• Honam Mathematical Journal
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• v.19 no.1
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• pp.139-144
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• 1997

In this paper, we make some results on the direct limit of the locally nilpotent direct system. We study the ($T^{**}$) - properties of the above direct limit and homotopy equivalence of the direct limits.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.4
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• pp.409-415
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• 2006

In this paper, we study the condition that a given homeomorphism has a square root and give an example of a wandering homeomorphism without square roots.

• Journal of the Korean Statistical Society
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• v.24 no.1
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• pp.219-224
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• 1995

A central limit theorem with random indices is obtained for stattionary martingale difference sequences.

• Communications of the Korean Mathematical Society
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• v.12 no.4
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• pp.1033-1038
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• 1997

A functional central limit theorem for a class of nonlinear stationary Markov processes which are geometrically Harris ergodic is derived.

• Communications of the Korean Mathematical Society
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• v.10 no.4
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• pp.963-974
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• 1995

We formulate central limit theorems for non-linear functionals of stationary Gaussian vector processes with long-range dependence.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.569-575
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• 2006

In this paper, we define the positive and negative limit sets in the hemicompact space and establish their dynamical properties.

• Communications of the Korean Mathematical Society
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• v.15 no.3
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• pp.541-547
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• 2000

In this paper, we discuss various limit sets of projectively flat manifolds and relationship between them.

• Journal of the Chungcheong Mathematical Society
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• v.35 no.1
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• pp.69-76
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• 2022

In this article, we investigate minimality, transitivity and mixing property for a shift map on the orbital inverse limit systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.135-140
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• 2010

A new treatment is proposed to handle a deflection limit in the open-loop-onset-point (OLOP), which is commonly used in the prediction of pilot in-the-loop oscillation (PIO) due to a rate saturation. The new approach is motivated by the frequency response of a stand-alone actuator in that, unlike the suggestion by the original OLOP procedure, the rate limit onset is not delayed to a higher frequency by a deflection limit. Indeed, if a feedback control loop is closed, the rate limit onset can be shifted to a lower frequency since the controller tends to react with larger commands when deflection limited. The amplitude of the command at this onset frequency is combined with the deflection limit to estimate the associated gain reduction in the open-loop-onset-point in the final step of the OLOP process. The comparison of the new approach with the previous method reveals that an inaccurate optimism which can occur in the previous method is corrected by the proposed treatment.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.103-108
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• 2018

Since tower cranes are susceptible to wind loads, the operation of the tower crane should be ceased when it exposed to a strong wind. For this reason, even in Korea, the operation limit for wind loading on the tower crane is regulated by a law. Recently the Korean law in which provided the wind speed limit to cease the tower crane operation has been revised from "instantaneous wind speed of 20 m/s" to "instantaneous wind speed of 15 m/s". Although this revision is expected to reduce safety risks in tower crane operation, some field operators still insist to lower the wind speed limit. However, in many countries "wind speed of 20 m/s" is normally used as the maximum in-service wind speed for tower cranes. Therefore, the investigation of the proper wind speed for regulation would be helpful to secure the safety of the tower crane operation under windy condition. In this study the validity of the revised wind speed limit is investigated with the surveys targeted to both tower crane practitioners and parties of concerned in construction companies, in which various questions was provided for a suitable wind speed limit and the answers were analyzed. The results showed that the revised wind speed limit is acceptable to tower crane practitioners as well as the parties of concerned in construction companies and is satisfying the structural stability requirement for in-service state tower crane. Therefore, it can be concluded that the revised wind speed limit is valid in humanly safety point of view.