• 지역연구
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• 제10권1호
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• pp.39-52
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• 1994

This paper primarily aims to analyze the growth rate differentials of the economic activities in chung-Nam area. The research has been undertaken to find out the potentials of the economic activities and economic bases in the area. To analyze the economic potentials of the industries, the study employed the economic Growth Rate Differential Analysis by Henderson which is revised form of Shift-Share Analysis Methods. The research employed the employment data according to the standardized two-digit-classification-system during the period of 10 years from 1981 through 1991. The Growth Rate Differential Analysis calculates Total Growth Differentials which are dicomposed into two parts: Weight Part and Rate Part. Total Growth Differential can be calculated as the difference between national growth rate and regional growth rate by industry. The foundings are as follows: First, the economic bases of Chung-Nam area were found to be very weak, largely depending on primary industries such as agriculture and fisheries. Second, there was a great decline in urban industries in Tae Joeon, Cheon An and other cities over period of 1971-1981. It is strongly recommended that the planned items and products of each industrial complex must be reorgnized in a fashion to match those with high competitive power found in this research.

• Corrosion Science and Technology
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• 제18권1호
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• pp.33-38
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• 2019

Alloy 600/182 with excellent mechanical/chemical properties have been utilized for nuclear power plants. Although both alloys are known to have superior corrosion resistance, stress corrosion cracking failure has been an issue in primary water environment of nuclear power plants. Therefore, primary water stress corrosion crack (PWSCC) growth rate tests were conducted to investigate crack growth properties of Alloy 600/182. To investigate PWSCC growth rate, test facilities including water chemistry loop, autoclave, and loading system were constructed. In PWSCC crack growth rate tests, half compact-tension specimens were manufactured. These specimens were then placed inside of the autoclave connected to the loop to provide primary water environment. Tested conditions were set at temperature of $360^{\circ}C$ and pressure of 20MPa. Real time crack growth rates of specimens inside the autoclave were measured by Direct Current potential drop (DCPD) method. To confirm inter-granular (IG) crack as a characteristic of PWSCC, fracture surfaces of tested specimens were observed by SEM. Finally, crack growth rate was derived in a specific stress intensity factor (K) range and similarity with overseas database was identified.

• 대한치과기공학회지
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• 제28권1호
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• pp.103-120
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• 2006

In this study, we investigated the growth rate on the basis of the sex and the year among the subjects of the licensed dental technicians from the year 1970 to 2003 in Korea. In line with this investigation, this study aims to provide a basic material with regard to the state of dental technician workforce by sex and to suggest a need to reassignment of workforce by sex in accordance with the specific job description. The results of the study are as follows; First, among the licensed dental technicians from 1970 to 2003, males came to 11,589 and females, 5,976, which shows the number of males are 1.9 times higher than that of females. To put the mean sexual composite from 1970 to 2003, male was 82.9% and female 17.1%, indicating the number of males are 4.8 higher than that of females. Second, Of the mean increasing rate until the year 2003 in contrast to 1970, male was about 351 and female was about 181, which shows the number of males increased 1.94 times higher than the females. Comparing to the mean increasing rate of the last year, female came to 25.56% and male 10.73%, which reveals that the females were about 2.4 times higher than the males. In the case of the growth rate, females increased by 1,196,20 times and the males, 26,41. As a result the growth of females are about 45.3 times higher than the males. Third, in the case of the growth rate from 1980 to 2003, females came to 47.85 times and males 9.16, which shows the growth rate of the females was about 5.2 times higher than the males. In contrast to the year 1987, the growth rate until 2003 shows that the females came to 5,13 times and the males 2.70, which indicates the growth rate of females was about 1.9 times higher than males. Fourth, Compared to the year 1990, the growth rate until 2003 shows that females came to 3.40 times and males 2.03 indicating the growth rate of the females was about 1.7 times higher than males. In contrast to the year 2000, the growth rate till 2003 shows that females was 1,34 times and males 1.15 times increased. Fifth, the ratio of sex by the year among the licensed dental technicians is as follows; ratio of male to female in 1970 was 91.2 to 1. In 2003 the ratio came to 2.0 to 1. The number of growth by sex in 1970 came to 24.0 males to 1 female. But the figure was equalled in 2003.

• 연구논문집
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• 통권26호
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• pp.95-102
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• 1996

The carbide growth behavior of MAR-M247 LC alloy was investigated by directional solidification and quench method. The carbide volume fraction, trapping and growth behavior were correlated with the growth rate. It was found that the carbide volume fraction decreases at slower growth rate. This decreasing was caused by lower solid-liquid interface trapping ability at the slower growth rate.

• Nuclear Engineering and Technology
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• 제33권5호
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• pp.526-538
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• 2001

Fatigue tests in air and in room temperature water were performed to obtain comparable data and stable crack measuring conditions. In air environment, fatigue crack growth rate was increased with increasing temperature due to an increase in crack tip oxidation rate. In room temperature water, the fatigue crack growth rate was faster than in air and crack path varied on loading conditions. In simulated light water reactor (LWR) conditions, there was little environmental effect on the fatigue crack growth rate (FCGR) at low dissolved oxygen or at high loading frequency conditions. While the FCGR was enhanced at high oxygen condition, and the enhancement of crack growth rate increased as loading frequency decreased to a critical value. In fractography, environmentally assisted cracks, such as semi-cleavage and secondary intergranular crack, were found near sulfide inclusions only at high dissolved oxygen and low loading frequency condition. The high crack growth rate was related to environmentally assisted crack. These results indicated that environmentally assisted crack could be formed by the Electrochemical effect in specific loading condition.

