• Title/Summary/Keyword: 특성실험

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Exploring the contextual factors of episodic memory: dissociating distinct social, behavioral, and intentional episodic encoding from spatio-temporal contexts based on medial temporal lobe-cortical networks (일화기억을 구성하는 맥락 요소에 대한 탐구: 시공간적 맥락과 구분되는 사회적, 행동적, 의도적 맥락의 내측두엽-대뇌피질 네트워크 특징을 중심으로)

  • Park, Jonghyun;Nah, Yoonjin;Yu, Sumin;Lee, Seung-Koo;Han, Sanghoon
    • Korean Journal of Cognitive Science
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    • v.33 no.2
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    • pp.109-133
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    • 2022
  • Episodic memory consists of a core event and the associated contexts. Although the role of the hippocampus and its neighboring regions in contextual representations during encoding has become increasingly evident, it remains unclear how these regions handle various context-specific information other than spatio-temporal contexts. Using high-resolution functional MRI, we explored the patterns of the medial temporal lobe (MTL) and cortical regions' involvement during the encoding of various types of contextual information (i.e., journalism principle 5W1H): "Who did it?," "Why did it happen?," "What happened?," "When did it happen?," "Where did it happen?," and "How did it happen?" Participants answered six different contextual questions while looking at simple experimental events consisting of two faces with one object on the screen. The MTL was divided to sub-regions by hierarchical clustering from resting-state data. General linear model analyses revealed a stronger activation of MTL sub-regions, the prefrontal lobe (PFC), and the inferior parietal lobule (IPL) during social (Who), behavioral (How), and intentional (Why) contextual processing when compared with spatio-temporal (Where/When) contextual processing. To further investigate the functional networks involved in contextual encoding dissociation, a multivariate pattern analysis was conducted with features selected as the task-based connectivity links between the hippocampal subfields and PFC/IPL. Each social, behavioral, and intentional contextual processing was individually and successfully classified from spatio-temporal contextual processing, respectively. Thus, specific contexts in episodic memory, namely social, behavior, and intention, involve distinct functional connectivity patterns that are distinct from those for spatio-temporal contextual memory.

Changes in Sink capacity and Source Activity of Rice Cultivars in Response to Shift of Heading date (벼 품종들의 출수기에 따른 동화산물 생산능력 및 수용기관 크기 변화)

  • Lee, Sok-Young;Kwon, Yong-Woong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.260-267
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    • 1995
  • In temperate zone planting rice at different date subjects the Crop to different climatic condition. The present study aimed at comparison of the change in source-sink relationship of the Japonica(J) and that of IndicaxJaponica(I$\times$J) type rice cultivars caused by shift of heading date. Two J- and two I$\times$J-type cultivars were made to head on August 16, August 26, and September 5. Sink capacity was changed by shift of heading date in different mode between the types of cultivars. In both types major determinant of sink capacity was number of effective tillers, and the number of spikelets per panicle was the minor. In J-type earlier planting/heading was beneficial to increased panicle numbers and this was due mainly to a larger diurnal difference in temperature. I$\times$J-type cultivars favored a higher daily mean temperature to increase the sink capacity. The ability of source at heading, in terms of leaf area per panicle, chlorophyll content per spiklet, photosynthetic ability of leaves per unit area at 25$\^{\circ}C$, carbohydrate and N contents of leaves, was not so different among different heading dates in both types. However, the source activity was governed principally by temperature during grain filling. The J-type cultivars headed on Sept. 5 and I$\times$J-type cultivars headed later than August 16 could not have had sufficient source activity in grain filling due to lower temperature.

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Thermal Behavior and Leaf Temperature in a High Pressure Sodium Lamp Supplemented Greenhouse (고압나트륨등 보광 온실의 열적 거동 및 엽온 분석)

  • Seungri Yoon;Jin Hyun Kim;Minju Shin;Dongpil Kim;Ji Wong Bang;Ho Jeong Jeong;Tae In Ahn
    • Journal of Bio-Environment Control
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    • v.32 no.1
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    • pp.48-56
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    • 2023
  • High-pressure sodium (HPS) lamps have been widely used as a useful supplemental light source to emit sufficient photosynthetically active radiation and provide a radiant heat, which contribute the heat requirement in greenhouses. The objective of this study to analyze the thermal characteristics of HPS lamp and thermal behavior in supplemented greenhouse, and evaluate the performance of a horizontal leaf temperature of sweet pepper plants using computational fluid dynamics (CFD) simulation. We simulated horizontal leaf temperature on upper canopy according to three growth stage scenarios, which represented 1.0, 1.6, and 2.2 plant height, respectively. We also measured vertical leaf and air temperature accompanied by heat generation of HPS lamps. There was large leaf to air temperature differential due to non-uniformity in temperature. In our numerical calculation, thermal energy of HPS lamps contributed of 50.1% the total heat requirement on Dec. 2022. The CFD model was validated by comparing measured and simulated data at the same operating condition. Mean absolute error and root mean square error were below 0.5, which means the CFD simulation values were highly accurate. Our result about vertical leaf and air temperature can be used in decision making for efficient thermal energy management and crop growth.

