Search results for: Seong Hyeon Park
551 Pervaporation of Dimethyl Carbonate / Methanol / Water Mixtures Using Zeolite Membranes
Authors: Jong-Ho Moon, Dong-Ho Lee, Hyunuk Kim, Young Cheol Park, Jong-Seop Lee, Jae-deok Jeon, Hyung-Keun Lee
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A novel membrane reactor process for DMC synthesis from carbon dioxide has been developing in Korea Institute of Energy Research. The scheme of direct synthesis of DMC from CO₂ and Methanol is 'CO₂ + 2MeOH ↔ DMC + H₂O'. Among them, reactants are CO₂ and MeOH, product is DMC, and byproduct is H₂O (water). According to Le Chatelier’s principle, removing byproduct (water) can shift the reaction equilibrium to the right (DMC production). The main purpose of this process is removing water during the reaction. For efficient in situ water removal (dehydration) and DMC separation, zeolite 4A membranes with very small pore diameter and hydrophilicity were introduced. In this study, pervaporation performances of binary and ternary DMC / methanol / water mixtures were evaluated.Keywords: dimehtyl carbonate, methanol, water, zeolite membrane, pervaporation
Procedia PDF Downloads 359550 Polymer Nanocarrier for Rheumatoid Arthritis Therapy
Authors: Vijayakameswara Rao Neralla, Jueun Jeon, Jae Hyung Park
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To develop a potential nanocarrier for diagnosis and treatment of rheumatoid arthritis (RA), we prepared a hyaluronic acid (HA)-5β-cholanic acid (CA) conjugate with an acid-labile ketal linker. This conjugate could self-assemble in aqueous conditions to produce pH-responsive HA-CA nanoparticles as potential carriers of the anti-inflammatory drug methotrexate (MTX). MTX was rapidly released from nanoparticles under inflamed synovial tissue in RA. In vitro cytotoxicity data showed that pH-responsive HA-CA nanoparticles were non-toxic to RAW 264.7 cells. In vivo biodistribution results confirmed that, after their systemic administration, pH-responsive HA-CA nanoparticles selectively accumulated in the inflamed joints of collagen-induced arthritis mice. These results indicate that pH-responsive HA-CA nanoparticles represent a promising candidate as a drug carrier for RA therapy.Keywords: rheumatoid arthritis, hyaluronic acid, nanocarrier, self-assembly, MTX
Procedia PDF Downloads 285549 Investigation on Performance of Optical Shutter Panels for Transparent Displays
Authors: Jaehong Kim, Sunhee Park, HongSeop Shin, Kyongho Lim, Suhyun Kwon, Don-Gyou Lee, Pureum Kim, Moojong Lim, JongSang Baek
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Transparent displays with OLEDs are the most commonly produced forms of see-through displays on the market or in development. In order to block the visual interruption caused by the light coming from the background, the special panel is combined with transparent displays with OLEDs. There is, however, few studies performance of optical shutter panel for transparent displays until now. This paper, therefore, describes the performance of optical shutter panels. The novel evaluation method was developed by measuring the amount of light which can form a transmitted background image. The new proposed method could tell how recognizable transmitted background images cannot be seen, and is consistent with viewer’s perception.Keywords: optical shutter panel, optical performance, transparent display, visual interruption
Procedia PDF Downloads 524548 Network Mobility Support in Content-Centric Internet
Authors: Zhiwei Yan, Jong-Hyouk Lee, Yong-Jin Park, Xiaodong Lee
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In this paper, we analyze NEtwork MObility (NEMO) supporting problems in Content-Centric Networking (CCN), and propose the CCN-NEMO which can well support the deployment of the content-centric paradigm in large-scale mobile Internet. The CCN-NEMO extends the signaling message of the basic CCN protocol, to support the mobility discovery and fast trigger of Interest re-issuing during the network mobility. Besides, the Mobile Router (MR) is extended to optimize the content searching and relaying in the local subnet. These features can be employed by the nested NEMO to maximize the advantages of content retrieving with CCN. Based on the analysis, we compare the performance on handover latency between the basic CCN and our proposed CCN-NEMO. The results show that our scheme can facilitate the content-retrieving in the NEMO scenario with improved performance.Keywords: NEMO, CCN, mobility, handover latency
Procedia PDF Downloads 464547 Fabrication of Optical Tissue Phantoms Simulating Human Skin and Their Application
Authors: Jihoon Park, Sungkon Yu, Byungjo Jung
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Although various optical tissue phantoms (OTPs) simulating human skin have been actively studied, their completeness is unclear because skin tissue has the intricate optical property and complicated structure disturbing the optical simulation. In this study, we designed multilayer OTP mimicking skin structure, and fabricated OTP models simulating skin-blood vessel and skin pigmentation in the skin, which are useful in Biomedical optics filed. The OTPs were characterized with the optical property and the cross-sectional structure, and analyzed by using various optical tools such as a laser speckle imaging system, OCT and a digital microscope to show the practicality. The measured optical property was within 5% error, and the thickness of each layer was uniform within 10% error in micrometer scale.Keywords: blood vessel, optical tissue phantom, optical property, skin tissue, pigmentation
