• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.100-107
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• 2024

Currently, in Korea, due to the rapid aging and deterioration of facilities, the minimum Maintenance Level and Performance Level' of facilities are required by the 'Facility Safety Act' or 'Infrastructure Management Act'. Since infrastructure assets have a long lifespan and the pattern of deterioration over time is complex, it is very difficult to maintain infrastructure as 'minimum maintenance state' or 'minimum performance state' by the current way of management. 'Asset Management' shall be performed not only by a technical perspective, but also by an accounting perspective such as cost and asset value. However, due to lack of awareness of 'asset management' among stakeholder, only technical perspective management is being carried out in practice. In order to effectively manage infrastructure assets, complex consideration of various asset value factors such as budget and service as well as safety and durability are required. In this paper, we presented a theory to evaluate and quantify the road network value for efficient asset management of the road network. We also presented a method of simulation to apply the theory presented in this paper. Through simulation and the results derived from this study, it is possible to specify the budget for the future national asset management, and to optimize the strategy for the management of old road facilities.

• Korean Institute of Interior Design Journal
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• v.26 no.4
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• pp.42-56
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• 2017

In Korea, which has three sides of the sea, various waterfront spaces are being developed and developed along with various coastal landscapes. However, there are a lot of cases that do not consider the regional characteristic of the coast or the characteristic of the coastal landscape. In many cases, the street facilities cause the landscape degradation and the use inconvenience because of incongruity with the scenery, aging and lax management. Therefore, it is necessary to reflect the specificity of the coastal landscape in planning and directing the street facilities, harmonizing with the surrounding natural environment, and consideration of sustainability. However, there is no research or planning index for sustainable street facilities considering the coastal characteristics. Therefore, this study suggests plan elements to improve the sustainability of the street facilities on the shore and proposes them as basic plan elements, and suggests what kind of improvements should be made to improve the sustainability of coastal facilities in Korea. Based on the plan elements derived from the plan, we checked the problems and complementary points of coastal street facilities in Korea by analyzing the current status of the street facilities around the Jeju Island beach from a sustainable point of view, and suggested plan indicators that should be supplemented to improve sustainability. We surveyed the street facilities such as walkway blocks, benches, pagoda, drinking fountain, trash cans, bicycle shelters, fences, guide maps, streetlights, and shower rooms in 10 beaches in Jeju Island. This study analyzed the sustainability characteristics of the each factor of these facilities by surveying the reflectivity of the 23 plan indicators from the six aspects derived from the sustainability planning factor as conformity, partial reflection, non - reflection, and nonconformity. The results of the analysis showed that the functional aspect was the highest with 68.3%, the material aspect (53%), the landscape aspect (22.3%), the productive aspect (14.7%) and the morphological aspect (12.2%), and maintenance / management (10.6%). In addition, the facilities with the lowest fitness in each aspect are bicycle shelter in landscape aspect, bicycle storage box and trash can in form aspect, shower room in material aspect, trash can in functional aspect, showroom, guide maps and drinking fountain in product aspect, showroom In maintenance aspect. In order to improve the sustainability of coastal facilities in the future, it is necessary to complement the administrative and landscape aspects. In coastal facilities, it is necessary to consider the sustainability planning index, especially for showers, taking into account the specificity of beaches. Consideration should be given to various aspects of sustainability for bike shelters and trash facilities. Through this study, we have proposed the plan elements to systematize, supplement, and improve the planning index for sustainability improvement in coastal facilities planning.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.167-174
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• 2008

Number of long-span bridge construction has been increased recently so that seismic consideration of design has become significant. To adapt such significance to design, seismic design in the newly revised 'Cable Steel Bridge Design Handbook' specifies some of wave travelling effect and local site effect. In this study, a cable-stayed bridge with main span of 500m is analysed having variables of uniform excitation, wave travelling effect, and wave travelling effect plus local site effect. Result shows that wave travelling effect in cable-stayed bridge affects considerably to its seismic response under weak soil condition even though the span length is relatively short. What's more, regardless of soil type, the seismic response has become higher for analysis with wave travelling effect and local site effect than with wave travelling effect only. Consequently, in seismic response analysis of long-span bridge, consideration should be given to application of wave travelling effect and local site effect.

