• Journal of Sensor Science and Technology
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• v.6 no.5
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• pp.346-355
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• 1997

In this paper, the analyses of the stress disturibution and frequency characteristics of silicon microstructures for an accelerometer were performed using the general purpose finite element simulation program, ANSYS. From the analyses, we determined the parameter values of a new 6-beam piezoresistive accelerometer applicable to the accelerometer's specification in airbag system of automobile. Then, the mass paddle radius, beam length, beam width, and beam thickness of the designed accelerometer were$500{\mu}m$, $350{\mu}m$, $100{\mu}m$, and $5{\mu}m$, respectively and two different seismic masses with 0.4 mg and 0.8 mg were defined on the same sensor structure. The designed 6- beam accelerometers were fabricated on the selectively diffused (111)-oriented $n/n^{+}/n$ silicon substrates and the characteristics of the fabricated accelerometers were investigated. Then, we used a micromachining technique using porous silicon etching method for the formation of the micromechanical structure of the accelerometer.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.609-623
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• 2004

Various metadata registries have been built in many countries of the world. Although the metadata registry is an international standard, it does not provide a consistent access interface for handling the metadata registries. Therefore, all systems for managing them were developed by using different operations and access interfaces. It requires duplicate efforts on the same operations whenever metadata registry systems are developed. As a result, it causes unnecessary costs and efforts for building metadata registries, and also incurs inconsistency between the metadata registries because the previous developed systems use the different interfaces for the metadata registry elements This paper analyzes and defines operation patterns that are commonly used for the metadata registries. We defined and designed SQL/MDR extended from SQL using the analyzed operation patterns. SQL/MDR provides a standardized access interface for developing metadata registry systems. This paper shows the implementation of SQL/MDR and the result that we actually applied it to the bibliographical databases. By developing the metadata registry systems using SQL/MDR, we can reduce much time and efforts owing to its standard interface. It allows metadata registries to be accessed consistently. Additionally, it makes all metadata registries follow the international standard, ISO/IEC ll179.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.1-9
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• 2019

In the recent marine sector, the development and standardization regarding S-100, which is the universal hydrographical data model standard for development of marine space information, was progressed, and for the effectiveness of marine chart production work and the multi-purpose use of water level data in S-100, S-102(Bathymetric Surface grid) standard development and various studies of BAG formats combined with water level and uncertainty, property information is being progressed. Since the water level information that is important in the operation of the ship is provided based on S-102, the calibration method of the location information when producing S-102 is an important factor in deciding the water level. In this study, the hydrographical surveying was conducted by piloting the standardized method for the production of S-102 in Korea, and have compared the accuracy of water level information according to the GNSS post treatment calibration method. As a result of comparing the water level in 2 places in the rocky terrain of the study area, the northern water level of Namu-do was shown as DL 0.79~0.83m, the eastern water level of Daeho-do was DL 12.63~12.91m, and the horizontal position errors of the intermittent sunshine water level were confirmed to be within 1m. As a result, the intermittent sunshine water level according to the location calibration method when producing the BAG was confirmed that it was in the available range for a ship's safe voyage. However, the accuracy verification for the location of the ship when conducting hydrographical surveying was judged that there is a need for a various additional study about regional characteristics and environment factor.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.372-381
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• 2019

This study was conducted to find proof for the hypothesis that the God tree of Chosun has been misrepresented in Chosun-Gersu-Nosu-Myungmokji (CGNM). The following results were obtained. First, it was established that 64 species and 3170 trees were recorded in CGNM. An old, big tree is classified as a God tree if linked to it there are testimonies and legends about divine elements, and it is classified as a Noble tree if linked to it there are testimonies and legends of historical elements. In total, 2632 trees of eight species were analyzed, from the Zelkova serrata, which has the greatest number of trees, to the eighth most frequent, Abies holophylla. The means of diameter at breast height (DBH), height, and age of the God and the Noble trees were calculated for each of the eight species. In seven out of eight species, the DBH and age of the Noble tree were more than those of the God tree. In addition, the height of the Noble tree was more than that of the God tree in six out of eight species. The fact that the God tree is smaller than the Noble tree, contrary to the common expectation that the Noble tree is a small size tree, was confirmed. This hypothesis was proved by the data gathered. Second, the Japanese Government-General of Korea has pursued a policy to defeat the village ritual based on the God tree being linked with superstition. For such a policy, the God tree should be small and unattractive, and it would have been good for the tree to be superstitious. The CGNM was created as explanatory material or evidence for distorting the sacredness of the God tree of Chosun. Third, CGNM compiled a chronological order of DBH data to make it easy to explain the fabricated facts that the God tree of Chosun is smaller and dwarfed compared to the Noble tree.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.130-137
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• 2021

This study evaluated newly introduced, commercial super sweet corn hybrids (Zea mays L.) for their potential as breeding materials. Agronomic traits were measured and variance components were obtained using a linear mixed model to estimate the heritability. The trials were carried out in 2018 at two locations (Haenam and Oksan in South Korea). All traits had low heritability, except for mid tasseling and silking days. These traits with low heritability mostly had low genetic variance component estimate. In case of ear height ratio, significant genotype by location appeared to be responsible for low genetic variance, which in turn led to low heritability. Low heritability estimates from the trials with commercial hybrids were perhaps because those hybrids were highly improved for commercial success. Hence, this does not necessarily point to them having poor potential as breeding materials. To overcome low heritability, significant genotype by environment interaction, and achieve high selection efficiency, intermating among hybrids is recommended to create new recombinants before inbred line development.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.129-151
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• 2022

