• 제목/요약/키워드: Top Down Method

검색결과 392건 처리시간 0.03초

Study on collapse mechanism and treatment measures of portal slope of a high-speed railway tunnel

  • Guoping Hu;Yingzhi Xia;Lianggen Zhong;Xiaoxue Ruan;Hui Li
    • Geomechanics and Engineering
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    • 제32권1호
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    • pp.111-123
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    • 2023
  • The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m3 formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

협력적인 상호작용을 위한 테이블-탑 디스플레이 기술 동향 (Survey: The Tabletop Display Techniques for Collaborative Interaction)

  • 김송국;이칠우
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.616-621
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    • 2006
  • 최근에 인간과 컴퓨터 상호작용을 위한 사용자 의도 및 행위 인식에 관한 비전 기반 연구가 활발히 진행되고 있다. 그 중에서도 테이블-탑 디스플레이 시스템은 터치 감지 기술의 발전, 협력적인 작업 추구에 발맞추어 다양한 응용으로 발전하였다. 이전의 테이블-탑 디스플레이는 오직 한명의 사용자만을 지원하였으나 현재에는 멀티터치를 통한 멀티유저를 지원하게 되었다. 따라서 테이블-탑 디스플레이의 궁극적인 목적인 협력적인 작업과 네 가지 원소 (인간, 컴퓨터, 투영된 객체, 물리적 객체)의 상호작용이 실현 가능하게 되었다. 일반적으로 테이블-탑 디스플레이 시스템은 다음의 네 가지 요소; 맨 손을 이용한 멀티터치 상호작용, 동시적인 사용자 상호작용을 통한 협력적인 작업의 구현, 임의의 위치 터치를 이용한 정보 조작, 상호작용의 도구로서 물리적인 객체의 사용을 중심으로 설계되어 있다. 본 논문에서는 테이블-탑 디스플레이 시스템을 위한 최첨단의 멀티터치 센싱 기술을 시각기반 방법, 비-시각 기반 방법으로 분류하고 비판적인 견해에서 분석을 하였다. 또한 테이블-탑 디스플레이 관련 연구들을 시스템 구성방식에 따라 분류하고 그 장단점과 실제 사용되는 응용 분야에 대해 기술하였다.

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멀티터치를 위한 테이블-탑 디스플레이 기술 동향 (Survey: Tabletop Display Techniques for Multi-Touch Recognition)

  • 김송국;이칠우
    • 한국콘텐츠학회논문지
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    • 제7권2호
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    • pp.84-91
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    • 2007
  • 최근에 인간과 컴퓨터 상호작용을 위한 사용자 의도 및 행위 인식에 관한 비전 기반 연구가 활발히 진행되고 있다. 그 중에서도 테이블-탑 디스플레이 시스템은 터치 감지 기술의 발전, 협력적인 작업 추구에 발맞추어 다양한 응용으로 발전하였다. 이전의 테이블-탑 디스플레이는 오직 한 명의 사용자만을 지원하였으나 현재에는 멀티터치를 통한 멀티유저를 지원하게 되었다. 따라서 테이블-탑 디스플레이의 궁극적인 목적인 협력적인 작업과 네 가지 원소 (인간, 컴퓨터, 투영된 객체, 물리적 객체) 의 상호작용이 실현 가능하게 되었다. 일반적으로 테이블-탑 디스플레이 시스템은 다음의 네 가지 측면; 맨 손을 이용한 멀티 터치 상호작용, 동시적인 사용자 상호작용을 통한 협력적인 작업의 구현, 임의의 위치 터치를 이용한 정보 조작, 상호작용의 도구로서 물리적인 객체의 사용을 중심으로 설계되어 있다. 본 논문에서는 테이블-탑 디스플레이 시스템을 위한 최첨단의 멀티터치 센싱 기술을 시각기반 방법, 비-시각 기반 방법으로 분류하고 비판적인 견해에서 분석을 하였다. 또한 테이블-탑 디스플레이 관련 연구들을 시스템 구성방식에 따라 분류하고 그 장단점과 실제 사용되는 응용 분야에 대해 기술하였다.

일제시대 농촌지도사업의 성격과 의의 (The Characteristics and meanings of the Agricultural Extension Work during the Period of Japanese Rule)

  • 이한기
    • 농촌지도와개발
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    • 제4권1호
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    • pp.231-243
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    • 1997
  • Objective of the study was to investigate characteristics and meanings of the agricultural extension work during the period of Japanese $rule(1906{\sim}1945)$ through historical review on the work. The agricultural extension work during the period of Japanese rule was categorized into six patterns such as agricultural extension work by (1) government agricultural administration system, (2) agricultural experiment/research institute, (3) public school, (4) through the movement of rural development(Nong-chon-Jinheung Undong), (5) pro-government private organization, and (6) pure private organization. In conclusion, the characteristics of the extension work were defined; 1) a tool and/or method for colonial rule, 2) non-democratic and top-down extension work by administration, 3) authoritative and coercive work initiated by governmental system, 4) nation wide work of cooperation with public and private organization, 5) extension work focused on production increasing food and industrial materials, and 6) extension work initiated by government system without participation of pure private organization. The meanings of the extension work were reviewed in two ways. Firstly, in macro point of view, the work has negative meaning that was utilized as a tool and/or method for Japanese colonial rule, since the extension work was implemented under the direction of agricultural policy and was also directly related to the policy of Japanese colonial government. Secondly, in micro point of view, the work has significant meaning either negative or positive such as 1) beginning of modernized extension work based on experiment and research, 2) introduction of forcible agricultural extension work, 3) inducement of distrust tendency to agricultural policy and agricultural extension work, 4) establishment of basis in hardware of agricultural extension work, 5) production of experience in software of agricultural extension work, and 6) improvement of recognition toward scientific farming and improvement of level in agricultural techniques.

