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Self-Supervised Knowledge Transfer via Loosely Supervised Auxiliary Tasks [article]

Seungbum Hong, Jihun Yoon, Junmo Kim, Min-Kook Choi
2021 arXiv   pre-print
Knowledge transfer using convolutional neural networks (CNNs) can help efficiently train a CNN with fewer parameters or maximize the generalization performance under limited supervision. To enable a more efficient transfer of pretrained knowledge under relaxed conditions, we propose a simple yet powerful knowledge transfer methodology without any restrictions regarding the network structure or dataset used, namely self-supervised knowledge transfer (SSKT), via loosely supervised auxiliary
more » ... For this, we devise a training methodology that transfers previously learned knowledge to the current training process as an auxiliary task for the target task through self-supervision using a soft label. The SSKT is independent of the network structure and dataset, and is trained differently from existing knowledge transfer methods; hence, it has an advantage in that the prior knowledge acquired from various tasks can be naturally transferred during the training process to the target task. Furthermore, it can improve the generalization performance on most datasets through the proposed knowledge transfer between different problem domains from multiple source networks. SSKT outperforms the other transfer learning methods (KD, DML, and MAXL) through experiments under various knowledge transfer settings. The source code will be made available to the public.
arXiv:2110.12696v1 fatcat:tcpuknyr2vbsvduijufglz3zay

Plug-in nanoliter pneumatic liquid dispenser with nozzle design flexibility

In Ho Choi, Hojin Kim, Sanghyun Lee, Seungbum Baek, Joonwon Kim
2015 Biomicrofluidics  
Kim contributed equally to this work. b) Author to whom correspondence should be addressed. Electronic mail: joonwon@postech.ac.kr. Tel.: þ82-54-279-2185. Fax: þ82-54-279-2960.  ... 
doi:10.1063/1.4935937 pmid:26594263 pmcid:PMC4644146 fatcat:wp6yp3l4ofhgnjpkdb3anu3gei

Injection charge assisted polarization reversal in ferroelectric thin films

Yunseok Kim, Simon Bühlmann, Seungbum Hong, Seung-Hyun Kim, Kwangsoo No
2007 Applied Physics Letters  
The authors have investigated the polarization reversal on ferroelectric thin films caused by a grounded tip on 50-nm-thick Pb͑Zr, Ti͒O 3 films. Backswitching occurred when the grounded tip recontacted a "freshly" switched area. It is believed that the upper part of the film switches back due to the field between the grounded tip and previously injected charges. During dynamic operation, partial backswitching was observed during pulsed writing using pulse widths of 1 ms. The results show that
more » ... larization reversal is an issue, which has to be addressed in the writing scheme of future probe-based storage devices.
doi:10.1063/1.2679902 fatcat:tgh5lyepl5a4rkvkskmbpkib6i

Brain–Gut–Bone Marrow Axis

Monica M. Santisteban, Seungbum Kim, Carl J. Pepine, Mohan K. Raizada
2016 Circulation Research  
Hypertension is the most prevalent modifiable risk factor for cardiovascular disease and disorders directly influencing cardiovascular disease morbidity and mortality, such as diabetes mellitus, chronic kidney disease, obstructive sleep apnea, etc. Despite aggressive attempts to influence lifestyle modifications and advances in pharmacotherapeutics, a large percentage of patients still do not achieve recommended blood pressure control worldwide. Thus, we think that mechanism-based novel
more » ... es should be considered to significantly improve control and management of hypertension. The overall objective of this review is to summarize implications of peripheral-and neuroinflammation as well as the autonomic nervous system-bone marrow communication in hematopoietic cell homeostasis and their impact on hypertension pathophysiology. In addition, we discuss the novel and emerging field of intestinal microbiota and roles of gut permeability and dysbiosis in cardiovascular disease and hypertension. Finally, we propose a brain-gut-bone marrow triangular interaction hypothesis and discuss its potential in the development of novel therapies for hypertension. (Circ Res.
doi:10.1161/circresaha.116.307709 pmid:27081113 pmcid:PMC4834860 fatcat:2cuc3uizancyhdx6caihxsp7pe

