• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3C
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• pp.191-200
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• 2006

The micropile, which is a kind of the in-situ manufactured pile with small diameter of 100~300mm, is constructed by installing a steel bar or pipe and injecting grout into a borehole. The application fields of micropile are being gradually expanded in a limited space of down-town area, because the micropile has various advantages with low vibration and noise in method and compact size in machine, etc. Mostly, the micropile has been applied to secure the safety of structures, depending on the increment of bearing capacity and the restraint of displacement. The micropile is expected to be used in various fields due to its effectiveness and potentiality in the future. The model test, focused on the interaction between micropile and soil in this study, was carried out. The micropile is installed under footing(concept of "structure supporting"). With the test results and soil deformation analysis, the reinforcement effect(relating to bearing capacity and settlement) was analysed in a qualitative and quantitative manner, respectively. Consequently, it is hoped to demonstrate the improvement of an efficiency and application in the design and construction of micropile.

• Design & Manufacturing
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• v.17 no.4
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• pp.14-23
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• 2023

The electric vehicle market is developing rapidly around the world. Also, parts of electric vehicles require precision.In order to produce high-precision motor cores,Press equipment must also have good precision. Drive motor cores are an important technology for electric vehicles. It uses a large high-speed press to mass-produce drive motor cores. Because it's a large high-speed press, there are many reasons why the precision is not good. One of the causes is vibration and noise. Recently, as environmental demands have become stricter, regulations on noise and vibration have been strengthened. It is important for press machines to reduce vibration first for sound insulation and dust proofing. This is because the "breakthrough" phenomenon occurs in the press. Dynamic precision is the precision under the load of the press, Design considering strain and stiffness shall be made. Vibration and noise may occur due to SPM of high-speed press,And vibration and noise can cause structural deformation of the press. Structural deformation of the press can affect the precision of the product.Noise and vibration also cause problems for workers and work environments. Problems with vibration and noise occur during press processing, and vibration and noise lead to damage to the mold or defects in the product. Reliability in high-quality technology must be secured with low noise and low vibration during press processing. Modular shape and deformation energy effects were analyzed through finite element analysis. In this study, a study on vibration and noise countermeasures was conducted through finite element analysis of a large high-speed press.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8408-8415
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• 2015

The purpose of this study is to propose and analyse new technology of structural elements design for Korean-style house(Hanok). Design of modern apartment building adopts many aesthetic elements from Hanok, however, these are only for the decorations of interior. In this study, projected Hanok eaves were studied in terms of the length of solar insolation. Inclined front slab system has been proposed utilizing sloping roof to an apartment building section. This system can provide the same sunshine radiation length and outside view to all levels of building to overcome the limitation of traditional hanok. It also can be applied to all residences the vertical garden concept of hanok. Inclined slab system showed 20% more efficient than flat slab system in terms of solar insolation length. This study also suggested a double deck slab system for not only reducing apartment floor impact noise but also connecting concept of traditional maru system in hanok. Double deck system reduces 66% of floor impact noise comparing with single deck slab of modern apartment buildings.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.66-66
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• 2011

