• Title/Summary/Keyword: Direct/indirect methods

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Evaluation of Indirect Methods of Engine Torque Measurement (엔진 토크의 간접적(間接的)인 측정(測定) 방법(方法)에 관한 연구(硏究))

  • Ryu, K.H.;Kang, S.B.
    • Journal of Biosystems Engineering
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    • v.16 no.1
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    • pp.1-8
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    • 1991
  • This study was carried out to evaluate indirect methods of engine torque measurement. Three indirect methods based on throttle valve opening, exhaust gas temperature and inlet air pressure were compared. The indirect method based on throttle valve opening appeared to be the most satisfactory in terms of accuracy and response time. The discrepancies between the direct method and the indirect method based on throttle valve opening in measuring engine torque were 2% on t he average.

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An Introduction to Causal Mediation Analysis With a Comparison of 2 R Packages

  • Sangmin Byeon;Woojoo Lee
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.4
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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.

Effects of particle size and adaptation duration on the digestible and metabolizable energy contents and digestibility of various chemical constituents in wheat for finishing pigs determined by the direct or indirect method

  • Fan, Yuanfang;Guo, Panpan;Yang, Yuyuan;Xia, Tian;Liu, Ling;Ma, Yongxi
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.4
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    • pp.554-561
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    • 2017
  • Objective: This experiment was conducted as a $3{\times}2{\times}2$ factorial design to examine the effects of particle size (mean particle size of 331, 640, or $862{\mu}m$), evaluation method (direct vs indirect method) and adaptation duration (7 or 26 days) on the energy content and the apparent total tract digestibility (ATTD) of various chemical components in wheat when fed to finishing pigs. Methods: Forty-two barrows ($Duroc{\times}Landrace{\times}Yorkshire$) with an initial body weight of $63.0{\pm}0.8kg$ were individually placed in metabolic cages and randomly allotted to 1 of 7 diets with 6 pigs fed each diet. For the indirect method, the pigs were fed either a corn-soybean meal based basal diet or diets in which 38.94% of the basal diet was substituted by wheat of the different particle sizes. In the direct method, the diets contained 97.34% wheat with the different particle sizes. For both the direct and indirect methods, the pigs were adapted to their diets for either 7 or 26 days. Results: A reduction in particle size linearly increased the digestible energy (DE) and metabolizable energy (ME) contents as well as the ATTD of gross energy, crude protein, organic matter, ether extract (EE) and acid detergent fiber (ADF) (p<0.05), and had a trend to increase the ATTD of dry matter of wheat (p = 0.084). The DE, ME contents, and ATTD of gross energy, crude protein, dry matter and organic matter were higher (p<0.05) when determined by the direct method, but the ATTD of ADF, EE, and neutral detergent fiber were higher when determined by the indirect method (p<0.05). Prolongation of the adaption duration decreased the ATTD of neutral detergent fiber (p<0.05) and had a trend to increase the ATTD of EE (p = 0.061). There were no interactions between particle size and the duration of the adaptation duration. The ATTD of EE in wheat was influenced by a trend of interaction between method and adaptation duration (p = 0.074). The ATTD of ADF and EE in wheat was influenced by an interaction between evaluation method and wheat particle size such that there were linear equations (p<0.01) about ATTD of ADF and EE when determined by the direct method but quadratic equations (p = 0.073 and p = 0.088, respectively) about ATTD of ADF and EE when determined by the indirect method. Conclusion: Decreasing particle size can improve the DE and ME contents of wheat; both of the direct and indirect methods of evaluation are suitable for evaluating the DE and ME contents of wheat with different particle sizes; and an adaptation duration of 7 d is sufficient to evaluate DE and ME contents of wheat in finishing pigs.

