• 정보처리학회논문지D
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• 제10D권4호
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• pp.567-576
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• 2003

대용량의 공간데이터베이스로부터 암시적이고 유용한 지식을 자동적으로 추출하는 공간데이터 마이닝은 데이타 양이 급격히 증가하면서 필요성이 더욱 증대되고 있다. 공간데이터 마이닝에서 데이타를 분석하여 유사한 그룹으로 분류하는 공간 클러스터링은 매우 중요한 분야이다. 기존 연구에서 공간 클러스터링을 위한 여러 가지 알고리즘들이 제시되었지만, 다음과 같은 문제점들이 있다. 먼저 클러스터링을 위하여 객체들 간의 거리론 기반으로 하므로 데이타 양이 많아질수록 계산 비용이 커진다. 또한, 메모리 상주 데이타를 대상으로 하므로 대용량의 데이타인 경우에 효율이 떨어진다. 본 논문에서는 공간데이터 마이닝을 위하여 그리드 셀을 기반으로 한 효율적인 공간 클러스터링 방법을 제시한다. 이 클러스터링에서는 기존 공간 클러스터링 기법들의 문제점을 해결하는데 중점을 둔다. 세부적으로 공간 클러스터링의 효율성을 높이기 위하여 클러스터링시에 발생하는 비용(계산량)을 감소시키는 것이다. 이를 위해서 공간지역성을 보장하는 대표적인 공간분할 방법인 그리드 셀을 기반으로 한 공간 클러스터링 기법을 제시한다.

• 정보처리학회논문지C
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• 제14C권2호
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• pp.191-198
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• 2007

이동성을 가진 다수의 노드들로 구성된 MANET (Mobile Ad-hoc Networks)에서는 네트워크 토폴로지의 빈번한 변화에 효과적으로 대응할 수 있는 요구기반 (On Demand) 방식의 라우팅 프로토콜이 주로 사용된다. 대표적인 요구기반 라우팅 프로토콜인 AODV (Ad-hoc On demand Distance Vector)는 데이터 전송을 위하여 경로의 다음노드 (Next Hop)가 기록된 각 노드의 경로테이블을 기반으로 운영되며 선정된 경로는 유효기간이 만료되거나 경로단절이 발생되지 않을 경우에 그대로 유지된다. 본 연구에서는 AODV를 기반으로 설정된 경로의 2홉 범위 내에서 동적 경로변경을 제공하는 부분적응형 경로유지 기법 (AODV PA)을 제안한다. 제안된 기법은 경로탐색 과정에서 경로의 다음노드 뿐 아니라 다음노드의 다음노드 (즉, 2홉 다음노드) 정보를 취득하여 상황에 따라 보다 효율적인 경로를 선택할 수 있도록 하며 이러한 경로변경으로 인한 예기치 못한 경로단절 발생을 막기 위하여 HELLO 메시지를 통한 부가적인 경로테이블 관리를 수행한다. NS 2를 이용한 시뮬레이션 결과는 제안된 기법이 기존의 AODV 보다 패킷 전달비율, 지연시간, 라우팅부하 측면에서 향상된 성능을 제공함을 보여준다.

• 대한한의학방제학회지
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• 제28권4호
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• pp.313-325
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• 2020

Objectives : To explore the associated potential pathways and molecular targets of Hwangryunhaedok-tang(HHT) by the approaches of network pharmacology and bioinformatics in traditional chinese medicine(TCM). Methods : Hwangryunhaedok-tang constituent drugs(Coptidis Rhizoma, CR; Scutellariae Radix, SR; Phellodendri Cortex, PC; Gardeniae Fructus, GF) and their processing types were searched from TCM systems pharmacology(TCMSP). The databases of TCMSP, Kyoto Encyclopedia of Genes and Genomes(KEGG), MCODE and STRING were used to gather information. The network of bioactive ingredients and target gene was constructed by Cytoscape software(version 3.8). Results : A total of 94 HHT active compounds(CR, 12; SR, 35; PC, 33; GF, 14, respectively) were found, and HHT were identified by TCMSP. Applications of KEGG and MCODE analysis indicates that total of 6 bioactive ingredients in the top 10% ranking were obtained and 32 diseases of HHT were screened. The molecular pathway analysis revealed that HHT exerts cancer, inflammation and cerebrovascular diseases effects by acting on several signaling pathway. In addition, HHT found that three genes(e.g. SPIN1, TRIM25, and APP) correlate with the aforementioned diseases. Conclusions : This study showed that network pharmacology analysis is useful to elucidate the complex mechanisms of action of HHT.

