• Conservation Science in Museum
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• v.5
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• pp.49-57
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• 2004

The Divine Bell of King Seongdeok was completed in 771 A.D. It is a true masterpiece both grand in its size and style (height 3.66 m, diameter 2.23 m, thickness 20.3 cm, weight 18.9 ton), illustrating the essence of the Korean bronze culture. However, there are no remaining records about its casting: where the raw material came from, how the materials were mixed and how the bell was casted. The absence of such records has limited the understanding of the bell. This article contains analysis of three samples collected from a protruding part inside of the bell during a safety test for the bell by the Gyeongju National Museum. The main issues are the element composition of the bell, microstructure on the casting time and the source where the raw material came from.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.291-297
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• 2008

The launch of the COMS by using Ariane-5 launch vehicle is introduced. First, the COMS is introduced briefly, and then, the Ariane-5 launch vehicle is introduced including detail description of the improvement of Vulcain-1 engine of Ariane-5G to Vulcain-2 engine of Ariane-5ECA for 20% increase of thrust. Then, the launch process of the COMS is introduced. The COMS will be launched from the Guiana Space Center in Kourou, French Guiana. After the final check at PPF the COMS is transferred to HPF in the same building for fueling, and it is integrated to the launch vehicle adaptor at HPF, too. Then, this assembly is transferred to Final Assembly Building. After the satellites to be launched together are integrated to the launch vehicle on the launch table in the Final Assembly Building, the launch table loaded with the launch vehicle is moved to the launch pad for launch. The events during the launch vehicle flight is also introduced.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.3
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• pp.376-389
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• 2012

Ethnic entrepreneurship, an important means by which immigrants improve economic status, is widely believed to be facilitated by their residential concentration, i.e. ethnic enclaves. However, the recent immigrants' residential dispersion and re-clustering in some selected well-to-do suburbs portend changes in the role of ethnic enclave as a nest of immigrant entrepreneurship. This paper investigates the impacts of the residential dispersal on ethnic entrepreneurship with a case study of Korean small businessmen in Chicago, Illinois PMSA. The research utilizes the Public Use Microdata Sample (PUMS) to know the overall changes in Korean entrepreneurship through 1990s and conducts a survey to understand reactions and surviving strategies of Korean enclave businessmen to the residential shifts. Relevant to those analyses is the enclave-economy hypothesis which argues benefit from spatial clustering of co-ethnic entrepreneurs by yielding more business opportunities and higher returns.

• Journal of the Korean Geosynthetics Society
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• v.3 no.4
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• pp.41-48
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• 2004

Recently a method for increasing the bearing capacity by laying the reinforcing materials with three or four layers as a method reinforcing the ground was studied recently. The purpose of this study is to examine the method for increasing shear-strength factor of the ground by reinforcing the ground under the foundation. According a method of wrapping ground with bakk-shape or semicircle-shape by geotextile was developed in this study and it looks likes anaspect that spreading footing exits under spread footing. A simulation loading-test using Aluminum sticks was carried out in order to examine the mechanism about bearing capacity of spread footing reinforced by geotextile. Increase of ultimate bearing capacity was verified in this simulation loading-test when charging loads to spread footing, which is propose from this study, reinforced by geotextile. And moving directions of points of the ground were also checked by grid-type indication method, and the areas where plastic failure appeared were checked by B-shutter photographing.

• Journal of Appropriate Technology
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• v.6 no.1
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• pp.28-36
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• 2020

Sustainable appropriate technology requires user-centered design with consideration of the political, cultural and environmental aspects of the area. However, in the preparation of appropriate technology, there is a limit to the prior grasp of the user's intention and experience leading to the actual behavior of the user after the dissemination. As a result, appropriate technologies are often inconvenient for practical use or used for other purposes, contrary to the designer's intention. This study analyzes the case of appropriate technology with an analysis framework that reflects Maier's affordance theory, and proposes a design solution that can overcome the limitations of existing design. Affordance theory is the theory of factors that cause the user to identify and use features through interpretation based on prior knowledge and experience about things. The analysis cases in this study are the interviews with the designers, management education materials, and manager interviews for water purification systems at three of six schools in Binh Dinh Province, Vietnam, from August 2015 to January 2018. The case was attempted to be improved by periodic installation, maintenance, and inspection, but similar problems continued to occur. First, the facility inspections and manager interviews are compared with manager training materials distributed at the time of installation to find inconsistencies. Next, we analyze the designer's intended affordance and the affordances that actually influenced the management behavior. And then, we propose design solutions based on commonly found problems and affordances. This study suggests that it is necessary to apply the design considering the user's behavior before distributing the appropriate technology, and this study will be precedent in the process of finding the improvement through the analysis framework based on the affordance.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.86-90
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• 2009

