교량은 국가의 사회경제 발전과 국민 안전에 중대한 영향을 미치는 중요한 인프라이다. 하지만 다수 의 국내 교량이 1970년대와 1980년대의 고도의 경제성장기에 완공되었으며, 현재 교량의 노후화 비중 은 전체 교량의 30%에 달하고 있다. 현재 노후화 교량에 대한 유지 보수 시스템의 부족으로 인해 교 량 붕괴 사고가 발생한 사례들이 발생하고 있다. 따라서 노후화가 진행되는 교량에 대해 효율적으로 관리하기 위한 우선순위 평가 모델 개발은 중요시된다. 본 연구에서는 개발한 유지관리 우선순위 모델 을 개발하였고, 이를 실제 교량에 대해 적용하여 평가하였다. 제안된 모델의 활용을 통해 위험에 노출 된 교량의 유지 보수 및 관리를 효율적이고 신뢰할 수 있게 수행할 수 있을 것으로 판단된다.

본 연구에서는 탄소나노튜브(CNT) 패치 센서를 기반으로 하여 구조물의 이상 거동을 감지하고 대 응할 수 있도록 하는 첨단 스마트 모니터링 시스템을 제안한다. 복합소재로 제작되는 CNT 센서는 유 연한 특성을 갖게 되어 다양한 형태의 구조물 표면에 적용할 수 있으며, 이를 통해 충격이나 피로 등 에 의해 발생되는 균열과 같은 비정상적인 거동을 감지할 수 있다. CNT 센서를 통해 수집한 데이터 는 IoT 시스템을 통해 실시간으로 분석되어 구조물의 거동 상태를 확인하고 건전성을 모니터링 할 수 있게 한다. 이 시스템의 성능 검증 및 사용성 검토를 위해 미국 소재 교량에서 실증 테스트를 하였으 며, 테스트 결과 CNT 센서를 이용한 구조물 거동 감지 시스템을 통해 구조물의 이상 거동을 효과적 으로 감지하고 모니터링하여 구조물에서 발생 될 수 있는 잠재적 문제를 사전에 예방할 수 있음을 확 인하였다. 이와 같은 기술은 추후 다양한 분야에서 적극적으로 활용될 수 있을 것으로 기대된다.

The objective of this study was to conduct research and analysis using Group Focus Interview to survey the between construction site workers and managers implementing for the Severe Accident Punishment Act. Focused on measures to improve safety management effectiveness for the effectiveness of establishing a safety management system. A plan to improve the efficient safety management system was presented to 50 construction industrial managers and workers. In order to ensure the industrial accident prevention policies appropriately, it is necessary to be aware of safety obligations for workers as well as business operators. In addition, despite the existence of a commentary on the Serious Accident Punishment Act, confusion in the field still persists, so in the event of a major accidents, the obligation to take safety and health education is strengthened, and effective case education is proposed by teaching actual accident cases suitable for actual working sites. It is necessary to make all training mandatory, and it is necessary to reconsider awareness through writing a daily safety log, awareness of risk factors, etc., and writing down risk information. Above all, at the construction ordering stage, it is necessary to keep the construction safety, request corrections and supplements for problems issues that arise, and consult between the orderer and the construction company about the problems issues. Rather than having only the construction company correct or supplement the safety management plan, the contents should be shared with supervisors and workers to establish a more practical solution. Results of this study will contribute to improving the effectiveness of the serious accident and construction safety management system.

In the modern society, the sports industry is becoming an important industry that plays an important role in cultural exchange and economic development between countries. Along with this, the size of sports equipment manufacturers is also increasing, and especially in the archery field, domestic companies occupy a high share in the global market. However, in the case of precision accessories, foreign products are imported and used. Among the precision archery accessories, the cushion plunger is subjected to repetitive loads, and the surface damage due to wear affects the accuracy of the archery, so fatigue and wear analysis taking this into account are required. In this paper, a friction simulation was performed to calculate the fatigue life and wear amount of the cushion plunger among the precision archery accessories, and the validity of the analysis model was evaluated by comparing the friction test results.

The towing distance, which is speed over the ground, and the water flow quantity, which is speed through the water, were used when estimating the amount of Metapenaeus joyneri resources that rose to the surface at night using the swept area method in order to compare and analyze the difference. It was conducted using a shrimp dredge, trial fishing gear for catching Metapenaeus joyneri. Catch during the entire survey period was 188.9 kg. Monthly catch ranged from 3.1 to 109.2 kg, highest in June and lowest in September. The swept volume calculated using the speed over the ground was about 13% higher than using the speed through the water. Metapenaeus joyneri resources estimated using the towing distance ranged from 320.1 to 14,649.8 kg. Resources estimated using the water flow quantity ranged from 278.5 to 12,886.3 kg. Therefore, the amount of Metapenaeus joyneri resources estimated using the speed over the ground was about 14% higher than the method using the speed through the water, indicating that the amount of resources was overestimated.

