• Title/Summary/Keyword: Path-analysis

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Simulation on the Reduction of Interior Noise using the Transfer Path Analysis of the Active Engine Mount (엔진마운트의 전달경로해석을 통한 실내소음저감 시뮬레이션)

  • Lee, Choong-Hwi;Kim, Young-Ho;Choy, Hyun-Joon;Won, Jong-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.166-170
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    • 2008
  • In this study, it proved that transfer path analysis is a proper technique to estimate the interior noise from comparing measured interior noise in case of 3 point supported engine mount system. And the simulation of the vibration isolation for active engine mount using FXLMS algorithm is performed. Also, it verified that reduction of estimated interior noise from transfer path analysis and simulation of the vibration isolation.

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Analysis of the Cause of Hindrance for Ride Quality with OPAX and OTPA (변수모델을 이용한 전달경로분석법(OPAX)과 전달률 함수를 사용한 전달경로분석법(OTPA)을 사용한 승차감 저해요인분석)

  • Kim, Jongsik;Sin, Kwangsoo;Choi, Sangil;Im, Sebin;Kim, Jindong;Lee, Sangkwon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.12
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    • pp.935-942
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    • 2014
  • The ride quality investigation is on-going topic in the car industry since its global standard has not evaluated and it is difficult to point out one part that hinders the ride quality. Since the traditional transfer path analysis that is widely used in car industry to investigate the ride quality requires a lot of test time to process the full data so that there are problems to conduct in industry. Based on these disadvantages, new approaches have developed such as OPAX(operational path analysis with eXogeneous inputs) and OTPA(operational transfer path analysis) for last decades. The OTPA only requires the operational data for evaluate the contribution of vibration sources and the OPAX has advantage of using parametric model to estimate the operating load and needs a minimum set of extra tests with excitation. In this paper, for evaluating the hindrance of ride quality two methods are used and the result is compared with another result of a car having higher ride quality.

Analysis of Cause and Effect Structure for Nogwonsang (노권상(勞倦傷)의 인과 구조 분석)

  • Yoon, Kyu-Jin;Lee, Sang-Chul;Kim, Min-Yong;Park, Young-Bae;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.14 no.1
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    • pp.1-14
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    • 2010
  • Backgrounds : Bojungikgitang is one of the most common herbal prescriptions in Oriental Medicine, and it is highly recommended prescription for Nogwonsang syndrome. The Author developed Nogwonsang questionnaire for quantitative evaluation. Nogwonsang questionnaire is consisted of causes that induce fatigue, symptoms that directly associated with fatigue, and secondary symptoms that is induced from fatigue. Purposes : This study aims to verify whether the Bojungikgitang Questionnaire has causality and meaningful path structure by path analysis. Methods : 242 patients from 12 OMD clinics participated in this study. The patients executed a question investigation in the object. Factor analysis was conducted for extraction of factor and abridgment of items. Path analysis was conducted to verify path structure. SPSS 15.0 for Windows and AMOS 7.0 were used for statistical analysis. Results : Overwork factor explains fatigue factor. Coefficient is 0.771. Fatigue factor explains digesting and cold factor. Individually coefficient is 0.632 and 0.465. Model fit is $X^2=61.395$(df=51), GFI=0.960, AGFI=0.939, NFI= 0.924, CFI=0.986, RMSEA=0.029. Path structure is proved to be significant. Conclusions : Further research is needed Gold standard of Nogwonsang. Establishment of Gold standard leads and the collection of data and the research which are objective are possible. Connection of the clinical indexes which are objective on the paperweight outside and leads and the development of the diagnosis tool which is fixed quantity is demanded.

