• 천문학회보
• /
• 제44권1호
• /
• pp.75.2-75.2
• /
• 2019

Low surface brightness (LSB) dwarf galaxies hold a key to resolve the small-scale problems of Lambda Cold Dark Matter (LCDM) paradigm such as missing satellites problem. Many recent studies found LSB dwarf galaxies around massive galaxies beyond Local Group up to 10Mpc. Motivated by this, we can increase the number of them by searching for LSB dwarf galaxies around galaxies up to 40Mpc. We use stacked deep (${\mu}_R{\sim}26.2mag\;arcsec^{-2}$) optical B, R-band images taken from Maidanak 1.5m telescope, one of facilities of Intensive Monitoring Survey of Nearby Galaxies (IMSNG) which monitored nearby galaxies in a day cadence from 2014 to 2016. Extended LSB sources in ambient regions of 16 nearby galaxies are selected using central surface brightness and total R magnitude criteria. After that, 24 LSB dwarf candidates are selected with visual inspection. To identify if the candidates are satellites or not, we are trying to compare the number density of LSB dwarf candidates around massive galaxies with those in Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS) wide fields which have no dominant massive galaxies for control sample.

• Korean journal of medical education
• /
• 제30권4호
• /
• pp.295-308
• /
• 2018

Purpose: Although medical curricula are now better structured for integration of biomedical sciences and clinical training, most teaching and learning activities still follow the older teacher-centric discipline-specific formats. A newer pedagogical approach, known as Collaborative Learning Cases (CLCs), was adopted in the medical school to facilitate integration and collaborative learning. Before incorporating CLCs into the curriculum of year 1 students, two pilot runs using the action research method was carried out to improve the design of CLCs. Methods: We employed the four-phase Kemmis and McTaggart's action research spiral in two cycles to improve the design of CLCs. A class of 300 first-year medical students (for both cycles), 11 tutors (first cycle), and 16 tutors (second cycle) were involved in this research. Data was collected using the 5-points Likert scale survey, open-ended questionnaire, and observation. Results: From the data collected, we learned that more effort was required to train the tutors to understand the principles of CLCs and their role in the CLCs sessions. Although action research enables the faculty to improve the design of CLCs, finding the right technology tools to support collaboration and enhance learning during the CLCs remains a challenge. Conclusion: The two cycles of action research was effective in helping us design a better learning environment during the CLCs by clarifying tutors' roles, improving group and time management, and meaningful use of technology.

• Korean Chemical Engineering Research
• /
• 제59권4호
• /
• pp.639-643
• /
• 2021

본 연구에서는 3차원 다층 미세유체 디바이스를 제작하기 위한 접착제로서 불소화 에틸렌 프로필렌(fluorinated ethylene propylene, FEP) 나노입자를 연구하였다. FEP 분산 용액을 1500 rpm에서 30초 동안 단순 스핀 코팅하여 기판에 3 ㎛ 두께의 균일하게 분포된 FEP 나노 입자 층을 형성하였다. FEP 나노입자는 300 ℃에서 1시간 동안 열처리 후 소수성 박막으로 변형되었으며, FEP 나노입자를 이용하여 제작된 폴리이미드 필름 기반 미세유체 디바이스는 최대 2250 psi의 압력을 견디는 것을 확인하였다. 마지막으로 기존의 포토리소그래피로 제작하기 어려운 16개의 마이크로 반응기로 구성된 3차원 다층 미세유체 디바이스를 FEP가 코팅된 9개의 폴리이미드 필름을 간단한 1단계 정렬로 성공적으로 구현하였다. 개발된 3차원 다층 미세유체 디바이스는 화학 및 생물학의 다양한 응용을 위한 고속대량 스크리닝, 대량 생산, 병렬화 및 대규모 미세유체 통합과 같은 강력한 도구가 될 가능성이 있습니다.

• Korean Journal of Acupuncture
• /
• 제38권3호
• /
• pp.175-181
• /
• 2021

A 57-year-old female diagnosed with L5-S1 lumbar intervertebral disc herniation, suffering from severe pain despite taking tapentadol received combined Korean medicine treatment, including acupotomy, acupuncture, pharmacopuncture, and herbal therapies for 53 days. To assess pain, Numeric Rating Scale (NRS) and lumbar range of motion (ROM) were checked daily from the day of admission. Moreover, the Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) were used to evaluate function and quality of life. After combined Korean medicine treatment, reabsorptioin of intervertebral disc was confirmed by radiological examination; pain reduced from NRS 5~7 to NRS 1~2; lumbar ROM in extention increased from 20° to 30°; and function and quality of life improved. The results suggest the possibility that a combined Korean medical treatment, including acupotomy, can be used as an alternative to opioids for pain management of lumbar vertebral disc herniation.

