• Title/Summary/Keyword: normalizing

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Microstructural, mechanical, and electrochemical analysis of carbon doped AISI carbon steels

  • Muhammad Ishtiaq;Aqil Inam;Saurabh Tiwari;Jae Bok Seol
    • Applied Microscopy
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    • v.52
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    • pp.10.1-10.15
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    • 2022
  • The effect of carbon doping contents on the microstructure, hardness, and corrosion properties of heat-treated AISI steel grades of plain carbon steel was investigated in this study. Various microstructures including coarse ferrite-pearlite, fine ferrite-pearlite, martensite, and bainite were developed by different heat treatments i.e. annealing, normalizing, quenching, and austempering, respectively. The developed microstructures, micro-hardness, and corrosion properties were investigated by a light optical microscope, scanning electron microscope, electromechanical (Vickers Hardness tester), and electrochemical (Gamry Potentiostat) equipment, respectively. The highest corrosion rates were observed in bainitic microstructures (2.68-12.12 mpy), whereas the lowest were found in the fine ferritic-pearlitic microstructures (1.57-6.36 mpy). A direct correlation has been observed between carbon concentration and corrosion rate, i.e. carbon content resulted in an increase in corrosion rate (2.37 mpy for AISI 1020 to 9.67 mpy for AISI 1050 in annealed condition).

Multivariate Time Series Analysis for Rainfall Prediction with Artificial Neural Networks

  • Narimani, Roya;Jun, Changhyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.135-135
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    • 2021
  • In water resources management, rainfall prediction with high accuracy is still one of controversial issues particularly in countries facing heavy rainfall during wet seasons in the monsoon climate. The aim of this study is to develop an artificial neural network (ANN) for predicting future six months of rainfall data (from April to September 2020) from daily meteorological data (from 1971 to 2019) such as rainfall, temperature, wind speed, and humidity at Seoul, Korea. After normalizing these data, they were trained by using a multilayer perceptron (MLP) as a class of the feedforward ANN with 15,000 neurons. The results show that the proposed method can analyze the relation between meteorological datasets properly and predict rainfall data for future six months in 2020, with an overall accuracy over almost 70% and a root mean square error of 0.0098. This study demonstrates the possibility and potential of MLP's applications to predict future daily rainfall patterns, essential for managing flood risks and protecting water resources.

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A Variable Step Size LMS Algorithm Using Normalized Absolute Estimation Error

  • Kim, D. W.;S. H. Han;H. K. Hong;H. B. Kang;Park, J. S.
    • Journal of Electrical Engineering and information Science
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    • v.1 no.2
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    • pp.119-124
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    • 1996
  • Variable step size LMS(VS-LMS) algorithms improve performance of LMS algorithm by means of varying the step size. This paper presents a new VS-LMS algorithm using normalized absolute estimation error. Normalizing the estimation error to the expected valus of the desired signal, we determined the step size using the relative size of estimation error, Because parameters and computational load are less, our algorithm is easy to implement in hardware. The performance of the proposed algorithm is analyzed theoretically and estimated through simulations. Based on the theoretical analysis and computer simulations, the proposed algorithm is shown to be effective compared to conventional VS-LMS algorithms.

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Biocreative Alveolar Molding Plate Treatment (BioAMP) for neonatal unilateral cleft lip and palate with excessively wide alveolar cleft and maxillary arch width

  • HyeRan Choo;HyoWon Ahn
    • The korean journal of orthodontics
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    • v.54 no.1
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    • pp.69-73
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    • 2024
  • Since its inception in Europe in the 1950s, alveolar molding treatment for neonates with complete cleft lip and palate has undergone significant evolution in both design and application methodology, demonstrating effectiveness in normalizing the alveolar cleft and nasal shape. However, excessively wide alveolar clefts accompanied by disproportionately wide total maxillary arch pose significant challenges when utilizing conventional alveolar molding methods involving cyclical adding and grinding of acrylic on molding plates. The current report introduces a novel alveolar molding method named Biocreative Alveolar Molding Plate Treatment (BioAMP), which can normalize the maxillary alveolar cleft and arch shape without laborious conventional acrylic procedures. BioAMP sets the target arch form and provides unrestricted space for natural growth of the maxillary alveolar bones while systematically reducing the total maxillary arch width in precise increments. Two exemplary cases are presented as proof-of-concept, showcasing the clinical innovation of BioAMP.