• Tribology and Lubricants
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• v.36 no.1
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• pp.34-38
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• 2020

The powertrain of the waterjet system of a special-purpose vehicle makes use of the cardan shaft, which is composed of universal joints and shafts. These universal joints, composed of spiders and needle roller bearings, have to be designed with consideration for the bending and compressive stresses of the spiders and needle roller bearings, and the rating lives of the bearings. The bending and compressive stresses of the spider and bearing of a universal joint have been studied by many researchers. However, to design a universal joint effectively, overall consideration of the different specifications of needle roller bearings is necessary. In this study, the bending stresses of spiders and compressive stresses of needle roller bearings are calculated to design universal joints for powertrain cardan shafts with different roller diameters of bearing. Furthermore, the rating lives of the needle roller bearings are predicted using the calculated basic dynamic load ratings of the bearings. As a result, roller diameters less than 𝜙2.5 mm are found suitable through an analysis of the bending stress of the spider. All compressive stresses between spider and bearing, regardless of roller diameter, satisfy the requirements. Moreover, roller diameters of more than 𝜙2 mm are found suitable for the required rating life.

• KIEAE Journal
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• v.9 no.3
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• pp.61-68
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• 2009

Gwangju Metropolitan Government & Ministry of Environment have signed a model city in response to Climate Change agreement. The agreement calls for Gwangju to cut greenhouse gas emissions 10% below 2005 levels by 2015. Gwangju has seen this agreement as an opportunity to cut pollution and conserve the environment as well as to reinvigorate local economy. According to policy of Gwangju, Gwangju held design competition for Gwangju City Arboretum on march, 2009. The purpose of design competition was to give a wide publicity to Gwangju as Hub City of Asian Culture and construct carbon-neutral arboretum in accordance with the policy of 'Low-Carbon and Green Growth'. First of all, a design concept of arboretum is 'winding, round, overlay 'to reflect the landscape of Nam-do which is surrounded by mountains and river flows through the village. Second, the arboretum has five different places with these themes - Forest of Festivals, Health, Nature, Nostalgia, Education and Future. Each place has a symbolic theme park and different flow planning respectively. Third, the most critical point is that the arboretum is a carbon-neutral park. Gwangju arboretum will soon be developed in metropolitan sanitary landfill and constructed as the O2 arboretum based on low carbon strategy. Fourth, the O2 arboretum suggests specialized issue : 'Energy Saving', 'Recycling System', 'Green Network', 'Water System(rainwater maintenance and wetland development)'. Besides, main buildings(greenhouse, visitor center, Nam-do experience exhibition hall, and forest museum) is designed in consideration of harmony with topography character, surroundings. Also, planting will be a multilayer plant based on native landscape trees in consideration of function and the growth characteristics.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1999.12a
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• pp.21-25
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• 1999

Planning support systems(PSS) add more advanced spatial analysis functions than Geographic information systems(GIS) and intertemporal functions to the functions of spatial decision support systems(SDSS). This paper reports the continuing development of a PSS providing a framework that facilitates urban planners and civil engineers in conducting coherent deliberations about planning, design and operation & maintenance(O&M) of water-distribution networks for urban growth management. The PSS using dynamic optimization model, modeling-to-generate-alternatives, value engineering(VE) and life-cycle cost(LCC) can generate network alternatives in consideration of initial cost and O&H cost. Users can define alternatives by the direct manipulation of networks or by the manipulation of parameters in the models. The water-distribution network analysis model evaluates the performance of the user-defined alternatives. The PSS can be extended to include the functions of generating sewer network alternatives, combining water-distribution and sewer networks, eventually the function of planning, design and O&H of housing sites. Capacity expansion by the dynamic water-distribution network optimization model using MINLP includes three advantages over capacity expansion using optimal control theory(Kim and Hopkins 1996): 1) finds expansion alternatives including future capacity expansion times, sizes, locations, and pipe types of a water-distribution network provided, 2) has the capabilities to do the capacity expansion of each link spatially and intertemporally, and 3) requires less interaction between models. The modeling using MINLP is limited in addressing the relationship between cost, price, and demand, which the optimal control approach can consider. Strictly speaking, the construction and O&M costs of water-distribution networks influence the price charged for the served water, which in turn influence the. This limitation can be justified in rather small area because price per unit water in the area must be same as that of neighboring area, i.e., the price is determined administratively. Planners and engineers can put emphasis on capacity expansion without consideration of the relationship between cost, price, and demand.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.1
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• pp.55-70
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• 2003

