• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.8
• /
• pp.36-41
• /
• 2006

Computer Loads can be found in all of modern society. The switching mode power supplies used in personal computers are major sources of harmonic currents. Harmonic currents can cause lots of harmonic problems such as disruption in computer performance. A series resonant filter is very effective in harmonic reduction for personal computer loads. Voltage sags are short duration reductions in rms voltage. The main causes of voltage sags at faults, motor starting, and transformer energizing. Personal computers are another example of devices sensitive to voltage sags. A serious voltage sag at the terminals way lead mis-operation of the equipment. This paper presents an in depth analysis to evaluate the effect of harmonics reduction based on the IEC 61000-3-2 and the effect of voltage sag using ITI curve by applying a series resonant filter for personal computer loads.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.429-432
• /
• 2009

The deformation and burst pressure of composite motor case highly depends on fiber material properties. Therefore, measuring exact fiber material properties is a priority item to develop a advanced composite motor case. However, the fiber material properties in composite motor case is very sensitive on the various processing variables (equipment, operator and environmental condition etc..)and size effect, so the fiber material properties can't be measured exactly from the existing specimen test method. This paper suggests a newly developed test method, hoop ring test, that is capable of pressure testing with ring specimens extracted from real composite motor case. The results of hoop ring test showed excellent agreement with measured fiber material properties from hydro-burst test with full scale composite motor cases.

• Korean Journal of Optics and Photonics
• /
• v.15 no.6
• /
• pp.519-526
• /
• 2004

We developed a 2-D imaging system to detect ultra weak biophoton by using a high sensitive fast CCD camera. We installed an illumination apparatus to generate delayed luminescence from plant leaves. Shutters at the illumination system and detector were synchronized to each other. The lens system of the CCD camera was newly designed to accommodate the specific requirements to enhance the collection efficiency for biophoton. Based on the lens simulation, commercial lenses were chose for the lens system. All the equipment was installed in a multi-purpose dark box and the delayed luminescence of Euonymus japonica was successfully acquired.

• Composites Research
• /
• v.23 no.3
• /
• pp.37-42
• /
• 2010

The fiber material properties, elastic constant and strength, are the most important factors among the various material properties for the design of composite pressure vessel, because of it's dominant influence on the performance of composite pressure vessel. That is, the deformation and burst pressure of pressure vessel highly affected by the fiber material properties. Therefore, the establishment of test method for exact fiber material properties is a priority item to design a composite pressure vessel. However, the fiber material properties in filament wound pressure vessel is very sensitive on various processing variables (equipment, operator and environmental condition etc..) and size effect, so that it isn't possible to measure exact fiber material properties from existing test methods. The hydro-burst test with full scale pressure vessel is a best method to obtain fiber material properties, but it requires a enormous cost. Thus, this paper suggests a newly developed test method, hoop ring test, that is capable of pressure testing with ring specimens extracted from real composite pressure vessel. The fiber material properties from hoop ring test method showed good agreement with the results of hydro-burst test with full scale composite pressure vessels.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.126-126
• /
• 2014

Label-free biomolecular assay based localized surface plasmon resonance (LSPR) of noble metal nanoparticles enables simple and rapid detection with the use of simple equipment. Nanosized metal nanoparticles exhibit a strong absorption band when the incident light frequency is resonant with the collective oscillation of the electrons, which is known as the LSPR. Here we demonstrate localized surface plasmon resonance (LSPR) substrates such as plasmonic Au nanodisks fabricated by a nanoimprinting process and gold nanorod-immobilized surfaces and their applications to highly sensitive and/or label-free biosensing. To increase detection sensitivity various bioreceptors weree designed. A single chain variable fragment (scFv) was used as a receptor to bind C-reactive protein (CRP). The results of this effort showed that CRP in human serum could be quantitatively detected lower than 1 ng/ml. Aptamers, which were immobilized on gold nanorods, were used to detect mycotoxins. The specific binding of ochratoxin A (OTA) to the aptamer was monitored by the longitudinal wavelength shift of LSPR peak in the UV-Vis spectra resulting from the changes of local refractive index near the GNR surface induced by accumulation of OTA and G-quadruplex structure formation of the aptamer. According to our results, OTA could be quantitatively detected lower than 1 nM level. Additionally, aptamer-functionalized GNR substrate was quite robust and can be regenerated many times by rinsing at 70 OC to remove bound target. During seven times of washing steps, the developed OTA sensing system could be reusable. Moreover, the proposed biosensor exhibited selectivity over other mycotoxins with an excellent recovery for detection in grinded corn samples, suggesting that the proposed LSPR based aptasensor plays an important role in label-free detection of mycotoxins.

