• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.5
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• pp.9-16
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• 2013

This study finds the characteristics of long-term settlement of Bottom Ash and to review the application of Singh-Mitchell creep equation and Burgers Model to the creep behavior of Bottom Ash. In the undrained state, it was confirmed that creep behavior appeared in the range to 30-80 % of the maximum deviator stress by applying condition in other three stresses through triaxial compression test after isotropically consolidation. By using sieve analysis, it was compared to each sample that was passed through 9.5 mm, 2 mm, 0.25 mm sieves. Also, using Singh-Mitchell creep equation and Burgers Model, it was compared between the theoretical behavior and the observed behavior for each sample. In the result, it is found that creep behavior of Bottom Ash is similar to the theoretical behavior of Singh-Mitchell creep equation and Burgers Model in early stage and it is possible to predict creep behavior of Bottom Ash by these models.

• Geotechnical Engineering
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• v.14 no.4
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• pp.117-128
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• 1998

Solid mattress foundation using geogrid has often been used on soft grounds to increase the bearing capacity, and its effect has received much recognition. Geogrid-mattress system is the method of construction which increases the bearing capacity and the effect of controlling settlement by dispersing load to wider foundation through its stiffness. But ifs mechanism has not been examined exactly yet. considered to be influential factors in the experiments. As a result of the experiments, the characteristic of dispersing stress under mattress foundations was understood and the way of calculating the bearing capacity in designing the mattress foundations was suggested.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1455-1460
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• 2005

This paper presents the results of an experimental study on the ground deformation by trench excavation for Diaphragm Wall construction. The model tests are performed to investigate the back ground deformation by lowering of slurry level in trench after excavating. Through these, the deformation characteristic of the back ground due to stress release of excavated space was investigated. This study considered relative density of soil mass and the distance between trench and surcharge. An experiment was performed in order to observe the failure pattern of a slurry-supported trench excavated in sandy ground. From model tests, in order to predict reasonably the deformation behavior of the adjacent ground due to the underground excavation, it is significantly recommended that the ground settlement by trench excavation should be considered.

• Journal of the Korean Geosynthetics Society
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• v.8 no.2
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• pp.1-9
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• 2009

When some structures are constructed over the sanitary landfill, the waste should be treated by means of replacement and other ways. Otherwise, various problems like a ground contamination, settlement, reduction of bearing capacity and others may be generated. To find out the optimal method of treatment, the properties of the ground have to be inspected. In this study, the preliminary investigation was conducted to find out the characteristic of this site which is considered as insanitary waste landfill. Furthermore, the shape and the amount of the waste was investigated by subsurface investigation like a boring and sampling methods. In addition, the degree of ground contamination and disposal method of refuse was examined.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.839-846
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• 1988

If we use the 2-dimensional analyzing method with the magnetic vector potential for the analysis of eddy current distribution in electric machinery, we can obtain the magnitude of eddy current but can't have the characteristic of eddy current distribution. For the settlement of this problem, we have induced the governing equation with the current vector potential and attemptted 2-dimensional analysis of eddy current distribution by finite element method. And the time domain weighted residual method is used in treatment of time differential term and we have developed the algorithm by it. And then, we analyze eddy current distributions of analytic model and aluminium disk in singlephase watt hour meter. Consequently we have verified the propriety and utility of above mentioned method.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.228-230
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• 2002

Recently, electric power reliability of our country has been improved. However, there are still remaining problems which are short-duration variations like instantaneous and momentary interruption and voltage sag by nature calamity ; typhoon, lightning, snow, etc. Besides, power quality ; harmonics, caused by using power electronics equipments, become a hot issue Malfunction of controller and stop machinery, and losing the important data are caused by poor power quality at a couple of second. Due to those, UPS, which is made up battery, has being used, but there are several disadvantages ; long charge and discharge time, environmental problem by acid and heavy metal, and short life time. As generally know, micro-SMES is a method to settle those mentioned. However, there need huge system apparatuses in order to verify the effect of system efficiency and stability considering the size of micro-SMES, the sort of converter type, and various conditions ; inner temperature, magnetic field, quench characteristic of micro-SMES, and etc. In this paper, in order to bring the mentioned above to a settlement, a micro-SMES is modeled with characteristics of micro-SMES is interfaced to EMTOC program using Fortran program interface method. We obtained hopeful answers and made the simulation model of micro SMES.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.85-98
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• 2002

