• Title/Summary/Keyword: Phases change

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Early Hydration Properties of BFS by a Change of pH (pH 변화에 따른 고로수쇄 BFS의 초기 수화 특성)

  • Kang, Hyun Ju;Lee, Woong Geol;Song, Myong Shin;Kang, Seung Min;Kim, Kyeng Nam
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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    • pp.442-447
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    • 2012
  • This study investigated on the early hydration and physical characteristics of BFS by pH variation. NaOH solution was used as a pH activator. In the range from pH 12 to pH 14, Experiment was compared the hydration propertied of OPC(Ordinary Portland Cement) and BFS(Blast Furnace BFS) and BFS containing 2 wt% of gypsum. It was found that CAH(Calcium Aluminate Hydrates) phases and CSH(Calcium Silicate Hydrates) phases were formed during the early hydration of BFS, and that CAH phases, CSH phases and ettringites were formed during the early hydration of BFS containing 2 wt% of gypsum. Furthermore, early hydration of BFS and BFS containing 2 wt% of gypsum were faster then OPC at pH 14, and the 1 day compressive strength of BFS increased by approximately 30% compared to OPC, and BFS containing 2 wt% of gypsum also increased by approximately 40% compared to OPC.

Health-Illness Transition of Patients with Young-Onset Parkinson's Disease (젊은 나이에 발병한 파킨슨병 환자의 건강-질병 전환 경험 과정)

  • Kim, Sung Reul;Lee, Sook Ja
    • Journal of Korean Academy of Nursing
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    • v.43 no.5
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    • pp.636-648
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    • 2013
  • Purpose: The purpose of this study was to explore the health-illness transition of patients with Young-Onset Parkinson's Disease (YOPD). Methods: From June to November 2011, 17 patients with YOPD who visited a neurologic clinic in a tertiary hospital participated in the study. Data were collected through in-depth interviews and analyzed using the grounded theory of Strauss and Corbin. Results: The core category of the participants' health-illness transition emerged as 'reshaping identity following uncontrollable changes'. The participants' health-illness transition process consisted of six phases in sequence: ego withdrawal, loss of role, frustration, change of thought, modification of life tract, and second life. Although most participants proceeded through the six phases chronologically, some returned to the frustration phase and then took up the remaining phases. Conclusion: The study results provide an in-depth understanding of health-illness transition experiences in the participants. These findings suggest a need to develop appropriate nursing intervention strategies according to the different phases in the health-illness transition of patients with YOPD.

Analysis of Thermodynamics for Formation of Single Phase in $Bi_2Sr_2Ca_nCu_{n+1}O_x$ Thin Films ($Bi_2Sr_2Ca_nCu_{n+1}O_x$ 박막의 단상 형성을 위한 열역학 해석)

  • Cheon, Min-Woo;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1208-1211
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    • 2003
  • High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

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Study on Guidelines for Using Therapeutic Modalities According to Injury Phases of Soft Tissue (치료적 방법을 연부조직 손상단계에 따라 사용하기 위한 지침에 관한 연구)

  • Kwon Won-An;Kim Sik_hyun;Jun Kyong-hee
    • The Journal of Korean Physical Therapy
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    • v.12 no.3
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    • pp.497-507
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    • 2000
  • This study was performed to understanding on guidelines for using therapeutic modalities according to injury phases of soft tissue. Clinical decisions on how and when therapeutic modalities may be used should be based on recognition of signs and symptoms. as well as some awareness of the time frames associated with the various phases of the Healing process. The physical therapist must have a sound understanding of that process in terms of the sequence of the various process of healing stage. The results of this study are as follows: 1. Once an acute injury has occured, the healing process consists of the imflammatory response phase, the fibroblastic-repair phase, and the maturation-remodeling phase and can impede by various pathologic factors. 2. Modality use in the initial acute injury phase and the inflammatory response phase should be directed toward limiting the amount of swelling and reducing pain. 3. Modality use in the Fibroblastic repair phase may be change from cold to heat. The purpose of heat is to increase circulation to the injured area to promote healing. 4. During the Maturation-Remodeling phase, some type of heating modalities, ultrasound, or short wave and microwave diathermy should be used to increase circulation to the deeper tissue. In this phases, physical therapists must control training and conditioning habits to allow the injury to heal sufficiently.

