• Proceedings of the KSR Conference
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• 2001.10a
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• pp.240-246
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• 2001

The main objective of the study is to provide the criteria for determining the proper life cycle of rebuiled diesel-electric locomotive currently being operated in KNR. We predicted the most critical sections of the cast-iron bogie and tested the diesel-electric locomotive vehicle to measure dynamic stresses applied to the bogie. The fileld test of the diesel-electric locomotive estimated 9.90years based on the fatigue-life estimation when they are continuously used in the present operation condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.369-377
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• 2013

This paper deals with the state of charge(SOC) and life cycle evaluation algorithm for lead-acid battery, which is essential factor of the electric vehicle(EV) and the stabilization of renewable energy in the smart grid. In order to perform the effective operation of the lead-acid battery, SOC and life cycle evaluation algorithm is required. Specific gravity with the change of electrolyte temperature inside battery case should be obtained to evaluate the SOC of lead-acid battery, however it is difficult to measure the electrolyte temperature of sealed type lead-acid battery. To overcome this problem, this paper proposes the equation of thermal transmission to compensate internal temperature of the lead-acid battery. Also, it is difficult to exactly evaluate the life cycle of battery, depending on the operation conditions of lead-acid battery such as charging and discharging state, self discharging rate and environmental issue. In order to solve the problem, this paper presents the concept for gravity accumulation of charge and discharge cycle, which is the value converted at $20^{\circ}C$. By using the proposed algorithm, this paper propose the test device based on the Labview software. The simulation results show that it is a practical tool for the maintenance of lead-acid battery in the field of industry.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.4
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• pp.33-42
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• 2007

This paper describes the state-of-the art research activities on seismic isolation systems for improving the seismic capacities of the bridges in Korea. Though Korea is located in a region of low-to-moderate seismicity, the construction of seismic isolation systems has increased rapidly. The application of seismic isolation system has become popular worldwide because of its stable behavior and economical construction especially for bridge structures. Since optimal reliability level of isolated bridges can be determined as the one that provides the highest net life-cycle benefit to society, or the minimum Life-Cycle Cost (LCC), an optimal design procedure based on minimum LCC concept is more expedient for the design of seismically isolated bridges in areas of low-to-moderate seismicty. To verify the adequacy of the new design concept based on the LCC minimization, experimental studies on seismically isolated bridge are introduced as well, which include pseudo-dynamic test of scaled pier and dynamic field test of full-scale. With the application of seismic isolation systems, many kinds of dampers to improve the seismic capacity of structure are also applied not only to new bridges but also to existing bridges.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.13-16
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• 2005

Generally, as corrosive protection processing of a steel structure, zinc galvanizing and heavy duty coating paint are applied. However, zinc galvanizing has the difficulty of restriction of a size, or on-site construction. Moreover, heavy duty coating paint has a problem with many administrative and maintenance expenses with short problem of adhesion, corrosion generating of a damage portion, and maintenance management cycle. In this study, a salt water spray test, CASS test, and the electrochemistry examination were carried out for the thermal metal spray method of construction for corrosive protection performance evaluation. Moreover, the corrosive protection life of a thermal metal spray method of construction was quantitatively calculated on the basis of this experiment. in consideration of LCC, the economical efficiency of a general corrosive protection method of construction and a thermal metal corrosive protection method of construction was compared. Consequently, although initial construction expense was estimated 16 to $30\%$ high, as for a thermal metal spray method of construction, it turns out that the administrative and maintenance expenses for 100 years became cheap 9.3 to 13 or more times.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1708-1711
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• 2007

This paper presents high cycle fatigue properties of an Al-3%Ti thin film, used in a RF (radio-frequency) MEMS switch for a mobile phone and also describes new test method for obtaining static and dynamic characteristics of thin film and reliability evaluation method on MEMS device with thin film developed by authors. Durability should be ensured for such devices under cycling load. Therefore, with the proposed specimen and test procedure, tensile and fatigue tests were performed to obtain mechanical and fatigue properties. The specimen was made with dimensions of $1000{\mu}m$ long, $1.0{\mu}m$ thickness, and 3 kinds of width, 50, 100 and $150{\mu}m$. High cycle fatigue tests for each width were also performed, from which the fatigue strength coefficient and the fatigue strength exponent were found to be 193MPa and .0.02319 for $50{\mu}m$, 181MPa and -0.02001 for $100{\mu}m$, and 164MPa and -0.01322 for $150{\mu}m$, respectively. We found that the narrower specimen is, the longer fatigue life of Al-3%Ti is and the wider specimen is, the more susceptible to stress level fatigue life of Al-3%Ti was.

• Korean Journal of Community Nutrition
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• v.7 no.1
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• pp.130-140
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• 2002

The purpose of this study was to examine the customer’s perception of the importance of restaurant quality by using a developed SERVQUAL model. In particular, it was intended to provide the basic information for nutrition education for family’s eating out. the data were collected through the survey over 440 families who have lived around the apartments in Kyongju and Seoul. The structure questionnaire included 35 items evaluating the quality of restaurants, adapting SERVQUAL model and adding other factors related to restaurant and the general characteristics of the families. The data were analyzed using SPSS 10.0 WIN program for descriptive analysis, a chi-square test and Pearson’s correlation test. The major results were as follows: From the factor analysis, the 35 items related to the quality of restaurant have been categorized into 10 factors, ie., ‘Health’, ‘Reliability’, ‘Employee’, ‘Food’, ‘Facilities’, ‘Product’, ‘Empathy’, ‘Access’, ‘Comfort’, and ‘Safety’. From the analysis of the correlation between family life cycle of four steps and 10 factors, four factors such as ‘Health’, ‘Facilities’ (p<0.001), ‘Comfort’ (p<0.01) and ‘Product’ (p<0.05) showed statistical significance. ‘Health’ and ‘Product’ factors marked the highest score in the family with senior couple live without children or single, but the lowest score in the family with young couple without children or single. ‘Facilities’ and ‘Comfort’ factors showed the highest scores in the family with under elementary school children, and the lowest scores in the family with over elementary school children.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.81-90
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• 2002

