This study explores the seismic performance of steel diaphragm walls in underground structures, a critical aspect of structural engineering. The study focuses on the effects of slab diaphragm flexibility, an often overlooked factor in seismic design. Traditional seismic designs often assume the slab acts as a rigid diaphragm, leading to inaccuracies in predicting how forces are distributed between the slab and walls during an earthquake. To address this, the authors model steel diaphragm walls using equivalent cross-sections and analyze shear forces in both rigid and semi-rigid diaphragm scenarios. Results show that semi-rigid diaphragms reduce the shear forces on the exterior walls while increasing them on the internal core, thereby affecting the overall stiffness of the structure. The study emphasizes the importance of considering diaphragm flexibility in seismic design to achieve more accurate predictions of structural behavior and improve construction efficiency.

This study analyzes the impact of ESG (Environmental, Social, and Governance) activities on Corporate Financial Performance(CFP) using machine learning techniques. To address the linear limitations of traditional multiple regression analysis, the study employs AutoML (Automated Machine Learning) to capture the nonlinear relationships between ESG activities and CFP. The dataset consists of 635 companies listed on KOSPI and KOSDAQ from 2013 to 2021, with Tobin's Q used as the dependent variable representing CFP. The results show that machine learning models outperformed traditional regression models in predicting firm value. In particular, the Extreme Gradient Boosting (XGBoost) model exhibited the best predictive performance. Among ESG activities, the Social (S) indicator had a positive effect on CFP, suggesting that corporate social responsibility enhances corporate reputation and trust, leading to long-term positive outcomes. In contrast, the Environmental (E) and Governance (G) indicators had negative effects in the short term, likely due to factors such as the initial costs associated with environmental investments or governance improvements. Using the SHAP (Shapley Additive exPlanations) technique to evaluate the importance of each variable, it was found that Return on Assets (ROA), firm size (SIZE), and foreign ownership (FOR) were key factors influencing CFP. ROA and foreign ownership had positive effects on firm value, while major shareholder ownership (MASR) showed a negative impact. This study differentiates itself from previous research by analyzing the nonlinear effects of ESG activities on CFP and presents a more accurate and interpretable prediction model by incorporating machine learning and XAI (Explainable AI) techniques.

According to the recently revised seismic design standards, seismic design of underground structures is required. Concrete underground outer walls are installed separately from temporary earth retaining walls as permanent underground outer walls. This raises issues of constructability, economy, and space narrowness. Therefore, a steel underground continuous wall is developed to promote construction efficiency, safety, and economy by introducing the off-site construction (OSC) method of underground structures. The steel underground continuous wall will be used as a permanent underground continuous wall along with the temporary earth retaining wall. To this end, it must satisfy structural performance equivalent to or higher than the concrete underground outer wall. The integrity and in-plane shear resistance performance between single panel members must be satisfied to be used as a permanent wall. The interlocking effect through geometric bonding is intended to enhance the bonding effect between these members. Therefore, trapezoidal members were developed, and bending performance tests and analyses of each member were performed to confirm the structural bending performance of these members. The bending performance improvement effect of the combined multiple members was confirmed. As a result, it was confirmed that the integration of members and structural performance was improved due to the interlocking effect of the absence of joints. The seismic design analysis of the demonstration site was performed with these developed members, and it was confirmed that the structural performance was equivalent to or higher than that of the existing RC underground continuous wall. As a result, it was confirmed that the steel underground continuous wall can be used as a permanent underground wall together with the temporary earth retaining wall.

