• 제목/요약/키워드: Mixed Effects Models

검색결과 170건 처리시간 0.028초

TENS와 SSP가 전류지각역치 및 통증역치에 미치는 효과 (The Effect of Current Perception Threshold and Pain Threshold through Transcutaneous Electrical Nerve Stimulation and Silver Spike Point Therapy)

  • 윤미정;이완희
    • The Journal of Korean Physical Therapy
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    • 제23권2호
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    • pp.53-59
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    • 2011
  • Purpose: This study was designed to compare the effects of transcutaneous electrical nerve stimulation (TENS) and silver spike point (SSP) therapy on current perception threshold (CPT) and mechanical pain threshold (MPT). Methods: Forty-five healthy adult male and female subjects were studied. Fourteen of them were males and twenty-one were females. Subject were randomly assigned to receive; (1) TENS (80/120 Hz alternating frequency), (2) SSP (3 Hz), or (3) no treatment (control group). Electric stimulation was applied over LI4 and LI11 on acupuncture points of the left forearm for 30 minutes. CPT and MPT were recorded before and after electrical stimulation. The data were analyzed using linear mixed models, with group treated as a between subject factor and time a within-subject factor. Results: At 30 minutes after cessation of electrical stimulation the CPT of C fibers and A${\delta}$fibers was reduced in the TENS group that of C fibers was reduced in the SSP group (p<0.05). After cessation of electrical stimulation, the MPT of C fibers and A${\delta}$fibers increased in the TENS group, and that of A${\delta}$fibers increased in the SSP group (p<0.05). Conclusion: After TENS and SSP stimulation, MPT of C fibers and A${\delta}$fibers were selectively increased. In particular, the TENS group showed increases in both C and A${\delta}$fibers, while the SSP group showed increases only in A${\delta}$fibers.

방사열 자극실험쥐에서 Ketorolac과 Morphine의 병용투여 효과 (The Analgesic Interaction between Ketorolac and Morphine in Radiant Thermal Stimulation Rat)

  • 노장호;최동훈;이윤우;윤덕미
    • The Korean Journal of Pain
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    • 제18권1호
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    • pp.10-14
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    • 2005
  • Background: Previous studies have suggested synergistic analgesic drug interactions between NSAIDs and opioids in neuropathic and inflammatory pain models. The aim of this study was to investigate the analgesic drug interaction between intraperitoneal (IP) ketorolac and morphine in radiant thermal stimulation rat. Methods: Initially, we assessed the withdrawal latency time of the hindpaw to radiant thermal stimulation every 15 min for 1 hour and every 30 min for next 1 hour after IP normal saline 5 ml (control group). The latency time was changed into percent maximal possible effect (%MPE). Next, IP dose response curves were established for the %MPE of morphine (0.3, 1, 3, 10 mg/kg) and ketorolac (3, 10, 30 mg/kg) to obtain the $ED_{50}$ for each agent. And we confirmed that the IP morphine effect was induced by opioid receptor through IP morphine followed by IP naloxone. At last, we injected three doses of IP ketorolac (3, 10, 30 mg/kg) mixed with one dose of morphine (2 mg/kg) for fixed dose analysis. Results: IP morphine delayed the paw withdrawal latency time dose dependently, but not ketorolac. $ED_{50}$ of IP morphine was 2.1 mg/kg. And the IP morphine effect was reversed to control level by IP naloxone. IP ketorolac + morphine combination showed no further additional effects on paw withdrawal latency time over morphine only group. Conclusions: IP ketorolac did not produce antinociceptive effect during radiant thermal stimulation. There was neither additional nor synergistic analgesic interaction between IP morphine and ketorolac in thermal stimulation rat.

