본 연구는 미세플라스틱이 유발하는 독성 영향을 체계적으로 평가하기 위해 표준작업절차 (Standard Operating Procedure; SOP)를 수립하는 데 목적을 둔다. 시험 생물로는 우리나라 전 해역에 널리 분포하며 실험실 조건에서의 사육과 독성 평가가 비교적 용이한 해산 곤쟁이(Neomysis awatschensis)를 선정하였다. 제안된 SOP는 미세플라스틱 시료의 불균질성을 최소화하기 위한 전처리 과정부터 시작하여, 미세플라스틱의 동태 여부, 96시간 급성 독성 시험법과 40일간의 장기 노출에 따른 만성 영향 평가 절차를 포괄적으로 포함하고 있다. 본 연구에서 구축된 SOP는 미세플라스틱의 환경적 위해성을 보다 정밀하게 평가할 수 있는 과학적 기반을 제공하며, 향후 관련 규제 및 관리 정책 수립 과정에서 표준화된 지침으로 활용될 수 있을 것으로 기대된다.

게임 콘텐츠가 점점 복잡해짐에 따라 기존의 수동 테스트 및 스크립트 기반 테스트 방법 은 비용과 테스트 범위 측면에서 한계를 보이고 있다. 본 연구에서는 픽셀 수준의 시각 정 보만을 사용하여 게임의 그래픽 사용자 인터페이스(GUI)와 상호작용하는 딥 강화학습(DRL) 기반 자동 게임 테스트 에이전트를 제안한다. 제안된 에이전트는 ResNet18 기반 시각 인식 모듈과 Proximal Policy Optimization(PPO) 알고리즘을 결합하여, 게임에 대한 어떠한 선 해 정보 없이도 게임 내 장애물을 만났을 때 점프, 웅크리기, 벽 오르기와 같은 회피 방법 을 효과적으로 선택할 수 있다. 실험 결과, 제안된 에이전트는 다양한 장애물 구성 환경에 서 무작위 기준 모델 대비 더 높은 과제 성공률과 안정적인 학습 성능을 보였으며, 이를 통해 블랙박스 게임 환경에서 DRL 기반 자동 테스트의 실현 가능성을 입증하였다.

As the web game market grows, ensuring service stability through load testing has become increasingly important. Web games comprise a variety of functions with distinct internal logic, ranging from simple data retrieval to complex transaction processing. Therefore, a comparative performance analysis of load-testing tools that accounts for these functional characteristics is crucial for achieving reliable and efficient service operation. This paper evaluates the performance of four widely used load-testing tools—JMeter, k6, Gatling, and Locust—under representative web-game workloads. To emulate realistic database read and write patterns, we implement the core server logic of the web game Pokerogue in a cloud environment rather than simply issuing HTTP requests. We classified workload patterns into write-intensive, read-intensive, and mixed types using distributed tracing, and measured request-generation capability and system resource consumption across five key game functions. Our experiments show that each tool demonstrates distinct strengths depending on the characteristics of individual web-game functions. Specifically, k6 demonstrated high request-generation performance in write-intensive scenarios, while JMeter showed strong performance in read-oriented tasks; Gatling exhibited efficient memory usage in mixed workloads, whereas Locust proved suitable for resource-constrained environments. These results indicate that the selection of a load-testing tool should be informed not only by its request-generation performance but also by the workload characteristics of the target game function. By systematically analyzing function-specific workload patterns together with the performance and resource-usage behavior of each tool, this study aims to provide empirical evidence that can be usefully applied in practical load-testing workflows for web-game services.

연근해 소형선박의 질소산화물(NOx)과 입자상물질(PM)의 배출 저감은 강화되는 해양환경 규제 대응을 위해 필수적이다. 본 연 구에서는 총톤수 21톤, 정격출력 367 kW(@1,800 rpm)의 고속디젤엔진을 장착한 연근해 소형선박에 배출저감설비(DPF+SCR)를 적용하여 해상실증 시험을 수행하였다. 가스상물질은 NOx Technical Code와 ISO 8178 기준을 준용한 장비를 사용하였으며 입자상물질(매연)은 국제 해사기구(IMO)에서 논의 중인 블랙카본 측정 방법 중 스모크미터를 이용하여 측정하였다. 황 함유량 0.03%S 이하 연료를 사용하여 20일 간 실제 운항 데이터를 모니터링하고, 모니터링 전·후 시험조건에 따라 1, 2차 성능시험을 수행하였다. 시험결과, NOx 저감효율은 62.0~97.8%, PM 저감효율은 93.0~97.4%를 나타냈으며, 배압은 60mbar 이하를 유지하였다. 운항 조건을 고려한 최적 저감효율은 70~80%이 며, 요소수 탱크 용량은 연료 저장 탱크 용량 대비 최소 4% 이상 요구된다. 본 연구는 연근해 소형선박의 NOx와 PM 동시 저감을 위한 배 출저감설비(DPF+SCR) 적용 가능성을 확인하였다.

