• Imaging Science in Dentistry
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• 제50권1호
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• pp.15-22
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• 2020

Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliability of 2-dimensional(2D) photography and 3-dimensional(3D) soft tissue imaging. Materials and Methods: Facial images of 50 volunteers(25 males, 25 females) were captured with a Nikon D800 2D camera (Nikon Corporation, Tokyo, Japan), 3D stereophotogrammetry (SPG), and laser scanning (LS). All subjects were imaged in a relaxed, closed-mouth position with a normal smile. The 2D images were then exported to Mirror^® Software (Canfield Scientific, Inc, NJ, USA) and the 3D images into Proplan CMF^® software (version 2.1, Materialise HQ, Leuven, Belgium) for further evaluation. For an objective evaluation, 2 observers identified soft tissue landmarks and performed linear measurements on subjects' faces (direct measurements) and both linear and angular measurements on all images(indirect measurements). For a qualitative analysis, 10 dental observers and an expert in facial imaging (subjective gold standard) completed a questionnaire regarding facial characteristics. The reliability of the quantitative data was evaluated using intraclass correlation coefficients, whereas the Fleiss kappa was calculated for qualitative data. Results: Linear and angular measurements carried out on 2D and 3D images showed excellent inter-observer and intra-observer reliability. The 2D photographs displayed the highest combined total error for linear measurements. SPG performed better than LS, with borderline significance (P=0.052). The qualitative assessment showed no significant differences among the 2D and 3D imaging modalities. Conclusion: SPG was found to a reliable and accurate tool for the morphological evaluation of soft tissue in comparison to 2D imaging and laser scanning.

• Journal of Korean Dental Science
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• 제15권1호
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• pp.1-8
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• 2022

Purpose: Intraoral scanners, desktop scanners, and cone-beam computed tomography (CBCT) are being used in a complementary way for diagnosis and treatment planning. Limited patient-based results are available about dimensional reproducibility among different three-dimensional imaging systems. This study aimed to evaluate dimensional reproducibility among patient-derived digital models created from an intraoral scanner, desktop scanner, and two CBCT systems. Materials and Methods: Twenty-nine arches from sixteen patients who were candidates for implant treatments were enrolled. Different types of CBCT systems (KCT and VCT) were used before and after the surgery. Polyvinylsiloxane impressions were taken on the enrolled arches after the healing period. Gypsum casts were fabricated and scanned with an intraoral scanner (CIOS) and desktop scanner (MDS). Four test groups of digital models, each from CIOS, MDS, KCT, and VCT, respectively, were compared to the reference gypsum cast group. For comparison of linear measurements, intercanine and intermolar widths and left and right canine to molar lengths were measured on individual gypsum cast and digital models. All measurements were triplicated, and the averages were used for statistics. Bland-Altman plots were drawn to assess the degree of agreement between each test group with the reference gypsum cast group. A linear mixed model was used to analyze the fixed effect of the test groups compared to the reference group (α=0.05). Result: The Bland-Altman plots showed that the bias of each test group was -0.07 mm for CIOS, -0.07 mm for MDS, -0.21 mm for VCT, and -0.25 mm for KCT. The linear mixed model did not show significant differences between the test and reference groups (P>0.05). Conclusion: The linear distances measured on the digital models created from CIOS, MDS, and two CBCT systems showed slightly larger than the references but clinically acceptable reproducibility for diagnosis and treatment planning.

• 대한핵의학회지
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• 제39권4호
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• pp.257-262
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• 2005

목적 : 위배출신티그래피는 일반적으로 15분 간격으로 2시간 동안 촬영된다. 본 연구는 수학적 함수를 이용하여 90분까지 얻은 위잔류율 측정치를 가지고 비선형 곡선을 구한 후, 120분의 위잔류율을 예측함으로써 90분 이후의 지연영상 촬영시간을 절약할 수 있는지에 대하여 알아보았다. 대상 및 방법 : 환자들은 74 MBq (2 mCi) Tc-99m DTPA가 들어 있는 계란찜을 섭취한 직후 촬영을 시행하였다. 환자들을 반위배출시간에 따라 두 군으로 나누어 후향적으로 연구하였다. Group I은 반위배출시간이 90분 이하($T_{1/2}\;{\leq}90\;min$)인 51명(남자 21명, 여자: 30명, 평균나이: $44.6{\pm}13.5$세)이었고, Group II는 90분 초과 120분 이하($90\;min)인 45명(남자: 15, 여자:30, 평균나이 $45.6{\pm}15.9$)이었다. 0, 15, 30, 45, 60, 75, 90분에서의 위잔류율을 측정하여 비선형 곡선인 단순지수함수, power exponential function, modified power exponential function을 구하였고, 또한 50, 75, 90분의 측정치로 후기 단순지수함수를 구하였다($MATLAB^{\circledR}$ 5.3). 얻어진 함수식을 통해 120분에서의 위잔류율 예측치를 구한 후, 120분 측정치와의 상관관계를 알아보았다. ($MedCalc^{\circledR}$ 6.0). 결과: 120분 위잔류율의 측정치와 예측치의 상관계수(r)는 각각의 함수식에 따라 다음과 같다; 단순지수함수 (Group I: 0.8858, Group II: 0.5982, p<0.0001), power exponential function (Group I: 0.8755, Group II: 0.6008, p<0.0001), modified power exponential function (Group I: 0.8892, Group II: 0.5882, p<0.0001), 후기 단순지수함수 (Group I:0.9085, Group II:0.6832, p<0.0001). Group I에서만 함수식 모두에서 측정치와 예측치 간에 통계학적으로 의미있게 강한 상관관계를 보였다. 각 상관계수 간에 유의한 차이는 없었으나 후기지수함수식이 다른 함수식에 비하여 변수(parameter)와 입력될 측정치의 개수가 적어 예측치를 구하기가 간편하였다. 결론: 반위배출 시간이 90분 이하인 경우에 120분에서의 위잔류율을 예측할 수 있어 90분 이후의 촬영시간을 절약할 수 있다. 또한, 후기지수함수식이 다른 함수식에 비하여 예측치를 구하기가 간편하므로 임상적으로 더 유용하다.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권5호
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• pp.189-193
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• 2003

