• Polymer(Korea)
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• v.25 no.6
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• pp.855-865
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• 2001

The optimization condition of injection molding for a commercial product of TV speaker grille of A Company was induced using a CAE software of Moldflow. The flow and packing phase analysis was performed by using flow balance, runner balance, and the intermediate one by using the above two balances, which were used for controlling the amount of packing resins into the cavity, Later, the analysis performed by using the measured viscosity (local database) at various shear rates and the results were compared with the computer simulation using the standard database. Flow balance induced minimized weld line resulted in a better appearance and physical properties of the were line, but exhibited a disadvantage of large deformation and gas formation due to over-packing of the molten resin in the center of the speaker grille. Runner balance improved the disadvantage of the flow balance by controlling the amount of molten resin injected from the gate, however resulted reduced mechanical properties and poor appearance of the weld line. However, the modified method induced from the flow and runner balance improved the disadvantages by changing the runner size. In addition, the analyses based on the local database and the standard database were compared. Although the measured viscosity was slightly higher and the temperature distribution was broader than the standard database, no distinct difference was obtained from the analysis using the two different databases.

• Journal of Korean Medicine Rehabilitation
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• v.27 no.4
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• pp.33-53
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• 2017

Objectives This study was designed to review animal studies about the efficacy of herbal medicine for Rheumatoid arthritis animal model which was published in Korea after 2008. We also systematically investigated the reporting quality of the animal studies. Methods We systematically searched original articles in 8 databases since 2008. And manual searching was conducted through 10 Korean medicine journals from 2008. Studies were included if they used animal experimental model(s) with orally administered herbal medicine. Data were extracted regarding animal model, rheumatoid arthritis indicator and detail of intervention. Reporting quality of each study was also assessed by the STARA and ARRIVE guidelines. Results Nine hundred two articles were screened. Finally, 35 articles were included. 35 studies all showed that the herbal medicine used in the studies has significant effect on alleviating the macroscopic indicators, hematological indicators, histological indicators, genetic indicators, osteological indicator of Rheumatoid Arthritis and others. Species of animals was reported in 100% while ventilation and noise were reported in 0% in STRASA guidelines. Ethical statement was reported in 42.9%, experimental animals and sample size were reported in 24%, 29% and there was no study reporting funding. Conclusions These results suggest that herbal medicine might be effective treatment for Rheumatoid Arthritis. It should be improved by clinical studies. And there is a need for studying about efficacy and safety of each specific herbal medicine. And we should improve the Reporting quality of the animal studies published in Korea.

• Journal of fish pathology
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• v.25 no.1
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• pp.39-46
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• 2012

Experiments were carried out to determine the hematological changes in freshwater tilapia Oreochromis niloticus, after water temperature (20, 25 and $30^{\circ}C$) and arsenic concentrations (200, and 400 ppb) exposure 20 days. The RBC count and hematocrit (Ht) were significantly increased in As 400 ppb and water temperature $30^{\circ}C$. Hemoglobin (Hb) was significantly increased under combined As (200 and 400 ppb) and water temperature $30^{\circ}C$. The tilapia exposed to water temperature $30^{\circ}C$ and As concentration 400 ppb increase significantly in calcium concentration. The high concentrations of total protein and glucose concentrations were observed at water temperature $30^{\circ}C$ and As concentration 400 ppb. A significant increment GOT and GPT activities in the tilapia serum noticed at water temperature (25 and $30^{\circ}C$) and As concentration (200, 400 ppb). These results indicate that tilapia can be affected by high water temperature ($30^{\circ}C$) and As concentration (400 ppb) in terms of inorganic matter, organic matter and enzyme activity in serum.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.835-842
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• 2009

DVB-SSP is a new broadcasting system for hybrid satellite communications, which supports mobile handheld systems and fixed terrestrial systems. However, a critical factor must be considered in upper layer decoding which including erasure Reed-Solomon error correction combined with cyclic redundancy check. If there is only one bit error in an IP packet, the entire IP packet is considered as unreliable bytes, even if it contains correct bytes. IF, for example, there is one real byte error, in an If packet of 512 bytes, 511 correct bytes are erased from the frame. Therefore, this paper proposed two kinds of upper layer decoding methods; LLR-based decoding and hybrid decoding. By means of simulation we show that the performance of the proposed decoding algorithm is superior to that of the conventional one.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.531-536
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• 2005

Inductively coupled plasma reactive ion etching of CoTb and CoZrNb magnetic materials with the photoresist mask was performed using $Cl_2/Ar$ and $C_2F_6/Ar$ gas mixtures and characterized in terms of etch rate and etch profile. As the concentrations of $Cl_2$ and $C_2F_6$ gases increased, the etch rates of magnetic films decreased and the etch slopes became slanted. The $Cl_2/Ar$ gas was more effective in obtaining fast etch rate and steep sidewall slope than the $C_2F_6/Ar$ gas. As the coil rf power and dc bias increased, fast etch rate and steep etch slope were obtained but the redeposition on the sidewall was observed. This is due to the increase of ion and radical densities in plasma with increasing the coil rf power and the increase of incident ion energy to the substrate with increasing the dc bias voltage. By applying high density reactive ion etching to magnetic tunnel junction stack containing various magnetic films and metal oxide, steep etch slope and clean etch profile without redeposition were obtained.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.246-252
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• 2016

