• Macromolecular Research
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• v.15 no.7
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• pp.656-661
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• 2007

The effects of a neutral solvent of dioctyl phthalate (DOP) on the phase behavior of symmetric polystyrene-block-poly(n-butyl methacrylate) copolymers (PS-b-PnBMA) were assessed herein. Closed-loop phase behavior with a lower disorder-to-order transition (LDOT) and an upper order-to-disorder transition (UODT) was observed for PS-b-PnBMA/DOP solution when the quantity of DOP was carefully controlled. When the molecular weight of PS-b-PnBMA became larger, the LDOT did not appreciably change at smaller quantities of DOP. With larger quantities of DOP, the reduction in the UODT is greater than the increase in the LDOT. This behavior is discussed in accordance with a molecular theory predicated on a compressible random-phase approximation.

• Proceedings of the Korean Society of Rheology Conference
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• 2002.11a
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• pp.151-154
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• 2002

No Abstract, See Full Text

• The Korean Journal of Applied Statistics
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• v.20 no.3
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• pp.449-458
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• 2007

Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in person's mood, energy, and ability to function. Compared with manic episode, the depression episode causes more serious results such as restless, loss of interest or pleasure, or thoughts of death or suicide and the cure rate of depression episode is lower than that of manic episode. Furthermore, a long term use of antidepressants in bipolar patients may result in manic episode. Our interest is to investigate the effect of antidepressant on switch of moods of bipolar patients and to estimate the transition probabilities of switch between moods, depression and (hypo) manic. In this study, three approaches are applied in terms of multi state model. Parametric model is applied using left censoring data and nonparametric model is implemented under illness-death model with counting process. In order to estimate the effect of covariates, a multiplicative model is used. These all methods have similar results.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.71-72
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• 2006

We investigated a simultaneous living anionic polymerization process of isoprene (I) and 4styrene-d_8$ (S) in $benzene-d_6$ as a solvent with sec-buthyllithium as an initiator into polyisoprene(PI)-block-poly($styrene-d_8$)(PS) and the polymerization-induced molecular self-assembling process. This process was observed in-situ by time-resolved small-angle neutron scattering (SANS) experiment. The SANS profiles measured exhibited three time regions, where (i) the selective growth of PI chains occurs; (ii) the living chain ends switch from isoprenyllithium to styryllithium, and (iii) the SANS exhibited the polymerization induced disorder-to-order transition and order-to-order transition.

• Journal of Oral Medicine and Pain
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• v.37 no.1
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• pp.33-45
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• 2012

This study was designed to assess follow-up study of condylar bone changes using cone beam computed tomography in patients with osteoarthritis. The author performed clinical examination for osteoarthritis patients who visited Orofacial Pain Clinic, Department of Oral Medicine, Pusan National University Hospital. CBCT(Cone beam computed tomography) was taken for 228 joints in 114 subjects. After average 10 months, CBCT was retaken. A Oral medicine and Oral radiologist evaluated CBCT each other. Condyle bone changes were classified by no bone change, flattening, erosion, osteophyte and sclerosis. The obtained results were as follow. 1. The condylar bone changes of osteoarthritis in temporomandibular disorder were as follow: 1) The transitions of each types of condylar bone changes was maintained at the initial state of the majority. 2) The transition of erosion was distributed erosion, flattening, sclreosis, osteohyte in order. 3) The transition of flattening was distributed flattening, osteohyte, normal, sclreosis in order. 4) The transition of osteohyte was distributed osteohyte, erosion, sclreosis, flattening in order. 5) The transition of sclreosis was distributed sclreosis, osteohyte, erosion, normal in order. 2. The signs and symptoms according to transition of each types of condylar bone changes were as follow 1) In the transition of condylar bone changes from erosin to erosion, pain, noise, LOM and MCO had symptomatic improvement. In the transition of condylar bone changes from erosin to flattening, pain, LOM, MCO had symptomatic improvement. In the transition of condylar bone changes from erosin to no bony change, pain, noise, LOM had symptomatic improvement. In the transition of condylar bone changes from erosion to flattening than the maintenance of eosion, MCO had symptomatic improvement. 2) In the transition of condylar bone changes from flattening to flattening, pain, noise and MCO had symptomatic improvement. In the transition of condylar bone changes from flattening to sclerosis, LOM had symptomatic improvement. 3) In the transition of condylar bone changes from osteophyte to osteophyte, pain, LOM and MCO had symptomatic improvement.

• Journal of Korean Academy of Nursing
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• v.44 no.5
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• pp.563-572
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• 2014

Purpose: The study was done to identify the construct validity and reliability of the life transition scale (LTS) for parents who have children with autism. Methods: Exploratory factor analysis (EFA) and confirmative factor analysis (CFA) were conducted to identify the most adequate measurement model for structural validity. Convergent validity and discriminant validity were also conducted for structural validity. Data were collected from 208 parents through self-reported questionnaires and analyzed with SPSS/WIN 15.0 and AMOS 20.0 version. Results: A four factor-structure was validated (${\chi}^2$=541.23, p<.001, GFI=.82, RMSEA=.07, IFI=.89, CFI=.89, PNFI=.73, Q (${\chi}^2/df$)=2.20) at the 3rd order of EFA and CFA, and factors were named as denying, wandering, despairing, and accepting. Both convergent and determinant validity for LTS were 100%. Cronbach's alphas for the reliability of each structure were .77-.90 and .83 for total structure. Conclusion: The four structures, 24-item instrument showed satisfactory reliability and validity. LTS has the potential to be appropriate for assessing the transition process of life for parents who have children with autism and provides basic directions for differentiated support and care at each stage.

