148 results on '"Dong-Hyun Seo"'
Search Results
2. Ductile mode machining of piezoelectric single crystal by laser-assisted diamond turning process
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Jong-Keun Sim, Dong-Hyun Seo, Eun-Ji Gwak, Ji-Young Jeong, Hwan-ho Maeng, Tae-Jin Je, Doo-Sun Choi, Shinill Kang, and Jun Sae Han
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Laser-assisted diamond turning ,Piezoelectric single crystal ,PMN-PT single crystal ,Ductile mode machining ,Ultrasonic transducer ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Piezoelectric single crystals are multifunctional materials used in advanced ultrasound devices owing to their exceptional piezoelectric properties. Nevertheless, machining methods for these single crystals have been limited due to their brittle nature and material deterioration issues. Herein, we established a ductile machining process of piezoelectric single crystal based on a laser-assisted diamond turning process through comprehensive analysis. In order to achieve defect-free surfaces, we analyzed the cutting behavior of softened piezoelectric single crystals concerning crystal orientation and machining direction. The experimental studies examined the effects of processing parameters on mechanical, chemical, crystallographic, and piezoelectric properties. The cutting status was characterized by measuring acoustic emission signals and analyzing the cutting chip formation. By optimizing the process and establishing a ductile mode of diamond turning mechanisms of piezoelectric material, we machined the brittle single crystal into various shapes, such as double-sided and multi-scale microstructure, without showing any defects all over the crystal orientation. We also demonstrated the validity of the machining process for piezoelectric material through an ultrasound characteristic test, which showed that the fabricated ultrasound transducers with machined single crystal maintained ultrasonic performance without deterioration in underwater experiments.
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- 2024
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3. Melt-quenched carboxylate metal–organic framework glasses
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Minhyuk Kim, Hwa-Sub Lee, Dong-Hyun Seo, Sung June Cho, Eun-chae Jeon, and Hoi Ri Moon
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Science - Abstract
Abstract Although carboxylate-based frameworks are commonly used architectures in metal-organic frameworks (MOFs), liquid/glass MOFs have thus far mainly been obtained from azole- or weakly coordinating ligand-based frameworks. This is because strong coordination bonds of carboxylate ligands to metals block the thermal vitrification pathways of carboxylate-based MOFs. In this study, we present the example of carboxylate-based melt-quenched MOF glasses comprising Mg2+ or Mn2+ with an aliphatic carboxylate ligand, adipate. These MOFs have a low melting temperature (T m) of 284 °C and 238 °C, respectively, compared to zeolitic-imidazolate framework (ZIF) glasses, and superior mechanical properties in terms of hardness and elastic modulus. The low T m may be attributed to the flexibility and low symmetry of the aliphatic carboxylate ligand, which raises the entropy of fusion (ΔS fus), and the lack of crystal field stabilization energy on metal ions, reducing enthalpy of fusion (ΔH fus). This research will serve as a cornerstone for the integration of numerous carboxylate-based MOFs into MOF glasses.
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- 2024
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4. Manufacturing of stretchable substrate with biaxial strain control for highly-efficient stretchable solar cells and displays
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Ji-Youn Kwak, Ji-Young Jeong, Ye-Pil Kwon, Dong-Hyun Seo, Chung-Mo Kang, Dong-Hyeon Kim, Jun Sae Han, Eun-Ji Gwak, Doo-Sun Choi, Ju-Young Kim, Tae-Jin Je, and Eun-chae Jeon
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Medicine ,Science - Abstract
Abstract There has been significant research focused on the development of stretchable materials that can provide a large area with minimal material usage for use in solar cells and displays. However, most materials exhibit perpendicular shrinkage when stretched, which is particularly problematic for polymer-based substrates commonly used in stretchable devices. To address this issue, biaxial strain-controlled substrates have been proposed as a solution to increase device efficiency and conserve material resources. In this study, we present the design and fabrication of a biaxial strain-controlled substrate with a re-entrant honeycomb structure and a negative Poisson’s ratio. Using a precisely machined mold with a shape error of less than 0.15%, we successfully fabricated polydimethylsiloxane substrates with a 500 μm thick re-entrant honeycomb structure, resulting in a 19.1% reduction in perpendicular shrinkage. This improvement translates to a potential increase in device efficiency by 9.44% and an 8.60% reduction in material usage for substrate fabrication. We demonstrate that this design and manufacturing method can be applied to the fabrication of efficient stretchable devices, such as solar cells and displays.
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- 2023
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5. PG-CAS: Pro-Active EM-SCA Probe Detection Using Switched-Capacitor-Based Patterned-Ground Co-Planar Capacitive Asymmetry Sensing
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Dong-Hyun Seo, Archisman Ghosh, Debayan Das, Mayukh Nath, Santosh Ghosh, and Shreyas Sen
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Side-channel attack ,electromagnetic leakage ,patterned-ground ,capacitive asymmetry ,switched capacitor ,AES protection ,Electric apparatus and materials. Electric circuits. Electric networks ,TK452-454.4 - Abstract
This paper presents the design and analysis of a pro-active strategy to detect the presence of an electromagnetic (EM) side-channel analysis (SCA) attack, using Patterned-Ground co-planar Capacitive Asymmetry Sensing (PG-CAS) system. The PG-CAS system senses the asymmetry created in the plate-ground capacitance and turns on a SCA countermeasure in presence of an EM probe. The proposed PG-CAS system for approaching probe consists of the EM SCA detection sensor plate and circuits. The EM SCA detection sensor is implemented as a grid of four metal plates of the same dimensions using the top metal layer along with a patterned-ground plane at the immediate lower metal layer. The EM SCA detection system consists of a proximity to capacitance conversion circuit, digital synchronization logic circuit to detect and alarm the IC, and an EM SCA countermeasure. When an attack is detected, the countermeasure is turned on based on the deviation of the symmetry of the plate-ground capacitance pairs. The PG-CAS system-level post-layout simulation results using TSMC 65nm technology and Ansys Maxwell show a $>5\times $ improvement in the detection range and a $\sim 29\times $ improvement in power consumption over existing inductive sensing methods for attack detection.
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- 2023
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6. Single-Frame-Based Data Compression for CAN Security
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Shi-Yi Jin, Dong-Hyun Seo, Yeon-Jin Kim, Yong-Eun Kim, Samuel Woo, and Jin-Gyun Chung
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CAN ,data reduction ,entropy ,security ,signal grouping ,Information technology ,T58.5-58.64 - Abstract
To authenticate a controller area network (CAN) data frame, a message authentication code (MAC) must be sent along with the CAN frame, but there is no space reserved for the MAC in the CAN frame. Recently, difference-based compression (DBC) algorithms have been used to create a space inside the frame. DBC has the advantage of being very efficient, but its drawback is that, if an error occurs in one frame, the effects of that error propagate to subsequent frames. In this paper, a CAN data compression algorithm is proposed that compresses the current frame without relying on previous frames. Therefore, an error generated in one frame cannot be propagated to subsequent frames. In addition, a CAN signal grouping technique is proposed based on entropy analysis. To efficiently authenticate CAN frames, the length of the compressed data must be 4 bytes or less (4BL). Simulation shows that the 4BL-compression ratio of a Kia Sorento vehicle is 99.36% in the DBC method, but 100% in the proposed method. In an LS Mtron tractor, the 4BL-compression ratio is 98.58% in the DBC method, but 100% in the proposed method. In addition, the execution time of the proposed compression algorithm is only 27.39% of that of the DBC algorithm. The results show that the proposed algorithm has better compression characteristics for CAN security than the DBC algorithms.