Procedia PDF Downloads 443546 Research of Applicable Ground Reinforcement Method in Double-Deck Tunnel Junction
Authors: SKhan Park, Seok Jin Lee, Jong Sun Kim, Jun Ho Lee, Bong Chan Kim
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Because of the large economic losses caused by traffic congestion in metropolitan areas, various studies on the underground network design and construction techniques has been performed various studies in the developed countries. In Korea, it has performed a study to develop a versatile double-deck of deep tunnel model. This paper is an introduction to develop a ground reinforcement method to enable the safe tunnel construction in the weakened pillar section like as junction of tunnel. Applicable ground reinforcement method in the weakened section is proposed and it is expected to verify the method by the field application tests.Keywords: double-deck tunnel, ground reinforcement, tunnel construction, weakened pillar section
Procedia PDF Downloads 403545 A Study on the Iterative Scheme for Stratified Shields Gamma Ray Buildup Factor Using Layer-Splitting Technique in Double-Layer Shield
Authors: Sari F. Alkhatib, Chang Je Park, Gyuhong Roh, Daeseong Jo
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The iterative scheme which is used to treat buildup factors for stratified shields of three-layers or more is being investigated here using the layer-splitting technique. The second layer in a double-layer shield was split into two equivalent layers and the scheme was implemented on the new 'three-layer' shield configuration. The results of such manipulation for water-lead and water-iron shields combinations are presented here for 1 MeV photons. It was found that splitting the second layer introduces some deviation on the overall buildup factor. This expected deviation appeared to be higher in the case of low Z layer followed by high Z. However, the iterative scheme showed a great consistency and strong coherence with the introduced changes.Keywords: build-up factor, iterative scheme, stratified shields, radiation protection
Procedia PDF Downloads 571544 Prediction of the Performance of a Bar-Type Piezoelectric Vibration Actuator Depending on the Frequency Using an Equivalent Circuit Analysis
Authors: J. H. Kim, J. H. Kwon, J. S. Park, K. J. Lim
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This paper has investigated a technique that predicts the performance of a bar-type unimorph piezoelectric vibration actuator depending on the frequency. This paper has been proposed an equivalent circuit that can be easily analyzed for the bar-type unimorph piezoelectric vibration actuator. In the dynamic analysis, rigidity and resonance frequency, which are important mechanical elements, were derived using the basic beam theory. In the equivalent circuit analysis, the displacement and bandwidth of the piezoelectric vibration actuator depending on the frequency were predicted. Also, for the reliability of the derived equations, the predicted performance depending on the shape change was compared with the result of a finite element analysis program.Keywords: actuator, piezoelectric, performance, unimorph
Procedia PDF Downloads 457543 Correlation between Meaning in Life and Academic Performance in Japanese College Students
Authors: Jihyun Park
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This research suggests that meaning in life or Ikigai can be associated with better academic performances in Japanese college students. To measure meaning in life in Japanese college students, the Ikigai questionnaire and the Meaning in Life Questionnaire (MLQ) are both used, and the survey was collected using Microsoft Teams Forms for a total of 80 Japanese college students. The data revealed that students who have a higher than a 3.0 grade point average (GPA) showed the highest score in both the Ikigai and MLQ. The participants with between a 2.0 and a 3.0 GPA reported lower scores in both MLQ and Ikigai than the previous participants. The group of students who have lower than a 2.0 GPA had the lowest scores for MLQ and Ikigai. This result can indicate that implementing meaning in life or Ikigai to early college students can bring about better academic performance, which also can improve students’ college life better as well.Keywords: college students' academic performance, Ikigai, meaning in life, purpose of life
Procedia PDF Downloads 87542 Investigation on Optical Performance of Operational Shutter Panels for Transparent Displays
Authors: Jaehong Kim, Sunhee Park, HongSeop Shin, Kyongho Lim, Suhyun Kwon, Don-Gyou Lee, Pureum Kim, Moojong Lim, JongSang Baek