• 한국초지조사료학회지
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• 제13권3호
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• pp.190-194
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• 1993

This experiment was conducted to investigate the effects of concentrated sulfate on the germination rate, growth rate and the productivity of weight of kudzu (Pueraria thwnbergiana Bentham). The germination rate of kudzu seed by one or two treatment retreatment with the concentrated sulfate for minutes of 5. 10, 15 and 20 were determined respectively. The results obtained were summarized as follows; 1. In the time of concentrated sulfate treatment, the germination rate was the highest in the once treatment for 20 minute. and the retreatment was higher than the once treatment in the germination rate. 2. The changes of plant length by growth stage was grown gradually until for 60 day and rapidly after for 60 day. The growth rate was the highest in treatment for 15 minute than in other treatments. 3. The stem diameter. stem weight. fresh weight and root weight by the treatment with sulfate 15 minute as the treatment with once were high degree of productivity. 4. The number of branch. number of nodes and root weight by the growth stage were higher growth rate before for 90 day than after for 90 day, however stem weight and fresh weight were high degree of productivity after for 60 day.

• 한국해양공학회지
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• 제6권1호
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• pp.122-130
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• 1992

The effect of loading waveform on elevated temperature low-cycle fatigue crack growth behavior in a SUS 304 stainless steel have been investigated under symmetrical trangular (fast-fast), trapezoidal and asymmetrical(fast-slow, slow-fast) waveforms at 650.deg. C. It was found that the crack growth rate in fast-slow loading waveform appeared to be higher a little and the crack growth rate in slow-fast loading waveform much higer than that in fast-fast loading waveform, and difference in crack growth rate between fast-show and slow-fast waveforms nearly didn't appear in the region of da/dN>10/sup -2/ The crack growth rate in the trapezoidal loading waveform with t/sub h/=500sec appeared to be faster than that in slow(500sec)-fast(1sec). In addition, parameter modified J-integral could be considered as useful parameter for fatigue crack growth rate in all waveforms. The result obtained are as follow. da/dN=4.91*10/sup -3/ (.DELTA. J/sub c/)/sup 0.565/.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1139-1146
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• 1999

Reliability analysis of structures based on fracture mechanics requires knowledge on statistical characteristics of the parameter C and m in the fatigue crack growth law, $da/dN=C({\Delta}K)^m$. The purpose of the present study is to investigate if it is possible to predict fatigue crack growth rate by only the fluctuation of the parameter C. In this study, Paris-Erdogan law is adopted, where the author treat the parameter C as random and m as constant. The fluctuation of crack growth rate is assumed only due to the parameter C. The growth resistance coefficient of material to fatigue crack growth (Z=1/C) was treated as a spatial stochastic process, which varies randomly on the crack path. The theoretical crack growth rates at various stress intensity factor range are discussed. Constant ${\Delta}K$ fatigue crack growth tests were performed on the structural steel, SM45C. The experimental data were analyzed to determine the autocorrelation function and Weibull distributions of the fatigue crack growth resistance. And also, the effect of the parameter m of Paris' law due to variation of fatigue crack growth resistance was discussed.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.241-246
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• 1989

Quadrupole mass spectrometer를 이용한 발효 배기가스의 분석을 통해 세포의 증식을 on-line monitoring하고자 model 균주로 Candida utilis에 대해 연구하였다. Quadrupole mass spectrometer와 interface된 16-bit 개인용 컴퓨터 (IBM PC-AT)에서 산소 소비속도(OUR)와 이산화탄소 발생속도(CER)를 on-line 계산할 수 있었고 계속해서 이들 계산치로부터 세포농도와 증식속도 및 비증식속도를 계산하였다. 계산된 값들은 실험적으로 측정한 세포농도 및 비증식속도와 잘 일치함을 알 수 있었다.

• Journal of Ginseng Research
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• 제7권1호
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• pp.52-62
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• 1983

This study was undertaken to investigate the influence of kinetin and 2, 4-dichlorophenoxyacetic acid on the rate of growth, the contents of RNA, DNA, and protein. And also the effect of plant growth regulator on isoperoxidases in callus derived from root (root-callus) and petiole (petiolecallus) was investigated. The rate of growth in petiole-callus was higher than the rootcallus at 0.1 mg/l kinetin and 1mgfl 2,4-D. At 1mgll kinetic, the rate of growth increased, but at high concentration the rate of growth decreased fast. The contents of RNA, DNA and protein also increased, but it did not coincide with the increase of the growth rate of callus. The isoperoxidases of callus grown at various amounts of 2,4-D and kinetic occurred in an almost fashion, but those of root-callus appeared different from those of petiole-callus.