Environmental Geochemistry and Heavy Matel Contamination of Ground and Surface Water, Soil and Sediment at the Kongjujuil Mine Creek, Korea (공주제일광산 수계에 분포하는 지하수, 지표수, 토양 및 퇴적물의 환경지구화학적 특성과 중금속 오염)

  • 이찬희
    • Economic and Environmental Geology
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    • v.32 no.6
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    • pp.611-631
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    • 1999
  • Enviromental geochemisty and heary metal contamination at the Kongjueil mine creek were underaken on the basis of physicohemical properties and mineralogy for various kinds of water (surface, mine and ground water),soil, precipitate and sediment collected of April and December in 1998. Hydrgeochemical composition of the water samples are characterized by relatively significant enricant of Ca+Na, alkiali ions $NO_3$ and Cl inground and surfore water, wheras the mine waters are relatively eneripheral water of the mining creek have the characteristics of the (Ca+Mg)-$(HCO_3+SO_4)$type. The pH of the mine water is high acidity (3.24)and high EC (613$\mu$S/cm)compared with those of surface and ground water. The range of $\delta$D and $\delta^{18}O$ values (relative to SMOW) in the waters are shpwn in -50.2 to -61.6% and -7.0 to -8.6$\textperthousand$(d value=5.8 to 8.7). Using computer program, saturation index of albite, calcite, dolomite in mine water are nearly saturated. The gibbiste, kaolinite and smectite are superaturated in the surface and ground water, respectively. Calculated water-mineral reaction and stabilities suggest that weathing of silicate minerals may be stable kaolinite owing to the continuous water-rock reaction. Geochemical modeling showed that mostly toxic heavy metals may exist larfely in the from of metal-sulfate $(MSO_4\;^2)$and free metal $(M^{2+})$ in nmine water. These metals in the ground and surface water could be formed of $CO_3$ and OH complex ions. The average enrichment indices of water samples are 2.72 of the groundwater, 2.26 of the surface water and 14.15 of the acid mine water, normalizing by surface water composition at the non-mining creek, repectively. Characteristics of some major, minor and rate earth elements (Al/Na, K/Na, V/Ni, Cr/V, Ni/Co, La/Ce, Th/Yb, $La_N/Yb_N$, Co/Th, La/Sc and Sc/Th) in soil and sediment are revealed a narrow range and homogeneous compositions may be explained by acidic to intermediate igneous rocks. And these suggested that sediment source of host granitic gneiss colud be due to rocks of high grade metamorphism originated by sedimentary rocks. Maximum concentrations of environmentally toxic elements in sediment and soil are Fe=53.80 wt.% As=660, Cd=4, Cr=175, Cu=158, Mn=1010, Pb=2933, Sb=4 and Zn=3740 ppm, and extremely high concentrations are found are found in the subsurface soil near the ore dump and precipitates. Normalizing by composition of host granitic gneiss, the average enerichment indices are 3.72 of the sediments, 3.48 of the soils, 10.40 of the precipitates of acid mine drainage and 6.25 of the soils near the main adit. The level of enerichment was very severe in mining drainage sediments, while it was not so great in the soils. mineral composition of soil and sediment near the mining area were partly variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. reddish variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. Reddish brown precipitation mineral in the acid mine drainage identifies by schwertmanite. From the separated mineralgy, soil and sediment are composed of some pyrite, arsenopyite, chalcopyrite, sphalerite, galena, malachite, goethite and various kinds of hydroxied minerals.

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Dynamic Manipulability Analysis of Underwater Robotic Arms with Joint Velocities (관절속도를 가지는 수중로봇팔의 동적 조작도 해석)

  • JEON BONG-HWAN;LEE JIHONG;LEE PAN-MOOK
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.204-209
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    • 2004
  • This paper describes dynamic manipulability analysis of robotic arms moving in viscous fluid. The Manipulability is a functionality of manipulator system in a given configuration and under the limits of joint ability with respect to the tasks required to bt performed. To investigate the manipulability of underwater robotic arms, a modeling and analysis method are presented. The dynamic equation of motion of underwater manipulator is derived from the Lagrange - Euler equation considering with the hydraulic forces caused by added mass, buoyancy and hydraulic drag. The hydraulic drag term in the equation: is established as analytical form using Denavit - Hartenberg (D-H) link coordination of manipulator. Two analytical approaches based on Manipulability Ellipsoid are presented to visualize the manipulability of robotic arm moving in viscous fluid. The one is scaled ellipsoid which transforms the boundary of joint torque to acceleration boundary of end-effector by normalizing the torque in joint space while the other is shifted ellipsoid which depicts total acceleration boundary of end-effector by shifting the ellipsoid in work space. An analysis example of 2-link manipulator with proposed analysis scheme is presented to validate the method.