A spring-type piezoelectric energy harvester

Dongjin Kim, Seungbum Hong, Dongjun Li, Hee Seok Roh, Gun Ahn, Jiyoon Kim, Moonkyu Park, Jongin Hong, Tae-hyun Sung, Kwangsoo No
2013 RSC Advances  
We developed a three-dimensional spring-type piezoelectric energy harvester using a dip-coating method and multi-directional electrode deposition. The energy harvester consists of a bilayered structure composed of a surface electrode and a ferroelectric polymer, on a conventional spring which has two rolesthe core electrode and the mechanical substrate for the ferroelectric polymer. The energy harvester generated an output voltage of up to 88 mV as a function of cycling compression stress,
more » ... leads to a piezoelectric constant of 28.55 pC N 21 for unpoled P(VDF-TrFE) films. Since the spring structure significantly decreases the resonance frequency of the harvester, the springtype energy harvester can effectively generate electricity using low-frequency vibration energy abundant in the nature.
doi:10.1039/c2ra22554a fatcat:lyxr2qbntbbmlgcpb7cokz22qi

The Gut, Its Microbiome, and Hypertension

Elaine M. Richards, Carl J. Pepine, Mohan K. Raizada, Seungbum Kim
2017 Current Hypertension Reports  
Richards, Pepine, Raizada, and Kim declare no conflicts of interest relevant to this manuscript.  ... 
doi:10.1007/s11906-017-0734-1 pmid:28444579 pmcid:PMC5846192 fatcat:kkt75m36rfhuhkaev4mvqpc4gu

Visualization of three dimensional domain structures in ferroelectric PbTiO3 nanotubes

Hyunjun Yoo, Changdeuck Bae, Myungjun Kim, Seungbum Hong, Kwangsoo No, Yunseok Kim, Hyunjung Shin
2013 Applied Physics Letters  
We report visualization of three-dimensional domain structures in ferroelectric PbTiO 3 (PTO) nanotubes (NTs) using piezoresponse force microscopy (PFM). The domain distributions of the x, y, and z-axes in PTO NTs were separately measured out-of and in-planes at angles of 0 and 90 by vertical and lateral PFM. The separately obtained PFM images were combined to reconstruct the complex domain structures based on some basic assumptions and finite element modeling. The cross-sectional domain
more » ... rations of the PTO NTs were visualized by the proposed approach. The results can provide insight into complex domain configurations of ferroelectric nanostructures.
doi:10.1063/1.4813239 fatcat:73rafettrvaxfmvilbt5hndkcm

The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Ångström Resolution

Binyang Hou, Seunghyun Kim, Taeho Kim, Jongjin Kim, Seungbum Hong, Chi Bum Bahn, Changyong Park, Ji Hyun Kim
2016 Scientific Reports  
Recently, Kim et al. used in-situ Raman spectroscopy to confirm the phase transformation of oxide film on zirconium alloy surface under hydrothermal conditions 9 .  ... 
doi:10.1038/srep27916 pmid:27302473 pmcid:PMC4908582 fatcat:b77s7c3sffhcrn5qowhqasmfzq

Long‐term trend and variability of surface humidity from 1973 to 2018 in South Korea

Ju‐Young Shin, Kyu Rang Kim, Jinwon Kim, Seungbum Kim
2021 International Journal of Climatology  
Water vapour is among the most critical variables that shape the Earth's energy balance and hydrologic cycle. Surface relative humidity (RH) and specific humidity (SH) are the main measures of atmospheric moisture. Long-term changes in these variables in South Korea vary regionally as well as locally, but have not been explored using long-term observation data. This study analyzes the annual trends of the means and SD of RH, surface air temperature, and SH in South Korea at 55 stations for the
more » ... eriod 1973-2018. Three trend detection tests based on the Mann-Kendall test have been performed to detect trends at the 5% significance level for the annual and monthly statistics (means and SD) of these variables. Significant decreasing and increasing trends have been detected in the annual means of RH and air temperature, while the annual mean of SH has remained nearly constant. Overall, the surface air in South Korea has become drier over the study period, particularly in winter. The trend in RH and SH varies widely according to months to result in the increase in the SD over the annual cycle. The monthly SD of RH, SH, and surface air temperature show especially large positive trends for March and September, when the transition from winter to spring and summer to fall, respectively, occurs. K E Y W O R D S climate change, global warming, relative humidity, specific humidity, trend analysis
doi:10.1002/joc.7068 fatcat:zx3v46zhc5atnja6i4gsbvgmdy

