• 제목/요약/키워드: rate-independent model

검색결과 497건 처리시간 0.026초

Discriminative validity of the timed up and go test for community ambulation in persons with chronic stroke

  • An, Seung Heon;Park, Dae-Sung;Lim, Ji Young
    • Physical Therapy Rehabilitation Science
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    • 제6권4호
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    • pp.176-181
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    • 2017
  • Objective: The timed up and go (TUG) test is method used to determine the functional mobility of persons with stroke. Its reliability, validity, reaction rate, fall prediction, and psychological characteristics concerning ambulation ability have been validated. However, the relationship between TUG performance and community ambulation ability is unclear. The purpose of this study was to investigate whether the TUG performance time could indicate community ambulation levels (CAL) differentially in persons with chronic stroke. Design: Cross-sectional study. Methods: Eighty-seven stroke patients had participated in this study. Based on the self-reporting survey results on the difficulties experienced when walking outdoors, the subjects were divided into the independent community ambulation (ICA) group (n=35) and the dependent community ambulation group (n=52). Based on the area under the curve (AUC), the discrimination validity of the TUG performance time was calculated for classifying CAL. The Binomial Logistic Regression Model was utilized to produce the likelihood ratio of selected TUG cut-off values for the distinguishing of community ambulation ability. Results: The selected TUG cut-off values and the area under the curve were <14.87 seconds (AUC=0.871, 95% confidence interval=0.797-0.945), representing a mid-level accuracy. Concerning the likelihood ratio of the selected TUG cut-off value, it was found that the group with TUG performance times shorter than 14.87 seconds showed a 2.889 times higher probability of ICA than those with a TUG score of 14.87 seconds or longer (p<0.05). Conclusions: The TUG can be viewed as an assessment tool that is capable of classifying CAL.

파모티딘-양이온 교환수지 복합체의 약물방출 특성 및 흰쥐에서의 체내동태 (Drug Release Characteristics of Famotidine-Cationic Exchange Resin Complexes and Their Pharmacokinetics in Rats)

  • 신동선;송우헌;최영욱
    • Journal of Pharmaceutical Investigation
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    • 제27권4호
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    • pp.313-321
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    • 1997
  • Ion exchange resin complexes of famotidine have been prepared by the reaction of famotidine solution with activated ion exchange resins. Complex formation efficiency between famotidine and ion exchange resin was about $80{\sim}90%$ in average, calculated by HPLC determination. Drug release characteristics from the resin complexes were evaluated by the modified percolation method. Famotidine release was dependent on the type of ion exchange resins. In the case of weakly acidic resin complexes, the cumulative released amount of famotidine was more than 90% for 1hr in pH 1.2 buffer solution. However, in the case of strongly acidic resin complexes, it was less than 5% for 3hr in the same medium. Strongly acidic resins revealed some advantages over weakly, acidic resins for overcoming instability of famotidine in gastric juice. In addition, strongly acidic resin complexes showed controlled release of famotidine in pH 6.8 buffer solution, showing the result of about 60 to 70% of drug release for 5hr. After oral administrations of famotidine-resin complexes to rats as dose of 40 mg equivalent/kg, the pharmacokinetic parameters of famotidine were obtained by model independent analysis and compared with those of famotidine solution or suspension. $C_{max}$ of famotidine-resin complex was lower than that of famotidine solution or suspension. MRT, MAT, and MDT of the complexes were greater than those of famotidine solution or suspension. From these results, it was expected that famotidine was released slowly from the complexes and absorbed continuously into systemic circulation. It was recognized that drug release from the complexes was the rate-limiting step in drug absorption, since there were close correlations between in vitro drug release and in vivo pharmacokinetic parameters.

