• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.111-121
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• 2010

Purpose: This 3D-FEA study was performed to investigate the influence of marginal bone loss pattern around the implant to the stress distribution. Material and methods: From the right second premolar to the right second molar of the mandible was modeled according to the CT data of a dentate patient. Teeth were removed and an implant ($\Phi\;4.0{\times}10.0mm$) was placed in the first molar area. Twelve bone models were created; Studied bone loss conditions were horizontal bone loss and vertical bone loss, assumed bone loss patterns during biologic width formation, and pathologic vertical bone loss with or without cortification. Axial, buccolingual, and oblique force was applied independently to the center of the implant crown. The Maximum von Mises stress value and stress contour was observed and von Mises stresses at the measuring points were recorded. Results: The stress distribution patterns were similar in the non-resorption and horizontal resorption models, but differed from those in the vertical resorption models. Models assuming biologic width formation showed altered stress distribution, and weak bone to implant at the implant neck area seams accelerates stress generation. In case of vertical bone resorption, contact of cortical bone to the implant may positively affect the stress distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1288-1298
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• 2002

To implement elliptic curve cryptosystem in GF(2$\^$m/) at high speed, a fast divider is required. Although bit-parallel architecture is well suited for high speed division operations, elliptic curve cryptosystem requires large m(at least 163) to support a sufficient security. In other words, since the bit-parallel architecture has an area complexity of 0(m$\^$m/), it is not suited for this application. In this paper, we propose a new serial-in serial-out systolic array for computing division operations in GF(2$\^$m/) using the standard basis representation. Based on a modified version of tile binary extended greatest common divisor algorithm, we obtain a new data dependence graph and design an efficient bit-serial systolic divider. The proposed divider has 0(m) time complexity and 0(m) area complexity. If input data come in continuously, the proposed divider can produce division results at a rate of one per m clock cycles, after an initial delay of 5m-2 cycles. Analysis shows that the proposed divider provides a significant reduction in both chip area and computational delay time compared to previously proposed systolic dividers with the same I/O format. Since the proposed divider can perform division operations at high speed with the reduced chip area, it is well suited for division circuit of elliptic curve cryptosystem. Furthermore, since the proposed architecture does not restrict the choice of irreducible polynomial, and has a unidirectional data flow and regularity, it provides a high flexibility and scalability with respect to the field size m.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.148-155
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• 2002

Multithreaded models improve the efficiency of parallel systems by combining inner parallelism, asynchronous data availability and the locality of von Neumann model. This model executes thread code which is generated by compiler and of which quality is given by the method of generation. But multithreaded models have the demerit that execution model is restricted to a specific platform. On the contrary, Java has the platform independency, so if we can translate from threads code to Java bytecode, we can use the advantages of multithreaded models in many platforms. Java executes Java bytecode which is intermediate language format for Java virtual machine. Java bytecode plays a role of an intermediate language in translator and Java virtual machine work as back-end in translator. But, Java bytecode which is translated from multithreaded models have the demerit that it is not secure. This paper, multhithread code whose feature of platform independent can execute in java virtual machine. We design and implement translator which translate from thread code of multithreaded code to Java bytecode and which check secure problems from Java bytecode.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.431-440
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• 2014

To propose the improvement and management plans to strengthen the pollutant removal efficiency of dam reservoir's constructed wetlands(CWs), the operation status and configuration of CWs (including water depth, operational flow, water flow distribution, residence time, and pollutant removal efficiency, aspect ratio, open water/vegetation ratio etc.) were analyzed in 10 major wetlands constructed in dam reservoirs. The pollutant concentrations in the inflows of the studied CWs were lower than those of American and European constructed wetlands. Especially, organic matter concentrations in all of inflows were below 3 mg/L(as BOD) due to advanced treatment of sewage disposal plant and an intake of low concentration water during dry and normal seasons. The average removal efficiency of total nitrogen(TN) and total phosphorus(TP) for 10 CWs ranged from 7.6~67.6%(mean 24.9%) and -4.9~74.5%(mean 23.7%), respectively, showing high in wetlands treating municipal wastewater. On the other hand, the removal efficiency of BOD was generally low or negative with ranging from -133.3 to 41.7%. From the analysis of the operation status and configuration of CWs, it is suggested that the low removal efficiency of dam reservoir's CWs were caused by both structural (inappropriate aspect ratio, excessive open water area) and operational (neglecting water-level management, lack of facilities and operation for first flush treatment, lake of monitoring during rainy events) problems. Therefore, to enable to play a role as a reduction facility of non-point source(NPS) pollutants, an appropriate design and operation manuals for dam reservoir's CW is urgently needed. In addition, the monitoring during rainy events, when NPS runoff occur, must be included in operation manual of CW, and then the data obtained from the monitoring is considered in estimation of the pollutant removal efficiency by dam reservoir's CW.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.103-115
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• 2016