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- 2024
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7. Design and Analysis of a Resistive Sensor Interface With Phase Noise-Energy-Resolution Scalability for a Time-Based Resistance-to-Digital Converter
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Dong-Hyun Seo, Baibhab Chatterjee, Sean M. Scott, Daniel J. Valentino, Dimitrios Peroulis, and Shreyas Sen
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resistive sensor ,sensor interfacing circuit ,resistance-to-digital converter ,time-based ADC ,low-power ,RMS jitter ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
This article presents the design and analysis of a resistive sensor interface with three different designs of phase noise-energy-resolution scalability in time-based resistance-to-digital converters (RDCs), including test chip implementations and measurements, targeted toward either minimizing the energy/conversion step or maximizing bit-resolution. The implemented RDCs consist of a three-stage differential ring oscillator, which is current starved using the resistive sensor, a differential-to-single-ended amplifier, and digital modules and serial interface. The first RDC design (baseline) included the basic structure of time-based RDC and targeted low-energy/conversion step. The second RDC design (goal: higher-resolution) aimed to improve the rms jitter/phase noise of the oscillator with help of speed-up latches, to achieve high bit-resolution as compared to the first RDC design. The third RDC design (goal: process portability) reduced the power consumption by scaling the technology with the improved phase-noise design, achieving 1-bit better resolution as that of the second RDC design. Using time-based implementation, the RDCs exhibit energy-resolution scalability and consume a measured power of 861 nW with 18-bit resolution in design 1 in TSMC 0.35 μm technology (with 10 ms read-time, with one readout every second). Measurements of designs 2 and 3 demonstrate power consumption of 19.2 μW with 20-bit resolution using TSMC 0.35μm and 17.6 μW with 20-bit resolution using TSMC 0.18μm, respectively (both with 10 ms read-time, repeated every second). With 30 ms read-time, design 3 achieves 21-bit resolution, which is the highest resolution reported for a time-based ADC. The 0.35-μm time-based RDC is the lowest-power time-based ADC reported, while the 0.18-μm time-based RDC with speed-up latch offers the highest resolution. The active chip-area for all three designs is less than 1.1 mm2.
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- 2022
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8. MAC-Based Compression Ratio Improvement for CAN Security
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Jinhui Piao, Shiyi Jin, Dong-Hyun Seo, Samuel Woo, and Jin-Gyun Chung
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CAN ,security ,data compression ,authentication ,header bits ,Triple ID ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Information security in a controller area network (CAN) is becoming more important as the connections between a vehicle’s internal and external networks increase. Encryption and authentication techniques can be applied to CAN data frames to enhance security. To authenticate a data frame, a message authentication code (MAC) needs to be transmitted with the CAN data frame. Therefore, space for transmitting the MAC is required within the CAN frame. Recently, the Triple ID algorithm has been proposed to create additional space in the data field of the CAN frame. The Triple ID algorithm ensures every CAN frame is authenticated by at least 4 bytes of MAC without changing the original CAN protocol. However, since the Triple ID algorithm uses six header bits, there is a problem associated with low data compression efficiency. In this paper, we propose an algorithm that can remove up to 15 bits from frames compressed with the Triple ID algorithm. Through simulation using CAN signals of a Kia Sorento vehicle and an LS Mtron tractor, we show that the generation of frames containing compressed messages of 4 bytes or more is reduced by up to 99.57% compared to the Triple ID method.
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- 2023
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9. Decreased Bone Volume and Bone Mineral Density in the Tibial Trabecular Bone Is Associated with Per2 Gene by 405 nm Laser Stimulation
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Yeong-Min Yoo, Myung-Han Lee, Ji Hyung Park, Dong-Hyun Seo, Sangyeob Lee, Byungjo Jung, Han Sung Kim, and Kiho Bae
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tibia ,trabecular bone ,Per2 ,ALP ,Runx ,low-level laser therapy ,minimally invasive laser needle system ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Low-level laser therapy/treatment (LLLT) using a minimally invasive laser needle system (MILNS) might enhance bone formation and suppress bone resorption. In this study, the use of 405 nm LLLT led to decreases in bone volume and bone mineral density (BMD) of tibial trabecular bone in wild-type (WT) and Per2 knockout (KO) mice. Bone volume and bone mineral density of tibial trabecular bone was decreased by 405 nm LLLT in Per2 KO compared to WT mice at two and four weeks. To determine the reduction in tibial bone, mRNA expressions of alkaline phosphatase (ALP) and Per2 were investigated at four weeks after 405 nm laser stimulation using MILNS. ALP gene expression was significantly reduced in the LLLT-stimulated right tibial bone of WT and Per2 KO mice compared to the non-irradiated left tibia (p < 0.001). Per2 mRNA expression in WT mice was significantly reduced in the LLLT-stimulated right tibial bone compared to the non-irradiated left tibia (p < 0.001). To identify the decrease in tibial bone mediated by the Per2 gene, levels of runt-related transcription factor 2 (Runx2) and ALP mRNAs were determined in non-irradiated WT and Per2 KO mice. These results demonstrated significant downregulation of Runx2 and ALP mRNA levels in Per2 KO mice (p < 0.001). Therefore, the reduction in tibial trabecular bone resulting from 405 nm LLLT using MILNS might be associated with Per2 gene expression.
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- 2015
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10. Promoter mutation-independent TERT expression is related to the immune-enriched milieu in papillary thyroid cancer.
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Dong Hyun Seo, Seul Gi Lee, Soon Min Choi, Ha Yan Kim, Sunmi Park, Sang Geun Jung, Young Suk Jo, and Jandee Lee
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TELOMERASE reverse transcriptase , *NF-kappa B , *BIOLOGICAL variation , *IODINE isotopes , *HUMAN carcinogenesis , *THYROID cancer , *BRAF genes - Abstract
Telomerase reverse transcriptase promoter mutation (pTERT MT) promotes human carcinogenesis via aberrant expression of telomerase reverse transcriptase (TERT). However, the tumorigenic impact of TERT expression independent of pTERT MT remains unclear despite numerous mechanisms of TERT being suggested. To tackle this issue, we employed comprehensive bioinformatics to assess biological variations noticed among different TERT expression mechanisms. Papillary thyroid cancer (PTC) with pTERT MT (pTERT MT PTC) presented aggressive clinical behavior and exhibited biological profiles associated with cellular immortality and genomic instability. PTC with TERT expression but without pTERT MT (TERT (+) PTC), also exhibited poor clinicopathological characteristics and was enriched with immune responses. In accordance, c-MYC/E2F and nuclear factor kappa B (NFκB) were dominant transcription factors in pTERT MT PTC and TERT (+) PTC, respectively. Notably, we revealed TERT hypermethylated oncological region (THOR) as a potential TERT expressing mechanism in TERT (+) PTC patients. Furthermore, three unique subtypes of papillary thyroid cancer were deciphered using a combination of machine learning-based scoring systems. Our proposed scoring system was clinically significant, especially in microcarcinoma, predicting survival outcomes and inferring therapeutic responses to radioactive iodine therapy. Finally, our analysis was expanded to endocrine-related cancers, unveiling various regulatory mechanisms of TERT with poor clinical outcomes and biological behaviors. [ABSTRACT FROM AUTHOR]
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- 2024
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11. PG-CAS: Patterned-Ground Co-Planar Capacitive Asymmetry Sensing for mm-Range EM Side-Channel Attack Probe Detection.