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Effects of Heart Fatty Acid-binding Protein Genotype on Intramuscular Fat Content in Duroc Pigs Selected for Meat Production and Meat Quality Traits

  • Uemoto, Yoshinobu;Suzuki, Keiichi;Kobayashi, Eiji;Sato, Syushi;Shibata, Tomoya;Kadowaki, Hiroshi;Nishida, Akira
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권5호
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    • pp.622-626
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    • 2007
  • Using multi-trait animal model BLUP, selection was conducted over seven generations for growth rate (DG), real-time ultrasound loin-eye muscle area (LEA), backfat thickness (BF), and intramuscular fat content (IMF) to develop a new line of purebred Duroc pigs with enhanced meat production and meat quality. This study was intended to investigate the relationship between restriction fragment length polymorphism (RFLP) of a heart fatty acid-binding protein (H-FABP) gene and intramuscular fat content (IMF) of this Duroc purebred population. The present experiment examined the RFLP of 499 slaughtered pigs. The DNA was separated from the blood or ear tissue of the pigs, which were slaughtered at 105 kg of body weight. Intramuscular fat content of the longissimus muscle was measured using chemical analysis. A significant difference was detected in the breeding value of IMF among the H-FABP PCR RFLP genotypes. The AA genotype has a significantly larger positive effect on the IMF breeding value than do the Aa and aa genotypes for the MspI RFLP. In addition, the DD genotype has a significantly greater positive effect on IMF breeding value than the Dd and dd genotypes for the HaeIII RFLP. For the HinfI RFLP, the hh genotype has a significantly larger positive effect on IMF breeding value than the HH genotype. Multiple regression analysis was performed using the IMF breeding values as the dependent variable and the three H-FABP genotypes as independent variables. Results revealed that the contribution of the genotypes to variation in IMF breeding values was approximately 40%. These results demonstrated that H-FABP RFLPs affect IMF in this Duroc population.

Elevated PIVKA-II is Associated with Early Recurrence and Poor Prognosis in BCLC 0-A Hepatocellular Carcinomas

  • Wang, Bei-Li;Tan, Qi-Wen;Gao, Xing-Hui;Wu, Jiong;Guo, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6673-6678
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    • 2014
  • Background: To investigate the prognostic value of serum PIVKA-II (prothrombin induced by the absence of vitamin K or antagonist-II) in BCLC (Barcelona Clinic Liver Cancer) 0-A hepatocellular carcinoma (HCC) patients after curative resection. Materials and Methods: Preoperative sera were collected from 140 patients with BCLC 0-A HCCs undergoing curative resection during 2011-2012 in Zhongshan Hospital. Follow-up ended on November 2013. ELISA was used to detect the serum concentrations of preoperative PIVKA-II. The prognostic value of PIVKA-II and other clinicopathological factors was analyzed by the Kaplan-Meier method and the multivariate Cox proportional hazards model. Results: During follow-up, 39 of 140 patients suffered recurrence and the 1-year recurrence rate was 27.9%. The high-PIVKA-II expression group had lower 1-year time to progression (TTP) compared with the low-expression group (54.8% vs 20.2%, p<0.001). Patients with high preoperative PIVKA-II expression showed a relatively higher risk of developing postoperative recurrence than those with low expression in the low-recurrence-risk subgroups, including ${\alpha}$-fetoprotein ${\leq}400ng/mL$ (45.4% vs 16.7%; p=0.006), tumor size ${\leq}5cm$ (54.2% vs 18.1%; p<0.001), single tumor (56.0% vs 19.1%; p<0.001), absence of satellite lesions (53.3% vs 19.8%; p=0.001), absence of vascular invasion (52.6% vs 14.9%; p=0.002), and Edmondson stage I/II (60.9% vs 20.3%; p<0.001). PIVKA-II was the strongest independent prognostic factor for TTP (hazard ratio, 2.877; 95% CI 1.524-5.429; p=0.001). Conclusions: Elevated PIVKA-II is associated with early recurrence of BCLC 0-A HCC after curative resection and can be considered a novel prognostic predictor.

MOSFET의 RF 성능 최적화를 위한 단위 게이트 Finger 폭에 대한 $f_T$$f_{max}$의 종속데이터 분석 (Analysis of $f_T$ and $f_{max}$ Dependence on Unit Gate Finger Width for RF Performance Optimization of MOSFETs)

  • 차지용;차준영;정대현;이성현
    • 대한전자공학회논문지SD
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    • 제45권9호
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    • pp.21-25
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    • 2008
  • 본 연구에서는 MOSFET의 RF 성능을 극대화하기 위해 단위 게이트 finger 폭($W_u$)에 대한 $f_T$$f_{max}$의 종속데이터를 측정하고 이 결과를 소신호 모델 파라미터들을 추출함으로써 새롭게 분석하였다. 이러한 물리적 분석결과로 $f_T$의 최대값이 존재하는 원인은 좁은 $W_u$에서 $W_u$에 무관한 parasitic gate-bulk capacitance와 넓은 $W_u$에서 트랜스컨덕턴스의 증가율이 감소하는 wide width effect에 의한 것임을 알 수 있다. 또한, $f_{max}$의 최대값은 게이트저항이 좁은 $W_u$에서 크게 줄어들고 넓은 $W_u$에서 점점 일정하게 되는 non-quasi-static effect에 의해 발생된다는 사실이 밝혀졌다.

