Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 426

Search results for: Jeong II Choi

426 A Study on Analysis of Magnetic Field in Induction Generator for Small Francis Turbine Generator

Authors: Young-Kwan Choi, Han-Sang Jeong, Yeon-Ho Ok, Jae-Ho Choi

Abstract:

The purpose of this study is to verify validity of design by testing output of induction generator through finite element analysis before manufacture of induction generator designed. Characteristics in the operating domain of induction generator can be understood through analysis of magnetic field according to load (rotational speed) of induction generator. Characteristics of induction generator such as induced voltage, current, torque, magnetic flux density (magnetic flux saturation), and loss can be predicted by analysis of magnetic field.

Keywords: electromagnetic analysis, induction generator, small hydro power generator, small francis turbine generator

Procedia PDF Downloads 549
425 Effect of Laser Ablation OTR Films on the Storability of Endive and Pak Choi by Baby Vegetables in Modified Atmosphere Condition

Authors: In-Lee Choi, Min Jae Jeong, Jun Pill Baek, Ho-Min Kang

Abstract:

As the consumption trends of vegetables become different from the past, it is increased using vegetable more convenience such as fresh-cut vegetables, sprouts, baby vegetables rather than an existing hole piece of vegetables. Selected baby vegetables have various functional materials but they have short shelf life. This study was conducted to improve storability by using suitable laser ablation OTR (oxygen transmission rate) films. Baby vegetable of endive (Cichorium endivia L.) and pak choi (Brassica rapa chinensis) for this research, around 10 cm height, cultivated in glass greenhouse during 3 weeks. Harvested endive and pak choi were stored at 8 ℃ for 5 days and were packed by PP (Polypropylene) container and covered different types of laser ablation OTR film (DaeRyung Co., Ltd.) such as 1,300 cc, 10,000 cc, 20,000 cc, 40,000 cc /m2•day•atm, and control (perforated film) with heat sealing machine (SC200-IP, Kumkang, Korea). All the samples conducted 5 times replication. Statistical analysis was carried out using a Microsoft Excel 2010 program and results were expressed as standard deviations. The fresh weight loss rate of both baby vegetables were less than 0.3 % in treated films as maximum weight loss rate. On the other hands, control in the final storage day had around 3.0 % weight loss rate and it followed decreasing quantity. Endive had less 2.0 % carbon dioxide contents as maximum contents in 20,000 cc and 40,000 cc. Oxygen contents was maintained between 17 and 20 % in endive, 19 and 20 % in pak choi. Ethylene concentration of both vegetables maintained little lower contents in 20,000 cc treatments than others at final storage day without statistical significance. In the case of hardness, 40,000 cc film was shown little higher value at both baby vegetables without statistical significance. Visual quality was good at 10,000 cc and 20,000 cc in endive and pak choi, and off-flavor was not appeard any off-flavor in both vegetables. Chlorophyll (SPAD-502, Minolta, Japan) value of endive was shown as similar result with initial in all treatments except 20,000 cc as little lower. And chlorophyll value of pak choi decreased in all treatments compared with initial value but was not shown significantly difference each other. Color of leaves (CR-400, Minolta, Japan) changed significantly in 40,000 cc at endive. In an event of pak choi, all the treatments started yellowing by increasing hunter b value, among them control increased substantially. As above the result, 10,000 cc film was most reasonable packaging film for storing at endive and 20,000 cc at pak choi with good quality.

Keywords: carbon dioxide, shelf-life, visual quality, pak choi

Procedia PDF Downloads 624
424 Evolution of Floating Photovoltaic System Technology and Future Prospect

Authors: Young-Kwan Choi, Han-Sang Jeong

Abstract:

Floating photovoltaic system is a technology that combines photovoltaic power generation with floating structure. However, since floating technology has not been utilized in photovoltaic generation, there are no standardized criteria. It is separately developed and used by different installation bodies. This paper aims to discuss the change of floating photovoltaic system technology based on examples of floating photovoltaic systems installed in Korea.

Keywords: floating photovoltaic system, floating PV installation, ocean floating photovoltaic system, tracking type floating photovoltaic system

Procedia PDF Downloads 442
423 3D Printed Multi-Modal Phantom Using Computed Tomography and 3D X-Ray Images

Authors: Sung-Suk Oh, Bong-Keun Kang, Sang-Wook Park, Hui-Jin Joo, Jong-Ryul Choi, Seong-Jun Lee, Jeong-Woo Sohn

Abstract:

The imaging phantom is utilized for the verification, evaluation and tuning of the medical imaging device and system. Although it could be costly, 3D printing is an ideal technique for a rapid, customized, multi-modal phantom making. In this article, we propose the multi-modal phantom using 3D printing. First of all, the Dicom images for were measured by CT (Computed Tomography) and 3D X-ray systems (PET/CT and Angio X-ray system of Siemens) and then were analyzed. Finally, the 3D modeling was processed using Dicom images. The 3D printed phantom was scanned by PET/CT and MRI systems and then evaluated.

