• 한국세라믹학회지
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• 제31권10호
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• pp.1231-1239
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• 1994

In this study, gel powder which had relatively high hydration reactivity in CaO and P2O5 rich composition of CaO-P2O5-SiO2-H2O system was prepared by sol-gel process and its hydrated specimen was manufactured. The it was investigated to appropriate calcination temperature in sol-gel process which hydrated specimen of gel powder have proven to strength and the effect of factors influenced strength in hydration process. The major product of before and after hydration reaction was hydroxyapatite, and crystalline phase of C-S-H was already formed during gelation process. After hydration reaction of pressed specimen, crystalline phase of C-S-P-H was formed. It was hydrated product of silicocarnotite (5CaO.P2O5.SiO2). Gel phases of C-S-H and C-S-P-H occured as a result of partial substitution of amorphous silica by P2O5 was formed. The strength of hydrated hardened body is developed by strong bonding and bridging between the gel phases of C-S-H or C-S-P-H and the crystalline products such as hydroxyapatite, Ca(OH)2 C-S-H and C-S-P-H. In addition, the ultrafine gel powder have an great effect on increase of hydration reaction.

• 성인간호학회지
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• 제18권3호
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• pp.345-356
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• 2006

Purpose: This study was conducted to compare the process of change, decisional balance, and self-efficacy according to the stages of change of exercise on the basis of the Transtheoretical Model in order to investigate factors associated with the change of exercise in adult diabetic patients. Method: Data were collected from January to April 2005. The subjects were 160 patients in the G university hospital and public health center in J city. Results: The entire process of change showed the significant difference depending on the stage of change(F=20.007, p=.000). For each process of change, the Consciousness Raising(F=14.602, p=.000), Dramatic Relief(F=7.751, p=.000), Environmental Re-evaluation(F=11.843, p=.000), Self Re-evaluation(F=16.035, p=.000), Social Liberation(F=10.968, p=.000), Counter-conditioning (F=24.090, p=.000), Helping Relationships(F= 7.625, p=.000), Reinforcement Management(F= 16.693, p=.000), Self Liberation(F=11.990, p= .000) and Stimulus Control(F=4.020, p=.002) demonstrated significant differences depending on the stages of change of exercise. For the decisional balance, the Pros showed the significant difference depending on the stage of change(F=14.121, p=.000). For the self efficacy showed significant difference depending on the stage of change(F=17.137, p=.000). Conclusion: In order to proceed the stage of change of exercise in patients with Diabetes Mellitus, intensive use of a specific process of change, a stage of change matching is needed.

• 응용통계연구
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• 제29권2호
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• pp.301-308
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• 2016

공정이 특정 허용범위 내에서 생산을 할 수 있는 지 여부를 결정하는 데 공정능력지수가 사용된다. 공정능력지수 $C_p$, $C_{pk}$ 그리고 $C_{pm}$ 등은 공정의 현황을 추적할 수 있는 활용성이 높은 관리도구로서 특별한 관심을 가진다. 대부분 공정능력지수에 대한 계산결과는 통계적 추정과 가설검정에 초점을 맞춘다. 따라서 $C_p$, $C_{pk}$ 그리고 $C_{pm}$의 추정치 ${\hat{C}}_p$, ${\hat{C}}_{pk}$ 그리고 ${\hat{C}}_{pm}$ 사이의 점근적 성질을 조사하는 것이 의미가 있을 것이다. 이 논문에서는 BN(${\mu}_x,{\mu}_y,{\sigma}^2_x,{\sigma}^2_y,{\rho}$) 하에서 세 가지 추정치 ${\hat{C}}_p$, ${\hat{C}}_{pk}$ 그리고 ${\hat{C}}_{pm}$ 간의 점근적 상관관계를 연구한다. 비정규성을 가진 공정에서는 두 종류의 공정능력지수 간에 상관관계를 정립할 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.337-342
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• 1989

The control of a pH value in radwaste treatment process is difficult due to the nonlinearity of the titration curve and its strong sensivity to disturbances. This paper describes an adaptive control strategy which is model-based and allows for direct use of available measurements. This algorithm forces the nonlinear process to follow a desired linear system trajectory, and were applied to the control of a simulated pilot-scale pH process. The simulation study showed that it has the potential advantage over the transformation methods that control effort saturation can be accomodated readily.

• 분석과학
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• 제18권6호
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• pp.535-541
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• 2005

본 연구에서는 오존/활성탄 혼합공정에서 부식산의 초기 pH(pH 3~pH 11)와 반응온도 ($0^{\circ}C$, $20^{\circ}C$, $40^{\circ}C$)를 변화시켰을 때 생성되는 알데히드류의 생성을 조사하였으며, 오존/활성탄 혼합공정 외에 활성탄 흡착과 오존 단독공정을 실험하여 공정에 따른 차이를 비교하였다. 오존 주입농도는 0.08g $O_3/g$ DOC, 활성탄 충진율은 16.5 v/v%였으며, 생성되는 알데히드류는 PFBOA법으로 전처리하여 GC/PDECD로 분석하였다. 오존/활성탄 혼합공정에서 생성되는 알데히드류를 분석한 결과, 포름알데히드와 글리옥살만이 검출되었으며, 그 생성량은 오존단독 공정에 비하여 오존/활성탄 혼합공정에서 더 적게 생성되었다. 오존/활성탄 혼합공정에서 부식산의 초기 pH를 변화시켰을 때, pH 11과 pH 7 에서 반응초기에 포름알데히드가 높은 농도(약 400 ppb)로 생성되었으며, 반응이 진행됨에 따라 포름알데히드와 글리옥살 농도는 모두 감소하는 경향을 나타냈다. 반응온도에 따른 실험에서는 온도가 가장 높은 $40^{\circ}C$에서 포름알데히드와 글리옥살이 가장 많이 생성되었으며, 이때 반응초기의 최고 농도는 각각 약 520 ppb, 120 ppb이었다.

