• International Journal of Concrete Structures and Materials
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• v.8 no.3
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• pp.229-238
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• 2014

Typical high-performance concrete (HPC) mixtures are characterized by low water-cementitious material ratios, high cement contents, and the incorporation of admixtures. In spite of its superior properties in the hardened state, HPC suffers from many practical difficulties such as its sensitivity to early-age cracking (which is associated with self-desiccation and autogenous shrinkage). In this context, conventional curing procedures are not sufficiently effective to address these limitations. In order to overcome this issue, two strategies,which are based on the use of internal reservoirs of water, have been recently developed.One of these strategies is based on the use of lightweight aggregates (LWA), while the other is based on the use of superabsorbent polymers (SAP). This paper studies and compares the efficiency of the LWA and SAP approaches.Moreover, some of the theoretical aspects that should be taken into account to optimize their application for internal curing of HPC are also discussed. Two fine LWA's and one SAP are studied in terms of autogenous deformation and compressive strength. Increasing the amounts of LWAor SAP can lead to a reduction of the autogenous deformation and compressive strength (especially when adding large amounts). By selecting appropriate materials and controlling their amount, size, and porosity, highly efficient internal water curing can be ensured.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.290-299
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• 2005

Two decommissioning projects are carried out at the KAERI (Korean Atomic Energy Research Institute), one for the Korea research reactors, KRR-1 and KRR-2, and another for the uranium conversion plant (UCP). The concept of the management of the wastes from the decommissioning sites was reviewed with a relation of the decommissioning strategies, technologies for the treatment and the decontamination, and the characteristics of waste. All the liquid waste generated from KRR-1 and KRR-2 decommissioning site is evaporated by a solar evaporation facility and all the liquid waste from the UCP is treated together with lagoon sludge waste. The solid wastes from the decommissioning sites are categorized into three groups; not contaminated, restricted releasable and radioactive waste. The not-contaminated waste will be reused and/or disposed at an industrial disposal site, and the releasable waste is stored for the future disposal at the KAERI. The radioactive waste is packed in containers, and will be stored at the decommissioning sites till they are sent to a national repository site. The reduction of the radioactive solid waste is one of the strategies for the decommissioning projects and could be achieved by the repeated decontamination. By the achievement of the minimization strategy, the amount of radioactive waste was reduced and the disposal cost will be reduced, but the cost for manpower, for direct materials and for administration was increased.

• Wind and Structures
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• v.21 no.3
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• pp.331-352
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• 2015

A series of wind tunnel tests were conducted on tapered super high-rise buildings with a square cross section by applying synchronous pressure measurement technology. The effects of global strategy of chamfered modification on aerodynamic loads and wind-induced responses were investigated. Moreover, local aerodynamic strategies of opening a ventilation slot in the corner of equipment and refuge floors were carried out. Results show that the global strategy of tapered elevation increased the vortex shedding frequency, but reduced vortex shedding energy, leading to reduction of across-wind aerodynamic loads and responses. Chamfered modification suppressed the across-wind vortex shedding effect on tapered buildings. Opening the ventilation slot further suppressed the strength of vortex shedding and reduced the residual energy related to vortex shedding in aerodynamic loads of chamfered buildings. Finally, the optimized locations of local aerodynamic strategies were suggested.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.2
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• pp.82-86
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• 2005

E-learning programs in every organizations are increasing rapidly every year. As the internet and multimedia tool spreads into every departments of organization work settings, the paradigm of education has changed. In the context of government and public organization, e-Learning has merits in the convenience of access, the reduction of costs, self-directed learning and so on. The purpose of this study is to find out some insights and lessons from the case analysis of e-Learning introduction strategies in ministry of labor.

• Journal of the Korean Society of Combustion
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• v.22 no.1
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• pp.1-7
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• 2017

This paper presents an experimental study on the effect of double injection strategies on combustion characteristics in a single-cylinder diesel engine. These studies are applied to the double injection strategies, such as $2^{nd}$ injection timing variations with fixed injection interval (8 degree) and variations of injection pressures with fixed injection timing and intervals. The injection quantity was 7 + 7 mg for double injections, and 14 mg for single injection. When the injection pressure was increased, the ignition delay was shortened, and the ISFC (indicated specific fuel consumption) was increased due to the fast termination of combustion by the shortened energizing duration. In addition, the retardation of injection timings toward TDC (top dead center) caused the reduction of ignition delay and the decrease of ISFC with the decrease of FMEP (friction mean effective pressure).