The current study examined the potential language and literacy factors that best explain the L2 reading comprehension abilities of Korean EFL learners. A total of 70 intermediate-level Korean high school students participated in this study and were tested on L1 and L2 reading comprehension, L2 vocabulary, and L2 syntactic knowledge. The findings indicated that, between L1 reading skills and L2 proficiency, L2 proficiency played a more crucial role in predicting L2 reading comprehension. Throughout the analyses, the linguistic threshold hypothesis was supported, demonstrating a threshold level of language proficiency above which learners can effectively transfer their L1 reading skills to L2 reading comprehension. These results highlight the important pedagogical implications for the critical role of L2 proficiency and show the threshold level of proficiency necessary for Korean EFL learners. The insights gained from this study are expected to provide targeted instructional strategies and recommendations, aimed at effectively supporting EFL learners with diverse skills and abilities.

This study investigates the seismic performance of beam-column connections using Thin-Walled Steel Composite (TSC) beams and Prestressed Reinforced Concrete (PSRC) columns. TSC beams are constructed from U-shaped thin steel plates that are filled with concrete, allowing for composite action with slabs through the use of shear connectors. They are widely applied in industrial buildings due to excellent strength, stiffness, and constructability. However, slender web plates are prone to local buckling, which may compromise their performance during seismic events. To mitigate this issue, internal supports have been introduced to enhance web stability and concrete confinement. Cyclic loading tests on three specimens—with and without internal supports—demonstrated that the supports increased moment capacity, improved energy dissipation, and effectively reduced buckling. Even slender sections demonstrated performance comparable to that of compact sections. All specimens reached peak strength at a 2.44% rotation angle, with damage localized near the supports. A practical connection detail was also proposed, taking into account constructability and structural reliability. The results provide valuable guidance for the seismic design of composite systems in large-scale structures.

To address the issues of slow magnetization current tracking speed, prolonged magnetization time, and low accuracy during magnetic particle testing of ship castings, forgings, and welded components, this study designed a high-precision rapid current tracking control system. By integrating the predictive characteristics of the Newton interpolation algorithm with the robustness of PID control, a compound control algorithm with a pre-judgment mechanism was developed. An innovative three-phase zero-crossing detection circuit architecture was also implemented, combining high-speed A/D converters and CS5460 chips to optimize current tracking methods, resolving the conflict between initial tracking phase deviation and dynamic process overshoot in conventional approaches. Experimental results demonstrated that this method significantly improves magnetization speed, achieving target current tracking within 0.5 seconds with errors below 2%, meeting the design requirements for non-destructive testing in ship welding applications.

This study aimed to investigate the difference that convolutional neural network(CNN) shows in the determining osteoporosis on panoramic radiograph by performing a paired test by inputting the original image and the limited image including the cortical bone of the posterior border of the mandible used by radiologists. On panoramic radiographs of a total of 661 subjects (mean age 66.3 years ± 11.42), the area including the cortical bone of the posterior part of the mandible was divided into the left and right sides, and the ROI was set, and the remaining area was masked in black to form the limited image. For training of VGG-16, panoramic radiographs of 243 osteoporosis subjects (mean age 72.67 years ± 7.97) and 222 normal subjects (mean age 53.21 years ± 2.46) were used, and testing 1 and testing 2 were performed on the original and limited images, respectively, using panoramic radiographs of 51 osteoporosis subjects (mean age 72.78 years ± 8.3) and 47 normal subjects (mean age 53.32 years ± 2.81). The accuracy of VGG-16 for determining osteoporosis was 97%, in the testing 1 and 100% in the testing 2. When determining osteoporosis on the original image, CNN showed sensitivity in a wide range of areas including not only the inferior cortical bone of the mandible but also the maxillary and mandibular cancellous bone, cervical spine, and zygomatic bone. When the same ROI including the lower inferior cortical border of the mandible of the osteoporosis group was applied and the sensitive region was compared between the original image and the limited image, the original image showed wider sensitive region in cancellous bone and cortical bone than on the limited image (p<.05). Since osteoporosis is a disease that affects throughout the skeletal system, this finding seems very valid.