• 제목/요약/키워드: A level-set method

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Seismic Reliability Assessment of Mid- and High-rise Post-tensioned CLT Shear Wall Structures

  • Sun, Xiaofeng;Li, Zheng;He, Minjuan
    • 국제초고층학회논문집
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    • 제9권2호
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    • pp.175-185
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    • 2020
  • Currently, few studies have been conducted to comprehend the seismic reliability of post-tensioned (PT) CLT shear wall structures, due to the complexity of this kind of structural system as well as due to lack of a reliable structural model. In this paper, a set of 4-, 8-, 12-, and 16-storey benchmark PT CLT shear wall structures (PT-CLTstrs) were designed using the direct displacement-based design method, and their calibrated structural models were developed. The seismic reliability of each PT-CLTstr was assessed based on the fragility analysis and based on the response surface method (RSM), respectively. The fragility-based reliability index and the RSM-based reliability index were then compared, for each PT-CLTstr and for each seismic hazard level. Results show that the RSM-based reliabilities are slightly less than the fragility-based reliabilities. Overall, both the RSM and the fragility-based reliability method can be used as efficient approaches for assessing the seismic reliabilities of the PT-CLTstrs. For these studied mid- and high-rise benchmark PT-CLTstrs, following their fragility-based reliabilities, the 8-storey PT-CLTstr is subjected to the least seismic vulnerability; while, following their RSM-based reliabilities, the 4-storey PT-CLTstr is subjected to the least seismic vulnerability

문제제기 전략을 강조한 수업과 학업 성취도와의 관계분석: 방정식을 중심으로 (A study of the effects of problem posing strategies on mathematics achievement.)

  • 전미라;허혜자
    • 대한수학교육학회지:수학교육학연구
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    • 제8권2호
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    • pp.709-722
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    • 1998
  • This thesis is to see if the classes using problem posing is effective to improve the students' grades in math. So I set up research subjects as follow. 1. Do the classes focused on problem posing have any influence on the students' achievement\ulcorner 2. Do the classes focused on problem posing have any different influence on the students' achievement according to their levels\ulcorner 3. Do the classes focused on problem posing have any different influence on the students' achievement according to the categories in math\ulcorner I close four classes in the first grade of K middle school in Kangnung, Kangwon province for this thesis. First I divided them into two groups. Each group consisted of two classes. One is the experimental group. The other is the comparative group. The experimental group was taken classes using problem posing. The comparative group was taken classes by the traditional teaching method. And then I analyzed the difference of the achievement between two groups. As a result of this research, I came to the conclusion as follow. First, the classes focused on problem posing is more effective than traditional teaching method for the improvement of the students` achievement Second, both the classes using problem posing and the traditional teaching method doesn`t affect to the advanced students. Third, the classes using problem posing is more effective to the intermediate students and lower level students than the traditional teaching method. Especially it is very effective in teaching the students the linear equation.

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PESQ-Based Selection of Efficient Partial Encryption Set for Compressed Speech

  • Yang, Hae-Yong;Lee, Kyung-Hoon;Lee, Sang-Han;Ko, Sung-Jea
    • ETRI Journal
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    • 제31권4호
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    • pp.408-418
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    • 2009
  • Adopting an encryption function in voice over Wi-Fi service incurs problems such as additional power consumption and degradation of communication quality. To overcome these problems, a partial encryption (PE) algorithm for compressed speech was recently introduced. However, from the security point of view, the partial encryption sets (PESs) of the conventional PE algorithm still have much room for improvement. This paper proposes a new selection method for finding a smaller PES while maintaining the security level of encrypted speech. The proposed PES selection method employs the perceptual evaluation of the speech quality (PESQ) algorithm to objectively measure the distortion of speech. The proposed method is applied to the ITU-T G.729 speech codec, and content protection capability is verified by a range of tests and a reconstruction attack. The experimental results show that encrypting only 20% of the compressed bitstream is sufficient to effectively hide the entire content of speech.