Keywords: imaging phantom, MRI (Magnetic Resonance Imaging), PET / CT (Positron Emission Tomography / Computed Tomography), 3D printing

Procedia PDF Downloads 411
422 A Study on Improvement of Straightness of Preform Pulling Process of Hollow Pipe by Finete Element Analysis Method

Authors: Yeon-Jong Jeong, Jun-Hong Park, Hyuk Choi

Abstract:

In this study, we have studied the design of intermediate die in multipass drawing. Research has been continuously studied because of the advantage of better dimensional accuracy, smooth surface and improved mechanical properties in the case of drawing. Among them, multipass drawing, which is a method to realize complicated shape by drawing, was discussed in this study. The most important factor in the multipass drawing is the dimensional accuracy and simplify the process. To accomplish this, a multistage shape drawing was performed using various intermediate die shape designs, and finite element analysis was performed.

Keywords: FEM (Finite Element Method), multipass drawing, intermediate die, hollow pipe

Procedia PDF Downloads 218
421 The Effect of Nepodin-Enrich Plant on Dyslipidemia and Hyperglycemia in High-Fat Diet-Induced Obese C57BL/6J Mice

Authors: Mi Kyeong Yu, Seon Jeong Lee, So Young Kim, Bora Choi, Young Mi Lee, Su-Jung Cho, Je Tae Woo, Myung-Sook Choi

Abstract:

A high-fat diet (HFD) induces excessive fat accumulation in white adipose tissue (WAT), which increases metabolic disorders such as obesity, dyslipidemia and type 2 diabetes. Many plants are known to have effects that improve metabolic disorders. Therefore, the aim of this present study is to investigate the effect of nepodin-enrich plant extract on dyslipidemia, hyperglycemia in high fat diet-induced C57BL/6J mice. Male C57BL/6J mice were randomly divided into two groups, and fed HFD (20% fat, w/w) or HFD supplemented with nepodin-enrich plant extract (NPE 0.005%, w/w) for 16 weeks. Body weight and food intake were measured every week. And we also analysed metabolic rates (respiratory quotient), blood glucose level, and plasma high-density lipoprotein (HDL)-cholesterol, free fatty acid, apolipoprotein (apo) A-1 and apo B levels. Food intakes and body weights were not different between NPE group and HFD group, while plasma apo B, free fatty acid levels, and blood glucose concentration were significantly decreased in NPE group than in HFD group. Furthermore, plasma apo A and HDL-cholesterol levels in NPE group were remarkably increased than in HFD group. Metabolic rates (respiratory quotient) were significantly increased in NPE group than in HFD group. These results indicate that NPE can alleviate dyslipidemia, hyperglycemia. Further studies are required to identify the effects of NPE on metabolic disorders.

Keywords: dyslipidemia, hyperglycemia, metabolic disorders, nepodin enrich plant extract

Procedia PDF Downloads 267
420 The Effects of Eriocitrin on Obesity and Hepatic Steatosis in High-Fat Diet-Induced Obese C57BL/6 Mice

Authors: So Young Kim, Eun-Young Kwon, Bora Choi, Mi Kyeong Yu, Seon Jeong Lee, Myung-Sook Choi

Abstract:

Lemon (Citrus limon) has various beneficial effect. Eriocitrin (eriodictyol 7-rutinoside) is the main ingredient of lemon fruit and is known to have antioxidative effects. However, there has been little research about the effects of eriocitrin on obesity and regulation of lipid profiles levels. In the present study, we investigated the anti-obesity and lipid-lowering effects of eriocitrin in mice fed high-fat diet (HFD). The 4 week-old male C57BL/6 mice were randomly divided into two groups and were fed HFD (20% fat, w/w) and HFD supplemented with eriocitrin (0.005%, w/w, EC) for 16 weeks. Food intake, body weight and white adipose tissue weight (WAT) were measured and plasma free fatty acid (FFA), apolipoprotein (Apo) B100 level and hepatic enzyme activity were analyzed. No differences were shown between the HFD and EC groups in body weight and food intake. However EC supplementation significantly reduced the weights of epididymal, subcutaneous and total WAT. In addition, the levels of plasma FFA and Apo B100 were significantly decreased in the EC group compared with the HFD group. Moreover, the activities of glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME) related to fatty acids synthesis were significantly lower in the EC group than in the HFD group in liver. Therefore, this study indicates that eriocitrin has beneficial effects on adiposity and nonalcholic fatty liver diseases by modulating hepatic lipid-regulating enzyme activities and plasma lipid profile.

Keywords: antiobesity, eriocitrin, high fat diet, lipid lowering

Procedia PDF Downloads 278
419 Evaluation of Progressive Collapse of Transmission Tower

Authors: Jeong-Hwan Choi, Hyo-Sang Park, Tae-Hyung Lee

Abstract:

The transmission tower is one of the crucial lifeline structures in a modern society, and it needs to be protected against extreme loading conditions. However, the transmission tower is a very complex structure and, therefore, it is very difficult to simulate the actual damage and the collapse behavior of the tower structure. In this study, the actual collapse behavior of the transmission tower due to lateral loading conditions such as wind load is evaluated through the computational simulation. For that, a progressive collapse procedure is applied to the simulation. In this procedure, after running the simulation, if a member of the tower structure fails, the failed member is removed and the simulation run again. The 154kV transmission tower is selected for this study. The simulation is performed by nonlinear static analysis procedure, namely pushover analysis, using OpenSEES, an earthquake simulation platform. Three-dimensional finite element models of those towers are developed.

