• 한국세라믹학회지
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• 제14권1호
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• pp.12-18
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• 1977

In our former paper, tremolitic talc, -wollastonite-clay system was studied. In this study blast furnace slag was used(B.F.S.) instead of wollastonite for developing a fast-firing wall tile body. The wall tile bodies consisting of tremolitic talc and B.F.S. asmajor constituents have been fired in the temperature range 1000-120$0^{\circ}C$. Some of these bodies have showed good properties for wall tile manufacture. According to the increased content of B.F.S the fired bodies have showed the decreased thermal expansion which was resulted from the fact that the amounts of diopside and anorthite were gradually increased and those of quartz relatively decreased. Being reasonable in low price and thermo-stable properties tremolitic talc and B.F.S. will be good materials for the fast-firing tile body.

• 음성과학
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• 제8권3호
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• pp.93-104
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• 2001

The author analyzed acoustic parameters of ten Korean numbers produced by ten male students using Praat. Variations of f0, F1, F2 and F3 within and between speakers were examined by determining an average and standard deviation of the parameters of each number and by comparing the acoustic values with one another. Results showed that each subject produced the numbers within a certain range of variation across time. Thus, speaker identification can be more certain using dynamic information of the acoustic parameters within each vocalic segment. Also, percent difference of within-subjects' variation to that of between-subjects can be utilized to determine which sounds would be better stimuli for speaker identification. According to the criteria, the number '2' proved the best stimulus while the number '7' was the worst. Future studies will be necessary to explore robust methods of speaker identification under noisy conditions.

• 근관절건강학회지
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• 제23권2호
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• pp.95-104
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• 2016

Purpose: The purpose of this study was to examine body composition and dietary self-efficacy in nursing students. Methods: The study was a descriptive, correlational study with a convenience sample of 197 female nursing students. This study was conducted from April 1st to May 31th in 2015. SPSS 21.0 program was used for data analysis. Results: The average of body protein was $7.90{\pm}1.17kg$ and normal range was 33%. A BMI's average was $21.02{\pm}2.94kg/m^2$ and 62.9 fell into standard range. The average of dietary self-efficacy of subjects was $3.42{\pm}0.53$. The subjects performed intense physical activities during three or more days had higher body protein (F=5.89, p=.003), body minerals (F=6.15, p=.003) and body-efficacy (F=4.13, p=.017) but remarkably lower body fat (F=4.04, p=.019). There is no noticeable correlation of body composition with dietary self-efficacy. However, it is obvious that each category of body composition had a significant positive correlation. Conclusion: This study demonstrated that students who were inclined to overeat had higher body protein, body minerals, body fat, and BMI. Students performed intense physical activities had high body protein, body minerals, and dietary self-efficacy, whereas they had low body fat. Each entry between the body composition had a significant positive correlation.

• 한국식품과학회지
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• 제23권6호
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• pp.723-731
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• 1991

레토르트 카레 소스를 생산하기 위한 최적 살균 조건을 산출하기 위하여, $3^{2}{\times}2^{1}$ 요인 실험을 통하여 살균 온도, 시간 및 방법을 변화시켜 18개 조건에 대한 살균 공정이 행하여졌다. 살균 전후의 제품에 대한 품질평가 항목은 비타민(niacin) retention, pH, 색차 및 관능 검사(맛, 색상, 점도)등 이었다. 각 살균 조건에 대한 $F_{o}$ 값도 측정되었다. 살균 후 제품의 품질은 주로 살균 온도 및 시간에 의해 영향을 받았으며, 살균 방법에 의해서는 거의 영향을 받지 않았다. 품질을 저하시키는 영향에 있어 살균 시간의 연장이 살균 온도의 상승보다 큰 영향을 나타내었는데, 이는 고온 단시간 살균의 장점을 제시해준 결과라 하겠다. 반응 표면 분석에 의해 추정된 최적 살균 범위는 $123.5^{\circ}C$, 21.5분-$127.5^{\circ}C$, 17분 부근이었다. 이 범위에서 측정된 냉점에서의 $F_{o}$ 값은 15분 정도였다.