Since thermal power plant (TPP) equipment is operated under very high pressure and temperature, failures of the equipment give rise to severe losses of life and property. To prevent the losses, fault detection method is, therefore, absolutely necessary to identify abnormal operating conditions of the equipment in advance. In this paper, we present Mahalanobis distance (MD) based fault detection method for steam boiler tube in TPP. In the MD-based method, it is supposed that abnormal data samples are far away from normal samples. Using multivariate samples collected from normal target system, mean vector and covariance matrix are calculated and threshold value of MD is decided. In a test phase, after calculating the MDs between the mean vector and test samples, alarm signals occur if the MDs exceed the predefined threshold. To demonstrate the performance, a failure case due to boiler tube leakage in 200MW TPP is employed. The experimental results show that the presented method can perform early detection of boiler tube leakage successfully.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.72-79
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• 2013

In the paper, a pattern analysis to decide whether the 1st local peak power point near open circuit voltage is the global peak power point or not, in case that the voltage and current at the 1st local peak power point are in a specific range, for Maximum Power Point Tracking on the photo voltaic power conversion system. When a solar cell panel array is shaded partially, multi-local peak power points can occur. That makes it hard to search the global peak power point. Through Tableau analysis using by piecewise linear solar cell model, V-I characteristic of a solar cell panel array circuit when partial shading problem happens, is simulated. The global peak power and the local peak power points is confirmed by simulations. Voltage and current values and patterns of V-I characteristic are analyzed. The generating efficiency of the solar cell panel array is improved, when the solar cell panel array circuit is operated at the power point estimated by setting up specific range.

• Journal of the Korean Geosynthetics Society
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• v.15 no.1
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• pp.21-35
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• 2016

It is a current trend that the concrete track is applied for high speed railway. In the case of the railway embankment constructed on soft ground, the damage to concrete track which is sensitive to settlement such as distortion and deflection could be caused by very small amount of long term settlement. Pile Supported Embankment method can be considered as the effective method to control the residual settlement of the railway embankment on soft ground. The Geosynthetics is used inside of the embankment to maximize the arching effect transmitting the load of the embankment to the top of the piles. But, PHC piles that are generally used for bridge structures are also applied as the pile supporting the load of embankment concentrated by the effect of the Geosynthetics. That is very low efficiency in respect of pile material. So, in this study, the cast in place concrete pile was selected as the most suitable pile type for supporting the embankment by a case study and the optimum mixing condition of concrete using a by-product of industry was induced by performing the mixing designs and the compressive strength designs. And it is shown that the cast in place pile with the optimum mixing condition using the by-product of industry is 2.8 times more efficient than the PHC pile for the purpose of Pile Supported Embankment by the finite element analysis method.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.3
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• pp.65-79
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• 2015

Objectives The aim of this study is to identify the satisfaction of Korean medicine treatment by traffic accident. Methods This study was carried out 103 cases of traffic accident patients which had been treatment in Dongshin university Korean medicine hospital and Chung-Yeon Korean medicine hospital from June, 2014 to September, 2014. The survey used by preceding articles was accepted for assessment of the satisfaction degree of patients in this study. All data were coded by SPSS v18.0 and analyzed by descriptive maneuver, x2-test, T-test and correlation. Results According to the survey, 93.2% of patients included this study were hospitalized in the Korean medical hospital within 2 weeks from TA and 90.3% were satisfied with the current medical service. The answer that Korean medicine is superior to western medicine for TA treatment was the main reason for selecting Korean medical hospital. 46.6% of patients satisfied Acupuncture treatment and 29.1% of patients satisfied Korean physical treatment. There were no differences in the satisfaction degree with sex, age, education and occupation. The satisfaction degree of the current Korean medical service was significantly correlated with doctor's service, use the procedure and reuse intention. Conclusions We could see that the satisfaction of Korean medicine treatment is relatively high. The continuous and repetitive research is needed in order to improve the quality of Korean medicine hospital service and the satisfaction of patients by traffic accident.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.3
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• pp.65-71
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• 2001

The nuclear power plant(NPP) should be shut down for inspection and tests prior to a return to power if the earthquake exceeds the operating basis earthquake(OBE). The OBE at the plant is considered to have been exceeded if the computed cumulative absolute velocity(CAV) from the earthquake record is greater than 0.16g-sec. However, the CAV criterion should be determined considering the seismic and structural characteristics of the plant. An experimental study using shaking table is conducted in this study to evaluate intensity of CAV criterion. Appropriate level of CAV is evaluated based on the test results using the developed seismic damage indicator(SDI) model. The model consists of stacked acrylic cylinders and is developed to behave consistently for each directional seismic load. The result of the experimental study in dicates that the CAV criterion of 0.16g-sec is conservative enough to be applied to Korean NPPs since the CAV value of the seismic input motion of the Korean standard NPPs ranges from 0.3 to 0.5 g-sec. The developed SDI is expected to be useful not only in easily determining OBE exceedance but also in evaluating earthquake damage quantitatively to provide guidelines for better post-shutdown inspection and test.