• Title/Summary/Keyword: Difference-In-Difference (DiD)

Search Result 34, Processing Time 0.03 seconds

Comparison of different impression techniques for edentulous jaws using three-dimensional analysis

  • Jung, Sua;Park, Chan;Yang, Hong-So;Lim, Hyun-Pil;Yun, Kwi-Dug;Ying, Zhai;Park, Sang-Won
    • The Journal of Advanced Prosthodontics
    • /
    • v.11 no.3
    • /
    • pp.179-186
    • /
    • 2019
  • PURPOSE. The purpose of this study was to compare two novel impression methods and a conventional impression method for edentulous jaws using 3-dimensional (3D) analysis software. MATERIALS AND METHODS. Five edentulous patients (four men and one woman; mean age: 62.7 years) were included. Three impression techniques were used: conventional impression method (CI; control), simple modified closed-mouth impression method with a novel tray (SI), and digital impression method using an intraoral scanner (DI). Subsequently, a gypsum model was made, scanned, and superimposed using 3D analysis software. Mean area displacement was measured using CI method to evaluate differences in the impression surfaces as compared to those values obtained using SI and DI methods. The values were confirmed at two to five areas to determine the differences. CI and SI were compared at all areas, while CI and DI were compared at the supporting areas. Kruskal-Wallis test was performed for all data. Statistical significance was considered at P value <.05. RESULTS. In the comparison of the CI and SI methods, the greatest difference was observed in the mandibular vestibule without statistical significance (P>.05); the difference was < 0.14 mm in the maxilla. The difference in the edentulous supporting areas between the CI and DI methods was not significant (P>.05). CONCLUSION. The CI, SI, and DI methods were effective in making impressions of the supporting areas in edentulous patients. The SI method showed clinically applicability.

Effect of University Closure on the Prices of Nearby Apartments -In the Case of Dong-Pusan College- (대학의 폐교지정이 주변 지역 공동주택 가격에 미치는 영향 -동부산대학교를 중심으로-)

  • Kim, Min Kyu;Kim, Hyunsoo;Choi, Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.42 no.2
    • /
    • pp.273-279
    • /
    • 2022
  • In a recent decade, university closures have been a critical regional issue as a total of 17 universities have been closed while many more are facing closure in Korea. The local impact of university closures in the regions with declining populations has been far more detrimental and considered as one of the significant factors of the declining local economy, especially in the neighboring residential sectors. This study has taken an empirical approach to investigate the local impact of university closure on the housing market through a case of Dong-Pusan College in Busan, Korea. The study utilized Difference-in-Difference (DiD) to analyze the housing prices in proximity to the university and identified several factors associated with the local decline in the housing market in relation to university closure.

A standardization model based on image recognition for performance evaluation of an oral scanner

  • Seo, Sang-Wan;Lee, Wan-Sun;Byun, Jae-Young;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
    • /
    • v.9 no.6
    • /
    • pp.409-415
    • /
    • 2017
  • PURPOSE. Accurate information is essential in dentistry. The image information of missing teeth is used in optically based medical equipment in prosthodontic treatment. To evaluate oral scanners, the standardized model was examined from cases of image recognition errors of linear discriminant analysis (LDA), and a model that combines the variables with reference to ISO 12836:2015 was designed. MATERIALS AND METHODS. The basic model was fabricated by applying 4 factors to the tooth profile (chamfer, groove, curve, and square) and the bottom surface. Photo-type and video-type scanners were used to analyze 3D images after image capture. The scans were performed several times according to the prescribed sequence to distinguish the model from the one that did not form, and the results confirmed it to be the best. RESULTS. In the case of the initial basic model, a 3D shape could not be obtained by scanning even if several shots were taken. Subsequently, the recognition rate of the image was improved with every variable factor, and the difference depends on the tooth profile and the pattern of the floor surface. CONCLUSION. Based on the recognition error of the LDA, the recognition rate decreases when the model has a similar pattern. Therefore, to obtain the accurate 3D data, the difference of each class needs to be provided when developing a standardized model.

