• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.173-177
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• 2011

In this study, the formation of $AlPO_4$-type porous materials from alum sludge was investigated. The materials were synthesized by the reaction of aluminum hydroxide and phosphoric acid with an organic template. Cationic surfactant, natural humic acid, and amino acids were used for the organic template. The residual organic templates were removed by calcination at $600^{\circ}C$ in the air. Powder X-ray diffraction patterns showed the charicteristic patterns of the $AlPO_4$-type porous materials. The morphology of the material was examined using a scanning electron microscopy. The coordination environment of $Al^{3+}$ ion was investigated by $^{27}Al$ MAS NMR technique. Both tetrahedrally and octahedrally coordinated$Al^{3+}$ ions were found in the as-synthesized samples while all $Al^{3+}$ ions were tetrahedrally coordinated in the calcined products. The development of mesopore in the solid material was confirmed by the measurement of BET specific surface area. Finally, they were used for removal of toxic formaldehyde from the air and the formaldehyde molecules were adsorbed on the surface of pores. In conclusion, $AlPO_4$-type porous materials from alum sludge might be applicable in the removal of toxic volatile organic compounds from the air.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.501-507
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• 2011

To develop environmental-friendly insulating composite materials, natural cellulose and porous ceramic balls were used as core materials and activated Hwangtoh was used as a binder. Various specimens were prepared with different water/binder ratios and core material/binder ratios. The physical properties of these specimens were then investigated through compressive strengths, flexural strengths, absorption test, hot water resistance test, pore analysis, thermal conductivity, and observation of micro-structures using scanning electron microscope. Results showed that the maximum compressive strength varied appreciably with the water/binder ratios and core material/binder ratios, but the flexural strength increased with the core material/binder ratios regardless of water/binder ratios. The compressive strength and the flexural strength measured after the hot water resistance test decreased remarkably compared to those measured before test. The pore analysis measured after the hot water resistance test showed that total pore volume, porosity and average pore diameter decreased, while bulk density increased by the acceleration of hydration reaction of binder in the hot water. The thermal conductivity decreased gradually with an increase of core material/binder ratios. It can be evaluated that the composite insulation materials having good insulating properties and mechanical strengths can be used in the field.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.4
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• pp.60-69
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• 2020

This research is a preliminary study to find out the module of 20 students in a classroom. This research investigated the widths of passages in the 30 classrooms of 5 elementary schools in Namyangju City, Korea. The conclusions were as follows: First, the area of unit for 1 student was 650 (W) × 950 (D). Second, the desk placements for most classrooms were one-way types (87%), and group-study types constituted 13%. Third, the width between the blackboard and the very front desk was 2.17 m. The width of passage between the very back seat and the backside lockers was 1.32 m. The width of passage between the sidewall and the nearby desk was 0.8 m. The width of passage between the window and the nearby desk was 0.8 m. The average widths of 2 vertical passages between the desks were respectively 0.67 m and 0.68 m. Fourth, the area of the teacher was 2.1-2.25 m × 2.16 m = 4.5-4.8 ㎡.

• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.430-440
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• 2020

The application contents, process, and its limitations are discussed for the setting of Korean legal guides & criteria for water cycle and ecological condition in development project of land use by thorough comparison and examination of prerequisites and credits of water cycle and soil+vegetation by USA's SITES (Sustainable Sites Initiative). In the case of SITES, due to the implementation procedure operated as a non-governmental independent assessment system by Green Business Certification, Inc, the natural condition of water cycle and soil-vegetation items-the key element of ecosystem services can be quantitatively assessed, well along with its legal and institutional guidelines and regulations. On the other hand, in the case of Korea, as a part of the national certification procedure for green building, the ecological area ratio system still have very limited role as an only amenity resource in the creation of artificial green spaces and insufficiency of management system for rain water. In conclusion, it was understood as an urgent situation in necessary for prompt establishment of site's sustainability certification system at the national level, based on management of water circulation and natural soil & vegetation in developed area with consideration of various land uses and types of development projects.

• Journal of the Korean Regional Science Association
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• v.37 no.1
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• pp.3-14
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• 2021

Due to COVID-19, the importance of public medical facilities, especially hospitals specializing in infectious diseases, is rising. Despite the government's strong will, the establishment of public medical facilities and infectious disease hospitals has not been properly established. This is because the overall system related to the construction of public medical facilities does not sufficiently reflect social and economic changes and the trend of the times. The purpose of this study is to derive limitations and problems related to the guidelines for preliminary feasibility studies of public medical facilities and to present alternatives. This study proposes 'Option Value' as an alternative. Since the option value is a willingness to pay for an uncertain situation, it is theoretically reasonable and reasonable to reflect it as an additional benefit. Normally, the value of existence is not seen, but the system that is seen in a crisis is in the 'medical and health'. Therefore, it is necessary to find a system that is invisible even in the feasibility evaluation in the medical and health, and constantly improve and develop a methodology that can estimate changes in the welfare of citizens within the system. I expect this study to play a role as a catalyst.