음성 신호 특징과 셉스트럽 특징 분포에서 묵음 특징 정규화를 융합한 음성 인식 성능 향상 (Voice Recognition Performance Improvement using the Convergence of Voice signal Feature and Silence Feature Normalization in Cepstrum Feature Distribution)

  • 황재천
    • 한국융합학회논문지
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    • 제8권5호
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    • pp.13-17
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    • 2017
  • 음성 인식에서 기존의 음성 특징 추출 방법은 명확하지 않은 스레숄드 값으로 인해 부정확한 음성 인식률을 가진다. 본 연구에서는 음성과 비음성에 대한 특징 추출을 묵음 특징 정규화를 융합한 음성 인식 성능 향상을 위한 방법을 모델링 한다. 제안한 방법에서는 잡음의 영향을 최소화하여 모델을 구성하였고, 각 음성 프레임에 대해 음성 신호 특징을 추출하여 음성 인식 모델을 구성하였고, 이를 묵음 특징 정규화를 융합하여 에너지 스펙트럼을 엔트로피와 유사하게 표현하여 원래의 음성 신호를 생성하고 음성의 특징이 잡음을 적게 받도록 하였다. 셉스트럼에서 음성과 비음성 분류의 기준 값을 정하여 신호 대 잡음 비율이 낮은 신호에서 묵음 특징 정규화로 성능을 향상하였다. 논문에서 제시하는 방법의 성능 분석은 HMM과 CHMM을 비교하여 결과를 보였으며, 기존의 HMM과 CHMM을 비교한 결과 음성 종속 단계에서는 2.1%p의 인식률 향상이 있었으며, 음성 독립 단계에서는 0.7%p 만큼의 인식률 향상이 있었다.

대향류 확산화염에서 확산-전도 불안정의 비선형 거동에 대한 수치해석 (Numerical Simulations on Nonlinear Behaviors of Diffusional-Thermal Instabilities in Counterflow Diffusion Flames)

  • 이수룡;김종수
    • 대한기계학회논문집B
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    • 제26권5호
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    • pp.695-702
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    • 2002
  • Nonlinear dynamics of striped diffusion flames, by the diffusional-thermal instability with Lewis numbers sufficiently less than unity, is numerically investigated by examining various two-dimensional flame-structure solutions. The Lewis numbers for fuel and oxidizer are assumed to be identical and an overall single-step Arrhenius-type chemical reaction rate is employed in the model. Particular attention is focused on identifying the flame-stripe solution branches corresponding to each distinct stripe pattern and hysteresis encountered during the transition. At a Damkohler number slightly greater than the extinction Damkohler number, eight-stripe solution first emerges from one dimensional solution. The eight-stripe solution survives Damkohler numbers much smaller than the extinction Damkohler number until the transition to four-stripe solution occurs at the first forward transition Damkohler number. At the second forward transition Damkohler number, somewhat smaller than the first transition Damkohler number, the transition to two-stripe solution occurs. However, anu further transition from two-stripe solution to one-stripe solution is not always possible even if one-stripe solution can be independently accessed for particular initial conditions. The Damkohler number ranges for two-stripe and one-stripe solutions are found to be virtually identical because each stripe is an independent structure if distance between stripes is sufficiently large. By increasing the Damkohler number, the backward transition can be observed. In comparison with the forward transition Damkohler numbers, the corresponding backward transition Damkohler numbers are always much greater, thereby indicating significant hysteresis between the stripe patterns of strained diffusion flames.