In this study, we designed and manufactured a large angular contact ball bearing (LACBB) with low deformation using JIS-SUJ2 steel and analyzed changes in its structural characteristics and chemical composition upon heat treatment. The bearing was produced by hot forging and heat treatment including a quenching and tempering (Q/T) process, and its properties were analyzed using 4 mm thick specimens. A difference in the size distribution of the carbide in the outer and inner parts of the bearing was observed and it was confirmed that large and non-uniform carbide was distributed in the inner part of the bearing. After heat treatment, the hardness value of the outer part increased from 13.4 HRC to 61 HRC and the inner part increased from 8.0 HRC to 59.7 HRC. As a result of X-ray diffraction (XRD) measurements, the volume fraction of the retained austenite contained in the outer part was calculated to be 3.5~4.8 % and the inner part was calculated to be 3.6~5.0 %. The surface chemical composition and the content of chemical bonds were quantified through X-ray photoelectron spectroscopy (XPS), and a decrease in C=C bonds and an increase in Fe-C bonds were confirmed.

Pinus densiflora is a fixed-growth coniferous species that elongates its shoot once a year and finishes growing in early summer. However, it may produce additional shoots in the same year in response to external stimuli, called abnormal shoot growth. This study investigated the effects of open-field summer warming and drought on the abnormal shoot growth of P. densiflora seedlings. In March 2022, two factorial combinations were constructed, including two temperature treatments (control and 4°C increase) and two precipitation treatments (control and drought), with five replicates for each combination. The temperature treatment was performed for 87 days from May 14 to August 8, 2022, and the precipitation treatment was performed for 33 days from May 14 to June 15, blocking 100% of the ambient rainfall. The abnormal shoot occurrence rate and leaf unfolding stages were measured in November, and the shoot and root collar diameter growth rates were calculated by comparing the seedling height and root collar diameter measured in August (after the cessation of treatment) and October (after the end of growing period) with the initial values (i.e., May 2022). The abnormal shoot occurrence rate significantly increased under the warming treatment, showing a 410.6% increase in the warming plots (38.4%) compared to the control plots (7.5%). There was no significant difference in the shoot and root collar diameter growth rate regarding warming and drought treatments. Abnormal shoots may have been affected by high temperatures by inducing early transition to the next ontogenetic stage.

본 연구는 ESG 경영에 대한 에너지 관련 산업과 기업의 전략적 발전방향 모색을 위하여 글로벌 ESG 경영에서 선도적인 역량과 경험을 갖고 있는 것으로 평가되는 한국중부발전의 사례를 분석해 성공 요인을 도출하고자 하였다. 사례 분석 결과 한국중부발전은 한 발 앞서 ESG 경영에 관심을 갖기 시작해 기후위기 대응과 청정에너지 및 신재 생에너지 사업 분야로 진출하였고, 동반성장과 지역사회 공헌, 부패방지와 윤리경영에 역점을 두고 미래성장과 지 속가능경영을 계속해 객관적인 수치와 실적을 기반으로 우수한 성과를 달성한 것으로 확인되었다. 또한 한국 중부 발전이 글로벌 ESG 경영에 성공할 수 있었던 것은 기존의 글로벌 경영 역량 보유와 이를 제고하고자 전문인력 양 성을 바탕으로 전사적인 조직을 중심으로 하는 지속적인 노력, ESG 리스크에 대한 선제적 관리와 수치목표 중심의 성과관리, 동반성장과 상생경영의 기업문화, 글로벌 ESG 경영에 대한 CEO와 경영진의 판단과 의지가 주요한 요 인으로 작용하였기 때문이라고 분석되었다.

The demand for high-strength steel is rising due to its economic efficiency. Low-cycle fatigue (LCF) tests have been conducted to investigate the nonlinear behaviors of high-strength steel. Accurate material models must be used to obtain reliable results on seismic performance evaluation using numerical analyses. This study uses the combined hardening model to simulate the LCF behavior of high-strength steel. However, it is challenging and complex to determine material model parameters for specific high-strength steel because a highly nonlinear equation is used in the model, and several parameters need to be resolved. This study used the particle swarm algorithm (PSO) to determine the model parameters based on the LCF test data of HSA 650 steel. It is shown that the model with parameter values selected from the PSO accurately simulates the measured LCF curves.

