Search results for: Sang Wook Park

Authors: Myung Kwon Cho, Seul Ki Min, Gwang Heum Yoon, Jung Hyun Joo, Sang Jun Sim, Hwa Sung Shin

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Mechanotransduction is a mechanism that external mechanical stimulation is converted to biochemical activity in the cell. When applying this mechanism to the unicellular green algae Chlamydomonas reinhardtii, the dramatic result that the accumulation of intracellular lipid was up to 60% of dry weight basis occurred. Furthermore, various variations in cellular physiology occurred, but there is a lack of the development of the system and related research for applying that technology to control the mechanical stress and facilitate molecular analyses. In this study, applying a mechanical stress to microalgae, the microfluidic device system that finely induced direct membrane distortion of microalgae. Cellular membrane distortion led to deflagellation, calcium influx and lipid accumulation in microalgae. In conclusion, cytological studies such as mechanotransduction can be actualized by using this system and membrane distortion is a promising inducer for biodiesel production.

Keywords: mechanotransduction, microalgae, membrane distortion, biodiesel

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Authors: Hyu Sang Jo, Gyo Woo Lee

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In this study, the evaluation of thermal stability of the micrometer-sized silica particle reinforced epoxy composite was carried out through the measurement of thermal expansion coefficient and Young’s modulus of the specimens. For all the specimens in this study from the baseline to those containing 50 wt% silica filler, the thermal expansion coefficients and the Young’s moduli were gradually decreased down to 20% and increased up to 41%, respectively. The experimental results were compared with filler-volume-based simple empirical relations. The experimental results of thermal expansion coefficients correspond with those of Thomas’s model which is modified from the rule of mixture. However, the measured result for Young’s modulus tends to be increased slightly. The differences in increments of the moduli between experimental and numerical model data are quite large.

Keywords: thermal stability, silica-reinforced, epoxy composite, coefficient of thermal expansion, empirical model

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Authors: Sankaran Potti Narasimhan

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Costal Karnataka is sandwiched between Arabian Sea and the biodiversity hotspot of Western Ghats. This has provided a rich vegetation, canopy and humidity for the sustainable growth and evolution of many orchid populations. Similar to many other biodiversity hostpot regions of India and the world, this region also faces threat from anthropogenic activities and climate change. Hence, there is a need to study the current orchid diversity and trends in population as well as an effective conservation strategy. Costal belt of Karnataka state of India extends over 325 kilometers and an area of 18,000 km2. The region encompasses two national parks such as the Anshi National Park and the Kudremukh National Park. The study regions also include two Wild Life Sanctuaries such as the Someshwara Wildlife Sanctuary and Mookambika Wildlife Sanctuary. The estimated number of orchids in the region includes 30 genera and 45 species. Both terrestrial and epiphytic orchids are found in this region. The region contains many red listed orchids such as Trias stocksii (Critically endangered), Eriad alzellii (Lower risk vulnerable) and Dendrobnium ovatum (Vulnerable). The important terrestrial orchids of the region are Geodorum, Habenaria, Lipparis, Malaxis, Nervilia, Pachystoma, Pectelis, Peristylus, Tropidia and Zeuxine. The epiphytic forms includes Acampe, Aerides, Bulbophyllum, Cleisostoma, Conchidum, Cottonia, Cymbidium, Dendronium, Eria, Flickingeria, Gastrochilus, Kingidium, Luisia, Oberonia, Phalaenopsis, Pholidota, Porpax, Rhynchostylis, Sirhookera and Trias. The current paper discusses the population strength and changes in the population structure of these orchids along with proposed conservation strategies.

Keywords: orchid diversity, bulbophyllum, dendrobium, orchid conservation

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Authors: Hyun Young Kim, Chung Kwang Lee, Han Hee Cho, Sang Woon Cho, Yong Seo Koo

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In this paper, we proposed a novel SCR (Silicon Controlled Rectifier) - based ESD (Electrostatic Discharge) protection device for I/O and power clamp. The proposed device has a higher holding voltage characteristic than conventional SCR. These characteristics enable to have latch-up immunity under normal operating conditions as well as superior full chip ESD protection. The proposed device was analyzed to figure out electrical characteristics and tolerance robustness in term of individual design parameters (D1, D2, D3). They are investigated by using the Synopsys TCAD simulator. As a result of simulation, holding voltage increased with different design parameters. The holding voltage of the proposed device changes from 3.3V to 7.9V. Also, N-Stack structure ESD device with the high holding voltage is proposed. In the simulation results, 2-stack has holding voltage of 6.8V and 3-stack has holding voltage of 10.5V. The simulation results show that holding voltage of stacking structure can be larger than the operation voltage of high-voltage application.

