• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.155-167
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• 1991

There have been many cooperative meetings from the past in our country. "Kye" is the most popular and current exisiting meeting of them in our society. Therefore, study of "Kye" at this point will be useful for life, attitude, value in urban area. The concret purposes of this study are to investigate: (1) Participationg rate of the city housewives' "Key" meeting. (2) Purpose of the city housewives' "Kye" meeting. (3) The order of the most influential variable among the socio-economic variables, the family life cycle variables, and the residence variables on the city housewives' "Kye" meeting. For the purpose of this main study, 600 questionnaires were distributed to housewives living in Seoul and collected during the six months, from November, 1989 to April, 1990. And method of data analysis for this survey was Multiple Regression. The major results are as follows: (1) Participating rate of city housewives' "Kye" meeting is 52.2%. (2) Purpose of city housewives' "Kye" meeting is in the order of "for saving", "for friendly gatherings", "for commodity purchase". The order of the most influential factor (3) among the socio-economic variables is the age of respondents (β:.187), the average income of all house members(β:.177), and the schooling years (β:-.147), (4) among the family life cycle variables is the family life cycle(β:.261), number of children(β:-.212), (5) among the residence variables is the duration of current residence(β:.221), kind of house(β:.118). Comparing the past studies, the purpose of "Key" meetings has changed from the family centered events method such as worship or marriage of family members to out of the family and friends centered events such as social gatherings among the people in urban community.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.84-93
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• 2021

Each equipment has a durable life. The state of the equipment may change or fail until it is introduced, operated and disposed of. It is difficult for each organization to have a significant amount of these equipment and to understand each issue. Therefore, systematic life cycle management of equipment is more necessary than just for inventory purposes. In this paper, we design and implement an integrated management system for information assets. If it is an environment that can use the Internet based on the web, it can easily and easily access computerized information resource data through PCs, tablets, and smartphones. In addition, an integrated management system was established to limit the functions of higher and lower institutions through centralized management and user-level empowerment methods and to understand the overall status of resources.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.65-76
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• 2013

We investigated the gametogenic cycle and spawning seasons of the male Chlamys (Azumapecten) farreri nipponensis by qualitative and quantitative analyses, and also the size at 50% of group sexual maturity was calculated by the data of first sexual maturity. In this study, the male gametogenic cycle of this species by qualitative analysis was divided into five successive stages: early active stage (January to March), late active stage (March to April), ripe stage (April to August), partially spawned stage (July to September), and spent/inactive stage (August to January). The male gametogenic cycle showed similar patterns with monthly changes in the gonadosomatic index and condition index. Particularly, spawning in male scallop occurred once a year from July to September, unlike the spawning period of this species (from June to August) reported by the previous researchers. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by spermatogenic stages to the testis areas in males showed a maximum in June, and then sharply dropped from July to September, 2006. From these data, it is apparent that the spawning season of C. (A.) farreri nipponensis occurred once per year from July to early September, indicating a unimodal gametogenic cycle during the year. Shell heights at 50% of group sexual maturity (RM50) fitted to an exponential equation were estimated to be 49.90 mm in males (considered to be one year old), and it was 100% for male scallops over 61.0 mm (considered to be two years old).

• Korean Journal of Construction Engineering and Management
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• v.17 no.6
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• pp.40-52
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• 2016

In the 1960s and 1970s when Korea experienced rapid economic growth, a considerable number of buildings were constructed in the country. And since 2000, a large number of sizable and complex buildings have been being built. Specifically, as the operation and maintenance cost alone accounts for 85% of the life cycle cost of a building, efficient Facility Management (FM) is required. However, data needed in the operation and maintenance phase are not sufficiently exchangeable with data created in other phases like the planning, design and construction phases. The upper phase has higher value of data but data exchange rate is low, resulting in inefficiency. To this end, this research derived major business functions for facility management: three categories and 19 detailed functions in classification from owner's perspective. Based on the derived items, this research proposes a methodology to evaluate the 'FM Workload', 'Facility Management (FM) Data', and 'FM Data Created in Engineering and Construction Phases' thereby analyzing plans for efficient operation and maintenance. The applicability of proposed methodology was tested by examining real-world cases of public and private companies.

• International Journal of Railway
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• v.5 no.1
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• pp.1-9
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• 2012

Reliability means that a product maintains its initial quality and performance at a certain period of time (time, distance, cycle etc) under given condition without failure. The given conditions include both environmental condition and operating condition. Environmental condition means a common natural environment such as temperature, humidity, vibration, and working condition means an artificial environment such as voltage, current load, place for installment, and hours of use, which occurs during the life of the product. In the field of railway vehicles, it is mandatory to use a part with the proved reliability as the extension of the life of vehicle become highly necessary. But the reliable assessment method for the reliability of the part is insufficient. If the reliability of the railway vehicle parts could be assessed by using the field data, the reliability of the entire system could also be evaluated reliably. In this study, life span of micro-switch for master controller is analyzed and prediction is performed based on its field data given by an operator considering the special circumstances of railway vehicles such as the operation of a large number of trains on the same line.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.384-389
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• 2006

