• Journal of the Korean Orthopaedic Association
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• v.55 no.3
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• pp.244-252
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• 2020

Purpose: Total femoral replacement (TFR) is an extreme form of limb salvage. Considering the rarity of this procedure, reports have focused on the complications and a proper indication is unclear. This study analyzed 36 patients with TFR who were asked the following: 1) prognostic factors related to survival in patients who underwent TFR with a tumoral cause; 2) overall implant and limb survival; 3) complications, functional outcome, and limb status for patients surviving for more than 3 years. Materials and Methods: According to the causes for TFR, 36 patients were categorized into three groups: extensive primary tumoral involvement (group 1, 15 cases), tumoral contamination by an inadvertent procedure or local recurrence (group 2, 16 cases), and salvage of a failed reconstruction (group 3, 5 cases). The factors that may affect the survival of patients included age, sex, cause of TFR, and tumor volume change after chemotherapy. Results: The overall five-year survival of the 36 patients was 31.5%±16.2%. The five-year survival of 31 patients with tumoral causes was 21.1%±15.6%. The five-year survival of 50.0%±31.0% in patients with a decreased tumor volume after chemotherapy was higher than that of increased tumor volume (p=0.02). The five-year survival of 12 cases with a wide margin was 41.7%±27.9%, whereas that of the marginal margin was 0.0%±0.0% (p=0.03). The ten-year overall implant survival of 36 patients was 85.9%±14.1%. The five-year revision-free survival was 16.6%±18.2%. At the final follow-up, 12 maintained tumor prosthesis, three underwent amputation (rotationplasty, 2; above knee amputation, 1), and the remaining one had knee fusion. Among 16 patients with a follow-up of more than three years, 14 patients underwent surgical intervention and two patients had conservative management. Complications included infection in 10 cases, local recurrences in two cases, and one case each of hip dislocation, bushing fracture, and femoral artery occlusion. Conclusion: Patients showing an increased tumor volume after chemotherapy and having an inadequate surgical margin showed a high chance of early death. In the long-term follow-up, TFR showed a high infection rate and the functional outcome was unsatisfactory. Nevertheless, this procedure is an inevitable option of limb preservation in selected patients.

• Korea journal of population studies
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• v.17 no.1
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• pp.1-16
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• 1994

Since 1962, the population growth control has been one of the most important aims in the 5-Year So-cioeconomic Development Plans of Korea. The annual population growth rate has dropped to tess than 1 percent in 1990 from about 3 percents in 1960s, and projected to reach to $\ulcorner$0$\urcorner$ percent in 2021. From 2021, Korean population will decrease and the age structure will be distorted because birth rate will drop suddenly and continuously. Thus, we can consider $\ulcorner$0$\urcorner$ growth population for minimizing the prob- lems on the decreasing population. To discuss the problems caused from the changes of population size and age- sex composition, we projected three kinds of population including two kinds of $\ulcorner$0$\urcorner$ growth population under different as- sumptions. The first is the population which extended the projection of National Statistical Office up to 2090. Because the TFR is assumed and fixed as low as 1.63 after 1990, the population growth rate will be under $\ulcorner$0$\urcorner$ in 2021 and drop by about 1 percent every year from around 2050. This population trend results to old age population : 38.1 of old- age dependency ratio and 46.5 years of median age. The second is the population which the size in 2021 projected by the NOS continues after 2021. To change over from the decreasing population after 2021 to the $\ulcorner$0$\urcorner$ growth one, the TFR should be in-creased up to over 3.0 in 2040-2050, which fertility level would be too high to be accepted. The third is the population which approaches to the $\ulcorner$0$\urcorner$ growth population under the assumptions that the TFR increases from 1.63 to 2.1 in the period of 2010-2030 and then the same level continues. Although the maximum population size reaches 51, 503 thousand persons, the population will approach to the stationary population with about 42.4 million persons around 2090. In this projected population there is no more serious problems on population composition, on the rapid decrease of population, and on the increase TFR level. When the $\ulcorner$0$\urcorner$ growth population continues the problems of over population caused by the populationincrease wou]d be minimized, and the problems of unusual age composition resulted from the popula-tion decrease would not be found any more. Furthermore, when the changes of population size and composition is continuing slowly, the factors of population would effect moderately to socioeconomic development and help social changes. Therefore, with the attention of the present population changes, we should adapt new and detailde population policy which is able to get the $\ulcorner$0$\urcorner$ growth population.

