This study aimed to investigate the effect of visual input enhancement (VIE) on the comprehension of reading texts and the learning of two grammatical forms: English relative clauses and articles. Individual learners’ working memory (WM) capacity was also tested to explore its impact on the effectiveness of VIE. A total of 48 Korean college learners of English were assigned into three groups: (a) relative group receiving VIE on relative clauses (b) article group receiving VIE on articles, and (c) a control group receiving no VIE. Results showed that VIE did not have any negative effect on the learners’ reading comprehension. Rather, it had positive effects on the learning of the two grammatical forms. According to the findings, VIE on relative clauses enhanced the learners’ receptive knowledge of the grammatical form, whereas VIE on articles enhanced the learners’ productive knowledge of the form. There was a potential link between the effectiveness of VIE and the learners’ working memory processing ability. Pedagogical implications are also discussed based on these findings.

본 연구는 실봇을 병용한 인지강화 프로그램이 주관적 기억력 저하를 호소하는 노인의 인지기 능, 우울 및 치매예방행위에 미치는 효과를 알아보고자 하였다. 대상자는 경기도 성남시에 거주하는 노인 17명을 대상으로 복지관에서 수행되었다. 실봇과 인지강화를 병용한 총 20회기 프로그램을 개발하여 적용 하였으며 중재 전과 후에 한국 몬트리올 인지평가(K-MoCA), 우울(GDS), 치매예방행위(DPB)를 평가하였 다. 연구결과, 실봇을 병용한 인지강화 프로그램은 노인의 인지기능(t=-4.49, p<.001), 우울(t=2.58, p=.023)에서 통계적으로 유의한 차이가 있었다. 따라서 실봇을 병용한 인지강화 프로그램이 노인의 인지기 능 향상 및 우울 완화에 유용한 프로그램이 될 것으로 기대된다.

In this study, we evaluate artificial neural network (ANN) models that estimate the positions of gamma-ray sources from plastic scintillating fiber (PSF)-based radiation detection systems using different filtering ratios. The PSF-based radiation detection system consists of a single-stranded PSF, two photomultiplier tubes (PMTs) that transform the scintillation signals into electric signals, amplifiers, and a data acquisition system (DAQ). The source used to evaluate the system is Cs-137, with a photopeak of 662 keV and a dose rate of about 5 μSv/h. We construct ANN models with the same structure but different training data. For the training data, we selected a measurement time of 1 minute to secure a sufficient number of data points. Conversely, we chose a measurement time of 10 seconds for extracting time-difference data from the primary data, followed by filtering. During the filtering process, we identified the peak heights of the gaussian-fitted curves obtained from the histogram of the time-difference data, and extracted the data located above the height which is equal to the peak height multiplied by a predetermined percentage. We used percentage values of 0, 20, 40, and 60 for the filtering. The results indicate that the filtering has an effect on the position estimation error, which we define as the absolute value of the difference between the estimated source position and the actual source position. The estimation of the ANN model trained with raw data for the training data shows a total average error of 1.391 m, while the ANN model trained with 20%-filtered data for the training data shows a total average error of 0.263 m. Similarly, the 40%-filtered data result shows a total average error of 0.119 m, and the 60%-filtered data result shows a total average error of 0.0452 m. From the perspective of the total average error, it is clear that the more data are filtered, the more accurate the result is. Further study will be conducted to optimize the filtering ratio for the system and measuring time by evaluating stabilization time for position estimation of the source.

As Korea has relatively small land area and large population density compared to other countries considering the DGD concept such as Finland and Sweden, improvements of disposal efficiency in the viewpoint of the disposal area might be needed for the current disposal system to alleviate the difficulties of site selection for the HLW repository. In this research, we conduct a numerical investigation of the disposal efficiency enhancement for a high-level radioactive waste (HLW) repository through three design factors: decay heat optimization, increased thermal limit of buffer, and double-layer concept. In the optimized decay heat model, seven SNFs with the maximum and minimum decay heat depending on actual burn-up and cooling time are iteratively combined in a canister. Thermal limit of buffer is assumed as 100°C and 130°C for reference and high-efficiency repository concepts, respectively. By implementing an optimized decay heat model and a single-layer concept with a thermal limit of buffer set at 100°C, the disposal efficiency increases to 2.3 times of the improved Korean Reference disposal System (KRS+). Additionally, incorporating either an increased thermal limit of buffer to 130°C or a double-layer concept leads to a further 50% improvement in disposal efficiency. By integrating all three design factors, the disposal efficiency can be enhanced up to five times that of the KRS+ repository. Our analysis of rock mass stability reveals that increasing the thermal limit of buffer can generate rock spalling failure in a wider area. However, when accounting for the effect of confining stress by swelling of buffer and backfill using the Mohr-Coulomb failure criteria, the rock mass failure only occurred at the corner between the disposal tunnel and deposition hole when the thermal limit of buffer was increased and a single-layer concept was applied. The results given in this study can provide various options for designing the high-efficiency repository in accordance with the target disposal area and quality of the rock mass in the potential repository site.

