• Title/Summary/Keyword: Structure improvement

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The Reality and Problem of Soft Ground Improvement Construction (연약지반 개량 시공의 실제와 문제점)

  • Choi, Gwi-Bong;Hwang, Soung-Won;Kim, Jong-Ryeol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.672-679
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    • 2008
  • During recent years, the large soft ground improvements very rapidly increase with industrial development and it is the types and scales of structure that is enlarged by degree. Then, we must enter construct equipment to improve soft ground and we fulfilled works by carrying out soft clay soil to gain trafficability for them. For improving the soft ground, we lay geotextile on soft clay ground and fill the filter sand that can drain the pore water. Then, we landfill cover soil for come by trafficability of construction tools. Ater that we penetrate vertical drain for dehydration through soft ground. there are very complicated works. For these reason we suggest the methods of soft ground improvement constructions.

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A Design of Low Noise RF Front-End by Improvement Q-factor of On-Chip Spiral Inductor (On-Chip 나선형 인덕터의 품질계수 향상을 통한 저잡음 RF 전치부 설계)

  • Ko, Jae-Hyeong;Jung, Hyo-Bin;Choi, Jin-Kyu;Kim, Hyeong-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.2
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    • pp.363-368
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    • 2009
  • In the paper, we confirmed improvement Noise figure of the entire RF front-end using spiral inductor with PGS(Patterned Ground Shield) and current bleeding techniques. LNA design is to achieve simultaneous noise and input matching. Spiral inductor in input circuit of LNA inserted PGS for betterment of Q-factor. we modeling inductor using EM simulator, so compared with inductor of TSMC 0.18um. We designed and simulation the optimum structure of PGS using Taguchi's method. We confirmed enhancement of noise figure at LNA after substituted for inductor with PGS. Mixer designed using current bleeding techniques for reduced noise. We designed LNA using inductor with PGS and Mixer using current bleeding techniques, so confirmed improvement of noise figure.

Experience Participating in the Pregnancy Recognition Program

  • Kim, Jungae
    • International Journal of Advanced Culture Technology
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    • v.7 no.1
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    • pp.28-34
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    • 2019
  • The purpose of this study is to analyze the meaning and structure of the experiences of 20 years old women who participated in the pregnancy recognition improvement program developed by JA Kim et al. The participants of the study were interviewed three times in total for 20 years old of 6 women. The interview period was from December 1 to December 30, 2018. The interview data were processed through the analysis and interpretation process using the phenomenological research of Giorgi method. As a result, 33 semantic units were derived, and then divided into 4 subcomponents and divided into 2 categories. After participating in the program, they tried to maintain their health, use appropriate welfare policies, and deeply consider their lives as mysterious mothers. In conclusion, this study suggests that the implementation of the pregnancy awareness improvement program for young women in a small group, more systematically and continuously, effectively implements low fertility measures in Korea.

Performance Improvement of MIMO MC-CDMA system with multibeamforming

  • Kim, Chan Kyu
    • International Journal of Internet, Broadcasting and Communication
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    • v.11 no.2
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    • pp.76-83
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    • 2019
  • In this paper, we propose the beamforming algorithm for the performance improvement of MIMO MC-CDMA system. The proposed multibeamforming of MIMO MC-CDMA structure having the same number of beamformer as the number of transmit antenna is derived by calculating the error signals between the coded pilot symbols and the corresponding received signals from the multiple transmitters of the desired user in the frequency domain, transforming the frequency-domain error signals into time-domain error signals, and updating the weights of the multibeamformer in the time-domain in the direction minimizing the mean squared error (MSE). The proposed approach can track each direction of arrival (DOA) of the signals from multi-antennas of a desired user. The performance improvement is investigated through computer simulation by applying the proposed approach to MIMO MC-CDMA system in a multipath fading channel with multiusers.

Structural Safety Evaluation of PBD Composite Perforator's Leader for Soft Ground Improvement (연약지반 개량 PBD 복합천공기 리더의 구조 안전성 평가)

  • Kim, Min-Ho
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.6
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    • pp.894-900
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    • 2018
  • Among the soft ground improvement methods, PBD is the most common construction method because it is cheap and construction is fast. However, if the ground is rigid, additional work is required. In this study, the structural safety, natural vibration, and safety angle of the steel vertical tower structure were evaluated in the development of the PBD composite perforator which can be combined with drilling work and PBD construction. Structural safety was assessed when the wind load of 20 m/s was simultaneously applied to the PBD construction load of 20 tons, the perforating operation of 25 tons, and the wind speed of 50 m/s was applied only to the wind load. The natural frequencies were evaluated up to the sixth mode, and the safety angle was evaluated for static and dynamic safety angles.

Development of Standard Hill Technology for Image Encryption over a 256-element Body

  • JarJar, Abdellatif
    • Journal of Multimedia Information System
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    • v.8 no.1
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    • pp.45-56
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    • 2021
  • This document traces the new technologies development based on a deep classical Hill method improvement. Based on the chaos, this improvement begins with the 256 element body construction, which is to replace the classic ring used by all encryption systems. In order to facilitate the application of algebraic operators on the pixels, two substitution tables will be created, the first represents the discrete logarithm, while the second represents the discrete exponential. At the same time, a large invertible matrix whose structure will be explained in detail will be the subject of the advanced classical Hill technique improvement. To eliminate any linearity, this matrix will be accompanied by dynamic vectors to install an affine transformation. The simulation of a large number of images of different sizes and formats checked by our algorithm ensures the robustness of our method.

