• Korean Journal of Construction Engineering and Management
• /
• v.5 no.1 s.17
• /
• pp.99-106
• /
• 2004

Efficiency and efficient management on maintenance/repair/operation (MRO) phase is getting important with advance in technologies and complex functionalities of building and facility, Using software systems as well as advanced hardware systems in MRO area is spreading along with this trend to take advantage of information technology. Information of building and facility for MRO phase is derived from engineering/procurement/construction (EPC) phase. But most current commercial software systems in EPC and MRO are focusing on their own phase, which arise lack of consistency of information from EPC to MRO phase. But, the information system now used at the MRO phase stop flowing the building and the facilities information and then newly create. Moreover, from an asset management point of view, asset particulars such as the structures and equipments are different the value fluctuation. In order to reflect these information rationally, the construction costs are correctly distributed and the initial price of the asset particulars have to be estimated. In this study, develop the information model which can apply the cost information at the EPC phase to the MRO phase.

• Korean Journal of Remote Sensing
• /
• v.34 no.2_1
• /
• pp.179-190
• /
• 2018

The purpose of this study is an analysis of the risk of soil erosion before and after the maintenance of riparian area using the Revised Universal Soil Loss Equation (RUSLE) model based on GIS and digitizing data. To analysis of soil erosion loss in the study area, land cover maps, topographical maps, soil maps, precipitation and other data were used. After digitizing the riparian area of the Geumhogang, the area is divided into administrative district units, respectively. Amount of soil loss was classified into 5 class according to the degree of loss. Totally, 1 and 5 class were decreased, and 2-4 class were increased. Daegu and Yeongcheon decreased the area of 5 class, and Gyeongsan did not have area of 5 class. The reason for this is thought to be the decrease of the 5 class area due to the park construction, expansion of artificial facilities, and reduction of agricultural land. Simplification of riverside for river dredging and park construction has increased the flow rate of the riverside and it is considered that the amount of soil erosion has increased.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.8
• /
• pp.478-488
• /
• 2017

Stormwater filtration is widely used for the urban runoff treatment. However, intensive maintenance and lack of information about the performance have resulted in an increased need of proper evaluation. In this study, the performance of an upflow stormwater runoff filtration system, consisting of a supporting unit and a filtration unit filled with a ceramic media, was investigated. The maximum head loss increase was about 3 cm under the suspended solid (SS) load of $30kg/m^2$ and the SS removal was more than 96%, when the filtration velocity was 20-40 m/h. The head loss and the porosity of the media can successfully be described by a power model. It was confirmed that the a significant amount of SS can effectively be removed at supporting unit, minimizing SS load to the filter media bed. Several backwashing strategies have been tested to establish the optimum condition. It was found that the stagnant water discharge is important to minimize the SS release immediately after backwashing. Also, the filter bed loaded with $400-450kg/m^2$ SS can almost completely be washed to reduce the head loss to the that of empty bed. The results in this study indicate that the upflow ceramic media filter is an excellent alternative to stormwater treatment, with high SS removal and long lifespan.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.516-522
• /
• 2020

Water trees can cause considerable damage to the performance of underground cables. Theymay formwithin the dielectric used in buried or water-immersed high voltage cables. They grow in a bush-like or tree-like form, often taking decades before causing damage to a cable's performance. They are usually found on very old underground cables, often in an inaccessible place. It is costly and time-consuming to detect watertrees in underground cables. Tree detection technology, including mathematical modeling,can reduce the maintenance cost and time necessary for detecting these trees.To simulate detection of water trees in this study, a mathematical model ofan XLPE cable and a water tree were developed. The complex water tree structure was simplified, based on two identified patterns of aventedtree. A Matlab simulation was performed to calculate and analyze the capacitance and resistance of a cable insulation layer,based on growth of a watertree. Capacitance size increased about 0.025×10^-13[Farads/mm] compared to normal when the tree area of the cable was advanced to 95% of the insulation layer. The resistance value decreased by about 0.5×10¹⁶[ohm/m]. These changesand changesshowninaBurkes paper physical modeling simulation are similar.The value of mathematical modeling for detecting water trees and damage to underground cables has been demonstrated.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.1-21
• /
• 2020

