• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.12
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• pp.1009-1015
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• 2014

The present study investigated the effects of non-equilibrium condensation with the angle of attack on the coefficients of pressure, lift, and drag in the transonic 2-D flow of NACA0012 by numerical analysis of the total variation diminishing (TVD) scheme. At $T_0=298k$ and ${\alpha}=3^{\circ}$, the lift coefficients for $M_{\infty}=0.78$ and 0.81 decreased monotonically with increasing ${\Phi}_0$. In contrast, for $M_{\infty}$ corresponding to the Mach number of the force break, $C_L$ increased with ${\Phi}_0$. For ${\alpha}=3^{\circ}$ and ${\Phi}_0=0%$, $C_D$ increased markedly as $M_{\infty}$ increased. However, at ${\Phi}_0=60%$ and ${\alpha}=3^{\circ}$, which corresponded to the case of the condensation having a large influence, $C_D$ increased slightly as $M_{\infty}$ increased. The decrease in profile drag by non-equilibrium condensation grew as the angle of attack and stagnation relative humidity increased for the same free stream transonic Mach number. At ${\Phi}_0=0%$, the coefficient of the wave drag increased with the attack angle and free stream Mach number. When ${\Phi}_0$ > 50%, the coefficient of the wave drag decreased as ${\alpha}$ and $M_{\infty}$ increased. Lowering ${\Phi}_0$ and increasing $M_{\infty}$ increased the maximum Mach number.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1010-1013
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• 2009

The youths of the farming village have moved to the metropolis, thus the most of the manpower which engages to a production remained in the village reaches layer old age and all thing sprouts long the whole and it is one. So to remove the waste of barn rather than to give feed to the livestock is hard that what step all automation of this part is necessary. Consequently we have developed the automation system in order to reduce the massive death of the livestock at the time of intense cold and hot. The system will be able to clean the waste of the barn and confront quickly in the change of temperature which is sudden it came. And we proposed also the system that will be able to watch at real-time and monitor the operational environment from a remote using CCD camera. In this paper, we proposed the remote control system which uses PDA in order to control the automation system of a stall while moving. The proposed system was embodied in order for the control and the monitor while the user is mobile using PDA screens. We also added a protection system in that system. The system sends the case warning and SMS while will have the fire and the intrusion from the outside and prevents a robbery.

• Food Science and Preservation
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• v.18 no.3
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• pp.302-309
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• 2011

This study was performed to analyze the physicochemical and sensory properties of Acanthopanacis cortex and Aralia elata according to their blanching conditions and thawing methods. In terms of their Hunter colors, the A. cortex and A. elata that were blanched without adding salt to them for 7 min and 4 min, respectively, had the highest L values. The chlorophyll content (148.7 mg%) of A. cortex that was blanched with 1% salt for 4 min was higher than those of the other samples, and the chlorophyll content of A. elata was 32.4 mg% when it was blanched for 4 min without salt addition. The sensory test results showed the highest overall preference for the sample that was blanched without salt for 4 min among all the samples. The Hunter color of A. cortex did not significantly differ with different thawing methods, but the value of A. elata that was thawed in a microwave oven was higher than those of the other samples. The chlorophyll contents of A. cortex and A. elata that were thawed in a microwave oven were the highest among all the samples. As for the overall preference for the samples according to the thawing method, A. cortex and A. elata scored highest in the case of thawing at $25^{\circ}C$ and in a microwave oven, respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.1-29
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• 2019

