• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.796-804
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• 2003

The use of fracture mechanics has traditionally concentrated on crack growth under an opening mechanism. However, many service failures occur from cracks subjected to mixed-mode loading. Hence, it is necessary to evaluate the fatigue behavior under mixed-mode loading. Under mixed-mode loading, not only the fatigue crack propagation rate is of importance, but also the crack propagation direction. In modified range 0.3$\leq$a/W$\leq$0.5, the stress intensity factors (SIFs) of mode I and mode II for the compact tension shear (CTS) specimen were calculated by using elastic finite element analysis. The propagation behavior of the fatigue cracks of cold rolled stainless steels (STS304) under mixed-mode conditions was evaluated by using K$\_$I/ and $_{4}$ (SIFs of mode I and mode II). The maximum tangential stress (MTS) criterion and stress intensity factor were applied to predict the crack propagation direction and the propagation behavior of fatigue cracks.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.116-124
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• 2002

Natural resources fur the construction materials such as good soil, sand, and coarse aggregates have been encountered to be short due to excessive use by human. Even though some soil has been found to be unsuitable for construction materials, soil with reinforcement can naturally be an answer to these alternatives. According to recently published papers on fiber mixed soil, fiber mixed with soil can improve shear strength, compressive strength and post-peak load strength retention. In this study, a series of tests were performed to clarify the characteristics of fiber mixed soil and to give basic data for design and construction and their engineering properties, that is, unconfined compressive strength, splitting tensile strength, shear strength, crack by drying, freeze-thaw, creep and Poisson\`s ratio, were investigated and analyzed. It has been shown that fiber mixed soil is one of good alternatives fur the civil and building construction materials.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.299-310
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• 1998

Actually mixed assembly line is mixed with open and close type workstation. This workstation is called hybridworkstation. The propose of this paper is to determine the sequencing of model that minimize line length for actual(hybridworkstation) mixed model assembly line. we developed three mathematical formulation of the problem to minimize the overall length of a line with hybrid station. Mathematical formulation classified model by operato schedule. Mixed model assembly line is combination program and NP-hard program. Thus computation time is often a critical factor in choosing a method of determining the sequence. This study suggests a tabu search technique which can provide a near optimal solution in real time and use the hill climbing heuristic method for selecting initial solution. Modified tabu search method is compared with MIP(Mixed Integer Program). Numerical results are reported to demonstrate the efficiency of the method.

• East Asian mathematical journal
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• v.38 no.3
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• pp.293-319
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• 2022

In this paper, we introduce a higher order split least-squares characteristic mixed element scheme for Sobolev equations. First, we use a characteristic mixed element method to manipulate both convection term and time derivative term efficiently and obtain the system of equations in the primal unknown and the flux unknown. Second, we define a least-squares minimization problem and a least-squares characteristic mixed element scheme. Finally, we obtain a split least-squares characteristic mixed element scheme for the given problem whose system is uncoupled in the unknowns. We establish the convergence results for the primal unknown and the flux unknown with the second order in a time increment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.327-328
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• 2021

In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.177-186
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• 1992

In this study, the proper mixing ratio of fly ash to bottom ash is evaluated and bearing capacity of this mixed ash is examined for use of highway embankment and subgrade materials in large quantities. Independently of the mixing ratio of fly ash to bottom ash or the method of compaction test, maximum dry density ${\gamma}_{dmax}$ and CBR value of anthracite mixed coal ash is greater than that of bituminous mixed coal ash. The mixed ashes to contain more fly ash than that of which the ratio of fly ash to bottom ash is 8 : 2, are slaked readily when the water contents of compaction are greater than optimum moisture content O.M.C. The proper mixing ratios of fly ash to bottom ash are about 5 : 5 to 6 : 4. Coal ashes mixed with these ratios exhibit proper physical and geotechnical properties for use of highway embankment and subgrade materials, and enable coal ashes to be used in large quantities.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.6
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• pp.19-26
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• 2017

