• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.8 no.1
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• pp.23-27
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• 1978

The purpose of the present investigation is to determine how frequently radiopaque zones are seen on standard intraoral films and to research some other things about radiopaque zones. This study obtained the following results: 1. According to the standard intraoral films of the charts that were kept at the Dept. of Oral Diagnosis in Seoul National University Hospital, radiopaque zones were found in the rate of 4.1% among 1150 cases of amalgam-restored teeth that were treated at least two years ago. 2. Out of teeth that possessed radiopaque zones, 38.3% had radiolucent area between amalgam restoration and radiopaque zone. 3. Out of teeth that possessed radiopaque zones, 36.2% had cement base between amalgam restoration and radiopaque zone. 4. Out of teeth that possessed radiopaque zones, no tooth had periapical radiolucency. 5. Radiopaque zones were found more frequently in the mandibular teeth than the maxillary teeth. 6. According to the result of direct x-ray taking of 50 teeth that were treated at least 2 years ago, 6% had radiopaque zone.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2B
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• pp.131-137
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• 2012

River areas are classified as conservation, restoration, and recreation zones depending on engineers' opinions from their experiences at present. For conservation zones, almost all engineers have the same opinions because natural characteristics are considered for classification. However, it is difficult to decide a basis in classifying restoration and recreation zones in mixed areas by urban and rural streams. This study attempted to prove an application of a previous study (Song & Yoon, 2008) that suggested two classification techniques to classify conservation or maintenance zones, and reclassify maintenance zones into restoration or recreation zones. The suggested classification techniques of river zones were used to estimate 46 reaches of 20 urban streams, 47 reaches of 29 rural streams, and 48 reaches of 19 mountainous streams to achieve a purpose of this study. The conservation, restoration, and recreation zones were reasonably divided by results of the suggested techniques. A possibility that quantified criterion could be used to classify river zones was proven in this study.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.448-461
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• 2024

Purpose: The purpose of this study is to establish a life zone class suitable for Korean characteristics in the post-COVID-19 era and to classify the types for the installation and operation of living SOC facilities. Method: The concept of the life zone was established through policies and previous studies related to the life zone, and data in various fields such as population, employment, transportation, economy, and education were classified using the z-score technique. Result: Korea's life zones can be classified into metropolitan life zones, regional life zones, urban life zones, village life zones, and neighborhood life zones, and depending on their roles, they can be classified into central life zones, workplace-residential balanced life zones, residential life zones, industrial life zones, and low-density life zones. Conclusion: The results of this study show that proper life zone establishment and proper living SOC supply can prevent the decline of underdeveloped areas and contribute to balanced regional development

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.3
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• pp.121-127
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• 1998

For the seismic design of bridges in Korea classified as the low to moderate seismic zones, the design concepts provided in the Standard Specification for Highway Bridges, Division I-A: Seismic Design, are adopted, which is basically developed for the strong seismic zones by AASHITO. Accordingly, the design procedures provided for the low to moderate seismic zones are simplified too much to fulfill the purpose of the seismic design. In this paper the design procedures given for the low to moderate seismic zones in the Standard are summarized and discussed in view of the seismic design purpose. From the discussion results some revisions are proposed as conclusions for the reasonable a, pp.ication of the Standard for bridges located in the low to moderate seismic zones.

• The Korean Journal of Malacology
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• v.9 no.2
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• pp.68-84
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• 1993

A study on the distribution and seasonal changes of the benthic macroinvertebrate community was performed on the 4 intertidal rocky shores of Biyang-do in Chehu Island throughout four seasons from January 1992 to january 1993. The macroinvertebrates composed of 8 phyla, 15 classes, 31 orders, 71 families, 168 species. The seasonal appearing species were 135 species in summer, 127 species in spring, 124 species in winter and 121 species in autumn, respectively. The dominant species of the upper zones were Nodilittorina exigua, Nerita japonica, Pollicipes mitella, the middle zones were Turbo coronata coreensis, Monodonta neritoides, petrolisthes japonicus and the lower zones were Pagurus samuelis, Chthamalus pilsbryi, Chlorostoma argyrostoma lischkei. The community dominance indices of the upper zones were much higher than the middle and lower zones. The seasonal appearnace in species in the lower zones were remarkable, but individual numbes were not. Species diversity and evenness in all investigated zones were highest in spring and lowest in winter. But species richness was highest in summer, lowest in autumm.

