Search results for: Joon Hong Park
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1504

Search results for: Joon Hong Park

574 Shear Buckling of a Large Pultruded Composite I-Section under Asymmetric Loading

Authors: Jin Y. Park, Jeong Wan Lee

Abstract:

An experimental and analytical research on shear buckling of a comparably large polymer composite I-section is presented. It is known that shear buckling load of a large span composite beam is difficult to determine experimentally. In order to sensitively detect shear buckling of the tested I-section, twenty strain rosettes and eight displacement sensors were applied and attached on the web and flange surfaces. The tested specimen was a pultruded composite beam made of vinylester resin, E-glass, carbon fibers and micro-fillers. Various coupon tests were performed before the shear buckling test to obtain fundamental material properties of the I-section. An asymmetric four-point bending loading scheme was utilized for the shear test. The loading scheme resulted a high shear and almost zeros moment condition at the center of the web panel. The shear buckling load was successfully determined after analyzing the obtained test data from strain rosettes and displacement sensors. An analytical approach was also performed to verify the experimental results and to support the discussed experimental program.

Keywords: strain sensor, displacement sensor, shear buckling, polymer composite I-section, asymmetric loading

Procedia PDF Downloads 432
573 A New Perspective: The Use of Low-Cost Phase Change Material in Building Envelope System

Authors: Andrey A. Chernousov, Ben Y. B. Chan

Abstract:

The use of the low-cost paraffinic phase change material can be rather effective in smart building envelopes in the South China region. Particular attention has to be paid to the PCM optimization as an exploitation conditions and the envelope insulation changes its thermal characteristics. The studied smart building envelope consists of a reinforced aluminum exterior, polymeric insulation foam, phase change material and reinforced interior gypsum board. A prototype sample was tested to validate the numerical scheme using EnergryPlus software. Three scenarios of insulation thermal resistance loss (ΔR/R = 0%, 25%, 50%) were compared with the different PCM thicknesses (tP=0, 1, 2.5, 5 mm). The comparisons were carried out for a west facing enveloped office building (50 storey). PCM optimization was applied to find the maximum efficiency for the different ΔR/R cases. It was found, during the optimization, that the PCM is an important smart component, lowering the peak energy demand up to 2.7 times. The results are not influenced by the insulation aging in terms of ΔR/R during long-term exploitation. In hot and humid climates like Hong Kong, the insulation core of the smart systems is recommended to be laminated completely. This can be very helpful in achieving an acceptable payback period.

Keywords: smart building envelope, thermal performance, phase change material, energy efficiency, large-scale sandwich panel

Procedia PDF Downloads 706
572 Heat Transfer Characteristics on Blade Tip with Unsteady Wake

Authors: Minho Bang, Seok Min Choi, Jun Su Park, Hokyu Moon, Hyung Hee Cho

Abstract:

Present study investigates the effect of unsteady wakes on heat transfer in blade tip. Heat/mass transfer was measured in blade tip region depending on a variety of strouhal number by naphthalene sublimation technique. Naphthalene sublimation technique measures heat transfer using a heat/mass transfer analogy. Experiments are performed in linear cascade which is composed of five turbine blades and rotating rods. Strouhal number of inlet flow are changed ranging from 0 to 0.22. Reynolds number is 100,000 based on 11.4 m/s of outlet flow and axial chord length. Three different squealer tip geometries such as base squealer tip, vertical rib squealer tip, and camber line squealer tip are used to study how unsteady wakes affect heat transfer on a blade tip. Depending on squealer tip geometry, different flow patterns occur on a blade tip. Also, unsteady wakes cause reduced tip leakage flow and turbulent flow. As a result, as strouhal number increases, heat/mass transfer coefficients decrease due to the reduced leakage flow. As strouhal number increases, heat/ mass transfer coefficients on a blade tip increase in vertical rib squealer tip.

Keywords: gas turbine, blade tip, heat transfer, unsteady wakes

Procedia PDF Downloads 356
571 Stereo Camera Based Speed-Hump Detection Process for Real Time Driving Assistance System in the Daytime

Authors: Hyun-Koo Kim, Yong-Hun Kim, Soo-Young Suk, Ju H. Park, Ho-Youl Jung

Abstract:

This paper presents an effective speed hump detection process at the day-time. we focus only on round types of speed humps in the day-time dynamic road environment. The proposed speed hump detection scheme consists mainly of two process as stereo matching and speed hump detection process. Our proposed process focuses to speed hump detection process. Speed hump detection process consist of noise reduction step, data fusion step, and speed hemp detection step. The proposed system is tested on Intel Core CPU with 2.80 GHz and 4 GB RAM tested in the urban road environments. The frame rate of test videos is 30 frames per second and the size of each frame of grabbed image sequences is 1280 pixels by 670 pixels. Using object-marked sequences acquired with an on-vehicle camera, we recorded speed humps and non-speed humps samples. Result of the tests, our proposed method can be applied in real-time systems by computation time is 13 ms. For instance; our proposed method reaches 96.1 %.

