• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1511-1517
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• 2013

This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of life span. Regression of Life Span on Lifetime profit indicated that there was an increase of 3,800 Won (approximately $3.45) of lifetime profit per day increase in life span. This is evidence that care of each cow is necessary to improve net return and important for farms maintaining profitable cows. The estimates of heritability of age at first calving, first two calving intervals, days in milk for lifetime, lifespan, milk income and lifetime profit were 0.111, 0.088, 0.142, 0.140, 0.143, 0.123, and 0.102, respectively. The low heritabilities indicated that the productive life and economical traits include reproductive and productive characteristics. Age at first calving and interval between first and second calving had negative genetic correlation with lifetime profit (-0.080 and -0.265, respectively). Reducing age at first calving and first calving interval had a positive effect on lifetime profit. Lifetime profit increased to approximately 2,600,000 (2,363.6) from 800,000 Won ($727.3) when age at first calving decreased to (22.3 month) from (32.8 month). Results suggested that reproductive traits such as age at first calving and calving interval might affect various economical traits and consequently influenced productive life and profitability of cows. In conclusion, regard of the age at first calving must be taken with the optimum age at first calving for maximum lifetime profit being 22.5 to 23.5 months. Moreover, considering the negative genetic correlation of first calving interval with lifetime profit, it should be reduced against the present trend of increase.

• Korean Journal of Child Studies
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• v.10 no.2
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• pp.1-18
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• 1989

This documentary study explored the stages of human development and education in the Choson Dynasty with the use of "Non Eu, Ye Gi, So Hak, Tae Gyo Sin Gi, and Dong Yi Bo Gam. The findings were compared with Western writings of a comparable period. It was found that education in the Choson Dynasty was largely concerned with mental attitude and conduct in ordinary life (education for manners and living). Education claimed to stand for unity of knowledge and behavior. It was founded on a Confucian view of education with a saint as the ideal model to be emulated. In the early years, home influence was emphasized. This was later replaced by institutional education. Additional education frequently extended to ten years and even forty or more years for the development of leaders. Based on the above findings. It was concluded that (1) the Western stages of human development exemplified by the Puritans and by Rousseau were concerned only with progressive changes from the postnatal stage to adolescence but the stages or the Choson Dynasty applied to the entire life span, from prenatal life through old age: (2) the developmental stages of males and females were defined differently as a result of differences in educational contents and sex-role distinctions: (3) life span educational objectives were Confucian and the preparatory stages were long coming to fruition in late senescence: and (4) although education was centered on manners and based on Confucianism, much of human development in the Choson Dynasty corresponds to that of modern times.

• Journal of the Korean Institute of Navigation
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• v.16 no.1
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• pp.94-97
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• 1992

In this paper, the individual number of the future has depended not only upon the present individual number but upon the present individual age, considering the stochastic process model of individual number when the life span of each individual number and the individual age as a set, this becomes a Markovian. Therefore, in this paper the individual is treated as invariable, without depending upon the whole record of each individual since its birth. As a result, suppose {N(t), t>0} be a counting process and also suppose $Z_n$ denote the life span between the (n-1)st and the nth event of this process, (n{$geq}1$) : that is, when the first individual is established at n=1(time, 0), the Z$Z_n$ at time nth individual breaks, down. Random walk $Z_n$ is $Z_n=X_1+X_2+{\cdots}{\cdots}+X_A, Z_0=0$ So, fixed time t, the stochastic model is made up as follows ; A) Recurrence (Regeneration)number between(0.t) $N_t=max{n ; Z_n{\leq}t}$ B) Forwardrecurrence time(Excess life) $T^-I_t=Z_{Nt+1}-t$ C) Backward recurrence time(Current life) $T^-_t=t-Z_{Nt}$

• Membrane and Water Treatment
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• v.8 no.2
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• pp.137-147
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• 2017

A water treatment utility in South Korea operates a large system of pressurized hollow fiber membrane (PHFM) modules. The optimal selection of membrane module for the full scale plant was critical issue and carried out using Risk-based Life Cycle Cost (RbLCC) analysis based on the historical data of operation and maintenance. The RbLCC analysis was used in the process of decision-making for replacing aged modules. The initial purchasing cost and the value at risk during operation were considered together. The failure of modules occurs stochastically depending on the physical deterioration with usage over time. The life span of module was used as a factor for the failure of Poisson's probability model, which was used to obtain the probability of failure during the operation. The RbLCC was calculated by combining the initial cost and the value at risk without its warranty term. Additionally, the properties of membrane were considered to select the optimum product. Results showed that the module's life span in the system was ten years (120 month) with safety factor. The optimum product was selected from six candidates membrane for a full scale water treatment facility. This method could be used to make the optimum and rational decision for the operation of membrane water purification facility.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.357-361
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• 2022