The domestic abandoned mines are generating subsidence and it is difficult to predict this subsidence and evaluate the risk. The study of the subsidence risk evaluation using the existing numerical analysis only applies the integrative property to the geological structure and ground condition, and analyzes the goaf peripheral plastic domain. Also, there is a realistic limit that only restricted materials can be apprehended in securing the input information, which leads to the low reliability of the numerical analysis result. In this study, 2-dimensional modeling was performed by applying the field geological structure and ground information targeting abandoned mine where the subsidence occurred. Also, the analysis model was revised by repeating the numerical analysis for the difference between the real subsidence ground information and the analysis result to be minimized by modifying the ground property. This revision was automated by applying the optimization technique and the gradational optimal design method dividing multiple ground properties was developed.

• Korean Journal of Adult Nursing
• /
• v.12 no.1
• /
• pp.40-51
• /
• 2000

Purpose : This study was carried out to identify the factor of decisional balance for exercise. This was composed of a set of variables at the level of decision making when the elderly decide to do exercise. It was used to classify and identify the characteristics of the stages of change for exercise to which the elderly belong, and was used to identify the variables of decisional balance which influence the stage of change for exercise in the elderly. Methods : Convenient samples of 198 subjects over age 60 in Seoul( mean age=70) were selected from community living, mentally competant older adults and the data was collected from April 1, 1999 to May 31, 1999. The research instrument was the Decisional Balance Measure for Exercise(Marcus & Owen., 1992), Stage of Change Measure(Marcus et al,1992). The data was analyzed by SAS Program. Results: 1. According to stage of change measure, without missing data,191 subjects were distributed in each stage of change for exercise : 50 subjects(26.1%), 7 subjects (3.6%), 52 subjects(27.2%), 4 subjects(2%), and 78(40.8%) belonged to the precontemplation stage, contemplation stage, preparation stage, action stage and maintenace stage. 2. Factor analysis identified 3 factors of decisional balance as appropriate factors for exercise of the elderly and named by researchers; 1)'Perceived Physical-psychological benefit', 2)'Perceived Physical-psychological burden', and 3)'Perceived time burden'. 3. The analysis of variance showed that the two components Perceived Physical - psychological benefit(F=45.95, P=.0001), and Perceived Physical-psychological burden (F=26.52, P=.0001) were significantly associated with stage of change. 4. Through the discriminant analysis, it was found that both 'Self Perceived Physical - Psychological benefit' and 'Perceived Physical-Psychological burden' were the influential variables in discriminating the three stages of change(pre-contemplation, preparation, and maintenance). Conclusion : Results are consistent with the application of the Transtheoretical model, which has been used to understand how people change health behaviors. Even though this study is a cross-sectional, not a longitudinal study, the findings of this study give useful information for exercise intervention about especially the factors relating to decision making for exercise of the elderly in the different stages of change of exercise.