계층 간 특징 복원-예측 네트워크를 통한 피라미드 특징 압축 (Pyramid Feature Compression with Inter-Level Feature Restoration-Prediction Network)

  • 김민섭;심동규
    • 방송공학회논문지
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    • 제27권3호
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    • pp.283-294
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    • 2022
  • 딥 러닝 네트워크에서 사용되는 특징 맵은 일반적으로 영상보다 데이터가 크며 특징 맵을 전송하기 위해서는 영상의 압축률보다 더 높은 압축률이 요구된다. 본 논문은 딥러닝 기반의 영상처리에서 객체의 크기에 대한 강인성을 가지는 FPN 구조의 네트워크에서 사용되는 피라미드 특징 맵을 높은 압축률로 전송하기 위해 제안한 복원-예측 네트워크를 통해 전송된 일부 계층의 피라미드 특징 맵으로 전송하지 않은 계층의 피라미드 특징 맵을 예측하며, 압축으로 인한 손상을 복원하는 구조를 제안한다. 제안한 방법의 COCO 데이터셋 2017 Train images에 대한 객체 탐지의 성능은 rate-precision 그래프에서 VTM12.0을 통해 특징 맵을 압축한 결과 대비 BD-rate 31.25%의 성능향상을 보였고, PCA와 DeepCABAC을 통한 압축을 수행한 방법 대비 BD-rate 57.79%의 성능향상을 보였다.

은닉 마르코프 모델과 레벨 빌딩을 이용한 한국어 연속 음성 인식 (Recognition of Continuous Spoken Korean Language using HMM and Level Building)

  • 김경현;김상균;김항준
    • 전자공학회논문지C
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    • 제35C권11호
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    • pp.63-75
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    • 1998
  • 한국어 연속 음성에서 발생하는 조음결합문제를 해결하기 위하여 단어를 기본 인식 단위로 사용할 경우 각 단어의 효율적인 표현 방법, 연속된 단어로 이루어진 여러 문장의 표현 방법 그리고 입력된 연속음성을 연속된 여러 단어로의 정합 방법에 관한 연구가 선행되어야 한다. 본 논문에서는 은닉 마르코프 모델과 레벨빌딩 알고리즘을 이용한 한국어 연속 음성 인식 시스템을 제안한다. 각 단어는 은닉 마르코프 모델로 표현하고 문장을 표현하기 위하여 단어 모델을 연결한 형태인 인식 네트워크를 구성한다. 인식네트워크의 탐색 알고리즘으로는 레벨 빌딩 알고리즘을 사용한다. 제안한 방법은 항공기 예약 시스템에 적용한 실험에서 인식율과 인식속도면에서 실용적이었으며 또한 비교적 적은 저장공간으로 전체 문장을 표현하고 쉽게 확장할 수 있다는 장점을 가지고 있다.

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Blackboard Scheduler Control Knowledge for Recursive Heuristic Classification

  • Park, Young-Tack
    • 지능정보연구
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    • 제1권1호
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    • pp.61-72
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    • 1995
  • Dynamic and explicit ordering of strategies is a key process in modeling knowledge-level problem-solving behavior. This paper addressed the important problem of howl to make the scheduler more knowledge-intensive in a way that facilitates the acquisition, integration, and maintenance of the scheduler control knowledge. The solution a, pp.oach described in this paper involved formulating the scheduler task as a heuristic classification problem, and then implementing it as a classification expert system. By doing this, the wide spectrum of known methods of acquiring, refining, and maintaining the knowledge of a classification expert system are a, pp.icable to the scheduler control knowledge. One important innovation of this research is that of recursive heuristic classification : this paper demonstrates that it is possible to formulate and solve a key subcomponent of heuristic classification as heuristic classification problem. Another key innovation is the creation of a method of dynamic heuristic classification : the classification alternatives that are selected among are dynamically generated in real-time and then evidence is gathered for and aginst these alternatives. In contrast, the normal model of heuristic classification is that of structured selection between a set of preenumerated fixed alternatives.

