• Title/Summary/Keyword: A level-set method

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A Development and Application of the Checklist for Evaluating Software Usability (소프트웨어 사용성 평가를 위한 체크리스트의 개발과 적용)

  • 진영택;하수정
    • The Journal of Society for e-Business Studies
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    • v.6 no.2
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    • pp.73-85
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    • 2001
  • Usability is defined by the effectiveness, efficiency and satisfaction with which specified users can achieve specified goal in particular environment. Today, many factors such as software acquisition, business re-engineering and the trend of software market have software industry considers usability as an important quality of software products. Therefore, the specification and measurement method for establishing the acceptable usability level of software is required during software development acquisition and evaluation. To evaluate whether software products is usable or not, we need evaluation method for software usability. This paper is not only to provide a framework for specifying the usability attributes of a product and establishing a comprehensive set of usability criteria, but also assessing usability metrics of the software. The usability metrics and checklist is developed based on the properties of the user interface using ISO standard and general usability principles with product-oriented view which means the Product has attributes contributing to determine the usability. This paper also suggested the way to weight the relative importance of the individual usability item depending on the software categories.

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A Contrastive Learning Framework for Weakly Supervised Video Anomaly Detection

  • Hyeon Jeong Park;Je Hyeong Hong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2022.11a
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    • pp.171-174
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    • 2022
  • Weakly-supervised learning is a widely adopted approach in video anomaly detection whereby only video labels are utilized instead of expensive frame-level annotations. Since the success of multi-instance learning (MIL), almost all recent approaches are based on maximizing the margin between the set of abnormal video snippets and those of normal video snippets. In this work, we present a simple contrastive approach for weakly supervised video anomaly detection (WS-VAD) with aims to enhance the performance of existing models. The method is generic in nature and introduces a loss function to encourage attraction of output features from the same video class and repel those from different video classes. Experimental results demonstrate our method can be applied to existing algorithms to improve detection accuracy in public video anomaly dataset.

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Molecular authentication of Lepidii seu Descurainiae Semen by the development of matK amplification primers and analysis of sequences (matK 증폭용 primer 개발 및 염기서열 분석을 통한 정력자(葶藶子) 유전자 감별)

  • Moon, Byeong Cheol;Kim, Wook Jin;Yang, Sungyu;Park, Inkyu;Yeo, Sang Min;Noh, Pureum
    • The Korea Journal of Herbology
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    • v.33 no.3
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    • pp.25-35
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    • 2018
  • Objectives : Lepidii seu Descurainiae Semen has been frequently adulterated with the seeds of several inauthentic plant species. However, the accurate identification of these plant seeds is very difficult. To develop a reliable genetic authentication tool for Lepidii seu Descurainiae Semen, we analyzed matK sequence. Methods : To obtain the matK sequences of plant materials, genomic DNA was extracted from 24 samples and PCR amplification was carried out using matK-AF/matK-8R universal primer set and matK-LDSF/matK-LDSR primer set. For identifying species-specific nucleotides and phylogenetic analysis, matK regions were sequenced and comparatively analyzed by the ClustalW and Maximum Likelihood method. Results : We developed a new primer set to amplify matK region in Lepidii seu Descurainiae Semen and closely related plant samples. From the comparative analysis of matK sequences, we identified species-specific marker nucleotides for D. sophia, L. apetalum, L. latifolium, E. cheiranthoides, E. macilentum, and D. nemorosa, respectively. Furthermore, phylogenetic analysis revealed clear classification depending on the species. These results indicated that the matK sequence obtained a new primer set in this study was useful to identify Lepidii seu Descurainiae Semen in species level. Conclusions : We developed a primer set and identified species-specific marker nucleotides enough to distinguish authentic Lepidii seu Descurainiae Semen and adulterants at the species level based on the matK sequences. These genetic tool will be useful to prevent adulteration and to standardize the quality of Lepidii seu Descurainiae Semen.

Bilayer Segmentation of Consistent Scene Images by Propagation of Multi-level Cues with Adaptive Confidence (다중 단계 신호의 적응적 전파를 통한 동일 장면 영상의 이원 영역화)

  • Lee, Soo-Chahn;Yun, Il-Dong;Lee, Sang-Uk
    • Journal of Broadcast Engineering
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    • v.14 no.4
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    • pp.450-462
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    • 2009
  • So far, many methods for segmenting single images or video have been proposed, but few methods have dealt with multiple images with analogous content. These images, which we term consistent scene images, include concurrent images of a scene and gathered images of a similar foreground, and may be collectively utilized to describe a scene or as input images for multi-view stereo. In this paper, we present a method to segment these images with minimum user input, specifically, manual segmentation of one image, by iteratively propagating information via multi-level cues with adaptive confidence depending on the nature of the images. Propagated cues are used as the bases to compute multi-level potentials in an MRF framework, and segmentation is done by energy minimization. Both cues and potentials are classified as low-, mid-, and high- levels based on whether they pertain to pixels, patches, and shapes. A major aspect of our approach is utilizing mid-level cues to compute low- and mid- level potentials, and high-level cues to compute low-, mid-, and high- level potentials, thereby making use of inherent information. Through this process, the proposed method attempts to maximize the amount of both extracted and utilized information in order to maximize the consistency of the segmentation. We demonstrate the effectiveness of the proposed method on several sets of consistent scene images and provide a comparison with results based only on mid-level cues [1].

