• Title/Summary/Keyword: Evaluation statistics

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Sound Quality evaluation of the interior noise for the driving vehicle using Mahalanobis Distance (Mahalanobis Distance 를 이용한 주행중 차량 실내소음의 음질평가)

  • Park, Sang-Gil;Kim, Ho-San;Bae, Chul-Yong;Lee, Bong-Hyun;Oh, Jae-Eung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.318-321
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    • 2007
  • Since human listening is very sensitive to sound, a subjective index of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. Many researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. Threrefore, in this study Mahalanobis distance for the vehicle interior noise was derived using the objective SQ except jury test. Finnaly, the results of the SQ evaluation was analyzed discrimination between reference and abnormal group.

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Sound Quality Evaluation and Grade Construction of the Level D Noise for the Vehicle Using MTS (MTS기법을 이용한 차량 D단 소음의 음질 평가 및 음질 등급화 구축)

  • Park, Sang-Gil;Park, Won-Sik;Sim, Hyoun-Jin;Lee, Jung-Youn;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.4
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    • pp.393-399
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    • 2008
  • The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

A study on equating method based on regression analysis (회귀분석에 기초한 균등화 방법에 관한 연구)

  • Cho, Jang-Sik
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.3
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    • pp.513-521
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    • 2010
  • Most of universities have carried out course evaluation to apply the performance appraisal for professor. But, course evaluation depends on characteristics of each class such as class size, type of lecture, evaluator's grade and so on. As the results, such characteristics of each class lead to serious bias which makes lecturers distrust the course evaluation results. Hence, we propose a equating method for the course evaluation by regression analysis which use stepwise variable selection. And we compare proposed method with the other method by Cho et al. (2009) with respect to efficiencies. Also we give the example to which the method is applied.

Preliminary Study to Develop the Instrument of Oriental Medical Evaluation for Hwa-Byung (화병 한의 평가도구 개발을 위한 기초 연구)

  • Cheong, Myung-Hee;Lee, Sang-Ryong;Kang, Wee-Chang;Jung, In-Chul
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.2
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    • pp.141-155
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    • 2010
  • Objectives : This study was performed to develop a standard instrument of oriental medical evaluation for hwa-byung. Methods : The advisor committee on this study was organized by 17 neuropsychiatry professors of oriental medical colleges. The items and structure of the instrument were quoted from the instrument of pattern identification for hwa-byung. We took consultation twice from the advisor committee and we also took additional advices by e-mail. Results : We discriminated between bian-zheng and su-zheng from the answers of the advisor committee. We got the mean weight of each symptom and sign from the answers of the advisor committee. We got the final weight from the combination of the ratio of bian-zheng to the number of all answers of the advisor committee and mean weight. Conclusions : The instrument of oriental medical evaluation for hwa-byung was developed through experts' discussion. If the validity and reliability of this instrument is confirmed through additional clinical trial, the instrument of oriental medical evaluation for hwa-byung is expected to be applied to the subsequent research.

Sound Quality Evaluation of Interior Noise of Driving Vehicle Using Mahalanobis Distance (Mahalanobis Distance를 이용한 주행 중 차량 실내소음의 음질평가)

  • Park, Sang-Gil;Lee, Hae-Jin;Bae, Chul-Yong;Lee, Bong-Hyun;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.1
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    • pp.57-60
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    • 2008
  • Since human listening is very sensitive to sound, for evaluating of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. My researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are highly dependent on jury test and have many difficulties due to various environmental factors. So, to reduce jury test weight. we suggested a new method using Mahalanobis distance for SQ evaluation. Threrefore, in this study Mahalanobis distance for the vehicle interior noise was derived using the objective SQ except jury test. Finnaly, the results of the SQ evaluation was analyzed discrimination between reference and abnormal group.

