• 제목/요약/키워드: linear mixed regression

검색결과 132건 처리시간 0.019초

해수 포말분리공정의 해석 및 모델 (Modeling of Foam Separator for Sea Water Treatment)

  • 허현철;서재관;박은주;김성구
    • 한국수산과학회지
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    • 제32권2호
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    • pp.165-169
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    • 1999
  • 포말분리 장치를 이용한 해수 중의 단백질 제거 특성을 조사한 결과, 단백질 농도가 높을 수록 또한 폭기량이 높을수록 단백질의 제거속도는 증가하는 것으로 나타났다. 이러한 각각의 제거특성을 통계학적으로 비선형 회귀분석하여 각각의 인자의 변화에 따른 단백질 농도의 변화를 다음의 식으로 나타낼 수 있었다. $$f\;(Co,\;u)=1.5712\times10^{-7}\timesCo^{3.061}\timesu^{1.258}$$ 위 식을 이용하여 유한차분법으로 시뮬레이션을 수행한 결과 실제 포말분리 운전에서 나타난 결과와 상관성이 아주 높은 결과를 얻을 수 있었다.

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New prediction equations for the estimation of maxillary mandibular canine and premolar widths from mandibular incisors and mandibular first permanent molar widths: A digital model study

  • Shahid, Fazal;Alam, Mohammad Khursheed;Khamis, Mohd Fadhli
    • 대한치과교정학회지
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    • 제46권3호
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    • pp.171-179
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    • 2016
  • Objective: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. Methods: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. Results: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, $r^2=0.7395$) and mandibular (r = 0.8708, $r^2=0.7582$) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on $Y=15.746+0.602{\times}sum$ of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), $Y=18.224+0.540{\times}(SMI+molars)$, and $Y=16.186+0.586{\times}(SMI+molars)$ for both genders, and to estimate mandibular arches the parameters used were $Y=16.391+0.564{\times}(SMI+molars)$, $Y=14.444+0.609{\times}(SMI+molars)$, and $Y=19.915+0.481{\times}(SMI+molars)$. Conclusions: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.

Plate waste study among hospitalised patients receiving texture-modified diet

  • Razalli, Nurul Huda;Cheah, Chui Fen;Mohammad, Nur Mahirah Amani;Manaf, Zahara Abdul
    • Nutrition Research and Practice
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    • 제15권5호
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    • pp.655-671
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    • 2021
  • BACKGROUND/OBJECTIVES: While plate waste has been widely investigated in hospitals, there have been minimal studies specific to the texture-modified diet (TMD). This study aims to determine the percentage of plate waste among patients prescribed with TMD and its contributory factors. SUBJECTS/METHODS: This was a single-centre study conducted in the university hospital on three types of TMD (blended diet, mixed porridge, minced diet) during lunch and dinner meals. Weighing method and visual estimation method assisted by digital photograph were adopted in this study. Face to face interview was carried out to investigate on 1) the food/food service quality factors in terms of patients' satisfaction level towards sensorial quality of food and food services provided and 2) the clinical/external factors including appetite, the provision of oral nutrition support, time taking the diet, the need for feeding assistance and the length of hospital stay. RESULTS: The mean percentage of overall plate waste of 95 patients receiving TMD was high (47.5%). Blended diet was identified as the most wasted diet (65%) followed by minced diet (56%) and mixed porridge (35%). Satisfaction level among patients was moderate. Patients on TMD in general had higher satisfaction level on the aspect of food service as compared to food quality. Substantial association between sensorial qualities of food and plate waste were varied according to individual TMD type. A multiple linear regression showed that only the satisfaction level toward the aspects of appearance and variety of foods were the predictors of TMD plate waste (R2 = 0.254, P < 0.05). CONCLUSIONS: A significant relationship between the percentage of plate waste and the overall satisfaction level of patients receiving TMD suggests that vigorous strategies are needed to reduce the food waste of TMD which will lead to a better nutritional status and clinical outcomes among the patients.