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Dong-Hyun Seo, Mayukh Nath, Debayan Das, Baibhab Chatterjee, Santosh Ghosh, and Shreyas Sen
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- 2021
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12. Enhanced Detection Range for EM Side-channel Attack Probes utilizing Co-planar Capacitive Asymmetry Sensing.
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Dong-Hyun Seo, Mayukh Nath, Debayan Das, Santosh Ghosh, and Shreyas Sen
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- 2021
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13. 27.3 EM and Power SCA-Resilient AES-256 in 65nm CMOS Through >350× Current-Domain Signature Attenuation.
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Debayan Das, Josef Danial, Anupam Golder, Nirmoy Modak, Shovan Maity, Baibhab Chatterjee, Dong-Hyun Seo, Muya Chang, Avinash Varna 0001, Harish Krishnamurthy, Sanu Mathew, Santosh Ghosh, Arijit Raychowdhury, and Shreyas Sen
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- 2020
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14. A Digital Cascoded Signature Attenuation Countermeasure with Intelligent Malicious Voltage Drop Attack Detector for EM/Power SCA Resilient Parallel AES-256.
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Archisman Ghosh, Dong-Hyun Seo, Debayan Das, Santosh Ghosh, and Shreyas Sen
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- 2022
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15. Immune-related Adverse Effect after BNT162b2 Vaccination with Parallel Immune Checkpoint Inhibitor Therapy: A Case Report
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Won Myung Kim, Mun Su Park, Dong Hyun Seo, Jung Yun Lee, and Jung Yoon Pyo
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General Medicine - Abstract
COVID-19 vaccination is essential in cancer patients. However, there is limited evidence of the prognosis of these patients, especially for those taking immune checkpoint inhibitors (ICIs). We present a patient on pembrolizumab for advanced endometrioid adenocarcinoma experiencing continuous diarrhea and subsequent episodes of fever with pain in multiple joints following a second dose of the BNT162b2 mRNA COVID-19 vaccine. An ICI-induced immune-related adverse effect (irAE) was the main diagnosis; cytokine release syndrome and rheumatoid arthritis were also considered. Notably, the novel irAE occurred after the 19th pembrolizumab trial, highlighting the potential effect of changes in systemic immunogenicity after BNT162b2 vaccination. Ultimately, the patient was treated with steroid, which alleviated her symptoms. Here, we report a rare adverse effect after COVID-19 vaccination in an endometrioid carcinoma patient on ICI therapy. This report shows that there is a need to consider and investigate vaccine-related adverse events.
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- 2023
16. EICO: Energy-Harvesting Long-Range Environmental Sensor Nodes With Energy-Information Dynamic Co-Optimization
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Shitij Avlani, Dong-Hyun Seo, Baibhab Chatterjee, and Shreyas Sen
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Computer Science - Networking and Internet Architecture ,Networking and Internet Architecture (cs.NI) ,Signal Processing (eess.SP) ,FOS: Computer and information sciences ,Computer Networks and Communications ,Hardware and Architecture ,Signal Processing ,FOS: Electrical engineering, electronic engineering, information engineering ,Electrical Engineering and Systems Science - Signal Processing ,Computer Science Applications ,Information Systems - Abstract
Intensive research on energy harvested sensor nodes with traditional battery powered devices has been driven by the challenges in achieving the stringent design goals of battery lifetime, information accuracy, transmission distance, and cost. This challenge is further amplified by the inherent power intensive nature of long-range communication when sensor networks are required to span vast areas such as agricultural fields and remote terrain. Solar power is a common energy source is wireless sensor nodes, however, it is not reliable due to fluctuations in power stemming from the changing seasons and weather conditions. This paper tackles these issues by presenting a perpetually-powered, energy-harvesting sensor node which utilizes a minimally sized solar cell and is capable of long range communication by dynamically co-optimizing energy consumption and information transfer, termed as Energy-Information Dynamic Co-Optimization (EICO). This energy-information intelligence is achieved by adaptive duty cycling of information transfer based on the total amount of energy available from the harvester and charge storage element to optimize the energy consumption of the sensor node, while employing in-sensor analytics (ISA) to minimize loss of information. This is the first reported sensor node < 35cm2 in dimension, which is capable of long-range communication over > 1Km at continuous information transfer rates of upto 1 packet/second which is enabled by EICO and ISA.
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- 2022
17. The diagnosis of cerebrospinal fluid leakage after microvascular decompression surgery and management via lumbar drain
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Dong Hyun Seo, Kyung Rae Cho, Hyun Seok Lee, and Kwan Park
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Objective: In posterior fossa surgery such as microvascular decompression (MVD), cerebrospinal fluid (CSF) leakage is a crucial problem. In this study, we explored the accurate diagnosis and effective non-surgical management of postoperative CSF leakage.Methods: We reviewed 749 patients who underwent MVD surgery from August 2018 to April 2022. Although we significantly reduced the CSF leakage problem by using the triple-layer closing technique (TLCT), CSF leakage was still a problem in a few cases. We managed these patients with the same diagnostic flow and treatment regimen using a lumbar drain (LD).Results: Among the 749 patients in the cohort, 11 (1.4%) had CSF leakage, and each of those cases presented with rhinorrhea. Five patients (45.5%) had the symptom on the first day, two patients (18.2%) on the second day, one patient (9.1%) on the third day, and three patients (27.3%) on the fifth day after surgery. After conservative treatment including CSF drainage via LD for 5.4 days on average, none of the patients had recurrent symptoms suggesting CSF leakage; thus, there was no need for wound repair surgery.Conclusion: Despite diligent attempts to prevent CSF leakage in open microsurgery, leaks inevitably occur in some cases and are more frequent in posterior fossa surgery. Although we cannot fully prevent leakage, we should limit the complication to ensure that it does not progress into other severe problems, such as meningitis. A closing technique such as TLCT is useful, but the early diagnosis and management of CSF leakage with LD is also important.
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- 2022
18. Sole vein offenders confirmed by disappearance of the lateral spread response during microvascular decompression for hemifacial spasm
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Dong Hyun Seo, Kyung Rae Cho, and Kwan Park
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Sole vein offenders are rare and can be difficult to identify on preoperative magnetic resonance imaging (MRI) and intraoperative microscopy. The objective of this case review was to investigate factors resulting in successful decompression in venous offender cases. Among 234 cases of microvascular decompression surgery performed for hemifacial spasm from September 2020 to April 2022 at Konkuk University Medical Center, only two cases were identified as having a definite venous offender. We reviewed preoperative MRI and intraoperative microscopic findings and studied the correlation between decompression and lateral spread response (LSR) changes. Our two patients had possibility of a small venous offender on preoperative MRI, but it was ambiguous. A definite venous offender was identified on the operative microscopic findings and decompressed successfully, referring to the disappearance of the LSR waveform. Postoperatively, spasm disappeared or significantly improved. A venous offender is difficult to identify on preoperative MRI findings or even on intraoperative microscopic findings. In such cases, changes in the LSR waveform in response to decompressing the suspected vein can be a valuable reference for successful facial outcomes.