Effect of Hold-Relax Technique for College Students with Hamstring Shortening (슬괵근 단축이 있는 대학생에 대한 유지-이완 기법의 효과)

  • Oh, Yeong-Taek
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.433-441
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    • 2013
  • PURPOSE: The purpose of this study was to determine the effectiveness of three PNF stretching techniques for improving hamstring flexibility and to compare the effectiveness of three PNF stretching techniques(direct and indirect and mix(direct&indirect) of hold-relax technique). METHODS: The subjects were randomly assigned into three groups: group1-direct-hold-relax technique(n=10); group2-indirect-hold-relax technique(n=8); group3-mix(direct&indirect)-hold-relax technique(n=10). For each group, stretch was performed three times a week for a period of three weeks. Hamstring flexibility for each group was measured using the ASLR and PSLR. RESULTS: The results showed significant improvement in hamstring flexibility for all subjects of three groups. However, were not significantly different between the three groups. CONCLUSION: In conclusion, three PNF stretching techniques are confirmed to be useful for improving hamstring flexibility. The choice for a qualified technique has to be made individually according to patient and therapist.

Comparison of Jump-Preserving Smoothing and Smoothing Based on Jump Detector

  • Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • v.16 no.3
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    • pp.519-528
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    • 2009
  • This paper deals with nonparametric estimation of discontinuous regression curve. Quite number of researches about this topic have been done. These researches are classified into two categories, the indirect approach and direct approach. The major goal of the indirect approach is to obtain good estimates of jump locations, whereas the major goal of the direct approach is to obtain overall good estimate of the regression curve. Thus it seems that two approaches are quite different in nature, so people say that the comparison of two approaches does not make much sense. Therefore, a thorough comparison of them is lacking. However, even though the main issue of the indirect approach is the estimation of jump locations, it is too obvious that we have an estimate of regression curve as the subsidiary result. The point is whether the subsidiary result of the indirect approach is as good as the main result of the direct approach. The performance of two approaches is compared through a simulation study and it turns out that the indirect approach is a very competitive tool for estimating discontinuous regression curve itself.

Analysis of Line of Sight Stabilization Performance based on Direct vs. Indirect of a 2-axis Gimbaled Servo System for Millimeter Wave Seeker (밀리미터파 탐색기 2축 직구동 김발 서보 시스템의 직접 및 간접 시선안정화 성능 분석)

  • Shin, Seungchul;Lee, Sung-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.11
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    • pp.1555-1561
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    • 2018
  • Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

1 YEAR FOLLOW-UP STUDY OF DIRECT AND INDIRECT COMPOSITE RESTORATIONS (직접법과 간접법으로 수복한 복합레진의 1년간의 임상적인 평가)

  • Park, Sung-Ho
    • Restorative Dentistry and Endodontics
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    • v.27 no.3
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    • pp.284-289
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    • 2002
  • Background : The purpose of the present study was to evaluate the direct and indirect composite restorations which had been placed for 1 year Methods : The composite restorations which had been placed between 1999. Mar and 1999, Dec was evaluated after 1 year For direct restorations. Spectrum (Dentsply, USA) and Z100 (3M, USA) were used in the anterior teeth and Surefil (Dentsply, USA) were used. For class V restorations of anterior and posterior teeth. Spectrum was used. For indirect restorations, Targis/Vectris system (Vivadent/Ivoclar, Liechtenstein) was used 2 examiners evaluated marginal quality, proximal contact. discoloration, presence of 2$^{nd}$ caries, loss of filling and hypersensitivity of restorations. The restorations was clinically evaluated by modified methods based on USPHS. Results : 60 teeth were evaluated. 59 were clinically acceptable and 1 restoration which was placed in class v cavity in the posterior tooth was fallen out. In most cases, the restorations were clinically accept-able. For restorations which had been directly placed in the class II cavities, loose proximal contact was indicated as the main complaints. Conclusions : Most of Anterior and posterior restorations which bad been directly or indirectly placed for 1 year were clinically acceptable. For posterior teeth, loose proximal contact was indicated as the main problem in the directly placed Class II restorations. Long term clinical study is needed.

