• Communications for Statistical Applications and Methods
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• 제30권6호
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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.

• 방송공학회논문지
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• 제21권1호
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• pp.76-86
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• 2016

연구에서는 입체시 측정방법과 양안시차에 따라 지각되는 입체시 깊이 차이를 살펴보기 위해서 실시되었다. 직접비교 조건에서는 깊이를 평가할 가상자극과 깊이 평가에 사용된 실제 LED들이 모두 정면의 동일 공간에 제시되어 있었고, 간접비교 조건에서는 가상자극은 정면에 제시되었지만 깊이 평가에 사용된 LED들은 45도 오른쪽에 놓여있었다. 따라서 직접비교 조건에서는 동일 공간에 제시된 두 자극의 깊이를 비교하면서 대응시킬 수 있었지만, 간접비교 조건에서는 가상 자극의 깊이를 평가한 후 오른쪽 방향에 있는 LED를 이용하여 깊이를 추정할 수 있었다. 이 들 두 측정 방법에서 지각되는 입체시 깊이가 달라지는 지를 확인하고 부가적으로 관찰자들의 입체시력에 따라 지각되는 깊이가 달라지는 지를 살펴보았다. 실험 결과 직접비교 조건에서 지각된 깊이는 간접비교 조건에서 지각된 깊이보다 더 기하학적으로 예측된 깊이와 유사하였다. 또한 입체시력이 좋은 사람들은 그렇지 않은 사람들보다 기하학적으로 예측된 깊이와 유사한 깊이를 지각하였다. 이러한 결과는 동일한 양안 시차를 가진 자극들이라도 이들 가상자극들만 제시되는 것보다 현실자극과 가상자극이 동일 공간에 제시될 때 지각된 깊이가 더 크게 지각됨을 보여주는 것이다. 따라서 양안시차를 가진 자극만 제시되는 가상현실에서 지각되는 입체 자극의 깊이보다 현실영상과 가상영상이 함께 제시되는 증강현실에서 보다 큰 깊이가 지각될 수 있음을 시사한다.

• 한국멀티미디어학회논문지
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• 제23권6호
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• pp.738-746
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• 2020

In this paper, we propose an indirect PIN entry method that provides enhanced security against smudge, recording, and thermal attacks. Conventional mobile PIN entry methods use on-screen numeric keypad for both use of display and entry. Thus These methods are vulnerable to aforementioned attacks. In our method, passcode is same as that of the conventional PIN entry methods, and that is user-friendly way for mobile device users. Therefore, our method does not reduce user convenience which is one of the advantages of the conventional methods. In addition, our method is not a method of directly touching the on-screen numeric keypad for entering passcode like the conventional PIN methods. Unlike the conventional methods, our method uses an indirect passcode entry method that applied a passcode indicating key. According to the performance comparison result, proposed method provides user convenience similar to the conventional methods, and also provides a higher level of security and safety against recording, smudge, and thermal attacks than the conventional methods.

• Journal of Power Electronics
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• 제6권1호
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• pp.67-72
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• 2006

This paper introduces two different types of AC current control methods for an indirect vector controlled induction motor using a matrix converter. The proposed methods combine the advantages of matrix converters with the advantages of the indirect vector AC current control methods. The first proposed method explains the basic idea of the hysteresis current control method for matrix converters and shows its capability and stability in comparison to the conventional method usually used for VSI. With the aid of the special configuration of the matrix converter, we also propose another current method which is modified from the first one in order to reduce both current ripple and torque ripple. Simulation results have verified the feasibility and the effectiveness of the proposed methods.

• Journal of Preventive Medicine and Public Health
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• 제56권4호
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• pp.303-311
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• 2023

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, 'medflex' and 'mediation', to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

• 한국학교수학회논문집
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• 제21권1호
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• pp.19-37
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• 2018

