• Polymer(Korea)
• /
• v.37 no.1
• /
• pp.5-14
• /
• 2013

In this paper the effect of UV (ultraviolet) exposure on HDPE (high density polyethylene)-smooth and f-PP (flexible polypropylene) geomembranes is evaluated under UVB-313 (ultraviolet wavelength 290-315 nm) exposure. Tensile property, melt flow index (MFI), oxidation induction time (OIT), both standard-OIT and high pressure-OIT and Fourier transform infrared spectroscopy/attenuated total reflectance (FTIR/ATR) results are discussed. Although tensile properties of the exposed geomembrane samples remained unchanged, the depletion of antioxidants was found higher for f-PP than for HDPE geomembrane. Arrhenius model by extrapolation was used on the data to predict the antioxidant lifetime to a typical site temperature of $20^{\circ}C$. There was no significant difference between the MFI value of the virgin and UV exposed HDPE geomembrane samples but a decrease in MFI was found in f-PP geomembrane that signifies that crosslinking has occurred. From FTIR spectra, the small peak (near $1750\;cm^{-1}$) observed in the spectrum of UV exposed sample corresponds to a carbonyl (C=O) linkage, which suggests that oxidation has occurred in the polymer structure, and another new band for f-PP between 3100 and $3500\;cm^{-1}$ is attributed to a hydroxyl bond and/or hydroperoxide bond.

• Journal of Korea Water Resources Association
• /
• v.51 no.7
• /
• pp.555-564
• /
• 2018

The detention reservoir is a hydraulic structure that constructs a levee on the inland of river and sets up side weir in a section of the levee, and this facility stores a part of the flood volume in case of a flood event over a certain scale. In order to optimize the operation of detention reservoir, it is necessary to review the linkage with existing facilities in the river. In this study, the effect of water level reduction and the flow distribution was analyzed according to the location of the side weir in the detention reservoir considering the run-of-the-river gate. Two radial gates were installed in the experimental channel, and the water level in channel and the overflow of weir were measured by moving the location of the side weir upstream from the gate. As a results of experiment, it was confirmed that the water level reduction is more remarkable as the location of the side weir was closer to the gate, and the effect of flow distribution is not greatly changed. When two or more side weirs were operated, it is confirmed that the sufficient storage space was secured and the water level reduction effect with the location of the side weir is not large. In addition, the water level reduction rate according to the location of the side weir was estimated by empirical formula and it is provided as basic data that can be used in the planning of the detention reservoir.

• The Journal of the Korea Contents Association
• /
• v.21 no.9
• /
• pp.299-311
• /
• 2021

The purpose of this study is to analyze the ripple effect of the Chinese education industry on the national economy by using the industry-related table of 2017 by the China Statistical Office to use it as policy data for revitalization of the Chinese education industry in the future. To achieve this purpose, 149 industries in the basic classification of the industry-related table were classified into 32 industries. Based on these classifications, by analyzing the production induction coefficient, sensitivity coefficient, influence coefficient, yield inducement coefficient, production tax induction coefficient, and labor induction coefficient, etc. The purpose of this study is to understand the relationship between different industries and to find out the economic impact of the Chinese education industry. The analysis results show that in 2017, the total production induction coefficient of China's education industry was 1.7188, the row total was 1.0626, the sensitivity coefficient was 0.01211, the influence coefficient was 0.01958, the income induction coefficient was 0.6667, the production tax induction coefficient was 0.035, and the final demand was 1 billion yuan. When this occurs, the labor induction coefficient shows a total of 31,254 persons (indirect 15,541 persons, direct 15,713 persons). Based on the analysis results, this study suggested the implications that government support, technology introduction and application of new operating models, policy regulations, and efficient supervision of the system and president are required for further development of the Chinese education industry.

• Journal of Korea Port Economic Association
• /
• v.37 no.1
• /
• pp.19-30
• /
• 2021

The 21st Century Maritime Silk Road (MSR) is an important part of Belt and Road Initiative(BRI). As an economic and trade corridor for dozens of countries in Asia, Europe and Africa, and the port as an important link node, the efficiency of port operation directly affects the implementation of BRI's strategy. On the basis of combining BRI and related evaluation methods of port efficiency, this paper uses DEA-BCC model to select port production berth number and production berth length as input index container throughput and cargo throughput as output index to analyze the port efficiency of 14 ports in China. The results show that: (1) The overall efficiency level of the ports along the MSR is relatively low. Most of the ports have not reached the DEA efficiency and there are different degrees of problems in scale investment and technological improvement. However, this situation is accompanied by the implementation of China's maritime cooperation strategy and becoming better year by year. (2) The low operating efficiency of ports along China's MSR is mainly due to the lack of coordination between scale efficiency and technical efficiency, which is caused by insufficient scale investment in the port itself, weak economic linkage between the hinterland and the port, (3) Whether a port has a strong comprehensive strength does not entirely depend on the cargo throughput or scale but also includes the port's operating efficiency.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.31 no.6
• /
• pp.339-346
• /
• 2018

An Industry Foundation Classes(IFC), which is a data schema developed focusing on architecture, is being expanded to civil engineering structures. However, it is difficult to create an information model based on extended IFC since the BIM software cannot provide support functions. To manage a railway track based on the extended IFC, this paper proposed a method to create an alignment-centered separated railway track model and convert it to an extended IFC-based information model. First, railway track elements have been classified into continuous and discontinuous structures. The continuous structures were created by an alignment-based software, and discontinuous structures were created as independent objects through linkage of the discretized alignment. Second, a classification system and extended IFC schema for railway track have been proposed. Finally, the semantic information was identified by using the property of classification code and user interface. The availability of the methods was verified by developing an extended IFC-based information model of the Osong railway site.

