• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.45-52
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• 2016

One commercial package for magnetic analysis was used to apply repulsive forces of permanent magnetics to bicycle cushion system. Reliabilities of finite element analysis were acquired by comparing with those of experimental measurements. Equivalent spring stiffnesses corresponding to various sizes of magnetics were implemented into the bicycle dynamic model with three degree of freedom. Input force caused at front and rear wheels due to road unevenness was considered in the dynamic model. Dynamic behaviors were observed in terms of vertical displacements of the rider and the front reach as well as pitching displacement of the mass center when the bicycle ran over half-triangular bump. The methodology suggested in this paper by the finite element analysis and numerical model will be an useful tool for more accurate prediction of cushion design for any vehicle system if magnetic forces are utilized.

• Journal of the Korean GEO-environmental Society
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• v.24 no.1
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• pp.25-36
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• 2023

In Korea, the rockfall prevention fence is designed with 50kJ of rockfall kinetic energy in order to prevent damages such as falling rocks and landslides. In the case of rockfall kinetic energy, it is highly dependent on the shape of the slope on which it occurs. As a previous study, a fence performance evaluation was conducted for 100kJ rockfall impact energy using ETAG 27. However, previous studies have focused on newly installed rockfall prevention fences. In this study, a reinforcing materials was installed on the existing rockfall prevention fence through numerical analysis, and the structural performance of the high-strength rockfall prevention fence capable of defending against 120kJ of rockfall kinetic energy was evaluated.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.343-343
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• 2020

본 연구는 해안 및 도서지역에서 기후변화에 따라 재해위험이 증가되고 있으므로 '해일대비 신개념 침수방어벽 기술 개발'을 통해, 침수방어벽을 ICT와 연계하여 국민의 재산과 생명을 보호할 수 있도록 하는 연구이다. 이를 위해 국내·외 침수방어벽 자료를 조사하여 연구방향을 설정한 후, 국내·외 침수방어장치에 대한 개선방안을 제시하고자 한다. 기존 침수방어벽의 경우 ICT와 연계되어 있지 않아서 침수 예보나 경보 상황에 대응할 수 없는 실정이었다. 본 연구에서는 ICT 연계 방안을 제시하여 침수에 즉각적으로 대응할 수 있도록 함으로써 국민의 재산과 생명을 보호할 수 있도록 하고자 한다. 본 연구에서는 제시된 ICT 연계 침수방어벽에 대한 설치 대상지 검토 및 사업 대상 후보지를 선정하고, 조건별 수치모의(SWMM, 3D flow, FEM 등)를 통해 능력 검토를 수행하고자 한다. 향후 침수방어벽 시제품을 제작하면서 구조적인 안정성을 확보하도록 하였다. 침수센서의 경우 지주식으로 침수방어벽과 일체형으로 하고, 투명 침수방어벽의 경우 유리에 직접 디스플레이가 가능하도록 하였다. 본 연구에서는 기존에 보유하고 있는 직립형 고무보와 투명 홍수방어벽 기술에 대하여 재질과 구동방식, 시공성, 경제성, 유지관리 용이성 등을 재검토하여 해안 및 도서지역에 적합한 침수방어벽 기술에 대한 시제품과 운영시스템을 개발하고자 하며, 이를 통해 국민의 재산과 생명을 보호하고, 국내 물 시장에서 침수를 방지하여 국민경제에 기여할 수 있으며, 향후 ODA 사업에서 홍수예·경보 및 구조적 대책 분야에 진출하여 수출증대 효과를 얻을 수 있을 것이다.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.29 no.4
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• pp.142-149
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• 2018

In this study, 844 Hanwoo proven bulls in South Korea (called KPN) were classified into 8 groups based on their birth year. Microsatellite (MS) marker information for paternity identification of each individual is provided at the homepage of the National Agricultural Cooperation Federation, Korea (NACF) and is mainly for the analysis of genetic diversity and structural changes. The polymorphism analysis of KPN whole groups revealed the average number of alleles in each marker (number of alleles), the expected heterozygosity ($H_{ex}$), the observed heterozygosity ($H_{ob}$), the polymorphism information content (PIC) and the $F_{is}$ mean as 10.54, 0.764, 0.773, 0.727 and -0.014, respectively. For group D, with the birth year 2004-2005, the $H_{ex}$ and $H_{ob}$ were 0.777 and 0.792 respectively and the PIC was 0.740. The $H_{ex}$ of group C and D, with birth years 2003-2004 and 2007-2008, respectively, were greater than $H_{ob}$. In all the other groups, $H_{ob}$ was greater than $H_{ex}$. Genetic composition and structure were analyzed using STRUCTURE software. According to the analyzed results, the generation of Hanwoo groups showed changes in specific genetic components according to the flow. It was confirmed that the continuous improvement in the Hanwoo affects the genetic structure of the proven bulls group. The results of this study are expected to be used for enhancing the efficiency of Hanwoo improvement project.