• Korean Journal of Hydrosciences
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• v.7
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• pp.1-8
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• 1996

The location and the shape of a freshwater transition zone in a coastal aquifer are affected by many hydraulic variables. To data most works to determine the effects of these variables are limited to qualitative comparison of transiton zones. In this work characteristics of transition zones are analyzed quantitatively. The investigation is limited to a steady-state transition zones. Three dimensionless variables are defined to represent characteristics of steady-state transition zones. They are maximum introsion length, thickness, and degree of stratification. Effects of principal hydraulic variables (velocity and dispersivity) on these characteristics are studied using a numerical model. Dimensional analysis is used to systematically analyze entire model results. Effects of velocity and dispersivity are seem clearly. From this study, increase in velocity is found to cause shrinkage of transition zones. This observation contradicts claims by some that, because dispersion is proportional to velocity, increase in velocity would cause expansion of transition zones.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.49-52
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• 2008

The design strength of panel zones, which was based on Krawinkler model, was investigated by comparing it with existing test and FEM results. The design strength overestimates of the strength of panel zones with thick column flange while it matches well with the strength of panel zones with thin column flange. More extensive studies are needed to develop a mathematical model which can properly define the inelastic behavior of panel zones with various column flange thicknesses and to determine a more rational design strength.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.3
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• pp.114-127
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• 2010

This study aimed at reviewing the case examples of environmental assessment of development projects within management zones, identifying problems and improvement opportunities and suggesting the direction of environmental assessment for management zones that are increasingly segmented Findings showed that first, the assessment of environment soundness in management zones must incorporate the national land environmental map and wide-area ecological axes established by the Ministry of Environment. Second, regarding development activities in management zones, rather than an issue of simply destroying natural environment in a development site itself during a development period, an issue of permanently isolating ecosystems from surrounding areas in a mid/long-term perspective and continually polluting water in mid-stream/upstream regions where sites are located must be considered. Third, in the case of development projects with vast areas, existing plant communities will be disturbed and the naturalness of vegetation will gradually decline due to foreign tree species introduced for landscape architecture. Therefore, creating buffer forests at forest boundaries and planting native tree species that are same as nearby tree species must be examined. Last but not least, when assessing the environmental soundness of management zones, it would be crucial to comprehensively review the environmental, social and locational features of management zones, including surrounding areas, and set the direction of environmental assessment accordingly.

• Journal of the Korean association of regional geographers
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• v.23 no.2
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• pp.288-310
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• 2017

This paper aims to provide a conceptual framework to see the special zones in East Asia in relation to the territorialities of the state. For this, it will introduce Aihwa Ong's notion of 'spaces of exception', and provide some critical discussions on it. Unlike Ong, I do not see the spaces of exception as an outcome of neoliberal changes of the state. Instead, I propose to see the special zones in terms of the internal limitations of the modern state territoriality. In particular, I try to theorize the special zones in relation to the dialectics of the contradictory relations between mobility and fixity inherent in the territoriality of the modern nation state. In addition, it will be suggested to see special zones as an essential part of the spatiality of the East Asian developmental states, given the spatio-temporal contexts of the East Asian capitalist development. On the basis of these theoretical discussions, this paper will divide the special zones that have been developed in East Asia since the 1960s into 3 different types, including 1) developmentalist special zones, 2) neo-liberal special zones, and 3) special zones for transition, and discuss their characteristics.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.27-35
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• 2018

Food consumption pattern changes, including a decrease in rice consumption and increasing demand for fresh vegetables, along with declining food self-sufficiency rate, more importance is being placed on agricultural industry within Korea. Taking these changes into consideration, there is an increasing necessity for managing upland fields on agricultural sector to revitalize agricultural land use. Therefore, in this study, upland use type was classified into agricultural economic, environmental conservation, and rural social frames. The purpose of this study was to suggest upland use plan with farm manager registration information and spatial data. As results of this analysis, the mean area of agricultural economic frame in Haenam (16.47 ha) was found to be wider than Muan (3.17 ha), and scale improvement zones (54 zones) were located in only Haenam. In case of environmental conservation frame, there's no zone of scenic agriculture land in both study areas, but landuse transition zones were located in Muan (278 zones) and Haenam (604 zones). Agro-healing zones of rural social frame were 1,018 zones in Muan and 1,588 zones in Haenam and kitchen garden sites were 342 zones in Muan and 370 zones in Haenam. These results could be used when we establish the plan of an agricultural infrastructure project or select places for a collaborative agricultural land use project.