• 제목/요약/키워드: Variation analysis

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수질오염총량관리 단위유역의 유량변화 특성분석 - 금강수계를 대상으로 - (Characterization on the Variation of Streamflow at the Unit Watershed for the Management of Total Maximum Daily Loads - in Guem River Basin -)

  • 박준대;오승영;최옥연
    • 한국물환경학회지
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    • 제27권6호
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    • pp.914-925
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    • 2011
  • The variation of streamflow is regarded as one of the most influential factors on the fluctuation of water quality in the stream. The characteristics of the variation should be taken into account in the plans for the management of Total Maximum Daily Loads (TMDLs). This study analysed and characterized spatial distribution and temporal variation of streamflow at each unit watershed in Guem-river basin. For the analysis of the distribution of streamflow, the type and the extent of the distribution were investigated for the unit watershed. For the analysis of the variation, short and long term changes of streamflow were examined. The result showed that most of the distributions were not log-normalized and the extent of variation tends to be greater at the unit watershed placed on the tributaries in the basin. A kind of margin could be granted to the unit watershed involving high variations so as to establish the water quality goal and load allotment more reasonably and effectively in view of whole waterbody.

3 차원 벤딩 머신에서 정밀 성형을 위한 공정 개발에 관한 연구 (A study on the process for precision forming by 3-dimension bending machine)

  • 김현진;임상헌;이춘만
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1897-1900
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    • 2005
  • The purpose of this study is to investigate the bending process for manufacturing of sound pipe by 3 dimension bending machine. The arbitrarily-bended pipe is widely used in a heat exchanger system. The pipe should be formed precisely for assembling of heat changer. And, spring back effect and variation of the pipe thickness should be controlled effectively. We described the change of spring back amount and thickness variation of the pipe according to the change of bending radius and bending angle by FEM analysis. The analysis is adopted the elasic-plastic analysis and contact analysis on MARC software.

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Clustering Analysis on Heart Rate Variation in Daytime Work

  • Hayashida, Yukuo;Kidou, Keiko;Mishima, Nobuo;Kitagawa, Keiko;Yoo, Jaesoo;Park, SunGyu;Oh, Yong-sun
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2017년도 춘계 종합학술대회 논문집
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    • pp.257-258
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    • 2017
  • Modern society tends to bring excessive labor to people and, therefore, further health management is required. In this paper, by using the clustering technique, one of machine learning methods, we try to bring out the measure of fatigue from heart rate (HR) variation during daytime work, helping people to get high-quality of healthy and calm life.

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AE고유동화제 첨가량 변화에 따른 콘크리트의 특성분석에 관한 실험적 연구 (An Experimental Study on Analysis of Concrete Properties According to the Dosage Variation of AE Superplasticizer)

  • 윤기원;한천구;반호용
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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    • pp.19-22
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    • 1992
  • Properties of concrete has effected on the dosage variation of AE superplasticizer agent, Therefore, this study is designed for analysis of concrete properies according to the dosage variation of AE superplasticizer agent , and is aimed to analyze the effect slump, air content, compressive strength, resistance of freezing-and-thawing and for presenting the reference data on the practical use.

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통계분석기법을 이용한 군산연안해역의 수질평가 (The Evaluation of Water Quality in Coastal Sea of Kunsan Using Statistic Analysis)

  • 이남도;김종구
    • 한국환경과학회지
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    • 제16권3호
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    • pp.369-376
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    • 2007
  • This study was conducted to evaluate water quality in coastal sea of Kunsan using multivariate analysis. The analysis data in Coastal Sea of Kunsan use of surveyed data by the NFRDI from April 2000 to November 2002. Twelve water Quality parameter were determined on each sample. The results was summarized as follow ; Water quality in coastal sea of Kunsan could be explained up to 62.782% by four factors which were included in loading of nitrogen-nutrients by Keum river(24.688%), suspended solids variation (12.180%), seasonal climate variation (18.367%) and variation of DIP (10.546%). To analyze spatially and monthly variation by factor score, it was divided by inner area and outer area spatially, and spring and summer monthly. The result of time series analysis by factor score, inner area of Kunsan coastal sea(St.1 and St. 2) was the most affected by nitrogen-nutrient and suspended solids due to runoff by Keum river. It could be suggested from these results that it is important to reduce tile pollution loads from Kuem river for the control of the water quality in coastal sea of Kunsan.