Keywords: transmission tower, OpenSEES, pushover, progressive collapse

Procedia PDF Downloads 261
418 Analytical Investigation of Replaceable Links with Reduced Web Section for Link-to-Column Connections in Eccentrically Braced Frames

Authors: Daniel Y. Abebe, Sijeong Jeong, Jaehyouk Choi

Abstract:

The use of eccentrically braced frame (EBF) is increasing day by day as EBF possesses high elastic stiffness, stable inelastic response under cyclic lateral loading, and excellent ductility and energy dissipation capacity. The ductility and energy dissipation capacity of EBF depends on the active link beams. Recently, there are two types EBFs; these are conventional EBFs and EBFs with replaceable links. The conventional EBF has a disadvantage during maintenance in post-earthquake. The concept of removable active link beam in EBF is developed to overcome the limitation of the conventional EBF in post-earthquake. In this study, a replaceable link with reduced web section is introduced and design equations are suggested. In addition, nonlinear finite element analysis was conducted in order to evaluate the proposed links.

Keywords: EBFs, replaceable link, earthquake disaster, reduced section

Procedia PDF Downloads 233
417 Development of Orbital TIG Welding Robot System for the Pipe

Authors: Dongho Kim, Sung Choi, Kyowoong Pee, Youngsik Cho, Seungwoo Jeong, Soo-Ho Kim

Abstract:

This study is about the orbital TIG welding robot system which travels on the guide rail installed on the pipe, and welds and tracks the pipe seam using the LVS (Laser Vision Sensor) joint profile data. The orbital welding robot system consists of the robot, welder, controller, and LVS. Moreover we can define the relationship between welding travel speed and wire feed speed, and we can make the linear equation using the maximum and minimum amount of weld metal. Using the linear equation we can determine the welding travel speed and the wire feed speed accurately corresponding to the area of weld captured by LVS. We applied this orbital TIG welding robot system to the stainless steel or duplex pipe on DSME (Daewoo Shipbuilding and Marine Engineering Co. Ltd.,) shipyard and the result of radiographic test is almost perfect. (Defect rate: 0.033%).

Keywords: adaptive welding, automatic welding, pipe welding, orbital welding, laser vision sensor, LVS, welding D/B

Procedia PDF Downloads 549
416 Anti-Diabetic Effect of High Purity Epigallocatechin Gallate from Green Tea

Authors: Hye Jin Choi, Mirim Jin, Jeong June Choi

Abstract:

Green tea, which is one of the most popular of tea, contains various ingredients that help health. Epigallocatechin gallate (EGCG) is one of the main active polyphenolic compound possessing diverse biologically beneficial effects such as anti-oxidation, anti-cancer founding in green tea. This study was performed to investigate the anti-diabetic effect of high-purity EGCG ( > 98%) in a spontaneous diabetic mellitus animal model, db/db mouse. Four-week-old male db/db mice, which was induced to diabetic mellitus by the high-fat diet, were orally administered with high-purity EGCG (10, 50 and 100 mg/kg) for 4 weeks. Daily weight and diet efficiency were examined, and blood glucose level was assessed once a week. After 4 weeks of EGCG administration, fasting blood glucose level was measured. Then, the mice were sacrificed and total abdominal fat was sampled to examine the change in fat weight. Plasma was separated from the blood and the levels of aspartate amino-transferase (ALT) and alanine amino-transferase (AST) were investigated. As results, blood glucose and body weight were significantly decreased by EGCG treatment compared to the control group. Also, the amount of abdominal fat was down-regulated by EGCG. However, ALT and AST levels, which are indicators of liver function, were similar to those of control group. Taken together, our study suggests that high purity EGCG is capable of treating diabetes mellitus based in db / db mice with safety and has a potent to develop a therapeutics for metabolic disorders. This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry (IPET) through High Value-added Food Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (317034-03-2-HD030)

Keywords: anti-diabetic effect, db/db mouse, diabetes mellitus, green tea, epigallocatechin gallate

Procedia PDF Downloads 108
415 Linear Frequency Modulation-Frequency Shift Keying Radar with Compressive Sensing

Authors: Ho Jeong Jin, Chang Won Seo, Choon Sik Cho, Bong Yong Choi, Kwang Kyun Na, Sang Rok Lee

Abstract:

In this paper, a radar signal processing technique using the LFM-FSK (Linear Frequency Modulation-Frequency Shift Keying) is proposed for reducing the false alarm rate based on the compressive sensing. The LFM-FSK method combines FMCW (Frequency Modulation Continuous Wave) signal with FSK (Frequency Shift Keying). This shows an advantage which can suppress the ghost phenomenon without the complicated CFAR (Constant False Alarm Rate) algorithm. Moreover, the parametric sparse algorithm applying the compressive sensing that restores signals efficiently with respect to the incomplete data samples is also integrated, leading to reducing the burden of ADC in the receiver of radars. 24 GHz FMCW signal is applied and tested in the real environment with FSK modulated data for verifying the proposed algorithm along with the compressive sensing.