Employing the available technologies and utilizing the advanced means to improve the level of health care provided to citizens in their various locations. Citizens have the right to get a proper health care services despite the location of their residency or the distance from the health care delivery centers, a goal that can be achieved by utilizing air ambulance systems. In such systems, aircrafts and their life spans are the essential component, the flight duration of the aircraft during its life span is determined by the maintenance schedule. This research, enhances the air ambulance systems by presenting a proposal that maximizes the aircraft flight duration during its life span. The enhancement will be reached by developing a set of algorithms that handles the aircraft maintenance problem. The objective of these algorithms is to minimize the maximum completion time of all maintenance tasks, thus increasing the aircraft operation time. Practical experiments performed to these algorithms showed the ability of these algorithms to achieve the desired goal. The developed algorithms will manage the maintenance scheduling problem to maximize the uptime of the air ambulance which can be achieved by maximizing the minimum life of spare parts. The developed algorithms showed good performance measures during experimental tests. The 3LSL algorithm showed a higher performance compared to other algorithms during all performed experiments.

• Journal of Families and Better Life
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• v.8 no.2
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• pp.49-68
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• 1990

Family Life Education(FLE) is an educational specialty which was originated in reaction to changing social conditions, industrialization, and urbanization It deals with the perceived inadequacies of families to cope with these changes, thereby reducing social problems involved with and improving family life. With an assumption that the studies about FLE have not been so active in Korea, the present thesis examines the FLE in Korea; i.e. the definition, the objectives, the scope, the approximation of family life education, and the necessity of marital education in Korea based upon the published theories of FLE in th United Stated of America. Also it attempts to formulate a tentative plan for the promotion of a FLE program in Korea. The concept of FLE in Korea was manifested in the social educational law and life-span education, specified as the 4th among ten presidential regulations; and it has drawn an institutional, governmental attention It is defined as " the life-span developmental education to enhance the quality of human life, to solve family problem, to develop an individual's potentiality, and to strengthen the family correlations." of the FLE programs, the marital education is considered one of the crucial subjects because it is the core of the family life. With this premise, FLE tries to support the healthy marital relations, , subsequently helping to explore the family potentiality and to strengthen family ties, Considering the seemingly dual characteristics of the Korean family types, the contents of marital education program should be consisted of the following; marital communication, role cooperation, and effective expressions of mutual affection, In addition, reciprocal understanding and cooperation of the married couples to overcome the differences of value, personality, hobby, and religion, the educational methods in raising kids, and the effective management of home economics should be included. The objects of the FLE program are unmarried, pre-married, and married persons. Fro the married persons, the FLE program should be arranged in accordance with their marital status divided by the family life cycle so that they may prevent possible family problems at each stage of the family life. Also, to prevent the problems incurred in the curse of carrying out family functions, the FLE program should be provided with on the basis of a family unit, thereby improving the quality of the family functions.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.29-34
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• 2017

Many household appliances, including vacuum cleaners, are being subjected to various of impact damages, and made of plastic. However, researches on the damage of appliances materials by repetitive impacts have been rarely conducted. the mechanical stress exerted upon impact-modified polycarbonate (PC) has a great influence not only on the quality of the product but also on the life span. The purpose of this research was to quantify the effects of repetitive impact on the polycarbonate. Second, it was to design the repetitive impact tester for controlling the impact energy. The mechanical properties of tensile strength, yielding stress and strain on the specimens subjected to cyclic impacts were discussed. Tensile strength was sharply declined at the beginning of the impact cycles, while the strain gradually decreased during impact cycles.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.29-46
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• 1999

The performance based design obligates quantitative assessment of required performances by means of transparent and objective science. In this design scheme, simulation of both macro and micro-scale structural behaviors is thought to be a powerful tool. This paper proposes a way how to unify the structural safety and serviceability check method and durability assessment of RC structures. Though component chemical-physical processes are crudely assumed, system dynamics of micro-scale pore structure formation and macro-scale defects and deformation of structures was shown as possible and promising approach in future. The authors understand that the unification of structural and durability design has just started. For further progress and development, predictive tool of structural behaviors from birth to death of concrete under any specified environment and load serves as an essential technicality.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.795-799
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• 1994

Some components and antitumor effect of antler and fermented antler with Bacillus P-92 were determined. By fermenting the antler with Bacillus P-92, the amount of free amino acids, polypeptides and other compounds were increased. The free amino acid of the fermented antler was 6-fold higher than those of the untreated antler. Sarcoma 180 cells were intraperitoneally implanted into ICR mice to determine the effect of fermented antler and untreated antler on life span prolongation. The life span of ICR mouse treated with antler and fermented antler were prolonged to 24.4% and 39.2%(p<0.05), and survival rates were 22% and 33%, respectively. In addition, the induction of neutrophil was 2.3-fold and 3.4-fold, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1012-1017
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• 2010

Sewer Pipes are not being managed for twenty years after laying. So, The life span of sewer pipes is on the decrease. For solve the life span decrease of sewer pipes, correct checking of questions and measure preparation are necessary through investigation in sewer pipes. This research investigated on the state of sewer pipes in the housing and industrial sites through CCTV(closed-circuit television) and device of digitalized strain investigation. And, a result is as follows. A results of PE, PVC, GRP, CSP investigations were found of pipe-transformation state by earth pressure and external load.