• 한국음향학회지
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• 제15권1호
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• pp.40-45
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• 1996

이 논문에서는 최적의 빔패턴을 얻기 위한 비선형 최적 설계 기법을 제시하였다. 제시된 방법을 사용하여 진동체 사이의 자기 및 상호 방사 임피던스를 고려하여 최대 허용 부엽준위가 주어진 경우 빔폭이 최소화된 빔 패턴을 설계할 수 있다. 그리고 37개의 진동체가 X, Y 및 $45^{circ}$축에 대칭으로 배열된 평면 배열에 대해 제안된 기법을 적용한 결과 빔폭은 변화없이 상당히 낮은 부엽 준위를 얻었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.579-584
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• 2001

A method is described for predicting crack with and spacing in Steel Fiber Reinforced Concrete (SFRC). The crack behavior of SFRC influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack width in serviceability limit states. The proposed method predicts crack widths in cracking stage of the beam. Calculated crack widths obtained for reinforced concrete beams and different volume and type of steel fiber, strength of concrete showed good agreement with experimental results.

• 한국철도학회논문집
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• 제8권4호
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• pp.293-298
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• 2005

A method is described for predicting crack with and spacing in Steel Fiber Reinforced Concrete (SFRC). The crack behavior of SFRC influenced by longitudinal reinforcement ratio, volume and type of sleet fiber, strength of concrete. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack width in serviceability limit stales. The proposed method predicts crack widths in cracking stage of the beam. Calculated crack widths obtained for reinforced concrete beams and different volume and type of steel fiber, strength of concrete showed good agreement with experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.105-108
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• 2000

With exact analysis of cracks in RC beam, present or past stress states can be traced. For analysis of Flexural cracks, experiments are carried out focusing on variation of crack widths and crack spacing due to stress, beam properties. The crack width expectation formulas of each code are compared and initial crack spacing expectation formula is proposed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.627-630
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• 2004

This paper investigates a study on the bending behavior of beam strengthened with CFS under repeated loading. The test specimen consisted of 20cm in width, 40cm in depth, and 15cm in CFS width. We find the strength decrease under repeated loading test comparing with the monotonic incremental loading test.

• Transactions on Electrical and Electronic Materials
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• 제6권6호
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• pp.276-279
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• 2005

Influences of sustain pulse-width on electrical characteristics and luminous efficiency are experimentally investigated for surface discharge of AC-PDP. A square pulse with variable duty ratio and fixed rising time of 300 ns has been used in the experiment. It is found that the memory coefficient is significantly increased at the critical pulse-width. And the wall charges and wall voltages as well as capacitances are experimentally measured by Q- V analysis method along with the voltage margin relation, in terms of the sustain pulse-width in the range of $1{\mu}s$ to $5{\mu}s$ under driving frequency of 10 kHz to 180 kHz. And the luminous efficiency is also experimentally investigated in above range of sustain pulse-width with driving frequency of 10 kHz to 180 kHz. It is noted that the luminous efficiency for 10 kHz and 180 kHz are 1.29 1m/W and 0.68 1m/W respectively, since the power consumption for 10 kHz is much less than that for 180 kHz. It has been concluded that the optimal sustain pulse-width is in the range of $2.5 {\~}4.5{\mu}s$ under driving frequency range of 10 kHz and 60 kHz, and in the range of $1.5 {\~} 2.5{\mu}s$ under driving frequency range of 120 kHz and 180 kHz based on observation of memory coefficient, and wall voltage as well as luminous efficiency.

