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Influence of Concrete Strength and Lateral Ties on Behavior of High-Strength Concrete Columns Subjected to Eccentric Compressive Load (편심 압축력을 받는 고강도 콘크리트 기둥의 거동에 미치는 띠철근 및 콘크리트 강도의 영향)

  • Lee, Young Ho;Chung, Heon Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.3
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    • pp.95-104
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    • 2007
  • This study was focused on the effect of concrete strength and lateral ties of concrete columns subjected to eccentric compressive loads. The twenty-four concrete columns with $200mm{\times}200mm$ square cross-section were tested. The main variables were concrete strength, spacing and configuration of lateral ties, and eccentricity ratios. From the experiment, the followings were investigated ; 1) In all cases, it was observed that the increase of concrete compressive strength led to the decrease of ductility. Also, as the eccentricity ratios increased, the effect of ductility enhancement by lateral ties decreased. 2) As the ties spacing decreased from 100mm to 30mm, the magnitude of axial load acting on the concrete column showed an enhancement of 1.1~1.2 times and the descending curve after a peak moment presented a smooth decline. 3) The high-strength concrete columns required a design of lateral ties to increase the volumetric ratios and density of tie spacing to sustain a proper strength and ductility. Accordingly, regardless of concrete strength, the current AIK design code to specify the maximum tie spacing of concrete columns was proven to lead to the poor strength and ductility for seismic design. Therefore, it is necessary to develop a new seismic design code that connects volumetric ratios and tie spacing of concrete columns with concrete strength.

The study of the relationship of the defense industry-specific factors effect the innovation of manufacturing technology and the market share. (방위산업의 시장구조 결정요인이 기술혁신과 시장지배에 미치는 영향)

  • Chung, Young-Hyun
    • Journal of National Security and Military Science
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    • s.5
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    • pp.241-280
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    • 2007
  • This study examines the relationship of the industry-specific factors that effect innovation of manufacturing technology and the market share within the defense industry. Since the establishment of the basic defense industry framework in 1973, there were numerous interactions of the industry-specific factors of the defense industry structure with the technological innovation and market organization of the defense industry. During last three decades, the domestic defense industry has achieved the considerable level but the framework of the basic system has not developed much in areas of the military science and the defense manufacturing technology. Industry-specific factors were formed in the process and appeared in a variety of behavioral characteristics as subsystems. Currently, there IS a growing trend where the management of defense industry is gradually deteriorating due to limitation of the domestic industry-specific factor (e.g. defense technologies, amount of demand, etc.). If there is a prominent imbalance of the industry-specific factors. it can trigger the potential problem of conflict, lack of cooperation and control, slowing the growth of the manufacturing technology thereby diminishing the market and deteriorating the defense supply/demand relationship. In a research conducted by Joe S. Bain, Bain analyzed the relationship of the traditional industrial organization where industry-specific factor(S) not only impacts the conductor(C). And, conductor(C) influences the shaping of the performance(P) of relationship of the traditional industrial organization. Consequently, the researcher has identified the demand monopoly, barriers to entry, and market competition with comparison of defense industry issues. These defense issues were three industry-specific factors identified, which are 1) The demand monopoly and The entry barriers to new market competition, 2) the industrial technical factor to a production technical competitiveness and a market sharing competitiveness, 3) the probability factor to revolution for military affairs(RMA) and a R&D production. According to baseline with these factors, the following research model is established from the special companies group(Group A), the systematization companies group(Group B), and the general companies group(Group 0. The hypothesis is that if there are more industry-specific factors, then there will be more relationships of defense industry relation statutes. This research is an empirical study on the relationship that the industry specific factors effects the innovation of manufacturing technology and the shaping of the market in the defense industry. Moreover, the existing models to evaluate the industry specific factors of the defense industry IS much to be desired with the controlled statistical analysis of the result. It is vital to study on current situation with suggesting alternative strategy to the efficient strategy. The descriptive analysis approach analysis is conducted with SPSSWIN to conduct reliability test, factor analysis, correlation analysis, cross-tabulation analysis, one-way ANOVA, and multiple regression analysis. However, there were some limitations of the survey such as the rigidity of concept about the technical factors and various market management factors. The wishes is that the decision-maker could be utilized these defence industrial factors to formulate efficient defence policy and strategy in the future.

