• The Science & Technology
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• v.10 no.2 s.93
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• pp.8-8
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• 1977

미국 포드대통령은 지난1월17일 ,1977년 10월부터 시작되는 1978년도 예산교서를 발표한바 있다. 이 예산안은 카터 신임대통령 및 국회에 의해 수정될 가능성은 있으나 그중 과학기술에 관한 예산에는 별변동이 없을 것으로 예상되고 있다. 이 예산안에 따르면 과학기술 예산총액은 280억불, 한화로 14조원(500:1비로볼때)이라는 방대한 규모이다. 이것은 1977년도에 비해 약8%가 증가된 것이나 인프레에 따르는 6%의 물가상승률을 감안할 때 실질적으로는 2%의 증가로 봄이 옳을 것이다. 주요부문의 연구개발비와 그 증가율 및 기초연구에 해당액은 다음과 같다.

• 프린팅코리아
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• v.11 no.2
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• pp.88-95
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• 2012

2011년 인쇄업계는 전반적인 가격하락으로 인해 어려운 시간을 보냈다. 특히 상반기에는 달러화 약세, 내수경기부진과 함께 원자재가격 상승이 맞물려 더욱 어려웠다. 전반적으로 어려운 가운데 등락폭이 고르지 않고, 높고 낮음이 뚜렷해 더욱 불안한 한해였다고 할 수 있다. 예를 들면 업황실적의 경우 6월은 69를 기록했으나 12월에는 103을 기록하는 등 그 차이가 30을 넘기도 했다. 업황실적뿐 아니라 매출실적, 생산실적, 신규수주실적, 가동률실적, 원재료 구입가격실적 등도 편차가 30이 넘은 것으로 나타났다. 특히 채산성실적과 자금사정실적, 인력사정실적이 나아지지 않고 일년내내 어려움이 계속됐다.

• Journal of the Korean Data and Information Science Society
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• v.22 no.1
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• pp.73-80
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• 2011

The purpose of this study is to analyse the influence of product portfolio and interest rate on the lapse ratio. This issue is very important because of the recent introduction of IFRS and CFP. The fixed-effect model and the random-effect model are estimated with using panel data and the Hausman test is employed in order to select a model. The results of this study is summarized as follows. Firstly, the random effect model is selected. According to the model, the lapse rate increases as the portfolio of savings plan, sickness, and death increases and the interest rate is high. Secondly, health insurance and variable insurance product show a negative relationship with the lapse rate.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.1
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• pp.35-44
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• 2000

The winter case of the near-field dilution at the Masan outfalls has been studied by field measurements and CORMIX model simulations. Dilution rates of the wastewater discharge in winter were obtained by a salinity deficit method using the field data observed in the neap tidal period of February, 1999. The observed dilution rates in winter season were found to be very high in the range of 90～130 due to the isopycnal mixing of ambient density compared with the summer range of 30～40 under weak neap tidal currents. The results of CORMIX model simulations also show that the winter dilution rates under a weak ambient current(Ua=6.0ms/s) were increased by 3-fold of the summer dilution rates. However, the difference between two seasons becomes small by 30% under a strong current(Ua=15.5cm/s). This result indicates that the dilution and hydrodynamic mixing process of the effluents are more influenced by ambient crossflow condition than by ambient density stratification at the outfalls site.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.765-772
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• 2011

The present study summarizes a series of compressive tests on concrete cylinder in order to examine the stressstrain relationship of alkali-activated (AA) slag concrete. The compressive strength and unit weight of concrete tested ranged from 8.6 MPa to 42.2 MPa and from $2,186kg/m^3$ to $2,343kg/m^3$, respectively. A mathematical equation representing the complete stress-strain curve was developed based on test results recorded from 34 concrete specimens. The modulus of elasticity, strain at peak stress, slopes of ascending and descending branches of stress-strain curves were generalized as a function of compressive strength and unit weight of concrete. The mean and standard deviation of the coefficient of variance between measured and predicted curves were 6.9% and 2.6%, respectively. This indicates that the stress-strain relationship of AA slag concrete is represented properly with more accuracy in the proposed model than in some other available models for ordinary portland cement (OPC) concrete.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.216-223
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• 2019

The objective of this study is to propose a reliable stress-strain model in compression for lightweight concrete using bottom ash aggregates and air foam(LWC-BF). The slopes of the ascending and descending branches in the fundamental equation form generalized by Yang et al. were determined from the regression analyses of different data sets(including the modulus of elasticity and strains at the peak stress and 50% peak stress at the post-peak performance) obtained from 9 LWC-BF mixtures. The proposed model exhibits a good agreement with test results, revealing that the initial slope decreases whereas the decreasing rate in the stress at the descending branch increases with the increase in foam content. The mean and standard deviation of the normalized root-square mean errors calculated from the comparisons of experimental and predicted stress-strain curves are 0.19 and 0.08, respectively, for the proposed model, which indicates significant lower values when compared with those(1.23 and 0.47, respectively) calculated using fib 2010 model.