중위도 이북의 건물에서 고층건물의 혹한기 연돌효과는 건물의 여러 가지 기능에 큰 영향을 미치며, 승강기 승강로는 화재시 차압 때문에 연기의 주된 전파통로가 된다. 외피의 밀폐성능을 높여 건물 내부의 연도효과를 줄일 수 있으나, 외피의 밀폐기능은 비상시 피난을 위해 피난경로를 개방하는 순간 일시에 무력화된다. 또한 건물 외피의 밀폐성능이 우수할수록 연돌효과 그 자체로써 건물외피에 미치는 구조적 영향이 커진다. 고층부의 연돌효과는 외피를 밖으로 밀어내는 작용이므로 풍하측에서는 마이너스 풍압에 더하여 건물 외피에 부담을 증가시킨다. 그러므로 고층건물에 발생하는 혹한기 연돌효과의 영향을 정리하자면 다음과 같다. ${\bullet}$ 건물 외벽 및 창문에 미치는 구조적 영향 ${\bullet}$ 제연 시스템의 기능 저해 ${\bullet}$ 승강기 문 개폐 장애와 소음 등 설비 기능의 부정적 영향 ${\bullet}$ 공조기능 장애 ${\bullet}$ 화재시 승강기 승강로 등 수직 샤프트를 통한 연기 전파 혹한기 건물 안팎의 온도차가 40K일 때 높이 600m인 초고층 건물 최상층에 발생하는 연돌효과에 의한 차압은 풍속으로 환산할 때 32m/s에 달한다. 그러므로 초고층 건물 설계시에는 최상층의 풍하측에 설계상의 예상 최대풍속에다 이러한 환산풍속을 더한 고속 풍력이 창문을 밖으로 밀어내는 것으로 보아야 한다. 또한 공조 및 환기시스템에서는 이러한 차압을 고려하지 않으면 고층부에서 환기 성능이 무력화될 수 있다. 다음과 같은 방법들을 이용하여 고층건물의 연돌효과를 효과적으로 줄일 수 있다. 1) 계단실의 연돌효과 저감 방법 계단실에 발생하는 연돌효과에 의한 차압은 계단실에 상승기류를 발생시킨다. 이러한 차압과 상승기류는 계단실 상하부를 개방하면 자연적으로 평형을 이루게 되므로 별도의 제어가 필요 없게 된다. 또한 화재감지기와 연동하여 상하부 외벽의 개구부를 열어두게 되면 피난상황에 따라 문이 여닫힘으로써 발생하는 압력상태의 변화를 고려할 필요가 없게 된다. 2) 승강기 승강로의 연돌효과 승강로의 상하부에 대규모 개구를 두면 대규모의 외기가 도입되어 상승 유동 후 배출되므로 승강로 내부 온도 저하로 연돌효과가 저감되고, 승강로로 유입된 연기는 대규모의 외기에 희석되어 농도가 낮아지고 대부분 외부로 배출된다. 3) 샤프트 복합효과를 이용하는 방법 거실 평면적에 비해 승강기나 계단이 아주 많고 누설틈새 등 개구의 면적 합계가 크면 샤프트들이 서로 복합효과를 이루어 연돌효과에 의한 차압이 줄어든다. 연돌효과 제어용 샤프트를 하나 더 보조적으로 설치함으로써, 보조샤프트에 의해 발생하는 차압으로 거실을 가압 혹은 감압하여 문제가 되는 차압을 어느 정도 상쇄할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.28-36
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• 2018

Islands are supplied with power from diesel generation or from photovoltaic power generation, and problems with offshore environmental impacts (age deterioration, salt pollution), environmental pollution (exhaust gas, noise, dust) and power generation costs (installation, maintenance) have increasingly emerged. In 2016, the cost recovery rate was only 27%, and deficits reached 73% on 65 islands managed by KEPCO. In terms of deficits, the costs incurred in the power generation sector accounted for 91%, with the ratio of fixed costs at about 60%. Analysis suggests that operating costs can be reduced with an optimal power supply system that improves power generation efficiency and makes operating systems more efficient. Therefore, it is possible to simplify fuel transportation and facility maintenance, because one island integrates the power plants of remote islands, and offshore cable is used to supply power to the other islands. From the economic evaluations in this paper, an algorithm deciding offshore cable layout validity for an integrated power supply between adjacent islands is presented. Simulation results based on the proposed algorithm confirmed that an integrated power supply is economical for existing stand-alone operations on islands having diesel generation, low peak power, and near distances.

• Cartoon and Animation Studies
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• s.47
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• pp.125-148
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• 2017

This paper analyzes Korean aesthetic characteristics of Korean independent animation, which is closely related to artistic and social characteristics, by searching Korean independent animation image for the winner of "Indie AniFest", the only independent animation film festival in Korea. And social communication methods. There are three ways in which Korean Independence Animation shows the way of speaking through award-winning works. The first is a method of expressing feelings, impulses, and desires in a formative way, and a direct and sensuous image as in sign language or sound. In the second method of speaking differently with images, in the third method, It makes the voice of the fringe through the real world of the story sound as a story of reality. Animation is a medium that 'originalizes and communicates meaning' as an image, and has implemented and constructed a new way of speaking, which is different from existing social voices. Nevertheless, it is not easy to find a research that approaches animation from the viewpoint of social and political speech through images. Therefore, this paper is necessary for the balanced development of animation. In addition, this study can contribute to re - examining Korean independent animation from an academic point of view and to discover and evaluate fair value from a wider perspective.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.190-194
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• 2010

