• Title/Summary/Keyword: prior studies

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Obtaining 3-dimensional shape of hybrid reflectance surfaces using indirect diffuse illumination (간접 확산 조명을 이용한 혼성반사 표면의 3차원 형상 취득)

  • 김태은;안호근;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.301-312
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    • 1996
  • A new approach is presented for recovering the 3-D shape from shading image. Photometric Stereo Method (PSM) is generally based on the direct illumination. In this paper, the reflectance function is derived by introduceing the indirect diffuse illumination in PSM and then applied to hybrid reflectance model which consists fo two components; the Lambertian reflectance and the speclar reflectance. Under the hybrid reflectance model and the indirect diffuse illumination circumstances, the 3-D shape of object can be recovered from the suface normal vector extracted from the surface roughness, the surface reflectance ratio, and the intensity value of a pixel. This method is rapid because of using the reference table and simplifies the restriction condition about the reflectance function existing in prior studies. The recovery efficiency in our method is better than that in prior studies. Also, this method is applied to various types of surfaces by defining general reflectance function.

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Ammunition Allocation Model using an Interactive Multi-objective Optimization(MOO) Method (상호작용 다목적 최적화 방법론을 이용한 전시 탄약 할당 모형)

  • Jeong, Min-Seop;Park, Myeong-Seop
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.513-524
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    • 2006
  • The ammunition allocation problem is a Multi-objective optimization(MOO) problem, maximizing fill-rate of multiple user troops and minimizing transportation time. Recent studies attempted to solve this problem by the prior preference articulation approach such as goal programming. They require that all the preference information of decision makers(DM) should be extracted prior to solving the problem. However, the prior preference information is difficult to implement properly in a rapidly changing state of war. Moreover they have some limitations such as heavy cognitive effort required to DM. This paper proposes a new ammunition allocation model based on more reasonable assumptions and uses an interactive MOO method to the ammunition allocation problem to overcome the limitations mentioned above. In particular, this article uses the GDF procedure, one of the well-known interactive optimization methods in the MOO liter-ature, in solving the ammunition allocation problem.

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Bayesian Methods for Generalized Linear Models

  • Paul E. Green;Kim, Dae-Hak
    • Communications for Statistical Applications and Methods
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    • v.6 no.2
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    • pp.523-532
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    • 1999
  • Generalized linear models have various applications for data arising from many kinds of statistical studies. Although the response variable is generally assumed to be generated from a wide class of probability distributions we focus on count data that are most often analyzed using binomial models for proportions or poisson models for rates. The methods and results presented here also apply to many other categorical data models in general due to the relationship between multinomial and poisson sampling. The novelty of the approach suggested here is that all conditional distribution s can be specified directly so that staraightforward Gibbs sampling is possible. The prior distribution consists of two stages. We rely on a normal nonconjugate prior at the first stage and a vague prior for hyperparameters at the second stage. The methods are demonstrated with an illustrative example using data collected by Rosenkranz and raftery(1994) concerning the number of hospital admissions due to back pain in Washington state.

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Adaptive Algorithm in Image Reconstruction Based on Information Geometry

  • Wang, Meng;Ning, Zhen Hu;Yu, Jing;Xiao, Chuang Bai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.2
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    • pp.461-484
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    • 2021
  • Compressed sensing in image reconstruction has attracted attention and many studies are proposed. As we know, adding prior knowledge about the distribution of the support on the original signal to CS can improve the quality of reconstruction. However, it is still difficult for a recovery framework adjusts its strategy for exploiting the prior knowledge efficiently according to the current estimated signals in serial iterations. With the theory of information geometry, we propose an adaptive strategy based on the current estimated signal in each iteration of the recovery. We also improve the performance of existing algorithms through the adaptive strategy for exploiting the prior knowledge according to the current estimated signal. Simulations are presented to validate the results. In the end, we also show the application of the model in the image.

Block Sparse Signals Recovery Algorithm for Distributed Compressed Sensing Reconstruction

  • Chen, Xingyi;Zhang, Yujie;Qi, Rui
    • Journal of Information Processing Systems
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    • v.15 no.2
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    • pp.410-421
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    • 2019
  • Distributed compressed sensing (DCS) states that we can recover the sparse signals from very few linear measurements. Various studies about DCS have been carried out recently. In many practical applications, there is no prior information except for standard sparsity on signals. The typical example is the sparse signals have block-sparse structures whose non-zero coefficients occurring in clusters, while the cluster pattern is usually unavailable as the prior information. To discuss this issue, a new algorithm, called backtracking-based adaptive orthogonal matching pursuit for block distributed compressed sensing (DCSBBAOMP), is proposed. In contrast to existing block methods which consider the single-channel signal reconstruction, the DCSBBAOMP resorts to the multi-channel signals reconstruction. Moreover, this algorithm is an iterative approach, which consists of forward selection and backward removal stages in each iteration. An advantage of this method is that perfect reconstruction performance can be achieved without prior information on the block-sparsity structure. Numerical experiments are provided to illustrate the desirable performance of the proposed method.

Meta-Analysis of AIDS Prevention Programs

  • Kim, Yeon-Hee
    • Korean Journal of Health Education and Promotion
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    • v.3 no.1
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    • pp.129-142
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    • 2001
  • Meta-analysis methods are becoming a central part of research integration in behavioral and medical science studies. The main goal of the meta-analysis is combining the quantitative findings from several studies which address the same research problem and is sharing conclusions in a published report. The purpose of this research is to develop meta-analysis approach to evaluate effectiveness of instructional program design to improve school-age children's knowledge and understanding of Acquired Immune Deficiency Syndrome (AIDS). To achieve this purpose, meta-analysis is applied to analyze and synthesize findings for AIDS instructional programs from several prior studies.