Difference in Chemotype Composition of Fusarium graminearum Populations Isolated from Durum Wheat in Adjacent Areas Separated by the Apennines in Northern-Central Italy

  • Prodi, A.;Purahong, W.;Tonti, S.;Salomoni, D.;Nipoti, P.;Covarelli, L.;Pisi, A.
    • The Plant Pathology Journal
    • /
    • v.27 no.4
    • /
    • pp.354-359
    • /
    • 2011
  • Chemotype composition of Fusarium graminearum strains, isolated from durum wheat kernels from naturally FHB infected fields in Northern and Central Italy, was investigated by multiplex PCR. The different climatic and environmental conditions of the two examined areas separated by the Apennines affected the composition of chemotypes. 15Ac-DON chemotype was predominant in both the sub areas. Nivalneol chemotype was more frequent in the warmer sub area.

The effect of acute diaphragmatic breathing exercise using DiP Belt on diaphragm motion and forced vital capacity (딥벨트를 이용한 일회성 가로막 호흡운동이 가로막 움직임과 노력성 폐활량에 미치는 영향)

  • Lee, Jae Seok;Kang, Tae Wook
    • Journal of Korean Physical Therapy Science
    • /
    • v.29 no.2
    • /
    • pp.57-65
    • /
    • 2022
  • Background: This study was to determine whether the diaphragmatic breathing exercise using a DiP Belt(Diaphragmatic Pressure Belt) is effective in increasing the diaphragmatic motion and forced vital capacity. Design: Pretest-Posttest design. Methods: A total of 44 subjects(15 male, 29 female) participated in this study. All subjects were measured the diaphragmatic motion with a sonography and the Forced Vital Capacity(FVC) was measured with a digital spirometer. After 4 weeks, the subjects were intervened the diaphragmatic breathing exercise using a DiP belt and were remeasured for diaphragm motion and FVC. Results: After exercise intervention, quiet breathing significantly increased with the change in diaphragmatic motion and showed a moderate effect size (p<.01, Cohen's d = -0.53). In addition, it was significantly increased in deep breathing and showed a high effect size (p<.001, Cohen's d = -1.32). The mean diaphragmatic contraction pressure increased, but there was no significant difference and the peak diaphragmatic contraction pressure increased significantly (p<.05). Both diaphragmatic contraction pressure showed small effect sizes (respectively Cohen's d = -0.28, -0.33). In spirometry, FVC, Forced Expiratory Volume in 1 second (FEV1), and FEV1/FVC% all increased, but there was no significant difference. Only peak expiratory flow increased significantly and showed a small effect size (p<.05, Cohen's d = -0.41). Conclusion: The DiP belt diaphragmatic breathing exercise that the principle of visual feedback can correct diaphragm breathing in a short time, so it is a useful breathing exercise device that can help the diaphragm breathing exercise in the right way in clinical practice.

The Influence of Dietary Characteristics on the Milk Quantity and Quality of Riverine Buffaloes: Estimate of the Energy/Protein Requirements, for a Medium-high Production, in the First Ninety Days of Lactation

  • Terramoccia, S.;Bartocci, A.;Giovanni, S. Di;Bartocci, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.3
    • /
    • pp.335-340
    • /
    • 2012
  • The data used came from two trials undertaken under the same climatic conditions (spring-summer). In both trials pluriparious buffaloes were utilized similar in weight, body condition score, and milk production from the previous year. From the first trial the data used was from the sub-period 23-88 DIM provided by seven animals fed ad libitum with diet A (6.69 MJ/kg DM; 158.30 g/kg of crude protein) with a forage/concentrate ratio of 48/52. From the second trial the data used was from the sub-period 33-90 DIM provided by seven animals fed ad libitum with diet B (6.63 MJ/kg DM; 179.50 g/kg of crude protein) and by seven animals fed ad libitum with diet C (5.99 MJ/kg DM; 155.40 g/kg of crude protein), each of the diets had the same forage/concentrate ratio (53/47). A significant difference was found in milk production between group B and C (13.08 vs. 11.56 kg/d, p<0.05), an intermediate production (12.10 kg/d) was noted in group A. A significant difference was found between fat (76.58 vs. 69.24 g/kg, p<0.05), protein (46.14 vs. 43.16 g/kg, p<0.05) and casein (39.94 vs. 34.98 g/kg, p<0.05) of the milk of group B with respect to group A. The milk of group C gave fat values (71.80 g/kg), protein (45.52 g/kg) and casein (39.06 g/kg) statistically equal to those of group B. The milk of groups B and C, in respect to the milk of group A, gave values of $K_{20}$ (1.77, 1.82 vs. 3.68 min, p<0.05), statistically lower and values of $A_{30}$ (48.28, 47.27 vs. 40.64 mm, p<0.05) statistically higher. Two simple linear regressions were calculated where the independent variable (x) was the daily standardized milk production, the dependent variable (y) or the daily intake of net energy or crude protein. Equation 1) NE (MJ/d) = 74.4049+2.8308${\times}$kg of normalized milk; equation 2) CP (kg/d) = 1.4507+0.1085${\times}$kg of normalized milk, both the equations were significant (p<0.05) with determination coefficients of 0.58 and 0.50 respectively. For a production of normalized milk that varies from 9 to 13 kg, the respective energy-protein concentrations fluctuate from 6.09 to 6.78 MJ/kg DM and from 148.00 to 174.46 g/kg DM.

