• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.447-454
• /
• 2022

The purpose of this study was to strengthen the practicality of preliminary teachers in preparation for future education, to respond to structural changes in the teacher training system due to a decrease in the school-age population, and to seek a future-oriented direction for the curriculum of teacher training institutions. To this end, we analyzed the competency diagnosis items of the teacher training institutes in the 5th cycle from 2019 to 2020, and based on the proposal for the development plan for the teacher training system announced by the Ministry of Education in July 2021 and the contents of the 4 discussions, content was presented. The results were as follows. First, to nurture creative and convergence-type talents, teacher training institutions need to develop multi-curricular competency and reorganize the curriculum into a future-oriented curriculum. Second, in order to foster the competence of teachers and preliminary teachers in teacher training institutions, it is essential to strengthen the competence of teachers through the introduction of the metaverse, general teaching methods, and ICT-using teaching methods. Third, teachers' training institutions will introduce and strengthen the 'education practice teacher homeroom system' to strengthen school field-oriented practical competencies, 'dedicated mentor-mentee' centered on seniors and juniors, 'monitoring system' led by university professors, and 'probationary teacher system'

• Tunnel and Underground Space
• /
• v.32 no.6
• /
• pp.435-450
• /
• 2022

In step-by-step site selection for geological disposal of high-level radioactive waste, parameters necessary for site selection will be acquired through deep drilling surveys from the basic survey stage. Unlike site investigations of rock mass structures such as tunnels and underground oil storage facilities, those related to the geological disposal of high-level radioactive waste are not only conducted in relatively deep depths, but also require a high level of quality control. In this report, based on the 750 m depth drilling experience conducted to acquire the parameters necessary for deep geological disposal, the methodology for deep drilling and the geology, geophysics, geochemistry, hydrogeology and rock mechanics obtained before, during, and after deep drilling are discussed. The procedures for multidisciplinary geoscientific investigations were briefly described. Regarding in-situ stress, one of the key evaluation parameter in the field of rock engineering, foreign and domestic cases related to the geological disposal of high-level radioactive waste were presented, and variations with depth were presented, and matters to be considered or agonized in acquiring evaluation parameters were mentioned.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.102-113
• /
• 2023

This review discusses the cellular and molecular mechanisms by which the endometrial estrogen and progesterone receptors regulate local estrogen production, expression of the specific estrogen receptors, progesterone resistance, inflammatory responses and the differentiation and survival of endometriotic cells in endometrial inflammation. The epigenetic aberrations of endometrial stromal cells play an important role in the pathogenesis and progression of endometriosis. In particular, differential methylation of the estrogen receptor genes changes in the stromal cells the dominancy of estrogen receptor from ERα into ERβ, and results in the abnormal estrogen responses including inflammation, progesterone resistance and the disturbance of retinoid synthesis. These stromal cells also stimulate local estrogen production in response to PGE2 and the SF-1 mediated induction of steroidogenic enzyme expression, and the increased estradiol then feeds back into the ERβ to repeat the vicious inflammatory cycle through the activation of COX-2. In addition, high levels of ERβ expression may also change the chromatin structure of endometrial mesenchymal stem cells, and together with the repeated menstrual cycles can induce formation of the endometriotic tissue. The cascade of these serial events then leads to cell adhesion, angiogenesis and survival of the differentiation-disregulated stromal cells through the action of inflammatory factors such as ERβ-mediated estrogen, TNF-α and TGF-β1. Therefore, understanding of the dynamic hormonal changes during the menstrual cycle and the corresponding signal transduction mechanisms of the related nuclear receptors in endometrium would provide new insights for treating inflammatory diseases such as the endometriosis.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.465-465
• /
• 2023