Nuclear Safety and Security Commission (NSSC) and KINAC review a Cyber Security Plan (CSP) by「ACT ON PHYSICAL PROTECTION AND RADIOLOGICAL EMERGENCY」. The CSP contains cyber security implementation plans for the licensee’s nuclear power plant, and it shall meet the requirements of KINAC/RS-015, a regulatory standard. The KINAC/RS-015 provides more detailed information on the legal requirements, so if licensees implement cyber security under the approved CSP, they can meet the law. To protect nuclear facilities from cyber-attacks, licensees should identify their essential digital assets, so-called “Critical Digital Assets” (CDAs). Then, they apply cyber security controls (countermeasures for cyber-attacks) on CDAs consisting of technical, operational, and management security controls. However, it is hard to apply cyber security controls on CDAs because of the large amounts of CDAs and security controls in contrast to the shortage of human resources. So, licensees in the USA developed a methodology to solve this problem and documented it by NEI 13-10, and US NRC endorsed this document. The main idea of this methodology is, by classifying CDAs according to their importance, applying small amounts of security controls on less important CDAs, so-called non-direct CDAs. In the case of non-direct CDAs, only basic cyber security controls are applied, that is, baseline cyber security controls. The baseline cyber security controls are a minimum set of cyber security controls; they consist of control a) from control g) a total of 7 controls. Although non-direct CDAs are less critical than other CDAs (direct CDAs), they are still essential to protect them from cyber-attacks. This paper aims to suggest a cyber security enhancement method for non-direct CDAs by analyzing the baseline cyber security controls. In this paper, baseline cyber security controls were analyzed respectively and relatively and then concluded how to apply small amounts of cyber security controls on non-direct CDAs rather than direct CDAs without scarifying cyber security.

본 논문은 남북 정상회담에서 합의했고, 문재인 전 대통령이 유엔연설 에서 여러 차례 제의한 종전선언을 북한이 받아들이지 않은 이유를 김일 성이 밝힌 ‘3대혁명역량강화방침’에 입각해서 추론한 것이다. ‘북조선 혁 명역량강화’에서는 핵무력을 보유한 군사적 역량은 어느 때보다 강하지 만 국제제재와 경제난으로 주민들의 불만이 고조되는 등 정치·경제적 역 량은 매우 약화되었다. 이러한 체제내구력 보완을 위해 ‘강한 외부의 적’ 인 ‘미 제국주의’가 필요하므로 평화체제로 전환하는 첫 단계인 종전선언 카드를 받지 못한 것으로 볼 수 있다. ‘남조선 혁명역량강화’에서는 ‘이 석기 내란 선동 사건’처럼 제도권 침투를 비롯해 노동, 교육, 문화, 종교 계 등 사회 저변에 친북·반미 의식이 폭넓게 퍼져있다. 따라서 미-북 간 종전선언으로 인해 평화체제로 전환된다면 반미 명분이 약화되어 70여 년간 축적된 남한의 혁명역량이 치명적 타격을 받을 수 있다. ‘국제 혁명 역량강화’의 핵심은 국제사회에서 반제·반미 통일전선을 형성하여 미국을 고립시켜 궁극적으로 ‘혁명의 가장 큰 장애물’인 주한미군을 철수시키는 것이다. 미-북 간 종전선언이 합의된다면 적대관계가 청산되어 미국을 비롯한 반제·반미 이데올로기로 연대한 ‘국제 혁명역량’이 와해될 수도 있다. 따라서 향후 북한은 자체의 힘으로 충분한 대미 핵 억제력 및 체 제 내구력을 갖추고, 전술핵무기와 배합된 남조선 혁명역량을 완비할 때 까지 ‘종전선언 카드’를 받지 않을 것으로 전망된다.

Thermoelectric materials and devices are energy-harvesting devices that can effectively recycle waste heat into electricity. Thermoelectric power generation is widely used in factories, engines, and even in human bodies as they continuously generate heat. However, thermoelectric elements exhibit poor performance and low energy efficiency; research is being conducted to find new materials or improve the thermoelectric performance of existing materials, that is, by ensuring a high figure-of-merit (zT) value. For increasing zT, higher σ (electrical conductivity) and S (Seebeck coefficient) and a lower к (thermal conductivity) are required. Here, interface engineering by atomic layer deposition (ALD) is used to increase zT of n-type BiTeSe (BTS) thermoelectric powders. ALD of the BTS powders is performed in a rotary-type ALD reactor, and 40 to 100 ALD cycles of ZnO thin films are conducted at 100oC. The physical and chemical properties and thermoelectric performance of the ALD-coated BTS powders and pellets are characterized. It is revealed that electrical conductivity and thermal conductivity are decoupled, and thus, zT of ALD-coated BTS pellets is increased by more than 60% compared to that of the uncoated BTS pellets. This result can be utilized in a novel method for improving the thermoelectric efficiency in materials processing.

