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An Experimental Study on the Influence of Masonry InFilled Walls on the Seismic Performance of Reinforced Concrete Frames with Non-seismic Details (정적실험을 통한 조적채움벽체가 비내진상세 RC 골조의 내진성능에 미치는 영향 평가)

  • Kim, Kyoung-Min;Choen, Ju-Hyun;Baek, Eun-Rim;Oh, Sang-Hoon;Hwang, Cheol-Seong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.114-120
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    • 2017
  • In this paper, the effect of the masonry infill walls on the seismic performance of the reinforced concrete(RC) frames with non-seismic details was evaluated through the static test of an masonry infilled RC frame sub-assemblage with non-seismic details of real size, and comparison with the test results of the RC frame sub-assemblage with non-seismic details. As the test results, lots of cracks occurred on the surface of the entire frame due to the compression of the masonry infilled wall, and the beam-column joint finally collapsed with the expansion of the shear crack and buckling(exposure) of the reinforcement. On the other hand, the stiffness of the shear force-story drift relationship decreased due to the wall sliding crack and column flexural cracks, and the strength finally decreased by around 60% of the maximum strength. The damage that concentrated on the upper and lower parts of columns was dispersed in the entire frame such as columns, a beam, and beam-column joints due to the wall, and the specimen was finally collapsed by expansion of the shear crack of the joint, not the shear crack of the column. Also, the stiffness of RC frame increased by 12.42 times and the yield strength by 3.63 times, while the story drift at maximum strength decreased by 0.18 times.

Relative Abundance of a Vector of Scrub Typhus, Leptotrombidium sialkotense, in Southern Yunnan Province, China

  • Lv, Yan;Guo, Xian-Guo;Jin, Dao-Chao;Song, Wen-Yu;Fan, Rong;Zhao, Cheng-Fu;Zhang, Zhi-Wei;Mao, Ke-Yu;Zou, Yun-Ji;Yang, Zhi-Hua
    • Parasites, Hosts and Diseases
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    • v.58 no.2
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    • pp.153-159
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    • 2020
  • The chigger mite Leptotrombidium sialkotense is one of the 6 main vectors of scrub typhus in China. Before present study, L. sialkotense was found in some parts of Hunan province, China with a narrow geographical distribution. During field investigation 2016-2017, we found L. sialkotense in Jingha, southern Yunnan, China. Of 15 small mammal host species, L. sialkotense were collected from 6 species of the hosts. Rattus brunneusculus was a dominant host of L. sialkotense, from which 98.3% of the mites were collected. The chigger mite showed a relatively high infestation prevalence (PM =11.7%) and mean abundance (MA=0.5) in comparison with the rest 5 host species. These results reveal a certain host specificity of L. sialkotense to a rat R. brunneusculus. The mite L. sialkotense showed an aggregated distribution on the host (P<0.05). A positive correlation observed between L. sialkotense and the body length of hosts. There was a positive interspecific association between L. sialkotense and 2 other dominant vectors, L. deliense and L. scutellare.

Thermal-hydraulic research on rod bundle in the LBE fast reactor with grid spacer

  • Liu, Jie;Song, Ping;Zhang, Dalin;Wang, Shibao;Lin, Chao;Liu, Yapeng;Zhou, Lei;Wang, Chenglong;Tian, Wenxi;Qiu, Suizheng;Su, G.H.
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2728-2735
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    • 2022
  • The research on the flow and heat transfer characteristics of lead bismuth(LBE) is significant for the thermal-hydraulic calculation, safety analysis and practical application of lead-based fast reactors(LFR). In this paper, a new CFD model is proposed to solve the thermal-hydraulic analysis of LBE. The model includes two parts: turbulent model and turbulent Prandtl, which are the important factors for LBE. In order to find the best model, the experiment data and design of 19-pin hexagonal rod bundle with spacer grid, undertaken at the Karlsruhe Liquid Metal Laboratory (KALLA) are used for CFD calculation. Furthermore, the turbulent model includes SST k - 𝜔 and k - 𝜀; the turbulent Prandtl includes Cheng-Tak and constant (Prt =1.5,2.0,2.5,3.0). Among them, the combination between SST k - 𝜔 and Cheng-Tak is more suitable for the experiment. But in the low Pe region, the deviation between the experiment data and CFD result is too much. The reason may be the inlet-effect and when Pe is in a low level, the number of molecular thermal diffusion occupies an absolute advantage, and the buoyancy will enhance. In order to test and verify versatility of the model, the NCCL performed by the Nuclear Thermal-hydraulic Laboratory (Nuthel) of Xi'an Jiao tong University is used for CFD to calculate. This paper provides two verification examples for the new universal model.