Keywords: ESD, SCR, holding voltage, stack, power clamp

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Authors: Kwangman Park, Jinhee Kang, Suhee Kim, Dohyeon Yu, Kyoungseong Choi, Jinho Park

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Statement of the Problem: Diarrhea is a major cause of death in young calves. This causes great economic damage to the livestock industry. These diarrhea cause dehydration, decrease blood flow, lower the pH and degrade enzyme function. In the past, serum screening was not possible in the field. However, now with the spread of portable serum testing devices, it is now possible to conduct tests directly on field. Thus, accurate serological changes can be identified and used in the field of large animals. Methodology and Theoretical Orientation: The test groups were calves from 1 to 44 days old. The status of the feces was divided into four grade to determine the severity of diarrhea (grade 0,1,2,3). Grade 0, 1 is considered to have no diarrhea. Grade 2, 3 is considered to diarrhea positive group. One or more viruses were detected in this group. Diarrhea negasitive group consisted of 57 calves (Asan=30, Samrye=27). Diarrhea positive group consisted of 34 calves (Kimje=27, Geochang=7). The feces of all calves were analyzed by PCR Test. Blood sample was measured using an automatic blood analyzer(i-STAT, Abbott inc. Illinois, US). Calves were divided into 3 groups according to age. Group 1 is 1 to 14 days old. Group 2 is 15 to 28 days old. Group 3 is more than 28 days old. Findings: Diarrhea caused an increase in HCT due to dehydration. The difference from normal was highest in 15 to 28 days old (p < 0.01). At all ages, bicarbonate decreased compared to normal, and therefore pH decreased. Similar to HCT, the largest difference was observed between 15 and 28 days (p < 0.01). The pCO₂ decreases to compensate for the decrease in pH. Conclusion and Significance: At all ages, HCT increases, and bicarbonate, pH, and pCO₂ decrease in diarrhea calves. The calf from 15 days to 28 days shows the most difference from normal. Over 28 days of age, weight gain and homeostasis ability increase, diarrhea is seen in the stool, there are fewer hematologic changes than groups below 28 days of age.

Keywords: calves, diarrhea, hematological changes, i-STAT

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Authors: Hyuk Sang Yoo, Young Ju Son, Wei Mao, Myung Gu Kang, Sol Lee

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Biomedical applications of electrospun nanofibrous meshes have been received tremendous attentions because of their unique structures and versatilities as biomaterials. Incorporation of growth factors in fibrous meshes can be performed by surface-modification and encapsulation. Those growth factors stimulate differentiation and proliferation of specific types of cells and thus lead tissue regenerations of specific cell types. Topographical cues of electrospun nanofibrous meshes also increase differentiation of specific cell types according to alignments of fibrous structures. Wound healing treatments of diabetic ulcers were performed using nanofibrous meshes encapsulating multiple growth factors. Aligned nanofibrous meshes and those with random configuration were compared for differentiating mesenchymal stem cells into neuronal cells. Thus, nanofibrous meshes can be applied to drug delivery carriers and matrix for promoting cellular proliferation.

Keywords: nanofiber, tissue, mesh, drug

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Authors: Nirupama Sam

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COVID-19, the greatest pandemic since the turn of the century, presents several issues for urban planners, the most significant of which is determining appropriate mitigation techniques for creating pandemic-friendly and resilient public spaces. The study is conducted in four stages. The first stage consisted of literature reviews to examine the evolution and transformation of public spaces during pandemics throughout history and the role of public spaces during pandemic outbreaks. The second stage is to determine the factors that influence the success of public spaces, which was accomplished by an analysis of current literature and case studies. The influencing factors are categorized under comfort and images, uses and activity, access and linkages, and sociability. The third stage is to establish the priority of identified factors for which a questionnaire survey of stakeholders is conducted and analyzing of certain factors with the help of GIS tools. COVID-19 has been in effect in India for the last two years. Kerala has the highest daily COVID-19 prevalence due to its high population density, making it more susceptible to viral outbreaks. Despite all preventive measures taken against COVID-19, Kerala remains the worst-affected state in the country. Finally, two live case studies of the hardest-hit localities, namely Subhash bose park and Napier Museum park in the Ernakulam and Trivandrum districts of Kerala, respectively, were chosen as study areas for the survey. The responses to the questionnaire were analyzed using SPSS for determining the weights of the influencing factors. The spatial success of the selected case studies was examined using the GIS interpolation model. Following the overall assessment, the fourth stage is to develop strategies and guidelines for planning public spaces to make them more efficient and robust, which further leads to improved quality, safety and resilience to future pandemics.

