• 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 Furniture Society
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• v.23 no.1
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• pp.26-37
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• 2012

This is the study about the New Formation Developement, the Changeable Table Design with Units that made of Wasted Wood to use restricted material rationally and to improve the space efficiency in the Table Design. We made some changeable table design with units that made of laminated wood wasted. And we found out the following formative characteristic and physical merits through this study. First, the space efficiency can be improve technically through the unit combination and organic transfomation of the specific form and a new method by laminated wood make the personal originality and the structral stability be built up. Second, there are some merits, moveable convenience and variable layout by the combination or transformation or personal fondness so that economical efficiency and variable of design can be improved. Third, we can remove original faults inside wood like a knot or not-uniform of wood organ when we laminate wood so that we use proper units that have original beauty of wood and can represent mild mood of furniture wholly. Fourth, much more strengthen tensile strength by the reciprocal action among the units that be made of laminated wood reduces wood's metamorphosis like bending or twisting so that the uniformity of wood can be gain and furniture's metamorphosis can be reduced. According to changes of nature environment, the difficulty of supply and demand for wood may be happen. According to changes of life style these days, supply and demand for environment friendly material, processing technique and developement of design to improve the efficiency of using space must be very important factor in morden furniture design. So we propose changeable furniture design by using new environment friendly meterial and processing method from this study.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.332-339
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• 2008

This study was carried out to develop the score table for prediction of landslide hazard in Gyeongsangbuk-Do province. It was studied to 172 places landslided in 23 cities and counties of Gyeongsangbuk-Do province. An analyze of the score table for landslide hazard was carried out through the multiple statistics of quantification method (I) by the computer. Factors effected to landslide occurrence quantity were shown in order of slope position, slope length, bedrock, aspect, forest age, slope form and slope. As results of the development of score table for prediction of landslide hazard in Gyeongsangbuk-Do province, total score range was divided that 107 under is stable area (IV class), 107~176 is area with little susceptibility to landslide (III class), 177~246 is area with moderate susceptibility to landslide (II class), above 247 area with severe susceptibility to landslide (I class).

• Korea journal of population studies
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• v.9 no.2
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• pp.13-29
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• 1986

This study was carried out to calculate working life expectancy and its potential gains according to the degree of reduction in the specific causes of death. It sought to ascertain what potential gains in labor force longevity might be reasonably achieved through efforts to reduce mortality from injuries and poisoning, diseases of circulatory system, neoplasms and the other causes of death. The data were drawn from the three sources such as "The 1982 Causes of Death Statistics," "Abridged Life Table for Korea 1978~'79" and "The 1982 annual Report of Economically Active Population" issued by Economic Planning Board. Analytical tools used in this study were the cause-deleted life table and the Wolfbein Wool's working life table method. Partial life expectancy was adopted as an index of this study, This application will be widely used as a good demographic tool for analyzing the dynamics of labor force and causes of death. Some of the findings are summerized as follows. 1. Partial life expectancies from initial age 15, 25, and 45 respectively to terminal age 65 are 44.86, 35.59 and 17.41 year in life expectancy itself, 37.08, 32.83 and 15.21 year in working life expectancy, 7.78, 2.76 and 2.20 years in inactive life years. 2. Potential gains in working expectancy from initial age 15, 25 and 45 to terminal age 65 by the complete elimination of the specific causes of death are 1.36, 0.94 and 0.27 years in injuries and poisoning, 0.88, 0.83 and 0.54 years in diseases of circulatory system, 0.56, 0.54 and 0.37 years in neoplasms, 1.13, 1.02 and 0.58 years in the other causes of death. The relationship between degree of reduction in causes of death and potential gains in working life years is in direct proportion. The prime orders of reduction effectiveness in age groups by the causes of death are injuries and poisoning in age 15-24, the other causes of death in age 25-49 and diseases of circulatory system in age 50 and over. 3. If it were possible to reduce 25%, 50% and 75% in mortality condition 1978~'79, the average length of working life would be 38.08, 39.13 and 40.17 years in age 15, and 33.68, 34.57 and 35.44 years in age 25, and 15.67, 16.14 and 16.63 years in age 45.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.591-598
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• 2019

Today, due to the development of the industrial society, the need for sustainable research and development for energy depletion and environmental protection is increasing. Among sustainable research, remanufacturing is an ideal way to meet environmental and economic aspects. In this paper, we investigated the End-of-Life Vehicle(ELV) in order to find the recovery method of the core which is the preceding stage of remanufacturing. The number of End-of-Life Vehicle is increasing year by year, but the core recovery rate from ELV is still low. Therefore, a methodology to determine the disassembly priority of each part is proposed to increase the core recovery rate. Based on the analysis Table through the disassembly process, the decision rule was selected and the weighted score evaluation Table was completed to complete the disassembly priority system. Finally, evaluation was made on gasoline vehicles to determine priorities.

