Earticle

매우 다양한 건물들로 구성된 캠퍼스의 모든 건물들과 각 건물의 층별 호실(Room)들에 대한 정보를 쉽게 알 수 있는 방법은 거의 없다. 그런 이유로 본 논문에서는 캠퍼스 건물 정보의 입체적인 가시화를 위한 3D 시뮬레 이션 시스템을 개발하였다. 본 시스템을 위해서는 실제 도면을 기반으로 각 건물 및 층별 단면도를 3D로 모델링하 였으며, 실제 건물 외부 사진들을 사용하여 텍스처 매핑하였다. 사용자 인터페이스는 3D 뷰어, 메뉴 프레임으로 구 분하였다. 만약 메뉴에서 건물명을 선택하면, 3D 뷰어는 선택한 건물을 줌(Zoom)하여 보여주고 메뉴 프레임은 건물 과 관련된 각종 정보들을 보여주게 된다. 그리고 층별 호실(Room)을 선택하면 별도의 웹브라우저를 통하여 3D로 확 인할 수 있게 하였다. 또한 3D 뷰어에서 건물을 클릭하면, 선택한 건물에 대한 정보들을 보여주게 된다. 본 시스템 은 캠퍼스에 대한 건물 정보를 실감나게 제공해줄 수 있다는 점에서 매우 유용하다.

The campus has been composed of a very variety buildings. However, there is almost no easy way to see information about room number of each floor of the buildings and all buildings. For that reason, in this paper, we have developed a 3D simulation system for the 3D visualization of campus building information. Each building and cross section of floor was modeled in 3D based on the actual drawing. And texture mapping were using real photos. The user interface was divided into frames for menu and 3D viewer. When you select a building name from the menu, 3D viewer shows the selected building by zooming. And menu frame is shown the various information related to the building. Also when you select a room number of each floor, a separate web browser shows the cross section by VRML viewer. Conversely, when you click on the building in the 3D viewer, menu frame is shown the various information related to the building. This system is very useful in that provide realistic building information of campus.

최근 4차 산업혁명으로 스마트팩토리를 구성하는 요소 기술의 중요성이 높아지고 있으며, 이러한 기술들을 학습하기 위한 도구로 시뮬레이션이 널리 이용되고 있다. 특히 PID제어는 실제 응용 분야에서 다양하게 사용되고 있는 자동제어 기법으로서, 대부분 특정 상황에서 수학적 모델을 분석하거나 제어기가 내장된 애플리케이션 개발 에 대한 연구가 이루어지고 있으며, 실제 교육적인 환경에서는 PID 제어 원리뿐만 아니라, 게인 값 조정 및 제어기 사용 방법 등에 대한 PID 시뮬레이터 교육이 필요하다. 본 논문에서는 3D 시뮬레이션을 통해 다양한 PID 제어의 교육과 실습이 가능한 모델을 제안 한다. 제안 모델은 가상의 Ball과 Fan을 구현하여 Fan에서 발생한 공기 압력 에 의해 Ball에 양력이 받을 수 있도록 시스템을 구성하여 PID 제어를 실시하였다. 이때 Ball의 높이를 PID제어기 의 각 게인 값에 따라 그래프로 표현 후 실제 시스템과의 비교를 진행하였으며, 이를 통해 실제 수업에 충분히 적용할 만한 만족한 결과를 확인 할 수 있었다. 제안 모델을 통해 급격히 증가하는 스마트팩토리의 요소 기술을 원격 수업 환경에서 다양한 방법으로 활용 될 수 있을 것으로 기대된다.

Recently, the importance of elemental technologies constituting smart factories is increasing due to the 4th Industrial Revolution, and simulation is widely used as a tool to learn these technologies. In particular, PID control is an automatic control technique used in various fields, and most of them analyze mathematical models in certain situations or research on application development with built-in controllers. In actual educational environment requires PID simulator training as well as PID control principles. In this paper, we propose a model that enables education and practice of various PID controls through 3D simulation. The proposed model implemented virtual balls and Fan and implemented PID control by configuring a system so that the force can be lifted by the air pressure generated in the Fan. At this time, the height of the ball was expressed in a graph according to each gain value of the PID controller and then compared with the actual system, and through this, satisfactory results sufficiently applicable to the actual class were confirmed. Through the proposed model, it is expected that the rapidly increasing elemental technology of smart factories can be used in various ways in a remote classroom environment.

