• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.211-218
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• 2013

Cyclic wet and dry conditions in the marine environment structures corrosion is known to be the fastest rising. For that reason, accelerated corrosion test methods for the reproduction of tidal environment has been actively conducted. However, many studies have estimated threshold value for steel corrosion or concentrated in chloride penetration analysis. In this study, cyclic wet and dry conditions to reproduce the structure of the environment in accelerated corrosion and chloride penetration test analysis was performed. Corrosion was determined by the result of reinforcement corrosion monitoring based on galvanic potential measurement and half-cell potential method. Accelerated corrosion test results for each formulation was different corrosion periods, the order OPC> FA> BS> High-strength concrete. FEM durability interpretation program DuCOM was conducted under the same conditions as in accelerated corrosion test. The experimental RCPT tests demonstrated the validity of the result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.7
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• pp.785-790
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• 2008

In this paper, a new balun is proposed. This proposed balun has a DGS(Defected Ground Structure) pattern on the ground plane. The transmission-line is transformed by microstrip-to-slotline transition. DGS pattern on the ground plane and transition of the lines can be easily made a property of the balun. Resonance frequency of the DGS leads to operating frequency of the balun. Also the transition produces $180^{\circ}$ out-of-phase between two output ports without additional transmission line. In this paper, a new balun with VPDGS(Vertically Periodic Defected Ground Structure) effectively lower the operating frequency. To validate the proposed design method, the new balun is designed, fabricated and measured at 2 GHz.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.54-59
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• 2006

Biophotonic sensors based on polymer waveguide with Bragg reflection grating are demonstrated in this work. Waveguide Bragg reflectors were designed by using the effective index method and the transmission matrix method. The grating pattern was formed by exposing the laser interference pattern on a photoresist. On top of the inverted rib waveguide, the Bragg reflection grating was inscribed by the O2 plasma etching. In order to perform the bio-molecule detection experiment, a calixarene molecule was self-assembled on top of thin Au film deposited on the waveguide Bragg reflector. To measure the response of the sensor, several PBS solutions with different concentrations of potassium ion from 1 pM to $100\;{\mu}M$ were dropped on the sensor surface. The shift of Bragg reflection wavelength was observed from the fabricated sensor device, which was proportional to the concentration of potassium ion ranging from 1 pM to 108 pM.

• PNF and Movement
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• v.15 no.2
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• pp.125-132
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• 2017

Purpose: This study reviewed articles to identify the optimal rhythmic stabilization or stabilizing reversals application method for improving balance. Methods: The Cochrane, EBSCO, eArticle, Embase, DBpia, KISS, Medline, ProQuest, PubMed, SAGE, ScienceDirect, Scopus, Springer, and Wiley databases were used to search articles from 1990 to January 2017. The search terms included: "rhythmic stabilization" and "stabilizing reversals." Only experimental human studies (randomized controlled trials) that compared the effects of varying the optimal application of rhythmic stabilization or stabilizing reversals to improve balance were included in the review. Non-English language (except Korean) and unpublished studies were excluded. Results: During the research, 1,098 articles were initially identified. Of these articles, nine were randomized controlled trials. Of these nine articles, five were in English, and four were in Korean. In addition, three of the trials did not measure the patients' balance, two did not report the intensity and location of the resistance, and three performed the rhythmic stabilization incorrectly. Only one article met the inclusion and exclusion criteria. The remaining study evaluated the participants' performance of the alternating trunk flexor and extensor isometric contraction of the scapulae using the optimal resistance for 10 seconds in a sitting position. The participants completed three sets of eight repetitions with rest intervals of 30 seconds between the repetitions and 60 seconds between the sets. Conclusion: Due to the lack of the scientific research on the topic, this review may not provide the evidence needed to support the optimal application of rhythmic stabilization or stabilizing reversals to improve balance. Future research should consider the methodological quality to identify the proper rhythmic standardization and stabilizing reversals application method.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.35-43
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• 1998

Electrodes using for the anode electrode of direct methanol fuel cell with Pt/C and Pt/Ru/C catalyst were prepared and characterized by SEM, TEM, thermal analysis and electrochemical analysis. The half cell tests were carried out with 1 M $H_2SO_4$ electrolyte and 1 M $CH_3OH$ in order to evaluate the electrode performance. The employed electrochemical methods were cyclic vol-tammetry and potentiodynamic polarization experiments. It was found that 20 w% polytetrafluoroethylene (PTFE) content in catalyst showed the best performance due to the best platinum utilization on PTFE-containing catalyst layer. It was found that Pt/Ru/C binary catalyst inhibited the poisoning of anode electrode showing improved performance compared to the Pt/C catalyst by the adsorption of oxygen containing species on the electrode surface at same time. The apparent activation energy for methanol oxidation on the Pt/Ru/C and Pt/C catalyst layer was 11.60 kJ/mol and 26.85 kJ/mol, respectively.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.399-403
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• 1999

