• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제16권4호
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• pp.76-91
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• 2017

The Area of a domestic railway station is designed based on the 4-step traffic demand forecasting model with the average daily passenger count as one of its parameter. However, nowadays, due to increasing rate of railway station's function, the non-passengers are increasing. In order to consider those non-passengers who aren't using trains, assumed volume are added to the average daily passenger count of station to estimate the area, but the criteria being applied has no concrete basis. Therefore, this study aimed to recalculate the increasing non-passenger rate based on actual survey data of station users in any type of railway station to obtain the optimum area. Subsequently, the the design area was performed through pedestrian simulation. According to the result of the simulation, it was found that the total space of the exciting railway stations can be reduced up to 45% and will still satisfy the level of service(LOS) requirement.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제37권4호
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• pp.705-716
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• 2017

As many environmental pollution problems have arisen, various studies related to the environmental evaluation have been carried out in the construction industry. However, there is no methodology for estimating the environmental load quickly for design alternatives of civil facilities in the design phase. This study aim to establish criteria of works information and designed parts which can efficiently estimate environmental loads of PSC beam bridge based on standard quantity at the early design phase. For this purpose, a detailed environmental loads database was constructed by performing Life Cycle Assessment (LCA) based on detailed design data of 25 bridges. In addition, major work with high impact on environmental load were selected, and the analysis of characteristics of environmental load according to the required materials and 8 impact categories were conducted. As a result, the superstructure accounted for 42.91%. In the superstructure, remicon of the material base and PSC beam work occupied 53.13% and 31.25%. In the substructure, remicon, rebar, and cement, which are material base, accounted for more than 93%. It is expected that this major work and material information for each part of bridge can be utilized in the construction of the model, which can estimate the approximate environmental load, reflecting the characteristics of the structure in the design phase.

• Journal of the Korean Geotechnical Society
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• 제27권7호
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• pp.17-33
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• 2011

Recently, the utilization of recycled aggregates for backfilling a power transmission pipeline trench has been considered due to the issues of eco-friendly construction and a lack of natural aggregate resource. It is important to identify the physical and thermal properties of domestic recycled aggregates that can be used as a backfill material. This paper evaluated thermal properties of concrete-based recycled aggregates with various particle size distributions. The thermal properties of the recycled aggregates and river sand provided by local vendors were measured using the transient hot wire method and the transient needle probe method after performing the standard compaction test. The needle probe method considerably overestimated the thermal resistivity of recycled aggregates especially at the dry of optimum water content because of experiencing disturbance while the needle probe is being inserted into the specimen. Similar to silica sand, the thermal resistivity of recycled aggregates decreased when the water content increased at a given dry density. Also, this paper evaluated some of the existing prediction models for the thermal resistivity of recycled aggregates with the experimental data, and developed a new prediction model for recycled aggregates. This study shows that recycled aggregates can be a promising backfill material substituting for natural aggregates when backfilling the power transmission pipeline trench.

• Journal of Families and Better Life
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• 제21권2호
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• pp.1-18
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• 2003

In recent years, Korean society has witnessed an increased interest in the observance of everyday life proprieties, building healthy families, and psychological well-being of family members. The main purpose of this research was to examine the relationships among the practice of everyday life proprieties, dynamics of family systems, and psychological well-being of Korean married couples. A self-report Questionnaire was used to collect data from married couples with a child over four-years-old who are currently residing in Seoul. 513 couples(1026 individuals) were used for the final data analysis. Statistical analyses were conducted using frequencies, percentages, means, standard deviations, Cronbach'α, Pearson correlation, paired t-test, factor analysis, and multiple regression. The findings of this study are as follows: First, the level of the practice of everyday life propriety was relatively high in both husbands and wives, and no significant gender difference was found in the level. Yet, there were some statistically significant differences in certain sub-dimensions. Wives showed a higher degree of performance in public decorum and social etiquette, whereas husbands exhibited a higher degree of performance in family decorum and communication manners. The family systems were highly dynamic, according to both husbands and wives, and there was no difference between husbands and wives. As for the sub-dimensions, the extent of communication was found to be higher among husbands than among wives. Psychological well-being was again relatively high for both husbands and wives, with husbands significantly higher than wives. Second, the findings indicate that the causal model did fit the data well, and that a myriad of background variables had direct and indirect impacts on psychological well-being, and these relationships were mediated by several variables in the sub-dimension of proprieties observance, family adaptability, and the degree of communication. The implication is that the practice of life propriety, an intervening variable, is crucial in improving psychological well-being of married couples. The findings of this research demonstrate that there are significant causal relationships among the practice of everyday life propriety, family systems dynamics, and psychological well-being. In addition, the observance of proprieties is shown to be a concept that can be used as an important predictor in the area of family resource management. Further research is needed to expand its focus on the practice of proprieties in the family resource management. More concrete and specialized family life education programs should be developed to help build healthy families. Lastly, the results indicate that proprieties education needs to be incorporated in family policies in order to promote the quality of family life.

