• Journal of Institute of Control, Robotics and Systems
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• v.4 no.5
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• pp.585-591
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• 1998

It is proposed a new compensation method in the rotor time constant of indirect vector controlled induction motor. The proposed scheme is an on-line method using the stator current error that is the difference between current command and estimated current calculated from terminal voltages and currents. As the current error becomes to zero, the rotor time constant in the vector controller approaches the real value. The proposed method shows good performances in the transient region as well as in the steady state region regardless of load torque variation, and it is verified by the computer simulation using SIMULINK in Matlab.

• Journal of Power Electronics
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• v.18 no.1
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• pp.300-308
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• 2018

An online estimation method for wireless power transfer (WPT) systems is presented without using any measurement of the secondary side or the load. This parameter estimation method can be applied with a controlling strategy that removes both the receiving terminal controller and the wireless communication. This improves the reliability of the system while reducing its costs and size. In a wireless power transfer system with an LCCL impedance matching circuit under a rectifier load, the actual load value, voltage/current and mutual inductance can be reflected through reflected impedance measuring at the primary side. The proposed method can calculate the phase angle tangent value of the secondary loop circuit impedance via the reflected impedance, which is unrelated to the mutual inductance. Then the load value can be determined based on the relationships between the load value and the secondary loop impedance. After that, the mutual inductance and transfer efficiency can be computed. According to the primary side voltage and current, the load voltage and current can also be detected in real-time. Experiments have verified that high estimation accuracy can be achieved with the proposed method. A single-controller based on the proposed parameter estimation method is established to achieve constant current control over a WPT system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.6 no.1
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• pp.147-163
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• 1998

The purpose of this research is to look for the best description of calculating the reasonable Landing Fee. Landing Fee is consisted one of major revenues for maintaining an airport. Traditional Landing Fee Rate has been charged based on the weight factor; Maximum take-off weight, Maximum landing weight, or Maximum authorized weight. To achieve a better reliable value of Landing Fee Rate, The elements of Noise and Peak-Time have to be considered as well as the aircraft weight. This research designs the algorithms for calculating Landing Fee Rate and also Landing Fee, based on the aircraft weight. The Network is also applied to above. That is, CGI(Common Gate Interface) is constructed to interface the terminal of calculating Landing Fee Rate, and the terminal of collecting and transmitting the data such as the Weight. The computer language on the CGI was made by C++ and PERL. The main point of this research is to integrate the airport and Information System and to construct the database which is based on the different perspective of calculating Landing Fee Rate. However, the result of the most efficient and reliable will be computed based on above. This research will broaden the range of application up to the each case of airports.

• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.30-36
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• 2008

This paper suggests the best work conditions, including short break time and number of mouse clicks on a computer, to prevent MSDs(Musculoskeletal Disorders) on VDT(Visual Display Terminal) work. Discomfort measures are calculated according to the Borg's CR-10 Scale. The short break time conditions are grouped into 7, 15, and 30 seconds after every 10-minute work period and the number of mouse clicks are divided into 10 clicks/min, 20clicks/min, and 30clicks/min. The result of the ANOVA on the shift value of subjective discomfort shows the following: 1) Regarding the break time and the number of mouse clicks, there are statistical differences between the measured values for the neck and the wrist(p<0.05). 2) Regarding the number of mouse clicks, there are statistical differences between the measured values for the shoulder and the forearm(p<0.1). 3) Regarding the break time and the number of mouse clicks, there are no statistical differences between the measures values for the eyes, upper arms and back(p<0.1).

• KSBB Journal
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• v.14 no.6
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• pp.724-730
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• 1999

Characteristics and enzyme activity comparison was made between urokinase isolated from urine and pro-urokinase separated from CHO(Chinese Hamster Ovary) cell culture broth. Both of purified urokinase and pro-urokinase resulted 54Kd single band in electrophoresis. Urokinase which was proved as a single molecule by gel filtration showed two separated 33Kd and 21Kd bands by 2-mercaptoethanol reduction. Isoelectric forcusing resulted same pl value of 8.6 for both of them. N-terminal amino acid sequence of urokinase after 159th Ile was Ile-Gly-Gly-Glu-Phe-Thr-Thr-Ile-Glu which was different from another N-terminal sequence of Ser-Asn-Glu-Leu-His-Gln-Val-Pro-Ser-Asn. Thrombolytic activities of both of them were propotional to the enzyme concentration. Urokinase showed thrombolytic activities in an short period of reaction time. Pro-urokinase, however, showed high thrombolytic activity for 2 hours or longer period of reaction time.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.638-645
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• 2017