본 논문은 회전교차로 상징 조형물의 잘못된 설치사례를 찾아 분석하고 회전교차로 상징 조형물을 제작 하는 작가에게 운전자의 안전을 위한 작품 설치 가이드라인을 제공하기 위함이다. 지름 18m 내외인 소형 회전교 차로로 연구범위를 한정하고 조형물의 형태적, 재료적인 연출 방법 과실 사례를 비교 분석하고 회전 교차로 접근 주행 시 운전자의 인지 반응 및 운전자의 시야 높이, 특성을 연구하고 개선된 상징 조형물 연출 가이드라인을 3D 시뮬레이션으로 제시한다. 본 연구를 통해 회전교차로에 설치되는 조형물은 운전자와의 거리 70m와 20m 사이 지 점에서 작가의 의도가 전달되는 형태로 디자인되어야 하며 차량이 회전교차로의 진입부에 들어와서는 운전자의 눈의 높이인 지상으로부터 1m와 3.2m 사이의 시야 확보를 방해하지 않는 작품 형태로 제작되어야 한다. 작품의 재료는 시중에 판매되는 반사율이 높은 밀러 또는 폴리싱 스테인리스 재질은 금지해야 될 것이다. 앞으로 본 연구 는 상징 조형물의 형태와 통행량 그리고 교통사고 빈도수 관계로 확장되어야 할 것이다.

The purpose of this paper is to find and analyze unfortunate cases of roundabout symbol sculptures, and to provide installation guidelines for the safety of drivers to artists who installing roundabout symbol sculptures. We limit the research scope to small rotational intersections approximately 18 meters in diameter, compare examples of morphological, material directing of sculptures, study driver's cognitive response and driver's height of eyes and characteristics when approaching roundabout, and present improved symbolic sculpture produce guidelines by 3D simulations. Through this study, the sculpture installed at the roundabout should be designed in a way that the artist's intention should communicated at a distance between 70m and 20m from the driver. And it should be made in the form of a work that does not obstruct the visibility between 1m and 3.2m, Materials for the work should be banned from high-reflectivity millers or polishing stainless steel on the market. This study should be extended to the relationship between the shape of symbolic sculptures, traffic volume and frequency of traffic accidents.

Owing to the advent of ubiquitous computing technologies, the concept of Intelligent Environments has emerged, as an alternative approach to overcome the limitation of the built environment. Intelligent Environments can be more responsive to user-and context-specific human activities by automatically and dynamically modifying their settings without explicit human intervention. However, the conventional approach to the development of Intelligent Environments has mainly focused on the technical issues without paying much attention to the dynamic interrelationship between the user and the built environment. Therefore, differing or conflicting needs of multiple simultaneous users remain unresolved. The objective of this study is to present types of environmental conflicts and their resolution through agent collaboration and negotiation. For the demonstration and validation of the conflict resolution process, a set of hypothetical test cases is simulated in a 3D test environment. The result of the case simulations shows that the proposed approach is computationally feasible and applicable to the development of Intelligent Environments, and, furthermore, it can overcome the drawback of the conventional approach.

최근 콘텐츠 영상으로서 3D 컴퓨터 애니메이션의 발전과 함께 클로스 시뮬레이션(Cloth Simulation)은 사실적인 의상과 의류에 대한 표현이 가능하다. 또한 H/W와 S/W의 눈부신 발달로 인해 기존과 달리 참여도와 접근성이 높아 졌다. 하지만 높은 품질의 영상을 제작하기 위해서는 최적화된 제작 파이프라인이 필요하다. 본 논문에서는 기존의 3D 컴퓨터 애니메이션 제작 파이프라인의 단점을 보완하기 위해서 클로스시뮬레이션에 대한 최적화된 제작 파이프라인을 제안 및 설계 한다. 제안하는 제작 파이프라인은 기존 파이프라인의 각 파트에 대한 연계구조적 한계를 보완하기 위해 유동성을 고려하여 최적화 배치를 하고, Dummy cloth를 활용하여 애니메이션 파트와의 연계성을 해결함으로서 성능 향상을 꾀한다. 제안한 파이프라인을 실제 애니메이션 제작에 도입하였으며 도입결과 제작시간과 제작인력 소모에 대한 성능의 향상을 보였다. 이를 통해 직접적인 영상을 제작함으로 보다 연계성을 강조하여 최적화를 보장한다.