• Journal of International Area Studies (JIAS)
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• v.14 no.1
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• pp.129-153
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• 2010

The guiding research question of this paper is to discover 'why the UK could not develop a general structure in which transnational corporations were born during the end of the 19th ~ beginning of the 20th century like other countries'. In response to this question, although acknowledging its imperfections, the author would like to explore the causality in the context of 'Social Construction' which is reflected in the attributes of British society. As such, researchers are strongly recommended to take into account the actors' interests and the increased value effect of events which is driven by control power. This paper concludes that: firstly, not only was contempt for industrial capitalism prevalent in British society, the British government was unable to recognize the necessity of promoting policies for the development of transnational corporation. In addition, the increase in the clout of commercial-financial capitalists in the city of London along with the expansion of gentlemanly elites interfered with the transnationality of British companies. Secondly, the foundation of the political and economic structures in the UK experienced continuity and challenge simultaneously. Since the 1850's, the British social structure has been progressively characterized by the strengthening power of the commercial-financial elites in London, which resulted not in the transnationality of manufacturing but that of financial services. Finally, the configuration of the social network driven by the British elites consists of the actors' interests and control power in association with severance and connection. Unlike the complementarity of interests, in the initial stage, intended connection based on voluntary motivation between gentries and commercial-financial elites occurred in terms of control power. However, ultimately, the holding of power was transferred to the commercial-financial elites excluding the industrial capitalists and resulted in the reconfiguration of the social network.

• Journal of the Korean Geotechnical Society
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• v.33 no.1
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• pp.17-30
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• 2017

There are many limitations for ensuring structural stability of retaining wall. Especially, L-shaped retaining wall and gravity retaining wall need large space, and massive concrete, respectively. Assembled Earth Retailing (AER) wall was developed to overcome the shortcomings. In this paper, stability of AER wall is verified by field model tests and the 3D-numerical analysis. The results show that horizontal displacement of AER wall was reduced by maximum 67.84% for conventional retaining walls, and earth pressure acting on the retaining wall was reduced by maximum 73.19%.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.18-26
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• 2004

The cost of underground work is a dominant factor to determine the total construction fee. It is generally 2 ${\~}$ 2.5 times higher than that of above ground for building with the same height. 'A new precast prestressed framing plan for underground parking building' was suggested with the beam of the least depth - U-type beams. The depth of regular rectangular reinforced concrete beam which is currently used in the underground parking of apartments could be reduced up to 12 ${\~}$ 34cm/story due to the development of a U-beams from the optimum process. Two full scale prototype U-beams were tested in this study. It was found that the Wide U-beams in the test showed higher strength than calculated nominal and design, however need to provide temporary supports to meet the flexural moment of construction load at the simply supported state before the lopping concrete hardens.

• Applied Microscopy
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• v.41 no.2
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• pp.117-122
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• 2011

Sperm morphology of Pipistrellus savii velox was examined by transmission electron microscope. The sperm head of P. savii velox was bullet in shape. The sperm head was 3.1 ${\mu}m$ in length, whose posterior 3.0 ${\mu}m$ was occupied by a nucleus with 1.8 ${\mu}m$ in width. The segmented columns were about 14~15 in number. The total number of mitochondrial gyres was 57. Number of 1, 5, and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were evidence, but the fibrous sheath was not seen at the end piece. In the present study, the length of the sperm head of P. savii velox were very shorter than those of other bats.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.82-89
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• 1998

PI controller has been used in the servo system. However the time response of the system designed using the PI control scheme does not provide with desirable time response in case of variation in system parameters or perturbation like a torque disturbance. LMFC(Linear model following controller) is being used to make the response of the system follow that of the model even though the parameter variation or the perturbation occurs. In this paper, a design method, RMFC(Robust Model Following Controller) is proposed, which use an auxiliary model in addition to the LMFC, which affords robustness against the low frequency load torque disturbance. The proposed method is more useful to rejecting the low frequency torque disturbance than LMFC. Proposed method is verified by simulation and experiment.

• Applied Microscopy
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• v.39 no.2
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• pp.89-99
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• 2009

To investigate the morphological characteristics of spermatozoa of the grey red-blacked vole (Clethrionomys rufocanus) belongings to the subfamily Cricetinae, subgenus Clethrionomys were examined by scanning and transmission electron microscopes. The sperm head of C. rufocanus was an ax or hatchet in shape with a curved single dorsal hook. The total length of C. regulus sperm was 95.8 ${\mu}m$. The length of sperm head was 7.8 ${\mu}m$, and the tail (88.0 ${\mu}m$) consisted of four major segments: the neck (1.0 ${\mu}m$), middle piece (22.0 ${\mu}m$), and principal piece plus end piece (65.0 ${\mu}m$), respectively. The segmented columns were about 10~12 in number. The number of gyres of mitochondria ranged from about 170 to 178. The post-nuclear cap occupied about a half of nucleus. The equatorial segment is located between the post-nuclear cap segment and acrosomal cap on the nuclear surface. Nos. 1, 5 and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were in evidence, but the fibrous sheath was not seen at the end piece. In conclusion, the morphological structures of sperm head and tail may be useful information to patterning of sperm evolution and classifying of species.