• Interdisciplinary Bio Central
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• 제2권3호
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• pp.8.1-8.5
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• 2010

Introduction: Recently identified human homologues of ALKB protein have shown the activity of DNA damaging drugs, used for cancer therapy. Bioinformatics study of hABH2 and hABH3 had led to the discovery of a novel DNA repair mechanism. Very little is known about structure and function of hABH4, one of the members of this superfamily. Therefore, in present study we are intended to predict its structure and function through various bioinformatics tools. Materials and Methods: Modeling was done with modeler 9v7 to predict the 3D structure of the hABH4 protein. This model was validated with the program Procheck using Ramachandran plot statistics and was submitted to PMDB with ID PM0076284. The 3d2GO server was used to predict the functions. Residues at protein ligand and protein RNA binding sites were predicted with 3dLigandSite and KYG programs respectively. Results and Discussion: 3-D model of hABH4, ALKBH4.B99990003.pdb was predicted and evaluated. Validation result showed that 96.4 % residues lies in favored and additional allowed region of Ramachandran plot. Ligand binding residues prediction showed four Ligand clusters, having 24 ligands in cluster 1. Importantly, conserved pattern of Glu196-X-Pro198- Xn-His254 in the functional domain was detected. DNA and RNA binding sites were also predicted in the model. Conclusion and Prospects: The predicted and validated model of human homologue hABH4 resulted from this study may unveil the mechanism of DNA damage repair in human and accelerate the research on designing of appropriate inhibitors aiding in chemotherapy and cancer related diseases.

• 정보관리학회지
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• 제33권4호
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• pp.245-267
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• 2016

국제 기록관리자 및 행정가협회(ARMA International)는 기록정보관리 원칙에 대한 교육과 출판을 주도하고 있는 국제기관으로 그 관심사와 활동을 살펴보는 것은 해당분야의 이슈와 고민을 읽을 수 있는 기회를 제공해 준다. 이에 본 연구에서는 해당 협회의 기관지인 Information Management에서 다루고 있는 주제들을 분석함으로써 기록정보관리 분야의 주요 관심사와 이슈의 특징과 동향을 파악하고자 하였다. 또한 다루어진 주제 중 주목할 필요가 있는 정보거버넌스, 이디스커버리, 전자의료기록, 클라우드에 대해서 그 개념을 좀 더 심도 있게 짚어보고 우리나라의 현황과 비교함으로써 향후과제를 도출하고자 하였다. 민간분야 기록정보관리의 필요성이 설득력 있게 제시되지 못하고 있는 우리나라의 현실에서 이러한 해외의 경험과 사례들은 분명한 시사점을 제공할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.926-935
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• 2015

The efficiency of genome-wide association analysis (GWAS) depends on power of detection for quantitative trait loci (QTL) and precision for QTL mapping. In this study, three different strategies for GWAS were applied to detect QTL for carcass quality traits in the Korean cattle, Hanwoo; a linkage disequilibrium single locus regression method (LDRM), a combined linkage and linkage disequilibrium analysis (LDLA) and a $BayesC{\pi}$ approach. The phenotypes of 486 steers were collected for weaning weight (WWT), yearling weight (YWT), carcass weight (CWT), backfat thickness (BFT), longissimus dorsi muscle area, and marbling score (Marb). Also the genotype data for the steers and their sires were scored with the Illumina bovine 50K single nucleotide polymorphism (SNP) chips. For the two former GWAS methods, threshold values were set at false discovery rate <0.01 on a chromosome-wide level, while a cut-off threshold value was set in the latter model, such that the top five windows, each of which comprised 10 adjacent SNPs, were chosen with significant variation for the phenotype. Four major additive QTL from these three methods had high concordance found in 64.1 to 64.9Mb for Bos taurus autosome (BTA) 7 for WWT, 24.3 to 25.4Mb for BTA14 for CWT, 0.5 to 1.5Mb for BTA6 for BFT and 26.3 to 33.4Mb for BTA29 for BFT. Several candidate genes (i.e. glutamate receptor, ionotropic, ampa 1 [GRIA1], family with sequence similarity 110, member B [FAM110B], and thymocyte selection-associated high mobility group box [TOX]) may be identified close to these QTL. Our result suggests that the use of different linkage disequilibrium mapping approaches can provide more reliable chromosome regions to further pinpoint DNA makers or causative genes in these regions.