군집 특정 변량효과를 포함한 유한 혼합 모형의 베이지안 분석 (Bayesian analysis of finite mixture model with cluster-specific random effects)

  • 이혜진;경민정
    • 응용통계연구
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    • 제30권1호
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    • pp.57-68
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    • 2017
  • 대량의 데이터에 있어 전반적인 특성 및 구조를 파악하는데 유용하기 때문에 다양한 분야에서 군집분석을 사용하고 있다. Dempster 등 (1977)에서 정의된 expectation-maximization(EM) 알고리즘은 가장 보편적으로 사용되는 군집분석 방법이다. 선형모형의 유한혼합물(finite mixture of linear model) 기법 또한 군집분석 방법 중 많이 사용되는 방법이며 베이지안 군집방법은 Bernardo와 Giron (1988)이 군집에 대한 가중치 확률만 모를 경우 처음 적용하였다. 우리는 이 연구에서 일반적인 선형모형의 유한혼합물이 아닌 군집특정(cluster-specific) 변량효과를 모형에 포함하여 베이지안 분석방법인 깁스표집법(Gibbs sampling)을 사용한다. 제안한 모형의 특성 및 표집법에 대하여 설명하였고 모의실험 및 실제 데이터 분석을 통하여 모형의 유용성을 파악하였다. Hurn 등 (2003)의 CO2 데이터에 모형을 적용하여 변량효과가 없는 모형, 개체특정(subject-specific) 변량효과 모형과 비교하였다.

Association Analysis of Charcoal Rot Disease Resistance in Soybean

  • Ghorbanipour, Ali;Rabiei, Babak;Rahmanpour, Siamak;Khodaparast, Seyed Akbar
    • The Plant Pathology Journal
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    • 제35권3호
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    • pp.189-199
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    • 2019
  • In this research, the relationships among the 31 microsatellite markers with charcoal rot disease resistance related indices in 130 different soybean cultivars and lines were evaluated using association analysis based on the general linear model (GLM) and the mixed linear model (MLM) by the Structure and Tassel software. The results of microsatellite markers showed that the genetic structure of the studied population has three subpopulations (K=3) which the results of bar plat also confirmed it. In association analysis based on GLM and MLM models, 31 and 35 loci showed significant relationships with the evaluated traits, respectively, and confirmed considerable variation of the studied traits. The identified markers related to some of the studied traits were the same which can probably be due to pleiotropic effects or tight linkage among the genomic regions controlling these traits. Some of these relationships were including, the relationship between Sat_252 marker with amount of charcoal rot disease, Satt359, Satt190 and Sat_169 markers with number of microsclerota in stem, amount of charcoal rot disease and severity of charcoal rot disease, Sat_416 marker with number of microsclerota in stem and amount of charcoal rot disease and the Satt460 marker with number of microsclerota in stem and severity of charcoal rot disease. The results of this research and the linked microsatellite markers with the charcoal rot disease-related characteristics can be used to identify the suitable parents and to improve the soybean population in future breeding programs.

개념적 수문분할모형의 보정에 미치는 수문기후학적 조건의 영향 (Effects of Hydro-Climate Conditions on Calibrating Conceptual Hydrologic Partitioning Model)

  • 최정현;서지유;원정은;이옥정;김상단
    • 한국물환경학회지
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    • 제36권6호
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    • pp.568-580
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    • 2020
  • Calibrating a conceptual hydrologic model necessitates selection of a calibration period that produces the most reliable prediction. This often must be chosen randomly, however, since there is no objective guidance. Observation plays the most important role in the calibration or uncertainty evaluation of hydrologic models, in which the key factors are the length of the data and the hydro-climate conditions in which they were collected. In this study, we investigated the effect of the calibration period selected on the predictive performance and uncertainty of a model. After classifying the inflows of the Hapcheon Dam from 1991 to 2019 into four hydro-climate conditions (dry, wet, normal, and mixed), a conceptual hydrologic partitioning model was calibrated using data from the same hydro-climate condition. Then, predictive performance and post-parameter statistics were analyzed during the verification period under various hydro-climate conditions. The results of the study were as follows: 1) Hydro-climate conditions during the calibration period have a significant effect on model performance and uncertainty, 2) calibration of a hydrologic model using data in dry hydro-climate conditions is most advantageous in securing model performance for arbitrary hydro-climate conditions, and 3) the dry calibration can lead to more reliable model results.

