• Title/Summary/Keyword: Variance reduction

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The Speaker Recognition System using the Pitch Alteration (피치변경을 이용한 화자인식 시스템)

  • Jung JongSoon;Bae MyungJin
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.115-118
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    • 2002
  • Parameters used in a speaker recognition system are desirable expressing speaker's characteristics filly and have in a speech. That is to say, if inter-speaker than intra-speaker variance a big characteristic, it is useful to distinguish between speakers. Also, to make minimum error between speakers, it is required the improved recognition technology as well as the distinguishing characteristics. When we see the result of recent simulation performance, we obtain more exact performance by using dynamic characteristics and constant characteristics by a speaking habit. Therefore we suggest it to solve this problem as followings. The prosodic information is used by a characteristic vector of speech. Characteristics vector generally using in speaker recognition system is a modeling spectrum information and is working for a high performance in non-noise circumstance. However, it is found a problem that characteristic vector is distorted in noise circumstance and it makes a reduction of recognition rate. In this paper, we change pitch line divided by segment which can estimate a dynamic characteristic and it is used as a recognition characteristic. we confirmed that the dynamic characteristic is very robust in noise circumstance with a simulation. We make a decision of acceptance or rejection by comparing test pattern and recognition rate using the proposed algorithm has more improvement than using spectrum and prosodic information. Especially stational recognition rate can be obtained in noise circumstance through the simulation.

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A SHEAR BOND STRENGTH OF RESIN CEMENT BONDED TO HUMAN UNCUT ENAMEL, CUT ENAMEL, AND DENTIN IN VITRO

  • Lee Jong-Yeop
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.319-324
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    • 2003
  • Statement of problem. Adhesives in dentistry playa major role in the success of restorative treatments. In the treatment of all ceramic restoration it is needed to find the adequate bond strength between enamel and dentin. Purpose. The purpose of this study was to evaluate shear bond strength of resin cement bonded to extracted human uncut enamel, cut enamel, and dentin in vitro. Material and methods. Ten freshly extracted anterior teeth without any previous restorative treatments were chosen. The extracted teeth were embedded in PMMA cold acrylic in the shape of a cylinder, 25 mm in diameter by 25 mm in height. The bonding system used was as follow: Uni-Etch (32% phosphoric acid), One-Step adhesive, Duolink resin cement. The specimens were acid etched and rinsed with water. Two layers of One-Step adhesive were coated with a disposable brush on the uncut enamel. VIP curing light at $500mV/cm^2$ was used to cure the adhesive. For cut enamel shear bond test, the specimen used for uncut enamel was further reduced approximately $0.3{\sim}0.5mm$ using a laminate preparation diamond bur (0.3 mm in depth). The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit SiC paper and cleaned with distilled water. The bonding procedure on the cut enamel was same as uncut enamel bonding procedure. For dentin bonding test, the specimen used for cut enamel was further reduced approximately $0.5mm{\sim}1.0mm$ using a laminate preparation diamond bur (0.5 mm in depth of diamond cutting). The amount of reduction was evaluated with the silicone mold. The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit silicon carbon paper and cleaned in distilled water. The bonding procedure on the dentin was same as uncut enamel bonding procedure. All samples were mounted and secured on the Ultradent shear bond test sample holder, and Ultradent restricted shear bond testing device was used with Universal Instron machine until fracture. Analysis of variance (ANOVA) test was performed comparing the result at P<0.05. Multiple comparison (Tukey) was used to compare each groups. Result. The result showed that the mean value in shear bond strength of resin cement bonded to uncut enamel, cut enamel and dentin were 27.04 Mpa, 30.25 Mpa and 26.39 Mpa with respect. Conclusion. Within the limitation of this study, the mean value of the shear bond strength of cut enamel was higher than those of uncut enamel or dentin. However there existed no statistical differences between three different human dentition substrates due to increased adhesive characteristics.

Refinement and Evaluation of Korean Outpatient Groups for Visits with Multiple Procedures and Chemotherapy, and Medical Visit Indicators (한국형 외래환자분류체계의 개선과 평가: 복수시술 및 항암제 진료와 내과적 방문지표를 중심으로)

