• Title/Summary/Keyword: Developing Measurement

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Characteristics Analysis of Measurement Variables for Detecting Anomaly Signs of Thermal Runaway in Lithium-Ion Batteries (리튬이온 배터리의 열폭주 이상징후 감지를 위한 측정 변수 특성 분석)

  • LIM, BYUNG-JU;CHO, SUNG-HOON;LEE, GA-RAM;CHOI, SEOK-MIN;PARK, CHANG-DAE
    • Journal of Hydrogen and New Energy
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    • v.33 no.1
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    • pp.85-94
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    • 2022
  • To detect anomaly signs of thermal runaway in advance, this study analyzed the signals from various sensors installed in lithium-ion batteries. The thermal runaway mechanism was analyzed, and measurement variables for anomalies of a battery cell were surface temperature, strain, and gas concentration. The changes and characteristics of three variables during the thermal runaway process were analyzed under the abuse environment: the overheat and the overcharge. In experiment, the thermal runaway of the battery proceeded in the initial developing stage, the outgassing stage, and the ignition stage. Analysis from the measured data indicated that the suitable variable to detect all stages of thermal runaway is the surface temperature of the battery, and surface strain is alternative.

A study on a Carbon Trust OWA Stage 2 Domestic Verification Case in the Yellow Sea (서해 해상 환경에서 선박형 부유식 라이다의 Carbon Trust OWA Stage 2 국내 인증 사례에 대한 고찰)

  • Yong-Soo Gang;Dong-Chan Chang;Su-In Yang;Baek-Bum Lee
    • Journal of Wind Energy
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    • v.15 no.1
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    • pp.50-59
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    • 2024
  • Floating LiDAR systems provide significant savings in cost and time compared to the fixed meteorological mast measurement type, and have the advantage of being able to be deployed in various locations due to less restriction on the depth of the installation site. However, to use the wind data collected by a floating LiDAR system commercially, verification procedure is required to ensure that the collected data have sufficient availability. The Carbon Trust OWA roadmap presents guidelines in three stages for the reliability of the wind data collected using a floating LiDAR system. Companies developing wind farms are requesting at least Stage 2 (pre-commercial stage) presented by OWA, and many overseas companies are leading the domestic and overseas markets. In this paper, we introduce the case of OWA Stage 2 certification for the commercial operation of floating LiDAR systems.

A Study on the Development of Career Exploration Support Centers' Measurement Indices of the Performance (진로체험지원센터 성과평가 기준 개발)

  • Chang, Heajung;Yun, Yeju
    • 대한공업교육학회지
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    • v.45 no.2
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    • pp.46-69
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    • 2020
  • The primary purpose of this study was to develop performance evaluation indices for measuring the results of the work and performance of the career exploration support centers. For the study, First, to describe the current status of the management system across the 228 centers, examine the staff's perceptions of the current evaluation method and system of each center, and analyze the needs of measuring indices of each center for its performance evaluation, a cross-sectional survey method was employed. Second, relevant literature was reviewed. Next, measurement indices were developed employing the Delphi method with a panel of 15 experts in developing instruments of accomplishment. Based upon the conclusion of this study, The measurement indices developed in this study focuses on the core measurement indices. These indices include a checkbox of necessary and unnecessary in each item so that each local department of education or each center can select indicating items (indices) according to its own needs. The newly developed measurement indices consists of four domains to assess: (1) Institutional competencies-goals, budget, system, and resources, (2) Practitional competences-qualities of programs, administration of experiential career program providers, promotion of centers and programs, management of human resources such as instructors or guides, and establishment of community-center cooperative networking system, (3) Accomplishments-finding new experiential career program providers, the number of participants such as schools and students, reciprocal system, and the degree of participants' satisfaction with the center and programs, and (4) specialized indicators-extra scores for center-based specialized programs.

A Melon Fruit Grading Machine Using a Miniature VIS/NIR Spectrometer: 2. Design Factors for Optimal Interactance Measurement Setup