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Modeling the Visual Target Search in Natural Scenes

  • Park, Daecheol;Myung, Rohae;Kim, Sang-Hyeob;Jang, Eun-Hye;Park, Byoung-Jun
    • 대한인간공학회지
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    • 제31권6호
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    • pp.705-713
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    • 2012
  • Objective: The aim of this study is to predict human visual target search using ACT-R cognitive architecture in real scene images. Background: Human uses both the method of bottom-up and top-down process at the same time using characteristics of image itself and knowledge about images. Modeling of human visual search also needs to include both processes. Method: In this study, visual target object search performance in real scene images was analyzed comparing experimental data and result of ACT-R model. 10 students participated in this experiment and the model was simulated ten times. This experiment was conducted in two conditions, indoor images and outdoor images. The ACT-R model considering the first saccade region through calculating the saliency map and spatial layout was established. Proposed model in this study used the guide of visual search and adopted visual search strategies according to the guide. Results: In the analysis results, no significant difference on performance time between model prediction and empirical data was found. Conclusion: The proposed ACT-R model is able to predict the human visual search process in real scene images using salience map and spatial layout. Application: This study is useful in conducting model-based evaluation in visual search, particularly in real images. Also, this study is able to adopt in diverse image processing program such as helper of the visually impaired.

Experimental investigation of force-distribution in high-strength bolts in extended end-plate connections

  • Abdalla, K.M.;Abu-Farsakh, G.A.R.;Barakat, S.A.
    • Steel and Composite Structures
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    • 제7권2호
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    • pp.87-103
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    • 2007
  • This paper presents some of the results from an experimental research project on the behavior of extended end-plate connections subjected to moment conducted at the Structural Laboratory of Jordan University of Science and Technology. Since the connection behavior affects the structural frame response, it must be included in the global analysis and design. In this study, the behavior of six full-scale stiffened and unstiffened cantilever connections of HEA- and IPE-sections has been investigated. Eight high strength bolts were used to connect the extended end-plate to the column flange in each case. Strain gauges were installed inside each of the top six bolts in order to obtain experimentally the actual tension force induced within each bolt. Then the connection behavior is characterized by the tension force in the bolt, extended end-plate behavior, moment-rotation relation, and beam and column strains. Some or all of these characteristics are used by many Standards; therefore, it is essential to predict the global behavior of column-beam connections by their geometrical and mechanical properties. The experimental test results are compared with two theoretical (equal distribution and linear distribution) approaches in order to assess the capabilities and accuracy of the theoretical models. A simple model of the joint is established and the essential parameters to predict its strength and deformational behavior are determined. The equal distribution method reasonably determined the tension forces in the upper two bolts while the linear distribution method underestimated them. The deformation behavior of the tested connections was characterized by separation of the column-flange from the extended end-plate almost down to the level of the upper two bolts of the lower group and below this level the two parts remained in full contact. The neutral axis of the deformed joint is reasonably assumed to pass very close to the line joining the upper two bolts of the lower group. Smooth monotonic moment-rotation relations for the all tested frames were observed.

주민참여와 농촌 마을만들기 사업성과의 관계에서 거버넌스의 매개효과 실증분석 - 제주 웃뜨르권역 사례를 중심으로 - (An Empirical Study of the Mediating Effect of Governance in Relationship between Resident Participation and Rural Community Design Project Performance - Focused on the Case of Utturu Village -)

  • 강기호;이진희
    • 농촌계획
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    • 제21권1호
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    • pp.103-115
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    • 2015
  • As rural development projects, mostly carried out in a top-down development method in the past came to take a bottom-up development method in earnest, entering the 2000s, resident participation became an essential element of a rural community design project, to the extent that it can influence the success or failure of a rural community design project. It is taken for granted that rural residents independently participate in community design projects, but as they are accustomed to various subsidy projects carried out by the government and become increasingly aging, it is not easy to induce their spontaneous participation in farming areas with such problems. Especially, to prevent the distrust between administrative agencies and residents from serving as an obstacle in the residents' spontaneous participation, it is necessary to construct horizontal governance among the village residents, administrative agencies and the group of experts supporting for the project. This study attempted to verify the mediating effect of governance in the relationship between resident participation and the performance of the rural community design project based on this problem recognition, and for this purpose, the results of a survey with residents in Utturu Village, Hangyeong-myeon, Jeju-si, which was completed by carrying out a comprehensive rural development project, the typical bottom-up community design project was used for an empirical analysis. The results of the study can provide implications for setting directions, establishing strategies and constructing governance of rural community design projects in the future, and especially, it can be said that this study has academic significance in that governance is recognized as an important variable related to the project performance.

