• Title/Summary/Keyword: measurement and modeling

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Study on Computational Fluid Dynamics(CFD) simulation for NOx dispersion around combined heat and power plant (열병합발전소 질소산화물 확산에 관한 전산유체역학 simulation 연구)

  • Kim, Ji-Hyun;Park, Young-Koo
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.1
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    • pp.62-71
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    • 2015
  • In order to deal with the globally increasing electric power demand and reduce $CO_2$ emission, complex thermoelectric power plants are being constructed in densely populated downtown areas. As the environmental regulations are continuously strengthened, various facilities like low NOx burner and SCR are being installed to reduce NOx emission. This study is applied using the TMS emission of $NO_2$ from combined heat and power plant located in Goyang-si Gyeonggi-do. Applying data to the computational fluid dynamics(CFD), and compared with the actual measurement results. It is judged that even though there might be differences between actual measurements and CFD results due to the instant changes of wind direction and wind speed according to measurement time during measurement period, modeling results and actual measurement results showed similar concentration at most forecasting areas and therefore, the forecasting concentration could be deducted which is close to actual measurement by calculating the contribution concentration considering the surrounding concentration in the future.

Topic Modeling based Interdisciplinarity Measurement in the Informatics Related Journals (토픽 모델링 기반 정보학 분야 학술지의 학제성 측정 연구)

  • Jin, Seol A;Song, Min
    • Journal of the Korean Society for information Management
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    • v.33 no.1
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    • pp.7-32
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    • 2016
  • This study has measured interdisciplinarity using a topic modeling, which automatically extracts sub-topics based on term information appeared in documents group unlike the traditional top-down approach employing the references and classification system as a basis. We used titles and abstracts of the articles published in top 20 journals for the past five years by the 5-year impact factor under the category of 'Information & Library Science' in JCR 2013. We applied 'Discipline Diversity' and 'Network Coherence' as factors in measuring interdisciplinarity; 'Shannon Entropy Index' and 'Stirling Diversity Index' were used as indices to gauge diversity of fields while topic network's average path length was employed as an index representing network cohesion. After classifying the types of interdisciplinarity with the diversity and cohesion indices produced, we compared the topic networks of journals that represent each type. As a result, we found that the text-based diversity index showed different ranking when compared to the reference-based diversity index. This signifies that those two indices can be utilized complimentarily. It was also confirmed that the characteristics and interconnectedness of the sub-topics dealt with in each journal can be intuitively understood through the topic networks classified by considering both the diversity and cohesion. In conclusion, the topic modeling-based measurement of interdisciplinarity that this study proposed was confirmed to be applicable serving multiple roles in showing the interdisciplinarity of the journals.

Cellular Force Measurement for Force Feedback-Based Biomanipulation (힘반향 기반의 바이오매니퓰레이션을 위한 세포 조작력 측정)

  • Kim, Duk-Ho;Kim, Byung-Kyu;Yoon, Seok;Kang, Hyun-Jae
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.237-240
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    • 2003
  • In biological cell manipulation, manual thrust or penetration of an injection pipette into an embryo cell is currently performed by a skilled operator, relying on visual feedback information only. Accurately measuring cellular forces is a requirement for minimally invasive cell injections. Moreover, the cellular farce sensing is essential in investigating the biophysical properties for cell injury and membrane modeling studies. This paper presents cellular force measurements for the force feedback-based biomanipulation. Cellular force measurement system using piezoelectric polymer sensor is implemented to measure the penetration force of a zebrafish egg cell. First, measurement system setup and calibration are described. Second, the force feedback-based biomanipulation is experimentally carried out. Experimental results show that it successfully supplies real-time cellular force feedback to the operator at several tens of uN and thus plays a main role in improving the reliability of biological cell injection tasks.

