• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.230-237
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• 2017

Various drones have extended application area very fast. In this paper, we define two contradictions in designing a portable-size drone by using TRIZ technique. The first is a physical contradiction between high rigidity and good portability, and the second is a technical contradiction between high stability and good portability. Through TRIZ technique, six design principles, which guide direction for optimal design, were driven. Consequently, an umbrella mechanism and design criteria were proposed for a portable-size drone. Detail design is verified through finite element method. Test results for the portable-size prototype drone show good performance, and prove its usefulness to be equivalent to a general full-size drone.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.184-191
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• 2003

In this paper, a mathematical framework based on a homogenisation technique to simulate 'umbrella arch reinforcement system' (UARS) and its implementation into a 3D Finite Element program that can consider stage construction situations are presented. The constitutive model developed allows considering the main design parameters of the problem and only requires geometrical and mechanical properties of the constituents. Additionally, the use of a homogenisation approach implies that the generation of the Finite Element mesh can be easily produced and that re-meshing is not required as basic geometrical parameters such as the orientation of the pipes are changed. The model developed is used to simulate tunnelling with the UARS. From the analyses, the effects of the main design parameters on the elastic and the elastoplastic analyses are considered.

• The Korean Journal of Applied Statistics
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• v.9 no.1
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• pp.139-152
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• 1996

In this paper we propose nonparametric tests using optimal weights for umbrella alternatives in a randomized block design. We obtain the optimal weights by maximizing the asymptotic relative efficiency of the proposed test statistics with respect to Mack and Wolf(1981) type test statistic, and investigate asymptotic relative efficiencies of the proposed test statistics using these optimal weights relative to Mack and Wolfe type statistics and linear rank statistic. Throughout simulations for small samples, the proposed test statistic has good powers rather than the other two tests when the block sizes are different.

• Journal of the Korean GEO-environmental Society
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• v.21 no.7
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• pp.5-16
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• 2020

Currently, the seismic design standards have been strengthened due to the occurrence of the Gyeongju and Pohang earthquake, and seismic performance evaluation of existing facilities is being conducted. It aims to secure a seismic performance effect during earthquakes by improving the micro-pile method, which can be constructed in limited confined places while minimizing damage to existing facilities. The improvement method is to construct all the piles in the square-tray-type plate on the top of the pile by constructing the slope pile in the form of an umbrella around the vertical pile, the main pillar. In this paper, the numerical analysis was performed to analyze the horizontal displacement behavior of an umbrella-type micropile for various real-measurement seismic waves in sandy soil. As a result of numerical analysis, the softer the ground, the better the effect of horizontal resistance of umbrella-type micropile. The horizontal displacement reduction effect was pronounced when the embedded depth was 15 m or more at the same ground strength, and it was found to be effective in earthquakes if it was settled on the ground with an N value of 30 or more. The embedded depth and horizontal displacement suppression effect of the micropile was proportional. Generally, the weaker the ground, the greater the displacement suppression effect. Umbrella-type micropile had a composite resistance effect in which the vertical pile resists the moment and inclined pile resists the axial force.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.139-146
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• 1999

Geological and geotechnical surveys, in general, should precede the excavation to ensure the stability of the tunnel md should be followed up according to the various geological condition during the excavation. However actually the standard support patterns which were decided during the design phases used be insisted for the whole excavation phases in spite of the various geological conditions. When $\bigcirc$$\bigcirc$ tunnel was excavated up to 25m long, the severe displacement was generated in the Portal area of $\bigcirc$$\bigcirc$ tunnel and the tunnel face was pally collapsed. Therefore, this paper present the case study on construction associated with the Umbrella Arch Method used in silty ground by the NATM.

