• International Journal of Internet, Broadcasting and Communication
• /
• 제9권2호
• /
• pp.1-10
• /
• 2017

The high costs of electric vehicle supply equipment (EVSE) and installation are currently a stumbling block to the proliferation of electric vehicles (EVs). The cost-effective solutions are needed to support the expansion of charging infrastructure. In this paper, we develope EV charging system based on the big data analysis of the power consumption patterns. The developed EV charging system is consisted of the smart EV outlet, gateways, powergates, the big data management system, and mobile applications. The smart EV outlet is designed to low costs of equipment and installation by replacing the existing 220V outlet. We can connect the smart EV outlet to household appliances. Z-wave technology is used in the smart EV outlet to provide the EV power usage to users using Apps. The smart EV outlet provides 220V EV charging and therefore, we can restore vehicle driving range during overnight and work hours.

• Nuclear Engineering and Technology
• /
• 제42권5호
• /
• pp.590-599
• /
• 2010

Recently, efficient operation and practical management of power plants have become important issues in the nuclear industry. In particular, typical aging parameters such as stress and cumulative usage factor should be determined accurately for continued operation of a nuclear power plant beyond design life. However, most of the major components have been designed via conservative codes based on a 2-D concept, which do not take into account exact boundary conditions and asymmetric geometries. The present paper aims to suggest an effective fatigue evaluation methodology that uses a prototype of the integrated model and its transfer functions. The validity of the integrated 3-D Finite Element (FE) model was proven by comparing the analysis results of individual FE models. Also, mechanical and thermal transfer functions, known as Green's functions, were developed for the integrated model with the standard step input. Finally, the stresses estimated from the transfer functions were compared with those obtained from detailed 3-D FE analyses results at critical locations of the major components. The usefulness of the proposed fatigue evaluation methodology can be maximized by combining it with an on-line monitoring system, and this combination, will enhance the continued operations of old nuclear power plants.

• 한국초전도ㆍ저온공학회논문지
• /
• 제9권1호
• /
• pp.86-90
• /
• 2007

The cryoprobe used in cryosurgery should be fabricated in milimeter-order size for its practical usage. In general a miniature J-T(Joule-Thomson) refrigerator is applied to a cryoprobe. In case of the miniature J-T refrigerator, the mass flow rate of working fluid is small due to considerable friction in a minute flow path. For that reason, the miniature J-T refrigerator has a limited cooling power. To obtain the large cooling power from the J-T refrigerator, the refrigerator should have large mass flow rate and effective J-T temperature drop. These quantities are closely related to the geometry of the heat exchanger and the expansion nozzle in a cryoprobe, and are contradictory. The large mass flow rate leads to the small J-T temperature drop and vice versa in the miniature J-T refrigerator. Therefore, the optimal design of a cryoprobe to achieve maximum cooling power at fixed tube size and fixed operating temperature is required. This paper presents the design procedure of such case.

• International Journal of Computer Science & Network Security
• /
• 제22권10호
• /
• pp.113-130
• /
• 2022

Sophisticated automation-based electronics world, more electrical and electronic devices are being used by people from different regions across the universe. Different manufacturers and vendors develop and market a wide variety of power generation and utilization devices under different operating parameters and conditions. People use a variety of appliances which use electrical energy as power source. These appliances or gadgets utilize the generated energy in different ratios. Night time the utilization will be less when compared with day time utilization of power. In industrial areas especially mechanical industries or Heavy machinery usage regions power utilization will be a diverse at different time intervals and it vary dynamically. This always causes a fluctuation in the grid lines because of the random and intermittent use of these apparatus while the power generating apparatus is made to operate to provide a steady output. Hence it necessitates designing and developing a method to optimize the power generated and the power utilized. Lot of methodologies has been proposed in the recent years for effective optimization and economical load dispatch. One such technique based on intelligent and evolutionary based is Black Widow Optimization BWO. To enhance the optimization level BWO is hybridized. In this research BWO based optimize the load for multi area is proposed to optimize the cost function. A three type of system was compared for economic loads of 16, 40, and 120 units. In this research work, BWO is used to improve the convergence rate and is proven statistically best in comparison to other algorithms such as HSLSO, CGBABC, SFS, ISFS. Also, BWO algorithm best optimize the cost parameter so that dynamically the load and the cost can be controlled simultaneously and hence effectively the generated power is maximum utilized at different time intervals with different load capacity in different regions of utilization.

