• Korean Journal of Heritage: History & Science
• /
• v.55 no.4
• /
• pp.118-135
• /
• 2022

The primary purpose of this study is to estimate the structure of Byeongpungsadaseok (屛風莎臺石) and Nanganseok (欄干石) in Geonwonneung (建元陵) and Heonneung (獻陵), which were built in the early of 15th century, based on the Annals of King Sejong. In addition, the ultimate purpose of this study is to reveal structural changes and their significance by comparing the differences with the contents of the dismantlement survey. Geonwonneung, Jereung(齊陵), and Heonneung were repaired at the same time in 1442, and the structural changes were the similar. The purpose of the repair in 1442 was to prevent water from flowing into the underground palace with smooth drainage. As a result of estimating the structure of Geonwonneung and Heonneung according to the records of the Annals of King Sejong, it was created in a very similar form to the Hyeonneung and Jeongneung of Goryeo. And it was clearly recognized that the Royal Tomb of Goryeo was followed. However, as the structure was improved in 1442, the unique characteristics of the Royal Tomb of the Joseon Dynasty were formed. First is the appearance of the Bokbuhyeong lime (覆釜形石灰, which is a convex roof on the Byeongpungsadaseok that serves to prevent rainwater from penetrating into the burial mound. It also plays a role in connecting and fixing the Manseok (滿石) and the Inseok (引石), which are the upper structures of the Sadaseok (莎臺石). Second, the Bakseok (薄石) between the nanganseok and the sadaseok has been transformed into the Sangseok (裳石) with a slope. This plays a role in protecting the inner stone chamber by expanding the length of the bakseok, which forms an overall slope, like the eaves of the roof. After both of these features were first attempted in 1442, they were applied to all Royal Tombs of the Joseon Dynasty and became unique features of these Royal Tombs.

• 한국체육학회지인문사회과학편
• /
• v.54 no.5
• /
• pp.867-876
• /
• 2015

This study was intended to closely examine an effect that the level of physically challenged person's participation in community sports had on positive psychological capital. In order to accomplish the purpose of study, data on 212 physically challenged persons who lived in B city and participated in community sports were analyzed. Korean version of positive psychological capital created by Taehong Lim (2014) through the reconstruction of scales developed by Luthans, Youssef and Avolio(2007) and Sangwan Jeon and Jonghun Yang's (2009) level of participation in community sports was reconstructed through modification·improvement as measurement instrument. An exploratory factor analysis, reliability test, paired difference test, and multiple regression analysis was carried out by using SPSS 18.0 program for data processing. First, It was shown that there was a significant difference in positive psychological capital according to gender, age, and disability grade among physically challenged persons' socio-demographic characteristics. Second, it was shown that, among sub-variables (period, frequency and intensity) of level of physically challenged persons' participation in community sports, the frequency of participation and the intensity of participation had a significant effect on self efficacy. On the other hand, it was shown that the period of participation didn't have a significant effect. Third, it was shown that the frequency of participation had a significant effect on optimism. On the other hand, it was shown that the period of participation and the intensity of participation didn't have a significant effect. Fourth, it was shown that the frequency of participation and the intensity of participation had a significant effect on hope. On the other hand, it was shown that no significant effect was produced on the period of participation. Fifth, it was shown that the frequency of participation had a significant effect on resilience. On the other hand, it was shown that no significant effect was produced on the period of participation and the intensity of participation. Sixth, it was shown that the frequency of participation and the intensity of participation had a significant effect on positive psychological capital. And it was shown that no significant effect was produced on the period of participation.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.6-7
• /
• 2021

Vegetation development in rivers is one of the important issues not only in academic fields such as geomorphology, ecology, hydraulics, etc., but also in river management practices. The problem of river vegetation is directly connected to the harmony of conflicting values of flood management and ecosystem conservation. In Korea, since the 2000s, the issue of river vegetation and land formation has been continuously raised under various conditions, such as the regulating rivers downstream of the dams, the small eutrophicated tributary rivers, and the floodplain sites for the four major river projects. In this background, this study proposes a method for classifying the distribution of vegetation in rivers based on remote sensing data, and presents the results of applying this to the Naeseong Stream. The Naeseong Stream is a representative example of the river landscape that has changed due to vegetation development from 2014 to the latest. The remote sensing data used in the study are images of Sentinel 1 and 2 satellites, which is operated by the European Aerospace Administration (ESA), and provided by Google Earth Engine. For the ground truth, manually classified dataset on the surface of the Naeseong Stream in 2016 were used, where the area is divided into eight types including water, sand and herbaceous and woody vegetation. The classification method used a random forest classification technique, one of the machine learning algorithms. 1,000 samples were extracted from 10 pre-selected polygon regions, each half of them were used as training and verification data. The accuracy based on the verification data was found to be 82~85%. The model established through training was also applied to images from 2016 to 2020, and the process of changes in vegetation zones according to the year was presented. The technical limitations and improvement measures of this paper were considered. By providing quantitative information of the vegetation distribution, this technique is expected to be useful in practical management of vegetation such as thinning and rejuvenation of river vegetation as well as technical fields such as flood level calculation and flow-vegetation coupled modeling in rivers.