사회경제적 위치와 유방암 수술 후 총 사망위험과의 관련성 (Association Between Socioeconomic Status and All-Cause Mortality After Breast Cancer Surgery: Nationwide Retrospective Cohort Study)

  • 박미진;정우진;이선미;박종혁;장후선
    • Journal of Preventive Medicine and Public Health
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    • 제43권4호
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    • pp.330-340
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    • 2010
  • Objectives: This study aims to evaluate and explain the socioeconomic inequalities of all-cause mortality after breast cancer surgery in South Korea. Methods: This population based study included all 8868 females who underwent radical mastectomy for breast cancer between January 2002 and June 2003. Follow-up for mortality continued from January 2002 to June 2006. The patients were divided into 4 socioeconomic classes according to their socioeconomic status as defined by the National Health Insurance contribution rate. The relationship between socioeconomic status and all-cause mortality after breast cancer surgery was assessed using the Cox proportional hazards model with adjusting for age, the Charlson’s index score, emergency hospitalization, the type of hospital and the hospital ownership. Results: Those in the lowest socioeconomic status group had a significantly higher hazard ratio of 2.09 (95% CI =1.50 - 2.91) compared with those in the highest socioeconomic group after controlling for all the identifiable confounding variables. For allcause mortality after radical mastectomy, all the other income groups showed significantly higher 3-year mortality rates than did the highest income group. Conclusions: The socioeconomic status of breast cancer patients should be considered as an independent prognostic factor that affects all-cause mortality after radical mastectomy, and this is possibly due to a delayed diagnosis, limited access or minimal treatment leading to higher mortality. This study may provide tangible support to intensify surveillance and treatment for breast cancer among low socioeconomic class women.

Demographics, Social Media Use and Perceived Academic Stress of Secondary School Students in St. Thomas Aquinas College, Akure, Nigeria

  • Igbinovia, Magnus Osahon;Idhalama, Ogagaoghene Uzezi;Alex-Nmecha, Juliet C.
    • International Journal of Knowledge Content Development & Technology
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    • 제9권4호
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    • pp.7-29
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    • 2019
  • The study was carried out to investigate the influence of demographics and social media use on perceived academic stress of secondary school students in St. Thomas Aquinas College, Akure, Nigeria. This was achieved using five research questions and four null hypotheses. The population of the study consisted of 1,107 students at ISCED level 3, out of which 286 were selected based on the Israel (2003) model for determining sample size. The Ex-Post Facto (EPT) research design of the correlational type was employed to investigate the study while questionnaire was used for data elicitation. Out of the 286 copies distributed, 192 (67% response rate) were retrieved and analyzed using descriptive statistics (frequency, percentage, mean and standard deviation) and inferential statistics (correlation and multiple regression). The findings revealed that there is high frequency of social media use among secondary school students, majorly for meeting new friends and chatting. The perceived academic stress (PAS) of the students was found to be moderate. Of the three demographics considered, only class had significant influence on PAS. Use of social media did not have significantly influence on PAS of the students. When combined, demographics and social media use predicted PAS; and when considered relatively, of the independent variables, only class as an aspect of demographics predicted PAS. Therefore, the authors concluded that PAS of secondary school students is not directly influenced by demographics (except for class) and social media use. Based on the study's conclusion, recommendations were made.

연립방정식을 이용한 운전유형별 회전교차로 사고모형 (Simultaneous Equation Models for Evaluating Roundabout Accidents According to Different Driving Types)

  • 김경환;박병호
    • 대한교통학회지
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    • 제30권5호
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    • pp.3-10
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    • 2012
  • 이 연구는 회전교차로의 교통사고를 다루고 있다. 연구의 목적은 연립방정식을 이용한 회전교차로의 운전유형별 교통사고모형을 구축하는데 있다. 이를 위해 이 연구는 국내 회전교차로 39개소에서 발생한 148건의 사고자료와 통계 프로그램인 SPSS 17.0을 이용하였다. 또한 사고모형은 2SLS(2단계 최소자승) 추정법을 이용하여 구축하였다. 주요 결과는 다음과 같다. 첫째, 사고건수와 EPDO는 쌍방적 관계를 갖는 것으로 평가되었다. 둘째, 운전유형별로 개발된 6개의 연립방정식은 통계적으로 유의한 것으로 분석되었다. 셋째, 개발된 모형은 공통변수와 특정변수를 사용하여 비교 분석되었다. 마지막으로 독립변수에는 ADT, 상충비, 중차량 비율, 회전차로 폭, 회전차로 수, 접근로 차로폭, 접근로 평균 차로 수, 주차시설 유무 및 정류장 유무가 채택되었다.