• Title/Summary/Keyword: mixed-effects model

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Participation Intention of Activity-oriented Program of Local Residents of Rural and Mountain Villages - Policy Implication for the Eco-Mountain Village Project - (농산촌체험마을 지역주민의 체험프로그램 참여의향 - 산촌생태마을사업을 위한 정책적 제언 -)

  • Lee, Duk-Jae;Kim, Jong-Ho;Jeon, Jun-Heon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.1
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    • pp.1-11
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    • 2008
  • Factors for promoting the resident participation in mountain villages are suggested to introduce the activity-oriented program of green tourism using a multinomial logit model(MNLM). Direct surveying, using a structured questionnaire was performed on local residents in the different types of rural tourism villages such as mountain villages, agricultural themed villages, and the mixed types of villages. The MNLM revealed that participation intention in the program was significantly higher for males, those with lower education, and residents in mountain villages. The participation intention of the program had a negative relationship with the increase of expected problems not from the program itself, but from the results of the program such as income distribution and nature destruction. Participation intention also increased with the indirect effects of an investment by the Village Development Project, such as local cooperativeness, public mind, etc. It was suggested that to introduce the activity-oriented program in mountain villages, negative effects from the results had to be minimized, and positive effects from the indirect changes between local residents had to be maximized through better communication and policy endeavors.

Projection analysis for balanced incomplete block designs (균형불완비블럭설계의 사영분석)

  • Choi, Jaesung
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.2
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    • pp.347-354
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    • 2015
  • This paper deals with a method for intrablock anlaysis of balanced incomplete block designs on the basis of projections under the assumption of mixed effects model. It shows how to construct a model at each step by the stepwise procedure and discusses how to use projection for the analysis of intrablock. Projections are obtained in vector subspaces orthogonal to each other. So the estimates of the treatment effects are not affected by the block effects. The estimability of a parameter or a function of parameters is discussed and eigenvectors are dealt for the construction of estimable functions.

Symmetric and Asymmetric Effects of Financial Innovation and FDI on Exchange Rate Volatility: Evidence from South Asian Countries

  • QAMRUZZAMAN, Md.;MEHTA, Ahmed Muneeb;KHALID, Rimsha;SERFRAZ, Ayesha;SALEEM, Hina
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.23-36
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    • 2021
  • The study explores the nexus between foreign direct investment (FDI), financial innovation, and exchange rate volatility in selected South Asian countries for 1980 to 2017. The study applies the unit root test, Autoregressive Distributed Lagged, nonlinear ARDL, and causality test following Toda-Yamamoto. Unit root tests ascertain that variables are integrated in a mixed order; few variables are stationary at a level and few after the first difference. Empirical model estimation with ARDL, Long-run cointegration revealed with the tests of FPSS, WPSS, and tBDM by rejecting the null hypothesis of "no cointegration." This finding suggests that, in the long-run financial innovation, FDI inflows, and exchange rate volatility move together. Moreover, study findings established adverse effects running from FDI inflows and financial innovation to exchange rate volatility in the long run. These findings suggest that continual FDI inflows and innovativeness in the financial system assist in lessening the volatility in the foreign exchange market. Furthermore, nonlinear ARDL confirms the presence of asymmetric cointegration in the model. The standard Wald test established asymmetric effects running from FDI inflows and financial innovation to exchange rate volatility, both in the long and short run. Directional causality unveils feedback hypothesis holds for explaining causality between FDI, financial innovation, and exchange rate volatility.

Panel analysis of radish yield using air temperature (기온을 이용한 무 생산량 패널분석)

  • Kim, Yong-Seok;Shim, Kyo-Moon;Jung, Myung-Pyo;Jung, In-Tae
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.481-485
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    • 2014
  • According to statistical data the past ten years, cultivation area and yield of radish are steadily decreasing. This phenomenon cause instability of radish's supply due to meteorological chage, even if radish's yield per unit area is increasing by cultivation technological development. These problems raise radish's price. So, we conducted study on meteorological factors for accuracy improvement of radish yield estimation. Panel analysis was used with two-way effect model considering group effect and time effect. As the result, we show that mixed effects model (fixed effect: group, random effects: time) was statistical significance. According to the model, a rise of one degree in the average air temperature on August will decrease radish's yield per unit area by $428kg{\cdot}10a^{-1}$ and that in the average air temperature on October will increase radish's yield per unit area by $438kg{\cdot}10a^{-1}$. The reason is that radish's growth will be easily influenced by meteorological condition of a high temperature on August and by meteorological condition of a low temperature on Octoboer.