The definition of edible ice is frozen water for the use of food manufacturing, processing, or cooking, as well as for the direct eating. It has been reported that in the process of ice manufacturing and its selling, edible ice is contaminated with some microorganisms, which causes food poisoning and gastroenteritis. It was shown that besides in the edible ice, germ growth caused by various reasons occurred in the mineral water, tap water, water filtering system, and water purifier. With public awareness, in order to examine the sanitary conditions of edible ice in the Northern area of Daegu metropolitan city, 15 places were randomly selected. As a result, 14 places were found to be contaminated with microorganisms. After incubating on the Brain Heart Infusion (BHI) agar plate, 80% of Gram-negative bacilli, 17% of Gram-positive cocci, and 3% of Gram-negative cocci were cultured. Enterobacter cloacae, Chryseomonas luteola, Pantoea spp., Klebsiella pneumoniae, Acinetobacter baumannii, Acinetobacter calcoaceticus or Providencia rettgeri were detected. Gram-positive cocci cultured in BHI agar plate from 5 specimens were identified as Staphylococcus aureus or Staphylococcus xylosus, which is well known bacteria causing strong food poisoning. This present paper raises questions on the importance and awareness of sanitary conditions of edible ice and the identification of pathogenic microorganisms living in the edible ice in relation to their distribution. The examination of sanitary conditions of edible ice in other areas in Daegu seems to be also needed to find out if there are similar cases.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.175-181
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• 1993

Radiosurgery requires integral procedure where special devices and computer systems are needed for localization, dose planning and treatment. The aim of this work is to verify the overall mechanical accuracy of our LINAC and develop dose calculation algorithm for LINAC radiosurgery. The alignment of treatment machine and the performance testing of the entire system were extensively carried out and the basic data such as percent depth dose, off-axis ratio and output factor were measured. A three dimensional treatment planning system for stereotactic radiosurgery has been developed. We used an IBM personal computer with C programming language (IBM personal system/2, Model 80386, IBM Co., USA) for calculating the dose distribution. As a result, deviations at isocenter on gantry and table rotation for our treatment machine were acceptable since they were less than 2 mm. According to the phantom experiments, the focusing isocenter were successful by the error of less than 2 mm. Finally, the mechanical accuracy of our three dimensional planning system was confirmed by film dosimetry in sphere phantom.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.84-92
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• 2020

Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.

• Journal of the Korean earth science society
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• v.43 no.3
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• pp.446-463
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• 2022

This study suggests the need for polar literacy education as an effective conceptual system to explain climate change in terms of science education in line with the common effort of humankind to respond to global environmental changes. To this end, we investigated the status of polar literacy in high school students through quantitative tests and qualitative interviews and discussed the resulting implications. A total of 329 high school sophomore students from two high schools participated in a test consisting of 25 true and false questions developed by referring to the Polar Literacy Principles, while 13 students agreed to be interviewed. The results showed that a somewhat insufficient understanding and conceptual gaps appeared regarding several areas of the Polar Literacy Principles. Knowledge of the geographic features of the polar regions was weak, and little was known about the components and key characteristics of the cryosphere. The lack of understanding of these concepts results in the inability of students to link the operational mechanisms of polar and global climate change sufficiently. While accepting unsatisfactory concepts in the school curriculum without criticism from outside media, students perceived the mechanism of climate change as somewhat monotonous or distorted. Moreover, linguistic information, analogies, and visual observation were used as cognitive strategies to compensate for the ambiguous understanding of polar and climate change. Based on the abovementioned results, we argue that polar literacy education should be introduced as a new knowledge system that can be used to aid a systematic and comprehensive understanding of climate change within the school science curriculum. Additionally, we suggest the following implications: review the consistency of knowledge related to polar literacy in other subjects, provide critical standards for out-of-school media information related to climate change, examine students' misconceptions, and identify improved thinking strategies.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.501-508
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• 2021

The purpose of this study was to evaluate the application of ATP bioluminescence assay for effect assessment of hygiene visiting education on children's foodservice facilities in the local small town. The sanitary inspection results of the hygiene visiting education showed significant improvement in all items except 'To regularly disinfect cooking facilities, storage rooms, etc.' ATP bioluminescence analysis was performed on cooking utensils to evaluate the educational effect, and the results showed a correlation with the effect in most items. In the case of knives and cutting boards, all facilities showed a value of 20 RLU/cm² or less after the educational support, and in particular, it was approximately 10 RLU/cm² or less in national/public, corporation and private facilities. Correlation analysis between the post-education sanitary inspection results and ATP values for three items related to knives and cutting boards showed that they have a negative and high correlations.