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A Study on Sanitation Management Recognition and Employee Performance in the Kitchens and Food and Beverage Departments of Deluxe Hotels (특급 호텔 조리 식음료 종사자의 위생 관리 인지도 및 수행도에 관한 연구)

  • Kim, Bo-Ra-Mi;Lee, Ra-Rae;Lee, Mi-Ho;Lee, Sung-Jae;Cho, Yu-Jin;Yoon, Hyun-Joo;Yoon, Ki-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.6
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    • pp.943-956
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    • 2007
  • This study was conducted to assess the current status of food safety/sanitation training programs, including HACCP, for kitchen and hall employees at major hotels, as well as how differently the training can affect the employees' recognition and performance of food safety/sanitation management in areas related to the facility, food, and their personal hygiene. A questionnaire for assessing the recognition and performance of sanitation management was developed and distributed to 430 employees currently working in the kitchens and halls of 5 hotels located in Seoul, Korea. A total of 324 questionnaires (kitchen: 138, hall: 186) were subjected to frequency analysis, chi-square tests, one way ANOVA, and Pearson correlation analysis using SPSS/windows software. Ninety-one percent of the respondents had received food safety/sanitation training, which was conducted by a hygienist or a cook once a month. However, only 55% of the respondents had HACCP training. The employees that did not have HACCP training had lower recognition scores than those who had HACCP training, especially in the washing procedures for tablewares, handwashing tools, cross contamination, reheating, and HACCP definitions. Trained, full-time employees received significantly higher recognition and performance scores than untrained, contract, or part-time employees. Significant differences in the recognition and performance scores were found among the employees of the 5 different hotels, indicating various levels for the outcome of their sanitation training. In addition, Pearson's correlation analysis confirmed that the recognition and performance scores were significantly correlated (r=0.473, p<.001). This study indicates that hotel foodservice employees must receive systematic food safety/sanitation training, including HACCP, which provides the foundation for safe foodservice operations.

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$BBPY^{(R)}$ graft for periodontal intrabony defects and molar furcation lesions: Case Report (다양한 치주 골내낭과 이개부 병변의 처치를 위한 $BBP^{(R)}$ 이식재의 임상적 효과)

  • Kim, Myung-Jin;Lee, Ju-Youn;Kim, Sung-Jo;Choi, Jeom-Il
    • Journal of Periodontal and Implant Science
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    • v.38 no.1
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    • pp.97-102
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    • 2008
  • Purpose: Periodontal intrabony defects have great deal of importance since they contribute to the development of periodontal disease. Current treatment regimens for intrabony defects involve grafting of numerous bony materials, GTR using biocompatible barriers, and biomodification of root surface that will encourage the attachment of connective tissue. Xenograft using deproteinized bovine bone particles seems to be very convenient to adjust because it doesn't require any donor sites or imply the danger of cross infections. These particles are similar to human cancellous bone in structure and turned out to be effective in bone regeneration in vivo. We here represent the effectiveness of grafting deproteinized bovine bone particles in intrabony defect and furcation involvements that have various numbers of bony walls. Materials and methods: Open flap debridement was done to remove all root accretions and granulation tissue from the defects within persisting intrabony lesions demonstrating attachment loss of over 6mm even 3 months after nonsurgical periodontal therapy have been completed. Deproteinized bovine bone particles($BBP^{(R)}$, Oscotec, Seoul) was grafted in intrabony defects to encourage bone regeneration. Patients were instructed of mouthrinses with chlorohexidine-digluconate twice a day and to take antibiotics 2-3 times a day for 2 weeks. They were check-up regularly for oral hygiene performance and further development of disease. Probing depth, level of attachment and mobility were measured at baseline and 6 months after the surgery. The radiographic evidence of bone regenerations were also monitored at least for 6 months. Conclusion: In most cases, radio-opacities increased after 6 months. 2- and 3-wall defects showed greater improvements in pocket depth reduction when compared to 1-wall defects. Class I & II furcation involvements in mandibular molars demonstrated the similar results with acceptable pocket depth both horizontally and vertically comparable to other intrabony defects. Exact amount of bone gain could not be measured as the re-entry procedure has not been available. With in the limited data based on our clinical parameter to measure pocket depth reduction following $BBP^{(R)}$ grafts, it was comparable to the results observed following other regeneration techniques such as GTR.

