• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.809-814
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• 2009

Deep mixing method has been used for ground improvement and foundation system for embankment, port and harbor foundations, retaining wall, and liquefaction mitigations. It has attractive benefits because it is not only improved strength of soft ground but superior for prevention of settlement. However, the quality controls of improved mass affect to the efficiency of the deep mixing method is not properly established. These effects vary depending upon the construction environments and conditions of agitation in consideration of an agitator. The strength and shape of the improved column are not unique and these are affected by mechanical properties of agitators. In this study, in order to investigate the efficiency of deep mixing method for ground improvement on a soft clay ground, experimental studies are performed considering mechanical properties of agitator; the location of exit-hole of admixtures, an angle of mixing wing and a speed of revolution. The experiments are conducted with the simulated apparatus for deep mixing plant that reduced the scale in 1:8 of the real plant. According to the results, the diameter and shape of improved column mass vary depending on the mechanical properties and operating conditions of agitator. Its quality is better when the exit-hole of admixtures is located in the mixing wing, when an angle of mixing wing is large, and when the speed of revolution is rapid.

• Geomechanics and Engineering
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• v.34 no.1
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• pp.87-102
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• 2023

The cover plate and the building loads often make the semi-covered deep excavations with existing buildings bearing asymmetric load, presenting different deformation characteristics with normal excavations, which is not absolutely clear in current studies. Based on a typical engineering, the building storeys, the basement storeys, the pile length, the existence of the cover plate (CP) and the depth of the diaphragm walls (DW) were selected as variables, and 44 groups of simulation were designed to study the influence of existing buildings and the semi-covered supporting system on the deformation of the excavations. The results showed that the maximum lateral displacement of DW, δ_hm, and the depth of δ_hm, H_m, are affected seriously by the building storeys and the basement storeys. Asymmetric structures and loading lead to certain lateral displacement of DW at the beginning of excavation, resulting in different relationships between δ_hm and excavation depth, H. The maximum surface settlement outside the pit, δ_vm, increases significantly and the location, d_m, moves away from the pit with the building storeys increases. δ_vm has a quadratic correlation with H due to the existing buildings. CP and building load will affect the style of the lateral displacement curve of DW seriously in different aspects.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.359-364
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• 2008

Using multi beam echo sounder, side scan sonar and scuba diving equipment, ceramic type, uneven type and semicircle-ramus type reefs into sandy bottom were ascertained, the depth of submersion in 7.2-10.3m on the coast of Gangneung, East of Korea, forty uneven type artificial reefs(AR) were totally buried into the sandy bottom. Two of five semicircle-ramus type ARs had only of their top area exposed. For most of the 45 ceramic reefs, only the upper 25-150cm of ARs were visible. The burial pattern is different in west and east side of the reefs, where the east side is deeply buried compared to the west side. From these results. it is recommended that sufficient analysis of bottom structure and materials especially in the sandy sea area should be undertaken in order to determine the best type of artificial reefs to be deployed and the best location for depoloyment.

• Journal of Korean Physical Therapy Science
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• v.16 no.2
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• pp.45-55
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• 2009

Background: This thesis aims at suggesting the direction for the introduction of public free treatment support system according to the establishment of [Special Education Law] and the right settlement of therapeutic support service. Method: It introduced the characteristics and the contents of school based PT & OT, diagnosis and evaluation, and operation method. It set up question items and presented intervention plan, and substantial intervention, beginning from the request of whole process. The diagnostic evaluation was described from 4 aspects, which are consideration matters in the time of document drawing and diagnostic evaluation, chiefly centering around SOAP. The flow of overall treatment support service, the allocation of 16 handicapped children for 1 therapist, and the weekly treatment frequency according to the treatment support location and environment were suggested in the concrete operation method. Result: The concrete method should be explored in order to provide handicapped students with requisite services, which are offered by various experts in the amended 'Special Education Law'. In addition, work condition and social welfare, which are equal to school teachers, should be provided for all experts. Conclusion: Along with these things, special education support center should establish the road-map for the education rehabilitation of the handicapped children from the evaluation of early diagnosis of the handicapped children to treatment support and lifelong education.

• Journal of the Korean housing association
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• v.15 no.5
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• pp.107-118
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• 2004

The purpose of this study is to analyze the unique characteristics of the vernacular house of Ulleung-Do(island), which shows a different residential culture from the main land. For this purpose, this study examined the characteristics of the location, spatial arrangement, and floor-plan of the house and also tried to understand how these basic elements were changed and why these changes were occurred. The result of this study is as follows: First, the house was located on the mountain area and was oriented toward the various bearings. Second, the house usually did not have annexes and most residential space was installed on a main building. Third, the floor-plan of the house was developed from a basic two-Kan (with single row) house type in a early settlement period to three-Kan, four-Kan, and five-Kan house types in later periods. While the development of house type proceeded. the main building was functioned as a complex space for both residential and storage purposes. Some houses were gradually developed into a middle and upper-class house shape by installing annexes. The change of the floor-plan and the house size was the result of self-sustained living culture influenced by the natural environment of the island and of changes of residential conditions as well.

