Autonomous vehicle technology is targeted for commercialization in 2027. However, a mixed traffic environment of conventional vehicles and autonomous vehicles is expected to be inevitable. In mixed traffic, conventional vehicles drive at reduced speeds due to limited visibility, while autonomous vehicles can drive at normal speeds using sensors. The difference in driving speeds between the two vehicles creates a mismatch in traffic flow, and the risk of congestion and accidents is likely to increase. It is necessary to analyze the impact of the interaction between autonomous vehicles and regular vehicles on traffic safety in advance and develop management measures to mitigate it. In this study, we aim to analyze the effect of reducing the speed deviation between general vehicles and autonomous vehicles by providing the driving speed deceleration level information to autonomous vehicles in the event of fog to induce the same traffic flow and improve the safety level accordingly. We examined the method of delivering the driving speed deceleration level information to autonomous vehicles. When providing speed limit information to autonomous vehicles through systems such as VMS, each country has different ways of recognizing regulatory symbols. Due to these differences, it may not be easy to provide regulatory information to overseas vehicles through external systems such as VMS in Korea. For this reason, there is a possibility that autonomous vehicles may violate laws and regulations by not recognizing them properly, and there are still limitations in defining the responsibility for applying laws and regulations between countries. Therefore, we adopted an information provision approach that encourages autonomous vehicles to maintain a harmonious traffic flow with regular vehicles by sharing safe driving speed information to be encouraged at the public center level. To analyze the effectiveness of these safe driving speed management measures, we used a quantitative indicator, the number of observable conflicts, to distinguish the mixing ratio of regular vehicles and autonomous vehicles. The analysis was divided into early (30%), mid (50%), and late (80%) periods of autonomous vehicle introduction. As a result of giving autonomous vehicles the same traffic flow as regular vehicles, the number of collisions decreased by 128 collisions/hour in the early period, 393 collisions/hour in the mid period, and 337 collisions/hour in the late period. This indicates that the interaction between autonomous vehicles and conventional vehicles becomes more complex as the mixing ratio increases, and the effectiveness of the safe speed management measures proposed in this study increases accordingly. These results can be used as an important basis for transportation policy and design.

산업 발전에 따라 도로 연장이 지속적으로 증가하면서 폐 아스팔트 발생량이 늘어나자, 국내에서는 순환골재를 의무적으로 사 용하도록 관련 규정을 마련하였다. 현장 플랜트에서 순환 아스팔트 혼합물을 생산할 때 재생첨가제를 투입해야 하는 경우, 국 토교통부 “아스팔트 콘크리트 포장 시공 지침“에서는 재생첨가제와 아스팔트를 동시에 투입하도록 명시하고 있다. 그러나 혼합 시간이 부족하거나 혼합 과정이 불량할 경우, 재생첨가제가 균일하게 분산되지 않아 혼합물 품질이 저하될 우려가 있다. 이에 본 연구에서는 기존의 건식 혼합 방식에서 발생하는 문제점을 해소하고자, 아스팔트 플랜트의 Pre-Mixer를 활용하여 아스팔트 바인더와 첨가제를 사전에 혼합하고, 혼합 시간을 달리한 시료를 추출하여 DSR(Dynamic Shear Rheometer) 장비를 통한 MSCR 시험을 수행하였다. 그 결과, 혼합시간이 증가함에 따라 Jnr 값은 증가하고, %Recovery 값은 감소하는 경향이 확인되었 으며, 혼합 시간이 바인더 특성 변화에 유의미한 영향을 미치는 것을 확인하였다. 추가적으로 t-검정을 통해 이러한 경향의 통 계적 유의성을 검증한 결과, Jnr 값은 3-5분, 7-9분, %Recovery 값은 1-3분, 3-5분, 7-9분 구간에서 p값이 0.05 이상으로 나타 나 통계적으로 유의미한 차이가 없었다.

