• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.383-383
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• 2021

강수는 수자원 분석 및 지리학적 연구에 가장 핵심적으로 쓰이는 수문인자이며, 최근 기후변화와 방재 관련한 다양한 연구에서 정확한 강수자료의 중요성이 부각되고 있다. 특히, 강수는 지표에서의 유출, 침투, 증발 등 다양한 수문현상으로 이어지므로, 수문순환, 물수지 분석에 있어 강우강도 등 강수 발생 양상과 유형에 대한 정확한 자료는 필수불가결하다. 강수량은 Automatic Weather Station (AWS)을 통해 비교적 정확하게 측정되고 있으나, 이러한 계측자료는 기상학적, 지형적 영향을 크게 받으며 대표성이 좁다는 단점을 가지고 있어 유출 및 기후 등 공간적 범위를 대상으로 한 연구에 활용하기에 한계점을 가지고 있다. 이러한 한계점을 극복하기 위해 지상강우레이더를 통한 국지적 강수자료 및 인공위성 기반 전 지구적 강수 관측 자료가 활용되고 있다. 특히 인공위성을 활용한 강우 측정방법은 미계측 유역에서 수자원 측정 및 관리 계획을 세우거나 전 지구적으로 장기적 변화를 분석하는데 있어 가장 활용도가 높다. National Aeronautics and Space Administration (NASA)의 Tropical Rainfall Measuring Mission (TRMM)을 포함한 기존 강수측정 보조 위성에 더하여 2014년 Global Precipitation Measurement (GPM) 핵심 위성이 발사된 이후 다양한 기관에서 여러 인공위성을 결합한 강수 산출물들을 제공하고 있다(NASA-IMERG, JAXA-GSMAP, NOAA-CMORPH). 본 연구에서는 세 가지 위성 기반 강수 자료의 산출 알고리즘을 비교□분석하고, 강우강도에 따른 산출물들의 정확도를 평가하였다. 본 연구결과는 높은 강우강도 발생 시 나타나는 위성 강수자료의 불확실성을 개선하는 데 기여할 수 있을 것으로 판단되며, 이후 신뢰도 높은 다중 위성 융합 강수 산출물을 구현하기 위한 바탕이 될 것으로 기대된다.

• Korean Journal of Schizophrenia Research
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• v.21 no.2
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• pp.74-80
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• 2018

Objectives : This study investigated whether long-acting injectable (LAI) paliperidone is different from its oral form in terms of the effect on cognitive function in schizophrenia spectrum and other psychotic disorders. Methods : We reviewed the medical records of patients in Seoul National University Bundang Hospital who were diagnosed as having schizophrenia and/or other psychotic disorders based on DSM-5 from 2016 to 2017. Seven patients were treated with oral paliperidone and 11 were treated with paliperidone palmitate. All patients underwent clinical and neuropsychological assessment, including the Korean version of the MATRICS Consensus Cognitive Battery (MCCB) at their first visit or within one month of their initial treatment. MCCB was repeated within three to 12 months after the initial assessment. Results : There was no significant difference between the two groups in most cognitive domains including speed of processing, attention and vigilance, working memory, verbal learning, visual learning and reasoning and problem solving domain. However, patients treated with paliperidone palmitate showed better improvement in social cognition domain than those taking oral paliperidone. The standardized values of social cognition domain scores had significantly improved over time in patients under paliperidone palmitate, demonstrating a significant time-by-group interaction. Conclusion : Our results show that long-acting injectable paliperidone could be helpful in some aspects of improving cognitive function in schizophrenia spectrum and other psychotic disorders. Further studies with other antipsychotics are necessary to generalize the results.

• Korean Journal of Legislative Studies
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• v.25 no.1
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• pp.79-106
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• 2019

Local governments within the boundaries of a state need increasing flexibility to satisfy diverse economic, social, and environmental goals in their particular geographical setting. However, many candidates in the local election in South Korea tend to see local politics as an extension of national-level politics. In particular, this paper mainly deals with how the voters' evaluation of a president's performance has influenced subnational elections in South Korea. Our analysis suggests that the fate of candidates in subnational elections is shaped by the performance of the incumbent president in both economic development and foreign affairs.

• Journal of the Korea Institute of Building Construction
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• v.23 no.6
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• pp.821-830
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• 2023

This research aims to identify risk factors for fall accidents at small and medium-sized construction sites through a comprehensive regression analysis. Initially, the study involved collecting a decade's worth of fall accident data from these sites. A t-test confirmed a significant variation in the treatment duration following fall accidents between two distinct groups: small and medium-sized versus large construction sites. Subsequently, a regression analysis was conducted to establish a model highlighting the risk factors associated with safety accidents. The factors influencing fall accidents were determined to be, in descending order of impact, the time of the accident, the day of the accident, and the occupational classification. The findings from this study are expected to serve as foundational data for enhancing policies and conducting statistical analyses tailored to construction site sizes. They also provide crucial information for future research on risk quantification at small and medium-sized construction sites.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.43-53
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• 2024

Background: Exposure assessment is an important part of risk assessment for consumer products. Exposure models are used when estimating consumer exposures by considering exposure routes, subjects, and circumstances. These models differ based on their tiers, types, and target populations. Consequently, exposure estimates may vary between models. Objectives: This study aimed to compare the results of different exposure models using identical exposure factors. Methods: Chemical exposure from consumer products was calculated using four consumer exposure assessment models: Targeted Risk Assessment 3.1, Consumer Exposure Model 2.1 (CEM), ConsExpo web 1.1.1, and the Korean Exposure Algorithm (primary and detailed) issued by the Ministry of Environment, No. 972 (MOE). The same exposure factors were used in each model to calculate inhalation and dermal exposures to acetaldehyde, d-limonene, and naphthalene in all-purpose cleaners, leather coating sprays, and sealants. Results: In the results, TRA provided the highest estimate. Generally, MOE (detailed), CEM and ConsExpo showed lower exposures. The inhalation exposure for leather coating spray showed the largest differences between models, with differences reaching up to 1.2×10⁷ times. Since identical inputs were used for the calculations, it is likely that the models significantly influenced the estimated results. Conclusions: Despite using the same exposure factors to calculate dermal and inhalation exposures, the results varied substantially based on the model's exposure algorithm. Therefore, selecting an exposure model for assessing consumer products should be done with careful consideration.