• Applied Biological Chemistry
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• 제25권4호
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• pp.224-231
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• 1982

liposome에 결합되어 있는 ${\alpha}-Tocopherol$의 형광을 이용하여 liposome의 상전이온도를 측정할 수 있었다. 이는 ${\alpha}-Tocopherol$의 vitamin E로서의 중요성 이외에 형광성 프로브로서의 새로운 가치의 발견이다. 형광성 프로브로서 그 응용의 확대를 위한 필수적인 기초자료의 수집을 위해, 분자분광학적성질을 조사하였다. 용액중의 ${\alpha}-Tocopherol$은 monomer와 dimer의 두가지 형태로 존재하며, 단파장흡수대$(291{\sim}294nm)$의 monomer는 형광성인데 반하여 dimer는 298nm 부근을 흡수하는 비형광성이고 분자간수소결합에 의하여 형성되었음이 밝혀졌다. liposome에 결합된 ${\alpha}-Tocopherol$은 각종 유기용매 중에서의 ${\alpha}-Tocopherol$과는 판이한 형광성질을 갖고 있었고 chromanolate이온형태의 화학종으로부터 생긴 것으로 해석되었다.

• Journal of Communications and Networks
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• 제14권4호
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• pp.434-442
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• 2012

Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with themaximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.

• 천문학회지
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• 제48권1호
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• pp.21-55
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• 2015

If the Universe is dominated by cold dark matter and dark energy as in the currently popular ${\Lambda}CDM$ cosmology, it is expected that large scale structures form gradually, with galaxy clusters of mass $M{\geq}10^{14}M_{\odot}$ appearing at around 6 Gyrs after the Big Bang (z ~ 1). Here, we report the discovery of 59 massive structures of galaxies with masses greater than a few times $10^{13}M_{\odot}$ at redshifts between z = 0.6 and 4.5 in the Great Observatories Origins Deep Survey fields. The massive structures are identified by running top-hat filters on the two dimensional spatial distribution of magnitude-limited samples of galaxies using a combination of spectroscopic and photometric redshifts. We analyze the Millennium simulation data in a similar way to the analysis of the observational data in order to test the ${\Lambda}CDM$ cosmology. We find that there are too many massive structures (M > $7{\times}10^{13}M_{\odot}$) observed at z > 2 in comparison with the simulation predictions by a factor of a few, giving a probability of < 1/2500 of the observed data being consistent with the simulation. Our result suggests that massive structures have emerged early, but the reason for the discrepancy with the simulation is unclear. It could be due to the limitation of the simulation such as the lack of key, unrecognized ingredients (strong non-Gaussianity or other baryonic physics), or simply a difficulty in the halo mass estimation from observation, or a fundamental problem of the ${\Lambda}CDM$ cosmology. On the other hand, the over-abundance of massive structures at high redshifts does not favor heavy neutrino mass of ~ 0.3 eV or larger, as heavy neutrinos make the discrepancy between the observation and the simulation more pronounced by a factor of 3 or more.

• Toxicological Research
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• 제26권1호
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• pp.21-28
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• 2010

As the frequency and the intensity of so called Asian dust (AD) events have increased, public concerns about the adverse health effects has spiked sharply over the last two decades. Despite the recent reports on the correlation between AD events and the risk for cardiovascular and respiratory disease, the nature of the toxicity and the degree of the risk are yet largely unknown. In the present study, we investigated the effects of the dichloromethane extract of AD (AD-X) and that of urban dust (NAD-X) collected during a non-AD period on gene expression in HL-60 cells using Illumina Sentrix HumanRef-8 Expression BeadChips. Global changes in gene expression were analyzed after 24 h of incubation with 50 or 100 ${\mu}g$/ml AD-X and NAD-X. By one-way analysis of variance (p < 0.05) and Benjamini-Hochberg multiple testing correction for false discovery rate of the results, 573 and 297 genes were identified as AD-X- and NAD-X-responsive, respectively. The genes were classified into three groups by Venn diagram analysis of their expression profile, i.e., 290 AD-X-specific, 14 NAD-X-specific, and 283 overlapping genes. Quantitative realtime PCR confirmed the changes in the expression levels of the selected genes. The expression patterns of five genes, namely SORL1, RABEPK, DDIT4, AZU1, and NUDT1 differed significantly between the two groups. Following rigorous validation process, these genes may provide information in developing biomarker for AD exposure.