Analysis of the Pricing effect due to Improvement of Awareness in Art market - focusing on the case of Dansekhwa in Korean art auction market (미술시장에서 인지도 상승의 가격효과 분석 - 국내 미술 경매시장의 단색화 사례를 중심으로 -)

  • You, Eun ji;Lee, Yong-Kwan
    • Review of Culture and Economy
    • /
    • v.21 no.1
    • /
    • pp.85-104
    • /
    • 2018
  • The studies related to the price of artworks have focused on how factors that are determined on production level, such as artists and the artwork materials of the studies, affect the artwork prices. As 'Dansekhwa' is in the spotlight within local Korean art auction matket, this study would like to analyze the trend of the price changes of 'Dansekhwa' with its growing popularity among the public. We have estimated the price changes based on 4,199 auction data of 20 artists with top 20 auction prices selected by the Korean Art Price Appraisal Association, between 2005 and 2016. Also, in order to compare and analyze the price changes of the 'Dansekhwa' products, we have classified the 20 artists into groups of Dansekhwa and non-Dansekhwa. Starting from 2013, when Dansekhwa has first appeared, we applied the Difference in the Difference model(DiD) to estimate the result. As a result, the difference between two groups showed 71% of price difference due to the increase in popularity of Dansekhwa. This result proves that recognition level has an important role for increase in price of an artwork. Moreover, the fact that the formalized style of Dansekhwa has linked to the appreciation of the price means that production of information could play an essential role in growth of art market. As recognition level of Korean artists and their artworks is considerably low within the local art market, putting in the effort to increase the popularity of artworks among the public might be a helpful way to magnify the potential demand.

A Study on Personality Traits of the Patients with TMJ Dysfunction through the MMPI (MMPI를 중심으로 한 악관절 기능장애 환자의 인성에 관한 연구)

  • 고명연;김영구
    • Journal of Oral Medicine and Pain
    • /
    • v.10 no.1
    • /
    • pp.17-31
    • /
    • 1985
  • Personality characteristics of TMJ dysfunction patients was studied by means of MMPI test. 100 TMJ dysfunction patients and 100 healthy controls were subjected at the Department of Oral Diagnosis and Oral Medicine, Pusan National University Hospital, during the period from March 1983 to February 1985. All the patients were divided into 2 groups namely, acute group and chronic group by duration of path and discomfort problems for 6 months or longer. The obtained results were as follows : 1. Mean value of T-scores on each clinical scale was within normal range in both patient and control group. 2. There was significant difference in scales of Hs, D. Hy, Pt, Sc and IR between patient and control group. 3. As compared with control group by sexual subclass, scales of Hs, Hy and Pt of both sex, scales of Sc and M-DI of male and scales of D of female in patient group were significantly higher than those in control group 4. The longer was duration of TMJ problems, i.e., in increasing order of control, acute and chronic group, the higher was mean value of T-scores on scales of Hs, D, Hy, Pt, Sc, IR and M-DI. 5. Mean values of T-scores on scales of Hs, D and Hy were the highest in all the clinical scales of total class and subclasses(i. e. male group, female group, acute group and chronic group) with TMJ dysfunction and showed 1-:i-2 (Hs, -Hy, -D. ) profile pattern, conversion "V.ot;V.