Keywords: data fusion, round types speed hump, speed hump detection, surface filter

Procedia PDF Downloads 495
570 The Influence of Swirl Burner Geometry on the Sugar-Cane Bagasse Injection and Burning

Authors: Juan Harold Sosa-Arnao, Daniel José de Oliveira Ferreira, Caice Guarato Santos, Justo Emílio Alvarez, Leonardo Paes Rangel, Song Won Park

Abstract:

A comprehensive CFD model is developed to represent heterogeneous combustion and two burner designs of supply sugar-cane bagasse into a furnace. The objective of this work is to compare the insertion and burning of a Brazilian south-eastern sugar-cane bagasse using a new swirl burner design against an actual geometry under operation. The new design allows control the particles penetration and scattering inside furnace by adjustment of axial/tangential contributions of air feed without change their mass flow. The model considers turbulence using RNG k-, combustion using EDM, radiation heat transfer using DTM with 16 ray directions and bagasse particle tracking represented by Schiller-Naumann model. The obtained results are favorable to use of new design swirl burner because its axial/tangential control promotes more penetration or more scattering than actual design and allows reproduce the actual design operation without change the overall mass flow supply.

Keywords: comprehensive CFD model, sugar-cane bagasse combustion, swirl burner, contributions

Procedia PDF Downloads 423
569 Impact of Working Capital Management Strategies on Firm's Value and Profitability

Authors: Jonghae Park, Daesung Kim

Abstract:

The impact of aggressive and conservative working capital‘s strategies on the value and profitability of the firms has been evaluated by applying the panel data regression analysis. The control variables used in the regression models are natural log of firm size, sales growth, and debt. We collected a panel of 13,988 companies listed on the Korea stock market covering the period 2000-2016. The major findings of this study are as follow: 1) We find a significant negative correlation between firm profitability and the number of days inventory (INV) and days accounts payable (AP). The firm’s profitability can also be improved by reducing the number of days of inventory and days accounts payable. 2) We also find a significant positive correlation between firm profitability and the number of days accounts receivable (AR) and cash ratios (CR). In other words, the cash is associated with high corporate profitability. 3) Tobin's analysis showed that only the number of days accounts receivable (AR) and cash ratios (CR) had a significant relationship. In conclusion, companies can increase profitability by reducing INV and increasing AP, but INV and AP did not affect corporate value. In particular, it is necessary to increase CA and decrease AR in order to increase Firm’s profitability and value.

Keywords: working capital, working capital management, firm value, profitability

Procedia PDF Downloads 162
568 Effects of Gamification on Lower Secondary School Students’ Motivation and Engagement

Authors: Goh Yung Hong, Mona Masood

Abstract:

This paper explores the effects of gamification on lower secondary school students’ motivation and engagement in the classroom. Two-group posttest-only experimental design were employed to study the influence of gamification teaching method (GTM) when compared with conventional teaching method (CTM) on 60 lower secondary school students. The Student Engagement Instrument (SEI) and Intrinsic Motivation Inventory (IMI) were used to assess students’ intrinsic motivation and engagement level towards the respective teaching method. Finding indicates that students who completed the GTM lesson were significantly higher in intrinsic motivation to learn than those from the CTM. Although the result were insignificant and only marginal difference in the engagement mean, GTM still show better potential in raising student’s engagement in class when compared with CTM. This finding proves that the GTM is likely to solve the current issue of low motivation to learn and low engagement in class among lower secondary school students in Malaysia. On the other hand, despite being not significant, higher mean indicates that CTM positively contribute to higher peer support for learning and better teacher and student relationship when compared with GTM. As a conclusion, gamification approach is flexible and can be adapted into many learning content to enhance the intrinsic motivation to learn and to some extent, encourage better student engagement in class.

Keywords: conventional teaching method, gamification teaching method, motivation, engagement

Procedia PDF Downloads 501
567 Affective Factors on Citizens’ Participations in Plants Clinics in Iran

Authors: Mohammad Abedi Sh. Khodamoradi

Abstract:

The main aim of this research is to assess effective factors on citizens’ participations in plants clinics. Statistical society includes 153 citizens of region 15 of Tehran municipality, which in first six months of 2015 participated in educational classes held by Plant education center of Pardis and Pamchal Park located in region no.15. Sample size was calculated by Cochran formula and 10% was added to sample size in order to prevent probable problems and the final sample was n=124. Validity of questionnaire was calculated by professors of extension and education group in Oloom Tahghighat university of Tehran and reliability was 0.82 which was reported by editors. Data then was analyzed by SPSS software, and frequency table, comparing mean and correlation and regression also were assessed. Correlation was proved between age, type of activity and participation extent in plant clinics. Also participation would be increased in plant clinics due to positive and significant relation between educational factors and participation extent with improving educational factors. Moreover, there is inverse relation between literacy level and participation in level of 5%. Finally, regression analysis was used in order to predict each change which independent variable determines for dependent one.

