• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.157-159
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• 2015

In this study, $CF_4$ decomposition was experimentally investigated in a high temperature flow reactor. Effects of temperature, reactant composition and concentration, and residence time on its decomposition into other stable species were analyzed. Then the results were compared to numerical results obtained using Chemkin Plug Flow Reactor model with Princeton Chemistry. As a preliminary result higher decomposition rate is obtained for higher reactor temperature and long residence time when proper reactants are supplied.

• 생명과학회지
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• 제10권2호
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• pp.169-176
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• 2000

At Koppl area, undamaged natural habitat of sundew, I have analysed interspecific affinities and community composition through mathematical method and important environmental factors. Interspecific affinities of the species with frequency of more than 5% in vegetation table were analysed through chi-square test and showed obvious group of Drosera rotundifolia, Vaccinium uliginosum, Calluna vulgaris, Eriophorum angustifolium and 21 species. The result of ordination anlysis using DECORANA of VESPAN II showed eigenvalue of 0.6047 for axis I, 0.2024 for axis II and 0.0763 for axis Ⅲ. And it divided into 4 groups of quadrat number 1-5 for Sphagnum squarrosum-community, 6-10 for Crepis paludosa-community. 11-25 for Carex panicea-community and 26-35 for Scorpidium scorpioides-community. By the classification using TWINSPAN, the 7 areas divided into 2 groups of 1-10 and 11-35 at first level of division with high eigenvalue of 0.588 and indicator was Sphagnum squarrosum. At second level of division it divided into 4 groups as the results of DECORANA with eigenvalues of 0.268 and 0.423 and indicators were Pinguicula vulgaris and Scorpidium scorpioides. Microclimatic environment of studied area was low in temperature and high in humidity and soil environment showed high in field moisture capacity, acid, high organic matter content, low NO3 and K2O content, compare to normal soil, and high ground water level.

• 동력기계공학회지
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• 제19권6호
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• pp.5-11
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• 2015

The 6DOF (degrees of freedom) Parallel Manipulators have some advantages that are high power, high rigidity, high precision for positioning and compact mechanism compared with conventional serial link manipulators. For these Parallel Manipulators, it can be expected to work in the new fields such that the medical operation, high-precision processing technology and so on. For this expectation, it is necessary to control the action reaction pair of forces which act between the Parallel Manipulator and the operated object. In this paper, we analyze the dynamics of the 6DOF Parallel Manipulator and present numerical simulation results.

• 한국식품조리과학회지
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• 제31권3호
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• pp.248-254
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• 2015

We conducted this study to investigate the amount of RS and cooking characteristics of the commercial extrusion-cooked noodles. Ten kinds of noodles were selected and grouped according to the storage conditions; dry noodles (3), refrigerated noodles (2), freeze noodles (4), and dry noodle made from wheat flour as a control (not extrusion-cooked). The total starch of commercial noodles ranged from 62.50% to 84.13%, Refrigerated Naengmyeon and dry Dangmyun had high proportions of total starch (respectively 84.13% and 80.13%, respectively). The amounts of apparent amylose ranged from 25.01% to 42.93% and RS ranged from 0.61% to 5.99%. A high proportion of the total starch was rendered digestible by extrusion cooking, and a small amount of RS remained in the samples. Dry Dangmyun had the highest percentages of RS (5.99%), followed by refrigerated Naengmyeon C (2.41%) and dry Jjolmyeon (1.94%), and those of the other noodles were lower than that of the control (1.86%). Cooking properties and texture measurements were evaluated. Cooking loss and turbidity of cooking water were highest in dry Jjolmyeon and dry Naengmyeon. There was little cooking loss in dry Dangmyun and freeze rice noodles. In particular, dry Dangmyun and refrigerated Naengmyeon C containing high amounts of RS and amylose had relatively high measurements of hardness and tensile strength.