The acoustic cue-weighting and the L2 production-perception link: A case of English-speaking adults' learning of Korean stops

  • Kong, Eun Jong;Kang, Soyoung;Seo, Misun
    • 말소리와 음성과학
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    • 제14권3호
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    • pp.1-9
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    • 2022
  • The current study examined English-speaking adult learners' production and perception of L2 Korean stops (/t/ or /t'/ or /th/) to investigate whether the two modalities are linked in utilizing voice onset time (VOT) and fundamental frequency (F0) for the L2 sound distinction and how the learners' L2 proficiency mediates the relationship. Twenty-two English-speaking learners of Korean living in Seoul participated in the word-reading task of producing stop-initial words and the identification task of labelling CV stimuli synthesized to vary VOT and F0. Using logistic mixed-effects regression models, we quantified group- and individual-level weights of the VOT and F0 cues in differentiating the tense-lax, lax-aspirated, and tense-aspirated stops in Korean. The results showed that the learners as a group relied on VOT more than F0 both in production and perception (except the tense-lax pair), reflecting the dominant role of VOT in their L1 stop distinction. Individual-level analyses further revealed that the learners' L2 proficiency was related to their use of F0 in L2 production and their use of VOT in L2 perception. With this effect of L2 proficiency controlled in the partial correlation tests, we found a significant correlation between production and perception in using VOT and F0 for the lax-aspirated stop contrast. However, the same correlation was absent for the other stop pairs. We discuss a contrast-specific role of acoustic cues to address the non-uniform patterns of the production-perception link in the L2 sound learning context.

자원봉사활동과 고혈압 및 관련 현상과의 전향적 연구 (Volunteering, Hypertension Risks, and Related Phenomena: A Prospective Cohort Study)

  • 이현기
    • 한국노년학
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    • 제41권3호
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    • pp.397-420
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    • 2021
  • 본 논문은 전향적 설계를 통하여 중장년 및 노년기 성인 자원봉사와 고혈압 발생, 고혈압증세 호전, 일상생활활동 어려움발생, 약복용 및 치료 등과의 관계를 규명하고자 한다. 이를 위해 2008년~2018년까지 10년에 걸쳐 수집된 종단 패널데이터를 사용했으며 분석 코호트 약 5,867명을 표본 추출하여 멀티레벨 혼합효과일반화선형 모델로 통계분석을 수행했다. 분석결과 자원봉사를 적어도 연 200시간 이상 한 사람은 안했을 때 보다 고혈압발생위험이 3.4배 낮았고, 연 50~99시간 한 사람은 안했을 때 보다 고혈압 증세호전이 더 크게 증가하였으며, 연 200시간 이상 자원봉사를 한 사람은 안했을 때 보다 활동어려움 발생확률이 7.7배 낮았으며, 그리고 연 50~99시간 자원봉사를 한 사람은 안했을 때 보다 약 복용 및 치료 발생 확률이 2.5배 낮은 것으로 나타났다. 이 결과는 중장년 및 노년기 성인의 자원봉사는 고혈압 및 관련 현상에 유익한 개선 효과가 있다는 것을 함의한다. 그리고 연구 한계점, 추후 연구방향, 실천함의를 논의했다.

Impact of combined at-home bleaching and whitening toothpaste use on the surface and color of a composite resin

