• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.439-444
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• 2005

Shotcrete lining is likely to be deteriorated due to the ground water which the lining is exposed to. Some tunnel collapses seemed to be affected by shotcrete degradation were reported. But there isn't any assessment method of shotcret long-term degradation. So, Experimental technology for shotcrete long-term degradation modeling was developed in this study. The shotcrete long-term degradation modeling, developed in other study in Korea Institute of Construction Technology, require the time-history of volume change. Digital strain observation system was used to acquire the time-history of volume change. To verify the Strain Observation Digital System, the measurement using the system was compared to the one using a micrometer. Through this process, The experiment for shotcrete long-term degradation modeling was set up.

• 유통과학연구
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• 제12권5호
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• pp.49-59
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• 2014

Purpose - This research aims to explore factors that could facilitate and/or impede consumers' long-term goal-relevant food consumption, in the pursuit of a long-term goal. Research Design, Data, and Methodology - The main experiment's sample comprised 289 female students at C University. The structural equation model of the Amos 18.0 program was used to verify the hypotheses. Results - Hypotheses concerning positive effects of long-term goal commitment and expectancy of long-term goal attainment, and negative effects of pleasure-seeking needs on long-term goal-relevant food consumption behaviors were accepted. Furthermore, self-efficacy's positive effects on long-term goal commitment and expectancy of long-term goal attainment, and negative effects on the strength of pleasure-seeking were explored. Appearance self-esteem negatively affected long-term goal commitment. Conclusions - Individuals' self-efficacy positively affects long-term goal commitment and expectancy of long-term goal attainment, and significantly weakens the need to seek pleasure in food consumption behaviors. Appearance self-esteem negatively affects long-term goal commitment. Both long-term goal commitment and expectancy of long-term goal attainment significantly positively influence long-term goal-relevant food consumption behaviors. However, those heavily needing pleasure-seeking are less likely to engage in such behaviors.

• Computers and Concrete
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• 제22권3호
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• pp.261-267
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• 2018

Long-term deformation of a steel-reinforced concrete (SRC) column is different from that of a reinforced concrete (RC) column due to the different moisture distribution. Wide-flange steel in an SRC column obstructs diffusion and makes long-term deformation slower. Previous studies analyzed the characteristics of long-term deformation of SRC columns. In this study, an additional experiment is conducted to more precisely investigate the effect of wide-flange steel on the long-term deformation of SRC columns. Long-term deformation, especially creep of SRC columns with various types of wide-flange steel, is tested. Wide-flange steel for the experiment is made of thin acrylic panels that can block diffusion but does not have strength, because the main purpose of this study is to exclusively demonstrate the long-term deformation of concrete caused by moisture diffusion, not by the reinforcement ratio. Experimental results show that the long-term deformation of a SRC column develops slower than that in a RC column, and it is slower as the wide-flange steel hinders diffusion more. These experimental results can be used for analytical prediction of long-term deformation of various SRC columns. An example of the analytical prediction is provided. According to the experimental and analytical results, it is clear that a new prediction model for long-term deformation of SRC columns should be developed in further studies.

• 한국산업정보학회논문지
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• 제26권1호
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• pp.1-10
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• 2021

본 연구에서는 EEG 신호를 기반으로 감정 인식에 유용한 딥러닝 기법을 제안한다. 감정이 시간에 따라 변화하는 특성을 반영하기 위해 Long-Short Term Memory 네트워크를 사용하였다. 또한, 특정 시점의 감정적 상태가 전체 감정 상태에 영향을 미친다는 이론을 기반으로 특정 순간의 감정 상태에 가중치를 주기 위해 어텐션 메커니즘을 적용했다. EEG 신호는 DEAP 데이터베이스를 사용하였으며, 감정은 긍정과 부정의 정도를 나타내는 정서가(Valence)와 감정의 정도를 나타내는 각성(Arousal) 모델을 사용하였다. 실험 결과 정서가(Valence)와 각성(Arousal)을 2단계(낮음, 높음)로 나누었을 때 분석 정확도는 정서가(Valence)의 경우 90.1%, 각성(Arousal)의 경우 88.1%이다. 낮음, 중간, 높음의 3단계로 감정을 구분한 경우 정서가(Valence)는 83.5%, 각성(Arousal)은 82.5%의 정확도를 보였다.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.131-134
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• 2000

