• Journal of Industrial Convergence
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• v.21 no.8
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• pp.51-58
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• 2023

Blockchains have recently struggled to design for the ideal distributed trust networks by solving scalability trilemma. However, local conflicts between some countries lead to imbalance on energy distribution. Besides, blockchain networks (e.g., Bitcoin) currently consume enormous energy for transaction and mining. The existing data volume based trust model evaluated an increasing blockchain size better than Lubin's trust model in scalability trilemma. In this paper, we propose a scalability based energy model to evaluate sustainability for blockchain networks, considering energy consumption for transaction, time duration, and the blockchain size of growing blockchain networks. Through the rigorous numerical analysis, we compare the proposed scalability based energy model with the existing model for the satisfaction and optimal blockchain size. Thus, the scalability based energy model will provide an assessment tool to choose the proper blockchain networks to solve scalability trilemma problem and prove sustainability.

• Steel and Composite Structures
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• v.19 no.2
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• pp.277-292
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• 2015

Previous research has shown that steel plate shear walls (SPSWs) are efficient lateral force-resisting systems against both wind and seismic loads. A properly designed SPSW can have high initial stiffness, strength, and energy absorption capacity as well as superior ductility. SPSWs have been commonly designed with unstiffened and stiffened infill plates based on economical and performance considerations. Recent introduction and application of corrugated plates with advantageous structural features has motivated the researchers to consider the employment of such elements in stiffened SPSWs with the aim of lowering the high construction cost of such high-performing systems. On this basis, this paper presents results from a numerical investigation of the hysteretic performance of SPSWs with trapezoidally corrugated infill plates. Finite element cyclic analyses are conducted on a series of flat- and corrugated-web SPSWs to examine the effects of web-plate thickness, corrugation angle, and number of corrugation half-waves on the hysteretic performance of such structural systems. Results of the parametric studies are indicative of effectiveness of increasing of the three aforementioned web-plate geometrical and corrugation parameters in improving the cyclic response and energy absorption capacity of SPSWs with trapezoidally corrugated infill plates. Increasing of the web-plate thickness and number of corrugation half-waves are found to be the most and the least effective in adjusting the hysteretic performance of such promising lateral force-resisting systems, respectively. Findings of this study also show that optimal selection of the web-plate thickness, corrugation angle, and number of corrugation half-waves along with proper design of the boundary frame members can result in high stiffness, strength, and cyclic performances of such corrugated-web SPSWs.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.442-446
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• 2015

As electricity consumption is increasing rapidly these days, an urgent. need exists to minimize consumption through smart and intelligent ways in order to prevent a future energy crisis. For this purpose, development of an intelligent peak power management system should be required. As the number of appliances and consumer electrical devices increase, power consumption in unit business tends to grow. Generally, electricity consumption can be minimized using a peak power management system capable of. effectively controlling the load power by continuously monitoring the power. In this work, a peak power management system which consists of arduino microprocessor equipped with ethernet and Zigbee shield is presented. To verify the feasibility of the proposed scheme, laboratory-scale experiments are carried out.

• Journal of the Semiconductor & Display Technology
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• v.22 no.1
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• pp.104-112
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• 2023

Agriculture plays an industrial and economic role, as well as an environmental and ecological conservation role, group harmony and the inheritance of traditional culture. However, no matter how advanced the industry is, the basic food necessary for human life can only be produced through the photosynthesis of plants with natural resources such as the sun, water, and air. The Food and Agriculture Organization of the United Nations (FAO) predicts that the world's population will increase by another 2 billion people by 2050, and it faces a myriad of complex and diverse factors to consider, including climate change, food security concerns, and global ecosystems and political factors. In particular, in order to solve problems such as increasing productivity and production of agricultural products, improving quality, and saving energy, it is difficult to solve them with traditional farming methods. Recently, with the wind of the 4th industrial revolution, ICT convergence technology and artificial intelligence have been rapidly developing in many fields, but it is also true that the application of new technologies is somewhat delayed due to the unique characteristics of agriculture. However, in recent years, as ICT and artificial intelligence utilization technologies have been developed and applied by many researchers, a revolution is also taking place in agriculture. This paper summarizes the current state of research so far in four categories of agriculture, namely crop cultivation environment management, soil management, pest management, and irrigation management, and smart farm research data that has recently been actively developed around the world.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.904-910
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• 2013

