• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.47-54
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• 2014

Precise Point Positioning (PPP) algorithms using GPS code pseudo-range measurements were developed and their accuracy was validated for the purpose of implementing them on a portable device. The group delay, relativistic effect, and satellite-antenna phase center offset models were applied as fundamental corrections for PPP. GPS satellite orbit and clock offsets were taken from the International GNSS Service official products which were interpolated using the best available algorithms. Tropospheric and ionospheric delays were obtained by applying mapping functions to the outputs from scientific GPS data processing software and Global Ionosphere Maps, respectively. When the developed algorithms were tested for four days of data, the horizontal and vertical positioning accuracies were 0.8-1.6 and 1.6-2.2 meters, respectively. This level of performance is comparable to that of Differential GPS, and further improvements and fine-tuning of this suite of PPP algorithms and its implementation at a portable device should be utilized in a variety of surveying and Location-Based Service applications.

• Journal of Powder Materials
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• v.14 no.3 s.62
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• pp.157-164
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• 2007

An electron energy loss spectroscopy (EELS) instrument attached on transmission electron microscopy (TEM) becomes a powerful and analytical tool for extracting the noble information of materials using the enhancement of TEM images, elemental analysis, elemental or chemical mapping images, electron energy loss near edge structure (ELNES), and extended energy-loss fine structure (EXELFS). In this review, the principle and applications of EELS which is widely used in material, life, and electronic sciences were introduced.

• Spatial Information Research
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• v.22 no.3
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• pp.35-46
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• 2014

Population data are usually provided at administrative spatial units in Korea, so areal interpolation is needed for fine-grained analysis. This study aims to compare various methods of areal interpolation for population subgroups rather than the total population. We estimated the number of elderly people and single-person households for small areal units from Dong data by the different interpolation methods using 2010 census data of Seoul, and compared the estimates to actual values. As a result, the performance of areal interpolation methods varied between the total population and subgroup populations as well as between different population subgroups. It turned out that the method using GWR (geographically weighted regression) and building type data outperformed other methods for the total population and households. However, the OLS regression method using building type data performed better for the elderly population, and the OLS regression method based on land use data was the most effective for single-person households. Based on these results, spatial distribution of the single elderly was represented at small areal units, and we believe that this approach can contribute to effective implementation of urban policies.

• BMB Reports
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• v.40 no.1
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• pp.95-99
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• 2007

Bovine coding region single nucleotide polymorphisms located proximal to quantitative trait loci were identified to facilitate bovine QTL fine mapping research. A total of 692,763 bovine SNPs was extracted from 39,432 UniGene clusters, and 53,446 candidate SNPs were found to be a depth >3. In order to validate the in silico SNPs experimentally, 186 animals representing 14 breeds and 100 mixed breeds were analyzed. Genotyping of 40 randomly selected candidate SNPs revealed that 43% of these SNPs ranged in frequency from 0.009 to 0.498. To identify non-synonymous SNPs and to correct for possible frameshift errors in the ESTs at the predicted SNP positions, we designed a program that determines coding regions by protein-sequence referencing, and identified 17,735 nsSNPs. The SNPs and bovine quantitative traits loci informations were integrated into a bovine SNP data: BcSNPdb (http://snugenome.snu.ac.kr/BtcSNP/). Currently there are 43 different kinds of quantitative traits available. Thus, these SNPs would serve as valuable resources for exploiting genomic variation that influence economically and agriculturally important traits in cows.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.135-143
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• 2013

Friction Stir Welding (FSW) was developed, it is successfully commercialized in the field of transportation vehicles. In this study, we analyzed the defects of A2024-T4 alloy using non-destructive test of radiograph, ultrasonic, electrical conductivity and destructive test of microstructure observation, tensile strength. As the results of experiment, mapping of defects was obtained. Fine defects which were not detected in radiograph test were detected in ultrasonic test, and it enabled efficient detection of defects by difference of sound pressure and color. The values of electrical conductivity was decreased as amount of defects was increasing. Joint efficient of defect-free weldment that found by non-destructive and destructive test was 91%. Therefore it was considered that non-destructive test of friction stir welded A2024-T4 Alloy was an efficient method.

• Journal of the Korean Home Economics Association
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• v.29 no.4
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• pp.45-64
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• 1991

Each of us has personal and unique "Mental Images" of environment that are the results of a two-way process between an observer and his environment. By understanding of people's image on their physical settings through cognitive maps, congruent with their design environment. In this context, this study is to fine out the characteristics of the resident's image in apartment housing that are modern housing. This paper is theoretically based on Appleyard's cognitive maps types, Lynch's the components of image, Harrison and Howard's image enhancing factors and Applyard's image enhancing factors of buildings. For the purpose of this study, two-instruments were used. One was sketch mapping, that told of visual aspects of cognitive map. Another was verbal questionnaire, which was composed of nonvisual aspects of image components and image enhancing factors. For the methods of research analysis, Percentage, Frequency, and Chi-square test were used. The results of this study are as follows. Firstly, as for the types of cognitive maps, the rate of sequential maps and spatial maps are nearly same. Secondly, as for the components of images, landmarks and districts are significant elements in apartment housing, and edges, nodes and paths are rare element. Thirdly, with regard to image enhancing factors, landscaping is shown to be most effective at landmarks and districts. And finally, in examing the differences of images between various social groups, significant variables are years of living and housing size. Age and income are the next. In this study of image, we can learn about manner in which individuals come to see, understand, and cope with the environment at a personal level. So, user-oriented approach is useful in environmental design, and particularly, it is useful in the apartment housing of the future life space.