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Transparent displays with OLEDs are the most commonly produced forms of see-through displays on the market or in development. In order to block the visual interruption caused by the light coming from the background, the special panel is combined with transparent displays with OLEDs. There is, however, few studies optical performance of operational shutter panel for transparent displays until now. This paper, therefore, describes the optical performance of operational shutter panels. The novel evaluation method was developed by measuring the amount of light which can form a transmitted background image. The new proposed method could tell how recognize transmitted background images cannot be seen, and is consistent with viewer’s perception.Keywords: transparent display, operational shutter panel, optical performance, OLEDs
Procedia PDF Downloads 436541 Renewable Integration Algorithm to Compensate Photovoltaic Power Using Battery Energy Storage System
Authors: Hyung Joo Lee, Jin Young Choi, Gun Soo Park, Kyo Sun Oh, Dong Jun Won
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The fluctuation of the output of the renewable generator caused by weather conditions must be mitigated because it imposes strain on the system and adversely affects power quality. In this paper, we focus on mitigating the output fluctuation of the photovoltaic (PV) using battery energy storage system (BESS). To satisfy tight conditions of system, proposed algorithm is developed. This algorithm focuses on adjusting the integrated output curve considering state of capacity (SOC) of the battery. In this paper, the simulation model is PSCAD / EMTDC software. SOC of the battery and the overall output curve are shown using the simulation results. We also considered losses and battery efficiency.Keywords: photovoltaic generation, battery energy storage system, renewable integration, power smoothing
Procedia PDF Downloads 276540 Exposure to Particulate Matter Taking Various Transportation Modes in Cebu City, Philippines
Authors: Mona Loraine M. Barabad, Duckshin Park, Michael E. Versoza
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This study gives a comparison of the commuters’ exposure to particulate matter while taking different transportation mode (jeepney, motorcycle and taxi) in Cebu City, Philippines. A personal aerosol monitor (Sidepak AM510) was used for data collection; in addition, both temperature and humidity were also documented. Analysis was done and showed that Jeepney, which is the most commonly used mode in the country, has the highest PM collected having an average of 358.0μg/m^3, followed by the motorcycle with an average of 244.6 μg/m^3. The taxi recorded to have an average of 50.0 μg/m^3 and the lowest between the microenvironments sampled. The outcome was greatly significant to the traffic volume together with several factors that could possibly affect the result. However, due to the lack of time and resources, the data collected was limited. Further and thorough investigation should be implemented to provide more essential information regarding the subject.Keywords: air quality, particulate matter, Philippines, transportation
Procedia PDF Downloads 358539 Sampled-Data Control for Fuel Cell Systems
Authors: H. Y. Jung, Ju H. Park, S. M. Lee
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A sampled-data controller is presented for solid oxide fuel cell systems which is expressed by a sector bounded nonlinear model. The sector bounded nonlinear systems, which have a feedback connection with a linear dynamical system and nonlinearity satisfying certain sector type constraints. Also, the sampled-data control scheme is very useful since it is possible to handle digital controller and increasing research efforts have been devoted to sampled-data control systems with the development of modern high-speed computers. The proposed control law is obtained by solving a convex problem satisfying several linear matrix inequalities. Simulation results are given to show the effectiveness of the proposed design method.Keywords: sampled-data control, fuel cell, linear matrix inequalities, nonlinear control
Procedia PDF Downloads 562538 A Review of Deformation and Settlement Monitoring on the Field: Types and Applications
Authors: Hassan Ali, Abdulrahman Hamid
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This paper discusses using of instruments to monitor deformation and settlement. Specifically, it concentrates on field instruments such as inclinometer and plate load test and their applications in the field. Inclinometer has been used effectively to monitor lateral earth movements and settlement in landslide areas, embankments and foundations. They are also used to monitor the deflection of retaining walls and piles under load. This paper is reviewing types of inclinometer systems, comparison between systems, applications, field accuracy and correction. The paper also will present a case study of using inclinometer to monitor the creep movements within the ancient landslide on The Washington Park Station. Furthermore, the application of deformation and settlement instruments in Saudi Arabia will be discussed in this manuscript.Keywords: inclinometer, plate load test, backfills, sand, deformation and settlement
