교량, 터널 등 콘크리트 구조물의 건설 또는 사용 중 사고는 심각한 재산 및 인명 피해를 야기하기 때문에, 콘크리트 구조물의 증가와 동시에 Structural health monitoring(SHM)의 중요성 또한 높아졌 다. 하지만 현재까지 콘크리트 구조물의 안전 관리 및 유지관리는 주로 인력에 의한 육안 점검이 주를 이루고 있으며, 이는 주관적이고 정성적인 관리 수준에 머무르고 있어 안전성 평가 결과에 대한 신뢰 성 및 실시간 상태 파악과 대응 측면에 한계가 존재한다. 이에 본 연구에서는 현재 활발하게 연구되고 있는 탄소나노튜브를 활용하여 기다란 바 형태의 Carbon nanotube reinforced polymer(CNRP) Bar를 개발하였으며, 이를 콘크리트 구조물에 적용하였다. 구조물 변형에 따른 CNRP Bar의 센싱 성능을 파 악하기 위해 3점 굽힘 시험을 진행하였고, 동시에 콘크리트 구조물 내 CNRP Bar의 전기적 변화를 분석하였다. 실험 결과 콘크리트 구조물에 균열 발생 전 굽힘 응력에 의해 CNRP Bar의 저항이 감소 하였고, 균열 발생 후 균열이 커짐에 따라 저항이 증가하는 거동을 보였다. 이를 통해 CNRP Bar는 콘크리트 구조물에 용이하게 적용할 수 있는 매립형 센서로써 사용 가능하고, 이는 콘크리트 구조물의 안전성을 효율적으로 모니터링하는 시스템으로 발전 가능할 것으로 판단된다.

구조물 보수 부위의 손상, 재 박리 등의 2차 피해가 이어지며, 보수 부위의 새로운 거동 평가 기법 에 대한 연구의 필요성이 대두되고 있다. 현재 구조물 보수 부위의 거동을 알기 위해서 주로 인력 중 심의 구조물 외관 검사를 진행하고 있으나, 단편적인 검사 결과를 얻게 되어 지속적이고 세밀한 점검 이 어려운 실정이다. 따라서, 본 연구에서는 탄소나노튜브 기반 폴리머 콘크리트를 활용해 압축과 같 은 외부 응력에 대한 탄소나노튜브 함량별 전기적 변화를 분석하였으며, 균열이 발생한 콘크리트 구조 물을 보수 후 응력을 가해 거동에 따른 전기적 변화를 평가하였다. 압축 시험 결과, 응력에 따른 탄소 나노튜브 기반 폴리머 콘크리트의 전기 저항이 감소하며, 탄소나노튜브 함량이 낮을수록 응력에 대한 저항 감소 폭이 넓게 나타나며 민감도가 증가하였다. 균열 보수 시험 결과, 보수 부위에 응력이 가해 졌을 때 전기 저항이 감소해 앞서 진행된 실험 결과와 동일한 경향을 보였으며, 또한 응력이 가해지지 않을 때 초기 저항으로 회복하는 경향을 보여 구조물 보수 부위 거동에 대한 평가가 가능한 것으로 검 증되었다. 이를 통해, 탄소나노튜브 기반 폴리머 콘크리트는 구조물에 적용이 가능하며, 구조물 보수 후에도 가해지는 응력에 대한 지속적인 감지가 가능해 보수 부위 거동 평가가 가능할 것으로 판단된다.

