• Journal of Korea Foundry Society
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• v.32 no.2
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• pp.81-85
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• 2012

The effects of section size and melt holding time on the mechanical properties and microstructure of high silicon ductile cast iron were investigated. The strength, elongation and hardness of the test specimen with smaller cross-section were higher than those with larger one. The nodule count and volume fraction of pearlite of the former were higher than those of the latter. The mechanical properties decreased with increased melt holding time before pouring. Nodularity and nodule count decreased and the volume fraction of pearlite rather slightly increased with it.

• Journal of the Korean Ceramic Society
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• v.30 no.7
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• pp.549-556
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• 1993

Interfacial shear strength plays an important role in determining the mechanical properties of a fiber-reinforced ceramic composites. In this study, the effect ofinterlayer thickness on mechanical properties of Nicalon-fiber-reinforced SiC composites fabricated via polymer solution infiltration/chemical vapor infiltration (PSI/CVI) was studied. It was found that the flexural strength and fracture toughness of the composites were increased with the interlayer thickness and showed maximum value at the interlayer thickness of 0.66${\mu}{\textrm}{m}$. Typical flexural strength and fracture toughness of Nicalon-fiber-reinforced SiC composites with interlayer thickness of 0.66${\mu}{\textrm}{m}$ were 391.7$\pm$34.6MPa and 15.1$\pm$1.8MPa.m1/2, respectively.

• Korean Journal of Adult Nursing
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• v.24 no.3
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• pp.244-252
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• 2012

Purpose: The purpose of the study was to develop a knowledge scale of risk factors for fall among community-dwelling older adults. Further, the validity and reliability of the scale was developed. Methods: A preliminary scale was developed through content validity by five experts and targeted subjects using the CVI (Content Validity Index). Following the establishment of content validity, the scale was used with 359 community-dwelling older adults to further establish both validity and reliability of the scale. Specifically, construct validity using known-group comparison technique, and reliability using Cronbach's ${\alpha}$ were established. Results: After content validity testing, 44 preliminary items were selected. Construct validity was established by known group-comparison, in which scores between the fall and no fall groups were compared. The Cronbach's ${\alpha}$ of the final scale was .83. Conclusion: Reliability and validity of the scale were confirmed. This tool may be used for measuring knowledge of fall risk factor for the community-dwelling older adults.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.87-93
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• 2017

The purpose of this study is to design and develop of digital contents to improve computational thinking in the online education environment. First, we planned the design and development of contents with 19 experts of Software education. Digital content was designed from the point of view of improving the educational quality and the quality of contents for the improve of computing thinking. The content type is classified into the SW education area; computer science, programming, physical computing, convergent computing, computing thinking, and software education that improves the computing thinking. And we designed 45 learning programs for each SW education area. Designed learning contents were developed in 464 lessons to suit the online education environment. The content validity of the proposed content was verified by the expert group and the average CVI value was over .83. Through this, we could analyze that the developed contents will help learners to expand their computing thinking.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.29-34
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• 2014

A dosimeter using tissue-equivalent scintillator by photon-counting method was developed and evaluated in its performance. The dosimeter is portable and can be operated by low power from lap-top computer. A data-acquisition software of the dosimeter system was developed by Labwindows/CVI based on Windows. The energy to channel ratio for energy calibration was 0.839 keV/ch. obtained from pulse height spectrum of $^{137}Cs$ and $^{60}Co$ gamma-ray. Using the dosimeter system, the absorbed dose of environmental radiation in Gyungju was 0.18 ${\mu}Sv/h$.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.521-523
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• 1997

In this paper, We carried out investigation of monitoring algorithm development for electric car inspection and repair. For transmitting a data, reliable RS-422 is adopted. The LabWindows/CVI development tool of National Instruments Co. is used for the formation of monitoring screen. The experimental set-up is composed of a PC to PC system. It is applicable to electric car imspection and repair.

• Korean Journal of Adult Nursing
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• v.15 no.1
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• pp.88-93
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• 2003

Purpose: This study was conducted to develop nursing outcome indicators based on nursing activities done for stroke patients. Method: focus group meeting and delphi technique, which consisted of clinical nurse experts, neurologist, and nursing professors. CVI(Index of Content Validity) and user validity test was performed. Result: 12 nursing diagnoses, 29 nursing interventions and nursing outcomes were identified. The former were from NIC and the latter were developed according to nursing interventions. They were verified by experts in focus group. 199 nursing activities were identified, 133 nursing outcome indicators were developed. In user validity, usefulness and usability were tested. Conclusion: This systemic approach of measuring nursing outcomes verified nurses' positive effects in changing patients health status and nursing contributions in the health care system as a profession.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2124-2126
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• 1998

In this paper, we carried out investigation of monitoring algorithm development for examination of inverter system. For transmiting data, RS-422C is adopted. The LabWindows/CVI development tool of National Instruments Co. is used for the formation of monitoring screen. The experimental set-up is composed of a PC to PC system. It is applicable to electric car inspection and repair.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1921-1924
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• 2007

In order to measure the superconducting transition temperature, the critical current and the alternating current(AC) loss on short samples of high temperature superconductor, a cryocooler cooled cryostat has been designed and built. Two closed-cycle coolers provide cooling with an ultimate sample temperature below 16K. Temperature regulation is provided by 50W of electrical heater that opposes the cooling power from the cold heads. Temperature control feedback is by means of a cernox temperature sensor co-located with the heaters on the second stage of the cold head. Additional temperature sensors are located on the sample mount(B1), on the CVI cold head(B2) and on the Dakin cold head(B3). AC losses on the sample high temperature superconductor were measured at 30K so that the developed device performance was evaluated. In this paper, the design, fabrication and test results on the cryocooler cooled cryostat are presented.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.601-603
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• 2005

군집 유효화 평가는 군집화 알고리즘을 진정한 의미의 비감독 학습이 가능하도록 만든다는 의미에서 그 중요성이 더해지고 있다. 본 논문에서는 이 군집 유효화 평가에 일반적으로 이용되는 군집 유효화 지수들의 설계원리를 분석하고 기존 지수들의 부합성을 분석한다. 우리는 제 (I) 부에서 합 형식의 지수들을 다루었으며, 본 논문에서는 비 형식의 지수들을 다룬다. 합형식의 CVI에서처럼 저역 필터링의 문제점을 해결하였으며, 또한, 부작용 없이 비형식의 지수들의 성능을 향상시킬 수 있는 새로운 기법을 제시한다. 새로운 지수들의 성능은 실험 학습을 통해 제시된다.