• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.593-604
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• 2021

In this study, a comparative test was conducted on a specially developed elastic waterproof paint and general water-based paint for the purpose of responding to cracks occurring on the outer wall of concrete structures and improving watertightness. Through the comparative experiment, it was confirmed that the watertightness could be improved by securing the crack shielding property, and it was also confirmed that about 10 times more crack responsiveness was secured compared to general water-based paint. In addition, it was confirmed that the adhesion performance of at least 1.3MPa and resistance to a water permeation pressure of 0.1MPa were possible, confirming that stability was secured from a waterproofing perspective.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.42-56
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• 2022

The thesis is automated traffic control equipment system aims to improve. Areas where improvement is needed about the existing automated traffic control equipment by applying the latest technology and to improve the things that can be derived. Reflecting the derived improvements, we intend to present a plan for the design and implementation of a new unmanned traffic control device. The main improvements were designed to change the housing material of the unmanned traffic control equipment, simplify the configuration of the equipment, reduce the weight of the equipment, and change the purpose of the software. In order to evaluate the objective performance of the improved unmanned traffic control equipment through this study, it was requested to a public certification authority. The reliability of the equipment was secured through KC certification and durability test. It is intended to present the feasibility of securing the marketability of the unmanned traffic control equipment by comparing and evaluating the construction period and installation cost with the existing unmanned traffic control equipment.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.511-518
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• 2017

In recent years, many interests and researches on the insulations required the multiple performances other than insulation performance. The purpose of this paper is to find the optimal ratio between wood fiber and rice-husks charcoal to develop a structural board with carbonized rice-husks. Based on these rice-husks charcoals, basic research was carried out to develop thermal insulation materials with structural performance, and the following conclusions were obtained. The MC of the board using the carbonized rice-husks was 3.2-4.1% and the density was 0.58-0.68, indicating the possibility of excellent structural material. The bending strength was 9.1-32.6 MPa in the length direction and 9.2-34.1 MPa in the width direction. It is possible to obtain the bending strength of the normally used MDF level and to find the possibility of development of the thermal insulation material having the structural performances.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.23-34
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• 2020

Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high integration and high-efficiency energy sources. III-V compound semiconductor cells have proven performance based on high reliability in the aerospace field, but have characteristics that require absolute support of the balance of systems (BOS) such as solar position trackers, receivers with heat sinks, and housing instruments. To determine the optimum parameters of secondary optical elements (SOEs) design for CPV systems, we designed three types of CPV modules, classified as non-SOEs type, reflective mirror type, and CPC lens type. We measured the I-V and P-V characteristics of the prototype CPV modules with the angle of inclination varying from 0° to 12° and with a 500-magnification Fresnel lens. The experimental results assumed misalignment of the solar position tracker or module design of pinpoint accuracy. As a result, at the 0° tilt angle, the CPC lens produced lower power due to the quartz transmittance ratio compared to that by other SOEs. However, for tilt angles greater than 3°, the CPC lens type module achieved high efficiency and stability. This study is expected to help design high-performance CPV systems.

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.91-101
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• 2012

The purposes of this study were to identify the living environment in rural fishing area and to suggest checking methods for implementation performance. Rural service standard is the key factor of rural development in Korea. In 2012. The first Implementations of performance was announced. The results were presented to the unit by the City and the County. Because of Fishing villages exists as a unit by the haengjeongri. It is difficult to know the status of the fishing villages by the Rural service standard. In order to look for the actual conditions in rural fishing village it was investigated in the 100 Eochongye. The data used in the analysis is 577 questionnaires. Analysis showed that rural fishing areas were superior to general state of rural in the 8 items of rural service standard. Especially housing, transportation and health care sector in rural fishing area wes better than general state of rural. But Public safety and order is relatively poor. This is because Fishing village contains islands. Presenting to improve rural service standard based on the results of research. The items of rural service standard should be measured the actual residents' accessibility than opportunity of the public service, and after setting the rural service standard clearly related to the quality of life of residents in each sector. Accessibility aspects of the customer for the public services should be considered. Checking the performance for the unit by the City and the County should be replaced as a living zone in order to consider the facilities using nearby.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.81-93
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• 2024

