• Title/Summary/Keyword: two-stage mixture analysis

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A Study on Site Repeat Visit and Purchase Decision-Making of On-line Consumer using Two-Stage Mixture Regression Analysis - Focus on Internet Shopping Mall - (2단계 Mixture Model을 이용한 온라인 소비 자의 방문행동특성이 사이트 재방문과 구매에 미치는 영향에 관한 연구 - 온라인 쇼핑몰을 중심으로 -)

  • Lee, Young-Seung
    • Journal of Global Scholars of Marketing Science
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    • v.13
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    • pp.135-158
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    • 2004
  • On-line consumers have some visit behavior characteristics when they visit internet-shopping mall between visit-stage and purchase-stage. Therefore, information of on-line consumers have influenced on internet-shopping mall's profitabilities at site manager's perspectives. For examples, Are any on-line consumers continuous visiting under any situations? Or are any on-line consumers purchased on any specific internet-shopping mall? Expecially in this paper, researcher tried to understand visit behavioral characteristics of on-line consumers using two-stage mixture regression analysis. Throughout this process, it could be proposed method, which could be reinforced competitiveness of internet-shopping mall by segmental decision-making method. Additionally, it is expected that visit behavioral characteristics' information could be supplied strategic implications between visit-stage and purchase-stage Throughout empirical test it could be proved two-stage decision-making process, which decision-making process of on-line consumers would be processed visit-stage and purchase-stage. In this study, researcher proposed suitable response strategy after understanding visiting behavioral characteristics of on-line consumers. This paper has some academical contributions, which visit behavioral characteristics of on-line consumers could be grasped the meaning by site stickiness and navigation pattern.

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INFLUENCE OF INITIAL COMBUSTION IN SI ENGINE ON FOLLOWING COMBUSTION STAGE AND CYCLE-BY-CYCLE VARIATIONS IN COMBUSTION PROCESS

  • Lee, Kyung-Hwan;Kim, Kisung
    • International Journal of Automotive Technology
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    • v.2 no.1
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    • pp.25-31
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    • 2001
  • It is necessary to understand the combustion process and cycle-by-cycle variation in combustion to improve the engine stability and consequently to improve the fuel economy and exhaust emissions. The pressure related parameters instead of mass fraction burned were compared for the effect of initial combustion pressures on the following combustion and the analysis of cycle-by-cycle variation in combustion for two pen injected SI engines. The correlation between IMEP and pressures at referenced crank angles showed almost the same trends for equivalence ratios, but the different mixture preparations indicated different tendency. The dependency of IMEP on pressure at the referenced crank angles increases as the mixture becomes leaner for both engines. The mixture distribution in the combustion chamber was varied with the coolant temperature and intake valve deactivation due to the evaporation of fuel and air motion. The correlation between pressure related parameters were also compared for the coolant temperatures and air motion.

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Object Detection Based on Deep Learning Model for Two Stage Tracking with Pest Behavior Patterns in Soybean (Glycine max (L.) Merr.)

  • Yu-Hyeon Park;Junyong Song;Sang-Gyu Kim ;Tae-Hwan Jun
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.89-89
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    • 2022
  • Soybean (Glycine max (L.) Merr.) is a representative food resource. To preserve the integrity of soybean, it is necessary to protect soybean yield and seed quality from threats of various pests and diseases. Riptortus pedestris is a well-known insect pest that causes the greatest loss of soybean yield in South Korea. This pest not only directly reduces yields but also causes disorders and diseases in plant growth. Unfortunately, no resistant soybean resources have been reported. Therefore, it is necessary to identify the distribution and movement of Riptortus pedestris at an early stage to reduce the damage caused by insect pests. Conventionally, the human eye has performed the diagnosis of agronomic traits related to pest outbreaks. However, due to human vision's subjectivity and impermanence, it is time-consuming, requires the assistance of specialists, and is labor-intensive. Therefore, the responses and behavior patterns of Riptortus pedestris to the scent of mixture R were visualized with a 3D model through the perspective of artificial intelligence. The movement patterns of Riptortus pedestris was analyzed by using time-series image data. In addition, classification was performed through visual analysis based on a deep learning model. In the object tracking, implemented using the YOLO series model, the path of the movement of pests shows a negative reaction to a mixture Rina video scene. As a result of 3D modeling using the x, y, and z-axis of the tracked objects, 80% of the subjects showed behavioral patterns consistent with the treatment of mixture R. In addition, these studies are being conducted in the soybean field and it will be possible to preserve the yield of soybeans through the application of a pest control platform to the early stage of soybeans.