A Study on the Application Plan of Basic Original Technology in Science & Research Parks : Focus on Science Parks in Korea (과학연구단지의 기초원천 기술 활용방안에 관한 연구 : 지방과학연구단지를 중심으로)

  • Lee, Won Cheul;Choi, Jong-In
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.3
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    • pp.63-74
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    • 2014
  • From the 1950s, the science parks were begun the composition as a way for innovation and commercialization in the world around developed countries. Since the 1980s, Korea also starting with quantitative investment in R & D for technology innovation, so far has been a continuous effort. Korea's patent creation level according to these R & D investment is already within the world's top 10, but the fact that the domestic technology trade balance appearing current competitive level compared to the developed technology is very insufficient. This means that the creation of economic value is low as compared with financial commitment. Therefore the plans to ensure the economic value through technology are required. As one of plans to do this for local economy activation through technical advances, constructing regional innovation systems and making science parks have been made. These science parks are required to develop the basic original technology in order to secure new growth engines, but the science parks in Korea are facing difficulties of performing research and development for regional industry advancement and local economy activation. Accordingly, this study attempts to organize the concept of 'science park' is similar but there is difference, and to compare institutions with similar functions based on regional innovation systems theory. In addition, the study is to obtain the application plans of basic original technology in science & research Parks through the model for overcoming weaknesses of Korea's innovation system and enabling organic cross-linking between institutions.

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A Convergence Study on Influencing Factors of Paid Care Service: Andersen's Behavioral Model (유급 간병서비스 이용 영향요인에 관한 융복합적 연구: Andersen's Behavioral Model)

  • KIM, Han-Kyoul;Kim, Sung Kuk;Shim, Hyun-Jin;Lee, Hee Myung;Rhee, Hyunsill
    • Journal of Digital Convergence
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    • v.15 no.4
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    • pp.327-337
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    • 2017
  • The purpose of this study is to identify the current state of paid care services and to identify the factors that affect the utilization of private nursing services. This study constructed and utilized the Korean Health Panel data (2011-2014) in the form of panel data, and selected 5,110 patients who had experience using one or more hospitalization services per year. STATA 12.0 SE was used for data processing and analysis of this study. Frequency analysis was performed to confirm basic characteristics of hospitalized patients. Cross-analysis and t-test were conducted to confirm the status of paid care services according to characteristics. Respectively. Finally, panel logistic regression was performed by applying a hierarchical method to stepwise modeling the three categories of Andersen's Behavioral Model to identify factors affecting the use of paid care services for inpatients. The results showed that the use of paid nursing services was higher in women, elderly, long - term hospitalized and disabled. On the other hand, significant household income variables in private employment did not show significant results. The results of this study are expected to be used as basic data for the selection of the nursing care integrated services under discussion. In addition, detailed discussions on the selection of subjects should be made in the future.

A Microwave Push-Push VCO with Enhanced Power Efficiency in GaInP/GaAs HBT Technology (향상된 전력효율을 갖는 GaInP/GaAs HBT 마이크로파 푸쉬-푸쉬 전압조정발진기)

  • Kim, Jong-Sik;Moon, Yeon-Guk;Won, Kwang-Ho;Shin, Hyun-Chol
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.9
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    • pp.71-80
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    • 2007
  • This paper presents a new push-push VCO technique that extracts a second harmonic output signal from a capacitive commonnode in a negativegm oscillator topology. The generation of the $2^{nd}$ harmonics is accounted for by the nonlinear current-voltage characteristic of the emitter-base junction diode causing; 1) significant voltage clipping and 2) different rising and falling time during the switching operation of core transistors. Comparative investigations show the technique is more power efficient in the high-frequency region that a conventional push-push technique using an emitter common node. Prototype 12GHz and 17GHz MMIC VCO were realized in GaInP/GaAs HBT technology. They have shown nominal output power of -4.3dBm and -5dBm, phase noise of -108 dBc/Hz and -110.4 dBc/Hz at 1MHz offset, respectively. The phase noise results are also equivalent to a VCO figure-of-merit of -175.8 dBc/Hz and -184.3 dBc/Hz, while dissipate 25.68mW(10.7mA/2.4V) and 13.14mW(4.38mA/3.0V), respectively.

Physicians' Knowledge about Hereditary Breast Cancer in South Korea (국내 임상 의사의 유전성 유방암에 대한 지식도)

  • Choi, Kyung-Sook;Tae, Young-Sook;So, Hyang-Sook;Lee, Woo-Sook;Hur, Myung-Haeng;Kang, Mi-Young;Son, Song-Yi;Lee, Mi-Hi;Lee, Young-Lan;Choi, In-Soon;Jang, Eun-Sil;Kim, Seong-Jae;Jun, Myung-Hee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.13 no.1
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    • pp.105-113
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    • 2007
  • Background: Cancer genetics have gained public attention dramatically. Everyday physicians and nurses use the knowledge of cancer genetics in their practices. Despite the importance of the knowledge of the health care providers on cancer genetics, there is a paucity of literature investigating the levels of knowledge about cancer genetics among health care providers. Purpose: This study aimed to describe the Korean physicians' current knowledge level about hereditary breast and ovarian cancer (HBOC). Method: This nation-wide survey used a 15-item questionnaire which is modified from the Breast Cancer Genetic Counseling Knowledge Questionnaire originally developed by Erblich et al.(2005). One hundred and forty-four physicians participated in this survey from October 1, 2006 to March 31, 2007. Result: Physicians' knowledge level about hereditary breast cancer was 11.94 (S.D=2.46). Physicians with short-term careers (less than one year), the position of Intern, or who were involved in breast or ovarian cancer care demonstrated the highest knowledge about HBOC. Conclusion: Genetic courses in medical education seemed to contribute to the high level of physicians' genetic knowledge. Also, nursing discipline needs to incorporate genetics or genetic counseling courses into the formal educational curriculum in order to deliver up to date cancer care services which are sensitive to ever-changing cancer genetic information.