구스 아스팔트(Guss Asphalt) 혼합물은 다짐 없이 시공이 가능한 포장재료로, 1970년대부터 강바닥판 교량에 활용되어 왔다. 본 연구 는 박스 구스 아스팔트 혼합물 공용수명 예측 및 생애주기 비용을 비교분석하기 위해 폴리머 개질 구스, TLA 및 SMA 세 가지 혼합 물의 반사균열 시험, 동탄성계수 시험 및 소성변형시험을 수행하였다. 또한, TxACOL 프로그램을 사용하여 공용수명을 예측하였으며, 예측 결과를 기반으로 각 포장의 생애주기 비용을 분석하였다. 본 연구의 목적은 혼합물의 성능평가를 통해 폴리머 개질 구스 아스팔 트 혼합물의 공용수명을 예측하고 생애주기 비용을 분석하는 것이다. 성능평가 시험결과 폴리머 개질 구스 아스팔트 혼합물이 TLA 구스, SMA 아스팔트 혼합물보다 반사균열, 피로균열 및 소성변형 저항성이 높은 것으로 나타났다. 포장설계 수명 예측 및 생애주기 비용분석결과 폴리머 개질 구스를 사용한 포장설계의 공용성이 가장 우수하며 가장 경제적인 것으로 나타났다.

다결정성 ZIF-8 분리막의 C3H6/C3H8 kinetic 분리 성능 향상을 목적으로 상대적으로 부피가 큰 2, 4-dimethylimidazole (dmIm)이 ZIF-8 구조 내 2-methylimidazole들을 일부 대체한 혼합 리간드 ZIF-8 유사체 분리막을 이차성장법을 이용 하여 제조하였다. 25°C, 1 bar의 feed 압력에서 C3H6/C3H8 (50/50, V/V) 혼합가스를 대상으로 측정된 분리막의 선택도는 ~180이었으며, 이는 기 보고된 대부분의 다결정성 ZIF-8 분리막들의 선택도보다 높았다. 선택도 향상의 원인인 ZIF-8 구조 내 dmIm 도입으로 인한 기공 입구 크기의 축소를 77 K에서의 질소 등온흡착실험과 Maxwell-Stefan model을 이용하여 C3H6 와 C3H8 막투과도 데이터로부터 계산된 확산계수들을 통해 증명하였다.

본 연구는 한국어교육 분야의 기존 메타버스 관련 개별 연구를 혼합연 구의 방법으로 종합적으로 분석하고 수업 모형 개발을 통해 구체적인 교 육 방안을 제시하는 데 목적이 있다. 이를 위해 먼저 일차 선정된 한국 어교육 분야의 학술지 논문 및 학위논문 52편을 대상으로 통합 요소를 도출하고, 양적·질적·혼합적 방법으로 결과를 통합하였다. 먼저 양적 통 합 결과 교육 분야에서 많이 활용되는 플랫폼, 학습자 대상 및 숙달도 수준의 경향성을 확인할 수 있었다. 다음으로 혼합적 통합 결과 메타버 스 활용 수업에 대한 인식과 기대, 몰입감 및 실재감과 관련된 의견을 통합할 수 있었다. 마지막으로 질적 통합 결과 기존 연구에서 제안한 수 업 모형 사례를 분석하고 교육 방안과 방향성 내용을 통합하였다. 이를 바탕으로 본 연구에서는 메타버스 활용 모듈식 한국어 수업 모형을 제안 하였다. 이 모형은 지식 중심, 상호작용 중심, 수행 중심 모듈로 구분되 며 수업 환경이나 학습자에 따라 적용할 수 있도록 구성되어 효용성이 높다는 점에서 의의가 있다.

This study evaluates the applicability of mastic asphalt concrete for backfilling mini-trenches of communication cables. Characterization tests, such as the dynamic modulus, flow-number, Texas overlay, four-point bending beam, and Hamburg wheel tracking tests, were conducted on conventional mastic asphalt concrete and lower-temperature mastic asphalt concrete. A structural analysis of the backfilling of mini-trenches of mastic asphalt concrete was performed and compared with the results of conventional soil backfilling methods using the finite-element method. The performance year was calculated based on the strain behavior and the results of the structural analysis. A life-cycle cost analysis (LCCA) was performed based on net-present-value method. The results of laboratory experiments show that the lower-temperature mastic asphalt concrete performs better than conventional mastic asphalt concrete in terms of resistance to permanent deformation and fatigue cracking. The performance year of the mastic asphalt concrete is three times longer than that of the conventional sand-backfilling mini-trench. The LCCA results indicate that the cost of backfilling by the mastic asphalt concrete is two times lower than that by the conventional sand-backfilling mini-trench.

