• Restorative Dentistry and Endodontics
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• v.27 no.5
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• pp.502-514
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• 2002

The aim of this study was to evaluate the marginal adaptation of direct class II sandwich restoration with packable composites(P-60), resin modified glass ionomer cement(Fuji-II LC), flowable compomer(Dyract Flow), flowable composites(Filtek Flow) in comparison with total bond restorations. In addition, for sandwich restorations, influence of different sandwich techniques was also evaluated. Large butt-joint box typed class II cavites with cervical margins 1mm below the cemento-enamel junction were cut into 70 extracted human molars. The cavities(7 groups, n=10) were filled using a closed/open sandwich restoration or total bond restoration technique with materials according to the manufacturer's recommandation using the single-component bonding agent for each system. Teeth were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 30-second dwell time. The teeth were then coated with nail polish 1mm short of the restoration, placed in a 2% methylene blue for 24 hours, and sectioned with diamond wheel. Sections were examined with a stereoscope to determine the extent of microleakage. Dentine /Cementum margins were analyzed for microleakage on scale of 0(no leakage) to 4(entire axial wall) and interface between materials, on scale of 0(no leakage) to 3(axial wall). Results were evaluated with Kruskal Wallis Test, corrected for ties, to determine whether there were statistically significant differences among the seven groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Dunn s Method. The results were as follows : 1. All groups showed some micoleakage in cervical portion. But there were no microleakage in interface between materials. 2. Closed sandwich restorations with Fuji-II LC and Filtek Flow had significantly lower leakage rating than total restorations with only P-60. However, open sandwich restorations with Dyract Flow showed significantly higher (P<0.05) 3. Closed sandwich restorations had significantly lower leakage rating than total restorations. However open sandwich restoration s showed significantly higher (P<0.05). 4. Sandwich restorations with Fuji-II LC were iou$.$or leakage than only P-60. Filtek Flow, Dyract Flow. But there were no statistically differences among the materials. From the results above, it could be concluded, closed sandwich restorations was effective in reducing microleakage of class II restorations. The best results showing the least microleakage were for the closed sandwich technique with Fuji-II LC and Filtek Flow.

• Journal of Hospice and Palliative Care
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• v.19 no.2
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• pp.109-118
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• 2016

The purpose of this study was to evaluate Korean advance directives (K-AD) by examining the degree of adults' acceptance and reliability of the directive itself. Methods: Survey was performed with 181 adults aged 20 or older who were recruited from three regions. A questionnaire used to examine the participants' acceptance of their K-AD in terms of visual analogue scale score of complexity, difficulty, necessity, satisfaction, recommendation. Then, a retest was carried out by asking participants to write up a K-AD again to confirm the reliability of the directives. Results: On a scale of 100, the average acceptance score was 70 or above, which represents rather high level of acceptance in all five categories. The test-retest reliability kappa values ranged from 0.592 to 0.950, and the conformity degree was moderate or high. Regarding K-AD components such as values, treatment preference, proxy appointment, differences among age groups were observed in each component. Conclusion: The results of this study suggest that K-AD is a feasible instrument to analyze its acceptability and reliability for adult population. K-AD could be utilized to help people make their own decision on their end-of-life care. Further studies are needed to confirm this study results and promote widespread use of K-AD.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.238-244
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• 1983

The cooking quality of irradiated chestnut after longterm storage were evaluated. 1. Color degree and tannin content of irradiated chestnut were slightly increased with the storage, but there was a little difference according to the radiation dose after nine months storage. 2. The main component of free sugars in the irradiated chestnut were identified as sucrose, glucose, fructose and the amino acids of chestnut were identified in the decreasing order of glutamic acid, aspartic acid, leucine, arginine, glycine, alanine, serine, pheylalanine, threonine, valine, isoleucine, tyrosine, methionine and cystein. Free sugars and amino acids of 25 Krad irradiated group showed a little difference compared with those of control group after nine months storage. 3. The calorie of candied chestnut prepared from nine months stored was marked 199 Kcal/100g of edible parts compared with 159 Kcal of raw chestnut. 4. Texture and sensory evaluation of candied chestnut prepared from nine months stored were better in 20-25 Krad irradiated group than in control group.

