• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.278-281
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• 2011

This system can predict the maximum output about all illumination levels so that the PV system designer can design the system having the best efficiency. For the output prediction exact about the solar cell, that is the device the basis most in the PV system, the basis has to be in order to try this way. The solution based on Lambert W-function are presented to express the transcendental current-voltage characteristic containing parasitic power consuming parameters like series and shunt resistances. A simple and efficient method for the extraction of a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. And the explicit analytic expression for V is obtained. This analytic expression is directly used to fit the experimental data and extract the device parameters. The I-V curve of the solar cell was expressed through the modeling using Lambert W-function and the numerical formula where there is the difficulty could be logarithmically expressed This method expresses with the I-V curve through the modeling using Lambert W-function which adds other loss ingredients to the equation2 as to the research afterward. And the solar cell goes as small and this I-V curve can predict the power penalty in the system unit.

• Membrane Journal
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• v.17 no.4
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• pp.277-286
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• 2007

The technology of seawater desalination has been received much attentions to solve the problem of water shortage through all over the world. In this study, it attempts to confirm the use-possibility of cellulose triacetate (CTA) for preparation of reverse osmosis membranes which have been highlighted as high efficiency and low energy consumption process for seawater desalination. The effects of casting dope parameters like an acetyl content, solvent, additives on the membrane performance were investigated. It was possible to produce the membranes which have high water flow rate and salt rejection with the increase of acetyl content and dioxane content among various dioxane/acetone ratios. Acetic acid and maleic acid were preferred for additives to produce high performance membranes. It was verified that $HOLLOSEP^{(R)}$ module which is commercialized CTA membrane by TOYOBO Co. can produce stable water production and high-quality water for long-term operation in the practice plants without any chemical treatments.

• Membrane Journal
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• v.27 no.1
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• pp.104-107
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• 2017

Among many methods in solving the organic contamination in the reverse osmosis operation, caustic soda (NaOH) wash method is efficient and commercially affordable. In continuation of our many organic pollution removal works, this study focused mainly on caustic soda wash with micro-bubble to removal the organic contamination of the spent membrane from reverse osmosis process. First, the membrane was forced the pollute using known organic pollutants such as Humic acid, Bovine serum albumin, Sodium alginate drug. The organic contamination on the membrane was monitored flux. The decontamination of organic contaminants was derived flux variation at individual caustic soda was injected micro-bubble methods and combined method as well. the found results explain removal of organic contaminants effective only by combined caustic soda wash with micro-bubble methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.43-50
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• 2010

DDC(Digital Down Converter) is a conversion technology to decimate to a lower sampling rate and DDC for the future development of communications technology has the necessary skills. So, it has been recognized in the wireless and the SDR(Software Defined Radio) system as essential components. In addition, research is underway on spectrum sensing for efficient communications environment due to the shortage of frequency resources. In this paper, the DDC systems were analyzed for CIC(Cascaded Integrator Comb) Filter, WDF(Wave Digital Filter), SRC(Sample Rate Conversion) each module. Moreover, we proposed a linkage effectively between DDC system and Spectrum Sensing for improve the efficiency of use of frequency by computer simulations. The simulation results of the DDC system was applied to the spectrum sensing capabilities. Also, performance and complexity of the results were derived and proposed system was the result of the check.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.217-224
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• 2016

As livestock diseases such as foot-and-mouth disease are highly infectious and likely to inflict nationwide damage, it is important to detect such diseases in advance. Infection of foot-and-mouth disease is determined in the field through examination of external symptoms such as rise in body temperature. However, as the disease is carried around initially by travelling veterinarians in some cases, it is critical to measure the body temperature of livestock to detect abnormal temperature pattern early on and transmit temperature reading data remotely to a veterinarian remotely to expedite decision. In this study, we have developed a telemedicine system designed to connect veterinarians and livestock farmers and measure the body temperature of Korean beef cattle with IR sensor module linked to ubiquitous ICT platform as a solution for controlling health conditions of Korean beef cattle and improving the efficiency of livestock farming operations at individual farm, regional, and national level by converging ubiquitous ICT platform and livestock farming practices. Successfully employing the state-of-the-art IT technologies of Korea, the system proposed herein is expected to make Korea's livestock farming industry more sustainable and help the nation to secure technological preeminence in the global livestock products market.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.322-323
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• 2015

Traditional rotation type large beacon was characterized by frequent failure, long repair time and high cost etc. These problems are caused by traditional light sources(metal halide lamps or tungsten halogen lamps). In order to solve these problems, IALA standards-based(efficiency and reliability) large LED beacon technologies are needed. we developed by applying a LED. The object of the this project, to design a reflective optics and the high power LED lighting engine module. And to develop a rotational speed control system for controlling flash pattern of beacon. As a result, to develop of LED beacon for landfall mark that distance to reach the light 20NM to 27NM.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.189-194
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• 2014

In this paper, PV modules using a low-temperature conductive film(LT-CF) as a bonding material between a cell and a solder free ribbon were produced and chracterized, which is more environmental-friendly, cost effective and high efficient. Mainly, filed electrical performance of PV modules using three different types of bonding material; a convetional solder ribbon(SR), a LT-CF and a light-capturing Ribbon(LCR) were compared to comfirm the feasibility of LT-CF as a bonding material. The filed test were conducted for 3 months and results were discussed in terms of amount of output energy production and efficiency.

• Journal of the Korea Institute of Building Construction
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• v.14 no.3
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• pp.244-251
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• 2014

Project Management Information System (PMIS) has not yet fully met needs of the construction industry. Based on the deficiency of the current system, the present study performed a survey to identify a need for mobile PMIS in the industry. The survey revealed that most respondents expect the development of mobile PMIS would contribute to improving the productivity and efficiency of field operations. Based on the survey findings, this study proposes a suite of modules for mobile PMIS, which are focused on construction management, document management, schedule management, and field information management. Mobile PMIS would allow to access from the field through mobile devices by using tablet computers and smart-phones. The study also suggests that the effectiveness of the system can be enhanced by user interfaces that are customized for each module.

• Korean Journal of Construction Engineering and Management
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• v.21 no.3
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• pp.76-84
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• 2020

The rate of application of the modular plant in the plant industry is increasing, and for the success of the modularization projects, it is essential to develop and implement a systemized methodology across all phases of the project. However, Korean EPC firms lack project management capability when it comes to apply standardized methodology. Therefore, it is important to establish and systematize the cost/schedule integrated management method which are the two core elements of project management technology. This study was conducted to develop a methodology and guidelines for integrated management process for modular plant projects. The researchers developed a methodology for planning and managing cost and schedule, and integrated by module unit. Integrated cost and schedule methodology and guidelines developed can be used for various EPC modular plant projects to enhance the efficiency of project management.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.16-21
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• 2010

It is well-known that Boron-doped Cz Si solar cells suffer light-induced degradation due to boron-oxygen defect which is responsible of a reduction in lifetime and hence efficiency. In this paper, we assume that PV solar cell has been connected with variable load to account the real operating condition and it shows different light-induced degradation of Si solar cell. To evaluate the effect of light-induced degradation for solar cell with various load, Single crystalline solar cells are connected with open and short circuits during light exposure. Isc-Voc curve evaluate light induced degradation of solar cells and the reason is explained as a change for serial resistance. From the results, Electrical characteristics of solar cells show better performance under short circuit conditions, after light exposure.