Recently, it was possible to represent the realistic clothes in the cloth simulation along with growth of 3D computer animation such as visual contents. In addition, because of the development of H/W(Hardware) and S/W(Software), the accessibility and participation are growing. However, in order to make the image of high quality of 3D animation, the optimized production pipeline was need. In this paper, in order to overcome the limitation of exiting 3D computer animation production pipeline, we propose the optimized production pipeline of the cloth simulation. Our production pipeline makes the optimization arrangement in consideration of the mobility in order to supplement the related structure limit toward each part of the existing pipeline. Moreover, by utilizing the dummy cloth the association nature with the animation part is solved and a performance is improved. The proposal pipeline actually introduced to the animation production. And then we can improve the performance production time and production manpower consumption. Consequently, our pipeline is guaranteed an optimized work by emphasizing a connection in the direct image production.

The mass-spring model has been typically employed in physical-based simulators for clothes or patches. The mass-spring model frequently utilizes equal mass and the gravity factor. The model structure of masses supports a shape applicable to fishing nets. Therefore, to create a simulation model of a fishing net, we consider the mass-spring model and adopt the tidal-current and buoyancy effects in underwater environments. These additional factors lead to a more realistic visualization of fishing-net simulations. In this paper, we propose a new mass-spring model for a fishing-net and a method to simplify the calculation equations for a real-time simulation of a fishing-net model. Our 3D mass-spring model presents a mesh-structure similar to a typical mass-spring model except that each intersection point can have different masses. The motion of each mass is calculated periodically considering additional dynamics. To reduce the calculation time, we attempt to simplify the mathematical equations that include the effect of the tidal-current and buoyancy. Through this research, we expect to achieve a real-time and realistic simulation for the fishing net.

Cold ring rolling is a much complex physical process with multi-factors. Two forming parameters, the feed rate of mandrel and the rotational speed of main roll, affect the quality of deformed ring significantly and the feed amount per revolution of ring in the form of their ratio. By their ratio, the interactive effects of the two forming parameters on the T-shaped cold ring rolling process are explored through 3D-FEM in Abaqus software. The results show: firstly the study objects (roll force, growth rate of diameter, degree of inhomogeneous deformation, filling capability of groove, average side spread and fishtail coefficient) are almost invariable if the two parameters are increased (or decreased) proportionally; secondly whether the ratio is changed by the feed rate of mandrel or by the rotational speed of main roll, the variation of each study object with the ratio is approximately the same; thirdly the increase of the ratio is beneficial to the growth of diameter and the restrictions of inhomogeneous deformation, average side spread and fishtail coefficient, but it causes the roll force to increase and the filling capability of groove to decrease.

본 연구의 목적은 3D Virtual Simulation을 활용하여 교육용 팬츠 패턴의 맞음새를 비교·분석하는 것이 다. 이를 위해 20대 여성 평균 체형을 기준으로 기본형 제도법 10종을 1.1.1.1.1. Yuka apparel CAD system으로 제도한 후 CLO 3D 프로그램을 활용하여 가상착의를 실시하였다. 분석 결과, 패턴 제도법에 따라 인체치수 적용 방식과 여유량, 중심선 구조 및 샅냄폭, 다트 위치와 길이 등이 상이하였으며 이는 착의 외관과 실루엣에 큰 영향 을 미쳤다. 3D Virtual Simulation 결과, 패턴 H, J, I는 좋은 맞음새를 보였으며, 패턴 G, D는 나쁜 맞음새를 보 였다. 이를 통해 샅냄폭과 중심선 위치, 앞·뒤판의 다트 구조, 허리~엉덩이 실루엣 형성 등이 패턴설계의 주요 구 성 요소임을 알 수 있었다. 본 연구는 팬츠 패턴 설계 자동화를 위한 기초자료를 제공하며, 향후 연령별·체형별 패턴 개선을 위한 활용 가능성을 시사한다.

This study aimed to compare and analyze the fit of educational pants patterns. Using Yuka apparel CAD system, ten basic pants patterns were drafted for the average body measurements of women in their 20s. virtual try-ons were subsequently performed in CLO 3D. The results showed that the application of body measurements, ease allowances, center line construction, crotch width, and dart placement and length varied across patterns, significantly affecting the appearance and silhouette of the garments. In 3D virtual simulations, patterns H, J, and I exhibited good fit, whereas patterns G and D performed poorly. These results indicate that crotch width, centerline placement, front- and back-panel dart configuration, and waist?hip silhouette shaping are key factors in pants pattern design. This study provides foundational data for the automation of pants pattern design and suggests its applicability in developing improved patterns tailored to different age groups and body types.