High-temperature and high-pressure post-processing applied to sintered thermoelectric materials can create nanoscale defects, thereby enhancing their thermoelectric performance. Here, we investigate the effect of hot isostatic pressing (HIP) as a post-processing treatment on the thermoelectric properties of p-type Bi0.5Sb1.5Te3.0 compounds sintered via spark plasma sintering. The sample post-processed via HIP maintains its electronic transport properties despite the reduced microstructural texturing. Moreover, lattice thermal conductivity is significantly reduced owing to activated phonon scattering, which can be attributed to the nanoscale defects created during HIP, resulting in an ~18% increase in peak zT value, which reaches ~1.43 at 100oC. This study validates that HIP enhances the thermoelectric performance by controlling the thermal transport without having any detrimental effects on the electronic transport properties of thermoelectric materials.

The research on dye-sensitized solar cells (DSSCs) is in the advanced stage today. The only concern observed so far has been regarding its stability and efficiency. Its power conversion efficiency can be increased by incorporating various methods and materials based on nanotechnology. Several attempts have been employed to develop advanced methods for eco-friendly, commercially viable, and sustainable DSSCs to minimize the energy crisis in the future. Photoanode is one of the essential components of DSSCs that can be modified using different nanostructures to enhance its efficiency. The TiO2 nanoparticlebased photoanode with gold and silver has proven to be potent materials for getting efficient DSSCs. The plasmonic and quantum confinement effects also play a vital role in efficiency enhancement. In this review, we discuss numerous attempts made by researchers in the last decade to modify the photoanode and their progress. We also look at different types of nanostructures, such as quantum dots, metal oxide doping, layered structures, nanocomposites, and thin film formation, that improve the efficiency of DSSCs. Several methods were reviewed to modify photoanodes to optimize electron transportation, light scattering, trapping power, surface area, and reduce charge recombination. The trend in the efficiency enhancement of DSSCs using TiO2, Au, ZnO, Ag, and graphene nanostructures-based photoanodes have been explored in great detail.

Sucrose (suc) is a disaccharide that consists of glucose (glu) and fructose (fru). It is a carbohydrate source that acts as a nutrient molecule and a molecular signal that regulates gene expression and alters metabolites. This study aimed to evaluate whether suc-specific signaling induces an increase in bioactive compounds by exogenous suc absorption via roots or whether other factors, such as osmotic stress or biotic stress, are involved. To compare the osmotic stress induced by suc treatment, 4-week-old cultured mugwort plants were subjected to Hoagland nutrient solution with 10 mM, 30 mM, and 50 mM of suc or mannitol (man) for 3 days. Shoot fresh weight in suc and man treatments was not significantly different from the control. Both man and suc treatments increased the content of bioactive compounds in mugwort, but they displayed different enhancement patterns compared to the suc treatments. Mugwort extract treated with suc 50 mM effectively protected HepG2 liver cells damaged by ethanol and t-BHP. To compare the biotic stress induced by suc treatment, 3-week-old mugwort plants were subjected to microorganism and/or suc 30 mM with Hoagland nutrient solution. Microorganisms and/or suc 30 mM treatments showed no difference about the shoot fresh weight. However, sugar content in mugwort treated with suc 30 mM and microorganism with suc 30 mM treatment was significantly higher than that of the control. Suc 30 mM and microorganism with suc 30 mM were effective in enhancing bioactive compounds than microorganism treatment. These results suggest that mugwort plants can absorb exogenous suc via roots and the enhancement of bioactive compounds by suc treatment may result not from osmotic stress or biotic stress because of microorganism, but by suc-specific signaling.

