• Geomechanics and Engineering
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• v.28 no.5
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• pp.505-520
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• 2022

In recent years, geotextile-encased gravel columns (usually called stone columns) have become a popular method to increasing soil shear strength, decreasing the settlement, acceleration of the rate of consolidation, reducing the liquefaction potential and increasing the bearing capacity of foundations. The behavior of improved loose base-soil with gravel columns under shear loading and the shear stress-horizontal displacement curves got from large scale direct shear test are of great importance in understanding the performance of this method. In the present study, by performing 36 large-scale direct shear tests on sandy base-soil with different fine-content of zero to 30% in both not improved and improved with gravel columns, the effect of the presence of gravel columns in the loose soils were investigated. The results were used to predict the shear stress-horizontal displacement curve of these samples using support vector machines (SVM). Variables such as the non-plastic fine content of base-soil (FC), the area replacement ratio of the gravel column (Arr), the geotextile encasement and the normal stress on the sample were effective factors in the shear stress-horizontal displacement curve of the samples. The training and testing data of the model showed higher power of SVM compared to multilayer perceptron (MLP) neural network in predicting shear stress-horizontal displacement curve. After ensuring the accuracy of the model evaluation, by introducing different samples to the model, the effect of different variables on the maximum shear stress of the samples was investigated. The results showed that by adding a gravel column and increasing the Arr, the friction angle (ϕ) and cohesion (c) of the samples increase. This increase is less in base-soil with more FC, and in a proportion of the same Arr, with increasing FC, internal friction angle and cohesion decreases.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.48-56
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• 2010

Since ancient times, Korea has been called a land of beauty. Scenic sites under the Cultural Properties Protection Act include picturesque places that are famous for their natural scenic beauty as well as their historical and cultural value. Scenic sites are managed as natural assets to promote their preservation and use. However, the management of scenic sites can produce adverse effects on regional development and ownership rights. Moreover, the purpose of their designation as cultural assets is not fully understood because scenic sites are managed by focusing on restraint on users' act the same as was applied to historic sites. Therefore, the purpose of this study is to protect inhabitants' rights of ownership by arranging the boundaries of designated areas and by providing standard permission for condition changes in the Buryeongsa Valley, which was designated as a Scenic Site in 1979. The results of this study can be summarized as follows: First, arranging the boundaries of the designated area includes the arrangement of the edge lines standardized on the visual range of the mountain ridge, preventing the loss of landscape beauty in the designated district; the internal clearing district focuses on the existing settlement. Gearing the designated areas after the arrangement of the boundaries results in $11,928,932m^2$, 38.6% compared to the existing designated areas. Second, it establishes a 500m buffer zone inside the radius of the boundary of the cultural asset as a standard for condition changes that seriously affect landscape preservation. Third, the standards for permission on building 'height regulations' are divided into flat and gable, according to the roof shape. The adopted standard is 8m high for 2 story flat roofs, and 12m high for 2 story gable roofs.

• Journal of the Korean Geosynthetics Society
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• v.8 no.1
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• pp.33-40
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• 2009

The laboratory tests and field plate load test were carried out to evaluate the reinforcement effect of geocell for road construction. The geocell-reinforced subgrade shows the increment of cohesion and friction angle with comparison of non-reinforced subgrade. In addition, the field plate load test was performed on the geocell-reinforced subgrade to estimate the bearing capacity of soil. The direct shear test was conducted with utilizing a large-scale shear box to evaluate the internal soil friction angle with geocell reinforcement. The number of cells in the geocell system is varied to investigate the effect of soil reinforcement. The theoretical bearing capacity of subgrade soil with and without geocell reinforcement was estimated by using the soil internal friction angle. The field plate load tests were also conducted to estimate the bearing capacity with geocell reinforcement. It is found out that the bearing capacity of geocell-reinforced subgrade gives 2 times higher value than that of unreinforced subgrade soil. The settlement and the distribution of deformation were also estimated by using the finite element method. The magnitude of settlements on the geocell-reinforced subgrade and unreinforced subgrade are 6.8cm and 1.2cm, respectively.

• Journal of Hospice and Palliative Care
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• v.7 no.1
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• pp.17-28
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• 2004

Purpose: Even though there have been various efforts for the dying with dignity of terminal patients, no researches focused on the public attitudes. Methods: In February 2004, we sampled 1,055 persons over 20 years of age from the sixteen cities and local districts of Korea through the quota sampling method according to their gender, age, and location. We conducted a telephone survey with a structured questionnaire on the attitudes toward dying with dignity and hospice palliative care. Results: The most important conditions for the dying with dignity on the patients' views were 'removing burdens for other people' (27.8%). Over the half of the samples chose their home as a preference for place of death (54.8%). 82.3% of the respondents agreed to the idea of withdrawing the medically futile life-sustaining treatment. Fifty seven percents of the answered public said that they intended to use the hospice service in case of terminal illness. Eighty percents thought that health care insurance should cover hospice service, and 80.9% gave positive response to the necessity of advance directives. Respondents emphasized 'the financial support for the terminal patients' (29.8%), 'covering hospice service with health insurance' (16.5%), and 'the education and public relation for settlement of desirable dying culture and hospice service' (15.9%) as the roles and responsibilities of the government for the dying with dignity. Conclusion: This study shows that there is a possibility of significant consensus on hospice and palliative care system for the dying with dignity of patients and reduction of the suffering for their families among the general public.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.113-122
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• 2013

