• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.421-428
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• 2008

The DVS(Dynamic Voltage Scaling) technique is the method to reduce the dynamic energy consumption. As using slack times, it extends the execution time of the big load operations by changing the frequency and the voltage of variable voltage processors. Researches, that controlling the energy consumption of the processors and the data transmission among processors by controlling the bandwidth to reduce the energy consumption of the entire system, have been going on. Since operations in multiprocessor systems have the data dependency between processors, however, the DVS techniques devised for single processors are not suitable to improve the energy efficiency of multiprocessor systems. We propose the new scheduling algorithm based on DVS for increasing energy efficiency of multiprocessor systems. The proposed DVS algorithm can improve the energy efficiency of the entire system because it controls frequency and voltages having the data dependency among processors.

• Convergence Security Journal
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• v.15 no.3_1
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• pp.75-82
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• 2015

Recently, lot of researches on multi-level protocol have been done to balance the sensor node energy consumption of WSN and to improve the node efficiency to extend the life of the entire network. Especially in multi-hop protocol, a variety of models have been studied to improve energy efficiency and apply it in real system. In multi-hop protocol, we assume that energy consumption can be adjusted based on the distance between the sensor nodes. However, according to the physical property of the actual WSN, it's hard to establish this. In this paper, we propose low-power sub-cluster protocol to improve the energy efficiency based on the spread of distance. Compared with the previous protocols, the proposed protocol is energy efficient and can be effectively used in the wireless sensing network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11C
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• pp.1059-1066
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• 2009

In this paper, we propose the precoder with superimposed pilots for orthogonal frequency-division multiple access (OFDMA) systems in order to enhance the transmission efficiency of the system and reduce peak-to-average power ratio (PAPR) which is the problem in OFDMA uplink. In wireless communication systems, the way to improve transmission efficiency is 1) to reduce bit error rate (BER) or 2) to increase data rate. In the proposed scheme, we design the precoder and superimposed pilots in the transmitter and use them in the receiver for increasing data rate, caused by the saved transmission bandwidth thanks to the superimposed pilots. In addition, we improve BER performance with the help of the frequency diversity gain caused by precoding. Also using superimposed pilots, we enhance the PAPR performance by increasing the average output power of the signal.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1149-1157
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• 2017

The satisfiability problem is always a core problem in artificial intelligence (AI). And how to improve the efficiency of algorithms solving the satisfiability problem is widely concerned. Algorithm IER (Improved Extension Rule) is based on extension rule. The number of atoms and the number of clauses affect the efficiency of the algorithm IER. DPLL rules are helpful to reduce these numbers. Then a complete algorithm CIER based on splitting rule and extension rule is proposed in this paper in order to improve the efficiency. At first, the algorithm CIER (Complete Improved Extension Rule) reduces the scale of a clause set with DPLL rules. Then, the clause set is split into a group of small clause sets. In the end, the satisfiability of the clause set is got from these small clause sets'. A strategy MOAMD (maximum occurrences and maximum difference) for the algorithm CIER is given. With this strategy, a better arrangement of atoms could be got. This arrangement could make the number of small clause sets fewer and the scale of these sets smaller. So, the algorithm CIER will be more efficient.

• The Journal of Korean Medicine
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• v.41 no.1
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• pp.1-10
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• 2020

Objectives: This study investigated the financial performance of Korean Medicine hospitals in Korea in order to understand the current status of hospital management and improve its efficiency. Methods: Financial statements of 24 medical corporations, 19 juridical foundations and 18 school hospitals from 2016 to 2018 were obtained from the secondary data published by the Health Insurance Review and Assessment Service, the National Tax Service and the Korea Advancing Schools Foundation. Financial performance was measured on 6 dimensions: liquidity, profitability, activity, growth, cost and productivity (investment efficiency) by analyzing 8 financial indicators: Liability to Total Assets, Net Profit to Patient Service Revenues, Total Assets Turnover, Growth Rate of Patient Service Revenues, Operating Expenses to Patient Service Revenues, Value Added to Patient Service Revenues, Value Added to Total Assets, and Value Added to Personnel Expenses. Results: Korean Medicine hospitals showed lower Liability to Total Assets, Liquidity and Value Added to Total Assets than Western Medicine hospitals did. They also showed higher Value Added to Patient Service Revenues and Value Added to Personnel Expenses than Western Medicine hospitals did. They also showed higher Value Added to Patient Service Revenues and Value Added to Personnel Expenses than those of Western Medicine hospitals do. The net profit decreased significantly (-50.8%) in 2018 whereas Patient Service Revenues increased (6.9%) for the same period due to Operating Expenses increase and Non-Operating loss. Conclusions: These findings suggest that the Korean Medicine hospital sector in Korea needs to improve liquidity and financial structure and to enhance profitability by reducing Personnel Expenses and generating Non-operating revenues in order to improve its investment efficiency and competitiveness.