다양한 원인으로 콘크리트 구조물에 하중이 작용되며, 이에 대한 적절한 대응이 이루어지지 않으면 구조물에 열화가 발생하고, 붕괴와 같은 대규모 재난을 초래할 수 있다. 구조물에 발생하는 하중을 감 지하는 연구는 지속적으로 이루어지고 있지만, 안전성 모니터링을 위한 혁신적인 시스템에는 여전히 부족함이 존재한다. 탄소나노튜브/폴리우레탄 복합체는 다양한 공학 분야에서 구조물 건전성 모니터링 을 위한 센서로 활용되어 센싱 효과가 뛰어난 것으로 알려져 있다. 따라서 본 연구에서는 다양한 공학 분야에서 구조물 건전성 모니터링 센서로 활용되고 있는 탄소나노튜브/폴리우레탄 복합체를 제작하여 모니터링 시스템을 개발하였다. 다양한 하중에 대한 센싱 성능을 파악하기 위해 인장, 압축, 충격 시험 을 진행하였고, 동시에 센서의 전기적 변화를 분석하였다. 추가적으로 본 센서가 구조물 표면에 적용 됨에 따라 온도, 습도와 같은 환경적 영향성을 분석하여 활용 가능성을 평가하였다. 또한, 최대 48행, 48열의 다중 계측이 가능한 IoT 기반 다중 모니터링 시스템을 개발하고, 이를 구조물에 적용된 센서 와 연계하여 스마트 모니터링 시스템으로서의 성능을 평가하였다. 이를 통해 탄소나노튜브/폴리우레탄 복합체 기반 센서는 구조물 하중 감지 시스템으로 활용이 가능할 것으로 판단되었다.

Given the recent increases in feed cost, the demand for rice straw has been increasing on dairy farms because it is cheaper than expensive imported forages. Therefore, it is necessary to study the effect of rice straw feeding on the growth and productivity of dairy heifers. This study compared how feeding tall fescue and rice straw affects the growth, age at first calving, and feed cost of heifers. we compared the growth, age at first calving, and feed cost for each group during the breeding period. Body height was higher in the tall fescue-fed group than in the rice straw-fed group (p<0.05). The length of the growing stage was significantly shorter in the tall fescue group than in the rice straw group (p<0.001) and the age at calving also showed a significant reduction in the tall fescue group compared to the rice straw group (p<0.001). However, the feed cost was lower in the rice straw group because of the difference in the unit price of forage (p<0.001). Based on these results, during the growing period, the rice straw group had delays in growth and the age at first calving compared to the tall fescue group, but also had reduced feed costs in the short term.

This study aimed to explore the impact of AI image generators on the affective factors of college-level English learners and the correlations among these factors. During a four-week instructional period, 65 participants were asked to use Midjourney as an AI tool for their user experiences. Affective factors including interest, confidence, and participation were measured through pre- and post-surveys. Using Jamovi for analysis, significant improvements were discovered across all affective factors. Noteworthy improvements occurred in confidence, indicating a favorable impact by AI-generated images on English learning. Additionally, correlation analysis demonstrated significant positive relationships between interest and confidence, as well as confidence and participation. This confirms the interconnected nature of these affective elements in the learning process. The findings suggest that the educational use of image-generating AI tools can beneficially influence English learners’ affective domains. The study calls for further investigation into the pedagogical applications of image AI to foster a more interactive, engaged, and self-assured attitude towards language learning.

이 연구의 목적은 내면화된 수치심이 정서표현 양가성과 자기자비의 조 절된 매개효과를 통해서 부부관계 진솔성에 영향을 미친다는 가설을 경험 적으로 검증하는 것이었다. 이를 위해, 기혼상태의 남녀 609명의 자기보고 자료를 수집하고 위계적 회귀분석 방법으로 검토하였다. 연구 결과, 내면화 된 수치심은 정서표현 양가성과는 통계적으로 유의미한 정적 상관을 보였 고, 자기자비 및 부부관계 진솔성과는 통계적으로 유의미한 부적 상관을 보였다. 또한 내면화된 수치심과 부부관계 진솔성의 관계를 정서표현 양가 성이 부분적으로 매개할 것이라는 가설 및 그 관계를 자기자비 수준이 조 절할 것이라는 가설이 모두 검증되었다. 이것은 내면화된 수치심과 부부관 계 진솔성의 관계에서 정서표현 양가성의 매개효과가 자기자비의 수준에 따라서 체계적인 차이를 보인다는 것을 시사하는 결과였다. 마지막으로 이 러한 발견의 임상적 시사점과 방법적 한계점을 논의하였다.