• Korea journal of population studies
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• v.9 no.2
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• pp.67-78
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• 1986

With Economic Development Plan, the Korean National Family Plan Program was introduced in early 1960's. The program, which has been a way for constraining population increase, has obtained excellent results. In other word, it has had an important role in controlling the increase in population. The purpose of this study is to analyze the change of fertility rates since 1970 and the lever of completed fertility of Korean women since 1960. There are Age-specific Fertility Rate(ASFR), Total Fertility Rate(TFR), Gross Reproduction Rate(GRR) and Net Reproduction Rate(NRR) etc. in indices of period fertility. It is also possible to be seen the completed fertility rates by using Parity Progression Ratio. The data necessary for this study were obtained from Population & Housing Census Report from the year of 1960 to 1980 and Vital Statistics from 1980 to 1984, which conducted by Economic Planning Board, Republic of Korea. The summarized results of this study were as follows : 1. Age-specific Fertility Fertility Rate(ASFR) has been continuously decreasing till now. The ASFR for the women aged 25 to 29 was higher than those of any other groups and the ASFR for the women aged 20 to 24 was higher than that of the women aged 30 to 34 since the mid 1970's. 2. There are Total Fertility Rate(TFR), Gross Reproduction Rate(GRR) and Ney Reproduction Rate(NRR) etc. in reproduction rates. First of all, TFR and GRR have been declining except late of 1970's and TFR showed 2.23 per ever-married women, GRR was 1.05 in 1982. Next, the change of NRR could not be found without life table by year and only NRR for the time of census was to be found. In 1980, NRR showed 1.27 per ever-married women and the level was still out of reach at replacement level of population. 3. Specific Fertility Rate by Birth Order(SFRBO) showed to be declined continually since 1972. Especially the SFRBO of the third live birth was decreased from about 22 per 1,000 ever-married women in 1972 to 12 or so in 1982. 4. To know the level of completed fertility, the mean number of completed live births per ever-married women was calculated from 1960 to 1980. The number of completed live births was more than 5 per ever-married women by the year of 1975 but have been declining and resulted in 4.69 in 1980.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.190-199
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• 2014

In the last years, fault problem in power electronics has been more and more investigated both from theoretical and practical point of view. The fault problem can cause equipment failure, data and economical losses. And the analyze system require to ensure fault problem and also rectify failures. The current errors on these faults are applied for identified type of faults. This paper presents technique to detection and identification faults in three-phase voltage source inverter (VSI) by using time-frequency distribution (TFD). TFD capable represent time frequency representation (TFR) in temporal and spectral information. Based on TFR, signal parameters are calculated such as instantaneous average current, instantaneous root mean square current, instantaneous fundamental root mean square current and, instantaneous total current waveform distortion. From on results, the detection of VSI faults could be determined based on characteristic of parameter estimation. And also concluded that the fault detection is capable of identifying the type of inverter fault and can reduce cost maintenance.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.991-993
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• 1999

This study proposed a new algorithm to assess autonomic function activity using Time-Frequency Representation(TFR). TFR is a way of describing the time-valiant energy of a signal. A discrete Wigner representation that is capable of filtering out any cross terms occuring in the Wigner-Ville Distribution(WVD) is used for time-variant energy distribution of heart rate variability(HRV) signals. And the marginal condition are evaluated to estimate power spectrum of HRV signals. The proposed algorithm showed that estimated power spectrum of HRV signals well describe the autonomic nerve system function and also showed the dynamics of autonomic nervous system response.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.275-278
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• 2000

