• Steel and Composite Structures
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• v.28 no.4
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• pp.427-438
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• 2018

Static stability is a decisive factor in the design of domes. Stability-related external factors, such as load and supports, are incorporated into structural vulnerability theory by the definition of a relative rate of joint well-formedness ($r_r$). Hence, the instability mechanism of domes can be revealed. To improve stability, an optimization model against instability, which takes the maximization of the lowest $r_r$ ($r_{r,min}$) as the objective and the discrete member sections as the variables, is established with constraints on the design requirements and steel consumption. Optimizations are performed on two real-life Kiewitt-6 model domes with a span of 23.4 m and rise of 11.7 m, which are initially constructed for shaking table collapse test. Well-formedness analyses and stability calculation (via arc-length method) of the models throughout the optimization history demonstrate that this proposed method can effectively enhance $r_{r,min}$ and optimize the static stability of shell-like structures. Additionally, seismic performance of the optimum models subjected to the same earthquake as in the shaking table test is checked. The supplemental simulations prove that the optimum models are superior to the original models under earthquake load as well.

• Journal of the Korean Home Economics Association
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• v.11 no.1
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• pp.44-56
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• 1973

The effect of the temperature and the time of scalding, and the addition of various seasoning on the remaining % of total Vitamin C contained in Spinach (Spinacia oleracea) was studied and discussed by means of chemical kinetics. The quantitative measurements of total Vitamin C were made by 2,4-dinitrophenyl hydrazine (DNPH) method with Clinical Electrophotometer (Fisher). The sample spinach contains 39.88mg. % of total vitamin C on the average, and the ratio of oxidized and reduced forms of Vitamin C is 1 : 4.7. When the sample spinach was scalded, the kinetics of the decrease of the remaining total vitamin C. % was observed to follow the first order reactions regardless of the temperatures applied (i,e. 70$^{o}$ , 80$^{o}$ , 90$^{o}$ and 100$^{o}$ ) with half-life range of 2.10 - 1.47 minutes. In the case of the addition of various seasonings, the addition of various seasonings, the kinetics remaining Vitamin C % showed to be the zero order reactions regardless of the kinds of seasonings and storage temperatures. With the addition of seasonings, the stability of Vitamin C was found to be increased in the order table salt+sesame oil+vinegar+soybean sauce, without seasoning, table salt+sesame oil, table salt+sesame oil+soybean sauce.

• Journal of the Korea Society of Computer and Information
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• v.20 no.11
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• pp.1-8
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• 2015

Flash memory has advantages in that it is fast access speed, low-power, and low-price. Therefore, they are widely used in electronics industry sectors. However, the flash memory has weak points, which are the limited number of erase operations and non-in-place update problem. To overcome the limited number of erase operations, many wear leveling techniques are studied. They use many tables storing information such as erase count of blocks, hot and cold block indicators, reference count of pages, and so on. These tables occupy some space of main memory for the wear leveling techniques. Accordingly, they are not appropriate for low-power devices limited main memory. In order to resolve it, a wear leveling technique using bit array and Bit Set Threshold (BST) for flash memory. The proposing technique reduces the used space of main memory using a bit array table, which saves the history of block erase operations. To enhance accuracy of cold block information, we use BST, which is calculated by using the number of invalid pages of the blocks in a one-to-many mode, where one bit is related to many blocks. The performance results illustrate that the proposed wear leveling technique improve life time of flash memory to about 6%, compared with previous wear leveling techniques using a bit array table in our experiment.

• Journal of Preventive Medicine and Public Health
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• v.53 no.2
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• pp.143-148
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• 2020

Objectives: We calculated life expectancy and inequalities therein by income for the period of 2016-2018 across the 253 electoral constituencies of the 20th National Assembly election in Korea. Methods: We obtained population and death data between 2016 and 2018 from the National Health Information Database and constructed abridged life tables using standard life table procedures according to gender and income quintiles for the electoral constituencies of the 20th National Assembly election held in 2016. Results: Life expectancy across the 253 constituencies ranged from 80.51 years to 87.05 years, corresponding to a gap of 6.54 years. The life expectancy difference by income across the 253 constituencies ranged from 2.94 years to 10.67 years. In each province, the difference in life expectancy by income across electoral constituencies was generally greater than the inter-constituency differences. Constituencies in capital and metropolitan areas showed a higher life expectancy and a lower life expectancy difference by income than constituencies in rural areas. Conclusions: Pro-rich inequalities in life expectancy by income existed in every electoral constituency in Korea. Both intra-constituency and inter-constituency socioeconomic inequalities in health should be highlighted in future policy-making in the National Assembly.

