• Title/Summary/Keyword: Estimation Methodology

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Improved GPS-based Satellite Relative Navigation Using Femtosecond Laser Relative Distance Measurements

  • Oh, Hyungjik;Park, Han-Earl;Lee, Kwangwon;Park, Sang-Young;Park, Chandeok
    • Journal of Astronomy and Space Sciences
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    • v.33 no.1
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    • pp.45-54
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    • 2016
  • This study developed an approach for improving Carrier-phase Differential Global Positioning System (CDGPS) based realtime satellite relative navigation by applying laser baseline measurement data. The robustness against the space operational environment was considered, and a Synthetic Wavelength Interferometer (SWI) algorithm based on a femtosecond laser measurement model was developed. The phase differences between two laser wavelengths were combined to measure precise distance. Generated laser data were used to improve estimation accuracy for the float ambiguity of CDGPS data. Relative navigation simulations in real-time were performed using the extended Kalman filter algorithm. The GPS and laser-combined relative navigation accuracy was compared with GPS-only relative navigation solutions to determine the impact of laser data on relative navigation. In numerical simulations, the success rate of integer ambiguity resolution increased when laser data was added to GPS data. The relative navigational errors also improved five-fold and two-fold, relative to the GPS-only error, for 250 m and 5 km initial relative distances, respectively. The methodology developed in this study is suitable for application to future satellite formation-flying missions.

Design of Level 2 Control System for Continuous Reheat Furnaces (연속식 가열로의 Level 2 제어 시스템 설계)

  • Ryu, BoHyun;Lee, JaeYong;Rhim, DongRyul;Cha, JaeMin;Yeom, ChoongSub
    • Journal of the Korean Society of Systems Engineering
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    • v.12 no.1
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    • pp.113-120
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    • 2016
  • Steel in a continuous reheat furnace is heated to higher temperature to be treated in the rolling steel process. Due to this reason the continuous reheat furnace system requires an optimal control system to adjust the temperature inside the furnace. Level 2 control systems for continuous reheat furnaces generate automatic heating set points for the level 1 system of the furnace based on the mathematical thermal model which can give a good estimation of steel heating inside the furnace and is used to adjust heating requirements to optimize furnace combustion. For the current study the analytic methodology based on the design procedure from the systems engineering to develop new level 2 control system of a continuous reheat furnace was proposed. The system analysis and the requirements of the level 2 control system were derived using the unified modeling language (UML) 2.0, and the design of database and the graphic user interface (GUI) for the level 2 control system were conducted.

Growth of Loan Distribution and Bank Valuation: Evidence from Vietnam

  • HOANG, Lam Xuan;HOANG, Phi Dinh;DANG, Duong Quy
    • Journal of Distribution Science
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    • v.18 no.5
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    • pp.5-13
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    • 2020
  • Purpose: The aim of this article is to test the link between growth of loan distribution and Bank Valuation in Vietnam's banking sector. At the same time, the study also compared the differences in the effect of growth of loan to valuation bank in banks of different sizes, ownership rates and bank values. Research design, data and methodology: With panel data estimation techniques along with robust standard error for a sample of the banks listed on Vietnam stock exchange from 2012 to 2019. Results: Growth of loan has a positive impact on Bank Valuation (by Tobin's Q). A closer investigation provides evidence for the differential valuation effect of loan growth depending on different features of banks. Specifically, loan growth is found positively and significantly associated with Bank Valuation in small and non-state-owned banks only. Besides, bank size, deposit, and return on equity are found negatively associated with Tobin's Q, while loan loss provisions exhibit a positive relation with this measure of Bank Valuation. Conclusions: These findings provide contributions to the literature on the existence of the effect of loan growth on Bank Valuation. At the same time, the study also provides practical implications for policy makers in banks and investors.