More than 50% of defects and errors in the software development projects are related to the requirements[14]. But the development methodologies can not provide enough supports to the requirements management and changes. In the real world, the requirements keep changing as the requirements at the early development phase are usually incomplete, the developer′s understanding of the problem will be constantly changed during the software process, and new requirements may emerge with the organizational and environmental changes. In this paper, a requirements management process that can be integrated into the development methodologies is proposed to extend the requirements management over the whole development life-cycle and to support the requirements changes at the design/implementation/test phases. To evaluate the proposed process, it was compared to the existing requirements managements processes and models, and examined through a integration test with a widely used development methodology "MaRMI" to show the expected improvements at each development phase.

• Journal of Families and Better Life
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• v.2 no.1
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• pp.35-55
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• 1984

This study aims to present basic data for a reasonable home management through investigating the change of home economy conditions incidental to the family life cycle, also through analyzing the effect of socio-anthropological variables on the family-life cycle. The data investigation using the questionnaires method was conducted on housewives in Seoul as the central census tract. Housewives as the subject of investigation were chosen by the method of the purpose-sampling in consideration of the regional differences and the socio-economical strata. Nine hundred and forty questionnaires were distributed to housewives but seven hundred questionnaires were collected. Only five hundred and ten questionnaires of them were analyzed in this study. The frequency and the percentage of collected data, first of all, were founded in order to grasp the general characteristics of the subject of investigation. To classify the stage of family life cycle, the correlations of the classifying factors among each group were examined x2 Test and One-Way ANOVA were applied to explore the differences among each stage of the change of household-economy. And the effect of socio-anthropological variables on the change of household- economy was analyzed by Two-way ANOVA. the conclusions derived from the results of this study are as follows; 1) The marriage-period and the educational conditions of the first child were selected as the classifying factors through analyzing correlation among the age, the marriage-period and the educational conditions of their children. As a result of this analysis, the family life cycle were classified into seven stages: Stage 1; Establishment Stage 2; Preschool family Stage 3; Elementary school family stage 6; Adult period family Stage7; Marriage period family . 2) The change of household economy incidental to the progress of family life cycle has a significant differences in all of variables (except the other member of family's income) Stage 1; Though the husband's income and the income from property are on a low level, the total income is on a high level due to the housewife's income. Stage 2; The total income is on a low level owing to the decrease of house wife's income, though the husband's income keep growing. Stage 3; Owing to the increase of husband's income, the cost of living as well as the total income keeps growing but the savings are on the decrease. Stage 4; Compared with Stage 3, the total income tends to be on a low level but the living expenses are on the increase. Stage 5; The husband's income is on the highest level in the stages of family life cycle. The total income and the living expenses are on a high level. Stage 6; The income of husband and housewife are on the remarkable decrease but the children's income is on the increase. Stage 7; Owing to the increase of the children's income and the income from property, the total income is on the highest level in the stages of family life cycle. 3) Considering the effect of socio-anthropological variables on the conditions of household-economy, family system has an significant effect on children's income. the husband's occupation exerts a significant effect upon the housewife's and children's income. The husband's schooling exercises an effect upon the children's income. S.E.S has a important effect on the income of husband, housewife and children. From the above results, it is found that the change of household-economy conditions is incidental to the progress of family life cycle. Therefore, a suitable measure to cope with the desire of family and the conditions of household-economy should be prepared, in order to carry on a reasonable home management.

• Journal of Families and Better Life
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• v.21 no.3
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• pp.133-146
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• 2003

The purpose of this study was to analyze the need for family life welfare service program, and to develope the program for managing in the Community Centers. The survey was conducted by interviewing 356 users and 360 non-users of Community Center, total 716 persons living in Daegu City, from October 8 to October 30 in 2002. The data were analyzed by the SPSS PC+ program applying t-test and ANOVA. The results were as follows : First, overall the needs for family life welfare service program, consisting of education program, facilities management and counseling program, and event program, was higher than 3.7 points. The needs level for event program was a little higher than other two programs. Second, the level of needs for family life welfare service program differed between user group and non-user group of the Community Centers. Third, the level of needs for family life welfare service program varied according to the demographic variables, such as sex, age, marital status, family life cycle, education level, vocation, monthly average income and housing type. Finally, Based on the results of needs analysis, 11 education programs, 4 facilities management and counseling programs and 5 event programs were developed for family life welfare service program. These programs developed in this study could be applied to diverse groups classified by age, social class, family life cycle of citizens. Also the programs should be applied in terms of family unit, as well as individual base to enhance the function of family life.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.61-66
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• 2004

In this paper, the effect of underfill packages was investigated by numerical approach and experimental test. Reliability improvement was the main issue in the package technology. BGA, CSP and small-sized packages, have problems due to concentration of the stress in solder joints. One of the latest technologies to overcome is underfill encapsulant. Mainly, it is noticed the effect of the underfill in the packages. The predicted thermal fatigue lifes are performed by Coffin-Manson's equation with ANSYS (v.5.62). Also, thermal cycle test during from 218K to 423K was included. Finally we could find that underfill greatly reduce the concentration stress in solder joint, thus the fatigue life was improved than without underfill.