• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.601-608
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• 2000

Steel fiber and Polymer are used widely for the reinforcement material of RC structures because of its excellence of durability, serviceability as well as mechanical properties. Polymer-Steel fibrous high strength concrete beam's input ratio are 1.0%. The shear span-to-depth ratio are 1.5, 2.8 and 3.6, compressive strength of specimens 320kg/㎠, 436kgf/㎠ and 520kgf/㎠ in 28 days. The static test was carried out to measure the ultimate load, the initial load of flexural crack and of diagonal crack, from which crack patte군 and fracture modes are earned. Also, stress-strain, load-strain and load-deflection are examined during the test cracks(shear crack, flexural crack, and diagonal tension crack), when the load values are sketched according to the growth of crack. Result are as follows; (1) The failure modes of the specimens increase in rigidity and durability in accordance with the increase of mixing steel fiber and polymer. (2) The load of initial crack was the same as the theory of shear-crack strength (3) Polymer-Steel fibrous high strength concrete beams have increased the deflection and strain at failure load, improving the brittleness of the high strength concrete. (4) In this result of study, an additional study need to make a need formular because the study is different from ACI formular and Zsutty formular.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.484-487
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• 2015

The purpose of this study is designing a daily diet according to the nutrition by using genetic algorithms. The ratio of the amount of nutrients needed for each individual is different. For example, people who want to lose, maintain or gain the weight need different amount of nutrition and ratio. In addition, the nutrition should be different between the age groups such as child, youth and senior. So, it is important for each person to individualize content of nutrition that they need not the nutritional standard table. Thus, in this study, by using the genetic algorithm, our study is about the program that can make a daily diet which is optimized for individual. The program has the information of main dish, soup and side dish that we entered before. And person who uses the program can see the daily diet which is optimized related by nutrition what the person entered before. Generally, it is really difficult to design a meal by considering all of the nutrition at home because there are a lot of things to be considered. Therefore, the goal of our study is to make the program what can make a balanced daily diet at home.

• Animal cells and systems
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• 제4권2호
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• pp.131-140
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• 2000

The pattern of variations in cone sex ratio and pollen traits such as pollen number and size was examined for two years in populations of red pines In Korea. We evaluated; (1) the relationship between tree size and cone sex ratio, (2) the relationship between year and cone sex ratio, and (3) the relationship between cone sex ratio and pollen traits. Larger trees in height and circumference at breast height produced more male as well as female cones. However, cone sex ratio was independent of these plant sizes. Across the two populations, both female cone numbers per tree and male cone numbers per new shoot increased 2.2 and 1.2 times, respectively, in 1999 compared to 1998, while the yearly pattern of male cone-bearing shoots per tree differed significantly between populations. Thus, cone sex ratio varied significantly between years in one of the two populations. Pollen traits such as the number of pollen grains and diameter did not vary significantly among populations. Pollen diameter and grain numbers per male cone were significantly negatively correlated with the cone sex ratio in two populations and one population, respectively. Trees which stopped female cone production in the first year and those which produced female cones in both years differed in the cone sex ratio and pollen size in the second year. The long duration of one reproductive episode and the potential of masting in red pines emphasize the need to conduct long-term studies on the dynamics of cone production, cone sex ratio, and simultaneous changes in pollen traits in red pines.

• 한국유체기계학회 논문집
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• 제14권3호
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• pp.50-58
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• 2011

To utilize wind resources effectively around buildings in urban area, the magnitudes of wind velocity and turbulence intensity are important, which means the need of the information about the relationship between the magnitude of wind velocity and that of fluctuating wind velocity. In the paper, wind-tunnel experiments were performed to provide the information about Characteristic of Wind flow around buildings with the spanwise distance and the side ratio of buildings as variables. For a single building with the side ratios of one and two, the average velocity ratio was 1.4 and the velocity standard deviation ratio ranged from 1.4 to 2.6 at the height of 0.02m at the corner of the windward side, in which flow separation occurred. For twin buildings with the side ratios of one and two, the velocity ratio ranged from 2 to 2.5 as the spanwise distance varied at the height of 0.02m, and the velocity standard deviation ratio varied near 1.25. For twin buildings with the side ratios of one and two, the maximum velocity ratio was 1.75 at the height of 0.6m, and the maximum velocity standard deviation ratio was 2.1. It was also found from the results of CFD analysis and wind-tunnel experiments that for twin buildings with the side ratios of one and two, the difference between the velocity ratio of CFD analysis and that of wind-tunnel experiments at streamwise distances was near 0.75.

