• Title/Summary/Keyword: Y-deflection

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Experimental Performance Evaluation of Steel Mesh as Maintenance and Reinforcement Materials (Steel Mesh Cement Mortar의 보수⋅보강 성능 평가)

  • Kim, Yeon-Sang;Choi, Seung-Jai;Kim, Jang-Ho Jay
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.50-58
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    • 2014
  • Due to the cost burden of new construction, the necessity of repair and retrofitting of aged structures is sharply increasing as the domain of repair and retrofitting construction is expanding. Because of the necessity, new technologies for repair and retrofitting are continuously studied in Korea and foreign countries. Steel adhesive method, fiber reinforced plastic (FRP) surface adhesive method, and external prestressing method are used to perform the repair and retrofitting works in Korea. In order to consider a repair method using steel mesh reinforced cement mortar (SMCM), 3-point flexural member test was conducted considering repair area and layer number of SMCM. Five types of specimens including ordinary reinforced concrete (RC) specimen with dimensions of $1400{\times}500{\times}200$ (mm) were cast for testing the deflection measurement, a LVDT was installed at the top center of the specimens. Also, a steel strain gauge and a concrete strain gauge were placed at the center of the specimens. A steel strain gauge was also installed on the shear reinforcement. The 3 point flexural member test results showed that the maximum load of SMCM reinforced specimen was higher than that of basic RC specimen in all of the load-displacement curves. Also, the results showed that, when the whole lower part of the basic RC specimen was reinforced, the maximum load and strain were 1.18 and 1.37 times higher than that of the basic RC specimen, respectively. Each specimen showed a slightly different failure behavior where the difference of the results was caused by the difference in the adhesive level between SMCM and RC. Particularly, in SM-B1 specimen, SMCM spalled off during the experiment. This failure behavior showed that the adhesive performance for RC must be improved in order to utilize SMCM as repair and retrofitting material.

Experimental Study on Structural Behavior of Precast PSC Curved Girder Bridge (프리캐스트 PSC 곡선 거더교의 구조거동에 대한 실험적 연구)

  • Kim, Sung Jae;Kim, Sung Bae;Uhm, Ki Ha;Kim, Jang Ho Jay
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.6
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    • pp.1731-1741
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    • 2014
  • Recently, many overpasses, highway, and advanced transit systems have been constructed to distribute the traffic congestion, thus small size of curved bridges with small curvature such as ramp structures have been increasing. Many of early curved bridges had been constructed by using straight beams with curved slabs, but curved steel beams have replaced them due to the cost, aesthetic and the advantage in building the section form and manipulating the curvature of beams, thereby large portion of curved bridges were applied with steel box girders. However, steel box girder bridges needs comparatively high initial costs and continuous maintenance such as repainting, which is the one of the reason for increasing the cost. Moreover, I-type steel plate girder which is being studied by many researchers recently, seem to have problems in stability due to the low torsional stiffness, resulting from the section characteristics with thin plate used for web and open section forms. Therefore, in recent studies, researchers have proposed curved precast PSC girders with low cost and could secured safety which could replace the curved steel girder type bridges. Hence, this study developed a Smart Mold system to manufacture efficient curved precast PSC girders. And by using this mold system a 40 m 2-girder bridge was constructed for a static flexural test, to evaluate the safety and performance under ultimate load. At the manufacturing stage, each single girder showed problems in the stability due to the torsional moment, but after the girders were connected by cross beams and decks, the bridge successfully distributed the stress, thereby the stability was confirmed. The static loading test results show that the initial crack was observed at 1,400 kN when the design load was 450 kN, and the load at the allowable deflection by code was 1,800 kN, which shows that the safety and usability of the curved precast PSC bridge manufactured by Smart Mold system is secured.

A Study on the Working Environment Recognition and the Caracter Disposition of Nurse Aides (간호조무사의 근무환경인식과 성격성향에 관한 연구)