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Modeling the Spatial Dynamics of Urban Green Spaces in Daegu with a CA-Markov Model (CA-Markov 모형을 이용한 대구시 녹지의 공간적 변화 모델링)

  • Seo, Hyun-Jin;Jun, Byong-Woon
    • Journal of the Korean Geographical Society
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    • v.52 no.1
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    • pp.123-141
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    • 2017
  • This study predicted urban green spaces for 2020 based on two scenarios keeping or freeing the green-belt in the Daegu metropolitan city using a hybrid Cellular Automata(CA)-Markov model and analyzed the spatial dynamics of urban green spaces between 2009 and 2020 using a land cover change detection technique and spatial metrics. Markov chain analysis was employed to derive the transition probability for projecting land cover change into the future for 2020 based on two land cover maps in 1998 and 2009 provided by the Ministry of Environment. Multi-criteria evaluation(MCE) was adopted to develop seven suitability maps which were empirically derived in relation to the six restriction factors underlying the land cover change between the years 1998 and 2009. A hybrid CA-Markov model was then implemented to predict the land cover change over an 11 year period to 2020 based on two scenarios keeping or freeing the green-belt. The projected land cover for 2009 was cross-validated with the actual land cover in 2009 using Kappa statistics. Results show that urban green spaces will be remarkably fragmented in the suburban areas such as Dalseong-gun, Seongseo, Ansim and Chilgok in the year 2020 if the Daegu metropolitan city keeps its urbanization at current pace and in case of keeping the green-belt. In case of freeing the green-belt, urban green spaces will be fragmented on the fringes of the green-belt. It is thus required to monitor urban green spaces systematically considering the spatial change patterns identified by this study for sustainably managing them in the Daegu metropolitan city in the near future.

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GEOTECHNICAL DESIGNS OF THE SHIP IMPACT PROTECTION SYSTEM FOR INCHEON BRIDGE

  • Choi, Sung-Min;Oh, Seung-Tak;Park, Sang-Il;Kim, Sung-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.72-77
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    • 2010
  • The Incheon Bridge, which was opened to the traffic in October 2009, is an 18.4 km long sea-crossing bridge connecting the Incheon International Airport with the expressway networks around the Seoul metropolitan area by way of Songdo District of Incheon City. This bridge is an integration of several special featured bridges and the major part of the bridge consists of cable-stayed spans. This marine cable-stayed bridge has a main span of 800 m wide to cross the vessel navigation channel in and out of the Incheon Port. In waterways where ship collision is anticipated, bridges shall be designed to resist ship impact forces, and/or, adequately protected by ship impact protection (SIP) systems. For the Incheon Bridge, large diameter circular dolphins as SIP were made at 44 locations of the both side of the main span around the piers of the cable-stayed bridge span. This world's largest dolphin-type SIP system protects the bridge against the collision with 100,000 DWT tanker navigating the channel with speed of 10 knots. Diameter of the dolphin is up to 25 m. Vessel collision risk was assessed by probability based analysis with AASHTO Method-II. The annual frequency of bridge collapse through the risk analysis for 71,370 cases of the impact scenario was less than $0.5{\times}10^{-4}$ and satisfies design requirements. The dolphin is the circular sheet pile structure filled with crushed rock and closed at the top with a robust concrete cap. The structural design was performed with numerical analyses of which constitutional model was verified by the physical model experiment using the geo-centrifugal testing equipment. 3D non-linear finite element models were used to analyze the structural response and energy-dissipating capability of dolphins which were deeply embedded in the seabed. The dolphin structure secures external stability and internal stability for ordinary loads such as wave and current pressure. Considering failure mechanism, stability assessment was performed for the strength limit state and service limit state of the dolphins. The friction angle of the crushed stone as a filling material was reduced to $38^{\circ}$ considering the possibility of contracting behavior as the impact.

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