In Korea, numerous large-scale infrastructure construction projects and housing site developments are being undertaken. However, due to limited land availability, sourcing high-quality backfill materials that meet the standards for railroad and road embankment compaction and mechanically stabilized earth (MSE) retaining wall construction poses significant challenges. Concurrently, there has been an increase in structural failures of many MSE retaining walls, attributed primarily to reduced bearing capacity and impaired drainage performance, resulting from inadequate backfill compaction. This study aimed to analyze the structural performance and safety of an MSE retaining wall using recycled soil as backfill. We conducted small-scale model tests utilizing 3D printing technology combined with two-dimensional numerical analysis. The study quantitatively evaluated the MSE retaining wall's performance concerning the recycled soil mixing ratio and reinforcement installation methods. Furthermore, the utility of 3D printing was confirmed through the production of an experimental wall designed to facilitate easy reinforcement attachment, mirroring the conditions of actual MSE retaining wall construction.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.289-293
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• 2008

In performance-based on fire safety design of buildings, design fires are assumed to be relatively coarse information on potential combustible objects described by its name, weight, size and main constituent materials. As early as 1970s, researchers from Japan has employed various methods of research regarding combustibles investigations. In result, researchers came up with one method that is being presently used. Therefore, our country basis in collection of data for combustibles yielded average measure, receipt rate of furniture usage and execution of combustible investigations to occupancy zone of university respondents. We have found out problem about excessive usage of multi-outlet extensions through research.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.500-505
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• 2009

This paper presents temperature control of engine cooling system using a controllable magnetorheological (MR) fan clutch. An appropriate size of MR fan clutch is devised and modeled on the basis of Bingham model. Subsequently, an optimization to determine design parameters such as width of housing is undertaken by choosing the reciprocal of the controllable torque as an objective function. Under consideration of spatial limitation, design parameters are optimally determined using finite element analysis. A sliding mode controller is then designed to control the angular velocity of the MR fan clutch using experimentally determined parameters. The designed controller is experimentally implemented and control performances of the MR fan clutch system are evaluated.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.197-202
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• 1999

A mechanical face seal is a tribe-element intended to control the leakage of working fluid at the interface of a rotating shaft and its housing. The leakage of working fluid decreases as the seal surfaces get closer each other. But a very small seal clearance results in a drastic reduction of seal life because of high wear and heat generation. Therefore, in the design of mechanical face seals the compromise between low leakage and acceptable life is important and presents a difficult design problem. And the gap geometry of seal clearance affects seal performance very much and becomes an important design variable. In this study the Reynolds equation for the sealing dam of mechanical face seals is numerically analyzed using the Galerkin Finite Element Method, which can be readily applied to various seal geometries. The film pressures of the sealing dam are analyzed, including the effects of the seal face coning and tilt. Then, opening forces, restoring moments, leakages, and dynamic coefficients are calculated.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.195-204
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• 2000

The finite element analysis (FEA) is widely used in modern structural dynamics because the performance of structure can be predicted in early stage. However, due to the difficulty in determination of various uncertain parameters, it is not easy to obtain a reliable finite element model. To overcome these difficulties, a updating program of FE model is developed by consisting of pretest, correlation and update. In correlation, it calculates modal assurance criteria, cross orthogonality, mixed orthogonality and coordinate modal assurance criteria. For the model updating, the continuum sensitivity analysis and design optimization tool(DOT) are used. The SENSUP program is developed for model updating giving physical parameter sensitivity. The developed program is applied to practical examples such as the BLDC spindle motor of HDD, and upper housing of induction motor. And the sensor placement for the square plate is compared using several methods.