Keywords: compressive sensing, LFM-FSK radar, radar signal processing, sparse algorithm

Procedia PDF Downloads 342
414 Two-Step Patterning of Microfluidic Structures in Paper by Laser Cutting and Wax Printing for Mass Fabrication of Biosensor

Authors: Bong Keun Kang, Sung Suk Oh, Jeong-Woo Sohn, Jong-Ryul Choi, Young Ho Kim

Abstract:

In this paper, we describe two-step micro-pattering by using laser cutting and wax printing. Wax printing is performed only on the bridges for hydrophobic barriers. We prepared 405nm blue-violet laser module and wax pencil module. And, this two modules combine x-y plot. The hollow microstructure formed by laser patterning define the hydrophilic flowing paths. However, bridges are essential to avoid the cutting area being the island. Through the support bridges, microfluidic solution spread out to the unnecessary areas. Chromatography blotting paper was purchased from Whatman. We used 20x20 cm and 46x57 cm of chromatography blotting paper. Axis moving speed of x-y plot was the main parameter of optimization. For aligning between the two patterning, the paper sheet was taped at the bottom. After the two-step patterning, temperature curing step was done at 110-130 °C. The resolution of the fabrication and the potential of the multiplex detection were investigated.

Keywords: µPADs, microfluidic, biosensor, mass-fabrication

Procedia PDF Downloads 375
413 Prerequisites for the Acquisition of Mammalian Pathogenicity by Influenza A Virus with a Prototypic Avian PB2 Gene

Authors: Chung-Young Lee, Se-Hee Ahn, Ilhwan Kim, Du-Min Go, Dae-Yong Kim, Jun-Gu Choi, Youn-Jeong Lee, Jae-Hong Kim, Hyuk-Joon Kwon

Abstract:

The polymerase of avian influenza A virus (AIV) is a heterotrimer composed of PB2, PB1 and PA. PB2 plays a role in overcoming the host barrier; however, the genetic prerequisites for avian PB2 to acquire mammalian pathogenic mutations have not been well elucidated. Here, we demonstrated that key amino acid mutations (I66M, I109V and I133V, collectively referred to as MVV) of prototypic avian PB2 increase the replication efficiency of recombinant PR8 virus carrying the mutated PB2 in both avian and mammalian hosts. The MVV mutations caused no weight loss in mice, but they did allow replication in infected lungs, and the viruses acquired fatal mammalian pathogenic mutations such as Q591R/K, E627K, or D701N in the infected lungs. The MVV mutations are located at the interfaces of the trimer and are predicted to increase the strength of this structure. Thus, gaining MVV mutations might be the first step for AIV to acquire mammalian pathogenicity. These results provide new insights into the evolution of AIV in birds and mammals.

Keywords: avian influenza A virus, prototypic PB2, polymerase activity, mammalian pathogenicity, first-step mutations

Procedia PDF Downloads 262
412 Fault Detection of Pipeline in Water Distribution Network System

Authors: Shin Je Lee, Go Bong Choi, Jeong Cheol Seo, Jong Min Lee, Gibaek Lee

Abstract:

Water pipe network is installed underground and once equipped; it is difficult to recognize the state of pipes when the leak or burst happens. Accordingly, post management is often delayed after the fault occurs. Therefore, the systematic fault management system of water pipe network is required to prevent the accident and minimize the loss. In this work, we develop online fault detection system of water pipe network using data of pipes such as flow rate or pressure. The transient model describing water flow in pipelines is presented and simulated using Matlab. The fault situations such as the leak or burst can be also simulated and flow rate or pressure data when the fault happens are collected. Faults are detected using statistical methods of fast Fourier transform and discrete wavelet transform, and they are compared to find which method shows the better fault detection performance.

Keywords: fault detection, water pipeline model, fast Fourier transform, discrete wavelet transform

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411 Influence of Sintering Temperatures in Er³⁺/Yb³⁺/Tm³⁺ Tri-Doped Y₂O₃ Nanophosphors

Authors: Hyeon Mi Noh, Ju Hyun Oh, Jung Hyun Jeong, Haeyoung Choi, Jung Hwan Kim

Abstract:

The Er³⁺/Yb³⁺/Tm³⁺ tri-doped Y₂O₃ nanophosphors were synthesized by solvothermal method and its temperature dependence of the white upconversion emission has been studied by using 975 nm laser diode. The upconversion emission spectra in 1 mol% Er³⁺/5 mol% Yb³⁺/xTm³ tri-doped Y₂O₃ nanophosphors sintered at 1000 °C with x from 0 to 0.5 mol%. The blue emission intensity increase with Tm³⁺ concentration from 0 to 0.5 mol%, it is due to the 2F7/2→2F5/2 transition of Yb³⁺ around 10,000 cm-1 could easily reach the Tm³⁺ sates. The white light is composed with the blue (1G4→3H6 of Tm³⁺), green (2H11/2, 4S3/2→4I15/2 of Er³⁺), and red (4F9/2→4I15/2 of Er³⁺) upconversion radiations. The Y₂O₃: Er³⁺/Yb³⁺/Tm³⁺ nanophosphors show from white to green upconversion emission at power of 600 mW/cm² as sintering temperature increased. The calculated Commission Internationale de l’Eclairage (CIE) coordinates can be located in the white area with various sintering temperatures, in sintered at 1000 °C, and their color coordinates are very close to the standard white-light emission (0.33, 0.33). Their upconversion processes were explained by measuring the upconversion luminescence spectra and pump power dependence and energy level diagram.