Quality Changes of 'Baumkuchen' Cake with Modified Atmosphere Packaging during Storage (변형기체포장 처리에 따른 '바움쿠헨' 케이크의 저장 중 품질 특성 변화)

  • Myungho Lee;Minhwi Kim;Youn Suk Lee
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.2
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    • pp.87-94
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    • 2023
  • Fresh bakery products are widely consumed worldwide and therefore particular requirements for their quality characteristics have been established. The shelf life of bakery products is mainly subjected to microbial spoilage and staling. This study investigated the optimum conditions of modified atmosphere packaging (MAP) application to extend the shelf life of the bakery products. The gas conditions of the headspace in 'Baumkuchen' cake were 0, 30, 70, and 100% CO2 concentrations and stored at 30℃ for 5 days. The bakery samples were evaluated weight loss, hardness, color change, pH and total aerobic bacteria, yeast and molds count throughout the storage period. Values of the weight loss and hardness were increased over the storage period, meanwhile pH was significantly decreased. However, no significant color changes were observed during storage. It was also found no significant difference between the different gas treatments. Total aerobic bacteria count of the stored samples after day 5 was increased by 6.94 log CFU/g in the air filled package, compared to 6.20 log CFU/g in the 100% CO2 filled package and 6.02 log CFU/g in the 70% CO2 filled package. Yeast and molds count were 3.65 log CFU/g in air filled package, 2.66 log CFU/g in 100% CO2 filled package, 2.64 log CFU/g in 70% CO2 filled package, 2.86 log CFU/g in 30% CO2 filled package and 3.31 log CFU/g in 100% N2 filled package on day 2. In conclusion, it was shown that 70% and 100% CO2 treatments in the package were effective to reduce microbial growth.

Dynamic Equilibrium Position Prediction Model for the Confluence Area of Nakdong River (낙동강 합류부 삼각주의 동적 평형 위치 예측 모델: 감천-낙동강 합류점 중심 분석 연구)

  • Minsik Kim;Haein Shin;Wook-Hyun Nahm;Wonsuck Kim
    • Economic and Environmental Geology
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    • v.56 no.4
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    • pp.435-445
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    • 2023
  • A delta is a depositional landform that is formed when sediment transported by a river is deposited in a relatively low-energy environment, such as a lake, sea, or a main channel. Among these, a delta formed at the confluence of rivers has a great importance in river management and research because it has a significant impact on the hydraulic and sedimentological characteristics of the river. Recently, the equilibrium state of the confluence area has been disrupted by large-scale dredging and construction of levees in the Nakdong River. However, due to the natural recovery of the river, the confluence area is returning to its pre-dredging natural state through ongoing sedimentation. The time-series data show that the confluence delta has been steadily growing since the dredging, but once it reaches a certain size, it repeats growth and retreat, and the overall size does not change significantly. In this study, we developed a model to explain the sedimentation-erosion processes in the confluence area based on the assumption that the confluence delta reaches a dynamic equilibrium. The model is based on two fundamental principles: sedimentation due to supply from the tributary and erosion due to the main channel. The erosion coefficient that represents the Nakdong River confluence areas, was obtained using data from the tributaries of the Nakdong River. Sensitivity analyses were conducted using the developed model to understand how the confluence delta responds to changes in the sediment and water discharges of the tributary and the main channel, respectively. We then used annual average discharge of the Nakdong River's tributaries to predict the dynamic equilibrium positions of the confluence deltas. Finally, we conducted a simulation experiment on the development of the Gamcheon-Nakdong River delta using recorded daily discharge. The results showed that even though it is a simple model, it accurately predicted the dynamic equilibrium positions of the confluence deltas in the Nakdong River, including the areas where the delta had not formed, and those where the delta had already formed and predicted the trend of the response of the Gamcheon-Nakdong River delta. However, the actual retreat in the Gamcheon-Nakdong River delta was not captured fully due to errors and limitations in the simplification process. The insights through this study provide basic information on the sediment supply of the Nakdong River through the confluence areas, which can be implemented as a basic model for river maintenance and management.