Related to the previous paper on the typical crack pattern of tunnel lining with NATM, the characteristic defects in reinforced cement concrete lining of NATM tunnel have analyzed with the precise inspection with safety and diagnosis (PISD) by KISTEC. Depending on the reinforcing materials, steel rebar, steel fiber, and glass fiber have been implemented to reinforcing lining in various NATM tunnel constructions. Reinforcing lining with rebar are prevailed on NATM tunnel to countermeasure the weak geological circumstances, to pursuit the economical tunnel sections, and to resist the risk of tunnel deterioration. By the special act on the safety control of public facilities, the reinforced NATM tunnels for more than 1 km length are scrutinized closely to characterize defects; crack, reinforcement exposure, and lack of lining. Crack resistance by reinforcing is shown in comparison with the normalized crack to the length of tunnel. Typical exposed reinforcements in lining have exemplified with various sections. The lack of lining due to the mal-construction, spalling, fire, earthquake and leaching has been analyzed. The cause and mechanism with the field inspections and other studies has also been verified. Detailed cases are selected by the above concerns as well as the basic information from FMS (Facilities Management System). Likewise the previous paper, this study provides specialized defects in reinforced lining of NATM and it can be widely used in spreading the essential technics and reporting skills. Furthermore, it would be advised and amended for the detail guideline of Safety Diagnosis and PISD (tunnel).

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.240-246
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• 2021

The Chironomidae is a benthic macroinvertebrate commonly found in freshwater ecosystems, along with Ephemeroptera and Trichoptera, which can be used for environmental health assessments. There are approximately 15,000 species of Chironomidae worldwide, but there are limited studies on species identification of domestic Chironomidae larvae. In the present study, we carried out species classification of the Chironomidae larvae that found in Jeju's tap water purification plants using morphological characteristics and genetic identification based on cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA. Body shape, mentum, antenna, mandible in the head capsule, and claws were observed in the larvae for morphological classification. Analysis of 17 larvae collected from faucets and fire hydrants of domestic tap water purification plants revealed the presence of two species, including 14 Orthocladius tamarutilus and 3 Paratrichocladius tammaater. These results will aid the use of the criteria information about species classification of the Chironomidae for water quality management in water purification plants and diversity monitoring of freshwater environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.691-702
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• 2021

This study aimed to provide basic data for safety education by surveying the status of safety education and general safety awareness among high school students by gender and school type in Chungnam area. From July 16th to October 15th, 2015, 1214 copies collected from 16 schools were analyzed using SPSS ver 23.0. Regarding safety education, females and general high school students (GHS) responded more frequently that safety education was more necessary for school life compared to males and specialized high school students (SHS), whereas males were more interested in safety education content than females. Males and SHS lost interest when learning unfamiliar content compared to females and GHS, respectively. In terms of general safety awareness, males and GHS usually followed safety rules better than females and SHS, and males demonstrated greater knowledge of first aid. Males and SHS acted according to their beliefs towards safety rather than knowledge compared to females and GHS, respectively. This study found a significant difference in safety education and general safety awareness among high school students by gender and type of school, and the results suggest that differentiated safety education is necessary.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.1
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• pp.83-93
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• 2021

Objectives: 'Confined space' was only defined in the Safety and Health Regulations as a place where oxygen deficiency and hydrogen sulfide must be dealt with at the time of the initial enactment (1982). The danger of fire and explosion were added in 2003. We will compare and review the regulations related to confined space work under the current safety and health rules alongside regulations in other countries and prepare a plan to improve the system through enhanced clarity and execution. Methods: In a comparison of systems for the prevention of suffocation in confined spaces in major countries (Germany, United States, Japan) different concepts of the definition of confined spaces in different countries apparently due to differences in each country's legal implementation system, accident analysis methods, the status of safety and health implementation in workplaces, the precautions against actual confined space work, and the definition of confined spaces were found to be not much different between Korea and the other foreign countries. Results: In the case of Germany and the United States, a confined space is defined as a contextual concept rather than a place, so more careful attention is needed from operators or enclosed space managers as it is often necessary to judge the actual workplace. In the case of Korea and Japan, the interior of the place is mainly defined as a place, especially in the case of Japan, which concentrates on oxygen deficiency and hydrogen sulfide poisoning. Conclusions: For measures to improve regulations on the prevention of suffocation accidents in Korea, I would like to propose three major measures to improve the system in the rules on domestic industrial safety and health standards. It is necessary to prepare and provide a guide to ensure that the 18 types of confined spaces currently defined as confined spaces are clearly understood by field management supervisors or workers.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.908-921
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• 2022