Keywords: white upconversion emission, nanophosphors, energy transfer, solvothermal method

Procedia PDF Downloads 218
410 Postharvest Losses and Handling Improvement of Organic Pak-Choi and Choy Sum

Authors: Pichaya Poonlarp, Danai Boonyakiat, C. Chuamuangphan, M. Chanta

Abstract:

Current consumers’ behavior trends have changed towards more health awareness, the well-being of society and interest of nature and environment. The Royal Project Foundation is, therefore, well aware of organic agriculture. The project only focused on using natural products and utilizing its highland biological merits to increase resistance to diseases and insects for the produce grown. The project also brought in basic knowledge from a variety of available research information, including, but not limited to, improvement of soil fertility and a control of plant insects with biological methods in order to lay a foundation in developing and promoting farmers to grow quality produce with a high health safety. This will finally lead to sustainability for future highland agriculture and a decrease of chemical use on the highland area which is a source of natural watershed. However, there are still shortcomings of the postharvest management in term of quality and losses, such as bruising, rottenness, wilting and yellowish leaves. These losses negatively affect the maintenance and a shelf life of organic vegetables. Therefore, it is important that a research study of the appropriate and effective postharvest management is conducted for an individual organic vegetable to minimize product loss and find root causes of postharvest losses which would contribute to future postharvest management best practices. This can be achieved through surveys and data collection from postharvest processes in order to conduct analysis for causes of postharvest losses of organic pak-choi, baby pak-choi, and choy sum. Consequently, postharvest losses reduction strategies of organic vegetables can be achieved. In this study, postharvest losses of organic pak choi, baby pak-choi, and choy sum were determined at each stage of the supply chain starting from the field after harvesting, at the Development Center packinghouse, at Chiang Mai packinghouse, at Bangkok packing house and at the Royal Project retail shop in Chiang Mai. The results showed that postharvest losses of organic pak-choi, baby pak-choi, and choy sum were 86.05, 89.05 and 59.03 percent, respectively. The main factors contributing to losses of organic vegetables were due to mechanical damage and underutilized parts and/or short of minimum quality standard. Good practices had been developed after causes of losses were identified. Appropriate postharvest handling and management, for example, temperature control, hygienic cleaning, and reducing the duration of the supply chain, postharvest losses of all organic vegetables should be able to remarkably reduced postharvest losses in the supply chain.

Keywords: postharvest losses, organic vegetables, handling improvement, shelf life, supply chain

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409 Correlation between Resistance to Non-Specific Inhibitor and Mammalian Pathogenicity of an Egg Adapted H9N2 Virus

Authors: Chung-Young Lee, Se-Hee Ahn, Jun-Gu Choi, Youn-Jeong Lee, Hyuk-Joon Kwon, Jae-Hong Kim

Abstract:

A/chicken/Korea/01310/2001 (H9N2) (01310) was passaged through embryonated chicken eggs (ECEs) by 20 times (01310-E20), and it has been used for an inactivated oil emulsion vaccine in Korea. After sequential passages, 01310-E20 showed higher pathogenicity in ECEs and acquired multiple mutations including a potential N-glycosylation at position 133 (H3 numbering) in HA and 18aa-deletion in NA stalk. To evaluate the effect of these mutations on the mammalian pathogenicity and resistance to non-specific inhibitors, we generated four PR8-derived recombinant viruses with different combinations of HA and NA from 01310-E2 and 01310-E20 (rH2N2, rH2N20, rH20N2, and rH20N20). According to our results, recombinant viruses containing 01310 E20 HA showed higher growth property in MDCK cells and higher virulence on mice than those containing 01310 E2 HA regardless of NA. The hemagglutination activity of rH20N20 was less inhibited by egg white and mouse lung extract than that of other recombinant viruses. Thus, the increased pathogenicity of 01310-E20 may be related to both higher replication efficiency and resistance to non-specific inhibitors in mice.

Keywords: avian influenza virus, egg adaptation, H9N2, N-glycosylation, stalk deletion of neuraminidase

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408 Mannequin Evaluation of 3D-Printed Intermittent Oro-Esophageal Tube Guide for Dysphagia

Authors: Yujin Jeong, Youkyung Son, Myounghwan Choi, Sanghyub Lee, Sangyeol Lee, Changho Hwang, Kyo-in Koo

Abstract:

Dysphasia is difficulty in swallowing food because of oral cavity impairments induced by stroke, muscle damage, tumor. Intermittent oro-esophageal (IOE) tube feeding is one of the well-known feeding methods for the dysphasia patients. However, it is hard to insert at the proper position in esophagus. In this study, we design and fabricate the IOE tube guide using 3-dimensional (3D) printer. The printed IOE tube is tested in a mannequin (Airway Management Trainer, Co., Ltd., Copenhagen, Denmark) mimicking human’s esophagus. The gag reflex point is measured as the design point in the mannequin. To avoid the gag reflex, we design various shapes of IOE tube guide. One structure is separated into three parts; biting part, part through oral cavity, connecting part to oro-esophageal. We designed 6 types of IOE tube guide adjusting length and angle of these three parts. To evaluate the IOE tube guide, it is inserted in the mannequin, and through the inserted guide, an endoscopic camera successfully arrived at the oro-esophageal. We had planned to apply this mannequin-based design experience to patients in near future.

