• Title/Summary/Keyword: source analysis

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a Study on Heat Source Equations for the Prediction of Weld Shape in Laser Micro-welding (미세 레이저 용접에서 용융부 형상예측을 위한 열원의 방정식에 관한 연구)

  • 장원석;나석주
    • Journal of Welding and Joining
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    • v.18 no.4
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    • pp.76-81
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    • 2000
  • In this research, various heat source equations that have been proposed in previous study were calculated and compared with new model in various laser parameters. This is to treat the problem of predicting, by numerical analysis, the thermo-mechanical behaviors of laser spot welding for thin stainless steel plates. A finite element code, ABAQUS is used for the heat transfer analysis with a three-dimensional plane assumption. Experimental studies if the laser spot welding have also bee conducted to validate the numerical models presented. The results suggest that temperature profiles and weld dimensions are varied according to the heat source of the laser beam. For this reason, it is essential to incorporate an accurate description of the heat source.

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The Sensitivity Analysis and Modeling for the Atmospheric Dispersion of Point Source (점오염원의 대기확산에 관한 민감도 분석과 모델링)

  • 이화운;원경미;배성정
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.57-64
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    • 2000
  • The sensitivity analysis of two short-term models (ISCST3, INPUFF2.5) is performed to improve the model accuracy. It appears that the sensitivities on the changes of wind speed, stack height and stack inner diameter in the near distance from source, stability and mixing height in the remote distance form source, are significant. Also the gas exit velocity, stack inner diameter, gas temperature and air temperature which affect the plume rise have some effects on the concentration values of each model within the downwind distance where final plume rise is determined. And in modeling for the atmospheric dispersion of point pollutant source INPUFF2.5 can calculate amount, trajectory of puff and concentration versus time at each receptors. So, it is compatible to analyze distribution of point pollutants concentration at modeling area.

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Prioritization of Control Areas using Vulnerable Areas by Non-point Source Pollution (비점오염 취약지역을 고려한 관리우선순위 설정)

  • Kim, Hong Tae;Shin, Dong Seok;Kim, Yong Seok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.6
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    • pp.11-18
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    • 2014
  • Vulnerable areas by non-point source pollution and prioritizing control areas were researched using hydrological and geomorphological data, non-point source loads, and water quality data. Using overlay analysis, vulnerable areas were graded with various scenarios. Vulnerable areas were selected near the metro city with impermeable landuse because non-point source loads and water quality data had influence on overlay analysis to rank vulnerable area. Analysis scenarios and weighted values can be changed under regional characteristics and given conditions.

Numerical Analysis on Effect of the Environmental Velocity for Circular Heating Source with Heat Generation (열생성을 가진 원형발열체의 외부 유속의 영향에 대한 수치해석)

  • Bae, K.Y.;Ji, M.K.;Chung, H.S.;Chung, H.T.;Jeong, H.M.
    • Journal of Power System Engineering
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    • v.8 no.1
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    • pp.30-35
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    • 2004
  • This paper represents the numerical analysis on effect of the environmental velocity for circular heating source with heat generation. In general heating system, the oil and sheath heater is widely used, but these systems have many problems. So, the heating source with carbon ingredient has been researched in many country about manufacture, thermal and electrical properties. In this research, a circular heating source was studied through numerical analysis on several conditions of unsteady state, beat generation and environmental velocity. The temperature distributions at steady state is appeared as a non-linear pattern with variations of environmental velocity. So, the correlation equation between temperature at steady state and environmental velocity was obtained.

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A Comparative Analysis of Wedding Dress Style Preference, Information Source, and Store Selection Criteria for Korean and Chinese Consumers (한.중 소비자의 웨딩드레스 스타일 선호도, 정보원, 점포선택기준에 대한 비교 연구)

  • Shi, Xiaoming;Yoh, Eun-Ah
    • Journal of the Korean Home Economics Association
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    • v.47 no.10
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    • pp.1-11
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    • 2009
  • The purpose of this study was to explore differences in style preference, information source, and store selection behaviors of Korean and Chinese wedding dress shoppers. Data obtained from 141 Chinese and 143 Korean females were analyzed through descriptive analysis, t-test, cross-tabulation and factor analysis. Results for Chinese and Korean consumers depended on the marketer-driven information source as well as on the consumer-driven information source. Both groups considered the aesthetics of the wedding dress as the most important criterion for store selection. There were some differences between Chinese and Korean consumers in style preferences and store selection criteria. Chinese consumers liked a wider range of wedding dress styles compared to Korean consumers. Also, Chinese consumers regarded fashionability as more significant whereas Koreans considered economic benefits more importantly when selecting stores for a wedding dress.

Source Environment Feature Related Phylogenetic Distribution Pattern of Anoxygenic Photosynthetic Bacteria as Revealed by pufM Analysis

  • Zeng, Yonghui;Jiao, Nianzhi
    • Journal of Microbiology
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    • v.45 no.3
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    • pp.205-212
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    • 2007
  • Anoxygenic photosynthesis, performed primarily by anoxygenic photosynthetic bacteria (APB), has been supposed to arise on Earth more than 3 billion years ago. The long established APB are distributed in almost every corner where light can reach. However, the relationship between APB phylogeny and source environments has been largely unexplored. Here we retrieved the pufM sequences and related source information of 89 pufM containing species from the public database. Phylogenetic analysis revealed that horizontal gene transfer (HGT) most likely occurred within 11 out of a total 21 pufM subgroups, not only among species within the same class but also among species of different phyla or subphyla. A clear source environment feature related phylogenetic distribution pattern was observed, with all species from oxic habitats and those from anoxic habitats clustering into independent subgroups, respectively. HGT among ancient APB and subsequent long term evolution and adaptation to separated niches may have contributed to the coupling of environment and pufM phylogeny.

