• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.521-536
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• 2021

As life expectancies increase continuously over the world, the accuracy of forecasting mortality is more and more important to maintain social systems in the aging era. Currently, the most popular model used is the Lee-Carter model but various studies have been conducted to improve this model with one of them being 6-parametric factor model (6-PFM) which is introduced in this paper. To this new model, long short-term memory (LSTM) and regularized LSTM are applied in addition to vector autoregression (VAR), which is a traditional time-series method. Forecasting accuracies of several models, including the LC model, 4-PFM, 5-PFM, and 3 6-PFM's, are compared by using the U.S. and Korea life-tables. The results show that 6-PFM forecasts better than the other models (LC model, 4-PFM, and 5-PFM). Among the three 6-PFMs studied, regularized LSTM performs better than the other two methods for most of the tests.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.2
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• pp.94-97
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• 2007

The desin and implementation of a CMOS analog integrated circuit that provides dual-mode modulations, PWM for active clamp reset converter and PFM for LLC resonant converter, is described. The proposed controller is capable of implementing programmable soft start and current-mode control with compensating ramp for PWM and frequency shifting soft start for PFM. Also it provides delay time for both modes. PWM mode is implemented by active clamp reset converter and PFM mode is implemented by LLC resonant convereter, respectively. The chip is fabricated using the 0.6um high voltage CMOS process.

• Journal of Technologic Dentistry
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• v.29 no.1
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• pp.35-48
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• 2007

The purpose of this study was to evaluate shade selection using conventional visual assessment in vivo natural teeth and porcelain-fused-to-metal (PFM) crown. Maxillary central incisors, lateral incisors and canines of one hundred twenty four college women were used as vivo natural teeth. Fifty one PFM crown for maxillary central incisor fabricated by dental laboratory were used as experimental materials. Using Vitapan Classical Shade Guides, shade selection of natural teeth was measured by each college woman and shade selection of PFM crown was measured by three ceramists with more than ten years career. Both natural teeth and PFM crown shade selection were measured through Shade Eye-Ex. From the shade selection comparing, following results were obtained. The results were as follows: 1. The shade matching identification of natural teeth between the shade selection using Vitapan Classical Shade Guides and the shade selection using Shade Eye-Ex was 27.4% in maxillary central incisor, 13.7% in lateral incisor and 18.5% in canine. 2. Among the shade selection of PFM crown by three ceramists, the shade evaluation of three ceramists were same only in ten cases. In twenty case, those of two ceramists were same. 3. The shade matching identification of PFM crown between the shade selection using Vitapan Classical Shade Guides and the shade selection using Shade Eye-Ex was 38.6% in average. These results suggest that the shade selection using conventional visual assessment should be dealt with care in clinic and need a credible method for shade matching color.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.693-700
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• 2004

The probabilistic fracture mechanics(PFM) is a useful analytical tool to assess the integrity of reactor pressure vessel(RPV) at the event of pressurized thermal shock(PTS). In PFM, the probabilities of flaw initiation and propagation are estimated by comparing the applied stress intensity factor with the fracture toughness calculated by the simulation of various stochastic variables. It is known that the results of PFM analyses are dependent on the choice of the stochastic parameters and assumptions. Of the various variables and assumptions, we investigated the effects of the RT$_{NDT}$ shift equations, fracture toughness curves, and flaw distributions on the PFM results for the three PTS transients. The results showed that the combined effects of the RT$_{NDT}$ shift equations and fracture toughness curves are complicated and dependent on the characteristics of the transients, the chemistry of the materials, the fast neutron fluence, and so on.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.103-110
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• 2001

Predictive food microbiology(PFM) is an emerging area of food microbiology since the later 1980’s. It does apply mathematical models to predict the responses of microorganism to specified environmental variables. Although, at present, PFM models do not completely developed, models can provide very useful information for microbiological responses in HACCP(Hazard Analysis Critical Control Point) system and Risk Assessment. This study illustrates the possible use of PFM models(PMP: Pathogen Modeling Program win5.1) with milk in several elements in the HACCP system, such as conduction of hazard analysis and determination of CCP(Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage fixed factors were pH 6.7, Aw 0.993 and NaCl 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage (Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The variable factor was storage temperature at the range of 4~15$^{\circ}C$ and the fixed factors were pH 6.7, Aw 0.993 and NaC 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage temperature.