Procedia PDF Downloads 268537 Regulation of Differentiating Intramuscular Stromal Vascular Cells Isolated from Hanwoo Beef Cattle by Retinoic Acid and Calcium
Authors: Seong Gu Hwang, Young Kyoon Oh, Joseph F. dela Cruz
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Marbling, or intramuscular fat, has been consistently identified as one of the top beef quality problems. Intramuscular adipocytes distribute throughout the perimysial connective tissue of skeletal muscle and are the major site for the deposition of intramuscular fat, which is essential for the eating quality of meat. The stromal vascular fraction of the skeletal muscle contains progenitor cells that can be enhanced to differentiate to adipocytes and increase intramuscular fat. Primary cultures of bovine intramuscular stromal vascular cells were used in this study to elucidate the effects of extracellular calcium and retinoic acid concentration on adipocyte differentiation. Cell viability assay revealed that even at different concentrations of calcium and retinoic acid, there was no significant difference on cell viability. Monitoring of the adipocyte differentiation showed that bovine intramuscular stromal vascular cells cultured in a low concentration of extracellular calcium and retinoic acid had a better degree of fat accumulation. The mRNA and protein expressions of PPARγ, C/EBPα, SREBP-1c and aP2 were analyzed and showed a significant upregulation upon the reduction in the level of extracellular calcium and retinoic acid. The upregulation of these adipogenic related genes means that the decreasing concentration of calcium and retinoic acid is able to stimulate the adipogenic differentiation of bovine intramuscular stromal vascular cells. To further elucidate the effect of calcium, the expression level of calreticulin was measured. Calreticulin which is known to be an inhibitor of PPARγ was down regulated by the decreased level of calcium and retinoic acid in the culture media. The same tendency was observed on retinoic acid receptors RARα and CRABP-II. These receptors are recognized as adipogenic inhibitors, and the downregulation of their expression allowed a better level of differentiation in bovine intramuscular stromal vascular cells. In conclusion, data show that decreasing the level of extracellular calcium and retinoic acid can significantly promote adipogenesis in intramuscular stromal vascular cells of Hanwoo beef cattle. These findings may provide new insights in enhancing intramuscular adipogenesis and marbling in beef cattle.Keywords: calcium, calreticulin, hanwoo beef, retinoic acid
Procedia PDF Downloads 297536 Architecture Design of the Robots Operability Assessment Simulation Testbed
Authors: Sang Yeong Choi, Woo Sung Park
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This paper presents the architecture design of the robot operability assessment simulation testbed (called "ROAST") for the resolution of robot operability problems occurred during interactions between human operators and robots. The basic idea of the ROAST architecture design is to enable the easy composition of legacy or new simulation models according to its purpose. ROAST architecture is based on IEEE1516 High Level Architecture (HLA) of defense modeling and simulation. The ROAST architecture is expected to provide the foundation framework for the easy construction of a simulation testbed to order to assess the robot operability during the robotic system design. Some of ROAST implementations and its usefulness are demonstrated through a simple illustrative example.Keywords: robotic system, modeling and simulation, simulation architecture, operability assessment
Procedia PDF Downloads 351535 Design of Middleware for Mobile Group Control in Physical Proximity
Authors: Moon-Tak Oh, Kyung-Min Park, Tae-Eun Yoon, Hoon Choi, Chil-Woo Lee
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This paper is about middle-ware which enables group-user applications on mobile devices in physical proximity to interact with other devices without intervention of a central server. Requirements of the middle-ware are identified from service usage scenarios, and the functional architecture of the middle-ware is specified. These requirements include group management, synchronization, and resource management. Group Management needs to provide various capabilities to such applications with respect to managing multiple users (e.g., creation of groups, discovery of group or individual users, member join/leave, election of a group manager and service-group association) using D2D communication technology. We designed the middle-ware for the above requirements on the Android platform.Keywords: group user, middleware, mobile service, physical proximity
Procedia PDF Downloads 502534 A Case Study on Tension Drop of Cable-band Bolts in Suspension Bridge
Authors: Sihyun Park, Hyunwoo Kim, Wooyoung Jung, Dongwoo You