The aim of this study was to investigate the eating behavior and nutritional status of subjects according to their purpose of exercise. A total of 214 subjects, 20 to 30 years of age, who visited fitness centers in Seoul were enrolled. Anthropometrics, exercise habits, nutritional knowledge, and eating behaviors were analyzed using a questionnaire. Nutritional status was assessed by serial 24 h recalls. The subjects were divided into two groups based on their purpose of exercise: increasing muscle (Muscle growth, n=107) or losing body weight (Weight loss, n=107). The Muscle growth group contained a higher percentage of men, whereas the Weight loss group contained a higher percentage of women. The Muscle growth group showed significantly higher scores of nutritional knowledge and eating behaviors compared to the Weight loss group. The Muscle growth group also had a significantly higher intake of energy and protein compared to the Weight loss group. In fact, the intake of energy in the Weight loss group was lower than the estimated energy requirement (EER) for both men and women subjects. The intake of protein in the Muscle growth group was twice as much as the recommended nutrient intake (RNI). The intake of calcium in both groups was less than the RNI. In conclusion, those who exercised with the aim of increasing muscle took excess dietary protein and those who exercised with the aim of weight loss had a lower energy intake than the EER.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.81-88
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• 2018

Every day a huge amount of paper is being used, most of them are thrown after using. This directly impacts on the environment. Therefore, waste paper management is necessity to protect the environment from its annihilation and pollution. Paper recycling products consist of printing paper, newspaper, corrugated containers, magazine paper and so on. Reuse waste paper will reduce the consumption of wood and virgin pulp as recycling one ton of newsprint can save approximately 1 ton of wood, meanwhile recycling 1 ton of printing paper can save more than 2 tons of wood. With increasing recycling rates, lower quality paper fractions may be included. Thus the selection of a paper recycling technology is a crucial first design consideration. The paper recycling must be accompanied by appropriate technology to manage a huge volume of wastepaper. The specific objectives of this study were as follows: (1) comprehensive literature reviews of paper production and consumption, (2) figure out about paper recovery and utilization, (3) investigate the paper recycling in the sustainable times, (4) introduce eco-friendly recycling technology to paper industry.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.286-293
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• 2010

Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.278-279
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• 2015

Recently, With the development of smart devices of interest in the intelligent indoor positioning service with a smart terminal it is increasing. The BLE(Bluetooth Low Energy) is an indoor location positioning technology has attracted the attention. However, there is no way to check the reliability of the position information collected by the smart terminal receiving a big location data. This is because the reliability of an indoor position information because of a signal interference to drop. In this paper, we propose a method of managing big data collected in order to obtain reliable position information from the position information of iBeacon.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.529-545
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• 2013

With the increasing concern on climate changes and energy shortage, anaerobic membrane bioreactors (AnMBR) become a promising alternative to aerobic processes for domestic wastewater treatment. Two major advantages of AnMBRs are energy production and sludge reduction. Recently, several different configurations of AnMBRs have been proved to produce high quality effluent at reasonable hydraulic retention time and ambient temperature. One of the major problems of the AnMBR is membrane fouling control, and some solutions are already suggested. Other problems to be solved before the full application of the AnMBR are recovery of dissolved methane, management of residual nutrients and sulfide. Considering the potential advantages and future technology development, AnMBR will become major domestic wastewater treatment process in near future.

• Journal of the Korean Solar Energy Society
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• v.40 no.3
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• pp.1-20
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• 2020

In accordance with the Government's policy, renewable power generation is expanding very largely. This leads to increasing uncertainty in the power market and power system owing to the intermittent and fluctuating output characteristics of renewable power generators. Data on the acquisition of renewable power generators can be largely classified according to the operation of the power market and power system. Data on the settlement for the payment for the power amount are acquired in the power market, and real-time data for monitoring the status and output of the generators are acquired in the power system. However, renewable power generators operating in the power market have different acquisition cycles depending on the method of communication of the power meter. They acquire data only for settlement purposes and have no real-time data, which requires improvement. In this paper, the acquisition status is reviewed by classifying the data of renewable power generators into settlement and real-time data. In addition, measures and acquisition criteria for real-time data of renewable power generators for improving the acquisition method are proposed.