• 한국균학회지
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• 제34권1호
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• pp.54-58
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• 2006

액체질소 보존법은 동결 건조 보존이 불가능한 것을 포함한 곰팡이를 가장 효과적으로 보존할 수 있는 방법 중의 하나로서, 유전적인 변화와 오염을 방지하고 장기보존이 가능한 이점을 가진다. 크료튜브 대신 액체질소 보존에 사용할 수 있는 폴리프로필렌 스트로는 경제성, 안전성, 편리성 그리고 공간 이용성 등의 이점을 가진다. 이에 한국농업미생물자원센터(KACC)에서는 폴리프로필렌 스트로를 이용한 곰팡이의 액체질소 보존법을 정립하였으며, 이를 상세하게 소개하였다.

• 한국대기환경학회지
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• 제12권3호
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• pp.243-254
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• 1996

The main purpose of this study is to investigate the collection efficiency characteristics of a cylindrical ESP. To do that, it is necessary to analyze the electric field, gas flow field, and mechanism of particle movement by numerical simulation based on EHD model. For a gas flow field, Navier-Stokes equation involving the electric source term was solved by SIMPLE algorithm. In case of the electric field, the current continuity and electric field equations were solved by S.O.R. method. The analysis of particle movement was performed on the basis of PSI-CELL model from the Lagrangian viewpoint. The results showed that the influence on the gas flow field by the electric field is almost negligible in a cylindrical ESP. The particle drift velocity $V_P$ toward the collection surface is increased continuously by the electrostatic force due to the rise of particle charge as the particle is moving to the flow direction and the particle size becomes larger. The collection efficiency is to quitely higher with the increase of applied voltage for the same particle size, while becomes smaller as the inlet velocity is increased.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.598-605
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• 2000

The design of a current collection system of high speed train requires the fundamental understandings fer the dynamic characteristics of a catenary system and pantograph. The stiffness of the catenary system of high speed train has the varying characteristics for the change of the contact point with a pantograph, since the supporting pole and hanger make the different boundary conditions for the updown stiffness of a trolley wire. The variation of stiffness results in Mathiue equation, which characterizes the stability of the system. However, the two terms variation of the stiffness due to span length and hanger distance cannot be solved analytically. In this paper, the stiffness variations are calculated, and the physical reasoning of linear model and one term Mathieu equation are reviewed. And the numerical analysis for the two term variation of the stiffness is done for the several design parameters of the pantograph.

• 한국가시화정보학회지
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• 제19권1호
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• pp.62-67
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• 2021

Selective catalytic reduction(SCR) is an exhaust gas reduction device to remove nitro oxides (NOx). SCR operation of ship can be controlled through valves for minimizing economic loss from SCR. Valve in SCR-high pressure (HP) system is directly connected to engine exhaust and operates in high temperature and high pressure. Long-term thermal deformation induced by engine heat weakens the sealing of the valve, which can lead to unexpected failures during ship sailing. In order to prevent the unexpected failures due to long-term valve thermal deformation, a failure prediction system using autoregressive integrated moving average (ARIMA) was proposed. Based on the heating experiment, virtual data mimicking temperature range around the SCR-HP valve were produced. By detecting abnormal temperature rise and fall based on the short-term ARIMA prediction, an algorithm determines whether present temperature data is required for failure prediction. The signal processed by the data collection algorithm was interpolated for the failure prediction. By comparing mean average error (MAE) and root mean square error (RMSE), ARIMA model and suitable prediction instant were determined.

• Wind and Structures
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• 제31권1호
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• pp.21-29
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• 2020

The wind field measurement of severe winds such as hurricanes (or typhoons), thunderstorm downbursts and other gales is important issue in wind engineering community, both for the construction and health monitoring of the wind-sensitive structures. Although several wireless data transmission systems have been available for the wind field measurement, most of them are not specially designed for the wind data measurement in structural wind engineering. Therefore, the field collection is still dominant in the field of structural wind engineering at present, especially for the measurement of the long-term and high-frequency wind speed data. In this study, for remote wind field measurement, a novel wireless long-term and high-frequency wind data acquisition system with the functions such as remote control and data compression is developed. The system structure and the collector are firstly presented. Subsequently, main functions of the collector are introduced. Also novel functions of the system and the comparison with existing systems are presented. Furthermore, the performance of this system is evaluated. In addition to as the wireless transmission for wind data and hardware integration for the collector, the developed system possesses a few novel features, such as the modification of wind data collection parameters by the remote control, the remarkable data compression before the data wireless transmission and monitoring the data collection by the cell phone application. It can be expected that this system would have wide applications in wind, meteorological and other communities.