Forest vegetation in Korea can be largely divided into warm temperate, cool temperate and frigid forest zone. The cool temperate forest zone of them occupies the largest part of the Korean peninsula and it is generally divided into three subdivisions such as northern, central and southern subzone. The Forestry Research Institute established three long-term ecological research sites at Kwangnung Experiment Forest in the central subzone of the cool temperate forest zone, at the Mt. Kyebangsan Forest in the northern subzone of the cool temperate forest zone. and at the Mt. Keumsan Forest in the warm temperate forest zone. The objectives of long-term ecological research in the Forestry Research Institute, Korea are to study long-term changes of the forest ecosystems in energy fluxes, water and nutrient cycling, forest stand structure, biological diversity, to quantify nutrient budgets and fluxes among forest ecosystem compartments and to integrate ecological data with a GIS - assisted model. To achieve the objectives, forest stand dynamics. environmental changes in soil properties, stream water quality, nutrient cycling, air pollution and biological diversity have been investigated and plant phonology as an indicator of climate change has been monitored in the LTER sites.

• Environmental Analysis Health and Toxicology
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• 제24권4호
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• pp.311-320
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• 2009

The short term (24-hr) and long term (21 days) effects of copper, cadmium, fenbendazole and sulfathiazole on the survival of the Korean fairy shrimp Branchinella kugenumaensis were evaluated. The 24-hr median lethal concentrations ($LC_{50}$) of copper, cadmium, fenbendazole, and sulfathiazole were 39, 512, 182, and 31,818 ${\mu}g/L$, respectively. The toxicity of copper is highest among 4 chemicals used in this study, while sulfathazole the lowest. After the long term (21 days) exposure experiment, the $LC_{50}$ copper, cadmium, fenbendazole, and sulfathiazole were 1.12, 2.1, 0.1, 6.6 ${\mu}g/L$, respectively. The long term effects of antibiotics were highly enhanced while the short-term effects were not strong. The sensitivities of B. kugenumaensis to copper and cadmium were higher than or comparable to those of other freshwater branchiopods (Streptocephalus spp., Thamnocephalus sp.), and far higher than the marine species (Artemia sp.). There were significant effects on the survival of B. kugenumaensis after long term exposure to relatively lower concentrations of copper, cadmium, fenbendazole and sulfathiazole. Therefore, B. kugenumaensis seems quite a good candidate species for the ecotoxicological assessments of freshwater environments.

• 생약학회지
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• 제44권2호
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• pp.200-208
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• 2013

The aim of this study was to evaluate the shelf-life of Bojungikgi-tang (Buzhongyiqi-tang in Chinese) by long-term storage test. Experiments were performed to evaluate the stability such as the selected physicochemical, pH, identification, heavy metal, microbiological experiment, and amount of marker compounds under a long-term storage test of Bojungikgi-tang decoction. The significant change was not showed in pH, heavy metal, microbiological, and identification test based on long-term storage test. Furthermore, the HPLC analysis was performed for the determinations of liquiritin, glycyrrhizin, nodakenin, and hesperidin in Bojungikgi-tang by long-term storage test. We were calculated shelf-life of Bojungikgi-tang decoction based on the amount change of four constituents. Consequently, Shelf-life by four compounds at room temperature was predicted 23 month. The suggested shelf-life would be helpful on the storage and distribution of herbal medicine.