실감형 콘텐츠 관련 연구가 활발히 진행되고 있다. AR을 중심으로 한 실감형 콘텐츠의 발전은 스마트 폰을 이용하여 실세계에 3D 가상 콘텐츠를 추가하는 것을 넘어, 대형 건축물에 Projection Mapping을 하는 Media Facade 콘텐츠로 발전되었다. 최근 Projection Mapping을 이용한 Media Facade를 활용한 광고 콘텐츠의 수요가 증가하면서 Projection Mapping콘텐츠에 대한 교육과 시스템개발이 요구 되고 있다. Projection Mapping을 처음 배우는 교육생의 경우, 투사할 사물 및 건축물을 만드는 것부터 큰 어려움으로 작용된다. 사물 및 건축물을 구축하기 위해서는 그만한 자원과 재원이 요구되며, 한번 만들고 나면 다시 자원 을 활용하여 바꾸기 쉽지 않다. 본 논문에서는 Projection Mapping 교육을 위한 Unity 3D Engine 기반 Projection Mapping Simulation을 제안한다. 제안된 Projection Mapping Simulation는 Unity 3D Engine을 기반하였기 때문에 무료로 교육생들이 사용이 가능하며, 다양한 3D Object File를 활용하여 사물 및 건축물을 나타내고 조작할 수 있다. 또한, Projection Mapping에 쓰이는 영상을 Video 뿐 아니라, 실시간 3D Rendering으로 사용할 수도 있다. 본 논문에서 제안한 Projection Mapping Simulation는 교육생들에게 공간과 사 물 및 건축물의 이해를 돋기 위한 실험의 장이 될 것이며, Projection Mapping 콘텐츠 연구 자들에게는 여러 Projection Mapping 기법을 실험 및 연구할 수 있는 장이 되길 희망한다.

Research on realistic content is actively underway. The development of realistic content centered on AR has gone beyond adding 3D virtual content to the real world using smartphones and has developed into Media Facade content that uses projection mapping on large buildings. Recently, as the demand for advertising content using Media Facade using Projection Mapping increases, education and system development for Projection Mapping content are required. For trainees learning Projection Mapping for the first time, creating objects and buildings to project poses a great challenge. Building objects and buildings requires a lot of resources and resources, and once created, it is not easy to use resources to change them again. In this paper, we propose Projection Mapping Simulation based on Unity 3D Engine for projection mapping education. Because the proposed Projection Mapping Simulation is based on the Unity 3D Engine, it can be used by trainees for free, and objects and buildings can be represented and manipulated using various 3D Object Files. In addition, the video used for projection mapping can be used not only as video but also for real-time 3D rendering. We hope that the Projection Mapping Simulation proposed in this paper will be a place for experimentation to enhance trainees' understanding of space, objects, and buildings, and for Projection Mapping content researchers to experiment and research various projection mapping techniques.

Amid the escalating climate crisis, forest disasters are occurring more frequently and with greater intensity, prompting a paradigm shift in forest disaster response at the national security level. In line with the growing emphasis on proactive disaster management, the Korea Forest Service is establishing a prevention-centered framework through the enactment of 'the Forest Disaster Prevention Act' and is advancing policies and research to build a comprehensive forest disaster safety network. Concurrently, the advancement of digital twin-based forest management—integrating high-precision 3D spatial data with artificial intelligence, big data analytics, and predictive modeling—has underscored the importance of data-driven, locationspecific approaches to problem-solving in forest disaster prevention. This study aims to enhance forest disaster preparedness by implementing a digital twin system based on 'Forest watershed numerical maps' that closely resemble real forest conditions. Through the application of 3D debris flow simulation, the research visually predicts the locations and paths of potential landslides, enabling the development of preemptive disaster response strategies. Furthermore, it proposes practical applications of digital twin technology for improving disaster safety management in forest areas and advancing forest disaster prevention in the era of climate change.

