• Women's Health Nursing
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• v.4 no.1
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• pp.5-35
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• 1998

This study attempted to determine the relation between the maternal role strain and their husbands' support in employed and nonemployed first-time mothers, and how it changed over time. A descriptive, longitudinal and comparative study design was conducted to collect and analyzed the data at three times(at 3-4days, at 4-6wks and at 3-month postpartum) regarding the change of maternal role strain and their husbands' support in employed and nonemployed first-time mothers. The subjects were 133 first-time mothers who delivered vaginally at K university hospital in Deagu, Korea from Dec., 1994 to Oct., 1995. Among these 58 were employed and 75 were nonemployed first-time mothers. This instruments used to data collection in this study were by Hobbs(1968 : The Difficulty Index for First-time Parents), Staffensmeier(1982: Transition Difficulty Measure), Tayer(1976: Emotional Support from Husband), Lee, Hae Kyoung(1992 : Physical Support from Husband). The analysis of data was done with SAS/PC program which included percentage, $x^2$-test, Pearson correlation, Repeated Measure ANOVA, Time Contrast Analysis and t-test. The results were as follows : 1. There was a significant negative correlation only at 3-4days(r=-.19, P=.0265) and at 4-6wks postpartum(r=-.18, P=.0392) between maternal role strain and husband's support of the first-time mothers. Thus, the more support from husband, the less maternal role strains the first-time mothers felt. Therefore, the 1st hypothesis that "the more husband's support the first-time mother felt at all the time of testing, the less maternal role strains they got" was partially supported at 3-days and 4-6 weeks postpartum. There was no correlation between maternal role strain and t husband's support of the employed first-time mothers at al testing times(at 3-4days postpartum : r=-.95, P=.9548, at 4-6wks postpartum : r=-.0960, P=.4733 and at 3-month postpartum : r=-.05, P=7306). On the contrary, the unemployed first-time mothers felt less maternal role strain when they received more support from their husband at 3-4 days postpartum(r=-.31, P=.0073) and at 4-6wks postpartum(r=-.23, P=.0490). 2. There was no difference of maternal role strain between two groups with regards to employment status(F=.97, P=.3270). But the maternal role strains of two groups were changed differently each other over time(F=3.89, P=.00234). Therefore, the 2nd hypothesis that "there was the difference in the maternal role strains with regard to employment status and over time" was rejected. 3. There was no difference in husband's support between the employed and the nonemployed first-time mothers(F=3.06, P=.0826). But there was a significant interaction between employment status and over time(F=3.64, P=.0267), so the support from husband of the employed and the unemployed first-time mothers was changed differently each other over time. The support from husband of the employed first-time mothers was lowered significantly and continuously at 4-6wks (F=5.20, P=.0263) and at 3-month postpartum(F=6.47, P=.0137) than at 3-4 days postpartum. On the contrary, there was no difference in change of husband's support of the employed first-time mothers between the 3-4 days and the 4-6wks postpartum(F=1.70, P=.1962) and between the 3-4 days and the 3-month postpartum(F=.21, P=.6513). Mean husband's support of the nonemployed first-time mothers was raised at 4-6wks postpartum than at 3-4 days postpartum but lowed at 3-month postpartum. The support form husband of both groups was tending downwards at 3-month postpartum than at 4-6wks postpartum, but the one between two groups was changed differently each other over time. The husband's support of the employed first-time mothers(M${\pm}$SD=64. 26${\pm}$8.63) was higher than the one of the nonemployed first-time mothers(M${\pm}$SD=59.16${\pm}$11.11) (t=-2.98, P=.0035), so the 3rd hypothesis that "there was the difference in the husband's support with regard to employment status and over time" was supported. On the basis of these conclusions, the following suggestion is proposed. This study examined the change and relationship between maternal role strain and husband's support in the employed and the nonemployed first-time mothers. So the further study regarding the comparison between the employed and the nonemployed multiparas is necessary.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.55-79
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• 2013

In this paper, we propose a hybrid genetic algorithm (HGA) approach to effectively solve the reverse logistics network with centralized centers (RLNCC). For the proposed HGA approach, genetic algorithm (GA) is used as a main algorithm. For implementing GA, a new bit-string representation scheme using 0 and 1 values is suggested, which can easily make initial population of GA. As genetic operators, the elitist strategy in enlarged sampling space developed by Gen and Chang (1997), a new two-point crossover operator, and a new random mutation operator are used for selection, crossover and mutation, respectively. For hybrid concept of GA, an iterative hill climbing method (IHCM) developed by Michalewicz (1994) is inserted into HGA search loop. The IHCM is one of local search techniques and precisely explores the space converged by GA search. The RLNCC is composed of collection centers, remanufacturing centers, redistribution centers, and secondary markets in reverse logistics networks. Of the centers and secondary markets, only one collection center, remanufacturing center, redistribution center, and secondary market should be opened in reverse logistics networks. Some assumptions are considered for effectively implementing the RLNCC The RLNCC is represented by a mixed integer programming (MIP) model using indexes, parameters and decision variables. The objective function of the MIP model is to minimize the total cost which is consisted of transportation cost, fixed cost, and handling cost. The transportation cost is obtained by transporting the returned products between each centers and secondary markets. The fixed cost is calculated by opening or closing decision at each center and secondary markets. That is, if there are three collection centers (the opening costs of collection center 1 2, and 3 are 10.5, 12.1, 8.9, respectively), and the collection center 1 is opened and the remainders are all closed, then the fixed cost is 10.5. The handling cost means the cost of treating the products returned from customers at each center and secondary markets which are opened at each RLNCC stage. The RLNCC is solved by the proposed HGA approach. In numerical experiment, the proposed HGA and a conventional competing approach is compared with each other using various measures of performance. For the conventional competing approach, the GA approach by Yun (2013) is used. The GA approach has not any local search technique such as the IHCM proposed the HGA approach. As measures of performance, CPU time, optimal solution, and optimal setting are used. Two types of the RLNCC with different numbers of customers, collection centers, remanufacturing centers, redistribution centers and secondary markets are presented for comparing the performances of the HGA and GA approaches. The MIP models using the two types of the RLNCC are programmed by Visual Basic Version 6.0, and the computer implementing environment is the IBM compatible PC with 3.06Ghz CPU speed and 1GB RAM on Windows XP. The parameters used in the HGA and GA approaches are that the total number of generations is 10,000, population size 20, crossover rate 0.5, mutation rate 0.1, and the search range for the IHCM is 2.0. Total 20 iterations are made for eliminating the randomness of the searches of the HGA and GA approaches. With performance comparisons, network representations by opening/closing decision, and convergence processes using two types of the RLNCCs, the experimental result shows that the HGA has significantly better performance in terms of the optimal solution than the GA, though the GA is slightly quicker than the HGA in terms of the CPU time. Finally, it has been proved that the proposed HGA approach is more efficient than conventional GA approach in two types of the RLNCC since the former has a GA search process as well as a local search process for additional search scheme, while the latter has a GA search process alone. For a future study, much more large-sized RLNCCs will be tested for robustness of our approach.