Establishment of a Safety Inspection System for Public Institutions Ordered Construction Projects (건설공사 발주 공공기관의 안전점검 체계구축에 관한 연구)

  • Eung Ho Park;Sudong Lee;Kihyo Jung
    • Journal of the Korea Safety Management & Science
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    • v.25 no.3
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    • pp.55-62
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    • 2023
  • Public institutions have a responsibility to ensure the safety of their employees and the public. One way to do this is to implement a systematic safety inspection system based on risk assessments and continuous improvements. This study developed a systematic safety inspection system for public institutions that are ordered construction projects. The proposed system in this study consists of a three-step process: (1) developing safety grade evaluation tables, (2) preparing and conducting safety inspections, and (3) evaluating and improving safety management grades. The first step is to develop safety grade evaluation tables by analysis and diagnosis of the construction site's work type, disaster statistics, and related laws. The second step is to conduct safety inspections using the developed evaluation tables. The third step is to determine the safety management grade based on the results of the safety inspection, and to improve risk factors found during the safety evaluation. The proposed system was implemented in highway construction projects carried out by public institutions. The results showed that the proposed system has two major effects: (1) reducing accident-related deaths and injuries, (2) improving safety management levels by continuous evaluation and improvement. The proposed system can be utilized in construction projects ordered by public institutions to improve the level of occupational safety and health.

An Improved Method of Evaluation of Network Reliability with Variable Link-Capacities

  • Lee, Chong-Hyung;Park, Dong-Ho;Lee, Seung-Min
    • Proceedings of the Korean Reliability Society Conference
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    • 2001.06a
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    • pp.455-462
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    • 2001
  • We propose a new method to evaluate the network reliability which greatly reduces the intermediate steps toward calculations of maximum capacity flow by excluding unnecessary simple paths contained in the set of failure simple paths. By using signed simple paths and signed flow, we show that our method is more efficient than that of Lee and Park (2001a) in the number of generated composite paths and in the procedure for obtaining minimal success composite paths. Numerical examples are given to illustrate the use and the efficiency of the method.

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Stochastic Traffic Congestion Evaluation of Korean Highway Traffic Information System with Structural Changes

  • Lee, Yongwoong;Jeon, Saebom;Park, Yousung
    • Asia pacific journal of information systems
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    • v.26 no.3
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    • pp.427-448
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    • 2016
  • The stochastic phenomena of traffic network condition, such as traffic speed and density, are affected not only by exogenous traffic control but also by endogenous changes in service time during congestion. In this paper, we propose a mixed M/G/1 queuing model by introducing a condition-varying parameter of traffic congestion to reflect structural changes in the traffic network. We also develop congestion indices to evaluate network efficiency in terms of traffic flow and economic cost in traffic operating system using structure-changing queuing model, and perform scenario analysis according to various traffic network improvement policies. Empirical analysis using Korean highway traffic operating system shows that our suggested model better captures structural changes in the traffic queue. The scenario analysis also shows that occasional reversible lane operation during peak times can be more efficient and feasible than regular lane extension in Korea.

Using Minimal Path Sets for the Evaluation of the Reliability of DRDT Interconnection $Networks^+$

  • Lim , Hae-Hak;Lee, Chong-Hyung;Cho, Byung-Yup
    • Journal of Korean Society for Quality Management
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    • v.28 no.1
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    • pp.105-118
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    • 2000
  • In this paper, we consider an interconnection network, DRDT (Dual Receive Dual Transmit), that is a double-loop ring topology and adopts the concept of multiple packets transmission. For three types of DRDT configurations, we investigate some properties related to path sets and discuss the method for finding minimal path sets. Using the concept of the terminal reliability and the path sets approach, we evaluate the reliability of the DRDT networks and compare them with a single ring network and a unidirectional double-loop ring network.

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Time Series Models for Performance Evaluation of Network Traffic Forecasting (시계열 모형을 이용한 통신망 트래픽 예측 기법연구)

  • Kim, S.
    • The Korean Journal of Applied Statistics
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    • v.20 no.2
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    • pp.219-227
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    • 2007
  • The time series models have been used to analyze and predict the network traffic. In this paper, we compare the performance of the time series models for prediction of network traffic. The feasibility study showed that a class of nonlinear time series models can be outperformed than the linear time series models to predict the network traffic.