  • Carolina Meneghin Barbosa;Renata Siqueira Scatolin;Waldemir Francisco Vieira-Junior;Marcia Hiromi Tanaka;Laura Nobre Ferraz
    • Restorative Dentistry and Endodontics
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    • 제48권3호
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    • pp.26.1-26.12
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    • 2023
  • Objective: This in vitro study aimed to evaluate the effects of different whitening toothpastes on a composite resin during at-home bleaching with 10% carbamide peroxide. Materials and Methods: Sixty samples (7 mm × 2 mm) were used for color and roughness analyses, while another 60 samples (3 mm × 2 mm) were utilized to assess microhardness. The factors analyzed included toothpaste, for which 5 options with varying active agents were tested (distilled water; conventional toothpaste; whitening toothpaste with abrasive agents; whitening toothpaste with abrasive and chemical agents; and whitening toothpaste with abrasive, chemical, and bleaching agents). Brushing and application of whitening gel were performed for 14 days. Surface microhardness (SMH), surface roughness (Ra), and color (ΔL*, Δa*, Δb, ΔE*ab, and ΔE00) were analyzed. The Ra and SMH data were analyzed using mixed generalized linear models for repeated measures, while the color results were assessed using the Kruskal-Wallis and Dunn tests. Results: Between the initial and final time points, all groups demonstrated significant increases in Ra and reductions in SMH. No significant differences were found between groups for SMH at the final time point, at which all groups differed from the distilled water group. Conventional toothpaste exhibited the lowest Ra, while whitening toothpaste with abrasive agent had the highest value. No significant differences were observed in ΔL*, Δa*, and Δb. Conclusions: While toothpaste composition did not affect the color stability and microhardness of resin composite, combining toothbrushing with whitening toothpaste and at-home bleaching enhanced the change in Ra.

Comparative analysis of two methods of laser induced boron isotopes separation

  • K.A., Lyakhov;Lee, H.J.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.407-408
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    • 2011
  • Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

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수변구역 조성녹지의 탄소저감 효과 및 증진방안 (Effects and Improvement of Carbon Reduction by Greenspace Establishment in Riparian Zones)

  • 조현길;박혜미
    • 한국조경학회지
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    • 제43권6호
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    • pp.16-24
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    • 2015
  • 본 연구는 국내 4대강 유역에 조성된 수변녹지를 대상으로 탄소의 저장 및 연간 흡수를 계량화하고, 수변녹지의 탄소저감 효과를 증진하기 위한 조성방안을 모색하였다. 표본 선정한 40개소 연구 대상지의 녹지구조 및 식재기법은 흉고직경이 평균 $6.9{\pm}0.2cm$이고 식재밀도가 $10.4{\pm}0.8$주/$100m^2$로서, 소형 수목의 저밀 단층식재로 대표된다. 식재수목에 의한 단위면적당 탄소의 저장량과 연간 흡수량은 각각 평균 $8.2{\pm}0.5t/ha$, $1.7{\pm}0.1t/ha$/년이고, 식재밀도가 높을수록 증가하는 경향을 보였다. 토양의 유기물함량과 단위면적당 탄소저장량은 각각 $1.4{\pm}0.1%$, $26.4{\pm}1.5t/ha$이었다. 대상지의 수목과 토양은 1ha당 약 61kL의 휘발유 소비에 상당하는 탄소량을 저장하고, 수목은 해마다 1ha당 3kL의 휘발유 소비에 기인한 탄소배출량을 상쇄하는 효과를 나타냈다. 이 탄소저감은 식재 후 5년 이상~10년 미만 생장한 효과로서 식재수목의 생장과 더불어 훨씬 더 증가할 것으로 예측된다. 연구 대상지와 상이한 식재기법의 조성모델들을 선정하여 향후 30년 동안 수목생장에 따른 연간 탄소흡수량의 변화를 비교 시뮬레이션하였다. 그 결과, 경과년도별 누적 탄소흡수량은 식재규격이 더 크고 식재밀도가 더 높은 다층 군식의 생태식재모델에서 저밀 단층식재인 대상지보다 10년 및 30년 경과시 각각 약 1.9배, 1.5배 더 많았다. 수변녹지의 탄소저감 효과를 증진하기 위해서는 규격이 상대적으로 큰 수목을 혼식하는 다층 군식, 속성수를 포함하여 연간 생장률이 양호한 자생수종의 중 고밀 식재, 식재수종의 정상적 생장에 적합한 토양조건 구비 등이 요구된다. 본 연구결과는 조성 초기단계인 수변녹지 사업에서 수질보전 및 생물서식에 부가하여 탄소흡수원의 역할을 제고하기 위한 실용적 지침이 될 것으로 기대한다.