• Journal of the Korean GEO-environmental Society
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• v.8 no.6
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• pp.53-60
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• 2007

L/EPS, manufactured in the shape of block and used for civil engineering, is a lightweight material with an excellent resistance to compression, and provides a superb self-sufficient stability. EPS is a suitable material capable of resolving the problem of settlement and lateral flow if it is applied as the soil on soft ground. The Korean Standards (KS) has not yet proposed any testing method for use of EPS as an engineering banking material. Only its testing and quality ordinance as a heat insulation material has been standardized. The design criteria for EPS has been established and applied through the trial construction of KHC (Korea Highway Corporation) and quality test of manufacturer, but most studies on them have been confined to factory products. This study is focused on comparing and analyzing long-term durability by conducting cyclic load test, freezing and thawing test, absorption rate test and others. EPS used in the test was chosen from construction sites and factory products, focusing on the long-term durability of EPS depending on the passage of time. Unconfined compression test results indicated that the strength of collected samples was lower than factory products. While the triaxial compression test results indicated that the shear strength increased in proportion to the increase of confining pressure, and factory products had declining shear strength as the confining pressure rose.

• Korean Journal of Biological Psychiatry
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• v.22 no.3
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• pp.140-148
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• 2015

Objectives The aim of this study is to investigate the correlation between degenerative changes in brain [i.e., global cortical atrophy (GCA), medial temporal atrophy (MTA), white matter hyperintensities (WMH)] and neurocognitive dysfunction in Korean patients with Alzheimer's disease. Methods A total of 62 elderly subjects diagnosed with Alzheimer's disease were included in this study. The degenerative changes in brain MRI were rated with standardized visual rating scales (GCA or global cortical atrophy, MTA or medial temporal atrophy, and Fazekas scales) and the subjects were divided into two groups according to the degree of degeneration for each scale. Cognitive function was evaluated with Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) and several clinical features, including apolipoprotein E ${\varepsilon}4$ status, lipid profile and thyroid hormones, were also examined. Chi-square test and Fisher's exact test were performed to analyze the relationship between the degree of cerebral degeneration and neurocognitive functions. Results Demographic and clinical features, except for the age, did not show any significant difference between the two groups divided according to the degree of cerebral degenerative changes. However, higher degree of GCA was shown to be associated with poorer performance in verbal fluency test, word list recall test, and word list recognition test. Higher degree of MTA was shown to be associated with poorer performance in Mini-Mental State Examination in the Korean Version of CERAD Assessment Packet (MMSE-KC), word list recognition test and construction praxis recall test. Higher degree of white matter hyperintensities was shown to be associated with poorer performance in MMSE-KC. Conclusions Our results suggest that severe brain degeneration shown in MRI is associated with significantly poorer performance in neurocognitive tests in patients with Alzheimer's disease. Moreover, the degree of GCA, MTA and white matter hyperintensities, represented by scores from different visual rating scales, seems to affect certain neurocognitive domains each, which would provide useful information in clinical settings.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.1
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• pp.89-96
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• 1997

This study was designed to determine whether cognitive impairment was evident in patients with SLE. Also, it aimed to examine the association of cognitive impairment with other clinical variables. The subjects consisted of 20 patients with mildly active SLE and 20 healthy controls. Methods : A total of 20 SLE patients and 20 normal controls completed a computerized neuropsychological test battery using Vienna Test System. These included Cognitrone test, Continuous attention test, Corsi block tapping test, Standard progressive matrices. Also, neuro-behavioral cognitive status examination was done. The symptom severity of depression was measured with Beck Depression Inventory, Hamilton Depression Rating Scale, and current medications were documented. Disease activity was rated using the SLE diasease activity index (SLEDAI). Results : SLE patients had poorer performance than normal controls on the tests of Cognitrone, attention, nonverbal IQ and memory, independent of age, education, disease activity, steroid use and depression status. Conclusion : Cognitive dysfunction was not uncommon in ambulatory SLE patients as measured by standardized neuropsychological tests. It seemed to occur independently of various clinical variables. These findings would suggest that cognitive dysfunction in SLE may be explained by reflecting subclinical central nervous system(CNS) involvement, rather than coexisting psychological distress due to chronic illness or side effect of medication.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.17-24
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• 2018

