• Journal of the Korean Society of Safety
• /
• v.27 no.1
• /
• pp.105-110
• /
• 2012

Although reinforcement of work intensity caused by the recent prosperity of shipbuilding businesses and the steady increasing of results which produces orders has difficulties with heavy workload, unique work circumstance in shipbuilding industry where main and subcontractor do the job together is not easy to manage its safety systematically. According to KOSHA(Korea Occupational Safety & Health Agency), there were 2, 587 deaths of 95,806 disaster victims a year on average for late 6 years(2003-2008), therein 36,605 disaster victims and 646 death in manufacture where shipbuilding have 2,287 victims, 6.25% of total disaster victims and 45 deaths, 6.97%. Moreover it shows much higher accident rate in shipbuilding industry in Korea than well developed countries in this industry as Japan, Singapore, Taiwan and so it does about 3 to 10 times higher in case of death. Compared to Japan with a shipbuilding competition of orders received system, 2 times and 2.3 times higher for each and it is more than 2 times higher than accident rate of all domestic industries. These increasing of disaster result in a labor-management dispute and it is necessary that more positive efforts and investments because there occurs blind spot, neglected industry safety and health management by lack of them, Therefore this study, for the effective safety and health management of shipbuilding industry, attempts to analyze risk on kinds of ships and budget needed in safety management through classifying ships that are being made recently by three dominate major companies. For this, we carried out a survey and interview targeting experts related to shipbuilding industry and used AHP(Analytic Hierarchy Process) for result analysis. It is considered that cost of safety and health management will be spent more effectively on the results about risk on kinds of ships and budget needed in safety management in the study and that this study can contribute to decreasing disasters in shipbuilding industry.

• Computers and Concrete
• /
• v.22 no.3
• /
• pp.261-267
• /
• 2018

Long-term deformation of a steel-reinforced concrete (SRC) column is different from that of a reinforced concrete (RC) column due to the different moisture distribution. Wide-flange steel in an SRC column obstructs diffusion and makes long-term deformation slower. Previous studies analyzed the characteristics of long-term deformation of SRC columns. In this study, an additional experiment is conducted to more precisely investigate the effect of wide-flange steel on the long-term deformation of SRC columns. Long-term deformation, especially creep of SRC columns with various types of wide-flange steel, is tested. Wide-flange steel for the experiment is made of thin acrylic panels that can block diffusion but does not have strength, because the main purpose of this study is to exclusively demonstrate the long-term deformation of concrete caused by moisture diffusion, not by the reinforcement ratio. Experimental results show that the long-term deformation of a SRC column develops slower than that in a RC column, and it is slower as the wide-flange steel hinders diffusion more. These experimental results can be used for analytical prediction of long-term deformation of various SRC columns. An example of the analytical prediction is provided. According to the experimental and analytical results, it is clear that a new prediction model for long-term deformation of SRC columns should be developed in further studies.

• Journal of the Korean Society for information Management
• /
• v.37 no.3
• /
• pp.157-175
• /
• 2020

This study aimed to understand why small libraries, which have been continuously extended by the increase of social interest in them and the enactment of 「Promotion of Small Library Act」, an independent law about small libraries, are poorly activated. To this end, it examined the actual status of small library operation, related policies, support and legislations. By summarizing the results, it proposed a policy direction and tasks for activating small libraries. The policy tasks for activating them consist of three main tasks such as 'the improvement of laws and institutions for establishing the base of policies and securing practical momentum', 'the reestablishment of roles by policy units and the reinforcement of cooperation systems' and 'the construction of stable operation support system for small libraries', and their 14 sub-tasks, under the vision of 'the activation of small libraries support local residents' happy life' and the core value of 'a comprehensive policy ground, the innovation of policy systems and sustainable management support'.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.3
• /
• pp.2279-2286
• /
• 2015

Recently it has been actively studied that the use of hybrid GFRP-concrete structure with dual purpose of both a permanent forwork and main tensile reinforcement of GFRP plank. In applying general analysis and design technique to evaluate the performance of hybrid structures with cast-in-place high strength concrete and GFRP plank, it is essential that the characteristics of the bond slip model is identified. In this study a simplified bilinear bond slip model for hybrid structure with GFRP plank and cast-in-place high strength concrete is proposed. Maximum average bond stress of simple bond slip relationship that has been proposed in this study is 3.29MPa, initial slope is 35.66MPa/mm, the total slip is 0.23mm and interfacial fracture energy is 0.37kN/m.

• Structural Monitoring and Maintenance
• /
• v.2 no.1
• /
• pp.35-48
• /
• 2015

The main objective of this study is to evaluate the long-term performance of various concrete composites in natural marine environment prevailing in the Gulf region. Durability assessment studies of such nature are usually carried out under aggressive environments that constitute seawater, chloride and sulfate laden soils and wind, and groundwater conditions. These studies are very vital for sustainable development of marine and off shore reinforced concrete structures of industrial design such as petroleum installations. First round of testing and evaluation, which is presented in this paper, were performed by standard tests under laboratory conditions. Laboratory results presented in this paper will be corroborated with test outcome of ongoing three years field exposure conditions. The field study will include different parameters of investigation for high performance concrete including corrosion inhibitors, type of reinforcement, natural and industrial pozzolanic additives, water to cement ratio, water type, cover thickness, curing conditions, and concrete coatings. Like the laboratory specimens, samples in the field will be monitored for corrosion induced deterioration signs and for any signs of failureover initial period ofthree years. In this paper, laboratory results pertaining to microsilica (SF), ground granulated blast furnace slag (GGBS), epoxy coated rebars and calcium nitrite corrosion inhibitor are very conclusive. Results affirmed that the supplementary cementing materials such as GGBS and SF significantly impacted and enhanced concrete resistivity to chloride ions penetration and hence decrease the corrosion activities on steel bars protected by such concretes. As for epoxy coated rebars applications under high chloride laden conditions, results showed great concern to integrity of the epoxy coating layer on the bar and its stability. On the other hand corrosion inhibiting admixtures such as calcium nitrite proved to be more effective when used in combination with the pozzolanic additives such as GGBS and microsilica.

