Earticle

Logistics cost of domestic company has been improved continuously and annually, it is still higher than other main comparative countries. So, in this study, as optimizing the logistic network of distribution, it was trying to find methods decreasing logistics cost and storage cost, which occupies 86% of logistics cost of companies. through the efficiency of transportation and delivery routing, it could be also possible to decrease the logistics cost. And, it is also checked to find the logistics cost could be decreased by 10% by optimizing the routes of transportation and delivery, improving the transportation mode, etc

The study of optimal preventive maintenance interval is an important topic primarily because it is an efficient way to maximize operational availability of a weapon system using only small resources. A study of this kind is handled by using simulation methods. In this paper, we propose a modeling method of weapon systems that may be used for optimal preventive maintenance interval and analyzed optimal alternatives. The Modeling and Simulation (M&S) method is quite useful compared with the mathematical approach, since M&S is a stochastic analysis. It considers the randomness of the failure rate, repair time and operation schedule. Using this method, therefore, allows us to achieve more reliable results from other mathematical approaches. First, we analyze the mathematical approach using the existing papers. Second, we introduce a model, called the General Model, which reflects the operational concept and maintenance policies of a general weapon system. It may be customized to fit specific systems. Third, we present a specific case using UAV (Unmanned Aerial Vehicle) system, and customize that model. Finally, we arrive at an optimal solution by simulating that model.

Purpose: Simulation-based education plays a critical role in nursing by allowing stu- dents to acquire clinical competencies in a safe and controlled environment. However, current evaluation tools for simulation scenarios often lack standardization, resulting in inconsistencies when assessing the effectiveness of such programs. Methods: This study aimed to develop a comprehensive Nursing Simulation Scenario Evaluation Tool using the Real-Time Delphi method. A panel of 10 experts in nursing and simulation education participated in two rounds of surveys. The evaluation criteria were derived from the International Nursing Association for Clinical Simulation and Learning Standards of Best Practice and relevant literature. Survey items were refined through expert consensus using content validity ratios and coefficient of variation val- ues. The finalized tool was further enhanced with artificial intelligence (AI)?based evalu- ation capabilities to support objective and systematic assessment. The tool was registered and patented in the Republic of Korea (Korean Intellectual Property Office Registration No. 10-2024-0051234) to acknowledge its innovation and technical merit. Results: The process resulted in an evaluation tool comprising eight key domains and 36 items, covering scenario structure, learning objectives, preparation, script development, debriefing, facilitation, expected outcomes, and scenario validity. A Kendall’s coefficient of concordance of 0.739 indicated strong agreement among the experts. Conclusion: This study successfully developed a standardized and validated tool to im- prove the reliability and effectiveness of simulation-based education in nursing. The tool addresses a key gap in current educational practices and enhances consistency in evalu- ating nursing simulation scenarios. Future studies should focus on validating its applica- tion across diverse educational environments.

Earthquake was called The Head of Catastrophe in many countries because of its sudden, wide-ranging, and severe loss characteristics. Due to the density of people, economy and buildings in cities, the development and evolution of the earthquake disaster chain presents more complex and varied systemic features. There have been many studies of seismic scenarios, most of which focus on the simulation of the disaster itself, but little attention has been paid to the disaster mechanism and its control methods within the urban system. In the view of urban systemic characteristics, this paper analyzes the evolution and development of earthquake disaster scenarios in urban systems. Based on the interaction of various elements of the urban system, the content system of urban seismic scenario research is clarified. Finally, considering the dual scenarios of disaster and response, an urban seismic scenario construction method is proposed which covers risk assessment, disaster simulation, task and capability matching, emergency preparedness plan. We hope that this research can develop the urban earthquake scenario research and provide reference for the earthquake disaster reduction.

This paper presents an interim result of a study on virtual LiDAR sensor modeling for autonomous driving simulators. Based on a basic knowledge on the characteristics of pulsed light beams, which may be dependent on the color and material of the object to be reflected, a simple model of equation for the intensity is used for modeling the reflected power of beams of LiDAR. Experiments using a real LiDAR and a virtual one to distinguish colors reveals that the accessibility to colors of the objects is essential for modeling of LiDAR sensors in autonomous driving simulators.