The 106 buildings of 200 meters' height or greater were completed around the world in 2015 (CTBUH, The Council on Tall Buildings and Urban Habitat). They beat every previous year on record, including the previous record high of 99 completions in 2014. This brings the total number of 200-meter-plus buildings in the world to 1,040, exceeding 1,000 for the first time in history and marking a 392% increase from the year 2000, when only 265 existed. South Korea recorded three completions during 2015 - improving slightly over 2014, in which it had one. This study focused on the fact that high-rise building development project risks have not reduced in Korea in spite of numerous studies and measures. And it attempted to examine whether existing studies and measures have been presented on the basis of the accurate analysis of existing studies and measures and classify and analyze the characteristics of each phase' s risk factors in the hope that its results would be one reference point as to the measure to prevent high-rise building development project risks in the future. A high-rise building development project is the high risk project as compared with the low-rise project. Because a high-rise development project takes long and is very sensitive to the changing environment. Therefore, in order to succeed the project it becomes necessary to effectively manage the risk involved in the process of the high-rise building development project. The result of this study can be used as the guideline to make the risk management system for the high-rise development project.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.483-490
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• 2009

The aims of this study were to evaluate the removal efficiency for various pollutants in urban storm runoff by a filtration device, and to determine design parameters depending on filter media properties. Appropriate selection of filter media will affect the size and life time of the filtration device. Sets of column tests were performed in order to evaluate the removal efficiency by perlite and a synthetic resin. An investigation of surface properties including CEC (cation exchange capacity) and zeta-potential suggested that the perlite had a superior adsorption capability for cationic pollutants. TCODcr and turbidity were analyzed to investigate the removal characteristic of particulate pollutant. In both columns, the particles in the collected storm runoff was almost completely capture with a small EBCT (empty bed contact time) of 2.5 minutes. Complete clogging at the EBCT of 2.5 minutes occurred after 630 minutes in the perlite column and 810 minutes in the resin column. The removal efficiency of TCODcr and turbidity at the EBCT of 2.5 minutes decreased to below 70% due to an wall effect. The removal efficiency for dissolved pollutant (SCODcr) was negligible due to the insufficient contact time for adsorption. The removal of heavy metals (Cu, Zn, Pb) was mostly ascribed to the filtration of particles containing metals, since the relationship between CEC and the removal efficiency was not apparent. The result of this study would be valuable for the application of filtration device to control of urban storm runoff.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.238-259
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• 2021