Keywords: plants clinics, participations, Tehran, Iran

Procedia PDF Downloads 211
566 Seismic Performance of Nuclear Power Plant Structures Subjected to Korean Earthquakes

Authors: D. D. Nguyen, H. S. Park, S. W. Yang, B. Thusa, Y. M. Kim, T. H. Lee

Abstract:

Currently, the design response spectrum (i.e., Nuclear Regulatory Commission - NRC 1.60 spectrum) with the peak ground acceleration (PGA) 0.3g (for Safe Shutdown Earthquake level) is specified for designing the new nuclear power plant (NPP) structures in Korea. However, the recent earthquakes in the region such as the 2016 Gyeongju and the 2017 Pohang earthquake showed that the possible PGA of ground motions can be larger than 0.3g. Therefore, there is a need to analyze the seismic performance of the existing NPP structures under these earthquakes. An NPP model, APR-1400, which is designed and built in Korea was selected for a case study. The NPP structure is numerically modeled in terms of lumped-mass stick elements using OpenSees framework. The floor acceleration and displacement of components are measured to quantify the responses of components. The numerical results show that the floor spectral accelerations are significantly amplified in the components subjected to Korean earthquakes. A comparison between floor response spectra of Korean earthquakes and the NRC design motion highlights that the seismic design level of NPP components under an earthquake should be thoroughly reconsidered. Additionally, a seismic safety assessment of the equipment and relays attached to main structures is also required.

Keywords: nuclear power plant, floor response spectra, Korean earthquake, NRC spectrum

Procedia PDF Downloads 140
565 Health Monitoring of Primates in a Conservation Unit in Brazil

Authors: Elisângela de Albuquerque Sobreira Borovoski, Ricardo Willian Borovoski

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Microbiological infections acquired by animals pose a risk to public health. In public health, monitoring the health of primates is linked to the risk of transmission of zoonoses through scratches, bites and contact with biological samples. The project was approved by the Ethics Committee on the Use of Animals Protocol No. 170/2019. It was authorized by ICMBio Protocol No. 52117-1. The study was carried out in the period 2019-2022 in the municipality of Anápolis. Iron and galvanized wire traps were used and the animals were anesthetized with 4.4mg/kg zolethyl intramuscularly and saliva was collected through swabs. Fifty-three capuchin monkeys were captured from the Onofre Quinan Environmental Park in Anápolis-Goiás for health monitoring purposes. In the laboratory, the samples were deposited on the agar surface and seeded by exhaustion to obtain isolated colonies. These colonies were analyzed according to morphocolonial characteristics. Morphometric characterization and biochemical tests for bacterial identification were performed. A total of 861 bacterial samples were isolated, nine of which were strict anaerobic bacteria of the genus Peptostreptococcus. Previous and constant knowledge of the prevalence of pathogenic agents in biological samples is essential to be prepared to act in pandemic situations.

Keywords: Brazil, microbiology, monkeys, public health

Procedia PDF Downloads 59
564 Real Time Monitoring and Control of Proton Exchange Membrane Fuel Cell in Cognitive Radio Environment

Authors: Prakash Thapa, Gye Choon Park, Sung Gi Kwon, Jin Lee

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The generation of electric power from a proton exchange membrane (PEM) fuel cell is influenced by temperature, pressure, humidity, flow rate of reactant gaseous and partial flooding of membrane electrode assembly (MEA). Among these factors, temperature and cathode flooding are the most affecting parameters on the performance of fuel cell. This paper describes the detail design and effect of these parameters on PEM fuel cell. Performance of all parameters was monitored, analyzed and controlled by using 5KWatt PEM fuel cell. In the real-time data communication for remote monitoring and control of PEM fuel cell, a normalized least mean square algorithm in cognitive radio environment is used. By the use of this method, probability of energy signal detection will be maximum which solved the frequency shortage problem. So the monitoring system hanging out and slow speed problem will be solved. Also from the control unit, all parameters are controlled as per the system requirement. As a result, PEM fuel cell generates maximum electricity with better performance.

Keywords: proton exchange membrane (PEM) fuel cell, pressure, temperature and humidity sensor (PTH), efficiency curve, cognitive radio network (CRN)

Procedia PDF Downloads 444
563 A Numerical Study for Mixing Depth and Applicability of Partial Cement Mixing Method Utilizing Geogrid and Fixing Unit

Authors: Woo-seok Choi, Eun-sup Kim, Nam-Seo Park

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The demand for new technique in soft ground improvement continuously increases as general soft ground methods like PBD and DCM have a application problem in soft grounds with deep depth and wide distribution in Southern coast of Korea and Southeast. In this study, partial cement mixing method utilizing geogrid and fixing unit(CMG) is suggested and Finite element analysis is performed for analyzing the depth of surface soil and deep soil stabilization and comparing with DCM method. In the result of the experiment, the displacement in DCM method were lower than the displacement in CMG, it's because the upper load is transferred to deep part soil not treated by cement in CMG method case. The differential settlement in DCM method was higher than the differential settlement in CMG, because of the effect load transfer effect by surface part soil treated by cement and geogrid. In conclusion, CMG method has the advantage of economics and constructability in embankment road, railway, etc in which differential settlement is the important consideration.