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Regular maintenance works are very important on the axial forces of the cable-band bolts in suspension bridges. The band bolts show stress reduction for several reasons, including cable wire creep, the bolt relaxation, load fluctuation and cable rearrangements, etc., with time. In this study, with respect to the stress reduction that occurs over time, we carried out the theoretical review of the main cause based on the field measurements. As a result, the main cause of reduction in the cable-band bolt axial force was confirmed by the plastic deformation of the zinc plating layer used in the main cable wire, and thus, the theoretical process was established for the practical use in the field.Keywords: cable-band Bolts, field test, maintenance, stress reduction
Procedia PDF Downloads 329533 Compressive Strength Evaluation of Underwater Concrete Structures Integrating the Combination of Rebound Hardness and Ultrasonic Pulse Velocity Methods with Artificial Neural Networks
Authors: Seunghee Park, Junkyeong Kim, Eun-Seok Shin, Sang-Hun Han
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In this study, two kinds of nondestructive evaluation (NDE) techniques (rebound hardness and ultrasonic pulse velocity methods) are investigated for the effective maintenance of underwater concrete structures. A new methodology to estimate the underwater concrete strengths more effectively, named “artificial neural network (ANN) – based concrete strength estimation with the combination of rebound hardness and ultrasonic pulse velocity methods” is proposed and verified throughout a series of experimental works.Keywords: underwater concrete, rebound hardness, Schmidt hammer, ultrasonic pulse velocity, ultrasonic sensor, artificial neural networks, ANN
Procedia PDF Downloads 524532 Study on Network-Based Technology for Detecting Potentially Malicious Websites
Authors: Byung-Ik Kim, Hong-Koo Kang, Tae-Jin Lee, Hae-Ryong Park
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Cyber terrors against specific enterprises or countries have been increasing recently. Such attacks against specific targets are called advanced persistent threat (APT), and they are giving rise to serious social problems. The malicious behaviors of APT attacks mostly affect websites and penetrate enterprise networks to perform malevolent acts. Although many enterprises invest heavily in security to defend against such APT threats, they recognize the APT attacks only after the latter are already in action. This paper discusses the characteristics of APT attacks at each step as well as the strengths and weaknesses of existing malicious code detection technologies to check their suitability for detecting APT attacks. It then proposes a network-based malicious behavior detection algorithm to protect the enterprise or national networks.Keywords: Advanced Persistent Threat (APT), malware, network security, network packet, exploit kits
Procedia PDF Downloads 357531 Use of Adjunctive Cannabinoids in Opioid Dosing for Patients with Chronic Pain
Authors: Kristina De Milt, Nicole Huang, Jihye Park
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Opioids have been a mainstay of the treatment of chronic pain, but their overprescription and misuse have led to an opioid epidemic. Recently, as an attempt to decrease the number of opioids prescribed, the use of cannabinoid therapy has become an increasingly popular adjunctive chronic pain management choice among providers. This review of literature investigates the effects of adjunctive cannabinoids to opioids in the management of chronic pain. The nine articles are included in the literature review range from observational studies to meta-analyses published in the year 2016 and after. A majority of the studies showed a decrease in the need for opioids after adjunctive cannabinoids were introduced and, in some instances, the cessation of opioid consumption. More high-quality evidence is needed to further support this stance and providers should weigh the benefits and risks of adjunctive cannabinoids according to the clinical picture.Keywords: cannabis, chronic pain, opioids, pain management
Procedia PDF Downloads 249530 Machine Learning Approach to Project Control Threshold Reliability Evaluation
Authors: Y. Kim, H. Lee, M. Park, B. Lee
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Planning is understood as the determination of what has to be performed, how, in which sequence, when, what resources are needed, and their cost within the organization before execution. In most construction project, it is evident that the inherent nature of planning is dynamic, and initial planning is subject to be changed due to various uncertain conditions of construction project. Planners take a continuous revision process during the course of a project and until the very end of project. However, current practice lacks reliable, systematic tool for setting variance thresholds to determine when and what corrective actions to be taken. Rather it is heavily dependent on the level of experience and knowledge of the planner. Thus, this paper introduces a machine learning approach to evaluate project control threshold reliability incorporating project-specific data and presents a method to automate the process. The results have shown that the model improves the efficiency and accuracy of the monitoring process as an early warning.Keywords: machine learning, project control, project progress monitoring, schedule