  • Suh, Sang-Ryong;Lee, Kyeong-Hwan;Yu, Seung-Hwa;Shin, Hwa-Sun;Yoo, Soo-Nam;Choi, Yong-Soo
    • Journal of Biosystems Engineering
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    • v.37 no.3
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    • pp.177-183
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    • 2012
  • Purpose: In near infrared spectroscopy, interactance configuration of a light source and a spectrometer probe can provide more information regarding fruit internal attributes, compared to reflectance and transmittance configuration. However, there is no through study on the parameters of interactance measurement setup. The objective of this study was to investigate the effect of the parameters on the estimation of soluble solids content (SSC) and firmness of muskmelons. Methods: Melon samples were taken from greenhouses at three different harvesting seasons. The prediction models were developed at three distances of 2, 5, and 8 cm between the light source and the spectrometer probe, three measurement points of 2, 3, and 6 evenly distributed on each sample, and different number of fruit samples for calibration models. The performance of the models was compared. Results: In the test at the three distances, the best results were found at a 5 cm distance. The coefficient of determination ($R_{cv}{^2}$) values of the cross-validation were 0.717 (standard error of prediction, SEP=$1.16^{\circ}Brix$) and 0.504 (SEP=4.31 N) for the estimation of SSC and firmness, respectively. The minimum measurement point required to fully represent the spectral characteristics of each fruit sample was 3. The highest $R_{cv}{^2}$ values were 0.736 (SEP=$0.87^{\circ}Brix$) and 0.644 (SEP=4.16 N) for the estimation of SSC and firmness, respectively. The performance of the models began to be saturated when 60 fruit samples were used for developing calibration models. The highest $R_{cv}{^2}$ of 0.713 (SEP=$0.88^{\circ}Brix$) and 0.750 (SEP=3.30 N) for the estimation of SSC and firmness, respectively, were achieved. Conclusions: The performance of the prediction models was quite different according to the condition of interactance measurement setup. In designing a fruit grading machine with interactance configuration, the parameters for interactance measurement setup should be chosen carefully.

Wax Appearance Temperature Measurement of Opaque Oil for Flow Assurance in Subsea Petroleum Production System (해저 석유 생산시스템 내 유동안정성 확보를 위한 불투명 오일의 왁스생성온도 측정법)

  • Lim, Jong-Se;Back, Seung-Young;Kang, Pan-Sang;Yul, Seung-Ryul;Kim, Hyo-Sang;Park, Ji-Hong
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.1
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    • pp.185-194
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    • 2012
  • Deepwater oil is becoming more attractive because most onshore and shallow water oil is developing or developed. With the on-going trend to deepwater oil developments, flow assurance problems which prevent oil flow from reservoir to processing facilities are becoming an issue because deposited material can be occurred in case oil is exposed to very different environment from reservoir. Wax deposition which is one of flow assurance problems can be a major technical and economic issue because it is very sensitive to temperature. In order to predict and mitigate wax problems, the precise measurement of wax appearance temperature (WAT) which is the starting temperature of wax precipitation is very important. Various methods have been suggested for WAT measurement of opaque oil because there is no standard method for opaque oil. In this study, the WAT of opaque oil samples was measured using viscosity measurement method, differential scanning calorimetry, filter plugging method, and pressurized filter plugging method. Wax deposition test and high temperature gas chromatography analysis were applied to verify measured WAT. As a result of study, the WAT of opaque oils was successfully measured and verified. If WAT measurement methods of opaque oil related to oil characteristics is systematized using the results of this study, it can be a valuable tool for WAT measurement of opaque oil and flow assurance related to wax deposition.

Secondary Pre-service Science Teachers' Image of Scientists and Perception on the Science-Related Career (중등 예비 과학교사들의 과학자 이미지 및 과학 관련 직업에 대한 인식)

  • Song, Youngwook;Cho, Hyukjoon
    • Journal of The Korean Association For Science Education
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    • v.38 no.5
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    • pp.753-763
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    • 2018
  • The image of scientists that learners have has an important impact on science learning and on science-related career choices. The image of the scientist was mainly analyzed using the drawing analysis method. Drawing analysis has limitations on drawing, mainly analyzing the external image of scientist. Science teachers' images of scientists and their perception of science-related careers are important factors in students' science learning and science-related career choices. However, research on science teachers is lacking. Therefore, the purpose of this study is to investigate the usefulness of measurement tools by developing and applying a scientist image measurement tool through the semantic analysis method, and to discuss the educational implications of the research by investigating the image of scientists and science-related professions of secondary pre-service science teachers. The subjects of the study were 79 male and 55 female for a total of 134 students in the 2nd and 3rd grades majoring in science education at a teachers college. The results of the research show that the image measurement tool consisted of four components: 'ability,' 'evaluation,' 'activity,' and 'emotion,' in 24 items. As a result of applying the developed measurement tool to the secondary pre-service science teachers, the image of the 'evaluation,' 'ability,' and 'activity' elements of the scientist were high, but 'emotion' was low. There was no statistically significant difference according to gender. It is found that science-related career perceive them as 'hard,' 'professional,' 'smart,' and 'complex.' In particular, male students perceive themselves as 'hard and difficult' while female students perceive it as 'challenging and complicated'. Finally, we discussed the usefulness of using the image measurement tool of the scientists, the image of the scientists of the secondary pre-service science teachers, and the educational implications on science-related career.