• Journal of Microbiology and Biotechnology
• /
• 제32권10호
• /
• pp.1325-1334
• /
• 2022

Global warming has accelerated in recent decades due to the continuous consumption of petroleum-based fuels. Cyanobacteria-derived biofuels are a promising carbon-neutral alternative to fossil fuels that may help achieve a cleaner environment. Here, we propose an effective strategy based on the large-scale cultivation of a newly isolated cyanobacterial strain to produce phycobiliprotein and biodiesel, thus demonstrating the potential commercial applicability of the isolated microalgal strain. A native cyanobacterium was isolated from Goryeong, Korea, and identified as Pseudanabaena mucicola GO0704 through 16s RNA analysis. The potential exploitation of P. mucicola GO0704 was explored by analyzing several parameters for mixotrophic culture, and optimal growth was achieved through the addition of sodium acetate (1 g/l) to the BG-11 medium. Next, the cultures were scaled up to a stirred-tank bioreactor in mixotrophic conditions to maximize the productivity of biomass and metabolites. The biomass, phycobiliprotein, and fatty acids concentrations in sodium acetate-treated cells were enhanced, and the highest biodiesel productivity (8.1 mg/l/d) was achieved at 96 h. Finally, the properties of the fuel derived from P. mucicola GO0704 were estimated with converted biodiesels according to the composition of fatty acids. Most of the characteristics of the final product, except for the cloud point, were compliant with international biodiesel standards [ASTM 6761 (US) and EN 14214 (Europe)].

• Structural Engineering and Mechanics
• /
• 제81권3호
• /
• pp.293-303
• /
• 2022

As infrastructure ages and traffic load increases, serious public concerns have arisen for the well-being of bridges. The current health monitoring practice focuses on large-scale bridges rather than short span bridges. However, it is critical that more attention should be given to these behind-the-scene bridges. The relevant information about the construction methods and as-built properties are most likely missing. Additionally, since the condition of a bridge has unavoidably changed during service, due to weathering and deterioration, the material properties and boundary conditions would also have changed since its construction. Therefore, it is not appropriate to continue using the design values of the bridge parameters when undertaking any analysis to evaluate bridge performance. It is imperative to update the model, using finite element (FE) analysis to reflect the current structural condition. In this study, a FE model is established to simulate a concrete culvert bridge in New South Wales, Australia. That model, however, contains a number of parameter uncertainties that would compromise the accuracy of analytical results. The model is therefore updated with a neural network (NN) optimisation algorithm incorporating Monte Carlo (MC) simulation to minimise the uncertainties in parameters. The modal frequency and strain responses produced by the updated FE model are compared with the frequency and strain values on-site measured by sensors. The outcome indicates that the NN model updating incorporating MC simulation is a feasible and robust optimisation method for updating numerical models so as to minimise the difference between numerical models and their real-world counterparts.

• Advances in nano research
• /
• 제14권3호
• /
• pp.211-224
• /
• 2023

This work presents a modified analytical model for the bending behavior of axially functionally graded (AFG) carbon nanotubes reinforced composite (CNTRC) nanobeams. New higher order shear deformation beam theory is exploited to satisfy parabolic variation of shear through thickness direction and zero shears at the bottom and top surfaces.A Modified continuum nonlocal strain gradient theoryis employed to include the microstructure and the geometrical nano-size length scales. The extended rule of the mixture and the molecular dynamics simulations are exploited to evaluate the equivalent mechanical properties of FG-CNTRC beams. Carbon nanotubes reinforcements are distributed axially through the beam length direction with a new power graded function with two parameters. The equilibrium equations are derived with associated nonclassical boundary conditions, and Navier's procedure are used to solve the obtained differential equation and get the response of nanobeam under uniform, linear, or sinusoidal mechanical loadings. Numerical results are carried out to investigate the impact of inhomogeneity parameters, geometrical parameters, loadings type, nonlocal and length scale parameters on deflections and stresses of the AFG CNTRC nanobeams. The proposed model can be used in the design and analysis of MEMS and NEMS systems fabricated from carbon nanotubes reinforced composite nanobeam.