• Journal of Families and Better Life
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• v.4 no.2
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• pp.25-34
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• 1986

This study aimed to find out the suitable design of footwear cabinet. The questionnaire data from 1969 persons of 400 families about footwear cabinet showed following results. 1) The number of shoes was related with sex, age, occupation, family income, the number of family members and educational level of housewives. 2) The size of shoes in the range of 80% of the investigated shoes was 30cm of height, 30cm of length, and 10cm of width. 3) The satisfaction with footwear cabints was mainly decided by the size and space of the cabinet. 4) Umbrella, tools and shoe polish and brush were usually kept in the footwear cabinet as well as shoes. On the basic of the results above. The size of 108cm of length (20cm for umbrella), 35cm of width and 105cm of height is sugested as the desirable footwear cabinet for the General public housing scale apartment for 5 family members and this cabinet should have 5 divider and one flexible divider by 30cm which may be adjusted by 20cm.

• The Korean Journal of Applied Statistics
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• v.5 no.1
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• pp.41-57
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• 1992

Distribution-free test for umbrella alternatives in a randomized block design is proposed and asymptotic properties test statistics and the asymptotic relatives efficiency (ARE) of the proposed test statistics with respect to the Puri's parametric method are investigated. For given peak points 2,3,4, with 4 blocks and 5 treatments, and with 3 blocks and 5 treatments : for given peak point 3, with 2 blocks and 4 treatments : from the small sample Monte Carlo Study, the empirical powers between the proposed test and Puri's test are compared. Throughout the simulation results, the proposed test statistic is efficient for the heavy tailed distributions.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.327-335
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• 2018

The current study challenges to suggest an umbrella strategy applied to different type of crisis, which is different from normative principle in crisis communication. The umbrella or comprehensive strategy in this study is identification framing. Identification framing is strategic message for organizational identification, which is close to social identification. The current study employed experimental design manipulating crisis types, crisis response types, and identification framing. The crisis types were internal versus external crisis, crisis responses were denial versus apology, and using identification framing $2{\times}2{\times}2$ factorial design were used. Two hundreds forty students participated in the experiment. The result showed the significant effectiveness of identification framing in different crisis types and crisis responses.

• Journal of the Korean Geotechnical Society
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• v.20 no.3
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• pp.97-106
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• 2004

In case of tunnel construction with a shallow soil cover in cohesionless soils or highly weathered rocks, reinforcement measures are required for a tunnel stability during the tunnel construction. Recent developments show that the use of Umbrella Arch Method(UAM) as tunnel reinforcement and water cut-off in domestic projects has increased. Unfortunately, guidelines for the design and construction of UAM have not been established, only empirical designs and applications in tunnel construction have been performed so far. In this study, behaviour of the steel pipes installed on the tunnel roof was analyzed through the monitoring of bending and axial stresses of the pipes with the advance of the tunnel face. The monitoring results were used in the establishment of the loading mechanism around the pipe. This paper suggests, the guidelines used in the determination of the total length, overlapping length and lateral spacing of the reinforcing pipes obtained from the established loading mechanism.

• Ocean Systems Engineering
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• v.1 no.2
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• pp.157-169
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• 2011

To provide more rational design solutions at conceptual design level, axiomatic design method has been applied to solve critical part of a new engineering problem called Mobile Harbor. In the implementation, the Mobile Harbor, a functional harbor system that consists of a vessel with container crane approaches to a container ship anchored in the open sea and establishes a secure mooring between the two vessels to carry out loading and unloading of containers. For this moving harbor system to be able to operate successfully, a reliable and safe strategy to moor and maintain constant distance between the two vessels in winds and waves is required. The design process of automatic ship-to-ship mooring system to satisfy the requirements of establishing and maintaining secure mooring has been managed using axiomatic design principles. Properly defining and disseminating Functional Requirements, clarifying interface requirements between its subsystems, and identifying potential conflict, i.e. functional coupling, at the earliest stage of design as much as possible are all part of what need to be managed in a system design project. In this paper, we discuss the automatic docking system design project under the umbrella of KAIST mobile harbor project to illustrate how the Axiomatic Design process can facilitate design projects for a large and complex engineering system. The solidified design is presented as a result.