• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.105-113
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• 2022

Mulching film was produced by LDPE and LLDPE adding biomass byproducts and MA(maleic anhydride), talc/clay/CaO/CaCO₃. And also surveyed to tensile strength, elongation, TGA and DSC according to the UV irradiation time. The tensile strength and elongation showed 20 N/cm² and 5% after UV irradiation 100 hours, and those was nearly 0 N/cm² and 0% after 200 hours, respectively. TGA of film was showed to peak of polymer itself, and DSC was slightly higher than that of initial value. At the pilot scale test, we were able to see the differentiate of degradation between control and developed film after 12 weeks, and also torn off at several part of mulching film. The degradation of mulching film after growing corn showed similar to a pilot scale test. Above the results, the developed mulching film adding biomass will be to used for agricultural farming.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.241-250
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• 2001

Purpose: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH). We assessed the role of acetazolamide-enhanced brain perfusion SPECT (ACZ-SPECT) with Tc-99m ECD for predicting the prognosis of patients with aSAH. Materials and methods: Two SPECT studios (baseline with 740 MBq and ACZ-SPECT with 1480 MBq) with image subtraction were performed in 21 patients with aSAH. All patients had brain CT and angiogram. Vasoreactivity on ACZ-SPECT, perfusion defect on baseline SPECT, and vasospasm on angiogram were correlated with Hunt-Hess grading, extent of SAH (unilateral or bilateral) on CT, and clinical outcome. Vasoreactivity was considered decreased when cerebral/cerebellar uptake ratio difference from baseline SPECT to ACZ-SPECT was greater than 2SD of normal control values. Results: Decreased vasoreactivity was observed in 38% (8/21), perfusion defect in 81% (17/21), and vasospasm in 38% (8/21). The preserved vasoreactivity group showed better outcome scale (92%, 12/13) and the decreased vasoreactivity group showed poorer outcome scale (62.5%, 5/8) (p=0.014). Extensive SAH was more frequently seen in the decreased vasoreactlvlty group (87.5%, 7/8) than in the preserved vasoreactivity group (30.7%, 4/13)(p=0.017). The perfusion defect and vasospasm did not show good correlation with outcome scale, extent of SAH, and Hunt-Hess grading (p=ns). Vasoreactivity represented the patient's outcome better than the vasospasm in all of the vasoreactivity/vasospasm-mismatched cases (6 cases). Conclusions: Our data show that decreased vasoreactivity on ACZ-SPECT does not always represent vasospastic condition. But patients with decreased vasoreactivity reveal poorer outcome than patients with angiographic vasospasm do. Therefore ACZ-SPECT is a valuable, noninvasive test for predicting the prognosis of patients with aSAH.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.21-29
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• 2004

Purpose: Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. On this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less $H_2^{15}O-PET$ to investigate coronary endothelial dysfunction caused by smoking noninvasively. Materials and methods: This study enrolled eighteen young male volunteers consisting of 9 smokers $(23.8{\pm}1.1\;yr;\;6.5{\pm}2.5$ pack-years) and 9 nonsmokers $(23.8{\pm}2.9 yr)$. They do not have any cardiovascular risk factor or disease history. Myocardial $H_2^{15}O-PET$ was performed at rest, during cold ($5^{\circ}C$) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. Results: There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41 ml/g/min and non-smokers: $1.37{\pm}0.41$ ml/g/min p=NS). during cold pressor stimulation, MBF in smokers was significantly lower than 4hat in non-smokers ($1.25{\pm}0.34$ ml/g/min vs $1.59{\pm}0.29$ ml/gmin; p=0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; $90{\pm}24%$ in smokers and $122{\pm}28%$ in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers ($5.81{\pm}1.99$ ml/g/min vs $5.11{\pm}1.31$ ml/g/min ; p=NS). Conclusion: in smokers, MBF during cold pressor stimulation was significantly lower compared wi4h nonsmokers, reflecting smoking-Induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.22-30
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• 2020

In March 2016, a 6.67-ton fishing boat capsized owing to the loss of stability during crane operations. Capsizing occurs when a boat or ship is flipped over (or turned upside down) for reason other than accidents caused by collisions, contact, stranding, fire or explosion. Over the past nine years (2010-2018), capsize accidents have accounted for 2.34 % of all marine accidents and are gradually increasing. The loss of stability from improper shipping is the main cause of most capsizes, especially for small fishing vessels weighing 10 tons. According to the Fishing Vessel Act, small fishing vessels weighing less than a ton are exempted from inspections on stability and load cranes. This study analyzes the issue cited as the reason for the capsizing of the small fishing boat in Goseong, namely, the reduction of restoring moment due to increased weight of the crane. Fishing boats with similar loading conditions were modeled on the basis of re-determination, and their stability before and after the accident was assumed. The fishing boats with heavier cranes were found to be at higher risk of capsizing owing to the reduction of the restoring moment and the angle of deck immersion. Under standard loading conditions, the stability moments of fishing vessels are lesser during fishing, compared to when they depart from or arrive at the port.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.469-476
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• 2017