Piezoelectric technology, which converts mechanical energy into electrical energy, has recently attracted drawn considerable attention in the industry. Among the many kinds of piezoelectric materials, BaTiO3 nanotube arrays, which have outstanding uniformity and anisotropic orientation compared to nanowire-based arrays, can be fabricated using a simple synthesis process. In this study, we developed a flexible piezoelectric energy harvester (f-PEH) based on a composite film with PVDF-coated BaTiO3 nanotube arrays through sequential anodization and hydrothermal synthesis processes. The f-PEH fabricated using the piezoelectric composite film exhibited excellent piezoelectric performance and high flexibility compared to the previously reported BaTiO3 nanotube array-based energy harvester. These results demonstrate the possibility for widely application with high performance by our advanced f-PEH technique based on BaTiO3 nanotube arrays.

In this study, quality properties of rapeseed oil by different roasting temperatures (140, 160, 180, and 200℃) were investigated. Roasted-pressed oil (RPO) showed a decrease in lightness and an increase in redness and yellowness with an increase in temperature compared to cold-pressed oil (CPO). In addition, the β-carotene and tocopherol content also increased in RPO as the roasting temperature increased. The tocopherol content increased by 18~20% in RPO at 200℃ compared to CPO. This increase in bioactive components led to improved radical scavenging activity dependent on roasting temperature, and RPO at 200°C showed a 2.7-fold improvement compared to CPO. Finally, it was observed that higher roasting temperatures resulted in an extended oxidation induction period, increasing by up to 3.3 times. In conclusion, roasting is an effective method for enhancing the oil functionality of domestic rapeseed varieties. This study provides basic data for producing high-quality oil.

Mangroves are distributed in intertidal zones of coastal environments or estuarine margins, playing a critical role in the global carbon cycle. However, understanding of the carbon cycle role of mangrove associates in the Republic of Korea is still limited. This research measured soil respiration and leaf gas exchange in three habitats of Hibiscus hamabo (Gimnyeong, Seongsan, and Wimi) and analyzed the impacts on sites and months. Soil respiration was measured once a month from June to October 2022 and leaf gas exchange was measured monthly from June to September 2022. Soil respiration in August (5.7±0.8 μmol CO2 m-2 s-1) was significantly higher than that in other months (p<0.001) and soil respiration increased as air temperature increased (p<0.001). In Seongsan, net photosynthesis in July (9.0±0.9 μmol m-2 s-1) was significantly higher than that in other months (p<0.001). Net photosynthesis increased as stomatal conductance and transpiration rate increased during the entire period (p<0.001). Furthermore, a weak positive linear relationship was observed between soil respiration and net photosynthesis (r2=0.12; p<0.01). The results indicated that soil respiration was influenced not only by air temperature and season but also by net photosynthesis. This study is expected to provide basic information on the carbon dynamics of mangrove associates.

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project’s target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

우리나라 여러 해양환경 지역으로부터 확보한 370주의 해양세균, 균류, 미세조류로부터 기초생 리활성(항산화, 항염, 항균, 항암, 항바이러스)을 조사하여 채집지, 분리원, 종(種) 수준에서의 활성결과를 비교하였다. 해양세균의 경우, 일반적으로 유용성이 많이 알려진 Streptomyces 속 과 Bacillus 속에 속하는 균주들이 두드러진 강한 효능이 관찰되었고, 주로 해양퇴적물로부터 유용한 자원을 분리할 수 있었다. 해양균류와 미세조류의 경우에도 종 특이적으로 활성이 강 하게 나타나는 결과를 확인할 수 있었고, 효능 특이적으로 활성을 보이는 결과도 얻을 수 있었 다. 이러한 결과를 바탕으로 추후 특정질병에 선택적으로 효능을 보이는 화학물질 연구 또는 자원 기반 연구 수행 시 유용성을 전제로 한 자원 확보 전략 수립과 산업 활성화를 위한 전 략소재로 우선적 접근이 용이할 수 있는 연구결과라 생각된다. 또한, 이들 결과를 해양바이오 뱅크를 통한 분양소재로 활용함으로써 학계, 산업계에서 활용하여 해양바이오산업 활성화에 좀 더 빠른 접근을 도울 수 있다고 생각한다.