Analysis of Moving Heat Source for Laser Assisted Machining of Plate by Feed Rate Control (이송속도 조절에 의한 평판 레이저 보조가공의 이동 열원해석)

  • Kim, Kwang-Sun;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.12
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    • pp.1341-1346
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    • 2011
  • Currently, many researches are carried out for laser assisted machining, which is one of the important fields in materials difficult to process. However, a prediction of heat source is difficult because of moving heat source. In this paper, a thermal analysis of laser assisted machining of plate by change of heat source size is performed, and preheating temperature by adjusting the feed rate is controlled. It was recognized that the maximum preheating temperature increases according to the decrease in heat source size, and feed rate need to adjust as high speed. The results of this analysis can be used as a reference for preheating temperature prediction in laser assisted milling.

Studies on the Chemical Compositions and Distributions of Ambient Sumicron Aerosols (Submicron 부유분진의 화학적 조성 및 분포에 관한 연구)

  • 황인조;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.1
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    • pp.11-23
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    • 1998
  • The purpose of this study was to survey chemical distribution of inorganic elements and ions in the submicron particles, to characterize qualitatively emitting sources by factor analysis, and finally to reveal existing patterns in terms of chemical compounds by a stepwise multiple regression analysis. Total of 141 samples were collected by a cascade impactor from 1989 to1996. Fifteen chemical species (Al, Ba, Cd, K, Pb, Cu, Fe, Ni, $Cl^-, NO_3^-, SO_4^{2-}, K^+, Mg^{2+}, Ca^{2+}, and Na^+$) were characterized by AAS and IC. The study showed that average seasonal levels of submicron particulate matters $(d_p<0.43 \mum)$ were 18.7 $\mug/m^3$ in spring, 15.5 $\mug/m^3$ in summer, 15.7 $\mug/m^3$ in fall, and 24.5 $\mug/m^3$ in winter, respectively. All of the anion concentrations in the particle were highest in the winter season. By applying a factor analysis, 5 source patterns were qualitatively obtained, such as sulfate related source, nitrate related source, oil burning source, calcium related source, and coal combustion source. Finally, when applying a stepwise multiple regression analysis, the results clearly showed that $Na^+ and Ca^{2+}, K^+ and Ca^{2+}, NO_3^-$ and relative humidity, $Cl^-$ and ambient temperature, $Ca^{2+} and Cl^-, Mg^{2+} and SO_4^{2-}, Na^+ and NO_3^-, and Ca^{2+} and NO_3^-$, respectively, are negatively contributed to each other. As a result of those statistical analysis, we could suggest that some chemical compounds in the submicron particles such as$NaNO_3, MgSO_4, Ca(NO_3)_2, and CaCl_2$ may not exist on the filter as final composing products; however, other compounds may possibly exist in the form of $Mg(NO_3)_2, CaSO_4, Na_2SO_4, K_2SO_4, MgCl_2, NaCl, and KCl$. Thus, it must be necessary to identify differences between the results of above statistical analysis and of the real world by laboratory experiments.

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Thermal Analysis for Laser Assisted Turning of Square Bar using Laser Heat Source Projection Method (사각형재의 레이저 예열 선삭에서 레이저 열원 투영법을 이용한 열해석)

  • Kim, Jae-Hyun;Choi, Jun-Young;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.12
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    • pp.1353-1358
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    • 2011
  • LAT(Laser Assisted Turning) is a method that applies a machining process after softening a workpiece in which a preheating process is locally applied to its machining section using laser heat source. LAT shows several advantages, such as high productivity, reduction of manufacturing cost, high quality. Analysis of temperature distribution after preheating for LAT is very difficult due to its very small heat input area and large energy and its movement. Also, the LAT for a square bar is more difficult because the shape of a laser heat source can be changed according to the rotation of the workpiece. In this study, thermal analysis for LAT of square bar was performed using laser heat source projection method. And, the analysis results were compared with the results of the prior study of numerical calculation method. It is thus shown that the proposed method is efficient for the thermal analysis of a shaped bar.

A Source Code Cross-site Scripting Vulnerability Detection Method

  • Mu Chen;Lu Chen;Zhipeng Shao;Zaojian Dai;Nige Li;Xingjie Huang;Qian Dang;Xinjian Zhao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.6
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    • pp.1689-1705
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    • 2023
  • To deal with the potential XSS vulnerabilities in the source code of the power communication network, an XSS vulnerability detection method combining the static analysis method with the dynamic testing method is proposed. The static analysis method aims to analyze the structure and content of the source code. We construct a set of feature expressions to match malignant content and set a "variable conversion" method to analyze the data flow of the code that implements interactive functions. The static analysis method explores the vulnerabilities existing in the source code structure and code content. Dynamic testing aims to simulate network attacks to reflect whether there are vulnerabilities in web pages. We construct many attack vectors and implemented the test in the Selenium tool. Due to the combination of the two analysis methods, XSS vulnerability discovery research could be conducted from two aspects: "white-box testing" and "black-box testing". Tests show that this method can effectively detect XSS vulnerabilities in the source code of the power communication network.