Keywords: urban design, public space, covid-19, post-pandemic, public spaces

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Authors: Urooj Shafique, Salman Jamil

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In the context of an urban human life, city requires to meeting some standards which, at a glance are called the standards of a quality life. Measuring the quality of life according to particular social, economic and cultural conditions of a country and also the emphasis of a country twenty years visions on this issue has special importance. Cultural gathering spaces improve social and economic vitality on one side and on the other side provide favorable conditions for citizen leisure. But unfortunately these cultural gathering spaces in our society are losing their meaning and importance with time. Like coffee houses and libraries. Dedhee was the most prominent place among the cultural gathering spaces in Hazara division. People used to visit them in order to get something out of these spaces. At present they lie in our cities as places of no interest. Libraries are converted into storage houses where books lie untouched for years and years. The aim of my project is to create unique space that engage community members in the learning and creation process, where people can share their knowledge with others as well as enjoy their personal space. The spaces are flexible enough to accommodate people of different moods and interests, with the purpose of helping communities to become aware of their own cultures and to be socially engaged. The site for this specific project has been selected near Cantonment Park Abbottabad, Pakistan. The city of Abbottabad is famous for its writers, poets and storytellers. The site is selected next to the Cantonment Park, at a central location in the whole city so that it can attract users from almost every point of the city. The project provides a cultural gathering space for the people of the city where they can sit and discuss their ideas within a creative and expressive environment, which can represent the cultures of a community.

Keywords: cultural gathering space, Dedhee, Hazara literature, intellectuals’ hub

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Authors: Jung Ae Park, Jooyong Park

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Writing is an important learning activity that cultivates higher level thinking. Effective and immediate feedback is necessary to help improve students' writing skills. Peer assessment can be an effective method in writing tasks because it makes it possible for students not only to receive quick feedback on their writing but also to get a chance to examine different perspectives on the same topic. Peer assessment can be practiced frequently and has the advantage of immediate feedback. However, there is controversy about the accuracy of peer assessment. In this study, we tried to demonstrate experimentally how the accuracy of peer assessment could be improved. Participants (n=76) were randomly assigned to groups of 4 members. All the participant graded two sets of 4 essays on the same topic. They graded the first set twice, and the second set or the posttest once. After the first grading of the first set, each group in the experimental condition 1 (discussion group), were asked to discuss the results of the peer assessment and then to grade the essays again. Each group in the experimental condition 2 (reading group), were asked to read the assessment on each essay by an expert and then to grade the essays again. In the control group, the participants were asked to grade the 4 essays twice in different orders. Afterwards, all the participants graded the second set of 4 essays. The mean score from 4 participants was calculated for each essay. The accuracy of the peer assessment was measured by Pearson correlation with the scores of the expert. The results were analyzed by two-way repeated measure ANOVA. The main effect of grading was observed: Grading accuracy got better as the number of grading experience increased. Analysis of posttest accuracy revealed that the score variations within a group of 4 participants decreased in both discussion and reading conditions but not in the control condition. These results suggest that having students discuss their grading together can be an efficient means to improve peer assessment accuracy. By discussing, students can learn from others about what to consider in grading and whether their grading is too strict or lenient. Further research is needed to examine the exact cause of the grading accuracy.

Keywords: peer assessment, evaluation accuracy, discussion, score variations

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Authors: Wenlong Liu, Ru Zhang, Wangjie Li, Shenghui Sang

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The boom of smart cities in the age of population aging has caused concerns about the subjective well-being of the elderly. By employing the data from China Health and Retirement Longitudinal Study (CHARLS) 2015, this study uses an ordinary least square to analyze the influence of smart city development on the subjective well-being of the elderly in China. The results of this study suggest that smart cities will improve the life satisfaction of the elderly but reduce their happiness of them. In terms of the moderating effect, social capital negatively moderates the impact of the smart city on the subjective well-being of the elderly. Combined with the results of heterogeneous analysis, it is found that smart city has a stronger impact on the subjective well-being of the elderly with lower levels of personal social capital. To sum up, in the context of the country's vigorous promotion of smart city development, society and families should actively help the elderly to improve their social capital level, enhance the subjective well-being of the elderly, and alleviate the negative effects of smart city development, thereby improving the quality of life of the elderly.