• International Journal of Knowledge Content Development & Technology
• /
• 제11권3호
• /
• pp.7-27
• /
• 2021

This study was carried out to examine the awareness and use of social media tools by library and information professionals (LIPs) in selected academic libraries in South-west, Nigeria and the challenges they face in the use of social media technologies. Descriptive survey was adopted for this study. The population of the study comprised 217 library and information professionals from 10 selected academic libraries in south-west, Nigeria. A total enumeration technique was used to cover all the library and information professionals, 136 respondents filled and returned the questionnaire, given a response rate of 62.7%. The questionnaire was used as instrument for data collection. Descriptive statistics was used to analyze the data collected. The findings show that majority of LIPs possessed a high level of awareness in the use of social media tools. The study also revealed that social network tools were highly used by LIPs in the academic libraries studied and the types of social media used by LIPs was also revealed. The major challenges faced in the use of social media include inadequate power supply, lack of Internet access and time constraints. The paper recommended that to enhance the use of social media by LIPs, there is need for constant awareness of the importance of social media tools to LIPs and libraries in effective service delivery, LIPs should be ready to learn, unlearn and be learned in the use of social media and university libraries should provide enabling environment such as internet connectivity, power supply and policy to guide LIPs in social media usage.

• 산업경영시스템학회지
• /
• 제41권1호
• /
• pp.84-93
• /
• 2018

In this paper, we propose an Elman recurrent neural network to predict and analyze a time series of power energy consumption. To this end, we consider the volatility of the time series and apply the sample variance and the detrended fluctuation analyses to the volatilities. We demonstrate that there exists a correlation in the time series of the volatilities, which suggests that the power consumption time series contain a non-negligible amount of the non-linear correlation. Based on this finding, we adopt the Elman recurrent neural network as the model for the prediction of the power consumption. As the simplest form of the recurrent network, the Elman network is designed to learn sequential or time-varying pattern and could predict learned series of values. The Elman network has a layer of "context units" in addition to a standard feedforward network. By adjusting two parameters in the model and performing the cross validation, we demonstrated that the proposed model predicts the power consumption with the relative errors and the average errors in the range of 2%~5% and 3kWh~8kWh, respectively. To further confirm the experimental results, we performed two types of the cross validations designed for the time series data. We also support the validity of the model by analyzing the multi-step forecasting. We found that the prediction errors tend to be saturated although they increase as the prediction time step increases. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric and the gas energies.

• 한국철도학회논문집
• /
• 제8권6호
• /
• pp.610-616
• /
• 2005

The Incheon International Airport Express(I'Rex) is the railroad that connects Incheon International Airport, Gimpo Airport and Seoul Station. I'Rex is now under construction, and it will be connected to Gimpo Airport by 2007, to Seoul Station by 2010. However, there has been no discussion on how th connect different routes of railway Systems. Therefore it seems likely that rail passenger demand will be lower than that of limousine bus. Therefor, this paper proposes 4 effective connecting methods for I'Rex - (1) Shuttle transport, (2) Short-distance connecting transport (Inside I'Rex, Seoul Subway Line 9, 'Han-River line') (3) Mid-distance connecting transport (Jung-ang, Tae-baek, Young-dong line) (4) Long-distance connecting transport (Korean Train Express (Korean high speed railroad)) These methods can increase the connectivity of I'Rex with existing railroads and the competition power of I'Rex against a highway.

