• Journal of Industrial Technology
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• v.39 no.1
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• pp.27-31
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• 2019

Semiconductor logistics systems are facing difficulties in increasing production as production processes become more complicated due to the upgrading of fine processes. Therefore, the purpose of the research is to design predictive models that can predict traffic during the pre-planning stage, identify the risk zones that occur during the production process, and prevent them in advance. As a solution, we build FABs using automode simulation to collect data. Then, the traffic prediction model of the areas of interest is constructed using deep learning techniques (keras - multistory conceptron structure). The design of the predictive model gave an estimate of the traffic in the area of interest with an accuracy of about 87%. The expected effect can be used as an indicator for making decisions by proactively identifying congestion risk areas during the Fab Design or Factory Expansion Planning stage, as the maximum traffic per section is predicted.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.7
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• pp.19-26
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• 2018

This study tested 25 lightweight aggregate concrete (LWAC) mixtures using the expanded bottom ash and dredged soil granules to examine the compressive strength gain of such concrete with different ages. The test parameters investigated were water-to-cement ratios and the natural sand content for the replacement of lightweight fine aggregate. The compressive strength gain rate in the basic equation specified in fib model code was experimentally determined in each mixture and then empirically formulated as a function of the water-to-cement ratio and oven-dried density of concrete. When compared with 28-day compressive strength, the tested LWAC mixtures exhibited relatively low gain ratios (0.49~0.82) at an age of 3 days whereas the gain ratios (1.16~1.41) at 91 days were higher than that (1.05~1.15) of the conventional normal-weight concrete. Thus, the fib model equations tend to overestimate the early strength gain of LWAC but underestimate the long-term strength gain. The proposed equations are in good agreement with the measured compressive strength development of LWAC at different ages, indicating that the mean and standard deviation of the normalized root mean square errors determined in each mixture are 0.101 and 0.053, respectively.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.4
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• pp.185-192
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• 2019

In this study, we, through case studies, formulated a method to implement net-zero energy daycare center at the current insulation and technology level, and calculated its energy expense. The reference model was a medium sized daycare center whose number of children was 99. We analyzed the energy consumption status for the reference model and developed TRNSYS simulation analytical model to realize net-zero energy . We assumed the reference model to be "All Electric Building" where all energy including cooking is supplied by electricity. The result is summarized as follows: First, the annual electricity consumption of daycare center was 53,291kWh. Plug load occupied the largest share of 48% followed by lighting, 10%, cooling, 9%, cooking, 9%, heating, 8%, hot water, 5% and ventilation, 2%. Second, the photovoltaic installation capacity to realize net-zero energy was 40.32kWp and its annual generation was 53,402kWh. Third, the annual energy expense(electricity bill) by realizing net-zero energy was 2,620,390won.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.41-48
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• 2018

Carbonation is one of the major detrimental factors to the reinforced concrete structures owing to penetration of atmospheric CO2 through the micro pores, thereby it reduces the durability of the concrete. The maintenance periods and cost for concrete according to the coefficient variation of different finishing materials is documented in literature. However, it is required to carry out the systematic and well planned studies. Therefore, keeping them in mind, surface repair was carried out to the carbonated concrete and the maintenance cost was calculated to measure the durability life after repair with different variable. The deterministic and probabilistic methods were applied for durability and repair cost of the concrete. In the existing deterministic model, the cost of repair materials increases significantly when the concrete structure reaches its service life. In present study using a stochastic model, the maintenance period and cost was evaluated. According to obtained results, there was no significant difference in the number of maintenance of the coefficient variation. The initial durability has a great influence on the maintenance time and cost of the structure. Unlike the deterministic model, the probabilistic cost estimating model reduces the number of maintenance to the target service life expectancy.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.579-590
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• 2018

Anomaly detection on building energy consumption has been regarded as an effective tool to reduce energy saving on building operation and maintenance. However, it requires energy model and FDD expert for quantitative model approach or large amount of training data for qualitative/history data approach. Both method needs additional time and labors. This study propose a machine learning and data science approach to define faulty conditions on hourly building energy consumption with reducing data amount and input requirement. It suggests an application of Support Vector Data Description (SVDD) method on training normal condition of hourly building energy consumption incorporated with hourly outdoor air temperature and time integer in a week, 168 data points and identifying hourly abnormal condition in the next day. The result shows the developed model has a better performance when the ${\nu}$ (probability of error in the training set) is 0.05 and ${\gamma}$ (radius of hyper plane) 0.2. The model accuracy to identify anomaly operation ranges from 70% (10% increase anomaly) to 95% (20% decrease anomaly) for daily total (24 hours) and from 80% (10% decrease anomaly) to 10%(15% increase anomaly) for occupied hours, respectively.