A Study on the Development of H2 Fuel Cell Education Platform: Meta-Fuelcell (연료전지 교육 플랫폼 Meta-Fuelcell 개발에 관한 연구)

  • Duong, Thuy Trang;Gwak, Kyung-Min;Shin, Hyun-Jun;Rho, Young-J.
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.29-35
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    • 2022
  • This paper proposes a fuel cell education framework installed on a Metaverse environment, which is to reduce the burden of education costs and improve the effect of education or learning. This Meta-Fuel cell platform utilizes the Unity 3D Web and enables not only theoretical education but also hands-on training. The platform was designed and developed to accommodate a variety of unit education contents, such as ppt documents, videos, etc. The platform, therdore, integrates ppt and video demonstrations for theoretical education, as well as software content "STACK-Up" for hands-on training. Theoretical education section provides specialized liberal arts knowledge on hydrogen, including renewable energy, hydrogen economy, and fuel cells. The software "STACK-Up" provides a hands-on practice on assembling the stack parts. Stack is the very core component of fuel cells. The Meta-Fuelcell platform improves the limitations of face-to-face education. It provides educators with the opportunities of non-face-to-face education without restrictions such as educational place, time, and occupancy. On the other hand, learners can choose educational themes, order, etc. It provides educators and learners with interesting experiences to be active in the metaverse space. This platform is being applied experimentally to a education project which is to develop advanced manpower in the fuel cell industry. Its improvement is in progress.

Analysis of spatial interpretation and cultural valorization of groundwater resource using open data (공공데이터를 활용한 지하수자원의 공간적 해석과 문화적 가치부여에 대한 제안)

  • Han-Na, CHOI;Yong-Cheol, KIM;Jeong-Hyun, YU;Ye-Yeong, LEE;So-Jung, IN;Jong-Gyu, HAN
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.4
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    • pp.81-93
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    • 2022
  • There are many natural hot springs and mineral springs as well as the cultural heritage of the three kingdoms period in the Geum River basin including Chungcheong region. No specific regeneration and publicity plans for deteriorated facilities in this area has been presented. This study aims to suggest promising hot spots and complex water culture belt in the Chungcheong region and Geum River basin through the spatial interpretation of resources. The northern part of the Geum River basin is expected to become a therapeutic spring belt with many hot springs and CO2-rich springs. In the central and southern parts of the Geum River basin, it is considered that it will be possible to promote convergence publicity by using groundwater resources and cultural assets.

A Study on the Policies Evaluation Framework for Environmentally Friendly City (환경친화적 도시 조성을 위한 정책평가체계에 관한 연구 - 저부하형 도시 조성을 중심으로 -)

  • Yoon, So Won
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.6 no.4
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    • pp.8-16
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    • 2003
  • In terms of climate change communities have only during the 1990s begun to recognize that all greenhouse gas(GHG) emissions are directly or indirectly generated locally, through acts of agency, production or consumption. This has provided a boost to the role of local places in the debate since GHGs can be allocated and made understood locally and hence form the basis for specific policies, programs, plans and projects. The objectives of this study are to define a framework for making Environmentally Friendly City through enhancing integrated energy-urban policies and present framework to do comprehensive evaluation on energy related policies response and also explore the interrelation between energy related activities in each sector and policy and applies to Seoul mega city in Korea. Despite the growing recognition of the seriousness of urban environmental problems and their contribution to global environmental and social concerns, most analysts continue to study cities in parts rather than as a whole; we study sectoral sub-systems such as transport, air pollution or energy. While specialization is useful for detailed thinking, we also need to see each issue in the context of how each city works environmentally, economically, socially and politically. We therefore need integrative approaches to study of cities and need to understand how they function as systems. These framework presented in this study allows an organized and systematic analysis. These research results can provide useful, credible and timely input into the urban planning process. This study will be a helpful exercise to draw some policy implications of other cities in Korea and also East Asia that are in a similar stage with the these cities and developing plans on how to address them.

Development of a Bio-mimetic Entertainment Robot with Autonomous Feeding Functionality

  • Cho, Ik-Jin;Choi, Byoung-Jun;Jeong, Kil-Woong;Lee, Yun-Jung
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1525-1529
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    • 2004
  • Most of the recently developed robots are human friendly robots which imitate an animal or human such as entertainment robot, bio-mimetic robot and humanoid robot. Interest in these robots are increasing since the social trend is focused on health, welfare, and graying. By these social backgrounds, robots become more human friendly and suitable for home or personal environment. The more bio-mimetic robots resemble living creature, the more human feels familiarity. People feel close friendship not only when they feed a pet, but also when they watch a pet having the food. Most of entertainment robots and pet robots use internal-type batteries and have a self-recharging function. Entertainment robots and pet robots with internal-type batteries are not able to operate during charging the battery. So far there have been a few robots that do not depend on a battery. However, they need a bulky energy conversion unit and a slug or foods as an energy source, which is not suitable for home or personal application. In this paper, we introduce a new bio-mimetic entertainment robot with autonomous feeding functionality, called ELIRO-1(Eating LIzard RObot version 1). The ELIRO-1 is able to find a food (a small battery), feed by itself and evacuate. We describe the design concept of the autonomous feeding mechanism of the ELIRO-1, characteristics of sub-parts of the manufactured mechanism and the control system.