A model for predicting the transport velocity was proposed using the correlation of the particle entrainment rate in the gas fluidized bed. The emptying time method was simulated using correlations of Choi et al. and Li and Kato. In order to exclude the influence of the unit of the gas velocity, the dimensionless velocity obtained by dividing the gas velocity by the terminal velocity was used as the value of the x-axis. The inverse of the particle entrainment rate was used as the value of the y-axis. When increasing the gas velocity, the non-dimensional velocity, at which the decreasing slope of the y-value is 0.398 [$m^2s/kg$] in absolute value, was considered as the transport velocity. The transport velocity predicted by the model was in good agreement even at high temperature and high pressure.

• Journal of Hospice and Palliative Care
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• v.19 no.4
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• pp.296-302
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• 2016

Purpose: This study examined the effectiveness of a hand massage combined with analgesics on pain control in hospice patients with terminal cancer. Methods: This study is a quasi-experimental study with a single group time series design. The study included 25 terminal cancer patients who were admitted to a hospice ward. Each patient's pain level was measured after analgesics use only (control group). When patients complained of pain again, the pain level was assessed after administering a combination of hand massage and analgesics (experimental group). As for the experimental treatment, the participants were provided with oil hand massage on each hand for 5 minutes. Results: The experimental group and the control group showed no significant differences in the changes of pain score (F=0.74, P=0.3939). Conclusion: Although the pain level of the experimental group did not significantly improve compared with the control group, their pain levels tended to be low to begin with. Thus, a complementary utility value of hand massage cannot be completely excluded in terminal cancer patients. Since the pain level significantly changed according to the dosage of analgesic, nurses need more education and research on analgesic drug therapy for terminal cancer patients.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.3
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• pp.374-379
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• 2007

This paper focuses on the improvement of fault detection algorithm in FRTU(feeder remote terminal unit) on the feeder of distribution power system. FRTU is applied to fault detection schemes for phase fault and ground fault. Especially, cold load pickup and inrush restraint functions distinguish the fault current from the normal load current. FRTU shows FI(Fault Indicator) when the fault current is over pickup value or inrush current. STFT(Short Time Fourier Transform) analysis provides the frequency and time Information. FCM(Fuzzy C-Mean clustering) algorithm extracts characteristics of harmonics. The neural network system as a fault detector was trained to distinguish the inruih current from the fault status by a gradient descent method. In this paper, fault detection is improved by using FCM and neural network. The result data were measured in actual 22.9kV distribution power system.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.996-1001
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• 2010

In this paper, network selection algorithm for services of mobile IPTV(internet protocol television) and implementation of a hierarchical processing system for reducing overload by terminal with low speed is proposed. This algorithm selects the network according to the following priorities derived from formulas; value that uses remaining bandwidth, network cost, signal strength. If terminal has a low processing power for using selected network and TV service, quality of service declines due to the system overloading. Hence, we implemented system which processes selected network and TV services accomplished by layer divided. Through experiments results, the method of direct user network selection waits for bandwidth assignment. However, on the one hand, that waiting time in exhausted situation will be very long. On the other hand, if we consider the priority plot of used networks, we should select the network with the best state. Therefore, data transmission rate will keep on average and the waiting time will be low.

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.359-367
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• 2013

The amount of international trade is rapidly increasing as a result of globalization. It is well known that as the size of a vessel becomes larger, the transportation cost per container decreases. That is, the economy-of-scale holds even in maritime container transportation. As a result, the sizes of containerships have been steadily increased for reducing transportation costs. In addition, various handling technologies and handling equipment have been introduced to increase the throughput capacities of container terminals. Quay crane (QC) that carries out load/unload operations plays the most important role among various handling equipment in terminals. Two typical examples of advanced QC concepts proposed so far are double trolley QC and supertainer QC. This paper suggests a method of estimating the expected value and the standard deviation of the container handling cycle time of the advanced QCs that involve several handling components which move at the same time. Numerical results obtained by the proposed estimation procedure are compared with those obtained by simulation studies. In order to demonstrate the advantage of advanced QCs, we compared their expected cycle times with those of a conventional QC.