• Journal of Korean Academy of Dental Administration
• /
• v.5 no.1
• /
• pp.22-30
• /
• 2017

Objective: The purpose is to study the factors to impact on the satisfaction of field practice among dental hygiene students and to provide the basic data for the quality improvement of the field practices for dental hygiene students. Methods: A self-reported questionnaires were filled out by 108 dental hygiene students in C city. Questionnaires were composed with the general characteristics, satisfaction to major, and satisfaction to field clinical practice. The data was analyzed by chi-square statistics using SPSS 20.0 program. Results: The higher satisfaction to communication with professor or seniors in department was associated with the higher satisfaction to field clinical practice (p<0.05). The higher satisfaction to field clinical practice hours per week was associated with the higher satisfaction to field clinical practice (p<0.05). The higher interest to major subjects and the satisfaction to the laboratory environment were associated with the higher satisfaction to field clinical practice (p<0.05). Conclusions: The higher satisfaction to major was associated with the higher satisfaction to field clinical practice. Therefore, the systematic curriculum development is needed to improve the satisfaction with major and clinical practice.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.25 no.2
• /
• pp.80-98
• /
• 2023

This study explores the effectiveness of various data preprocessing algorithms for improving subseasonal to seasonal (S2S) climate predictions from six climate forecast models and their Multi-Model Ensemble (MME) using a deep learning-based postprocessing model. A pipeline of data transformation algorithms was constructed to convert raw S2S prediction data into the training data processed with several statistical distribution. A dimensionality reduction algorithm for selecting features through rankings of correlation coefficients between the observed and the input data. The training model in the study was designed with TimeDistributed wrapper applied to all convolutional layers of U-Net: The TimeDistributed wrapper allows a U-Net convolutional layer to be directly applied to 5-dimensional time series data while maintaining the time axis of data, but every input should be at least 3D in U-Net. We found that Robust and Standard transformation algorithms are most suitable for improving S2S predictions. The dimensionality reduction based on feature selections did not significantly improve predictions of daily precipitation for six climate models and even worsened predictions of daily maximum and minimum temperatures. While deep learning-based postprocessing was also improved MME S2S precipitation predictions, it did not have a significant effect on temperature predictions, particularly for the lead time of weeks 1 and 2. Further research is needed to develop an optimal deep learning model for improving S2S temperature predictions by testing various models and parameters.

• Analytical Science and Technology
• /
• v.20 no.4
• /
• pp.261-267
• /
• 2007

The 20 L small chamber test method is to evaluate pollutants such as TVOC, formaldehyde emitted from building materials. This method was only designed to evaluate the surface emission of sample exposed in the chamber. In this method, building materials cut with a fixed standard size are fixed in a sample sealing box. The sample sealing box is put into the 20 L test chamber. This chamber is ventilated at a standard air change rate with purified air for 7 days then the sample from the chamber is collected and analyzed to measure the emission rate of TVOC and formaldehyde. In this method, however, if the sealing box does not guarantee airtightness, accurate evaluation for the building materials can not be achieved due to the pollutants emitted from edge of the sample so called, edge effect. This edge effect can be much greater when evaluating panels such as plywood, flooring due to their surface treatment. In this study, flooring was tested to check airtightness of the sample sealing box with analytic results between 1L and 20 L test chamber. Furniture materials like LPM coated one side surface treatment and MDF coated both sides surface treatment with LPM were tested to identify whether the improvement of the sample sealing box airtightness is possible with the comparison between existing and improved test method that low VOC emission tape was used to seal the sample edge. After 7 days, MDF TVOC emission rate was different according to the existence and nonexistence of tape. The emission rate of the existing test method was $0.009mg/m^2h$ and that of improved test method was $0.003mg/m^2h$. Relative standard deviation for the existing test method was $0.004mg/m^2h$ and relative standard deviation for the improved test method was $0.002mg/m^2h$ when the same sample was analyzed three times. The improved test method in this study using low VOC emission tape was effective and able to reduce the heterogeneous effect of the edge from the sample sealing box.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.4C
• /
• pp.247-254
• /
• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.1D
• /
• pp.25-32
• /
• 2009

