• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.90-93
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• 2006

Buried pipeline is a indispensable factor of leading smoothly a society as a primary role. Recently, as a matter of convenience of construction and the economical purpose, the use of Precast Concrete products quickly increased. But there was various damage forms in a part of joint of Precast Concrete buried pipeline. The purpose of this study is to propose the new type of the flexible rubber packing material (EF) which could resist a permanent deformation of the ground or an earthquake and to investigate its safety together with effectiveness as conducting experiment and analysis.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.129-139
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• 2003

The response displacement method is the most frequently used method for seismic design of buried structures. This method is pseudo-static method, and the evaluations of velocity response spectrum of seismic base and response displacement of surrounding soil are the most important steps. In this study, the evaluation of velocity response spectrum of seismic base according to the Korean seismic design guide and the simple method of calculating the response displacement were studied. It was found that velocity response spectrum of seismic base can be estimated by direct integrating the ground-surface acceleration response spectrum of soil type $S_{A}$, and the evaluation of the response displacement using double cosine method assuming two layers of soil profile shows the advantages in the seismic design.n.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.277-285
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• 2014

The usage of efficient microorganism (EM) is increasing in concern for server purposes including odor removal during carcasses degradation. In this study, we have studied the type of soil and its effect on efficient microorganisms for the removal of odorous gases during buried carcasses degradation in lab-scale reactor. The carcasses are buried in the reactor with various soil types such as normal soil, 20% sandy and 20% clay soil with the efficient microorganism KEM. The efficient microorganisms KEM have the ability to stabilize the degradation of carcasses of the burial site. We have focused on the analysis of odorous gases such tri-methylamine (TMA), hydrogen sulfide ($H_2S$), methyl mercaptan (MM), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), carbon dioxide ($CO_2$), and methane ($CH_4$) along with the changes of microbial community changed during complete degradation of buried carcasses for a year. The results suggested that the 20% sandy soil contain lesser level of $H_2S$ and MM (0.09 and 0.35 mg) but 20% clay has higher nitrogen compound removing effect and leave only less amount of ammonia and TMA (0.31 and 2.06 mg). The 20% sandy soil also has the ability to breakdown the carcasses more quality compared with other types of soil. Based on the data obtained in this study suggesting that, the use of 20% sandy soil can effectively control sulfur compounds whereas 20% clay soil controls nitrogen compounds in the buried soil. Depending on the type of the soil, the dominant of microbial communities and the distribution was change.

• Journal of Conservation Science
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• v.33 no.6
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• pp.541-552
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• 2017

All excavated "buried cultural properties" are supervised by the Cultural Heritage Administration that decides whether to conserve them or not, depending on the necessity for conservation. Currently, there is no legal regulation concerning the administration of relics (including artifacts) and remains (including archaeological sites) that are relocated and restored based on such conservation decisions. Thus, administration of these cultural properties is inadequate. Under these circumstances, this paper recommends the current state of conservation and conservation methods for buried cultural properties excavated at Chungcheongnam-do thus far. Conservation of buried cultural properties excavated at Chungcheongnam-do primarily employ the "relocating and restoration" method; 23 relics and 46 remains employed relocation after dismantling and soil layer transcription method. Moreover, 27 remains were relocated after dismantling and 14 remains employed the transcription method. In terms of area, Buyeo-gun and Gongju-si had 12 relics accounting for about 50%, while according to the period, Baekjae period had 16 relics, accounting for about 70%. In terms of conservation facility, open-air facility had 33 relics, accounting for about 72%. Results of investigating the state of relics' management indicated that public institutions like a museum with a recognizable management system had their own work force and consequently ensured excellent conservation, whereas if there were no apparent responsible bodies, remains were subjected to considerable damage due to mismanagement. Therefore, this problem can be resolved by identifying a recognizable management body as well as ensuring periodical management and supervision. The excavated buried cultural properties are utilized not only for academic purposes, but also for PR or as exhibition material. Hence, this study confirms that meticulous management of buried cultural properties is currently required.