• Journal of Climate Change Research
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• v.7 no.1
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• pp.41-48
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• 2016

Korea has introduced Korea Emissions Trading Scheme (Korea ETS) since 2015. However, not many companies voluntarily participate in the emissions trading. The goal of this paper is to provide the way to improve the Korea ETS. This study compares the Korea ETS with EU Emissions Trading System, which has been practiced for a decade, and suggests three strategies to activate the Korea Emissions Trading Scheme. The first thing is to encourage more companies to participate in the emissions trading since the number of companies in the emissions trading in Korea is quite limited compared with that of EU. The second thing is to activate the trading of Korean Credit Unit in order to stimulate various emission reduction mechanisms. Currently, the most of the trading in the emissions market is through the Korean Allowance Unit. The third thing is to establish concrete measures to continuously improve the Korea ETS. A comprehensive evaluation of the Korea ETS is needed along with the ongoing convergence with the associated comments. The improvement of Korea ETS would be one of the most efficient ways to compete the climate change, and would also play a role to raise the status of Korea.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.905-916
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• 2018

The purpose of this study was to analyze factors affecting US beef consumption intention in the future, to identify the causes of US beef import growth and to derive implications and strategies for domestic beef producers. Since the KORUS FTA was signed in 2012, US beef imports in 2017 totaled 379,064 tons, an annual increase of 3.5 percent. US beef imports have been steadily increasing due to cuts in FTA tariffs and changes in consumer preferences. The data used in this study utilized a sample of 3,290 grocery purchasers from the Korea Rural Economic Institute's 2016 Food Consumption Behavior Survey. The analytical method used the Ordered Logit Model to analyze what factors influence a consumer's subjective evaluation. As a result, the major factors affecting US beef consumption intention in the future are price, taste and safety. In particular, it has to do with the recent surge in U.S. imports of good-tasting chilled meat. Because chilled meat does not differentiate the market from Hanwoo beef produced in Korea, it is necessary to have differentiated taste and low price through cost reduction. By age and family group, people aged 30 - 40 years and single-person households are the main consumption group. As a result of this study, it is necessary to establish marketing strategies for producers such as rational pricing, safety, taste promotion, and small-scale sales to extend the demand for Hanwoo beef in the younger generation to enhance the competitiveness of the domestic beef market.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.465-472
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• 2022

Manual material handling is the one of the leading causes for musculoskeletal disorders (MSDs) and lower back discomfort. According to a study, construction formworkers suffer greater rates of muscular injuries and related illness due to manual activities. However, there is still a paucity of information on MSD, preventive posture issues, and corresponding solutions for construction aluminum formworkers. As a result, MSD and disregard of worker health and safety continue to exist at construction sites. Although preventive measures and strategies have been studied in previous research, we believe it is imperative to shed light on this problem through this study. This study aims to 1) implement a simple and cost-effective elevated bench to reduce MSDs, and 2) determine the rapid upper limbs assessment (RULA) and Ovako working posture analyzing system (OWAS) action catagory of workers in different postures to assess their MSD conditions and obtain an optimal position and posture using the Jack human modeling software and simulation tool. The study findings reveal a considerable reduction in MSD discomfort and which posture is acceptable in post-intervention instances.Thus results provide inexpensive and simple ergonomic interventions with favorable RULA and OWAS ratings that can be applied at construction sites. This study demonstrates workstation ergonomic intervention cases that can aid in understanding the urgency of applying existing research strategies into practice.

• Clinical Endoscopy
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• v.56 no.4
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• pp.433-445
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• 2023

Endoscopic retrograde cholangiopancreatography (ERCP) plays a crucial role in the management of pancreaticobiliary disorders. Although the ERCP technique has been refined over the past five decades, it remains one of the endoscopic procedures with the highest rate of complications. Risk factors for ERCP-related complications are broadly classified into patient-, procedure-, and operator-related risk factors. Although non-modifiable, patient-related risk factors allow for the closer monitoring and instatement of preventive measures. Post-ERCP pancreatitis is the most common complication of ERCP. Risk reduction strategies include intravenous hydration, rectal nonsteroidal anti-inflammatory drugs, and pancreatic stent placement in selected patients. Perforation is associated with significant morbidity and mortality, and prompt recognition and treatment of ERCP-related perforations are key to ensuring good clinical outcomes. Endoscopy plays an expanding role in the treatment of perforations. Specific management strategies depend on the location of the perforation and the patient's clinical status. The risk of post-ERCP bleeding can be attenuated by preprocedural optimization and adoption of intra-procedural techniques. Endoscopic measures are the mainstay of management for post-ERCP bleeding. Escalation to angioembolization or surgery may be required for refractory bleeding. Post-ERCP cholangitis can be reduced with antibiotic prophylaxis in high risk patients. Bile culture-directed therapy plays an important role in antimicrobial treatment.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.237-250
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• 2024

The emission of noxious gases is a significant problem in pig production, as it can lead to poor production, welfare concerns, and environmental pollution. The noxious gases are the gasses emitted from the pig manure that contribute to air pollution. The increased concentration of various harmful gasses can pose health risks to both animals and humans. The major gases produced in the pig farm include methane, hydrogen sulfide, carbon dioxide, ammonia, sulfur dioxide and volatile fatty acids, which are mainly derived from the fermentation of undigested or poorly digested nutrients. Nowadays research has focused on more holistic approaches to obtain a healthy farm environment that helps animal production. The use of probiotics, prebiotics, dietary enzymes, and medicinal plants in animal diets has been explored as a means of reducing harmful gas emissions. This review paper focuses on the harmful gas emissions from pig farm, the mechanisms of gas production, and strategies for reducing these emissions. Additionally, various methods for reducing gas in pigs, including probiotic interventions; prebiotic interventions, dietary enzymes supplementation, and use of medicinal plants and organic acids are discussed. Overall, this paper provides a comprehensive review of the current state of knowledge on reducing noxious gas in pigs and offers valuable insights for pig producers, nutritionists, and researchers working in this area.