2,882 results on '"S S Kim"'
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2. DEVELOPMENT OF MULTI-SENSOR MODULE MOUNTED MOBILE ROBOT FOR DISASTER FIELD INVESTIGATION
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Y. H. Jung, D. H. Cho, J. W. Hong, S. H. Han, S. B. Cho, D. Y. Shin, E. T. Lim, and S. S. Kim
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
Disasters are not easy to predict because they occur suddenly, and the scale of disasters is increasing compared to the past. Since a new type of disaster field always appears, when a disaster occurs, responders who are put into the site recognize the same risk as secondary damage and are put into the field. In this regard, the robot performs missions such as search and rescue in the initial response process at the disaster field. It is a technology with high potential to reduce damage to people and property. Most of the robots are equipped with site accessibility and monitoring through cameras and remote control, but considering the specificity of the disaster field, it is not easy to fully monitor the site with a camera sensor as the possibility of poor visibility is very high. LiDAR uses a laser to recognize the distance to a nearby object in a relatively wide range and acquires three-dimensional information, so its accuracy and precision are higher than other sensors.In this study, one multi-sensor module was manufactured by combining LiDAR and IMU sensor with a computing board for real-time monitoring so that it could be used in the field of robots. In addition, we studied how to stably mount this multi-sensor module to a robot so that it can maintain optimal accuracy at disaster field, and it is intended to be utilized as a prior research for field operation of robots equipped with sensors in the future.
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- 2022
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3. LIDAR-BASED MULTI-SENSOR MODULE DEVELOPMENT AND ASSESSMENT OF APPLICABILITY FOR DAMAGE INVESTIGATION OF INDOOR DISASTER
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D. Y. Shin, D. H. Cho, J. W. Hong, S. H. Han, S. B. Cho, E. T. Lim, Y. H. Jung, and S. S. Kim
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
As the risk of disaster scenes increases, the number of cases of acquiring disaster scenes information using unmanned robots is increasing. Because unmanned robots can be remotely controlled, sensors such as LiDAR and optical cameras are installed so that investigators can safely observe disaster scenes and acquire information. In particular, the information that can be acquired is different depending on the sensor characteristics, and a sensor module suitable for the purpose is being developed. Accordingly, the National Disaster Management research Institute(NDMI) also developed a investigation robot capable of acquiring information on disaster sites independently. Based on 3D point cloud data, we developed a multi-sensor module and SLAM algorithm customized to the investigation robot to collect quantitative information on the damage situation. To test the performance of the independently developed multi-sensor module, SLAM mapping was performed in a disaster building reproduced like a disaster scene, and various SLAM algorithms and distance comparison were performed. As a result, PackSLAM developed in this study showed the lowest error. In the future, to increase applicability at disaster sites, more precise experiments will be conducted by conducted by establishing a rough terrain environment.
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- 2022
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4. SMALL UAVS-BASED DISASTER DAMAGE INVESTIGATION: FOCUSED ON FLOODING DISASTER AND CHEMICAL ACCIDENT
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E. T. Lim, Y. H. Jung, D. Y. Shin, and S. S. Kim
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
Disasters that occur in recent years are linked to various factors and occur in a chain, and the scale is also increasing. In order to solve the more complex and serious disaster problem, it is necessary to expand the affect scope of the disaster and to acquire and manage information by integrating and operating various sensors. With the introduction of UAVs for disaster work, various studies such as investigation of the affected area, rescue of survivors, and establishment of emergency communication networks are being conducted. This is useful for strengthening the field of disaster management because it is very effective in terms of time and human resources. In addition, it is possible to acquire high-resolution images, and by using the 3D point cloud data and ortho-mosaic imagery generation, it is possible to produce a disaster scene close to the real world. Therefore, if UAV information can be linked to disaster types and characteristics prior to supporting disaster damage investigation, it is possible to establish a response method according to the disaster damage situation and help decision-making. In order to examine the applicability of UAV technology for actual disaster sites, this study conducted data collection and analysis of damaged areas targeting sites damaged by heavy rain and chemical accidents. In the heavy rain damage site, flooding damage occurred in the ginseng cultivation patches due to river overflow caused by the torrential rain, and the damaged area and lots were investigated. The site of the chemical accident was damaged by hydrochloric acid gas leaking into the atmosphere, and the surrounding forest, crops, and residential facilities were identified and the affected area was calculated. As a result of investigating the damage from heavy rain and chemical accidents using UAV, it was possible to quickly collect data on a wide disaster site. In addition, it was easy to calculate the damaged area based on ortho-imagery, and the limitations of spatial analysis were reduced, so that it could be used more specifically and efficiently to the disaster site.
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- 2022
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5. DISASTER DAMAGE INVESTIGATION USING ARTIFICIAL INTELLIGENCE AND DRONE MAPPING
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S. S. Kim, D. Y. Shin, E. T. Lim, Y. H. Jung, and S. B. Cho
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
This study aims to testify the applicability of UAV photogrammetry and artificial intelligence (AI) for the management of natural disaster. Recently artificial intelligence is considered as an emerging tool for recognizing disaster events from aerial imagery of drones. In this paper, we present firstly the approach related to use of AI techniques for disaster detecting and identification. Secondly, we suggest small easy-to-use UAV-based investigation procedure for natural disaster damaged area in the phase of disaster recovery in Korea. Finally, we evaluate the mapping accuracy and work efficiency of drone mapping for disaster investigation application through comparing with traditional investigation work process which was dependent on labor-intensive field survey. The resolution ortho-image map of within less 5cm of GSD generated by aerial photos acquired from UAVs at the altitude of 100m–250m enabled us to check damage information such as facilities destroy or the trace of soil erosion around the river flooded and reservoir collapsed area. The photogrammetry-based drone mapping technology for the disaster damage investigation is expected to be an alternative approach to support or replace the labor-intensive disaster site survey that needs to investigate the disaster site quickly and timely.