About 50 years ago, authority of physics academy concluded that Big bang theory is right by the discovery of Cosmic Microwave Background radiation (CMB). But soon, people found serious problem in the Big bang theory so conception called ‘Inflation’ invited, which implies that there was great expansion of space after Big bang between 10-30 s and 10-33 s ~ 10-32 s. At that time, inflaton that caused inflation included asymmetry throughout space. After the inflation, the energy that inflaton had was released as the form of a matter. So, asymmetric inflaton also derived asymmetry of matter. Because of this asymmetry, large scale structure and CMB became to have these days’ shape. In this research, we are going to set simple model of inflaton that contains asymmetry and compare with these day’s CMB by using laplace series. Finally, we could get a result that resemble our universe’s CMB power spectrum.

Abnormal regulation, hyperphosphorylation, and aggregation of the tau protein are the hallmark of several types of dementia, including Alzheimer's Disease. Increased activity of Glycogen Synthase Kinase-3β (GSK-3β) in the Central Nervous System (CNS), increased the tau hyperphosphorylation and caused the neurofibrillary tangles (NFTs) formation in the brain cells. Over the last two decades, numerous adenosine triphosphate (ATP) competitive inhibitors have been discovered that show inhibitory activity against GSK-3β. But these compounds exhibited off-target effects which motivated researchers to find new GSK-3β inhibitors. In the present study, we have collected the dataset of 31 C-Glycosylflavones derivatives that showed inhibitory activity against GSK-3β. Among the dataset, the most active compound was docked with the GSK-3β and molecular dynamics (MD) simulation was performed for 50 ns. Based on the 50 ns MD pose of the most active compound, the other dataset compounds were sketched, minimized, and aligned. The 3D-QSAR based Comparative Molecular Field Analysis (CoMFA) model was developed, which showed a reasonable value of q 2=0.664 and r 2=0.920. The contour maps generated based on the CoMFA model elaborated on the favorable substitutions at the R2 position. This study could assist in the future development of new GSK-3β inhibitors.

Background/Objectives: This paper describes an analysis of the effectiveness for an anti-ARM technique to protect a radar system. Methods/Statistical analysis: We investigate the optimum deployment of decoy antennas which are widely using for anti-ARM and the electromagnetic field at the ARM receiver. The simulation results regarding the performance of decoys based on the signal's Angle of Arrival (AoA) in 3D geometry. To verify the effect of decoy antennas, we analyze the field intensity and phase at the receiver and develop a numerical simulation program using Matlab. Findings: We conduct an analysis of ARM attack in case of using multiple decoy antennas and these results can be used to decide the optimum positions of the decoys for anti-ARM. The findings indicate that the angle of deployment for the decoys in relation to the radar is a crucial element for effective radar protection. Improvements/Applications: The results from this study can enhance radar wave avoidance techniques by employing decoy antennas and will serve as foundational technology for future research in systematic radar defense methods.

본 연구에서는 도시열섬 시뮬레이션 분석 시 다양한 환경에서 시뮬레이션이 가능하도록 건축물들의 건폐율·용적률·높이 등을 변경하면서 사용 가능한 필지 내에서 3D 건축물이 생성 가능하도록 알고리즘을 개발하였다. 생성모델은 법에서 정의하고 있는 몇몇 규제를 안에서 필지의 정보만 이용하여 각 필지마다 최대로 개발할 수 있는 건축물을 생성한다. 서 울시 마포구 서교동 대상으로 알고리즘을 적용하였으며 약 30초 후 모든 필지에 건축물이 생성됨을 확인할 수 있었다.

In this study, we developed an algorithm to 3D buildings within usable pacel information by changing the occupancy rate, volume ratio, height, etc. of buildings to enable simulation in various environments.. This algorithm to create a 3D building model in a parcel that can be used in performing an urban heat island simulation. By using the information on parcels within the legal limits, a 3D building model creates a building that can be constructed to the maximum for each parcel. The algorithm was applied for parcels in Seogyo-dong, Mapo-go, Seoul, and after about 30 minutes, buildings were found to be created in all parcels.