Structure Analysis and Scale Model Test for Strength Performance Evaluation of Submersible Mooring Pulley Installed on Floating Offshore Wind Turbine (부유식 해상풍력발전기용 반잠수식 계류 풀리의 강도 성능평가를 위한 구조해석과 축소 모형시험)

  • Chang-Yong Song
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.479-487
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    • 2023
  • Recently, the destructive power of typhoons is continuously increasing owing to global warming. In a situation where the installation of floating wind turbines is increasing worldwide, concerns about the huge loss and collapse of floating offshore wind turbines owing to strong typhoons are deepening. A new type of disconnectable mooring system must be developed for the safe operation of floating offshore wind turbines. A new submersible mooring pulley considered in this study is devised to more easily attach or detach the floating of shore wind turbine with mooring lines compared with other disconnectable mooring apparatuses. To investigate the structural safety of the initial design of submersible mooring pulley that can be applied to an 8MW-class floating type offshore wind turbine, scale-down structural models were developed using a 3-D printer and structural tests were performed on the models. For the structural tests of the scale-down models, tensile specimens of acrylonitrile butadiene styrene material that was used in the 3-D printing were prepared, and the material properties were evaluated by conducting the tensile tests. The finite element analysis (FEA) of submersible mooring pulley was performed by applying the material properties obtained from the tensile tests and the same load and boundary conditions as in the scale-down model structural tests. Through the FEA, the structural weak parts on the submersible mooring pulley were reviewed. The structural model tests were conducted considering the main load conditions of submersible mooring pulley, and the FEA and test results were compared for the locations that exceeded the maximum tensile stress of the material. The results of the FEA and structural model tests indicated that the connection structure of the body and the wheel was weak in operating conditions and that of the body and the chain stopper was weak in mooring conditions. The results of this study enabled to experimentally verify the structural safety of the initial design of submersible mooring pulley. The study results can be usefully used to improve the structural strength of submersible mooring pulley in a detailed design stage.

Antioxidant Effects of Cysteine-containing Peptides of Different Lengths in Human HaCaT Keratinocytes Exposed to Hydrogen Peroxide (과산화수소에 노출된 인간 각질형성세포에서 길이가 다른 시스테인 함유 펩타이드의 항산화 효과)

  • Jae Won Ha;Joon Yong Choi;Yong Chool Boo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.49 no.3
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    • pp.193-201
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    • 2023
  • Hydrogen peroxide (H2O2) is a type of active oxygen species (ROS) that causes oxidative stress in cells and affects cell growth, proliferation, senescence, and death. The purpose of this study is to find active peptides that attenuate cytotoxicity of H2O2. A positional scanning synthetic tetrapeptide combinatorial library was screened to predict the sequence of potentially active peptides. As a result of comparing the effect of peptide pools on H2O2-induced death of human keratinocytes (HaCaT cells), various active peptide sequences were predicted. Especially, peptides containing cysteine (C) residue were predicted to be active. In follow-up experiments, the cytotoxicity and activity of cysteine-containing peptides of different lengths, such as C-NH2, CC-NH2, CCC-NH2, and CCCC-NH2 were examined. C-NH2 and CC-NH2 showed no significant cytotoxicity up to 1.0 mM, but CCC-NH2, and CCCC-NH2 showed relatively strong cytotoxicity. C-NH2 and CC-NH2 alleviated H2O2-induced cytotoxicity. CC-NH2 was more cytoprotective compared to C-NH2, C, N-acetyl cysteine (NAC), and glutathione (GSH). When intracellular ROS was measured by flow cytometry, H2O2 increased ROS production, and CC-NH2 suppressed ROS production more effectively than C-NH2, and it was as effective as C, NAC, and GSH. This study suggests that CC-NH2 of the cysteine-containing peptides of different lengths has an antioxidant property that safely and effectively alleviates H2O2-induced cytotoxicity and ROS production.

