• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.431-439
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• 2015

The methods which decrease the accident hazards of LPG(Liquefied Petroleum Gas) terminal on the basis of butane & propane storage tanks by applying HAZOP(Hazard and Operability), LOPA(Layer of Protection Analysis) and SIL(Safety Integrity Level) are suggested. The accident scenarios were derived by analyzing latent risks through the HAZOP. The scenarios which would have the big damage effect in accidents were selected and then LOPA was assessed by analyzing IPL(Independent Protection Layer) about the correspond accident scenarios. The improved methods were proposed on the basis of level of SIF(Safety Instrumented Functions) as a IPL considering satisfied condition of risk tolerance criteria($1.0{\times}10^{-05}/y$). In addition, The proposed IPLs were basis on the economic analysis. The effect of SIF as a IPL considering the changes of accident frequency was studied in case of the accident scenarios derived from the concerned process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.357-361
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• 2011

The terminal current in voltage driven systems is an essential role for characterizing the pattern of electric discharge such as corona, breakdown, etc. Until now, to evaluate this terminal current, Sato's equation has been widely used in areas of high voltage and plasma discharge. Basically Sato's equation was derived by using the energy balance equation and its final form described physical meaning explicitly. To give more general abilities in Sato's equation, we present a generalized approach by directly using the Poynting's theorem incorporating the finite element method. When the magnetic field effect or the time-dependent voltage source is considered, this generalized energy method can be easily applicable to those problems with any dielectric media such as gas, fluid, and solid. As an alternative approach, the integral Ohm's law resulting in small numerical errors has an ability to be applied to multi-port systems. To test the generalized energy method and integral Ohm's law, first, the results from two prosed methods were compared to those from Sato's approach and an analytic solution in parallel plane electrodes. After verification, the generalized method was applied to the tip-sphere electrodes for evaluating the terminal current with three carriers and the Fowler-Nordheim field emission condition. From these results, we concluded that the generalized energy method can be a consistent technique for evaluating the discharge current with various dielectric materials or large magnetic field.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.9-18
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• 2007

This paper proposes the modeling of sensorless drive system using 120 degree conduction method for IPM (Interior Permanent Magnet) BLDC motors and analyzes characteristics of the terminal voltage that is used to detect the rotor position. This paper shows that the ZCP (Zero-Crossing Point) of the measured terminal voltage used In sensorless control is ahead of that of the back EMF of IPM motors because they have a saliency. This research also analyzes that the amount of position detection error is related to saliency, rotor speed, and load condition. In addition, this paper shows that motors have bigger advance angles than we have expected because the ZCP of terminal voltage precedes the actual ZCP, and under operation conditions such as heavy load and high speed it may generate abnormal currents that flow toward opposite direction after phase current becomes zero.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2147-2152
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• 2011

This study of bimodal integration management system in conjunction with the tram and the tram cars bimodal integrated management system that occupies a part of the system to perform its role as a bimodal tram vehicle configuration, a device for the vehicle's infrastructure ryureul development and it is aimed to build on the vehicle. Bimodal tram vehicle infrastructure systems, internal and external information of the larger vehicles, and vehicles used to collect information for its own part and the integrated operations management center, or providing partial information from the station and collect/provide for the transfer of information to the communication part consists In this study, the core of these devices, the configuration of the vehicle infrastructure systems for the overall management and control of vehicles operating a computer's central processing device, vehicle infrastructure systems that make it manages and stores all jangchiryu Integrated Operations Management Center is reporting. In addition, seamless integration with operational management center for interactive communication in a vehicle mounted communications devices to maintain the best condition to manage. Current general traffic management system in a similar terminal device being used, but bimodal tram vehicles operating the computer of the vehicle operates the infrastructure to configure the devices around the one to configure the system in terms of step enhanced the active type, the operating terminal unit of inter active type. In this study, considering the future alignment of the accounting fee system, the expansion of the system reliability and stability around the activities that are underway.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.2
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• pp.54-60
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• 2015

Papiliocin, from the swallowtail butterfly, Papilio xuthus, shows high bacterial cell selectivity against Gram-negative bacteria. Recently, we designed a 22mer analog with N-terminal helix from $Lys^3$ to $Ala^{22}$, PapN. It shows outstanding antimicrobial activity against Gram-negative bacteria with low toxicity against mammalian cells. In this study, we determined the 3-D structure of PapN in 300 mM DPC micelle using NMR spectroscopy and investigated the interactions between PapN and DPC micelles. The results showed that PapN has an amphipathic ${\alpha}$-helical structure from $Lys^3$ to $Lys^{21}$. STD-NMR and DOSY experiment showed that this helix is important in binding to the bacterial cell membrane. Furthermore, we tested antibacterial activities of PapN in the presence of salt for therapeutic application. PapN was calcium- and magnesium-resistant in a physiological condition, especially against Gram-negative bacteria, implying that it can be a potent candidate as peptide antibiotics.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.476-482
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• 2009