• Journal of the Korean Magnetics Society
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• v.26 no.2
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• pp.62-66
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• 2016

We designed a model composed a ring type magnet, a yoke, and a sensing coil buried in a projectile for calculating the muzzle velocity based on the voltage induced from sensing coil by simulation. The muzzle velocity was calculated from the master curve obtained through the voltage induced from sensing coil by simulation. The induced voltage increased with increasing the diameter of sensing coil. The projectile's velocity was proportional to the induced voltage when the sensing coil was buried in projectile. The projectile will be surely exploded at the target region by inputting the information of muzzle velocity variation corrected the diameter effect of induced voltage of sensing coil.

• Corrosion Science and Technology
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• v.16 no.3
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• pp.115-127
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• 2017

Coal tar-coated pipes buried in a domestic nuclear power plant have operated under the cathodic protection. This work conducted the simulation of the coating performance of these pipes using a FEM method. The pipes, being ductile cast iron have been suffered under considerably high cathodic protection condition beyond the appropriate condition. However, cathodic potential measured at the site revealed non-protected status. Converting from 3D CAD data of the power plant to appropriate type for a FEM simulation was conducted and cathodic potential under the applied voltage and current was calculated using primary and secondary current distribution and physical conditions. FEM simulation for coal tar-coated pipe without defects revealed over-protection condition if the pipes were well-coated. However, the simulation for coal tar-coated pipes with many defects predict that the coated pipes may be severely degraded. Therefore, for high risk pipes, direct examination and repair or renewal of pipes are strongly recommended.

• Journal of the Korean GEO-environmental Society
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• v.15 no.10
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• pp.53-62
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• 2014

In Korea, the pipe type that has been well used as sewage pipe from the past is primarily a rigid pipe which is represented by concrete hume pipe, but the use of it is being decreased sharply because of the problems such as tube erosion and incomplete watertightness securing through the time. On the other hand, the use of flexible pipe has been increased because its construction ability is excellent on account of its light weight as well as it is resistant to corrosion. However, because there are lacks of market's confidence in flexible pipe and occurrence cases of partial damage incomplete caused by compaction control, cause analysis and management for them are needed. Therefore, this study tried to estimate the deformation characteristics of pipe caused by each condition through numerical analysis changing construction sequence, rigidity of pipe, strength of ground concrete under the pipe, relative compaction ratio of sand foundation under the pipe and relative compaction ratio of backfill material above the pipe. Evaluation result is that influence on each factor is confirmed and the quality control of sand around the pipe are turned up to be important.

• Journal of Korean Neurosurgical Society
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• v.37 no.5
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• pp.345-349
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• 2005

Objective: Anterior screw fixation provides the best anatomical and functional results for type II odontoid process fracture (type II-A, II-N, and II-P) with intact transverse ligament. The purpose of this study is to evaluate the usefulness of the 4.5mm diameter, cannulated Herbert screw in anterior screw fixation. Methods: From Jan. 2003 to Feb. 2004, consecutive 10cases of type II odontoid process fractures were treated with anterior screw fixation using a Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. It was originally developed for treating scaphoid fractures. Results: There were 8male and 2female patients whose ages ranged from 15 to 67years (mean 42.1years). The fracture type was type II-A in 4patients, II-N in 3 patients, and II-P in 3 patients. The fracture line was oblique downward and backward in 6cases, oblique downward and forward in 1 case, and horizontal in 3cases. The range of follow-up was 5 to 18months (mean 12months). Bone fusions were achieved in all cases without any instrumental failures or postoperative complications. Conclusion: The Herbert screw is very useful in anterior fixation for type II odontoid process fracture. This series showed successful results also in type II-A odontoid fracture when treated with the Herbert screw, but further more studies are required.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1091-1092
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• 2011

영구자석형 발전기는 외부의 여자 전원이 필요 없어서, 비상 전원으로 뿐 아니라, 소형 발전설비에서의 발전기의 여자 전원으로도 사용될 수 있다. 특히, 내삽형 영구자석형 동기발전기는 자석보다 극의 자속밀도를 더 높일 수 있어, 저가, 고성능 발전기 제작이 가능하다. 본 연구에서는 이러한 발전기에 필요한 발전기 해석기술을 개발한다. 정밀 해석을 위한 등가회로를 모델링하고, 이로부터 해석적인 결과를 얻는다. 전기자 저항을 고려한 경우와 고려하지 않은 경우를 비교하여 해석의 타당성을 검증한다.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 1999.11a
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• pp.131-135
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• 1999