Effects of different feeding systems on ruminal fermentation, digestibility, methane emissions, and microbiota of Hanwoo steers

  • Seul Lee;Jungeun Kim;Youlchang Baek;Pilnam Seong;Jaeyong Song;Minseok Kim;Seungha Kang
    • Journal of Animal Science and Technology
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    • 제65권6호
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    • pp.1270-1289
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    • 2023
  • This study evaluates how different feeding systems impact ruminal fermentation, methane production, and microbiota of Hanwoo steers native to Korea. In a replicated 2 × 2 crossover design over 29 days per period, eight Hanwoo steers (507.1 ± 67.4 kg) were fed twice daily using a separate feeding (SF) system comprising separate concentrate mix and forage or total mixed rations (TMR) in a 15:85 ratio. The TMR-feeding group exhibited a considerable neutral detergent fiber digestibility increase than the SF group. However, ruminal fermentation parameters and methane production did not differ between two feeding strategies. In addition, TMR-fed steers expressed elevated Prevotellaceae family, Christensenellaceae R-7 group, and an unidentified Veillonellaceae family genus abundance in their rumen, whereas SF-fed steers were rich in the Rikenellaceae RC9 gut group, Erysipelotrichaceae UCG-004, and Succinivibrio. Through linear regression modeling, positive correlations were observed between the Shannon Diversity Index and the SF group's dry matter intake and methane production. Although feeding systems do not affect methane production, they can alter ruminal microbes. These results may guide future feeding system investigations or ruminal microbiota manipulations as a methane-mitigation practice examining different feed ingredients.

Analysis of eating behavior of Indonesian women from multicultural and non-multicultural families

  • Ulya Ardina;Su-In Yoon;Jin Ah Cho
    • Journal of Nutrition and Health
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    • 제57권2호
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    • pp.228-243
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    • 2024
  • Purpose: This study aimed to identify the distinctions in dietary and health-related behaviors among Indonesian women who marry Koreans or into multicultural families (MF) and those who marry Indonesians living in Korea (IK) and in Indonesia (II). Methods: The study was performed with 192 subjects using an online questionnaire regarding food choice, dietary and health behavior, and nutrition quotient (NQ). The analysis used Pearson's chi-squared test, the Fisher's exact test, multinomial logistic regression, and the general linear model. Results: The MF group consumed Korean food more than once a day and Indonesian food 1-2 times monthly (p < 0.001). The main challenge for the IK and II groups in consuming Korean food was the presence of pork and the different food flavors (p < 0.001). The MF group tended to have normal body mass index, consumed more vitamin and mineral supplements (p = 0.014), and exercised regularly ≥150 min/week compared to the IK and II groups (p < 0.001). However, the MF group had the highest rate of skipping breakfast (p = 0.040). When evaluating the NQ of the participants, the MF group consumed more vegetables (p = 0.026), mixed grains (p = 0.031), and spicy and salt soups (p = 0.006). The II group consumed more fish (p = 0.005), beans (p = 0.009), and nuts (p = 0.003). The IK group checked the nutrition labels the most (p = 0.005), while their consumption of vegetables, fish, beans, and nuts was lowest. The MF group had a higher balance score, which resulted in a substantially more nutritious food intake compared to the other two groups (p = 0.037). Conclusion: The MF group consumed more vegetables and mixed grains, adequate fish, beans, and nuts, and engaged in longer daily physical activity. However, the IK group had a relatively low-quality diet and nutritional intake status compared to the other two groups, and this needs to be improved in the future.

A Study on the Acute Effects of Fine Particles on Pulmonary Function of Schoolchildren in Inner-Mongolia, China

  • Kim, Dae-Seon;Yu, Seung-Do;Ahn, Seung-Chul;Na, Jin-Gyun
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 국제학술대회
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    • pp.311-314
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    • 2005
  • To evaluate the acute effects of fine particles on pulmonary function, a longitudinal study was conducted. This study was carried out for the schoolchildren(3rd and 4th grades) living in Inner-Mongolia, China. 113 Chinese children were asked to record their daily levels of peak expiratory flow rate(PEPR) using portable peak flow meter(mini-Wright) for 40 days and 3 time everyday(12 April 2004 to 21 May 2004). The atmospheric concentration of fine particles in study area was also determined everyday during same period. The relationship between dailypeak expiratory flow rate(PEFR) and fine particle levels was analyzed using a mixed linear regression models including gender, age, height, the presence of respiratory symptoms, and daily average relative humidity as extraneous variables. The analysis showed that the increase of fine particle concentrations was negatively associated with the variability in PEPR. The IQR(inter-quartile range) increments of $PM_{10}$ or $PM_{2.5}(66.0{\mu}g/m^3$ and $118.9{\mu}g/m^3$, respectively) were also shown to be related with 1.422L/min(95% Confidence intervals: 0.270 ${\sim}$ 2.574) and 1.214L1min(95% Cl: 0.010 ${\sim}$ 2.418) decline in PEFR.