• Journal of the Korean Regional Science Association
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• v.37 no.1
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• pp.29-44
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• 2021

Particulate matter(PM) is one of the leading causes of lung cancer. Recognizing its considerable risk to human health, people change their behaviors when a concentration level of PM is high. The impact of particulate matter on urban activities may vary depending on the lasting days of PM and PM matter alerts. In addition, the level of averting behavior may vary depending on the types and physical characteristics of urban activities and the degree of vulnerability to PM among people. Although the way people respond to PM may vary depending on these various factors, previous research evidence on this is very insufficient. Therefore, this study multilaterally analyzed the impact of PM on the urban activities in Jongno-gu, one of the CBD areas of Seoul. For this, we linked SKT's mobile phone signal data to land use data to extract the daily number of active people by urban activity types and ages. According to multiple regression analysis, the averting behavior varies depending on the type of urban activity, the physical characteristics of the place of activity(inside and outdoor), the lasting days of PM, PM alerts and the age of people. The results of this study can be used as basic data to policy makers who establish policies for adapting to air pollution policies by providing various effects of PM on the urban activities.

• Journal of the Korean Regional Science Association
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• v.38 no.1
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• pp.21-32
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• 2022

The purpose of this study is two things. First, it is to develop and demonstrate a sharong taxi platform. To this end, the implications for platform development were derived by analyzing consumers' perceptions of existing taxi services using IPA. As a result, abnormal business activities and safe services in the maintenance area were found to be safe rides and easy rides in the key improvement area. Safety such as usage fee level and driver information provision were derived in the areas subject to improvement, and friendly response and internal and external cleanliness were derived in the areas of excessive investment. The second purpose of this study is to estimate the value given to users for sharing taxi service platforms using the CVM. As a result of estimating the value of the demonstration service of the shared taxi platform developed through this study, the WTP was 3,621 won/per household/per year when expanding throughout Gimhae-si, and 2,515 won/per household/per year. Compared to the willingness to pay for empirical services, only 69.5% of the willingness to pay for the spread project in Gimhae-si. This is the result of a combination of service spread to an unspecified number of people and concerns about service quality due to spatial expansion. This suggests that it is necessary to build data through continuous demonstration and to carefully build a roadmap for spread by upgrading services based on this.

• Journal of the Korean Society for information Management
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• v.39 no.2
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• pp.255-273
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• 2022

This study is a basic study for establishing a comprehensive operation plan for the Incheon Global Campus Library in preparation for the 4th Industrial Revolution and the post-corona era. Based on this, it was intended to propose a direction for establishing a comprehensive operation plan in the future. As a result of the study, in the case of the first collection, a mid- to long-term plan for continuous expansion of the collection is required, and in particular, it seems that the expansion of major-related collections is necessary. In the case of the second service, it is necessary to support users' research by providing information services customized for each stage of research by users, information services customized for researchers, and research support services for departments, and it is necessary to provide information utilization education programs. Third, in the case of space, IGC users have very high demands for learning and research space, so it is necessary to improve education and related spaces that users want through space reorganization in the future. It is also necessary to expand the creative collaboration space as a place closely related to the lives of students, such as rest, etc. Lastly, in order to activate the homepage in relation to the homepage and information system, it is necessary to first expand the various contents and up-to-date data that users want on the homepage. In addition, it seems that the domestic electronic journal and DB provision plan should be implemented.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.480-493
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• 2021

Since the generalized Hoek-Brown criterion (GHB) provides an efficient way of identifying its strength parameter values with the consideration of in-situ rock mass condition via Geological Strength Index (GSI), this criterion is recognized as one of the standard rock mass failure criteria in rock mechanics community. However, the nonlinear form of the GHB criterion makes its mathematical treatment inconvenient and limits the scope of its application. As an effort to overcome this disadvantage of the GHB criterion, the explicit approximate analytical equations for the minimum principal stress, which is associated with the maximum principal stress at failure, are formulated based on the Taylor polynomial approximation of the original GHB criterion. The accuracy of the derived approximate formula for the minimum principal stress is verified by comparing the resulting approximate minimum principal stress with the numerically calculated exact values. To provide an application example of the approximate formulation, the equivalent friction angle and cohesion for the expected plastic zone around a circular tunnel in a GHB rock mass are calculated by incorporating the formula for the approximate minimum principal stress. It is found that the simultaneous consideration of the values of mi, GSI and far-field stress is important for the accurate calculation of equivalent Mohr-Coulomb parameter values of the plastic zone.

• Journal of Cadastre & Land InformatiX
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• v.52 no.1
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• pp.105-118
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• 2022

The demand for information related to 3D spatial objects model in metaverse, smart cities, digital twins, autonomous vehicles, urban air mobility will be increased. 3D model construction for spatial objects is possible with various equipments such as satellite-, aerial-, ground platforms and technologies such as modeling, artificial intelligence, image matching. However, it is not easy to quickly detect and convert spatial objects that need updating. In this study, based on spatial information (features) and attributes, using matching elements such as address code, number of floors, building name, and area, the converged building DB and the detected building DB are constructed. Both to support above and to verify the suitability of object selection that needs to be updated, one system prototype was developed. When constructing the converged building DB, the convergence of spatial information and attributes was impossible or failed in some buildings, and the matching rate was low at about 80%. It is believed that this is due to omitting of attributes about many building objects, especially in the pilot test area. This system prototype will support the establishment of an efficient drone shooting plan for the rapid update of 3D spatial objects, thereby preventing duplication and unnecessary construction of spatial objects, thereby greatly contributing to object improvement and cost reduction.