본 연구에서는 전지구 해양 예측 모델 결과를 동아시아 지역 해양 모델인 ROMS의 초기 및 경계 조건에 적용 한 역학적 규모 축소 모의 실험을 수행하였다. 우선 ROMS 모델의 성능을 AMOR3D, EN4, 정선 관측 자료, 인공위성 영상 및 기존에 발표된 MOHID 모델과 비교하여 검증하였다. 전반적으로 봄과 가을에는 관측 자료와 잘 일치하였으나, 해양 성층화가 강화되는 여름에는 모델 성능이 저하되는 것을 확인하였다. 또한, 동해와 남해보다 황해에서 더 우수한 성능을 보였으며, MOHID 모델보다 아표층 모의 성능이 개선되었다. RCP 4.5 시나리오를 적용하여 2015년부터 2030 년까지 예측한 CM2.1 전지구 해양 모델의 결과를 사용한 역학적 규모 축소 모의를 수행한 결과, 한반도 남서 연안의 저수온 영역, 황해난류의 경로 및 쿠로시오 해류의 사행 등 실제 해양의 다양한 현상이 잘 재현되었다. 또한, 지역 모델은 저해상도 전구 모델보다 평균 수온의 경년 변동 폭이 커지는 것을 확인하였다. 본 연구를 통해 ROMS를 이용한 역학적 규모 축소 결과의 신뢰성이 확인되었으나, 향후 동해 및 남해와 같은 특정 지역의 ROMS 모델의 모의 성능 개 선과 2030년 이후의 장기 시뮬레이션 연구가 추가로 필요할 것으로 보인다.

As digital transformation accelerates, platform business has become a core business model in modern society. Platform business has a network effect where the winner takes all. For this reason, it is crucial for a company's pricing policy to attract as many customers as possible in the early stages of business. Telecommunication service companies are experiencing stagnant growth due to the saturation of the smartphone market and intensifying competition in rates, but the burden of maintaining communication networks is increasing due to the rapid increase in traffic caused by domestic and foreign CSPs. This study aims to understand the dynamic characteristics of the telecommunications market by focusing on pricing policy. To this end, we analyzed how ISPs, CSPs, and consumers react to changes in pricing policy based on the prisoner's dilemma theory. The analysis of the dynamic characteristics of the market was conducted through simulation using the Agent-Based Model.

본 연구는 간 자기공명영상 검사 시 프리모비스트(Gd-EOB-DTPA) 조영제를 사용한 동적 동맥기(dynamic arterial phase)에서 호흡기 운동인공물을 최소화하기 위한 최적의 방법을 연구하였다. 연구는 총 세 집단으로 나누 어 진행되었으며, 첫 번째 집단은 별도의 사전 교육(pre-scan preparation, PSPP) 없이 촬영한 집단, 두 번째 집단은 사전 교육만 시행하고 촬영한 집단, 세 번째 집단은 사전 교육과 검사 중 숨 참기 보조 신호(breath-holding assistance signal, BHAS)를 제공한 집단으로 구성되었다. 각 집단의 촬영 결과를 비교한 결과, 사전 교육과 검사 시 숨 참기 보조 신호를 함께 시행한 집단에서 동적 동맥기 영상의 호흡기 운동인공물이 가장 적었으며, 영상의 품질 도 더 높게 평가되었다. 이러한 결과는 간 MRI 촬영의 동적 동맥 단계 검사에서 사전 교육과 검사 중 숨 참기 보조 신호가 결합한 접근법이 환자의 숨 참기 협조를 강화하여 영상 품질을 개선하고, 정확한 진단에 기여할 수 있음을 시사한다.

이 논문에서는 부유식 구조체의 계류선에 작용하는 장력을 계산함에 있어서 동적 효과를 고려할 수 있는 준동적 계류선 해석 방법 을 제안하였다. 준동적 계류선 해석 방법은 매 시간 단계에서 계류선의 탄성 현수선 해석해에 기반한 정적 장력을 계산한 후, 준동적 장력 계수를 적용해 속도와 가속도에 따른 항력 및 관성력의 영향을 반영하는 방법이다. 제안하는 방법은 정적 탄성 현수선 해석해를 구할 때 계산 효율성을 높이기 위해 응답면 기법을 도입하고, 수평 및 수직 방향의 동적 계수를 결합하여 준동적 장력 계수를 결정하 는 새로운 방법을 제안하였다. 제안된 모델은 계류된 바지선의 운동 해석을 통해 검증하였으며, 다양한 파 조건에서 동적, 준정적, 준 동적 모델을 비교한 결과, 제안된 준동적 모델은 상대적으로 계류선의 동적 효과가 큰 주파수 대역에서 동적 모델과 유사한 장력 응답 을 도출할 수 있음을 확인하였다.

