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A Study on Thermodynamics for Compositional Separation in Co-Cr magnetic Alloy Films (Co-Cr 자성합금 박막의 조성적 상분리 현상의 열역학적 고찰)

  • Song, O-Seong;Jeon, Jeon-An
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.341-344
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    • 1999
  • We reported compositional separation(CS) into Co-enriched and Cri-enriched components inside the grains of Co-Cr based thin films prepared by rf sputtering. CS strongly depends on the sputtering conditions of substrate temperature and target composition. Tuning the microstructure of the Co-Cr films is important in order to employ the CS for high-density magnetic recording. We investigated the origin of CS from thermodynamic viewpoint. We employ a spinodal decomposition-like model to describe the origin of the CS in Co-Cr films. We consider the total free energy of the Co-Cr films as the sum of several free energies of; 1) thermodynamic mixing entropy of a binary solid solution, 2) magnetic ordering interaction(MOI) energy below the Curie temperature, and 3) excess interaction energy(XS) caused by the sputtering process as a function of temperature and composition. Those energies distorted the total free energy like the spinodal decomposition and caused the compositionally separated fine microstructure inside the grains. If the second derivative of the total free energy with respect to Cr composition becomes negative at a given substrate temperature, we may observe a metastable compositional separation inside the Co-Cr alloy films. We expect to exploit the microstructure of CS for ultra-high density magnetic recording.

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Enhancement of the Ionic Conductivity and Mechanical Strength of Micro-porous Separator by Uni-axial Drawing

  • Lee Je-An;Seol Wan-Ho;Lee Yong-Min;Park Jung-Ki
    • Journal of the Korean Electrochemical Society
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    • v.9 no.1
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    • pp.29-33
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    • 2006
  • A new porous separator based on poly(vinyl chloride) (PVC)/poly(vinylidene fluoride-co-hexafluoro-propylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA) was prepared by a phase inversion method. To enhance mechanical property, the membrane was stretched uniaxially at high temperature. Tensile strength and ionic conductivity were measured for various draw ratios. The tensile strength and ionic conductivity were increased with increasing draw ratio. The tensile strength of the separator reached 52MPa after stretching to draw ratio of 5, and the ionic conductivity of the separator was increased from $1.9Xs10^{-4}S/cm\;to\;4.6X10^{-4}S/cm\;at\;25^{\circ}C$. The stretched separator immersed in liquid electrolyte was electrochemically stable up to 4.7 V. The cell based on the stretched separator was maintained at about 99% of the initial discharge capacity after 10th cycle operation at 0.2C rate.

A Study on Sizing System for Child Hospital Gown (어린이 환자복의 치수 규격에 관한 연구)

  • Cheon, Jong-Suk;Seo, Dong-Ae
    • Journal of the Ergonomics Society of Korea
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    • v.17 no.3
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    • pp.81-90
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    • 1998
  • This study was performed to devise a sizing system for child hospital gown(uniform). The researchers surveyed the usage of child hospital gown and developed a sizing system for the child hospital gown. The suitability of revised size specification of gown was evaluated. 219 child inpatients participated in the survey and 13 child inpatients took part in the wear test. The results of the study were as following. 1) 71.7% of the subjects wore the uniform shirts. however numerous number of subjects did not wear uniform pants that the hospital provided(52.5%). The 68.2% of children who were shorter than 100cm did not wear uniform pants. 2) The most significant reason not wearing the hospital gown was unsuitable sizing system (42.1%). Inconvenience for donning and doffing comes next(26.2%). 3) The least satisfied garment size problems were the pants length and sleeve length. 4) The researchers developed a sizing system for the child hospital gown. The system provides 4 different sizes for children age from 2 months to 12 years. One-piece dress style was suggested for the smallest size(XS). The larger sizes(S. M. L) were designed in pajama style. 5) The sizing system developed in this study was moderately satisfied by the users.