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- 2022
19. Point-defect engineering of nanoporous CuBi2O4 photocathode via rapid thermal processing for enhanced photoelectrochemical activity
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Li Qu, Runfa Tan, Arumugam Sivanantham, Min Je Kang, Yoo Jae Jeong, Dong Hyun Seo, Sungkyu Kim, and In Sun Cho
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Fuel Technology ,Electrochemistry ,Energy Engineering and Power Technology ,Energy (miscellaneous) - Published
- 2022
20. Lymph node metastasis‐dependent molecular classification in papillary thyroid carcinoma defines aggressive metastatic outgrowth
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Dong Hyun Seo, Seul Gi Lee, Hwa Young Lee, Seonhyang Jeong, Sunmi Park, Jandee Lee, and Young Suk Jo
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Molecular Medicine ,Medicine (miscellaneous) - Published
- 2023
21. Highly impermeable and flexible silica encapsulation films synthesized by sol—gel process
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Si-Hoon Kim, Gyeong-Seok Hwang, Donghwan Koo, Dong-Hyun Seo, Ye-Pil Kwon, Hansuek Lee, Hyesung Park, Eun-chae Jeon, and Ju-Young Kim
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General Materials Science ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics - Published
- 2022
22. Spatially-Segmented Colored Radiative Cooler With Angle-Robustness
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Dong Hyun Seo, Se-Yeon Heo, Do Hyeon Kim, Young Min Song, and Gil Ju Lee
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Electrical and Electronic Engineering ,Atomic and Molecular Physics, and Optics - Published
- 2022
23. Multiple Thymoma with Myasthenia Gravis
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Dong Hyun Seo and Sukki Cho
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Thymoma ,Thymectomy ,Myasthenia gravis ,Video-assisted thoracic surgery (VATS) ,Thymus ,Surgery ,RD1-811 - Abstract
The actual incidence of multiple thymoma is unknown and rarely reported because it remains controversial whether the cases represent a disease of multicentric origin or a disease resulting from intrathymic metastasis. In this case, a patient underwent total thymectomy for multiple thymoma with myasthenia gravis via bilateral video-assisted thoracic surgery. A well-encapsulated multinodular cystic mass, measuring 57 mm×50 mm×22 mm in the right lobe of the thymus, and a well-encapsulated mass, measuring 32 mm×15 mm×14 mm in the left lobe, were found. Both tumors were type B2 thymoma. Few cases of multiple thymoma with myasthenia gravis have ever been reported in the literature. We report a case of synchronous multiple thymoma associated with myasthenia gravis.
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- 2017
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24. The characteristics of pediatric emergency department visits in Korea: An observational study analyzing Korea Health Panel data.
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Dong Hyun Seo, Min Joung Kim, Kyung Hwan Kim, Junseok Park, Dong Wun Shin, Hoon Kim, Woochan Jeon, Hyunjong Kim, and Joon Min Park
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Medicine ,Science - Abstract
OBJECTIVE:We investigated the characteristics of pediatric emergency department (ED) patients in Korea and determined factors associated with hospital admission after ED treatment. METHODS:Korea Health Panel data from 2008 through 2013 were analyzed retrospectively; we included patients under 18 years old who visited the ED at least once. We collected patient and household epidemiologic data such as sex, age group, region of residence, disability, chronic disease, household income quintile, national health insurance type, use of private insurance, and annual frequency of ED visits. We also examined data related to each ED visit, such as reason for visit, medical service provided, and hospital size/ownership. We then investigated which factors were correlated with case disposition (discharge home or hospital admission) after ED treatment. RESULTS:In total, 3,160 pediatric ED visits occurred during the six-year period. Males (57.5%) and children aged 0-5 years (47.7%) made more visits than females and older children, respectively. The proportion of ED visits for disease (67.7%) was much higher than for injury or poisoning (32.2%), and 452 cases (14.3%) required hospital admission. For hospital admission, the odds ratio (OR) of females was 0.73 compared to males, and the OR of children aged 6-11 was 0.68 compared to children aged 0-5. The OR of capital residents was 0.69 compared to province residents, and the OR of the highest income quintile was 0.51 compared to the lowest quintile. The OR of children with private insurance coverage was 0.49 compared to those lacking private insurance, and the OR of ED visits due to disease was 1.82 compared to visits due to injury/poisoning. CONCLUSION:This analysis of clinical and demographic characteristics of pediatric ED visits and hospital admissions can serve as the foundation of future prospective studies required for establishing appropriate policies for the Korean pediatric emergency medical system.
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- 2018
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25. Chemical Plant Explosion Accident (Cause) Analysis Using AcciMap and FRAM
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Dong-Hyun Seo, Tae-Ho Kim, and Chae-Chil Koo
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Cause analysis ,Forensic engineering ,Environmental science ,Chemical plant ,Accident (philosophy) - Abstract
To prevent accidents in chemical plants, it is important to identify the root cause of the accident and suggest countermeasures. When accident factors are known, eliminating the cause of the accident can increase its prevention. The number of factors, including social factors, in addition to human factors, is increasing. When analyzing the cause of an accident when it is complex, advanced, and the connection between processes is high, there is a growing need to approach it with an integrated system analysis method related to the organization, along with a sequential approach to determine the direct cause of the accident. Several countries have introduced and applied techniques for integrated analysis of accidents from a systematic viewpoint, such as AcciMap and the functional resonance accident model (FRAM) that were developed around 2000. However, it remains difficult to find cases or research results applied in Korea. In this study, accidents in Korean chemical factories are analyzed using systematic accident analysis techniques, and a plan to utilize systematic analysis techniques for future accident investigations is developed.
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- 2021
26. Analysis of Explosion Accidents in a Chemical Plant using STAMP, a Systematic Cause-and-effect Analysis Technique
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Dong-Hyun Seo, Pil-Hyeok Lee, and Chae-Chil Koo
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Waste management ,Cause and effect analysis ,Environmental science ,Chemical plant - Abstract
The process safety management system for chemical plants was introduced approximately 25 years ago. With the improvement in the safety management levels for the safe operation of the chemical plants, the number of serious industrial accidents has gradually decreased; however, increased damages have been observed when accidents do occur. The cause of accidents has also increased in cases where several factors, including social and cultural factors, are complexly related, in addition to facility and human factors. The need for an overall integrated systemic approach related to society, technology, and organization, and a sequential approach for finding the direct cause of accidents, is growing while analyzing the accidents. For this reason, foreign countries have introduced and applied a method to analyze accidents in an integrated manner from a systemic point of view; however, reports of cases or research results used in Korea. In this study, the case of explosion accidents, which occurred during a trial operation at a domestic chemical plant, was analyzed using Systems-Theoretic Accident Model and Processes, a systematic accident analysis technique, to reveal the primary cause, organizational, and operational problems, so that it can be used for future investigations when other accidents occur.
- Published
- 2021
27. Effects of Cutting Parameters on Surface Roughness in Planing Using Taguchi Method
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Hwan-Jin Choi, Eun-chae Jeon, Dong-Hyun Seo, Young-Jae Kim, and Ye-Pil Kwon
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Taguchi methods ,Materials science ,Surface roughness ,Composite material - Published
- 2021
28. Graphene Antiadhesion Layer for the Effective Peel-and-Pick Transfer of Metallic Electrodes toward Flexible Electronics
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Jihyung Seo, Hyesung Park, Dong-Hyun Seo, Jeong Min Baik, Gyujeong Jeong, Eun-chae Jeon, Geunsik Lee, and Yongchul Kim
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Inert ,Materials science ,Graphene ,Nanotechnology ,02 engineering and technology ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Flexible electronics ,0104 chemical sciences ,law.invention ,Metal ,symbols.namesake ,law ,Electrical resistivity and conductivity ,visual_art ,symbols ,visual_art.visual_art_medium ,General Materials Science ,van der Waals force ,0210 nano-technology ,Layer (electronics) - Abstract
Owing to its exceptional physicochemical properties, graphene has demonstrated unprecedented potential in a wide array of scientific and industrial applications. By exploiting its chemically inert surface endowed with unique barrier functionalities, we herein demonstrate antiadhesive monolayer graphene films for realizing a peel-and-pick transfer process of target materials from the donor substrate. When the graphene antiadhesion layer (AAL) is inserted at the interface between the metal and the arbitrary donor substrate, the interfacial interactions can be effectively weakened by the weak interplanar van der Waals forces of graphene, enabling the effective release of the metallic electrode from the donor substrate. The flexible embedded metallic electrode with graphene AAL exhibited excellent electrical conductivity, mechanical durability, and chemical resistance, as well as excellent performance in flexible heater applications. This study afforded an effective strategy for fabricating high-performance and ultraflexible embedded metallic electrodes for applications in the field of highly functional flexible electronics.