• Journal of Applied Reliability
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• v.2 no.1
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• pp.15-22
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• 2002

This paper is concerned about an Accelerated Life Test for Micro Display Device which is being used in a Projection TV, in order to find a failure mode occurred in field in a short time, to identify a major factor to affect a life, and to estimate a mean life. For this purpose, we selected a temperature as a accelerated factor to perform a test and measured degradation of display device using visual inspection and chromaticity table. In the result of Accelerated Life Test, it is confirmed that failure mode is equal to the degradation of display device by vendor and the Temperature is a major factor to affect a failure. Besides, according as the display device is turned to green as degraded, it is identified that the change of the chromaticity value is one method to measure the degree of the degradation . So, we applied the optimal condition, which consider a cost and life to lower the Temperature which is a major factor acquired by the result of ALT, to PTV design

• Korea journal of population studies
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• v.13 no.2
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• pp.1-18
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• 1990

This is a study which attempt to analyze changing patierns of economic active popu-lation, t o estimato- future patterns, and exa- mine vartons problems arises by changing c ire u mst ances of t he labor force market in- clunging soici al, economic ic, heathl th and demoi-graph ic aspects. We have constructed series of wotking life table which are useful in syt uiolyioig the lirocess of growth and structural change of labor force. Work i ng life tables represent ihie life eyele of econrmic' activity in hi ypothetical cohorts, that is. gen-erat i on of men Sn bject at eat' b period ot f their lives th given ra to's o mor tali it y and of par-- tici pation in economic activities. The tabloes prot' ide measorues of the alvet'age he ng t able of economically aeti \- e life. and agespecific rates of en trannee' into and retirement from the hahn' force. In const routing working life tables, age-specific activity rates and life tabole popula- titoto which represents contemporary condi-tions of moortality in Korea au'e the basic' maltoerials. We have derived the age-specific rates foorm economically active population survey, whoich were conducted by the Bureau of Statistics, Economic Planning Borard of the Korean government. Working life tables are constructed for men wtable these materi- als in the year of 1970, 1980 and 1988 by a modified Wolfbein-Wool's method. Some of the findings may be summerized as follow : 1) A central part of constructing working life table is calculation of stationary' economic active population, which represents the number of men in the stationtary population extoected to be in the labor force at each age group in the life span. The stationary economic active population by age have generally a universal pattern, where they rise sharply in the early twenties, approach its' peak in the thirties decline thereafter. at first graolually and then more rapidly at an advanced age. Korean men show the same general pa ttern of age distribution of stationary eco-- nomic active population with sharp increase hegining from the age interval of 20 to 24, reaching to maximum level at older age. The population. however, presumably, increased substantially due to increaseing school atte endance rates. Another difference exiSts in the youngest age groups, that is the activity rate in the year of 1988 is lower than that of Japan. The table shows an analysis of changes in the age distrihution of labor force between 1970, 1980 and 1988. 2) It was shown an analysis of changes in the age distribution and cause of separation from labor force. The entrance rate to labor force has increased from 18~\5 persons to 299 persons per 1000 head of stationary population between that of 1980 than that of 1988 for Korean men in 20~24 age group. The entrace rate to labor force shows a rapid entrance appearance concentrated on the 15~24 age group. The separation rate from labor force by retirment in Korea in the year of 1988 shows a great difference of the about four times as much as that of Japan. 3) The functions of table illustrate the patterns of working life of males in Korea in 1970, 1980 and 1988. The average remaining number of economically active years, e at age 15 in 1988 is 46.39 which is 2.12 years of increase compared with that of at age 15 in 1970,1980 and 1988 are 43.90,44.27 and 46.39 respectively, showing steadily increase dur- ing the past double decade the increase in the length of economically active life various age may be considered to have come both from extention of general life expectancy and from increasing entrance rate to economic activity in high age that of working is far greater in 1988 than that of 1980. The gaps between expectation of life and average remaining years of economically active widened due to rapid improvement of mortality level in Ko- rea. This observation together with the population pressure by the appearance of a group of younger population implies that constant increase of economically inactive population among older age group.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.317-322
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• 2015

The metal oxide varistor (MOV) is a major component of the surge protection devices (SPDs) currently in use. The device is judged to be faulty when fatigue caused by the continuous inflow of lightning accumulates and reaches the damage limit. In many cases, induced lightning resulting from lightning strikes flows in to the device several times per second in succession. Therefore, the frequency or the rate at which the SPD is actually exposed to stress, called a surge, is outside the range of human perception. For this reason, the protective device should be replaced if it actually approaches the end of its life even though it is not faulty at present, currently no basis exists for making the judgment of remaining lifetime. Up to now, the life of an MOV has been predicted solely based on the number of inflow surges, irrespective of the magnitude of the surge current or the amount of energy that has flowed through the device. In this study, nonlinear data that shows the damage to an MOV depending on the count of surge and the amount of input current were collected through a high-voltage test. Then, a failure prediction algorithm was proposed by preparing a look-up table using the results of the test. The proposed method was experimentally verified using an impulse surge generator

• Korean Journal of Social Welfare
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• v.61 no.3
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• pp.307-328
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• 2009

This study aims to investigate the patterns and causes of the marital duration. Data used for this study are ten waves of Korean Labor and Income Panel Study(KLIPS) in 1998~2007, in which the final sample consists of 2,397 households. The Life-table method is used for describing the overall patterns of marital duration by birth-cohorts and different education groups, and the Cox proportional hazard regression model is used to identify significant factors on the marital duration. The results show that among the all respondents, the 0.79% has divorced or separated within five years after marriage, 2.12% within 10 years, and 5.84% within 20 years, respectively. In addition, the Cox regression results show that the marital duration is significantly affected by the birth-cohorts of respondents and their spouses, education level, earning of spouses, co-residence with parents, and household income. This implies that the hazard rate of marital disruption is higher for younger cohorts, individuals with lower education and economic status, persons living with parents-in-law, compared to their counterparts. Thus, it is necessary to implement social welfare policies applicable for these persons.