• Journal of Internet of Things and Convergence
• /
• v.8 no.6
• /
• pp.21-26
• /
• 2022

This study aims to enhance the cultivation of SW·AI basic competencies of middle school students by forming and distributing SW·AI education programs for middle school students who form the basis of their lives. In addition, by planning SW·AI education programs in connection with the regular curriculum, it is intended to serve as a cornerstone for the public education of SW·AI education that will be implemented from 2025. To this end, the concept of SW and AI in middle school was first defined and a plan to link software/artificial intelligence learning factors to the regular curriculum was proposed, and based on this, SW·AI education programs for middle school students were prepared. Based on literature research, the understanding of artificial intelligence technology, the value of data, and the use of artificial intelligence technology in real life were set as SW·AI education contents, and educational programs were organized by linking them with the current middle school curriculum. All SW·AI education was organized in the form of practice rather than theory so that classes could be conducted centered on participants, and the purpose of the course was to cultivate the ability to use artificial intelligence technology in real life based on understanding artificial intelligence technology.

• The Journal of the Korea Contents Association
• /
• v.21 no.8
• /
• pp.424-441
• /
• 2021

The research is to analyze current situation of the coordinated development of "5 Region" and "4 Road" in Henan Province and put forward problems about the coordinated development of the "5 Region" and "4 Road" with the inland geographical location in China by drawing on the experience of the coordinated development of related industries in developed countries and regions based on China's "One Belt And One Road". According to the problems, a plan for the promotion of opening up to the outside world is provided. Through research, the following problems are found: First, the superposition advantage of five districts' and "four roads' has not been fully brought into play. Second, the collaborative linkage mechanism is not sound. Third, modern comprehensive transportation hub facilities are not fully completed. Fourth, the industrial support capacity is insufficient. Fifth, basic support is difficult to meet the needs of future development. The plan is as follows: First, building a top-level strategic platform and improve the policy support system. Second, we need to enhance the advantages of the four Silk Roads and accelerate their interconnected development. Third, establishing a coordination and mutual assistance mechanism to stimulate the superposition effect of industrial clusters. The significance of this study is that it can be used as research data to predict the future direction of China's "One Belt and One Road" policy and enlightenment to stimulate the economic revitalization of inland provinces.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.1
• /
• pp.19-29
• /
• 2022

This study was conducted with the aim of verifying the effects of restaurant video taping and job communication drawing board production activities on cooking job skills of high school students with intellectual disabilities. The study participants consisted of three students with intellectual disabilities enrolled in the high school course of a special school, and the experimental environment consisted of a kitchen in the restaurant and a classroom in the special school. For the research design, the technique of multiple probe design across subjects according to a single subject research was used. The intervention program consisting of independent variables was applied as a linkage procedure in which study participants videotaped the kitchen's environmental facilities, tools, materials, and staff perform cooking job skills and then taped data from the classroom scene on a job communication drawing board. Cooking job skills consisting of dependent variables are defined as the performance of research participants cooking gimbap directly in the kitchen of the restaurant. As a result of the study, it was found that participants effectively acquired, maintained, and generalized cooking job skills through intervention programs.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.4
• /
• pp.581-590
• /
• 2022

It is important to create a decent pedestrian space in order to realize a public space that can ultimately improve the quality of life based on guaranteeing people's right to move while also enhancing urban activity. The goal of this study is to develop a pedestrian path evaluation system in order to lay the foundation for data construction leading to the creation of such elegant walking space. First, a basic system was established in keeping with factors and the space, and this system was used as the basic framework of the study. The trends identified in the literature can be divided into eight categories, denoted here as: Walking safety policy, Walking focused plan, Recognition transition, Transportaion system, Activity-linked walking, Facility utilization walking, Nature and history linked walking and Content convergence walking. The macro- and micro-indices and factors mentioned in related studies were synthesized and classified, and the basis for universality and differentiation was established by integrating them. Next, according to the basic composition of the walking system, Walking potential and slope safety in the Safety category, Basic walking connectivity and Traffic linkage in the Efficiency category, Walking arrangement and Rest convenience in the Health category, and Resource connectivity and Activity abundance in the Comfortability category macro evaluation system of the eight categories were established and a corresponding measurement method was developed.

• Korean Journal of Mineralogy and Petrology
• /
• v.35 no.3
• /
• pp.199-214
• /
• 2022

The Yeongnam Massif is one of representative basement provinces in the Korean Peninsula, which has experienced high-temperature, low-pressure (HTLP) regional metamorphism and partial melting. Here we reviewed recent developments in Paleoproterozoic (1.87-1.84 Ga) hot orogenesis of the Yeongnam Massif, typified by the granulite-facies metamorphism and partial melting recorded in the HTLP rocks. In particular, spatiotemporal linkage between the metamorphic and magmatic activities, including the Sancheong-Hadong anorthositic magma as a heat source, provides a key to understand the widespread HTLP metamorphism and partial melting in the Yeongnam Massif. Crustal anatexis, resulting from the fluid-present melting and muscovite/biotite dehydration melting, has yielded various types of leucosomes and leucogranites. Zircon and monazite petrochronology, using in-situ U(-Th)-Pb data from the secondary ion mass spectrometry, indicates that the HTLP metamorphism and anatexis lasted over a period of ~15 Ma at ca. 1870-1854 Ma. In addition, a fluid influx event at ca. 1840 Ma was locally recognized by the occurrence of incipient charnockite. Taken together, the Yeongnam Massif preserves a prolonged evolutionary record of the HTLP metamorphism, partial melting, and fluid influx diagnostic for a hot orogen. Such an orogen is linked to the Paleoproterozoic orogeny widespread in the North China Craton, and most likely represents the final phase of crustal evolution in the Columbia/Nuna supercontinent.