The Effect of Corporate Integrity on Stock Price Crash Risk

  • YIN, Hong;ZHANG, Ruonan
    • Asian Journal of Business Environment
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    • v.10 no.1
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    • pp.19-28
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    • 2020
  • Purpose: This research aims to investigate the impact of corporate integrity on stock price crash risk. Research design, data, and methodology: Taking 1419 firms listed in Shenzhen Stock Exchange in China as a sample, this paper empirically analyzed the relationship between corporate integrity and stock price crash risk. The main integrity data was hand-collected from Shenzhen Stock Exchange Website. Other financial data was collected from CSMAR Database. Results: Findings show that corporate integrity can significantly decrease stock price crash risk. After changing the selection of samples, model estimation methods and the proxy variable of stock price crash risk, the conclusion is still valid. Further research shows that the relationship between corporate integrity and stock price crash risk is only found in firms with weak internal control and firms in poor legal system areas. Conclusions: Results of the study suggest that corporate integrity has a significant influence on behaviors of managers. Business ethics reduces the likelihood of managers to overstate financial performance and hide bad news, which leads to the low likelihood of future stock price crashes. Meanwhile, corporate integrity can supplement internal control and legal system in decreasing stock price crash risks.

The Impact of Technology Adoption on Organizational Productivity

  • LAKHWANI, Monika;DASTANE, Omkar;SATAR, Nurhizam Safie Mohd;JOHARI, Zainudin
    • The Journal of Industrial Distribution & Business
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    • v.11 no.4
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    • pp.7-18
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    • 2020
  • Purpose: This research investigates the impact of technology adoption on organisation productivity. The framework has three independent variables viz. technological change, information technology (IT) infrastructure, and IT knowledge management and one dependent variable as organisational productivity. Research design, data and methodology: An explanatory research design with a quantitative research method was employed, and data was collected using a self-administered questionnaire using online as well as an offline survey. The sample consisted of 300 IT managers and senior-level executives (production as well as service team) in leading IT companies in Malaysia selected using snowball sampling. Normality and reliability assessment was performed in the first stage utilising SPSS 22, and Confirmatory Factory Analysis (CFA) was performed with maximum likelihood estimation to assess the internal consistency, convergent validity, and discriminant validity. Finally, Structural Equation Model (SEM) and path analysis are conducted using AMOS 22. Results: The research findings demonstrated that technological change and IT infrastructure positively and significantly impact the organisation's productivity while IT knowledge management has significant but negative impact on organizational productivity of IT companies in Malaysia. Conclusion: The research concludes that all three factors plays important role in deciding organizational producvity. Recommendations, implications, limitations and future research avenues are discussed.

Study on a Optimal Inspection Cycle of Electrical facility of Railroad (철도전기설비의 최적점검주기에 관한 기초연구)

  • Chu, Cheol-Min;Kim, Jae-Chul;Lee, Tae-Hee;An, Jae-Min;Moon, Jong-Fil
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.224-228
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    • 2007
  • It is focused on a methodology to establish a optimal inspection cycle of electrical facility of railroad Decision method of optimal inspection cycle is a process which establishes maintenance plan for facilities' immanent function as using reliability theory in operation term In order to ensure normal operation in a given condition, the decision method is logical for selecting effective maintenance plan to consider characteristic of system In estimation of failure rate, critical facility is selected firstly. After that, proper distribution function on each facility is decided to investigate distribution function for extraction of failure rate. Next, cost produced by the case that facility's failure is occurred is surveyed. Finally, maintenance method developed until now is investigated, before suitable model for the facility applying maintenance method is developed, and that maintenance decision is made. Therefore, this process is the method to find optimal inspection cycle for reasonable cost and effective reliability on facility.