본 연구의 목적은 전산화단층촬영 (computed tomography, CT)영상으로부터 각각의 검색창 크기가 설정된 3차원 비지역적 평균 (3D non-local means, 3DNLM) 알고리즘을 적용하여 이에 대한 영상 특성 및 시간 분해능의 경향성을 분석하는 것이다. 이를 위해 Gaussian 및 poisson 노이즈가 부가된 3D Shepp-Logan phantom 영상을 모델링한 후 평활화 상수 및 패치크기가 각각 0.01 및 3×3×3으로 설정된 3DNLM 알고리즘의 검색창 크기를 3×3×3부터 2×2×2 간격으로 15×15×15 크기까지 변경하여 각각 적용하였다. 이에 대한 영상 특성의 정량적 평가를 위해 contrast to noise ratio (CNR) 및 peak signal to noise ratio (PSNR)을 측정하였으며, 시간 분해능 분석을 위해 3DNLM 알고리즘의 연산 시간을 측정하였다. 결과적으로, CNR은 검색창이 증가함에 따라 개선됨을 보였으며, PSNR 은 5×5×5 크기의 검색창에서 가장 개선된 결과를 보였다. 시간분해능의 경우 검색창의 크기가 증가함에 따라 지수함수 적으로 증가함이 확인되었다. 결론적으로, CT 영상으로부터 3DNLM 알고리즘을 효율적으로 적용하기 위해서 영상 특성 및 시간분해능이 모두 고려된 검색창의 크기를 설정하는 것이 중요함을 확인하였다.

The purpose of this study was to analyze the tendency of image characteristics and time resolution by applying a 3D non-local means (3DNLM) algorithm, which each search window size was set, in computed tomography (CT) images. For this purpose, the 3D Shepp-Logan phantom images were modeled by adding Gaussian and poisson noise. Then, search window size of 3DNLM algorithm with smoothing factor and patch size set to 0.01 and 3×3×3, respectively, changed from 3×3×3 to 15×15 ×15 at interval 2×2×2 and applied, respectively. To quantiative evaluate of image characteristics, contrast to noise ratio (CNR) and peak signal to noise ratio (PSNR) were measured, and the operation time of the 3DNLM was measured for time resolution analysis. As a result, the CNR showed improvement as the search window increased, and PSNR showed the most improved in the search window size of 5×5×5. In addition, time resolution was confirmed that it increased exponentially as the search window size increased. In conclusion, we confirmed that setting the search window size considering both image characteristics and time resolution to efficiently apply the 3DNLM algorithm in CT images.

본 논문에서는 Foot Placement Estimator (FPE)를 사용하여 point foot을 갖는 이족 로봇의 3차원 시뮬레이션을 진행하고 이족로봇의 균형유지를 연구하였다. FPE 방법은 에너지 보존에 근거한 제어 방법으로서 보행 중인 로봇의 모든 에너지가 위치 에너지로 변환되는 지점에 로봇이 발을 디뎌 몸체가 넘어지지 않고 균형을 유지하며 이동하도록 하는 제어방법이다. 본 연구에서는 로봇이 이동하지는 않고 제자리에서 균형을 유지하며 서 있는 시뮬레이션을 진행하였다. 이를 위해 point foot을 갖는 6자유도 이족 로봇을 모델링하였으며 바닥과의 접촉 및 마찰 환경을 구현하였다. 로봇의 무게는 1kg이며 지면과 무게 중심점과의 거리는 1m로, 무게중심점은 로봇 몸체의 정 중앙에 위치하도록 설계하였다. 다음으로 로봇 몸체의 각속도와 직선속도 그리고 무게 중심점의 높이로 부터 FPE 지점을 계산하고 로봇이 해당 지점을 디뎌 균형을 유지하게 끔 하였다. 몸체의 초기 각도를 $5^{\circ}$, $-5^{\circ}$로 변화시키며 시뮬레이션 한 결과, 모든 초기 조건에서 로봇이 쓰러지지 않고 자세의 균형을 유지하며 서 있는 것을 확인할 수 있었다.

In this study, we investigate balance of a biped robot applying Foot Placement Estimator (FPE) in simulation. FPE method is used to determine a stable foot location for balancing the biped robot when an initial orientation of the robot body is statically unstable. In this case, the 6-DOF biped robot with point foot is modelled considering contact and friction between foot and the ground. For simulation, the mass of the robot is 1 kg assuming the center of robot mass (COM) is located at the center of the robot body. The height from the ground to the COM is 1 m. Robot balance is achieved applying stable foot locations calculated from FPE method using linear and angular velocities, and the height of the COM. The initially unstable angular postures, $5^{\circ}$ and $-5^{\circ}$, of the robot body are simulated. Simulation results confirm that the FPE method provides stable balance of the robot for all given unstable initial conditions.

