• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.263-271
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• 2017

The application of mass spectrometry to polymer science has rapidly increased since the development of MALDI-TOF MS. This review summarizes current polymer analysis methods using MALDI-TOF MS, which has been extensively applied to analyze the average molecular weight of biopolymers and synthetic polymers. Polymer sequences have also been analyzed to reveal the structures and composition of monomers. In addition, the analysis of unknown end-groups and the determination of polymer concentrations are very important applications. Hyphenated techniques using MALDI-tandem MS have been used for the analysis of fragmentation patterns and end-groups, and also the combination of SEC and MALDI-TOF MS techniques is recommended for the analysis of complex polymers. Moreover, MALDI-TOF MS has been utilized for the observation of polymer degradation. Ion mobility MS, TOF-SIMS, and MALDI-TOF-imaging are also emerging technologies for polymer characterization because of their ability to automatically fractionate and localize polymer samples. The determination of polymer characteristics and their relation to the material properties is one of the most important demands for polymer scientists; the development of software and instrument for higher molecular mass range (> 100 kD) will increase the applications of MALDI-TOF MS for polymer scientists.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.273-296
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• 2013

The purpose of this study is to examine the data coverage and citation threshold for analyzing SPLC(Search Path Link Count) as a main path of a historiograph of a certain topic in order to provide 'core' papers of global research trends to a researcher affiliated with a local R&D institution. 5 datasets were constructed by retrieving and collecting 2,318 articles on RGB LED on Web of Science published from 1990-2013 and 20,109 articles which cited these original 2,318. The SPLC analysis was performed on each dataset by increasing the threshold of citation counts, and the changes and resilience of the 28 extraced networks were compared. The results of user feedback on 198 unique core papers from 28 SPLC networks received from LED researchers affiliated with a Korean government-sponsored research institution were also analyzed. As a result, it is found that the nodes in each SPLC network in each dataset were differentiated by the citation counts, while the changes in the structure of SPLC networks were slight after the networks' citation counts were set at 40. Additionally, the user feedback showed that personalized research interest generally matched to the global research trends identified by the SPLC analysis.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.389-397
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• 2016

This study investigates convergent influence on childbirth perception and its association with job seeking stress, depression and hopelessness among some college women. The survey was administered to 531 college women in Jeonbuk area from March 28th to April 29th, 2016. The structured self-administered questionaries were used. The childbirth perception of respondents according to general characteristics turned out to be significantly higher in following groups: that of old age, that of religion, that of school life satisfaction, that of non drinker. The childbirth perception are significantly higher in higher job seeking stress group, moderate & severe hopeless group and moderate & major depression group. The childbirth perception was positively correlated with job seeking stress, hopelessness and depression. With the analysis of covariance structure, we could confirm relationship among the four factors such as job seeking stress, hopelessness, depression and childbirth perception. Job seeking stress was more influential on the childbirth perception than hopelessness and depression. The results are expected to be useful for health education to increase the positive thinking of childbirth perception of the college women. In the following study, the analysis about additional factors of convergent influence on childbirth perception will be needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.557-565
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• 2016

The risk of collapse in hydraulic structures has become more elevated, due to the increased probability and scale of flooding caused by global warming and the resulting abnormal climatic conditions. When a levee, a typical hydraulic structure, breaks, an enormous breach flow pours into the floodplain and much flood damage then occurs. It is important to accurately calculate the breach discharge in order to predict this damage. In this study, the variation of the breach discharge with the asymmetry in the cross-section of the levee breach was analyzed. Through hydraulic experiments, the cross-section of the breach was analyzed during the collapse using the BASD (Bilateral ASymmetry Degree), which was developed to measure the degree of asymmetry. The relationship of the breach discharge was identified using the BASD. Additionally, the variation of the breach flow measured by the BASD was investigated through a 3-D numerical analysis under the same flow conditions as those in the experiment. It was found that the assumption of a rectangular breach cross-section, which is generally used for the estimation of the inundation area, can cause the breach discharge to be overestimated. According to the BASD, the breach flow is decreased by the interference effect in the breach section of the levee. If the breach flow is calculated while considering the BASD in the numerical analysis of the flooding, it is expected that the predicted inundation area can be estimated accurately.

• Journal of Sasang Constitutional Medicine
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• v.33 no.3
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• pp.54-71
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• 2021

Objectives The purpose of this study was to revise Sasang Digestive Function Inventory (SDFI) and improve its validity and reliability using clinical data. Methods The Sasang type and Cold-Heat pattern differentiation by certified clinical specialist and responses to SDFI items were acquired from 419 hospital patients. The revision of SDFI was performed using item analysis and Explorative Factor Analysis (EFA). Furthermore, the validity and reliability of the revised SDFI (rSDFI) were investigated using Confirmatory Factor Analysis (CFA), Internal Consistency and Item Response Theory (IRT). And, clinical significance of the rSDFI was examined for the differentiation of Sasang types and Cold-Heat patterns. Results The number of the SDFI items were modified from 21 to 15. And, the validity and reliability of the rSDFI subscale structure were found to be acceptable. The scores of rSDFI-total and rSDFI-E significantly decreased in the order of Tae-Eum (TE), So-Yang (SY), So-Eum (SE) types, and the rSDFI score of SE type was significantly lower than that of TE and SY types. The rSDFI-total score could differentiate Cold-Heat pattern in both SY and SE types. And the difference of digestive function between Cold and Heat pattern of SE type could be explained with the rSDFI-D score. The rSDFI-total score in Cold pattern significantly decreased in the order of TE, SY, and SE types, and the rSDFI-total score of TE type is significantly higher than that of SE type in Heat pattern. Conclusions Current results demonstrated the reliability, validity and clinical usefulness of the rSDFI in clinical patients. Therefore, rSDFI can be utilized as an objective clinical measure supporting the differential diagnosis of Sasang typology.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1105-1112
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• 1997

