• Title/Summary/Keyword: quality control tests

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A Study for Deriving Target CMV (Compaction Meter Value) of Intelligent Compaction Earthwork Quality Control (토공사 지능형 다짐 품질관리를 위한 목표 CMV(Compaction Meter Value) 도출 방안에 관한 연구)

  • Choi, Changho;Jeong, Yeong-Hoon;Baek, Sung-Ha;Kim, Jin-Young;Kim, Namgyu;Cho, Jin-Woo
    • Journal of the Korean Geotechnical Society
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    • v.37 no.9
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    • pp.25-36
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    • 2021
  • Recently, the intelligent compaction technology for quality control of earthworks has brought attention as a quality control standard for earthworks. In this study, intelligent compaction technology and earthwork quality control methods were investigated and earthwork quality control procedures using intelligent compaction technology were considered based on field tests. Through the field compaction test of the silty sand (SM) fill material, it was confirmed that CMV and bearing capcaity index from plate load tests increased as the number of compactions increased. Based on the field test data, the average CMV and quality control target CMV were derived. The target CMV (34.2) was calculated through the correlation with the bearing capacity index of the plate load test, and the target CMV (36.6) was calculated through the analysis of the CMV increase rate. In this paper, the on-site compaction quality management procedure and methodology using intelligent compaction technology were discussed, and an intelligent compaction quality management method was proposed to promote the applicability of the technology.

A Study on the Control Law Design and Analysis Process (비행제어법칙 설계 및 해석 절차에 관한 연구)

  • Hwang Byung-moon;Cho In-jae;Kim Chong-sup
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.11
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    • pp.913-919
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    • 2005
  • An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modem version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements and improve stability. Standard CLDA (Control Law Design and Analysis) process is provided that reduce the development period of the flight control system. In addition, if this process is employed in developing flight control laws, it reduces the trial and error development and verification of control laws. This paper details the design process of developing a flight control law for the RSS aircraft, utilizing military specifications, linear and nonlinea, analysis using XMATH and ATLAS(Aircraft, Tim Linear and Simulation), handling quality tests using the HQS (Handling Quality Simulator), and real flight test results to verify aircraft dynamic flight responses.

Development of EMU Traction Control System (전동차 추진제어장치 개발)

  • 이일호;이인석;정은성;한성수;배본호
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.659-665
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    • 2000
  • EMU Traction Control System has been largely relied on foreign technology until now. In this time, this system is developed by own local technology according to national technology development policy during 3 years. In this paper, the new developed Traction Control System of EMU and its testing results are introduced. The Traction Control System is consisted latest IGBT switching elements and its traction control algorithm is realized by the state-of-the-art technology, vector control. The system is fully tested in various conditions and the quality is well verified in those tests.

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Evaluation of Industrial Hygiene Laboratories by on-Site Investigation for Revised Quality Control System (개정된 정도관리제도를 적용한 작업환경측정기관의 실험실 현장 평가)

  • Shin, Jung-Ah;Yi, Gwang-Yong;Park, Seung-Hyun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.3
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    • pp.243-249
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    • 2013
  • Objectives: This study assessed the status of domestic industrial hygiene laboratories using data from on-site investigation for revision of quality control systems in 2012-2013. Methods: The target laboratories were 60 industrial hygiene laboratories chosen by random selection and nationwide distribution which had participated in on-site investigations for revision of quality control systems from March 2012 to August 2013. The investigation was performed on-site following standard quality control procedures. The score between each group was compared using Mann-Whitney and Kruskal-Wallis tests, and the correlation between analytical career, sex, academic major of analyst and score of analytical performance was expressed as Spearman's rank correlation coefficient. Results: The assessment revealed that the items to be improved, in sequence, were effort at staff training (score 65.5), ability to calculate data (score 73.4), establishment of internal quality control guidelines (score 75.7), laboratory facilities (score 77.1), degree of understanding and skill at gas chromatography (score 77.1). Analysis performance showed a positive correlation with career of analyst (r=0.56, p<0.01). Conclusions: The practice of on-site investigation for quality control systems showed the current status of industrial hygiene laboratories in the first trial. There were many laboratories which needed improvement and development of analytical systems. This assessment can provide information for the systematic operation and improvement of facilities at each laboratory. Further practice of this investigation will lead to a proficiency testing and accreditation system for autonomous quality control as is the practice in many countries, rather than mandatory practice by legal regulation.

A Tentative Methodology for Quality Control of Trackbed Fills Using Field and Laboratory P-Wave Measurements

  • Park, Chul-Soo;Park, In-Beom;Kim, Eun-Jung;Mok, Young-Jin
    • International Journal of Railway
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    • v.1 no.2
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    • pp.64-71
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    • 2008
  • The quality of track-bed fills of railways has been controlled by field measurements of density $({\gamma}_d)$ and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The Key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC${\pm}$2% as well as the p-wave velocity.

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A Consistent Quality Bit Rate Control for the Line-Based Compression

  • Ham, Jung-Sik;Kim, Ho-Young;Lee, Seong-Won
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.5
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    • pp.310-318
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    • 2016
  • Emerging technologies such as the Internet of Things (IoT) and the Advanced Driver Assistant System (ADAS) often have image transmission functions with tough constraints, like low power and/or low delay, which require that they adopt line-based, low memory compression methods instead of existing frame-based image compression standards. Bit rate control in the conventional frame-based compression systems requires a lot of hardware resources when the scope of handled data falls at the frame level. On the other hand, attempts to reduce the heavy hardware resource requirement by focusing on line-level processing yield uneven image quality through the frame. In this paper, we propose a bit rate control that maintains consistency in image quality through the frame and improves the legibility of text regions. To find the line characteristics, the proposed bit rate control tests each line for ease of compression and the existence of text. Experiments on the proposed bit rate control show peak signal-to-noise ratios (PSNRs) similar to those of conventional bit rate controls, but with the use of significantly fewer hardware resources.

