• The Journal of the Convergence on Culture Technology
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• 제6권4호
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• pp.753-760
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• 2020

In this study, the structural safety of the bearing support was analysed by applying the vertical load (bearing design load) and horizontal load (horizontal force generated during an earthquake) using a precise three-dimensional numerical model. The results of stress and displacement of newly-poured concrete and welded rebars were confirmed numerically. Numerical results show that the increase in the horizontal force and the height of the beam causes the concrete cracking and the stress increase of the rebar connections due to the increase of the stress at the new concrete interface. Therefore, it was analyzed that the increase in the height of bearing support is directly related to the horizontal force and it is necessary to apply the bearing support height appropriate for the bearing support capacity. It was proposed that a method of setting the height of the bearing support suitable for the bearing capacity and determining the reinforcement by presenting the guideline with the correlation between the horizontal force acting on the bearing support and its height.

• Journal of the Earthquake Engineering Society of Korea
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• 제24권5호
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• pp.211-217
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• 2020

Earthquake preparedness has become more important with recent increase in the number of earthquakes in Korea, but many existing structures are not prepared for earthquakes. There are various types of liquefaction prevention method that can be applied, such as compaction, replacement, dewatering, and inhibition of shear strain. However, most of the liquefaction prevention methods are applied before construction, and it is important to find optimal methods that can be applied to existing structures and that have few effects on the environment, such as noise, vibration, and changes in underground water level. The purpose of this study is to estimate the correlation between the displacement of a structure and variations of pore water pressure on the ground in accordance with the depth of the sheet file when liquidation occurs. To achieve this, a shaking table test was performed for Joo-Mun-Jin standard sand and an earth pressure, accelerometer, pore water pressure transducer, and LVDT were installed in both the non-liquefiable layer and the liquefiable layer to measure the subsidence and excess pore water pressure in accordance with the time of each embedded depth. Then the results were analyzed. A comparison of the pore water pressure in accordance with Hsp/Hsl was shown to prevent lateral water flow at 1, 0.85 and confirmed that the pore water pressure increased. In addition, the relationship between Hsp/Hsl and subsidence was expressed as a trend line to calculate the expected settlement rate formula for the embedded depth ratio.

• Korean Journal of Agricultural Science
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• 제47권2호
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• pp.337-347
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• 2020

Since 2012, despite the fact that tariff rate quotas (TRQ) in the form of dried peppers has not been imported, the imports of pepper-related items such as low- tariff frozen peppers (27%) and other sauces (45%) have increased, there has been a problem in the domestic pepper industry, in which the domestic self-sufficiency rate has declined. The purpose of this study was to find out whether the operation of chili pepper TRQ has the effect of suppressing the imports of pepper-related items from China. We analyzed the import substitution effect (import suppression effect) through causal analysis of the imports of red pepper TRQ, frozen peppers, and other sauces using the structural equation model analysis method. As a result of the hypothetical scenario analysis, when the government imports and releases 7,185 tons of pepper TRQ in 2019/20 (scenario), private imports were estimated to decrease by only 3,060 tons. In other words, the import substitution effect between imported items was estimated to decrease about 2,079 tons of private dried peppers, and about 981 tons of imported pepper-related items. There was an effect of suppressing the imports of pepper-related items such as frozen peppers, but it was analyzed to be insignificant. That reason was that the replacement substitution elasticity of the pepper-related items for TRQ import was less than 1 (inelastic). Therefore, it is judged that the government's operation of the pepper TRQ is preferably focused on stabilizing domestic prices rather than focusing on import control of pepper-related items.

• Journal of the Korea Institute of Building Construction
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• 제15권3호
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• pp.273-280
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• 2015

In this study, tests were carried out to find out a method to ensure the fire resistance performance of high-performance non-refractory coating CFT columns. For the high performance concrete fabrication with 100MPa, blast furnace slag(BS) and steel and nylon fibers were used. It was found that the partial replacement with BS improved the fire resistance performance of the concrete. Based on the results of lab tests, the large fire test was conducted. For this test, the CFTs with the size of ${\phi}500{\times}4,200mm$ and the reinforcement of SS 400 steel were prepared and they were subjected to a loading condition. It was found that as the level of load increased, the level of fire resistance decreased. For example, In with the loading condition of 2000kN the CFT could resist the fire for over 240 minutes, whereas, with the loading condition of 3,000kN and 4000kN applying to equivalent CFTs, the resisting time against fire were 184 minutes, and 120 minutes, respectively.