• 한국지진공학회논문집
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• 제8권3호
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• pp.23-32
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• 2004

본 논문에서는 국내 148개 지반에 대한 전단파속도 주상도, 기반암 깊이 및 지반의 동적변형특성을 획득하여 미국 서부해안지역의 지반특성과 비교하였고, 등가선형해석을 수행하였다. 해석은 1등급 붕괴방지수준인 0.154g를 암반노두에 적용하여 수행하였다. 해석결과 국내 지반특성에 적합한 증폭계수 $F_a$와 $F_v$는 UBC 기준의 증폭계수와 매우 다른 경향을 보였다. 단주기 증폭계수 $F_a$의 경우 UBC 기준보다는 큰 값이 얻어졌고, 장주기 증폭계수 $F_v$는 UBC 기준보다 작은 값으로 나타났다. 따라서, 국내 지반특성을 적절히 반영할 수 있는 설계지반운동 결정방법을 개선해야할 필요를 확인하였다.

• 대한치과교정학회지
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• 제40권1호
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• pp.40-49
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• 2010

본 연구의 목적은 martensitic (M-NiTi), austenitic (A-NiTi) 및 thermodynamic nickel-titanium wire (T-NiTi)의 물리적 특징과 상전이 정도를 평가하는 것이다. 재료는 $0.016\;{\times}\;0.022$ inch의 M-NiTi (Nitinol Classic, NC), A-NiTi (Optimalloy, OPTI)와 T-NiTi (Neo-Sentalloy, NEO)이었으며, differential scanning calorimetry (DSC), 3점굽힘실험, X-ray diffraction (XRD), 미세구조 분석을 시행하였으며, ANOVA test로 통계처리하였다. DSC분석 결과 OPTI와 NEO는 heating curve에서 2개의 peak, cooling curve에서 1개의 peak를 보였고, NC는 heating과 cooling curve에서 1개의 넓고 약한 peak를 보였다. Austenite finishing ($A_f$) 온도는 OPTI $19.7^{\circ}C$, NEO $24.6^{\circ}C$, NC $52.4^{\circ}C$였다. 3점굽힘실험 결과 NC, OPTI, NEO 모두 residual deflection을 보였으며, NC와 OPTI의 load range가 NEO보다 컸다. XRD와 미세구조 분석결과 OPTI와 NEO는 Martensite finishing ($M_f$)에서 martensite와 austenite가 섞여 있음이 관찰되었다. NEO와 OPTI는 NC보다 개선된 물리적 특징과 상전이 행태를 보였다. NiTi 호선의 물리적, 온도에 따른 행태는 예상되었던 상전이 정도에 의해 완벽하게 설명되지 않았으며, 그 이유는 복잡한 martensite variants의 존재와 열과 stress에 의해 유도된 독립적인 상전이에 기인한다고 생각된다.

• 한국응용과학기술학회지
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• 제38권2호
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• pp.378-388
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• 2021