  • PDF

Conformational Analysis of Catecholamines-Raman, High Resolution NMR, and Conformational Energy Calculation Study

  • Park Mi-Kyung;Yoo Hee-Soo;Kang Young Kee;Lee Nam-Soo;Ichiro Hanazaki
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.3
    • /
    • pp.230-235
    • /
    • 1992
  • The conformational analysis has been done for catecholamines (dopamine, norepinephrine, and epinephrine) in the cationic and di-anionic states. The species responsible for adsorption on silver metal surface is anionic deprotonated at hydroxyl groups of catechol moiety, i.e., di-anionic states of catecholamines. This was deduced from Fourier-transform Raman spectra of sodium salts of catecholamines. High resolution proton NMR (400 MHz) spectra of catecholamines in basic and neutral $D_2O$ solution show that the conformations of norepinephrine and epinephrine in the di-anionic states are preferred in gauche, but not for dopamine in the di-anionic state. However the energy difference between trans and gauche of catecholamines in the protonated cationic states is small enough to rotate freely through C-C bond in ethylamine moiety. The conformational calculations using an empirical potential function and the hydration shell model (a program CONBIO) show consistent with above experimental results. The calculations suggest that the species of catecholamines adsorbed on silver metal surface would be in favor of the gauche conformations.

Manikin Model Study on Reproducibility and Accuracy of Maxillofacial Measurements Determined by Stereocamera: Comparative Study of Direct Anthropometry, Digitizer and Stereophotogrammetery (스테레오 카메라를 이용한 안면부 측정의 재현성과 정확도에 대한 마네킨을 이용한 연구: 직접 인체계측, Digitizer, Stereophotogrammetry의 비교 연구)

  • Jeoung, Youn-Wook;Yang, Ji-Woong;Chung, Kwang;Kook, Min-Suk;Oh, Hee-Kyun
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.34 no.1
    • /
    • pp.17-25
    • /
    • 2012
  • Purpose: Recently, a three dimensional approach to hard and soft tissues of the maxillofacial area has been widely used. This study was to evaluate the reproducibility and accuracy of a stereocamera compared to actual measurement methods using a digital caliper and digitizer. Methods: The stereoscopies of 7 head dummies with different sizes and shapes were obtained using a Di3D system (Dimensional Imaging, Glasgow, UK) after marking reference points on facial areas. From the obtained stereoscopy, 10 measurements representing the width, height and depth of each of the facial sections of the dummy were measured twice using a three dimensional reverse engineering software program (RapidForm$^{TM}$ 2006, Inus, Seoul, Korea). The x, y, and z coordinates of each of the three dimensional measurements were obtained and distances between two points were calculated. All procedures were repeated twice. The actual measurement method was performed twice, directly on dummies, using a digital caliper and values were compared with the previously determined values. Results: The results were as follows. In the ANOVA analysis, there were no significant statistical differences among the three measurement methods. In the Bonferroni analysis, with adjustments applied for multiple comparisons, there was no difference between actual measurement methods using a digitizer and a digital caliper. However, there was some difference between using a stereocamera and actual measurement methods using a digitizer and a digital caliper in values of $Ex_{Rt}-Ex_{Lt}$, $En_{Rt}-En_{Lt}$, $Ala_{Rt}-Ala_{Lt}$, $Ch_{Rt}-Ch_{Lt}$, G-Pg', $Ala_{Rt}$-Prn, $Ala_{Rt}$-Prn. The mean value for technical error in measurement (TEM) in Di3D (0.98 mm) was slightly higher than for a digital caliper (0.17 mm) and a digitizer (0.30 mm). In an intraclass correlation coefficient (ICC) there were no significant differences among the three measurement methods, but the Di3D system with the stereocamera showed relatively lower reproducibility compared to actual measurement methods using a digitizer and a digital caliper. Conclusion: These results indicate that some complementary measures may be needed to improve accuracy and reproducibility in the Di3D system with stereocamera.