Application of Eddy Current Sensor for Measurement of TBM Disc Cutter Wear (TBM 디스크커터의 마모량 측정을 위한 와전류센서의 적용 연구)

  • Min-Sung Park;Min-Seok Ju;Jung-Joo Kim;Hoyoung Jeong
    • Tunnel and Underground Space
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    • v.33 no.6
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    • pp.534-546
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    • 2023
  • If the disc cutter is excessively worn or damaged, it becomes incapable of rotating and efficiently cutting rockmass. Therefore, it is important to appropriately manage the replacement cycle of the disc cutter based on its degree of wear. In general, the replacement cycle is determined based on the results of manual inspection. However, the manual measurements has issues related to worker safety and may lead to inaccurate measurement results. For these reasons, some foreign countries are developing the real-time measurement system of disc cutter wear by using different sensors. The ultrasonic sensors, eddy current sensors, magnetic sensors, and others are utilized for measuring the wear amount of disc cutters. In this study, the applicability of eddy current sensors for real-time measurement of wear amount in TBM disc cutters was evaluated. The distance measurement accuracy of the eddy current sensor was assessed through laboratory tests. In particular, the accuracy of eddy-current sensor was evaluated in various environmental conditions within the cutterhead chamber. In addition, the measurement accuracy of the eddy current sensor was validated using a 17-inch disc cutter.

Development of Automatic Water Sampler with Sensor for Practical Measurement (현장측정용 센서부착 자동채수기 개발)

  • Kim, Jin-Hyok;Han, Seong-Kuk;Lee, Jin-Pill;Kim, Jae-Yong
    • Applied Chemistry for Engineering
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    • v.21 no.6
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    • pp.632-637
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    • 2010
  • Considering the water quality regulation of total emission system which is enforced with hydro TMS and so on operating currently, automatic water sampler must be necessary in the viewpoint of national interest for conservation of water resources. This study aimed to develope automatic water sampler for the purpose of decreasing spends on foreign currency which is relied on import from abroad and upgrading the functional efficiency simultaneously. We have made an effort for developing results as follows with some cases. First, flow meter with a sensor equiped into automatic water sampler for field measurement which can perform linkage operation was developed. Second, remote-D/L system was developed which was able to monitor and store some transmitted data from practical measurement sensor. Also, automatic water sampler was developed in this research that operates in a sewage treatment plant, and finally, we confirmed that our system is able to apply to the field well.

Development of Framework for Effectiveness Measurement of LVC Synthetic Battlefield Training System (LVC 합성전장 훈련체계 효과도 측정 프레임워크 개발)

  • Kwon, Kybeom;Min, Seungin;Yee, Kwanjung;Seol, Hyeonju;Oh, Jihyun;Sim, Inbo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.5
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    • pp.704-713
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    • 2018
  • The purpose of this study is to develop a systematic framework that can scientifically and quantitatively evaluate the effectiveness of an LVC training system. The proposed framework is based on QFD(Quality Function Development) methodology. The process of developing the framework begins with identifying various needs of stakeholders related to the introduction of the LVC training system. Then the effectiveness areas and factors are derived based on the needs. The measured effectiveness for each factors on alternatives by L, V, C systems are finally synthesized into the one overall effectiveness of each training system for relative comparison among them. In addition, we developed an Excel$^{TM}$-based tool based on the proposed framework methodology to provide an ease-of-use environment for rapid evaluation on the effectiveness of each training system with the given stakeholder need importance combinations, training scenarios and assets. The suggested framework and the measurement tool are expected to be useful for efficient knowledge-based decision making on an acquisition of the LVC training system.

Short Distance ASF Measurement by using 9930M Loran Signal (9930M Loran신호 이용 근거리 ASF 측정)

  • Yang, Sung-Hoon;Lee, Chang-Bok;Lee, Jong-Gu;Kim, Young-Jae;Lee, Sang-Jeong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.04a
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    • pp.370-371
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    • 2010
  • The Long Range Navigation (LORAN) had been mainly used world-wide until GPS (Global Positioning System) activation. In particular. it was essential junctionality for the ships to sail the oceans. However, according to the industry's developing, the current accuracy of Loran is insufficient for the utilization such as the harbour approach, the land navigation and the field of precise timing. Therefore it is necessary the study on the improvement of the positioning accuracy of Loran. The method of its improvement is to measure and compensate the propagation time delay, that is, additional secondary factor (ASF) between the transmitter and user's receiver. This study shows the technique for the absolute time delay measurement without a time of coincidence (TOC) table, and represents the ASF measurement result between Pohang transmitter station(9930M) and each measure points.

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