Gameunsa Temple is a Buddhist temple from the mid-Silla period. Construction began during the reign of King Munmu and was completed during the second year of King Sinmun's reign (682). This study is based on the results of excavations at the Gameunsa Temple site, exploring the findings presented in the literature in the field of history. This study also investigates the characteristics of the construction plan of Gameunsa Temple and its correlation with the political, social, and religious environment of the time. The results of the study are as follows: (1) First, it is confirmed that all of the buildings in the central block of Gameunsa Temple, such as the pagoda and corridor, the central gate, and the auditorium, fit within 216 cheoks by 216 cheoks (Goguryeo unit of measurement, estimated dimensions 353.30 mm), in terms of the base structure. This fact is highly significant considering the intent of the King in the mid-Silla period to advocate Confucian political ideals at the Donghaegu sites (Daewangam, Igyeondae Pavilion, and Gameunsa Temple), as confirmed by the relationship between the 'Manpasikjeok legend' and the Confucianism of the etiquette and the music; the relationship between the name of the 'Igyeondae Pavilion' and the 'I Ching'; and the relationship between the 'Taegeuk stones excavated from the Gameunsa Temple site' and the 'I Ching.' Additionally, it may be presumed that the number in the "Qian 216" on the Xici shang of 'I Ching' was used as a basis for determining the size of the central block in the early stages of the design of Gameunsa Temple. The layout of the halls and pagodas of Gameunsa Temple was planned to be within a 216-cheok-by-216-cheok area, from the edge to the center, i.e., on the central axis of the temple, in the following order: the central gate and auditorium, the north-south position of Geumdang Hall, the south corridor, the east-west buildings of the auditorium and the winged corridor, the east-west corridor, and the central position of the east-west stone pagoda. (2) Second, the coexistence of Confucianism and Buddhism in the architecture of Gameunsa Temple is based on the understanding of the Golden Light Sutra, originating from the aspirations of King Munmu to obtain the immeasurable merits (陰陽調和時不越序 日月星宿不失常度 風雨隨時無諸災横) and the light of the Buddha, which is metaphorically represented by the sun and the moon illuminating the whole world of Silla, a new nation with a Confucian political ideology, for a long time by "circumambulating the Buddha (旋繞)". It is also presumed that Gyeongheung, who was appointed by King Munmu to be the Guksa in his will and appointed as the Gukro after the enthronement of King Sinmun, was deeply involved in the conception and realization of the syncretism of Confucianism and Buddhism.

• Food Science and Industry
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• v.55 no.2
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• pp.188-202
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• 2022

In the insect industry, as the scope of application of insects is expanded from pet insects and natural enemies to feed, edible and medicinal insects, the demand for quality control of insect raw materials is increasing, and interest in securing the safety of insect products is increasing. In the process of expanding the industrial scale, controlling the temperature and humidity and air quality in the insect breeding room and preventing the spread of pathogens and other pollutants are important success factors. It requires a controlled environment under the operating system. European commercial insect breeding facilities have attracted considerable investor interest, and insect companies are building large-scale production facilities, which became possible after the EU approved the use of insect protein as feedstock for fish farming in July 2017. Other fields, such as food and medicine, have also accelerated the application of cutting-edge technology. In the future, the global insect industry will purchase eggs or small larvae from suppliers and a system that focuses on the larval fattening, i.e., production raw material, until the insects mature, and a system that handles the entire production process from egg laying, harvesting, and initial pre-treatment of larvae., increasingly subdivided into large-scale production systems that cover all stages of insect larvae production and further processing steps such as milling, fat removal and protein or fat fractionation. In Korea, research and development of insect smart factory farms using artificial intelligence and ICT is accelerating, so insects can be used as carbon-free materials in secondary industries such as natural plastics or natural molding materials as well as existing feed and food. A Korean-style customized breeding system for shortening the breeding period or enhancing functionality is expected to be developed soon.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.2
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• pp.1-10
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• 2023

This study aims to explore the significance of historic changes and cultural characteristics of landscape architecture in Korean Seowon. Seowon refers to educational private institutes that also served as Confucian shrines and were prevalent during the mid-to-late Joseon dynasty. Seowon comprised three distinct functional spaces: a shrine, a school, and a garden. The concept of Seowon's garden extended beyond designed landscapes to include the surrounding natural environment. The importance of landscape architecture in Seowon is rooted in its connection to the educational philosophy of these institutes. During the Joseon dynasty, scholars revered nature as a manifestation of Confucian ideals, and they believed that close engagement with nature was integral to self-discipline and learning. This research investigated fifteen relatively well-preserved garden in South Korea and conducted a comprehensive analysis of their gardens. The analysis revealed two key findings. Firstly, gardens in Seowon were actively designed and constructed during the early phase of Seowon culture but gradually diminished after the 17th century. This can be attributed to the shift in Seowon's purpose, with a greater emphasis on its religious function over education. Consequently, the significance and presence of landscape architecture in Seowon, which was closely related with its Confucianist education, declined. Secondly, the study explored the historical backgrounds of each Seowon's landscape architecture and found that many of them were designed or influenced by individuals who were later memorialized and deified in the Seowon's shrines. The landscape architecture created by these predecessors was carefully preserved by the faculties and students as a form of respect. Therefore, landscape architecture in Korean Seowon not only conveys the institutional purpose as an educational hub for the local society but also reflects the institute's strong relationship with the figures they worship as shrines.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.57-70
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• 2009

Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.