• Title/Summary/Keyword: Difference-In-Difference

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A STUDY ON THE ACCURACY OF DENTAL CAST AND DIE MATERIALS USING PHOTO-SCANNING (사진 주사(走査)를 이용한 치과용 모형재의 정확도에 관한 연구)

  • Yang, Seong-Wook;Lim, Ju-Hwan;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.2
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    • pp.320-334
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    • 1996
  • Dental cast and die materials are essential material using in almost dental prsthodontic procedure and it's most important requirement is accuracy for reqorducing the oral anatomical structures. In this study, 5 abutments A, B, C, D, E were fabricated on the metal master model to simulate the arch form and specimens were poured with 4 cast materials. Inter-abutment distances, A-B, A-C, A-D, A-E, B-C, B-D were calculated using the photo-scanning and the deviations from the metal master model were also evaluated. The results were as follows; 1. The distance between A-B, A-C, A-D, A-E, B-C, B-D of the abutments A, B, C, D, E of each cast material was calculated. And after comparing the deviations between the metal master model. $Fujirock^{(R)}$ showed the lowest value with $0.20{\pm}0.22mm$, and the deviation increased in the order of $Suprastone^{(R)}$, Epoxy $Die^{(R)}$, Die $Keen^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and Epoxy $Die^{(R)}$, Die $Keen^{(R)}$. 2. In each calculation area, the difference in measurements between cast material and metal master model showed singificant difference between A-B and Cross arch measure-ments of A-D, B-D, A-E(p<0.05). 3. The difference in measurements between cast material and metal master model in the A-B area showed $Fujirock^{(R)}$ to be the lowest with $0.05{\pm}0.04$mm and increased in the order of Die $Keen^{(R)}$, $Suprastone^{(R)}$, Epoxy $Dies^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and $Suprastone^{(R)}$, Epoxy $Die^{(R)}$ (p<0.05). 4. The difference in measurements between cast material and metal master model in the B-C area showed $Fujirock^{(R)}$ to bo the lowest with $0.17{\pm}0.11$mm and increased in the order of $Suprastone^{(R)}$, Die $Keen^{(R)}$, Epoxy $Dies^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and Die $Keen^{(R)}$, Epoxy $Die^{(R)}$(p<0.05). 5. The difference in measurements between cast material and metal master model in the B-D area showed $Fujirock^{(R)}$ to bo the lowest with $0.13{\pm}0.07$mm, Epoxy $Dies^{(R)}$and increased in the order of $Suprastone^{(R)}$, Die $Keen^{(R)}$. There was significant difference between $Fuji-rock^{(R)}$ and Die Keen(p<0.05). 6. In this experiment, Epoxy $Dies^{(R)}$ showed mean contraction in every calculation area. And when reconstruction cross arch restorations it is thought that distortion should be considered in every cast material.

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The Effects of Complex Exercise Program with Visual Feedback on Navicular Bone Height, Plantar Pressure and Low Extremity Alignment in Flat-Footed Patients (시각적 피드백을 병행한 복합운동프로그램이 편평발 환자의 발배뼈 높이, 족저압 및 다리 정렬에 미치는 영향)

  • Hoe-Song Yang;Chan-Joo Jeong;Young-Dae Yoo;Hyo-Jeong Kang;Min-Kyu Kim
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.269-279
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    • 2023
  • Purpose : The most effective intervention for flat foot is strengthening exercises for the intrinsic and extrinsic of the foot. Additionally, visual feedback is necessary for movement accuracy. However, the effectiveness of the intervention when combined with visual feedback was not revealed. To confirm this, the research was to investigate the effect of visual feedback and a complex exercise program on navicular bone height, plantar pressure, and lower extremity alignment. Methods : The twenty eight adult men and women with flat foot were randomly assigned to group 1 (n=14) and group2 (n=14), group1 performed complex exercises with visual feedback, and group 2 performed only complex exercises. Both groups performed a 40 minute compound exercise program three times a week. Navicular drop test, plantar pressure test, and lower extremity alignment test were performed equally in both group. Results : As a result of comparing the change in navicular height within the group according to the intervention, both groups showed a significant difference before and after the exercise (p>.05). There was not significant difference comparing the difference between the groups in the navicular height (p>.05). Comparing the change in plantar pressure within groups, there was not significant difference in the change in plantar pressure in both groups (p>.05). Coparing the difference before and after exercise between groups, there was not significant plantar pressure (p>.05). Comparing the change in leg alignment within the group, there was a significant difference in the change in ankle before and after exercise in group 1 (p<.05), but there was not significant difference in group 2. There was not significant difference in pelvic tilt and knee tilt before and after exercise in both groups (p>.05). Comparing the before and after exercise difference between groups, there were not significant in all variables of leg alignment (p>.05). Conclusion : The results of this study showed that complex exercise applied to patients with flat foot were effective in increasing the height of the navicular bone and ankle angle, but there was no effect due to visual feedback.