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Solving Mixed Strategy Nash-Cournot Equilibria under Generation and Transmission Constraints in Electricity Market

  • Lee, Kwang-Ho
    • Journal of Electrical Engineering and Technology
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    • 제8권4호
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    • pp.675-685
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    • 2013
  • Generation capacities and transmission line constraints in a competitive electricity market make it troublesome to compute Nash Equilibrium (NE) for analyzing participants' strategic generation quantities. The NE can cause a mixed strategy NE rather than a pure strategy NE resulting in a more complicated computation of NE, especially in a multiplayer game. A two-level hierarchical optimization problem is used to model competition among multiple participants. There are difficulties in using a mathematical programming approach to solve a mixed strategy NE. This paper presents heuristics applied to the mathematical programming method for dealing with the constraints on generation capacities and transmission line flows. A new formulation based on the heuristics is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations.

HMM-Based Transient Identification in Dynamic Process

  • Kwon, Kee-Choon
    • Transactions on Control, Automation and Systems Engineering
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    • 제2권1호
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    • pp.40-46
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    • 2000
  • In this paper, a transient identification based on a Hidden Markov Model (HMM) has been suggested and evaluated experimentally for the classification of transients in the dynamic process. The transient can be identified by its unique time dependent patterns related to the principal variables. The HMM, a double stochastic process, can be applied to transient identification which is a spatial and temporal classification problem under a statistical pattern recognition framework. The HMM is created for each transient from a set of training data by the maximum-likelihood estimation method. The transient identification is determined by calculating which model has the highest probability for the given test data. Several experimental tests have been performed with normalization methods, clustering algorithms, and a number of states in HMM. Several experimental tests have been performed including superimposing random noise, adding systematic error, and untrained transients. The proposed real-time transient identification system has many advantages, however, there are still a lot of problems that should be solved to apply to a real dynamic process. Further efforts are being made to improve the system performance and robustness to demonstrate reliability and accuracy to the required level.

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Genome-wide Response of Normal WI-38 Human Fibroblast Cells to 1,763 MHz Radiofrequency Radiation

  • Im, Chang-Nim;Kim, Eun-Hye;Park, Ae-Kyung;Park, Woong-Yang
    • Genomics & Informatics
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    • 제8권1호
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    • pp.28-33
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    • 2010
  • Increased exposure of human to RF fields has raised concerns for its potential adverse effects on our health. To address the biological effects of RF radiation, we used genome wide gene expression as the indicator. We exposed normal WI-38 human fibroblast cells to 1763 MHz mobile phone RF radiation at a specific absorption rate (SAR) of 60 W/kg with an operating cooling system for 24 h. There were no alterations in cell numbers or morphology after RF exposure. Through microarray analysis, we identified no differentially expressed genes (DEGs) at the 0.05 significance level after controlling for multiple testing errors with the Benjaminiochberg false discovery rate (BH FDR) method. Meanwhile, 82 genes were differentially expressed between RF-exposed cells and controls when the significance level was set at 0.01 without correction for multiple comparisons. We found that 24 genes (0.08% of the total genes examined) were changed by more than 1.5-fold on RF exposure. However, significant enrichment of any gene set or pathway was not observed from the functional annotation analysis. From these results, we did not find any evidence that non-thermal RF radiation at a 60-W/kg SAR significantly affects cell proliferation or gene expression in WI-38 cells.

WMSN에서 QoS 지원을 위한 다중 경로 라우팅 기법 (Multipath Routing Method for QoS Support in WMSNs)

  • 배시영;이성근;박경욱
    • 한국전자통신학회논문지
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    • 제8권3호
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    • pp.453-458
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    • 2013
  • WMSNs에서 에너지 효율적인 사용과 전체 네트워크 수명의 연장 이외에도 물체 추적과 데이터 수집과 같이 실시간 데이터 처리를 위해 QoS지원이 필수적이다. 본 논문에서는 싱크 노드까지의 거리, 노드의 에너지 잔량 및 링크 품질을 고려한 다중 경로 라우팅 알고리즘을 제안한다. 제안한 알고리즘은 높은 품질의 링크로 구성된 다중 경로 설정을 제공함으로써 에너지 소모가 집중되는 현상과 이로 인해 경로가 재구성되는 것을 방지한다. 또한 패킷의 특성을 고려하여 트래픽 패턴에 따라 서비스 품질 패턴과 서비스 품질 레벨을 지정하여 QoS 보장에 대한 서비스 차별화를 지원한다.