• Journal of the Korea Institute of Building Construction
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• 제14권5호
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• pp.423-432
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• 2014

The aim of this study to propose an efficient method in selecting the type of new and renewable energy applied in at the planning phase of buildings. This study applied geothermal energy facilities with high adaptability to buildings. This study considered the energy reduction and reduced cost by comparing the values with the energy consumption before applying of geothermal energy facilities. In order to propose more reliable criteria of economic evaluation, maintenance costs reflecting the replacement cycles and initial construction costs by drawings and specifications for installation facilities for practical geothermal energy based on construction statement for life-cycle cost analysis. The results will help to effectively select economic types of facilities for new and renewable energy of the planning phase of buildings.

• Journal of the Korea Concrete Institute
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• 제14권1호
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• pp.67-75
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• 2002

For the design of concrete structures in the serviceability limit state, the uniaxial static modulus of elasticity may be a most important parameter. In particular, this may be so just for a deflection control of the structure. Even in new concrete codes, however, the elastic modulus is normally presented on the form of general empirical relationships with the compressive strength and density of concrete. Normally, there is a large uncertainty associated with the general equations obtained by regression. Thus, in a typical plot of static modulus of elasticity vs. compressive strength, a large scatter can be observed at same strength. The aim of this study is to present the method for obtain the maximum modulus of elasticity at same compressive strength. In the present paper report the effects of mix ingredients on the modulus of elasticity of high-strength concrete. The test of 284 cylinder specimens arc conducted for type I with 11 ％ replacement of fly-ash cement concretes. Different water-hinder ratio, amounts of water and coarse aggregate as variables were investigated. And also analyzed it statistically by using SAS.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.446-449
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• 2007

For the restoration of construction industry, the government have offered the policy since the end of 1990. It has offered to develop the world-class technology and establish the effective production structure. In the government policy, the delivery and contracting method has improved so that construction industry could be recognized. Foreign countries have conducted the R&D and application of Innovative Contracting for improvement of facilities, reduction of LCC and innovation of contractor. Among the Innovative Contracting, 'Performance Warranty Contracting' is defined that A guarantee of the integrity of a product and of the makers responsibility for the replacement or repair of deficiencies. Performance Warranty Contracting is used for technology developments of contractor, improvement of quality, reduction of LCC, prevention of early deficiencies and reduction of owner's inspection works. This paper analyzes concept and effects of Performance Warranty Contracting and presents considerations according to the introduction.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제41권4호
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• pp.221-228
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• 2017

We proposed a novel method to remove PM2.5 dusts without HEPA filters aiming at applications in kitchens or enclosed work spaces generating PM2.5 at high concentrations. Many workers are exposed to PM2.5 owing to lack of air purification because the high replacement costs of HEPA filters make their application impractical. A key idea is to use the condensational growth of nanoparticles. Once particles grow to the size of a few micrometers, it is much easier to remove them because of their increased inertia. We developed and tested a prototype consisting of an air saturator (equipped with water spray nozzles), a condenser in which humid air was cooled down to make the particles grow, and a multi-impactor assembly for collecting the grown particles.

• Korean Institute of Interior Design Journal
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• 제21권3호
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• pp.103-110
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• 2012

Interior Coordination is the activity of making characteristic living space by planning and harmonizing various interior elements. In modern society, the taste and needs of the residents are getting varied and segmented, and the role of interior coordination is getting more important because that reflects cultural codes and trends and satisfies residents' needs. This study aims to investigate awareness and needs about interior coordination targeting apartment residents, and to provide fundamental data that could attribute to the planning of unique and diverse residential spaces. Methods of study include the literature research and the empirical study. Elements of interior coordination were extracted through the literature review, and the questionnaire was developed using these elements. And then a survey was carried out targeting apartment residents of Busan. The result shows that most of the residents were much interested in interior coordination, and they recognized it's importance. They wanted to plan and select the elements by themselves, but were passive in actual execution because of the difficulties in execution methods and economical conditions. There were certain differences between the styles of their own houses and the preferred styles, but they did not try actively to reconcile the differences. Therefore, various methods of interior coordination should be developed and proposed which are easy and effective for actual execution, and various media should be provided by which residents could easily get informations on design elements. Also, the concept and method of interior coordination should be considered from the very first stage of residential planning, and the replacement and modification of interior coordination could be easily done according to the change of life cycle and life styles.

• Journal of Sensor Science and Technology
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• 제6권4호
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• pp.307-315
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• 1997

In this paper, a sample chamber which provide easy replacement of ISFET sensor and consume only small sample volume for electrolyte analysis is designed and a 4-channel electrolyte analyzer employing 2-point calibration method is implemented. In addition, we proposed sample loading detection circuit for minimizing sample and calibration solutions and implemented it. Developed electrolyte analyzer consists of control system part and flow system part. For the effective control of the developed hardware, system software is developed as three individual routines ; measuring routine, calibration routine and washing routine.