In this paper, we present an interim result of the study on the effective testing and verification method of autonomous driving algorithms by configuring a simulator-tosimulator (S2S) co-simulation test environment prior to the simulator-to-real (S2R) co-simulation test. The method is configured by two driving simulators where one driving simulator is regarded as a mimic of the vehicle on road in a realistic world whereas the other is used as a test simulator to emulate the various driving environment in a virtual world. Since autonomous driving algorithms developed via virtual scenarios and object information can be easily tested and verified with the ultimate safety, the system reliability can be increased in development phase. Therefore, the proposed S2S co-simulation test method is expected to contribute to establishing a S2R co-simulation test environment.

교통체증은 도시지역에서 심각한 경제적, 사회적 비용을 초래하는 원인으로 간주되고 있다. ITS기법은 첨단 센싱, 컴퓨팅, 그리고 통신기술을 이용해 교통체증을 경감시킬 수 있는 훌륭한 수단이다. 본 연구는 차량과 주변 인프라 그리고 차량 간의 무선통신을 통한 중앙제어식 그리고 분산식 첨단통행자정보시스템의 프레임워크를 제안하고 전형적인 6X6 도시형 도로망에서 그 효과를 시뮬레이션 기법을 이용하여 분석하고자 한다. 본 논문의 연구결과로서는 교통류, 무선통신 라디오 레인지 그리고 통신차량의 보급률 등에 따라 제안된 첨단통행자정보시스템은 교통사고로 야기된 정체지역을 우회할 수 있는 최적의 노선을 제공함으로써 운전자의 통행시간을 줄여주는 효과를 보였다. 다양한 연구 환경에서도 중앙제어식 그리고 분산식 첨단통행자정보시스템은 거의 동일한 효과를 보였는바, 분산식 첨단통행자정보시스템은 고가의 건설비와 설치 운영비를 요구하는 중앙제어식 첨단통행자정보시스템을 대신할 수 있는 시스템으로 기대된다.

Traffic congestion is a source of significant economic and social costs in urban areas. Intelligent Transportation Systems (ITS) are a promising means to help alleviate congestion by utilizing advanced sensing, computing, and communication technologies. This paper proposes and investigates a basic and advanced ITS framework Advanced Traveler Information System (ATIS) using wireless Vehicle to Roadside (Centralized ATIS model: CA model) and Vehicle to Vehicle (DeCentralized ATIS model: DCA model) communication and assuming an ideal communication environment in the typical 6X6 urban grid traffic network. Results of this study indicate that an ATIS using wireless communication can save travel time given varying combinations of system characteristics: traffic flow, communication radio range, and penetration ratio. Also, all tested metrics of the CA and DCA models indicate that the system performance of both models is almost identical regardless of varying traffic demand and penetration ratios. Therefore, DCA model can be a reasonable alternative to the fixed infrastructure‐based ATIS model (CA model

The flow between two rotating concentric cylinders, also known as Taylor-Couette flow system, is one of the most widely studied systems in the classical fluid dynamics. In this work, a two-dimensional Taylor-Couette flow system is simulated using the lattice Boltzmann method combined with the smoothed profile method. The fluid flow between the rotating cylinders is solved by lattice Boltzmann equation while the curved boundaries of the cylinders are treated with a smoothed profile function. To assess the validity of the present simulation technique, three different cases of rotation of the cylinders were considered: ⅰ) inner cylinder is only rotating, ⅱ) outer cylinder is only rotating, and ⅲ) both inner and outer cylinders are rotating. For all the three cases, the numerical results of the flow velocity in azimuthal direction and the hydrodynamic torque acting on the cylinders are in good agreement with the corresponding analytical solution results.

집광형태양광발전시스템은 집광형태양전지 셀, 모듈, PCS, 태양위치추적기, 시스템설비와 그에 따른 시스템주변창치들로 구성된다. 이러한 다양한 요소를 반영하여 시스템모델링이 이루어져 집광형태양광발전시스템에 대한 분석과 모델링방법이 적용되어야 한다. 본 논문에서 제안된 이러한 다양한 요소를 반영하여 최적의 CPV 시스템 시뮬레이션을 제안하여 집광형태양광발전시스템 모델링과 에너지의 발생분석에 대한 최적 설계가 이루어지도록 모델링에 중점 두어 설계하였다. 손실 파라미터 계산 방법에 관한 일반화된 집광형태양광발전시스템의 계산 된 시뮬레이션 결과는 높은 신뢰성과 안정성을 갖는 집광형태양광발전시스템의 최적의 설계가 가능하다. 손실 파라미터 계산 방법은 CPV 시스템 설계의 경제적 분석을 위한 시뮬레이션 및 다양한 데이터 활용을 위한 시뮬레이션방법을 활용할 수 있다.