다중 운집 사고는 주로 도시 내 밀집된 공간에서 발생하며, 보행자의 자유로운 이동이 제한될 때 더욱 위험하다. 이러한 상황에서 군중의 물리적 압력이 더해지면 대형 참사로 이어질 수 있어 예방과 신속한 대응이 필수적이다. 사고 발생 가능성을 최소화하기 위해 서는 실시간으로 군중 밀도를 모니터링하고, 위험 상황을 사전에 경고할 수 있는 예측 시스템 구축이 필요하다. 그러나 현재 사용되는 CCTV 기반 모니터링 시스템은 특정 구역에 국한되며, 설치 및 유지 비용이 높아 광범위한 모니터링에는 한계가 있다. 이에 본 연구 에서는 Cell Transmission Model(CTM)을 기반으로 한 양방향 보행 시뮬레이션 프레임워크를 개발하고, 이를 모바일 통신 데이터로 검증하였다. 연구 과정에서는 먼저 1)단방향 보행 CTM을 구축하고, 2)이를 양방향 보행 CTM으로 확장하여 경계 셀을 재설정하고 유 입량을 조정하는 방식으로 진행했다. 또한, 다중 운집 사고를 구현하기 위해 체류 개념을 추가했다. 검증 단계는 1)대상지 선정, 2)보행 네트워크 구축, 3)시뮬레이션 적용, 4)모바일 통신 데이터와의 비교 검증 순으로 이루어졌다. 대상지는 이태원 참사가 발생했던 이태원 역 부근으로, 20×20m 셀 단위로 보행 네트워크를 구축했다. 시뮬레이션 결과, 모바일 통신 데이터와의 높은 유사도를 보였다. 본 연구 에서 개발한 시뮬레이션은 대규모 행사나 혼잡한 보행 환경에서 군중 밀집을 예측하고, 사고 가능성을 조기에 경고하는 데 활용될 수 있다. 특히, 대형 이벤트나 도시 재난 관리에서 실시간 대응 시스템의 기초 자료로 사용할 수 있다.

This study investigated the diversity of butterfly communities inhabiting agroecosystems and examined the effect of latitude and longitude. The ecological characteristics of butterflies inhabiting rural ecosystems, such as habitat preference and food plant range, were also examined. This study was conducted from 2019 to 2022, selecting 10 locations nationwide and conducting line transect surveys every two weeks for four years, confirming a total of 112 species and 21,901 individuals. There was no difference in the number of species and individuals by region, but there was a clear difference in community composition. The most abundant species in rural ecosystems were Pieris rapae, Polygonia c-aureum, Zizeeria maha, and Colias erate, in that order. There was no significant difference in the number of species and individuals by latitude and longitude, indicating no peninsula effect. Habitat preference showed that butterflies preferring grasslands and forest edges were much more common than those preferring the forest interior, and the food breadth was mostly oligophagous, followed by monophagous and polyphagous. Butterflies inhabiting agroecosystems had ecological characteristics that preferred open spaces such as grasslands and forest edges or relatively diverse foods, due to the similarity of the environmental characteristics of the survey points. Through this study, we believe that continuous monitoring is necessary to determine whether climate change, which is currently underway and habitat change are affecting butterflies in agroecosystems.

This study was conducted to analyze relationships between depression indices, mini nutritional assessment scores, and nutritional quotients among 80 elderly in Yangpyeong-gun and to identify factors that help prevent depression and malnutrition. Nutrition assessment scores were low in the high-risk group (PHQ-9 score 10), and nutritional quotient scores were lower in the high-risk group than in the normal group (PHQ-9 score 4). Interestingly, the consumption frequencies of fruits, eggs, and nuts were low in the high-risk group, and subjective health awareness, dental condition, and sleep were poorer. The total PHQ-9 score was correlated with malnutrition, body mass index, calf circumference, weight change, independent daily living, reduced meal amount, water intake, and the need for help when eating. Analysis of correlations between items of the PHQ-9 and nutritional status evaluation indices showed that a self-perceived feeling of depression, low energy, difficulty controlling sleep or appetite, negative thoughts (e.g., failure, disappointment), and difficulty concentrating were negatively correlated with total nutritional status scores. These results show that attention is required when food or water intake decreases and that deviation from normal sleep and appetite cycles flags the need to prepare guidelines to prevent depression.