• Environmental Engineering Research
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• 제20권3호
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• pp.285-289
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• 2015

Complicated and expensive seawater desalination technology is a big challenge in boron removal process. Conventional seawater desalination process of coagulation utilized for pre-treatment is difficult to remove boron. Boron can be removed more effectively in Reverse Osmosis (RO) process than any other processes. In this study, a coagulant with the name Mineral Cluster was examined its boron removal ability. Boron removal efficiency of Mineral Cluster depended on pH value and Mineral Cluster dosage. Desalination process combines the pre-treatment process with Mineral cluster diluted at the ratio of 1:2500 and the RO membrane process. The original sea water could be desalinated to drinking water quality, 1 mg/L, without any pH adjustments. Therefore, if the Mineral cluster is added without any other chemicals for adjusting pH, the desalination process would be much safer, efficient and economical.

• 한국환경보건학회지
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• 제31권5호
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• pp.404-410
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• 2005

The pH efforts on the removal of 1,4-dioxane and the biodegradobility enhancement of dioxane contaminated water were investigated using $O_3/H_2O_2$ baled advanced oxidation process. Experiments were conducted using a bubble column reactor under different initial pH. The $O_3/H_2O_2$ process effectively converted 1,4-dioxane to more biodegradable intermediates which had a maximum $BOD_5$ enhancement at pH 11 within the experimental range, precisely, when the initial pH increased, $BOD_5$ enhanced. However, in case of removal efficiencies of 1,4-dioxane during $O_3/H_2O_2$ oxidation the optimum condition was shown at pH 9 compared with pH 6 and 11. TOC and COD values were not largely changed for all reaction time. From the results of 1,4-dioxane removal efficiency, TOC, COD, and $BOD_5$ enhancement with reaction time, it was surely observed that 1,4-dioxane was just converted to biodegradable materials, not completely oxidized to carbon dioxide.

• 한국콘텐츠학회논문지
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• 제10권6호
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• pp.312-322
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• 2010

본 연구는 간호관리학 임상실습에 액션러닝 프로그램을 개발하고 적용한 후 간호대학생의 문제해결과정에 미치는 영향을 알아보고자 시도되었다. 2006년 5월부터 2007년 10월 까지 G광역시의 일 간호대학생 99명을 대상으로 6단계로 구성된 액션러닝프로그램을 2주간 적용하였다. 연구결과는 다음과 같다. 액션러닝을 적용하기 전 보다 적용한 후 간호대학생의 문제해결과정은 유의한 향상을 보였다(t=-4.718, p=.000). 하위영역에서는 문제발견 영역(t=-1.858, p=.066)을 제외한 문제 정의(t=-4.123, p=.004), 문제해결책 고안(t=-2.973, p=.002), 문제해결책 실행(t=-3.264, p=.000)과 문제 해결검토(t=-3.677, p=.000)영역에서 유의한 향상을 보였다. 결론적으로 액션러닝은 간호학생들의 문제해결과정의 향상을 가져올 수 있고 졸업 후 임상적응력을 높일 수 있는 간호임상실습의 새로운 대안이 될 수 있다고 본다.

• 환경위생공학
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• 제19권1호
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• pp.1-7
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• 2004

This study was conducted to supply basic informations on development of water treatment process for the ozonation of ammonia depend on pH variation with or without bromide catalysis. The results were as follows: The oxidation rate of ammonia increased depend on pH increase at ozone/bromide process. It was found that overall kinetics was zero order with respect to reaction time and reaction velocity constant of zero order increased depend on pH increase from 4.9 to 9.5 and the equation of linearization was $k_{o}$ = 0.00565 ${\times}$ [pH] + 0.0069 at ozone/bromide process. The denitrification reaction of ammonia was superior as the pH increase in the presence of bromide.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.129-135
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• 1997

Previous studies has shown that the curve of low-cycle fatigue life was not expressed with the single line subjected to Manson-Coffin's law type and bent to short life in low ${\Delta}{\varepsilon}_p$ region. The main cause of this phenomenon has been considered that the localization of plastic strain in the crack initiation process fosters the crack initiation. In this study, the low-cycle fatigue life was investigated for each specimens omitted crack initiation process and it was found that fatigue life curve in log(${\Delta}{\varepsilon}_p$)-log($N_f$)was bent in low ${\Delta}{\varepsilon}_p$ region as ever. Therefore, the main cause of appearance of knee point in fatigue life curve is not found in the crack initiation process but in the crack propagation process. In the crack propagation process, the localization of the plastic strain in the vicinity of crack tip and the influence of test environment on the crack propagation rate were observed and these inclinations were more remarkable in low ${\Delta}{\varepsilon}_p$ region. Hence, it was concluded that these two phenomena in the crack propagation process were proved to the main cause which accelerates the crack propagation in low ${\Delta}{\varepsilon}_p$ region and bent the fatigue life curve in result.