• Title/Summary/Keyword: 사이중심도

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Comparison of a Qualitative and a Quantitative Approach to Evaluate the Performance of R&D Projects: A Case Study (연구개발 프로젝트 정성·정량평가 비교 분석을 통한 성과평가 발전방향 연구 : K연구원 사례를 중심으로)

  • Lee, Suchul;Ko, Mihyun
    • Journal of Korea Technology Innovation Society
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    • v.20 no.2
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    • pp.271-291
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    • 2017
  • This study measures and compares the performance of research and development (R&D) programs in government-funded research institutes (GRIs) in terms of qualitative and quantitative approaches to find out strategic insights for improving performance evaluation policy. In particular, we adopt the evaluation results from the real data of K institute in 2015 for a qualitative evaluation and the results of data envelopment analysis (DEA) for a quantitative evaluation. Comparative analysis of the R&D performance of 14 programs finds that the difference between the evaluation results of qualitative and quantitative approaches is significant. From this finding, we suggest several strategic directions to complement two approaches each other.

A Study of Extensional Viscosity of Fluid M1 in Converging Channel Rheometer Using K-BKZ Intergral Constitutive Equation (수렴관 유변측정기에서 K-BKZ 적분형 구성식을 사용한 M1유체의 신장점도에 관한 연구)

  • 김동회
    • The Korean Journal of Rheology
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    • v.6 no.1
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    • pp.30-40
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    • 1994
  • 고분자 물질의 신장점도를 측정하기 위하여 설계된 수렴관을 지나는 시험 유체 M1 에대하여 유한요소방법으로 수치모사를 수행하였다. 구성방정식은 세 개의 이완시간을 가진 적분형 K-BKZ모형을 사용하였다. 신장변형이 지배적이고 변형속도가 매우 큰 흐름에 대하 여 실험적 방법으로 측정이 가능한 범위까지 수치모사를 수행하였다. 두 개의 압력 측정꼬 지 사이의 벽면 압력차에 대하여 압력 신호로 측정한 실험값을 수치모사결과와 비교하였다. 걷보기 전단속도가 매우 큰 1300s-1에 이르는 높은 유속의 전 실험범위에 대하여 안정된 수 치해를 얻을수 있었다. 3$0^{\circ}C$에서는 모든 실험범위의 유속에서 압력차에 대한 수치모사 결과 가 실험값과 잘일치했다. 21$^{\circ}C$에서는 0.1$\times$10-3m3/s보다 낮은 유속범위에서 실험값과 일치하 는 결과를 얻었으나 그보다 높은 유속에서 실험값과 일치하는 결과를 얻었으나 그보다 높은 유속에서 실험값과 다른 경향의 결과를 얻었다. 이것은 낮은 온도 높은 유속 조건에서 M1 유체의 성질이 불안정하고 또한 그러한 조건의 실험에서 발생한 압력 측정꼭지 부근의 기포 들이 정확한 압력측정에 영향을 끼쳤기 때문이다. 수치모사 결과로부터 얻은 압력과 응력분 포로부터 수렴관 유변측정기의 유동특성을 밝힐수 있었다. 이는 실험적 방법을 통해서는 얻 기 어려운 결과들로서 중요한의미를 가진다. 특별한 모양을 갖도록 설계된 수렴관을 통과하 는 M1 유체가 중심부근에서 일정한 신장변형속도로 변형됨을 확인할 수 있었으며 수직응력 은 지수적으로 증가하다가 축소부분을 지난 후 매우 장점도를 얻기 위하여 신장변형속도가 일정한 구역이 두 배로 확장된 수렴관이 수치적으로 다루어졌고 이를 통하여 기존의 수렴관 에서 구한 값보다 큰 신장점도를 얻을 수 있었다.

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The characteristics of quaternary fault and coastal terrace around Suryumri area. (수렴리 일대에 발달하는 신기단층 및 해안단구의 층서 고찰)

  • 이병주;감주용;양동윤;정혜정
    • The Journal of Engineering Geology
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    • v.10 no.2
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    • pp.133-149
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    • 2000
  • The study area which contains the coastal terrace of the southeastern part of Korean peninsula, well developed the lineaments which are NNE, NE and WNW directions. The area crops out Cretaceous sedimentary rocks and granite porphyry, Tertiary conglomerate, tuffite and basalt and Quarternary deposits. Coastal terraces are subdivided into low, middle and upper terraces(LT, MT, UT) based on the topographic levels. Terrace gravels are deposited on these wave-cut erosional surface during the initial lowering stage of sea level fluctuation. Terrace gravels are typified by granule to pebble layers with slightly inclined beddings. These gravels are interpreted as beach gravels belonging to berm or swash zone based on the present distribution of beach gravels. The Suryum fault is characterized by the thrust which is gradationally changing the strike from ENE to NNE. The extension of the fault is about 200m and Maximum displacement is about 1.5m.