본 연구에서는 우리나라의 2015 개정 초등학교 수학과 교육과정과 일본의 2017 개정 초등학교 수학과 교육과정 <측정 영역>의 7개 외연량 시간, 길이, 들이, 무게, 넓이, 각도, 부피의 지도 실정을 비교, 측정, 어림재기의 세 관점에서 비교 분석하고 있다. 이러한 비교 분석의 결과로부터 우리나라의 차기 초등학교 수학 교과서 및 차기 초등학교 수학과 교육과정 개발과 관련하여 다음과 같은 논의가 필요하다는 것을 제안할 수 있다. 첫째, 시간, 길이, 들이, 무게, 넓이, 각도, 부피 각각에 대해 비교(직관적 비교, 직접 비교. 간접 비교), 직접 측정(임의 단위에 의한 측정, 표준 단위에 의한 측정), 간접 측정, 어림재기의 취급 범위를 명확히 하는 것에 대한 논의가 필요하다. 둘째, 직관적 비교가 곤란한 경우에 직접 비교를 하게 하는 것에 대한 논의가 필요하다. 셋째, 무게의 간접 비교를 재고하는 것에 대한 논의가 필요하다. 넷째, 임의 단위에 의한 각도의 측정을 재고하는 것에 대한 논의가 필요하다. 다섯째, 넓이 $1cm^2$와 $1m^2$ 및 부피 $1cm^3$와 $1m^3$가 각각 어느 정도의 크기인지를 짐작할 수 있게 하는 B류 어림재기를 취급하는 것에 대한 논의가 필요하다.

• 한국의류학회지
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• 제29권9_10호
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• pp.1241-1252
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• 2005

This study tried to compare and analyze the body measurements of female adults in China by various age groups. As for the study method, direct and anthropometric measurements were used on the 357 female subjects living in Yenbien and Harbin, China, consisting of 122 women in their 20's, 114 women in their 40's, and 121 women in their 60's. The results were as follows: 1. The comparison of major body measurements between Korean Chinese and Korean in land indicated that the former were shorter and plumper than the latter. Those groups in their 60's did not show any significant difference in height related measurements and revealed less differences in body measurements comparing to other age groups. 2 The comparison of Chinese anthropometric measurements among age groups of Korean Chinese indicated that, higher the age, shorter the height measurements, the leg length shorter, the upper-half body length longer, and the chest drooping due to the breast descent. 3. The comparison of indirect measurements among age groups of Koreans Chinese indicated that those in their 60's showed many items of big discrepancies in comparison with those in their 20's or 40's, with wide gap in discrepancies, thus resulting in large differences among individuals.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.656-660
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• 2004

The Mobile Mapping System is an effective method to acquire the position and image data using vehicle equipped with the GPS (Global Positioning System), IMU (Inertial Measurement Unit), and CCD camera. It is used in various fields of road facility management, map update, and etc. In the general photogrammetry such as aerial photogrammetry, GCP (Ground Control Point)s are needed to compute the image exterior orientation elements (the position and attitude of camera). These points are measured by field survey at the time of data acquisition. But it costs much time and money. Moreover, it is not possible to make sufficient GCP as much as we want. However Mobile Mapping System is more efficient both in time and money because it can obtain the position and attitude of camera at the time of photographing. That is, Indirect Georeferencing must use GCP to compute the image exterior orientation elements, but on the other hand Direct Georeferencing can directly compute the image exterior orientation elements by GPS/INS. In this paper, we analyze about the positional accuracy comparison of ground point using the Direct Georeferencing and Indirect Georeferencing.

• Steel and Composite Structures
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• 제45권1호
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• pp.119-131
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• 2022

Due to the complexity of the structure and the limits of classical SEA, a combined SEA approach is employed, with angle-dependent SEA in the low- and mid-frequency ranges and advanced SEA (ASEA) considering indirect coupling in the high-frequency range. As an important component of the steel box girder, the dynamic response of an L-junction periodic ribbed plate is calculated first by the combined SEA and validated by the impact hammer test and finite element method (FEM). Results show that the indirect coupling due to the periodicity of stiffened plate is significant at high frequencies and may cause the error to reach 38.4 dB. Hence, the incident bending wave angle cannot be ignored in comparison to classical SEA. The combined SEA is then extended to investigate the vibration properties of the steel box girder. The bending wave transmission study is likewise carried out to gain further physical insight into indirect coupling. By comparison with FEM and classical SEA, this approach yields good accuracy for calculating the dynamic responses of the steel box girder made of periodic ribbed plates in a wide frequency range. Furthermore, the influences of some important parameters are discussed, and suggestions for vibration and noise control are provided.

• 한국안전학회지
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• 제16권3호
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• pp.111-116
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• 2001

This study is conducted to review the ratio of direct and indirect cost accompanied by industrial accident in construction sites. It is surveyed that how to use safety cost in construction work is most efficient in comparison with several items of safety cost through the regression analysis.