• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권8호
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• pp.825-836
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• 2010

정보통신의 발전으로 인한 전자 기록물의 등장은 기록물 관리 체계에 많은 변화를 가져 왔다. 전자 기록물의 등장으로 인한 기록물관리의 가장 큰 변화는 종이기록물 등의 물리적인 기록물에 대한 수동적인 관리체제에서 컴퓨터 시스템을 통한 전자형식 기록물의 자동화된 기록 관리체제로의 전환과 대량 대용량으로 발생하는 전자 기록물에 대한 효율적인 관리이다. 데이터 그리드 소프트웨어인 iRODS(Integrated Rule-Oriented Data System)는 규칙 기반 데이터 그리드 시스템으로서 지리적으로 분산된 컴퓨팅 자원을 네트워크로 연동하여 가상화를 통해 대용량 저장 인프라를 구성한다. 특히, 이 시스템은 규칙을 정의함으로써, 입력되는 전자 기록물에 대한 데이터를 분산 및 백업하는 등의 조작이 가능하다. 따라서 iRODS는 대량, 대용량으로 발생하는 전자기록물을 자동적으로 관리하는 전자기록물 관리시스템의 구축에 적합한 기술이다. 본 논문은 규칙 기반의 그리드 시스템인 iRODS를 이용하여 전자 기록물 관리 시스템을 설계 및 구현하였다. 본 논문에서 구축한 전자 기록물 관리 시스템은 iRODS의 규칙을 이용하여 기록물 유형에 따라 데이터를 자동 분산하며 데이터를 자동으로 백업한다. 그리고 iRODS의 메타데이터를 관리하는 iCAT DB를 이용하여 전자 기록물의 메타 데이터 저장 및 검색 기능을 제공한다.

• Tribology and Lubricants
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• 제14권4호
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• pp.51-57
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• 1998

Recently, bent-axis-type axial piston pumps driven by rods being in extensively used in the world, because of simple design, lightweight, effective cost. So, to guarantee the quality of bent-axis-type axial piston pumps driven by rods, it is necessary to know characteristics of the driving mechanism of rods. But, as they perform both reciprocating and spinning motions, it is difficult to understand driving mechanism. In this paper, I studied the theoretical driving mechanisms of cylinder block driven by rods through geometric method. I found that the cylinder block was driven by one rod in limited area and the driving area was changed by rod's tilting angle and cylinder block's swivel angle.

• 소성∙가공
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• 제17권4호
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• pp.284-291
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• 2008

It was investigated that two rods of aluminum can be welded by hot extru-pressure welding method with stepped welding dies, and that the welding pressure and metal flow on the welding surface were analyzed by computer simulation according to the stepped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using stepped welding dies could be higher than the welding pressure of aluminum rods without using stepped welding die. And it was known by experiments that two rods of aluminum can be welded on the end sections by hot extru-pressure welding method using stepped welding dies without relative rotational movement of contacted aluminum rods in the case of friction welding of rods.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.206-209
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• 2005

It was investigated that two rods of aluminium can be welded by hot extru-pressure welding method with stepped welding dies, and that the welding pressure on the welding surface were analyzed by computer simulation according to the stepped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using stepped welding dies without eccentricity is lowerer than the welding pressure of rods welded using stepped welding dies with eccentricity of welding surface, and that the welding pressure on the welding section of rods using eccentric-inclined stepped welding dies is higher than the welding pressure of rods using stepped welding dies without eccentricity. And it was known by experiments that two rods of aluminium can be welded on the end sections by hot pressure welding method using eccentric-inclined stepped welding dies without relative rotational movement of contacted aluminium rods needed for the purpose of friction heating and pressure.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.76-85
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• 1997

Recently, bent-axis-type axial piston pumps drived by rod being in extensively used in the world, because of simple design, lightweight, effective cost. So, to guarantee the quality of bent-axis-type axial piston pumps drived by rods, it is necessary to know chracteristics of the forces applied to rods and the driving mechanism of rods. But, as they perform both reciprocating and spinning motions, it is difficult to understand driving mechanism. In this paper, I explained the theoretical driving mechanisms of cylinder block drived by rods through geometric method and the characteristics of the forces applied to them.

• 한국농공학회지
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• 제25권2호
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• pp.67-75
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• 1983

The objectives of this paper were to measure the bond strengths of reinforced concrete in which the steel rods were coated with five different kinds of anticorrosion paints, and to compare their prevention effects in salt water. The paints used in the study were epoxy resin I . II . III, Z.R. P., and silicone resin, which were applied at rates recommended by the manufacturers. The bond strengths were measured on the 7-, 14-, and 28-th days after molding. Corrosion conditions of coated steel plate under fresh water, seawater, 10 % salt water, and 20% salt water, were inspected every month during four months test peoriods, respectively. The results obtained from tests are summarized as follows: 1. Paint-coating may reduce the bond strengths of reinforced concrete. Silicone resin paint showed some 20% reduction in the strength compared to those without the paint. However, the other paints seemed not to significantly affect the strength. 2. Picture analyses showed that epoxy resin I and II significantly prevented corrosion steel plates in seawater. Epoxy resin I and silicone resin coating did not do a good job in corrosion prevention. Z.R. P. paint was found to be moderate as preventive coating paint. 3. Varying soluble salt contents had little effects on the corrosion prevention of tested paints. 4. Epoxy resin I and II were found to be appropriate as a coating material to prevent the corrosion of steel rods in seawater. Z.R.P. may also be used for the purpose.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권2호
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• pp.193-212
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• 2017