  • Park, Hayoung;Kang, Gil-Won;Yoon, Sungroh;Park, Eun-Ju;Choi, Sungwoon;Yu, Seunghak;Yang, Eun-Ju
    • Health Policy and Management
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    • v.25 no.3
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    • pp.185-196
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    • 2015
  • Background: Issues concerning with the classification accuracy of Korean Outpatient Groups (KOPGs) have been raised by providers and researchers. The KOPG is an outpatient classification system used to measure casemix of outpatient visits and to adjust provider risk in charges by the Health Insurance Review & Assessment Service in managing insurance payments. The objective of this study were to refine KOPGs to improve the classification accuracy and to evaluate the refinement. Methods: We refined the rules used to classify visits with multiple procedures, newly defined chemotherapy drug groups, and modified the medical visit indicators through reviews of other classification systems, data analyses, and consultations with experts. We assessed the improvement by measuring % of variation in case charges reduced by KOPGs and the refined system, Enhanced KOPGs (EKOPGs). We used claims data submitted by providers to the HIRA during the year 2012 in both refinement and evaluation. Results: EKOPGs explicitly allowed additional payments for multiple procedures with exceptions of packaging of routine ancillary services and consolidation of related significant procedures, and discounts ranging from 30% to 70% were defined in additional payments. Thirteen chemotherapy drug KOPGs were added and medical visit indicators were streamlined to include codes for consultation fees for outpatient visits. The % of variance reduction achieved by EKOPGs was 48% for all patients whereas the figure was 40% for KOPGs, and the improvement was larger in data from tertiary and general hospitals than in data from clinics. Conclusion: A significant improvement in the performance of the KOPG was achieved by refining payments for visits with multiple procedures, defining groups for visits with chemotherapy, and revising medical visit indicators.

Calculation of Concrete Shielding Wall Thickness for 450 kVp X-ray Tube with MCNP Simulation and Result Comparison with Half Value Layer Method Calculation (MCNP 시뮬레이션을 통한 450 kVp 엑스레이 튜브의 콘크리트 차폐벽 두께 계산 및 반가층 방법을 이용한 계산과의 결과 비교)

  • Lee, Sangheon;Hur, SamSurk;Lee, Eunjoong;Kim, Chankyu;Cho, Gyu-seong
    • Journal of Radiation Industry
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    • v.10 no.1
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    • pp.29-35
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    • 2016
  • Radiation generating devices must be properly shielded for their safe application. Although institutes such as US National Bureau of Standards and National Council on Radiation Protection and Measurements (NCRP) have provided guidelines for shielding X-ray tube of various purposes, industry people tend to rely on 'Half Value Layer (HVL) method' which requires relatively simple calculation compared to the case of those guidelines. The method is based on the fact that the intensity, dose, and air kerma of narrow beam incident on shielding wall decreases by about half as the beam penetrates the HVL thickness of the wall. One can adjust shielding wall thickness to satisfy outside wall dose or air kerma requirements with this calculation. However, this may not always be the case because 1) The strict definition of HVL deals with only Intensity, 2) The situation is different when the beam is not 'narrow'; the beam quality inside the wall is distorted and related changes on outside wall dose or air kerma such as buildup effect occurs. Therefore, sometimes more careful research should be done in order to verify the effect of shielding specific radiation generating device. High energy X-ray tubes which is operated at the voltage above 400 kV that are used for 'heavy' nondestructive inspection is an example. People have less experience in running and shielding such device than in the case of widely-used low energy X-ray tubes operated at the voltage below 300 kV. In this study, Air Kerma value per week, outside concrete shielding wall of various thickness surrounding 450 kVp X-ray tube were calculated using MCNP simulation with the aid of Geometry Splitting method which is a famous Variance Reduction technique. The comparison between simulated result, HVL method result, and NCRP Report 147 safety goal $0.02mGy\;wk^{-1}$ on Air Kerma for the place where the public are free to pass showed that concrete wall of thickness 80 cm is needed to achieve the safety goal. Essentially same result was obtained from the application of HVL method except that it suggest the need of additional 5 cm concrete wall thickness. Therefore, employing the result from HVL method calculation as an conservative upper limit of concrete shielding wall thickness was found to be useful; It would be easy, economic, and reasonable way to set shielding wall thickness.

Height Control of Pot Chrysanthemum according to Daminozide Applications at Different Planting Period in C-Channel mat Irrigation System (C-형강 매트 저면관수 시스템을 이용한 분화 국화 재배 시 정식시기와 Daminozide 처리에 따른 초장 조절)

  • Kang, Seung Won;Seo, Sang Gyu;Lee, Gung Pyo;Pak, Chun Ho
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.1
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    • pp.30-36
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    • 2011
  • Effect of daminozide concentration and application methods, in combination with different planting period, on the growth of chrysanthemum was investigated for small pot-plant production. Daminozide, a plant growth regulator widely used for plant height control, was applied by drench or sub-application. For pot chrysanthemums of first planting time, plant height was reduced over $4,000mg{\cdot}L^{-1}$, when daminozide was drenched directly into the pot medium. However, $5,000mg{\cdot}L^{-1}$ of daminozide drench affected plant height reduction for secondarily planted pot chrysanthemum. Analysis of variance revealed the plant height was affected by planting time. For sub-application experiment of daminozide, it showed that the daminozide affected the number of flower buds formation and fresh and dry weight. These results suggest that planting period affected growth retardation of chrysanthemum. Therefore, application of growth retardant in combination with planting time and application methods may provide more efficient growth control for pot-chrysanthemum production.