음악적 몰입은 음악 청취, 악기 연주 등의 음악 활동에 참여하는 동안 음악에 깊게 집중하고 있는 심리적 상태를 의미한다. 특히 음악을 청취하는 동안 나타나는 몰입은 청취자로 하여금 긍 정적인 감정을 경험하게 하며, 이때 몰입을 자주 경험하는 사람일수록 주관적 행복감이 높은 것으 로 나타났다. 그렇다면 음악 청취 시 나타나는 음악적 몰입 상태를 어떻게 규정할 수 있으며, 청 취자가 몰입을 경험하고 있다는 것을 확인할 수 있는 방법에는 무엇이 있을까? 인지과학, 신경과 학 분야에서 다양한 연구들이 음악 청취자의 몰입 상태를 과학적으로 평가하고 정량화하고자 시 도하고 있다. 그러나 기존 연구에서는 플로우(flow), 몰두(absorption), 참여(engagement) 등 몰입 을 설명하는 여러 개념들이 혼재되어 사용되고 있어 음악적 몰입 현상을 개념화하기 어렵다는 문 제가 있다. 본 연구에서는 몰입에 관한 다양한 논문 리뷰를 통해 음악 청취 활동 시 나타나는 몰 입 모형이 선행요인-몰입 상태-결과의 3단계로 구분될 수 있음을 칙센트미하이(Csikszentmihalyi) 의 플로우 이론에 기반하여 확인할 것이다. 또한, 음악 청취의 몰입을 행동적, 생리학적, 신경과학 적으로 정량화할 수 있는 방법론과 향후 연구 방향을 제안하고자 한다.

Bellows expansion joints enhance the displacement performance of piping systems owing to their unique geometrical features. However, structural uncertainties such as wall thinning in convolutions, a byproduct of the manufacturing process, can impair their structural integrity. This study addresses such issues by conducting a global sensitivity analysis to assess the impact of these uncertainties on the performance of bellows expansion joints under monotonic loading. Global sensitivity analysis, which examines main and nth order interaction effects, is computationally expensive. To mitigate this, we employed a surrogate model-based approach using an artificial neural network. This model demonstrated robust prediction capabilities, as evidenced by metrics such as the coefficient of determination. The sensitivity indices of the main effect for the 2-ply and 3-ply bellows at the sixth convolution were 0.3340 and 0.3233, respectively. The sensitivity index of the sixth convolution was larger than that of other convolutions because the maximum deformation of the bellows expansion joint under monotonic bending load occurs around it. Interestingly, the sensitivity index for the interaction effect was negligible (0.01%) compared to the main effect, suggesting minimal activity between uncertainty factors across convolutions. Notably, bellows expansion joints under repetitive loading exhibit more complex behaviors, with the initial leakage typically occurring at the convolution. Therefore, future studies should focus on the structural uncertainties of bellows expansion joints under cyclic loading and employ a surrogate model for comprehensive global sensitivity analysis.

In this study, we detected the presence of residual pesticides in 341 agricultural products collected from local food outlets in western Gyeonggi Province. Residual pesticides were detected in 105 (30.8%) samples. Six samples exceeded the legal limits for residual pesticides, resulting in a non-compliance rate of 1.8%, which was slightly higher than the average non-compliance rate of 1.4% in the last three years. Among the tested agricultural products, only fruits and vegetables were found to have pesticide residues, with 24 of 34 fruits (a detection rate of 70.6%) and 81 of 277 vegetables (a detection rate of 29.2%) testing positive. In total, 59 types of pesticides, including acetamiprid, which was detected 208 times, were detected and had a detection range of 0.01–2.38 mg/kg. Among the 105 agricultural products containing pesticide residues, a single pesticide was detected in 62 samples (59%) and two or more pesticides were detected in 43 samples (41%). In particular, 14 pesticides were detected in the same sample of peaches; dinotefuran was detected 21 times. Upon examining the toxicity of the detected pesticides, Class III pesticides (moderate toxicity) were detected 44 times (21.2%) and Class IV pesticides (low toxicity) were detected 164 times (78.8%). Class I, II, and III pesticides with fish toxicity were detected 68 (32.7%), 14 (6.7%), and 126 times (60.6%), respectively. Upon examining the exposure to high-frequency pesticide components detected five or more times, the hazard index was found to be ≤2.8%. Accordingly, the hazard of residual pesticides based on dietary intake was deemed insignificant.