CPV system is composed with CPV cells, modules, PCS(power conditioning system), solar tracker, system installation and balance of systems(BOS). Mention about modelling method which is applied for CPV system simulation and evaluation system analysis. This paper focuses on CPV system modeling and optimal design of the electric energy production analysis through the development of proposed optimal CPV system simulation. Calculated simulation results of the generalized CPV system in regard to loss parameter calculation method can make out optimal configuration of CPV system with high reliability and stability. The loss parameter calculation method establish a mathematical modeling for the purposed of simulation and utilization various data for economical analysis of the CPV system design.

본 논문에서는 PBD(Position Based Dynamics) 물리 변형 기법을 활용하여 수술 전 촬영된 뇌의 영상을 통해 생성한 3차원 뇌 모델에 수술기구의 움직임으로 인한 뇌의 변형을 반영하고, 이를 가시화하는 AR(Augmented Reality) 기반 뇌실천자술 시뮬레이션 기법을 제안한다. 적외선 카메라 기반 AR 수술 환경을 구축하여 현실 세계 와 가상 공간을 일치시키고 수술 기구를 추적하였으며, 연체의 특성을 유지하며 안정적인 변형을 가능하도록 하기 위해 constraint를 이용한 변형 안정화 및 특성 유지 기법을 적용하였다. 스마트글래스에 증강되는 정보를 이용하 여 수술기구를 뇌실까지 삽입하여 뇌척수액 배액을 성공적으로 수행하였으며, 변형 시뮬레이션 속도는 평균 7.24fps를 보였다.

In this paper, We propose a simulation method of brain deformation caused by surgical instruments using position based dynamics. We used infrared cameras to build AR surgical environment. It is used to match virtual space with real world and to track surgical instruments. We applied the various constraint for stable deformation while maintaining softbody properties. We inserted surgical instruments to the ventricle using augmented information and successfully drained it. The simulation speed of our method was 7.24fps on average.

The molecular dynamic simulation method is usually used to analyse microscopic fluid fields. To use this method in engineering problems with real scales of molecules needs more time and greater computer power than we have now. To overcome these limitations, the expansion method using dimensionless and similarity of physical quantities of molecules is studied and introduced for the engineering scale fluid dynamics.

We consider the Fuzzy clustering which is devised for partitioning a set of objects into a certain number of groups by assigning the membership probabilities to each object. The researches carried out in this field before show that the Fuzzy clustering concept is involved so much that for a certain set of data, the main purpose of the clustering cannot be attained as desired. Thus we Propose a new objective function, named as Fuzzy-Entroppy Function in order to satisfy the main motivation of the clustering which is classifying the data clearly. Also we suggest Mean Field Annealing Algorithm as an optimization algorithm rather than the ISODATA used traditionally in this field since the objective function is changed. We show the Mean Field Annealing Algorithm works pretty well not only for the new objective function but also for the classical Fuzzy objective function by indicating that the local minimum problem resulted from the ISODATA can be improved.

Recently, all-electrified houses have constructed and some tasks are being carried out to monitor energy consumption patterns. The energy monitoring includes various elements such as temperature, pressure, water flow, CO2, and electricity. In this monitoring, electricity consumption is one of the essential factors because the performance and energy saving levels are described by this physical quantity. This quantity depends on materials, structure, operation of the house, which operation means consumer's life style and usage patterns of home appliances furthermore. Firstly, this paper shows a control simulation method which were developed a few years ago. And some different methods are proposed considering flexible experimental condition.