• 생약학회지
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• 제43권3호
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• pp.257-264
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• 2012

The purpose of this study was to estimate the shelf-life of Ssanghwa-tang by long-term storage test. Experiments were conducted to evaluate the stability such as the selected physicochemical, pH, identification, heavy metal, microbiological experiment under a long-term storage test of Ssanghwa-tang. The significant change was not showed in pH, heavy metal, microbiological, identification test and quantitative analysis based on long-term storage test. The contents of albiflorin, paeoniflorin, cinnamic acid, liquiritin, and glycyrrhizin in long-term storage test were 66.8-93.1 ${\mu}g/mL$, 429.0-495.0 ${\mu}g/mL$, 3.8-4.4 ${\mu}g/mL$, 32.0-38.1 ${\mu}g/mL$, and 66.8-71.7 ${\mu}g/mL$, respectively. Shelf-lifes by 5 compounds about 3 lots at room temperature were predicted 21-37, 14-21, and 16-72 months, respectively. The suggested shelf-life would be helpful on the storage and distribution of herbal medicine.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.809-812
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• 2008

지난 수년간 콘크리트의 염소이온 침투와 유관되어 실험방법론 및 해석적 모델 기법의 개발에 많은 발전이 있어왔다. 그러나 실제 콘크리트 구조물에는 다소의 균열이 존재하며 이는 장기 내구성에 큰 영향을 줄 수 있음에도 불구하고, 대부분의 연구들은 비균열의 콘크리트를 대상으로 연구되어 온 문제점이 있었으며 균열이 존재하는 콘크리트의 염소이온 침투에 대한 연구는 매우 드문 실정이다. 본 연구의 저자는 단기 촉진실험에 의하여 균열이 염소이온에 미치는 영향을 살펴보았다. 그러나 신뢰성있는 결과를 얻기 위해서는 장기 실험을 통한 고찰이 필요하다. 본 연구의 목적은 장기 및 단기 실험결과를 비교하였는데, 자기치료 효과에 의하여 균열이 시간이 경과함에 따라 감소하는 뚜렷한 경향을 확인할 수 있었다.이러한 경향은 균열 폭이 클수록 자기치료에 의한 균열감소 효과가 더욱 뚜렷하였다.

• 산경연구논집
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• 제9권10호
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• pp.83-89
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• 2018

Purpose - The purpose of this study examines when the optimism impact on financial asset price forecasting and the boundary condition of optimism in the financial asset price forecasting. People generally tend to optimistically forecast their future. Optimism is a nature of human beings and optimistic forecasting observed in daily life. But is it always observed in financial asset price forecasting? In this study, two factors were focused on considering whether the optimism that people have applied to predicting future performance of financial investment products (e.g., mutual fund). First, this study examined whether the degree of optimism varied depending on the direction of the prior price trend. Second, this study examined whether the degree of optimism varied according to the forecast period by dividing the future forecasted by people into three time horizon based on forecast period. Research design, data, and methodology - 2 (prior price trend: rising-up trend vs falling-down trend) × 3 (forecast time horizon: short term vs medium term vs long term) experimental design was used. Prior price trend was used between subject and forecast time horizon was used within subject design. 169 undergraduate students participated in the experiment. χ² analysis was used. In this study, prior price trend divided into two types: rising-up trend versus falling-down trend. Forecast time horizon divided into three types: short term (after one month), medium term (after one year), and long term (after five years). Results - Optimistic price forecasting and boundary condition was found. Participants who were exposed to falling-down trend did not make optimistic predictions in the short term, but over time they tended to be more optimistic about the future in the medium term and long term. However, participants who were exposed to rising-up trend were over-optimistic in the short term, but over time, less optimistic in the medium and long term. Optimistic price forecasting was found when participants forecasted in the long term. Exposure to prior price trends (rising-up trend vs falling-down trend) was a boundary condition of optimistic price forecasting. Conclusions - The results indicated that individuals were more likely to be impacted by prior price tends in the short term time horizon, while being optimistic in the long term time horizon.