The status of residual pesticides was investigated in four pepper seed oil samples and 36 pepperflavored oil samples oil distributed on the market from August to December 2022. A total of 179 pesticides were monitored in 40 samples, and 14 pesticides were detected in 39 of the samples, with a detection range of 0.01-2.16 mg/kg. In chili seed oil, 10 pesticides were detected 27 times with a range of 0.11-2.16 mg/kg, and in pepper-flavored oil, 9 pesticides were detected 94 times with a range of 0.01-0.80 mg/kg. The most frequently detected pesticides were tebuconazole, ethion, and difenoconazole, with ethion being detected in large concentrations in products using Chinese raw materials. Ethion, an unregistered pesticide in the Republic of Korea, has not been detected in the Gyeonggi-do area in the past 10 years. It is thought that the detection of ethion can be utilized as an indicator of products made in China. Peppers are a representative agricultural product for which many pesticides are used, and if the pesticides transferred to pepper seeds are not removed, the probability of detecting various types of pesticides in pepper seed oil is very high. Therefore, continuous research is needed to ensure the safety of pepper seed oil.

This study aimed to investigate the acrylamide content in frozen food products after cooking. Twenty samples of bread (Group 1) and 30 samples of processed tuberous and corn vegetable products (Group 2) were selected. Acrylamide levels were quantified using liquid chromatography tandem-mass spectrometry (LC-MS/MS). The frozen food samples were heated using the air fryer cooking method according to the product packaging and were compared to ready-to-eat French fries (Group 3). The results showed that the acrylamide content was the highest in group 3, followed by that in group 2 and group 1. The acrylamide content of all the samples was found to be within the domestic recommended standard of 1 mg/kg. However, when the samples that exceeded EU benchmark level (0.5 mg/kg) were selected and cooked using the deep-fat frying method according to the product packaging, one of them showed the acrylamide content of 1.83 mg/kg, which exceeded the domestic recommended standard. The present study highlights the need for continued evaluation and management to reduce acrylamide contents in frozen foods, as increasing domestic exposure to acrylamide is concerning.

This study was conducted to determine seafood product quality change in the fresh food cold chain logistics. Salmon was stored in three different simulated refrigerated distribution environments according to door opening time (0, 20, and 60 s) every 10 min before the samples’ qualities were evaluated. The temperature inside the refrigerator generally rose from the bottom to the top, and it was possible to confirm the rapid change in temperature in the order of A, B, and C as the door opening time increased. It was observed that the freshness of salmon decreased as the door opening time increased through the evaluation of various food qualities of salmon, such as its appearance, color, pH, VBN, moisture content, hardness, general bacteria, and E. coli bacteria. It was confirmed that fresh food quality is strongly associated with delivery temperature, while cold-chain delivery vehicles must reduce heat exposure time during delivery.

In this study, the AHP (analytic hierarchy process) technique was used to analyze the risk of expected risk factors and fishing possibilities during gillnet fishing within the floating offshore wind farms (floating OWF). For this purpose, the risks that may occur during gillnet fishing within the floating offshore wind farms were defined as collisions, entanglements, and snags. In addition, the risk factors that cause these risks were classified into three upper risk factors and ten sub risk factors, and the three alternatives to gillnet fishing available within the floating OWF were classified and a hierarchy was established. Lastly, a survey was conducted targeting fisheries and marine experts and the response results were analyzed. As a result of the analysis, among the top risk factors, the risk was the greatest when laying fishing gear. The risk of the sub factors for each upper risk was found to be the highest at the berthing (mooring), the final hauling of fishing net, and the laying of the bottom layer net. Based on the alternatives, the average of the integrated risk rankings showed that allowing full navigation/fisheries had the highest risk. As a result of the final ranking analysis of the integrated risk, the overall ranking of allowing navigation/fisheries in areas where bottom layer nets were laid was ranked the first when moving vessels within the floating OWF was analyzed as the lowest integrated risk ranking of the 30th at the ban on navigation/fisheries. Through this, navigation was analyzed to be possible while it was analyzed that the possibility of gillnet fishing within the floating OWF was not high.