We were fabricated of NiCr thin film resistors(TFR) on A1$_2$O$_3$(99.5%) substrates by dc magnetic sputtering system. The characteristics of electrical resistance (Sheet resistance & Temperature-Coefficient of the resistance-value:TCR) by annealing condition and reactive gas on the resistors were studied.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.15-20
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• 2018

This paper describes the fusing time characteristics of Light PVC Sheathed Circular Cord(VCTF) and Tray Frame Retardant(TFR) cables according to increased temperature under over current condition. The experimental equation will be used to determine the validity and reliability of the test results. The over current flowed 3, 5 and 10 times higher than the amount of allowable current using DC power supply with DAQ(Data Acquisition) measurement system. An infrared radiation heater, which was controlled by a variable AC auto transformer, was used to increase the temperature from room temperature to 50, 100 and 150 degrees Celsius. First, two type of cables were analyzed those with different cross-sectional areas with in the same structure and those with different structures with in the same cross-sectional areas. Then, it was determined how fusing time had been influenced according to the cross-sectional areas and different structures, respectively. The cable resistance was increased by joule heating according to increasing temperature. Therefore, the allowable current of cable is decreased. Finally, the fusing time of the cable was decreased due to increased temperatures at current flow, which were 3 times the amount of allowable current. The instantaneous breakdown was observed when current flow was 5 and 10 times over the amount of allowable current. The fusing time is directly affected by the structure of cable insulation.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.301-307
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• 2017

The purpose of this study is to investigate the electrical properties of thick-film resistor (TFR) prepared from $CaO-ZnO-B_2O_3-Al_2O_3-SiO_2$ (CZBAS) glass containing $RuO_2$ particles. $RuO_2$-glass composite powder was made by mixing and melting oxide powders of constituents. For comparison, $RuO_2$ powder was simply mixed with glass powder. $RuO_2$-40wt% glass composite and mixture were dispersed in an organic binder to obtain printable resistor paste and then thick-film was formed by screen printing, followed by sintering at the range between $750^{\circ}C$ and $900^{\circ}C$ for 10 min with a heating rate of $50^{\circ}C/min$ in an ambient atmosphere. $RuO_2$-glass composite sample showed much higher resistance compared to the simple mixed sample. This could be attributed to the difference in conducting mechanism. After sintering at $850^{\circ}C$, temperature coefficient of resistance of composite sample was lower than that of simple-mixed sample. TFR with dense and homogeneous microstructure could be obtained by using $RuO_2$-glass composite powder.

• International Area Studies Review
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• v.12 no.2
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• pp.125-145
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• 2008

Japan is now facing an aging society with fewer children. According to the demographic change in Japan, its economic effect on the economic growth has gained public attention. This paper focuses on the effect of the demographic change on economic growth in Japan, too. The first part illustrates the process of demographic transition in Japan. Thanks to successful Meiji Revitalizing Reform, Japan had experienced demographic transition earlier than the other East Asia countries. The second part of this paper describes relations between demographic factors and economic growth theoretically. In addition, it analyzes demographic effects on economic growth empirically using time series data of Japan from 1952 to 2005. It is the main finding of analyses that there are positive relations between demographic factor, including employment population rate, population rate and TFR, and economic growth. Therefore, in the near future, a decreasing labor force will cause economic stagnation in Japan. To overcome this problems, it is required to make various policies.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.607-612
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• 2021

This study estimated the impact of the shock of housing price increase on the total fertility rate and the contribution of each variable to changes in the TFR. This study is differentiated by estimating the contribution rate of each variable to the fertility rate through the Shapley decomposition and the panel VAR's forecast error variance decomposition, which previous studies have not attempted. The main results of this study are as follows. First, the decline in the TFR in Korea has been strongly influenced by the recent decline in the total fertility rate, and this influence is expected to continue in the future. In the case of housing costs, in the past, housing sales prices had a relatively small contribution to changes in the total fertility rate compared to the jeonse prices, but their influence is expected to increase in the long term in the future. It has been demonstrated that private education expenses other than housing sale price and Jeonse price also acted as a major cause of the decline in the total fertility rate.