집중호우시 농경지에서 발생하는 흙탕물은 수질 및 수생태계를 오염시키며, 환경오염에 따른 사회·경제적 문제를 지속적으로 초래하고 있다. 정부와 지자체는 흙탕물 발생이 심각한 지역을 '비점오염원관리지역'으로 지정·고시하여 흙탕물 저감사업을 추진하였으나, 뚜렷한 성과를 나타내지 못하고 있는 실정이다. 최근 정부의 흙탕물 저감사업은 저감시설 설치 등과 같은 구조적 방법에서 발생원관리 중심으로 패러다임이 전환되고 있다. 농경지에서 발생하는 비점오염원의 발생원관리를 위해서는 주민들의 적극적인 참여가 필수적이나, 아직까지 주민들의 비점오염원에 대한 인식이 낮은 수준에 머무르고 있다. 따라서, 본 연구에서는 주민참여 거버넌스를 구축하여 주민들의 인식을 개선하고, 주민들의 참여를 유도하여 농촌지역 실정에 맞는 주민참여형 농업비점오염 관리의 기반을 마련하고자 하였다. 연구대상지는 강원도 비점오염원관리지역인 가아지구 내 강원도 인제군 인제읍 가아2리 마을일원으로, 본 연구의 참여농가는 총 10농가, 참여농지 면적은 21.81 ha이다. 참여농가를 대상으로2022년 10월 9일, 10월 16일, 10월 23일 총 3회에 걸쳐 주민 교육을 실시하였으며, 주기적인 설문조사를 통해 교육 진행에 따른 주민 인식 변화를 측정하였다. 설문조사는 교육참여자를 대상으로 3회 실시하였으며, 농업비점오염 개념, 최적관리기법의 이해, 비점오염저감 활동참여 의지에 관한 내용으로 구성하였다. 설문조사 점수에 대한 기준은 전혀아니다(1점), 그렇지않다(2점), 보통이다(3점), 그렇다(4점), 매우 그렇다(5점)로 선정하였다. 설문조사 결과 농업비점오염원의 대한 이해도는 1차 62점, 2차 66점, 3차 80점, 최적관리기법의 이해도는 1차 59점, 2차 64점, 3차 75점, 비점오염저감 활동참여 의지도는 1차 61점, 2차 73점, 3차 80점으로 나타났다. 1차 설문조사 결과 대비 3차설문조사 결과 농업비점오염의 개념 및 최적관리기법의 이해도는 22.5, 21.3% 증가하는것으로 분석되었으며, 비점오염저감 활동참여 의지도는 23.8% 증가하는 것으로 분석되었다. 조사 결과와 같이 교육을 통해 주민들의 인식이 전환된 것으로 분석되었으며, 비점오염원 저감활동에 대한 의지가 표준 이상으로 나타나 주민 참여 거버넌스 구축 연구를 통해 실질적인 농촌 비점오염 관리가 가능할 것이라 기대된다.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.5
• /
• pp.403-411
• /
• 2023

Functional ultrasound imaging, such as elasticity imaging and micro-blood flow Doppler imaging, enhances diagnostic capability by providing useful mechanical and functional information about tissues. However, the implementation of functional ultrasound imaging poses limitations such as the storage of vast amounts of data in Radio Frequency (RF) data acquisition and processing. In this paper, we propose a sub-Nyquist approach that reduces the amount of acquired axial samples for efficient shear-wave elasticity imaging. The proposed method acquires data at a sampling rate one-third lower than the conventional Nyquist sampling rate and tracks shear-wave signals through RF signals reconstructed using band-pass filtering-based interpolation. In this approach, the RF signal is assumed to have a fractional bandwidth of 67 %. To validate the approach, we reconstruct the shear-wave velocity images using shear-wave tracking data obtained by conventional and proposed approaches, and compare the group velocity, contrast-to-noise ratio, and structural similarity index measurement. We qualitatively and quantitatively demonstrate the potential of sub-Nyquist sampling-based shear-wave elasticity imaging, indicating that our approach could be practically useful in three-dimensional shear-wave elasticity imaging, where a massive amount of ultrasound data is required.

• Geophysics and Geophysical Exploration
• /
• v.25 no.4
• /
• pp.227-241
• /
• 2022

Full waveform inversion (FWI) in the field of seismic data processing is an inversion technique that is used to estimate the velocity model of the subsurface for oil and gas exploration. Recently, deep learning (DL) technology has been increasingly used for seismic data processing, and its combination with FWI has attracted remarkable research efforts. For example, DL-based data processing techniques have been utilized for preprocessing input data for FWI, enabling the direct implementation of FWI through DL technology. DL-based FWI can be divided into the following methods: pure data-based, physics-based neural network, encoder-decoder, reparameterized FWI, and physics-informed neural network. In this review, we describe the theory and characteristics of the methods by systematizing them in the order of advancements. In the early days of DL-based FWI, the DL model predicted the velocity model by preparing a large training data set to adopt faithfully the basic principles of data science and apply a pure data-based prediction model. The current research trend is to supplement the shortcomings of the pure data-based approach using the loss function consisting of seismic data or physical information from the wave equation itself in deep neural networks. Based on these developments, DL-based FWI has evolved to not require a large amount of learning data, alleviating the cycle-skipping problem, which is an intrinsic limitation of FWI, and reducing computation times dramatically. The value of DL-based FWI is expected to increase continually in the processing of seismic data.

