• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.24-32
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• 2008

We made a new propellant formulation to improve the productivity of Base Bleed Unit(aka BBU) by reducing of the curing time. We made an experiment with new propellant formulation such as binder characteristics and manufacturing process. In addition, we already tested several basic characteristics and the final performance of the new propellant. According to the test report, it was not only satisfied with all requirements in the specification, but it also contributed to improve productivity and reduced 53% of the curing time.

• Management Science and Financial Engineering
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• v.12 no.2
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• pp.63-69
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• 2006

To generate a multicast routing tree guaranteeing the quality of service (QoS), we consider the hop constrained Steiner tree problem and propose a new mathematical formulation for it, which contains fewer constraints than a known formulation. An efficient procedure is also proposed to solve the problem. Preliminary tests show that the procedure reduces the computing time significantly.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.1-8
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• 1992

New formulation of diazinon as granule preparing with piperonyl butoxide(PBO) and triphenyl phosphate(TPP) known as the inhibitor of monooxygenase(mo) and esterase was tested with the mortality of rice leaf hopper. Also, the mixed formulation of diazinon with tricyclazole, carbofuran and EPN were investigated about the residual pattern of diazinon in submerged soil condition at $30{\pm}2^{\circ}C$. Although the mortality about rice leaf hopper was higher only 10% on new formulation of diazinon than commercial at recommended dose but was 30-60% at half dose. Half life of diazinon in the formulation with 0.1% of PBO+TPP was 4.53 days in sterilized soil and 2.33 days in non-sterilized soil, and it was delayed about 0.74 and 0.45 respectively in contrast with the commercial granule. Also, half life of the new formulation with 1% PBO and PBO+TPP was delayed 0.44(PBO) and 0.65day(PBO+TPP) in non-sterilized soil condition, respectively. Half life of mixed formulation with tricyclazole, carbofuran, EPN or EPN+Carbofuran was delayed 2.61, 1.04, 0.43 or 2.7 days, respectively. As a result, the persistence rate of new formulation and mixed formulation was increased by inhibition of two enzymes affecting to the dgradation of diazinon in submerged soil.

• Structural Engineering and Mechanics
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• v.51 no.4
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• pp.685-705
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• 2014

This paper presents a new formulation for forward scalar wave simulations in semi-infinite media. Perfectly-Matched-Layers (PMLs) are used as a wave absorbing boundary layer to surround a finite computational domain truncated from the semi-infinite domain. In this work, a hybrid formulation was developed for the simulation of scalar wave motion in two-dimensional PML-truncated domains. In this formulation, displacements and stresses are considered as unknowns in the PML domain, while only displacements are considered to be unknowns in the interior domain. This formulation reduces computational cost compared to fully-mixed formulations. To obtain governing wave equations in the PML region, complex coordinate stretching transformation was introduced to equilibrium, constitutive, and compatibility equations in the frequency domain. Then, equations were converted back to the time-domain using the inverse Fourier transform. The resulting equations are mixed (contain both displacements and stresses), and are coupled with the displacement-only equation in the regular domain. The Newmark method was used for the time integration of the semi-discrete equations.

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.239-251
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• 2019

In this paper we introduce a new formulation of symmetric homogeneous bivariate means that depends on the variation of a given continuous strictly increasing function on (0, ${\infty}$). It turns out that this class of means includes a lot of known bivariate means among them the arithmetic mean, the harmonic mean, the geometric mean, the logarithmic mean as well as the first and second Seiffert means. Using this new formulation we introduce a lot of new bivariate means and derive some mean-inequalities.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.267-269
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• 2007

콘크리트 중의 철근이 염분에 의해 부식되는 것을 억제 또는 예방하고, 각종 부식 환경으로부터 구조물의 수명을 연장할 목적으로 사용되는 방청혼화제의 최적 formulation과 그에 대한 물성 및 성능 시험을 실시하였다. 철근 부식에 대한 방청 메카니즘의 이해와 방청 혼화제의 formulation에 따른 물성시험과 성능평가를 실시하여 최적 조건을 확립하였다. 성능평가는 콘크리트 공시체의 Slump, 공기량, 압축강도(3일, 7일, 28일) 측정과 함께 염수침지시험 동의 방청성능 평가를 실시하였다.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.2
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• pp.156-163
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• 2002

This paper presents a new formulation to simplify the three resulting constraint equations of the direct kinematics of the 3-6 (Stewart-Gough) Platform. The conventional direct kinematics of the 3-6 Platform has been formulated through complicated steps with trigonometric functions in three angle variables and thus results in the computational burden. In order to reduce the formulation complexity, we replace an angle variable into a length one and express three connecting joints on the moving platform in the same frame. The proposed formulation yields considerable abbreviation of the number of the calculation terms involved in the direct kinematics. It is verified through a series of simulation results.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.3
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• pp.217-223
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• 2002

The paper presents a single constraint equation of the direct kinematic solution of 6-dof (Stewart-Gough) platforms. Many research works have presented a single polynomial of the direct kinematics for several 6-dof platforms. However, the formulation of the polynomial has potential problems such as complicated formulation procedures and discrimination of the actual solution from all roots. This results in heavy computational burden and time-consuming task. Thus, to overcome these problems, we use a new formulation approach, called the Tetrahedron Approach, to easily derive a single constraint equation, not a polynomial one, of the direct kinematics and use two well-known numerical iterative methods to find the solution of the single constraint equation. Their performance and characteristics are investigated through a series of simulation.

• Computers and Concrete
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• v.17 no.1
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• pp.87-106
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• 2016

This paper deals with the reliability analysis of design formulations derived for predicting the punching shear capacity of FRP-reinforced two-way slabs. Firstly, a new design code formulation was derived by means of gene expression programming. This formulation differs from the existing ones as the slab length (L) was introduced in the equation. Next, the proposed formulation was tested for its generalization capability by a parametric study. Then, the stochastic analyses of derived and existing formulations were performed by Monte Carlo simulation. Finally, the reliability analyses of these equations were carried out based on the results of stochastic analysis and the ultimate state function of ASCE-7 and ACI-318 (2011). The results indicate that the prediction performance of new formulation is significantly higher as compared to available design equations and its reliability index is within acceptable limits.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.396-399
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• 1995

This paper presents a new formulation of the kinematics of closed-chain mechanisms and its applications to obtaining the kinematic solutions and analyzing the singularities. Closed-chain mechanisms under consideration may have the redundancy in the number of joints. A closed-chain mechanism can be treated as the parallel connection of two open-chains with respect to a point of interest. The kinematics of a closed-chain mechanism is then obtained by imposing the kinematic constraints of the closed-chain on the kinematics of the two open-chains. First, we formulate the kinematics of a closed-chain mechanism using the kinematic constraint between the controllable active joints and the rest of joints, instead of the kinematic constraint between the two open-chains. The kinematic formulation presented in this paper is valid for closed-chain mechanisms with and without the redundancy. Next, based on the derived kinematics of a closed-chain mechanism, we provide the kinematic solutions which are more physically meaningful and less sensitive to numerical instability, and also suggest an effective way to analyze the singularities. Finally, the computational cost associated with the kinematic formulation is analyzed.