• Tunnel and Underground Space
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• v.24 no.1
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• pp.67-80
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• 2014

Long-term stability and delayed failure of granite were evaluated through the laboratory test based on Wilkins method and Brazilian disc test (BDT) which yields tensile strength, mode I fracture toughness and subcritical crack growth parameters. Then, the long-term strength of granite was estimated by using analytical models and long-term stability of compressed air-energy storage (CAES) pilot cavern pressurized up to 5 ~ 6 MPa was evaluated using numerical code, FRACOD with the determined subcritical crack growth parameters. The results of test and analyses showed that the subcritical crack growth index, n was determined as 29.39 and the inner pressure of 5 ~ 6 MPa had an insignificant effect on the long-term stability of pilot cavern. It was also found that the measurement and analysis of acoustic emission events can describe the accumulation of damage due to subcritical crack growth quantitatively. That is, AE monitoring can provide the current status of rock under loading if we make an identical installation condition in the field with that of the laboratory test.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.3
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• pp.95-102
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• 2015

This study conducted the survey on the resources of traditional villages based on AHP in the subjects with the specialists in Korea and China to seek the resource evaluation standards to apply the preservation and development of traditional villages, and the differences of the importance on the resources among the specialists in both countries. We classified three levels of evaluation items to aim the deductions of the importance and priority in the resources of traditional villages. Upon the analysis results, natural resources were important in the level 1; environmental, historical, facility resources were important in the level 2; and the factors such as air, topography, traditional houses, agricultural landscape, shared community facilities, interchanges between urban and rural areas, family activities, and so on were important in the level 3. The factors that both Korean and Chinese groups evaluated as the most important ones were the same. In terms of overall importance by evaluation items, the factors such as air, water quality, noise, traditional houses, topography, shared community facilities, and so on were rated as relatively important in both Korean and Chinese groups. That is, the traditional villages have the necessity to preserve the cultural resources like their duties, however, it is required to control the natural environment with good quality preferentially. This study results can compare the importance on the resources of traditional village between Korea and China. Moreover, with calculation of the priority and scores for the preservation and management of traditional villages, they are expected to be used as the tool to apply the quantitative data in the evaluation process of traditional village resources in both countries.

• Korean Journal of Construction Engineering and Management
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• v.1 no.3 s.3
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• pp.75-80
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• 2000

In scheduling multi-unit projects, several alternatives can exist in network construction due to repetitiveness of their activities. Project duration is affected not only by the duration of each activity but also by the arrangement of repeating activities in such projects. This paper provides a network compression method that assigns predecessors to each activity to minimize its float time. Different to the previous efforts that utilized line of balance as the base scheduling-model, this research adopts precedence diagram arranged in two coordinates, the space axis and the resource one. This method seeks the most appropriate predecessors for each activity in each direction of the two coordinates for the purpose of minimizing the idle resource and space. This activity arrangement method was applied to a multi-unit apartment-construction project, to prove its capability of network compression. The result shows that the method successfully sought room for saving construction duration by changing the activity arrangement. The network compression method presented in this research can be utilized in multi-unit construction projects such as apartment complex projects.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.34-42
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• 2012

Green frame technology intended to facilitate the remodeling of apartment housing complexes in Korea and extend their service life has been developed. Green frame design is a Rahmen structure using composite precast concrete members and, unlike a bearing-wall structure, lifting and installing structural members accounts for major steps of structural construction. Therefore, if green frame structure construction is to be scheduled appropriately, systematic lifting plan needs to be developed in advance. Development of lifting plan also requires unit lifting process of composite PC members (columns and beams) that consist of green frame to be analyzed first. Therefore, this study attempts to analyze the lifting process of composite PC members used in green frame structure. To that end, lifting procedure and time of composite PC column and beam are estimated and applied to a project case to analyze the lifting cycle of reference floor. Outcomes produced herein will be used as key data for development of lifting plan in subsequent green frame structure construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.422-425
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• 2003

The purpose of this study is using a TACT planning and scheduling for apartment houses construction that have many of same units. Because using a TACT planning and scheduling is concluded time reduction at same units as apartment plan. The main contents of this study are 1) window and door work through the field study, 2) adjust worker assignment to minimize work time variation, and 3) an effect of working time through a case study. As a result, the total working time can be improved $21.2\%$ by using the TACT planning and scheduling. The stu요 recommends that 1) establish an accurate data between work period and resource, and 2) preparation to measures minimization of waiting time before using a TACT planning and scheduling.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.611-634
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• 2017

In rapid urbanization, demand for utility tunnel increases more, and tunnel boring machine (TBM) has been used widely. Prediction of TBM penetration rate is important for proper estimation of construction period and cost. Although there are several methods, such as NTNU model and CSM model that require many input parameters, fundamental understanding on correlations between rock properties and TBM penetration rate is critical. In this study, we explored the brittleness indices of hard rocks according to various definitions, and the correlations between the brittleness indices and the TBM penentration rates.

• Korean Journal of Construction Engineering and Management
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• v.2 no.3 s.7
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• pp.101-109
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• 2001

Application of system form is very effective to continuous horizontal or vertical walls of the apartment housing. Though the system forms that are used in the construction field have the advantage of concrete quality improvement and increasing number of usages, there are some problems in reaching early planning scheduling goal due to schedule delay and low productivity. This study is initiated to solve the problem and suggest some improvements searching for reasons that diminish the productivity. A case study was done in apartment construction field where system form was used and the productivity is analyzed by work sampling. Finally, productivity improvements for assembly of the form, internal form and external form are suggested, respectively.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.469-474
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• 2008

The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.

• Journal of the Korea Society of Computer and Information
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• v.19 no.5
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• pp.109-117
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• 2014

This study tries to find the policy instruments that have used in the process of social insurance policy implementation. The results can be summarized as follows: First, in case of compulsory policy instrument, the government uses the regulation, public enterprise and government insurance in the process of implementing of all the social insurance policy. Second, in the case of mixed policy instrument, the government use the user' contribution in the process of implementing of all the social insurance policy but the subsidy was used in the process of implementing of the medical, pension, unemployment and long-term care insurance for the aged policy. Also, the information and discipline was used in the process of implementing of unemployment insurance policy and the partnership was used in the process of implementing of long-term care insurance for the aged policy. Third, in case of voluntary policy instrument, the government uses the family and community in the process of implementing of almost the whole social insurance policy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1523-1528
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• 2008

In this study, the ventilation system of connection passage and elevator hall of underground parking lot in apartment houses is investigated to extract the data for the installation and the application by the experimentation. In case of the elevator hall, actual air exchange rate is predicted fivefold higher than air exchange rate by infiltration and exfiltration. Ventilation system is installed good by supply air and return air. As the next best thing, it is installed by supply air because of IAQ control. The temperature of connection passage and elevator hall uniformly with $7{\sim}8^{\circ}C$, is maintained even if the operating condition of ventilation system is different. Therefore, the installation of the preheater, which is installed at the inlet of ventilation system for the cold draft in winter, is not essential in southern area of Korea.