The pullout test, a nondestructive testing(NDT), for pre-installed inserts is perhaps the most widely used technique to estimate the in-situ compressive strength of concrete. It measures the force needed to pullout a standardized metal insert embedded into concrete members. The pullout test was certified by the American Society for Testing and Materials(ASTM) and Canadian Standards Association(CSA) as a reliable method for determining the strength of concrete in concrete structures under construction. To easily estimate the strength of ultra-high-strength concrete, a simplified pullout tester, primarily composed of a standard 12mm bolt with a groove on the shaft as a break-off bolt, an insert nut, and a hydraulic oil pump without a load cell, was proposed. Four wall and two slab specimens were tested for two levels of concrete strength, 80MPa and 100MPa, using a simplified pullout tester with a load cell to verify the advantages of the pullout test and simplified pullout test. The compressive strength of concrete, pullout load, and the rupture of the break-off bolt were measured 11 times, day 1 to 7, 14, 21, 28, and 90. The correlation of the pullout load and the compressive strength of each specimen show a higher degree of reliability. Therefore, a simplified pullout test can be used to evaluate the in-place strength of ultra-high-strength concrete in structures. The prediction equation for the groove diameter of the break-off bolt(y) with the concrete strength(x) was proposed as y=0.0184x+5.4. The results described in this research confirm the simplified pullout's utility and potential for low cost, simplicity, and convenience.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.205-212
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• 2006

Background: Malignant pulmonary nodules account for about 30 to 40 percent of solitary pulmonary nodules (SPN). Therefore, tissue characterization of SPNs is very important. Recently, PET/CT has been widely used for tissue characterization, and has become of importance. The purpose of this study was to compare and to assess multiple factors in PET/CT comparing benign and malignant nodules. Materials and Method: Nineteen patients with SPN underwent PET/CT and biopsy. The difference of standardized uptake value 1 (SUV1), standardized uptake value 2 (SUV2) and retention index in PET/CT between malignancy and benignancy were compared by Levene's test. Result: There were twelve malignant and seven benign nodules. SUV1 and SUV2 were significantly different between malignant nodule and benign nodule (p=0.006 and 0.022), but retention index was not significantly different between malignant nodule and benign nodule (p=0.526). By receiver-operating-characteristic (ROC) analysis, the sensitivity was 66.7% and the specificity was 71.4% at a cut off value of 5.40 in SUV1. The sensitivity was 75% and the specificity was 71.4% at cut off value of 7.45 in SUV2. Conclusion: There was a statistically significant difference in SUV1 and SUV2 between benign and malignant nodules. However, the cut off value of SUV1 and SUV2 by receiver-operating-characteristic (ROC) analysis was 5.40 and 7.45 which is different from previous studies. Therefore, studies on a larger sample of patients are required for confirmation.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.509-523
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• 2015

This study introduces newly implemented geological well logs database for Jeju public water wells, built for a research project focusing on integrated hydrogeology database of Jeju Island. A detailed analysis of the existing 1,200 Jeju Island geological logs for the public wells developed since 1970 revealed six major indications to be improved for their use in Jeju geological logs DB construction: (1) lack of uniformity in rock name classification, (2) poor definitions of pyroclastic deposits and sand and gravel layers, (3) lack of well borehole aquifer information, (4) lack of information on well screen installation in many water wells, (5) differences by person in geological logging descriptions. A new Jeju geological logs DB enabling standardized input and output formats has been implemented to overcome the above indications by reestablishing the names of Jeju volcanic and sedimentary rocks and utilizing a commercial, database-based input structured, geological log program. The newly designed database structure in geological log program enables users to store a large number of geology, well drilling, and test data at the standardized DB input structure. Also, well borehole groundwater and aquifer test data can be easily added without modifying the existing database structure. Thus, the newly implemented geological logs DB could be a standardized DB for a large number of Jeju existing public wells and new wells to be developed in the future at Jeju Island. Also, the new geological logs DB will be a basis for ongoing project 'Developing GIS-based integrated interpretation system for Jeju Island hydrogeology'.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.139-148
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• 2019