This study focuses on cuisenaire rods that can be used when teaching fractions to elementary school students. First of all, this study critically examines the use of cuisenaire rods in learning of fraction proposed by various researches. Then, based on this review, this study explores in detail the use of cuisenaire rods in teachers' manuals developed from the revised curriculum by 2009 and in lessons related to fraction. The results of this study show that there are subtle differences in how to use cuisenaire rods in learning fractions and these subtle differences have a significant impact on students' understanding of the fractions. Therefore, the teachers should be able to accurately grasp the differences and utilize appropriate methods for teaching purpose. The followings are some of the implications for teachers or textbook developers when using cuisenaire rods in fraction learning: First, we should use cuisenaire rods in ways that can fully exploit the interpretations of the fraction as a part-whole and the fraction as a ratio. Second, we should focus on quantitative reasoning with unit to determine what each cuisenaire rod refers to. Third, it is necessary to take a more careful and sensitive approach to the use of cuisenaire rods. Teachers and textbook developers should constantly explore ways to make good use of mathematical manipulatives to help students understand conceptually in fractional learning. Furthermore, when teaching various mathematical topics using different manipulatives, I expect that there will be sufficient discussions and specific studies on how to use each of these manipulatives.

• Journal of Periodontal and Implant Science
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• 제33권2호
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• pp.247-257
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• 2003

The purpose of this study was to evaluate the difference of subgingival bacterial compositions between periodontally healthy and diseased sites. Subgingival plaque samples were obtained from 100 sites in 20 untreated adult periodontitis patients(experimental group), and 100 sites in healthy individuals(contro1 group). Before sampling, probing pocket depth(PPD) and clinical level of attachment(CAL), Plaque Index(PI), and Sulcus Bleeding Index(SBI) were recorded for each sampled sites. Microbial samples were collected from the bases of gingival sulci or periodontal pockets with sterile curettes. The samples were examined under darkfield microscope(${\times}$400). At least 150 bacteria were evaluated and categorized on the basis of bacterial morphology and motility, i.e. cocci, non-motile rods, motile rods, and spirochetes. In control group, subgingival microbial flora consisted of 73.7% of cocci, 20.0% of non-motile rods, 4.3% of motile rods, and 2.0% of spirochetes. The microbial samples from experimental group consisted of 51.5% of cocci, 19.4% of non-motile rods, 17.6% of motile rods, and 11.6% of spirochetes. The proportion of cocci was higher in control group than in experimental group. Proportions of motile rods and spirochetes were higher in experimental group than in control group. The proportion of nonmotile rods in experimental group and control group was not significantly different. Sulcus Bleeding Index and Plaque Index showed high correlation with the bacterial composition. These findings suggests that examination of subgingival bacterial proportion may serve as more sensitive mirror of the local periodontal status than clinical parameters.

• 농업과학연구
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• 제16권2호
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• pp.152-162
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• 1989

너도밤나무 삼림토양(森林土壤)의 각 층에는 저영양세균(低營養細菌)이 다수(多數) 존재(存在)해 있었다. 각 토양층으로 부터 분리(分離)한 저영양세균(低榮養細菌) 203주를 갖고 형태적(形態的), 생리적성질(生理的性質)을 검토한 결과 세포형태에 의해 크게 4개의 Group으로 대별되었다. (1) regular rods (73주), (2) curved/spiral rods (29주), (3) irregular rods (56주), (4) appendaged rods (45주)였다. 이와같이 저영양세균(低營養細菌)은 세포형태적(細胞形態的)으로 다양(多樣)한 세균의 집합이며, 그중에는 새로운 형태의 세균도 포함되어 있었다. 이들 각 Group에 속하는 균주의 생리적특질(生理的特質)에도 각각 특징(特徵)이 보여졌다. 그중에는 리그닌의 단위구조물질(單位構造物質)인 feruric acid, p-coumaric acid를 이용하는 균, methanol을 이용하는 균 및 질소고정능(窒素固定能)을 갖는 균 등 흥미(興味)있는 성질을 갖는 세균이 포함되어져 있음을 밝혔다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권11호
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• pp.717-723
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• 1999

The transient characteristics of grounding systems play a major role in the protection of power equipments, electronic circuits and info-communication facilities against surges which arise from lightning or ground faults. Electronic devices are very weak against lightning surges injected from grounding systems and can be damaged. The malfunction and damage of electronic circuits bring about bad operation performances, a lot of economical losses, and etc. Therefore, in order to obtain the effective protection measure of electronic devices from overvoltages and lightning surges, the analysis of the transient grounding impedances in essential. One of this work is to examine the transient behaviors of grounding impedances under steplike currents for various grounding systems. And the other of this work is to evaluate the transient behaviors of a grid with rods under impulse currents and to investigate the effect of grounding lead wire. Transient grounding impedances of a grid with rods under impulse current waves have been measured as a parameter of the length of the grounding leads. Z-t, Z-i and V-i curves of transient grounding impedance under impulse current waveforms have been measured and analyzed. It was found that the grounding impedance gives the inductive, resistive and capacitive aspects under steplike current. Transient grounding impedance characteristics were very different with shapes, geometries of ground electrodes. Also, they were dependent on the waveform and magnitude of impulse current.