A Dynamic Modeling of 6×6 Skid Type Vehicle for Real Time Traversability Analysis over Curved Driving Path (곡선주행 실시간 주행성 분석을 위한 스키드 차량의 동역학 모델링)

  • Joo, Sang-Hyun;Lee, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.4
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    • pp.359-364
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    • 2012
  • Real-Time Traversability should be analyzed from the equiped sensors' data in real time for autonomous outdoor navigation. However, it is difficult to find out such traversability that considers the terrain roughness and the vehicle dynamics especially in case of skid type vehicle. The traversability based on real time dynamic analysis was proposed to solve such problem but in navigation with strait driving path. To adapt the method into the navigation with curved driving path, a path following controller should be incorporated into the dynamic model even though it cause the real time problem. In this paper, a dynamic model is proposed to solve the real time problem in the traversability analysis based on real time dynamic simualtion. The dynamic model contains the control dummy which is connected to the vehicle body with a universal joint to follow the curved path without controller. Simulation and experimental results on $6{\times}6$ articulated unmanned ground vehicle demonstrate the method's effectiveness and applicability into the traversability analysis on terrain with bumps.

The Correlation of Agronomic Characters and Path Coefficient Analysis in Panax ginseng C.A. Meyer (고려인삼(Panax ginseng C.A. Meyer)의 년차간 형질상관 및 경로계수 분석)

  • Chung, Youl-Young;Chung, Chan-Moon;Choi, Kwang-Tae
    • Journal of Ginseng Research
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    • v.19 no.2
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    • pp.165-170
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    • 1995
  • This study was carried out to investigate the correlation of agronomic characters, their path coefficients in 2, 3 and 4-year old ginseng plants, and to provide a useful information for ginseng breeding. Correlation coefficients between stem fen변h, number of leaves and number of Iraflets in 2-year age, and stem diameter and leaf length in 3-year age showed highly significant correlation with number of fruits and root weight in 4-year age. The path coefficient analysis indicated that stem length and number of leaflets might give indirect effects on root weight regardless of plant age. On the other hand, stem length and number of leaflets in 2-year age and, stem diameter and leaf length in 3-year age showed direct effects on root weight in 4-year old ginseng. These results may be used for selection of high-yielding ginseng plants. Key words Selection information, correlation and path coefficient analysis.

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The Research for Higher Ride Quality with OPAX and OTPA (변수모델을 사용한 전달경로분석법(OPAX)과 전달률 함수를 사용한 전달경로분석법(OTPA)을 사용한 승차감 향상 연구)

  • Shin, Kwangsoo;Choi, Sangill;Kim, Jongsik;Lee, Sangkwon;Im, Sebin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.1
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    • pp.65-73
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    • 2015
  • The ride quality has become a key component of not only design but car selling as the technology developed and the requirement of passengers grew up. Thus car industry invests lots of time and cost for the higher ride quality. The evaluation of the ride quality mainly is expressed by subjective element that drivers felt. In this paper, instead of the original transfer path analysis method, relatively new methods such as OPAX(Operational path analysis with eXogeneous inputs) and OTPA(operational transfer path analysis) are used for analyzing the main hindrance element of ride quality. With those new method, contribution rate of all paths that the vibration propagate along analyzed after driving test on the roads having different characteristic. The comprehensive hindrance elements of ride quality are deduced from the contribution rate and the improve experiment by changing one of hindrance elements for higher ride quality.

Transverse seismic response of continuous steel-concrete composite bridges exhibiting dual load path

  • Tubaldi, E.;Barbato, M.;Dall'Asta, A.
    • Earthquakes and Structures
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    • v.1 no.1
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    • pp.21-41
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    • 2010
  • Multi-span steel-concrete composite (SCC) bridges are very sensitive to earthquake loading. Extensive damage may occur not only in the substructures (piers), which are expected to yield, but also in the other components (e.g., deck, abutments) involved in carrying the seismic loads. Current seismic codes allow the design of regular bridges by means of linear elastic analysis based on inelastic design spectra. In bridges with superstructure transverse motion restrained at the abutments, a dual load path behavior is observed. The sequential yielding of the piers can lead to a substantial change in the stiffness distribution. Thus, force distributions and displacement demand can significantly differ from linear elastic analysis predictions. The objectives of this study are assessing the influence of piers-deck stiffness ratio and of soil-structure interaction effects on the seismic behavior of continuous SCC bridges with dual load path, and evaluating the suitability of linear elastic analysis in predicting the actual seismic behavior of these bridges. Parametric analysis results are presented and discussed for a common bridge typology. The response dependence on the parameters is studied by nonlinear multi-record incremental dynamic analysis (IDA). Comparisons are made with linear time history analysis results. The results presented suggest that simplified linear elastic analysis based on inelastic design spectra could produce very inaccurate estimates of the structural behavior of SCC bridges with dual load path.