A study on the Difference Arrow of GDS (Geomagnetic Depth Sounding) Survey using 2-D MT (Magneto-Telluric) Modeling (2차원 MT(Magneto-Telluric)모델링을 이용한 지자기 수직탐사(Geomagnetic Depth Sounding)에서의 차이 지시자의 연구)

  • 양준모;오석훈;이덕기;윤용훈
    • Economic and Environmental Geology
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    • v.35 no.6
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    • pp.567-573
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    • 2002
  • Two-dimensional MT (Magneto-Telluric) modeling is performed to verify the validity of difference arrow for GDS(Geomagnetic Depth Sounding) survey. The electromagnetic mutual coupling between the sea and in-land conductor is used as a criterion that judges the validity of difference arrow. In this study, the mutual coupling between them is examined according to the spatial distance between them and the period of magnetic variations. The difference arrow is valid for conductors located at surface which are far from the sea or when the long period is used, but the mutual coupling is weak for buried conductor in all the periods. However, when a conductor extends vertically down to the deep part, the validity of difference arrow is in doubt, since the strong mutual coupling influences up to the long period. Therefore, to remove the known conductor effect such as sea effect from the observed induction arrow, the mutual coupling between them must be examined and the caution must be exercised in interpreting the resultant difference arrow if mutual coupling between them is strong.

Estimation of Time Difference Using Cross-Correlation in Underwater Environment (수중 환경에서 상호상관을 이용한 시간차이 추정)

  • Lee, Young-Pil;Moon, Yong Seon;Ko, Nak Yong;Choi, Hyun-Taek;Lee, Jeong-Gu;Bae, Young-Chul
    • Journal of Advanced Navigation Technology
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    • v.20 no.2
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    • pp.155-160
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    • 2016
  • Recently, underwater acoustic communication (UWAC) has been studied by many scholars and researchers. In order to use UWAC, we need to estimate time difference between the two signals in underwater environment. Typically, there are major three methods to estimate the time-difference between the two signals such as estimating the arrival time of the first non-background segment and calculate the temporal difference, calculating the cross-correlation between the two signal to infer the time-lagged, and estimating the phase delay to infer the time difference. In this paper, we present calculating the cross-correlation between the two signals to infer the time-lagged to apply UWAC. We also present the experimental result of estimating the arrival time by using cross-correlation. We get EXCORR = 0.003055 second as the estimation error in mean absolute difference.

A RADIOGRAPHIC STUDY OF THE MANDIBULAR ASYMMETRY IN TEMPOROMANDIBULAR DISORDER PATIENTS (악관절장애 환자의 하악골 비대칭에 대한 방사선학적 연구)

  • Oh Sung Ook;You Dong Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.20 no.2
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    • pp.201-210
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    • 1990
  • The purpose of this study was to observe the relationship between mandibular asymmetry and Temporomandibular Disorders by means of the cephalometry using the posteroanterior cephalogram and the submentovertex cephalogram which were taken in 35 Temporomandibular Disorder patients and 35 normal persons ranged from 20S to 30S. The results were as follows: 1. The angulation which was formed by the median line with the ANS-Menton line (MAP) was greater in patients group and there was statistically significant difference. 2. The angulation which was formed to the median line with the Menton-Odontoid process tip line (MES), the difference of the distances from the center of the posterior surface of the both condyles to the most anterior point of the chin (DD), the difference of the distances from the center of the both condyles to the horizontal reference line (DE), the difference of the angulations which were formed by the both condyles axes with the horizontal reference line (DCE), the difference of the lengths of the both condyles (CL) and the difference of the widths of the both condyles (DW) were greater in patients group and there were statistically significant differences. There was reversed correlation between MAP and the difference of the distances from the 3. bilateral points of the lateral margin of the both zygomaticofrontal sutures to the at the lateral inferior margin of the both antegonial protuberances in mandible (DH). There was reversed correlation between MES and DD, DE, DCE. 5. There was correlation between MAP and MES.