Keywords: dysphagia, feeding method, IOE tube guide, 3-D printer

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407 Comparison of Remifentanil EC50 for Facilitating I-Gel and Laryngeal Mask Airway Insertion with Propofol Anesthesia

Authors: Jong Yeop Kim, Jong Bum Choi, Hyun Jeong Kwak, Sook Young Lee

Abstract:

Background: Each supraglottic airway requires different anesthetic depth because it has a specific structure and different compressive force in the oropharyngeal cavity. We designed the study to investigate remifentanil effect-site concentration (Ce) in 50% of patients (EC50) for successful insertion of i- gel, and to compare it with that for laryngeal mask airway (LMA) insertion during propofol target-controlled infusion (TCI). Methods: Forty-one female patients were randomized to the i-gel group (n=20) or the LMA group (n=21). Anesthesia induction was performed using propofol Ce of 5 μg/ml and the predetermined remifentanil Ce, and i-gel or LMA insertion was attempted 5 min later. The remifentanil Ce was estimated by modified Dixon's up-and-down method (initial concentration: 3.0 ng/ml, step size: 0.5 ng/ml). The patient’s response to device insertion was classified as either ‘success (no movement)’ or ‘failure (movement)’. Results: Using the Dixon’s up and down method, EC50 of remifentanil Ce for i-gel (1.58 ± 0.41 ng/ml) was significantly lower than that for LMA (2.25 ± 0.55 ng/ml) (p=0.038). Using isotonic regression, EC50 (83% CI) of remifentanil in the i-gel group [1.50 (1.37-1.80) ng/ml] was statistically lower than that in the LMA group [2.00 (1.82-2.34) ng/ml]. EC95 (95% CI) of remifentanil in the i-gel group [2.38 (1.48-2.50) ng/ml] was statistically lower than that in the LMA group [3.35 (2.58-3.48) ng/ml]. Conclusion: We found that EC50 of remifentanil Ce for i-gel insertion (1.58 ng/ml) was significantly lower than that for LMA insertion (2.25 ng/ml), in female patients during propofol TCI without neuromuscular blockade.

Keywords: i-gel, laryngeal mask airway, propofol, remifentanil

Procedia PDF Downloads 291
406 Optimum Design of Combine Threshing Cylinder for Soybean Harvest

Authors: Choi Duckkyu, Choi Yong, Kang Taegyoung, Jun Hyeonjong, Choi Ilsu, Hyun Changsik

Abstract:

This study was carried out to develop a soybean combine thresher that enables to reduce the damage rate of soybean threshing and the rate of unthreshing. The combine threshing cylinder was developed with 6 circular axis at each end and fixed with disc plates. It was attached to the prototype combine thresher. A combine thresher that has a cylinder with circular rod type threshing pegs was used for a comparative test. A series of comparative tests were conducted using dae-won soybean. The test of the soybean thresher was performed at the cylinder speeds of 210, 240, 270 and 300 rpm, and with the concave clearance of 10, 13 and 16 mm. The separating positions of soybean after threshing were researched on a separate box with 4 sections. The soybean positions of front, center, rear and rear outside, of 59.5%, 30.6%, 7.8% and 2.2% respectively, were obtained. At the cylinder speeds from 210 rpm to 300 rpm, the damage rate of soybean was increased from 0.1% to 4.2% correspondingly to speeds. The unthreshed rate of soybean under the same condition was increased from 0.9% to 4.1% correspondingly to speeds. 0.7% of the damage rate and 1.5% of the unthreshed rate was achieved at the cylinder speed of 240 rpm and with the concave clearance of 10 mm. For Daewon soybean, an optimum cylinder speed of 240 rpm and the concave clearance of 10 mm were identified. These results will be useful for the design, construction, and operation of soybean threshing harvesters.

Keywords: soybean harvest, combine threshing, threshing cylinder, optimum design

Procedia PDF Downloads 388
405 The Effect of Yb3+ Concentration on Spectroscopic properties of Strontium Cerate Doped with Tm3+ and Yb3+

Authors: Yeon Woo Seo, Haeyoung Choi, Jung Hyun Jeong

Abstract:

Recently, the UC phosphors have attracted much attention owing to their wide applicability in areas such as biological fluorescence labeling, three-dimensional color displays, temperature sensor, solar cells, white light emitting diodes (WLEDs), fiber optic communication, anti-counterfeiting and other areas. The UC efficiency is mainly dependent on the host lattice and the interaction between the host lattice and doped ions. Up to date, various host matrices, such as oxides, fluorides, vanadates and phosphates, have been investigated as efficient UC luminescent hosts. Recently, oxide materials with low phonon energy have been investigated as the host matrices of UC materials due to their high chemical durability and physical stability. A series of Sr2CeO4: Tm3+/Yb3+ phosphors with different concentrations of Yb3+ ions have been successfully prepared using the high-energy ball milling method. In this study, we reported the UC luminescent properties of Tm3+/Yb3+ ions co-doped Sr2CeO4 phosphors under an excitation wavelength of 975 nm. Furthermore, the structural and morphological characteristics, as well as the UC luminescence mechanism were investigated in detail. The X-ray diffraction patterns confirmed their orthorhombic structure. Under 975 nm excitation, the emission peaks were observed at 478 nm (blue) and 652 nm (red), corresponding to the 1G4 → 3H6 and 1G4 → 3F4 transitions of Tm3+, respectively. The optimized doping concentration of Yb3+ ion was 10 mol%.

