• Environmental and Resource Economics Review
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• v.24 no.1
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• pp.85-107
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• 2015

This study analyzes the effect of applying hyperbolic social discount rate onto the results of benefit-cost analysis of environmental public investment projects in Korea. In order to check the application possibility to the actual feasibility study, the discount factors generated by hyperbolic function, rather than traditional exponential one, would be applied to the benefit and cost data from the pre-feasibility studies which peformed for environmental public investment projects. The results of this study shows that using hyperbolic social discount rate is effective for enhancing test results, only under the condition of which the full expansion of the time periods of analysis is satisfied. According to the simulation results of this study, to achieve higher benefit/cost ratio by using hyperbolic social discount rate, the period should be increased up to 120 to 150 years at least.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.31-39
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• 2005

Tests are conducted to analyze the compaction characteristics of domestic river sand used frequently for backfill in construction of electrical pipeline. As a result of test, the range of specific gravity of sand is found to be in between 2.63 and 2.67, and of maximum dry weight of sand is in between $1.70g/cm^3\;and\;1.86g/cm^3$. Also, the optimum moisture content is found to be in between 11.3% and 13.8%. The variability of compaction degree with respect to compaction energy is well captured by hyperbolic function.

• Geotechnical Engineering
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• v.2 no.1
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• pp.15-26
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• 1986

Consolidated undrained standard triaxial tests for two remoulded clays and one undisturbed clay were carried out in order to find out the relationship between excess pore water pressure and axial strain in mortally consolidatated saturated clays during undrained shear. Tests were performed with isotropically-normally consolidated specimens by strain controlled and stress controlled loading. As the result of this stud!'a hyperbolic function expressing the relationship between pore water pressure and strain was found out, and it showed the same form as the Kondner's hyperbolic function for stress·strain behaviour. Two parameters used for the function can be obtained by CU-triaxial test.

• Journal of the Korean Vacuum Society
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• v.4 no.2
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• pp.224-229
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• 1995

쌍곡선 모델을 사용하여 미시 통로죔을 통과하는 2차원 전자들의 양자 탄동적 수송현상을 연구하였다. 통로죔은 타원좌표계($\alpha$, $\beta$)에서 $\beta$=$\beta$o, $\pi$-$\beta$o로 주어지는 두 쌍곡선으로 기술하였다. 양자화된 88컨덕턴스 G는 타원좌표계에서 주어진 슈뢰딩거 방정식과 쌍곡선 경계조건을 만족하는 짝 매튜 함수를 이용하여 계산하였다. 그 결과는 채널수 Nc는 통로죔 폭 W뿐만 아니라 곡률 관련좌표 $\beta$o에 의존함을 나타내었다. 또한 곡률에 의존하는 터널링도 양자화된 G의 그래프의 모양을 나타내는 중요한 요소임을 나타내 주었다. 고정된 통로폭에서 Nc가 일정한 $\beta$o영역에서는 $\beta$o의 연속적 변화에 G는 연속적으로 변화하였지만 $\beta$o가 크게 변화할 때는 Nc가 변화하여 G는 불연속적으로 변화하였다. 만일 터널링이 거의 허용이 안되는 $\beta$o의 영역에서는 G는 계단식의 변화만 보여주었다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.53-55
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• 2008

본 논문에서는, 기존의 문헌에 사용되어 온 $\Gamma$형을 대체할 수 있는 새로운 T형 장거리 송전선로 모델을 제시한다. 특히, T-모델은 선로 양단의 병렬 어드미턴스와의 중복이 없다. 또한, 기존 문헌에 제시된 hyperbolic solution을 이용한 간단한 장거리 송전선로 A,B,C,D 파라미터 유도방법을 소개한다. hyperbolic solution으로 장거리 송전선로 파라미터를 유도할 경우, exponential solution보다 수식의 양을 줄일 수 있고, 초기값도 간단하게 구할 수 있다.

• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.39-42
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• 2014

The objective of this study was to estimate cardinal temperatures for germination of lettuce (Lactuca sativar L.) using bilinear, parabolic, and beta distribution functions. Seeds of lettuce were germinated in a growth chamber at 7 constant temperatures: 10, 14, 16, 20, 24, 28, and $32^{\circ}C$. Four replicates of 100 seeds were placed on two layers of filter paper in a 9 cm petri-dish. Radicle emergence of 1 mm was scored as germination. The time course of germination was modeled using a logistic function. These minimum, optimum, and maximum temperatures were estimated by regression of the inverse of time to 50% germination rate against the temperature gradient. In bilinear function, minimum, optimum, and maximum temperatures were $7.9^{\circ}C$, $23.3^{\circ}C$, and $28.0^{\circ}C$, respectively. In parabolic function, minimum, optimum, and maximum temperatures were $9.7^{\circ}C$, $19.5^{\circ}C$, and $29.4^{\circ}C$, respectively. In beta distribution function, minimum, optimum, and maximum temperatures were $3.7^{\circ}C$, $20.7^{\circ}C$ and $32.0^{\circ}C$, respectively. Minimum, optimum, and maximum ranges of temperatures were $3.7{\sim}9.7^{\circ}C$, $19.5{\sim}23.3^{\circ}C$, and $28.0{\sim}32.0^{\circ}C$, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.27-35
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• 1991

This paper presents a numerical analysis procedure and a characteristics for vibration and buckling of the cylinderical panels. The panels with simply-simply or simply-clamped edge supports are subjectes to circumferential compressive or flexural stresses. The differential equations governing vibration and buckling for these panels are derived by using the fundamental differential equation of the Love-Timoshenko and are solved numerically via the Galerkin method. The panel with simply-clamped edge supports is used a trigonometric function or a eigen function of a beam as a trial function and the effects of trial functions on numerical solutions are displayed. Numerical results are presented to demonstrate the effects of the flexural parameters in natural frequencies and coefficients of critical buckling and some typical mode shapes of vibration and buckling are also presented.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.737-748
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• 2000

This paper presents a numerical analysis procedure and a characteristics for dynamic of cylindrical panels. The panels with simply-simply or simply-clamped edge supports are subjectes to circumferential compressive or flexural stresses. The differential equations governing vibration and dynamic for these panels are derived by using the fundamental differential equation of the Love-Timoshenko and are solved numerically by the Galerkin method. The panel with simply-clamped edge supports is used a trigonometric function or an eigen function of a beam as a trial function and the effects of trial functions on numerical solutions are displayed. Numerical results are presented to demonstrate the effects of the flexural parameters in natural frequencies and coefficients of critical buckling, and some typical mode shapes of vibration and buckling are also presented.

• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.399-408
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• 1997

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.469-476
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• 2023

Soil plasticity models for cyclic and dynamic loads are essential in non-linear numerical analysis of geotechnical structures. While a single yield surface model shows a linear behavior for cyclic loads, J₂-bounding surface plasticity model with zero elastic region can effectively simulate a nonlinearity of the ground response with the same material properties. The radius of the yield surface inside the boundary surface converged to 0 to make the elastic region disappear, and plastic hardening modulus and dilatancy define plastic strain increment. This paper presents the stress-strain incremental equation of the developed model, and derives plastic hardening modulus for the hyperbolic model. The comparative analyses of the triaxial compression test and the shallow foundation under the cyclic load can show stable numerical convergence, consistency with the theoretical solution, and hysteresis behavior. In addition, plastic hardening modulus for the modified hyperbolic function is presented, and a methodology to estimate model variables conforming 1D equivalent linear model is proposed for numerical modeling of the multi-dimensional behavior of the ground.