• Journal of IKEEE
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• v.23 no.1
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• pp.254-260
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• 2019

The failure rate of bidirectional dc-to-dc converter is predicted through the failure mode and effect analysis (FMEA) and the fault-tree analysis (FTA) considering the operational risk. In order to increase the driving voltage of the electric vehicle efficiently, the bidirectional converter is attached to the front of the inverter. It has a boost mode for discharging battery power to the dc-link capacitor and a buck mode for charging the regenerative power to the battery. Based on the results of the FMEA considering the operating characteristics of the bidirectional converter, the fault-tree is designed considering the risk of the converter. After setting the design parameters for the MCU for the electric vehicle, we analyze the failure rate of the capacitor due to the output voltage ripple and the inductor component failure rate due to the inductor current ripple. In addition, we obtain the failure rate of major parts according to operating temperature using MIL-HDBK-217F. Finally, the failure rate and the mean time between failures (MTBF) of the converter are predicted by reflecting the part failure rate to the basic event of the fault-tree.

• Journal of the Korea Computer Industry Society
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• v.2 no.3
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• pp.363-368
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• 2001

This paper introduced cascading technique as a new technology composed of two pulse transformers and presented the experimental data and results. To obtain the stable pulse voltage adopted cascading technique, we designed and tested a compact pulse generator by adjusting the load resistors and input voltage. Adopting cascading technique to load, we found that average cascading voltage was about 62$\%$ of theoretical value. Cascading ratio was calculated at almost 19 compared with non cascading voltage.

• Korea Real Estate Review
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• v.24 no.1
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• pp.63-76
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• 2014

This study utilizes FGLS (Feasible Generalized Least Squares) to determine the impact of Jeju Olle trekking courses on nearby land prices. Official 2010 land price data for 7 areas surrounding different Jeju Olle Trails was examined with a GIS program to determine the exact distance of land parcels from nearby trekking courses. Distance and various other pricing factors were used as explanatory variables for increases in land prices. The dependent variable was the rate of change in land prices from 2002 to 2010. Unlike existing studies which have examined the effect of highways, subways and other transportation facilities on land prices, this paper examines the effect of Korea's first-ever trekking courses on nearby land prices. This study concludes that 7 different Olle Trails exert a significant influence on nearby land prices and that land prices decrease by 0.03% per meter as plots get further and further from Olle Trails. This result shows that not only transport infrastructure (highways, subways, etc.) but also non-traffic infrastructure such as Jeju Olle Trails and trekking courses can have positive effects on local real estate markets.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.5
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• pp.304-314
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• 2015

We have reviewed the current status of coastal vulnerability index(CVI) to be guided into an appropriate CVI development for Korean coast and applied a methodology into the east coast of Korea to quantify coastal vulnerability by future sea_level rise. The CVIs reviewed includes USGS CVI, sea_level rise CVI, compound CVI, and multi scale CVI. The USGS CVI, expressed into the external forcing of sea_level rise, wave and tide, and adaptive capacity of morphology, erosion and slope, is adopted here for CVI quantification. The range of CVI is 1.826~22.361 with a mean of 7.085 for present condition and increases into 2.887~30.619 with a mean of 12.361 for the year of 2100(1 m sea_level rise). The index "VERY HIGH" is currently 8.57% of the coast and occupies 35.56% in 2100. The pattern of CVI change by sea_level rise is different to different local areas, and Gangneung, Yangyang and Goseong show the highest increase. The land use pattern in the "VERY HIGH" index is dominated by both human system of housing complex, road, cropland, etc, and natural system of sand, wetland, forestry, etc., which suggests existing land utilization should be reframed in the era of climate change. Though CVI approach is highly efficient to deal with a large set of climate scenarios entailed in climate impact assessment due to uncertainties, we also propose three_level assessment for the application of CVI methodology in the site specific adaptation such as first screening assessment by CVI, second scoping assessment by impact model, and final risk quantification with the result of impact model.