By sequential degradation using partial acid hydrolysis of a weakly acidic polysaccharide (GL-4IIb2'), two acidic oligosaccharide fragments, PA-2' and PA-1-III were isolated and their structures were characterized. PA-2' consisted of almost equal proportion of a rhamnose (Rha) and an unusual sugar, 3-deoxy-D-manno-2-octurosonic acid (Kdo). When permethylated oligosaccharide-alditol derived from PA-2' was analyzed by GC-MS, the peak gave the fragment ions at m/z 189 $(bA_1,\;6-deoxyhexose)$ and at m/z 308 $(aJ_2,\;alditol\;from\;Kdo)$. The peak also gave the characteristic ion at m/z 162 but it did not give the fragment ion at m/z 177, suggesting that Kdo is substituted at C5 but not at C4. Methylation analysis also indicated that PA-2' was composed mainly of terminal Rhap and 5-substituted Kdo. When the reduced product from PA-2' was analyzed by $^1H-NMR$, it gave a signal at 5.09 ppm due to an anomeric proton of ${\alpha}-L-Rha$. These results indicated that PA-2' mainly contained ${\alpha}-L-Rhap-(1{\rightarrow}5)-Kdo$. On the other hand, PA-1-III mainly comprised Rha and Kdo in addition to small proportions of arabinose (Ara) and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). MS analysis of permethylated oligosaccharide-alditols from PA-1-III suggested that the major peak 1P was $Rhap-(1{\rightarrow}5)-Kdo$ whereas the minor peaks 2P and 3P possessed $Araf-(1{\rightarrow}5)-Dha$ unit and these peaks were produced as epimers during reduction of carbonyl groups in Dha.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2230-2240
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• 2011

This study was performed to determine the depression and its association with sleep quality, occupational stress and fatigue among small-scale manufacturing male workers. The self-administered questionnaires were given to 856 workers under 50 members of manufacturing industries during the period from April 1st to June 30th, 2010. As a results, the distribution of depression group(21 point and over at CES-D score) among all subjects were 44.3%, and it was positively correlated with occupational stress, fatigue and quality of sleep. With the analysis of covariance structure, occupational stress(KOSS) was more influential on the depression than quality of sleep and fatigue. It was found to have the inter-relational effects that the higher the occupational stress(KOSS) and fatigue(MFS), and the lower the quality of sleep, the higher the depression. Thus the effective strategy for depression reduction among workers requires the efforts to improve the work environment and job contents.

• Journal of KIBIM
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• v.2 no.2
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• pp.1-9
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• 2012

In Korea, recently, efforts have been made to introduce BIM(Building Information Modeling) to housing complex projects. However, there have been several problems including excessive competition for building design and outcome-oriented evaluation due to a lack of clear evaluation criteria and poorly organized management process. Under this circumstance, the study surveyed opinions of project managers and conducted a pilot test to improve evaluation criteria of BIM-based design for housing complexes. The objective is to assess the level of BIM technology and its applicability, and to propose a list of reasonable evaluation criteria for better project management. First, the study examined the current condition of evaluation on the BIM-based housing complexes, and identified 15 preliminary items that might be suitable for application of BIM. Second, the study conducted a pilot test for the 15 items to determine their suitability for the level of BIM technology, clarity of the calculation process, and the extent of fulfilling information quality, and short-listed eight items for application of BIM. In particular, in the design concept stage, mostly 3D visual images and area-related items are suitable for BIM-based evaluation. Accordingly, formerly used items such as project cost, energy and environmental analysis, building structure, and facilities were deemed more relevant to the subsequent stages of basic design and its implementation.

• Journal of the Korean Magnetics Society
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• v.18 no.1
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• pp.24-27
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• 2008

We have prepared $MnFe_2O_4$ nanoparticles with polyol method. The crystallographic and magnetic properties were measured by using X-ray diffraction(XRD), vibrating sample magnetometer(VSM) and $M\"{o}ssbauer$ spectroscopy. The high resolution transmission electron microscope(HRTEM) shows uniform nanoparticle-sizes with $6{\sim}8$ nm. The crystal structure is found to be single-phase cubic spinel with space group of Fd3m. The lattice constant of $MnFe_2O_4$ nanparticles is determined to be $8.418{\pm}0.001{\AA}$. $M\"{o}ssbauer$ spectrum of $MnFe_2O_4$ nanparticles at room temperature(RT) shows a superparamagnetic behavior. In VSM analysis, the diagnosis of the superparamagnetic behavior is also shown in hysteresis loop at RT. $M\"{o}ssbauer$ spectrum at 4.2K shows that the well developed two sextets are with different hyperfine field $H_{hfA}=498$(A-site) and $H_{hfB}=521$(B-site) kOe.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.10
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• pp.841-847
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• 2021

In this paper, the applicability of the low-density surface film copper mesh for aircraft applications have been analyzed. Recently, low-density surface film copper mesh is developed to reduce weight and cost compared with traditional surface film copper mesh. In order to apply low-density surface film copper mesh to aircraft, it is needed to analyze its electromagnetic effects as well as structural integrity with sandwich panels to prevent pinholes. The structural integrity and electromagnetic characteristics have been analyzed for 2 samples of low-density surface film copper mesh and 1 sample of surface film copper mesh. To review the applicability of the low-density surface film, it is combined with sandwich composite panel to confirm pinhole effects. The low-density surface film has been modeled as a periodic structure and analyzed with 3D electromagnetic simulation tool. The simulation results has been verified through measured electromagnetic transmission results using free space measurements. From the results, it will be possible to use these results for the analysis and the applicability of low-density surface film copper mesh for aircraft.