• 임상간호연구
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• 제14권1호
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• pp.99-111
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• 2008

Purpose: This study was done to provide basic data for developing an in-service education program to improve nurses' quality. First, frequency of nursing activities and competency levels of emergency nurses according to their career ladders were compared through job analysis and then practical education programs were presented on based of the results. Method: Data were collected from 335 nurses working in emergency rooms in 31 tertiary hospitals. Data collection was done from September to November 2005 using the job analysis questionnaire. Results: There were 41 nursing activities that showed differences in frequency and 78 activities that showed differences in perceived competency level. Irrespective of emergency nurses' careers, activities that show high frequency but low competency were sputum liquefying therapy, assessment of cranial nerve function, identification of diagnostic radiology, and communication with various departments. In-service education content according to nurse's career ladders was presented by adding high frequency nursing activities and activities with low competency level even though having high frequency. Conclusion: There is a need to develop and provide in-service education programs, which consider nurses' difference in frequency and competency level for their career ladders.

• 한국자기학회지
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• 제22권4호
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• pp.147-156
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• 2012

최근 들어 박막의 원자층 두께를 정밀하게 제어하는 여러 가지 박막 성장 방법에 관한 관심이 높다. 그 중에서 원자층 두께를 조절할 수 있는 PLD 방법은 매우 폭넓은 관심을 받고 있다. 우리는 기존의 PLD 방법과 Reflection high energy electron diffraction(RHEED)을 이용하여 원자층 제어 PLD 방법을 구현하였다. 이러한 방법을 이용하여 산화물에서의 원자층 두께를 정밀하게 제어하는 방법에 관한 실험을 수행하였다. 이와 같은 실험방법이 가지는 다양한 조건을 제어하여 최소한의 결함을 가지고 결정의 화학적 조성에 근접하는 고품질의 박막을 구축하여 이를 바탕으로 다양한 실험을 수행하였다. 본 논문에서는 최근 이러한 박막을 이용한 우리의 실험결과와 타 그룹의 실험 동향을 정리하여 보았다.

• 한국토양비료학회지
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• 제32권1호
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• pp.1-6
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• 1999

To find the latent effect of paper mill sludges (PMS) with and without alum, and alum paper mill sludge compost(PMSC) on aluminum toxicity of crops, the pH buffer capacity and the acidification resistance index (ARI) for PMSs and PMSC were investigated, comparing to upland soil. Buffer capacities of PMS with and without alum, and PMSC were significantly higher than $2.5cmol^+kg^{-1}$ of check soil as 137, 250, and $147cmol^+kg^{-1}$, respectively. Owing to such high buffer capacity of PMS and PMSC, they showed to be well-resisted to acidification.

• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.17-22
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• 2007

Vibration isolation equipments are mostly required in precise measurement and manufacturing system. Among all the vibration isolation equipments, air-spring is the most widely used equipment because of low resonant frequency and high damping ratio. In this study, we used Takagi-Sugeno fuzzy method to design an active vibration isolation system using air-spring, and compared the fuzzy method with passive control method and PID control method. Due to the non-linearity characteristics of air-spring, fuzzy controller was verified to be the most effective both in simulation and experiment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.951-955
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• 2004

Piezoelectric(PZT) actuator can substitute for solenoid which is used in fluid control field because it has faster response times and no possibility of explosion. Besides, it is available in a high temperature and it has low energy consumption. In this study, pneumatic micro valve, bimorph type PZT actuator using the softner type PZT, carbon plate as a shim and its controller circuit were suggested and investigated. Performance tests and characteristics analysis, such as displacement, force, hysteresis and frequency properties, were carried out. The displacement of the actuator measured at the end point was 63 ${\mu}m$., force of the actuator was 0.052 N and maximum operating frequency was 15Hz. Also, characteristics of the micro valve with PZT actuator were evaluated in a testing system. The results show that the suggested PZT actuator is suitable for micro valve.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.149-154
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• 2001

In case of high capacity load force as millions of tons, it is difficult to measure the force with load cell. But we can measure and calculate the force with applied pressure and ram area of hydraulic jack. The 5,200 ton compression load tester is composed of thirteen hydraulic jack with 400 ton capacity. This paper explains the method of measuring the vertical compression load and provides characteristics of unit jack, and displacement of upper structure under maximum load condition.