• The Korean Journal of Health Service Management
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• v.2 no.1
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• pp.84-104
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• 2008

In recent days, Korean society falls into disorder in sexual culture with transition of sexual consciousness by prevalence of sexual liberation trend through popularization of internet. Korean society, however, does not have essential counter-plans to cope with this disorder. In this paper, I investigated the realities about adolescent sexual consciousness, attitudes and behaviors around students in middle and high schools in order to propose educational courses for adolescent sexual problems. For the investigation, I made up a questionnaire and surveyed by 500 students in middle and high schools in a same area from 1st October, 2007 to 6th October, 2007 and I analyzed results from the survey. In the results, I found that males and the group having experience in acquaintance with the other sex reported more sexual consciousness. I also found that females and the group having no experience in acquaintance with the other sex reported more vestal consciousness.

• Fibers and Polymers
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• v.2 no.2
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• pp.98-107
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• 2001

The phase transition behavior isothermal micro-phase separation kinetics of polyester-based thermoplastic elastomer were studied using the synchrotron X-ray scattering(SAXS) method. The structural changes occurring during heating period were investigated by determining the changes of the one-dimensional correlation function, interfacial thickness and Porod constant. Based on the abrupt increases of the domain spacing and interfacial thickness, a major structural change occurring well below the melting transition temperature is suggested. Those changes are explained in terms of melting of the thermodynamically unstable hard domains or/and the interdiffusion of the hard and soft segments in the interfacial regions. SAXS profile changes during the micro-phase separation process were also clearly observed at various temperatures and the separation rate was found to be sensitively affected by the temperature. The peak position of maximum scattering intensity stayed constant during the entire course of the phase separation process. The scattering data during the isothermal phase separation process was interpreted with the Cahn-Hilliard diffusion equation. The experimental data obtained during the early stage of the phase separation seems to satisfy the Cahn-Hilliard spinodal mechanism. The transition temperature obtained from the extrapolation of the diffusion coefficient to zero value turned out to be about 147$\pm$$2^{\circ}$, which is close to the order-disorder transition temperature obtained from the Porod analysis. The transition temperature was also estimated from the inveriant growth rate. By extrapolating the inveriant growth rate to zero, a transition temperature of about 145$\pm$$\pm$$2^{\circ}$ was obtained.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.35-40
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• 1999

The variations of the glass transition, melting peaks, molecular weight and its distribution (polydispersity index: PI) due to the annealing temperature and time have been investigated using the thermoplastic segmented polyurethanes (TPUs) and its blends based on the contents of hard segment. The position of the melting peak and its magnitude have been increased with the annealing temperature and time. This may be arised from the rearrangement of the microdomain structure due to the long-range or short-range segmental motion, the order-disorder transition of non-crystalline microphase, the variation of the domain size or the degree of disorder of crystalline structure by given different thermal histories. The annealing temperature and time affected the molecular weights and polydispersity : the number and weight average molecular weights were increased, while the polydispersity index (PI) deceased at certain temperatures : for TPU-35 at $135^{\circ}C$, for TPU-44 at $170^{\circ}C$ and for TPU-53 at $180^{\circ}C$. The temperatures which give the variations in molecular weights and in PIs are consistent with the annealing temperatures of which $T_3$ solely exists for each sample. Thus it is suggested that the chain dissosiation and recombination simultaneously occur at the above mentioned temperature for each sample.

• Journal of Sensor Science and Technology
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• v.6 no.6
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• pp.500-507
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• 1997

For fine control of operating temperature of shape memory alloy, we investigated the effect of thermal teratment of shape memory alloy with the impurity kind. The martensitic transformation temperature in a Cu-17.25Zn-15Al and Cu-17.25Zn-15Al-1Ag/Fe was measured using electrical resistivity as a function of quenching temperature. Order-disorder phase transition temperatures in parent phase were measured and kind of transition were distinguised by DSC(differential scanning calorimeter) with heating rate variation. And structual changes were studied with XRD. For the Cu-17.25Zn-15Al shape memory alloy, the order-disorder phase transition temperature, $T_{B2}$ and $T_{L21}$ was 809K and 610K and for the Cu-17.25Zn-15Al-1Ag and Cu-17.25Zn-15Al-1Fe specimen $T_{B2}$ and $T_{L21}$ was 794K and 610K, and 803K and 613K, respectively. In all the specimens, quenching from near $T_{B2}$ leads to an increase in martensitic temperature, whereas quenching from near $T_{L21}$ leads to an decrease in martensitic temperature.