Recent Brazilian research on thunderstorm winds and their effects on structural design

  • Riera, Jorge D.;Ponte, Jacinto Jr.
    • Wind and Structures
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    • v.15 no.2
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    • pp.111-129
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    • 2012
  • Codes for structural design usually assume that the incident mean wind velocity is parallel to the ground, which constitutes a valid simplification for frequent winds caused by sypnoptic events. Wind effects due to other phenomena, such as thunderstorm downbursts, are simply neglected. In this paper, results of recent and ongoing research on this topic in Brazil are presented. The model of the three-dimensional wind velocity field originated from a downburst in a thunderstorm (TS), proposed by Ponte and Riera for engineering applications, is first described. This model allows the generation of a spatially and temporally variable velocity field, which also includes a fluctuating component of the velocity. All parameters are related to meteorological variables, which are susceptible of statistical assessment. An application of the model in the simulation of the wind climate in a region sujected to both EPS and TS winds is discussed next. It is shown that, once the relevant meteorological variables are known, the simulation of the wind excitation for purposes of design of transmission lines, long-span crossings and similar structures is feasible. Complementing the theoretical studies, wind velocity records during a recent TS event in southern Brazil are presented and preliminary conclusions on the validity of the proposed models discussed.

Mixed-Flow Pump Impeller-Diffuser Optimization Method by Using CFX and HEEDS (CFX 와 HEEDS 를 이용한 사류펌프 임펠러-디퓨저 최적화방법)

  • Lee, Yong Kab;Park, In Hyung;Shin, Jae Hyok;Kim, Sung;Lee, Kyoung Yong;Choi, Young Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.10
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    • pp.831-842
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    • 2015
  • An optimization process was developed to improve mixed-flow pump performance. The optimization process was combined with CFX (a computational fluid dynamics (CFD) code) and HEEDS (an optimization code). CFX is a widely used CFD software for turbo machinery, whereas HEEDS, which uses the SHERPA algorithm, is a newly introduced optimization code. HEEDS can use a large number of optimization variables; thus, it is possible to effectively consider interaction effects. In this paper, an impeller model, which is already optimized with design of experiments (DOE), is used as the base model. The optimization process developed in this paper shows an improved design within an acceptable timeframe.

Analysis of Rebound Effect from Road Extension in Seoul, Busan, Daegue, and Incheon (도로연장에 대한 반등효과 분석 -서울, 부산, 대구, 인천을 중심으로-)

  • Lee, Min Ha;Cho, Yongsung
    • Environmental and Resource Economics Review
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    • v.26 no.2
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    • pp.173-203
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    • 2017
  • The existence of rebound effect from road extension in Korea has been quantitatively verified using cross-sectional, time series data on four major cities - Seoul, Busan, Daegue and Incheon - between 2000 and 2013. The linear mixed effects model was constructed from six variables: total vehicle miles traveled (VMT), road extension, public transport users, gross regional domestic product (GRDP), regional population and fuel consumption. The main results can be summarized as VMT is positively correlated to road extension while negatively with public transport users. It indicates that the road extension-centered "supply-side" transportation policy induces "additional travel" and create "generated traffic" by enhancing driving efficiencies directly, or degrading other transport modes indirectly. Hence, the ultimate goal of road congestion reduction requires public transport-centered "demand management" rather than current supply-side policies.

Effects of Slow Programmable Cryopreservation on Preserving Viability of the Cultured Periodontal Ligament Cells from Human Impacted Third Molar

  • Kim, Jin-Woo;Kim, Tae-Yi;Kim, Ye-mi;Pang, Eun-Kyoung;Kim, Sun-Jong
    • Journal of Korean Dental Science
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    • v.8 no.2
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    • pp.57-64
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    • 2015
  • Purpose: This study was conducted to determine cell viability and differentiation capability of human periodontal ligament (PDL) cells and to elucidate the effects of cryopreservation on the activity of human third molar PDL cells by comparing PDL cells with and without cryopreservation. Materials and Methods: Human PDL fibroblasts obtained from immature third molars were cultured and divided into two groups. The experimental group was cryopreserved with a slow freezing rate of $0.5^{\circ}C/min$ from $4^{\circ}C$ to $-35^{\circ}C$ followed by plunging in liquid nitrogen at $-196^{\circ}C$ and cultured after fast thawing. The control group was cultured without cryopreservation. Cell viability, growth capacity and morphology were evaluated in both groups. Bivariate statistics were used to compare 2 groups and linear mixed model analysis was used to investigate the growth trends difference over time. Result: Cell viability and growth capacity were not significantly different between the 2 groups (P>0.05). Cultured cell of both groups showed fibroblast-like in appearance, and there were no significant differences in morphology between 2 groups. The mixed model analysis revealed no significant difference of growth capacity between 2 groups over time (${\beta}=-0.0009$; P=0.138). Conclusion: This study demonstrates that cryopreservation under control does not affect the biological properties of PDL cells, supporting the feasibility of autotransplantation of cryopreserved impacted third molars.