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Development of standard shoe-lasts that reflect BMI and foot characteristics of senior generation women (여성 시니어 세대 BMI와 발 특성에 따른 구두용 표준 라스트 개발)

  • Lee, Woong-Sub;Kim, Sun-Ah
    • The Research Journal of the Costume Culture
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    • v.25 no.2
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    • pp.175-191
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    • 2017
  • The purpose of this study is to analyze the body mass index(BMI) and foot characteristics of senior-generation women and to use those values to develop a standard shoe last for producing shoes that best fit the foot of senior-generation women. In order to develop a standard shoe last that reflects the BMI and foot characteristics of senior-generation women, I analyzed the morphometric characteristics of feet by conducting descriptive statistics for each item. The foot characteristics based on BMI were analyzed by conducting ANOVA and Duncan's tests via the foot's measured values. Subsequently, I developed a standard shoe last reflecting the BMI and the foot characteristics of senior-generation women by applying all those values. Senior-generation women showed significant differences among three groups based on BMI-normal weight, overweight, and obese-in all the items except for medial ball width and toe 5 angle. Through these values, I realized that as the value of the BMI becomes higher, the size of the foot becomes larger. This suggests that as a woman's weight increases or decreases, her shoes need to be replaced as well as her clothes. Deviations in the toe-side parts of the shoe could cause deformation of the foot. If someone keeps wearing shoes produced using a shoe last with a large deviation, she risks developing foot conditions like hallux valgus. This situation points to the need for shoe manufacture that utilizes a standard shoe last that reflects the BMI and foot characteristics of the senior generation.

A 5-DOF Ground Testbed for Developing Rendezvous/Docking Algorithm of a Nano-satellite (초소형 위성의 랑데부/도킹 알고리즘 개발을 위한 5자유도 지상 테스트베드)

  • Choi, Won-Sub;Cho, Dong-Hyun;Song, Ha-Ryong;Kim, Jong-Hak;Ko, Su-Jeong;Kim, Hae-Dong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.12
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    • pp.1124-1131
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    • 2015
  • This paper describes a 5-dof ground testbed which emulates micro-gravity environment for developing Rendezvous/docking algorithm of a nano-satellite. The testbed consists of two parts, the low part which eliminates friction force with ground and the upper part which has 3-dof rotational motion with respect to the low part. For Vison-based autonomous navigation algorithm, we use camera, LIDAR and AHRS as sensors and eight cold gas thrusters and three axis directional reaction wheels as actuators. All system software are implemented with C++ based on on-board computer and Linux OS.

Dual-wide-band absorber of truncated-cone structure, based on metamaterial

  • Kim, Y.J.;Yoo, Y.J.;Rhee, J.Y.;Kim, K.W.;Park, S.Y.;Lee, Y.P.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.235.1-235.1
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    • 2015
  • Artificially-engineered materials, whose electromagnetic properties are not available in nature, such as negative reflective index, are called metamaterials (MMs). Although many scientists have investigated MMs for negative-reflective-index properties at the beginning, their interests have been extended to many other fields comprising perfect lenses. Among various kinds of MMs, metamaterial absorbers (MM-As) mimic the blackbody through minimizing transmission and reflection. In order to maximize absorption, the real and the imaginary parts of the permittivity and permeability of MM-As should be adjusted to possess the same impedance as that of free space. We propose a dual-wide-band and polarization-independent MM-A. It is basically a triple-layer structure made of metal/dielectric multilayered truncated cones. The multilayered truncated cones are periodically arranged and play a role of meta-atoms. We realize not only a wide-band absorption, which utilizes the fundamental magnetic resonances, but also another wide-band absorption in the high-frequency range based on the third-harmonic resonances, in both simulation and experiment. In simulation, the absorption bands with absorption higher than 90% are 3.93 - 6.05 GHz and 11.64 - 14.55 GHz, while the experimental absorption bands are in 3.88 - 6.08 GHz and 9.95 - 13.84 GHz. The physical origins of these absorption bands are elucidated. Additionally, it is also polarization-independent because of its circularly symmetric structures. Our design is scalable to smaller size for the infrared and the visible ranges.

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