Currently, various types of TDM (Transportation Demand Management) policies are being studied and implemented in an attempt to overcome the limitations of supply oriented policies. In this context, this paper addressed issues of effectiveness and possible domestic implementation of the HOT lane. The possible site of implementation selected for this simulation study is part of the Kyung-bu freeway, where a dedicated bus lane is currently being operated. Minimum length of distance required in between interchanges and access points of the HOT lane for vehicles to safely enter and exit the lane, and traffic management policies for effectively managing the weaving traffic trying to enter and exit the HOT lane were presented. A 5.2km section of freeway from Ki-heuing IC to Suwon IC and a 8.3km section from Hak-uei JC to Pan-gyo JC have been selected as possible sites of implementation for the HOT lane, in which congestion occurs regularly due to the high level of travel demand. VISSIM simulation program has been used to analyze the effects of the HOT lane under the assumption that one-lane HOT lane has been put into operation in these sections and that the lane change rate were in between 5% to 30%. The results of each possible scenario have proven that overall travel speed on the general lanes have increased as well by 1.57~2.62km/h after the implementation of the HOT lane. It is meaningful that this study could serve as a basic reference data for possible follow-up studies on the HOT lane as one effective method of TDM policies. Considering that the bus travel rate would continue increase and assuming the improvement in travel speed on general lanes, similar case study can be implemented where gaps between buses on bus lane are available, as a possible alternative of efficient bus lane management policies.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3A
• /
• pp.201-209
• /
• 2010

Generally, PSC girder bridge uses total gross cross section to resist applied loads unlike reinforced concrete member. Also, it is used as short and middle span (less than 30 m) bridges due to advantages such as ease of design and construction, reduction of cost, and convenience of maintenance. But, due to recent increased public interests for environmental friendly and appearance appealing bridges all over the world, the demands for longer span bridges have been continuously increasing. This trend is shown not only in ordinary long span bridge types such as cable supported bridges but also in PSC girder bridges. In order to meet the increasing demands for new type of long span bridges, PSC hollow box girder with H-type steel as compression reinforcements is developed for bridge with a single span of more than 50 m. The developed PSC girder applies compressive prestressing at H-type compression reinforcements using unbonded PS tendon. The purpose of compressive prestressing is to recover plastic displacement of PSC girder after long term service by releasing the prestressing. The static test composed of 4 different stages in 3-point bending test is performed to verify safety of the bridge. First stage loading is applied until tensile cracks form. Then in second stage, the load is removed and the girder is unloaded. In third stage, after removal of loading, recovery of remaining plastic deformation is verified as the compressive prestressing is removed at H-type reinforcements. Then, in fourth stage, loading is continued until the girder fails. The experimental results showed that the first crack occurs at 1,615 kN with a corresponding displacement of 187.0 mm. The introduction of the additional compressive stress in the lower part of the girder from the removal of unbonded compressive prestressing of the H-type steel showed a capacity improvement of about 60% (7.7 mm) recovery of the residual deformation (18.7 mm) that occurred from load increase. By using prestressed H-type steel as compression reinforcements in the upper part of cross section, repair and rehabilitation of PSC girders are relatively easy, and the cost of maintenance is expected to decrease.

• Journal of Nutrition and Health
• /
• v.56 no.3
• /
• pp.315-329
• /
• 2023

Purpose: This study examined the meal-kit consumption practices of adults in their 20s and 30s and analyzed the properties that should be given priority for improvement among the selection attributes to improve the quality of meal-kits. Methods: Statistical analyses were conducted using the SPSS program (ver. 28.0) for χ²-test, t-test, one-way analysis of variance, Duncan's multiple range test, factor analysis, and Importance-Satisfaction Analysis (ISA). Results: Of the 249 subjects surveyed, 85.5% had some experience of purchasing meal-kits, with significantly more females than males (p < 0.01), significantly more married people than single people (p < 0.05), significantly more employed people than unemployed people (p < 0.05). Meal-kits were purchased most frequently for meals (60.6%), from discount stores or supermarkets (44.6%), and priced between 10,000 won and 20,000 won per person (46.9%). The overall satisfaction with meal-kits was 4.1 out of 5.0 points. The frequency of purchases was Korean soup dishes (69.5%), Korean main dishes (47.4%), and Korean street snacks (46.9%). Factor analysis of the meal-kit selection attributes revealed, 4 factors: 'quality of food,' 'packaging and diversity,' 'quality of meal-kit,' and 'convenience and price.' Compared to single-person households, multi-person households placed significantly higher importance on the 'quality of food,' 'packaging and diversity,' and 'quality of meal-kit.' The factor, 'packaging and diversity' were significantly higher in the importance evaluation scores for females (p < 0.01), married people (p < 0.05), and people in their 30s (p < 0.05) among meal-kit consumers. According to the ISA results, a critical aspect that meal-kit manufacturers or sellers should strengthen is 'price.' Conclusion: Meal-kit products will need to be developed for various purposes that offer high value for money that can satisfy the consumers' needs to improve the satisfaction of meal-kit consumers.