• Computers and Concrete
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• v.29 no.5
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• pp.303-321
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• 2022

The current design equations for predicting the torsional capacity of RC members underestimate the torsional strength of under-reinforced members and overestimate the torsional strength of over-reinforced members. This is because the design equations consider only the yield strength of torsional reinforcement and the cross-sectional properties of members in determining the torsional capacity. This paper presents an analytical model to predict the thickness of shear flow path in RC beams subjected to pure torsion. The analytical model assumes that torsional reinforcement resists torsional moment with a sufficient deformation capacity until concrete fails by crushing. The ACI 318 code is modified by applying analytical results from the proposed model such as the average stress of torsional reinforcement and the effective gross area enclosed by the shear flow path. Comparison of the calculated and observed torsional strengths of existing 129 test beams showed good agreement. Two design variables related to the compressive strength of concrete in the proposed model are approximated for design application. The accuracy of the ACI 318 code for the over-reinforced test beams improved somewhat with the use of the approximations for the average stresses of reinforcements and the effective gross area enclosed by the shear flow path.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.805-816
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• 2010

For earthquake simulation test it is essential to make sure the similitude in behaviors between the full scale prototype and the reduced scale model. This paper presents the test results obtained through the cyclic lateral-force test, on two-story RC wall subassemblages. A lower 2-story portion of the prototype structure was selected as subassemblages. The global behavior such as the strength and ductility, and the local behavior such as flexural, shear and uplift deformation were measured. The test results of the 3 : 5 scale specimens representing the prototype were compared with those of 1 : 7 scale models. Two types of subassemblages were used: One with lintel beams and one without lintel beams. The comparison shows that 1 : 7 scale model simulated in general successfully the global and local behaviors of the prototype.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.1
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• pp.45-53
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• 2014

In strength limit states design, it is assumed that after cracking, reinforcement carries all tension in the tension zone of reinforced concrete members. However, it can be seen the concrete between cracks will contribute to carrying a part of the tension stress in actual concrete members particularly at service load levels, this effect is referred as tension stiffening effect. In this study, tension stiffening models and high strength concrete beam flexural test results were verified through comparison. The relationship between moment-curvature and load-deflection was evaluated by result of tension stiffening model and test result values. The analysis results showed that ACI 318 and Owen & Damjanic generally shows good agreement.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.176-182
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• 2017

The housing market is divided into several sub-markets that operate independently. One of them is the distinction between rental and sales markets. Simultaneously, since the housing is a commodity as well as an asset, it has a close relationship between the rental market and the sales market. Due to the unique structure of Korea, it is difficult to apply the general method to analyze the housing market. This means there is a great deal of concern about side effects from the policy. Actually, the government's subsequent regulation of speculative demand in the future may be necessary to prevent market overheating, but at the same time, there is a fear that the rent will rise. Although changes in policy direction may be inevitable due to changes in market conditions, frequent and sudden changes in policy cause confusion in market participants, causing unrest in the housing market. This study aims to derive main factors and correlation with other housing market factor. These factors will be a base of qualitative housing market model to analyze the market effect of the demand-supply shift. Modeling is based on the system dynamics methodology, which is useful for identifying interactions between variables reflecting various variables in the housing market. The model discussed in this study is expected to provide integrated insight into the key variables of the housing market, away from the monopolistic thinking. It can also be useful as a means of assessing the effectiveness of policies.

• Korean Institute of Interior Design Journal
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• no.36
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• pp.37-43
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• 2003

This study investigates the characteristic traits of architectural design of Toyo Ito, who has been acclaimed as one of the most famous present-day Japanese architects. Ito' architecture is generally known as media architecture for its specific natures such as lightness, dematerialization, extensive use of shiny glass, etc. In this respect, Ito's architecture is a radical departure from the tradition of the architectural modernism mostly represented by Le Corbusier. In this study, the architectural world of Toyo Ito is divided into four main section: the conversation between architecture and nature, the architecture of the wind, simulation, and virtual reality, Each of these categories is given full investigation together with appropriate architectural model fit into them.