Synthesis and Characterization of TiO2/CuS Nanocomposite Fibers as a Visible Light-Driven Photocatalyst

  • An, HyeLan;Kang, Leeseung;Ahn, Hyo-Jin;Choa, Yong-Ho;Lee, Chan Gi
    • Journal of the Korean Ceramic Society
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    • v.55 no.3
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    • pp.267-274
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    • 2018
  • $TiO_2/CuS$ nanocomposites were fabricated by precipitation of nanosized CuS via sonochemical method on electrospun $TiO_2$ nanofibers, and their structure, chemical bonding states, optical properties, and photocatalytic activity were investigated. In the $TiO_2/CuS$ nanocomposite, the position of the conduction band for CuS was at a more negative than that of TiO; meanwhile, the position of the valence band for CuS was more positive than those for TiO, indicating a heterojunction structure belonging to type-II band alignment. Photocatalytic activity, measured by decomposition of methylene blue under visible-light irradiation (${\lambda}$ > 400 nm) for the $TiO_2/CuS$ nanocomposite, showed a value of 85.94% at 653 nm, which represented an improvement of 52% compared to that for single $TiO_2$ nanofiber (44.97% at 653 nm). Consequently, the photocatalyst with $TiO_2/CuS$ nanocomposite had excellent photocatalytic activity for methylene blue under visible-light irradiation, which could be explained by the formation of a heterojunction structure and improvement of the surface reaction by increase in surface area.

Regional Development Plan Based on the Characteristics of Demographic Structure in Farming Areas - Focusing on the Farming Areas in Gyeongnam Province - (농촌지역 인구구조 특성에 따른 지역발전 방안 - 경상남도 농촌지역을 중심으로 -)

  • Kim, Dong-Hwan;Ahn, Jung-Geun
    • Journal of Korean Society of Rural Planning
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    • v.22 no.4
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    • pp.159-169
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    • 2016
  • In recent years, the population structure has been changed by the progresses of 6th-industrialization and transportation in farming areas. This study aims to suggest a regional development plan of farming areas in accordance with the demographic changes. Population structure indicators were derived from previous studies and literature review in order to identify the types of farming areas. Demographic indicators separated to depopulation and population growth in farming areas through a standardized scoring method. This research found that the division of economy is not only the most important division in any other regional development divisions but also necessary to develop new sources of non-farm income through traditional culture, natural environment. In the social division, it is necessary to secure the facilities for the formation of a sense of community to multicultural families and existing residents in farming areas. In the environmental division, it is desirable to improve the quality and satisfaction of life for residents such as the sidewalk and park that utilize ecological environment, culture, history for both depopulation and population region. In the physical division, there is a need for improvement of the facilities of basic living infrastructure service such as roads, water supply and sewerage systems. In the institution division, sustainable financial support of the central government policy for farming areas is crucial for the improvement of residential environment in the farming areas of depopulation and population region.

A Study on Safety Standards of a Railway Crossing (철도 건널목 안전기준에 관한 연구)

  • Jeong, Yeon-Jeong;Lee, Seong-Mo;Park, Chang-Ho
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.83-95
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    • 2009
  • The railway crossing is very dangerous because the track intersects with the road there. Thus, The laws were designed for safety of the railway crossing and they are classified as to the acts for the road and the railroad. For safety of the railway crossing, there are 'Road/Railroad Crossing Improvement Promotion Act', 'Enforcement Decree of Road/Railroad Crossing Improvement Promotion Act', 'Rules on Construction of Railroad', 'Rules on Safety Standards of Railroad Installations', and 'Enforcement Ordinance of Cable way/Railway Track Act' in the acts for the railroad and there are 'Road Traffic Act', 'Enforcement Ordinance of The Road Traffic Act', 'Ruled on Structure and Facility Standards of The Road', 'Rules on Structure And Facility Standards Of The Rural Road' and 'Rules on Structure and Facility Standards of The Installations for Bicycle' in the acts for the road. Both the acts for the road and the railroad have standards for the structure of the railway crossing. However, they have different standards. Besides, they don't have standards for new facilities which were recently installed for safety of the railway crossing. Therefore, we suggest new standards for safety of the railway crossing.

A Study on the Technological Improvement of Strut as a Permanent Structure (구조물 겸용 흙막이 스트러트 공법의 개선 연구)

  • Kim, Sun-Kuk;Hong, Won-Kee
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.5
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    • pp.186-193
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    • 2008
  • The SPS, Strut as a Permanent System, method is widely adopted for the main structural member in addition to temporary strut function for the shuttering of excavation work. Although the SPS method has contributed to cost saving, time reduction, enhancement of structural stability, improvement of construction environment and so on at the building construction site, it caused the problems of increase of basement height and additional work for fire protection of steel structure. The increase of basement height caused the increase of shuttering depth and excavation, and the fire protection caused the additional cost as well as the deterioration of construction environment. In order to improve the problems, this paper is to propose a modularized hybrid structural system(HSD). The detail of the system is introduced and the structural performance and constructibility are proved through the experiment and site application.