• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.1
• /
• pp.41-51
• /
• 2010

In the research for driver assistance systems, traffic sign information to the driver must be a very important information. Therefore, the detection system of traffic signs located on the road should be able to handel real-time. To detect the traffic signs, color and shape of traffic signs is to use the information after images obtained using the CCD camera. In the road environment, however, using color information to detect traffic sings will cause many problems due to changes of weather and environmental factors. In this paper, to solve it, the candidate traffic sign regions are detected from road images obtained in a variety of the illumination changes using the HSI eign-color model. And then, using the invariant moment-based SVM classifier to detect traffic signs are proposed. Experimental results show that, traffic sign detection rate is 91%, and the processing time per frame is 0.38sec. Proposed method is useful for real-time intelligent traffic guidance systems can be applied.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.31 no.3
• /
• pp.235-256
• /
• 2020

The purpose of this study is to define a method of building an integrated service to provide various science and technology knowledge infrastructures that are helpful in R&D activities, and to show the cases that are adapted the methodologies. Knowledge infrastructures scattered throughout the entire R&D cycle, such as generating/development of ideas, finding the R&D project, performing the project, and spreading results, are segmented in terms of services, functions, information, and data, and links and converges to provide the knowledge infrastructure that desired by users in one place. We define the integrated service classification, integration level model, integrated architecture, and integrated user authentication system in consideration of logical linkage and integration rather than physical integration of individual knowledge infrastructures. Also, we considered the extensibility as the reference model for building of similar integrated service.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.141-141
• /
• 2011

생태적 기능이 담보되는 하안의 조성 및 복원은 필연적으로 하안공간에서 물리적 구조변화를 야기한다. 이러한 하안공간의 물리적 구조변화는 장기적으로 구간에서의 생태적 기능뿐만 아니라 단기적으로 하천의 수리특성변화를 야기한다. 이러한 수리특성변화는 복원구간에서의 생태적 기능에 직접적인 영향을 준다. 하천복잡도에 따른 수리특성의 변화는 자연형 하천복원에 영향을 주는 변수이므로 이들 변화를 예측할 수 있는 하천복잡도 시나리오의 수립은 매우 중요하다. 따라서 본 연구에서는 2차원 하상변동 수치모형인 CCHE2D 모형을 이용하여 하천유형에 따른 수리특성을 분석하고자 하였다. 하천복잡도 시나리오는 Rosgen (1994)에 의해 제안된 하천분류방법과 유량크기별 모의 시나리오를 작성하여 모델에 적용하였다. 연구대상지역은 안성천유역의 오산천과 진위천으로 하천분류결과 크게 C유형과 E 유형으로 분류되었다. 분류된 유형의 수리특성 분석을 위해 C 유형의 구간중 진위천 본류구간과 통삼천의 만곡구간을 선정하여 모형을 구동하였다. 모형의 입력자료인 유한요소망은 하천정비기본계획의 부도를 이용하여 생성하였으며 모델의 경계입력자료는 WMS HEC-1의 유출량 결과 자료를 사용하였다. 빈도별 강우량 자료를 Huff의 4분위 법을 적용하여 24시간으로 분포화하여 빈도별, 구간별 유출량 자료를 구축하여 모의 하였다. 선정한 하천유형구간에 대하여 유량크기별 수위, 유속, 한계유속, 소류력에 대한 흐름특성분석을 실시하였으며, 조도계수의 변화에 따른 흐름특성 변화를 분석하였다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.4
• /
• pp.453-462
• /
• 2007

The purpose of this study is to predict the ratios of increase in lateral stiffness for preliminary structural design of tall buildings. For this, the basic models of tall buildings with 60 stories are generated. The basic models have typical floor plan of Box or T type. And the factors for increase in lateral stiffness are selected as follows; the addition of outriggers, increase in material strength, and increase in member size of core walls, outrigger columns, and outrigger walls. Then these factors are applied to the basic models and their effects are investigated using the results of structural analysis. Finally, based on the investigation, the ratios of increase in lateral stiffness for preliminary structural design of tall buildings are proposed and applied to examples of tall building for verification of the ratios.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.279-286
• /
• 2010

Hypersonic aircraft technologies have been developed with increase in flight speeds. As hypersonic flight speeds increase, heat loads on an aircraft and it's engine increase. Researches on cooling technologies using endothermic fuels are progressing in the USA, France, and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical phase of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.