With technological and social development, high-rise atypical buildings have emerged. In order to take into account the structural vulnerability due to their high-rise atypical shape, systems such as vibration control system and seismic isolation can be applied. In this study, dynamic behavior characteristics analysis was conducted based on the location of the seismic isolation system installation of the atypical facade shape Tapered and reverse shell structure models. With the installation of Lead Rubber Bearing(LRB), the maximum story drift ratio showed a decrease, but the maximum absolute acceleration showed a phenomenon in which the response was amplified in the middle and low story. LRB1(base isolation system) is the most effective for simultaneous control of the two dynamic responses, but the 46th floor of ‘Nor’ and’ RS’ and the 41st floor of ‘TA’ are considered the most effective installation location of the seismic isolation system in consideration of the burden of the seismic isolation system and the structure stability.

In this study used Computational Fluid Dynamic analysis to examine NOx reduction in hydrogen combustion, analyzing six conditions with varying air/fuel ratios, temperatures, and concentrations. Results were compared between two combustor shapes and previous experimental data. Findings showed increased air/fuel ratios decreased flame temperature and increased post-combustion O2. NOx emissions peaked at high temperatures and low O2. Numerical results aligned with previous experimental trends, validating the approach. Combustor shape differences, reflecting variations in fuel and air pipes, significantly affected flow rates and combustion positions. This reduced NOx emissions up to a certain air/fuel ratio, but excessive increases diminished this effect. The study highlights the complex relationship between combustor design, operating conditions, and NOx emissions. Further research is needed to optimize NOx reduction by considering pipe numbers and combustion locations. Future studies should explore various combustor geometries, fine-tune air/fuel ratios, and investigate additional parameters influencing NOx formation and reduction in hydrogen combustion systems.

Onboard truck scales can accurately measure payload under static conditions. However, their performance is limited in accounting for dynamic environments encountered during driving, leading to inaccuracies in load estimation under real-world conditions. This study employs TruckCaliber, a dynamic state measurement system, to estimate real-time vehicle loads. Fusion sensor modules were installed on leaf spring suspensions and vehicle frames to collect tilt and IMU data. The system was implemented on a commercial truck, and driving tests were conducted with varying payloads. The analysis focused on curved sections under different dynamic conditions.

This study is about the evaluation for shock-proof performance of the system, elastically support the low accumulator of the naval artillery against underwater explosion, using DDAM. For the evaluation, the shock analysis procedure using DDAM, supported by MSC/NASTRAN, was briefly described. In addition, in order to perform the shock analysis, the elastic support system was modeled as a finite element. The shock analysis of the elastic support system was performed by selecting the analysis frequency range so that reliable results can be obtained. Finally, the shock-proof performance of the system was evaluated by comparing the shock analysis results with the properties of the elastic support system.

In order to overcome the limitations of linear vibration energy harvesters and those using mechanical plucking, magnetic plucking vibration energy harvesters (MVEs) have garnered significant interest. This paper presents parametric studies aimed at proposing design guidelines for MVEs and compares two magnetic force models that describe interactions between two permanent magnets. A mathematical model describing the energy harvester is employed, followed by the introduction of two magnetic force models: an analytic model and an inverse square model. Subsequently, numerical simulations are conducted to investigate dynamic characteristics of MVEs, analyzing results in terms of tip displacement, voltage output, and harvested energy. Parametric studies vary the distance between magnets, the speed of the external magnet, and the beam shape. Results indicate that reducing the distance between magnets enhances energy harvesting effectiveness. An optimal velocity for the external magnet is observed, and studies on beam shape suggest greater energy harvesting when the shape favors deflection.

We investigated dynamic interaction between adjacent magnetic loops in the solar atmosphere, which is a process of volume shrinkage with nonuniform acceleration caused by Lorentz force. When these loops locally have different thermal and dynamic properties, a significant discrepancy between their translational motions driven by means of that force may arise, leading to the dynamic interaction. We use both numerical simulation and analytic model of magnetic piston-driven wave to evaluate how much a single event of the interaction contributes to increasing the temperature in the upper chromosphere. The model shows a possibility that a chromospheric plasma is heated by the single event to have transition region temperature, which is typically several tens of times higher than chromospheric temperature. The model also provides an insight into the formation height of the transition region.

