• 한국인쇄학회지
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• 제3권1호
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• pp.1-10
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• 1985

In Graphic art reproduction process it is important to realize that which set of inks and their densities (film thickness) and which set of halftone positive should be aimed at. in order to meet the demand for good color reproduction. There have been various studies to calculation the color reproduction of the graphic arts. however. these study were based on the assumed characteristics of the materials. In this study the relationship between wet-trapping (wet on wet-printing) and increases of ink layer and printing sequence are examined.

• 충청수학회지
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• 제33권1호
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• pp.157-163
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• 2020

Conley introduced attracting sets and repelling sets for a flow on a topological space and showed that if f is a flow on a compact metric space, then 𝓡(f) = ⋂{A_U ∪ A*_U |U is a trapping region for f}. In this paper we introduce chain recurrent set, trapping region, attracting set and repelling set for a flow f on a TVS-cone metric space and prove that if f is a flow on a compact TVS-cone metric space, then 𝓡(f) = ⋂{A_U ∪ A*_U |U is a trapping region for f}.

• ETRI Journal
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• 제45권1호
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• pp.7-17
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• 2023

The error-rate floor of low-density parity-check (LDPC) codes is attributed to the trapping sets of their Tanner graphs. Among them, fully absorbing sets dominantly affect the error-rate performance, especially for short blocklengths. Efficient methods to identify the dominant trapping sets of LDPC codes were thoroughly researched as exhaustively searching them is NP-hard. However, the existing methods are ineffective for Raptor-like LDPC codes, which have many types of trapping sets. An effective method to identify dominant fully absorbing sets of Raptor-like LDPC codes is proposed. The search space of the proposed algorithm is optimized into the Tanner subgraphs of the codes to afford time-efficiency and search-effectiveness. For 5G New Radio (NR) base graph (BG) 2 LDPC codes for short blocklengths, the proposed algorithm finds more dominant fully absorbing sets within one seventh of the computation time of the existing search algorithm, and its search-effectiveness is verified using importance sampling. The proposed method is also applied to 5G NR BG1 LDPC code and Advanced Television Systems Committee 3.0 type A LDPC code for large blocklengths.

• 천문학회보
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• 제37권1호
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• pp.90.2-90.2
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• 2012

Geosynchronous electron flux dropouts are most likely due to fast drift loss of the particles to the magnetopause (or equivalently, the "magnetopause shadowing effect"). A possible effect related to the drift loss is the radial diffusion of PSD due to gradient of PSD set by the drift loss effect at an outer L region. This possibly implies that the drift loss can affect the flux levels even inside the trapping boundary. We recently investigated the details of such diffusion process by solving the diffusion equation with a set of initial and boundary conditions set by the drift loss. Motivated by the simulation work, we have examined observationally the energy spectrum and pitch angle distribution near trapping boundary during the geosynchronous flux dropouts. For this work, we have first identified a list of geosynchronous flux dropout events for 2007-2010 from GOES satellite electron measurements and solar wind pressures observed by ACE satellite. We have then used the electron data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measurements to investigate the particle fluxes. The five THEMIS spacecraft sufficiently cover the inner magnetospheric regions near the equatorial plane and thus provide us with data of much higher spatial resolution. In this paper, we report the results of our investigations on the energy spectrum and pitch angle distribution near trapping boundary during the geosynchronous flux dropout events and discuss implications on the effects of the drift loss on the flux levels at inner L regions.

• 한국통신학회논문지
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• 제35권5C호
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• pp.423-431
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• 2010

본 논문에서는 저밀도 패리티 검사부호의 복호에서 발생하는 트랩핑 세트에 갇힌 오류를 정정할 수 있는 수정 합-곱 알고리즘을 제안한다. 원래 합-곱 알고리즘과는 달리 제안된 방법은 반복복호의 실패 원인이 트랩핑 세트인지를 판단하는 과정과 트랩핑 세트에 갇힌 오류를 정정하는 2단계 복호과정으로 구성된다. 수정 합-곱 알고리즘에서는 트랩핑 세트에 포함된 변수노드를 검색하기 위하여 실패 검사노드 집합과 경판정 비트들의 천이패턴을 이용한다. 그리고 검색된 변수노드의 정보를 반전시킨 다음 합-곱 알고리즘을 수행함으로써 트랩핑 세트에 갇힌 오류를 정정한다. 모의실험 결과 제안된 복호알고리즘은 신호 대 잡음비의 증가에 따라 지속적으로 향상되는 오류성능을 보인다. 따라서 수정 합-곱 알고리즘은 저밀도 패리티 검사부호에서 발생하는 오류마루 현상을 현저히 감소시키거나 거의 제거할 수 있는 것으로 사료된다.