Fostering science-gifted individuals are very important for the future of the nation, and it is especially important to cultivate information-gifted individuals in the age of the fourth industry. There is no standardized curriculum for each gifted education center of the University. Therefore, in this study, we analyzed how effective the curriculum developed on the basis of computing thinking is to affect the characteristics of the information-gifted individuals. The curriculum developed on the components of computing thinking was applied to the information-gifted students of K University. In order to verify the effectiveness of the curriculum, we developed a creative personality test and an intrinsic motivation test, and conducted tests before and after the training. We compared pre-post test results by t-test with R program. The creative personality test consisted of 36 items with 6 factors: risk-taking, self - acceptance, curiosity, humor, dominance, and autonomy. The intrinsic motivation test consisted of 20 items with 5 items: curiosity and interest oriented tendency, challenging learning task preference orientation, independent judgment dependency propensity, independent mastery propensity, and internal criterion propensity. The effect of the curriculum on the creative personality of the experimental group was significant (0.009, 0.05). The significance level of the intrinsic motivation was 0.056 and was not significant at the 0.05 level of significance.

• The Journal of the Korea Contents Association
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• v.19 no.3
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• pp.416-428
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• 2019

The purpose of this study is to provide basic data for the development of pre-parent education program by grasping parent role recognition, educational needs and readiness of unmarried men and women. The subjects were 196 unmarried male and female students from K-do. Data were collected from November 1st to 20th, 2018, and analyzed using IBM SPSS WIN/21.0 to get frequency, percentage, average, standard deviation, t-test, ANOVA, sheffe-test, paired t-test, and IPA matrix. The average score of recognition of social pre-parent role was $3.41{\pm}0.27$ (out of 5 points), educational needs was $3.48{\pm}0.41$ points (out of 4 points), and educational readiness was $2.65{\pm}0.57$ points (out of 4 points). educational needs being higher than educational readiness. Through IPA matrix analysis, the area to be strengthened was 'family relation or parent role', and 'self understanding' was the area to encourage putting effort into other evaluation attributes. The area where no further effort is needed and needs improvement in the future was 'spouse selection and marriage', and 'pregnancy and childbirth' and 'child rearing' were the areas to intensively improve. Therefore, there is a need for establishing a standardized strategy in the area A, which has high degree of readiness and needs. Also, it is necessary to take strategies and countermeasures to raise the readiness of area C with low degree of readiness and needs, rather than accepting it as an unnecessary area of further effort input.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.3
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• pp.140-148
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• 2012

Aeronautical lights, which are internationally standardized sequence of colors and placements, are aeronautic safety devices that provide visual information to pilots by continuously adjusting their light intensity to appropriate level. In this paper, we consider the development testing for in pavement LED aeronautical light system such as taxiway centerline, stop line and temporary stop line. The test results of LED sourced lights have shown a drastic improvement in power consumption levels and cost efficiency compared to their halogen sourced counterparts The LED light used only 42.7% as much power as their halogen sourced counterparts. Taking installation costs into account, LED will cost only 58% of its halogen counterparts. These results suggest that developing the LED sourced aeronautical light would result in globally competitive products thar guarantees satisfaction to their consumers, and that both cost effective and energy efficient.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.291-298
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• 2015

In this study, the reverberation time of apartment living room was measured and distribution of the reverberation time was analyzed. In addition, sound field characteristics of mock-up test room similar with living room and timber structured bedroom was investigated with addition of furniture and sound absorption material. Average reverberation time of unfurnished apartment unit was 1.11 s, and reverberation time in 630 Hz~2000 Hz bands were longer than 1.2 s. It was found that from the field measurement results, reverberation time characteristic of furnished apartment living room was uniform in most of frequency bands. Averaged reverberation time of furnished living room was 0.48 s and the reverberation time of bedroom was 0.44 s. Standardized sound pressure level correction values were calculated from the average reverberation time of furnished and unfurnished apartment units. The correction value of unfurnished living room was −3.4 dB and that of furnished living room was 0.2 dB. Measured reverberation time of furnished and unfurnished apartment units indicated that reference reverberation time; 0.5 s, in KS and ISO standards is reasonable also in Korean residential environment.