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- 2022
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6. PO.4.86 Cluster analysis of initial laboratory findings identifies three clinical clusters in patients with systemic lupus erythematosus
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S-H Lee, C-H Suh, J-Y Jung, and S-S Kim
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Immunologic diseases. Allergy ,RC581-607 - Published
- 2022
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7. Paradoxical effects of cigarette smoke and COPD on SARS-CoV-2 infection and disease
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M. Tomchaney, M. Contoli, J. Mayo, S. Baraldo, S. Li, C. R. Cabel, D. A. Bull, S. Lick, J. Malo, S. Knoper, S. S. Kim, J. Tram, J. Rojas-Quintero, M. Kraft, J. G. Ledford, Y. Tesfaigzi, F. D. Martinez, C. A. Thorne, F. Kheradmand, S. K. Campos, A. Papi, and F. Polverino
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Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background How cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection and severity is controversial. We investigated the effects of COPD and CS on the expression of SARS-CoV-2 entry receptor ACE2 in vivo in COPD patients and controls and in CS-exposed mice, and the effects of CS on SARS-CoV-2 infection in human bronchial epithelial cells in vitro. Methods We quantified: (1) pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and/or TMPRSS2 mRNA levels by RT-qPCR in two independent human cohorts; and (2) pulmonary ACE2 protein levels by immunostaining and ELISA in C57BL/6 WT mice exposed to air or CS for up to 6 months. The effects of CS exposure on SARS-CoV-2 infection were evaluated after in vitro infection of Calu-3 cells and differentiated human bronchial epithelial cells (HBECs), respectively. Results ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus controls but similar in central airways. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice. CS treatment decreased viral replication in Calu-3 cells, as determined by immunofluorescence staining for replicative double-stranded RNA (dsRNA) and western blot for viral N protein. Acute CS exposure decreased in vitro SARS-CoV-2 replication in HBECs, as determined by plaque assay and RT-qPCR. Conclusions ACE2 levels were decreased in both bronchial and alveolar epithelial cells from COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-exposure potently inhibited SARS-CoV-2 replication in vitro. These findings urge to investigate further the controversial effects of CS and COPD on SARS-CoV-2 infection.
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- 2021
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8. Diagnostics of Streptococcal Infection by Emergency Department Doctors: First Experience of Application of the «Streptatest»
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N. F. Plavunov, V. A. Kadyshev, S. S. Kim, and N. A. Goncharova
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ambulance and emergency medical care ,group a β-hemolytic streptococcus ,«streptatest» ,Internal medicine ,RC31-1245 - Abstract
The effectiveness of the treatment of acute tonsillitis directly depends on the etiological diagnosis and adherence to the principles of rational etiotropic antibiotic therapy. Currently, streptococcal genesis of inflammation is considered as the only indication for the appointment of systemic antibiotic therapy. The article presents the results of clinical and statistical analysis of calls to patients with acute tonsillitis and express diagnostics of streptococcal infection using «Streptatest». For the period from 30.07.2018 until 30.11.2018 Doctors of the emergency department teams for adults and children performed express diagnostics of group A β-hemolytic streptococcus in 252 patients with acute tonsillitis complaining of «sore throat», whose age ranged from 3 to 44 years. This rapid diagnostic system «Streptatest», based on the method of immunochromatographic analysis, made it possible to identify as early as possible in 117 (46.4%) patients β-hemolytic streptococcus group A and promptly prescribe etiotropic antibiotic therapy to them. The second group consisted of 135 (53.6%) patients with a negative result of the «Streptatest» rapid test. In the group with a positive result of the express test, the main part was made up of children of preschool and school age — 92 (78.6%) patients. In 114 (97.5%) patients with diagnosed group A β-hemolytic streptococcus, clinical symptoms according to the McIsaас modified Centor scale were rated from 3 to 5 points. Early etiological verification of acute tonsillitis made it possible to follow the strategy of preventing the sp read of antimicrobial resistance and reducing the resistance of microorganisms to antibacterial drugs.
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- 2020
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9. RISK ASSESSMENT OF STEEP SLOPE USING DRONE MAPPING AND TERRESTRIAL LIDAR IN KOREA
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S. S. Kim, D. Y. Kim, and H. Nho
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
Due to abnormal weather caused by climate change in recently years, natural disaster damages caused by local torrential rains have been increased over the world. Particularly, Korea is very vulnerable to landslide disasters because more than 63% of the country is mountainous and it suffers from unpredictable localized heavy rainfall during monsoon season every year. This paper presents experimental results for risk assessment of steep slope using drone mapping and terrestrial LiDAR survey. First, we acquired the aerial imagery of steep slope site by small UAV and conducted a drone mapping process with the Pix4D software. For collecting the more detailed geological data and analysing quantitatively damage of steep slopes (crack length, bedrock weathering area, etc.), we scanned steep slope area using terrestrial LiDAR system. Finally, we evaluated the applicability of public safety for outputs of UAV photogrammetry and 3D point clouds derived from terrestrial LiDAR data to analyse and assess the risk of steep slope.
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- 2020
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10. UAV IMAGE FAST GEOCODING METHOD FOR DISASTER SCENE MONITORING
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H. Nho, D. Y. Shin, and S. S. Kim
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
Recently, UAVs are being used in various fields such as photography, precision agriculture, remote monitoring, surveying, mapping, and disaster management. In particular, UAVs can acquire real-time data and access hard-to-reach areas, which is advantageous for rapid spatial information generation. Spatial information can be generated by mounting a camera on the UAV and performing the geocoding process of image data using the location/location information acquired from the GPS/INS sensor. The use of multiple GCPs during the geocoding process can increase the image position accuracy. However, since a lot of time is consumed for surveying, it is disadvantageous to be used in disaster fields that require urgent data generation. Therefore, in this study, fast geocoding process of UAV image using the minimum GCP is proposed. The results obtained through this process can be used as basic data for on-site monitoring and decision-making in disasters and emergencies.
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- 2020
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11. Technical note: A simple method for retrieval of dust aerosol optical depth with polarized reflectance over oceans
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W. Sun, Y. Hu, R. R. Baize, G. Videen, S. S. Kim, Y.-J. Choi, K. Kang, C. K. Sim, M. Jeong, A. Omar, S. A. Stamnes, D. G. MacDonnell, and E. Zubko
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Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Our previous study shows that the angle of linear polarization (AOLP) of solar radiation that is scattered from clouds at near-backscatter angles can be used to detect super-thin cirrus clouds over oceans. Such clouds are too thin to be sensed using any current passive satellite instruments that only measure light's total intensity, because of the uncertainty in surface reflection. In this report, we show that with a method similar to the super-thin cloud detection algorithm, dust aerosols may also be detected and differentiated from clouds. We also show that the degree of polarization of reflected light can be used for retrieving the optical depth of dust aerosols in the neighborhood of the backscatter angle, regardless of the reflecting surface conditions. This is a simple and robust algorithm, which could be used to survey dust aerosols over midlatitude and tropical oceans.