본 연구는 중년여성의 자아탄력성, 부부의사소통, 정신건강이 행복감에 미치는 영향을 확인하기 위하여 수행되었다. 본 연구에 참여한 연구대상자는 239명으로, 평균연령은 54.15±6.38세 이었다. 연구분석 방법은 SPSS 21.0을 사용하여 일반적 특성에 따른 제 변수간의 차이, 자아탄력성, 부부의사소통, 정신건강, 행복감의 상관관계를 확인하였고, 중년여성의 행복감에 영향을 미치는 요인을 확인하기 위해 다중회귀분석을 실시하였다. 연구결과 자아탄력성 평균 3.46점((1-5점), 부부의사소통 평균 2.44점(1-5점), 정신건강 평균 1.82점(0-4점), 행복감 3,21점(1-5점)으로 나타났다. 일반적 특성에서 행복감의 차이는 교육수준(F=3.406, p=.035), 주관적 건강상태(F=7.385, p=.001)에서 통계적으로 유의한 차이를 보였다. 제 변수들간 상관관계를 확인한 결과 행복감은 자아탄력성(r=.393, p=<.001)은 정적상관관계를 보였고 신체화(r=-.134, p=.039), 우울(r=-.356, p<.001), 불안(r=-.269, p<.001)과는 부적상관 관계를 보였다. 중년여성의 행복감에 영향을 미치는 예측요인은 우울(β=-.437, p<.001)자아탄력성(β=.350, p<.001), 신체화(β=.239 p=.009), 건강상태: 보통(β=-.150, p=.009), 나쁨(β=-.147, p=.015)로 30.4%의 설명력을 보였고, 회귀모형은 통계적으로 유의하게 나타났다(F=14.02, p<.001). 본 연구 결과를 바탕으로 중년여성의 행복감을 증진시키기 위해 자아탄력성을 증진시키고 정신건강을 강화하는 교육 프로그램이 개발되어야 할 것이다.

• 한국재료학회지
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• 제22권5호
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• pp.215-219
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• 2012

Red phosphors $Ca_{1-1.5x}WO_4:{Eu_x}^{3+}$ were synthesized with different concentrations of $Eu^{3+}$ ions by using a solid-state reaction method. The crystal structure of the red phosphors was found to be a tetragonal system. X-ray diffraction (XRD) results showed the (112) main diffraction peak centered at $2{\theta}=28.71^{\circ}$, and the size of crystalline particles exhibited an overall decreasing tendency according to the concentration of $Eu^{3+}$ ions. The excitation spectra of all the phosphors were composed of a broad band centered at 275 nm in the range of 230-310 nm due to $O^{2-}{\rightarrow}W^{6+}$ and a narrow band having a peak at 307 nm caused by $O^{2-}{\rightarrow}Eu^{3+}$. Also, the excitation spectrum presents several strong lines in the range of 305-420 nm, which are assigned to the 4f-4f transitions of the $Eu^{3+}$ ion. In the case of the emission spectrum, all the phosphor powders, irrespective of $Eu^{3+}$ ion concentration, indicated an orange emission peak at 594 nm and a strong red emission spectrum centered at 615 nm, with two weak lines at 648 and 700 nm. The highest red emission intensity occurred at x = 0.10 mol of Eu3+ ion concentration with an asymmetry ratio of 12.5. Especially, the presence of $Eu^{3+}$ in the $Ca_{1-1.5x}WO_4:{Eu_x}^{3+}$ shows very effective use of excitation energy in the range of 305-420 nm, and finally yields a strong emission of red light.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.179-188
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• 2006

In this study, R/S analysis which was proposed by Mandelbrot & Wallis(1969) was applied to evaluate the presence of the fractal property in the cone tip resistance of in-situ CPT data. Hurst exponents(H) were evaluated in the range of $0.660\sim0.990$ and the average was 0.875. It was confirmed that a cone tip resistance data had the characteristic of fractals and it was expected that cone tip resistance data sets are well approximated by a fBm process with an Hurst exponent near 0.875. It was also observed that the boundary between layers were obviously identified as a result of R/S analysis and it will be usage in practices.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.398-404
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• 2008

A new solvent polymeric membrane electrode, based on N,N'-bis(salicylidene)-2,2-dimethylpropane-1,3-diamine Ni(II) as the ionophore, was designed. The oxalate-selective electrode has the dynamic range between 1.0 10-6 M and 1.0 10-1 M with a Nernstian slope of -28.7 1.0 mV per decade. The detection limit was 6.3 10-7 M. The proposed electrode revealed good selectivities for oxalate over a variety of other anions and could be used in a pH range of 2.0-7.8. The electrode can be used for at least two months without any considerable divergence in potential. The designed electrode was applied as an indicator electrode in the potentiometric determination of oxalate in real samples.