Purpose : To investigate the nature of deviant voice physiology in preoperative children with congenital heart disease. Methods : Ninety-four children with congenital heart disease were enrolled. Their cries and related acoustic variables (fundamental frequency, duration, noise to harmonic ratio, jitter and shimmer) were analyzed using a multi-dimensional voice program. Results : The average fundamental frequency showed a significant decrease in patent ductus arteriosus, ventricular septal defect, and tetralogy of Fallot, except in atrial septal defect and pulmonary stenosis. The length of the analyzed sample (duration) did not show a significant difference when compared with the control group. There was a significant increase in jitter percent in ventricular septal defect, patent ductus arteriosus, and atrial septal defect. There was an increase in shimmer in ventricular septal defect, patent ductus arteriosus, and atrial septal defect. The noise-to-harmonic ratio increased in ventricular septal defect, patent ductus arteriosus, and atrial septal defect but there was no significant difference in pulmonary stenosis and tetralogy of Fallot. While analyzing acoustic variables, the voice change was significantly higher, especially in patent ductus arteriosus followed by ventricular septal defect and atrial septal defect. Most of these acoustic variables were deviant in left-to-right shunt lesions in congenital heart disease, especially in patent ductus artriosus. Conclusion : The results of the voice change analysis of preoperative children with congenital heart disease revealed that the acoustic variables differed by each congenital heart disease. Moreover, the acoustic variables were prominently deviant in congenital heart disease with left-to-right shunts.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.445-451
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• 2017

Because of the supply-demand problem of aggregate, recently, the construction sites using 100% crushed sand are increasing and the use of low quality aggregate such as farmland sand is increasing too. When the low quality aggregate is used, the various quality defect of concrete such as the strength reduction, the increase of shrinkage and bleeding can be occurred. Therefore, in this study, the performance improvement PC admixture was developed to minimize the quality defect of plain concrete of basement parking area, when the low quality aggregate was used at the plain concrete of basement parking area. The slump loss to elapsed time test, the compressive strength test, the bleeding test and the drying shrinkage test were carried out.

• Korean Journal of Construction Engineering and Management
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• v.11 no.4
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• pp.100-108
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• 2010

With the rapid economic growth and improvement of living conditions in Korea, rebuilding and redevelopment of existing houses has also been rapidly increasing. As a result, considerable construction and demolition wastes have been produced. Demolition wastes, however, must be given special attention because of the various harmful substances in them. The construction waste has been produced most at demolition phase, but the research into that area has not being to make nearly within the country. The aim of this study was to evaluate and compare the contamination figures of the heavy metals and toxin organic substances in the soil and water caused by flying ashes generated and eventually accumulated in building demolition works. AB a result. most of the pollution levels were not worrisome, but some were increased after the demolition with the water used to prevent the dusty air and in the target buildings. However in the vicinity of the demolition sites with explosives there was no report of study in water and soil pollutions, so to minimize pollutions we need to make plans to select the harmful substance in the first place. Thus, this research is expected to be the important materials for future research into the construction waste area.

• 한국노년학
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• v.38 no.1
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• pp.1-14
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• 2018

Everyday hearing handicap caused by presbycusis ultimately reduces quality of life in older adults. The aim of this study was to explore effects of cognitive impairment on self-reported hearing handicap in older adults with early-stage presbycusis. We compared K-HHIE scores between 40 elderly subjects with mild cognitive impairment (MCI) and age- and hearing-threshold matched 40 cognitively normal elderly (CNE) subjects. The results are as follows: 1) The MCI group scored significantly higher than the CNE group on the social/situational and emotional sections, and in total. 2) The MCI group scored significantly higher than the CNE group on all four subscales, and the most significant group difference was on the first subscale relating to interpersonal relationships and social handicaps. 3) Both groups scored highest on the item 8 (problems hearing whispering sounds) and item 15 (problems hearing TV or radio sounds). Besides those two items, the MCI group also scored high on the item 21 (problems hearing in a restaurant), item 6 (problems hearing when attending a party), item 3 (avoiding groups of people), and item 20 (personal or social restrictions). Our findings suggest that, among older adults with early-stage presbycusis, older adults with cognitive impairment tend to report greater everyday hearing handicap than their peers with normal cognitive function. Especially, they show significant problems hearing in background noise or multi-talker situations, which cause social restrictions and social/emotional loneliness.