Purpose: As the connection between physical and non-physical structures in cities is expanding and becoming more complex, the risk of complex disaster which causes damage in a complex way is increasing. Preparing for these complex disasters, it is important to preemptively identify and manage disasters that can develop into complex disasters. Therefore, this study analyzes the disaster types studied as complex disasters by analyzing the trends of domestic and international studies related to complex disasters, and presents the direction of complex disaster management in the future. Method: We first established co-occurrence networks between disaster types based on 993 articles related to complex disasters published in disaster-related journals for the last 20 years (2002-2021). Then, through network analysis, domestic and international complex disaster research trends were compared and analyzed. Result: Research on complex disasters related to storm and flood damage, infrastructure failure and fire was high in domestic studies, and it was analyzed that research on complex disasters related to earthquakes and landslides has recently increased. However, in international studies, the proportion of studies on infrastructure failure along with storm and flood damage and earthquake was high, and various types of disasters such as tsunami and drought appeared. Conclusion: The results of this study are expected to increase the understanding of the trends in complex disaster research and provide suggestions of domestic complex disaster research in the future.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.2
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• pp.26-34
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• 2023

This study conducted interviews with former and current managers of Cheongwadae landscape architecture to provide basic information necessary to preserve, manage, and utilize Gyeongbokgung Palace's back garden, and the main conclusions summarized are as follows. First, the topography changed a lot with the construction of the main building and the official residence under President Roh Tae-woo. The water system was connected to Gyeongbokgung Palace in the past, but is now disconnected. Second, in the case of planting, the most important principles were the president's security and protocol, and accordingly, trees were placed or managed. Trees were planted by introducing excellent trees in various regions, and wildflowers and ground cover plants were frequently replaced according to the season. Third, facilities and roads were arranged for the president's protocol, hobbies, and workers' rest, and fire-fighting facilities were installed to prevent disaster in the forest area of Baegaksan Mountain. Fourth, the biggest inflection point of Gyeongbokgung Palace's back garden during Cheongwadae period was the change in topography due to the new construction of the main building and official residence during President Roh Tae-woo, the removal of A and B barbed wire fences that separated space during President Roh Moo-hyun, and the extensive landscaping carried out for the G20 Summit under President Lee Myung-bak. The area of Gyeongbokgung Palace's back garden is expected to face another inflection point due to the opening of Cheongwadae on May 10, 2022, and the work of evaluating the historical, academic, and landscape values of Gyeongbokgung Palace's back garden should be carried out while preserving the status.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.29-39
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• 2023

In the recent period, there have been numerous earthquakes both domestically and internationally, and buildings in South Korea are particularly vulnerable to seismic design and earthquake damage. Therefore, the objective of this study is to discover an effective method for assessing the seismic vulnerability of buildings and conducting a density analysis of high-risk structures. The aim is to model this approach and validate it using data from pilot area(Seoul). To achieve this, two modeling techniques were employed, of which the predictive accuracy of the statistical analysis technique was 87%. Among the machine learning techniques, Random Forest Model exhibited the highest predictive accuracy, and the accuracy of the model on the Test Set was determined to be 97.1%. As a result of the analysis, the district rating revealed that Gwangjin-gu and Songpa-gu were relatively at higher risk, and the density analysis of at-risk buildings predicted that Seocho-gu, Gwanak-gu, and Gangseo-gu were relatively at higher risk. Finally, the result of the statistical analysis technique was predicted as more dangerous than those of the machine learning technique. However, considering that about 18.9% of the buildings in Seoul are designed to withstand the Seismic intensity of 6.5 (MMI), which is the standard for seismic-resistant design in South Korea, the result of the machine learning technique was predicted to be more accurate. The current research is limited in that it only considers buildings without taking into account factors such as population density, police stations, and fire stations. Considering these limitations in future studies would lead to more comprehensive and valuable research.