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Performance Evaluation of Non-contact Atomic Force Microscopy Due to Vibration Characteristics of Cantilever (비접촉 원자간력 현미경의 탐침 외팔보 진동특성에 따른 성능 평가)

  • 박준기;권현규;홍성욱
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.263-268
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    • 2003
  • This paper presents a result of performance evaluation fur non-contact scanning probe microscopy with respect to the vibration characteristics of cantilevers with tips. One of the current issues of the scanning probe microscopy technology is to increase the measurement speed, which is closely tied with the dynamic characteristics of cantilevers. The primary concern in this research is to investigate the relation between the maximum possible speed of non-contact scanning probe microscopy and the dynamic characteristics of cantilevers. First, the finite element analysis is made fur the vibration characteristics of various cantilevers in use. The computed natural frequencies of the cantilevers are in good agreement with measured ones. Then, each cantilever is tested with topographic measurement for a standard sample with the scanning speed changed. The performances of cantilevers are analyzed along with the natural frequencies of cantilevers. Experiments are also performed to test the effects of how to attach cantilevers in the piezo-electric actuator. Finally, measurement sensitivity has been analyzed to enhance the performance of scanning probe microscopy.

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Unambiguous 3D Surface Measurement Method for a Micro-Fresnel Lens-Shaped Lenticular Lens Based on a Transmissive Interferometer

  • Yoon, Do-Young;Kim, Tai-Wook;Kim, Minsu;Pahk, Heui-Jae
    • Journal of the Optical Society of Korea
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    • v.18 no.1
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    • pp.37-44
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    • 2014
  • The use of a laser interferometer as a metrological tool in micro-optics measurement is demonstrated. A transmissive interferometer is effective in measuring an optical specimen having a high angle slope. A configuration that consists of an optical resolution of 0.62 micron is adapted to measure a specimen, which is a micro-Fresnel lens-shaped lenticular lens. The measurement result shows a good repeatability at each fraction of facets, however, a reconstruction of the lens shape profile is disturbed by a known problem of $2{\pi}$-ambiguity. To solve this $2{\pi}$-ambiguity problem, we propose a two-step phase unwrapping method. In the first step, an unwrapped phase map is obtained by using a conventional unwrapping method. Then, a proposed unwrapping method based on the shape modeling is applied to correct the wrongly unwrapped phase. A measured height of each facet is compared with a profile result measured by AFM.

Exploring the Latent Trait and the Measurement Properties of Korean World Health Organization Quality of Life-BREF Measure Applied to Cancer Survivors

  • Bongsam Choi
    • Physical Therapy Korea
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    • v.30 no.2
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    • pp.120-127
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    • 2023
  • Background: In general, measurement qualities of cross-culturally adapted quality of life (QOL) measures are altered in many aspects, although versions of them are well-validated measures. The latent trait and measurement qualities of the QOL measures for cancer-related samples should be considered when developing cross-culturally adapted measures. Objects: To investigate the latent trait of the translated into Korean World Health Organization Quality of Life-BREF (WHOQOL-BREF) administered to different cancer survivors who had palliative rehabilitation care service (PRCS). Methods: A cross-sectional study with 139 cancer survivors who had an experience of cancer survivorship with PRCS were conducted with a two-step analytic procedure including exploratory factor analysis (EFA) to confirm the latent trait and Rasch rating scale modeling to investigate the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure. Results: While the original WHOQOL-BREF measure constitutes a 4-latent trait, the EFA reveals that 24 items constitute six substantial factors. The item loadings are predominantly spread over factors 1 through 4 in a mixed manner of the latent traits, while the loadings of 'physical health' and 'environmental health' latent traits show similarity to what the original measure intended to assess. The latent trait of the cross-culturally adapted WHOQOL-BREF measure administered to different cancer survivors is likely to reveal more dimensions than the original WHOQOL-BREF measure. Person reliability (i.e., analogous to Cronbach's alpha) and separation are measured with 0.92 and 3.48, respectively. All items except the one item (medical treatment item) fit the Rasch rating model. Conclusion: Findings suggest that the latent trait and the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure should be taken into consideration when applying versions of it to various populations.