A Meta-Analytic Path Analysis on the Outcome Variables of Nursing Unit Managers' Transformational Leadership: Systemic Review and Meta-Analysis (간호단위 관리자의 변혁적 리더십 결과변인에 관한 메타경로분석)

  • Kim, Sunmi;Jeong, Seok Hee
    • Journal of Korean Academy of Nursing
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    • v.50 no.6
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    • pp.757-777
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    • 2020
  • Purpose: The purpose of this study was to identify the outcome variables of nursing unit managers' transformational leadership and to test a hypothetical model using meta-analytic path analysis. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. Data analysis, conducted using R version 3.6.2 software, included 49 studies for the meta-analysis and 119 studies for meta-analytic path analysis. Results: In the meta-analysis, four out of 32 outcome variables were selected. These four variables were empowerment, nursing performance, job satisfaction, and organizational commitment, which showed larger effect sizes than the median and more than five k. The hypothetical model for the meta-analytic path analysis was established by using these four variables and transformational leadership. A total of 22 hypothetical paths including nine direct effects and 13 indirect effects were set and tested. The meta-analytic path analysis showed that transformational leadership had direct effects on the four variables. Finally, eight direct effects, 12 indirect effects, and six mediating effects were statistically significant, and the hypothetical model was verified. Conclusion: Nursing unit managers can use the transformational leadership to improve empowerment, nursing performance, job satisfaction, and organizational commitment of nurses. This study empirically showed the importance of transformational leadership of nursing managers. This finding will be used as evidence to develop strategies for enhancing transformational leadership, empowerment, nursing performance, job satisfaction, and organizational commitment in nursing science and practice.

A Empirical Study on Influence of Safety on Elementary School Road Considering Commuting Distance & Mode Type (통학거리 및 수단특성을 반영한 초등학교 안전도 영향관계 실증연구)

  • Kim, Tae Ho;Kim, Seung Hyun;Lee, Soo Il
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.139-147
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    • 2015
  • This study deals with actual commuting distance and influence of risk factors depending on commuting distance and mode in order to reestablish actual commuting zone of primary school students. Data mining analysis(CHAID) was applied for this reestablishment using survey results from 6,927 primary school students in Seoul Metro. Six risk factors; convenience level of commuting path condition, convenience level of road crossing condition, vehicle speed on commuting path, segregation level between commuter and vehicle, congestion level of commuting path, and public security level and two mode; walking and cycle are considered in the analysis. As the results of CHAID analysis, commuting distance was divided into four zones; Internal Zone(0.491km under), External Zone(0.492 ~ 1.492km, 1.493 ~ 2.699km), Commutable Zone(2.70km over), and awareness level on safety is declined as commuting distance is increased. The risk factor affecting on safety is recognized differently by students depending on commuting distance and mode. For students commuting by walking, vehicle speed on commuting path and convenience level of commuting path condition are recognized as the prime risk factor within Internal Zone and Commutable Zone, respectively. For students commuting by cycle, convenience level of road crossing condition and vehicle speed on commuting path are recognized as the prime risk factor within Commutable Zone. Analysis results show that improved plan and program for commuting path for primary school students are required considering actual commuting distance and method.

Comparisonal Analysis of Path Planning Methods for Automatic Parking Control of a Car-Like Mobile Robot (자동주차를 위한 차량형 자율주행 로봇에 적합한 경로계획법의 비교분석)

  • Kwon, Hyun-Ki;Chung, Woo-Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.3
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    • pp.267-274
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    • 2012
  • We proposed the KPP (Korea university Path Planner) in our previous works. The KPP is the path planning scheme of a car-like mobile robot in parking environment. The objective of this paper is to investigate the advantage of the KPP through the quantitative and qualitative analysis compared with conventional RRT. For comparison, we proposed travel time for performance index. This paper shows that the KPP shows outstanding performances from the viewpoint of travel time and computational efficiency compared with RRT.