• Journal of information and communication convergence engineering
• /
• 제5권3호
• /
• pp.249-253
• /
• 2007

The Research on the ICT(Information & Communication Technology) is proposed the category to IT839 strategy by Government. Government is driving to researching on technology about IT839 Strategy. By transforming this category and research information into Semantic Web environment, it is possible to search function utilizing knowledge base and information object by use of TBox and ABox. In this regard, this study proposes technology for generation of Semantic Web Document about ICT Research Information. The ontology is constructed by using category to IT839 Strategy. The features of framework proposed in this study is to have used a skill to directly map Ontology instance and in case of inability of direct mapping, proposed a skill to establish reliable Semantic Web Document by suggesting indirect mapping skill using mechanical study. In addition, it is possible to establish low cost/high quality Semantic Web Document about ICT research information.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.917-922
• /
• 2004

As the tasks of robots become more diverse, some complicated tasks have come to require force and position hybrid control. A compliant device can be used to control force and position simultaneously by separating the twist of the robot's end effector from the twist of compliance and freedom by using stiffness mapping of the compliant device. The development of a fuzzy gain scheduling scheme of control for a robot with a compliant device is described in this paper. Fuzzy rules and reasoning are performed on-line to determine the gain of twists based on wrench error and twist error and twist of compliance and twist of freedom ratio. Simulation results demonstrate that better control performance can be achieved in comparison with constant gain control.

• 융복합기술연구소 논문집
• /
• 제12권1호
• /
• pp.1-5
• /
• 2022

This paper describes an algorithm for generating a terrain using a noise function and a height map as one of the procedural terrain generation methods. The polygon mesh data structure to represent the generated terrain concisely and render it is also described. The Perlin noise function is used as the noise technique for terrain mesh, and the height data of the terrain is generated by combining the four noise waves. In addition, the terrain height information can be also obtained from actual image data taken from the satellite. The algorithm presented in this paper generates the geometry part of the polygon topography from the height data obtained, and generated a material for texture mapping with two textures, that is, a diffuse texture and a normal texture. The validity of the terrain method proposed in this paper is verified through application examples, and its possibility can be confirmed through performance verification.

• 대한공간정보학회지
• /
• 제20권1호
• /
• pp.65-72
• /
• 2012

MEMS(Micro Electro Mechanical System)기술이 발전하여 작고 저렴한 IMU(Initial Measurement Unit)와 GPS(Global Positioning System)통합센서가 생산되어 다양한 분야에서 활용되고 있다. 본 연구에서는 모바일매핑시스템을 경량화하기 위해서 MEMS 기반 IMU/GPS 통합센서가 적합할 것으로 판단하고 XSens사 MEMS 기반 IMU/GPS 통합센서(MTi-G)의 특성 분석을 위한 실험을 수행하였다. 차량 대시보드에 통합센서를 고정하고 인천 송도 국제도시 도로구간과 터널구간을 주행하여 후처리 과정을 거치지 않은 좌표성과를 취득하였다. 전반적으로 위치결정 성과가 양호했지만 일부 구간(정지구간, 과속방지턱, 터널구간 등)에서 센서 특성, XKF(칼만필터) 특성 및 GPS 신호 수신환경 제한으로 인해 양호하지 못한 부분이 확인되었다. 실험결과 경량 모바일매핑시스템의 활용 가능성을 확인할 수 있었으며, 향후 다양한 GPS 신호 수신환경과 주행 조건에서의 실험과 보다 정밀한 정확도 분석이 요구된다.

• 한국음향학회지
• /
• 제40권1호
• /
• pp.92-98
• /
• 2021

발전소의 실내는 규모가 크고, 위치마다 소음레벨 편차가 매우 크기 때문에 소음관리가 어렵다. 따라서 실내소음을 효과적으로 관리하기 위해서 소음분포를 분석할 수 있는 소음 가시화 시스템이 필요하다. 터빈실 내를 모델링하고, 선정된 지점의 소음레벨을 측정하여 소음지도를 작성할 수 있는 소음 매핑 시스템을 개발하였다. 그리고 모델의 신뢰성을 높이기 위하여 소음지도와 실제 소음측정 결과와 비교하는 방법을 통하여 모델을 수정하였다. 소음지도에 대한 정기적인 분석을 통하여 설비 이상을 판단할 수 있고, 특정 지점의 현재와 이전 소음에 대한 주파수 및 레벨을 비교 분석함으로써 실내소음을 효과적으로 관리하는 방법을 제시하였다. 매핑 시스템을 활용하면 근무환경을 개선할 수 있는 소음대책의 수립이 가능하고, 기계의 이상 유무를 확인하고, 예방정비를 통해 설비의 신뢰성을 높일 수 있다.