Lightweighting is crucial in various industries, especially for bicycles where weight and stiffness are key. Traditional materials like steel, aluminum, and carbon each have pros and cons. This study compares hybrid tubes made of aluminum and carbon composites with conventional aluminum tubes. Using structural analysis and experimental testing, the hybrid tubes showed a weight reduction of up to 17.25% and maintained acceptable deformation levels. Finite element analysis confirmed these findings, demonstrating the hybrid tubes' potential as superior bicycle frame materials. Future research should focus on long-term durability and fatigue characteristics.

This study intends to analyze physical and chemical changes using Thermo-Gravimetric Analysis （TGA） of MGO-bioethanol mixed fuel oil. We will analyze the thermal stability and state changes of MGO-Bioethanol mixed fuel oil and conduct and utilize various basic experiments on its applicability as ship fuel oil in the future and eco-friendly alternative fuels. The physical and chemical conditions set through this experiment were set through non-isothermal heating at about 20°C to 933°C, and the heating rate was 100°C/min, the measurement time was 10 minutes, and the amount of samples in each mixed fuel oil was about 18mg-24mg. In the range of pyrolysis temperatures from 235.241°C to 253.320°C, the weight of BE0 was 30.992%, BE10 was 36.199.%, BE20 was 35.879%, and BE30 was 35.725%, indicating that the pyrolysis temperature and weight tended to increase as the bioethanol content increased.

This study conducted an acute toxicity assessment using Daphnia magna to evaluate the potential for increased toxicity when pharmaceuticals persist in aquatic environments not as single substances but in mixed forms. In single-substance toxicity tests, the antibiotics clarithromycin and sulfamethoxazole showed EC50 values of 22.3 mg L-1 and 61.05 mg L-1, respectively. However, the EC50 for the mixture of the two substances was determined to be 31.1 mg L-1. Based on these findings, applying the Similar Mode of Action (MOA) equation from the QSAR Toolbox, as recommended by OECD non-testing methods, produced an estimated EC50 of 33.7 mg L-1 for the mixture, showing a difference of 8.5% compared to the experimental value. This study confirms that combined exposure to pharmaceuticals can increase toxicity due to synergistic effects, indicating a significant potential risk to aquatic ecosystems. According to the UN-GHS classification criteria, clarithromycin, sulfamethoxazole, and their mixture were all classified as Category 3, indicating potential toxicity to aquatic organisms. These results emphasize the importance of toxicity assessments that consider interactions between multiple contaminants in real environmental settings, contributing to the development of effective toxicity evaluation and management strategies for the protection of aquatic ecosystems.

정보 기술이 교육에서 지속적으로 응용됨에 따라 ‘혼합형’ 수업 교육 모델이 대학 교의 개방 교육에 점차 융합되고 있다. 중국의 많은 대학교들은 시대의 조류를 따라 현대 정보 기술과 원격 개방 교육의 결합을 통해 온라인 핵심 과정, 온라인 학습 공 간, 온라인 교수진, 온라인 학습 서비스, 온라인 학습 평가, 온라인 교수 관리 등을 중심으로 한 ‘혼합형’ 교수 모델을 구축하고 있다. 본 연구는 중국 개방대학의 ‘응용 한국어’ 전공 교재 편찬에서 나타나는 특징을 분석하였다. 특히, 대학생을 중심으로 한 인터넷 플랫폼을 활용한 자율 학습을 강조하는 하는 교재 편찬 사고방식을 바탕으로, 온라인 교육 시대에 적합한 교재의 내용 및 디자인 방안을 논의하였다. 연구는 한국어 발음, 전문 용어, 한국어 문법 및 문법 프로젝트, 평가 방안 등 교재 편찬에 있어 중요한 요소들을 살펴보고, 각 항목 별로 제시되는 편찬 순서를 구체적으로 소 개하였다.