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Dependence of Ferroelectric Properties on the Crystalline Phases of HoMnO3 Thin Film (HoMnO3 박막의 강유전 특성의 결정상 의존성)

  • Kim, Eung-Soo;Kang, Dong-Ho
    • Korean Journal of Materials Research
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    • v.16 no.6
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    • pp.394-399
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    • 2006
  • Ferroelectric $HoMnO_3$ thin films were deposited on the Si(100) substrate at $700^{\circ}C$ for 2 hrs by metalorganic chemical vapor deposition (MOCVD) and post-annealed at 850oC by rapid thermal process (RTP). Electrical properties and crystalline phases of $HoMnO_3$ thin films were investigated as a function of postannealing time. Single phase of hexagonal symmetry with c-axis preferred orientation was obtained from $HoMnO_3$ thin films post-annealed at $850^{\circ}C$ for 5 min, while the c-axis preferred orientation was decreased with the increase of post-annealing time, and the thin films post-annealed at $850^{\circ}C$ for 15 min showed the mixture phases of hexagonal and orthorhombic symmetry. P-E (Polarization-Electric field) hysteresis loop of ferroelectric $HoMnO_3$ thin films was observed only for the single phase of hexagonal symmetry, but that was not observed for the mixture phases of the hexagonal and orthorhombic symmetry, which was discussed with the bond valence of Mn ion of crystalline phase. Leakage current density was dependent on the microstructure of thin films as well as the change of valence of Mn ion.

Analysis of Thermodynamics for Single Crystal Formation (단결정 형성을 위한 열역학 분석)

  • Cheon, Min-Woo;Yang, Sung-Ho;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.70-73
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    • 2006
  • High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 arid 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

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Neural Network Forecasting Using Data Mining Classifiers Based on Structural Change: Application to Stock Price Index

  • Oh, Kyong-Joo;Han, Ingoo
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.543-556
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    • 2001
  • This study suggests integrated neural network modes for he stock price index forecasting using change-point detection. The basic concept of this proposed model is to obtain significant intervals occurred by change points, identify them as change-point groups, and reflect them in stock price index forecasting. The model is composed of three phases. The first phase is to detect successive structural changes in stock price index dataset. The second phase is to forecast change-point group with various data mining classifiers. The final phase is to forecast the stock price index with backpropagation neural networks. The proposed model is applied to the stock price index forecasting. This study then examines the predictability of integrated neural network models and compares the performance of data mining classifiers.

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Artificial Neural Networks for Interest Rate Forecasting based on Structural Change : A Comparative Analysis of Data Mining Classifiers

  • Oh, Kyong-Joo
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.3
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    • pp.641-651
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    • 2003
  • This study suggests the hybrid models for interest rate forecasting using structural changes (or change points). The basic concept of this proposed model is to obtain significant intervals caused by change points, to identify them as the change-point groups, and to reflect them in interest rate forecasting. The model is composed of three phases. The first phase is to detect successive structural changes in the U. S. Treasury bill rate dataset. The second phase is to forecast the change-point groups with data mining classifiers. The final phase is to forecast interest rates with backpropagation neural networks (BPN). Based on this structure, we propose three hybrid models in terms of data mining classifier: (1) multivariate discriminant analysis (MDA)-supported model, (2) case-based reasoning (CBR)-supported model, and (3) BPN-supported model. Subsequently, we compare these models with a neural network model alone and, in addition, determine which of three classifiers (MDA, CBR and BPN) can perform better. For interest rate forecasting, this study then examines the prediction ability of hybrid models to reflect the structural change.

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A Study on Thermo-Physical Properties of Microencapsulated Phase Change Material Slurry (마이크로캡슐 잠열 축열재 혼합수의 열물성에 관한 연구)

  • 임재근;최순열;김명준
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.962-971
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    • 2004
  • This paper has dealt with thermo-physical properties of microencapsulated phase change material slurry as a latent heat storage material having a low melting point. The measured results of the thermo-physical properties of the test microencapsulated phase change material slurry, those are, density, specific heat, thermal conductivity and viscosity, were discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). The measurements of these properties of microencapsulated phase change material slurry have been carried out by using a specific-gravity meter, a water calorimeter, a differential scanning calorimeter(DSC), a transient hot wire method and rotating type viscometer, respectively. It was clarified that the additional properties law could be applied to the estimation of the density and specific heat of microencapsulated phase change material slurry and also the Euckens equation could be applied to the estimation of the thermal conductivity of this slurry.

Using Evolutionary Optimization to Support Artificial Neural Networks for Time-Divided Forecasting: Application to Korea Stock Price Index

  • Oh, Kyong Joo
    • Communications for Statistical Applications and Methods
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    • v.10 no.1
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    • pp.153-166
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    • 2003
  • This study presents the time-divided forecasting model to integrate evolutionary optimization algorithm and change point detection based on artificial neural networks (ANN) for the prediction of (Korea) stock price index. The genetic algorithm(GA) is introduced as an evolutionary optimization method in this study. The basic concept of the proposed model is to obtain intervals divided by change points, to identify them as optimal or near-optimal change point groups, and to use them in the forecasting of the stock price index. The proposed model consists of three phases. The first phase detects successive change points. The second phase detects the change-point groups with the GA. Finally, the third phase forecasts the output with ANN using the GA. This study examines the predictability of the proposed model for the prediction of stock price index.