• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.500-507
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• 1989

The improvement of volumetric efficiency of air charging into combustion chamber is a primary requirement to obtain better mean effective pressure of an engine. Since parameters such as the air resistances in intake and exhaust flow passages, valve lift and valve timing influence greatly to the volumetric efficiency, it is very convenient and time saving if we can optimize these parameters by computation before we enter into long time fact finding engine tests. In this study we have developed a semi-empirical engine simulation program for the determinations of intake and exhaust valve timings, valve lifts, intake and exhaust port diameters in order to obtain highest volumetric efficiency. In this computation it requires only the measured variational pressures in intake and exhaust port. Using these variational pressures as an input data for our simulation program, we can calculate volumetric efficiency more accurately and can save computing time drastically. To confirm the validity of our simulation program we have made engine operation test in parallel and taken the experimental data. Comparing the computation result with the experimental data obtained through real engine test it has shown only the difference of 3%.

• Journal of Families and Better Life
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• v.28 no.6
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• pp.169-181
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• 2010

The purpose of this study was to identify the effect of living cost reduction through social welfare services and programs and to suggest the further ways of saving living cost for low-income households. For the research purpose, low-income household type was divided into three representative groups such as senior household, household with school-aged children, and household with the disabled based on the literature review. Four case households which live in permanent rental apartment in Seoul were selected as research subjects. During March 14~April 10, 2010, each household was interviewed to examine the details of monthly income and expenditure structure and types of welfare services receiving. Although some differences exist among cases, there was a definite living cost reduction effect through welfare services and programs from 12% to 150%. Household with school-aged children required diversified education programs corresponding to the children's age. Meanwhile, households including senior and the disabled indicated the necessity of convenient transportation system.

• KIEAE Journal
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• v.2 no.1
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• pp.3-10
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• 2002

The purpose of this study is make a proposal for application skill of Ecological communal. Ecological communal is Environmentally friendly lifestyle and an alternative plan of Environmental pollution. There is growing international scientific consensus that human activities are having a discernible effect on the global climate. The environment was polluted the cause by The Development of scientific technique and economy. Recently, Environmental pollution spreads through over the world over. Moreover, An increasing gulf between the rich and the poor. In result, rise to the emergency in cooperation with the whole world. We need to advance a new direction for society to take in order to suffer environmental problems which have emerged as the most serious. The development of ecological communal is directed toward realizing a sustainable society. If life styles are to become less dependent on ecological resources and reduce externalities, same as Ecological communal, then a wide range of renewable energy technologies and energy saving measures are required. Up to now, the development of ecological communal has been actively initiated and still continues by some venture farmers whit a vision and strong will. These study results are definitely very conducive to spread ecological communal knowledge among the public.

• Journal of the Korean Institute of Educational Facilities
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• v.20 no.3
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• pp.41-52
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• 2013

In the current condition of seeking eco-friendly development, Green Building Certification Criteria can reduce environment burden that is able to be arose in life cycles of buildings. Moreover, it is a great help to induce to constructing pleasant environment. The ripple effect that also improves saving of energy and resources of the whole country, and green-house gases reduction effect and environment friendliness of other buildings can be expected by promoting eco-friendly education facilities which accounts for a great part of public buildings in comparison with other buildings. In this study, analysis of old and new indicators' contrast and contents in Green Building Certification, and post evaluation of education facilities and interviews on authorities were proceeded for improving evaluation indicator of each item in Green Building Certification Criteria. As a result, it analyzed problems in terms of institution and operations management, and drew implications accordingly. In addition, it has a significance in that it proposes improvements of substantively applicable indicators with high applicability.

• Advances in environmental research
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• v.3 no.4
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• pp.337-353
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• 2014

The determination of the effectiveness of the immobilization of blasting dust (waste generated in galvanic activities) in cement matrix, as well of mechanical, physical and microstructural properties of concrete paving blocks produced with partial replacement of cement was the objective of this work. The results showed that blasting dust has high percentage of silica in the composition and very fine particle size, characteristics that qualify it for replacement of cement in manufacturing concrete blocks. The replacement of Portland cement by up to 5% residues did not cause a significant loss in compressive strength nor increase in water absorption of the blocks. Chemical tests indicated that there is no problem of leaching or solubilization of contaminants to the environment during the useful life of the concrete blocks, since the solidification/stabilization process led to the immobilization of waste in the cement mass. Therefore, the use of blasting dust in the manufacture of concrete paving blocks is promising, thus being not only an alternative for proper disposal of such waste as well as a possibility of saving raw materials used in the construction industry.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.329-338
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• 2021