• 대한기계학회논문집B
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• 제26권8호
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• pp.1102-1114
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• 2002

An electret filter is composed of permanently charged electret fibers and is widely used in applications requiring high collection efficiency and low-pressure drop. In this work, the collection efficiency of the filter media used in manufacturing cabin air filters was investigated by using poly-disperse particles when submicron particles were loaded. Long-term experiments were conducted by applying two different charging states, which were spray electrification and charge equilibrium by bipolar ionization. In order to investigate the effect of particle loading in filter media, NaCl particles were generated from 0.1% and 1% solutions by an atomizer. Liquid DOS particles were used to evaluate the effect of liquid particles on the collection efficiency of an electret filter. The results show significant effect of charge amount and size distribution of loading particles on the collection performance of a filter media in submicron region. Smaller particles loaded in electret fibers cause a more rapid degradation in collection efficiency and have lower minimum efficiency with time. The pressure drop of a filter media do rarely increase when the collection efficiency decreases to the minimum value. For the larger particles charged by spray electrification, which have charge amounts more than that of Boltzmann equilibrium charge distribution, the pressure drop of a filter media slowly increases in comparison with that of equilibrium charged particles. For DOS particles it is shown that the charging level of an electret filter severely decreases and the collection efficiency is below 10% in some particle size range.

• Kyungpook Mathematical Journal
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• 제59권4호
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• pp.617-629
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• 2019

A term is called linear if each variable which occurs in the term, occurs only once. A hypersubstitution is said to be linear if it maps any operation symbol to a linear term of the same arity. Linear hypersubstitutions have some importance in Theoretical Computer Science since they preserve recognizability [7]. We show that the collection of all linear hypersubstitutions forms a monoid. Linear hypersubstitutions are used to define linear hyperidentities. The set of all linear term operations of a given algebra forms with respect to certain superposition operations a function algebra. Hypersubstitutions define endomorphisms on this function algebra.

• 지역사회간호학회지
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• 제31권3호
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• pp.375-383
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• 2020

Purpose: The purpose of this study was to investigate factors influencing care workers' intention of hand hygiene implementation in long-term care hospitals. Methods: A total of 180 care workers working at long-term care hospitals were recruited. Data collection was done from July 22 to September 7, 2018. Results: The significant TPB variables influencing the intention of hand hygiene implementation were perceived behavior control (β=.41, p<.001), normative belief (β=.28, p<.001) and attitude toward behavior (β=.15, p=.014). These factors explain 39% of care workers' intension of implementing hand hygiene in long-term care hospitals. Conclusion: In order to strengthen the commitment of hand hygiene, it is necessary to have a positive attitude toward hand hygiene by eliminating the obstacles to hand hygiene.

• 정보관리학회지
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• 제1권1호
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• pp.43-62
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• 1984

본(本) 연구는 두 개의 중요한 목적(目的)들을 가지고 있다. 첫째 목적(目的)은 새로운 단어(單語) 가중기법(加重技法)을 고안하는 것이다. 두번째 목적(目的)은 제안된 단어(單語) 가중기법(加重技法)과 다른 네개의 단어(單語) 가중기법(加重技法)들의 문헌검색결과들을 평가하는 것이다. 본 연구에서 실행된 실험결과는 비교적 간단한 스파크 죤스(Sparck Jones)의 역문헌빈도 가중기법(加重技法)과 제안된 단어(單語) 가중기법(加重技法)의 검색결과들이 더 복잡한 계산을 요하는 다른 세개의 단어(單語) 가중기법(加重技法)들의 검색결과들보다 더 나았다.

• 정보관리연구
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• 제34권4호
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• pp.85-107
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• 2003

본고는 KISTI 학술지 수집전략의 최적화를 위한 방편으로 학술지 원문복사 이용실적을 분석한 것이다. 정보자원개발정책에 부합하는 합리적인 학술지 수집을 목적으로 1997년과 2002년의 원문복사(DDS)실적의 비교분석을 통하여, 주제분야, 언어, 발행국, SCI 자료, 전자자료의 변화 추이가 분석되었다. 이를 통해 이용자 수요에 기초를 둔 학술지 수집정책을 구현하는 업무상의 전략적 가이드라인을 도출하였다.