- Published
- 2021
29. Context-Aware Collaborative Intelligence With Spatio-Temporal In-Sensor-Analytics for Efficient Communication in a Large-Area IoT Testbed
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Shreyas Sen, Shramana Chakraborty, Xiaofan Jiang, Charilaos Mousoulis, Ali Shakouri, Heng Zhang, Dong-Hyun Seo, Dimitrios Peroulis, Mustafa Abdallah, Shitij Avlani, Nithin Raghunathan, Saurabh Bagchi, and Baibhab Chatterjee
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Computer Networks and Communications ,Computer science ,business.industry ,Node (networking) ,020208 electrical & electronic engineering ,Real-time computing ,020206 networking & telecommunications ,Context (language use) ,02 engineering and technology ,Energy consumption ,Approx ,Bottleneck ,Computer Science Applications ,Hardware and Architecture ,Analytics ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,business ,Wireless sensor network ,Energy (signal processing) ,Information Systems - Abstract
Decades of continuous scaling has reduced the energy of unit computing to virtually zero, while energy-efficient communication has remained the primary bottleneck in achieving fully energy-autonomous Internet-of-Things (IoT) nodes. This article presents and analyzes the tradeoffs between the energies required for communication and computation in a wireless sensor network, deployed in a mesh architecture over a 2400-acre university campus, and is targeted toward multisensor measurement of temperature, humidity and water nitrate concentration for smart agriculture. Several scenarios involving in-sensor analytics (ISA), collaborative intelligence (CI), and context-aware switching (CAS) of the cluster head during CI has been considered. A real-time co-optimization algorithm has been developed for minimizing the energy consumption in the network, hence maximizing the overall battery lifetime. Measurement results show that the proposed ISA consumes $\approx 467\times $ lower energy as compared to traditional Bluetooth low energy (BLE) communication, and $\approx 69500\times $ lower energy as compared with long-range (LoRa) communication. When the ISA is implemented in conjunction with LoRa, the lifetime of the node increases from a mere 4.3 h to 66.6 days with a 230-mAh coin cell battery, while preserving >99% of the total information. The CI and CAS algorithms help in extending the worst case node lifetime by an additional 50%, thereby exhibiting an overall network lifetime of $\approx 104$ days, which is >90% of the theoretical limits as posed by the leakage current present in the system, while effectively transferring information sampled every second. A Web-based monitoring system was developed to continuously archive the measured data, and for reporting real-time anomalies.
- Published
- 2021
30. EM and Power SCA-Resilient AES-256 Through >350× Current-Domain Signature Attenuation and Local Lower Metal Routing
- Author
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Arijit Raychowdhury, Muya Chang, Shovan Maity, Dong-Hyun Seo, Josef Danial, Sanu Mathew, Harish K. Krishnamurthy, Anupam Golder, Shreyas Sen, Avinash L. Varna, Nirmoy Modak, Debayan Das, Santosh Ghosh, and Baibhab Chatterjee
- Subjects
Computer science ,Buck converter ,020208 electrical & electronic engineering ,Clock rate ,02 engineering and technology ,Switched capacitor ,Topology ,Power (physics) ,law.invention ,Capacitor ,CMOS ,law ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Routing (electronic design automation) ,Leakage (electronics) - Abstract
Mathematically secure cryptographic algorithms, when implemented on a physical substrate, leak critical “side-channel” information, leading to power and electromagnetic (EM) analysis attacks. Circuit-level protections involve switched capacitor, buck converter, or series low-dropout (LDO) regulator-based implementations, each of which suffers from significant power, area, or performance tradeoffs and has only achieved a minimum traces to disclosure (MTD) of $10M$ till date. Utilizing an in-depth white-box model, this work, for the first time, focuses on signature suppression in the current domain, which provides an $Attenuation^{2}$ enhancement in MTD, leading to orders of magnitude improvement in both power and EM side-channel analysis (SCA) immunities. Using a combination of current-domain “signature attenuation” (CDSA) along with local lower level metal routing, the critical correlated information in the crypto current is significantly suppressed before it reaches the supply pin. Especially, to prevent the EM leakage from its source (metal layers carrying the correlated crypto current acting as antennas), this work embraces lower level metal routing of the CDSA embedding the crypto-IP so that the signature becomes highly suppressed before it passes through the higher metal layers (which radiates significantly) to connect to the external pin. The 65-nm CMOS test chip contains both protected and unprotected parallel AES-256 implementations, running at a clock frequency of 50 MHz. Test vector leakage assessment (TVLA) on the protected CDSA-AES, demonstrated with on-chip measurements for the first time, shows that the higher level metal layers leak significantly more compared with the lower level metal routing. Correlational power and EM analysis (CPA/CEMA) attacks on the unprotected implementation were able to extract the secret key within $8k$ and $12k$ traces, respectively, while the protected CDSA-AES could not be broken even after $1B$ encryptions for both power and EM SCA, evaluated both in the time and frequency domains, showing an improvement of $100\times $ over the prior state-of-the-art countermeasures with comparable power and area overheads.
- Published
- 2021
31. A Wearable Real-Time CMOS Dosimeter With Integrated Zero-Bias Floating Gate Sensor and an 861-nW 18-Bit Energy-Resolution Scalable Time-Based Radiation to Digital Converter
- Author
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Shovan Maity, Dong-Hyun Seo, Dallas T. Morisette, Daniel J. Valentino, Anurag Kumar, Dimitrios Peroulis, Shreyas Sen, Sean Scott, Baibhab Chatterjee, and Charilaos Mousoulis
- Subjects
Voltage-controlled oscillator ,Dosimeter ,CMOS ,Computer science ,business.industry ,Electrical engineering ,Electrical and Electronic Engineering ,Radiation ,business ,Sensitivity (electronics) ,18-bit ,Energy (signal processing) ,Efficient energy use - Abstract
Radiation, being invisible and odorless, has become a major concern in modern-day healthcare, mining, security, and nuclear applications that require professionals to work in environments involving radioactive materials, often with only elementary training. Furthermore, the scenario is worsened by the absence of a real-time, accumulative radiation dosimeter of small/wearable form factor that can provide direct digital output for long-term continuous monitoring. In this article, we present the first monolithically integrated CMOS wearable radiation dosimeter, consisting a floating-gate (FG) resistive sensor with a sensitivity of 14 $\Omega $ /rad, and a time-domain resistance-to-digital-converter (RDC) that functions as an 18-bit voltage-controlled oscillator (VCO)-based ADC, consuming 861 nJ for 10-ms active read time (which translates to 861-nW at 1 S/s), with 3.29-pJ/conversion step energy efficiency. The proposed time-based RDC exhibits programmable energy-resolution scalability by controlling the measurement time (unlike traditional voltage/current-mode ADCs) and achieves 6-bit better resolution than the state-of-the-art VCO-based ADCs at low frequency (conversion time ≈10 ms). The implemented integrated dosimeter achieves 8-bit better resolution, 7.5 $\times $ lower power, and 40 $\times $ better sensitivity (up to 10-mrad dose) than the current CMOS FG dosimeters.