Background: Funnel chest is one of the most common anomaly of chest wall, which is manifested by depression of sternum and costal cartilage. Popular operative methods were Ravitch operation and Wada operation. Material and Method: From 1983 to 1996, 21 cases of funnel chest were corrected surgically in the department of thoracic surgery, National Medical Center. Investigated age and sex distribution, combined anomaly,clinical symptom, degree of correction and complication, postoperative satisfaction. We used 2 different surgical methods, one was Wada & its variants(17 cases), the other was Ravitch and it variants(4 cases). Most of operative indications were cosmetic problems. Result: The pre-operative Welch index was 4.188, but this index decreased to 3.46 after the operations.(p=0.046) The degree of correction was higher in Wada & it variant operation than the modified Ravitch operation.(p=0.54) Their results were satisfactory in 20 patients, while unsatisfactory in 1 patient because of a k-wire fracture. There was no recurrence of chest wall depression or postoperative death during the OPD follow up period. Conclusion: We recommend Wada operation in symmetric and small degree of depressive chest wall deformity in preand post school age.

• Korean Security Journal
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• no.17
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• pp.1-13
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• 2008

Conclusion is like below. First, as a private security area's mutual relationship and development device, it is necessary to bring up corresponding-terror expert. Second, a privatized corresponding-terror research center is necessary. Third, the importance of privatization's role for the corresponding-terror prevention law establishment. It is considered that a diversified examination research that can minimize a violation of human rights by bringing up various corresponding-terror expert, paradigm shift of workers related security area, and construct corresponding- terror education equipment as well as education content, it is not a special group's authority, should be continued by a following research. Academical area of terrorism's construction is necessary. You need to approach by private initiatively boldly with the academic world as an active mutual cooperation politically, culturally, socially, internationally, etc, rather than developing national institute initiatively. Also, in a following research, an academical research about a correlation of crime, war, terror should be done deeply, variously. It is necessary to establish an academic foundation of terror study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.93-100
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• 2014

Steel reinforcement buried in concrete structure in submerged zone does not easily become corroded due to lack of dissolved oxygen. For that reason, accelerated corrosion test in submerged state is performed with an electrochemical method, which is not suitable for actual corrosion mechanism and makes it difficult to find relevance with long-term behavior. In this study, accelerated corrosion test was performed with the temperature and chloride concentration as main variables in order to establish a method for accelerated corrosion test in submerged zone. Corrosion was determined by the result of reinforcement corrosion monitoring based on galvanic potential measurement and half-cell potential method. The accelerated corrosion test result showed that temperature had the most dominant influence. To determine the chloride content, chloride concentration by depth in the test sample was measured. With the same conditions, chloride penetration interpretation was performed by DuCOM, a FEM durability interpretation program. Also, a test was performed to measure dissolved oxygen according to soaking conditions of artificial seawater, which was used for verifying the validity of the accelerated corrosion test result.

• PNF and Movement
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• v.13 no.3
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• pp.119-125
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• 2015

Purpose: The current study seeks to examine the effects of stabilizing reversal(SR) and rhythmic stabilization(RS) in proprioceptive neuromuscular facilitation (PNF) techniques on static balance in normal female adults. Methods: Subjects included 20 healthy women in their 20s. They were randomly divided into SR and RS groups. To assess static balance before and after PNF intervention, the good balance system was used to measure the interior and exterior center of pressure (COP) movement distance, front and rear COP movement distance before and after the intervention, and velocity moment. Results: Interior and exterior COP movement distance, front and rear COP movement distance, and velocity moment decreased in the SR group, but no statistically significant differences were observed. In the RS group, the interior and exterior COP movement distance declined without any significant difference, while the front and rear COP movement distance and velocity moment significantly decreased. The interior and exterior COP movement distance, front and rear COP movement distance, and velocity moment declined more in the RS group than in the SR group. Conclusion: The findings of the current study indicate that the RS technique is more effective than the SR technique for improving the balance ability of healthy female adults. The results of this study can thus be utilized in the selection of effective interventions for improving the balance ability of healthy female adults.

• PNF and Movement
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• v.19 no.1
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• pp.105-113
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• 2021

Purpose: The purpose of this study was to investigate the effect of trunk-stabilization training using stabilizing reversal and rhythmic stabilization techniques of PNF on trunk muscle strength and respiratory function in elderly stroke patients. Methods: There were 26 stroke patients included in the study. Patients were divided into two groups, and all patients performed exercise 30 min five times per week for six weeks. The experimental group performed trunk stability exercise using stabilizing reversal and rhythmic stabilization techniques of PNF, and the control group performed flexibility and strength training. Trunk muscle strength, forced vital capacity, maximum inspiratory pressure, and maximum expiration pressure were measured to determine the changes after the intervention. For statistical processing, a paired t-test was performed within the group, and the value after intervention was performed as an independent t-test to find out the difference between the two groups. Results: In the experimental group, all of the trunk muscle strength, forced vital capacity, maximum inspiratory pressure, and maximum expiration pressure showed significant differences according to the intervention. In the control group, there were statistically significant differences in trunk muscle strength and forced vital capacity, but the maximum inspiratory pressure and the maximum expiration pressure did not show any statistical change. Conclusion: From these results, it can be seen that the trunk stability exercises that use the proprioceptive neuromuscular promotion method of stable reversal and rhythm stabilization can be a good intervention for the respiratory function of stroke patients.