Spin Wave Interference in Magnetic Nanostructures

  • Yang, Hyun-Soo;Kwon, Jae-Hyun;Mukherjee, Sankha Subhra;Jamali, Mahdi;Hayashi, Masamitsu
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2011년도 자성 및 자성재료 국제학술대회
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    • pp.7-8
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    • 2011
  • Although yttrium iron garnet (YIG) has provided a great vehicle for the study of spin waves in the past, associated difficulties in film deposition and device fabrication using YIG had limited the applicability of spin waves to practical devices. However, microfabrication techniques have made it possible to characterize both the resonant as well as the travelling characteristics of spin waves in permalloy (Py). A variety of methods have been used for measuring spin waves, including Brillouin light scattering (BLS), magneto-optic Kerr effect (MOKE), vector network analyzer ferromagnetic resonance (VNA-FMR), and pulse inductive microwave magnetometry (PIMM). PIMM is one of the most preferred methodologies of measuring travelling spin waves. In this method, an electrical impulse is applied at one of two coplanar waveguides patterned on top of oxide-insulated Py, producing a local disturbance in the magnetization of the Py. The resulting disturbance travels down the Py in the form of waves, and is inductively picked up by the other coplanar waveguide. We investigate the effect of the pulse width of excitation pulses on the generated spin wave packets using both experimental results and micromagnetic simulations. We show that spin wave packets generated from electrical pulses are a superposition of two separate spin wave packets, one generated from the rising edge and the other from the falling edge, which interfere either constructively or destructively with one another, depending upon the magnitude and direction of the field bias conditions. A method of spin wave amplitude modulation is also presented by the linear superposition of spin waves. We use interfering spin waves resulting from two closely spaced voltage impulses for the modulation of the magnitude of the resultant spin wave packets.

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Abnormal Behavior Recognition Based on Spatio-temporal Context

  • Yang, Yuanfeng;Li, Lin;Liu, Zhaobin;Liu, Gang
    • Journal of Information Processing Systems
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    • 제16권3호
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    • pp.612-628
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    • 2020
  • This paper presents a new approach for detecting abnormal behaviors in complex surveillance scenes where anomalies are subtle and difficult to distinguish due to the intricate correlations among multiple objects' behaviors. Specifically, a cascaded probabilistic topic model was put forward for learning the spatial context of local behavior and the temporal context of global behavior in two different stages. In the first stage of topic modeling, unlike the existing approaches using either optical flows or complete trajectories, spatio-temporal correlations between the trajectory fragments in video clips were modeled by the latent Dirichlet allocation (LDA) topic model based on Markov random fields to obtain the spatial context of local behavior in each video clip. The local behavior topic categories were then obtained by exploiting the spectral clustering algorithm. Based on the construction of a dictionary through the process of local behavior topic clustering, the second phase of the LDA topic model learns the correlations of global behaviors and temporal context. In particular, an abnormal behavior recognition method was developed based on the learned spatio-temporal context of behaviors. The specific identification method adopts a top-down strategy and consists of two stages: anomaly recognition of video clip and anomalous behavior recognition within each video clip. Evaluation was performed using the validity of spatio-temporal context learning for local behavior topics and abnormal behavior recognition. Furthermore, the performance of the proposed approach in abnormal behavior recognition improved effectively and significantly in complex surveillance scenes.

데이터 마이닝 기법을 이용한 군 통신·전자 분야 기술 분석 (Analysis of Defense Communication-Electronics Technologies using Data Mining Technique)

  • 백성호;강석중
    • 한국정보통신학회논문지
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    • 제24권6호
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    • pp.687-699
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    • 2020
  • 정부가 주도하는 종래의 하향식 무기체계 개발방식은 기술의 발전속도가 급격하게 빨라짐에 따라, 기술 진부화라는 문제에 직면하게 되었다. 이에 따라 정부는 방위산업 분야에도 기업 주도의 상향식 사업추진 방식을 점진적으로 확대 적용해오고 있다. 상향식 사업추진 방식의 핵심 성공요소는 무엇보다도 방산 기업의 기술기획 역량이다. 본 논문은 국내 방산 기업이 기술기획 활동에 활용할 수 있도록 데이터 마이닝 기법을 통해 특허 데이터를 분석하는 방법을 제시하였다. 주요 내용은 군 통신·전자 분야에 해당하는 기업선정 기법을 제안하고 국제특허분류(IPC)에 대해서 주성분 분석과 군집 분석을 수행하는 것이다. 이를 통해, 9개 기업의 특허를 기반으로 군 통신·전자 분야의 기술을 4개의 그룹으로 분류하고 각 그룹의 대표 기업을 도출하였다.