• Journal of the Earthquake Engineering Society of Korea
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• 제8권6호통권40호
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• pp.55-66
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• 2004

Recently, many high-rise apartment buildings using the box system, composed of only reinforced concrete walls and slabs, have been constructed. In residential buildings such as apartments, vibrations occur from various sources and these vibrations transfer to neighboring residential units through walls and slabs. It is necessary to use a refined finite element model for an accurate vibration analysis of shear wall building structures. But it would take significant amount of computational time and memory if the entire building structure were subdivided into a finer mesh. Therefore, an efficient analytical method, which has only translational DOFs perpendicular to walls or slabs by the matrix condensation technique, is proposed in this study to obtain accurate results in significantly reduced computational time. If all of the DOFs except those perpendicular to walls or slabs in the shear wall structure eliminated using the matrix condensation technique at a time, the computational time for the matrix condensation would be significant. Thus, the modeling technique using super elements and substructuring technique is proposed to reduce the computational time for the matrix condensation. Dynamic analysis of 3-story and 5-story shear wall example structures were performed to verify the efficiency and accuracy of the proposed method. It was confirmed that the proposed method can provide the results with outstanding accuracy requiring significantly reduced computational time and memory.

• Journal of the Earthquake Engineering Society of Korea
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• 제15권2호
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• pp.43-51
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• 2011

Probabilistic seismic hazard analysis (PSHA), which can effectively apply inevitable uncertainties in seismic data, considers a number of seismotectonic models and attenuation equations. The calculated hazard by PSHA is generally a value dependent on peak ground acceleration (PGA) and expresses the value as an annual exceedance probability. To represent the uncertainty range of a hazard which has occurred using various seismic data, a hazard curve figure shows both a mean curve and percentile curves (15, 50, and 85). The percentile performs an important role in that it indicates the uncertainty range of the calculated hazard, could be calculated using various methods by the relation of the weight and hazard. This study using the weight accumulation method, the weighted hazard method, the maximum likelihood method, and the moment method, has calculated the percentile of the computed hazard by PSHA on the Shinuljin 1, 2 site. The calculated percentile using the weight accumulation method, the weighted hazard method, and the maximum likelihood method, have similar trends and represent the range of all computed hazards by PSHA. The calculated percentile using the moment method effectively showed the range of hazards at the source which includes a site. This study suggests the moment method as effective percentile calculation method considering the almost same mean hazard for the seismotectonic model and a source which includes a site.

• Korean Journal of Construction Engineering and Management
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• 제14권3호
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• pp.107-114
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• 2013