Ammunition magazine, which is installed on the ground, has difficulty in protecting from the external attack, and accidental explosion should cause great damage to the life and property. For these reasons, it is needed to develop underground magazine that it has the advantages of safety, security and maintenance. This paper introduce the design case for blasting facilities, which should resist blasting pressure, as well as layout of underground magazine, which takes a safety for explosion and a working space of loading/unloading machine into consideration. On the layout, in case of ${\bigcirc}{\bigcirc}$ underground magazine, put three storage chambers in position almost parallel with principle stress direction, where less effected on discontinuity and hard rock area. Also, secured safe distance according to safety criteria of the Defense Ministry, and verified suitable layout by trace simulation for loading/unloading machine on working stage. Blasting design was performed on evaluation of maximum blast pressure between donar and acceptor chambers, and design condition for blast door, valve, etc. Diminution facilities against explosion, such as thrust block or debris trap, determined its size after plan in accordance with blasting criteria and calculation by structural analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.46-52
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• 2017

Recently durability design based on deterministic or probabilistic method has been attempted since service life evaluation in RC(Reinforced Concrete) structure exposed to chloride attack is important. The deterministic durability design contains a reasonable method with time effect on surface chloride content and diffusion coefficient, however the probabilistic design procedure has no consideration of time effect on both. In the paper, a technique on PDF(Probability of Durability Failure) evaluation is proposed considering time effect on diffusion and surface chloride content through equivalent surface chloride content which has same induced chloride content within a given period and cover depth. With varying period to built-up from 10 to 30 years and maximum surface chloride content from $5.0kg/m^3$ to $10.0kg/m^3$, the changing PDF and the related service life are derived. The proposed method can be reasonably applied to actual durability design with preventing conservative design parameters and considering the same analysis conditions of the deterministic method.

• Journal of the Korean housing association
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• v.23 no.2
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• pp.89-98
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• 2012

As the construction of multi-family housings, especially apartments, has been increased since 1970s, the multi-family housing becomes one of the main housing types in Korea. With the increase of multi-family housings, managing them becomes an important issue. Since 2010, the government has made a lowest price award system by a competitive bid compulsory to promote the development of housing management systems. Although competitive bids were implemented, the maintenance company was finally selected by the price without any other consideration. Consequently, the quality of management service was not enhanced. The purpose of this study is to suggest the improvement scheme of multi-family housing management system. In this study, the bidding data of "K-apt", the bidding method and the successful tendered price are analyzed. The results of analyzing bidding materials, the proportion of applying a lowest price system was 67.7%. Also many diverse ways to select the best management company were used, but most of these ways were violate the law and guidelines of Ministry of Land, Transport and Maritime Affairs. It meant that the lowest price award system was not implemented by strict standards and didn't correspond with the needs of residents of apartment. This condition made the housing maintenance quality low and deteriorated the management industry development. To enhance this condition, a new standard to select the management company, which are included contents of quality of managing quality, management expenses and companies' soundness, is necessary.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.409-414
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• 2008

The purpose of this study is to analyze the problem of BTL business through the sensitivity analysis of financial model and presented efficiency business strategy when private business owner propose their business. For this, we analyzed the sensitivity of financial model after analyzed costs of the school facility construction case for each place of business. The results of this study are as follows. 1)As the results of the sensitivity of financial model, requirement-earning rate for the results of analysis was decreased average 2.28 points (0.5%) per increasing 0.10% and Construction costs and the maintenance costs were decreased average 10.73 points (2.38%), 6.22 points(1.38%) for increasing 1billion won. 2) The Problem of BTL business according to the sensitivity analysis of financial model was analyzed that the price consultation low investments, and estimation from personal consideration caused it. So, it was analyzed to increase maintenance costs is more efficient method than to increase construction costs.