• Journal of the Korea Concrete Institute
• /
• v.16 no.1 s.79
• /
• pp.88-93
• /
• 2004

The objective of this study was to investigate applicability of epoxy injection method to cracked RC beams and structural behavior of repaired RC beams considering pre-loading conditions. For this purpose, five test beams were fabricated under two experimental variables. The main variables of this experimental study were pre-loading conditions and repair methods. The two pre-loading conditions were selected as $70\%$ and $90\%$ of nominal strength and the repair methods were to repair the cracked RC beams under free loading after crack and sustained loading. The comparative study was executed to evaluate effects of pre-loading conditions on the structural behavior of the cracked RC beams after crack-repair. The strains of reinforcement and concrete and deflections of beams at each loading step were measured and evaluated. As the results of this study, repair methods have much influence on structural behavior of epoxy injected RC beams and epoxy injection method for cracks of RC structures is appeared to be efficient.

• Magazine of the Korea Concrete Institute
• /
• v.7 no.4
• /
• pp.169-179
• /
• 1995

The purpose of this study is to spread beam plastic hinging zone of the high-strength($f'_c=700kg/cm^2$) reinforced concrete beam-column joints away from the column face by vertically anchored intermediate reinforcements. The newly proposed intermediate reinforcements which are vertically anchored by interlinking each intermediate rebars are tested to insure the ductile behavior of R /C beam-column joins. Main variable is the shape of intermediate reinforcements. From the test results, the newly proposed intermediate rebar detail can move arid expand the beam plastic hinging zone about 1.Od from column face and can delay the strength decay of the high-strength R /C beam-column joint. Also energy dissipation capacity of specimen IV-1.OD10 which is reinforced by vertically anchored intermediate rebars about 1.0d is 1.6 times as high as the specimen CM-STAN which is designed by ACI318-89.

• Journal of Korean Public Health Nursing
• /
• v.6 no.1
• /
• pp.5-14
• /
• 1992

The role of Community Health Practitioner(CHP) should be continuously adapted to the social changes and the needs for health care services. That is the reason CHP needs to be retrained through the continuing education program. This paper showed CHP's roles to be reinforced by analyzing his present . task performance and ability in seven task areas as well as the changes of the social environment. In addition, this paper presented retraining areas needed for the reinforcement of the CHP's role in the future, and the development strategy of related continuing education package. The major results are as follows: 1. CHP's main practice area is health care services and management & guidance, whereas the development of health information system is neglected. 2. As a result, CHP plays a role mainly as a health care supplier, a consultant and a health instructor. Therefore CHP's roles to be reinforced are management of the community health system, act as a spokesman and a team member, promotion, assessment, collection & maintenance of information, coordination and research. 3. The areas to be reinforced in CHP's continuing education are (]) aged people's health, (2)?drinking & smoking, (3)?young people's health(including drug and sexualissues), (4) rehabilitation, (5)?administration and management for community health, (6)?partnership & membership, (7) local residents' participation and community development, (8) collection & treatment of health information and (9) environmental issues for community health. 4. The priority in developing continuing education package should be given to the area, which is encountered often in rural area but important, and has a good opportunity to be resolved. The health management of aged people was selected as a top priority by members of the Community Nursing Academic Society. 5. It is recommended that the instruction materials be accommodated to the small scale workshop or seminar in order that CHPs can participate actively in the continuing education program.

• Journal of the Korea Concrete Institute
• /
• v.14 no.2
• /
• pp.231-238
• /
• 2002

Dry shrinkage md temperature change cause to develope concrete bridge decks on main girders have initial unidirectional cracks in longitudinal or transverse direction. As they receive traffic loads, the crack gradually propagate in different directions depending on the concrete dimension and reinforcement ratio. Since existing equations that predict crack width are mostly based on the one directional bond-slip theory, it is difficult to determine the actual crack width of a bridge deck with varying the spacing of rebar or strengthening material and to estimate the improvement rate in serviceability of the strengthened bridge deck. In this study, crack propagation mechanism is identified based on the test results and a new crack prediction equation is proposed for evaluation of serviceability. Although more accurate results are derived using the proposed equation, the extent of error is increased as the strain of the rebar or the strengthening material increases after the yielding of rebar Therefore, further research is required to better predict the crack width after the rebar yields under fatigue loading condition.

• Journal of the Korea Concrete Institute
• /
• v.15 no.6
• /
• pp.866-876
• /
• 2003

Experiments were performed for the real sized 12 reinforced concrete columns of 350${\times}$350${\times}$3350 mm with normal concrete in order to observe the fire-damaged behavior of these columns. Columns were heated according to the ISO heating curve. Main experimental parameters were: magnitude of axial load, heating time, cover thickness, and eccentricity. Effects of these parameters on the axial expansion and contraction, rotation, buckling, ISO fire resistance, and structural stability were experimentally quantified. It has been observed that the contraction rate of axial deformation was affected mostly by the duration of heating time and buckling of reinforcement or member by the magnitude of axial load, duration of heating time, cover thickness and eccentricity in order. Based on the experimental observations, ISO fire resistance criteria were qualiatively criticized.