• Journal of Families and Better Life
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• v.5 no.2
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• pp.45-64
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• 1987

In this study the phenomenon of commodity substitution of housework is approach in the contexts of economic system, patriachal family system and housework-related human resources. the objectives of this study are as follows: (1) To measure the level of commodity substitution of housework in large cities. (2)To investigate the factors influencing commodity substitution of housework. The samples were composed of 982 housewives dwelling in 6 large cities including Seoul. The statistics used for data analysis were frequency distribution, percetile. multiple regression analysis. The major findings are the following; (1) When the housework was divided into two subdomains , in the domain of food the purchase level was for below average while in the domain of clothes, the level was quite higher than average. This result hows that commodity substitution has become more common in the domain of clothes by mass production of clothes on a commercial scale. (2) the level of commodity substitution of housework was influenced by the family attribute variables such as housewife's age, family income. housewife's education, family types, housewife's brought-up regions, presence of sewing machine, employment status of housewife, by one patriarchal norm variable such as home-orientedness, and by tow human resource variables such as importance of housework and household tasks performance competnecy. Among variables house wife's age was the most influential one and such variables as family income, housewife's education, household task performance competency, importance of housework, and home-orientedness were also important. Considering that the influence of home-orientedness demonstrates the importance of patriarchy and that importance of housework and that performance competency also are determined by the patriarchal variables such as sex-role attitude and home-orientedness, we can conclude that Hartmann's theoretical approach with which the changes of housework were explained in the two contexts of economic system and family system is applied to the changes of housework in Korea.

• Economic and Environmental Geology
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• v.13 no.2
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• pp.69-79
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• 1980

Granitic rocks, from the Eonyang and the northwestern part of Ulsan area, were mainly studied from the petrochemical point of view. From field work, microscopic observation and the result of K-Ar ages, these granitic rocks are divided into six rock types of a, b, c, d, e and e', of which modal composition are given. Type a, c, e and e' are mainly granodiorite, type b is adamellite, and type d is granodiorite, adamellite and others (porphyritic rock, porphyry and felsitic rocks). Bulk chemical analyses of 22 samples of the granitic rocks are given. The petrographical and petrochemical characteristics of these rocks are discussed briefly. In the petrochemical compositions with their characteristic variation trends of several oxides and norm Or-Ab-An triangular diagram, type a, b and c show some similarity to that of San-yo granite of Japan and younger granite of Ogcheon geosynclinal zone, and then, type e and e', to San-in granite of Japan. But, some of granitic rock samples of type d are similar to San-yo granite and the others of type d to San-in granite because this type is composed of porphyritic rock, porphyry and felsitic rocks. According to the result of K-Ar ages (1976, Lee et al.) of rock samples from type a, b and care Cretaceous, on the otherwise, type d, e and e', are Tertiary granitic rocks. Judging from these evidences, granitic rocks in the area are correlated to the Cretaceous and Tertiary granitic rocks in the, southwestern Japan, that is, type a, band c are correlated to San-yo granite, and type d, e and e' to San-in granite.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1234-1243
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• 1992

A systematic procedure to design fuzzy PID controllers is developed in this paper. The concept of local fuzzy control cell is proposed by introducing both an adequate global control rule and membership functions to simplify a fuzzy logic controller. Fuzzy decision is made by using algebraic product and parallel firing arithematic mean, and a defuzzification strategy is adopted for improving the computational efficiency based on nonfuzzy micro-processor. A direct method, transforming the typical output of quasi-linear fuzzy operator to the digital compensator of PID form, is also proposed. Finally, the proposed algorithm is applied to an DC-servo motor. It is found that this algorithm is systematic and robust through computer simulations and implementation of controller using Intel 8097 micro-processor.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.325-333
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• 2001

The purpose of this study was to find out the effects of hallux valgus on the ankle plantarflexor and dorsiflexor peak torque, on the total work, on the average power, and on the Peak torque of plantarflexor to dorsiflexor ratio values. Isokinetic ankle plantarflexor and dorsiflexor strength was evaluated in 30 women(control: 15, hallux valgus: 15) by Cybex NORM System. Test data was gathered in the right ankle at a speed of 60/sec, 90/sec, 120/sec in the control group and the hallux valgus group. Statistical analysis was performed using SPSS 10.0 for windows software. Mean and standard deviations were measured and calculated for the General characterristic of subjects. A paired t-test was used to examine the differnces in the means for the ankle plantarflexor and dorsiflexor between two groups. Pearson coefficient correlation was used to examine the correlation of the hallux valgus and the peak torque. Analysis of variance indicated that isokinetic values of the control group were greater than the hallux valgus group(p<.05, p<.01).