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The Comparative Study on Teaching of Multiplication Tables in South Korea, China, Japan, Singapore (한국·중국·일본·싱가포르 수학교과서의 곱셈구구 지도내용 비교 연구)

  • Kim, Hyun;Cho, Youngmi;Joung, Youn Joon
    • Journal of Elementary Mathematics Education in Korea
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    • v.20 no.3
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    • pp.407-430
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    • 2016
  • In this study, we analyzed and discussed the instruction method of multiplication tables in mathematics textbooks from four countries in Asia; South Korea, China, Japan, and Singapore. The conclusions of remarks are states as follows: First. The teaching period and elements should be subdivided more structurally so that the learner could understand the concept and principle of multiplication tables better. Second. The bundle model, the linear model, and the array model of multiplication need to be presented so that the learners could experience various situations related to multiplication. Third, The concrete explanation and the higher frequency of presenting the commutative rules of multiplication is suggested so that the learner could understand the concept of the rules well. Fourth. The context related to multiplication by 1 and 0 should be presented so that the learner could comprehend the character of multiplication by 1 and 0. Fifth. The activities which helping memorizing a multiplication table should be suggested when the memorization is needed.

The Relationship Between Students' Perception Toward Mathematics Teachers' Instructional Practices and Attitude toward Mathematics: A Mediation Role of Self-Efficacy Beliefs (학생의 수학 수업에 대한 인식과 수학적 태도의 관계 분석: 자기효능감의 매개를 중심으로)

  • Hwang, Sunghwan
    • Journal of Elementary Mathematics Education in Korea
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    • v.23 no.4
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    • pp.383-403
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    • 2019
  • The purpose of this study was to examine how students' perception of their mathematics teachers' instructional practices is associated with students' attitude toward mathematics, taking into account their self-efficacy in mathematics. The sample contained 4669 Korean fourth graders who participated in Trends in International Mathematics Science Study 2015. We used exploratory factor analysis and confirmatory factor analysis to explore the factor structure of three latent variables and conducted structural equation modeling to examine the hypothesized model. The results revealed that when students positively perceived their teachers' instructional practices, they tended to have a positive attitude toward mathematics. We also found that students' self-efficacy beliefs in mathematics positively mediated the relationship between perceived teachers' instructional practices and personal attitude toward mathematics. We discuss the practical and methodological implications of these findings and offer directions for future studies.

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A Study on the Development of Ultrasonic Urine Volume Detection Sensor and the Correlation between Urine Volume and Bladder Interwall Distance (초음파 뇨량검출 센서의 제작 및 방광 벽간거리와 뇨량과의 상관관계에 관한 연구)

  • Choi, H.H.;Lee, E.H.
    • Journal of Sensor Science and Technology
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    • v.9 no.4
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    • pp.256-267
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    • 2000
  • In this paper, we studied the ultrasonic urine volume sensor of urinary alarm system for home use to detect the time of urination as a assistive methodology for the incontinence patients and the correlation between urine volume and bladder interwall distance by using developed sensor. The developed sensor was designed to minimize the measurement error by using ultrasound with 2.25 MHz center frequency which provides higher resolution as well as longer penetration depth. To verify usefulness of the developed sensor, we performed a preliminary experiment of estimating bladder volume from the measured distance between interior and posterior wall of bladder. In the preliminary experiment, bladder volume estimated from the result using a commercial ultrasonography system. The experimental results show there exists god correlation between the actual urine volume and the measured interwall distance of the bladder. In conclusion, the developed ultrasound bladder volume sensor can be applied to an urine alarm system which provides patient the exact time of urination, it will be contribute in health care and welfare society.