- Published
- 2020
32. An artificial intelligence model to predict hepatocellular carcinoma risk in Korean and Caucasian patients with chronic hepatitis B
- Author
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Kim, Hwi Young Lampertico, Pietro Nam, Joon Yeul Lee, Hyung-Chul Kim, Seung Up Sinn, Dong Hyun Seo, Yeon Seok and Lee, Han Ah Park, Soo Young Lim, Young-Suk Jang, Eun Sun and Yoon, Eileen L. Kim, Hyoung Su Kim, Sung Eun Ahn, Sang Bong and Shim, Jae-Jun Jeong, Soung Won Jung, Yong Jin Sohn, Joo Hyun Cho, Yong Kyun Jun, Dae Won Dalekos, George N. and Idilman, Ramazan Sypsa, Vana Berg, Thomas Buti, Maria and Calleja, Jose Luis Goulis, John Manolakopoulos, Spilios and Janssen, Harry L. A. Jang, Myoung-jin Lee, Yun Bin Kim, Yoon Jun Yoon, Jung-Hwan Papatheodoridis, George V. Lee, Jeong-Hoon
- Abstract
Background & Aims: Several models have recently been developed to predict risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). Our aims were to develop and validate an artificial intelligence-assisted prediction model of HCC risk. Methods: Using a gradient-boosting machine (GBM) algorithm, a model was developed using 6,051 patients with CHB who received entecavir or tenofovir therapy from 4 hospitals in Korea. Two external validation cohorts were independently established: Korean (5,817 patients from 14 Korean centers) and Caucasian (1,640 from 11 Western centers) PAGE-B cohorts. The primary outcome was HCC development. Results: In the derivation cohort and the 2 validation cohorts, cirrhosis was present in 26.9%-50.2% of patients at baseline. A model using 10 parameters at baseline was derived and showed good predictive performance (c-index 0.79). This model showed significantly better discrimination than previous models (PAGEB, modified PAGE-B, REACH-B, and CU-HCC) in both the Korean (c-index 0.79 vs. 0.64-0.74; all p
- Published
- 2022
33. Improved EM Side-Channel Analysis Attack Probe Detection Range utilizing Co-planar Capacitive Asymmetry Sensing
- Author
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Dong-Hyun Seo, Mayukh Nath, Debayan Das, Santosh Ghosh, and Shreyas Sen
- Subjects
Electrical and Electronic Engineering ,Computer Graphics and Computer-Aided Design ,Software - Published
- 2023
34. Using a CeO2 quantum dot hole extraction-layer for enhanced solar water splitting activity of BiVO4 photoanodes
- Author
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Dong Hyun Seo, Seo Yeong Hong, Tak Hyun You, Arumugam Sivanantham, and In Sun Cho
- Subjects
General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2022
35. Development of energy use benchmark data with respect to locations, housing types, gross area and construction year from household energy standing survey in Korea
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Na Hyeon Lee and Dong Hyun Seo
- Published
- 2021
36. Crystal Reconstruction of Mo:BiVO 4 : Improved Charge Transport for Efficient Solar Water Splitting
- Author
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Yoo Jae Jeong, Dong Hyun Seo, Ji hyun Baek, Min Je Kang, Bit Na Kim, Sung kyu Kim, Xiaolin Zheng, and In Sun Cho
- Subjects
Biomaterials ,Electrochemistry ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2022
37. PG-CAS: Patterned-Ground Co-Planar Capacitive Asymmetry Sensing for mm-Range EM Side-Channel Attack Probe Detection
- Author
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Santosh Ghosh, Baibhab Chatterjee, Mayukh Nath, Dong-Hyun Seo, Debayan Das, and Shreyas Sen
- Subjects
Materials science ,Electronic oscillator ,business.industry ,Low-pass filter ,Amplifier ,Capacitive sensing ,Optoelectronics ,business ,Signal ,Capacitance ,Sensitivity (electronics) ,Electronic circuit - Abstract
Electromagnetic (EM) side-channel analysis (SCA) attack, which breaks cryptographic implementations, has become a major concern in the design of circuits and systems. This paper presents the design and analysis of the EM side-channel attack detection system utilizing patterned-ground co-planar capacitive asymmetry sensing (PG-CAS) for approaching probe, targeting to improve sensitivity, detection range, and power consumption compared to LC oscillator utilizing inductive sensing. The PG-CAS consists of a grid of four metal plates of the same size at the top metal layer and a patterned ground plane at a lower metal. As an EM probe approaches, electric field lines between the plates and plate-ground get distorted, thereby breaking the symmetry of the inter-plate and the plate-ground capacitance system and this change in capacitance is sensed. The PG-CAS circuit consists of two LC oscillators, mixer, low pass filter (LPF), resistive feedback amplifier (RFA) and a digital logic. By down-converting sensing signal to low-frequency using mixer, LPF, RFA and digital logic, the detection range is significantly improved. At a distance of 1 mm between the sensing metal plates and the approaching EM probe, system-level simulation results using TSMC 65nm technology and Ansys Maxwell show a > 10% change in the output frequency from the baseline frequency, leading to a > 10× improvement in the detection range and a ~ 3× improvement in power consumption over existing inductive sensing methods.
- Published
- 2021
38. A Context-aware Reconfigurable Transmitter with 2.24 pJ/bit, 802.15.6 NB-HBC and 4.93 pJ/bit, 400.9 MHz MedRadio Modes with 33.6% Transmit Efficiency
- Author
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Dong-Hyun Seo, Baibhab Chatterjee, Abhishek Srivastava, David Yang, and Shreyas Sen
- Subjects
Narrowband ,business.industry ,Computer science ,Transmitter ,Electrical engineering ,Wireless ,Context (language use) ,Energy consumption ,business ,Data transmission ,Communication channel ,Efficient energy use - Abstract
The emerging Narrowband Human Body Communication (NB-HBC) technology, as well as MedRadio communication in the 400 MHz band promise better energy efficiencies than traditional Bluetooth Low Energy for wireless body area networks (WBAN) due to lower channel losses and lower frequencies, respectively. Although HBC offers less than 10pJ/bit energy efficiencies, it strictly demands both the transmitter and receiver to be on the body. Traditional MedRadio enables data transfer even when either devices are not on the body, but consumes orders of magnitude more energy than HBC, primarily due to large power consumption in LO generation. In this work, for the first time, we demonstrate a COntext-aware, Reconfigurable transmitter (COR-Tx) consisting sub-3pJ/bit HBC and sub-5pJ/bit MedRadio modes (both state-of-the-art), while supporting opportunistic switching between the two modes depending on the location of the receiver (on-body/off-body) for achieving optimum system-level energy with seamless communication. For 10 Mbps data rate, the HBC mode achieves an energy efficiency of 2.24pJ/bit, while the MedRadio mode achieves 4.93pJ/bit using a shared LO generation scheme that utilizes direct-modulated edge combination (EC) for minimizing energy consumption. The energy-efficiency improvement over the state-of-the-art is ~2.1X for HBC and ~90X for MedRadio.