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변이할당분석을 이용한 충청남도 금강권 산업구조 특성 분석 (A Study on Characteristics of Industrial Structure by Shift-Share Analysis : The Case of Chungnam Geumgang Area)

  • 김성록;이종상
    • 농촌계획
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    • 제20권1호
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    • pp.127-134
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    • 2014
  • This study, in order to complement instability of analysis result stemming from the choice between reference point and comparison point which is pointed out as the defect of shift-share analysis, conducted shift-share analysis using Gross Regional Domestic Product (GRDP) trend of Geumgang area, Chungcheongnam-do for the period from 2000 to 2011. As a result of the analysis, (1) industries that had both the positive Regional Share Effect (RSE) and Industrial Mixed Effect (IME) were service industries such as manufacturing industry, electricity gas, transportation industry, art, etc., which are positively influencing the regional industry. (2) industries that had both the negative RSE and IME were other service industries such as wholesale and retail businesses, lodging industry, food industry, real estate business and leasing service, business service industry, public administration, etc., which provide basic livelihood services for the residents. (3) industries that had the positive RSE and negative IME were agriculture, forestry and fishery industry, mining industry, construction industry, and educational service industry. (4) industries that had the negative RSE and positive IME were info-communications industry, financial and insurance businesses, health industry, etc.

The Impact of Increased Credit Card Usage on Costs Incurred by Merchant Establishments in Singapore

  • Seetharaman, A.;Patwa, Nitin;Niranjan, Indu;Kavuri, Srinivas Phani
    • The Journal of Asian Finance, Economics and Business
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    • 제3권4호
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    • pp.43-56
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    • 2016
  • The research aims to help merchant acquiring institutions gain a better insight on what merchant establishments in the Singapore market perceive of the costs they incur due to credit card acceptance. The research attempts to study the Singapore market and establish if increased credit card usage does increase costs for the merchant establishments that accept credit cards, this will help to acquire institutions in Singapore have a better understanding of merchant perceptions and what drives or deters credit card acceptance in the Singapore market. The survey was based on an interview of merchant establishments and the views of the merchants and was not based on their financial data. As a first step, the variables used in the survey were tested for interdependence using Chi-square tests; subsequently data reduction using factor analysis was performed and finally linear regression to establish a relation between dependent and independent variables. Merchant establishment believe accepting credit cards and increasing volume is costlier compared to another form of payment, but have mixed awareness about interchange fee. It also indicated that interchange fee and cardholder benefits are independent of the merchant establishments. The study only broadly attempts to gauge merchants view if increased credit card usage has increased costs for them.

토지이용별 로터리 및 회전교차로 사고율 모형개발 및 논의 (Modeling and Discussing the Accident Rate Model of Rotary and Roundabout by Type of Land Use)

  • 이민영;박병호
    • 한국안전학회지
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    • 제33권1호
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    • pp.135-141
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    • 2018
  • Rotary that causes traffic delays and safety issues by high-speed entry vehicles is currently being improved to roundabout. The operational difference between rotary and roundabout can cause driver's confusion and traffic accident. The purpose of this study is to develop the accident rate models which explain the factors related to the accidents by land use and intersection type. The main results are as follows. First, the null hypotheses that the type of land use and two intersections do not affect the accident rate are rejected. Second, the conflicting factors such as the number of crosswalk and bicycle lane should be carefully considered to reduce traffic accident at rotary. In the case of roundabout, greater than 3.5 m in circulatory lane width and two circulatory lane are analyzed to be important to prevent the accidents. Finally, the commercial and mixed areas are evaluated to be weak to traffic accidents than residential area.

Socioeconomic Status and Number of Children Among Korean Women: The Healthy Twin Study

  • Kim, Jinseob;Sung, Joohon
    • Journal of Preventive Medicine and Public Health
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    • 제46권1호
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    • pp.50-60
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    • 2013
  • Objectives: This study aimed to evaluate whether the birth rate is associated with socioeconomic status in the women of the Republic of Korea, where the birth rate is rapidly decreasing. Methods: This study included 732 females from the Healthy Twin Study, a family-twin cohort. The participants were classified into 3 socioeconomic groups according to their average income, education, and occupation. The association between socioeconomic status and number of children was assessed using gamma regression analysis with a generalized linear mixed model, adjusting for the age group, smoking/alcohol status, and family relationships. Results: The group with the highest education level had significantly fewer children compared with the group with the lowest education level (p=0.004). However, no significant associations were found according to household income level. The non-manual labor group had significantly fewer children compared with those working as homemakers (p=0.008). Conclusions: This study aimed to explain the causal relationship between socioeconomic status and number of children. Associations between some socioeconomic status and number of children were found in Korea.