Keywords: the elderly, smart city, social capital, subjective well-being

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Authors: Mohammed Panthakkal Abdul Muthalif, Shanmugasundaram Kanagaraj, Jumi Park, Hangyu Park, Youngson Choe

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The present study reports the incorporation of calcium ions into the CuS counter electrodes (CEs) in order to modify the photovoltaic performance of quantum dot-sensitized solar cells (QDSSCs). Metal ion-doped CuS thin film was prepared by the chemical bath deposition (CBD) method on FTO substrate and used directly as counter electrodes for TiO₂/CdS/CdSe/ZnS photoanodes based QDSSCs. For the Ca-doped CuS thin films, copper nitrate and thioacetamide were used as anionic and cationic precursors. Calcium nitrate tetrahydrate was used as doping material. The surface morphology of Ca-doped CuS CEs indicates that the fragments are uniformly distributed, and the structure is densely packed with high crystallinity. The changes observed in the diffraction patterns suggest that Ca dopant can introduce increased disorder into CuS material structure. EDX analysis was employed to determine the elemental identification, and the results confirmed the presence of Cu, S, and Ca on the FTO glass substrate. The photovoltaic current density – voltage characteristics of Ca-doped CuS CEs shows the specific improvements in open circuit voltage decay (Voc) and short-circuit current density (Jsc). Electrochemical impedance spectroscopy results display that Ca-doped CuS CEs have greater electrocatalytic activity and charge transport capacity than bare CuS. All the experimental results indicate that 20% Ca-doped CuS CE based QDSSCs exhibit high power conversion efficiency (η) of 4.92%, short circuit current density of 15.47 mA cm⁻², open circuit photovoltage of 0.611 V, and fill factor (FF) of 0.521 under illumination of one sun.

Keywords: Ca-doped CuS counter electrodes, surface morphology, chemical bath deposition method, electrocatalytic activity

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Authors: Pil Seong Park

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Homemade HPC clusters are widely used in many small labs, because they are easy to build and cost-effective. Even though incremental growth is an advantage of clusters, it results in heterogeneous systems anyhow. Instead of adding new nodes to the cluster, we can extend clusters to include some other Internet servers working independently on the same LAN, so that we can make use of their idle times, especially during the night. However extension across a firewall raises some security problems with NFS. In this paper, we propose a method to solve such a problem using SSH tunneling, and suggest a modified structure of the cluster that implements it.

Keywords: extension of HPC clusters, security, NFS, SSH tunneling

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Authors: Eun Young Park, Jongwon Park

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A physical touch of a product can provide ample diagnostic information about the product attributes and quality. However, consumers’ product judgments and purchases can be erroneously influenced by non-diagnostic haptic information. For example, consumers’ evaluations of the coffee they drink could be affected by the heaviness of a cup that is used for just serving the coffee. This important issue has received little attention in prior research. The present research contributes to the literature by identifying when and how non-diagnostic haptic information can have an influence and why such influence occurs. Specifically, five studies experimentally varied the content of non-diagnostic haptic information, such as the weight of a cup (heavy vs. light) and the texture of a cup holder (smooth vs. rough), and then assessed the impact of the manipulation on product judgments and decisions. Results show that non-diagnostic haptic information has a biasing impact on consumer judgments. For example, the heavy (vs. light) cup increases consumers’ perception of the richness of coffee in it, and the rough (vs. smooth) texture of a cup holder increases the perception of the healthfulness of fruit juice in it, which in turn increases consumers’ purchase intentions of the product. When consumers are cognitively distracted during the touch experience, the impact of the content of haptic information is no longer evident, but the valence (positive vs. negative) of the haptic experience influences product judgments. However, consumers are able to avoid the impact of non-diagnostic haptic information, if and only if they are both knowledgeable about the product category and undistracted from processing the touch experience. In sum, the nature of the influence by non-diagnostic haptic information (i.e., assimilation effect vs. contrast effect vs. null effect) is determined by the content and valence of haptic information, the relative impact of which depends on whether consumers can identify the content and source of the haptic information. Theoretically, to our best knowledge, this research is the first to document the empirical evidence of the interplay between cognitive and affective processes that determines the impact of non-diagnostic haptic information. Managerial implications are discussed.

Keywords: consumer behavior, haptic information, product judgments, touch effect

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Authors: Sang Heon Han, Daejun Chang, Won Yang

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NOx reduction characteristics of syngas fuel were numerically investigated for the 2MW pilot scale heavy oil furnace of KITECH (Korea Institute of Industrial Technology). The secondary fuel and syngas was fed into the furnace with two purposes- partial replacement of main fuel and reburning of NOx. Some portion of syngas was fed into the flame zone to partially replace the heavy oil, while the other portion was fed into the furnace downstream to reduce NOx generation. The numerical prediction was verified by comparing it with the experimental results. Syngas of KITECH’s experiment, assumed to be produced from biomass, had very low calorific value and contained 3% hydrocarbon. This study investigated the precise behavior of NOx generation and NOx reduction as well as thermo-fluidic characteristics inside the furnace, which was unavailable with experiment. In addition to 3% hydrocarbon syngas, 5%, and 7% hydrocarbon syngas were numerically tested as reburning fuels to analyze the effect of hydrocarbon proportion to NOx reduction. The prediction showed that the 3% hydrocarbon syngas is as much effective as 7% hydrocarbon syngas in reducing NOx.