Keywords: soft ground, geogrid, fixing unit, partial cement mixing, finite element analysis

Procedia PDF Downloads 364
562 Distribution Urban Public Spaces Among Riyadh Residential Neighborhoods

Authors: Abdulwahab Alalyani, Mahbub Rashid

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Urban Open Space (UOS) a central role to promotes community health, including daily activities, but these resources may not available, accessible enough, and or equitably be distributed. This paper measures and compares spatial equity of the availability and accessibility UOS among low, middle, and high-income neighborhoods in Riyadh city. The measurement mothdulgy for the UOSavailability was by calculating the total of UOS with respect to the population total (m2/inhabitant) and the accessibility indicted by using walking distance of a 0.25 mi (0.4 km) buffering streets network.All UOS were mapped and measured using geographical information systems. To evaluate the significant differences in UOS availability and accessibility across low, medium, and high-income Riyadh neighborhoods, we used a One-way ANOVA analysis of covariance to test the differences.The findings are as follows; finding, UOSavailability was lower than global standers. Riyadh has only 1.13 m2 per capita of UOS, and the coverage accessible area by walking distance to UOS was lower than 50%. The final finding, spatial equity of the availability and accessibility, were significantly different among Riyadh neighborhoods based on socioeconomic status. The future development of UOS should be focused on increasing Urban park availability and should be given priority to those low-income and unhealthy communities.

Keywords: distribution urban open space, urban open space accessibility, spatial equity, riyadh city

Procedia PDF Downloads 76
561 A Smart Monitoring System for Preventing Gas Risks in Indoor

Authors: Gyoutae Park, Geunjun Lyu, Yeonjae Lee, Jaheon Gu, Sanguk Ahn, Hiesik Kim

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In this paper, we propose a system for preventing gas risks through the use of wireless communication modules and intelligent gas safety appliances. Our system configuration consists of an automatic extinguishing system, detectors, a wall-pad, and a microcomputer controlled micom gas meter to monitor gas flow and pressure as well as the occurrence of earthquakes. The automatic fire extinguishing system checks for both combustible gaseous leaks and monitors the environmental temperature, while the detector array measures smoke and CO gas concentrations. Depending on detected conditions, the micom gas meter cuts off an inner valve and generates a warning, the automatic fire-extinguishing system cuts off an external valve and sprays extinguishing materials, or the sensors generate signals and take further action when smoke or CO are detected. Information on intelligent measures taken by the gas safety appliances and sensors are transmitted to the wall-pad, which in turn relays this as real time data to a server that can be monitored via an external network (BcN) connection to a web or mobile application for the management of gas safety. To validate this smart-home gas management system, we field-tested its suitability for use in Korean apartments under several scenarios.

Keywords: gas sensor, leak, gas safety, gas meter, gas risk, wireless communication

Procedia PDF Downloads 401
560 Application of Mobile Aluminium Light Structure Housing System in Sustainable Building Process

Authors: Wang Haining, Zhang Hong

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In China, rapid urbanization needs more and more buildings constructed for the growing population in cities. With the help of the methodology which contains investigation, contrastive analysis, design based on component with BIM and experiment before real construction, this research based on mobile light structure system, trying to the sustainable problems partly in present China by systematic study. The system cannot replace the permanent heavy structure completely. So the goal is the improvement of the whole building system by the addition of light structure. This house system uses modularized envelopes and standardized connections, which are pre-fabricated and assembled in factories and transported like containers. Aluminum is used as the structural material in this system, and inorganic thermal insulation material used in the envelope, which have high fireproof properties. The relationship between manufactory and construction of the system is progressive hierarchy. They exist as First Industrial, Second Industrial, Third Industrial and Site Assembly Stage. It could maximize the land usage capacity by fully exploit the area where normal permanent architecture can't take advantage of. Not only the building system itself especially the thermal isolated materials used and active solar photovoltaic system equipped can save energy, but also the way of product development is sustainable.