Background: Previous studies have highlighted the beneficial impact of trunk strength training on gross motor muscle function. Additionally, trunk strength training has been shown to enhance upper limb function and balance in children with cerebral palsy. Although numerous studies have explored dynamic and static balance for children with cerebral palsy, none have yet examined the combined application of kinetic link training (KLT) and bird dog exercise (BDE). Objectives: To investigated the effect of cerebral Palsy on the KLT and BDE. Design: A randomized controlled trial. Methods: This study involved 30 children diagnosed with cerebral palsy. They were randomly allocated to two groups: 15 children in the KLT group and 15 in the bird-dog group. During the intervention, four participants dropped out, resulting in 26 subjects for the final analysis (KLT=11, Bird-dog=15). After randomizing the subjects into two groups, we allocated their general characteristics. Prior to starting the intervention, initial measurements were taken using the Romberg test for static balance and the limit of stability (LOS) test for dynamic balance. Each group participated in KLT and BDE for 30 minutes, three times a week for eight weeks, under the supervision of a therapist. Follow-up measurements of static and dynamic balance were taken at the conclusion of the eight-week period. The collected data was analyzed using the SPSS ver. 21.0 program by paired t-test and independent t-test. Results: In the results for static balance, the within-group comparisons indicated a significant reduction in trace length, STD velocity, and velocity postintervention compared to pre-intervention for both the KLT and BDE groups, except for the C90 area (P<.05). Regarding dynamic balance, the withingroup comparisons demonstrated a significant increase in LOS in the forward direction for the BDE group from pre- to post-intervention (P<.05). Similarly, there was a significant increase in LOS in the backward direction for the KLT group from pre- to post-intervention (P<.05). The LOS in both the left and right directions showed significant increases in the BDE group from pre- to post-intervention (P<.05). Conclusion: An eight-week intervention involving KLT and BDE exercises improved both static and dynamic balance in children with cerebral palsy.

Background: Balance is the foundation of performing daily activities, and has been proven to be improved by various compression materials. As a new and never-before-seen means, the floss band improves joint range of motion, increases muscle flexibility, and affects balance. Several studies using the short-term application of a floss band to the ankle have been conducted. However, long-term effects of the floss band on the knee warrant further research. Objectives: This study aims to examine the long-term benefits of strength exercises with a floss band applied to the knee for static and dynamic balance. Design: Quasi-experimental design. Methods: A total of 28 participants (four men and 24 women, aged 20–60 years) with no orthopedic knee conditions were recruited and randomized into two groups, with 14 in the group using the strength exercises with floss bands applied to the knee (the floss band group), and 14 in the group using internal rotation of the tibia during mobilization with movements (MWM; the MWM group). A physical therapist with 10 years of clinical experience applied the intervention 10 times, measuring static and dynamic balance before and after the intervention using the Balance Trainer 4. Independent t-tests and paired t-tests were used for statistical analysis, with a significance level of ⍺=.05. Results: Statistically significant effects for static balance and dynamic balance were observed in the comparison from pre- to post-intervention between the floss band and MWM groups (P<.05). Additionally, a statistically significant effect for dynamic balance was noted in the pre- to post-intervention comparison in the floss band group (P<.05). Conclusion: The strength exercises with floss bands applied to the knee are expected to have a long-term effect on improving dynamic balance.

Due to the complexity of urban area, the city vehicle routing problem has been a difficult problem. The problem has involved factors such as parking availability, road conditions, and traffic congestion, all of which increase transportation costs and delivery times. To resolve this problem, one effective solution can be the use of parcel lockers located near customer sites, where products are stored for customers to pick up. When a vehicle delivers products to a designated parcel locker, customers in the vicinity must pick up their products from that locker. Recently, identifying optimal locations for these parcel lockers has become an important research issue. This paper addresses the parcel locker location problem within the context of urban traffic congestion. By considering dynamic environmental factors, we propose a Markov decision process model to tackle the city vehicle routing problem. To ensure more real situations, we have used optimal paths for distances between two nodes. Numerical results demonstrate the viability of our model and solution strategy.

Concrete structures must maintain their shielding abilities and structural integrity over extended operational periods. Despite the widespread use of dry storage systems for spent nuclear fuel, research on the properties of deteriorated concrete and their impact on structural performance remains limited. To address this significant research gap, static and dynamic material testing was conducted on concrete specimens carefully extracted from the outer wall of the High-flux Advanced Neutron Application ReactOr (HANARO), constructed approximately 30 years ago. Despite its age, the results reveal that the concrete maintains its structural integrity impressively well, with static compression tests indicating an average compressive strength exceeding the original design standards. Further dynamic property testing using advanced high-speed material test equipment supported these findings, showing the consistency of dynamic increase factors with those reported in previous studies. These results highlight the importance of monitoring and assessing concrete structures in nuclear facilities for long-term safety and reliability.