Procedia PDF Downloads 239529 Analysis of Conflict and Acceptance Factors on Water and Land Photovoltaic Facility
Authors: Taehyun Kim, Taehyun Kim, Hyunjoo Park
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Photovoltaic facility occurs conflicts and disputes over environmental issues such as soil runoff, landscapes damage, and ecosystems damage. Because of these problems, huge social and economic cost occurred. The purpose of this study is to analyze resident‘s acceptability and conflict factors on the location of PV facilities, and suggest ways to promote resident’s acceptability and solutions for conflicts. Literature review, cases analysis, and expert interview on the acceptance and conflict factors related to the location of PV facilities are used to derive results. The results of this study are expected to contribute to the minimization of environmental impact and social conflict due to the development of renewable energy in the future.Keywords: acceptance factor, conflict factor, factor analysis, photovoltaic facility
Procedia PDF Downloads 172528 Effect of Discharge Pressure Conditions on Flow Characteristics in Axial Piston Pump
Authors: Jonghyuk Yoon, Jongil Yoon, Seong-Gyo Chung
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In many kinds of industries which usually need a large amount of power, an axial piston pump has been widely used as a main power source of a hydraulic system. The axial piston pump is a type of positive displacement pump that has several pistons in a circular array within a cylinder block. As the cylinder block and pistons start to rotate, since the exposed ends of the pistons are constrained to follow the surface of the swashed plate, the pistons are driven to reciprocate axially and then a hydraulic power is produced. In the present study, a numerical simulation which has three dimensional full model of the axial piston pump was carried out using a commercial CFD code (Ansys CFX 14.5). In order to take into consideration motion of compression and extension by the reciprocating pistons, the moving boundary conditions were applied as a function of the rotation angle to that region. In addition, this pump using hydraulic oil as working fluid is intentionally designed as a small amount of oil leaks out in order to lubricate moving parts. Since leakage could directly affect the pump efficiency, evaluation of effect of oil-leakage is very important. In order to predict the effect of the oil leakage on the pump efficiency, we considered the leakage between piston-shoe and swash-plate by modeling cylindrical shaped-feature at the end of the cylinder. In order to validate the numerical method used in this study, the numerical results of the flow rate at the discharge port are compared with the experimental data, and good agreement between them was shown. Using the validated numerical method, the effect of the discharge pressure was also investigated. The result of the present study can be useful information of small axial piston pump used in many different manufacturing industries. Acknowledgement: This research was financially supported by the “Next-generation construction machinery component specialization complex development program” through the Ministry of Trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT).Keywords: axial piston pump, CFD, discharge pressure, hydraulic system, moving boundary condition, oil leaks
Procedia PDF Downloads 242527 A Study on Fire Safety Standards through Case Study of Performance Based Design
Authors: Kyung Hoon Park, Hyung Jun Kim, Jong Wook Song
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Super-tall building, large-scale and multi-purpose underground spaces reflect changes in construction trend. As current laws and codes such as Fire Services Act and construction codes are not enough to secure the fire safety of those structures and spaces, it is required to provide systemic supplement for performance-based design to establish or revise laws and technical standards to cope with the changes flexibly. In this study, the performance-based design standards of structures designed in Korea are compared with specification based design standards in an attempt to find the ways to establish fire safety standards for structures in Korea.Keywords: performance based design, specification based design, fire safety design, life safety
Procedia PDF Downloads 370526 Structural Performance Evaluation of Power Boiler for the Pressure Release Valve in Consideration of the Thermal Expansion
Authors: Young-Hun Lee, Tae-Gwan Kim, Jong-Kyu Kim, Young-Chul Park
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In this study, Spring safety valve Heat - structure coupled analysis was carried out. Full analysis procedure and performing thermal analysis at a maximum temperature, them to the results obtained through to give an additional load and the pressure on the valve interior, and Disc holder Heat-Coupled structure Analysis was carried out. Modeled using a 3D design program Solidworks, For the modeling of the safety valve was used 3D finite element analysis program ANSYS. The final result to be obtained through the Analysis examined the stability of the maximum displacement and the maximum stress to the valve internal components occurring in the high-pressure conditions.Keywords: finite element method, spring safety valve, gap, stress, strain, deformation
