• Title/Summary/Keyword: deflection control

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A Study on the Development of Ability Women Specialist -Focused on the nursing specialist- (여성전문인의 능력발전에 관한 연구 - 전문간호사를 중심으로 -)

  • Kwon Ill Zoo
    • Journal of Korean Public Health Nursing
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    • v.3 no.1
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    • pp.101-119
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    • 1989
  • In the present, since a five-year plan for economic development which was started in the early 60's has been successfully promoted for a quarter century, with consolidation in a department of social welfare in our country the participation. in economic society for women is more required than any other times. As a professional occupation for women is incereaing through a high-standard specialization, I think the upbringing for productive woman expert who has a strong motive of accomplishment as a developed person as well as a technical and skilful capacity which can be contributed to the growth of organization is very important. So in this study, I am evaluating the technical disposition of character of professional nurses working with hospital and also trying to supply the basic data being served to th extension of a skillful ability as a nurse, understanding the important factor related to it. The research method applied here is that we used 527 of formed questionnaires which were distributed to 7 University and General Hospitals, somewhat large in a scale, located in Seoul as an analytical material. It was performed between October 11, 1988 and October 18, 1988. An implement which was invented by Cho Moo-Sung is used after being amended and supplemented, which can measure the disposition of professional character. The formation of questionnaires of the disposition of character is 26 totally, 10 for Open-disposition, 11 for Active-disposition, 5 for wise-disposition, and it was measured. 'Ye', or 'No' through an one-half-standard and the environment of hospital organization is composed 12 questions from one point of 'Very Good' to 5 points of 'Very Bad.' Collected materials were analysed through an electronic calculation into the average value, the standard deflection, percentage, person correlative number, $X^2-test, m$ stepwise multiple regression. Summarizing the result from this research is as follows; 1. The average age of the subjective person of this investigation is 28.6 and the average career as a nurse is 6.0 years. 2. The Open-disposition that technical nurses showed is mostly half and half. 3. The Active-disposition of professional nurses was discovered affirmative largely and what they said in their questionnaires describes that they are very active answering $88.2\%$ for the disposition of self-control, $87.3\%$ for the people who think the training more seriously. 4. It was found out that the wise·disposition of technical nurse showed $90.7\%$ of 'Yes' about a new alternative of inquisitive question and we can see a progressive and profound aspect here. 5. As technical character of nurses, mutual relations between Active-disposition, Active-disposition, and wise­disposition were very profitably revealed as 0.42 in justice relations and also suggested that relations between Open-disposition, Active-disposition, and wise-disposition are 0.27 and 0.20 respectively. 6. What nurses recognize about the environment of hospital organization is reasonably acceptable while they feel very bad about rewards and punishments showing average 3.1 comparing to average 2.2 about time­control each other. Considering the prosperity of Active-disposition upon the result what I mentioned above, th possibility which is contributed to the productive improvement of hospital organization is very great and I think it can be more developed as a professional woman who has a strong motive of accomplishment, in advance.

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Experimental Study on Blast Resistance Improvement of RC Panels by FRP Retrofitting (철근콘크리트 패널의 FRP 보강에 의한 방폭 성능 향상에 관한 실험 연구)

  • Ha, Ju-Hyung;Yi, Na-Hyun;Kim, Sung-Bae;Choi, Jong-Kwon;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.22 no.1
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    • pp.93-102
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    • 2010
  • Recently, FRP usage for strengthening RC structures in civil engineering has been increasing. Especially, the use of FRP to strengthen structures against blast loading is growing rapidly. To estimate FRP retrofitting effect under blast loading, blast tests with nine $1,000{\times}1,000{\times}150\;mm$ RC panel specimens, which were retrofitted with carbon fiber reinforced polymer (CFRP), Polyurea, CFRP with Poly-urea and basalt fiber reinforced polymer (BFRP) have been carried out. The applied blast load was generated by the detonation of 15.88 kg ANFO explosive charge at 1.5 m standoff distance. The data acquisitions not only included blast waves of incident pressure, reflected pressure, and impulse, but also included central deflection and strains at steel, concrete, and FRP surfaces. The failure mode of each specimen was observed and compared with a control specimen. From the test results, the blast resistance of each retrofit material was determined. The test results of each retrofit material will provide the basic information for preliminary selection of retrofit material to achieve the target retrofit performance and protection level.