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- 2019
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12. APPLICABILITY ASSESSMENT OF UAV MAPPING FOR DISASTER DAMAGE INVESTIGATION IN KOREA
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S. S. Kim, T. H. Kim, and J. S. Sim
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Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Applied optics. Photonics ,TA1501-1820 - Abstract
As natural disaster occurs, the local and the central government should investigate the damaged fields promptly, analyze quantitatively the degree of damage, and establish an appropriate disaster recovery plan in accordance with Framework Act on the Management of Disasters and Safety in Korea. The purpose of this study is to assess the applicability of UAV photogrammetry for the management of natural disaster. First, we suggest small easy-to-use UAV-based investigation procedure for natural disaster damaged area in the phase of disaster recovery in Korea. Before drone-based aerial surveying, the field survey can be performed with DGPS RTK for GCPs setting-up around disaster site. In this paper, we generate three dimensional terrain information and high-resolution ortho-imagery and then analyse quantitatively damage degree by natural disaster using commercial UAVs and drone mapping technique. Finally, we evaluate the mapping accuracy and work efficiency of drone mapping for disaster investigation application through comparing with traditional investigation work process which was dependent on labour-intensive field survey. The resolution ortho-image map of within less 5cm of GSD generated by aerial photographs acquired from UAVs at the altitude of 100m~250m enabled us to check damage information such as facilities destroy or the trace of soil erosion around the river flooded and reservoir collapsed area. In addition, three dimensional point cloud data of landslide-damaged areas enabled us to more accurately measure the width and the depth of outflows caused by landslides, soil runoff distance, and landslide damage area. The photogrammetry-based drone mapping technology for the disaster damage investigation is expected to be an alternative approach to support or replace the labour-intensive disaster site survey that needs to investigate the disaster site quickly and timely.
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- 2019
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13. Thermal and Structural Stabilities of LixCoO2 cathode for Li Secondary Battery Studied by a Temperature Programmed Reduction
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D.-H. Jung, N. Umirov, T. Kim, Z. Bakenov, J.-S. Kim, and S.-S. Kim
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thermal stability ,temperature programmed reduction ,lithium cobalt oxide ,secondary battery ,Chemistry ,QD1-999 - Abstract
Temperature programmed reduction (TPR) method was introduced to analyze the structural change and thermal stability of LixCoO2 (LCO) cathode material. The reduction peaks of delithiated LCO clearly represented the different phases of LCO. The reduction peak at a temperature below 250 °C can be attributed to the transformation of CoO2–like to Co3O4–like phase which is similar reduction patterns of CoO2 phase resulting from delithiation of LCO structure. The 2nd reduction peak at 300~375 °C corresponds to the reduction of Co3O4–like phase to CoO–like phase. TPR results indicate the thermal instability of delithiated LCO driven by CoO2–like phase on the surface of the delithiated LCO. In the TPR kinetics, the activation energies (Ea) obtained for as-synthesized LCO were 105.6 and 82.7 kJ mol-1 for Tm_H1 and Tm_H2, respectively, whereas Ea for the delithiated LCO were 93.2, 124.1 and 216.3 kJ mol-1 for Tm_L1, Tm_L2 and Tm_L3, respectively. As a result, the TPR method enables to identify the structural changes and thermal stability of each phase and effectively characterize the distinctive thermal behavior between as-synthesized and delithiated LCO.
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- 2019
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14. Reviews and syntheses: Ocean iron fertilization experiments – past, present, and future looking to a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES) project
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J.-E. Yoon, K.-C. Yoo, A. M. Macdonald, H.-I. Yoon, K.-T. Park, E. J. Yang, H.-C. Kim, J. I. Lee, M. K. Lee, J. Jung, J. Park, J. Lee, S. Kim, S.-S. Kim, K. Kim, and I.-N. Kim
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
Since the start of the industrial revolution, human activities have caused a rapid increase in atmospheric carbon dioxide (CO2) concentrations, which have, in turn, had an impact on climate leading to global warming and ocean acidification. Various approaches have been proposed to reduce atmospheric CO2. The Martin (or iron) hypothesis suggests that ocean iron fertilization (OIF) could be an effective method for stimulating oceanic carbon sequestration through the biological pump in iron-limited, high-nutrient, low-chlorophyll (HNLC) regions. To test the Martin hypothesis, 13 artificial OIF (aOIF) experiments have been performed since 1990 in HNLC regions. These aOIF field experiments have demonstrated that primary production (PP) can be significantly enhanced by the artificial addition of iron. However, except in the Southern Ocean (SO) European Iron Fertilization Experiment (EIFEX), no significant change in the effectiveness of aOIF (i.e., the amount of iron-induced carbon export flux below the winter mixed layer depth, MLD) has been detected. These results, including possible side effects, have been debated amongst those who support and oppose aOIF experimentation, and many questions concerning the effectiveness of scientific aOIF, environmental side effects, and international aOIF law frameworks remain. In the context of increasing global and political concerns associated with climate change, it is valuable to examine the validity and usefulness of the aOIF experiments. Furthermore, it is logical to carry out such experiments because they allow one to study how plankton-based ecosystems work by providing insight into mechanisms operating in real time and under in situ conditions. To maximize the effectiveness of aOIF experiments under international aOIF regulations in the future, we therefore suggest a design that incorporates several components. (1) Experiments conducted in the center of an eddy structure when grazing pressure is low and silicate levels are high (e.g., in the SO south of the polar front during early summer). (2) Shipboard observations extending over a minimum of ∼ 40 days, with multiple iron injections (at least two or three iron infusions of ∼ 2000 kg with an interval of ∼ 10–15 days to fertilize a patch of 300 km2 and obtain a ∼ 2 nM concentration). (3) Tracing of the iron-fertilized patch using both physical (e.g., a drifting buoy) and biogeochemical (e.g., sulfur hexafluoride, photosynthetic quantum efficiency, and partial pressure of CO2) tracers. (4) Employment of neutrally buoyant sediment traps (NBST) and application of the water-column-derived thorium-234 (234Th) method at two depths (i.e., just below the in situ MLD and at the winter MLD), with autonomous profilers equipped with an underwater video profiler (UVP) and a transmissometer. (5) Monitoring of side effects on marine/ocean ecosystems, including production of climate-relevant gases (e.g., nitrous oxide, N2O; dimethyl sulfide, DMS; and halogenated volatile organic compounds, HVOCs), decline in oxygen inventory, and development of toxic algae blooms, with optical-sensor-equipped autonomous moored profilers and/or autonomous benthic vehicles. Lastly, we introduce the scientific aOIF experimental design guidelines for a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES).
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- 2018
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15. Electrochemical Study of Graphene Coated Nickel Foam as an Anode for Lithium-Ion Battery
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A. Mukanova, A. Zharbossyn, A. Nurpeissova, S.-S. Kim, M. Myronov, and Z. Bakenov
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graphene ,nickel oxide ,nickel foam ,3D current collector ,CVD ,lithium-ion batteries ,Chemistry ,QD1-999 - Abstract
This study reports the synthesis of a few-layered graphene (GF) thin film on Ni foam by chemical vapor deposition (CVD) technique and investigation of its electrochemical performance as a negative electrode for lithium-ion batteries (LIBs). A standard deposition procedure with a methane precursor was employed to prepare the GF films. The SEM studies revealed the formation of a dark uniform film on the surface of Ni foam’s wires upon the CVD deposition. The film consisted of numerous GF sheets replicating the shape of the Ni grain boundaries over the Ni wire surface. The Raman spectroscopy of the prepared films on the Ni foam confirmed that the samples are a few-layered GF with high quality and purity. In order to evaluate the potential of the use of the prepared materials as an anode in LIBs, their electrochemical performance was studied in coin-type lithium half-cells using cyclic voltammetry (CV) and galvanostatic cycling. The results of CV showed that both graphene and native oxide layer (NiO) on nickel foam exhibit electrochemical activity with respect to lithium ions. Galvanostatic cycling revealed that both GF and NiO contribute to the overall capacity, which increases upon cycling with a stable Coulombic efficiency of around 99%. The designed 3D GF coated NiO/Ni anode demonstrated a gradual increase of its areal charge capacity from 65 μAh cm-2 at the initial cycle to 250 μAh cm-2 at the final 250th cycle.