- Published
- 2020
39. 27.3 EM and Power SCA-Resilient AES-256 in 65nm CMOS Through >350× Current-Domain Signature Attenuation
- Author
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Arijit Raychowdhury, Josef Danial, Debayan Das, Muya Chang, Harish K. Krishnamurthy, Baibhab Chatterjee, Dong-Hyun Seo, Anupam Golder, Avinash L. Varna, Santosh Ghosh, Sanu Mathew, Shreyas Sen, Nirmoy Modak, and Shovan Maity
- Subjects
business.industry ,Computer science ,Attenuation ,Advanced Encryption Standard ,Electrical engineering ,Regulator ,Voltage regulator ,law.invention ,Capacitor ,CMOS ,law ,business ,Shunt (electrical) ,Leakage (electronics) - Abstract
Computationally-secure cryptographic algorithms when implemented on physical platforms leak critical physical signals correlated with the secret key in the form of power consumption and electromagnetic (EM) emanations. This can be exploited by an adversary, leading to side-channel attacks (SCA) that can recover the secret key. Circuit-level on-chip countermeasures include a switched-capacitor current equalizer [1], charge-recovery logic [2], an integrated voltage regulator (IVR) [3], and an all-digital low-dropout (LDO) regulator [4], which suffer from performance degradation, high power/area overheads because of large embedded passives, as well as EM leakage from large metal-insulator-metal (MIM) capacitor top plates. Alternatively, simulations of shunt LDO-based regulators have been shown to be effective for power SCA resistance [5]. Noting that the correlated current is the source of both power (at supply pin) and EM leakage (radiation throughout current path), this work embraces current-domain ‘signature attenuation’ (CDSA) as a low-overhead generic countermeasure against both EM and power side-channel attacks to achieve the highest minimum traces to disclosure (MTD $> 1\mathrm{B})$ reported to date.
- Published
- 2020
40. Therapeutic Effects of Multimodal Biophysical Stimulation on Muscle Atrophy in a Mouse Model
- Author
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Seungkwan Cho, Byungjo Jung, Han Sung Kim, Dong-Hyun Seo, Jongbum Seo, Hana Lee, Donghyun Hwang, and Seo Hyun Kim
- Subjects
0301 basic medicine ,Pathology ,medicine.medical_specialty ,business.industry ,Mechanical Engineering ,Muscle structures ,Ultrasound ,Therapeutic effect ,Stimulation ,Biological tissue ,Stimulus (physiology) ,Industrial and Manufacturing Engineering ,Muscle atrophy ,03 medical and health sciences ,030104 developmental biology ,medicine ,Sciatic nerve ,Electrical and Electronic Engineering ,medicine.symptom ,business - Abstract
Muscle atrophy is defined as the decrease in the size and number of muscle fibers, and is associated with injury to muscle structures. Recently, biophysical therapies using laser, ultrasound, and vibration has been widely used to improve muscle atrophy. However, although the effects of these stimuli seem to be similar, the mechanisms by which they stimulate biological tissue may be different. From this point of view, we expected that it would be possible to produce synergetic effects through combining these three different types of biophysical stimuli on biological tissues, based on the therapeutic benefit of each stimulus. For this, 35 males, 12-week old, C57BL/6 mice (21 ± 1.2 g), were randomly assigned to five groups: a) a sciatic nerve neurectomized “control” group (C, n = 7), b) a MILNS (Minimally Invasive Laser Needle System) therapy after sciatic nerve neurectomized group (L, n = 7), c) a LIPUS (Low-Intensity Pulsed Ultrasound) therapy after sciatic nerve neurectomized group (U, n = 7), e) a PVS (Partial Vibration Stimulation) therapy after sciatic nerve neurectomized group (V, n = 7), and e) a multimodal biophysical stimulation after sciatic nerve neurectomized group (MS, n = 7).
- Published
- 2018
41. Repressive effects of red bean, Phaseolus angularis, extracts on obesity of mouse induced with high-fat diet via downregulation of adipocyte differentiation and modulating lipid metabolism
- Author
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Young Mi Park, Dong Hyun Seo, Jong Eun Lee, Je-Yong Choi, Eul-Won Seo, Joo Hee Seo, Jae-Hwan Lim, and Jee-In Kim
- Subjects
0301 basic medicine ,medicine.medical_specialty ,030109 nutrition & dietetics ,Triglyceride ,Chemistry ,Cell ,Blood lipids ,Lipid metabolism ,medicine.disease ,Applied Microbiology and Biotechnology ,Obesity ,03 medical and health sciences ,chemistry.chemical_compound ,medicine.anatomical_structure ,Endocrinology ,Downregulation and upregulation ,Internal medicine ,Adipocyte ,medicine ,Transcription factor ,Food Science ,Biotechnology - Abstract
Obesity is generally caused by quantitative changes in adipocyte differentiation and fat metabolism. Only a few studies have been determined the effect of red beans extract on obesity and plasma cholesterol concentration. We have been studied the functional activities of red-bean extracts including anti-oxidative effect against DNA and cell damages. Histological study including micro CT analysis showed that the accumulation of fat in hepatocytes and intestines was significantly decreased in red bean extract treated group. In addition, plasma cholesterol and triglyceride levels were decreased in blood samples. In addition, it was confirmed that the red bean extract inhibited the expression of PPARγ, Fabp4 and RETN genes, which regulate total adipocyte differentiation and lipid metabolism. Red bean extract inhibits the expressions of transcription factors associated with adipocyte differentiation in a dose-dependent manner, thereby inhibiting fat accumulation and decreasing blood lipid levels in obese mice induced by high fat diet.
- Published
- 2018
42. A study on the increasing advance length by pre-supported tunnelling method in heavily fractured rock condition
- Author
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Seung-Jin Shin, Kook-Hwan Cho, Dong-Hyun Seo, and Min Ho Shin
- Subjects
Geotechnical engineering ,Geology ,Quantum tunnelling - Published
- 2018
43. The effect of multi-frequency whole-body vibration on night-shifted mouse model
- Author
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Hansung Kim, Hana Lee, Young-Jin Jung, Donghyun Kim, Dong-Hyun Seo, Seo Hyun Kim, Seungkwan Cho, and Donghyun Hwang
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Physiology ,business.industry ,Adipose tissue ,Male mice ,030209 endocrinology & metabolism ,Normal group ,03 medical and health sciences ,Health problems ,030104 developmental biology ,0302 clinical medicine ,Neuropsychology and Physiological Psychology ,Endocrinology ,Neurology ,In vivo ,Physiology (medical) ,Internal medicine ,medicine ,Whole body vibration ,Circadian rhythm ,Tibia ,business - Abstract
The circadian rhythm controls several biological activities; therefore, a disorganized circadian rhythm may cause fatal health problems. The aim of this study was to assess the effects of circadian rhythm disturbances induced by simulated night shift activities on the abdominal adipose tissue, bone microstructures and muscle volume in the tibiae of mice. Moreover, we evaluated the effects of multi-frequency whole-body vibration as a countermeasure against the consequences of circadian rhythm disturbances. Twenty-four 5-week-old C57BL/6J male mice were equally assigned to three groups: the normal group (Nor), night shift group (NS), and night shift with multi-frequency whole-body vibration group (NS + V). The NS and NS + V groups were exposed to circadian rhythm disturbances for 4 weeks with 3-day intervals by changing the day and night cycle based on 7 o’clock. After 4 weeks, morphological changes in the adipose tissue, bone microstructures and muscle volume in the tibiae were evaluated from three-dimensional images using in vivo micro-computed tomography. As a result, the volume of the abdominal adipose tissue was significantly higher in the NS than in the Nor and NS + V groups. Also, the microstructures of the tibia were more enhanced in the NS + V than the NS group. The volume of tibial muscle was increased in all groups, while there were no significant changes in muscle volume. From these results, we can conclude that circadian rhythm disturbances induced by night shift activities may reduce bone condition and increase the accumulation of abdominal adipose tissue and these negative effects may be prevented or improved through applying multi-frequency whole-body vibration.