The mobile payment system has not only changed the payment pattern but also has improved the performance of small and medium-sized enterprises (SMEs) and individuals' quality of life by saving their energy, reducing the risk of taking cash, and enabling them to give more time to businesses and do international business. Besides, with the current advancement in the Internet as well as the digital transformation, SMEs are being forced to adopt mobile payment systems (MPS). The purpose of this study is to investigate the effects of technological-organizational-environmental (TOE) determinants on the adoption of MPS and its impact on SMEs' firm performance operating in Ghana. This research employed a closed-ended questionnaire to collect data from January 2020 - April 2020. This study used a structural equation modeling (SEM) approach using SmartPLS 3.0 for path analysis of 145 responses. The findings of the study include the statistically significant effects of technological (relative advantage and compatibility), organizational (top management support and employees' readiness), and environmental (social influence and competitive pressure) factors on the adoption of MPS. Furthermore, this study also proved the positive and statistically significant effect of MPS on SMEs' performance. This study demonstrated that the TOE factor explains 70% variations in the adoption of MPS.

• 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.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.385-392
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• 2022

As energy-saving techniques based on human behavior patterns have recently become an issue, the occupant-centered control system is adopted for estimating personal preference of indoor environment and optimizing environmental comfort and energy consumption. Accordingly, IoT devices have been used to collect indoor environmental quality (IEQ) data and personal data. However, the need to safely collect and manage data has been emerged due to cybersecurity issues. Therefore, this paper aims to present a framework that can safely transmit occupant-centered data collected from IoT to a private blockchain server using Hyperledger fabric. In the case study, the minimum value product of the mobile application and smartwatch application was developed to evaluate the usability of the proposed blockchain-based occupant-centered data collection framework. The results showed that the proposed framework could collect data safely and hassle-free in the daily life of occupants. In addition, the performance of the blockchain server was evaluated in terms of latency and throughput when ten people in a single office participated in the proposed data collection framework. Future works will further apply the proposed data collection framework to the building management system to automatically collect occupant data and be used in the HVAC system to reduce building energy consumption without security issues.

• Asia Marketing Journal
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• v.16 no.1
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• pp.229-241
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• 2014

In 1997 the Asian Foreign Currency Crisis hit Korean shores. In its wake, Korean consumers demanded cost-saving solutions which will increase both the use-life and the fuel efficiency their vehicles. Bullsoneshot's effects include increases in gas mileage as well as cleaner cylinders, intakes and exhaust valves, the product was welcomed by an explosive demand from people driving older cars in an adverse economy. The history of Bullsone can be categorized as two major stages. The First stage is lunching era of "Bullone Shot" following competitor brand. The second stage is extension stage of brand and line based on Bullsone's positive brand equity. Mr. Hyun Woo Shin, formal CEO of OXY inc. and also formal vice president of OCI (Oriental Chemical Industries) take charge of New CEO of Bullsone. He energetically push the Bullsone's family brands and got a desirable results. He also setup ambitious goal : reach 100bn KRW in gross sales within 3 years. "Ripping itself free from 30~40 bn KRW sales range in which the company has stagnated in the last 10 years, Bullsone intends to be aggressive enough in marketing to reach 150 bn KRW in sales in 2013, and reach 700 bn KRW by 2018." This is the goal iterated by Bullsone's top executive team.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.758-766
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• 2023

Multi-copter of unmanned aerial vehicle (UAV) was initially developed as strategic technology in the only military field, but it is developing into an industrial field with a wide range of applications in the civil sector based on the development and convergence of aviation technology and information and communication technology. Currently, the degree of utilization of multi-copter is increasing in various industries for the purpose of performing classic tactical missions, logistics transportation, farm management, internet supply, video filming, weather management, life-saving, etc, and active technology development responding to market demand. Existing commercial multi-copter mainly use an electric energy propulsion system consisting of an electric battery and a brushless direct current (BLDC) motor. It is the limitations for usage in the flying time (up to 20 minutes) and payload (less than 20 kg). this study aims to overcome these limitations and expand the commercialization of engine-powered multi-copter of UAV in various industries in the futures.