In this study, the traditional structure of the impact on the stability analysis. Korean traditional landscape architecture column space of stonework stable composition as the foundation of the fence for a long time been known to fall down and not maintained. The destination of research Ohgokmun Damyang Soswaewon fence which is in harmony with nature is one of the traditional structures that affect its shape without being kept so far came true. This includes our ancestral wisdom and that wisdom can guess guesswork. But I let the traditional reproduction incidence structures frequently. This deviation from the traditional method of construction application of shorthand stand. Thus, the subject of this study, the factors that do not fall down fences Ohgokmun solution is to indirectly gain the weak. In addition, epidemiological studies and the methods of calculation of the inferred physical examination, the results of the analysis were derived through the following. First, the internal factors of the fence Ohgokmun constituting the structural member and the coupling of the scheme. 1) based on stable ground. Greater role in the country rock The fact that the settlement will have no symptoms. 2) to minimize the friction caused by hydrological water to remove the two-pronged process through stone work building form and menu sustaining power in hydrology and flooding made against the bypass channel. 3) due to the load bearing capacity and durability to withstand the strength of the material and the construction of structures in the form of a dispersion of power between each individual to maximize the process of getting traction was applied. Second, external factors Ohgokmun fence the results obtained through the calculation of the dynamics of repair, is greatly affected by the wind and the water gate of the fence, but the action of the structural stability of the lack of power that hurt enough conclusion. In this study, the results of the structure of internal and external influence as well through the structure can be viewed as composed consisting. However, over the next follow-up in terms of climate and environmental factors due to the fact that the fall might.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.92-98
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• 2012

Purpose: The aim of this study was to evaluate the effects of different abutment materials on abutment screw loosening and settling-down effect in conical connection type implant system. Materials and methods: Three types of abutment, cementation, gold UCLA, and metal UCLA abutment were used. Two UCLA groups were fabricated in a similar pattern to cementation abutment. Type III gold alloy and Nickel-Chromium alloy was used for casting gold UCLA abutment and metal UCLA abutment, respectively. Fixture and abutment were tightened to 30 Ncm by using digital torque controller and re-tightening was conducted with same force after 10 minutes. Digital torque gauge was used to measure loosening torque and fixture/abutment length was measured by digital micrometer. Dynamic loads between 25 N and 250 N were applied with $0^{\circ}$ angle to the abutment axis. After loading, fixture/abutment length was re-measured and amount of settlement was calculated. Loosening torque value was also measured for comparison Results: All three groups showed significant differences of length when comparing before and after loading, but there was no significant difference of settling amount in all groups. Loosening torque values were significantly decreased when comparing before and after loading in all groups($P$<.05). However, there was no significant difference in loss of loosening torque values when compared to groups. Conclusion: In internal conical connection type implants, dynamic load affected on settlement and loosening torque of implant, but there was no differences between abutments materials. Likewise gold UCLA abutment, metal UCLA abutment might be able to withstand functional load.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.1-13
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• 2019

The purpose of this study is to examine the effect of soft ground improvement by dynamic replacement with utilizing crushed rock. In order to understand the ground improvement effect when applying dynamic replacement method with crushed rock, the laboratory test and field test were performed. The internal friction angle and apparent cohesion were derived through direct shear test. The dynamic replacement characteristics were identified by analyzing the weight, drop, and number of blows needed for dynamic replacement. Through the field plate bearing test and density test, the bearing capacity and settlement of the improved ground were measured, and the numerical analysis were conducted to analyze the behavior of the improved ground. In this study, it proposes modified soil experimental coefficient(C_DR) to 0.3~0.5 in the dynamic replacement method with crushed rock. Also when applying the dynamic replacement method using crushed rock, the particle size range is less than 100 mm, D₉₀ is less than 80 mm and D₁₅ is more than 30 mm.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.20-30
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• 2003

This study was carried out to examine the e-Business status of Korea Forest Product Industries and to propose the development. The use level of e-Business in korea forest product industries have stayed in internal company information network integration stages. But lots of companies located in the insufficient of e-Business models, the lack of qualified staffs, and the shortage of e-Business operating technology and implementation. As the result of this study, the followings must be considered; 1. For the promotion of e-Business use, it is needed to maintain price competitiveness, quality competitiveness, and market correspondence capacity. 2. For the settlement of e-Business models, it is important to connect information network among cooperation companies as like forest products standardize, common database, and standard electronic catalogue. Also, it needed developing program to strengthen the competitiveness of forest product industries, expanding to outsourcing and affiliated companies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

• Journal of the Korean association of regional geographers
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• v.17 no.6
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• pp.710-725
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• 2011

The purpose of this study is to analyze both residential conditions and the resident impressions of the transition zone of central Daegu. The results drawn from a questionnaire survey of the residents are summarized as follows: 1) The proportion of people over the age of 60 living on a low income is high and consists mostly of retired citizens who have lived in the transition zone, in their own homes, for an extended length of time 2) The condition of infrastructure in the transition zone is very poor, however, despite the housing deterioration, the internal repair and maintenance of houses is more satisfactory than their external appearance. 3) Residential satisfaction received high ratings in every category except pollution and housing price. This response appears to stem from the easy commute of residents as well as the ready availability of facilities in the city center. 4) In terms of residential satisfaction, the residents can be divided into two groups. The first, with a high satisfaction rate, consists mainly of senior citizens who possess both personal homes and a stable living, having resided in the city center for most of their lives. The second, with a lower satisfaction rate, is composed mostly of younger residents who have lived temporarily in inexpensive rental homes. As a results, the residential area in the transition zone of central Daegu does not appear to be a problematic area like the slum of the West, but instead a stable settlement for its residents.