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of piles when the adjacent tunnelling passes underneath grouped piles with a reinforced pile cap. In the current study, the numerical analysis studied the computed results regarding the ground reinforcement condition between the tunnel and pile foundation. In addition, several key issues, such as the pile settlements, the axial pile forces, the shear stresses and the relative displacements have been thoroughly analysed, and the IoT platform based preliminary design guidelines were also presented. The pile head settlements of the nearest pile from the tunnel without the ground reinforcement increased by about 70% compared to the farthest pile from the tunnel with the maximum level of reinforcement. The quality management factor data of the piles were provided as API (Application Programming Interface) of various forms by the collection and refinement. Hence it has been shown that it would be important to provide the appropriate API by defining the each of data flow process when the data were created. The behaviour of the grouped piles with the pile cap, depending on the amount of ground reinforcement, has been extensively analysed, and the IoT platform regarding the quality management of piles has been suggested.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1267-1273
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• 2022

Although the Korea shipbuilding industry has recently been receiving most of the orders for ships in the world, production processes are being disrupted due to a shortage of manpower at the production site. This is because the workers quit the shipyard as both work and wages were reduced due to the long slump in the shipbuilding industry. The main reason for the increase in orders was the large-scale orders for Qatar LNG carriers, and the situation in which the technical specifications required for ships are becoming more complex is also working to an advantage. Because the contract delivery time is of utmost importance for ships, the dock launch plan is the most important management item among the shipyard's major processes. The structure to be built in the dock may be a hull that has left the design work or a finished vessel, and in some cases, it is often at the level of some blocks of the hull. When launching, the hull is affected by the hogging or sagging moment due to the fluid force, and securing the safety of the structural strength of the block connection is of utmost importance. In a normal process, the connecting member launches after welding has been completed, but in actual shipbuilders, quick decision-making is needed on the conditions for securing structural safety to comply with the docking schedule. In this study, a detailed analysis method and applicability using a bending stress evaluation method and finite element analysis modelling were analyzed to rationally judge the above-mentioned problems from an engineering point of view. The main contents mentioned in the thesis can be used as good examples when conducting similar structural strength evaluations in the future.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.9
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• pp.815-823
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• 2017

The purpose of this study is to investigate the need for practical evaluation of special education field based on the analysis of the importance - performance of special education basic curriculum academic achievement evaluation area. The evaluation categories and areas for the analysis of importance and performance are set in 4 categories - 22 areas of life education derived from Delphi analysis and 7 categories- 27 areas in special education basic curriculum. As a result of analyzing the importance and performance of 126 teachers of intellectual disability special schools in P metropolitan city, statistically significant difference was shown between importance and performance in all areas. As a result of analysis of scatter plot with x - axis and significance as y axis based on averaging point, some elements of subject education showed low recognition level both in importance and execution. The results of this study suggest the necessity of restructuring the evaluation area and the evaluation system of the basic education curriculum of the special education and further revise the contents of the curriculum of the national level basic curriculum and the content area, It implies that discussion is needed.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.147-153
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• 2023

As it spreads to all industries of artificial intelligence technology, AIaaS equipped with artificial intelligence services is emerging. In particular, non-IT companies are suffering from the absence of software experts, difficulties in training big data models, and difficulties in collecting and analyzing various types of data. AIaaS makes it easier and more economical for users to build a system by providing various IT resources necessary for artificial intelligence software development as well as functions necessary for artificial intelligence software in the form of a service. Therefore, the supply and demand for such cloud-based AIaaS services will increase rapidly. However, the quality of services provided by AIaaS becomes an important factor in what is required as the supply and demand for AIaaS increases. However, research on a comprehensive and practical quality evaluation metric to measure this is currently insufficient. Therefore, in this paper, we develop and propose a usability, replacement, scalability, and publicity metric, which are the four metrics necessary for measuring reusability, based on implementation, convenience, efficiency, and accessibility, which are characteristics of AIaaS, for reusability evaluation among the service quality measurement factors of AIaaS. The proposed metrics can be used as a tool to predict how much services provided by AIaaS can be reused for potential users in the future.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.23-28
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• 2016

In spite of various merit of algae as biofuel, the production cost of algae is a considerable obstacle for commercialization. The concurrent development of essential technologies is needed for the cultivating, harvesting, extracting and energy transformation. The production cost of algae biofuel has still higher than that of the other commercial biofuel. The major research activity has been focused on the cultivating and the research of other processes has been done with relatively lower activity. It is difficult to separate the algae from water because of the similar magnitude of density each other. The agglomeration and extracting of algae with the hybrid technology using ultrasonic wave is rare effect of environmental hazard and also it is appropriate technology for the next generation energy resources. The present research is investigated for the effective separation of algae from water with the ultrasonics wave. The aim of the present research is focused on the establishment of optimal design of algae agglomeration system. For this purpose, the computational fluid dynamic analysis has been conducted in the flow field with ultrasonic wave and algae flow to clarify the mechanism of algae separation by ultrasonic wave.