Keywords: syngas, reburning, heavy oil, furnace

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Authors: Sang-Ryong Lee, Min-Woon Jung, Deugwoo Han, Kiyong Kim

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This study laid an emphasis on the possible employment of biochar generated from pyrolysis of animal excreta to establish a green platform for producing biodiesel. To this end, the pseudo-catalytic transesterification reaction using chicken manure biochar and waste cooking oil was investigated. Compared with a commercial porous material (SiO2), chicken manure biochar generated from 350 C showed better performance, resulting in 95.6% of the FAME yield at 350C. The Ca species in chicken manure biochar imparted strong catalytic capability by providing the basicity for transesterification. The identified catalytic effect also led to the thermal cracking of unsaturated FAMEs, which decreased the overall FAME yield. For example, 40–60% of converted FAMEs were thermally degraded. To avoid undesirable thermal cracking arising from the high content of the Ca species in chicken manure biochar, the fabrication of chicken manure biochar at temperatures ≥350C was highly recommended.

Keywords: Trasesterification, Animal excreta, FAME, Biochar, Chicken manure

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Authors: Ugochukwu Ejike Akpudo, Jank-Wook Hur

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The increasing demand for improved productivity, maintainability, and reliability has prompted rapidly increasing research studies on the emerging condition-based maintenance concept- Prognostics and health management (PHM). Varieties of fuel pumps serve critical functions in several hydraulic systems; hence, their failure can have daunting effects on productivity, safety, etc. The need for condition monitoring and assessment of these pumps cannot be overemphasized, and this has led to the uproar in research studies on standard feature extraction techniques for optimized condition assessment of fuel pumps. By extracting time-based, frequency-based and the more robust time-frequency based features from these vibrational signals, a more comprehensive feature assessment (and selection) can be achieved for a more accurate and reliable condition assessment of these pumps. With the aid of emerging deep classification and regression algorithms like the locally linear embedding (LLE), we propose a method for comprehensive condition assessment of electromagnetic fuel pumps (EMFPs). Results show that the LLE as a comprehensive feature extraction technique yields better feature fusion/dimensionality reduction results for condition assessment of EMFPs against the use of single features. Also, unlike other feature fusion techniques, its capabilities as a fault classification technique were explored, and the results show an acceptable accuracy level using standard performance metrics for evaluation.

Keywords: electromagnetic fuel pumps, comprehensive feature extraction, condition assessment, locally linear embedding, feature fusion

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

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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

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Authors: Murtada Ahmed Oshi, Jin-Wook Yoo

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Layer-by-layer (LBL) coating has gained popularity for drug delivery of therapeutic drugs. Herein we described a novel approach for enhancing the therapeutic efficiency of the locally administered dexamethasone (Dex) for inflammatory bowel disease (IBD). We utilized a LBL-coating technique on Dex microcrystals (DexMCs) with multiple layers of polyelectrolytes composed of poly (allylamine hydrochloride) (PAH), poly (sodium 4-styrene sulfonate) (PSS) and Eudragit® S100 (ES). The successful deposition of the layers onto DexMCs surfaces were confirmed through zeta potential measurement and confocal laser scanning microscopy. The surface morphology was investigated through scanning electron microscopy. The drug encapsulation efficiency was 95% with a mean particle size of 2 µm and negative surface charge (-40 mV). Moreover, in vitro drug release study showed a minimum release of the drug ( 15%) at an acidic condition during initial first 5 h, followed by sustained-release at an alkaline condition. For in vivo study, LBL-DxMCs were administered orally to ICR mice suffering from dextran sulfate sodium-induced colitis. LBL-DxMCs substantially enhanced anti-IBD activities as compared to DxMCs. Macroscopic, histological and biochemical (tumor necrosis factor-α, interleukin-6 and myeloperoxidase) examinations revealed marked improvements of colitis signs in the mice treated with LBL-DxMCs compared with those treated with DxMCs. Overall, LBL-DxMCs could be a suitable candidate for the treatment of IBD.