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Development of a WWTP influent characterization method for an activated sludge model using an optimization algorithm

  • You, Kwangtae;Kim, Jongrack;Pak, Gijung;Yun, Zuwhan;Kim, Hyunook
    • Membrane and Water Treatment
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    • v.9 no.3
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    • pp.155-162
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    • 2018
  • Process modeling with activated sludge models (ASMs) is useful for the design and operational improvement of biological nutrient removal (BNR) processes. Effective utilization of ASMs requires the influent fraction analysis (IFA) of the wastewater treatment plant (WWTP). However, this is difficult due to the time and cost involved in the design and operation steps, thereby declining the simulation reliability. Harmony Search (HS) algorithm was utilized herein to determine the relationships between composite variables and state variables of the model IWA ASM1. Influent fraction analysis was used in estimating fractions of the state variables of the WWTP influent and its application to 9 wastewater treatment processes in South Korea. The results of influent $S_s$ and $Xs+X_{BH}$, which are the most sensitive variables for design of activated sludge process, are estimated within the error ranges of 8.9-14.2% and 3.8-6.4%, respectively. Utilizing the chemical oxygen demand (COD) fraction analysis for influent wastewater, it was possible to predict the concentrations of treated organic matter and nitrogen in 9 full scale BNR processes with high accuracy. In addition, the results of daily influent fraction analysis (D-IFA) method were superior to those of the constant influent fraction analysis (C-IFA) method.

Segment-based Image Classification of Multisensor Images

  • Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.28 no.6
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    • pp.611-622
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    • 2012
  • This study proposed two multisensor fusion methods for segment-based image classification utilizing a region-growing segmentation. The proposed algorithms employ a Gaussian-PDF measure and an evidential measure respectively. In remote sensing application, segment-based approaches are used to extract more explicit information on spatial structure compared to pixel-based methods. Data from a single sensor may be insufficient to provide accurate description of a ground scene in image classification. Due to the redundant and complementary nature of multisensor data, a combination of information from multiple sensors can make reduce classification error rate. The Gaussian-PDF method defines a regional measure as the PDF average of pixels belonging to the region, and assigns a region into a class associated with the maximum of regional measure. The evidential fusion method uses two measures of plausibility and belief, which are derived from a mass function of the Beta distribution for the basic probability assignment of every hypothesis about region classes. The proposed methods were applied to the SPOT XS and ENVISAT data, which were acquired over Iksan area of of Korean peninsula. The experiment results showed that the segment-based method of evidential measure is greatly effective on improving the classification via multisensor fusion.

Measurement of the Organic and Biomass Fractions in Sewage by Respirometry (미생물 호흡률에 의한 유입 하수의 유기물질과 미생물 분율 측정)

  • 신항식;정형석;남세용
    • KSBB Journal
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    • v.16 no.4
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    • pp.351-355
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    • 2001
  • The information about organic and biomass fractions in sewage is essential for the optimal operation and model calibration of biological treatment processes. In the respect of that oxygen is directly associated with respiration and growth of biomass as well as substrate reduction, the respirometry is well known as a suitable method for the analysis of wastewater composition and active biomass. Thus, the organic and biomass fractions in sewage were measured using respirometry. The fraction of readily biodegradable substrate, slowly biodegradable substrate, inert soluble substrate and inert particular substrate are about 10-16%, 1-8%, 32-50% and 2-47%, respectively. The active heterotrophic biomass fraction is about 10-24%, but the autotrophic biomass was not detected in influent sewage.

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Vulnerability Defense of On-Zeroboard using CSRF Attack (CSRF 공격기법에 대한 제로보드상의 취약점 방어)

  • Kim, Do-Won;Bae, Su-Yeon;An, Beongku
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.57-61
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    • 2014
  • Zeroboard is a public bulletin board that can support PHP and MySQL. It has been used by many people because it is easy to use, but there is no more updates after Zeroboard4. So, there is a problem that its administrator will have nothing to do about it if zeroboard has a vulnerability. In this paper, we will discuss about CSRF(Cross Site request Forgery) which is developed and expanded by XSS(Cross Site Scripting). Also, we will find CSRF attacks and suggest an alternative method using VM-ware. The main features and contributions of the proposed method are as follows. First, make an environment construction using VM-ware and other tools. Second, analyze and prepare vulnerabilities using Proxy server. Performance evaluation will be conducted by applying possible countermeasure.