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The Study on Payment Difference of Health Examination Users in University Hospital Medical Center (대학병원 건강검진센터 이용자의 검진금액 차이에 관한 연구)

  • Cho, Duk-Young
    • Management & Information Systems Review
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    • v.32 no.2
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    • pp.47-58
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    • 2013
  • This study analyzes on payment difference of users in sex, age, region using 23-months data by a university medical center to figure out factors which help to hospital management. The meaningful results of this study as follow. First of all, there is not statistically significant difference between men and women. Secondly, the researcher categorizes users under 40s into group A and 40s users into group B, those in 60s or older into group C. Then, researcher accepted H2 that there might be a difference on the age range of users in each group. Finally, In the results on difference analysis of the payment, there is only statistical difference between Busan and Ulsan Gyeongnam. These results is expected to provide basic information for efficient management of medical center.

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Clinical Studies for the Development of Non-contact Thermometer to Take Easily the Body Temperature of Domestic Animals (가축에서 간이 체온측정 비접촉성 체온계 개발을 위한 임상적 연구)

  • 김용준;이대영;한경호
    • Journal of Veterinary Clinics
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    • v.20 no.3
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    • pp.357-363
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    • 2003
  • These studies were carried out to develop non-contact thermometer to take easily the body temperature of domestic animals instead of taking rectal temperature. For the studies, 86 cattle, 57 horses, 72 pigs, 43 goats, and 42 dogs were used and body parts as neck, flank, axilla, lateral abdomen, gluteus, inguinal region, or jugular groove were chosen for taking temperature according to different species. Two types of commercial non-contact thermometers were used to take the temperature of certain body part and at the same time the rectal temperature using digital thermo-meter was taken to compare the difference of temperature between rectum and certain body part. The difference of mean temperature in cattle between rectum and axilla and flank were 0.52 and $2.41^{\circ}C$, respectively, using non-contact thermometer I, whereas $3.02^{\circ}C$ between rectum and flank using thermometer II. The difference of mean temperature in horses between rectum and axilla, gluteus, and jugular groove were 0.52, 1.49, and $0.26^{\circ}C$, respectively, using thermometer I, whereas 2.28 ane $0.92^{\circ}C$ between rectum and gluteus or jugular groove using thermometer II. The difference of mean temperature in swine between rectum and flank, inguinal region, and neck were 1.23, 0.21, and $0.8^{\circ}C$, respectively, using thermometer I, whereas 1.42, 0.711, and $1.25^{\circ}C$ using thermometer II The difference of mean temperature in goats between rectum and lateral abdomen and inguinal region were 1.02 and $0.12^{\circ}C$, respectively, using thermometer I, whereas 1.96 and $1.01^{\circ}C$ using thermometer II. The difference of mean temperature in dogs between rectum and lateral abdomen, inguinal region, and neck were 3.26, 0.24, and $2.37^{\circ}C$, respectively, using thermometer I, whereas 3.45, 0.56, and $2.61^{\circ}C$ using thermometer II.

Identification of indirect effects in the two-condition within-subject mediation model and its implementation using SEM

  • Eujin Park;Changsoon Park
    • Communications for Statistical Applications and Methods
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    • v.30 no.6
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    • pp.631-652
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    • 2023
  • In the two-condition within-subject mediation design, pairs of variables such as mediator and outcome are observed under two treatment conditions. The main objective of the design is to investigate the indirect effects of the condition difference (sum) on the outcome difference (sum) through the mediator difference (sum) for comparison of two treatment conditions. The natural condition variables mean the original variables, while the rotated condition variables mean the difference and the sum of two natural variables. The outcome difference (sum) is expressed as a linear model regressed on two natural (rotated) mediators as a parallel two-mediator design in two condition approaches: the natural condition approach uses regressors as the natural condition variables, while the rotated condition approach uses regressors as the rotated condition variables. In each condition approach, the total indirect effect on the outcome difference (sum) can be expressed as the sum of two individual indirect effects: within- and cross-condition indirect effects. The total indirect effects on the outcome difference (sum) for both condition approaches are the same. The invariance of the total indirect effect makes it possible to analyze the nature of two pairs of individual indirect effects induced from the natural conditions and the rotated conditions. The two-condition within-subject design is extended to the addition of a between-subject moderator. Probing of the conditional indirect effects given the moderator values is implemented by plotting the bootstrap confidence intervals of indirect effects against the moderator values. The expected indirect effect with respect to the moderator is derived to provide the overall effect of moderator on the indirect effect. The model coefficients are estimated by the structural equation modeling approach and their statistical significance is tested using the bias-corrected bootstrap confidence intervals. All procedures are evaluated using function lavaan() of package {lavaan} in R.