• Journal of Distribution Science
• /
• v.11 no.5
• /
• pp.55-62
• /
• 2013

Purpose - This study aims to determine the problems and limitations of the Commercial Area Activation System, which was created by a special law for promoting traditional markets and shopping districts to revitalize and efficiently manage the central commercial area in different regions. We also suggest different options for its improvement. Research design, data, and methodology - We also look into the problems of which is being promoted as a demonstration project, from the aspects of legal text and guidelines. Results - The current commercial area activation system has several problems. First, the establishment of a comprehensive basic plan on the commercial area activation is not a requirement. Second, the benefit principle should be established to prevent the moral laxity of merchants who serve important roles in the main components of the commercial area activation business when they conduct their business. Third, the current special law constrains the commercial management organization, as under the civil law yields a limitation on finding a profitable business model. Fourth, to efficiently, constructing a system that links the other central government businesses and is needed. into a regional development budget or a budget for funding small businesses that the central government can control, which is effective. Further, we offer some suggestions for medium- and long-term policies. First, an integrated coordination mechanism at the central office level should be installed while setting the basic policy to revitalize the Based on this policy, local governments need a system that exclusively based on the after establishing a comprehensive plan for urban regeneration and getting approval from the integration organization. Second, a system that enables an understanding of the problems with business promotion by monitoring the procedure of supporting projects and regularly assessing business achievements is needed. Third, a plan is needed for resolving conflicts between various interested parties that adopts the commercial area activation system for carrying out a total redevelopment of the commercial area where small shops are densely located. A market maintenance project has been conducted as a means to recover our traditional market, which was economically depressed, and to revive the local economy, but it is mostly conducted in the form of reconstruction or redevelopment and represents the interests of landowners and merchants. Thus, it is most likely to lead to a gradual disappearance of traditional markets. Conclusions - This study looks primarily into the problems that appeared in the legal text or the guidelines regarding the direction of improvement of the commercial area activation business that has been going on as a demonstration project since 2011 and suggests some solutions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.11
• /
• pp.256-270
• /
• 2016

This purpose of this study is to present a new theoretical framework on birthrate recovery in advanced countries in the 21st century. As a result of socioeconomic development and individualism diffusion, the central axis of the family has transformed from the vertical axis of the father-son relation, to the horizontal axis of the husband-wife relation. This process is divided into 2 stages. In the industrialization stage, a nation or a society achieves equality of the individual in family formation, including marriage or divorce. In the post-industrialization stage, it accomplishes the couple equality in family maintenance, including child rearing and household labor. This paper grouped 33 OECD member countries as post- industrialization countries and 103 countries as industrialization countries. This study utilizes 6 variables affecting marriage and childbearing based on previous research. Research results find that during the industrialization stage, the birthrate falls as the education level of women is higher. In the post-industrialization stage, the birthrate rises as gender equality level is higher.

• International Journal of Highway Engineering
• /
• v.13 no.4
• /
• pp.167-175
• /
• 2011

Evaluation of fuel consumption for the various road condition and vehicle type is necessary to perform the economic analysis of road construction which is important for the efficient design and management of road. Economic analysis of road should consider the social cost which can be divided into agency cost including initial construction expense, maintenance cost, and so on, and user cost consisting of vehicle operating cost, congestion cost, etc. Since vehicle operating cost depends on the traffic volume, fuel consumption that is a major part of vehicle operating cost will change by traffic volume as well. Fuel consumption is significantly affected by vehicle speed and road condition, especially the roughness. Thus, fuel consumption should be evaluated in terms of road condition, which is not currently considered. In this study, the estimation model of fuel consumption for the passenger cars in Korea has been developed by considering the road condition. First, the relationship between vehicle speed and fuel consumption that is used to calculate the vehicle operating cost for investment evaluation of transportation facility and the initial feasibility study of road construction was investigated. Second, with the consideration of road roughness, fuel consumption of the passenger car was measured. From the measurement, it was found that fuel consumption increased by $80m{\ell}$ per 100km driving as the roughness increased by 1m/km. Therefore, it is recommended that for the economic analysis of road design and management, the fuel consumption should be a function of road roughness.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.5
• /
• pp.117-124
• /
• 2010

Most of the rivers which exist in nature are not a single river but the network that is composed of several branches and mainstreams. The river network are more complicated than other sigle rivers and streams. Therefore the hydraulic characteristics are sensitively changed by reduction and expansion of the width in the confluence or the variation of the flux. In this paper, the hydraulic characteristics were calculated by the change of the width and length in the confluence and the hydraulic model test. The deposit of confluence emerged at the left bank, right bank and the stagnation sector. As the total flow in the branch have increased, stagnation of the left bank and right bank have decreased. When the width of the downstream have been get smaller from 3 m to 2 m, the deposit of the left bank and right bank and stagnation sector have decreased. But as the eddy flow in the center of the confluence is occurred, the erosion has been increased. The result of this paper can be used as a basic data of water management around the junction and for maintenance on the ground of development of the river.