Behavior of RC beams strengthened with NSM CFRP strips under flexural repeated loading

  • Fathuldeen, Saja Waleed;Qissab, Musab Aied
    • Structural Engineering and Mechanics
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    • v.70 no.1
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    • pp.67-80
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    • 2019
  • Strengthening with near surface mounted carbon fibre reinforced polymers (NSM-CFRP) is a strengthening technique that have been used for several decades to increase the load carrying capacity of reinforced concrete members. In Iraq, many concrete buildings and bridges were subjected to a wide range of damage as a result of the last war and many other events. Accordingly, there is a progressive increase in the strengthening of concrete structures, bridges in particular, by using CFRP strengthening techniques. Near-surface mounted carbon fibre polymer has been recently proved as a powerful strengthening technique in which the CFRP strips are sufficiently protected against external environmental conditions especially the high-temperature rates in Iraq. However, this technique has not been examined yet under repeated loading conditions such as traffic loads on bridge girders. The main objective of this research was to investigate the effectiveness of NSM-CFRP strips in reinforced concrete beams under repeated loads. Different parameters such as the number of strips, groove size, and two types of bonding materials (epoxy resin and cement-based adhesive) were considered. Fifteen NSM-CFRP strengthened beams were tested under concentrated monotonic and repeated loadings. Three beams were non-strengthened as reference specimens while the remaining were strengthened with NSM-CFRP strips and divided into three groups. Each group comprises two beams tested under monotonic loads and used as control for those tested under repeated loads in the same group. The experimental results are discussed in terms of load-deflection behavior up to failure, ductility factor, cumulative energy absorption, number of cycles to failure, and the mode of failure. The test results proved that strengthening with NSM-CFRP strips increased both the flexural strength and stiffness of the tested beams. An increase in load carrying capacity was obtained in a range of (1.47 to 4.49) times that for the non-strengthened specimens. Also, the increase in total area of CFRPs showed a slight increase in flexural capacity of (1.02) times the value of the control strengthened one tested under repeated loading. Increasing the total area of CFRP strips resulted in a reduction in ductility factor reached to (0.71) while the cumulative energy absorption increased by (1.22) times the values of the strengthened reference specimens tested under repeated loading. Moreover, the replacement of epoxy resin with cement-based adhesive as a bonding material exhibited higher ductility than specimen with epoxy resin tested under monotonic and repeated loading.

A Study on the Flexural Fatigue Behavior of R/C Beams Repaired with Concrete-Polymer Composites (유기 및 유기재료로 보수된 R/C 보의 휨 피로거동에 관한 연구)

  • 심종성;황의승;배인환;이은호
    • Magazine of the Korea Concrete Institute
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    • v.7 no.6
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    • pp.233-241
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    • 1995
  • In this thesis, the fatigue tests were performed on a series of R /C beams repaired with co& crete-lmlyrner composites to investigate the fatigue bahavior. The three point loading system is used in the fatigue tests. In these tests, relations between the repeated loading cycles and mid-span deflections, number of repeated loading cycles when repaired beams were fractured, the bonding performance of repair materials were observed. On this basis, the mid-span deflections, the crack growth and failure mode of repaired R /C beams were studied. A S-N curve was drawn to present the fatigue strength of repaired beams. From the test results, it was shown that behavior of R /C beams repaired with polymer-cement series were very sirnillar to control beam about bonding performance, mid-span deflections and fatigue strength according to S-N curve drawn by the regression anlysis on the fatigue test results.

