• Steel and Composite Structures
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• v.45 no.4
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• pp.591-603
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• 2022

The flexural strengthening of reinforced concrete beams by external bonding of composite materials has proved to be an efficient and practical technique. This paper presents a study on the flexural performance of reinforced concrete continuous beams with three spans (one span and two cantilevered) strengthened by bonding carbon fiber fabric (CFRP). The model is based on equilibrium and deformations compatibility requirements in and all parts of the strengthened continuous beam, i.e., the continuous concrete beam, the FRP plate and the adhesive layer. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends. Remarkable effect of shear deformations of adherends has been noted in the results. The theoretical predictions are compared with other existing solutions that shows good agreement, and It shows the effectiveness of CFRP strips in enhancing shear capacity of continuous beam. It is shown that both the normal and shear stresses at the interface are influenced by the material and geometry parameters of the composite beam.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.485-492
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• 2008

To propose proper vessel characteristics for sustainable fisheries in Korean waters, we analyzed the fishing capacity, scale efficiency and utilization of large pair-trawl vessels based on the database of catch, effort and vessel characteristics (gross tonnage and engine power) in 1990 by applying data envelopment analysis (DEA). The input factors were gross tonnage, horse power and days operated; whereas the output factor was expected catch by vessel characteristics. The optimal vessel types, selected based on the input-oriented technical efficiency and gross tonnages, was 100 GT with engine power <600 HP. The output-oriented unbiased estimate of capacity utilization (CD) decreased with increasing vessel tonnage. For the same tonnage vessels, the CD decreased with increasing engine power.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.213-231
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• 2017

The development of new spatial technologies enables sustainability as well as the efficiency of future land management while maintaining the efficiency of current land management. In this context, what are the challenges facing land management and sustainability, how can set the relationship between the land management and sustainability? What is sustainable technology for land management? And how can sustainability challenges and technologies be applied to land management? and so on. Therefore, this study is to search sustainable land management direction by investigating and applying sustainable technologies for more efficient and continuous maintenance of land management. To describe and approach sustainable technologies for land management, in particular, capacity, security, IT resource, new device, standards, transparency, and data, access to data and so on that can be considered as the challenges of sustainability and land management.

• Advances in environmental research
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• v.1 no.2
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• pp.143-151
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• 2012

Nitrate removal from aqueous solution was investigated using $ZnCl_2$ and phosphoric acid activated carbon developed from pomegranate peel with particle size 0.4 mm. Potassium nitrate solution was used in batch adsorption experiments for nitrate removal from water. The effects of activated carbon dosage, time of contact, and pH were studied. The equilibrium time was fond to be 45 min. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir fit the isotherm with the theoretical adsorption capacity ($q_t$) was fond 78.125 mg g-1. Adsorption kinetics data were modeled using the pseudo-first, pseudo-second order, and intraparticle diffusion models. The results indicate that the second-order model best describes adsorption kinetic data. Results show activated carbon produced from pomegranate is effective for removal of nitrate from aqueous solution.

• The Journal of Economics, Marketing and Management
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• v.4 no.1
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• pp.1-8
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• 2016

The purpose of this paper is to discuss the methodology of optimizing delivery route scheduling using a capacity integer linear programming problem model developed to a previous case study. The methodology suggests a two-stage decision: the first, automatic, where the manager will obtain guidance generated by the solution of the linear programming model, later they could use post-optimization techniques to fine tune to the best operational solution. This study has the goal to reduce the size of service companies' ground transportation fleets, aiming not only to reduce costs and increase competitive advantages but also to lower levels of air pollution and its consequences, traffic and, therefore, the levels of carbon dioxide, allowing for a reduction in envir onmental disasters.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.749-763
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• 2022

The fulcrum of economic development is a sustainable supply of electricity. Nigeria is plagued with blackouts, with one of the lowest per capita electricity consumption in the world (circa. 120 kWh per capita). Hence, policies have been instigated to integrate electricity generation from nuclear power plants (NPP) on or before 2027. However, a critical requirement for NPP generation is the implementation of robust human resource development (HRD) programs. This paper presents the perspective of Nigeria in assessing human resources needs over the entire NPP lifecycle following the milestone approach and employing the IAEA's Nuclear Power Human Resource (NPHR) modeling tool. Three workforce organizations are in focus including the owner/operator, regulators, and construction workers following three decades timeframe (2015-2045). The results indicate that for the study period, a maximum of approximately 9045 personnel (73% construction workers, 24% owner/operator, and 3% regulators) should be directly involved in the NPP program just before the commissioning of the third NPP in 2033. However, this number decreases by about 73% (2465 personnel including 94% operator and 6% regulator) at the end of the study timeframe. The results can potentially provide clarity and guidance in HRD decision-making programs.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.2
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• pp.37-46
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• 2019

Although This study is to produce various considerations for the proper time and feasibility of new runway with Incheon international airport $4^{th}$ runway development case. In order to validate the feasibility of runway development, it is main considerations to be increased airport capacity for accommodating increase air traffic demand, secure stable airport operation without degrading service level, cope with emergency situation and maintain competitive among competitive airports which are developing new runway. Conclusionally, to develop new runwlay at the proper time for sustainable and stable airport operation without stop is the best way of maintaining competitiveness among foreign competitive airports.