• Culinary science and hospitality research
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• v.18 no.4
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• pp.59-69
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• 2012

This study examines the role of mathematics anxiety as a mediator between self efficacy and mathematics skills using a series of regression analyses suggested by Baron RM & Kenny DA(1986). The participants include college students who enrolled in the Food Service Production and Operation course in a department of hotel and restaurant management at a college in the United States. Descriptive analysis, principal component analysis, reliability test, and a series of regression analyses were used for data analysis using SPSS 19.0. In order to collect data for the study, General Self Efficacy Scale(GSES) and Math Anxiety Rating Scale(MARS) were utilized, and they turned out to be reliable(${\alpha}$=.906 and ${\alpha}$=.890, respectively). A significant negative relationship was found between self efficacy and mathematics anxiety. In addition, it was found that self-efficacious students performed better mathematics skills than those who had lower level of self efficacy. However, the relationship was no longer significant when the concept of mathematics anxiety was added, which satisfies the condition of mediation.

• Korean Journal of Psychosomatic Medicine
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• v.8 no.1
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• pp.58-64
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• 2000

Objectives : This study aimed to examine a correlation between the somatic complaints, emotion, vocabulary and alexithymia as a component of personality in normal persons. Methods : 204 subjects were collected by age-based systematic sampling from the 662 persons without confirmed medical illness. We used the Korean version of 20-item Toronto Alexithymia Scale(TAS-20K) to measure alexithymia. The somatic complaints were checked by the list of somatic symptoms on the diagnostic criteria of somatization disorder and major depressive episode in DSM-IV. The vocabulary was evaluated by the total number of associating-words from the spontaneous association of word and the secondary association to given words. The anxiety and depression were evaluated using 5-point self-report scale. Results : 1) The degree of alexithymia was significantly correlated with the somatic complaints, anxiety, depression. 2) The somatic complaints were significantly correlated with the anxiety and depression. 3) The number of associating-words showed negative correlation with the age. 4) The degree of alexithymia was not correlated with the number of associating-words. Conclusion : The more degree of alexithymia increased, the more somatic complaints appeared. There was a significant correlation between the degree of alexithymia, anxiety and depression. But the degree of alexithymia was not correlated with the amount of vocabulary.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.256-262
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• 2004

A key component of an autonomous mobile robot is to localize itself and build a map of the environment simultaneously. In this paper, we propose a vision-based localization and mapping algorithm of mobile robot using fisheye lens. To acquire high-level features with scale invariance, a camera with fisheye lens facing toward to ceiling is attached to the robot. These features are used in mP building and localization. As a preprocessing, input image from fisheye lens is calibrated to remove radial distortion and then labeling and convex hull techniques are used to segment ceiling and wall region for the calibrated image. At the initial map building process, features we calculated for each segmented region and stored in map database. Features are continuously calculated for sequential input images and matched to the map. n some features are not matched, those features are added to the map. This map matching and updating process is continued until map building process is finished, Localization is used in map building process and searching the location of the robot on the map. The calculated features at the position of the robot are matched to the existing map to estimate the real position of the robot, and map building database is updated at the same time. By the proposed method, the elapsed time for map building is within 2 minutes for 50㎡ region, the positioning accuracy is ±13cm and the error about the positioning angle of the robot is ±3 degree for localization.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.163-180
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• 2020

In this study, to build a spatial information infrastructure, which is a component of a smart city, a 3D digital twin model in the downtown area was built based on the latest spatial information acquisition technology, the drone. Several analysis models were implemented by utilizing. While the data processing time and quality of the three types of drone photogrammetry software are different, the accuracy of the construction model is ± 0.04 in the N direction and ± 0.03m in the E direction. In the m and Z directions, ± 0.02m was found to be less than 0.1m, which is defined as the allowable range of surveying performance and inspection performance for the boundary point in the area where the registration of the boundary point registration is executed. 1: 500 to 1 of the aerial survey work regulation: The standard deviation, which is the error limit of the photographic reference point of the 600 scale, appeared within 0.14 cm, and it was found that the error limit of the large scale specified in the cadastral and aerial survey was satisfied. In addition, in order to increase the usability of smart city realization using a drone-based 3D urban digital twin model, the model built in this study was used to implement Prospect right analysis, landscape analysis, Right of light analysis, patrol route analysis, and fire suppression simulation training. Compared to the existing aerial photographic survey method, it was judged that the accuracy of the naked eye reading point is more accurate (about 10cm) than the existing aerial photographic survey, and it is possible to reduce the construction cost compared to the existing aerial photographic survey at a construction area of about 30㎢ or less.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.293-301
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• 2017