The threat of North Korea's long-range firepower is recognized as a typical asymmetric threat, and South Korea is prioritizing the development of a Korean-style missile defense system to defend against it. To address this, previous research modeled North Korean long-range artillery attacks as a Markov Decision Process (MDP) and used Approximate Dynamic Programming as an algorithm for missile defense, but due to its limitations, there is an intention to apply deep reinforcement learning techniques that incorporate deep learning. In this paper, we aim to develop a missile defense system algorithm by applying a modified DQN with multi-agent-based deep reinforcement learning techniques. Through this, we have researched to ensure an efficient missile defense system can be implemented considering the style of attacks in recent wars, such as how effectively it can respond to enemy missile attacks, and have proven that the results learned through deep reinforcement learning show superior outcomes.

With the birth of ChatGPT, it has had a strong impact on the education industry, and the education association research is also diverse. This study aims to provide reference and new ideas for academic research in the educational field by analyzing the current research status, research hotspots, and research trends of ChatGPT in the field of education, and to provide some suggestions and new initiatives for education regulatory authorities. This study mainly used literature analysis and bibliometric methods to conduct quantitative and statistical analysis on the selected 452 advanced literature. At the same time, with the help of research tools such as CiteSpace 2022, WORDART2024, and XLSX2024, the data of the literature was input to generate visual charts. Through the interpretation of the charts, conclusions were drawn. This study analyzes the main characteristics of the current research situation through the distribution of literature time, disciplinary specialties, research level, and academic journals. Secondly, the distribution of research hotspots is revealed through keyword frequency statistics and keyword co-occurrence analysis. By analyzing the author's research trends and publishing institutions, it aims to explore the development trends in this field. Finally, this study found that the number of publications on the association between ChatGPT and education showed a steady upward trend, with the main disciplines focused on educational theory and computer application technology, and the publication journals concentrated on university sponsored academic journals and Chinese core journals. The research hotspots revolve around artificial intelligence, with strong intersection between hotspots. The research authors have strong independence and weak correlation. But there is strong integration and correlation between research institutions.

본 논문에서는 다이나믹크리깅 대리모델 기반 자동차 브레이크 패드 마모량 측정센서 브라켓의 설계최적화를 소개한다. 브레이크 작동시 마찰재 바닥의 온도가 600°C 이상으로 상승하고, 이 열이 전달되어 센서의 기능을 상실시킨다. 따라서 열전달을 최소화하는 브라켓 형상의 설계최적화는 필수적이다. 최적화에 소요되는 계산비용을 절감하기 위해 다이나믹크리깅 대리모델로 열전달 시뮬레 이션을 대체하였다. 다이나믹크리깅은 최적의 상관함수와 기저함수를 선정하였으며, 정확한 대리모델을 도출하였다. 최적화 결과 센 서위치의 온도가 초기모델에 비해 7.57% 감소하였으며, 이를 열전달 시뮬레이션으로 다시 한번 확인하여 대리모델 기반 최적설계가 유의미함을 검증하였다.

노후 구조물의 동적 특성 평가를 위해 대표적인 접촉식 센서인 LVDT와 가속도계를 활용한다. 전통 적인 센서의 데이터 신뢰성은 높지만, 작동 원리로 인하여 대상 구조물의 물리적 접근과 센서의 설치 가 필요하다. 조밀한 센서 설치를 위해선 많은 수의 센서와 데이터 수집장치도 추가적으로 필요하다. 이런 단점을 보완하고자 비접촉식 센서의 개발이 활발히 진행 중이며, 특히 비전센서를 활용한 동적 변위 측정에 관한 연구 및 개발에 많은 진척이 있다. 비전센서를 활용한 동적 변위 측정 시스템은 내 적 파라미터 및 외적 환경조건에 따라 측정 정확도가 크게 변화한다. 주된 내적 파라미터로 영상장비 의 공간분해능은 이미지 센서의 물리적 크리와 촬영거리의 증가 혹은 관심영역이 작아짐에 따라 영향 을 많이 받는다. 외적 환경조건으로 저조도 환경에서 타겟의 밝기차이가 줄어들어 이미지 프로세싱 과 정에서 불리한 조건이며, 이는 동적 변위 측정 정확도 저하로 이어진다. 본 연구에서 저조도 환경에서 비전센서의 운용거리 한계를 초해상화를 적용하여 극복하고자 하며, 인공적 및 자연적 타겟에 대한 동 적 변위 측정 성능을 비교 분석하였다. 동적 변위 측정 실내 실험을 위해 저조도 조건에서 3층 전단 구조물을 9Hz로 가진하였다. 동시에 Sony사의 DSC-100M7 카메라를 활용하여 조화진동으로 인해 발생되는 각층의 변위를 FHD화질 120FPS로 촬영하였고 측정 정확도 비교 분석을 각층의 LVDT 측 정값으로 진행하였다. 촬영거리를 10m를 기준으로 10m씩 증가하면서 최대 40m까지 변위 값을 측정 하였으며, 공간분해능 증가를 위해 GAN기반 초해상화 모델인 RealSR을 적용시켰다. 초해상화를 활용 하여 동적변위를 측정한 결과 저조도 환경에서도 비전센서의 운용 거리가 증가함을 확인할 수 있었으 며, 동시에 변위 측정 정확도도 함께 상승하는 것을 보여줬다.

