• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.178-183
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• 2004

PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.

• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.26-30
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• 2001

Up to now, Most studies of hydroelasticity are about frequency domain analysis. Those aren't suited for analysis of the landing take-off, and dropping of aircraft on a structure. So, the concern of this paper is the transient behavior of a VLFS subjected to dynamic load, induced by airplane landing and take-off. To predict the added mass, damping coefficient, and wave exciting force, the source-dipole distribution method was used in the frequency domain. The responses are accomplished by using the FEM scheme. A time domain analysis method is based on the Newmark β method to pursue the time step procedure, taking advantage of memory effect function for hydrodynamic effects.

• Korean Journal of Schizophrenia Research
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• v.21 no.2
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• pp.74-80
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• 2018

Objectives : This study investigated whether long-acting injectable (LAI) paliperidone is different from its oral form in terms of the effect on cognitive function in schizophrenia spectrum and other psychotic disorders. Methods : We reviewed the medical records of patients in Seoul National University Bundang Hospital who were diagnosed as having schizophrenia and/or other psychotic disorders based on DSM-5 from 2016 to 2017. Seven patients were treated with oral paliperidone and 11 were treated with paliperidone palmitate. All patients underwent clinical and neuropsychological assessment, including the Korean version of the MATRICS Consensus Cognitive Battery (MCCB) at their first visit or within one month of their initial treatment. MCCB was repeated within three to 12 months after the initial assessment. Results : There was no significant difference between the two groups in most cognitive domains including speed of processing, attention and vigilance, working memory, verbal learning, visual learning and reasoning and problem solving domain. However, patients treated with paliperidone palmitate showed better improvement in social cognition domain than those taking oral paliperidone. The standardized values of social cognition domain scores had significantly improved over time in patients under paliperidone palmitate, demonstrating a significant time-by-group interaction. Conclusion : Our results show that long-acting injectable paliperidone could be helpful in some aspects of improving cognitive function in schizophrenia spectrum and other psychotic disorders. Further studies with other antipsychotics are necessary to generalize the results.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.99-102
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• 2002

The present study describes a numerical analysis for simulation of the sloshing of flows with free-surface which contained in a rectangular tank The SOLA-VOF (Volume of fluid) method uses a fixed mesh for calculating the motion of flow and the free-surface. This Eulerian approach enables the VOF method to use only a small amount of computer memory for simulating sloshing problems with complicated free-surface contours. The VOF function, representing the volume fraction of a cell occupied by the fluid, is calculated for each cells, which gives the locating of the free-surface filling any some fraction of cells with fluid. Using SOLA-VOF method, the study describes visualization about simulation of the sloshing of flows and damping effect by baffle. Translation and pitching motion of the forms have been investigated The time-dependent changes of free-surface height are used for visualization subject to several conditions such as fluid height horizontal acceleration, sinusoidal motion, and viscosity. The free-surface heights were used for comparing wall-force, which is caused by sloshing of flows. Baffle was Installed to reduce the force on the wall by sloshing of flows. Damping effects was extensively expressed under the conditions such as baffle shape and position.

• Journal of Preventive Medicine and Public Health
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• v.46 no.sup1
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• pp.22-27
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• 2013

The purpose of this study was to examine the beneficial effects of a new cognitive intervention program designed for the care and prevention of dementia, namely Learning Therapy. The training program used systematized basic problems in arithmetic and Japanese language as training tasks. In study 1, 16 individuals in the experimental group and 16 in the control group were recruited from a nursing home. In both groups, all individuals were clinically diagnosed with senile dementia of the Alzheimer type. In study 2, we performed a single-blind, randomized controlled trial in our cognitive intervention program of 124 community-dwelling seniors. In both studies, the daily training program using reading and arithmetic tasks was carried out approximately 5 days a week, for 15 to 20 minutes a day in the intervention groups. Neuropsychological measures were determined simultaneously in the groups both prior to and after six months of the intervention. The results of our investigations indicate that our cognitive intervention using reading and arithmetic problems demonstrated a transfer effect and they provide convincing evidence that cognitive training maintains and improves the cognitive functions of dementia patients and healthy seniors.

• Journal of Semiconductor Engineering
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• v.3 no.2
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• pp.161-167
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• 2022

Electrical characteristics of LDMOS power device with LDD(Lightly Doped Drain) structure is studied with variation of the region of channel and LDD. The channel in LDMOSFET encloses a junction-type source and is believed to be an important parameter for determining the circuit operation of CMOS inverter. Two-dimensional TCAD MEDICI simulation is used to study hot-carrier effect, on-resistance Ron, breakdown voltage, and transient switching characteristic. The voltage-transfer characteristics and on-off switching properties are studied as a function of the channel length and doping levels. The digital logic levels of the output and input voltages are analyzed from the transfer curves and circuit operation. Study indicates that drain current significantly depends on the channel length rather than the LDD region, while the switching transient time is almost independent of the channel length. The high and low logic levels of the input voltage showed a strong dependency on the channel length, while the lateral substrate resistance from a latch-up path in the CMOS inverter was comparable to that of a typical CMOS inverter with a guard ring.