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Analysis of Soot Formation Characteristics in Diffusion Flames with Soot Particle Temperature Measurement (매연입자 온도 측정에의한 확산화염의 매연생성 특성 해석)

  • Lee, Won-Nam;Chung, Young-Hyun
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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    • pp.241-249
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    • 1999
  • Soot particle temperatures in co-flow diffusion flames have been measured using a two-color pyrometry at the pressure of 0.2 MPa(2 atm). The measured soot particle temperatures along with the integrated soot volume fractions are analyzed to understand soot formation characteristics. At 0.2 MPa, the addition of small amount of air into ethylene do not change the soot particle temperature in soot formation regions. This result showed that the increase of soot formation with addition of air is mostly due to the chemical effect of the added air, such as the increased role of C3 chemistry during the early stage of soot inception process. The addition of sufficient air into ethylene, however, changes soot particle temperatures and the understanding of soot formation characteristics becomes complicated. Measured soot particle temperatures also showed that there is no significant temperature effect for the synergistic effect of ethylene/propane mixture on soot formation.

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Numerical Analysis on Removal Efficiency of Water Droplets in a Curved Vane Mist Eliminator with Consideration of Evaporation and Condensation at Surface of Droplets (액적 표면에서 증발 및 응축을 고려한 곡면 형상 액적 제거장치의 제거 효율에 대한 수치 해석)

  • Song, Dong Keun
    • Particle and aerosol research
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    • v.12 no.4
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    • pp.135-143
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    • 2016
  • Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For accurate understanding of removal process in a curved vane mist eliminator, a numerical model including turbulent dispersion, evaporation and condensation of water vapor at surface of droplets is required. A two-stage curved vane mist eliminator has been modeled, and fluid flow of mixture of air and water vapor and droplet trajectories were solved simultaneously with taking into account two-way coupling. Removal efficiency of droplets with various inlet condition of relative humidities (RH, 40%, 90%, and 100%) were compared. As RH increased, the effect of evaporation decreased and inertial separation efficiencies of droplets obtained increased especially for droplets of diameter below 10 micrometers.

An Investigation of Effects of Fuel Stratification and Cooled EGR on DME HCCI Engine's Operating Ranges by Numerical Analysis (농도성층화와 Cooled EGR이 DME HCCI 엔진의 운전영역에 미치는 영향에 관한 수치해석)

  • Jeong, Dong-Won;Amarbayar, D.;Lim, Ock-Taeck
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.2
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    • pp.129-135
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    • 2010
  • Homogeneous charge compression ignition (HCCI) engines have the potential to provide both diesel-like efficiency and very low emissions of nitrogen oxide (NOx) and particulate matter(PM). However, several technical issues still must be resolved before HCCI can see application. Among these, steep pressure-rise rate which leads to narrow operating range of HCCI engine continues to be a major issue. This work investigates the combination of two methods to mitigate the excessive pressure-rise rates at high power output, namely fuel stratification and Cooled exhaust-gas recirculation (Cooled EGR), after identifying the each effects to pressure-rise rate. When applying the fuel stratification to simulation, total fuelling width of 0.15 at BDC is set as a equivalent ratio difference based on the previous research. In order to simulate the effects of cooled EGR, $CO_2$ mole fraction in pre-mixture is changed ranging from 0 to 30%. DME which has a characteristic of two-stage ignition is used as a fuel.

Effect of horizontal joints on structural behavior of sustainable self-compacting reinforced concrete beams

  • Ibrahim, Omar Mohamed Omar;Heniegal, Ashraf Mohamed;Ibrahim, Khamis Gamal;Agwa, Ibrahim Saad
    • Advances in concrete construction
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    • v.10 no.5
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    • pp.455-462
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    • 2020
  • This study investigated the effect of horizontal casting joints on the mechanical properties and structural behavior of sustainable self-compacting reinforced concrete beams (SCRCB). The experimental research consisted of two stages. The first stage used four types of concrete mixtures which were produced to indicate the effects of cement replaced with cement waste at 0%, 5%, 10%, and 15% by weight of cement content on fresh concrete properties of self-compacting concrete (SCC) such as, passing ability, filling ability, and segregation resistance. In addition, mechanical properties such as compressive, tensile, and flexural strength were also studied. The second stage selected the best mixture from the first stage and studied the effect of horizontal casting joints on the structural behavior of sustainable SCRCBs. The effect of horizontal casting joints on the mechanical properties and structural behavior were at the 25%, 50%, 75%, and 100% of sample height. Load deflection, failure mode, and theoretical analysis were studied. Results indicated that the incorporation of replacement with cement waste by 5% to 10% led to economic and environmental advantages, and the results were acceptable for fresh and mechanical properties. The results indicated that delaying the time for casting the second layer and increasing the cement waste in concrete mixtures had a great effect on the mechanical properties of SCC. The ultimate load capacity of horizontal casting joints reinforced concrete beams slightly decreased compared with the control beam. The maximum deflection of casting joint beams with 75% of samples height is similar with the control beam. The experimental results of reinforced concrete beams were substantially acceptable with the theoretical results. The failure modes obtained the best forced casting joint on the structural behavior at 50% height of casting in the beam.