• Elastomers and Composites
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• v.59 no.1
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• pp.8-16
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• 2024

As regulations on greenhouse gas emission have strengthened globally, the demand for improved fuel efficiency in automobiles continues to rise. In response, the tire industry is actively conducting research to improve fuel efficiency by enhancing tire performance. In this study, silica-filled epoxidized natural rubber (ENR)/butadiene rubber (BR) blend compounds were manufactured according to ENR types and silica contents, and their physical properties and vulcanizate structure were evaluated. ENR-50, which has a higher epoxide content than ENR-25, exhibited stronger filler-rubber interaction, resulting in superior abrasion resistance. In addition, because of its high glass transition temperature (T_g), the wet grip performance of ENR-50 improved, even though the rolling resistance increased. Increasing the amount of silica had little effect on the abrasion resistance due to the increase in filler-rubber interaction and decrease in toughness. In addition, ENR-50 exhibited better wet grip performance; however, the rolling resistance increased. The results indicated that truck bus radial (TBR) tire tread compounds can be designed by applying ENR-50 to improve wear resistance and wet grip performance. In addition, by applying ENR-25 and reducing the silica contents improve fuel efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.98-102
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• 1994

There are many difficulties in automatic polishing for die & mold surfaces. Even though the process has been studied in the past 15 years, it has not been achieved yet, but by the process of actual hand work of well-skilled workers. A new magentic assisted polishing process, which is one of the potential method for automation of surface finishing has been studied in the past 10 years by colleagues. The process has many merits, but on the other hand also has demerits, one being low efficiency of gridability by comparision with grinding wheel polish. Therefore, some attempts were tried to improve the grindability by adopting electropolishing, ultra-high speed milling, 5-axis controlled machine etc... most recently by collegues. This study also aims to improve the efficiency of polishing by introducing the easily-polished shape surface milling method equalizing the tool feed per tooth to the pick feed. This milling method was experimentally confirmed to have sufficient grindability to polish milled surface (with 10 .mu. mRmax surface roughness) into mirror surface (with 0.4 .mu. mRmax surface roughness).

• Journal of Agricultural Extension & Community Development
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• v.15 no.2
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• pp.293-323
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• 2008

The purpose of this study is to suggest some policy recommendations on the development of agricultural research of public agricultural institution. Critics say public agricultural institution are not working fast enough. As for efficiency itself, it seems reasonable to conclude that privatization plan is the best plan. The change that is needed to improve the efficiency of public agricultural institution is not the point in question. I will concentrate on the extraordinary nature of agriculture. We must not forget the important of extraordinary nature of agriculture. What is important is to have a genuine debate on extraordinary nature of agriculture and agricultural research. My aim is to highlight some aspects of agricultural research of public institution. Most important thing is, agricultural research is a valuable resource for nation. As I mentioned before, the change that is needed to improve the efficiency of public agricultural institution is not the point in question But there is much room for consideration for proper method. Impatient privatization without serious consideration could have a negative impact on the agricultural research.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.258-269
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• 2022

In these days, innovative functions are required to unmanned parcel delivery lockers. As non-face-to-face transactions become the center due to the recent COVID-19 pandemic, many problem occurs in society such as theft crimes and lack of loading space. Therefore, New concept storage device is developed in korea. It has the functions that minimizes empty spaces by using the internal transport device to enable efficient space loading and refrigerate goods such as foods. In order to systematically approach the system design of the unmanned parcel delivery lockers which is the new function is applied, We applied model-based system engineering to improve the development efficiency and use a system modeling language to express the system. We conducted interworking research of CAD data including system modeling and design data. it is expected that this method will increase the effective development efficiency such as maintenance traceability and reduction of development period and cost.

• Korean Journal of Health Education and Promotion
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• v.29 no.2
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• pp.71-81
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• 2012

Objectives: Effective and efficient response for public health crisis necessitate planning how to respond and mobilize the resources in schools. We preformed this study to develop the strategies to improve efficiency of school health education in an outbreak of pandemic disease. Methods: We tried to review the policies, regulations and response systems of all related sectors, and advanced cases associated with pandemic disease control measures by searching databases and on-line networks connected with the Korean Ministry of Education, Science and Technology. Results: It was important to implement a consistent and systematic approach for educational offices and schools to prevent confusion resulted from the inaccurate information. First, the systems and action plans for school health should be established to prepare and respond to an outbreak of pandemic disease. Secondly, the strategies to improve the efficiency of school health education in public health crisis should be in place. Finally, the personnel pool would be needed to provide the crisis management programs. Conclusion: In order for staffs and students to have abilities to respond in an outbreak of pandemic disease, comprehensive school health approaches and efficient educational efforts should be prepared in collaboration with related sectors.