• Progress in Superconductivity
• /
• v.10 no.1
• /
• pp.60-67
• /
• 2008

We present domestic efforts for superconducting fault current limiter (SFCL) application in the Korea Electric Power Corporation (KEPCO) grid and pending points at issue. KEPCO's decision to upgrade the 154 kV/22.9 kV main transformer from 60 MVA to 100 MVA cast a problem of high fault current in the 22.9 kV distribution lines. The grid planners supported adopting an SFCL to control the fault current. This environment friendly to SFCL application must be highly dependent upon the successful development of SFCL having specifications that domestic utility required. The required conditions are (1) small size of not greater than twice of 22.9 kV gas insulated switch-gear (GIS), (2) sustainability of current limitation without the line breaking by circuit breakers (CB) for maximum 1.5 seconds. Also, optionally, recommended is (3) the reclosing capability. Conventional resistive SFCLs do not meet (1) $\sim$ (3) all together. A hybrid SFCL is an excellent solution to meet the conditions. The hybrid SFCL consists of HTS SFCL components for fault detection and line commutation, a fast switch (FS) to break the primary path, and a limiter. This characteristic structure not only enables excellent current limiting performances and the reclosing capability, but also allows drastic reduction of HTS volume and small size of the cryostat, resulting in economic feasibility and compactness of the equipment. External current limiter also enables long term limitation since it is far less sensitive to heat generation than HTS. Semi-active operation is another advantage of the hybrid structure. We will discuss more pending points at issues such as maintenance-free long term operation, small size to accommodate the in-house substation, passive and active control, back-up plans, diagnosis, and so on.

• Korean Journal of Food Science and Technology
• /
• v.35 no.5
• /
• pp.928-936
• /
• 2003

Monte Carlo simulation was used to predict the contamination levels of Listeria monocytogenes and Yersinia enterocolitica in final pork products. Mean values of the estimated log contaminated levels of L. monocytogenes on carcasses, cut meats, and cut meats after storage were -4.59, -4.46 and -4.45 $log_{10}CFU/cm^2$ respectively. The mean values of estimated log contaminated levels of Y. enterocolitica on carcasses, cut meats, and cut meats after storage were -3.44, -4.00 and -3.97 $log_{10}CFU/cm^2$, respectively. Sensitivity analysis showed that L. monocytogenes and Y. enterocolitica in pork was most sensitive to the prevalence of L. monocytogenes and Y. enterocolitica in the equipment used.

• Bulletin of the Korean Space Science Society
• /
• 2004.10b
• /
• pp.347-350
• /
• 2004

A space radiation analysis has been used to evaluate an ability of electronic equipment boxes or spacecrafts to endure various radiation effects, so it helps design thicknesses of structure and allocate components to meet the radiation requirements. A comparison study of space radiation dose analysis programs SPENVIS Sectoring Tool (SST) and SIGMA II is conducted through some structure cases, simple sphere shell, box and representative satellite configurations. The results and a discussion of comparison will be given. A general comparison will be shown for understanding those programs. The both programs use the same strategy, solid angle sectoring with ray-tracing method to produce an approximate dose at points in representative simple and complex models of spacecraft structures. Also the particle environment data corresponding to mission specification and radiation transport data are used as input data. But there are distinctions between them. The specification of geometry model and its input scheme, the assignment of dose point and the numbers, the prerequisite programs and ways of representing results will be discussed. SST is a web-based interactive program for sectoring analysis of complex geometries. It may be useful for a preliminary dose assessment with user-friendly interfaces and a package approach. SIGMA II is able to obtain from RSICC (Radiation Safety Information Computational Center) as a FOR-TRAN 77 source code. It may be suitable for either parametric preliminary design or detailed final design, e.g. a manned flight or radiation-sensitive component configuration design. It needs some debugs, recompiling and a tedious work to make geometrical quadric surfaces for actual spacecraft configuration, and has poor documentation. It is recommend to vist RSICC homepage and GEANT4/SSAT homepage.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.9 no.2
• /
• pp.153-160
• /
• 2015

With the development of recent IT fusion technology, IT fusion technology of medical equipment has been dramatically development. The need to most basic preferential implementation of emergency is the respiration of the patient, it is necessary to first aid is maintained in emergency patients airway simultaneously. However, to the endotracheal intubation is a procedure to secure the airway, it requires experience and first aid, Inc. good career, very that may lead to sequelae in patients who otherwise have failed to procedures It is a sensitive and important procedure. For these reasons, the success rate of current endotracheal intubation technique is not at a high level and about 50 percent. In an attempt to complement these problems, in this paper, in the process of endotracheal intubation, intubated by inserting an endoscopic camera to Into Activation tube, the streaming is a real-time monitoring and wireless video transmission method using, there is a purpose of enabling the monitoring in smart devices increase the success rate of endotracheal intubation of first aid purchases.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.4
• /
• pp.23-30
• /
• 2000

Cogeneration systems are seen as a significant innovation for dispersed energy generation since they are both environmentally friendly and has comparatively high degrees of efficiency. It is especially suited for the decentralized provision of electricity and heat. However, it causes operational problems such as voltage regulation, voltage variation, protection and safety. Especially, it is expected that the interconnection/disconnection operation of cogeneration system has an effect on distribution voltage regulation and variation. Recently, with the increased use of customer-owned computers and other sensitive electronic equipment, electric power quality has become an important concerns. Therefore, the voltage quality problems with cogeneration system should be investigated because the voltage quality is an important part of electrical power quality. In this paper, the momentary voltage dips associated with the interconnection/disconnection operation of cogeneration system are analyzed, including restraint solutions at the customer level. In addition, the unit capacity of cogeneration systems per feeder are evaluated from the view point of momentary voltage variations. The results of this paper are useful analysis data for interconnection standards/guidelines of cogeneration systems and dispersed generation (DG)