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A study on the Influence of Consumer Behavior on the Brand Image (브랜드이미지가 소비자의 행동에 미치는 영향에 관한 연구)

  • Kim, Se-Hwan;Kim, Jong-Wan
    • Journal of Industrial Convergence
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    • v.6 no.2
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    • pp.29-42
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    • 2008
  • The prior studies for consumer-brand relationships vested brands with personalities after had personified them. In these studies, a brand become the object of consumer's attitude, and former researchers investigated the types and styles of consumer-brand relationships based on this theory. However, I though that these studies did not follow the original concept of 'relationship' for they approached consumer as the subject and a brand as the object.

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An Empirical Comparative Study on Evaluation of Bi-national Product: Focused on Purchasing Routes, Product Category, and Consumer Characteristics (복합원산지제품 평가에 관한 실증적 비교연구: 제품구입경로, 제품카테고리, 소비자 특성을 중심으로)

  • Son, Je-Young;Kang, In-Won
    • Korea Trade Review
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    • v.43 no.5
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    • pp.67-91
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    • 2018
  • A number of studies have been conducted on the evaluation of bi-national products, but studies that may be applied in practice are lacking. This study suggests several implications for bi-national products in the sub-market using a more specific approach than previous studies. To this end, this comprehensive comparative study reflects the purchasing routes, product category, and consumers' personal characteristics (regulatory focus, prior knowledge) of bi-national products. Results found the evaluation of bi-national products according to purchase routes showed that consumers in offline stores were more favorable than consumers in online stores. In comparison with product categories, necessities were more positive than luxury goods. On the other hand, according to consumer's personal characteristics, consumers with promotion focus tendency perceived brand preference more highly than consumers with preference focus tendency. Also, it was found that groups with high prior knowledge had a positive evaluation of products compared to low knowledge groups.

Prior Use of 3-Hydroxy-3-Methyl-Glutaryl-Coenzyme A Reductase Inhibitor, Simvastatin Fails to Improve Outcome after Experimental Intracerebral Hemorrhage

  • Jwa, Cheol-Su;Yi, Hyeong-Joong;Oh, Suck-Jun;Hwang, Se-Jin
    • Journal of Korean Neurosurgical Society
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    • v.50 no.5
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    • pp.403-408
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    • 2011
  • Objective : Contrary to some clinical belief, there were quite a few studies regarding animal models of intracerebral hemorrhage (ICH) $in$ $vivo$ suggesting that prior use of statins may improve outcome after ICH. This study reports the effect of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibitor, simvastatin given before experimental ICH. Methods : Fifty-one rats were subjected to collagenase-induced ICH, subdivided in 3 groups according to simvastatin treatment modality, and behavioral tests were done. Hematoma volume, brain water content and hemispheric atrophy were analyzed. Immunohistochemical staining for microglia (OX-42) and endothelial nitric oxide synthase (eNOS) was performed and caspase-3 activity was also measured. Results : Pre-simvastatin therapy decreased inflammatory reaction and perihematomal cell death, but resulted in no significant reduction of brain edema and no eNOS expression in the perihematomal region. Finally, prior use of simvastatin showed less significant improvement of neurological outcome after experimental ICH when compared to post-simvastatin therapy. Conclusion : The present study suggests that statins therapy after ICH improves neurological outcome, but prior use of statins before ICH might provide only histological improvement, providing no significant impact on neurological outcome against ICH.

A Study on the Calculation of Nonpoint Source EMCs using SWMM in Transportation Area (강우유출모형을 활용한 교통지역 비점오염원 EMCs 산정 연구)

  • Kwon, Heongak;Im, Toehyo;Lee, Jaewoon;Jeong, Hyungi;Lee, Chunsik;Cheon, Seuk
    • Journal of Wetlands Research
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    • v.17 no.2
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    • pp.193-202
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    • 2015
  • In this study, a long term monitering of nonpoint source pollution runoff is conducted at the area of transportation related and EMCs(Event Mean Concentrations) in terms of water quality items, such as BOD, $COD_{Mn}$, SS, T-N and T-P are determined for each not only runoff event and but also observation site. On the other hands, SWMM(Storm Water Management Model) model is constructed using the data collected in the transportation areas selected. Model calibration and verification of SWMM is carried out based on the data collected. And simulated EMCs was compared with observed EMCs by monitoring and prior studies. SWMM applicability estimation was Using the compared result. The results of simulation showed that BOD 5.787 ~ 14.475 mg/L, $COD_{Mn}$ 12.946 ~ 59.611 mg/L, SS 13.742 ~ 46.208 mg/L, T-N 2.037 ~ 5.213 mg/L, T-P 0.117 ~ 0.415 mg/L. And a differential between simulated EMCs and observed EMCs is too low so comparing result show high fit(BOD 4.27 %, $COD_{Mn}$ 4.87%, SS 2.31%, T-N 5.78%, T-P 14.45%). A results of compared with the prior studies, BOD and T-P are included range of prior studies, $COD_{Mn}$ and SS are lower than range of prior studies, T-N is higher than range of prior studies. Differential between simulated EMCs and prior studies EMCs was showing for survey seasonal and changing land-use, so from now on, EMCs of using the internal representatives value will be calculated by more monitoring toward various precipitation events.