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- 2018
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16. Optimal anticoagulation intensity with warfarin for the prevention of thromboembolism with minimal bleeding in Asian patients with atrial fibrillation: multi-center, randomized controlled trial
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K H Lee, S S Y Shin, K J S Koh, Y M Park, J M Lee, S S Kim, J H Kim, and D M Kim
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Physiology (medical) ,Cardiology and Cardiovascular Medicine - Abstract
Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Korean Society of Cardiology Background Anticoagulation with warfarin in Korean patients with atrial fibrillation (AF) often has been decreased as an international normalized ratio (INR) of prothrombin time between 1.6 to 2.6 for the fear of bleeding, although universal criteria recommends to adjust it between 2.0 to 3.0. Methods In this randomized, open-label trial, we compared low intensity anticoagulation (INR 1.6 to 2.6) with standard intensity anticoagulation (INR 2.0 to 3.0) with warfarin in 616 patients with AF and at least 1 risk factor for stroke. The per-protocol, intension-to-treatment analysis was designed to determine whether low-intensity anticoagulation (n=308) was non-inferior to standard-intensity anticoagulation (n=308) with warfarin for the primary end point of net clinical outcomes defined as the sum of stroke, systemic embolism, major bleeding and death. Results The median follow-up duration was 1.8 years. Baseline characteristics of the two groups were comparable. Median value of INR was significantly higher in standard-intensity group than low-intensity group (2.19 vs. 2.07, p=0.002), whereas that of time in the therapeutic range was comparable between the 2 groups. The rate of primary outcome was 1.55% per year in low-intensity anticoagulation, as compared with 2.46% per year in standard-intensity anticoagulation (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.22 to 1.74, p for non-inferiority Conclusion In Korean patients with AF, low-intensity anticoagulation with warfarin as INR 1.6 to 2.6 was non-inferior to standard-intensity anticoagulation with warfarin as INR 2.0 to 3.0 for the prevention of net-clinical outcome, and stroke or systemic embolism. There was no significant difference for the risk reduction of major bleeding.
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- 2023
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17. Kinetic effects on geodesic acoustic modes and Stringer spin-up driven by a poloidally asymmetric particle source
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Young-Hoon Lee, Hogun Jhang, S. S. Kim, and Jungpyo Lee
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Condensed Matter Physics - Abstract
The impact of the poloidally inhomogeneous particle source on the onset of Stringer spin-up (SSU) and geodesic acoustic mode (GAM) is investigated. Using a gyrofluid model with Hammet–Perkins closure, it was found that Landau damping stabilizes both waves and subsequently makes a threshold. To capture the full effects of Landau damping, a gyrokinetic model is adopted and results are compared with those from the gyrofluid model. Both models predicted the same value of the threshold for SSU, while for the case of GAM, the gyrofluid model overestimates the threshold value. Considering maximal throughput of the ITER pellet fueling system, the source intensity is calculated at a similar or slightly lower level compared to the source threshold for SSU.
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- 2023
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18. Demosaicking using inter-channel correlation in wavelet domain.
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H. S. Kim, Bo Gyu Jeong, S. S. Kim, and Il Kyu Eom
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- 2007
19. IMPACTS OF ECONOMIC UNCERTAINTY AND INTERDEPENDENCY OF INVESTMENTS AND FINANCIAL DECISIONS.
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S. S., Kim, V., Nugroho, and V., Budhidharma
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ECONOMIC uncertainty ,ECONOMIC impact ,ETHICAL investments ,FINANCIAL policy ,INVESTMENT policy ,DYNAMICAL systems - Abstract
Copyright of Polish Journal of Management Studies is the property of Czestochowa University of Technology, Faculty of Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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20. Genetic Algorithm for Satellite Customer Assignment.
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S. S. Kim, H. J. Kim, V. Mani, and C. H. Kim
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- 2006
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21. Ant Colony Optimization for Satellite Customer Assignment.
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S. S. Kim, H. J. Kim, V. Mani, and C. H. Kim
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- 2006
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22. Automatic Conversion of MPEG-7 Specification and Data into RDF(S) For Semantic Interoperability in Information Retrieval.
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J. M. Yoo, S. H. Myaeng, S. S. Kim, and M. H. Lee
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- 2005
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23. Paradoxical effects of cigarette smoke and COPD on SARS-CoV-2 infection and disease
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A Papi, Joshua Malo, L Shuaizhi, Scott D. Lick, Carly R. Cabel, Francesca Polverino, Curtis A. Thorne, Fernando D. Martinez, Julie G. Ledford, Marco Contoli, Joselyn Rojas-Quintero, Simonetta Baraldo, Monica Kraft, J Mayo, David A. Bull, Samuel K. Campos, Farrah Kheradmand, J Tram, M Tomchaney, S Knoper, Yohannes Tesfaigzi, and S S Kim
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Male ,Messenger ,Virus Replication ,Aged ,Aged, 80 and over ,Angiotensin-Converting Enzyme 2 ,Animals ,Bronchi ,COVID-19 ,Cell Line, Tumor ,Cigarette Smoking ,Female ,Humans ,Mice ,Middle Aged ,Patient Acuity ,Pulmonary Alveoli ,Pulmonary Disease, Chronic Obstructive ,RNA, Messenger ,Respiratory Mucosa ,SARS-CoV-2 ,Serine Endopeptidases ,Tobacco ,Smoke ,80 and over ,Receptor ,Virus quantification ,immunostaining ,COPD ,Tumor ,medicine.diagnostic_test ,Cigarette smoke ,respiratory system ,Monoclonal ,ELISA ,ACE2 receptor ,hormones, hormone substitutes, and hormone antagonists ,Pulmonary and Respiratory Medicine ,Chronic Obstructive ,human bronchial epithelial cells (HBECs) ,Calu-3 cells ,TMPRSS2 ,Article ,NO ,Cell Line ,Pulmonary Disease ,Diseases of the respiratory system ,Western blot ,In vivo ,medicine ,Cigarette smoke, COPD, SARS-CoV-2, ACE2 receptor, immunostaining, ELISA, RT-qPCR, Western Blot, Calu-3 cells, human bronchial epithelial cells (HBECs), Transmembrane Serine Protease 2 (TMPRSS2) ,RC705-779 ,business.industry ,Research ,RT-qPCR ,Western Blot ,Viral nucleocapsid ,medicine.disease ,In vitro ,Staining ,respiratory tract diseases ,Transmembrane Serine Protease 2 (TMPRSS2) ,Viral replication ,Cell culture ,Immunology ,RNA ,business ,Immunostaining - Abstract
