• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.978-983
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• 2000

This paper presents the system identification of a small-scale building model with an active mass driver and the controller design using Matlab program. As the AMD is a mechanical system which has a dynamic characteristic and whose mass can not be neglected compared to that of the building mass, the AMD-building interaction should be included in the controller design. The system identification is carried out for the AMD-building system with two acceleration inputs of the shaking table and the AMD and single acceleration output of the building. The mathematical model for the AMD-building is obtained and compared with the experimental result. The controller is designed based on the mathematical model using the optimal control algorithm of LQG strategy. The experimental results are compared with the numerical results. It is shown that both results are in good agreement in the system identification and the controlled responses.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.2
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• pp.47-60
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• 2012

Based on the Korean Building Standard Law, a building less than 3-stories and $1000m^2$ in area is defined as a small-level building and, as a result, this type of building has been excluded from the requirement to comply with seismic design. In order to prevent the loss of life and property under earthquake loadings, the small-scale building should satisfy the seismic performance specified in the current code through a seismic retrofit. In this study, a seismic retrofit scheme of a Buckling-Restrained Knee Brace (BRKB) was developed for non-seismic 2-story steel buildings, including small-scale buildings, using a fragility contour method. In order to develop an effective retrofit scheme of the BRKB for the building, a total of 75 BRKB analytical models were used to achieve the desired performance levels and analyzed using the fragility contour method. The seismic performance of the retrofitted building was evaluated in terms of the weight of the developed BRKB systems. This study shows that the fragility contour method can be used for rapid evaluation and is an effective tool for structural engineers.

• 한국벤처창업학회:학술대회논문집
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• 2006.11a
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• pp.275-299
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• 2006

This study aims at examining the early-stage financing scale for entrepreneur to build small & medium business. The data was collected from the DART (Data Analysis, Retrieval and Transfer System) of Korean Financial Supervisory Service(FSS) in the main. The results of this study show that small & medium business needs equipment & operation financing for about 37 months extent to reach Break-Even Point. The limitations of this study are data collections from registered firms on Korean FSS primarily and no showing about the early stage financing scale for building small & Medium Business concretely. Small & Medium business entrepreneur have to make a early stage finance plan according to a necessary equipment and operating cost in their business field for 37 months extent.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.95-102
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• 2003

A construction project's period is limited by the order manufacture. And a construction project is requested a specific place, and has the characteristic to be irregular. Today, construction is to be representative high-cost and low-efficiency. This kind of problems appears in small construction projects more often than large construction projects. According to this facts, we recognized necessity of making practical application in methods of construction management. Also, we suggest application and establishment of integrated responsibility management department, PMIS(Project Management Information System) and Data Base. From now on, methods of construction management could be good opportunities for small construction projects and local construction companies. Therefore, small and local construction companies should try to improve their abilities. Likewise, the countries systematize to constitute the relation laws.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.206-207
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• 2022

Currently, safety accidents in construction area are managed regardless of the size. Therefore, the objective of this study is to conduct for developing the quantitative risk assessment according to large and small and medium-sized construction sites. The scope of this study is limited to the fall accidents which is the biggest accidents in the construction sites. the regression analysis was conducted based on the collected data. As a result, it was confirmed that there was a statistically significant difference between larce and small and medium-sized construction sites. This study is expected to be used as basic data for research on the development of a risk quantitative model for small and medium-sized construction sites in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.261-262
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• 2021

Increasing construction costs are required due to increasing the supply of small type houses with changes in multi-family housing trends. However, a sharp rise in the construction cost of small type houses can raise the sale price, threatening the stability of national housing. Therefore, this study aims to estimate the change in the construction cost of small type houses from the basic construction cost of the sale price ceiling system and suggest an improvement plan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.347-348
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• 2023

In construction sites, small-scale construction quantities or limited work hours below the daily work volume may occur due to on-site conditions. For small-scale quantities, the input of equipment and labor is designed based on an hourly basis in the invoice, resulting in a difference from the actual cost. In this study, we aim to explore solutions from the perspective of construction cost standards to secure appropriate construction costs for small-scale and time-limited construction sites. Firstly, to preserve the basic construction costs on-site, we established standards where half the cost would be charged for construction quantities below four hours and a full day's cost would be designed for construction quantities between four to eight hours. Additionally, realistic construction cost calculation standards are expected to be provided by realizing a surcharge rate for work hour limitations to secure appropriate construction costs.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.197-204
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• 2018

In the present study, unsteady flow analysis has been conducted to investigate the blade forces and wake flow around a hybrid street-lamp having a vertical-axis small wind turbine and a photovoltaic panel. Uniform velocities of 3, 5 and 7 m/s are applied as inlet boundary condition. Relatively large vortex shedding is formed at the wake region of the photovoltaic panel, which affects the increase of blade torque and wake flow downstream of the wind turbine. It is found that blade force has a good relation to the variation of the angle of attack with the rotation of turbine blades. Variations in the torque on the turbine blade over time create a cyclic fluctuation, which can be a source of turbine vibration and noise. Unsteady fluctuation of blade forces is also analyzed to understand the nature of the vibration of a small wind turbine over time. The detailed flow field inside the turbine blades is analyzed and discussed.

• KIEAE Journal
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• v.13 no.2
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• pp.53-60
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• 2013

This study examined the building envelope structure used in small housings near urban area which have not good energy source in relation to the application of passive design for energy saving of small-sized architectural design firms in local cities and aimed to provide the basic materials of future design direction of designers and housing owners by analyzing economy of a project in order to know the amount of energy saving and additional expenses depending on the building envelope pattern. As a result of comparing and examining the energy saving cost from the period of use compared to investment by the thickness of insulating materials based on building envelope pattern for energy saving, it was found that the thicker the insulating materials are, the more energy saving amount is. While the current bead-type insulating materials have short payback period due to low initial investment, extruded insulating materials show the difference of five years compared to bead-type insulation because of its high initial investment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.466-471
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• 2009

Generally LED lamp has many advantages to compare with a general lamp, long life and no pollution matter like the mercury. Also it is excellence for color rendering and need to small consumption electric rower. However LED lamp has some disadvantages to compare to general fluorescent lamp and That is small light flux about 50% and narrow light distribution than fluorescent lamp. Therefore, to apply LED lamp in an office building, after analyze a illuminance distribution with an environment analysis and cooling, heating and light energy. The purpose of this study is to analyze light environment. light, cooling and heating energy simulation in Office building.