Keywords: aluminum house, light Structure, rapid assembly, repeat construction

Procedia PDF Downloads 471
559 Protective Effect of Essential Oil from Chamaecyparis obtusa on Anxiety-Related Behaviors and Cytokine Abnormalities Induced by Early Life Stress

Authors: Hae Jeong Park, Joo-Ho Chung

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In this study, the effect of essential oil from Chamaecyparis obtuse (EOCO) on early life stress using maternal separation (MS) rats was investigated. Anxiety-related behaviors were examined in MS rats using the elevated plus-maze (EPM) test. The changes of gene expressions by EOCO in the hippocampus of MS rats were analyzed using a microarray method. Rats in the MS groups were separated from their respective mothers from postnatal day (pnd) 14 to 28. Rats in the EOCO-treated groups were exposed to EOCO for 1 h or 2 h by inhalation from pnd 21 to 28. The EOCO-treated MS rats showed decreased anxiety-related behaviors compared to the MS rats in the EPM test. In the microarray analysis, EOCO downregulated the expressions of cytokine genes such as Ccl2, Il6, Cxcl10, Ccl19, and Il1rl in the hippocampus of MS rats, and it was also confirmed through RT-PCR. In particular, the expressions of Ccl2 and Il6 were predominantly decreased by EOCO in the hippocampus of MS rats. Interestingly, their protein expressions were also reduced by EOCO in MS rats. These results indicate that EOCO decreases MS-induced anxiety-related behaviors, and modulate cytokines, particularly Ccl2 and Il6, in the hippocampus of MS rats.

Keywords: anxiety-related behavior, Chamaecyparis obtuse, cytokine gene, early-life stress, maternal separation

Procedia PDF Downloads 377
558 A Development of Portable Intrinsically Safe Explosion-Proof Type of Dual Gas Detector

Authors: Sangguk Ahn, Youngyu Kim, Jaheon Gu, Gyoutae Park

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In this paper, we developed a dual gas leak instrument to detect Hydrocarbon (HC) and Monoxide (CO) gases. To two kinds of gases, it is necessary to design compact structure for sensors. And then it is important to draw sensing circuits such as measuring, amplifying and filtering. After that, it should be well programmed with robust, systematic and module coding methods. In center of them, improvement of accuracy and initial response time are a matter of vital importance. To manufacture distinguished gas leak detector, we applied intrinsically safe explosion-proof structure to lithium ion battery, main circuits, a pump with motor, color LCD interfaces and sensing circuits. On software, to enhance measuring accuracy we used numerical analysis such as Lagrange and Neville interpolation. Performance test result is conducted by using standard Methane with seven different concentrations with three other products. We want raise risk prevention and efficiency of gas safe management through distributing to the field of gas safety. Acknowledgment: This study was supported by Small and Medium Business Administration under the research theme of ‘Commercialized Development of a portable intrinsically safe explosion-proof type dual gas leak detector’, (task number S2456036).

Keywords: gas leak, dual gas detector, intrinsically safe, explosion proof

Procedia PDF Downloads 215
557 The Role of Reading Self-Efficacy and Perception of Difficulty in English Reading among Chinese ESL Learners

Authors: Kevin Chan, Kevin K. H. Chung, Patcy P. S. Yeung, H. L. Ip, Bill T. C. Chung, Karen M. K. Chung

Abstract:

Purpose: Recent evidence shows that reading self-efficacy and students perceived difficulty in reading are significantly associated with word reading and reading fluency. However, little is known about these relationships among students learning to read English as a second language, particularly in Chinese students. This study examined the contributions of reading self-efficacy, perception of difficulty in reading, and cognitive-linguistic skills to performance on English word reading and reading fluency in Chinese students. Method: A sample of 122 second-and third-grade students in Hong Kong, China, participated in this study. Students completed the measures of reading self-efficacy and perception of difficulty in reading. They were assessed on their English cognitive-linguistic and reading skills: rapid automatized naming, nonword reading, phonological awareness, word reading, and one-minute word reading. Results: Results of path analysis indicated that when students’ grades were controlled, reading self-efficacy was a significant correlate of word reading and reading fluency, whereas perception of difficulty in reading negatively predicted word reading. Conclusion: These findings underscore the importance of taking students’ reading self-efficacy and perception of difficulty in reading and their cognitive-linguistic skills into consideration when designing reading intervention and instructions for students learning English as a second language.

Keywords: self-efficacy, perception of difficulty in reading, english as a second language, word reading

Procedia PDF Downloads 177
556 Casual Effects of Informal Care and Health on Falls and Other Accidents among the Elderly Population in China

Authors: Hong Wu, Naiji Lu, Chenguang Wang, Xinming Tu

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This article analyzes the causal effects of informal care, mental health, and physical health on falls and other accidents (e.g. traffic accidents) among elderly people. To purge potential reversal causal effects, e.g., past accidents induce more future informal care, we use two-stage least squares to identify the impacts. By using longitudinal data from a representative national China Health and retirement longitudinal study of people aged 45 and older in China, our findings indicate that informal care decreases while poor health conditions increase the occurrence of accidents. We also find heterogeneous impacts on the occurrence of accidents, varying by gender, urban status, and past accident history. Our findings suggest the following three policy implications. First, policy makers who aim to decrease accidents should take informal care to elders into account. Second, ease of birth policy and postponed retirement policy are urgent to meet the demand of informal care. Third, medical policies should attach great importance to not only physical health but also mental health of elderly parents especially for older people with accident history.