Anal Diseases from Ingested Foreign Bodies

Hansuk Kim, Seungbum Ryoo, Eun Kyung Choe, Dosun Kim, Doohan Lee, Kyu Joo Park
2009 Journal of the Korean Society of Coloproctology  
Anal problems due to ingested foreign bodies are rare and usually present as acute anal pain. However, various clinical presentations are possible. This study was performed to identify the diverse manifestations of and the outcomes of treatments for anal diseases caused by ingested foreign bodies. Methods: Between September 1995 and June 2003, seven patients were treated for anal diseases due to the impaction of ingested foreign bodies in Seoul National University Hospital and Daehang Hospital.
more » ... We retrospectively reviewed the medical records of those unusual patients. Results: All patients were males, and their mean age was 49.4 yr (range, 37 to 74 yr). The detected foreign bodies were fish bones (n=3), fish fins (n=2), a chicken bone (n=1), and a toothpick (n=1). Four patients had acute anal pain as the primary symptom while two patients presented anal pus discharge, and one patient presented anal bleeding. In the four patients with acute anal pain, the foreign bodies were easily found on digital rectal examination and inspection with anoscopy. Those patients underwent simple removal of the foreign body at the outpatient clinic. In three patients, the foreign bodies were found during surgery for hemorrhoids or fistulas. The two fistulas detected were complex types and needed seton placement. Conclusion: Anal problems caused by ingested foreign bodies usually involve acute anal pain, but our results indicate that, in some cases, the anal foreign bodies are also the cause or an aggravating factor in chronic anal disease.
doi:10.3393/jksc.2009.25.6.387 fatcat:dnrcdtj2zbci3c5lmqfnt5nnmq

Effects of NH4F and distilled water on structure of pores in TiO2 nanotube arrays

Jaegyu Kim, Bongsoo Kim, Chungik Oh, Jeongjae Ryu, Hongjun Kim, Eugene Park, Kwangsoo No, Seungbum Hong
2018 Scientific Reports  
In this study, we report the influences of distilled water and ammonium fluoride (NH 4 F) on morphology of pores in honeycomb-like titanium dioxide (TiO 2 ) nanotube arrays. We observed the structure and arrangement of pores in the TiO 2 nanotube arrays based on scanning electron microscopy images and analyzed the spatial distribution of the pores using fast Fourier transform and Voronoi diagram. We studied the individual pore properties including pore diameter, wall thickness, and interpore
more » ... tance and found that locally connected ordering defects decreased with increasing distilled water concentration. Furthermore, we found that the optimum conditions of well-ordered hexagonal pore arrangement were 2 and 10 vol% distilled water with 0.2 and 0.4 wt% NH 4 F, respectively. Throughout this study, we provide a better understanding about the roles of distilled water and NH 4 F in forming well-ordered nanoscale pore structure with less ordering defects in the honeycomb-like TiO 2 nanotube arrays. TiO 2 nanotube arrays have gained a lot of interest because their high surface area and effective separation 1-5 for both photo-electrons and photo-holes are attractive for a variety of applications like photocatalysts 6,7 , solar cells 8,9 , gas sensors, supercapacitors 10,11 , and filtering systems 12 . The morphology, length and geometry of the TiO 2 nanotube arrays strongly affect their performance, such as the efficiency of photocatalysis. For example, specific surface area, controlled by porosity, affects the photocurrents of the TiO 2 nanotube arrays 13 . It is worth noting that electrolyte, concentrations of F − ion and distilled water, applied voltage, anodizing time, pH and temperature can control the dimension and the morphology of the nanotubes 14-24 . This is important because if we can control the morphology, we can custom-tailor the TiO 2 nanotube arrays for the aforementioned applications. As such, many groups have studied the effects of the above-mentioned factors on the shape, size, and properties of the TiO 2 nanotube arrays during the anodization 23-26 . For example, González et al. 27 and Kojima et al. 17 analyzed the effects of the concentrations of water and F − ion on the diameter, length and anodization rate of the TiO 2 nanotube arrays. Other groups characterized the effects of anodizing time 20 and applied voltage 28 on the structural properties of the nanotubes. However, there are few reports on the effects of additives in the organic electrolyte on the hexagonal ordering of the pores during the anodization. The hexagonal ordering is the closest stacking structure of pores in two-dimension, which means that the pores are arranged uniformly in the closest form. If the TiO 2 nanotube arrays have a specific functional layer on the surface of the nanotubes, the close packed hexagonally arranged pores, which form the most efficient channel structure, can be used in photocatalysis and self-cleaning systems 12 . To elucidate this effect, we analyzed the influences of the concentrations of NH 4 F and distilled water on the pore distribution of the TiO 2 nanotube arrays. Here, we visualize the pore distribution using Voronoi diagram and fast Fourier transform (FFT). In addition, we analyze the morphology of individual pores. To understand the hexagonal ordering of the pores, we propose the mechanism on the formation of the ordering defects. We also present the optimal concentrations of the ethylene glycol electrolyte for uniform distribution of the pores.
doi:10.1038/s41598-018-30668-3 pmid:30131574 pmcid:PMC6104029 fatcat:lghnmn2gpjcsrffeu75exqalvu