목적: 본 연구는 특수교육지원센터에서 근무하는 작업치료사의 직무 경험에 대해 알아보고 특수교육지원센터에 서의 작업치료사의 역할을 정립하고자 한다. 연구방법: 본 연구는 특수교육지원센터에 근무하는 작업치료사 5명을 대상으로 포커스 그룹 인터뷰를 진행하였 다. 작업치료사의 평균 임상 경력은 11년이고, 특수교육지원센터 근무 경력은 11년이었다. 특수교육지원센터 내 작업치료사의 역할에 대해 그룹으로 자유롭게 토의를 진행하였고, 모든 토의 내용은 클로버 노트로 녹음하여 텍스트 스크립트를 완성하였다. 현상학적 분석 방법으로 Giorgi 연구절차에 따라 5명의 연구자가 함께 중요의미 단위를 분석하였다. 아울러 텍스트 마이닝 분석을 위해 Python을 사용하였다. 결과: 특수교육지원센터에서 근무하는 작업치료사가 수행하고 있는 직무에 대한 의미단위 18개와 구성요소 7개를 도출하였다. 이로부터 다시 총 3개의 작업치료사의 직무를 최종 도출하였고, 직무에는 치료지원, 치료대상자 진단평가, 행정업무가 있었다. 결론: 본 연구결과를 통해 특수교육지원센터에서 근무하는 작업치료사의 직무역할을 정립하고 이를 토대로 특수교육지원센터에서 근무하는 작업치료사의 업무 매뉴얼을 개발하는데 기초자료로 활용하고자 한다.

This study proposes a weight optimization technique based on Mixture Design of Experiments (MD) to overcome the limitations of traditional ensemble learning and achieve optimal predictive performance with minimal experimentation. Traditional ensemble learning combines the predictions of multiple base models through a meta-model to generate a final prediction but has limitations in systematically optimizing the combination of base model performances. In this research, MD is applied to efficiently adjust the weights of each base model, constructing an optimized ensemble model tailored to the characteristics of the data. An evaluation of this technique across various industrial datasets confirms that the optimized ensemble model proposed in this study achieves higher predictive performance than traditional models in terms of F1-Score and accuracy. This method provides a foundation for enhancing real-time analysis and prediction reliability in data-driven decision-making systems across diverse fields such as manufacturing, fraud detection, and medical diagnostics.

Defective product data is often very few because it is difficult to obtain defective product data while good product data is rich in manufacturing system. One of the frequently used methods to resolve the problems caused by data imbalance is data augmentation. Data augmentation is a method of increasing data from a minor class with a small number of data to be similar to the number of data from a major class with a large number of data. BAGAN-GP uses an autoencoder in the early stage of learning to infer the distribution of the major class and minor class and initialize the weights of the GAN. To resolve the weight clipping problem where the weights are concentrated on the boundary, the gradient penalty method is applied to appropriately distribute the weights within the range. Data augmentation techniques such as SMOTE, ADASYN, and Borderline-SMOTE are linearity-based techniques that connect observations with a line segment and generate data by selecting a random point on the line segment. On the other hand, BAGAN-GP does not exhibit linearity because it generates data based on the distribution of classes. Considering the generation of data with various characteristics and rare defective data, MO1 and MO2 techniques are proposed. The data is augmented with the proposed augmentation techniques, and the performance is compared with the cases augmented with existing techniques by classifying them with MLP, SVM, and random forest. The results of MO1 is good in most cases, which is believed to be because the data was augmented more diversely by using the existing oversampling technique based on linearity and the BAGAN-GP technique based on the distribution of class data, respectively.

To develop a heat-generating asphalt pavement utilizing a phase-change material (PCM), this study evaluated the application method of a PCM as an asphalt material and the thermal and physical properties of asphalt mixtures. The selection of PCM materials according to the phase-change temperature range suitable for thermal asphalt pavements and the encapsulation method for application to asphalt materials were examined, and encapsulated PCMs (ePCMs) using various materials were produced. The thermal and physical properties were evaluated through chamber experiments and strength tests by applying the ePCMs to asphalt mixtures. The characterization results of the ePCMs showed that ePCM-C had the highest latent heat, thermal stability, and physical stability in the asphalt binder and mixture. The chamber test results showed that ePCM-C, which had high latent heat, had the longest temperature delay time under all conditions. The mixing ratio was calculated by volume to substitute low-density ePCM into the mixture; as the ePCM content increased, the asphalt content also increased. The results of the Marshall stability and indirect tensile strength tests indicated that as the ePCM content increased, the strength and crack resistance properties decreased. Asphalt mixtures containing ePCMs have demonstrated the ability to maintain temperature for a long time within a specific temperature range. If an ePCM is improved such that it is not damaged under the production conditions of asphalt mixtures, it is expected to be sufficiently utilized as a technology for preventing road freezing.

