• 한국정밀공학회지
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• 제22권8호
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• pp.118-127
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• 2005

A spatial 3 degrees-of-freedom mechanism employing Stewart Platform structure is proposed: the mechanism maintains the 3- RRPS structure of Stewart Platform but has an additional passive PRR serial sub-chain at the center area of the mechanism in order to constrain the output motion of the mechanism within the output motion space of the added PRR serial subchain. The forward and reverse position analyses of the mechanism are performed. Then the mechanism having both the forward and the reverse closed-form solutions is suggested and its closed form solutions are derived. It is confirmed, through the kinematic analysis of those two proposed mechanisms via kinematic isotropic index, that both the proposed mechanisms have fairly good kinematic characteristics compared to the existing spatial 3-DOF mechanisms in literature.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.27-30
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• 2008

For the purpose of developing economical and time-efficient formwork for Top-down construction, a Non-Supporting Form System has been proposed. The system is consisted of two parts: a hanging part to support a steel frame and a section of concrete slab, and the other hanging part to lower the steel frame. In this paper, the proposed system is compared to two existing systems of Non Supporting Top-down Method and Bracket Supported R/C Downward Method. It is expected that this system can be used in Top-down construction with further development.

• 비파괴검사학회지
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• 제29권3호
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• pp.230-234
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• 2009

As concrete ages, the surrounding environment is expected to have growing influences on the concrete. As all the impacts of the environment cannot be considered in the strength-estimating model of a nondestructive concrete test, the increase in concrete age leads to growing uncertainty in the strength-estimating model. Therefore, the variation of the model error increases. It is necessary to include those impacts in the probability model of concrete strength attained from the nondestructive tests so as to build a more accurate reliability model for structural performance evaluation. This paper reviews and categorizes the existing strength-estimating statistical models of nondestructive concrete test, and suggests a new form of the strength-estimating statistical models to properly reflect the model uncertainty due to aging of the concrete. This new form of the statistical models will lay foundation for more accurate structural performance evaluation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.185-186
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• 2018

The slabfrom, which is commonly used in construction sites, has drawbacks in that the workability of the workers is reduced due to their heavy weight. This study investigates the possibility of design optimization of euro form between structural stability and weight using harmonic search algorithm. The harmonic search algorithm is a metaheuristic optimization technique that obtains multiple optimal solution candidates through iterative. As a result of multiple attempts of optimization through the algorithm, it was possible to design the formwork which is structurally stable and light in weight than the existing formwork.

• 전자공학회논문지B
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• 제29B권1호
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• pp.18-25
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• 1992

In this paper, a rule checker which aids in composing a consistent knowledge base by checking redundancies and inconsistencies in a knowledge base is proposed. The proposed algorithm checks the rules by representing the rule connections as a network . The standard model of the rules adapted in this algorithm is in the Conjunctive Normal Form which includes NOT's, and rules of conventional expert system can be checked by converting them into the standard form by a rule form at converter. When compared with Ginsberg's KB-reducer which is conceptually most similar to the proposed algorithm among existing methods,it is shown by a computer simulation that with 360 rules, the checking time is three times faster and the rate increased as the number of rules increased, but the total memory requirement of the proposed agorithm is 1.2 times larger. The proposed algorithm has further advantages in that it can check circular rule chains and can find the paths of the redundant and inconsistent rules.

• 설비공학논문집
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• 제11권6호
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• pp.709-715
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• 1999

To optimize a heating and cooling system, we need an exact solution lot radiant heat transfer in any form of room or building. This paper describes the solution method of view factor by the area weighted average and graphical method to calculate the radiant heat exchange or daylighting level in any form of room or building. This study shows that the area weighted average and graphical methods have many points of merits(calculation speed, correctness and calculation capability in an arbitrary form of room shapes etc.) compared with existing methods

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.1976-1978
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• 2001

In this paper, a new robust deadbeat minimax FIR filter (DMFF) is proposed for continuous-time state space signal models. Linearity, deadbeat property, FIR structure, and independence of the initial state information will be required in advance, in addition to a performance index of the worst case gain between the disturbance and the current estimation error. The proposed DMFF is obtained by directly minimizing a performance index with the deadbeat constraint. The proposed DMFF is represented first in a standard FIR form and then in an iterative form. The DMFF will be shown to be used also for the IIR structure. It is shown that the DMFF is similar in form to the existing receding horizon unbiased FIR filter (RHUFF) with some noise covariances. The former is a deterministic filter, while the latter is a stochastic filter.

• 한국안전학회지
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• 제28권1호
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• pp.74-80
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• 2013

This study describes structural reliability analysis of actively-controlled structure for which random vibration analysis is incorporated into the first-order reliability method (FORM) framework. The existing approaches perform the reliability analysis based on the RMS response, whereas the proposed study uses the peak response for the reliability analysis. Therefore, the proposed approach provides us a meaningful performance measure of the active control system, i.e., realistic failure probability. In addition, it can deal with the uncertainties in the system parameters as well as the excitations in single-loop reliability analysis, whereas the conventional random vibration analysis requires double-loop reliability analysis; one is for the system parameters and the other is for stochastic excitations. The effectiveness of the proposed approach is demonstrated through a numerical example where the proposed approach shows fast and accurate reliability (or inversely failure probability) assessment results of the dynamical active control system against random seismic excitations in the presence of parametric uncertainties of the dynamical structural system.

• Molecules and Cells
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• 제21권1호
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• pp.76-81
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• 2006

Tubulin is synthesized in the cell body and must be delivered to the axon to support axonal growth. However, the exact form in which these proteins, in particular tubulin, move within the axon remains contentious. According to the "polymer transport model", tubulin is transported in the form of microtubules. In an alternative hypothesis, the "short oligomer transport model", tubulin is added to existing, stationary microtubules along the axon. In this study, we measured the translocation of microtubule plus ends in soma segments, the middle of axonal shafts and the growth cone areas, by expressing GFP-EB3 in cultured Xenopus embryonic spinal neurons. We found that none of the microtubules in the three compartments were transported rapidly as would be expected from the polymer transport model. These results suggest that microtubules are stationary in most segments of the axon, thus supporting the model according to which tubulin is transported in nonpolymeric form in rapidly growing Xenopus neurons.

• Structural Engineering and Mechanics
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• 제49권2호
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• pp.163-182
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• 2014

Safety factors proposed in codes CEB, B.A.E.L 91 and EUROCODE 1 cover a great number of uncertainties; making them inadequate for the assessment of existing structures. Suitable safety factors are established using a probabilistic assessment, once real dimensions, materials strength and existing structures deterioration mechanisms are taken into account. This paper presents a calibration method for safety factors using a typical set of RC bridges in France. It considers the principal stages of corrosion provoked by $CO_2$ and $Cl^-$ penetration and threshold indexes (${\beta}_0$) for existing structures. Reliability indexes are determined by the FORM method in the calibration method.