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Development of Thermal Distortion Analysis Method Based on Inherent Strain for TMCP Steels (TMCP 강판의 고유변형도 기반 열변형 해석법 개발)

  • Ha, Yun-Sok;Yang, Jin-Hyuk;Won, Seok-Hee;Yi, Myung-Su
    • Journal of Welding and Joining
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    • v.26 no.3
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    • pp.61-66
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    • 2008
  • As ships become to be larger than ever, the thicker plate and the higher tensile steel plate are used in naval shipyard. Though special chemical composition is needed for high-tensile steels, recent high-tensile steels are made by the TMCP(Thermo-Mechanical control process) skill. The increase of yield stress and tensile stress of TMCP steels is induced from bainite phase which is transformed from austenite, but that increased yield stress can be vanished by another additional thermal cycle like welding and heating. As thermal deformations are deeply related by yield stress of material, the study for prediction of plate deformation by heating should reflect principle of TMCP steels. This study developed an algorithm which can calculate inherent strain. In this algorithm, not only the mechanical principles of thermal deformations, but also the predicting of the portion of initial bainite is considered when calculating inherent strain. The simulations of plate deformation by these values showed good agreements with experimental results of normalizing steels and TMCP steels in welding and heating. Finally we made an inherent strain database of steels used in Class rule.

A Study on Chronic Pain, Pain Coping, and Depression according to Attributions of Somatic Symptoms among Elderly People (노인의 신체증상귀인에 따른 만성통증, 통증대처 및 우울)

  • Chang, Hae-Kyung
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.16 no.4
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    • pp.402-411
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    • 2009
  • Purpose: This study was done to examine differences in chronic pain, pain coping, and depression according to attributions of somatic symptoms among the elderly. Method: Data were collected by self-report questionnaires from 195 persons age 65 or over. Descriptive statistics, ANOVA, and Scheffe's test were used to analyze the data. Results: There were statistically significant differences in chronic pain among the elders according to educational level and duration of pain, and in passive coping according to gender, physical function and duration of pain. There were statistically significant differences among the elders in active coping according to amount of spending money, in depression according to age, educational level, amount of spending money, and physical function. There also were statistically significant differences in chronic pain, pain coping, and depression according to attributions of somatic symptoms. Conclusion: The results of this study indicate that elders who have somatic attributions are incline to complain more severe chronic pain, to cope passively, and to manifest more severe depression than elders who have normalizing attributions. Continuous research is needed to improve effective nursing interventions for attributions of somatic symptoms among elders.

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Effect of an Obesity Management Program on Body Weight, Body Mass Index and Physiological Index of High School Girl Students (비만 관리 프로그램이 여고생의 체중, 체질량지수 및 생리지표에 미치는 효과)

  • Cha Kyu-Jung
    • Journal of Korean Academy of Nursing
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    • v.34 no.7
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    • pp.1362-1371
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    • 2004
  • Purpose: This study was to examine the effect of an obesity management program on the body weight, body-mass index, and physiological index of obese female high school students. Method: Students from one school were selected as the experimental group, and students from another school as a control group so the latter group wasn't exposed to the experiment. The experimental group and the control group were each organized with 20 students. The experimental group received 60 minutes of behavior modification once a week, for eight weeks. Result: The Body weight, and Body mass-Index of the experimental group significantly decreased after the obesity management program. Total-cholesterol, T-G, and LDL-C significantly decreased and HDL-C increased in the experimental group. Total-cholesterol, T-G, LDL-C and HDL-C between the experimental group and control group showed significant differences. Conclusion: These results indicate that the obesity management program had a great effect on decreasing the body weight and body-mass index of the female obese high school students, normalizing their physiological index. In conclusion, this program turned out to be one of the safest and most effective obesity-management methods that could be applied to female high school students.

Contactless Palmprint Recognition Based on the KLT Feature Points (KLT 특징점에 기반한 비접촉 장문인식)

  • Kim, Min-Ki
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.11
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    • pp.495-502
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    • 2014
  • An effective solution to the variation on scale and rotation is required to recognize contactless palmprint. In this study, we firstly minimize the variation by extracting a region of interest(ROI) according to the size and orientation of hand and normalizing the ROI. This paper proposes a contactless palmprint recognition method based on KLT(Kanade-Lukas-Tomasi) feature points. To detect corresponding feature points, texture in local regions around KLT feature points are compared. Then, we recognize palmprint by measuring the similarity among displacement vectors which represent the size and direction of displacement of each pair of corresponding feature points. An experimental results using CASIA public database show that the proposed method is effective in contactless palmprint recognition. Especially, we can get the performance of exceeding 99% correct identification rate using multiple Gabor filters.