Derivation Method of Architectural Asset Value Enhancement Zones in South Korea

Donghwa Shon, Seungbum Kim, Nahyang Byun
2022 Land  
In June 2014, South Korea enacted a law to systematically preserve and utilize architectural assets to strengthen national competitiveness through the enhancement of architectural culture. An architectural asset value enhancement zone (AAVE) can be designated for an area in which a unique spatial environment has been created, centered on excellent architectural assets or in which architectural assets are densely concentrated. However, five years after the law was promulgated, while 14 local
more » ... rnments had completed basic investigations of architectural assets, only three had been designated as AAVE zones (as of March 2020). This is because the criteria for non-Hanok architectural assets are unclear, making it difficult to specify the scope of designation. This study aims to present and verify a methodology for deriving more effective AAVE zones. After establishing the criteria for architectural asset candidates, densely populated areas across the country were identified using GIS. Subsequently, a methodology was derived to classify candidate areas for the enhancement zone, based on the locations of these densely populated areas and designated/registered cultural heritage sites. The effectiveness of the methodology was reviewed through an actual area analysis, which indicated that the methodology is highly applicable to AAVE zones.
doi:10.3390/land11040584 fatcat:kh7ijaofibekjad6kfkpfwjviu

Visualization of Ion Channels in Membranes using Electrochemical Strain Microscopy [article]

Suran Kim, Chungik Oh, Hongjun Kim, Yuanyuan Shi, Mario Lanza, Kwangsoo No, Seungbum Hong
2019 arXiv   pre-print
Polymer composite electrolytes of Nafion and phosphotungstic acid (PWA) are fabricated and analyzed using electrochemical strain microscopy (ESM) and conductive atomic force microscopy (C-AFM) to visualize hydrophilic ion channels near the surface, which are composed of water and sulfonic acid groups. The results indicate that the fibrillar objects in ESM image, without significant changes in topography, are hydrophilic ion channels and additional ion channels formed by interaction between PWA
more » ... nd sulfonic groups in Nafion. In this study, the buried ion channels lying under the surface are probed as well as the inlet and outlet of the channels on the surface through combined use of ESM and C-AFM. The results further enhance the understanding of ionic conduction in composite polymer electrolytes in various fields.
arXiv:1909.00789v2 fatcat:ybtidi7urzhxpm5saljimjmfpi

Current Concepts of Anterior Interosseous Nerve Syndrome

Seungbum Chae, Jongmin Kim, Il-Jung Park
2021 Archives of Hand and Microsurgery  
ORCID Seungbum Chae, https://orcid.org/0000-0003-3469-9289 Jongmin Kim, https://orcid.org/0000-0002-9911-5048 Il-Jung Park, https://orcid.org/0000-0001-8262-4287  ... 
doi:10.12790/ahm.21.0100 fatcat:w2yfyamffzgrte2idnprga5xt4

Classification of homogeneous regions of strong wind and gust wind in Korea

Hyunuk Kim, Baek-Jo Kim, Hyoung-Gu Nam, Jong Hyeok Jung, Jaekwan Shim, Kyu Rang Kim, Seungbum Kim
2020 SOLA : Scientific Online Letters on the Atmosphere  
In particular, wind speed is greatly influenced by terrain features (Kim and Kim 2013; Wu et al. 2018) .  ...  Most studies on climatological or meteorological regional classification focus mainly on rainfall and snowfall (Choi 1990; Kim et al. 2012; Kim et al. 2017; Moon and Kim 2001; Um et al. 2011) .  ... 
doi:10.2151/sola.2020-024 fatcat:pocwbpj6lzbyrffndzdvaufb5e
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