Variation of reliability-based seismic analysis of an electrical cabinet in different NPP location for Korean Peninsula

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제54권3호
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    • pp.926-939
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    • 2022
  • The area of this study will cover the location-wise seismic response variation of an electrical cabinet in nuclear power point (NPP) based on classical reliability analysis. The location-based seismic ground motion (GM) selection is carried out with the help of probabilistic seismic hazard analysis using PSHRisktool, where the variation of reliability analysis can be understood from the relation between the reliability index and intensity measure. Two different approaches such as the first-order second moment method (FOSM) and Monte Carlo Simulation (MCS) are helped to evaluate and compare the reliability assessment of the cabinet. The cabinet is modeled with material uncertainty utilizing Steel01 as the material model and the fiber section modeling approach is considered to characterize the section's nonlinear reaction behavior. To verify the modal frequency, this study compares the FEM result with recorded data using Least-Squares Complex Exponential (LSCE) method from the impact hammer test. In spite of a few investigations, the main novelty of this study is to introduce the reader to check and compare the seismic reliability assessment variation in different seismic locations and for different earthquake levels. Alongside, the betterment can be found by comparing the result between two considered reliability estimation methods.

Variation in Significant Difference of Sausage Textural Parameters Measured by Texture Profile Analysis (TPA) under Changing Measurement Conditions

  • Shin, Sun-Hwa;Choi, Won-Seok
    • 한국축산식품학회지
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    • 제41권4호
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    • pp.739-747
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    • 2021
  • This study examined the measurement conditions of the texture profile analysis (TPA) experiments that are typically used to measure the physical properties of sausage. As the measurement conditions (compression ratio and cross-head speed) were changed, the significant differences between the values of textural parameters (hardness, adhesiveness, springiness, cohesiveness, chewiness) of samples changed. Furthermore, among the measurement conditions, there was more variation in the significant difference between the value of samples due to a change in the compression ratio than due to a change in the cross-head speed. The highest variation in significant difference was observed between the values of cohesiveness of samples due to changes in measurement conditions, whereas the lowest variation in significant difference was observed between the values of springiness of samples due to change in measurement conditions. Therefore, it is desirable to provide a clear basis for setting specific measurement conditions for TPA test, since significant differences in the values of textural parameters of samples were caused by differences in cross-head speed or compression ratio, not by a difference in samples, when analyzing the cohesiveness of sausage, especially.

Reverse Engineering을 이용한 석션 하우징의 음장해석 (A Study on the Acoustic-Field Analysis of the Suction Housing using the Reverse Engineering)

  • 양정직;이동주
    • 한국생산제조학회지
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    • 제20권4호
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    • pp.464-471
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    • 2011
  • We tried to analyze sound field of the interior of housing installed with an impeller using the Boundary Element Method (BEM) with the Kirchhoff-Helmholtz integral equation. In order to increase the accuracy of our analysis, reverse engineering technology, which has been developed in recent years. We measured and treated geometrical data with 3D scanning of the practical research object. After modeling by the reverse engineering, we analyzed variation of the BPF as adding vibration frequency and variation of the sound field of the interior of housing by changing the number of impeller blades. We also tried an analysis of free degree variation. Then, we proposed the analysis accuracy and noise reducing method by analysis result.

회전구조물의 진동 해석 및 실험 (Vibration Analysis and Experimental Study for Rotating Sturctures)

  • 박정훈;유홍희
    • 대한기계학회논문집A
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    • 제21권2호
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    • pp.272-280
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    • 1997
  • Comparative study on the analysis and experiment for the vibration of a rotating cantilever structure was made in this paper. Analysis results were obtained by using the modeling method which was developed in the previous work. The cross-section thickness variation due to the sensor attachment was additionally considered. In order to verify the accuracy of the analysis results, exerimental results were obtained. The analysis and experimental results were found to be in a good agreement. It was also shown that the aerodynamic and cross-section thickness variation effects significantly influenced the dynamic characteristics of the rotating structure.

회전자 슬롯치수에 따른 견인용 유도전동기 특성에 관한 연구 (A Study on Characteristics of Traction Induction Motor According to Rotor Slot-parameters)

  • 구대현;강도현;하회두;박정우;이재봉;김종무
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 A
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    • pp.230-233
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    • 1997
  • In this study, design and analysis of 3-phase induction moter are as follows. - Motor characteristics analysis by equivalent circuit ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-tip ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-mouse ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-opening

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