Analytical and experimental study on the quality improvement of 2 cavity injection-molded LCD frame (2 캐비티 LCD 사출품의 품질향상에 관한 해석 및 실험적 연구)

  • Son, Jae-Hwan;Jang, Eun-Sil;Han, Chang-Woo;Son, Jae-Yong;Lee, Young-Moon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.3815-3821
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    • 2012
  • The LCD frame is an important part which supports the BLU of medium/large sized TFT-LCD. To produce it efficiently, it is necessary to achieve the molding process improvement from 1 cavity to 2 cavity system. Because 2 cavity mold is compact and its hot-runner zone is broadened, it is difficult to control the temperature on the mold. In this study, injection molding analysis on the frame in 2 cavity process with FEA(Finite Element Analysis) software is carried out to estimate its quality. The calculated injection molding pressures and maximum deflection in 1 and 2 cavity processes are 41.13 MPa and 1.62 mm, 40.49 MPa and 1.66 mm respectively. The measured maximum flexure load and surface roughness of the left and right frame of 2 cavities are 209 N and 0.08 ${\mu}m$, 193 N and 0.10 ${\mu}m$ while those in 1 cavity are 140 N and 0.13 ${\mu}m$. Thermal image shows that the maximum standard deviation of the temperature on left and right side of 2 cavity mold is $1.23^{\circ}C$. The simulation and measurement results show that the quality of the frame in 2 cavity injection molding process as a whole is not worse than that of 1 cavity system. But maximum flexure loads of the frame in 2 cavity process are far greater than that in 1 cavity process.

A Study on the Pile Material Suited for Pile Supported Embankment Reinforced by Geosynthetics (토목섬유로 보강된 성토지지말뚝 구조에 적합한 말뚝재료의 개발)

  • Choi, Choong-Lak;Lee, Kwang-Wu;Kim, Eun-Ho;Jung, Ji-Won
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.1
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    • pp.21-35
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    • 2016
  • It is a current trend that the concrete track is applied for high speed railway. In the case of the railway embankment constructed on soft ground, the damage to concrete track which is sensitive to settlement such as distortion and deflection could be caused by very small amount of long term settlement. Pile Supported Embankment method can be considered as the effective method to control the residual settlement of the railway embankment on soft ground. The Geosynthetics is used inside of the embankment to maximize the arching effect transmitting the load of the embankment to the top of the piles. But, PHC piles that are generally used for bridge structures are also applied as the pile supporting the load of embankment concentrated by the effect of the Geosynthetics. That is very low efficiency in respect of pile material. So, in this study, the cast in place concrete pile was selected as the most suitable pile type for supporting the embankment by a case study and the optimum mixing condition of concrete using a by-product of industry was induced by performing the mixing designs and the compressive strength designs. And it is shown that the cast in place pile with the optimum mixing condition using the by-product of industry is 2.8 times more efficient than the PHC pile for the purpose of Pile Supported Embankment by the finite element analysis method.

Effects of Post-Tensioning Tendons and Vehicle Speeds on Dynamic Response of Concrete-Filled Steel Tubular Tied Arch Girder (긴장재 및 차량속도 변화에 따른 콘크리트 충전 타이드 아치형 거더의 동적거동)

  • Roh, Hwasung;Hong, Sanghyun;Park, Kyunghoon;Lee, Jong Seh
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3A
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    • pp.163-172
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    • 2011
  • The CFTA girder developed is a concrete filled steel tubular system with arched shape and external post-tensioning (PT) tendons which control the initial camber and the bending stress of the girder. In the present study the effects of the PT tendons on the dynamic behavior of the girder subjected to a moving vehicle load are numerically investigated. Various levels for the tendon quantity and the tendon forces are considered, using the existing FE model of the girder. The vehicle considered is a DB-24 truck and is modeled with two tracks-three axles. Equivalent-load pulse time histories are applied to each node to simulate the moving vehicle, depending on the time of arrival and the discretization. The vehicle speeds are varied from 40 km/hr to 100 km/hr with increment of 20 km/hr. The analysis results show that the tendon forces do not produce any influences on the dynamic responses of the girder. However the dymamic deflection of the girder increases when a smaller amount of tendons is used. The Dynamic Amplification Factors (DAF) are evaluated based on the static and dynamic responses. Much lower values of the DAF are obtained, even no tendons applied, than those provided by the design criteria of the AASHTO LRFD and the Korea Highway Standard Specification.