IntroductionHow cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severity is controversial. We investigated the protein and mRNA expression of SARS-CoV-2 entry receptor ACE2 and proteinase TMPRSS2 in lungs from COPD patients and controls, and lung tissue from mice exposed acutely and chronically to CS. Also, we investigated the effects of CS exposure on SARS-CoV-2 infection in human bronchial epithelial cells.MethodsIn Cohort 1, ACE2-positive cells were quantified by immunostaining in FFPE sections from both central and peripheral airways. In Cohort 2, we quantified pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and TMPRSS2 mRNA levels by RT-qPCR. In C57BL/6 WT mice exposed to air or CS for up to 6 months, pulmonary ACE2 protein levels were quantified by triple immunofluorescence staining and ELISA. The effects of CS exposure on SARS-CoV-2 infection were evaluated after 72hr in vitro infection of Calu-3 cells. After SARS-CoV-2 infection, the cells were fixed for IF staining with dsRNA-specific J2 monoclonal Ab, and cell lysates were harvested for WB of viral nucleocapsid (N) protein. Supernatants (SN) and cytoplasmic lysates were obtained to measure ACE2 levels by ELISA.ResultsIn both human cohorts, ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus both smoker and NS controls, but similar in central airways. TMPRSS2 levels were similar across groups. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice exposed to 3 and 6 months of CS. In Calu3 cells in vitro, CS-treatment abrogated infection to levels below the limit of detection. Similar results were seen with WB for viral N protein, showing peak viral protein synthesis at 72hr.ConclusionsACE2 levels were decreased in both bronchial and alveolar epithelial cells from uninfected COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-treatment did not affect ACE2 levels but potently inhibited SARS-CoV-2 replication in this in vitro model. These findings urge to further investigate the controversial effects of CS and COPD on SARS-CoV2 infection.
- Published
- 2021
24. Mobile Agent-Based Load Monitoring System for the Safety Web Server Environment.
- Author
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H. J. Park, K. J. Jyung, and S. S. Kim
- Published
- 2004
- Full Text
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25. A dispatching algorithm for parallel machines with rework processes.
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Yong Ha Kang, S. S. Kim, and Hyun Joon Shin
- Published
- 2010
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26. Sink-Independent Model in Wireless Sensor Networks.
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S. S. Kim, K. R. Jung, A. S. Park, and K. I. Kim
- Published
- 2008
27. Development of a Lyman-α Imaging Solar Telescope for the Satellite
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M. Jang, H.-S. Oh, C.-S. Rim, J.-S. Park, J.-S. Kim, D. Son, H.-S. Lee, S.-J. Kim, D.-H. Lee, S. S. Kim, and K.-H. Kim
- Subjects
space-based ultraviolet telescope ,solar space mission ,solar instrument ,Astronomy ,QB1-991 - Abstract
Long term observations of full-disk Lyman-α irradiance have been made by the instruments on various satellites. In addition, several sounding rockets dating back to the 1950s and up through the present have measured the Lyman-α irradiance. Previous full disk Lyman-α images of the sun have been very interesting and useful scientifically, but have been only five-minute ``snapshots" obtained on sounding rocket flights. All of these observations to date have been snapshots, with no time resolution to observe changes in the chromospheric structure as a result of the evolving magnetic field, and its effect on the Lyman-α intensity. The Lyman-α Imaging Solar Telescope(LIST) can provide a unique opportunity for the study of the sun in the Lyman-α region with the high time and spatial resolution for the first time. Up to the 2nd year development, the preliminary design of the optics, mechanical structure and electronics system has been completed. Also the mechanical structure analysis, thermal analysis were performed and the material for the structure was chosen as a result of these analyses. And the test plan and the verification matrix were decided. The operation systems, technical and scientific operation, were studied and finally decided. Those are the technical operation, mechanical working modes for the observation and safety, the scientific operation and the process of the acquired data. The basic techniques acquired through the development of satellite based solar telescope are essential for the construction of space environment forecast system in the future. The techniques which we developed through this study, like mechanical, optical and data processing techniques, could be applied extensively not only to the process of the future production of flight models of this kind, but also to the related industries. Also, we can utilize the scientific achievements which are obtained throughout the project. And these can be utilized to build a high resolution photometric detectors for military and commercial purposes. It is also believed that we will be able to apply several acquired techniques for the development of the Korean satellite projects in the future.
- Published
- 2005
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28. APPLICABILITY ASSESSMENT OF UAV MAPPING FOR DISASTER DAMAGE INVESTIGATION IN KOREA
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T. H. Kim, J. S. Sim, and S. S. Kim
- Subjects
lcsh:Applied optics. Photonics ,060102 archaeology ,business.industry ,lcsh:T ,Environmental resource management ,0211 other engineering and technologies ,Disaster recovery ,lcsh:TA1501-1820 ,Landslide ,Terrain ,Disaster recovery plan ,06 humanities and the arts ,02 engineering and technology ,lcsh:Technology ,Drone ,Wireless site survey ,Photogrammetry ,lcsh:TA1-2040 ,Environmental science ,0601 history and archaeology ,business ,Natural disaster ,lcsh:Engineering (General). Civil engineering (General) ,021101 geological & geomatics engineering - Abstract
As natural disaster occurs, the local and the central government should investigate the damaged fields promptly, analyze quantitatively the degree of damage, and establish an appropriate disaster recovery plan in accordance with Framework Act on the Management of Disasters and Safety in Korea. The purpose of this study is to assess the applicability of UAV photogrammetry for the management of natural disaster. First, we suggest small easy-to-use UAV-based investigation procedure for natural disaster damaged area in the phase of disaster recovery in Korea. Before drone-based aerial surveying, the field survey can be performed with DGPS RTK for GCPs setting-up around disaster site. In this paper, we generate three dimensional terrain information and high-resolution ortho-imagery and then analyse quantitatively damage degree by natural disaster using commercial UAVs and drone mapping technique. Finally, we evaluate the mapping accuracy and work efficiency of drone mapping for disaster investigation application through comparing with traditional investigation work process which was dependent on labour-intensive field survey. The resolution ortho-image map of within less 5cm of GSD generated by aerial photographs acquired from UAVs at the altitude of 100m~250m enabled us to check damage information such as facilities destroy or the trace of soil erosion around the river flooded and reservoir collapsed area. In addition, three dimensional point cloud data of landslide-damaged areas enabled us to more accurately measure the width and the depth of outflows caused by landslides, soil runoff distance, and landslide damage area. The photogrammetry-based drone mapping technology for the disaster damage investigation is expected to be an alternative approach to support or replace the labour-intensive disaster site survey that needs to investigate the disaster site quickly and timely.