Examining Influences of Asian dust on SST Retrievals over the East Asian Sea Waters Using NOAA AVHRR Data (NOAA AVHRR 자료를 이용한 해수면온도 산출에 황사가 미치는 영향)

  • Chun, Hyoung-Wook;Sohn, Byung-Ju
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.45-59
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    • 2009
  • This research presents the effect of Asian dust on the derived sea surface temperature (SST) from measurements of the Advanced Very High Resolution Radiometer (AVHRR) instrument flown onboard NOAA polar orbiting satellites. To analyze the effect, A VHRR infrared brightness temperature (TB) is estimated from simulated radiance calculated from radiative transfer model on various atmospheric conditions. Vertical profiles of temperature, pressure, and humidity from radiosonde observation are used to build up the East Asian atmospheric conditions in spring. Aerosol optical thickness (AOT) and size distribution are derived from skyradiation measurements to be used as inputs to the radiative transfer model. The simulation results show that single channel TB at window region is depressed under the Asian dust condition. The magnitude of depression is about 2K at nadir under moderate aerosol loading, but the magnitude reaches up to 4K at slant path. The dual channel difference (DCD) in spilt window region is also reduced under the Asian dust condition, but the reduction of DCD is much smaller than that shown in single channel TB simulation. Owing to the depression of TB, SST has cold bias. In addition, the effect of AOT on SST is amplified at large satellite zenith angle (SZA), resulting in high variance in derived SSTs. The SST depression due to the presence of Asian dust can be expressed as a linear function of AOT and SZA. On the basis of this relationship, the effect of Asian dust on the SST retrieval from the conventional daytime multi-channel SST algorithm can be derived as a function of AOT and SZA.

A Study on Subjective Happiness, Self-esteem, and Clinical Practice Stress of Nursing Students (간호대학생의 주관적 행복감, 자아존중감, 임상실습 스트레스에 관한 연구)

  • Baek, Myung-Wha;Ahn, Seong-Ah;Lee, Hae-Rang;Park, Chan-Gyeong;Kong, Jeong-Hyeon
    • Journal of the Health Care and Life Science
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    • v.8 no.2
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    • pp.165-172
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    • 2020
  • This study was conducted to identify the subjective happiness and self-esteem of nursing students and how these variables affect clinical practice stress. Participants consisted of 199 nursing students who were in the third and fourth years who had experienced clinical practice at two nursing universities located in Gyeongnam, and agreed to the survey. Data were collected using questionnaires from June 15 to August 29, 2020. Collected data were analyzed using the SPSS 22.0 statistics program with descriptive statistics, an independent t-test, ANOVA, Scheffe's test, and multiple regression. The mean score for subjective happiness was 4.87 (out of 7), the mean for self-esteem was 3.84 (out of 5), and clinical practice stress was 2.77 (out of 5). The significant predictors of the clinical practice stress were gender, major satisfaction and self-esteem, and the explanatory power of variance was 14.1%. Therefore, we need differentiated clinical practice stress reduction programs according to gender and various strategies that can enhance major satisfaction in order to reduce the clinical practice stress of nursing students.

Physicochemical properties of a calcium aluminate cement containing nanoparticles of zinc oxide