• Korean Journal of Remote Sensing
• /
• v.39 no.3
• /
• pp.257-268
• /
• 2023

Sea ice plays an important role in Earth's climate by regulating the amount of solar energy absorbed and controlling the exchange of heat and material across the air-sea interface. Its growth, drift, and melting are monitored on a regular basis by satellite observations. However, low-resolution products with passive microwave radiometer have reduced accuracy during summer to autumn when the ice surface changes rapidly. Synthetic aperture radar (SAR) observations are emerging as a powerful complementary, but previous researches have mainly focused on winter ice. In this study, sea ice drift tracking was evaluated and analyzed using SAR images and tracker with global positioning system (GPS) during late summer-early autumn period when ice surface condition changes a lot. The results showed that observational uncertainty increases compared to winter period, however, the correlation coefficient with GPS measurements was excellent at 0.98, and the performance of the ice tracking algorithm was proportional to the sea ice concentration with a correlation coefficient of 0.59 for ice concentrations above 50%.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.3
• /
• pp.817-823
• /
• 2023

Manufacturing plants face the challenge of reducing energy use in response to climate change. Reducing energy consumption can be seen as one of the most important issues, such as reducing production costs and improving efficiency. Among manufacturing industries, the increase in energy consumption in the food industry is gradually increasing along with the improvement of the standard of living and the increase in population. In order to save energy in food processing plants, it is important to identify and analyze energy consumption characteristics in energy-consuming processes. Prior to this, it is necessary to monitor and analyze existing energy consumption to derive reduction measures. In this study, a small and medium-sized food processing plant producing processed meat products was used as a case study to identify and analyze the energy consumption structure at typical cycle/stage level of the batch heating process. From this, we tried to establish realistic and quantitative goals that can be obtained under individual process operating conditions. The results of this study will be used as basic data for the development of diffusion and pervasive energy saving FEMS technology for common core processes of food factories of small and medium-sized enterprises in the future.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5B
• /
• pp.469-479
• /
• 2006

In order to investigate characteristics of the primary flow and the secondary currents in meandering channels, the laboratory experiments were conducted in S-curved channels with angle of bend, $150^{\circ}$, and sinuosity of 1.52. The experimental conditions was decided varying average depth and velocity. Under these experimental conditions, spatial variations of the secondary currents in multiple bends were observed. The experimental results revealed that the distribution of primary flow in straight section is symmetric without respect to the experimental condition and the maximum velocity line of the primary flow occurs along the shortest path in experimental channel, supporting the result of previous works. The secondary currents in second bend became more developed than those in first bend. Particularly, the outer bank cell developed distinctively and the secondary current intensity was low at the straight section and high at the bends, periodically. Also, the secondary current intensity at the bends was as twice to three times as that at the straight section, and has its maximum value at the second bend. The turbulent flow characteristics of meandering channel was investigated with turbulent intensity of the primary flow and Reynolds shear stress. It was observed that the turbulent intensity is increasing when the velocity deviation of the primary flow is large whereas Reynolds shear stress increases when both the velocity deviation of the primary flow and the secondary current are large.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.1A
• /
• pp.53-59
• /
• 2010

Recently, NDTs (Non-Destructive Techniques) using infrared camera are widely studied for detection of damage and void in RC (reinforced concrete) structures and they are also considered as an effective techniques for maintenance of infrastructures. The temperature on concrete surface depends on material and thermal properties such as specific heat, thermal conductivity, and thermal diffusion coefficient. Different porosity on cement mortar due to different mixture proportions can show different heat behavior in cooling stage. The porosity can affect physical and durability properties like strength and chloride diffusion coefficient as well. In this paper, active thermography which uses flash for heat induction is utilized and thermal characteristics on surface are evaluated. Samples of cement mortar with W/C (water to cement ratio) of 0.55 and 0.65 are prepared and physical properties like porosity, compressive strength, and chloride diffusion coefficient are evaluated. Then infrared thermography technique is carried out in a constant room condition (temperature $20{\sim}22^{\circ}C$ and relative humidity 55-60%). The mortar samples with higher porosity shows higher residual temperature at the cooling stage and also shows reduced critical time which shows constant temperature due to back wall effect. Furthermore, simple equation for critical time of back wall effect is suggested with porosity and experimental constants. These characteristics indicate the applicability of infrared thermography as an NDT for quality assessment of cement based composite like concrete. Physical properties and thermal behavior in cement mortar with different porosity are analyzed in discussed in this paper.