- Published
- 2019
29. Effects of organic acids on paraquat activity in maize
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Se Ji Jang, Yong In Kuk, S. S. Kim, Young Beom Yun, and H.Y. Bak
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fungi ,food and beverages ,Plant Science ,chemistry.chemical_compound ,Horticulture ,chemistry ,Paraquat ,Chlorophyll ,Tartaric acid ,Cultivar ,Malic acid ,Citric acid ,Weed ,Squash - Abstract
In our previous study (Yoon et al., 2011, Pesticide Biochem. Physiol. 99: 65–76), we found that the level of foliar injury from paraquat (PA) in squash was generally less prevalent in younger leaves than in older ones. In addition, another previous study (Hyun et al., 2012, Korean J. Weed Sci. 32: 211–221) showed that the substance responsible for PA detoxification in young squash leaves was likely malic acid. Therefore, this study was conducted to investigate the effects of various organic acids on PA activity in maize. The levels of citric acid and malic acid in the fourth leaves were consistently higher than those in the first leaves in control and PA-treated leaves in both cultivars. In contrast, the level of tartaric acid in the first leaf was consistently higher than that of the fourth leaf in control and PA-treated leaves in both cultivars. Leaf injuries did not appear in maize treated with PA + malic acid at 0.3, 0.5, or 1%, PA + oxalic acid at 0.1, 0.3, 0.5, or 1%, PA + citric acid at 0.1, 0.3, 0.5, or 1%, or PA + tartaric acid at 1%. However, leaf injuries were observed in 69–82% of maize plants treated with 100 μM PA alone. The relative water contents in maize leaves were not reduced by PA + organic acid treatments compared with 100 μM PA treatment alone. Moreover, the superoxide and H2O2 contents in maize were significantly reduced by PA + most organic acids at various concentrations compared with 100 μM PA treatment alone. Moreover, MDA production in maize was significantly reduced by PA + organic acid treatments (except for PA + succinic acid) when compared with 100 μM PA treatment alone. Generally, chlorophyll contents in maize were not affected by treatment by PA alone or PA + organic acid. Taken together, these results suggest that squash plants contain organic acids such as malic acid and citric acid, which could nullify PA activity.
- Published
- 2019
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30. Gyro-averaging operators with magnetic field inhomogeneity
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Hogun Jhang and S. S. Kim
- Subjects
Condensed Matter Physics - Abstract
We derive expressions for the gyro-averaging operator that is applicable to electrostatic fluctuations in a spatially inhomogeneous magnetic field. Both low and high wavenumber limits are considered. The gyro-averaging operator for the former case is represented by sums of Bessel functions with different orders. A simplified expression is provided as a Padé approximant in the low wavenumber limit. This form could be used in practical computations based on the gyrofluid formulation. In the high wavenumber limit, we find that the operator naturally involves fractional derivatives whose physical interpretations are yet to be explored. Discussions are made of a potential impact of this asymptotic expression in the high wavenumber limit.
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- 2022
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31. Development of usability evaluation indicator for a rehabilitation exercise enhancement device using cognitive-physical combined intervention among the elderly
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A. Lee, S.-H. Park, S.-S. Kim, J.-H. Kim, and Y.-H. Bae
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Biomedical Engineering ,Geriatrics and Gerontology ,Gerontology - Published
- 2022
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32. A conceptual exploration of cognition-motor dual task training for effective application in community-dwelling older adults
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A. Lee, S. H. Park, S. S. Kim, J. H. Kim, Y. R. Koo, H. Kwon, S. H. Ho, and Y.-H. Bae
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Biomedical Engineering ,Geriatrics and Gerontology ,Gerontology - Published
- 2022
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33. A conceptual exploration of service delivery system for activation of rehabilitation and sports technology with the elderly
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A. Lee, S.-H. Park, S.-S. Kim, J.-H. Kim, Y.-R. Koo, H. Kwon, S. H. Ho, and Y.-H. Bae
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Biomedical Engineering ,Geriatrics and Gerontology ,Gerontology - Published
- 2022
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34. Subblock sum matching algorithm for block-based interframe coding.
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S. S. Kim, J. S. Kim, and H. W. Park
- Published
- 1999
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35. Development and efficacy of a nested real-time quantitative polymerase chain reaction to identify the cytochrome c oxidase subunit 1 gene of Sarcoptes scabiei var. hominis for diagnosis and monitoring of ordinary scabies
- Author
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J K, Kim, E J, Chun, S Y, Yang, K S, Kim, S S, Kim, and C W, Kim
- Subjects
Electron Transport Complex IV ,Scabies ,Animals ,Humans ,Real-Time Polymerase Chain Reaction ,Sarcoptes scabiei - Published
- 2020
36. Emphysema Is Associated with Upregulated and Off-Targeted B Cell Responses
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Francesca Polverino, Scott D. Lick, J Tram, F. Hanak, J. Sullivan, Joshua Malo, H. Quiroz, J Mayo, David A. Bull, S S Kim, and S Knoper
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medicine.anatomical_structure ,Downregulation and upregulation ,Cancer research ,medicine ,Biology ,B cell - Published
- 2020
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37. Evaluation of weed control potential of meadowfoam (Limnanthes alba Benth.) plant
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Y. I. Kuk, S. J. Jang, S. S. Kim, Y. B. Yun, and R. N. Byeon
- Subjects
Plant composition ,Extraction (chemistry) ,Plant Science ,Biology ,Weed control ,Limnanthes alba ,food.food ,Horticulture ,food ,Germination ,Fermentation ,Agronomy and Crop Science ,Chemical composition ,Allelopathy - Published
- 2018
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38. Effect of plant extracts and emulsifiers on control of anthracnose (Colletotrichum coccodes) in persimmon trees
- Author
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Yong In Kuk, S. S. Kim, and Se Ji Jang
- Subjects
0106 biological sciences ,biology ,fungi ,Diospyros kaki ,04 agricultural and veterinary sciences ,Fungus ,Field tests ,Horticulture ,Colletotrichum coccodes ,biology.organism_classification ,01 natural sciences ,040103 agronomy & agriculture ,Organic farming ,0401 agriculture, forestry, and fisheries ,Fermentation ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
This study was conducted to determine suppression of the anthracnose fungus (Colletotrichum coccodes), causing disease in persimmon trees (Diospyros kaki Thunb), by (1) extracts from various parts ...
- Published
- 2018
- Full Text
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39. Inhibitory effects of Italian ryegrass (Lolium multiflorum Lam.) seedlings of rice (Oryza sativa L.)