컴퓨터 탐색을 이용한 재고관리 시스템의 최적화

  • 윤승철
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.477-480
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    • 1996
  • The main objective of this research is to develop the optimal control method for a Distribution Center - multi Branch inventory distribution system. With the continuous review policy, the distribution center places an order for specific order quantity to an outside supplier, and the order quantity is replenished after a certain lead time. Also, each branch places an order for particular order quantity to the distribution center to satisfy the customer demands, and receives the replenishment after a lead time. When an out of stock condition occurs during an order cycle, a backorder is placed to the upper level to fill the unfilled demands. With these situation, variable demand and variable lead time are used for better industrial practice. Futher, actual lead times with a generic lead time distribution are used in developing the control model. Under the actual lead time model, the customer service measures actually attained for the distribution center and each branch are explained as the effective customer service measures. Thus, throughout the optimal control (using computer search procedures), we can set the desired service levels for the distribution center and each branch to produce the effective service level for each branch which is consistent with the goal level of service for each branch. At the same time, the entire distribution system keeps minimum inventories.

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A Survey of the Harmonics Level on a Typical Household Loads by Field Measurements (현장 측정에 의한 일반 가정집 부하의 고조파 수준 조사)

  • Kim, Kyung-Chul;Oh, Kyung-Hoon;Choi, Hyoung-Bumb;Hong, Sa-Guen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.95-102
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    • 2008
  • Typical household loads have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads for one year period and the survey is conducted with the objectives to identify the trends of harmonic distortion level present and indentify the future trends of metering in the presence of nonsinusoidal current and voltage waveforms in the system.

An Assessment of Elastic and Damping Material Properties of PVC/MBS by an Acoustic Resonance Method (음향공진법을 이용한 PVC/MBS의 탄성 및 감쇠 특성 평가)

  • 박명균;박세만;최영식;박상규
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.10
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    • pp.766-772
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    • 2002
  • In this investigation, experimental attempts were made to observe and determine the variations in elastic and damping properties of the PVC depending on the amounts of MBS added to the mixture, PVC/MBS, and also on the thicknesses of the specimens. An acoustic resonance technique was used for the tests In this investigation. It serves as a method to characterize properties of materials set in vibrational motions, which is initiated by low level stresses generated by externally supplied acoustic energy. Substantial variations were observed in the test results with the addition of the MBS to the PVC. It was found that the magnitudes of elastic constants decrease while the damping capacity improve when MBS rubber was added in the range up to 9 phr.

Optimum Design of Rotor System Considering Fuzzy Constraints (퍼지 구속조건을 고려한 회전축계의 최적설계)

  • 양보석;공영모
    • Journal of Advanced Marine Engineering and Technology
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    • v.16 no.5
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    • pp.39-49
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    • 1992
  • The dynamic design object of rotor system is to optimize the system in stability at the operating speed, unbalance response in the vicinity of the rotor critical speed, bearing weighting and system weighting. In conventional optimization method, designers have to set mathematical modeling, such as objective function, constraints and design parameters, strictly and quantitavely. But in actual design process, they do not treat all of these values strictly and some of them are somehow "fuzziness". So, considering boundary conditions of seal diameter, clearance, and length in a typical double suction centrifugal pump is fuzzy, this paper is considered fuzzy in constraints. Fuzzy method is used .alpha.-level cut method. Then, the optimum dimensions of seal according to values are obtained and vibration characteristics are investigated.estigated.

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Wavelet-Based Variable Block Size Fractal Image Coding (웨이브렛 기반 가변 블록 크기 플랙탈 영상 부호화)

  • 문영숙;전병민
    • Journal of Broadcast Engineering
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    • v.4 no.2
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    • pp.127-133
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    • 1999
  • The conventional fractal image compression based on discrete wavelet transform uses the fixed block size in fractal coding and reduces PSNR at low bit rate. This paper proposes a fractal image coding based on discrete wavelet transform which improves PSNR by using variable block size in fractal coding. In the proposed method. the absolute values of discrete wavelet transform coefficients are computed. and the discrete wavelet transform coefficients of different highpass subbands corresponding to the same spatial block are assembled. and the fractal code for the range block of each range block level is assigned. and then a decision tree C. the set of choices among fractal coding. "0" encoding. and scalar quantization is generated and a set of scalar quantizers q is chosen. And then the wavelet coefficients. fractal codes. and the choice items in the decision tree are entropy coded by using an adaptive arithmetic coder. This proposed method improved PSNR at low bit rate and could achieve a blockless reconstructed image. As the results of experiment. the proposed method obtained better PSNR and higher compression ratio than the conventional fractal coding method and wavelet transform coding.rm coding.

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A displacement-based seismic design method with damage control for RC buildings

  • Ayala, A. Gustavo;Castellanos, Hugo;Lopez, Saul
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.413-434
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    • 2012
  • This paper presents a displacement-based seismic design method with damage control, in which the targets for the considered performance level are set as displacements and a damage distribution is proposed by the designer. The method is based on concepts of basic structural dynamics and of a reference single degree of freedom system associated to the fundamental mode with a bilinear behaviour. Based on the characteristics of this behaviour curve and on the requirements of modal spectral analysis, the stiffness and strength of the structural elements of the structure satisfying the target design displacement are calculated. The formulation of this method is presented together with the formulations of two other existing methods currently considered of practical interest. To illustrate the application of the proposed method, 5 reinforced concrete plane frames: 8, 17 and 25 storey regular, and 8 and 12 storey irregular in elevation. All frames are designed for a seismic demand defined by single earthquake record in order to compare the performances and damage distributions used as design targets with the corresponding results of the nonlinear step by step analyses of the designed structures subjected to the same seismic demand. The performances and damage distributions calculated with these analyses show a good agreement with those postulated as targets.