• The Journal of Advanced Prosthodontics
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• v.12 no.4
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• pp.181-188
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• 2020

PURPOSE. The effect of core design on the fracture resistance of zirconia-lithium disilicate (LS2) bilayered crowns for anterior teeth is evaluated by comparing with that of metal-ceramic crowns. MATERIALS AND METHODS. Forty customized titanium abutments for maxillary central incisor were prepared. Each group of 10 units was constructed using the same veneer form of designs A and B, which covered labial surface to approximately one third of the incisal and cervical palatal surface, respectively. LS2 pressed-on-zirconia (POZ) and porcelain-fused-to-metal (PFM) crowns were divided into "POZ_A," "POZ_B," "PFM_A," and "PFM_B" groups, and 6000 thermal cycles (5/55 ℃) were performed after 24 h storage in distilled water at 37 ℃. All specimens were prepared using a single type of self-adhesive resin cement. The fracture resistance was measured using a universal testing machine. Failure mode and elemental analyses of the bonding interface were performed. The data were analyzed using Welch's t-test and the Games-Howell exact test. RESULTS. The PFM_B (1376. 8 ± 93.3 N) group demonstrated significantly higher fracture strength than the PFM_A (915.8 ± 206.3 N) and POZ_B (963.8 ± 316.2 N) groups (P<.05). There was no statistically significant difference in fracture resistance between the POZ_A (1184.4 ± 319.6 N) and POZ_B groups (P>.05). Regardless of the design differences of the zirconia cores, fractures involving cores occurred in all specimens of the POZ groups. CONCLUSION. The bilayered anterior POZ crowns showed different fracture resistance and fracture pattern according to the core design compared to PFM.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.55-63
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• 2007

STSAT-2 (Science & Technology SATellite-2) is a Korea micro-satellite which will be launched at NARO Space center in Koheung, Korea. Launch vehicle for STSAT-2 is KSLV-1 (Korea Space Launch Vehicle-1) which is the first development in Korea space launch vehicle program. Starting development in 2002 EM(Engineering Model), PFM(Proto-Flight Model), and FM(Flight Model) were developed completely. Electrical functional test, space environmental test, and launch vehicle environmental test on system level are performed for testing those development models. In this paper we report the results of STSAT-2 PFM space environmental test and launch vehicle environmental test which is successfully completed.

• Journal of Korean Academy of Nursing
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• v.34 no.8
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• pp.1427-1433
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• 2004

Purpose. The elderly with UI experienced urine leakage for a long time. The prevalence of UI has increased and it makes costly. Particularly, the elderly were reluctant to visit a hospital or a clinic for the reasons of modesty and poverty. To solve this problem, incontinence intervention programs should be provided at the elderly welfare center. The purpose of this research was to develop Incontinence Intervention Program for the Elderly Women (IIPE) and evaluate in its effect. Methods. The study design was quasi-experimental with pre and post-test. The study was performed for ten weeks at one elderly welfare center, Seoul, Korea. The subjects were gathered through an official announcement and informed consent was obtained. IIPE, in this study, was consisted of diagnosis, education, exercise and evaluation. The study variables were PFM exercise adherence, pelvic muscle strength, Continence self-efficacy, geriatric depression and incontinence stress. The effects of the IIPE on PFM exercise adherence, pelvic muscle strength, Continence self-efficacy, geriatric depression and incontinence stress were also evaluated. Results. The mean age of the subjects was 75.2 years. The average attendance was 6.2 times. The IIPE improved PFM exercise adherence, intra-vaginal contraction power and CSE significantly. But it was not significant in incontinence stress and geriatric depression. Other important results were that the two-finger test and urine stream interruption were more useful for elderly women with rigid vaginas in teaching and evaluating. Conclusion. The Findings suggest that IIPE is effective to the community-residing elderly. Further investigation is needed on a long-term basis with control group.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.235-242
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• 2012

Purpose: The purpose of this study was to compare the fracture behavior of Zironia, glass infiltrated Alumina and PFM full crown system. Materials and methods: Fifteen crowns for each of 3 experimental groups (Zironia, glass infiltrated Alumina and PFM full crown) were made by the conventional method. The crowns mounted on the testing jig were inclined in 30 degrees to the long axis of the tooth and the universal testing machine was used to measure the fracture strength. Results: 1. The mean fracture strengths were $588.3{\pm}49.6MPa$ for zirconia system, $569.1{\pm}61.8MPa$ for PFM system and $551.0{\pm}76.5MPa$ for glass-infiltrated alumina system (P>.05). 2. The mean shear bond strengths were $25.5{\pm}5.6MPa$ for zirconia system, $38.9{\pm}5.0MPa$ for Ni-Cr alloy system and $39.4{\pm}5.1MPa$ for glass-infiltrated alumina system. 3. The chemical bonding was observed at interfaces between PFM or glass-infiltrated alumina and veneering porcelain, however, no chemical bonding was observed at interface between zirconia and veneering porcelain. Conclusion: With the study, the fracture strengths of PFM crown system had a higher fracture strength than conventional zirconia system crown and glass-infiltrated alumina crowns. and than the shear bond strengths glass-infiltrated alumina system had a higher shear bond strength than conventional PFM system and zirconia system.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1627-1633
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• 2018

A constant voltage AC-DC converter based on digital assistant technology is proposed in this paper, which has rapid dynamic response capability. The converter operates in the PFM (Pulse Frequency Modulation) mode. According to the load state, the compensation current produced by the digital compensation module was injected into the CS pin to adjust the switching pulse width dynamically and improve the dynamic response. The control chip is implemented based on NEC $1{\mu}m$ 5V/40V HVCMOS process. A 5V/1.2A prototype has been built to verify the proposed control method. When the load jumps from idle to heavy, the undershoot time is only 7.4ms.