• Journal of the Korean Institute of Educational Facilities
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• v.23 no.5
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• pp.11-18
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• 2016

This study aims at proposing the efficient settlement of middle school district and the appropriate allotment of middle school student. It focuses on the middle school district in Sejong city where has recently been developed. Firstly this study analyzes the long-term plans of school establishment, the current state of the student accommodation and the number of increasing students according to the continuing developments. To set up the efficient school district, it investigates the number of students per school district, school location and the commuting condition to each school. Throughout a question investigation to school parents, it analyzes the school choice factors - distant to school, school environment, school facilities, teacher's passion, the school curriculum, and so on. Furthermore it carries out focus group interview(FGI) targeting parents and teachers. It proposes a short-distance allotment method as an appropriate disposition of middle school student in Sejong city, which conducts a process of the first-application and the later-draw with a community as a unit.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.77-87
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• 2012

Recently, Load and Resistance Factor Design (LRFD) based on reliability analysis has become a global trend for economical and rational design. In order to implement the LRFD, quantification of uncertainty for load and resistance should be done. The reliability of result relies on input variable, and therefore, it is important to obtain exact uncertainty properties of load and resistance. Since soil stress is the main reason causing the settlement or deformation of ground and load on the underground structure, it is essential to clarify the uncertainty of soil stress distribution for accurately predict the uncertainty of load in LRFD. In this study, laboratory model test on silty sand bed under probabilistic load is performed to observe propagation of upper load uncertainty. The results show that the coefficient of variation (COV) of soil stress are varied depending on location due to non-linear relationship between upper load increment and soil pressure increment. In addition, when the load uncertainty is transmitted through ground, COV is decreased by damping effect.

• The Journal of Engineering Geology
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• v.19 no.1
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• pp.43-50
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• 2009

A 3-D numerical analysis was carried out to observe potential effects of orientation of inherent weak zones to tunnel behaviors and stress distributions during tunnel excavation. Weak zones used for the analysis were placed at the upper 1D part from crown, on the crown and on the center of face, using orientations derived from the 6th RMR parameter for assessment of joint orientation effect on tunnel. Mechanical properties of rock mass were derived through a in-situ displacement measurement-based back analysis. Finally, a classification chart for crown settlement with five ranks based on orientation and location of weak zones is suggested.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.1
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• pp.1-10
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• 2018

In order to give back-to-farm residents the stable settlement environment in the rural area, the 'community village' is desirable as the village type and its village planning guideline should be supported as well. The purpose of this study was to develop a guideline for the planning of back-to-farm community village in the living and social environmental aspects, based on the comprehensive comparative analysis about items that field survey and literature suggested. The guideline for the living environment was developed for 6 items; village structure(adequate size, lot, outer space for household), village landscape(allocation, space composition), road system and transportation(parking lot in village, placement of bus stops, village trail, public transportation, road and pedestrian system), common living facilities and common space(number, size, location & placement, plan type, planning type of common facilities), transfer space, individual housing(type, size, planning type). The guideline for the social environment was developed for 3 items; village making and establishment(resident participation type, resident participation tool, residents' construction participation) and resident education in the course of planning, resident participation(gathering resident opinion, decision making, composition of construction committee, community newsletter).

• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.37-47
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• 2006

Recently, due to the growing concern of the public in rural amenities and hobby farming works, much more urbanites, especially near-retirees, have been interested in rural life style than before. However, in spite of popular preference to ruralities, little has been known about their demand on retired rural life. Therefore, this study examined urbanites' attitude to preparatory works for out-migration, preferred residential site conditions and life style in the countryside. For this purpose, data were collected from a survey with the sample of 386 urban residents aged 40 to 65 rho hoped moving into the countryside after retirement, through structured questionnaires. Descriptive statistical works were performed using SPSS/PC windows program. The major findings of this study were as follows; (1) Host of urbanites, who answered in this study, planned to prepare ex-urban movement in their fifties and to put into practice in their sixties. (2) Key factors of location decision on movement were proximity/accessibility to centre city, medical service level, and distance to their family or friends. And about a half of respondents wanted second home in the countryside. (3) Most favoured rural life styles were nature-friendly well-being and hobby/healthy firming. Generally, the respondents of this survey had the positive attitude to do works in their later life, especially preferred to farming and volunteering in their communities.