• Korean Journal of Materials Research
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• v.10 no.10
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• pp.715-720
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• 2000

By the mechanical alloying method. Ni-WC composite materials were prepared to improve the deformation-resistance for creep and sintering of Ni-anode at the operating temperature of $650^{\circ}C$. Mechanically alloyed powder w was initially fabricated by ball milling for 80hr, and then amorphization was occurred by the destruction of ordered crystals based on XRD analysis. In order to investigate the electrochemical performance and sheet characteristics of Ni-WC anode, tape casting process was adopted. Finally, the obtained sheet thickness of Ni- we after sintering at $1180^{\circ}C$ for 60 minutes in $H_2$ atmosphere was O.9mm and the average pore size was $3~5{\mu\textrm{m}}$ with porosities of 55%. The second phase was not observed in Ni- W matrix while W particles were finely and uniformly distributed in Ni matrix. This fine and uniform distributed W particles in Ni matrix are expected to enhance the mechanical properties of Ni anode through the dispersion and solid solution hardening mechanisms.

• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.44-61
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• 2015

Mural tomb in Goa-ri(Goryeong) built in the 6th Century Gaya period investigated precisely by the scientific method. They were used to optical equipments for investigation and made a damage map according to the damaging types. The mortar layer was mostly exfoliated from the rest of the wall except for the burial chamber ceiling and corridor ceiling. Also painting layers rarely not observed. Most of the paintings were damaged except lotus painting in burial chamber ceiling. Various damage types that exfoliation, earthen dirt, film coating were found in murals. Damage factors of mural were the porous characteristics of mortar layer and the movement of moisture in the murals. They were caused physical damage such as crack, exfoliation. It was getting worse and causing to secondary damage like earthen dirt, film coating.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.607-613
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• 2019

Objective: Intramuscular fat (IMF) content plays an important role in meat quality. Identification of single nucleotide polymorphisms (SNPs) and genes related to pig IMF, especially using pig populations with high IMF content variation, can help to establish novel molecular breeding tools for optimizing IMF in pork and unveil the mechanisms that underlie fat metabolism. Methods: We collected muscle samples of 453 Chinese Lulai black pigs, measured IMF content by Soxhlet petroleum-ether extraction method, and genotyped genome-wide SNPs using GeneSeek Genomic Profiler Porcine HD BeadChip. Then a genome-wide association study was performed using a linear mixed model implemented in the GEMMA software. Results: A total of 43 SNPs were identified to be significantly associated with IMF content by the cutoff p<0.001. Among these significant SNPs, the greatest number of SNPs (n = 19) were detected on Chr.9, and two linkage disequilibrium blocks were formed among them. Additionally, 17 significant SNPs are mapped to previously reported quantitative trait loci (QTLs) of IMF and confirmed previous QTLs studies. Forty-two annotated genes centering these significant SNPs were obtained from Ensembl database. Overrepresentation test of pathways and gene ontology (GO) terms revealed some enriched reactome pathways and GO terms, which mainly involved regulation of basic material transport, energy metabolic process and signaling pathway. Conclusion: These findings improve our understanding of the genetic architecture of IMF content in pork and facilitate the follow-up study of fine-mapping genes that influence fat deposition in muscle.

• Journal of Environmental Health Sciences
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• v.49 no.1
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• pp.30-36
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• 2023

Background: Among various pollutants, fine particle (PM_2.5, defined as particle less than 2.5 nm in aerodynamic diameter) shows the most consistent association with adverse health effects. There is scientific evidence documenting a variety of adverse health outcomes due to exposure to PM_2.5. Objectives: This study aims to assess the health benefits of that would be achieved by meeting the World Health Organization's air quality guidelines for PM_2.5 using AirQ+ and BenMAP. Methods: We estimated PM_2.5 related health benefits in Korea from implementing the World Health Organization's air quality guidelines (annual average 5 ㎍/m³ and 10 ㎍/m³) and Korea's National Ambient Air Quality Standard (annual average 15 ㎍/m³). We used World Health Organization's AirQ+ and U.S. Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program. Results: The annual number of avoided PM_2.5 related premature deaths exceeding WHO guideline levels was assessed using both AirQ+ and BenMAP. We estimated that the health benefits of attaining the World Health Organization's air quality guidelines for PM_2.5 (annual average 5 ㎍/m³) would suggest an annual reduction of 26,128 (95% confidence interval [CI]: 17,363~34,024) and 26,853 (95% CI: 18,527~34,944) premature deaths. Conclusions: Our study provided useful information to policy makers and confirms that the reduction of PM_2.5 concentration would result in significant health benefits in Korea.