This paper describes the development of capacitive sensor for the diagnosis of liquid dielectrics, which is widely used as the electrical insulating oil of transformer, circuit breaker, cable and etc. To survey the dielectric properties of the virgin and aged electrical insulating oils, we utilized the highly precise measuring system, using the principle of cross capacitance. The measured properties were used to determine the design factors of the sensor. Then the factors were optimized with the help of computational analysis. To evaluate diagnosis by the sensor, we performed accelerated thermal aging test about electrical insulating oils. The condition of aged specimens were investigated by measurements of relative permittivity i.e. capacitance change by capacitive sensor. And to evaluate the hysteresis characteristics with the change of temperature, we constructed a testing system, which was composed with vacuum drying oven, oil chamber and measuring instruments, such as LCR meter, MUX and so forth. Through the results of this investigation, we confirmed the superior characteristics of the newly developed sensor.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.541-545
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• 2009

This study evaluated the contact resistance, insulation resistance, withstand voltage characteristics and insertion force, etc., of the wire connector used inside an integrated LITE WAY lighting fixture developed for efficient installation. Since the connector connecting the lighting fixture's internal wires is housed, it is easily connected and separated and has a structure enabling a close-fitting connection. The temperature and time applied to the high temperature characteristics test of the connector are $105^{\circ}C$ and 16 hours, respectively. The measured contact resistance of the high temperature tested connector was 3.258 mV/A, and its measured insulation resistance was greater than $10\;G{\Omega}$ All specimens demonstrated uniform insulation characteristics, which could be seen to be in good condition. From the withstand voltage test results found before and after performing the high temperature operation test on the connector for cable connection, it was confirmed that the withstand voltage characteristics between all terminals were good. The insertion force of the connector connecting the internal wiring averaged 9.67 kgf. It was observed that the insertion force between the plug housing and the female terminal, and that between the plug housing and the male terminal, were 0.680 kgf and 1.27 kgf on average, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.399-400
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• 2006

LMTT(Linear Motor based Transfer Technology) is a new type of transfer system used in the maritime container terminal fur the port automation, and largely consists of a controller, shuttle car, and rail. The shuttle car is divided into the frame part, the driving part, and wheels. In order to design this system, various researches on each part of it must be conducted. In this study, we dealt with the optimum design for the frame part of the shuttle car designed from previous studies on the strength of the frame with respect to the number of cross beams to minimize the weight of the shuttle car and to satisfy design criteria of cargo-handling systems in container terminal. For the optimization of the frame, thicknesses of each beam were adopted as design variables, the weight of the frame as objective function, and stress and deflection per unit length as constraint condition.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.417-424
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• 2006

An ubiquitous healthcare monitoring system for elderly person at home was designed for continuous healthy monitoring of elderly person or patients. Human vital signals, such as ECG and body temperature, were monitored by terminal PC or PDA via ECG and temperature sensor nodes on the patient's body. From the ECG data, the heart rate, tachycardia, bradycardia and arrhythmia were diagnosed on the terminal PC or PDA to assist doctor's or nurse's aid or patient itself to monitor the patient's condition and give medical examination. Artificial judgement support system was designed in server computer and the system support a doctor or nurser for management or treatment of the patient. This system can be applied to vital signal monitoring system for solitude elderly person at self house or home health care service part. And this ubiquitous healthcare system can reduce the medical expenses in coming aging or aged society.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.70-75
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• 2008

Two extracellular amylase isozymes were purified and characterized from alkalophilic Pseudomonas sp. KFCC 10818 for the production of maltooligosaccharides. The molecular weights of the homogeneous proteins were 50 kDa and 75 kDa, respectively. The 50 and 75 kDa amylases showed optimum temperatures at 35 and $40^{\circ}C$, respectively. The optimum pH of the enzymes ranged from pH 6-8, and the enzymes were resistant to an alkaline condition of pH 12. Via the enzyme's actions, the final products from maltooligosaccharides or soluble starch were maltose and maltotriose. Calcium was a potent activator of the 50 kDa amylase. Finally, the N-terminal amino acid sequences of the 50 and 75 kDa amylases were QTVPKTTFV and DTVPGNAFQ, respectively.