Keywords: Strontium Cerate, up-conversion, luminescence, Tm3+, Yb3+

Procedia PDF Downloads 170
404 Enhanced Energy Powers via Composites of Piezoelectric CH₃NH₃PbI₃ and Flexoelectric Zn-Al:Layered Double Hydroxides (LDH) Nanosheets

Authors: Soon-Gil Yoon, Min-Ju Choi, Sung-Ho Shin, Junghyo Nah, Jin-Seok Choi, Hyun-A Song, Goeun Choi, Jin-Ho Choy

Abstract:

Layered double hydroxides (LDHs) with positively charged brucite-like layers and negatively charged interlayer anions are considered a critical nanoscale building block with potential for application in catalysts, biological sensors, and optical, electrical, and magnetic devices. LDHs also have a great potential as an energy conversion device, a key component in common modern electronics. Although LDHs are theoretically predicted to be centrosymmetric, we report here the first observations of the flexoelectric nature of LDHs and demonstrate their potential as an effective energy conversion material. We clearly show a linear energy conversion relationship between the output powers and curvature radius via bending with both the LDH nanosheets and thin films, revealing a direct evidence for flexoelectric effects. These findings potentially open up avenues to incorporate a flexoelectric coupling phenomenon into centrosymmetric materials such as LDHs and to harvest high-power energy using LDH nanosheets. In the present study, for enhancement of the output power, Zn-Al:LDH nanosheets were composited with piezoelectric CH3NH3PbI3 (MAPbI3) dye films and their enhanced energy harvesting was demonstrated in detail.

Keywords: layered double hydroxides, flexoelectric, piezoelectric, energy harvesting

Procedia PDF Downloads 349
403 Metabolic Predictive Model for PMV Control Based on Deep Learning

Authors: Eunji Choi, Borang Park, Youngjae Choi, Jinwoo Moon

Abstract:

In this study, a predictive model for estimating the metabolism (MET) of human body was developed for the optimal control of indoor thermal environment. Human body images for indoor activities and human body joint coordinated values were collected as data sets, which are used in predictive model. A deep learning algorithm was used in an initial model, and its number of hidden layers and hidden neurons were optimized. Lastly, the model prediction performance was analyzed after the model being trained through collected data. In conclusion, the possibility of MET prediction was confirmed, and the direction of the future study was proposed as developing various data and the predictive model.

Keywords: deep learning, indoor quality, metabolism, predictive model

Procedia PDF Downloads 135
402 A Set of Microsatellite Markers for Population Genetics of Copper-Winged Bat (Myotis rufoniger) Using Saliva DNA

Authors: Junghwa An, Sungkyoung Choi, Eun Ye, San Hoon Han, Young-Gun Choi, Chul Oun Jung

Abstract:

The copper-winged bat (Myotis rufoniger) is the widely distributed medium body-sized bat in Asia, including Korea. This bat population has been decreasing because of habitat loss. This study reported the isolation and characterization of ten polymorphic microsatellite loci in endangered M. rufoniger. To do genetic studies, we use saliva DNA of bats during winter sleep period. The number of alleles per locus ranged from 2 to 9, and the observed and expected heterozygosities ranged from 0.063 to 0.750 and from 0.063 to 0.865, respectively. The average polymorphic information content (PIC) value of these markers was 0.37. Two loci of M. rufoniger showed departure from Hardy-Weinberg equilibrium(HWE). This demonstrated that the ten microsatellite loci can be used as genetic markers for further investigation of the copper-winged bat.

Keywords: copper-winged bat, microsatellite, population genetics, South Korea

Procedia PDF Downloads 249
401 A Study on Human Musculoskeletal Model for Cycle Fitting: Comparison with EMG

Authors: Yoon- Ho Shin, Jin-Seung Choi, Dong-Won Kang, Jeong-Woo Seo, Joo-Hack Lee, Ju-Young Kim, Dae-Hyeok Kim, Seung-Tae Yang, Gye-Rae Tack

Abstract:

It is difficult to study the effect of various variables on cycle fitting through actual experiment. To overcome such difficulty, the forward dynamics of a musculoskeletal model was applied to cycle fitting in this study. The measured EMG data were compared with the muscle activities of the musculoskeletal model through forward dynamics. EMG data were measured from five cyclists who do not have musculoskeletal diseases during three minutes pedaling with a constant load (150 W) and cadence (90 RPM). The muscles used for the analysis were the Vastus Lateralis (VL), Tibialis Anterior (TA), Bicep Femoris (BF), and Gastrocnemius Medial (GM). Person’s correlation coefficients of the muscle activity patterns, the peak timing of the maximum muscle activities, and the total muscle activities were calculated and compared. BIKE3D model of AnyBody (Anybodytech, Denmark) was used for the musculoskeletal model simulation. The comparisons of the actual experiments with the simulation results showed significant correlations in the muscle activity patterns (VL: 0.789, TA: 0.503, BF: 0.468, GM: 0.670). The peak timings of the maximum muscle activities were distributed at particular phases. The total muscle activities were compared with the normalized muscle activities, and the comparison showed about 10% difference in the VL (+10%), TA (+9.7%), and BF (+10%), excluding the GM (+29.4%). Thus, it can be concluded that muscle activities of model & experiment showed similar results. The results of this study indicated that it was possible to apply the simulation of further improved musculoskeletal model to cycle fitting.