Current studies have revealed the capacity of mesenchymal stem cells (MSCs) in term of immunomodulatory properties, and this distinct potential is downgraded according to the disease duration of patients-derived MSCs. In order to enhance the immunomodulatory and anti-tumorigenic properties of the rheumatoid arthritis (RA) joints-derived MSCs, we aggregate synovial fluid-derived MSCs from RA joints (RA-hMSCs) into 3D-spheroids by the use of hanging drop culture method. Cells were isolated from synovial fluids of RA joints with longstanding active status over 13 years. For aggregation of RA-hMSCs into 3D-spheroids, cells were plated in hanging drops in 30 μL of advanced DMEM (ADMEM) containing 25,000-30,000 cells/ drop and cultured for 48 h. To analyze the comparative immunomodulatory effects of 3D-spheroid and 2D monolayer cultured RA-hMSCs and then cells were cultured in ADMEM supplemented with 20% of synovial fluids of RA patients for 48 h and were evaluated by qRT-PCR for their expression of mRNA levels of inflammatory and antiinflammatory markers. Cellular aggregation of RA-hMSCs was observed and cells were aggregate into a single sphere. Following treatment of RA patient’s synovial fluids into the RA-hMSCs, spheroids formed RA-hMSCs showed significantly (p < 0.05) higher expression of TNFα stimulated gene/protein 6 (TSG-6) than the monolayer cultured RAhMSCs. Therefore, the 3D-spheroid culture methods of RA-hMSCs were more effective than 2D monolayer cultures in suppressing inflammatory response treated with 20% of RA-synovial fluids by expression of TNFα (TSG-6) according to the immune response and enhanced secretion of inflammatory factors.

본 연구는 새만금 농생명용지와 주변 지역의 간척 전후 생태계서비스를 평가하고 증진방안을 마련하기 위해 수행하 였다. 새만금 지역의 생태계서비스 기능은 토지 유형에 따라 다르게 나타났다. 간척 전 새만금은 공급, 조절, 문화, 지지서비스 기능이 모두 높았으나 간척 후에는 공급, 조절, 지지서비스 기능이 하락했다. 따라서 새만금 농생명 용지의 생태계서비스를 증진하려면 논 습지, 저수지 등의 반(半)자연생태계가 가지는 공급, 조절, 지지서비스를 강화하는 것이 필요하다. 현재 남아 있는 산림, 도서 지역 등의 자연생태계와 광활한 농경지를 농촌관광 및 생태관광을 특화하고, 농업과 관련된 교육․연구 위주의 문화서비스 기능을 강화할 필요가 있다. 이를 위해 넓은 농경지와 농업 기반을 활용하여 농업생산, 농촌관광 등을 활성화하고 고령화가 진행되고 있는 지역에 대한 정부의 지원이 필요하다.

최근 신체활동에 대해 인식하는 센서와 그 제품군에 대한 관심 및 수요가 증가하고 있다. 특히 유연하고 연신이 가능하 며 사용자의 생체신호를 감지할 수 있는 웨어러블 소재에 대한 개발이 주목받고 있다. 본 연구에서는 소수성 소재에 Micro Needle을 통해 미세 구멍을 형성한 후 SWCNT 분산용액에 대한 함침 효율을 향상시키는 실험을 수행하였다. 본 연구에서 는 구멍을 뚫지 않은 소재를 대조(control) 군으로 함침을 진행, 비교 분석하였다. 센서의 전기전도도를 평가하기 위해 Strain UTM (Universal Testing Machine, UTM, Dacell)과 저항을 측정하는 멀티미터(Keysight)를 이용해 센서를 인장했 을 때의 센서의 전기전도도를 측정하였다. 또한 센서의 내구성을 평가하기 위해 시료별로 500회 인장을 진행한 후에 센서 의 전기전도도를 평가하였다. 그 결과 Needling을 한 센서의 전기전도성이 Needling을 하지 않은 센서에 비해 최소 16배 이상 뛰어남을 알 수 있었다. 또한 센서의 초기 저항에 비해 게이지 팩터도 우수해 센서로서 좋은 성능을 확인할 수 있었다. 이를 통해 친수성 소재에 비해 물성이 뛰어나지만, 높은 표면장력 때문에 함침 효율이 좋지 않았던 소수성 소재의 함침 효율을 높여 신체의 움직임을 더 효과적으로 감지하고 내구성과 활용 가능성이 뛰어난 센서를 제작했다.

Climate change due to global warming causes a rise in atmospheric air temperature to rise and extreme shift in precipitation patterns. Carbon dioxide (CO2) is widely known as one of the major cause of global warming and accounts for about 72% of total greenhouse gas emissions. Agriculture is more vulnerable to climate change than other industries. Many studies have been conducted to investigate how agroecosystems, both natural and controlled, will respond to the rising level of CO2. Studies on the responses of crops and agricultural environments to climate change are crucial in predicting changes in agro-ecosystems. Research facilities for various types of CO2 treatment have been developed. The representative research facilities are SAR (Soil-Plant-Atmosphere-Research), OTC (Open Top Chamber), FACE (Free Air CO2 Enrichment System), and TGC & CTGC (Temperature Gradient Chamber & CO2-Temperature Gradient Chamber). Therefore, this study reviewed research data and their application in agriculture.