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A Study on the Impacts of SNS Usage on the Relationship and Effectiveness of Local Administration PR: Local Government vs. Residents Perspectives (자치행정PR을 위한 자치행정조직의 SNS 활용이 지역주민과의 관계 및 커뮤니케이션 증진과 행정의 관리 효과에 미치는 영향 : 자치행정조직과 지역주민간의 견해차 비교를 중심으로)

  • Seo, Hyun-Sik;Song, In-Kuk
    • Journal of Internet Computing and Services
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    • v.12 no.5
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    • pp.137-158
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    • 2011
  • The study aims to determine whether SNS Usage has significantly influence on local administration PR. With the advance in information and communication technologies, many administrative organizations began to work in public relation to their residents via SNS. Nowadays SNS is transforming practical standpoints from forming public opinion through communication message to forming relationship with their residents. Therefore the needs to identify the relationship of the administrative organizations and their residents are demanded with the needs to investigate impact levels of SNS use on the relationships. While there are many researches to simply identify the features of SNS and to introduce local administration, the research investigating the sequential impacts of SNS use on local adminstration PR does not exist. The study targeted a borough office and its residents and compare those two groups. Findings illustrate that the SNS usage of administrative organizations suffer from the shortage of resident's feedback. Finally the study recommends the various issue developments to strike chord with their residents to utilize SNS use in local governmental organizations.

Large-scale structure of circular jet in transitional region at reynolds number of ${10}^{4}$ (Reynolds수 ${10}^{4}$일때 천이영역에서의 왼형제트의 Large-Scale 구조에 관한 연구)

  • 이택식;최은수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.823-829
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    • 1986
  • The Large-scale structure of the circular jet in the transition region, which influences the subsequent flow in the turbulent region, was studied experimentally. Measuring equipments are composed of the two channel hot-wire anemometer, the computer controlled two-directional traverse mechanism, the data acquisition system, and FFT-analyzer. The circular jet has 50mm diameter. The mean velocity distribution, the velocity fluctuation, the auto 'cross correlations and the power spectra were acquired at moderate Reynolds number of 10$^{4}$. And the VITA method was used to measure the convection velocity of Large-scale eddy. The phase of u'is in advance of that of v'in all regions. .over bar. $R_{u}$(.tau.=0) is approximately zero in the potential core region, but a small regular deviation is observed. At a position in the mixing layer region the convection velocity is different along the part of the eddy, and in this experiment the convection velocity of the inner region is larger than the outer region. The averge convection velocity of the eddy along y/D=0 was approximately constant in the transition region.D=0 was approximately constant in the transition region.

Hydrogen Storage Technology by Using Porous Carbon Materials (다공성 탄소계 재료를 이용한 수소저장 기술)

  • Lee, Young Seak;Im, Ji Sun
    • Applied Chemistry for Engineering
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    • v.20 no.5
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    • pp.465-472
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    • 2009
  • The technologies for improving the capacity of hydrogen storage were investigated and the recent data of hydrogen storage by using various porous carbon materials were summarized. As the media of hydrogen storage, activated carbon, carbon nanotube, expanded graphite and activated carbon fiber were mainly investigated. The hydrogen storage in the carbon materials increased with controlled pore size about 0.6~0.7 nm. In case of catalyst, transition metal and their metal oxide were mainly applied on the surface of carbon materials by doping. Activated carbon is relatively cheap because of its production on a large scale. Carbon nanotube has a space inside and outside of tube for hydrogen storage. In case of graphite, the distance between layers can be extended by intercalation of alkali metals providing the space for hydrogen adsorption. Activated carbon fiber has the high specific surface area and micro pore volume which are useful for hydrogen storage. Above consideration of research, porous carbon materials still can be one of the promising materials for reaching the DOE target of hydrogen storage.

Mathematics as Engaged Practice: Professional Mathematicians' Conceptions of Mathematics (전문수학자의 수학에 대한 신념)

  • Ju, Mi-Kyung
    • Journal of Educational Research in Mathematics
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    • v.20 no.4
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    • pp.477-491
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    • 2010
  • This research took an interpretive approach to investigate professional mathematicians' conception of mathematics, particularly focusing on their beliefs about the nature of mathematics as a discipline, and the relation between the discipline and themselves as knowers. The analysis shows that the professional mathematicians consider mathematics as human practice. For mathematicians, mathematics as a product is considered as a crystalization of practice that emerges in the dialogical relation between the discipline and its practitioners. This dialogical nature of mathematics suggests that professional mathematicians consider mathematics not as isolated fixed knowledge but as something they are playfully engaged with. The results of this research extend our understanding of what mathematics is and provide an alternative perspective on mathematics to make the learning of mathematics more accessible by dismantling the myth of the rationalist pure objectivity in mathematics.

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