The purpose of this study is to propose measures to increase evacuation safety by calculating the habitable time using a fire and evacuation simulation program for the Room-escape cafe currently in operation, and comparing and analyzing it with the evacuation required time. Assuming a fire due to overheating of electric heaters in use in front of the warehouse, the habitable time was calculated through fire simulation, and the occupant's evacuation time calculated through evacuation simulation according installation of safety facilities, etc. was compared and analyzed with the habitable time. In the case of escape room cafes with safety facilities installed, evacuation safety was satisfied, but in escape room cafes without safety facilities, the evacuation safety was not secure. As a result of analyzing evacuation safety for each scenario based on the ASET analyzed in the fire simulation, it was found that in scenario 1, evacuation safety was secured and everyone successfully evacuated, while in scenario 2, no one succeeded in evacuation. These results can be said to confirm that the installation of safety facilities is very important in business establishments such as escape room cafes, which become enclosed structures when games are started.

The need for lightweight yet strong materials is being demanded in all industries. Carbon fiber-reinforced plastic is a material with increased strength by attaching carbon fiber to plastic, and is widely used in the aerospace industry, ships, automobiles, and civil engineering based on its low density. Carbon-reinforced fiber plastic is a material widely used in parts and manufactured products, and structural analysis simulation is required during design, and application of actual material properties is necessary for accurate structural analysis simulation. In the case of carbon-reinforced fiber plastics, it is reported that there is a porosity of around 0.5% to 6%, and it is necessary to check the change in material properties according to the porosity and pore shape. It was confirmed by applying the method. It was confirmed that the change in elastic modulus according to the porosity was 10.7% different from the base material when the porosity was 6.0%, and the Poisson's ratio was confirmed to be less than 3.0%. It was confirmed that the elliptical spherical pore derived different material properties from the spherical pore depending on the pore shape, and it was confirmed that the shape of the pore had to be confirmed to derive equivalent material properties.

This study was a qualitative investigation into the food security and food variety among the rural elderly. For the qualitative data collection, nineteen elderly people who lived in Yangpyeong-gun were interviewed individually. Food security and variety was evaluated based on accessibility and affordability. The participants seemed to have difficulty preparing their own meals and eating with their families or others. The frequency of vegetable intake was found to be high, as vegetables were available through cultivation. However, in terms of diversity, the intake of meat and milk, which are sources of protein and calcium, was found to be significantly low. This has to do with very poor physical accessibility. A lack of nutrition education was identified as the biggest reason for not following dietary therapy despite having a pre-existing disease condition. Therefore, for the elderly in Yangpyeong-gun, it is suggested that a basic nutrition policy for food supply that can increase their actual intake is more essential than education on cooking and nutrients. Moreover, periodic nutrition education or a regular counseling system for dietary therapy through local public health centers may help improve the health of the elderly.

In this study, we focus on the improvement of data quality transmitted from a weather buoy that guides a route of ships. The buoy has an Internet-of-Thing (IoT) including sensors to collect meteorological data and the buoy’s status, and it also has a wireless communication device to send them to the central database in a ground control center and ships nearby. The time interval of data collected by the sensor is irregular, and fault data is often detected. Therefore, this study provides a framework to improve data quality using machine learning models. The normal data pattern is trained by machine learning models, and the trained models detect the fault data from the collected data set of the sensor and adjust them. For determining fault data, interquartile range (IQR) removes the value outside the outlier, and an NGBoost algorithm removes the data above the upper bound and below the lower bound. The removed data is interpolated using NGBoost or long-short term memory (LSTM) algorithm. The performance of the suggested process is evaluated by actual weather buoy data from Korea to improve the quality of ‘AIR_TEMPERATURE’ data by using other data from the same buoy. The performance of our proposed framework has been validated through computational experiments based on real-world data, confirming its suitability for practical applications in real- world scenarios.