- Author
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Y. B. Yun, Y. I. Kuk, S. J. Jang, K. R. Kim, and S. S. Kim
- Subjects
Oryza sativa ,biology ,010405 organic chemistry ,Plant Science ,Lolium multiflorum ,010501 environmental sciences ,biology.organism_classification ,Coumaric acid ,01 natural sciences ,p-Coumaric acid ,0104 chemical sciences ,Ferulic acid ,chemistry.chemical_compound ,chemistry ,Botany ,Shoot ,Caffeic acid ,Agronomy and Crop Science ,Allelopathy ,0105 earth and related environmental sciences - Published
- 2018
- Full Text
- View/download PDF
40. EXAFS Spectroscopy of Fractional Mixed-Valence Charge Density Wave Systems
- Author
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Sirine C. Fakra, Nathan Turner, S. L. Dexheimer, S. S. Kim, James A. Brozik, and Matthew A. Marcus
- Subjects
Technology ,Valence (chemistry) ,Materials science ,Exafs spectroscopy ,Extended X-ray absorption fine structure ,Molecular physics ,Physical Chemistry ,Spectral line ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,General Energy ,Engineering ,Chemical Sciences ,Physics::Atomic and Molecular Clusters ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Charge density wave - Abstract
We present extended X-ray absorption fine structure (EXAFS) spectra and modeling of a series of structurally tunable quasi-one-dimensional mixed-valence platinum-halide linear chain materials, [Pt(en2)][Pt(en2)X2](ClO4)4 with X = Cl, Br, I. The materials exhibit a commensurate charge density wave with fractional charge states on alternating platinum ions in the chain, as well as a Peierls distortion with alternating platinum-halide bond lengths. The amplitude of the charge density wave and, correspondingly, the extent of the Peierls distortion are controlled by the identity of the bridging halide ion. We have carried out ab initio multiple scattering calculations using the FEFF9 code to relate the oriented Pt LIII EXAFS spectra to the tunable electronic and structural properties. The spectral modeling reveals distinct photoelectron threshold energy values for the two inequivalent platinum ions in each of the mixed-valence chains, with values that vary systematically with fractional valence state. The difference in the photoelectron threshold energies of the two inequivalent platinum ions within each material correlates directly with the amplitude of the charge density wave, reflecting the decrease in charge density wave strength through the halide series X = Cl, Br, and I. We use dynamical matrix modeling to relate the experimentally determined mean-square relative displacement parameters for the metal-halide bond distances to the chain-axis vibrational modes that modulate the charge density wave structure. In addition, we discuss the EXAFS fitting results for the Pt-I bond lengths in the [Pt(en2)][Pt(en2)I2](ClO4)4 complex in comparison to previous, mutually inconsistent structural determinations for this material.
- Published
- 2019
41. Transport simulations for the scrape-off layer and divertor plasmas in KSTAR tokamak.
- Author
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S. S. Kim and S. W. Yoon
- Published
- 2007
- Full Text
- View/download PDF
42. Experimental investigation of the ordering pathway in a Ni-33 at.%Cr alloy
- Author
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Bharat Gwalani, Talukder Alam, Michael J. Kaufman, Rajarshi Banerjee, S. S. Kim, Y. S. Kim, Tanaporn Rojhirunsakool, C. Miller, and Yang Ren
- Subjects
010302 applied physics ,Diffraction ,Morphology (linguistics) ,Materials science ,Polymers and Plastics ,Alloy ,Metals and Alloys ,02 engineering and technology ,Atom probe ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Isothermal process ,Synchrotron ,law.invention ,Electronic, Optical and Magnetic Materials ,Crystallography ,law ,Chemical physics ,Transmission electron microscopy ,0103 physical sciences ,engineering ,Ceramics and Composites ,Coupling (piping) ,0210 nano-technology - Abstract
The present study involves a detailed experimental investigation of the concurrent compositional clustering and long-range ordering tendencies in a Ni-33 at.%Cr alloy, carried out by coupling synchrotron-based X-ray diffraction (XRD), transmission electron microscopy (TEM), and atom probe tomography (APT). Synchrotron-based XRD results clearly exhibited progressively increasing lattice contraction in the matrix with increasing isothermal aging time, at 475 °C, eventually leading to the development of long-range ordering (LRO) of the Pt 2 Mo-type. Detailed TEM and APT investigations revealed that this LRO in the matrix is manifested in the form of nanometer-scale ordered domains, and the spatial distribution, size, morphology and compositional evolution of these domains have been carefully investigated. APT results also revealed the early stages of compositional clustering prior to the onset of long-range ordering in this alloy and such compositional clustering can potentially be correlated to the lattice contraction and previously proposed short-range ordering tendencies.
- Published
- 2016
- Full Text
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43. Quantum Tunneling of $$^3$$ 3 He in Solid $$^4$$ 4 He: A New Analysis
- Author
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S. S. Kim, Donald Candela, Chao Huan, and Neil Sullivan
- Subjects
Materials science ,Condensed matter physics ,Spin–lattice relaxation ,Quantum diffusion ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010305 fluids & plasmas ,Spin–spin relaxation ,Impurity ,0103 physical sciences ,Relaxation (physics) ,Condensed Matter::Strongly Correlated Electrons ,General Materials Science ,010306 general physics ,Quantum tunnelling - Abstract
We discuss the analysis of the experimental values of the nuclear spin–lattice and spin–spin relaxation times for the tunneling of $$^3$$ He as isotopic impurities in solid $$^4$$ He. These two relaxation times cannot be described quantitatively using a unique correlation time although it is often presented as such in the literature. In this paper, we discuss how to distinguish the high-frequency portion of the spectral densities that determine the spin–lattice relaxation rates from the low-frequency components which determine the spin–spin relaxation rates.
- Published
- 2016
- Full Text
- View/download PDF
44. Structural, electrical, and multiferroic properties of Aurivillius Bi6Fe2(Ti3-xVx)O18+δ thin films prepared by chemical solution deposition
- Author
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C. M. Raghavan, J. W. Kim, S. S. Kim, J. -W. Kim, and T. K. Song
- Subjects
Materials science ,Orders of magnitude (temperature) ,Analytical chemistry ,Nanotechnology ,02 engineering and technology ,Electrochemistry ,01 natural sciences ,Aurivillius ,symbols.namesake ,0103 physical sciences ,Materials Chemistry ,Multiferroics ,Electrical and Electronic Engineering ,Thin film ,010302 applied physics ,biology ,Doping ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,biology.organism_classification ,Electronic, Optical and Magnetic Materials ,Hysteresis ,Mechanics of Materials ,Ceramics and Composites ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
Aurivillius type five-layered V-doped Bi6Fe2(Ti3-xVx)O18+δ (x = 0.00, 0.03, 0.06, and 0.09) thin films were prepared on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. All the thin films were crystallized in Aurivillius structures, which have been confirmed by using X-ray diffraction and Raman spectroscopy studies. On comparing the thin films, the Bi6Fe2(Ti2.94V0.06)O18+δ thin film showed the most enhanced electrical and multiferroic properties, with a leakage current density value about four orders of magnitude lower than that of the Bi6Fe2Ti3O18 thin film, for example. All of these thin films showed anti-ferromagnetic hysteresis loops at room temperature. The significant decrease in the concentration of oxygen vacancies and the formation of a stable structure caused by doping with the donor V5+-ion are related to the improved properties in the V-doped Bi6Fe2(Ti3-xVx)O18+δ thin films.