- Published
- 2018
44. Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting
- Author
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Dong Hyun Seo, Su Ryeun Chung, Cheong Lim, Kay-Hyun Park, Dong Jung Kim, and Jun Sung Kim
- Subjects
Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,medicine.medical_treatment ,lcsh:Surgery ,Coronary artery bypass ,030204 cardiovascular system & hematology ,Coronary artery disease ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,Clinical Research ,Minimally invasive surgery ,Medicine ,Thoracotomy ,Survival rate ,Stroke ,Computed tomography angiography ,medicine.diagnostic_test ,business.industry ,Mortality rate ,lcsh:RD1-811 ,medicine.disease ,Intensive care unit ,Surgery ,medicine.anatomical_structure ,030228 respiratory system ,Cardiology and Cardiovascular Medicine ,business ,Artery - Abstract
Background: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients. Methods: All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected. Results: The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in t he i ntensive c are u nit and in t he h ospital were 1 .5 a nd 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively. Conclusion: MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.
- Published
- 2018
45. Synthesis, structure, and bonding of hypoelectronic SrIn4: direct example of a dominant size effect in structure selection
- Author
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Dong-Hyun Seo and Corbett, John
- Subjects
Chemical bonds -- Observations ,Chemistry, Technical -- Research ,Chemistry - Published
- 2000
46. Euphorbia factor L1 inhibits osteoclastogenesis by regulating cellular redox status and induces Fas-mediated apoptosis in osteoclast
- Author
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Narae Kim, Dong Hyun Seo, Hansem Shon, Woojin Jeong, Hye In Lee, Seong Eun Hong, Hansung Kim, Jiae Lee, You Jin Jo, Minjung Kwon, Doo Ri Park, Gong Rak Lee, Soo Young Lee, and Eun Kyoung Seo
- Subjects
Male ,0301 basic medicine ,Osteoclasts ,Apoptosis ,Biochemistry ,Fas ligand ,Mice ,0302 clinical medicine ,Osteogenesis ,Phenylpropionates ,NF-kappa B ,Cell Differentiation ,Fas receptor ,Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ,Cell biology ,medicine.anatomical_structure ,RANKL ,Caspases ,030220 oncology & carcinogenesis ,Female ,Diterpenes ,Signal transduction ,Proto-Oncogene Proteins c-fos ,Signal Transduction ,musculoskeletal diseases ,medicine.medical_specialty ,Fas Ligand Protein ,NF-E2-Related Factor 2 ,Primary Cell Culture ,Biology ,Bone resorption ,03 medical and health sciences ,Osteoclast ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,fas Receptor ,Bone Resorption ,NFATC Transcription Factors ,Macrophages ,RANK Ligand ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,Gene Expression Regulation ,biology.protein ,Reactive Oxygen Species - Abstract
Excessive bone resorption caused by increased osteoclast number or activity leads to a variety of bone diseases including osteoporosis, rheumatoid arthritis and periodontitis. Thus, the therapeutic strategy for these diseases has been focused primarily on the inhibition of osteoclast formation and function. This study shows that euphorbia factor L1 (EFL1), a diterpenoid isolated from Euphorbia lathyris, inhibited osteoclastogenesis and induced osteoclast apoptosis. EFL1 suppressed osteoclast formation and bone resorption at both initial and terminal differentiation stages. EFL1 inhibited receptor activator of NF-κB ligand (RANKL)-induced NFATc1 induction with attenuated NF-κB activation and c-Fos expression. EFL1 decreased the level of reactive oxygen species by scavenging them or activating Nrf2, and inhibited PGC-1β that regulates mitochondria biogenesis. In addition, EFL1 induced apoptosis in differentiated osteoclasts by increasing Fas ligand expression followed by caspase activation. Moreover, EFL1 inhibited inflammation-induced bone erosion and ovariectomy-induced bone loss in mice. These findings suggest that EFL1 inhibits osteoclast differentiation by regulating cellular redox status and induces Fas-mediated apoptosis in osteoclast, and may provide therapeutic potential for preventing or treating bone-related diseases caused by excessive osteoclast.
- Published
- 2017
47. Wavelet Histogram-Based Characteristic Analysis in Mouse with Arthritis
- Author
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Joomin Lee, Seung Rim Hwang, Dong-Hyun Seo, and Kim Jonghoon
- Subjects
Wavelet ,business.industry ,Computer science ,Histogram ,medicine ,Arthritis ,Pattern recognition ,Artificial intelligence ,business ,medicine.disease - Published
- 2017
48. Development and Implementation of the History of Science and Technology Program for Understanding of Technical High School Students about the Nature of Science
- Author
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Young Hee Lee, Hunkoog Jho, and Dong Hyun Seo
- Abstract
본 연구는 공업계열 특성화고 학생들을 위한 과학기술사 수업 프로그램을 개발하고 적용함으로써 과학의 본성에 대한 이해에 미치는 교육적 효과를 조사하였다. 프로그램은 고등학교 융합 과학 및 물리 I의 교육과정을 바탕으로 6개의 과학기술사 주제로 개발되었으며, 경기도에 위치한 공업계열 특성화고 학생 290명을 대상으로 적용되었다. 본 연구의 방법은 단일 그룹 사전-사후 검사로 설계되었으며. 학생들의 과학의 본성에 대한 이해를 조사하고자 프로그램 적용 전후에 설문을 실시하여 그 검사 결과를 SPSS 23을 이용하여 통계 분석을 실시하였다. 과학의 본성에 대한 설문도구는 선행연구에서 개발된 4가지 영역의 과학의 본성 개념 틀(Lee, 2014)을 수정 보완하여 사용하였다. 본 연구의 결과는 다음과 같다. 첫째, 공업계열 특성화고 학생들의 과학의 본성에 이해에 대한 사전·사후 비교 결과, 과학기술사 수업 프로그램이 학생들의 이해에 효과가 있는 것으로 나타났다. 둘째, 과학기술사 수업 프로그램의 효과는 특성화고 학생들의 성별 및 전공에 따른 차이는 없는 것으로 나타났다. 셋째, 과학의 본성 4가지 영역간의 상관관계 분석에 의하면, 4가지 영역들은 모두 상호 높은 상관관계가 있는 것으로 나타났으며, 특히 각 개별 영역들은 모두 과학과 기술, 그리고 사회와의 상호작용에 대한 과학의 본성 측면과 상관관계가 있는 것이 발견되었다. 한편, 과학기술사 수업 프로그램은 구체적으로 어떻게 학생들의 과학의 본성에 대한 이해에 효과가 있는지에 대한 후속 연구가 필요하다.
- Published
- 2017
49. A Study on Occupancy Estimation Method of a Private Room Using IoT Sensor Data Based Decision Tree Algorithm
- Author
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Seok-Ho Kim and Dong-Hyun Seo
- Subjects
Estimation ,Engineering ,Occupancy ,business.industry ,Decision tree learning ,Decision tree ,Data mining ,Internet of Things ,business ,computer.software_genre ,computer - Published
- 2017
50. Evaluation of Daylighting Performance in Office Building with Detailed Global Illuminance Data of Selected Korean Cities
- Author
-
Su-Hyun Choi, Sang-Yong Shin, and Dong-Hyun Seo
- Subjects
Architectural engineering ,Geography ,020209 energy ,021105 building & construction ,0211 other engineering and technologies ,0202 electrical engineering, electronic engineering, information engineering ,Illuminance ,02 engineering and technology ,Daylighting - Published
- 2016
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