Modulation Effects on Acute Orofacial Inflammatory Pain in Rats by Curcuma longa L., Curcuma aromatica Salisb., Zingiber officinale Rosc. Extracts

  • Kim, Hee-Jin;Choi, Ja-Hyung;Kim, Hye-Jin;Yoon, Hyun-Soe;Lee, Min-Kyung
    • Biomedical Science Letters
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    • v.25 no.3
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    • pp.247-255
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    • 2019
  • Curcuma longa L. (C.L), Curcuma aromatica Salisb. (C.A) and Zingiber officinale Rosc. (Z.O) of Zingiberaceae plants which are well known as effects of natural anti-oxidant, anti-cancer and anti-inflammatory. We examined that the Zingiberaceae plants are involved in development and modulation of orofacial pain in rats. Male, 7- to 8-week-old, Sprague-Dawley rats weighing 240~280 g were used in this study. Experiments were performed using acute pain model that was caused by the injection of 5% formalin into the right vibrissa pad. The number of scratching or rubbing to the injection site was recorded for 9 consecutive 5-minute intervals following injection of formalin. The experimental groups were acute orofacial inflammatory pain; control group (formalin, 5%), vehicle group (5% formalin after sodium carboxymethyl cellulose), single administration group, single mixed administration group, repeated administration group. The experiments were performed various concentrations of Zingiberaceae plants extract. Therefore, oral administration of C.L, C.A, and Z.O (p.o., concentrations of 12.5, 25 mg/mL) in orofacial inflammatory pain model substantially decrease the nociceptive behavior in a concentration dependent manner. And it tended to decrease at low concentration (12.5 mg/mL) of single mixed and repeated administration more than single administration. This result means that Zingiberaceae plants extract affects the modulation of acute orofacial inflammatory pain. Thus, Zingiberaceae plants extract may be a potential therapeutic treatment for orofacial inflammatory pain.

Risperidone Monotherapy in Children and Adolescents with Autism Spectrum Disorders : A Naturalistic Study

  • Won, Eun-Kyung;Park, Jin-Park;Lee, Young-Ryul;Nam, Yoon-Young;Min, He-Ji;Kim, Yeni
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.26 no.4
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    • pp.273-278
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    • 2015
  • Objectives : We retrospectively investigated the efficacy and tolerability of risperidone monotherapy in subjects with autism spectrum disorder (ASD). In addition, we did mixed effect model analysis of the effects of risperidone in patients with ASDs naturalistically treated in a routine clinical setting to determine whether the clinical effects were maintained and the side effects were tolerable. Methods : This retrospective study assessed children and adolescents with ASD, who were on risperidone monotherapy from July 2010 to July 2011 at the Child and Adolescent ASD Clinic at Seoul National Hospital. Outcome measures included the Clinical Global Impression-Severity of Illness (CGI-S) and the CGI-Improvement (CGI-I) scales along with other clinical indices: dosage, target symptoms, and side effects. Results : The mean dose of risperidone in 47 children and adolescents with ASD (40 males, 7 females; age range 5-19 years) who were on risperidone monotherapy was $1.6{\pm}0.8mg/day$, and the mean duration of the treatment period was $20.2{\pm}17.3months$. Aggressive behavior, stereotypic behavior, irritability, and self-injurious behavior were the most frequent target symptoms of risperidone. The most common side effects were weight gain followed by somnolence and extrapyramidal symptoms. In a mixed effects model analysis of CGI-I scores, the mean CGI-I score at the 1 month follow-up was significantly different from the mean CGI-I score of the 3-month follow-up (p=.046), and the CGI-I scores were equally maintained over 3 to 48 months [F(6, 28.9)=4.393, p=.003]. Of the 47 patients, 33 patients (70.2%) were identified as the response group, showing an end point CGI-I rating of 3 or under and having continued risperidone treatment for at least 6 months. The baseline CGI-S score showed significant association with clinical response to risperidone (p=.005), the mean baseline CGI-S was higher in the response group compared to the non-response group. Conclusion : In this study, clinical improvement of risperidone stabilized around 3 months and was equally maintained up to 48 months with tolerable side effects, supporting maintenance of risperidone treatment in children and adolescents with ASDs.