This study aimed to manufacture emulsified asphalt for free-heated asphalt mixtures with high solid contents using the high internal phase ratio (HIPR) technique and utilize it as basic research data by evaluating the basic properties. The optimal emulsifier was selected by considering the physical and chemical properties of the emulsifier used in the emulsified asphalt, and the solid content in the emulsified asphalt was increased using the HIPR technique. Emulsified asphalt was produced with solid contents of 90%, 80%, 70%, and 62% (current standard) in emulsified asphalt, and the basic properties of the emulsified asphalt were evaluated for each content. In addition, a free-heated asphalt mixture for the surface layer was produced by applying the emulsified asphalt produced for each content, and the performance was evaluated based on the quality standard items presented in the current guidelines of the Ministry of Land, Infrastructure and Transport. When utilizing the HIPR technique, we could manufacture up to 90% of the asphalt solid content in the emulsified asphalt; however, applying it to unheated asphalt mixtures because of the increase in viscosity was impossible. We determined that it could be applied up to a maximum solid content of 80%. In addition, in the free-heated asphalt mixture test, the ratio of the air void increased as the solids content increased, but the strength decreased. An examination of the fracture surface after the strength test revealed that it was brown, which is a characteristic color of emulsified asphalt. This was because the curing time became insufficient as the solid content increased, resulting in insufficient time for strength development. To ensure the performance of the free-heated asphalt mixture, we observed that the viscosity of emulsified asphalt with a high solid content should be reduced; securing the curing time accordingly was an important factor, and it was determined that additional research is necessary.

Purpose: This mixed methods study aimed to investigate the anxiety and nursing satisfaction levels and experiences among users of a general health checkup center. Methods: A total of 152 participants completed a questionnaire to assess their pre-checkup anxiety and post-checkup nursing satisfaction levels. Additionally, 11 participants were individually interviewed to determine their pre-checkup anxiety and post-checkup nursing satisfaction experiences. Survey data were analyzed using SPSS software, while qualitative data were analyzed using content analysis. Results: The mean anxiety scores were 2.80±2.24 on the Visual Analog Scale for Anxiety and 44.06±9.55 on the State-Trait Anxiety Inventory (STAI) scale. Education level was a significant factor influencing the STAI scores. Participants with a college education or higher had significantly lower STAI scores(p<.005), indicating the association between higher education levels and lower STAI scores. The mean nursing satisfaction score was 36.49±8.84, with male participants reporting higher nursing satisfaction levels. The pre-health checkup anxiety experience included three themes: “contrasting expectations about checkup results,” “various emotions felt during the checkup process,” and “physical and mental reactions.” The health checkup nursing satisfaction experience included four themes: “satisfaction with nurses’ support and care,” “comfort during the checkup process,” “dissatisfaction due to nurses’ habitual responses,” and “expectations for nurses’ emotional support and communication.” Conclusion: Providing comprehensive nursing information is essential to reduce user anxiety and improve nursing satisfaction. Moreover, integrating advanced technologies, such as virtual reality, augmented reality, and metaversing, into information delivery can enhance educational effectiveness and better address the experiences and needs of checkup users.

The lane designation and the bus-only lane system for traffic speed and road safety are difficult to crack down on, and for this purpose, crackdown methods using image recognition technologies are being studied. Existing studies require continuous learning or additional equipment, and it is difficult to classify combined vehicles such as vans and pickup trucks. Therefore, in this study, YOLO and EasyOCR were mixed to classify combined vehicles through vehicle type symbols. For combined vehicles, higher accuracy was shown than classification using YOLO. Due to the nature of Hangul, the accuracy was slightly lowered because the OCR was not accurately recognized, but if it is used with the existing YOLO classification, high accuracy of crackdown will be possible.