• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.769-774
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• 2000

The purpose of this study was to investigate the structural performance of reinforcement corrosion reinforced concrete beams strengthened with epoxy mortar system. Main test parameters are existence and the magnitude of the reinforcement corrosion and the reinforcing bar and the tensile reinforcement ratio of the specimens. eight beam specimens were tested to investigate the effectiveness of each test variables on maximum load capacity and failure mode. Test results showed that the ultimate moment of th specimens were higher tan the nominal moment and the flexural stiffness was increased about 2.5 times and the cracking moments occurred over 60% of the failure moment in comparison with same sized control beam. However, note that epoxy mortar may conduct member into brittle failure mode.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제10권2호
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• pp.59-70
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• 2004

This study aims to present the re-structuring strategies of healthcare facilities in Kwang-ju and Jon-nam province for it's competition power in the emerging global health care market. Kwang-Ju city and Jon-nam province have had difficulties in building a balanced healthcare system because of rapidly declining population, weakened healthcare infra-structure and geographical problems of healthcare supply by numerous islands. Now, Kwang-Ju city and Jon-nam province try to be a core place of economy and culture in the west-south asia. To do so, it is fundamentally necessary to reform their current social structure including healthcare system in large scale. This Study presents the current conditions and the problems of healthcare environment in these areas.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 학술대회 논문집
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• pp.125-127
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• 2005

This paper conducted to evaluate electrical continuity of steelworks within reinforced concrete apartment structures as the down conductor in external lightning protection system. The reinforcing bars in reinforced concrete structures can be used as the down conductor when their overall electrical resistance is not greater than the resistance value of 0.2 ohm between the uppermost part and the ground level. According to the results of electrical resistances measured by 4-terminal low resistance measurements, the steelworks in reinforced concretes structures exhibited the electrical continuity with low electrical resistance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.48-50
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• 2009

This paper presents an IAQ(Indoor Air Quality) Monitoring System using equipments for measurement of fine Particle($PM1{\sim}PM10$), $CO_2$, VOCs(Volatile Organic Compounds), temperature and humidity for IAQ monitoring of subway station which millions of people use a day. The necessity of IAQ monitoring system is getting increased for more effective subway station monitoring in line with the recent government's regulation for IAQ is reinforcing. Subway Station is an unusual case. The structure of subway station is closed and complicated. Therefore when data of equipments are transferred, transmission error can happen occasionally. To prevent transmission error, an IAQ Monitoring System is needed the appropriate position and selection of equipments or sensor module. In addition IT(Information Technology) can be utilized like "WiBro(Wireless Broadband)" and "GateWay" for facilitate movement of data and construction of IAQ monitoring system of subway station.

• 한국시스템다이내믹스연구
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• 제13권4호
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• pp.33-55
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• 2012

The research is to identify important diffusion factors and their effects on green car diffusion process using system dynamics perspectives and a causal-loop analysis. Through a deep review on previous research, we have found the important factors of green car diffusion process. Price, driving range, network effect, recharge system, fuel cost had important facilitation on consumer attraction and green car diffusion. Based on the review, we have constructed a causal loop diagram explaining hybrid car diffusion process. We have found 3 important reinforcing loops in the causal loop diagram. Loop for learning & economies of scale(supply side), loop for network effect(consumer side), and loop for battery development(technology side) had most significant roles in the whole diffusion process. Through a deliberate analysis on the 3 causal loops, we have found meaningful results. First, there seems to exist a critical mass in the diffusion. Second, of the 3 loops, the battery technology had most significant role. Third, not consumer installed base but sales must be a standard to decide whether the critical mass is achieved or not. Based on these findings, several meaningful implications are suggested for the government and corporations related to the green car industries.

• 한국IT서비스학회지
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• 제9권2호
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• pp.129-149
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• 2010

Although many organizations have implemented and used ERP systems for years, industry reports point out that the usage level does not reach their expectation. As a result, they do not enjoy the benefits from the investment into ERP systems. This study attempts to develop a research model and test the model empirically for identifying factors that affect the usage of an ERP system at a public organization. This study has classified potential factors into three groups of technical system characteristics (usability, usefulness), organizational support characteristics (operational support, education and training, evaluation and measurement), and user characteristics (organizational citizenship, self-efficacy). Then, a structural equation model has been established on the basis of previous literature and tested with empirical data. In summary, this study has found that self-efficacy, usefulness, and operational support have an effect on the ERP usage. Self-efficacy is the strongest factor; Usefulness is the second; and the third is operational support. On the contrary to the previous literature, this study has not found a significant effect of organizational citizenship on the usage. The result confirms that an organization can increase the ERP usage by improving the usefulness of an ERP system to some extent. However, to boost the usage further, the result implies that organizations need to strengthen the self-efficacy of their members by reinforcing operational support, providing education and training steadily, and establishing an evaluation mechanism in relation with the ERP usage.