Keywords: dexamethasone, inflammatory bowel disease, LBL-coating, polyelectrolytes

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Authors: Youn-Sung Kim, Hye-Mi Kim, Sang-Hoon Seo, Jaden Cha

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This International standard IEC 61508 sets out a generic approach for all safety lifecycle activities for systems comprised of electrical/electronic/programmable electronic (E/E/PE) elements that are used to perform safety functions. The control unit in stage control system is safety related facilities to control state and speed for stage system running, and it performs safety-critical function by stage control system. The controller unit is part of safety loops corresponding to the IEC 61508 and classified as logic part in the safety loop. In this paper, we analyze using FMEDA (Failure Mode Effect and Diagnostic Analysis) to verification for fault tolerance methods and functional safety of control unit. Moreover, we determined SIL (Safety Integrity Level) for control unit according to the safety requirements defined in IEC 61508-2 based on an analyzed functional safety.

Keywords: safety function, failure mode effect, IEC 61508-2, diagnostic analysis, stage control system

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Authors: H. Y. Jung, Jing Wang, J. H. Park, Hao Shen

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This brief addresses the passivity problem for neural networks with time-varying delays. The aim is focus on establishing the passivity condition of the considered neural networks.

Keywords: neural networks, passivity analysis, time-varying delays, linear matrix inequality

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Authors: Mohammad Ehsani, Iman Zarei, Soudabeh Moazemigoudarzi

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The aim of this study is to determine Pro-Environmental Behavioral Intention of Mountain Hikers to the Theory of Planned Behavior. According to many researchers nature-based recreation activities play a significant role in the tourism industry and have provided myriad opportunities for the protection of natural areas. It is essential to investigate individuals' behavior during such activities to avoid further damage to precious and dwindling natural resources. This study develops a robust model that provides a comprehensive understanding of the formation of pro-environmental behavioral intentions among climbers of Mount Damavand National Park in Iran. To this end, we combined the theory of planned behavior (TPB), value-belief-norm theory (VBN), and a hierarchical model of leisure constraints to predict individuals’ pro-environmental hiking behavior during outdoor recreation. It was used structural equation modeling to test the theoretical framework. A sample of 787 climbers was analyzed. Among the theory of planned behavior variables, perceived behavioral control showed the strongest association with behavioral intention (β = .57). This relationship indicates that if people feel they can have fewer negative impacts on national resources while hiking, it will result in more environmentally acceptable behavior. Subjective norms had a moderate positive impact on behavioral intention, indicating the importance of other people on the individual's behavior. Attitude had a small positive effect on intention. Ecological worldview positively influenced attitude and personal belief. Personal belief (awareness of consequences and ascribed responsibility) showed a positive association with TPB variables. Although the data showed a high average score in awareness of consequences (mean = 4.219 out of 5), evidence from Damavand Mount shows that there are many environmental issues that need addressing (e.g., vast amounts of garbage). National park managers need to make sure that their solutions result in awareness about proenvironmental behavior (PEB). Findings showed that negative relationship between constraints and all TPB predictors. Providing proper restrooms and parking spaces in campgrounds, strategies controlling limiting capacity and solutions for removing waste from high altitudes are helpful to decrease the negative impact of structural constraints. In order to address intrapersonal constraints, managers should provide opportunities to interest individuals in environmental activities, such as environmental celebrations or making documentaries about environmental issues. Moreover, promoting a culture of environmental protection in the Damavand Mount area would reduce interpersonal constraints. Overall, the proposed model improved the explanatory power of the TPB by predicting 64.7% of intention compared to the original TPB that accounted for 63.8% of the variance in intention.

Keywords: theory of planned behavior, pro-environmental behavior, national park, constraints

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Authors: Sang Kompiang Wirawan, Chandra Purnomo

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Carbon dioxide (CO2) adsorption on the activated Klaten-Indonesian natural zeolite (AKINZ) in a packed bed adsorber has been studied. Experiment works consisted of acid activation and adsorption experiments. The natural zeolite sample was activated using 0.3 M HCl at the temperature of 353 K. In the adsorption experiments the feed gas concentrations were 40 and 80 % CO2 in helium within various temperatures of 303; 323 and 373 K. The experiments were conducted by using transient step change adsorption and 20 % Ar/He tracer experiment was conducted to measure dispersion and time lag effect of the packed bed system. A mathematical model of CO2 adsorption had been set up by assuming plug flow;isothermal;isobaric and no gas film mass transport resistance. Single site Langmuir physisorption and Maxwell Stefan mass transport in micropore were applied. All the data were then optimized to get the best value of modified fitted parameter. The model was in a good agreement with the experiment data. Diffusivity tended to increase by increasing temperatures.