Keywords: accident, China, fall, informal care, mental health, physical health

Procedia PDF Downloads 465
555 Finite Element Modeling of Ultrasonic Shot Peening Process using Multiple Pin Impacts

Authors: Chao-xun Liu, Shi-hong Lu

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In spite of its importance to the aerospace and automobile industries, little or no attention has been devoted to the accurate modeling of the ultrasonic shot peening (USP) process. It is therefore the purpose of this study to conduct finite element analysis of the process using a realistic multiple pin impacts model with the explicit solver of ABAQUS. In this paper, we research the effect of several key parameters on the residual stress distribution within the target, including impact velocity, incident angle, friction coefficient between pins and target and impact number of times were investigated. The results reveal that the impact velocity and impact number of times have obvious effect and impacting vertically could produce the most perfect residual stress distribution. Then we compare the results with the date in USP experiment and verify the exactness of the model. The analysis of the multiple pin impacts date reveal the relationships between peening process parameters and peening quality, which are useful for identifying the parameters which need to be controlled and regulated in order to produce a more beneficial compressive residual stress distribution within the target.

Keywords: ultrasonic shot peening, finite element, multiple pins, residual stress, numerical simulation

Procedia PDF Downloads 434
554 The Synthesis and Characterization of Highly Water-Soluble Silane Coupling Agents for Increasing Silica Filler Content in Styrene-Butadiene Rubber

Authors: Jun Choi, Bo Ram Lee, Ji Hye Choi, Jung Soo Kim, No-Hyung Park, Dong Hyun Kim

Abstract:

The synthetic rubber compound, which is widely used as the core material for automobile tire industry, is manufactured by mixing styrene-butadiene rubber (SBR) and organic/inorganic fillers. It is known that the most important factor for the physical properties of rubber compound is the interaction between the filler and the rubber, which affects the rotational, braking and abrasion resistance. Silica filler has hydrophilic groups such as a silanol group on their surface which has a low affinity with hydrophobic rubbers. In order to solve this problem, researches on an efficient silane coupling agent (SCA) has been continuously carried out. In this study, highly water-soluble SCAs which are expected to show higher hydrolysis efficiency were synthesized. The hydrophobization process of the silica with the prepared SCAs was economical and environment-friendly. The SCAs structures were analysed by gas chromatography-mass spectrometry (GC/MS) and nuclear magnetic resonance (1H-NMR) spectroscopy. In addition, their hydrolysis efficiency and condensation side reaction in SBR wet master batch were examined by Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC), respectively.

Keywords: rubber, silane coupling agent, synthesis, water-soluble

Procedia PDF Downloads 282
553 Fabrication of Nanostructured Arrays Using Si-Containing Block Copolymer and Dually Responsive Photoresist

Authors: Kyoungok Jung, Chang Hong Bak, Gyeong Cheon Jo, Jin-Baek Kim

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Nanostructured arrays have drawn extensive attention because of their unique properties resulting from nanoscale features. However, it is difficult to achieve uniform and freestanding 1D nanostrcutures over a large area. Here, a simple and novel method was developed for fabrication of universal nanoporous templates for high-density nanostructure arrays, by combining self-assembly of a Si-containing block copolymer with a bilayer lithography system. We introduced a dually responsive photoresist bottom layer into which the nanopatterns of block copolymer are transferred by oxygen reactive ion etching. Because the dually responsive layer becomes cross-linked by heating, it can be used as a hard template during the etching process. It becomes soluble again by chain scission upon exposure to light. Therefore, it can be easily removed by the lift-off process. The template was applicable to the various conducting substrates due to the compatibility of the photoresist with a wide range of substrates and was used in electrodeposition for well-aligned and high-density inorganic and organic nanoarrays. We successfully obtained vertically aligned and highly ordered gold nanorods and polypyrrole dots on the substrate without aggregation, and these arrays did not collapse after removing the dually responsive templates by the simple lift-off process.

Keywords: block copolymer, dually responsive, nanostructure, photoresist

Procedia PDF Downloads 242
552 Human Action Recognition Using Variational Bayesian HMM with Dirichlet Process Mixture of Gaussian Wishart Emission Model

Authors: Wanhyun Cho, Soonja Kang, Sangkyoon Kim, Soonyoung Park

Abstract:

In this paper, we present the human action recognition method using the variational Bayesian HMM with the Dirichlet process mixture (DPM) of the Gaussian-Wishart emission model (GWEM). First, we define the Bayesian HMM based on the Dirichlet process, which allows an infinite number of Gaussian-Wishart components to support continuous emission observations. Second, we have considered an efficient variational Bayesian inference method that can be applied to drive the posterior distribution of hidden variables and model parameters for the proposed model based on training data. And then we have derived the predictive distribution that may be used to classify new action. Third, the paper proposes a process of extracting appropriate spatial-temporal feature vectors that can be used to recognize a wide range of human behaviors from input video image. Finally, we have conducted experiments that can evaluate the performance of the proposed method. The experimental results show that the method presented is more efficient with human action recognition than existing methods.