- Published
- 2016
- Full Text
- View/download PDF
45. Accumulated tolerance analysis of suspension by geometric tolerances based on multibody elasto-kinematic analysis
- Author
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Y. G. Cho, S. S. Kim, Hyunsung Jung, and Se-Il Kim
- Subjects
0209 industrial biotechnology ,Engineering ,Tolerance analysis ,business.industry ,Monte Carlo method ,Control engineering ,02 engineering and technology ,Kinematics ,Structural engineering ,MacPherson strut ,Computer Science::Robotics ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,0203 mechanical engineering ,Automotive Engineering ,Geometric dimensioning and tolerancing ,Wheel alignment ,business ,Suspension (vehicle) ,Stiffness matrix - Abstract
Tolerance design of vehicle suspension is an important factor that affects the ride and handling quality and cost of the vehicle. Also, applying geometric tolerance to an analysis model is found to be a difficult process. This paper presents a method for tolerance analysis of wheel alignment of vehicle suspension. Monte-Carlo simulation method is applied to multibody elasto-kinematic model to analyze the accumulated geometric tolerances. As an example, Macpherson Strut Type front half car model is used, and wheel alignment dispersion and contribution ratio to the dispersion by accumulated geometric tolerances is computed. This paper also presents an efficient modeling and analysis method for elasto-kinematic model of vehicle suspensions by computing the stiffness matrix analytically. The simulation results of a Macpherson Strut Type demonstrates the validity and accuracy of the proposed method.
- Published
- 2016
- Full Text
- View/download PDF
46. A Sum of Chebyshev Inequalities: 10687.
- Author
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James C. Owings Jr., Jeremy E. Dawson, Robin J. Chapman, Darryl K. Nester, Robert A. Agnew, John Beebee, David Callan, R. Garcia-Pelayo, V. Hernandez, J. Martin, J. Hickman, D. Jones, S. S. Kim, Olaf Krafft, Martin Schaefer, G. Letac, John H. Lindsey II, O. P. Lossers, K. Poelladennou, K. Schilling, and M. Shemesh
- Published
- 2000
47. Vorticity generation by finite Larmor radius effects from heat source and sink
- Author
-
Hogun Jhang and S. S. Kim
- Subjects
Physics ,geography ,geography.geographical_feature_category ,Gyroradius ,Turbulence ,Mechanics ,Plasma ,Vorticity ,Condensed Matter Physics ,01 natural sciences ,Sink (geography) ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,Phase space ,Electric field ,Physics::Space Physics ,0103 physical sciences ,Total energy ,010306 general physics - Abstract
We investigate the finite Larmor radius (FLR) effects that are associated with an external heat source or a sink in the full-f formulation of plasma dynamics. Specifically, we show that a gyrocenter or an additional vorticity source due to the FLR effect should be replenished in full-f turbulence simulations. A quantitative energetics analysis in particle phase space demonstrates that an additional vorticity source is required to satisfy the total energy conservation. A physics picture is presented to elucidate the mechanism of the vorticity source generation from the FLR effects of a heat source or a sink, which reproduces the main result obtained from the quantitative analysis. The additional vorticity source is expected to considerably enhance the generation of the radial electric field and subsequent E × B flow shear in the off-axis heating case.
- Published
- 2020
- Full Text
- View/download PDF
48. A conservative gyrofluid model: Effect of closure on energetics
- Author
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Hogun Jhang and S. S. Kim
- Subjects
Physics ,Tokamak ,Basis (linear algebra) ,Gyroradius ,Plasma turbulence ,Energetics ,Closure (topology) ,Mechanics ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Energy conservation ,Moment (mathematics) ,Physics::Plasma Physics ,law ,0103 physical sciences ,010306 general physics - Abstract
We develop a conservative gyrofluid model that is suitable for global flux-driven simulations of electrostatic tokamak plasma turbulence. On the basis of the general gyrofluid moment equations, we derive energy equations which enable us to manipulate the impact of a gyrofluid closure on energetics. We demonstrate that an artificial manipulation of high order moment contributions to gyrofluid moment equations via a closure model can lead to the violation of the energy conservation. A fluid closure is also found to restrict the maximum attainable order of finite Larmor radius terms, implying the loss of dynamical information by the closure.
- Published
- 2020
- Full Text
- View/download PDF
49. Spectral Evolution of Nonlinear Excitations in a Quasi-One-Dimensional Charge Density Wave Material
- Author
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J. A. Leicht, S. S. Kim, and S. L. Dexheimer
- Subjects
Physics ,Nonlinear system ,Spectral evolution ,Condensed matter physics ,Quasi one dimensional ,Charge density wave - Published
- 2019
- Full Text
- View/download PDF
50. Microstructural, electrical and ferroelectric properties of BiFe0.95Mn0.05O3 thin film grown on Ge-doped ZnO electrode
- Author
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J.W. Kim, S. S. Kim, Chinnambedu Murugesan Raghavan, and Tae Kwon Song
- Subjects
010302 applied physics ,Materials science ,business.industry ,Mechanical Engineering ,Doping ,Electrical breakdown ,02 engineering and technology ,Substrate (electronics) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Ferroelectricity ,Mechanics of Materials ,0103 physical sciences ,Electrode ,Optoelectronics ,General Materials Science ,Thin film ,0210 nano-technology ,business ,Current density ,Layer (electronics) - Abstract
The structural, electrical and ferroelectric properties of a Mn-doped BiFe 0.95 Mn 0.05 O 3 (BFMO) thin film grown on a (0 0 l ) textured Ge-doped ZnO (GZO)/Si(1 0 0) substrate are reported. The GZO served as a buffer layer for improving the grain growth and the crystallization of the BFMO thin film. Predominantly, the GZO layer, which promotes the grain growth of the ( l 0 0) textured BFMO thin film, was utilized as both top and bottom electrodes to assess the electrical and the ferroelectric properties of the BFMO thin film. A study of the electrical properties revealed a low leakage current density (4.95 × 10 −6 A/cm 2 at 100 kV/cm) and a large stability against electrical breakdown for the GZO/BFMO/GZO capacitor. The ferroelectric study determined a large value for the remnant polarization (2 P r ), 78.37 μC/cm 2 , at an applied electric field of 895 kV/cm for the GZO/BFMO/GZO capacitor. Furthermore, the GZO/BFMO/GZO capacitor showed stable polarization switching even after 1.44 × 10 10 electrical cycles.
- Published
- 2016
- Full Text
- View/download PDF
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