원자력발전소(원전) 내부에 설치되어 있는 주요 기기는 원전의 안정적인 운영을 돕는 주요 2차 구조 물이다. 경주 지진, 포항 지진과 같은 강한 지진이 발생하였을 때, 원전 주요 기기의 손상은 원전의 안정한 정지에 문제를 초래할 수 있다. 따라서, 원전 주요 기기의 지진응답을 저감시키기 위한 연구가 필수적으로 요구된다. 이러한 배경 아래, 본 연구에서는 원전 주요 기기의 내진성능 향상을 위하여 동 흡진장치(Dynamic Absorber)를 활용하였다. 연구에서 사용된 동흡진장치는 스프링, 댐퍼, 및 질량체로 구성된다. 이러한 동흡진장치를 설계하기 위하여 기존에 제안된 방법론들을 활용하였으며, 각 방법론 들을 기반으로 설계된 동흡진장치의 지진응답 저감효과를 비교 및 분석하였다. 구체적으로, 진동대 시 험 결과를 바탕으로 유한요소 모델을 검증하였다. 또한, 이를 기반으로 기존 동흡진장치의 설계방법론 에 따른 원전 주요 기기의 지진응답 저감 효과를 비교 및 분석하였다. 결과적으로 각 방법론들은 원전 주요기기의 가속도, 변위, 응력 응답을 평균적으로 약 30% 정도 감소시키는 효과를 보였다.

이 논문은 직전 연구인 메타버스의 함정을 극복하기 위한 게임화된 동적 습관 형성 모델의 후 속 연구다. 2022년 12월 논문 연구에서는 사용자 참여를 방해할 수 있는 일반적인 함정을 극 복하기 위해 메타버스 공간을 설계하는 데 초점을 맞춘 게이미피케이션 동적 습관 형성 모델 을 제안하였다. 당시 제안했던 4단계 접근법을 통합한 역학 모델은 낮은 상호작용(P4)의 온보 딩 접근법, 기본 상호작용(P3) 온보딩 접근법, 중간 상호작용(P2)의 온보딩 접근법, 높은 상호 작용(P1) 온보딩 접근법의 네 단계로 구성되었으며, 간단한 모델의 개요를 설명한 바 있다. 본 고에서는 4단계의 세부 연구에 집중하였는데, P4-튜토리얼, 시즌 이벤트, 소셜 이벤트 및 모 임, P3-기본 아바타, 가상경제 및 아이템 획득/거래, 소셜경쟁과 리더보드, 도전과 경쟁, 커뮤 니티 강화, P2-아바타 개인화, 사용자 제작 콘텐츠. 보상 메커닉스 강화, 피드백 및 진행 상황 추적, P1-대화형 튜토리얼, 사회적 상호작용, 내러티브 중심 퀘스트, 스토리 기반 업적, 인터 렉티브 스토리 요소 등의 습관형성 증진 방안을 제시하였다. 각 단계는 게이미피케이션 및 게 임디자인 기법과 사용자 중심 디자인 원칙을 통합하여 사용자의 참여를 유도하고, 습관 형성 을 촉진하는 방향에서의 온보딩 접근법을 제시하고자 하였다. 이 논문에서는 게이미피케이션 및 게임디자인 이론과 실무를 바탕으로 각 단계에 대한 예시와 전략을 제공하여 메타버스에서 학습환경을 구현하는 데 도움을 줄 것이다. 다만, ‘게임’과 ‘메타버스’와의 개념과 용어에서의 명확한 구분이 어려운 상황이어서, 게이미피케이션 및 게임디자인 분야의 기초적인 이론과 온 보딩 방법론을 다룰 수 밖에 없었다.