Procedia PDF Downloads 359525 Useful Lifetime Prediction of Chevron Rubber Spring for Railway Vehicle
Authors: Chang Su Woo, Hyun Sung Park
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Useful lifetime evaluation of chevron rubber spring was very important in design procedure to assure the safety and reliability. It is, therefore, necessary to establish a suitable criterion for the replacement period of chevron rubber spring. In this study, we performed characteristic analysis and useful lifetime prediction of chevron rubber spring. Rubber material coefficient was obtained by curve fittings of uni-axial tension, equi bi-axial tension and pure shear test. Computer simulation was executed to predict and evaluate the load capacity and stiffness for chevron rubber spring. In order to useful lifetime prediction of rubber material, we carried out the compression set with heat aging test in an oven at the temperature ranging from 50°C to 100°C during a period 180 days. By using the Arrhenius plot, several useful lifetime prediction equations for rubber material was proposed.Keywords: chevron rubber spring, material coefficient, finite element analysis, useful lifetime prediction
Procedia PDF Downloads 562524 Detecting the Blood of Femoral and Carotid Artery of Swine Using Photoacoustic Tomography in-vivo
Authors: M. Y. Lee, S. H. Park, S. M. Yu, H. S. Jo, C. G. Song
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Photoacoustic imaging is the imaging technology that combines the optical imaging with ultrasound. It also provides the high contrast and resolution due to optical and ultrasound imaging, respectively. For these reasons, many studies take experiment in order to apply this method for many diagnoses. We developed the real-time photoacoustic tomography (PAT) system using linear-ultrasound transducer. In this study, we conduct the experiment using swine and detect the blood of carotid artery and femoral artery. We measured the blood of femoral and carotid artery of swine and reconstructed the image using 950nm due to the HbO₂ absorption coefficient. The photoacoustic image is overlaid with ultrasound image in order to match the position. In blood of artery, major composition of blood is HbO₂. In this result, we can measure the blood of artery.Keywords: photoacoustic tomography, swine artery, carotid artery, femoral artery
Procedia PDF Downloads 246523 High Techno-Parks in the Economy of Azerbaijan and Their Management Problems
Authors: Rasim M. Alguliyev, Alovsat G. Aliyev, Roza O. Shahverdiyeva
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The paper investigated the role and position of high techno-parks, which is one of the priorities of Azerbaijan. The main objectives, functions and features of the establishment of high-techno parks, as well as organization of the activity of the structural elements, which are the parking complex and their interactions were analyzed. The development, organization and management of high techno-parks were studied. The key features and functions of innovative structures’ management were explained. The need for a comprehensive management system for the development of high-techno parks was emphasized and the major problems were analyzed. In addition, the methods were proposed for the development of information systems supporting decision making in systematic and sustainable management of the parks.Keywords: innovative development, innovation processes, innovation economy, innovation infrastructure, high technology park, efficient management, management decisions, information insurance
Procedia PDF Downloads 462522 Thermal Performance of Radial Heat Sinks for LED Applications
Authors: Jongchul Park, Chan Byon
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In this study, the thermal performance of radial heat sinks for LED applications is investigated numerically and experimentally. The effect of geometrical parameters such as inner radius, fin height, fin length, and fin spacing, as well as the Elenbaas number, is considered. In addition, the effects of augmentation of concentric ring, perforation, and duct are extensively explored in order to enhance the thermal performance of conventional radial heat sink. The results indicate that the Elenbaas number and the fin radius have a significant effect on the thermal performance of the heat sink. The concentric ring affects the performance much, but the degree of affection is highly dependent on the orientation. The perforation always brings about higher thermal performance. The duct can effectively prevent the bypass of the natural convection flow, which in turn reduces the thermal resistance of the radial heat sink significantly.Keywords: heat transfer, radial heat sink, LED, Elenbaas
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