Comparison between Isokinetic Peak Torque and Isotonic 1RM on the Knee Joint

  • Jaehyun Yoo
    • Physical Therapy Rehabilitation Science
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    • v.12 no.2
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    • pp.201-205
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    • 2023
  • Objective: Resistance exercise is a necessary element to improve quality of life, and measurement and evaluation of muscle strength provide important information for prescription and management of rehabilitation and exercise programs. This study analyzed the correlation between direct and indirect 1RM for isokinetic maximum torque of the knee joint in order to provide useful information in the field of exercise programs. In addition, the flexion-extension ratio and the difference in left-right deviation were verified. Design: A cross-sectional study Methods: The subjects of this study were 33 healthy adult men and women without medical problems who participated in the health exercise class program at S University in Seoul. The correlation between isokinetic maximum torque and direct and indirect 1RM was analyzed, and a dependent t-test was performed to analyze the flexion-extension ratio and left-right deviation. Results: There was a high correlation between the isokinetic maximum torque and direct and indirect 1RM, and no statistically significant difference was shown between the test methods in the analysis of the flexion-extension ratio and left-right deviation. Conclusions: Isokinetic muscle function measuring equipment is expensive, so it is difficult to use it in local exercise rehabilitation and training sites. Through this study, it was found that direct and indirect 1RM isokinetic maximum torque showed a high correlation, and there was no difference in evaluating muscle function such as flexion-extension ratio and left-right deviation. Therefore, it is considered that the muscle function evaluation using 1RM in general field can be usefully utilized.

Immediate Effects of Various Contract-Relax Techniques on the Peck Force and Range of Motion of Knee Extension -A Pilot Study- (수축-이완 기법 방법에 다른 최대 힘과 무릎관절 가동 범위에 미치는 즉각적인 효과 비교 -예비연구-)

  • Shin, Seung-Sub
    • PNF and Movement
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    • v.16 no.2
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    • pp.229-238
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    • 2018
  • Purpose: This study aimed to compare the immediate effects of various contract-relax (CR) techniques on the peck force and passive range of motion (ROM) of knee extension. Methods: This study recruited 17 adult males and females who obtained below $90^{\circ}$ in straight leg raising. The subjects randomly performed one of three different CR techniques (direct CR, indirect CR, and modified CR) on the right knee extension four times per day for three days. The subjects' peck force during each CR and their passive knee extension on the hip at a $90^{\circ}$ flexed position before and after each CR were measured. Results: The peck force was significantly higher in the direct and modified CR than in the indirect CR. The ROM in the passive knee extension significantly increased after direct and indirect CR. Comparing between each CR, the passive knee extension range was significantly more improved in the direct and indirect CR than in the modified CR. Conclusion: Direct and indirect CR are more effective than modified CR in the ROM of passive knee extension. The study results suggest that the modified CR did not have the same effect on the ROM of the knee extension as the direct and indirect CR and that further research is needed to recruit more subjects and to determine the effects on different muscles after modified CR.

The Case Report about Six Cancer Patients Added Eriobotryae Folium Fomentation to Mitigate Pain (통증완화를 위해 비파엽 찜질을 병행한 암환자 6례에 대한 증례보고)

  • Lee Jung-Hee;Jang Bo-Hyoung;Kweon Hyug-Sung;Kweon O-Seob
    • The Journal of Internal Korean Medicine
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    • v.24 no.4_2
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    • pp.995-1006
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    • 2003
  • Objective: The purpose of this study is to see whether pain in cancer patients is decreased by Eriobotryae Folium Fomentation. Methods: We examined the change in pain among six cancer patients, prescribing Eriobotryae Folium Fomentation. As for evaluating methods, we used the case history of pain, the direct evaluation of pain, the indirect evaluation of pain. The direct evaluation of pain is subdivided by the language expression, the non-language expression, and Visual analog scale(VAS). The indirect evaluation of pain is subdivided by the condition of walking, mood and the condition of sleep. Results: After two weeks, any remarkable pain decrease is not observed in both of the direct evaluation and indirect evaluation.

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