• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1455-1462
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• 2018

As the interests in eco-friendly energy has increased, the interests in Electric Vehicles(EVs) are increasing as well. Moreover, due to the government's economic support for EVs, penetration level of it has rapidly increased. These sharp increases, however, induce various problems in distribution system, such as voltage/frequency variations, peak demand increasement, demand control, etc. To minimize these possible matters, lots of research have conducted. Nevertheless, most of it assumed extremely important factors, such as numbers and charging patterns of EVs. It inevitably results in errors in their research, and thus make it difficult to prevent the possible matters from EVs. In this paper, therefore, we use actual EVs charging data from KEPCO, and analysis and deduction of it were conducted. The simulations were carried out for four aspect(season, region, purpose).

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.460-466
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• 1999

The huge amount of demand for feedgrains from this region could not possibly be met by producing countries from the other regions. In order to fulfill this increasing demand for conventional raw materials, an alternative for the conventional raw materials produced in the Asia and Pacific region is becoming increasingly more important. A potential alternative is concentrates or non-conventional concentrates produced locally in relative abundance in this region. These feedstuffs include feed grains, by-products from the milling, sugar industries, brewing and distilling industries. Vegetable, citrus, and animal by-products from abattoir, feather meal and blood meal are also possibilities. In addition to more widespread use of unconventional feed sources, the following approach is recommended to improve utilization and performance. These include establishing the nutritive value of non-conventional feeds, quality control to minimize variability, proper storage and processing to assure the nutritive value and prevent mycotoxin contamination, properly balance amino acids with protein sources, supplementation with synthetic amino acids and the use of enzymes to increase digestibility. Currently, practical applications for these resources in feed formulation are negligible despite the potential. The socio-economic aspects will dominate the use of these non-conventional concentrates. In the future, the feed industry will resolve the problems in using locally available raw feed materials.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.93-104
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• 2007

We consider a supply chain where products are shipped to warehouse from manufacturing system to customers. Products are supplied from either in-house regular manufacturing or the secondary source such as subcontractor. The inventory in warehouse is controlled by base-stock policy, that is, whenever a demand arrives from customer, an order is released to the manufacturing system. Unsatisfied demand is backlogged. The manufacturing system is modeled as M/M/s+1/c queueing system, and the orders exceeding the given limit care blocked and lost. The steady state distribution of the outstanding orders and the throughput of the manufacturing system are functions of the level of engagement In the secondary source. There is a profit obtained from throughput and cost not only due to the engagement of the secondary source in the manufacturing system but also inventory positions. We want to maximize the total production profit minus the total cost of the production system by simultaneously determining the optimal level of engagement of the secondary source and the optimal base-stock level of the inventory. We develop two algorithms : one without guarantee of the optimal solution but with the small number of computations, the other optimal but with more computations.

• Journal of the Korean Applied Science and Technology
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• v.19 no.4
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• pp.302-310
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• 2002

Demand for organic analysis increase as industries are growing and many products are spreaded in the daily life. One of many products is oil spill dispersant. It was used for oil accident in the ocean. When oil spill dispersant spread at the ocean, the petroleum in the ocean is dispersed. The oil spill dispersant is made of non ionic surfactant and petroleum oil. The non ionic surfactant disperse petroleum from oil accident. The other part is petroleum oil which has aromatic hydrocarbon. Because the aromatic hydrocarbon is cancerogenic material, it directly injure animals in the ocean. This cause the second pollution in the human body. Many oil accidents still are controlled by oil spill dispersant. Therefore quality control of the oil spill dispersant become important and this also demand for the exact quantitative analysis of aromatic hydrocarbon. Hereupon the first we develop separate petroleum oil from surfactant. The second standardize analytical method of aromatic hydrocarbon in the separated petroleum oil.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.157-164
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• 2006

From the hazard which it prepares in the hazards increase which it follows in information demand augmentation of information technical development and the consumer from inside systematizing integrity and solubility of information technological resources. inside against a confidentiality. The control against information and a system and a data outside is demanded. From the dissertation which it sees demand function and the structure which do information technical risk management system development it will be able to manage the danger which it infiltrates with the root which is various overview in hazard necessity it investigated the inside and outside of the country instance in the center and it analyzed. And it plans the dangerous civil official integrated process model ultimately as against a hazards it will be able to prepare in the dictionary in order, it put the place objective which it induces.