본 연구는 극한수문 사상 시 교량주변에서 발생하는 월류(overtoping) 및 압력흐름(Pressure flow)의 수리특성을 규명하기 위하여 RANS방정식 기반의 3차원 수치모형을 구축하였다. 자유수면 처리를 위하여 Density function기법을 난류모형으로는 비선형 k-ε모형을 적용하였다. 수치모의를 통하여 월류조건에서 상류영역에서는 배수효과로 인하여 유속이 감소하였지만 월류 흐름에 의한 최대유속은 U_over,max/U₀≈2.0이 발생하였으며 압력흐름에 의한 최대유속은 U_pressue,max/U₀=1.8-2.7으로 나타났다. 상류유량이 증가할수록 상·하류 수심차가 커지면서 교량하류에서 월류흐름 낙하에 의해 강한 전단층과 재순환 영역이 형성되었고 자유수면 변동이 수반되었다. 상·하류 수심차가 증가할수록 평균유속(U/U0) 및 고 난류 운동에너지(TKE/TKE₀)영역은 확산되는 것으로 나타났다. 잠수형 오리피스 유형의 압력흐름에서는 U_pressue,max/U₀=2.7로 나타났으며 월류조건으로 전이되면서 Δh/h₀=0.15-0.48에서 월류유량이 22%에서 37%로 나타났다. 본 연구는 극한 수문 조건하 교량의 수리 거동을 3차원적으로 규명하였으며, 향후 교량 설계 및 유지관리 시 수리안전성 평가의 기초자료로 활용될 수 있을 것으로 판단된다.

A three-dimensional numerical model based on the RANS equations was developed to investigate the hydraulic characteristics of overtopping and pressure flow around bridge structures under extreme hydrologic conditions. The free surface was treated using the density function method, and turbulence closure was achieved with a nonlinear k-ε turbulence model. Numerical simulations revealed that, under overtopping conditions, the upstream velocity decreased due to the backwater effect, while the maximum flow velocity induced by overtopping reached approximately U_over,max/U₀=2.0. For pressure flow, the maximum velocity ranged from U_pressue,max/U₀=1.8-2.7. As the upstream discharge increased, the difference in water depth between the upstream and downstream became larger, leading to the development of strong shear layers and recirculation zones downstream of the bridge, accompanied by significant free-surface fluctuations. An increase in Δh caused both the mean velocity ratio (U/U₀) and high turbulent kinetic energy zones (TKE/TKE₀) to expand. For the submerged-orifice type of pressure flow, the maximum velocity was predicted as U_pressue,max/U₀=2.7. As the flow transitioned to overtopping, Δh/h₀=0.15-0.48 resulted in an overtopping discharge ratio of 22%-37%. The results demonstrated that flow type transitions around bridges significantly alter shear and turbulence structures, which are closely related to local scour and hydraulic stability. This study provides three-dimensional insights into bridge hydraulics under extreme flow conditions and offers fundamental hydraulic data that can support future bridge design and maintenance for flood-safety assessment.

최근의 시뮬레이션 도구들은 새로 발표된 여러 가지 3차원 구현 기술들을 접목하여 제한된 2차원 화면 속에서 3차원 요소들을 효율적으로 구현 시켜 나가고 있는 추세이다. 본 논문에서는 이러한 현재의 기술적 상황에 기초를 둔 경관 시뮬레이션 도구를 구현하였으며, 자연과의 조화를 통한 인간의 보다 향상된 생활환경을 구상하여 설계할 수 있도록 고려하였다. 응용된 기술로는 인터넷을 기반으로 하는 가상현실구현에 대한 3차원상의 표준으로 주목받고 있는 VRML(Virtual Reality Modeling Language)과 자비를 연계한 EAI(External Authoring Interface)를 적용하였다.

Recent simulation tools combine the 3-dimensional graphic technique to implement the 3D visualization of the objects in the 2-Dimensional computer display. In this paper, a sight simulation tool is implemented using the recent 3D techniques. The proposed sight simulator can be applied to improve the human environment with the harmony of the nature. The system is consisted of modules for topography, object, and navigation. A sight database for the sight elements(objects) is implemented using Java. Combined with Java, VRML, which is considered as the standard for 3D virtual reality in the Internet is used to implement EAI(External Authoring Interface). EAI allows the users to communicate with a VRML scene.