an electrically conducting polar fluid in the presence of a transverse magnetic field and to a problem for the flow between two parallel fixed plates is obtained. The inversion of the Laplace transforms is carried out using a numerical approach. Numerical results for the velocity, angular velocity distribution and the induced magnetic field are given and illustrated graphically for each problems.

• 연구논문집
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• s.24
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• pp.49-61
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• 1994

In this paper, the experimental unit of the cross inductive radio line and two linear induction motors driven by IGBT inverter for train control was made. In actual condition, the track has straight line, but so as to be able to achieve in small space, the unit prepared was shaped into two circular plates. Then by detecting inductive signal, the position data could be obtained. Also the equipment representing speed and thrust of LIM and train position by means of the experimantal unit could be composed.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.65-78
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• 2021

Jagyeokru, an automatic striking water clock described in the Sejong Sillok (Veritable Records of King Sejong) is essentially composed of a water quantity control device and a time-signal device, with the former controlling the amount or the flow rate of water and the latter automatically informing the time based on the former. What connects these two parts is a signal generating device or a power transmission device called the 'Jujeon' system, which includes a copper rod on the float and ball-racked scheduled plates. The copper products excavated under Gongpyeong-dong in Seoul include a lot of broken plate pieces and cylinder-like devices. If some plate pieces are put together, a large square plate with circular holes located in a zigzag can be completed, and at the upper right of it is carved 'the first scheduled plate (一箭).' Cylinder-like devices generally 3.8 cm in diameter are able to release a ball, and have a ginkgo leaf-like screen fixed on the inner axis and a bird-shaped hook of which the leg fixes another axis and the beak attaches to the leaf side. The lateral view of this cylinder-like device appears like a trapezoid and mounts an iron ball. The function of releasing a ball agrees with the description of Borugak Pavilion, where Jagyeokru was installed, written by Kim Don (1385 ~ 1440). The other accounts of Borugak Pavilion's and Heumgyeonggak Pavilion's water clocks describe these copper plates and ball releasing devices as the 'Jujeon' system. According to the description of Borugak Pavilion, a square wooden column has copper plates on the left and right sides the same height as the column, and the left copper plate has 12 drilled holes to keep the time of a 12 double-hours. Meanwhile, the right plate has 25 holes which represent seasonal night 5-hours (Kyeong) and their 5-subhours (Jeom), not 12 hours. There are 11 scheduled plates for seasonal night 5-hours made with copper, which are made to be attached or detached as the season. In accordance with Nujutongui (manual for the operation of the yardstick for the clepsydra), the first scheduled plate for the night is used from the winter solstice (冬至) to 2 days after Daehan (大寒), and from 4 days before Soseol (小雪) to a day before the winter solstice. Besides the first scheduled plate, we confirm discovering a third scheduled plate and a sixth scheduled plate among the excavated copper materials based on the spacing between holes. On the other hand, the width of the scheduled plate is different for these artifacts, measured as 144 mm compared to the description of the Borugak Pavilion, which is recorded as 51 mm. From this perspective, they may be the scheduled plates for the Heumgyeonggak Ongru made in 1438 (or 1554) or for the new Fortress Pavilion installed in Changdeokgung palace completed in 1536 (the 31^st year of the reign of King Jungjong) in the early Joseon dynasty. This study presents the concept of the scheduled plates described in the literature, including their new operating mechanism. In addition, a detailed model of 11 scheduled plates is designed from the records and on the excavated relics. It is expected that this study will aid in efforts to restore and reconstruct the automatic water clocks of the early Joseon dynasty.

• Current Optics and Photonics
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• v.8 no.1
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• pp.56-64
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• 2024

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings. The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.430-434
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• 2011

Extraskeletal osteochondroma is an uncommon benign tumor that arises in soft tissues lacking continuity with an adjacent bone and joint. Due to similar histopathological findings, extraskeletal osteochondroma is often misdiagnosed for a conventional osteochondroma, the most common benign tumor that arises from the epiphyseal plates of long bones. The pathogenesis of extraskeletal osteochondroma is unclear, but metaplasia of synovial mesenchymal tissue is the best supported etiology. The most common sites of extraskeletal osteochondroma are the hands and feet, and it is rarely found in the maxillofacial area. We present a case of a two-year-old boy with a giant extraskeletal osteochondroma that developed in the masticatory space of the mandible along with a review of the relevant literature.

• Journal of Astronomy and Space Sciences
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• v.29 no.1
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• pp.69-77
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• 2012

This report describes the inception, development and extensive use over 30 years of elliptical polarimeters at the University of Pennsylvania. The initial Mark I polarimeter design utilized oriented retarder plates and a calcite Foster-Clarke prism as the analyzer. The Mark I polarimeter was used on the Kitt Peak 0.9 m in 1969-70 to accomplish a survey of approximately 70 objects before the device was relocated to the 0.72 m reflector at the Flower and Cook Observatory. Successive generations of automation and improvements included the early-80's optical redesign to utilize a photoelastic modulated wave plate and an Ithaco lock-in amplifier-the photoelastic modulating polarimeter. The final design in 2000 concluded with a fully remote operable device. The legacy of the polarimetric programs includes studies of close binaries, pulsating hot stars, and luminous late-type variables.

• Advanced Composite Materials
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• v.16 no.1
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• pp.31-44
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• 2007

The purpose of this study is to improve the examining and understanding of the bonding behavior of Fiber Reinforced Polymer (FRP) sheets bonded to concrete blocks and steel plates under fatigue loading. First, a series of experimental investigations is summarized in the paper. The fatigue behavior of bonding surface between FRP sheets and concrete is finally characterized by the conducted P-S-N diagram representing the relationship among the probability of FRP debonding (P), the bond stress amplitudes (S), and the number of cycles (N) at debonding on a semi-logarithmic scale. The different debonding modes for various fracturing surface are also investigated and evaluated.