• Smart Structures and Systems
• /
• 제30권6호
• /
• pp.687-701
• /
• 2022

Inevitable response loss under complex operational conditions significantly affects the integrity and quality of measured data, leading the structural health monitoring (SHM) ineffective. To remedy the impact of data loss, a common way is to transfer the recorded response of available measure point to where the data loss occurred by establishing the response mapping from measured data. However, the current research has yet addressed the structural condition changes afterward and response mapping learning from a small sample. So, this paper proposes a novel data driven structural response reconstruction method based on a sophisticated designed generating adversarial network (UAGAN). Advanced deep learning techniques including U-shaped dense blocks, self-attention and a customized loss function are specialized and embedded in UAGAN to improve the universal and representative features extraction and generalized responses mapping establishment. In numerical validation, UAGAN efficiently and accurately captures the distinguished features of structural response from only 40 training samples of the intact structure. Besides, the established response mapping is universal, which effectively reconstructs responses of the structure suffered up to 10% random stiffness reduction or structural damage. In the experimental validation, UAGAN is trained with ambient response and applied to reconstruct response measured under earthquake. The reconstruction losses of response in the time and frequency domains reached 16% and 17%, that is better than the previous research, demonstrating the leading performance of the sophisticated designed network. In addition, the identified modal parameters from reconstructed and the corresponding true responses are highly consistent indicates that the proposed UAGAN is very potential to be applied to practical civil engineering.

• 한국정밀공학회지
• /
• 제26권3호
• /
• pp.25-31
• /
• 2009

Femto-second laser ablation with the various feed velocities of the Invar alloy and the micro surface milling for the processing condition were studied. We used a regenerative amplified Ti:sapphire laser with a 1kHz repetition rate, 184fs pulse duration time and 785nm wavelength. Femto-second laser pulse was irradiated on the Invar alloy with the air blowing at the condition of various laser peak powers and feed velocities. An ablation characteristic according to feed velocity of the Invar alloy was appeared as the non-linear type at different zone of energy fluence. The micro surface milling of the Invar alloy using a mapping method was investigated. The optimal condition of micro surface milling was laser peak power of 22.8mW, feed velocity of 1 mm/s, beam gap of $1{\mu}m$. With the optimal processing condition, the fine rectangular shape without burr and thermal damage was achieved. Using the femto-second laser system, it demonstrates excellent tool for micro surface milling of the Invar alloy without heat effects and poor edge.

• 한국전산구조공학회논문집
• /
• 제30권1호
• /
• pp.1-6
• /
• 2017

본 논문에서는 비교적 최근 정립된 co-rotational 이론을 기반으로 한 4절점 평면요소 정식화를 확장하여 9절점 평면 요소에 적합한 CR 정식화를 제시하고자 한다. 그리고 등방성 재료의 소성 해석을 위해, 선형 경과 규칙(bi-linear hardening rule)을 바탕으로 하는 Newton-Raphson return-mapping 알고리즘을 적용하였다. 이때, von Mises 기준을 적용하여 소성 변형 상태를 예측하였다. Lagrange 승수를 도입하여 2차원 접촉에 대한 구속조건을 부여하였다. 개발한 요소는 상용프로그램인 ABAQUS 해석결과와 비교 검증하였다.

• 드라이브 ㆍ 컨트롤
• /
• 제19권4호
• /
• pp.97-103
• /
• 2022

Low fertility rates and increased life expectancy further exacerbate the process of an aging society. This is also reflected in the gradual increase in the proportion of vulnerable groups in the social population. The demand for improved mobility among vulnerable groups such as the elderly or the disabled has greatly driven the growth of the electric-assisted mobility device market. However, such mobile devices generally require a certain operating capability, which limits the range of vulnerable groups who can use the device and increases the cost of learning. Therefore, autonomous driving technology needs to be introduced to make mobility easier for a wider range of vulnerable groups to meet their needs of work and leisure in different environments. This study uses mini PC Odyssey, Velodyne Lidar VLP-16, electronic device and Linux-based ROS program to realize the functions of working environment recognition, simultaneous localization, map generation and navigation of electric powered mobile devices for vulnerable groups. This autonomous driving mobility device is expected to be of great help to the vulnerable who lack the immediate response in dangerous situations.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.134-137
• /
• 2008

The effects of residual stress and surface defects on the mechanical properties of the high carbon steel filament used for the automotive tire have been experimentally investigated. The samples were fabricated with annealing temperature. The residual stress was measured by focused ion beam and strain mapping software which has advantages, such as data with high accuracy and fast data acquisition time. Mechanical properties, such as tensile strength and fatigue resistance, were gradually increased up to $200^{\circ}C$ and then slightly decreased. From the measurement of residual stress and level of surface defect, it was revealed that the critical factor was varied with different temperature region. That is, the fatigue resistance increased due to decreasing the residual stress and decreased due to increasing the size and distribution of surface defect.