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GEO-LINEAMENT CHARACTERIZATION USING WAVELET APPROACH: A CASE STUDY IN THE UISEUNG CALDERA REGION

  • Kim, Mi-Kyung;Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.243-246
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    • 2006
  • Wavelet approach is regarded as a useful methodology for geo-environment analysis with respect to spatial objects with periodicity and spatial pattern, compared to autocorrelation analysis, Fourier analysis, variogram analysis and so on. However, there are a few case studies for geo-lineament characterization with the actual geo-based information such as remotely sensed imagery and DEM. In this study, wavelet approach in the Uiseung caldera region are carried out to delineate characterization for geolineament spatial pattern. There are high possibilities of the development of radial lineaments from the centre of round crater due to the eruption of a volcano and the subsidence of a crater. We have grasped the directionality of the whole linear structures of the caldera via rose diagram, and then performed wavelet analysis on the profiles of orthogonal directions for main directions of the lineaments. The result of this study is likely to be used as a fundamental data in order to grasp the outline of caldera structure prior to the close estimation

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Estimation of the Noise Variance in Image and Noise Reduction (영상에 포함된 잡음의 분산 추정과 잡음제거)

  • Kim, Yeong-Hwa;Nam, Ji-Ho
    • The Korean Journal of Applied Statistics
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    • v.24 no.5
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    • pp.905-914
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    • 2011
  • In the field of image processing, the removal noise contamination from the original image is essential. However, due to various reasons, the occurrence of the noise is practically impossible to prevent completely. Thus, the reduction of the noise contained in images remains important. In this study, we estimate the level of noise variance based on the measurement of the relative strength of the noise, and we propose a noise reduction algorithm that uses a sigma filter. As a result, the proposed statistical noise reduction methodology provides significantly improved results over the usual sigma filtering regardless of the level of the noise variance.

Trip Generation Model Using Backpropagation Neural Networks in Comparison with linear/nonlinear Regression Analysis (신경망 이론을 이용한 통행발생 모형연구 (선형/비선형 회귀모형과의 비교))

  • 장수은;김대현;임강원
    • Journal of Korean Society of Transportation
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    • v.18 no.4
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    • pp.95-105
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    • 2000
  • The Purpose of this study is to present a new Trip Generation Model using Backpropagation Neural Networks. For this purpose, it is compared the performance between existing linear/nonlinear Regression models and a new TriP Generation model using Neural Networks. The study was performed according to the below. First, it is analyzed the limits of conventional Regression models, next Proved the superiority of Neural Networks model in theoretical and empirical aspects, and lastly Presented a new approach of Trip Generation methodology. The results show that Backpropagation Neural Networks model is predominant in estimation and Prediction comparable to Regression analysis. Such results mean the possibility of Neural Networks\` application in Trip Generation modeling. Specially under the circumstances of the chancing transportation situations and unstable transportation on vironments, its application in transportation fields will be extended.

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Analysis of Nursing Intensity Related to Nursing Activities in Operating Room using the Relative Value Scale For Nursing Cost (간호수가 산정을 위한 상대가치를 이용한 수술실 간호행위 간호강도 분석)

  • Ha, Ru Mee;Kwon, Kyoung Ja;Woo, Jin Ha;Kim, Jung A
    • Journal of Korean Clinical Nursing Research
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    • v.20 no.2
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    • pp.162-176
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    • 2014
  • Purpose: The purpose of this study was to perform an operating room nursing activities analysis and estimate nursing intensity of each nursing activity based on the Relative Value Scale (RVS). Methods: The methodology for this study of RVS was based on the work of Hsiao et al. The first stage was to identify nursing activities and the second to measure intensity of nursing activities including technical skill, mental effort, and stress. Results: Calculation of the RVS for 99 nursing practices showed a score range from 300.00 to 1337.78. CS operation assistant, OS operation assistant, and obtaining certification had high nursing intensity. Surgical hand washing, putting on surgical gowns, surgical gloves and surgical caps and mask had low nursing intensity. Conclusion: The activities of operating room are not compensated separately but reimbursement is usually included in physician fees. In the future, an estimation of nursing cost should show the nursing contribution rate to total operation revenue.