Initial irreversible capacity (IIC) can be defined by means of the initial intercalation Ah efficiency (IIE) and the initial irreversible specific capacity at the surface (IICs) with the linear-fit range of the intercalation so as to precisely express the irreversibility of an electrode-electrolyte system. Their relationship was IIC = Qc - Q$_{D}$ = (IIE$^{-1}$ - 1) Q$_{D}$ + IICs in the linear-fit range of IIE. Here, Qc and Qd signify charge and discharge capacity, respectively, based on a complete lithium ion battery cell. Charge indicates lithium insertion to carbon anode. Two terms of IIE and IICs depended on the types of active materials and compositions of the electrode and electrolyte but did not change with charging state. In an ideal electrode-electrolyte system, IIE and IICs would be 100%, 0 mAh/g for the electrode and mAh for the cell, respectively. These properties can be easily obtained by the Gradual Increasing of State of Charge (GISOC).OC).

• 한국음향학회지
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• 제26권6호
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• pp.243-249
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• 2007

본 논문은 Group Delay(GD)를 이용한 음성신호 기반의 효과적인 성별인식 시스템을 제안한다. 일반적인 음성 인식과 관련된 시스템에서 사용되는 특징들은 위상에 관한 정보를 제거한 크기만의 정보를 이용하여 구성한다. 본 연구에서는 위상에 관한 정보를 토대로 유도되어 지는 GD의 성별에 따른 특징을 알아보고, 보다 향상된 성별인식을 위해 MFCC(Mel-frequency cepstral coefficient), LPC(linear predictive coding) 계수, 반사계수(reflection coefficient) 그리고 포만트(formant)등과 같은 크기 정보와 GD를 이용한 결합 특징 벡터를 적용하였다. 실험을 통해 성별에 따른 GD의 특징을 확인할 수 있었고, 이를 이용한 제안된 특징 벡터를 사용했을 때 우수한 인식 성능을 얻을 수 있었다.

• 보험의학회지
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• 제4권1호
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• pp.101-109
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• 1987

The present study was undertaken to establish the standard body weight by height in Korean adults by using the actually measured heights and weights of a total of 5,496 insured persons who were examined medically at the Honam Medical Room of Dong Bang Life Insurance Company, Ltd. from January, 1983 to January, 1986. The results were as follows: 1. The linear regression equations to establish the standard body weight of Korean adults were as follows: In male, for $18{\sim}19$ age group, $y=7.272{\times}10^{-6}{\times}x^3+23.560$ for $20{\sim}29$ age group, $y=8.187{\times}10^{-6}{\times}x^3+22.031$ for $30{\sim}39$ age group, $y=8.627{\times}10^{-6}{\times}x^3+23.169$ for $40{\sim}49$ age group, $y=9.561{\times}10^{-6}{\times}x^3+20.994$ and for $50{\sim}59$ age group, $y=8.604{\times}10^{-6}{\times}x^3+23.801$ In female, for $18{\sim}19$ age group, $y=8.252{\times}10^{-6}{\times}x^3+18.920$ for $20{\sim}29$ age group, $y=7.715{\times}10^{-6}{\times}x^3+22.409$ for $30{\sim}39$ age group, $y=8.808{\times}10^{-6}{\times}x^3+21.439$ for $40{\sim}49$ age group, $y=9.691{\times}10^{-6}{\times}x^3+21.940$ and for $50{\sim}59$ age group, $y=12.500{\times}10^{-6}{\times}x^3+11.031$ 2. The standard age, height, and weight tables by author were presented with the aid of linear regression equations. 3. The values of standard body weight by height established by author reveal to be a little higher than those of other Korean reports through all age groups of both sexes, and reveal to be considerably similar, compared with those of the reports in Japan for fourth and sixth decade of female group.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.596-608
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• 1997