A Comparative Study of the Effect of Two Analgesic Administration Methods on Post Operative Pain (수술환자에 었어서 마약성 진통제의 자가투여 방법과 근육주사 방법의 효과에 대한 비교연구)

  • 이정화
    • Journal of Korean Academy of Nursing
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    • v.27 no.2
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    • pp.401-410
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    • 1997
  • An acute pain is the common experience following surgery. Pain is a most miserable experience in person and most preoperative patients have fear o! postoperative pain. In nursing, it is very important to understand and relieve the pain of post oprative patients as much as possible. This study was designed to compare the descriptive patterns of pain between group of Patient Controlled Analgesia and group of traditional Muscular Injection in surgcal patients. This information can be utilited as data of understanding nursing care and treatment planning for pain in surgical patients. The subjects in this study were 45 post-hysterectomy patients in Gynecology ward in C. N. U. H., in Taejon. Data was collected from May 12 to June 27. 1996. The instrumants used for this study were subjective Visual Analog Scale, Objedive nonverbal pain scale composed of Facial Apperance. Vocal Sound Change, and Sweating score. and the Melzack's Mcgill pain Qusetionaire. nine Items of Developmental Pain Intensity Scale by Lee En Ok. Analysis of data was done by using S. P. S. S. percentage, t-test, x²-test. ANOVA, and Repeated measure ANOVA. Results were obtained as follows. 1. Hypothesis 1 : There was very highly statistically significant difference in subjective self-report pain score(Visual Analog Scale) between PCA Group and IM Group(P=0.0001). 2. Hypothesis 2 : There was very highly statistically significant difference in muscle strength score (Visual Analog Scale) between PCA Group and IM group(P0.0001). 3. Hypothesis 3 : There was very highly statistically significant difference in facial appearance score between PCA Group and IM group(P=0.0001). 4. Hypothesis 4 : There was very highly statistically significance difference in vocal sound change score between PCA Group and IM group(P=0.0001). 5. Hypothesis 5 : There was no statistically significant difference sweating scores between PCA group and IM group(F=2.50, P=0.1220). But, postoperation time of 12, 24 was statistically difference between two groups(P=0.0001). So, it was partially supported. 6. Hypothesis 6 : There was very highly statistically significant difference in vocabulary pain score between PCA Group and IM group. 7. Hypothesis 7 : There was very highly statistically significant difference in amounts of total analgesic between PCA Group and IM group. There was very highly statistically significant difference in Visual Analog Pain Score, Facial Appearance Score, Vocal Sound Change Score, Vocabulary Score, amounts of total analgesic between PCA group and IM group. So, It is verified to asses of postoperative pain with VAS, Checklist of facia appearance, vocal sound change, and sweating, and Vocabulary Scale.

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An Implementation of Gaze Direction Recognition System using Difference Image Entropy (차영상 엔트로피를 이용한 시선 인식 시스템의 구현)

  • Lee, Kue-Bum;Chung, Dong-Keun;Hong, Kwang-Seok
    • The KIPS Transactions:PartB
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    • v.16B no.2
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    • pp.93-100
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    • 2009
  • In this paper, we propose a Difference Image Entropy based gaze direction recognition system. The Difference Image Entropy is computed by histogram levels using the acquired difference image of current image and reference images or average images that have peak positions from $-255{\sim}+255$ to prevent information omission. There are two methods about the Difference Image Entropy based gaze direction. 1) The first method is to compute the Difference Image Entropy between an input image and average images of 45 images in each location of gaze, and to recognize the directions of user's gaze. 2) The second method is to compute the Difference Image Entropy between an input image and each 45 reference images, and to recognize the directions of user's gaze. The reference image is created by average image of 45 images in each location of gaze after receiving images of 4 directions. In order to evaluate the performance of the proposed system, we conduct comparison experiment with PCA based gaze direction system. The directions of recognition left-top, right-top, left-bottom, right-bottom, and we make an experiment on that, as changing the part of recognition about 45 reference images or average image. The experimental result shows that the recognition rate of Difference Image Entropy is 97.00% and PCA is 95.50%, so the recognition rate of Difference Image Entropy based system is 1.50% higher than PCA based system.