• Imaging Science in Dentistry
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• 제51권1호
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• pp.49-54
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• 2021

Purpose: This study was conducted to establish age- and sex-specific reference standards for pterygoid hamulus(PH) dimensions using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 1,000 patients(493 males and 507 females) were retrospectively assessed in coronal sections for length and width measurements of the PH by 3 investigators. The study data were divided into 3 age groups(group 1: <20 years, group 2: 20-50 years, group 3: >50 years). Length and width were compared using one-way analysis of variance and the t-test for age and sex, respectively. Results: The length of the PH on the right side significantly increased from group 1 (6.11±1.47mm), through group 2 (6.65±1.67 mm) to group 3 (6.99±1.79 mm) and on the left side from group 2 (6.58±1.63) to group 3 (6.98±1.70). The width of the PH significantly decreased from group 1 (1.81±0.39 mm) to group 2 (1.61±0.39 mm) on the right side, and similarly from 1.87±0.36mm to 1.67±0.37mm on the left side. PH length (7.18±1.81mm on the right side and 7.10±1.72 mm on the left side) and width (1.68±0.38 mm on the right side and 1.74±0.36 mm on the left side) were significantly greater in males than in females. Conclusion: The length of the PH increased with age, whereas width first decreased and then increased. Length and width measurements were significantly higher in males than in females. These findings will aid in the diagnosis of untraceable pain in the oropharyngeal region related to altered PH morphology.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.521-526
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• 2001

The flexural behavior of a strengthened beam that is a reinforced concrete beam with externally bonded carbon fiber sheets, is theoretically and experimentally investigated. A rectangular beam having a width of 20cm depth of 30cm and effective depth of 25cm is chosen. In order to have a variety of beams analyzed, three reinforcement ratios are chosen for the analysis: 1)$\frac{1}{2}$$\rho$$_{max}$, which is the most suitable reinforcement ratio for deflection consideration and the highest reinforcement ratio for practical designing beams as well; 2)$\rho$$_{max}$, which is the lowest reinforcement ratio for design purposes; and 3)the reinforcement ratio halfway from 1) and 2). Carbon fiber sheets with width of 15cm are externally bonded at the bottom fiber of the beam. The effect of the amount of carbon fiber sheets varying from 1 to 4 plies on the flexural capacity of the strengthened beam are also examined. Yield loads, ultimate loads, and flexural rigidities of the strengthened beam from the experimental results are composed with theoretical ones.nes.

• Steel and Composite Structures
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• 제28권4호
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• pp.471-482
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• 2018

The composite reinforced concrete and steel (RCS) structural systems have larger structural lateral stiffness, higher inherent structural damping, and faster construction speed than either traditional reinforcement concrete or steel structures. In this paper, four RCS subassemblies with or without the RC slab designed following a strong column-weak beam philosophy were constructed and tested under reversed-cyclic loading. Parameters including the width of slab and composite effect of the RC slab and beam were explored. The test results showed that all specimens performed in a ductile manner with plastic hinges formed in the beam ends near the column faces. The seismic responses of composite connections are influenced significantly by different width of slabs. Compared with that of the steel beam without the RC slab, it was found that the load carrying capacity of composite connections with the RC slab increased by 30% on average, and strength degradation, energy dissipation also had better performance, while the ductility of that were almost the same. Furthermore, the contribution of connection deformation to the overall specimen displacement was analyzed and compared. It decreased approximately 10% due to the coupling effect in the columns and beams with the RC slab. Based on the test result, some suggestions are presented for the design of composite RCS joints.

• 태양에너지
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• 제10권1호
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• pp.22-30
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• 1990

장방형 발열체 주위에서의 자연대류열전달 특성을 고찰하기 위하여, 주위유체가 공기인 정상 층류상태하에서 수평단열판에 부착된 등온 사각비임에서의 자연대류 열전달 해석을 비임의 형상과 Grashof수를 변수로 하여 수치해석하였다. 무차원 비임폭 W / L가 감소함에 따라 사각비임으로부터의 열전달은 증가하며 비임 상부면에서의 평균 Nusselt수는 W / L=0.25에서 최대, W / L=1.0에서 최소값을 나타내었다. 비임 측면의 경우는 W / L=1.0에서 최대, W / L=0.25에서 최소값을 나타내며 비임으로부터의 자연대류열절달은 비임폭의 지배적인 영향을 받는다.