• Journal of Convergence for Information Technology
• /
• v.9 no.8
• /
• pp.155-163
• /
• 2019

Laminar mixed convection of a nanofluid consists of water and $Al_2O_3$ in a horizontal circular tube has been studied numerically. Two-phase mixture model has been used to investigate hydrodynamic and thermal behaviors of the nanofluid with variables physical properties. Three dimensional Navier-Stokes, energy and volume fraction equations have been discretized using the finite volume method. The Brownian motions of nanoparticles have been considered to determine the thermal conductivity and dynamic viscosity of $Al_2O_3$-Water nanofluid, which depend on temperature. The calculated results show good agreement with the previous numerical data. Results show that in a given Reynolds number (Re), increasing solid nanoparticles volume fraction and Richardson number (Ri) increases the convective heat transfer coefficient and wall shear stress.

• The Journal of Society for e-Business Studies
• /
• v.24 no.3
• /
• pp.87-98
• /
• 2019

As artificial intelligence is actively studied, it is being applied to various fields such as image, video and natural language processing. The natural language processing, in particular, is being studied to enable computers to understand the languages spoken and spoken by people and is considered one of the most important areas in artificial intelligence technology. In natural language processing, it is a complex, but important to make computers learn to understand a person's common sense and generate results based on the person's common sense. Knowledge graphs, which are linked using the relationship of words, have the advantage of being able to learn common sense easily from computers. However, the existing knowledge graphs are organized only by focusing on specific languages and fields and have limitations that cannot respond to neologisms. In this paper, we propose an intelligent chatbotsystem that collects and analyzed data in real time to build an automatically scalable knowledge graph and utilizes it as the base data. In particular, the fine-tuned BERT-based for relation extraction is to be applied to auto-growing graph to improve performance. And, we have developed a chatbot that can learn human common sense using auto-growing knowledge graph, it verifies the availability and performance of the knowledge graph.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.10
• /
• pp.1453-1461
• /
• 2022

The accuracy of peripheral object recognition algorithms using 3D data sensors such as LiDAR in autonomous vehicles has been increasing through many studies, but this requires high performance hardware and complex structures. This object recognition algorithm acts as a large load on the main processor of an autonomous vehicle that requires performing and managing many processors while driving. To reduce this load and simultaneously exploit the advantages of 3D sensor data, we propose 2D data-based recognition using the ROI generated by extracting physical properties from 3D sensor data. In the environment where the brightness value was reduced by 50% in the basic image, it showed 5.3% higher accuracy and 28.57% lower performance time than the existing 2D-based model. Instead of having a 2.46 percent lower accuracy than the 3D-based model in the base image, it has a 6.25 percent reduction in performance time.

• Journal of Aerospace System Engineering
• /
• v.18 no.3
• /
• pp.17-26
• /
• 2024

Aircraft engines are exposed to high temperatures, high pressures, and stress caused by the rotation of the turbine shaft during flight. These loads can result in microcracks both on the inside and outside surfaces of the structure. Consequently, this can lead to structural defects and negatively impact the lifespan of the parts. To proactively prevent these defects, a finite element analysis is carried out to identify cracks. However, this process is time-consuming and requires significant effort due to the repetitive nature of crack modeling. This study aims to develop a crack modeling method based on the finite element model. To achieve this, the Constrained Delaunay Triangulation (CDT) technique is employed to triangulate the space while considering limitations on point connections. The effectiveness of this method is validated by comparing stress intensity factors for semi-elliptical cracks in plates and cylindrical vessels. This approach proves to be a valuable tool for crack analysis studies.

• The Journal of the Korea Contents Association
• /
• v.9 no.5
• /
• pp.61-75
• /
• 2009

Generally, the development of the database application includes the requirement analysis phase of creating ERD (Entity Relationship Diagram) and process models, coding, and testing. From the above phases, the analysis phase is not most formalized. It is usually hard task because (1) customers don't know the details of the desired system; (2) developers can't with ease understand the business logic of the customers; (3) the outcomes of the analysis, which are ERD and process models, are not easy to understand to the customers. This paper propose that the executional forms, which are better to understand the systems, should be presented to the customers instead of the ERD. These forms should accept the data input so that customers can review the various aspects of the outcome models. The developers should be able to instantly implement the business logic and also should be able to visually demonstrate the logic in order to get the details of it. For this goal, the customer supplied business logic should be able to be implemented by the references between forms, actions, constraints from the perspective of the data flow. The customers try to execute the forms implementing the business logic and review their supplied logic find new necessary business logic of their own. Iterating these processes for the requirement analysis would result in the success of the analysis which is sufficiently detailed without conflicts.