• Journal of Power Electronics
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• v.10 no.1
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• pp.85-90
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• 2010

In this paper the effects of a Static Synchronous Series Compensator, which is constructed with a 48-pulse inverter, on the power demand from the grid are studied. Extensive simulation studies were carried out in the MATLAB simulation environment to observe the compensation achieved by the SSSC and its effects on the line voltage, line current, phase angle and real/reactive power. The designed device is simulated in a power system which is comprised of a three phase power source, a transmission line, line inductance and load. The system parameters such as line voltage, line current, reactive power Q and real power P transmissions are observed both when the SSSC is connected to and disconnected from the power system. The motivation for modeling a SSSC from a multi-pulse inverter is to enhance the voltage waveform of the device and this is observed in the total harmonic distortion (THD) analysis performed at the end of the paper. According to the results, the power flow and phase angle can be controlled successfully by the new device through voltage injection. Finally a THD analysis is performed to see the harmonics content. The effect on the quality of the line voltage and current is acceptable according to international standards.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1318-1320
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• 1999

Recently, according to the growth of national economy and the improvement of lining conditions, electric power demand is increasing gradually. So it is being examined to construct large thermal power plants or nuclear plants. For the effective use of lands and for the economy of generations sites, the distance between generation and demand locations becomes farther and farther. At the same time, people desire higher quality or electric power. So in this paper, the optimal modulation controller for HVDC transmission system are designed by a recursive algorithm that determines the state weighting matrix Q of a linear quadratic performance. It means that the application of optimal modulation controller in HVDC transmission system can contribute the propriety to the improvement of the stability in HVDC transmission system.

• Journal of Environmental Science International
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• v.25 no.3
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• pp.447-456
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• 2016

Access to clean and affordable water is one of the fundamental human rights because water is essential to life and a foundation for socioeconomic development of any country in the world. Despite the efforts to secure water supply in Burundi, the amount of water supplied by public utilities does not meet the demand of the population because population keeps increasing with fluctuation of weather conditions. This study selected north Bujumbura that is a sprawling new residential area in the western part of Burundi as a case to investigate the potential of rainwater harvesting in meeting water demand of the country. Based on a long-term average monthly precipitation in the region, the rainwater harvesting potential was assessed as a function of roof sizes, number of households, and runoff coefficients of roof materials. For the entire region of north Bujumbura, the current water supply capacity of the local water company combined with the rainwater harvesting potential resulted in the water surplus of $468,604.1m^3/yr$. Although three communes among them still showed water deficit in dry season, they still got help from rainwater to relieve their water shortage. This suggests that at the regional scale, proper storages and water quality control for harvestable rainwater could contribute to relieving the regional water shortage and allow the population growth.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.96-102
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• 2001

High intensity vibro-acoustic testing is the appropriate method for flight qualification testing of space flight vehicle which must ensure the acoustic environment of launch. Growing demand for satellites and launch vehicles in korea has resulted in a recent increase in the demand for high intensity vibro-acoustic test facility. The test facility is designed to provide an acoustic environment of 152 ㏈( re 20 ${\mu}$Pa) overall sound pressure level over the band width of 30 Hz to 10,000 Hz in the reverberant chamber. The reverberant chamber has a volume of 1,000 ㎥ with interior dimensions of 8.7m${\times}$l0m${\times}$12m, which can accommodate not only satellites but also launch vehicle payload fairing. Korea Aerospace Research Institute and Korean industries have been carrying out the development of the reverberant chamber and auxiliary devices, such as automatic control system, monitoring/safety device, and jet nozzle, etc. This paper presents the detailed description of High Intensity Acoustic Chamber of KARI, which will be the first and unique testing facility in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.106-111
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• 1992

In order to achieve stable and efficient use of energy at iron and steel works, a model for the prediction of supply and demand of electric power system is developed on the basis of the information on operation and particular patterns of electric power consumption. The optimal amount of electric power to be purchased and the optimal fuel allocation for the in-house electric power plants are also obtained by a mixed-integer linear programming(MILP) and a nonlinear programming (NLP) solutions, respectively. The validity and the effectiveness of the proposed model are investigated by several illustrative examples. The simulation results show the satisfactory energy saving by the optimal solution obtained through this research.