Flexural Behavior of Large-Diameter Composite PHC pile Using In-Filled Concrete and Reinforcement (속채움 콘크리트와 철근으로 보강된 대구경 합성 PHC말뚝의 휨성능 평가)

  • Bang, Jin-Wook;Park, Chan-Kyu;Yang, Seong-Yeong;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.5
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    • pp.109-115
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    • 2016
  • A demand of high bearing capacity of piles to resist heavy static loads has been increased. For this reason, the utilization of large diameter PHC piles including a range from 700 mm to 1,200 mm have been increased and applied to the construction sites in Korea recently. In this study, in order to increase the flexural strength capacity of the PHC pile, the large diameter composite PHC pile reinforced by in-filled concrete and reinforcement was developed and manufactured. All the specimens were tested under four-point bending setup and displacement control. From the strain behavior of transverse bar, it was found that the presence of transverse bar was effective against crack propagation and controlling crack width as well as prevented the web shear cracks. The flexural strength and mid-span deflection of LICPT specimens were increased by a maximum of 1.08 times and 1.19 times compared to the LICP specimens. This results indicated that the installed transverse bar is in an advantageous ductility performance of the PHC piles. A conventional layered sectional analysis for the pile specimens was performed to investigate the flexural strength according to the each used material. The calculated bending moment of conventional PHC pile and composite PHC pile, which was determined by P-M interaction curve, showed a safety factor 1.13 and 1.16 compared to the test results.

Failure Behavior of FRP RC Beams without Shear Reinforcements (전단 보강이 없는 FRP RC보의 파괴 거동)

  • Lee, Jae-Hoon;Son, Hyun-A;Shin, Sung-Jin
    • Journal of the Korea Concrete Institute
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    • v.22 no.2
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    • pp.199-208
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    • 2010
  • In order to substitute FRP bar for steel bar in new structures, it is necessary to establish a reliable design code. But relatively little research has been conducted on the material in Korea. So, a total of 22 beam specimens (18 GFRP reinforced concrete and 4 conventional steel reinforced concrete) were constructed and tested. In the first phase of the experiment, it was carried out to observe flexural behavior, and collect deflection and crack data. In order to eliminate of the uncertainty by the shear reinforcements and induce flexural failure mode, any stirrup were not used and only shear span-depth ratio were adjusted. However, almost beams were broken by shear and the ACI 440.1R, CSA S806, which were used to design test beams, showed considerable deviation between prediction and test results of shear strengths. Therefore in the second phase of the study, shear failure modes and behavior were observed. A standard specimen had dimensions of 3,300 mm long ${\times}$ 800 mm wide ${\times}$ 200 mm effective depth. Clear span and shear span were 2,800 mm, 1,200 mm respectively. Control shear span-depth ratio was 6.0. Four-point bending test over simple support was conducted. Variables of the specimens were concrete compressive strength, type and elastic modulus of reinforcement, shear span-depth ratio, effective reinforcement ratio, the effect of bundle placing method and cover thickness.

The Cell Resequencing Buffer for the Cell Sequence Integrity Guarantee for the Cyclic Banyan Network (사이클릭 벤얀 망의 셀 순서 무결성 보장을 위한 셀 재배열 버퍼)

  • 박재현
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.9
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    • pp.73-80
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    • 2004
  • In this paper, we present the cell resequencing buffer to solve the cell sequence integrity problem of the Cyclic banyan network that is a high-performance fault-tolerant cell switch. By offering multiple paths between input ports and output ports, using the deflection self-routing, the Cyclic banyan switch offer high reliability, and it also solves congestion problem for the internal links of the switch. By the way, these multiple paths can be different lengths for each other. Therefore, the cells departing from an identical source port and arriving at an identical destination port can reach to the output port as the order that is different from the order arriving at input port. The proposed cell resequencing buffer is a hardware sliding window mechanism. to solve such cell sequence integrity problem. To calculate the size of sliding window that cause the prime cost of the presented device, we analyzed the distribution of the cell delay through the simulation analyses under traffic load that have a nonuniform address distribution that express tile Property of traffic of the Internet. Through these analyses, we found out that we can make a cell resequencing buffer by which the cell sequence integrity is to be secured, by using a, few of ordinary memory and control logic. The cell resequencing buffer presented in this paper can be used for other multiple paths switching networks.