Keywords: adsorption, Langmuir, Maxwell-Stefan, natural zeolite, surface diffusion

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Authors: Jin-Uk Park

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Recently, the semiconductor industry is rapidly demanding complicated structures and mass production. From the point of view of mass production, the ETCH industry is concentrating on maintaining the ER (Etch rate) of the wafer edge constant regardless of changes over time. In this study, two major thermal factors affecting process were identified and controlled. First, the filler of the thermal pad was studied. Second, the significant difference of handling the thermal pad during PM was studied.

Keywords: etcher, thermal pad, wet cleaning, thermal conductivity

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Authors: Nirman Kumar Ojha

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Bamboo plantation can be integrated for natural embankment against flood and live fencing against wild animals, at the same time provide economic opportunity for the poor farmers as a sustainable solution and adaptation alternative. 2010 flood in the Rui River completely inundated fields of four VDCs in Madi, Chitwan National Park with extensive bank erosion. The main aim of this action research was to identify an economically sustainable natural embankment against flood and also providing wildlife friendly fencing to reduce human-wildlife conflict. Community people especially poor farmers were trained for soil testing, land identification, plantation, and the harvesting regime, nursery set up and intercropping along with bamboo plantation on the edge of the river bank in order to reduce or minimize soil erosion. Results show that farmers are able to establish cost efficient and economically sustainable river embankment with bamboo plantation also creating a fence for wildlife which has also promoted bamboo cultivation and conservation. This action research has amalgamated flood control and wildlife control with the livelihood of the farmers which otherwise would cost huge resource. Another major impact of the bamboo plantation is its role in climate change and its adaptation process reducing degradation and improving vegetation cover contributing to landscape management. Based on this study, we conclude that bamboo plantation in Madi, Chitwan promoted the livelihood of the poor farmers providing a sustainable economic solution to reduce bank erosion, human-wildlife conflict and contributes to landscape management.

Keywords: climate change and conservation, economic opportunity, flood control, national park

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Authors: Hyu Sang Jo, Gyo Woo Lee

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In this study, the mechanical and thermal properties of epoxy composites that are reinforced with micrometer-sized silica particles were investigated by using the specimen experiments. For all specimens used in this study (from the baseline to specimen containing 70 wt% silica filler), the tensile strengths were gradually increased by 8-10%, but the ductility of the specimen was decreased by 34%, compared with those of the baseline samples. Similarly, for the samples containing 70 wt% silica filler, the coefficient of thermal expansion was reduced by 25%, but the thermal conductivity was increased by 100%, compared with those of the baseline samples. The improvement of thermal stability of the silica-reinforced specimen was confirmed to be within the experimented range, and the smaller silica particle was found to be more effective in delaying the thermal expansion of the specimens. When the smaller particle was used as filler, due to the increased specific interface area between filler and matrix, the thermal conductivities of the composite specimens were measured to be slightly lower than those of the specimens reinforced with the larger particle.

Keywords: carbon nanotube filler, epoxy composite, mechanical property, thermal property

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Authors: Jae-Il Jeong, Hoon-Jae Park, Jung-Woo Cho, Yang-Gon Kim, Jin-Young Park, Joo-Young Oh, Si-Geun Choi, Seock-Sam Kim, Young Tae Cho, Chan Gyu Kim, Jong-Hyoung Kim

Abstract:

Bearing component has strongly required to decrease vibration and wear to achieve high durability and life time. In the industry field, bearing durability is improved by surface treatment on the bearing surface by centrifugal casting or gravity casting production method. However, this manufacturing method has caused problems such as long processing time, defect rate, and health harmful effect. To solve this problem, there is a laser cladding deposition treatment, which provides fast processing and food adhesion. Therefore, optimum conditions of white metal laser deposition should be studied to minimize bearing contact axis wear using laser cladding techniques. In this study, we deposit a soft white metal layer on SCM440, which is mainly used for shaft and bolt. On laser deposition process, the laser power and powder feed rate and laser head speed factors are controlled to find out the optimal conditions. We also measure hardness using micro Vickers, analyze FE-SEM (Field Emission Scanning Electron Microscope) and EDS (Energy Dispersive Spectroscopy) to study the mechanical properties and surface characteristics with various parameters change. Furthermore, this paper suggests the optimum condition of laser cladding deposition to apply in industrial fields. This work was supported by the Industrial Innovation Project of the Korea Evaluation Institute of Industrial Technology (KEIT) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (Research no. 10051653).