The aim of this study is to suggest an improvement of BTL in Educational Facilities applying the concept of n-BPPP(non-Benefits Public-Private Partnerships). The research is based on four of ninety-nine completed projects of Mixed-use Educational Facilities since 2001. Ninety-nine projects are analyzed and categorized to the typology of architectural program. The architectural programs planned are uniform in function, such as gym, swimming pool, library, info-center, parking etc. The public parking is a main program in the BTL projects, where district offices are involved as partner. The difference between BTL and n-BPPP for educational facilities is the business units. The n-BPPP concerns in regional or district units in order to expand public infrastructure facilities based on the network of schools and local community. And the fund for n-BPPP does not come from the government but from the investors. The economic interest is to reinvest on the maintenance of the facilities. The benefits of n-BPPP will be not only for the Governments in terms of social welfare budgets but also for local residents and students in terms of a variety of high-quality public services. The concept of n-BPPP can be an alternative way for the Mixed-use Educational Facilities.

• KIEAE Journal
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• v.10 no.5
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• pp.165-170
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• 2010

Super high-rise mixed use buildings require a longer period for construction. Especially finishing work takes up about 40% of the whole construction period. Thus, finishing work is becoming an important factor in determining the construction period along with earth work and frame work. As the expected returns added by the reduction of the period and cost in constructing super high-rise mixed use buildings are huge, the expectations are now increasing for the possible gains. In this respect, as the period of finishing work is easier to be shortened than that of frame work, the efforts to acquire the technical knowledge to reduce the finishing work period are now being required. Accordingly, in this study, we aimed at suggesting the basic data for designing an economic plan for finishing-work procedure by analyzing the productivity of each work type of finishing work procedure on the basis of the execution and results of a construction method as a time-flexible finishing work plan. For this, we categorized the work types of finishing work procedure into each work unit and provided a work-system for each of them. Also, with case studies, we calculated the detailed amounts of the work-loads, required materials, productivity, and productivity index of the main work types of finishing work procedure and each of their separate work units as well as analyzed the relationship between the value results to suggest a better way to improve its productivity.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.4
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• pp.105-113
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• 2017

Purpose: While Japan undergoes super aged society, Japanese Elderly Facilities are trying to keep elderly residents from social isolation and expand regional interaction. Methods: This study analyzes regional linkage characteristics through 8 cases of Aichi-Elderly Facilities which realize regional interaction and symbiosis(life together) between various generations by visiting. Result: 1) Most researched facilities except SO provide and share opportunity for interaction with community and residents through space for regional interaction including cafe and various programs and interactive settings. 2) The facility which seeks regional linkage through Mixed-use of facilities can devide into (1) Mixed-use of facilities easy to found, (2) Addition of housing function (NM, SM, DM) and (3) Mixed-use with different facilities(HY, GM) 3) The characteristics of interaction and symbiosis between generations are (1) to adopt concept of life together to have interaction possibility with young generation and children: most studied facilities except SO (2) to establish elderly residence into facility to have interaction(FE, SM, GM) or place family room or single room into elderly residence (NM, DM, BN) (3) to disperse small facilities into community (FE) or facility or community realizing symbiosis through various facility arrangement (SM, GM). 4) Therefore, this study can categorize (1) Program network, (2) Temporary interaction, (3) Symbiosis residence, (4) Symbiosis community according to characteristics which regional linkage has. Implication: Regional Linkage is an important concept to improve social interaction in community-based facilities. It is a thought-provoking concept to Korean elderly facilities because Korean facilities are still far from a city and in isolated environment.

• Journal of the Korean Institute of Educational Facilities
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• v.13 no.4
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• pp.24-30
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• 2006

There is a new demand for functional sharing between existing schools and neighbouring community facilities. This study is to find out the priority of the existing schools at Nowon District for functional sharing development. Most schools are located geographically near the highly populated residential district. The development will be a form of multi-use school complex. The process starts with selecting the schools located in the center of local community. Since the school facilities occupies the relatively enough space, it is possible to expand other functions for the neighbouring communities. Accordingly many citizens can utilize them because of their greater activities. This study is based on the investigation and the analysis of actual situations related to the complex development of school facilities. As a result the suitable candidate schools for the multi-use development are listed under the searched conditions.