• Journal of Life Science
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• v.17 no.10
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• pp.1400-1405
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• 2007

The effect of supplementation with docosahexaenoic acid into n-3 fatty acid deficient diet on improvement of loaming related brain function was investigated. On the second day after conception, Sprague Dawley strain dams were subjected to a diet containing either n-3 fatty acid deficient (Def) or n-3 fatty acid deficient + docosahexaenoic acid (Def+DHA). After weaning, male pups were fed on the same diet of their respective dams until adulthood. Motor activity and Morris water maze tests were measured at 10 weeks old. In motor activity test, there were no statistically significant differences in moving time and moving distance between the Def and Def+DHA diet groups. The n-3 fatty acid deficient with DHA (Def+DHA) group exhibited a shorter escape latency, swimming time and swimming distance (P<0.05) compared to the n-3 fatty acid deficient group (Def) but there was no difference in resting time and swimming speed between the experimental diet groups. In memory retention trial, the number of crossing of the platform position (region A) was significantly greater than those of other regions for the Def+DHA group. However, the Def group swam randomly without preference for the provisions platform location, indicating poorer memory retention. From those results, supplementation with DHA into the n-3 fatty acid deficient diet improved the spatial loaming ability in rats as assessed by Morris water maze test.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.213-226
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• 2011

This study was performed to investigate the effect of essential oils and ethanolic extracts of approximately 650 plant species on acetylcholine esterase (AChE) enzyme activity using Ellman's colorimetric method in 96-well microplates. The results showed that the ethanolic extracts from twig of Sophora subprostrata, twig of Phellodendron amurense, seed of Corylopsis coreana, and essential oil (EO) from Citrus paradisi, Cupressus sempervirens, Ocimum basilicum, Pinus sylvestris and Rosmarinus officinalis inhibited more than 80% of AChE activity. Among these, EO from Pinus sylvestris, C. sempervirens and C paradisi exhibited higher values of AChE inhibitory activity, which were 75, 84 and 99% at a concentration of 50 ug/ml, respectively. Finally, EO from C paradisi (grapefruit, GEO) showed the highest inhibitory activity towards AChE, which showed 91% of inhibition at a concentration of 20 ug/ml. We also examined the anti-dementia effects of GEO in mouse by passive avoidance test and Morris water maze test. The model mouse (male, ICR) of dementia (negative control) was induced by administration of scopolamine (1 mg/kg body weight). The latency time of sample group administrated with GEO (100 mg/kg, p.o.) increased significantly as compared with negative control on passive avoidance test. There were significant recovery from the scopolamine-induced deficits on learning and memory in water maze test through daily administrations with GEO (100 mg/kg, p.o.). From these results, we conclude that GEO treatment might enhance the cognitive function, suggesting that the EO of C. paradis may be a potential candidate for improvement of perceptive ability and dementia.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.210-216
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• 2019

The purpose of this study is to investigate the effect of the multimodal cognitive intervention focusing on instrumental daily life on the cognitive function, depression and quality of life of the elderly with high-risk of dementia. This study was conducted on 24 elderly people with high-risk of dementia who participated in cognitive rehabilitation program from March to June, 2018 in Chungbuk A region. The intervention was applied to cognitive training and creative activities related to instrumental daily life. MMSE-DS, Subjective Memory Complaints Questionnaire, Short Geriatric Depression Scale-Korean version and Geriatric quality of life - Dementia were performed before and after the intervention. We confirmed that the subjects showed significant improvement in Subjective Memory Complaints and Quality of Life, but showed no significant changes in cognitive function and depression after the intervention program. Through this study, it was confirmed that this program which can affect the real life of the elderly can be usefully applied in the community. In the future, it will be necessary to develop a program that utilizes more diverse instrumental activities of daily living.

• Therapeutic Science for Rehabilitation
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• v.12 no.3
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• pp.79-88
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• 2023

Objective : This study was to apply a cognitive rehabilitation group program based on sensory activity in patients with dementia living in a facility and to check its effectiveness on cognitive function, depression, and quality of life (QOL). Methods : Sensory-based cognitive rehabilitation group programs (20 sessions) were conducted for eight elderly with dementia over the age of 65 living in a nursing facility located in H-gun, Gangwon-do. The participants' cognitive function, depression level, and QOL were evaluated before and after the program. Results : The mean of Mini-Mental State Examination-Dementia Screening increased; however, there was no statistically significant difference. In contrast, the mean post-test score of the Subjective Memory Complaints Questionnaire decreased, and there was a statistically significant difference (p < .05). The mean post-evaluation score of Short Geriatric Depression Scale measured to confirm the decrease in depression compared to the pre-evaluation score, but there was no statistically significant difference. Finally, the mean post-evaluation score of the World Health Organization QOL assessment instrument-Brief confirmed the change in the QOL, and there was a statistically significant difference (p < .001). Conclusion : This study will provide the basis for suggesting the usefulness of developing a sensory activity-based cognitive rehabilitation group program for dementia patients living in facilities.