• 한국지반환경공학회 논문집
• /
• 제11권5호
• /
• pp.25-34
• /
• 2010

본 연구에서는 전국 화력발전소에서 부산되는 7,200만톤에 이르는 누적 매립회량을 대량 활용하기 위해 매립회의 특성 연구를 진행하였다. 일부 화력발전소에서는 비회와 저회가 분리되어 매립되고 있으나, 대부분의 화력발전소에서는 혼합 매립되고 있어 매립회의 공학적 특성이 규명되지 않아 이러한 공학적 특성을 규명하고자 영흥화력본부, 삼천포화력본부에서 부산되는 매립회와 비회를 사용하여 실험을 실시한 후 두 발전소의 매립회와 비회의 공학적 특성을 비교 분석하였다. 석탄회를 건설재료로 활용하기 위해 시료의 물리적 특성을 규명하고자 비중, 단위중량, 입도분석시험을 실시하였고, 역학적 특성을 규명하고자 삼축투수시험, 직접전단시험, 일축압축강도시험, 다짐시험을 실시하였다. 그리고 각 발전소에서 부산되는 석탄회의 특성을 알아보고자 무연탄 및 유연탄을 사용하는 발전소에서 부산된 석탄회의 공학적 특성들을 비교 고찰하였다. 시험결과 경량성의 건설재료로써 유연탄 발전소에서 부산된 석탄회를 사용하는 것이 유리하며 뒷채움재로의 활용은 투수계수가 상대적으로 큰 무연탄을 사용하는 발전소에서 부산되는 석탄회를 사용하는 것이 효과적이라 판단된다. 본 논문에서는 영흥화력본부의 비회가 가장 작은 투수계수를 나타냈으므로 불투수층을 요구하는 현장에 적용하기에 가장 적합할 것이라 판단된다.

• Preventive Nutrition and Food Science
• /
• 제16권4호
• /
• pp.321-327
• /
• 2011

Water, methanol and ethanol extracts of ginseng leaves were assayed for total phenolics and flavonoids, ascorbic acid, cupric and ferrous ion chelating activities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) assay and ABTS radical cation decolourization (TEAC) assay for their antioxidant properties. The ethanol extract of ginseng leaves contained significantly (p<0.05) higher amounts of total phenolics and flavonoids (600.57 and 1701 mg/100 g) than methanol (374.43 and 1512.64 mg/100 g) and water extracts (248.30 and 680.05 mg/100 g). Among solvent extracts of ginseng leaves, the ethanol extract showed the most powerful antioxidant activities. However, the ferrous ion chelating activity of ginseng leaf extracts were lower than the cupric ion chelating ability. These differences in concentrations of key antioxidants among various solvent extracts seemed to be responsible for their differences in antioxidant activities. These results suggest that ethanol extract of ginseng leaves has the most effective antioxidant capacity compared to the methanol and water extracts tested in the present study. Thus, it can be applied for the effective extraction of functional material from ginseng leaves for the usage of pharmaceutical and/or food industries.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2008년도 학술발표회 논문집
• /
• pp.2122-2126
• /
• 2008

With the degradation of water quality and, at the same time increased water usage, the sources of high quality, for examples, river/stream, municipal reservoir, wells, artisan and surface water, are diminishing. Therefore, the importance of water quality has been emphasized over the years through publications and various literature sources. Even though considerable research has resulted in significant strides for providing interpretive information and mitigation strategies for improvement of waters, the quality of which is still questionable. This study aims to propose a completely independent self-contained system for purifying waters, solar-powered ozone generator. It is a semi-permanent and cost effective environmental solution. Functions of ozone treatment are: 1) to maintain oxidative flexibility, 2) remove harmful chemicals, wastes, and other substances, and 3) prevent epizootic microbial outbreaks. Recent advances in technology have allowed the development of the practical, self-contained and independent solar powered device. Solar electrical producing panels that charge batteries are the key to using these systems anywhere electrical power is not available. This paper invites the readers to examine the problem and consider the viable, proven solution the solar powered ozone purifying system. This paper also introduces basic concept and background of solar powered ozone generators and examine its feasibility for improving water quality in rivers and streams.