Keywords: musculoskeletal modeling, EMG, cycle fitting, simulation

Procedia PDF Downloads 437
400 Efficient Iterative V-BLAST Detection Technique in Wireless Communication System

Authors: Hwan-Jun Choi, Sung-Bok Choi, Hyoung-Kyu Song

Abstract:

Recently, among the MIMO-OFDM detection techniques, a lot of papers suggested V-BLAST scheme which can achieve high data rate. Therefore, the signal detection of MIMOOFDM system is important issue. In this paper, efficient iterative VBLAST detection technique is proposed in wireless communication system. The proposed scheme adjusts the number of candidate symbol and iterative scheme based on channel state. According to the simulation result, the proposed scheme has better BER performance than conventional schemes and similar BER performance of the QRD-M with iterative scheme. Moreover complexity of proposed scheme has 50.6 % less than complexity of QRD-M detection with iterative scheme. Therefore the proposed detection scheme can be efficiently used in wireless communication.

Keywords: MIMO-OFDM, V-BLAST, QR-decomposition, QRDM, DFE, iterative scheme, channel condition

Procedia PDF Downloads 357
399 Structural Analysis of Multi-Pressure Integrated Vessel for Sport-Multi-Artificial Environment System

Authors: Joon-Ho Lee, Jeong-Hwan Yoon, Jung-Hwan Yoon, Sangmo Kang, Su-Yeon Hong, Hyun-Woo Jeong, Jaeick Chae

Abstract:

There are several dedicated individual chambers for sports that are supplied and used, but none of them are multi-pressured all-in-one chambers that can provide a sports multi-environment simultaneously. In this study, we design a multi-pressure (positive/atmospheric/negative pressure) integrated vessel that can be used for the sport-multi-artificial environment system. We presented additional vessel designs with enlarged space for the tall users; with reinforcement pads added to reduce the maximum stress in the joints of its shells, and then carried out numerical analysis for the structural analysis with maximum stress and structural safety. Under the targeted allowable pressure conditions, maximum stresses occurred at the joint of the shell, and the entrance, the safety of the structure was checked with the allowable stress of its material.

Keywords: structural analysis, multi-pressure, integrated vessel, sport-multi-artificial environment

Procedia PDF Downloads 353
398 Estimation of Elastic Modulus of Soil Surrounding Buried Pipeline Using Multi-Response Surface Methodology

Authors: Won Mog Choi, Seong Kyeong Hong, Seok Young Jeong

Abstract:

The stress on the buried pipeline under pavement is significantly affected by vehicle loads and elastic modulus of the soil surrounding the pipeline. The correct elastic modulus of soil has to be applied to the finite element model to investigate the effect of the vehicle loads on the buried pipeline using finite element analysis. The purpose of this study is to establish the approach to calculating the correct elastic modulus of soil using the optimization process. The optimal elastic modulus of soil, which minimizes the difference between the strain measured from vehicle driving test at the velocity of 35km/h and the strain calculated from finite element analyses, was calculated through the optimization process using multi-response surface methodology. Three elastic moduli of soil (road layer, original soil, dense sand) surrounding the pipeline were defined as the variables for the optimization. Further analyses with the optimal elastic modulus at the velocities of 4.27km/h, 15.47km/h, 24.18km/h were performed and compared to the test results to verify the applicability of multi-response surface methodology. The results indicated that the strain of the buried pipeline was mostly affected by the elastic modulus of original soil, followed by the dense sand and the load layer, as well as the results of further analyses with optimal elastic modulus of soil show good agreement with the test.

Keywords: pipeline, optimization, elastic modulus of soil, response surface methodology

Procedia PDF Downloads 302
397 Measurements of Flow Mixing Behaviors Using a Wire-Mesh Sensor in a Wire-Wrapped 37-Pin Rod Assembly

Authors: Hyungmo Kim, Hwang Bae, Seok-Kyu Chang, Dong Won Lee, Yung Joo Ko, Sun Rock Choi, Hae Seob Choi, Hyeon Seok Woo, Dong-Jin Euh, Hyeong-Yeon Lee

Abstract:

Flow mixing characteristics in the wire-wrapped 37-pin rod bundle were measured by using a wire-mesh sensing system for a sodium-cooled fast reactor (SFR). The subchannel flow mixing in SFR core subchannels was an essential characteristic for verification of a core thermal design and safety analysis. A dedicated test facility including the wire-mesh sensor system and tracing liquid injection system was developed, and the conductivity fields at the end of 37-pin rod bundle were visualized in several different flow conditions. These experimental results represented the reasonable agreements with the results of CFD, and the uncertainty of the mixing experiments has been conducted to evaluate the experimental results.

Keywords: core thermal design, flow mixing, a wire-mesh sensor, a wire-wrap effect

Procedia PDF Downloads 362