A Study of interior design process and 6sigma application - Focused on display space design improvement in department store - (실내디자인 프로세스와 6시그마 적용 사례 연구 - 백화점내 연출 공간 디자인 개선을 중심으로 -)

  • Yeom, Dae-Keon
    • Korean Institute of Interior Design Journal
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    • v.16 no.2 s.61
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    • pp.322-330
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    • 2007
  • Because 6sigma is doing innovative success In management whole, estimate that can exert direct effect in interior Design management. Therefore, this study did by purpose that 6sigma that is scientific method that do customers satisfaction by ultimate purpose acts as basic study that can heighten practical use Possibility and result of interior Design management and value by interior design standardization process. Need to use marketing data that is scientific design component at schematic design step for successful interior design that can improve result. Hereupon, this study is doing to big dimension that utilizes 6sigma and makes standard process of only Interior Design, and did to dimension that present study phase verifies if '6sigma' is practical use possibility by intoner design process. Did by method that verification method of 6sigma practical use possibility analyzes "Information transmission efficiency improvement of department store display space" 6sigma project example. When see that example project is analyzed on Improvement constituent that "Design improvement" out of Vital few Xs of statistical analysis item must heighten the customers satisfaction rate conclusively, target process might be established because design becomes center of gravity if did design improvement very first time. Finally, possibility that 6sigma can utilize in process of interior design is verified, and it is scientific methodology that can utilize to all business members that there are not any special category of business even if is in practical use. Such scientific 6sigma method need persistent study that make standard process analyzing a lot of problems that is expected to be beaconed and happens substantially in here after to management development of interior design.

A Water Quality Management System at Mokhyun Stream Watershed Using GIS and RS (GIS와 RS를 이용한 목현천 수질관리 정보체계)

  • Lee, In Soo;Lee, Kyoo Seock
    • Journal of Environmental Impact Assessment
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    • v.8 no.4
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    • pp.1-12
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    • 1999
  • The purpose of this study is to develop a Water Quality Management System(WQMS), which calculates pollutant discharge and forecasts water quality with a water pollution model. Operational water quality management requires not only controlling pollutants but acquiring and managing exact information. A GIS software, ArcView 3.1 was used to enter or edit geographic data and attribute data, and Avenue Script was used to customize the user interface. PCI, a remote sensing software, was used to derive land cover classification from 20 m resolution SPOT data by image processing. WQMS has two subsystems, database subsystem and modelling subsystem. The database subsystem consisted of watershed data from digital maps, remote sensing data, government reports, census data and so on. The modelling subsystem consisted of NSPLM(NonStorm Pollutant Load Model) and SPLM(Storm Pollutant Load Model). It calculates the amount of pollutant and predicts water quality. These two subsystems were connected through a graphic display module. This system has been calibrated for and applied to Mokhyun Stream watershed.

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Six Sigma Robust Design of Composite Hand for LCD Glass Transfer Robot (LCD 유리 이송용 복합재료 로봇 핸드의 식스 시그마 강건설계)

  • Nam Hyunwook
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.3 s.234
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    • pp.455-461
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    • 2005
  • This research studied robust design of composite hand for LTR (LCD glass Transfer Robot). $1^{st}$ DOE (Design of Experiment) was conducted to find out vital few Xs. 108 experiments were performed and their results were statistically analyzed. Pareto chart analysis shows that the geometric parameters (height and width of composite beam) are more important than material parameters $(E_{1},\;E_{2})$ or stacking sequence angle. Also, the stacking sequence of mid-layer is more important than that of outer-layer. The main effect plots shows that the maximum deflection of LTR hand is minimized with increasing height, width of beam and layer thickness. $2^{nd}$ DOE was conducted to obtain RSM (Response Surface Method) equation. 25 experiments were conducted. The CCD (Central Composite Design) technique with four factors was used. The coefficient of determination $(R^{2})$ for the calculated RSM equation was 0.989. Optimum design was conducted using the RSM equation. Multi-island genetic algorithm was used to optimum design. Optimum values for beam height, beam width, layer thickness and beam length were 24.9mm, 186.6mnL 0.15mm and 2402.4mm respectively. An approximate value of 0.77mm in deflection was expected to be a maximum under the optimum conditions. Six sigma robust design was conducted to find out guideline for control range of design parameter. To acquire six sigma level reliability, the standard deviation of design parameter should be con trolled within $2{\%}$ of average design value