• Title/Summary/Keyword: standard measurement methods

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Evaluation Standards to Diagnosis Cables in Urban Railway Vehicles (도시철도차량 전선의 열화진단 평가기준)

  • Lim, Jea-Yoon;Lee, Jong-Pil;Lee, Dae-Jong;Ji, Pyeong-Shik;Kang, Seong-Hwa;Kim, Hyung-Chul
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.3
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    • pp.268-274
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    • 2010
  • Urban rail transit brings the benefits of various aspects of society. With the advent of fast and large trains, however, risk and scale of accidents have increased. Despite the fact that there is various safety features built into the modern metros, train faults happen from time to time. Especially, as urban railway vehicles in Korea have become deterioration rapidly, more advanced diagnosis methods are required to prevent various accidents. In this paper, we present diagnosis method for electrical wires to guarantee secure driving and authenticity more accurately in urban railway vehicles. Although there are kinds of conventional methods based on insulation resistance measurement and withstand test, it is extremely difficult to effectively diagnose obsolete equipments such as electrical wires and cables not new ones. This study is focused on development of diagnosis method and establishment of evaluation standard for electrical wires in urban railway vehicles.

A quantitative measurement of concrete air content using image analyses

  • Hwang, C.L.;Peng, S.S.;Wang, E.;Lin, S.H.;Huang, S.L.
    • Computers and Concrete
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    • v.7 no.3
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    • pp.239-247
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    • 2010
  • A proposed topology method is introduced to measure the air content of fresh cement paste and hardened concrete. The method takes advantage of chromatographic analysis in void areas that are highlighted using different color schemes and later calculated using built-in computer software. The air content measured by the topology method is compared with results obtained from the conventional ASTM methods. It is concluded that the proposed method is reliable, and costs less and is easier to operate compared with the ASTM methods. In addition, 3 dimensional pore models can be created using image post-processing techniques. The proposed method helps researchers in understanding the formation and existence of concrete pores. This paper reports a detailed test program demonstrating the standard operating procedure used for the proposed method and presents a comparison of results between the proposed method and conventional ASTM Specifications. It is also concluded that the air content increases with increasing size of pores and increasing percentage of coarse aggregates.

The Sizing Communications of Menswear on Retail Websites (온라인 쇼핑 사이트의 성인 남성복 제품 사이즈 정보 실태 분석)

  • Jaehyun Park;Ah Lam Lee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.47 no.1
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    • pp.73-84
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    • 2023
  • This study aims to identify the current sizing communication issues of menswear on retail websites and to suggest an effective size information presentation method. Based on sales frequency and awareness in the Korean menswear market, 22 brand websites were selected, and size-related information was investigated using 7 types of representative apparel items. The current diverse types of size codes had limitations in delivering actual product size information. Many websites preferred to display garment dimensions rather than basic body measurements, which is the suggested size designation method in Korean Standard. The websites posted fit model photos and customer reviews. However, the body size specifications, which consumers can use as a useful reference, were often omitted. There was also a high uncertainty in product size selection, with only the basic body measurement information listed, and there was a high deviation of garment dimensions within the same basic body measurements. The product size distribution did not match actual Korean body types. Based on the findings, we suggested improved effective sizing communication methods. These methods will contribute to a better online shopping environment for both consumers and retail sellers.

Development and Validation of a Recognition Scale for Childcare Teachers' Rights (보육교사 권리 인식 척도 개발 및 타당화)