This study aimed to develop an optimal greenhouse model for strawberry seedling during the summer high-temperature period based on the results of field surveys. We conducted a survey on the structure types of 46 strawberry seedling farms nationwide, including width, ridge height, eaves height, ventilation method, seedling bed width, and spacing. Based on the survey results, we derived the optimal greenhouse model by considering various factors. The greenhouse width was set at 14 meters to maximize the efficiency of seedling beds and overall space. The height was determined at 2 meters, taking into account ventilation during the summer season. To reduce stress on the supporting structure due to snow loads, we established a reinforcement installation angle of 50 degrees. We analyzed two different models that use support beams with dimensions of φ48.1×2.1t and φ59.9×3.2t, respectively, to ensure structural safety against meteorological disasters, considering regional design wind speeds and snow accumulation. We utilized these developed greenhouse model to conduct strawberry seedling experiments, resulting in a high survival rate of average 93.2%. These findings confirm the usefulness of the strawberry seedling greenhouse in improving the seedling environment and enhancing overall efficiency.

Mucoepidermoid carcinoma (MEC) is the most prevalent malignant tumor originating from the salivary gland. The gradation of MEC is determined histologically based on cellular composition, with high-grade MEC presenting with distinct characteristics and clinical implications. A 56-year-old male presented with a 3-month history of right facial swelling and a recent onset of pain. A subsequent biopsy confirmed a malignant epithelial tumor, with further imaging assisting in determining the surgical approach. Comprehensive surgery, involving the removal of the right submandibular gland and reconstructive procedures, was undertaken. Histopathological evaluation post-surgery confirmed a high-grade MEC. The differentiation between inflammatory conditions and neoplastic lesions in the orofacial region can be challenging. The gradation of MEC is important in guiding therapeutic decisions. Among various classification systems, the Brandwein system offers detailed histopathological criteria that correlate reliably with clinical features. High-grade MECs, although less frequent, are aggressive and have a lower 5-year survival rate. Accurate histopathological diagnosis is crucial in devising an effective treatment plan. The presented case underlines the importance of a meticulous yet periodic follow-up, considering the aggressive nature of high-grade MECs.

ATP luminescence measurements (using Relative Light Units, RLU) has been used to assess the levels of bacterial contamination on the surfaces of various materials. However, not much is known about their suitability in assessing bacterial contamination on paper surfaces. This study was conducted to evaluate the feasibility of using ATP luminometers in measuring levels of bacteria contamination on paper surfaces. The three ATP luminometers studied were Clean-Q, smart PD-30, and 3M™ Clean-Trace™ LM1 manufactured by different companies. There were some differences in RLU results among the three ATP luminometers when they were tested with different concentrations of Micrococcus luteus cell suspension. 106 - 107 cells were required in order to effectively detect Bacillus subtilis, Escherichia coli, and Micrococcus luteus on the surfaces of A4 printing sheets (100 cm2) when using the three ATP luminometers. The sizes and physical properties of surface areas varied slightly among the swabs used for the three ATP luminometers. Concentration-specific measurements (RLU) of M. luteus taken from the surfaces of six kinds of paper (fine print paper, medium print paper, ground paper, newsprint paper, practice paper, tracing paper) were possible using the smart PD-30 and LM1 ATP luminometers. ATP detection values of M. luteus varied among the six types of paper. The highest ATP detection values were found on the surfaces of tracing paper. If the RLU value is recorded at the level of 1000, this could indicate a very high bacterial contamination level of 105 to 106 CFU/4 cm2.

본 연구에서는 뇌혈류 신호를 측정할 수 있는 시변자계 기반의 비접촉식 직물센서를 설계하여 뇌혈류 신호 검출 및 감성평가의 가능성을 탐색하고자 하였다. 직물센서는 40 denier의 은사를 30합사 한 후 컴퓨터 기계 자수하여 코일 형 센서로 구현하였다. 뇌혈류 측정 실험을 위해 코일형 센서를 경동맥 부위에 부착하고, ECG (Electrocardiogram) 전극과 RSP (Respiration) 측정 벨트를 부착 및 착용하도록 하였으며, 동시에 초음파 진단기기를 사용해 도플러 초음 파 검사(Doppler Ultrasonography)를 수행하여 혈류 속도를 측정하였다. 피험자에게 Meta Quest 2를 착용시키고, 실 험을 위해 조작된 영상 시각 자극을 보여주면서 혈류 신호를 측정한 후 시각 자극에 대한 감성평가 설문지를 작성하 도록 하였다. 측정 결과, 도플러 초음파 검사를 통해 측정된 혈류 속도 신호에 변화가 생길 때 직물센서로 측정한 신호도 함께 변화하는 것으로 나타났다. 이를 통해 코일형 직물센서를 이용하여 뇌혈류활동 신호를 측정할 수 있다 는 것을 검증하였다. 또한, 감성평가를 위하여 ECG 신호와 PLL 신호(직물센서 신호)에서 추출한 HRV를 계산해서 비교한 결과, 시각 자극으로 인한 교감신경계와 부교감신경계의 활성화에 따른 비율의 변화에 대해서는 직물센서로 측정한 신호와 ECG 신호를 이용해 계산한 값이 비슷한 경향을 보이는 것으로 나타났다. 결론적으로, 본 연구에서 개발된 시변자계 기반의 코일형 직물 센서를 통해 뇌혈류 변화 측정 및 감성 모니터링이 가능할 것으로 사료된다.