본 연구는 스마트하이웨이 같은 첨단 도로 인프라가 구축이 되어 WAVE(Wireless Access for Vehicular Environments) 기술을 이용하여 차량의 정보를 수집하는 서비스를 시행할 경우, 차량데이터를 수집하는 전송간격의 결정 문제를 다루고 있다. 여기서 차량데이터는 위치정보이외에 속도, RPM, 연료소모량 및 DTC 코드와 같은 차량안전데이터를 포함하는 OBD II와 연계된 차량수집장치로부터 매초별로 수집될 수 있는 데이터이다. 이러한 차량데이터는 기존의 교통소통정보로 가공 및 제공이 가능할 뿐만 아니라 다각화된 서비스가 가능한 컨텐츠로 활용이 될 수 있다. 본 연구에서는 이러한 실시간 차량데이터를 일상적인 상황에서 수집될 경우 교통조건의 변화에 따라 전송간격(교통정보 수집주기)를 변경하는 방법으로 공간적, 시간적 교통상황을 고려하는 모델을 제안한다. 연구에서는 이러한 전송간격 결정모델에 대하여 교통상황묘사가 가능한 VISSIM이라는 미시적 교통시뮬레이터를 기반으로 시나리오를 약 32가지 설정하여 전송간격, 통신전송량, 통신간격, 통신수 및 BPS 등에 대하여 확인하여 보았다. 그 결과 2차로의 1km 고속도로 구간에서는 차량데이터를 2회 정도 수집할 경우에 통신전송량의 특성상 가장 적절할 것으로 확인되었다. 향후 다양한 도로상의 무선 통신 기술이 도입될 경우 교통 및 통신기술 특성을 동시적으로 고려한 전송간격 모델을 제시한 본 연구는 그 활용가치가 높을 것으로 판단되는 바이다.

This paper deals with the transmission interval of vehicle data in smart highway where WAVE (Wireless Access for Vehicular Environments) systems have been installed for advanced road infrastructure. The vehicle data could be collected at every second, which is containing location information of the vehicle as well the vehicle speed, RPM, fuel consuming and safety data. The safety data such as DTC code, can be collected through OBD-II. These vehicle data can be used for valuable contents for processing and providing traffic information. In this paper, we propose a model to decide the collection interval of vehicle information in real time environment. This model can change the transmission interval along with special and time-variant traffic condition based on the 32 scenarios using microscopic traffic simulator, VISSIM. We have reviewed the transmission interval, communication transmission quantity and communication interval, tried to confirm about communication possibility and BPS, etc for each scenario. As results, in 2-lane from 1km highway segment, most appropriate transmission interval is 2 times over spatial basic segment considering to communication specification. In the future, if a variety of wireless technologies on the road is introduced, this paper considering not only traffic condition but also wireless network specification will be utilized the high value.

The purpose of this paper is to examine the effect of urban spatial structure on transport sector CO2 emission using system dynamics simulation method and to find policy implication for urban planning. For this purpose, system dynamics model containing two competing arguments on the impact of high density development on air pollutant emission from transportation was built and simulated for four selected case cities representing different types of urban spatial structure; high density-monocentric city, high density- polycentric city, low density-monocentric city, and low density-polycentric city. Simulation results show that increasing both development density and mixed land use decrease number of car users, increase number of public transportation users, and decrease total CO2 emission from transport sector. And cities with higher density show higher CO2 reduction result in transportation sector than cities with lower density. In addition, high density-monocentric city shows better CO2 reduction rate than high density-polycentric city, indicating that monocentric compact city is better in reducing CO2 emission from transport sector.

Purpose: The global emphasis on preventing and systematically managing acute cardiac arrest necessitates improved education in cardiovascular emergencies. This study aims to provide foundational data on the effectiveness of simulation-based cardiovascular emergency management education, applying the think-aloud method for nurses. Method: A one-group pre-posttest experimental design was used from July 29 to August 15, 2022. Twenty-eight nurses participated in this study. Data were analyzed using descriptive statistics and the Wilcoxon signed-rank test with SPSS/WIN 25.0. Results: The educational intervention showed statistically significant improvements in outcomes: knowledge of cardiovascular emergency management (Z=-4.24, p<.001), confidence in cardiovascular emergency management (Z=-4.63, p<.001), clinical reasoning competence (Z=-4.16, p<.001), and self-efficacy for group work (Z=-3.47, p=.001), and self- regulation for group work (Z=-2.29, p=.022). Conclusion: This study indicates that the use of the think-aloud method in simulation-based learning can effectively enhance cardiovascular emergency management training by reducing learners’ cognitive load. Cardiovascular emergency management competencies can be strengthened through the development of diverse educational strategies and the expansion of training support.