Analysis on Composition and Strength of Lime-Soil Mixture Barrier Tombs at Guri Galmae Site in Joseon Dynasty (조선시대 구리 갈매유적 회곽묘의 조성 및 강도분석)

  • Lee, Chan Hee;Eo, Eon Il;Shin, Sook Chung
    • Korean Journal of Heritage: History & Science
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    • v.50 no.2
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    • pp.40-61
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    • 2017
  • This study investigated material characteristics of composition and variable strength measurement using physicochemical and petrographic analysis for lime-soil mixture barrier tombs of Guri Galmae site in Joseon Dynasty. The tomb barriers are composed mainly of microcrystalline calcite, quartz, feldspar and mica with lime matrix. The lime matrix shows compact sheet texture, and some samples show hydration aggregates with needle-shaped textures. Gypsum occurred as a secondary process where carbonization reactions were poor. Concentrations of CaO in the tomb barrier very widely ranged from 4.43 to 36.19 wt.%, specific gravity and absorption ratio of the materials show of 1.35 to 1.62 and 20.1 to 32.6%, respectively. As the rebound hardness, the materials ranged from 10.0 to 28.4 (mean 15.7). The values are higher in the $-90^{\circ}$ direction rather than in the $0^{\circ}$ direction with the consequence that the values indicate more strength toward the vertical direction. Difference in strength by directions was caused by the directions of the tomb barriers, which is related to the processes in each stage. In the tomb barriers, ultrasonic velocity and unconfined compressive strength ranged from 1,049.2 to 1,728.9m/s and under 5.00MPa, respectively. Variation patterns between the two are very similar in values. As the result of composition and strength, the materials of higher contents on CaO are higher in strength values. Generally, techniques and skills to make the lime-soil mixture barriers are interpreted as low qualities in relatively.

Does epidural analgesia delay the vaginal delivery of nulliparous women compared with non-epidural analgesia?: Retrospective observational study (경막외 진통은 비경막외 진통에 비해 초산부의 분만을 지연시키는가?: 후향성 관찰 연구)

  • Jang, So Young;Lee, Ae Ryoung;Yun, So-hui;Choi, Yun Suk;Park, Jong Cook;Cho, Woo Jin
    • Journal of Medicine and Life Science
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    • v.15 no.2
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    • pp.95-100
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    • 2018
  • We conduct this study to compare the difference in duration of labor in nulliparous women received epidural analgesia or non-epidural analgesia for labor pain. This retrospective, observational study based on the review of the medical records from February 2014 to July 2017. Epidural analgesia was initiated with a 10 mL epidural bolus of 1% lidocaine and was maintained with a 0.1% mixture of ropivacaine with fentanyl. Non-epidural analgesia was initiated with pethidine 12.5 mg bolus, followed by additional boluses as needed. The primary outcome was the duration of the labor. 149 healthy nulliparous women at term pregnancies with no evidence of fetal distress were enrolled in this study. 92 women received non-epidural analgesia (Group NE) and 57 women received epidural analgesia (Group E). There were no significant differences between the two groups in maternal demographic characteristics. Using a Kaplan-Meier survival analysis, there was no significant difference in the overall duration of the labor(P=0.233). The duration of the first stage of labor was $187.6{\pm}167.3min$ in Group NE, $248.6{\pm}168.7min$ in Group E (Mean${\pm}$SD, P=0.032). The duration of the second stage of labor was $67.1{\pm}57.8min$ in Group NE, $64.1{\pm}47.5min$ in Group E (Mean${\pm}$SD, P=0.693). Epidural analgesia delayed the first stage of labor in this study. But there were no significant differences between the two groups in the duration of the second stage and the total duration of labor.

Survival and Performance of Two Cellulose-Degrading Microbial Systems Inoculated into Wheat Straw-Amended Soil

  • Li, Peipei;Zhang, Dongdong;Wang, Xiaojuan;Wang, Xiaofen;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.1
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    • pp.126-132
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    • 2012
  • A cellulose-degrading composite microbial system containing a mixture of microbes was previously shown to demonstrate a high straw-degrading capacity. To estimate its potential utilization as an inoculant to accelerate straw biodegradation after returning straw to the field, two cellulose-degrading composite microbial systems named ADS3 and WSD5 were inoculated into wheat straw-amended soil in the laboratory. The microbial survival of the inoculant was confirmed by a denaturing gradient gel electrophoresis (DGGE) analysis, whereas the enhancement of straw degradation in soil was assessed by measuring the mineralization of the soil organic matter and the soil cellulase activity. The results indicated that most of the DGGE bands from ADS3 were detected after inoculation into straw-amended autoclaved soil, yet only certain bands from ADS3 and WSD5 were detected after inoculation into straw-amended non-autoclaved soil during five weeks of incubation; some bands were detected during the first two weeks after inoculation, and then disappeared in later stages. Organic matter mineralization was significantly higher in the soil inoculants ADS3 and WSD5 than in the uninoculated controls during the first week, yet the enhanced degradation did not persist during the subsequent incubation. Similar to the increase in soil organic matter, the cellulase activity also increased during the first week in the ADS3 and WSD5 treatments, yet decreased during the remainder of the incubation period. Thus, it was concluded that, although the survival and performance of the two inoculants did not persist in the soil, a significant enhancement of degradation was present during the early stage of incubation.