• Smart Structures and Systems
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• v.33 no.1
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• pp.55-64
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• 2024

This paper proposes a fusion imaging-based coating-defect classification method for steel structures that uses zero-shot learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured by an infrared (IR) camera, while photos of the coating surface are captured by a charge-coupled device (CCD) camera. The measured heat responses and visual images are then analyzed using zero-shot learning to classify the coating defects, and the estimated coating defects are visualized throughout the inspection surface of the steel structure. In contrast to older approaches to coating-defect classification that relied on visual inspection and were limited to surface defects, and older artificial neural network (ANN)-based methods that required large amounts of data for training and validation, the proposed method accurately classifies both internal and external defects and can classify coating defects for unobserved classes that are not included in the training. Additionally, the proposed model easily learns about additional classifying conditions, making it simple to add classes for problems of interest and field application. Based on the results of validation via field testing, the defect-type classification performance is improved 22.7% of accuracy by fusing visual and thermal imaging compared to using only a visual dataset. Furthermore, the classification accuracy of the proposed method on a test dataset with only trained classes is validated to be 100%. With word-embedding vectors for the labels of untrained classes, the classification accuracy of the proposed method is 86.4%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.2
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• pp.108-112
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• 2024

The pronation foot can increase muscle activity, and may result in muscle fatigue and overuse syndromes. This paper aims to examine the relationships between muscle fatigue indices and pronation angles (PRA) larger than 20° for pronated foot subjects. Twelve subjects in the 15-61 age range were participated, and EMG of their biceps femoris were measured during treadmill walking at 4.5 km/h for 30 seconds. Slopes of the median frequency and the magnitude in the low frequency band were estimated respectively as muscle fatigue indices (MFIs). We hypothesized that the relationships between MFIs and PRA for the subjects in this paper be similar to those for normal ones. The test results demonstrated that we could obtain the significant correlation coefficients between MFIs and PRA (r>0.60; p<0.05).

• Journal of the Korea Institute of Building Construction
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• v.24 no.2
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• pp.249-260
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• 2024

In recent years, the proportion of medium and small-sized apartments within the housing market has seen a noticeable increase, alongside a corresponding rise in disputes related to construction defects. Such disputes are most prevalent in the finishing works phase of construction, which not only are frequent in occurrence but also impose significant repair costs. Furthermore, there is a noticeable scarcity of research focused on the quality management of finishing work defects prior to the completion of construction. Addressing this issue necessitates a methodology capable of preemptively identifying defects by analyzing their frequency and associated costs across various defect types. Consequently, the aim of this study is to propose a risk assessment methodology by conducting an analysis of defect cases across 3,299 apartment units, considering aspects such as frequency and severity. The outcomes of this research endeavor are expected to offer practical management strategies to enhance the quality of apartment finishing works and serve as an academic foundation for the enhancement of construction management systems pertaining to apartment finishing works.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.141-145
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• 2024

Because of muscle fatigue, motor unit recruitment and firing rates decrease and EMG power spectrum shifts toward lower frequencies as spectral compression which represented by a falling shift in the median frequency. However, changes of this frequency shows relatively less than those of the magnitudes of the low frequency band. This paper aims to examine the moderate ranges of the frequency bands in the existed ones as spectral fatigue indices of biceps femoris muscle. Twelve subjects participate in this experiment, and EMG signals are measured from these muscles during treadmill walking on the speed of 4.5 km/h. ANOVA analysis is used to compare changes of the low and high frequency band with reference to those of median frequency. Experimental results demonstrate that the low frequency band 25-82 Hz and the high frequency band 142-300 Hz could be appropriate for spectral fatigue indices of biceps femoris muscles.

• Fire Science and Engineering
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• v.31 no.1
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• pp.116-123
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• 2017

The purpose of this paper is to improve the evacuation stability of residents in apartment fire. For this purpose, the actual condition survey about the obstacles was conducted on 3,056 escape stairs in the 183 apartments. In addition, the questionnaire investigation was carried out a survey targeting the residents of apartments about their experience of fire safety education, perception on safety management of escape stairs, and perception on fire safety. As a result of investigation, we confirmed that the obstacles were formed in the 1,916 escape stairs among the 3,056 escape stairs of the 183 apartments (percent of barricades in escape stairs: 62.70%). Furthermore, it showed that fire safety education experience was found to be 83.10% of subject. The perception on safety management of the subjects in the escape step and the perception on fire safety were $3.84{\pm}0.75%$, and $3.49{\pm}0.61$, respectively. In the results, most of the subjects had a fire safety education and knew how to safety management the escape stairs but, the practice of the safety management action was low. Based on the results in the paper, the policy proposal is that the fire safety education is emphasized to change from the perception to action.