• 펄프종이기술
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• 제44권3호
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• pp.41-48
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• 2012

Materials used for the inks in the printing industry is an important material following the paper. The composition of the ink is pigment and organic solvents. However, Ink is used in a variety of chemicals, they are classified as non-green. Therefore, rosin-modified phenolics manufactured by the reaction of phenol and formaldehyde can take the place of eco-phenol free resin and by experiment density, gloss, trapping, contrast and dot gain of printing has been studied as printability. The result of study can support that the properties of printing using eco-phenol free resin such as density, gloss, contrast and trapping is similar to existing ink. In the part of dot gain, the result is excellent. So we were thought to be able to improve some characteristics such as dispersion of black ink, that will be possible for the field applicability.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.665-669
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• 1992

We consider the problem of a random walker on a one-dimensional lattice (N sites) confronting a centrally-located deep trap (trapping probability, T=1) and N-1 adjacent sites at each of which there is a nonzero probability s(0 < s < 1) of the walker being trapped. Exact analytic expressions for < n > and the average number of steps required for trapping for arbitrary s are obtained for two types of finite boundary conditions (confining and reflecting) and for the infinite periodic chain. For the latter case of boundary condition, Montroll's exact result is recovered when s is set to zero.

• 한국전자통신학회논문지
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• 제9권10호
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• pp.1111-1116
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• 2014

본 논문에서는, LDPC 코드의 성능을 향상시키기 위해서, LDPC 코드의 에러 플로어(error floors)를 낮추어서 복호를 수행하는 효율 좋은 알고리듬을 제안한다. 이 방법은, 바람직하지 않은 구조 때문인데, Tanner 그래프의 트래핑 세트를 줄여서 복호를 하는 방법이다. 이 알고리듬은 트래핑 세트를 줄이는 방법으로 복호의 효율성을 얻는다. 모의시험을 통해서 이 알고리듬의 개선된 성능을 확인 할 수 있었다.

• Advances in nano research
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• 제13권1호
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• pp.77-86
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• 2022

This paper studied the peristaltic transport of upper convected Maxwell nanofluid through a porous medium in a heated (isothermal) symmetric vertical channel. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. These phenomena are modeled mathematically by a differential equations system by taking low Reynolds number and long-wavelength approximation, the yield differential equations have solved analytically. A suggested new technique to display and discuss the trapping phenomenon is presented. We discussed and analyzed the pumping characteristics, heat function, flow velocity and trapping phenomena which were illustrated graphically through a set of figures for various values of parameters of the problem. The numerical results show that, there are remarkable effects on the vertical velocity, pressure gradient and trapping phenomena with the thermal change of the walls.

• 한국물환경학회지
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• 제31권5호
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• pp.482-490
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• 2015

In this study, considering the factors that affects sediment trapping efficiency of Vegetative Filter Strips (VFS), the scenarios were designed to develop a regression equation to estimate sediment trapping efficiency of VFS for agricultural fields in South-Korea. For this, general conditions of agricultural fields in South-Korea were investigated. Then, based on these results, total 53,460 scenarios were set and simulated by Vegetative Filter Strip MODel (VFSMOD-w). Two variables were determined from the results of 53,460 scenarios. These two variables were applied to CurveExpert for development of a equation, which can estimate sediment trapping efficiency of VFS. The equation developed in this study can be used in SWAT model for estimation of sediment reduction efficiency of VFS to upland field in Korea. Moreover, it is expected that VFS will be effectively applied to agricultural fields in South-Korea.