• 제목/요약/키워드: Comparative Research

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인터넷에 기반한 내용기반 검색 시스템 설계 (Content-Based Retrieval System Design over the Internet)

  • 김영호;강대성
    • 제어로봇시스템학회논문지
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    • 제11권5호
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    • pp.471-475
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    • 2005
  • Recently, development of digital technology is occupying a large part of multimedia information like character, voice, image, video, etc. Research about video indexing and retrieval progresses especially in research relative to video. This paper proposes the novel notation in order to retrieve MPEG video in the international standards of moving picture encoding For realizing the retrieval-system, we detect DCT DC coefficient, and then we obtain shot to apply MVC(Mean Value Comparative) notation to image constructed DC coefficient. We choose the key frame for start-frame of a shot, and we have the codebook index generating it using feature of DC image and applying PCA(principal Component Analysis) to the key frame. Also, we realize the retrieval-system through similarity after indexing. We could reduce error detection due to distinguish shot from conventional shot detection algorithm. In the mean time, speed of indexing is faster by PCA due to perform it in the compressed domain, and it has an advantage which is to generate codebook due to use statistical features. Finally, we could realize efficient retrieval-system using MVC and PCA to shot detection and indexing which is important step of retrieval-system, and we using retrieval-system over the internet.

25MW급 대용량 멀티레벨 인버터의 시뮬레이션 기반 손실해석과 출력특성 비교 분석 (Simulation based Comparative Loss Analysis and Output Characteristic for 25MW Class of High Power Multi-level Inverters)

  • 김이김;박찬배;백제훈;곽상신
    • 전력전자학회논문지
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    • 제20권4호
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    • pp.337-343
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    • 2015
  • The multi-level inverters are highly efficient for high-power and medium-voltage AC driving applications, such as high-speed railway systems and renewable energy resources, because such inverters generate lower total harmonic distortion (THD) and electromagnetic interface (EMI). Lower switching stress occurs on switching devices compared with conventional two-level inverters. Depending on the multi-level inverter topology, the required components and number of switching devices are different, influencing the overall efficiency. Comparative studies of multi-level inverters based on loss analysis and output characteristic are necessary to apply multi-level inverters in high-power AC conversion systems. This paper proposes a theoretical loss analysis method based on piecewise linearization of characteristic curves of power semiconductor devices as well as loss analysis and output performance comparison of five-level neutral-point clamped, flying capacitor inverters, and high-level cascaded H-bridge multi-level inverters.

3D-QSAR Studies on Angiotensin-Converting Enzyme (ACE)Inhibitors: a Molecular Design in Hypertensive Agents

  • San Juan, Amor A.;Cho, Seung-Joo
    • Bulletin of the Korean Chemical Society
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    • 제26권6호
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    • pp.952-958
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    • 2005
  • Angiotensin-converting enzyme (ACE) is known to be primarily responsible for hypertension. Threedimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA ($q^2$ = 0.530, $r^2$ = 0.998) and CoMSIA ($q^2$ = 0.518, $r^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for better activity against ACE.

QSAR Studies on the Inhibitory Activity of New Methoxyacrylate Analogues against Magnaporthe grisea (Rice Blast Disease)

  • Song, Young-Seob;Sung, Nack-Do;Yu, Yong-Man;Kim, Bum-Tae
    • Bulletin of the Korean Chemical Society
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    • 제25권10호
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    • pp.1513-1520
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    • 2004
  • We investigate a series of synthesized ${\beta}$-methoxyacrylate analogues for their 3D QSAR & HQSAR against Magnaporthe grisea (Rice Blast Disease). We perform the three-dimensional Quantitative Structure-Activity Relationship (3D-QSAR) studies, using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) procedure. In addition, we carry out a two-dimensional Quantitative Structure-Activity Relationship (2D-QSAR) study, using the Hologram QSAR (HQSAR). We perform these studies, using 53 compounds as a training set and 10 compounds as a test set. The predictive QSAR models have conventional $r^2$ values of 0.955 at CoMFA, 0.917 at CoMSIA, and 0.910 at HQSAR respectively; similarly, we obtain cross-validated coefficient $q^2$ values of 0.822 at CoMFA, 0.763 at CoMSIA, and 0.816 at HQSAR, respectively. From these studies, the CoMFA model performs better than the CoMSIA model.

Prospect of plant molecular cytogenetics in the 21st century

  • Mukai, Yasuhiko
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2003년도 제40회 국제학술심포지움
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    • pp.14-27
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    • 2003
  • The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

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거푸집 선정기준에 의한 흙다짐용 거푸집 시스템의 특성 비교분석 (A Comparative Analysis on the Characteristics of Rammed Earth Form System based on Selection Criteria)

  • 이종국;이정제
    • KIEAE Journal
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    • 제7권6호
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    • pp.91-97
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    • 2007
  • This research examines the characteristics of the "rammed earth form" based on the criteria for the selection of forms. For this purpose, the paper first reviews the characteristics and orientation of the earth-construction and looks into the outline, the prerequisite, the current status and the tendency of the rammed earth form system through previous studies. Consequently, we aims to contribute to the criteria for the selection of rammed earth forms in the future through a comparative analysis of the construction cost, quality, safety and easiness of works between the veneer board form and the euroform, which are most widely used at earth housing project in the domestic country. The results reveals that the euroform is better than the veneer board with 21% of total cost in the cost analysis. But this better than that in the side of easiness of construction. In both cases, the buckling of wall panel form and the labor-oriented characteristics of the methods are the future research issues in the rammed earth form system.