The purpose of this study was to compare the apical leakage and adaptation to the dentinal wall of a glass ionomer root canal cement(Ketac-Endo) with those of AH-26 and Tubli-Seal. 102 single-rooted teeth were insrumented with step-back technique and randomly divided into four groups according to kinds of root canal cements: Ketac-Endo, AH-26, Tubli-Seal, and no root canal cement. Four experimental groups were as follows; Group 1 : Filling with gutta-percha and Ketac-Endo Group 2 : Filling with gutta-percha and AH-26 Group 3 : Filling with gutta-percha and Tubli-Seal Group 4 : Filling with gutta-percha without root canal cement All the specimens were obturated with lateral condensation technique, and stored in 100% humidity for 4 days. 20 teeth in each group were placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. And they were evaluated for linear dye leakage using a stereoscope and analyzed by one-way ANOVA. 22 teeth were split longitudinally and evaluated the adaptation to the dentinal wall using scanning electron microscope(4 teeth in each group) and stereoscope(2 teeth in 1, 2, 3 group). The obtained results were as follows ; 1. In case of not used root canal cement(Group 4), there was showed much degree of dye penetration comparerd with used root canal cements (Group 1, 2, 3)(P<0.01). 2. In the case of used root canal cements(Group 1, 2, 3), there was no significant difference in linear leakage in groups(P>0.01). 3. In the case of used root canal cements(Group 1, 2, 3), there was showed intimate adaptation to the dentinal wall independent on kinds of root canal cements. 4. Fractured surfaces indicated failure of cohesion in Ketac-Endo, and failure of adhesion to dentine in AH-26 and Tubli-Seal. 5. According to similar apical leakage and adaptability to the dentinal wall to another root canal cements, it is possible to be used glass-ionomer cement as root canal cement.

• Asian-Australasian Journal of Animal Sciences
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• 제18권8호
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• pp.1088-1097
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• 2005

Main objectives of this study were to investigate accuracy, bias and power of linear and threshold model segregation analysis methods for detection of major genes in categorical traits in farm animals. Maximum Likelihood Linear Model (MLLM), Bayesian Linear Model (BALM) and Bayesian Threshold Model (BATM) were applied to simulated data on normal, categorical and binary scales as well as to disease data in pigs. Simulated data on the underlying normally distributed liability (NDL) were used to create categorical and binary data. MLLM method was applied to data on all scales (Normal, categorical and binary) and BATM method was developed and applied only to binary data. The MLLM analyses underestimated parameters for binary as well as categorical traits compared to normal traits; with the bias being very severe for binary traits. The accuracy of major gene and polygene parameter estimates was also very low for binary data compared with those for categorical data; the later gave results similar to normal data. When disease incidence (on binary scale) is close to 50%, segregation analysis has more accuracy and lesser bias, compared to diseases with rare incidences. NDL data were always better than categorical data. Under the MLLM method, the test statistics for categorical and binary data were consistently unusually very high (while the opposite is expected due to loss of information in categorical data), indicating high false discovery rates of major genes if linear models are applied to categorical traits. With Bayesian segregation analysis, 95% highest probability density regions of major gene variances were checked if they included the value of zero (boundary parameter); by nature of this difference between likelihood and Bayesian approaches, the Bayesian methods are likely to be more reliable for categorical data. The BATM segregation analysis of binary data also showed a significant advantage over MLLM in terms of higher accuracy. Based on the results, threshold models are recommended when the trait distributions are discontinuous. Further, segregation analysis could be used in an initial scan of the data for evidence of major genes before embarking on molecular genome mapping.

• 한국수소및신에너지학회논문집
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• 제21권4호
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• pp.321-327
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• 2010

Current rechargeable battery cannot provide high energy density and the operational durations required. But linear engine/generators provide high energy density for portable power applications because fuel is more high density. In this paper, we suggest that basic design of powerpack using linear engine for assisting power output. Efficiency is relatively high because linear engine don't have crank mechanism compared with rotary engine. We made prototype engine and had experiments to know moving characteristic about the Linear Engine. It was possible to operate velocity at 50 Hz at the firing and pressure in cylinder was 16bar.

• 펄프종이기술
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• 제48권1호
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• pp.19-26
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• 2016

In the consumer products industry, it has been highly desirable to develop objective test methods to replace subjective evaluation methods. In developing an objective test method, subjective evaluation data should be on a linear scale. According to Thurstone's theory of comparative judgment, a%-preference from a paired-comparison test can be converted to a linear-scale value. The required number (N) of paired-comparison tests increases dramatically as the number of products increases. This problem should be solved by classifying the total products into several subgroups consisting of 3-4 products in each group. By doing so, it can not only significantly reduce the number of required paired-comparison tests, but it can also obtain more reliable, reproducible data.