Keywords: human action recognition, Bayesian HMM, Dirichlet process mixture model, Gaussian-Wishart emission model, Variational Bayesian inference, prior distribution and approximate posterior distribution, KTH dataset

Procedia PDF Downloads 337
551 The Role of Food System in Promoting Environmental Planning

Authors: Rayeheh Khatami, Toktam Hanaei, Mohammad Reza Mansouri Daneshvar

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Today, many local and national governments are developing urban agriculture as an effective tool in responding to challenges such as food security, poverty and environmental problems. In fact, urban agriculture plays an important role in food system, which can provide citizens' income and become one of the components of economic, social and environmental systems. The purpose of this paper is to analyze the urban agriculture and urban food systems in order to understand the impact of urban foods production on environmental planning in non-western city region context. To achieve such objective, we carry out a case study in Mashhad city of Iran by using qualitative approaches. A survey on documentary studies and planning tools integrate with face to face interview with experts which explain the role of food system in environmental planning process. The paper extends the use of food in the environmental planning, specifically to examine this role to create agricultural garden as a mean to improve agricultural system in non-western country. The paper is concluded with a set of recommendations for researchers and policymakers who seek to create spaces in order to implement urban agriculture in cities for food justice.

Keywords: urban agriculture , agricultural park, city region food system, Mashhad

Procedia PDF Downloads 109
550 Research on the Calculation Method of Smartization Rate of Concrete Structure Building Construction

Authors: Hongyu Ye, Hong Zhang, Minjie Sun, Hongfang Xu

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In the context of China's promotion of smart construction and building industrialization, there is a need for evaluation standards for the development of building industrialization based on assembly-type construction. However, the evaluation of smart construction remains a challenge in the industry's development process. This paper addresses this issue by proposing a calculation and evaluation method for the smartization rate of concrete structure building construction. The study focuses on examining the factors of smart equipment application and their impact on costs throughout the process of smart construction design, production, transfer, and construction. Based on this analysis, the paper presents an evaluation method for the smartization rate based on components. Furthermore, it introduces calculation methods for assessing the smartization rate of buildings. The paper also suggests a rapid calculation method for determining the smartization rate using Building Information Modeling (BIM) and information expression technology. The proposed research provides a foundation for the swift calculation of the smartization rate based on BIM and information technology. Ultimately, it aims to promote the development of smart construction and the construction of high-quality buildings in China.

Keywords: building industrialization, high quality building, smart construction, smartization rate, component

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549 Defying the Walls of Autocracy: The Role of the Catholic Church in the Resistance against Dictatorships in South Korea and the Philippines during the Early 1960s and Late 1980s

Authors: Marvin R. Tenecio

Abstract:

The analysis of "religious resistance" has been prevalent in Asian and Philippine studies. Discussions on religious resistance from a variety of perspectives are deemed as crucial turning points in the concept's ongoing development and expansion. By broadening the backdrop of religious protest between the early 1960s and the late 1980s, the researchers contend that a study examining the role carried by the Catholic Church in the upheavals against dictatorships in South Korea and the Philippines would be beneficial to the body of knowledge. This study examines a variety of historical writings about the activities occurring at that time. The researchers also compare and contrast the Catholic Church's contributions to the Korean and Philippine resistance against Park Chung-Hee and Ferdinand Marcos Sr., respectively, during the early 1960s until the late 1980s, using the lens of history from below, particularly the Pasyon and Revolution. The Catholic Church stood out against human rights abuses, promoted social justice, and mobilized the public for political reform in response to the dictatorships in South Korea and the Philippines. Even though the specific circumstances and personalities may have changed, the Church's position in both countries was vital in opposing authoritarian governments and supporting democratic movements.

Keywords: resistance, movements, catholic, church, dictatorship

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548 Effects of a Nursing Intervention Program Using a Rehabilitation Self-Management Workbook on Depression, Motivation and Self-Efficacy of Rehabilitation Inpatients

Authors: Young Ae Song, So Yun Kim, Nan Ji Kim, So Young Jang, Yun Mee Park, Mi Jin Lee, Ji Yeon Lee

Abstract:

Background & Purpose: Many patients have psychological problems such as depression and anxiety during the rehabilitation period. Such psychological instability affects the prognosis of the patient in the long term. We develop a nursing intervention program for rehabilitation inpatients using a rehabilitation self –management note and evaluate the effects of the program on depression, motivation, and self-efficacy. Methods: The study was conducted using a nonequivalent control group non-synchronized design. Participants were rehabilitation inpatients, 27 patients in the control group and 20 in the experimental group. Questionnaires were completed three times (pretest, 5 days, 10 days) Final data for 40 patients were analyzed, 23 patients in the control group and 17 in the experimental group. Data were analyzed using x2-test, t-test, and repeated measure ANOVA. Results: Depression in the experimental group decreased compared to the control group, but it was not significant. The motivation for the experimental group changed significantly (F=3.90, p=.029) and self-efficacy increased, but not significantly (F=0.59, p=.559) Conclusion: Results of this study indicate that nursing intervention programs for rehabilitation inpatients could be useful to decrease depression and to improve motivation and self-efficacy.