  • Jaekyeong Suk;Jungmin Kim
    • Korean Journal of Childcare and Education
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    • v.19 no.6
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    • pp.1-19
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    • 2023
  • Objective: The aim of the present study was to develop and validate a recognition scale for childcare teachers' rights. Methods: Statistical methods for data analysis involved the use of SPSS 20.0 and AMOS 20.0. To confirm the reliability and validity of the developed scale, various analyses, including item quality assessment, item discrimination, exploratory factor analysis, confirmatory factor analysis, and Pearson correlation analysis, were conducted. The maximum likelihood estimation method was employed for model fitting. Goodness of fit was assessed using SRMR, RMSEA and its 90% confidence interval, CFI, and TLI. Through these analyses, the scale's reliability and validity exceeded the standard. Consequently, 5 factors and 30 questions were ultimately selected as the recognition scale for childcare teachers' rights. Results: First, a recognition scale for childcare teachers' rights was developed to reflect changes in childcare settings. Second, an objective measurement was incorporated into the recognition scale of childcare teachers' rights. Third, the analysis using the proposed scale revealed a correlation between the recognition of childcare teachers' rights and life satisfaction. Conclusion/Implications: The study developed a scale capable of objectively measuring the recognition of childcare teachers' rights.

Evaluation of the accuracy of linear and angular measurements on panoramic radiographs taken at different positions

  • Nikneshan, Sima;Sharafi, Mohamad;Emadi, Naghmeh
    • Imaging Science in Dentistry
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    • v.43 no.3
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    • pp.191-196
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    • 2013
  • Purpose: This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. Materials and Methods: Two acrylic models were fabricated from a cast with normal occlusion. Straight and $75^{\circ}$ mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an $8^{\circ}$ downward tilt of the occlusal plane compared to the standard position, at an $8^{\circ}$ upward tilt of the anterior occlusal plane, and at a $10^{\circ}$ downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. Results: Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. Conclusion: Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than $10^{\circ}$ had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and $8^{\circ}$ upward tilt of the anterior part of the occlusal plane compared to other positions.

Introduction of Management System Case Study on Standardization of Quality Record Management to Improve Quality Performance Rate of SMEs (경영시스템 도입 중소기업의 품질이행율 향상을 위한 품질기록 관리운영의 표준화 사례연구)

  • Cho, Chul-Hee;Park, Byeong Hwa;Park, Jini
    • Journal of Korean Society for Quality Management
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    • v.47 no.4
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    • pp.911-926
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    • 2019
  • Purpose: In an infinite market competition, companies are adopting management systems to gain a competitive advantage. The expectancy effect of the management system is management performance improvement and accurate measurements. These can be made through quality records with integrity and maintainability. This paper examines the operation of records management standards, which are records, storage and management standards for quality records to understand the needs of records management standards and empathize with their needs. Methods: This paper examines PEC's (Pields Engineering Co., Ltd.) specific processes and standards for integrating individual management systems and establishing records management standards. We also look at the specific features of the Search Tool and Document Storage Management Standards that support records management standards. Results: The integration process of PEC's individual management system consists of five steps. A PDCA-based process was established to erode the confusion and inefficiencies caused by overlap between individual management systems. Also, by accurately grasping corporate competence, PEC established a record management standard suitable for the characteristics of the company. PEC's records management standards are used as a useful standard for organizing quality records, and have an impact on management performance improvement. Conclusion: PEC's records management standards enable the verification of quality performance rates and performance measures. Companies can implement appropriate quality improvement strategies based on the numbers identified by introducing records management standards. Companies can succeed in improving management performance when operating quality management that combines performance measurement techniques and records management standards.

Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

  • Dong, Ren G.;Sinsel, Erik W.;Welcome, Daniel E.;Warren, Christopher;Xu, Xueyan S.;McDowell, Thomas W.;Wu, John Z.
    • Safety and Health at Work
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    • v.6 no.3
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    • pp.159-173
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    • 2015
  • The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

Sheet Formation Properties of Morus Hanji (뽕나무 한지의 지합특성)