  • Lee Sun Yi
    • Journal of Korean Public Health Nursing
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    • v.4 no.1
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    • pp.57-74
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    • 1990
  • As the whole world took on the tendency to be highly industrialized, it became necessary for each field of occupation to require professional man power. Especially, since the World War n, the participation of woman power in economic activities has been continually increasing. In our country also, because of the rapid economic growth, change in the way of thinking of women as well as their participation in economic activities are increasing. Thus, woman power is being utilized in various occupational fields from simple physical labor to those that require high-professional skill. Also, continued economic development policies, by setting the establishment of welfare society as the ideology to be fulfilled, brought expansion of medical facilities in the field of public health and increase in man power in that field. As for the nursing specialists, more than 6000 have been being produced per year and as of the end of 1988, the total number of nursing specialists, reached 123, 115. Therefore, this study is done to recognize the professional knowledge and ability of nursing specialists, who take up $40\%$ of the total public-health related man power in our country, through evaluating their working environment and their disposition of character. This study, which was done from September 18th to September 30th 1989, took on the method of using formed questionnaires that had been amended and supplemented during two preparatory investigations, 322 of such questionnaires were used as an analytical material. In the formation of questionnaires, 12 questions were related to the working environment, and 26 in fortotal were related to the disposition of character, 5 for wise-disposition, 11 for activedisposition and 10 for open-disposition. The measuring method, which used 5-point-standard, allowed 5 points for affirmative recognition of the working environment, also 5 points for showing wise, active and open disposition of character and only point in opposite cases. Collected materials were analyzed, through an electronic calculation, into the average value, the standard deflection percentage, pearson corelative number and stepwise multiple regression. Summarizing the results from this study is as follows: 1. It was shown that the nursing specialists with the average of 3.07 have affirmative recognition of their working environment. The questions which drew most affirmative reaction were those concerning finance-management system such as hand, the questions that received negative reaction were those concerning communication method with the average of 2.49. Such reaction seems to have resulted from the cramming regulation by the superior authorities. Concerning the recognition of working environment in relation to employment conditions, more affirmative recognition is shown with the average of 3.14. at hospitals where injection job is not performed. The nursing specialists working at regular hospitals show more affirmative recognition than those at general hospitals, the averages being respectiely 3.16 and 3.03. 2. As for the disposition of character of the nursing specialists, active-disposition was highest with the average of 3.38, next was wise-disposition with 3.20 and the lowest was open-diposition with 2.98. Variable-wise disposition of character shows that wise-disposition and academic background are beneficially correlated by 0.12. Ative-disposition and open-disposition show correlation to the office term by respectively 0.16 and 0.21. In other words. better academic background leads to higher wise-disposition and more - experience results in higher active and open disposition. Also, the class that performs the injection job, in relation to the working environment, might cause change in the self-conceit that identify those in that class with the nurses; however, as far as professional judgment and action, in dealing with nursing job, being wise, active and open is concerned, not much effect is made. 3. The relation between the recognition of the working environment and the disposition of character is that more afirmative recognition- a nursing specialist has about her working environment, the higher the active-disposition becomes by 0.13. The degrees of the relation between recongnition of environment and wise and open dispositions show respectively 0.06 and -0.06 and -0.06. That is to say that when having more affirmative recognition of the working environment, a nursing specialist shows wise but closed disposition of character. This, howerver, didn't mean much statistically. When observing the results mentioned above, it is conspicuous that the nursing specialists, working as substitutes for the nurse at medical institutions of various sizes, get the feeling of being somewhat equal to the nurses and to some extent, fulfill their desire to accomplish their ego; however, as far as professional ability expansion if concerned. they lack wise and open dispositions. Therefore, considiering upon the results of this study, in medical institutions where the work of nursing specialists is regaded equal to that of the nurses, as a medical member who deals with human lives, it is desirable to make the nursing specialists work under the supervision of the nurses and to offer them continuous education to strengthen and improve their natural dispositions.

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A Study on Visual Identity of Korean Government (우리나라 행정부의 시각 정체성 연구)

  • Cho, Ju-Eun
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.261-272
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    • 2006
  • As we cannot think of our lives without a nation, it is closely related to almost every part of our daily lives. The role of government is becoming more important in the complex modern society as an essential element of national authority even though the government has indirect and secondary characteristics in its functional performance. Therefore, the government has to be efficient in planning and executing its policies, and it needs to be representative and fair as part of a national authoritative community. In the 21st century when symbolic and cultural importance of images are becoming more important, it is crucial for the government organizations to have an integrated identity design system that can satisfy both of these requirements of the government. However, the C.I.(Corporate Identity) of each Korean administrative branch has been developed separately and sporadically, which resulted in lack of consistency as part of the government. Shape and material of their C.I.s that follow short term design trend and popularity also lack uniqueness which can be distinguished from those of any private corporation. This may show that our government lacks systematic administrative capability, since image of a feature represents its characteristics and reality, and their recognition and evaluation from others become identity of the feature. In this perspective, the purpose of this thesis is to suggest an identity design system that has certain rules and regularity with wide variety of possible alterations for the central administration in Korea. In order to represent this visually, identity design system with both integrity and variety of possible alteration is created based on traditional Korean culture, especially the concept of Umyang-ohaeng and Samjae.

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A historical study on the flexibility square-format typeface and the prospects - Focused on the three-pairs fonts of hangeul - (탈네모글꼴에 관한 역사적 연구와 전망 - 세벌식 한글 글꼴을 중심으로 -)

  • Yu, Jeong-Mi
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.241-250
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    • 2006
  • Hangeul as the Korean unique characters were invented according to some character-making principles and based on scholars' exhaustive researches. While most of the characters in the world evolved naturally, Hangeul was invented based on a precise linguistic analysis of the time, and therefore, it is most scientific and reasonable among various characters throughout the world. Nevertheless, Hangeul typeface designs do not seem to inherit the ideology of scientific and reasonable Hangeul correctly. For the square forms have been used intact due to the influences from the Chinese characters which prevailed during the time. If a single set of square characters should be designed, as much as 11,172 fonts should be designed, which suggests that advantages of Mangeul may not well be used fully; Hangeul was invented to visualize every sound with the combinations of 28 vowels and consonants. Problems of such square fonts began to be identified since 1900's when typewriters were introduced first from the West. Since a typewriter is designed with 28 characters laid out on its keyboard by using such combinations, the letters may be easily combined on it. The so-called the flexibility square-format typeface was born as such. Specially, the three-pairs fonts of these can be combined up to 67 letters including vowels and consonants. The three-pairs fonts system can help to solve the problems arising form the conventional square fonts and inherit the original ideology of Hangeul invention. This study aims to review the history of the three-pairs fonts designs facilitated by mechanic encoding of Hangeul and thereupon, suggest some desirable directions for future Hangeul fonts. Since the flexibility square-format typeface is expected to evolve more and more owing to development of the digital technology, they would serve our age of information in terms of both functions and convenience. Just as Hunminjongum tried to be literally independent from the Chinese characters, so the flexibility square-format typeface designs would serve to recover identity of our Hangeul font designs.

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