본 연구에서는 밭가뭄을 선제적으로 대응하기 위한 자료를 구축하고자 충청도 지역 대표 밭작물의 시공간적 부족수량을 파악하였다. 고추 등 5개 대표 밭작물과 충청도의 5개 지역을 선정하였고, 작물별 필요수량과 지역별 공급량을 고려하여 부족수량을 산정하였다. 한국농어촌공사의 HOMWRS (Hydrological Operation Model for Water Resource System) 모형을 이용한 작물의 필요수량과 공공관정과 민간관정의 채수량, 상수도 공급량을 조사하여 지역별 용수공급량을 평가하였다. 2014년부터 2018년까지 5년간의 월별 평균 필요수량과 공급량의 차이에 따른 부족수량 을 기준으로 가뭄수준과 시기를 분석하였다. 공공관정, 민간관정, 상수도 공급량 순으로 필요수량과 차이를 산정한 결과 예산(사과)의 6월 부족수량이 가장 높았고, 괴산(콩)의 8월이 두번째로 나타났다. 그 외 지역에서는 관정과 상수도 공급량을 모두 고려할 경우 대체적으로 안정적인 공급이 가능하였으나, 청양(고추)에서 2018년 7월과 8월에 공급량이 부족한 것으로 나타났다. 시공간적 가뭄수준 분석 결과는 공간적 우선순위 결정과 시기별 공급량 확보를 위한 기초자료로 활용될 것으로 판단된다.

The purpose of this study is to explore how adolescents' psychological characteristics affect their sense of life safety according to gender. To this end, a survey was conducted on male and female high school students in six schools in the C area, and a total of 1,048 data were used for analysis. Differences in major variables according to gender were verified, and the effect of psychological characteristics on living safety awareness was analyzed through hierarchical multiple regression analysis. As a result of the analysis, depression, anxiety, type A characteristics, and the presence or absence of experience in accidents did not significantly affect life safety awareness in the male student group. On the other hand, in the female student group, anxiety and type A characteristics had a significant effect on life safety awareness. Anxiety negatively affects living safety awareness, and type A characteristics have been shown to have a positive effect on living safety awareness. The presence or absence of depression and accident experience did not significantly affect life safety awareness. The results of these studies suggest that gender differences should be considered in education to prevent life safety awareness and that education that reflects the psychological characteristics of adolescents is necessary.

최근 기후변화로 가뭄, 홍수 등 재해의 빈도와 강도가 높아지고 있다. 이러한 재해의 피해를 줄이기 위해서는 시공간적 현황 파악을 통한 대비가 필요하다. 본 연구에서는 가뭄의 피해를 최소화하고자 지역별 밭작물의 필요수량과 공급량을 고려하여 밭가뭄 지역 등급화 실시하였고, 월별 비교를 통해 가뭄 취약 시기를 파악하였다. 전국 148개 지역 중 안전지역(Ⅰ), 안전지역(Ⅱ), 우려지역, 상습지역으로 구분한 25개 지역을 선정하였으며, 이 지역의 월별 필요수량 대비 공급량 분석을 하였다. 필요수량 산정의 재배작물은 콩으로 선정하였으며, 공급량은 공공관정, 민간관정, 상수도 자료를 분석하였다. 필요수량 대비 공급량이 봄철은 안전지역(Ⅰ), 안전지역(Ⅱ), 우려지역, 상습지역에서 각 1,281.5%, 667.6%, 729.5%, 316.3%, 가을철에는 각 436.0%, 212.8%, 213.9%, 105.3%로 공급이 충분할 것으로 분석되었으나 여름철에는 각 82.4%, 40.6%, 42.6%, 20.0%로 용수공급 이 부족한 것으로 분석되었다. 콩의 재배 기간인 5~9월에 관정(공공+민간)으로의 공급량은 대부분 지역에서 부족한 것으로 분석되었다. 이러한 분석을 통해 용수 부족이 발생하는 재배기간 동안 용수확보 방안이 필요하다.

This study attempted to explore how the perception of the necessity of safety education for adolescents affects fire safety consciousness and whether personality factors control the relationship. To this end, a survey was conducted at a high school in region C, and data of 1,049 people who agreed to the survey and responded faithfully were used for analysis. Hayes’ macro was used to analyze the moderating effect, and as a result of the analysis, adolescents’ awareness of the need for safety education increased, and their relationship was significantly regulated by extroversion, openness, and conscientiousness among the five personality factors. A simple regression line analysis was conducted to find out the specific direction, and it was found that the higher the need for safety education in both the group with high extroversion, openness, and conscientiousness, the higher the awareness of safety education. These results suggest that changes in educational methods and contents are needed to raise awareness of the necessity of education in fire safety education and to improve educational motivation, and that it may be helpful to actively utilize students’ personality strengths in education.