Development of Tree Carbon Calculator to Support Landscape Design for the Carbon Reduction (탄소저감설계 지원을 위한 수목 탄소계산기 개발 및 적용)

  • Ha, Jee-Ah;Park, Jae-Min
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.1
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    • pp.42-55
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    • 2023
  • A methodology to predict the carbon performance of newly created urban greening plans is required as policies based on quantifying carbon performance are rapidly being introduced in the face of the climate crisis caused by global warming. This study developed a tree carbon calculator that can be used for carbon reduction designs in landscaping and attempted to verify its effectiveness in landscape design. For practical operability, MS Excel was selected as a format, and carbon absorption and storage by tree type and size were extracted from 93 representative species to reflect plant design characteristics. The database, including tree unit prices, was established to reflect cost limitations. A plantation experimental design to verify the performance of the tree carbon calculator was conducted by simulating the design of parks in the central region for four landscape design, and the causal relationship was analyzed by conducting semi-structured interviews before and after. As a result, carbon absorption and carbon storage in the design using the tree carbon calculator were about 17-82% and about 14-85% higher, respectively, compared to not using it. It was confirmed that the reason for the increase in carbon performance efficiency was that additional planting was actively carried out within a given budget, along with the replacement of excellent carbon performance species. Pre-interviews revealed that designers distrusted data and the burdens caused by new programs before using the arboreal carbon calculator but tended to change positively because of its usefulness and ease of use. In order to implement carbon reduction design in the landscaping field, it is necessary to develop it into a carbon calculator for trees and landscaping performance. This study is expected to present a useful direction for ntroducing carbon reduction designs based on quantitative data in landscape design.

Evaluation of Physical Properties and Material Characterization for Structural Frame at the Stained Glass Windows to Gongju Jeil Church of the Registered Cultural Heritage in Korea (국가등록문화재 공주제일교회 스테인드글라스 구조재의 재질특성과 물성 평가)

  • Bo Young Park;Hye Ri Yang;Chan Hee Lee
    • Economic and Environmental Geology
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    • v.56 no.1
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    • pp.103-114
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    • 2023
  • The Christian Museum of Gongju Jeil Church was first built in 1931 and was largely damaged during the Korean War, but the walls and chimneys have been preserved. This building has a high architectural values in that the chapel was reconstructed in 1956, and maintains its original form through repair of damaged parts rather than new construction. The stained glass windows were as installed in 1979 and has a great significance in the Dalle de Verre method using lump glass. However, some of the stained glass damaged partially, such as various cracks and splits, and vertical and horizontal cracks in the joint fillers of supporting the colored glass. As the structural materials of the stained glass window, an iron frame and cement mortar filled with it were used, and corrosion of iron, cracking of mortar and granular decomposition appear partially due to weathering. In the joint fillers, the content of Ca and S is very high, indicating that gypsum were used as admixtures, and the gypsums grow in a rhombohedral and forms a bundle, which is investigated to have undergone recrystallization. As a result of modeling the ultrasonic velocity at the joint fillers, the left and right windows at the entrance show relatively weak in the range of 800 to 1,600m/s, and the lower right corner of the altar window and the upper left corner of the center window were also 1,000 to 1,800m/s, showing relatively low physical properties. And gypsums produced during the neutralization of lime mortar were detected in the joint fillers and contaminants on the surface. Such salts may cause damage to the joint material due to freezing and thawing, so appropriate preventive conservation is required. Also, since various damage types are complexly appearing in stained glass window and joint filler, customized conservation treatment should be reviewed through clinical tests.

Synthesis of Uniform Silica Nanoparticles using Tap, Industrial, and Stream water and Their Application to Electro-responsive Smart Fluid System (상수, 공업용수, 및 하천수를 활용한 균일한 실리카 나노입자 합성 및 전기감응형 스마트유체로의 응용)

  • Ha-Yeong Kim;Suk Jekal;Neunghi Lee;Minki Sa;Dong Hyun Kim;Min Sang Kim;Jiwon Kim;Chang-Min Yoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.1
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    • pp.47-56
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    • 2023
  • This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous silica nanoparticles with sizes of 500-700nm are successfully prepared in large scale at once (ca. 12.0 g) with the described experimental method and showing similar structural and chemical characteristics with silica nanoparticles synthesized using the deionized water. The size of silica nanoparticles are varied according to the ion conductivity differences of tap, industrial, stream water, and deionized water. The size of silica nanoparticles decresed with the increased ion conductivity, indicating the ion suppression of growth of silica nanoparticles. Moreover, as-synthesized silica nanoparticles from various water sources of electro-responsive characteristic are investigated by the smart fluid application. The smart fluids containing silica nanoparticles synthesized by tap, industrial, and stream water exhibited higher shear stress compared to the deionized water, owing to the more rigid fibril-like structures formed by the smaller silica nanoparticles. Conclusively, uniform silica nanoparticles from various water sources without any purification are able to successfully prepared without usage of deionized water and resulting silica nanoparticles manifested higher electro-responsive performance.