• Journal of Information Science Theory and Practice
• /
• 제10권spc호
• /
• pp.46-55
• /
• 2022

Eight years have passed since the Sponsoring Consortium for Open Access Publishing in Particle Physics (SCOAP3) was launched. SCOAP3 is one of the most successful global partnerships and funds for Open Access and has been benchmarked by other Open Access initiatives. The Korea Institute of Science and Technology Information (KISTI) joined as the first Asian partner in 2011, and has supported its shared vision and contributed its financial commitment since the beginning of SCOAP3. SCOAP3-Korea is the first bottom-up collaboration for local libraries to re-direct funds previously used for subscriptions to Open Access publishing. This paper explores the roles and responsibilities of KISTI in the Open Access quest. It describes the commitment to SCOAP3 in South Korea, including how the collaboration model for SCOAP3-Korea differs from the global model. This paper also discusses the impact of SCOAP3-Korea by analyzing publications affiliated by Korean authors in SCOAP3 journals for the last six years (2014-2019). We have integrated the national R&D project and research outcome data from NTIS (National Science and Technology Information Service) to investigate the research articles benefited by SCOAP3 and research publications in non-SCOAP3 journals. The positive impact of SCOAP3 in increasing research publication in the discipline was revealed compared to non-SCOAP3 journals. In addition, the financial benefit of SCOAP3-Korea has been proven. With regard to the investment for readers, $137,094 USD was saved during the SCOAP3 Phase 1 and 2, while $748,923 USD was saved with regard to publication fees. We discussed the lessons from SCOAP3-Korea for commitment to a larger-scale Open Access transition.

• 동의신경정신과학회지
• /
• 제33권1호
• /
• pp.33-48
• /
• 2022

Objectives: Academic stress poses a significant risk for the mental health of medical students, and a feasible group intervention program for managing academic stress is required. The purpose of this study was to examine the clinical effectiveness of emotional freedom techniques (EFT) on the mental health of Korean medical students. Methods: The class of first-year medical school students (n=36) participated in an after-school EFT group intervention program comprising six sessions (15 minutes/session, three weeks) to analyze its clinical effectiveness as a single-group test-retest clinical study. The changes in the Perceived Stress Scale (PSS), Test Anxiety Inventory (TAI), Positive and Negative Affect Schedule (PANAS), and State-Trait Anxiety Inventory (STAI) scores were examined using a paired t-test and Cohen's D at post-EFT and two-week follow-up. Results: There were significant curtailments at post-EFT and follow-up measures in TAI-Total (t=2.704 and t=3.289), TAI-Worry (t=2.297 and t=2.454), TAI-Emotionality (t=2.763 and t=3.654), PSS-Negative Perspective (t=2.659 and t=3.877), and PANAS-Negative Affect (t=2.885 and t=3.259) subscales, however not in PSS-Positive Perspective (t=-1.279 and t=-1.101) and PANAS-Positive Affect (t=0.194 and t=-0.122) subscales. The trait anxiety (t=2.227) was significantly mitigated in the post-EFT measure and the state anxiety (t=2.30) in the follow-up measure. Conclusions: The EFT group intervention alleviated test stress, negative affect, and anxiety in the Korean medical students. This study contributes to an understanding of academic stress and EFT intervention in the competitive environment of medical education.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2020년도 학술발표회
• /
• pp.125-125
• /
• 2020

European Space Agency's Sentinel-1 has an improved spatial and temporal resolution, as compared to previous satellite data such as Envisat Advanced SAR (ASAR) or Advanced Scatterometer (ASCAT). Thus, the assumption used for low-resolution retrieval algorithms used by ENVISAT ASAR or ASCAT is not applicable to Sentinel-1, because a higher degree of land surface heterogeneity should be considered for retrieval. The assumption of homogeneity over land surface is not valid any more. In this study, considering that soil roughness is one of the key parameters sensitive to soil moisture retrievals, various approaches are discussed. First, soil roughness is spatially inverted from Sentinel-1 backscattering over Yanco sites in Australia. Based upon this, Artificial Neural Networks data (feedforward multiplayer perception, MLP, Levenberg-Marquadt algorithm) are compared with Fractal approach (brownian fractal, Hurst exponent of 0.5). When using ANNs, training data are achieved from theoretical forward scattering models, Integral Equation Model (IEM). and Sentinel-1 measurements. The network is trained by 20 neurons and one hidden layer, and one input layer. On the other hand, fractal surface roughness is generated by fitting 1D power spectrum model with roughness spectra. Fractal roughness profile is produced by a stochastic process describing probability between two points, and Hurst exponent, as well as rms heights (a standard deviation of surface height). Main interest of this study is to estimate a spatial variability of roughness without the need of local measurements. This non-local approach is significant, because we operationally have to be independent from local stations, due to its few spatial coverage at the global level. More fundamentally, SAR roughness is much different from local measurements, Remote sensing data are influenced by incidence angle, large scale topography, or a mixing regime of sensors, although probe deployed in the field indicate point data. Finally, demerit and merit of these approaches will be discussed.