• The Korean Journal of Applied Statistics
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• v.24 no.1
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• pp.115-125
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• 2011

By use of a mortality forecasting model and a life table, forecasting the average life expectancy is an effective way to evaluate the future mortality level. There are differences between the actual values of average life expectancy at present and the forecasted values of average life expectancy in population projection 2006 from Statistics Korea. The reason is that the average life expectancy forecasts did not reflect the increasing speed of the actual ones. The main causes of the problem may be errors from judgment for projection, from choice, or use of a mortality forecasting model. In this paper, we focus on the choice of the mortality forecasting model to inspect this problem. Statistics Korea should take a mortality forecasting model with considerable investigation to proceed population projection 2011 without the errors observed in population projection 2006. We compare the five mortality forecasting models that are the LC(Lee and Carter) model used widely and its variants, and the HP8(Heligman and Pollard 8 parameter) model for handling death probability. We make average life expectancy forecasts by sex using modeling results from 2010 to 2030 and compare with that of the population projection 2006 during the same period. The average life expectancy from all five models are forecasted higher than that of the population projection 2006. Therefore, we show that the new average life expectancy forecasts are relatively suitable to the future mortality level.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.257-265
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• 2011

To investigate host preferencse of Myzus persicae on 15 sweet pepper cultivars grown in Jeonnam Province, EPG (electrical penetration graph) and life table experiments were carried out in the laboratory. Phloem phase times were significantly longer on Ferrari, Jinju, Debla, and Rapido than Orobell and Thialf. Non-penetration times were conversely observed. Life span, reproduction period, total fecundity, and intrinsic rate of increase ($r_m$) of M. persicae, were higher on Ferrari, Debla, Orange glory, and Jinju than on Purple, GreenAce, Orobell, and Thialf. On the bases of these results, we conclude that M. persicae preferred Ferrari, Jinju, Orange glory, and Debla among the 15 tested sweet pepper varieties. However, we could not show the preference of the aphid for Purple, Orobell, and Thialf.

• The Korean Journal of Health Service Management
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• v.5 no.3
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• pp.123-132
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• 2011

To evaluate the impact of avoidable mortality on the changes in life expectancy at birth in Korea. Standard life table techniques and the Arriaga method were used to calculate and to decompose life expectancy changes by age, effects and groups of causes of avoidable mortality among two periods(1990-2000 and 2000-2009). A list of causes of avoidable mortality reached by consensus and previously published in Spain was used. Mortality in young adults produced a reduction in life expectancy at birth during the 1990-2000, but there was an important increase in life expectancy at birth during the 2000-2009; in both cases, this was the result of factors amenable to health policy interventions. The highest improvement in life expectancy at birth was due to non-avoidable causes, but avoidable mortality through health service interventions showed improvements in life expectancy at birth in those elderly people than 1 year and in those younger. Making a distinction between several groups of causes of avoidable mortality and using decomposition by causes, ages and effects allowed us to better explain the impact of avoidable mortality on the life expectancy at birth of the whole population and gave a new dimension to this indicator that could be very useful in public health.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.387-394
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• 2017

Temperature-dependent oviposition model and life table parameters of Paromius exiguus (Distant), the causal agent of 'pecky' rice grain were examined at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5, and $35{\pm}^{\circ}C$) and a photoperiod of 14:10 (L:D) h. Unit functions of the oviposition model were developed and life table parameters were estimated. The longevity of P. exiguus adults decreased with increasing temperature (123.8 days at $17.5^{\circ}C$ and 23.6 days at $32.5^{\circ}C$). Total fecundity was highest at $30^{\circ}C$ (585.2 eggs/female) and lowest at $17.5^{\circ}C$ (21.5 eggs/female). In order to develop a temperature-dependent oviposition model, adult aging-rate, temperature-dependent fecundity, age-specific survival rate, and age-specific cumulative oviposition rate equations were estimated. All unit equations ($r^2=0.92{\sim}0.98$) except for the temperature-dependent fecundity equation ($r^2=0.83{\sim}0.85$), described oviposition characteristics of P. exiguus adequately. Life table parameters of P. exiguus were estimated at various constant temperatures. Net reproduction rate ($R_0$) was highest at $30^{\circ}C$ (118.21). Mean generation time (T) was shortest at $32.5^{\circ}C$ (32.99 days) and doubling time (Dt) was shortest at $30^{\circ}C$ (5.69 days). The highest values of intrinsic rate of increase ($r_m$) and finite rate of increase (${\lambda}$) were 0.122 and 1.129 at $30^{\circ}C$, respectively.

• Journal of the Korea Furniture Society
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• v.23 no.2
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• pp.214-221
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• 2012

Sustainable energy consumption and increasing $CO_2$ emissions stimulate Eco-friendly industry. Wood has positive various properties as alternative energy such as solar, wind and water. Wood provide lumber, pallet, paper, pulp and fuel through production process. Even Korea republic has 63.7% of forest rates, weather condition makes low forestry production capacity. For utilization of domestic small diameter log needs study mechanical properties. In this study, various properties tested on domestic Japanese Larch small diameter lumbers and make mechanical properties table for allowable stress calculation. Result of compressive test, allowable compressive stress is 13 MPa. Allowable bending stress is 12 MPa.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.42-52
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• 2006

Tube erosion can be defined as a phenomenon for an increment of bore diameter, a declination of accuracy and utility of tube by firing. This study introduces the characteristics of tube life for the 155 mm K9 SHP Using a tube history book with bore measurement data and firing data of standard charge, this study analyzed the EFC vs Tube life and EFC with heat transfer effect formula as a consideration of continuous firing vs tube life. The results were compared with Firing Table(FT 155-K9-1) after the analysis. Also, this study suggests that CN98 tube can be rifled as 1000 EFC through the severe condition with continuous firing.