• Journal of Adhesion and Interface
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• v.23 no.4
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• pp.116-121
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• 2022

OFET have require fine patterning technology for organic semiconductor solution process to be used in actual electronics. In this study, we compared and analyzed the soft lithography method which can form fine patterns more than the conventional spin coating method in order to confirm that it can have better electrical characteristics. The soft lithography method produced a flexible master mold using nano patterns on compact disc surfaces and obtained a 650 nm wide 2,7-Dioctyl [1] benzothieno [3,2-b] [1] benzo thiophene (C_8-BTBT) nanowires. As a result, the field-effect mobility of devices fabricated by the spin coating method was 0.0036 cm²/Vs and mobility of devices produced by soft lithography method was 0.086 cm²/Vs, which was about 20 times higher than spin-coated devices and has better electrical performance.

• Journal of Powder Materials
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• v.15 no.4
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• pp.271-278
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• 2008

Sintering behavior of iron nanopowder agglomerate compact prepared by slurry compaction method was investigated. The Fe nanopowder agglomerates were prepared by hydrogen reduction of spray dried agglomerates of ball-milled $Fe_2O_3$ nanopowder at various reduction temperatures of $450^{\circ}C$, $500^{\circ}C$ and $550^{\circ}C$, respectively. It was found that the Fe nanopowder agglomerates produced at higher reduction temperature have a higher green density compact which consists of more densified nanopowder agglomerates with coarsed nanopowders. The sintering behavior of the Fe nanopowder agglomerates strongly depended on the powder packing density in the compact and microstructure of the agglomerated nanopowder. It was discussed in terms of two sintering factors affecting the entire densification process of the compact.

• Communications of the Korean Mathematical Society
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• v.33 no.1
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• pp.325-335
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• 2018

We prove every oriented compact cyclic 3-orbifold has a contact structure. There is another proof in the web by Daniel Herr in his uploaded thesis which depends on open book decompositions, ours is independent of that. We define overtwisted contact structures, tight contact structures and Lutz twist on oriented compact cyclic 3-orbifolds. We show that every contact structure in an oriented compact cyclic 3-orbifold contactified by our method is homotopic to an overtwisted structure with the overtwisted disc intersecting the singular locus of the orbifolds. In course of proving the above results we prove a classification result for compact oriented cyclic-3 orbifolds which has not been seen by us in literature before.

• Journal of applied mathematics & informatics
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• v.33 no.5_6
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• pp.485-502
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• 2015

A computational method for solving singularly perturbed boundary value problem of differential equation with shift arguments of mixed type is presented. When shift arguments are sufficiently small (o(ε)), most of the existing method in the literature used Taylor's expansion to approximate the shift term. This procedure may lead to a bad approximation when the delay argument is of O(ε). The main idea for this work is to deal with constant shift arguments, which are independent of ε. In the present method, we construct the formally asymptotic solution of the problem using the method of composite expansion. The reduced problem is solved numerically by using operator compact implicit method, and the second problem is solved analytically. Error estimate is derived by using the maximum norm. Numerical examples are provided to support the theoretical results and to show the efficiency of the proposed method.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.21-28
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• 2009

This paper proposes RCBT(Reduced Compact Binary trie) to correct faults of CBT (Compact Binary trie). First, in the case of CBT, a compact structure was tried for the first time, but as the amount of data was increasing, that of inputted data gained and much difficulty was experienced in insertion due to the dummy nodes used in balancing trees. On the other hand, if the HCBT realized hierarchically, given certain depth to prevent the map from increasing onthe right, reached the depth, the method for making new trees and connecting to them was used. Eventually, fast progress could be made in the inputting and searching speed, but this had a disadvantage of the storage space becoming bigger because of the use of dummy nods like CBT and of many tree links. In the case of RCBT in this thesis, a capacity is increased by about 60% by completely cutting down dummy nods.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.149-153
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• 2005

A new method of power amplifier's linearity improvement using a Compact Microstrip Resonant Cell(CMRC) is proposed. It is found out that a CMRC at the input side gives better performance than that at the output. Tuning lines are used in the input and the output matching network to get the optimum performance. As a result, the 14.77 dB improvement fur the third-order IMD is obtained. And the size of the CMRC is only $17.1\times5.22mm$.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.178-182
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• 2013

In mining and its similar industries, compact excavators are used commonly in narrow working spaces, of which bucket must be rotated essentially. Considering of those applications, many kinds of the compact excavators have been developed, but any stress evaluation of bucket rotating part had not been attempted. In this study, using of the finite element method and Spare solver, stress analysis has been performed on the bucket rotating parts and its adjacent parts of compact excavator, with using an excavation stress model, in various directions and positions. Resultantly, it has been defined that stress of connector in the rotating part is a little higher, due to its shape, than those remained parts of which stress are shown equally as 1 MPa. Especially in the moving parts, the stress of bucket pin and rotating pinion gear has been calculated as 7.7 MPa and 40 MPa respectively.

• Journal of Advanced Navigation Technology
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• v.17 no.5
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• pp.475-483
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• 2013

In this paper, the performances of modeling methods for combining corrections from multiple reference stations for network user were compared and analyzed. The longer the distance between reference station and user is, the more the GPS errors are decorrelated. Based on this point, multiple corrections from reference stations which is constituting a network should be combined properly to be applied for user observation to eliminate GPS errors. There are many widely used conventional modeling methods and they are applied for Compact Network RTK users and user position accuracy is predicted by using residual errors in observation of user. Compact Network RTK is a technique of generating corrections which was developed by Seoul National University. As a result, the horizontal and vertical accuracies were within about 5 cm and 7 cm respectively with 95 % probability for all conventional modeling methods. In addition, we analyzed condition for reference station constellation for modeling method using height information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5917-5930
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• 2011

This study suggests Compact City type urban development strategies and planning elements with the purpose of sustainable development. The suggestions are based on analysis of the development projects promoted in the cities within Green-Belt. Following are the findings of this study: First, in the late 20th century, Compact-City has been suggested as standard of sustainable urban development in the developed countries, and this promoted urban development plans were presented in detail. Second, The development plans are suggested plan elements by urban environment, space, community, and management. It was classified as an applicable element in Green belt and Compact City type. Finally, after comparing several city development projects (Gwacheon, Uiwang, Hanam), differences and Limitations between the Compact-City type urban development. Considering analysis of this study, urban development projects in Green Belt should be prepared to sustainable Compact city type urban development.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1112-1118
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• 2007

We propose a new-focusing method for test handlers of compact camera module (CCM), The MMD (max-min difference) method is applied to calculate the focus value quickly considering the noisy output of CCM. Also, the fuzzy search method is applied to find the maximum focus value effectively. We design a fuzzy processor to control the lens position by focus values and brightness values, which improves the focusing performance in the sense of speed and processor memory. The proposed method is implemented by computer program and installed at the CCM test handler machines. The simulation results are presented to verify the usefulness of the proposed method.