The needs for Light Railroad Transit(LRT) have been increased due to the heavy traffic congestions in large cities like Seoul, Korea. Korean government is seeking the LRT system development (including planning, designing, construction, and maintenance and operations) in terms of public-private-partnership (PPP). At the private sector side, it is crucial to estimate the life cycle cost (LCC) to project the cash flow during the O&M period. Since the most construction and O&M cost of LRT project is at the bridge construction, a cost analysis model and a cost breakdown structures (CBS) on LRT bridges are discussed through in depth literature reviews. Construction and maintenance cost of bridges are collected and analyzed. LCC is analyzed by types of bridge superstructures and historical data of repair and rehabilitation (R&R) is investigated. There have been scarce number of LCC analysis on railway bridges. This research delivers a well-defined CBS and maintenance cost data, which will be a great benefit to the systematic maintenance strategy development for railroad bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.110-121
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• 2016

In the decision-making, such as selection of structure, construction method, or time and scheme of maintenance, the evaluation of life-cycle cost(LCC) is of great importance. The maintenance cost occupy a large portion of the LCC of the railway track as well as the initial construction cost. Futhermore, the proportion of the maintenance cost is much higher in the ballasted track. Thus, the importance of the LCC evaluation is higher than in any other engineering structures. In this study, a LCC model that can consider various design parameters such as the type of track structure, annual traffic volume, axle load, train speed, and proportion of curve sections and engineering structures has been developed. Fundamental data for calculating costs also have been presented. Based on the model and data proposed, the trends in the variation of LCC according to the design parameters were examined and the most important design parameters in the LCC analysis of railway track were investigated. The results show that the proportion of renewal and operational costs is much higher in the ballasted track than in the concrete track, and the annual traffic volume and ballast taming period are most significant factors on the LCC of the ballasted track. On the contrary, it is revealed that the proportion of the initial construction costs in the concrete track is much higher, and the LCC of the concrete track is less sensitive to the traffic volume, train speed, and axle load.

• Explosives and Blasting
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• v.41 no.4
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• pp.9-16
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• 2023

To compare the global warming impact of the TBM and NATM method, which are representative tunnel excavation methods, a life cycle assessment was performed for each method. Life cycle assessment should compare the sum of carbon emissions by considering the pre-manufacturing stage, product manufacturing stage, usage stage, and disposal stage. However, access to TBM (Tunnel Boring Machine) manufacturing and disposal data is limited, so I had no choice but to focus on the analysis for the usage stage. In general, carbon emissions during the pre-product manufacturing stage and product manufacturing stage often exceed 90% of carbon emissions throughout the entire process. Therefore, since it is difficult to achieve the analysis goal only by comparing the usage stage, the analysis scope was expanded, and carbon emissions for the process were calculated for the NATM method with access to manufacturing data. As a result of comparing the relative impact on global warming, the carbon emissions of the TBM method were found to be higher than those of the NATM method even though TBM method was only considered for the usage stage. So there it is, the NATM method can be seen as environmentally friendly in the future when considering the impact of climate change (global warming), which has recently attracted attention among environmental impact fields.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.384-389
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• 2008

An accelerated fatigue test is essentially required to maintain the reliability of the actual structure of KTX under operation conditions. However, actual fatigue life cannot be obtained if specimens are not adequate to the conventional fatigue test. Moreover component maker did not provide data of loading stress (S) - cycles at the failure (N). In this study, we suggest a prediction method of the S-N curve for establishing an accelerating test under various load levels. Load history was acquired from the field tests. A Rainflow method was used on the cycle counting of the field load data, and then, an S-N curve was obtained through the iteration process under the condition that the damage index satisfies to 1 in the Miner's rule.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.140-150
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• 2018

For the estimation of greenhouse gas dynamics in forests, it is useful to use a model which simulates both carbon (C) and nitrogen (N) cycle simultaneously. A forest C model, called FBDC, was developed and validated in Korea. However, studies on development of forest N model are insufficient. This study aimed to suggest a development process of a forest C and N model. We analyzed the general features, structures, ecological processes, input data, output data, and methods of integrating C and N cycles of the VISIT, Biome-BGC, Forest-DNDC, and O-CN. The structure and features of the FBDC were also analyzed. The VISIT was developed by integrating forest C model with a N cycle module, and the new model also could be designed by combining the FBDC with a N cycle module. The VISIT and Forest-DNDC could estimate soil $N_2O$ emissions, and the integrated model should include the processes shared by these models. Especially, the overseas models linked C and N cycles based on N absorption, C absorption, and decomposition of dead organic matter. Therefore, the integration of the FBDC with N cycle module should apply this linkage of structures between C and N cycles. Climate, soil texture, and species distribution data, which are essential for the model development, were available in Korea. However, parameter data associated with N cycle and validation data for soil $N_2O$ emissions need to be obtained by field studies.