• ETRI Journal
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• 제37권2호
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• pp.338-347
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• 2015

The multi-carrier transmission signal in Multi-Carrier Code Division Multiple Access (MC-CDMA) has a high peak-to-average power ratio (PAPR), which results in nonlinear distortion and deteriorative system performance. An n-tuple selective mapping method is proposed to reduce the PAPR, in this paper. This method generates $2^n$ sequences of an original data sequence by adding n-tuple of n PAPR control bits to it followed by an interleaver and error-control code (ECC) to reduce its PAPR. The convolutional, Golay, and Hamming codes are used as ECCs in the proposed scheme. The proposed method uses different numbers of the n PAPR control bits to accomplish a noteworthy PAPR reduction and also avoids the need for a side-information transmission. The simulation results authenticate the effectiveness of the proposed method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.897-902
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• 2001

Recently, structure performance is maximized by using high strength concrete. In design of structure, concrete need combination with reinforcement, but use of common strength reinforcement make member complex bar placement, so high strength concrete members require increased strength reinforcement. If common strength reinforcement replaced by equal tension area of high strength reinforcement, reinforcement ratio increase and brittle failure of member may occur by material change. So, adequate upper limit of strength ratio is required to affirm ductile behavior in application of high strength reinforcement. In this study, ductility behavior was analysed by factor of reinforcement ratio, strength of concrete and reinforcement. The result indicate that ductile failure is shown under 0.35 $\rho_{b}$ in any reinforcement strength of same section and high strength concrete of 800kg/$cm^{2}$ used commonly is compatible with reinforcement of 5500kg/$cm^{2}$.

• Journal of Information Technology Applications and Management
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• 제15권4호
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• pp.21-36
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• 2008

As the great disturbance from abusing credit cards in Korea becomes stabilized, credit card companies need to interpret credit-card delinquents classification models from the viewpoint of profit. However, hit ratio which has been used as a measure of goodness of classification models just tells us how much correctly they classified rather than how much profits can be obtained as a result of using classification models. In this research, we tried to develop a new utility-based measure from the viewpoint of profit and then used this new measure to analyze two classification models(Neural Networks and Decision Tree models). We found that the hit ratio of neural model is higher than that of decision tree model, but the utility value of decision tree model is higher than that of neural model. This experiment shows the importance of utility based measure for credit-card delinquents classification models. We expect this new measure will contribute to increasing profits of credit card companies.

• 지역사회간호학회지
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• 제24권2호
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• pp.236-244
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• 2013

Purpose: This study was to investigate lifestyles and identify factors influencing the bone mineral density (BMD) among employees in a community. Methods: Data were collected from 199 employees. Their lifestyles and BMIs were measured with a self-report questionnaire. As for their BMDs, their calcanei were measured with Quantitative Ultrasound. Results: Assessing their BMDs with reference to the WHO standards, 52.8% of the subjects' calcaneus BMDs were normal and 44.2% showed osteopenis, 3.0% showed osteoporosis. Age (odds ratio=1.05, p=.029), exercise (odds ratio=.31, p=.006) and the number of eating meals per day (odds ratio=1.97, p=.046) were significant factors influencing the subjects' BMDs. Conclusion: Strategies to emphasize exercise and dietary habits in employees are important for improving their bone mineral density. Programs for improving bone mineral density based on life cycle need to be developed.

• 한국세라믹학회지
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• 제35권3호
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• pp.245-250
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• 1998

Field emission display (FED) is currently being explored as a potential flat panel display technology. The need of new materials for low voltage blue phosphors for FED focused our attention on the $Y_2O_3-Nb_2O_5$ sys-tem. Yttrium niobate doped with $Bi^{3+}$ was prepared by solid state reaction technique and the optimization of the luminescent properties with a control of $Bi^{3+}$ amounts and Y/Nb ratio was studied. Under 254 nm and low voltage electron excitations $Bi^{3+}-activated$ YNbO4 phosphors showed a strong and relatively narrow blue em-ission band with a range of 420 to 450 nm, Especially 0.4wt% $Bi^{3+}\;doped\;YNbO_4$ phosphors with Y/Nb ratio of 1/1 showed the maximum emission intensity. Under low voltage electron excitation maximum emission in-tensity appeared at the Y/Nb ratio of 0.495/0.505.

• 경영과학
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• 제27권2호
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• pp.55-66
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• 2010

In Korea, deap-sea fishing industry plays an important role in a food industry. However, it is in a difficult situation because of the more competitive business environment. Therefore, there is a need to restructure the deap-sea fishing industry by scraping superannuated ships. This paper is designed to present scrap programs for deap-sea fishing industry of Korea. We performed ratio analysis to evaluate financial performance of fishing companies and then applied a mixed integer programming (MIP) model to identify optimal schedule for scraping. The results of the financial ratio analysis indicates that it is legible to provide governmental aid to Atlantic trawl, Northern Pacific trawl, and Indian ocean trawl with minimum required rate of return (MRR) of 3%, and the Atlantic strip fishing industry is qualified to receive the governmental aid with MRR value of 5%. Furthermore, by applying the MIP model to develop scrap planning, we demonstrate how our model can be used to restructure the deap-sea fishing industry of Korea.