• Structural Engineering and Mechanics
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• 제83권6호
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• pp.799-810
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• 2022

This study investigated the effect of the strengthening efficiency of unbonded steel-bar truss system on the out-of-plane behavior of perforated masonry walls. Four full-scale unreinforced masonry (URM) walls with two different planes were prepared using the unbonded steel-bar truss system and a URM walls without strengthening. All masonry walls were tested under constant axial and cyclic lateral loads. The obtained test results indicated that the pinching effect in the out-plane behavior of masonry walls tends to decrease in the in- and out-of-plane strengthened URM walls using the unbonded steel-bar truss system with the higher prestressing force ratio (R_p) of vertical reinforcing bars in the unbonded steel-bar truss system, regardless of the perforated type of the masonry wall. Consequently, the highest maximum shear resistance and cumulative dissipated energy at peak load in the post-peak behavior were observed in the in- and out-plane strengthened URM walls with the highest R_p values, which are 2.7 and 6.0 times higher than those of URM. In particular, the strengthening efficiency of the unbonded steel-bar truss system was primarily attributed to the vertical prestressed steel-bars rather than the diagonal steel-bars, which indicates that the strains in the vertical prestressed steel-bars at the peak load were approximately 1.6 times higher than those in the diagonal steel-bars.

• Structural Engineering and Mechanics
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• 제82권4호
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• pp.435-444
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• 2022

This study proposes a novel longitudinal self-centering earthquake resistant system for reinforced concrete (RC) continuous bridges by using superelastic shape memory alloy (SMA) reinforcement and friction dissipation mechanism. The SMA reinforcing bars are implemented in the fixed piers to provide self-recentering forces, while the friction dampers are used at the movable substructures like end abutments to enhance the energy dissipation of the bridge system. A reasonable balance between self-centering and energy dissipation capacities should be well achieved by properly selecting the parameters of the SMA rebars and friction dampers. A two-span continuous bridge with one fixed pier and two abutments is chosen as a prototype for illustration. Different longitudinal earthquake resistant systems including the proposed one in this study are investigated and compared. The results indicate that compared with the designs of over-dissipation (e.g., excessive friction) and over-self-centering (e.g., pure SMAs), the proposed system with balanced design between self-centering and energy dissipation would perform satisfactorily in controlling both the peak and residual displacement ratios of the bridge system.

• 한국가금학회지
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• 제47권1호
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• pp.39-48
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• 2020

The present study intended to analyze and detect any possible shortcomings in the current egg distribution system in Korea through a questionnaire. The institutional system and cases of operation thereof in advanced countries such as the USA, Japan, and Germany for the development of the egg distribution industry in Korea. The results revealed the following issues: absent pricing system, ineffective egg distribution, and difficulty in balancing supply and demand. Suggestions for addressing these issues and the subsequent improvement were based on cases found in the instated systems of advanced countries, and were given as follows: (i) The existing GP Center needs to be separated from the farms of laying hens, and the current institutional system and its operations need to be improved and should be approved by the government. Parallel to the institutional improvement, establishing a distribution system centered on the GP Center would be desirable. (ii) Egg pricing regulations are needed as a standard to determine the price of eggs. (iii) The reinforcing control standards and securing means for egg preservation are pertinent to each stage of egg distribution and should take into account environmental factors such as egg preservation temperature to guarantee high hygiene standards and egg safety.

• 산업기술연구
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• 제23권A호
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• pp.69-81
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• 2003

Numerical analysis is important for the design, construction and maintenance of large caverns. The rock mass contains generally discontinuities such as faults, joints and fissures. The mechanical behavior and geometric characteristics of these discontinuities would have a significant impact on the stability of the caverns. In this research the Distinct Element Method(DEM) was used to analyze the structural stability of the large cavern. The Barton-Bandis Joint Model (B-B J.M) was used as a constitutive model for the joint. In addition, two different cases 1) analysis with a support system and 2) analysis with no support system, were analyzed to optimize a support system and to investigate reinforcing effects of a support system. The most significant parameters of in-situ stress, JRC of in-situ natural joints, and spatial distribution characteristics of discontinuities were acquired through field investigation. Displacement (horizontal, joint shear), maximum joint opening, maximum and minimum principal stresses, range of relaxed zone, rockbolt axial forces and shotcrete stresses were calculated at each excavation stage. As a result of analysis the calculated values proved to be under the allowable value Rockbolts also proved to be an efficient support measure to control joint shear displacement which had significant effects on extending the relaxed zone. As a consequence, the structural stability of the cavern was assured with an appropriate support system.