국내외 기관별 해상화학사고 대응 교육내용에 관한 비교분석 (A Comparative Analysis on the Education Contents of Domestic and Foreign Training Institutions in Response to Marine Chemical Incidents)

  • 김광수;이문진;박진형
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2017년도 추계학술발표회
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    • pp.165-165
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    • 2017
  • 해상화학사고가 증가함에 따라, 해상에 유출된 화학물질로 인한 피해가 커지기 때문에 해상화학사고 대응요원의 양성이 요구되고 있다. 본 연구에서는 해상화학사고 대응 전문요원 양성을 위한 국내외의 교육훈련 내용을 살펴보고, 국내 HNS사고 대응 교육훈련교재 개발에 활용하기 위하여 교육훈련 내용에 대한 비교분석을 실시하였다.

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Chemical coagulation and sonolysis for total aromatic amines removal from anaerobically pre-treated textile wastewater: A comparative study

  • Verma, Akshaya K.;Bhunia, Puspendu;Dash, Rajesh R.
    • Advances in environmental research
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    • 제3권4호
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    • pp.293-306
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    • 2014
  • The present study primarily focuses on the evaluation of the comparative effect of chemical coagulation and ultrasonication for elimination of aromatic amines (AAs) present in anaerobically pretreated textile wastewater containing different types of dyes including azo dyes. Color and COD reduction was also monitored at the optimized conditions. The production of AAs was measured spectrophotometrically in the form of total aromatic amines (TAAs) and also verified with high performance liquid chromatography (HPLC) selectively. A composite coagulant, magnesium chloride (MC) aided with aluminium chlorohydrate (ACH) in an equal ratio (MC + ACH) was utilized during the coagulation process, which yielded 31% of TAAs removal along with 85% of color and 52% of COD reduction. At optimized power (200 W) and sonication time (5 h), an appreciable TAAs degradation efficiency (85%) was observed along with 51% color reduction and 62% COD removal using ultrasonication. The chromatographic data indicate that sulphanilic acid and benzidine types of aromatic amines were produced after the reductive cleavage of utilized textile dyes, which were effectively mineralized after ultrasonication. The degradation followed the first order kinetics with a correlation coefficient ($R^2$) of 0.89 and a first-order kinetic constant (k) of $0.0073min^{-1}$.

소집단 탐구기법을 활용한 '지구와 달의 운동' 단원 수업이 과학학업성취도 및 과학적 태도에 미치는 효과 (The Effects of Science Academic Achievement and Scientific Attitudes on 'The Earth and Moon' Using Small Inquiry Method)

  • 이용섭;김윤경
    • 대한지구과학교육학회지
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    • 제9권1호
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    • pp.88-96
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    • 2016
  • The purpose of this study is to examine the effects of Jigsaw small inquiry method on science academic achievement and scientific attitudes. For this study, two classes of six graders were divided into a research group and a comparative group. The classes were pre-tested in order to ensure the same standard. The research group had the science class with Jigsaw small inquiry method, and the comparative group had the class with a teacher centered lectures for 12 classes for 12 weeks. The Jigsaw small inquiry method was focused on the introduction stage, the whole group activities, professional group activities, restart the whole group activities, supplementary structured study guide, results announced, and excellent group rewards. To prove the effects of this study, science learning motivation was split up based on the attention power, relation, confidence, and sense of satisfaction. The results of this study are as follows. First, Jigsaw small inquiry method is effective in science academic achievement. Second, Jigsaw small inquiry method is effective in scientific attitudes. Also, Jigsaw small inquiry method was approved by students. Consequently, Jigsaw small inquiry method had the great effects on developing science academic achievement for the elementary science class. That means the science class with Jigsaw small inquiry method has potential to develop science academic achievement and scientific attitudes.

ddY 마우스를 이용한 골다공증 모델에 대한 비교연구: 난소적출 및 신경절단 모델 (A comparative study on the osteoporotic animal models in ddY mouse: ovariectomized and neurectomized models)

  • 이형식;홍표원;구세광;이재현;함태수
    • 대한수의학회지
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    • 제44권4호
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    • pp.487-495
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    • 2004
  • In order to compare the induced time of osteoporosis between ovariectomized and neurectomized models in ddY mice. Experimental groups were divided into Sham, ovariectomized (OVX group) and neurectomized (NX group) group. The changes of body weight, tibia weight and histomorphometry of epiphyseal regions of tibia that were generally used as criteria index in osteoporosis, were evaluated at 2 and 4 weeks after operations with other generally used index-changes of serum osteocalcin. Also, calcium and phosphorus levels in the ash tibia were demonstrated with their ratio (Ca/P ratio). From the result of this study, evidences which reflect osteoporotic states of animals such as decrease of absolute and relative tibia weight, histomorphometrical index of epiphyseal region of tibia including trabecular bone volume %, and calcium and phosphorous contents in tibia, were generally detected from 4 weeks after ovariectomy and 2 weeks after neurectomy with increase of serum osteocalcin levels. In conclusion, it is considered that more rapid and favorable osteoporosis was induced in neurectomized model compared to that of ovariectomized model.