Keywords: laser deposition, bearing, white metal, mechanical properties

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Authors: Hyon I. Paek, Sang Rim Kim, Hyon A. Ryu

Abstract:

In functional linear regression, one typical problem is to reduce dimension. Compared with multivariate linear regression, functional linear regression is regarded as an infinite-dimensional case, and the main task is to reduce dimensions of functional response and functional predictors. One common approach is to adapt functional principal component analysis (FPCA) on functional predictors and then use a few leading functional principal components (FPC) to predict the functional model. The leading FPCs estimated by the typical FPCA explain a major variation of the functional predictor, but these leading FPCs may not be mostly correlated with the functional response, so they may not be significant in the prediction for response. In this paper, we propose a supervised functional principal component analysis method for a functional response model with FPCs obtained by considering the correlation of the functional response. Our method would have a better prediction accuracy than the typical FPCA method.

Keywords: supervised, functional principal component analysis, functional response, functional linear regression

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Authors: Sang-Myung Jung, Gwang Heum Yoon, Hoo Chul Lee, Hwa Sung Shin

Abstract:

Ceramide, a component of stratum corneum at epidermis, helps to construct a rigid and dense skin barrier to prevent pathogens that cause atopic dermatitis. However, ceramide was too hydrophobic to be directly absorbed into stratum corneum and has risks of side effects by excessive treatment. To overcome the obstacles, ceramide was embedded into PLGA nanoparticles coated with chitosan. PLGA and chitosan have been known as biocompatible materials. PLGA was squeezed when faced with water and pumped ceramide out of PLGA nanoparticle. In addition, the chitosan coating layer helped initial adherence of nanoparticles to skin and regulate ceramide release until removed. This coating was degraded at weakly acid state like skin surface, finally ceramide release could be controlled. Finally, the nanoparticle was demonstrated to be non-cytotoxic and regenerate stratum corneum of atopic dermatitis model. Overall the nanoparticle is suggested as a novel and effective nanodrug to apply atopic dermatitis.

Keywords: nanoparticle, controlled release, atopic dermatitis, chitosan coating, ceramide

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Authors: Jaydip De

Abstract:

Urban parks are open places, green fields and riverside gardens usually maintained by public or private authorities, or eventually by both jointly; and utilized for a multidimensional purpose by the citizens. These parks are indeed the lung of urban centers. In urban socio-environmental setup, parks are the nucleus of social integration, community building, and physical development. In contemporary cities, these green places seem to perform as the panacea of congested, complex and stressful urban life. The alarmingly increasing urban population and the resultant congestion of high-rises are making life wearisome in neo-liberal cities. This has made the citizen always quest for open space and fresh air. In such a circumstance, the mere existence of parks is not capable of satisfying the growing aspirations. Therefore in this endeavour, a structured attempt is so made to empirically identify the utility, visitors’ satisfaction, and future needs through the cases of two urban parks of Kolkata Metropolitan Area, India. This study is principally based upon primary information collected through visitors’ perception survey conducted at the Chinsurah ground and Chandernagore strand. The correlation between different utility categories is identified and analyzed systematically. At the same time, indices like Weighted Satisfaction Score (WSS), Facility wise Satisfaction Index (FSI), Urban Park Satisfaction Index (UPSI) and Urban Park Necessity Index (UPNI) are advocated to quantify the visitors’ satisfaction and future necessities. It is explored that the most important utilities are passive in nature. Simultaneously, satisfaction levels of visitors are average, and their requirements are centred on the daily needs of the next generation, i.e., the children. Further, considering the visitors’ opinion planning measures are promulgated for holistic development of urban parks to revitalize sustainability of citified life.

Keywords: citified life, future needs, visitors’ satisfaction, urban parks, utility

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Authors: Seung Hun Lee, Sang Yeoup Lee

Abstract:

Objectives: To investigate associations between degrees of obesity using correlations between obesity indices and cardiometabolic risk factors. Methods: BMI, waist circumference (WC), fasting insulin, fasting glucose, lipids, and visceral adipose tissue (VAT) area using computed tomographic images were measured in 113 obese female without cardiovascular disease (CVD). Correlations between obesity indices and cardiometabolic risk factors were analyzed in obese subgroups defined using sequential obesity indices. Results: Mean BMI and WC were 29.6 kg/m2 and 92.8 cm. BMI showed significant correlations with all five cardiometabolic risk factors until the BMI cut-off point reached 27 kg/m2, but when it exceeded 30 kg/m2, correlations no longer existed. WC was significantly correlated with all five cardiometabolic risk factors up to a value of 85 cm, but when WC exceeded 90 cm, correlations no longer existed. Conclusions: Our data suggest that moderate weight-loss goals may not be enough to ameliorate cardiometabolic markers in severely obese patients. Therefore, individualized weight-loss goals should be recommended to such patients to improve health benefits.

Keywords: correlation, cardiovascular disease, risk factors, obesity

Procedia PDF Downloads 357