A Sub-kWe small-scale experimental test loop was manufactured to investigate characteristics of the supercritical carbon dioxide power cycle. A high-speed turbo-generator was also designed and manufactured. The designed rotational speed of this turbo-generator was 200,000 rpm. Because of the low expansion ratio through the turbine and low mass flowrate, the rotational speed of the turbo-generator was high. Therefore, it was difficult to select the rotating parts and design the turbine wheel, axial force balance and rotor dynamics in the lab-scale experimental test loop. Using only one channel of the nozzle, the partial admission method was adapted to reduce the rotational speed of the rotor. This was the world's first approach to the supercritical carbon dioxide turbo-generator. A cold-run test using nitrogen gas under an atmospheric condition was conducted to observe the effect of the partial admission nozzle on the rotor dynamics. The vibration level of the rotor was obtained using a gap sensor, and the results showed that the effect of the partial admission nozzle on the rotor dynamics was allowable.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.151-161
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• 2009

Configuration of soil hydraulic property is an essential component to understand the hydrological processes at the hillslope scale. In this study, we investigated temporal variations in pore development and soil hydraulic properties during the period from March to October in 2008. Characteristics for macropore flow and hydraulic conductivity were measured at two hillslopes: one is the hillslope located at the Buprunsa in Sulmachun watershed, and the other is the hillslope located in Gwangneung Research Forest. Vertical fluxes through macropore were measured using a tension infiltrometer at the depth of surface. The saturated hydraulic conductivities in March, June, July and September were relatively high compared to those in May and October. Temporal variations in several soil hydraulic features could be explained by the differences in vegetation activity and soil moisture content determined by antecedent precipitation. Particularly, the features of macropores had a substantial impact on hydraulic conductivity in the forest hillslope. The temporal nonuniformity of the soil hydraulic properties observed in this study manifests the dynamic features of hydrological processes in the hillslope scale and the experimental results will be useful to understand the internal hydrological processes in the mountainous hillslope.

• Ocean and Polar Research
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• v.43 no.4
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• pp.307-320
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• 2021

Udo Rhodolith Beach is a small-scale, mixed sand-and-gravel beach embayed on the N-S trending rocky coast of Udo, Jeju Island, South Korea. This study analyzes the short-term topographic changes of the beach during the extreme storm conditions of four typhoons from 2016 to 2020: Chaba (2016), Soulik (2018), Lingling (2019), and Maysak (2020). The analysis uses the topographic data of terrestrial LiDAR scanning and drone photogrammetry, aided by weather and oceanographic datasets of wind, wave, current and tide. The analysis suggests two contrasting features of alongshore topographic change depending on the typhoon pathway, although the intensity and duration of the storm conditions differed in each case. During the Soulik and Lingling events, which moved northward following the western sea of the Jeju Island, the northern part of the beach accreted while the southern part eroded. In contrast, the Chaba and Maysak events passed over the eastern sea of Jeju Island. The central part of the beach was then significantly eroded while sediments accumulated mainly at the northern and southern ends of the beach. Based on the wave and current measurements in the nearshore zone and computer simulations of the wave field, it was inferred that the observed topographic change of the beach after the storm events is related to the directions of the wind-driven current and wave propagation in the nearshore zone. The dominant direction of water movement was southeastward and northeastward when the typhoon pathway lay to the east or west of Jeju Island, respectively. As these enhanced waves and currents approached obliquely to the N-S trending coastline, the beach sediments were reworked and transported southward or northward mainly by longshore currents, which likely acts as a major control mechanism regarding alongshore topographic change with respect to Udo Rhodolith Beach. In contrast to the topographic change, the subaerial volume of the beach overall increased after all storms except for Maysak. The volume increase was attributed to the enhanced transport of onshore sediment under the combined effect of storm-induced long periodic waves and a strong residual component of the near-bottom current. In the Maysak event, the raised sea level during the spring tide probably enhanced the backshore erosion by storm waves, eventually causing sediment loss to the inland area.