Keywords: depression, motivation, self-efficacy, rehabilitation inpatient, self-management workbook

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547 Development of a Scale for Evaluating the Efficacy of Vacationing

Authors: Ju Yeon Lee, Seol Ah Oh, Hong il Kim, Hae Yong Do, Sung Won Choi

Abstract:

The purpose of this study was to develop a Well-being and Moments Scale (WAMS) for evaluating the efficacy of ‘vacationing’ as a form of mental health recuperation. ‘Vacationing’ is defined as a going outside one’s usual environment to seek refreshment and relief from one’s daily life. To develop WAMS, we followed recommended procedures for scale development, including reviewing related studies, conducting focus group interviews to elucidate the need for this assessment area, and modifying items based on expert opinion. Through this process, we developed the WAMS. The psychometric properties of the WAMS were then tested in two separate samples. Exploratory factor analysis (EFA) was conducted using 1.41 participants (mean age = 30.45 years; range: 20-50 years) to identify the underlying 3-factor structure of 'Positive Emotions', 'Life Satisfaction' and 'Self-Confidence.' The 26 items retained based on the EFA procedures were associated with excellent reliability (i.e., α = 0.93). Confirmatory factor analysis was then conducted using 200 different participants (mean age = 29.51 years; range: 20-50 years) and revealed good model fit for our hypothesized 3-factor model. Convergent validity tests also revealed correlations with other scales in the expected direction and range. Study limitations as well as the importance and utility of WMAS are also discussed.

Keywords: vacationing, positive affect, life satisfaction, self-confidence, WAMS

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546 Analysis of CO₂ Capture Products from Carbon Capture and Utilization Plant

Authors: Bongjae Lee, Beom Goo Hwang, Hye Mi Park

Abstract:

CO₂ capture products manufactured through Carbon Capture and Utilization (CCU) Plant that collect CO₂ directly from power plants require accurate measurements of the amount of CO₂ captured. For this purpose, two tests were carried out on the weight loss test. And one was analyzed using a carbon dioxide quantification device. First, the ignition loss analysis was performed by measuring the weight of the sample at 550°C after the first conversation and then confirming the loss when ignited at 950°C. Second, in the thermogravimetric analysis, the sample was divided into two sections of 40 to 500°C and 500 to 800°C to confirm the reduction. The results of thermal weight loss analysis and thermogravimetric analysis were confirmed to be almost similar. However, the temperature of the ignition loss analysis method was 950°C, which was 150°C higher than that of the thermogravimetric method at a temperature of 800°C, so that the difference in the amount of weight loss was 3 to 4% higher by the heat loss analysis method. In addition, the tendency that the CO₂ content increases as the reaction time become longer is similarly confirmed. Third, the results of the wet titration method through the carbon dioxide quantification device were found to be significantly lower than the weight loss method. Therefore, based on the results obtained through the above three analysis methods, we will establish a method to analyze the accurate amount of CO₂. Acknowledgements: This work was supported by the Korea Institute of Energy Technology Evaluation and planning (No. 20152010201850).

Keywords: carbon capture and utilization, CCU, CO2, CO2 capture products, analysis method

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545 The Relation between Authenticity at Work and Job Satisfaction

Authors: Godiva Kwan, Winton Au, Fanny Cheung

Abstract:

Authenticity, being true to oneself and acting in congruence with one’s values and beliefs, is a basic human strength, and is instrumental to understanding well-being. While dispositional authenticity was found to be associated with positive affect and subjective well-being, others have demonstrated that individuals assumed different levels of authenticity when they took up different social roles, suggesting that state authenticity can be an alternative mechanism. This study examined the relation between workplace authenticity and job satisfaction. We hypothesize that state authenticity at work will be predicted by psychological safety climate (organizational climate where employees feel safe to speak up without being embarrassed or rejected). Employees are expected to experience higher subjective well-being and job satisfaction as a result of being authentic at work. Survey results provided support to the hypotheses. Psychological safety climate enhanced employees’ authenticity state at work, which in turn improved well-being and job satisfaction. In conclusion, we found that employees become more authentic at work in an organizational climate where they feel safe to express themselves, leading to a higher job satisfaction and well-being. The current study contributes to the understanding of underlying mechanisms behind experiencing authenticity at work among employees in Hong Kong. Our findings are expected to provide insights and to raise organizations’ awareness of creating an open and trustful culture in order to enhance job satisfaction of employees through encouraging them to “be themselves”.

Keywords: authenticity, job satisfaction, psychological safety climate, organizational climate

Procedia PDF Downloads 412