  • Amanda Freitas da Rosa;Thuany Schmitz Amaral;Maria Eduarda Paz Dotto;Taynara Santos Goulart;Hebert Luis Rossetto;Eduardo Antunes Bortoluzzi;Cleonice da Silveira Teixeira;Lucas da Fonseca Roberti Garcia
    • Restorative Dentistry and Endodontics
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    • v.48 no.1
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    • pp.3.1-3.14
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    • 2023
  • Objectives: This study evaluated the effect of different nanoparticulated zinc oxide (nano-ZnO) and conventional-ZnO ratios on the physicochemical properties of calcium aluminate cement (CAC). Materials and Methods: The conventional-ZnO and nano-ZnO were added to the cement powder in the following proportions: G1 (20% conventional-ZnO), G2 (15% conventional-ZnO + 5% nano-ZnO), G3 (12% conventional-ZnO + 3% nano-ZnO) and G4 (10% conventional-ZnO + 5% nano-ZnO). The radiopacity (Rad), setting time (Set), dimensional change (Dc), solubility (Sol), compressive strength (Cst), and pH were evaluated. The nano-ZnO and CAC containing conventional-ZnO were also assessed using scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Radiopacity data were analyzed by the 1-way analysis of variance (ANOVA) and Bonferroni tests (p < 0.05). The data of the other properties were analyzed by the ANOVA, Tukey, and Fisher tests (p < 0.05). Results: The nano-ZnO and CAC containing conventional-ZnO powders presented particles with few impurities and nanometric and micrometric sizes, respectively. G1 had the highest Rad mean value (p < 0.05). When compared to G1, groups containing nano-ZnO had a significant reduction in the Set (p < 0.05) and lower values of Dc at 24 hours (p < 0.05). The Cst was higher for G4, with a significant difference for the other groups (p < 0.05). The Sol did not present significant differences among groups (p > 0.05). Conclusions: The addition of nano-ZnO to CAC improved its dimensional change, setting time, and compressive strength, which may be promising for the clinical performance of this cement.

Effects of Relaxation Techniques on Flexibility and Balance of the Lower Limb in Adults with Hamstring Shortening (넙다리뒤근 단축이 있는 성인에게 이완 기법의 적용이 하지의 유연성과 균형에 미치는 영향)

  • Jung-Woo Lee;Seong-Min Jeon;Ha-Yeong Kim;Jong-Yeon Bae;Song-Chan Son;Eun-Jin Song;Sang-Eun Sim;Hyeong-Uk Lee;Hye-Kyeong Lee;Baek-Gwang Jo;Sung-Bin Jo;Jin-Hee Joo;Ha-Yeon Jin;Jeong-Hyeon Hwang;Min-Hee Kim
    • PNF and Movement
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    • v.22 no.1
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    • pp.55-70
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    • 2024
  • Purpose: The purpose of this study was to investigate the effects of three relaxation techniques, namely, Static Stretching Exercise (SSE), Eccentric Contraction Exercise (ECE), and Suboccipital Muscle Release (SMR) on the flexibility and balance of the lower limb in adults with hamstring shortening. Methods: The participants were 45 adults in their 20s with hamstring shortening. They performed three exercises (i.e., SSE, ECE, and SMR) for two weeks. We measured flexibility, muscle tone and stiffness, proprioception, and balance before and after the intervention, applying each relaxation technique. Data were analyzed using two-way repeated measures analysis of variance (ANOVA). The significance level was set at α=0.05. Results: Flexibility increased in the SSE, ECE, and SMR groups, with the SSE group showing the greatest improvement. Muscle tone and stiffness decreased in all groups, with the ECE group exhibiting the highest reduction. Proprioception increased in the SSE, ECE, and SMR groups, with SSE demonstrating the greatest enhancement. Balance also increased in all groups, with the ECE group showing the most pronounced improvement. Conclusion: Overall, all three relaxation techniques for hamstring shortening resulted in improved flexibility, muscle tone and stiffness, proprioception, and balance of the lower limb in adults with hamstring shortening. The findings of this study underscore the importance of selecting an appropriate technique according to the purpose of treatment and the condition of the patient.

Work·Family Compatibility Policy Usage and Parenting Stress : Focusing on Sex and Occupational Groups (일·가족 양립 정책 이용과 양육 스트레스 : 성별과 직업군을 중심으로)

  • Cho, Yoonjoo
    • Journal of Family Resource Management and Policy Review
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    • v.28 no.1
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    • pp.27-38
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    • 2024
  • Given the concern about the reduction in birth rate in Korea today, the objective of this study was to examine the association between Work·Family Compatibility policy and parenting stress, focusing on sex and occupational groups. Data from the 13th year Panel Study on Korean Children were analyzed by descriptive statistics, a one-way analysis of variance, and Duncan's post hoc test. The results of this study were as follows: First, the most commonly used aspect of the Work·Family Compatibility policy among both males and females was flextime, irrespective of occupational types. Also, flextime was the most used policy among professional workers. Second, regarding the use of related systems and parenting stress, it was found that all respondents perceived above average parenting stress. Specifically, the parenting stress scores of male users of flextime were higher than those of family care leave users. The parenting stress of military personnel were the lowest among males' occupational groups. Among females, the parenting stress scores of maternity leave users were higher than those of shorter workweek user. Diverse discussions and implications were suggested about promoting the usage of Work·Family Compatibility policy.