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.201-208
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• 2012

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, $71.38{\pm}2.79$ yrs) and a control group (CG: n=5, $73.4{\pm}5.94$), In all subjects, maximum isometric and isokinetic muscle strength of knee flexion and extension were measured using an isokinetic dynamometer (Cybex(R) Humac Norm Testing & Rehabilitation System, USA). Quadriceps muscle group CSA were measured using MRI (Philps, Intera 1.5 T, NE Netherlands). The results of this study showed that post-intervention isometric knee extension peak torque value were higher than pre-intervention measures in the EG. However, the EG did not show improvement in quadriceps muscle group CSA, Also, no differences in the shift of optimal knee joint angle were observed between pre and post-intervention exercise. Outdoor leg extension exercise showed small increases in muscle strength in comparison to other resistance training exercises. The results of this study suggest that because outdoor leg extension exercise machines lack a progressive loading mechanism, significant increases in muscle strength may not be obtained.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.161-170
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• 2007

The purpose of this study is to find the solution that overcomes the existing assumption of symmetric cost functions in multi-class assignment. In the assignment problem, the assumption of a symmetric cost function means that the link cost is determined by each unique mode and is not affected by any other modes. In this study, the authors have applied a diagonalized algorithm and a heuristic model based on column generation to a multi-class assignment model and analyzed the result. Through the study, the authors found that the diagonalized algorithm produces equilibrium solutions by the initial convergence condition. In contrast to the diagonalized algorithm, the column generation algorithm has improved the solution model to overcome the problem of equilibrium solutions in the diagonalized algorithm.

• Informatization Policy
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• v.18 no.1
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• pp.55-72
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• 2011

This study explores the causes of online helping behavior. This study tests the effects of various explanatory factors on the basis of previous studies on helping behavior. These factors include social demographic, situational, motivational, and social capital factors. According to the survey of 475 university students living in Seoul in 2010, age and religion have significant effects on online helping behavior. In addition, the perceived helping opportunity, time and effort cost to help, and social capital factor have significant effects on online helping behavior. Results reveal that the effect of social capital factor is the largest among other variables. However, it is shown that the effects of benefit from helping, empathy, and personal norm are not statistically significant. It is also revealed that the effect of social capital factor is important across all types of online helping behavior except information helping. The policy implications are discussed.

• The Journal of Art Theory & Practice
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• no.9
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• pp.195-215
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• 2010

Alberti's De re aedificatoria is the earliest case in the history of Italian Renaissance architectural treatises dealing with recovery of antiquity through textual and archaeological pursuits. The key source of the Renaissance theoreticians was Vitruvius' De architectura. However, Alberti was keenly aware of inaccuracy and Hellenization of Latinity in this classical text, and tried to compensate them in his own treatise. Furthermore he claimed a reformed discipline of the architects as well as the patrons, and prescribed how future buildings and cities should be built, based on the proper authority of ancient architecture in proper and intelligible Latin. Such an adaptation of classical usage in order to reestablish a modern norm preceded in his earlier work Momus, a satire on the contemporary Italian society of his own by following the model of Lucian. Alberti's suggestion of proper government in Momus's phrase was expanded in De re aedificatoria, for he consider the buildings are subject to the rules of morality and public interests. He proclaimed that the nature of beauty is the reasoned harmony of every part within a body, and architectural beauty also lies on the harmonized arrangement of all the elements within an individual building and of all individual buildings and facilities within a city. For the architects to execute this task, he formulated the concept of lineanenta, the form derived from the mind in order to prescribe the proper place, numbers, scale, and orders for whole building structure. It is the future oriented city-plans and building designs to serve the public interest and the good of all the individual citizens who make up the City-State that Alberti pursued in his treatise.

• Proceedings of the Safety Management and Science Conference
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• 2005.11a
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• pp.569-579
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• 2005

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. 'But, long-term & short-term interest rate is affected by Hanbo & Kia's bankruptcy, continuous large scale coporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge fund were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.79-88
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• 1998

Till now there are several rendering models for water and simulating other fluids and their dynamics. Especially in order to generate a curved surface of flexible objects such as liquid and snow, the implicit metaball formulation is widely used in favor of its simplicity and flexibility. This paper proposes one excellent method for generating water droplets, which would be deformed in gravitation field. In previous works, a water droplet was simply represented by approximated curved surfaces of a symmetric metaball. Thus the final result of the rendered water droplet was far from a realistic droplet, because they do not consider the gravitational effect in droplets. We propose a new metaball model for rendering water droplets placed on an arbitrary surface considering the gravitation and friction between droplet and plate. Our new metaball model uses a new vector field isosurface function to control the basic scalar metaball with respect to the norm of gravitational force. In several experiments, we could render a photo-realistic water droplets with natural-looking shadows by applying ray-tracing.