The Effects of Various Cement Type and Compositions on the Material Properties of high Strength Concrete (시멘트 특성의 변화가 고강도콘크리트의 재료특성에 미치는 영향)

  • 백상현;이종열;엄태선;임채용;안광원
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.47-52
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    • 2000
  • Recently, it is very necessary the development of the manufacturing techniques for high strength concrete(HSC) for the large-scale size and good quality of civil structure. But, the manufacture and quality control of HSC of which shrinkage, heat of hydration and workability at construction filed are considered, is very difficult due to its low water-cement ratio and high quantity of unit cement content. In the present study, we tried to know and assess the influences of chemical and physical properties of cement on the material properties of HSC. We analyzed basic properties of 4 kinds of cement whose chemical and physical properties are different each other through various tests such as chemical analysis and mortal test. Also, we performed the assessment of the material properties of HSC for each dement by the test for the conditions of same mix design and similar compressive strength. From the results in the study, the assessment of the important quality factors of cement influencing the properties of HSC may be utilized to quality control of applied cement to manufacture the HSC of high quality.

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Efficient Application of Westgard Multi-Rules and Quality Control Implementation Improvement (Westgard Multi-Rules의 효율적 적용과 조치사항의 개선)

  • Jung, Heung Soo;Oh, Youn Jung;Bae, Jin Soo;Baek, Jin Young;Hwang, Bo ra;Shin, Yong Hwan
    • The Korean Journal of Nuclear Medicine Technology
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    • v.21 no.1
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    • pp.60-64
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    • 2017
  • Purpose Westgard multi-rules application based on test quality improvement and commercialized international standard has been widely used in quality control. However, it is difficult to applicate the Westgard multi-rules in nuclear medicine in vitro tests due to the larger sample sizes and the simultaneous measurement of quality control material and patient sample. This study investigated the usefulness of Westgard multi-rules application in nuclear medicine in vitro tests. Materials and Methods A total of 282 systematic error multi-rules (22s, 101s) recorded in the samsung medical center computer system from January 2013 to June 2016 along with 117 cases of corrective measure record was analyzed. The Quality control implementation is recorded in Hospital information system were divided into 4 high-level areas including quality control material error, experimental procedural error, Kit lot number management error, and others. To prevent quality control material error, the existing method that each staff used their own method was changed. The staff who in charge of managing the quality control material was designated and daily consumption amount of every test was strictly controlled by one person. To prevent other errors, every test step was standardized so that the entire test procedures are identically implemented. Results The total quality control implementation was 117 cases; As a result, 62 quality control material errors were 62 cases, experimental process errors were 24 cases, Kit lot number control errors were 18 cases, and other errors were 13 cases. The quality control material error was corrected and could be used fresh materials within 2 days after thawing. The cases of systemic error were decreased to causes as quality control material error. The quality control materials were reduced above 10 vials to a monthly average. In addition, these errors of experimental processing and Kit lot number were improved by test standardization. Consequently, the cases of 101s and 22s in systematic error rules decreased at least 2 cases to a monthly average. Conclusion To confirm of systematic error through multi-rules application quickly, it is necessary to base on management of the QC material, target values and standard deviation. Moreover, in the event of a systematic error, it was found important to record measures based on test cause analysis. The experiment results are expected to contribute to internal quality control improvement and prompt and accurate result reporting through error recording and causal analysis based on Westgard multi-rules analysis.

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Quality Control and Assurance of Eddy Covariance Data at the Two KoFlux Sites (KoFlux 관측지에서 에디 공분산 자료의 품질관리 및 보증)

  • Kwon, Hyo-Jung;Park, Sung-Bin;Kang, Min-Seok;Yoo, Jae-Il;Yuan, Renmin;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.4
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    • pp.260-267
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    • 2007
  • This research note introduces the procedure of the quality control and quality assurance applied to the eddy covariance data collected at the two KoFlux sites (i.e., Gwangneung forest and Haenam farmland). The quality control was conducted through several steps based on micrometeorological theories and statistical tests. The data quality was determined at each step of the quality control procedure and was denoted by five different quality flags. The programs, which were used to perform the quality control, and the quality assessed data are available at KoFlux website (http://www.koflux.org/).

Internal Control and Stock Price Informativeness about Future Earnings (내부통제와 미래이익에 대한 주가 정보성)

  • Wanglan;Hee-woo Park
    • Asia-Pacific Journal of Business
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    • v.14 no.4
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    • pp.255-273
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    • 2023
  • Purpose - This study examines whether internal control has an effect on stock price informativeness about future earnings. High quality internal control provides continuous assurance for the quality of financial reports, and these future earnings-related information is accurately reflected in the current stock price. Design/methodology/approach - This study collected 12,862 data from 2006 to 2021 in China to make an empirical analysis using the future earnings response coefficient (FERC) and the multiple regression analysis were hired in order to analyze the data. Findings - We find that internal control strengthens the association between current returns and future earnings, indicating that more information about future earnings is reflected in current stock prices. This positive effect exists in both the main board market and the growth enterprise market of China's stock market, especially in the main board market after the implementation of the internal control policy. In addition, we find that the positive effect is weaker for firms that report internal control deficiencies or receives non unqualified internal control audit opinions. The results using earnings persistence yield similar findings, further supporting the results based on the FERC model. Research Implications or Originality - Our tests provide strong evidence that the quality of internal control affects FERC in China stock market.