  • Yi, Il-Roh;Cho, Nam-Seok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.3 s.116
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    • pp.47-60
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    • 2006
  • This study was carried out to investigate the sheet formation properties of Morus Hanjis, made of bast and whole stalk pulps by different pulping methods, such as alkali, alkali-peroxide and sulfomethylated pulping. Two species of Morus, M. alba and M. lhou, were used. Effect of morphological properties of pulp stocks on the sheet formation and its gray levels based on optical property were evaluated using an Image analyzer. In addition, the effect of fiber distribution index(FDI) which was calculated from tile data of Confocal laser scanning microscopy(CLSM) on the sheet formation and optical properties of Morus Hanji were also discussed. On the sheet formation, Hanji from whole stalk pulp was superior than that of bast pulp. The more the sheet formation improved, the more paper opacity decreased. In the aspect of Hanji's surface characteristics analyzed by an Image analyzer, the average gray level and its standard deviation of Hanji from the whole stalk pulp were rather lower than those of bast pulp because of better sheet formation of the former. However, high brightness Hanji showed high value of gray level. The sheet formation and paper opacity were increased with the decrease of standard deviation of gray level. From these results, gray level measurement could be used to predict the paper opacity as well as sheet formation. Sheet formation of whole stalk Hanji and its FDI measured by CLSM were higher than those of bast fibers. In conclusion, the sheet formation and opacity of Hanji could be evaluated by standard deviation value of Hanji's gray level using an Image analyzer and by fiber distribution index using CLSM.

Part I. What drives Korean adults to seek orthodontic treatment: Reliability and validity of a measurement instrument for the perception of orthodontic treatment

  • Oh, Min-Hee;Kim, Eun-A;Park, Ae-Hyun;Kim, MinSoo;Cho, Jin-Hyoung
    • The korean journal of orthodontics
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    • v.50 no.6
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    • pp.363-372
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    • 2020
  • Objective: To develop a standardized instrument to measure the level of cognition for orthodontic treatment in adults, and verify its reliability and validity for assessing perceptions of orthodontic treatment in adults. Methods: A total of 406 adults aged 19-64 years were surveyed by an internet research system. A tool was developed through the instrument development and verification stages. The data were analyzed by correlation analysis, exploratory factor analysis, confirmatory factor analysis, and Cronbach's α test. Results: The instrument consisted of 11 items covering four factors related to orthodontic treatment. Three items were related to general perception, four described the perception of the treatment for adults, two related to the treatment effects, and two related to the retention of orthodontic treatment. In the reliability test, Cronbach's α was 0.845 for the 11 items. In assessments for individual components, Cronbach's α was 0.764 for the general perception of orthodontic treatment, 0.705 for the perception of this treatment for adults, 0.707 for the effects of the treatment, and 0.701 for the retention of orthodontic treatment. Finally, a measurement instrument for the perception of orthodontic treatment in adults was designed to assess the 11 items on a four-point Likert scale. Conclusions: This study developed a standard measurement instrument for assessing the perception of orthodontic treatment in adults. The proposed instrument will enable additional studies on the influence of an adult's perception of orthodontic treatment on the decision to undergo treatment.

A New Semantic Distance Measurement Method using TF-IDF in Linked Open Data (링크드 오픈 데이터에서 TF-IDF를 이용한 새로운 시맨틱 거리 측정 기법)

  • Cho, Jung-Gil
    • Journal of the Korea Convergence Society
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    • v.11 no.10
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    • pp.89-96
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    • 2020
  • Linked Data allows structured data to be published in a standard way that datasets from various domains can be interlinked. With the rapid evolution of Linked Open Data(LOD), researchers are exploiting it to solve particular problems such as semantic similarity assessment. In this paper, we propose a method, on top of the basic concept of Linked Data Semantic Distance (LDSD), for calculating the Linked Data semantic distance between resources that can be used in the LOD-based recommender system. The semantic distance measurement model proposed in this paper is based on a similarity measurement that combines the LOD-based semantic distance and a new link weight using TF-IDF, which is well known in the field of information retrieval. In order to verify the effectiveness of this paper's approach, performance was evaluated in the context of an LOD-based recommendation system using mixed data of DBpedia and MovieLens. Experimental results show that the proposed method shows higher accuracy compared to other similar methods. In addition, it contributed to the improvement of the accuracy of the recommender system by expanding the range of semantic distance calculation.