The purpose of this study is to develop a land use planning model (LUPM) which can be applied to development of rural villages considering their spatial expansion. The LUPM finds out and allocates the new built site required for the improvement of existing villages. in the development of LUPM, CA (cellular automata) and land suitability analysis methods were applied combinedly. The model uses basically numerical data of CIS based on grid data. Agglomerated settlement, as a type of village for simulation, was adopted. Probability of land use change for optimizing development area was calculated by the six criteria: slope. drainage characteristic, direction of slope, as absolute suitability of grid itself, distance from road. distance from stream and distance from the village center, as relative probability by neighborhood cells. Weighting values of these criteria were quantified by AHP (analytic hierarchy process) method, which is one of MCE(multi-criteria evaluation) method. The algorithm of the model was verified by three example villages: an isolation village, a village with horizontal road, and a village with nodal point of cross road

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.613-620
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• 2002

Sand Compaction Pile(SCP) is a soil improvement method that a sand charge is introduced into the pipe, and the pipe is withdrawn part away while the sand pile is compacted and its diameter is enlarged. The sand used in this method should be of good quality. In Korea, crushed stone and washed sea sand are used frequently in SCP. However, use of these materials is restricted because of environmental problem and deficiency of supply. In the copper smelting process, about 0.7 million tons of copper slag are produced in Korea. The range of particle size distribution of copper slag is from 0.15mm to 5mm, so it can be a substitute for sand, and the relatively high specific gravity compared with the sand, is its characteristic. Copper slag is hyaline and so stable environmentally that in foreign country, such as Japan, Germany etc., it is widely used in harbor, revetment and offshore structure construction works. Therefore, in this study, the several laboratory tests were peformed to evaluate the applicability of copper slag as a substitute for sand of SCP. From the mechanical property test, the characteristics of sand and copper slag were compared and analyzed, and from laboratory model test, the strength of composite ground was compared and analyzed by monitoring the stress and ground settlement of clay, SCP and copper slag compaction pile. Specially, this study focused on the application of copper slag as sand substitute in SCP pilot tests based on laboratory tests results.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.747-756
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• 2015

Brown alga Undaria peterseniana has been interested in the commercial scale aquaculture for warm water species development in southern coastal area of Korea. However, this species was classified an endangered species caused by a decrease in habitat and natural population. In this study, inhabit characteristics of U. peterseniana was investigated in their natural habitat of Ulleung Island, Korea. The U. peterseniana population was occurred dense patches at 20~30m depth. Total length of the alga reached 1.0~2.0m and the largest width ranged 10.0~35.0cm during the study. In 2013, habitats of this species increased two sites compared with the previous year and their distribution extended to low depth (10m) of coastal area. In long-term data, seawater temperature revealed a continuous increment by strong going north of East Korea Warm Current or Ulleung Warm Eddy turning around the coast of Ulleung Island. It suggested that habitat extension of U. peterseniana may be caused by suitable settlement condition and increase of warm water around the coastal area. Current studies of this species may be continuously required in the possibility of fisheries resources as aquaculture species and index species of increment of water temperature at the fixed monitoring site in East Sea. This is the first study to research ecological feature U. peterseniana population at the natural habitat of Ulleung Island.

• Journal of the Korean housing association
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• v.24 no.3
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• pp.19-26
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• 2013

The purpose of this research is to provide basic data for the promotion strategy to activate modular construction system as residential facilities, through a study on the architectural planning, institutions and policies and research on connection details, for the use as residential facilities of the modular construction that is not actively supplied for the general residential facilities. As a result, I suggest sample model plan of domestic and foreign case analysis and characteristic of modular construction and practical application of modular construction for Residential Facilities. Owing to many advantages including short construction period structural stability and economic benefits, modular construction is expected to play a role as residential alternative of socially controversial affordable housing and weekend homes, and potential housing shortage after reunification; and to contribute to the development of design automation and industrialized constructions. Though Korea is still lacking development of the system that meets the domestic context, if supported by ongoing researches on the development of construction methods, materials and details, the settlement of appropriate modular residential facilities to suit the national situation will serve a possible alternative solution for many housing and environmental problems.