A Study on Designing Method of Framework for NGN QoS Management (NGN 운용과정의 QoS 관리를 위한 프레임워크 설계방법)

  • Noh, Si-Choon;Bang, Kee-Chun
    • Journal of Digital Contents Society
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    • v.9 no.1
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    • pp.101-107
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    • 2008
  • The level of transference of NGN is beginning as the operation of Access Gateway in korea at present, but NGN will keep developing continuously to the NGN integrated network until 2010. This research is finding the meaning and assignment of NGN QoS to deduct how to manage the control system and presenting the QoS control process and trial framework. The trial framework is the modeling of the QoS measurement metrics, the measurement time schedule, the section, hierarchy, instrument, equipment and method of measurement and the series of cycle & the methodology about analysis of the result of measurement. The objective standard of quality in communication service is guaranteed not by itself but by controlling and measuring continuously. Especially it's very important time to maintain the research about NGN QoS measurement and control because the big conversion of new network technology paradigm is now spreading.

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Two-Dimensional Hydrodynamic and Water Quality Simulations for a Coinjunctive System of Daecheong Reservoir and Its Downstream (대청호와 하류하천 연속시스템의 2차원 수리·모의)

  • Jung, Yong Rak;Chung, Se Woong;Ryu, In Gu;Choi, Jung Kyu
    • Journal of Korean Society on Water Environment
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    • v.24 no.5
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    • pp.581-591
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    • 2008
  • Most of our rivers are fragmented by the presence of at least one large dam. Dams are often the most substantial controller of the flow regimes and aquatic environments of natural river system. The quality of downstream water released from a stratified reservoir is highly dependent on upstream reservoir water quality. Thus, an integrated modeling approach is more efficient, compared to fragmented modeling approach, and necessary to better interpret the impact of dam operation on the down stream water quality. The objectives of this study were to develop an integrated reservoir-river modeling system for Daecheong Reservoir and its downstream using a two-dimensional laterally averaged hydrodynamic and water quality model, and evaluate the model's performance against field measurement data. The integrated model was calibrated and verified using filed data obtained in 2004 and 2006. The model showed satisfactory performance in predicting temporal variations of water stage, temperature, and suspended solid concentration. In addition, the reservoir-river model showed efficient computation time as it took only 3 hours for one year simulation using personal computer (1.88 Ghz, 1.00 GB RAM). The suggested modeling system can be effectively used for assisting integrated management of reservoir and river water quality.

Effects of Maximum Probe Spacing of Soil Resistivity Survery on Substation Grounding Analysis (변전소 접지설계를 위한 대지저항율 측정시 전극간 최대간격이 접지해석에 미치는 영향)

  • 정길조;곽희로;최종기
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.8
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    • pp.382-386
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    • 2001
  • Presently, typical maximum probe spacing of soil resistivity survey(Wenners 4 pin method) is 20 m in case of 154 K substation grounding design of KEPCO. This paper examined the effects of maximum probe spacing of wenner method on the equivalent soil modeling and the accuracy of grounding resistance measurement by comparing the calculated FOP(Fall-of-Potential) curves of various soil models with the measured one at 154kV H substation. The comparison results showed that the inaccurate estimation of deep soil resistivity, which is caused from the short probe spacing of soil resistivity survey, can produce large errors on measurement of grounding resistance. In this paper a quantitative analysis of FOP at H substation has been presented.

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A 3D Face Modeling Method Using Region Segmentation and Multiple light beams (지역 분할과 다중 라이트 빔을 이용한 3차원 얼굴 형상 모델링 기법)

  • Lee, Yo-Han;Cho, Joo-Hyun;Song, Tai-Kyong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.6
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    • pp.70-81
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    • 2001
  • This paper presents a 3D face modeling method using a CCD camera and a projector (LCD projector or Slide projector). The camera faces the human face and the projector casts white stripe patterns on the human face. The 3D shape of the face is extracted from spatial and temporal locations of the white stripe patterns on a series of image frames. The proposed method employs region segmentation and multi-beam techniques for efficient 3D modeling of hair region and faster 3D scanning respectively. In the proposed method, each image is segmented into face, hair, and shadow regions, which are independently processed to obtain the optimum results for each region. The multi-beam method, which uses a number of equally spaced stripe patterns, reduces the total number of image frames and consequently the overall data acquisition time. Light beam calibration is adopted for efficient light plane measurement, which is not influenced by the direction (vertical or horizontal) of the stripe patterns. Experimental results show that the proposed method provides a favorable 3D face modeling results, including the hair region.

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