Mini-Mental State Examination (MMSE) and naming tests have been used clinically as screening and diagnostic tools for mild cognitive impairment and dementia. Researches in other countries have reported that residential areas would affect one's cognitive abilities. In Korean, however, there was no systematic studies on geographical influences to cognitive ability among a sample of urban/rural residents. The aim of this study was to investigate the effect of urban/rural locality of residence on cognitive tests in normal elderly Korean. Residents aged 65 years and older (N=108) were administered the K-MMSE, confrontation/generative naming tests, and medical/socio-demographic interview. When comparing the total number of correct responses between urban residents and rural residents, the performances of rural group were significantly worse than those of the urban group in K-MMSE. Based on the results, our finding suggests that a factor of residential locality should be considered to examine the function and explain the cognitive decline in rural community-dwelling elders.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.127-133
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• 2016

The aim of this study was to examine the geriatric status, oral health, and oral health related quality of life of stroke patients hospitalized at a rehabilitatio ward and assess the relationships among these factors. A total of 78 stroke patients participated in this cross-sectional study. The following oral examinations were performed by a dentist and dental hygienist: Decayed, Missing, Filled Teeth, gingival, debris, calculus, and community periodontal index (CPI). The patients' sociodemographic and geriatric status were evaluated using the Barthel index and a mini-mental state examine (MMSE) according to their medical record and a questionnaire survey. Oral health related quality of life was assessed using the Oral Health Impact Profile (OHIP)-14 questionnaire. Except for three participants, most stroke patients had a gingival index of 2 or more, which means probing results in bleeding gums. Additionally, 53.8% of participants had a CPI code of 3 or 4, which indicates a probing depth of 4 mm or more. CPI index was significantly related to debris, calculus, and gingival index. The OHIP-14 score significantly related to the Barthel index and MMSE (p<0.05). The oral health of stroke patients in the rehabilitation ward was relatively poor and related to poor oral hygiene. Oral health related quality of life was related not to oral health but to geriatric status significantly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.283-296
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• 2008

The Urban Stream Assessment Technique (USAT) was suggested to give information about present urban stream condition. Domestic and foreign stream evaluation methods were analyzed and some streams were previously investigated to decide evaluation factors that could evaluate stream condition and have concern with characteristics and flood control of urban stream. The USAT consisted of three steps. High step has three characteristics concerned with functions of stream such as flood risk, stream, and ecology. In middle step, three characteristics were subdivided by ten features to describe changes and degradations of urban stream. Low step consisted of fifty three factors that explain the present condition of ten features. A survey of river experts was conducted to reflect weight among characteristics and features. The weights were calculated by analytic hierarchy process(AHP). The USAT was carried out to check over application of that in Suwon, Anyang, and Joongrang stream. The results of stream evaluation were expressed by factor index, feature index, characteristic index, total index, and evaluation grade. The results of the USAT were useful to realize changed and degraded areas. It is expected that the USAT can be used as base investigation for restoring and managing urban streams.

• Journal of dental hygiene science
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• v.12 no.1
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• pp.71-77
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• 2012

Sex Hormones exert significant influence in body physiology throughout life. Some reports suggested increased sex hormone levels correlate with an increased prevalence of gingivitis. The objectives of this pilot study are to(1) address the link between menstrual cycle and MMP-9, MMP-8, IL-$1{\beta}$ of gingival crevicular fluid during 4 weeks and (2) discuss the major biomarker of periodontal status. 7 female and 3 male volunteer who didn't have smoking habit, medical and dental disease after informed consent, were seen twice a week for 4 weeks. GCF samples were collected and GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ were measured by enzyme-linked immunosorbent assay. The GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ had fluctuation according to menstrual cycle, but the changes of those were not significant by Friedman matched samples test. There is no difference between female and male subjects by Mann-Whitney U test. The correlation of MMP-8, MMP-9 and IL-$1{\beta}$ showed strong by Spearman correlation(0.644-0.945). This study confirms menstrual cycle doesn't influence the periodontium of healthy female subjects.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.95-100
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.4
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• pp.277-286
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• 2002

Most of the problems in dealing with the tunnel construction are the uncertainties and complexities of the stress conditions and rock strengths in ahead of the tunnel excavation. The limitations on the investigation technology, inaccessibility of borehole test in mountain area and public hatred also restrict our knowledge on the geologic conditions on the mountainous tunneling area. Nevertheless an extensive and superior geophysical exploration data is possibly acquired deep within the mountain area, with up to the tunnel locations in the case of alternative design or turn-key base projects. An appealing claim in the use of artificial neural networks (ANN) is that they give a more trustworthy results on our data based on identifying relevant input variables such as a little geotechnical information and biological learning principles. In this study, error back-propagation algorithm that is one of the teaching techniques of ANN is applied to presupposition on Rock Mass Ratings (RMR) for unknown tunnel area. In order to verify the applicability of this model, a 4km railway tunnel's field data are verified and used as input parameters for the prediction of RMR, with the learned pattern by error back propagation logics. ANN is one of basic methods in solving the geotechnical uncertainties and helpful in solving the problems with data consistency, but needs some modification on the technical problems and we hope our study to be developed in the future design work.