본 연구는 한국인 인구집단에서 폭식행동, 음식중독을 식별하고, 해당 증상들이 비만 및 섭식행 동, 정신건강, 인지적 특성과 어떠한 연관성을 보이는지 규명하고자 하였다. 이를 위하여 정상체중 및 비만 체중에 해당하는 한국인 성인 257명을 대상으로 섭식문제(예: 폭식, 음식중독, 음식갈망), 정신건강(예: 우 울), 인지기능(예: 충동성, 정서조절)에 관한 임상심리검사 척도를 측정하였다. 비만 여부와 성별에 따라 그 룹을 나누었을 때, 비만체중 여성에서 폭식행동이 46.6%, 음식중독이 29.3%로 가장 빈도가 높았다. 성향 점수 매칭 후 데이터로 독립성 검정을 수행한 결과, 폭식행동 및 음식중독이 비만체중 집단에서 정상체중 집단보다 더 많이 나타나는 것을 확인하였다. 또한 폭식행동과 음식중독 유무에 각 심리검사 척도 요인이 미치는 영향력을 파악하고자, 전진선택법을 적용한 로지스틱 회귀모델을 구축하였다. 로지스틱 회귀분석 결과, 폭식행동에는 섭식장애, 음식갈망, 상태불안, 정서조절(인지적 재해석) 및 음식중독이 주로 관여하였 고, 음식중독에는 음식갈망, 폭식행동과 함께 비만과 연령의 교호작용, 교육년수가 유의하게 작용하는 것으 로 나타났다. 본 연구는 한국인 성인을 대상으로 한 체계적 연구로서, 폭식행동과 음식중독이 여성 및 비만 인에서 특히 더 많이 나타남을 확인하였다. 폭식행동과 음식중독에는 일부 섭식문제(예: 음식갈망)가 공통되게 관여하나, 정신건강 및 인지적 위험요인에는 차이가 있었다. 따라서 음식중독과 폭식행동은 서로 구 별되는 개념으로 두고, 각각의 기질적·환경적 위험요인을 깊이 있게 탐구하는 것이 필요하다.

LNG propulsion ships are actively being built as an eco-friendly fuel for ships, and ships with C-type LNG tanks are being widely built. In order to analyze the risk of LNG venting from operating ships and test-run ships, the flow characteristics according to operating conditions were reviewed using ANSYS FLUENT, a computational fluid dynamics (CFD) software. As a result of the study, it was confirmed that the distribution area exceeding the lower explosion limit of natural gas and the area where the natural gas temperature rose to 17 ° C had similarities. In addition, it was confirmed that the change in the horizontal direction was greater than the change in the vertical direction when the natural gas distribution range was changed. Since the valve opening has a greater effect than the tank pressure, if natural gas must be vented to the atmosphere inevitably, the risk can be reduced by operating the valve opening at 50% or less.

This study was conducted to provide basic data on the antioxidant activity, inhibition of adipocyte differentiation and reactive oxygen species (ROS) production of a mixture of Brassica juncea extract (BJE) and fermented black rice fraction (BRF). We investigated the total phenol content, total flavonoid content, antioxidant effects (DPPH radical scavenging, ABTS radical scavenging, reducing power, FRAP and ORAC assay) and anti-obesity activity of the mixture in 3T3-L1 cells. Our results showed that the total phenol and flavonoid content increased with increasing BRF mixture ratio. The antioxidant activity increased as the BRF mixture ratio increased. In addition, BJE and BRF mixtures did not show any cytotoxicity during the 3T3-L1 differentiation period. During adipocyte differentiation, BJE and BRF mixtures significantly inhibited lipid accumulation and ROS production compared to the control group. These results warrant further experiments to develop an anti-obesity functional food using a mixture of BJE and BRF.