• Computers and Concrete
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• v.9 no.6
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• pp.427-437
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• 2012

This article presents the effect of replacement fly ash (FA) with diatomite (DE) on the properties of geopolymer mortars. DE was used to partially replace FA at the levels of 0, 60, 80 and 100% by weight of binder. Sodium silicate ($Na_2SiO_3$) and sodium hydroxide (NaOH) solutions were used as the liquid portion in the mixture in order to activate the geopolymerization. The NaOH concentrations of 15M, $Na_2SiO_3$/NaOH ratios of 1.5 by weight, and the alkaline liquid/binder (LB) ratios by weight of 0.40, 0.50, 0.60 and 0.70 were used. The curing at temperature of $75^{\circ}C$ for 24 h was used to accelerate the geopolymerization. The flows of all fresh geopolymer mortars were tested. The compressive strengths and the stress-strain characteristics of the mortar at the age of 7 days, and the unit weights were also tested. The results revealed that the use of DE to replace part of FA as source material in making geopolymer mortars resulted in the increased in the workability, and strain capacity of mortar specimens and in the reductions in the unit weights and compressive strengths. The strain capacity of the mortar increased from 0.0028 to 0.0150 with the increase in the DE replacement levels from 0 to 100%. The mixes with 15M NaOH, $Na_2SiO_3$/NaOH of 1.5, LB ratio of 0.50, and using $75^{\circ}C$ curing temperature showed 7 days compressive strengths 22.0-81.0 MPa which are in the range of normal to high strength mortars.

• Korean System Dynamics Review
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• v.4 no.2
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• pp.71-94
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• 2003

The purpose of this dissertation is to build a development density control model and estimate optimum developmental density level for a sustainable urban growth management. To develop the model, system dynamics modeling approach was used. The model was developed to analyze how urban growth, transition, and decay occur depending on the interaction among population, houses, industry structure, land and urban infrastructure such as road, water supply, and sewage treatment facilities. The model was applied to Anyang city to estimate optimum density level. Extensive computer simulation was conducted to find out the maximum numbers of population, industry structure, houses, and cars that can be adequately sustained with the current Anyang city's infrastructure capacity. The computer simulation result shows that the city is overpopulated by some 90,000 people. It nab analyzed that 20％ increase of existing capacity of urban infrastructure is necessary to support current population of Anyang city. To reduce the population to the adequate level whereby the current urban infrastructure can sustain, the current city regulation on floor area ratio needs be strengthened at least 20％ to 35%.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.453-465
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• 2017

UN adopted the 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs) in 2015, a set of 17 objectives with 169 targets expected to guide actions over the next 15 years (2016-2030). One goal expressly focuses on the oceans, that is, SDG 14 'Conserve and sustainably use the oceans, seas and marine resources for sustainable development'. More than 30% of fish stocks worldwide were classified by FAO(2016) as overfished. Globally, world capture fisheries are near the ocean's productive capacity with catches on the order of 80 million metric tons. Aquaculture production is increasing rapidly and is expected to continue to increase, but aquaculture encounters some environmental challenges, including potential pollution, competition with wild fishery resources, potential contamination of gene pools, disease problems, and loss of habitat. Accordingly, there have been a variety of world organization and conferences stressing the importance of the implementation of the ecosystem-based fisheries management(EBFM) to overcome these problems. Annual catch of Korean fisheries have shown continuously declining patterns since late 1990s. Most fish stocks are currently known to be over-exploited, and some stocks are depleted due to the increase in fishing intensity and over-capitalization of fishing fleets. Other reasons for the depletion are land reclamations and coastal pollution, which destroy spawning and nursery grounds along the coastal regions. Aquaculture production is also increasing rapidly in Korea. However, several important issues such as gene pool and interaction with capture fisheries should be considered. The EBFM approach should use the best available information coupled with a reasonable application of the precautionary approach. The EBFM has global relevance, and so the real challenge will be to develop and use reliable, robust and cost-effective means of assessing and monitoring the status of ecosystems and their resources, and rapid means of detecting any undesirable and excessive impacts that threaten sustainable use. Future fisheries education should take into account UN's SDGs, which were adopted to achieve the global 2030 agenda. However, there are some difficulties in the current fisheries education system in Korea. First, the current education organizations are limited within the old frame of traditional fisheries sciences. Second, the fisheries education is currently lack of the future-oriented education system and of customized schools or departments. Third, the on-going fisheries education has been based upon few educational policies which are sufficiently relevant to holistic SDGs of the global standard. Accordingly, directions to modern fisheries education for achieving SDGs would be, first, the transition of fisheries education structure into the future-oriented and customized education system. Second, fisheries education needs to shift to the new paradigm, which combines traditional fisheries science education with related fields such as oceanography and environmental sciences to adopt the concept of EBFM. Lastly, fisheries education should accompany relevant policies for effectively achieving SDGs.