The interest in traditional Korean housing has greatly increasing in Korean housing market. However, it is difficult to wildly disseminate for a high construction cost reason. In order to effectively facilitate the Hanok construction, Korean government has initiated a project that develops a new style Korean housing, which meets the requirements of low cost and modernized life style. Cost of building is mainly affected by materials and construction methods. Hanok has some special commodities those significantly impact the cost. In order to effectively cut down the costs, well-organized planning for costs is very important. Also, improving the productivity by utilizing new materials and methods can result in cost down. In this context, this paper compared and analyzed two different types of Korean housing; one is a modernized Korean house which used new materials and methods, the other is a traditional Korean house which was build up by purely traditional methods. Productivity has also been compared and analyzed for 5 major commodities between two types of models. Based on these comparative data, effect of cost down by new model has been analyzed. As a result it is confirmed that by using the new materials and methods could highly effect to increasing productivity and cost down. Especially, the cost of Roofing have been more influenced by using new material while the Wood and Finishes have been influenced by new construction method. Construction cost of Foundation (Earthwork, Concrete, Masonry) and Openings were influenced both factors, changing of materials and methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제12권2호
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• pp.718-727
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• 2011

This research aims to empirically investigate into the relationship between venture entrepreneurs' social network and their social competence to utilize the network, which is known to help overcome the weaknesses of small-and-medium-sized ventures. An analysis was made of SEM set up with 211 entrepreneurs' responses, and the following are the findings from the analysis. First, venture entrepreneurs' networking ability has a significant, strong and positive effect on weak tie of their social network(${\beta}$=.527, C.R.=3.626), strong tie(${\beta}$=.594, C.R.=3.969), and the network centrality(${\beta}$=.418, C.R.=4.884). Second, their social astuteness also has a significant and positive effect on weak tie(${\beta}$=.192, C.R.=1.701), strong tie(${\beta}$=.269, C.R.=2.509) and the network centrality(${\beta}$=.228, p=2.283). Third, their interpersonal influence has a significant but negative effect only on strong tie(${\beta}$=-.264, C.R.=-1.862) and the network centrality(${\beta}$=-.394, C.R.=-2.914). Lastly, their apparent sincerity has no significant effect on the subordinate factors of social network. This research has not just empirically analyzed the relationship between the entrepreneurs' social network and their social competence. But also, results of the research provide practical and detailed information to entrepreneurs of small and medium ventures. Moreover, the research is significant in that it has suggested and empirically analyzed the concept of political competence, which is a concrete substance of social competence, and that it has offered theoretical foundations for future researches, which will tackle the issue of the entrepreneurs' competence in the sphere of entrepreneurship.

• Journal of the Korea institute for structural maintenance and inspection
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• 제14권2호
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• pp.67-74
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• 2010

A variation of temperature acting on a RC roof slab causes a change of stress in concrete since it expands during summer and is compressed during winter. This behavior repeats annually and makes an affection to the structural capacity of member for both serviceability and ultimate level. In this paper, a cyclic temperature loading variation is calculated by analyzing the weather data of Korea for 20 years. In addition, an experimental work is planned to find the long term effect of temperature variation. Six RC slab are made with same dimension. Test parameters are loading duration (10, 20, 30 year) and whether it has pre-damage or not. Observation of stiffness variations according to cyclic loading period shows that the serious stiffness drop happens after 10 year's cyclic loading at summer while after 30 year's loading at winter. From the fracture test about slabs damaged by long term cyclic loading, however, the capacity of member such as initial stiffness and maximum strength were not changed except yield strength according to the period of long term cyclic loading. The yield strength tends to decrease after 20 year's cyclic loading.

• Journal of Navigation and Port Research
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• 제37권6호
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• pp.727-732
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• 2013

This primary purpose of this study is to suggest strategies for developing the Gwangyagn region as a logistics city. In order to achieve such purpose, the following methodology is used. First, the literature survey on papers, related-organization's homepage, reports and journals related to Gwangyang Bay and Gwangyang port. Second, an pilot survey and field survey for suggesting SWOT analysis are carried out. Finally, questionnaire survey using a AHP analysis technique is distributed and analyzed. The strategies for developing as a logistics city are suggested as followings. First, ST strategy such as the development of the international hinterland logistics center related to the port logistics function is considered as the most important factor and followed by ST strategy, WT strategy and WO strategy. Second, creation of the revenue-creating logistics business model is to be considered as the most important factor and followed by development of the international hinterland logistics center related to the port logistics function, operation of the logistics center, creating high value-added of free trade area etc. For further research, more concrete and empirical study have to be carried out.