The purpose of this study is to analyze which factors affect safety awareness of foreign workers and international students. In the correlation analysis, individual characteristics related to the safety awareness of foreign workers were nationality, status of stay(visa types), place of work, educational background, and Korean proficiency while international students were relevant with only the types of residence. There were significant differences in the safety awareness of foreign workers in nationality, status of stay(visa types), region of residence, educational background, place of work, and Korean proficiency. However, there was a significant difference only in the types of residence for the international students. In the regression analysis of factors affecting safety awareness, there were significant differences in nationality, status of stay(visa types), place of work, and Korean proficiency in the case of foreign workers. It was analyzed that nationality and status of stay had a negative (-) effect, and the place of work and Korean proficiency had a positive (+) effect. In the case of international students, it was analyzed that only the types of residence had a negative (-) effect on safety awareness.

The purpose of this study is to present the direction of the plan to transform the residential complex into a space that can provide an open residential environment that can lead to social communication and exchange without being closed to the urban residential environment, especially in the apartment complex environment, which is becoming more dense. As a result of the Openness analysis of the ‘Codan Shinonome Canal Court’, the overall accessibility was good in terms of space utilization, and the openness was low in terms of the spatial composition, which is a physical environment due to the dense block type. When looking at the overall openness of the Codan Sinonome complex in terms of analysis by block, the corrected openness index (C.O.I) for all six blocks was 0.245, the corrected accessibility index (C.A.I) was 1.447 and the openness composite index (O.C.I) was assessed at 1.692. This was due to the formation of high-density block-type urban dwellings and the introduction of S-shaped streets and the layout of low-rise urban support facilities and commercial facilities. The Codan Sinonome Canal Court, which is considered an “open city residence,” quantitatively confirmed that it embodies macro-space structure and human-scale space environment even in high-precision environments.

본 연구는 직무 자원, 직무 요구, 개인 자원이 공직자들의 조직 몰입에 미치는 영향을 개인 수준과 조직 수준에서 분석하는 데 그 목적이 있다. 이를 위해 63개 기관에서 근무하는 공무원 4,339명으로부터 자료 를 수집한 4차 공직생활실태조사 자료를 활용하였다. 가설을 검증하기 위해 위계적 선형 모형을 활용하였 으며, 분석 결과, 공직자들의 조직 몰입은 조직에 따라 차이가 존재하는 것으로 나타났다. 구체적으로 변 화 지향성, 목표 명확성, 공공 봉사 동기, 공직 가치가 높을수록, 역할 모호성은 낮을수록 조직 몰입이 높 았고, 광역 자치 단체 공무원이 중앙 행정 기관 공무원보다, 남자 공무원이 여자 공무원보다, 대학원 졸업 이상의 교육 수준을 가진 공무원이 대졸 공무원들보다 조직 몰입이 높았다. 연구결과를 바탕으로 이론적 시사점을 논의하였고, 공직자들의 조직 몰입을 높이기 위한 실천적 방안을 제시하였다.

난자의 성숙과정과 노화에 관한 이해는 인공수정과 체외수정 최적기를 판단하기 위하여 가장 중요한 연구내용으로 알려져 있다. 이러한 기작은 번식 호르몬들에 의하여 조절되는 것으로 알려져 있으나 난자 세포질 변화에 관한 내용은 잘 알려져 있지 않다. 본 연구에서는 산화질소물(nitric oxide, NO)이 난자 성숙과정에서 증가하는 것을 밝혔으며 난자의 미성숙단계(germinal vesicle stage, GV)와 난자핵막붕괴단계(germinal vesicle breakdown, GVBD) 및 성숙완료단계(metaphase II, MII)단계에서 생산되는 NO의 양을 비교하였다. 또한, 난자를 체외에서 배양할 때, MII단계로 성숙되지 않는 성장 단계의 난자에서는 NO의 증가 현상을 관찰할 수 없었고, 세포질이 불균일한 노화된 난자에서는 NO가 증가된 상태로 유지되는 특성이 있음을 밝혔다. 이러한 결과는 NO의 작용이 난자의 성숙과정과 난자 노화과정에서 중요한 기능을 담당하고 있음을 보여주고 있다.