• Journal of Conservation Science
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• v.29 no.2
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• pp.187-196
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• 2013

This study is on the corrosion of iron objects caused by sulfides in undersea environment. The corrosion state of objects in seawater and their damage state after underwater and left in highly humid air were studied. The samples of this study were four iron objects which had been taken out from undersea mud layer located in Taean Mado, Chungcheongnamdo. SEM-EDS and XRD analyse on the objects to check whether they have sulfides or not. The result of analysis suggested that the major component of corrosion product generated in undersea deposit soil is sulfur(S) and iron sulfide(FeS) is formed as sulfide. However, there was no clear corrosion on the surface of objects which was exposed to sea water because of the impact of concretion which covered the surface. In order to check the damage status of iron objects after they had been taken out of sea water, exposure tests in high humidity environment and dehumidified environment were done on the corrosion products. The result of the test suggested that the oxidization of iron sulfide corrosion product makes iron sulfate ($FeSO_4$) and sulfuric acid ($H_2SO_4$) and they can cause secondary corrosion of iron objects. Therefore, it is believed that the iron sulfide corrosion product of iron objects taken out from underwater environment should be removed by all means and the keeping environment of the iron objects should also maintain dehumidified state.

• Physical Therapy Rehabilitation Science
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• v.7 no.3
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• pp.134-138
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• 2018

Objective: The aim of this research was to investigate the effects of functional electrical stimulation (FES) applied to the gluteus medius (Gm) and tibialis anterior (TA) during stair climbing in persons with stroke compared to FES applied to the TA only during stair climbing, and during stair climbing without FES in persons with stroke. Design: Cross-sectional study. Methods: Twenty subjects with stroke participated in this study. Subjects were included if: 1) they were diagnosed as stroke at least 6 months before; 2) had Mini Mental State Examination- Korean score of 24 or higher; 3) were able to climb a flight of 10 stairs independently (with or without walking aid). The patients walked 10 stairs 3 times with FES applied to the Gm and TA, only TA, or no FES. There was a 1-minute rest period between each bout. The assessments were made using the Timed Up & Down Test and the Wii Balance Board. Results: Stair climbing with FES applied to the Gm and TA was significantly faster than stair climbing with FES applied to the TA only and without FES (p<0.05). Stair climbing with FES applied to the Gm and TA exhibited significantly greater sway velocity than stair climbing without FES (p<0.05). However, maximal sway distances were not significantly different between groups. Conclusions: Stair climbing with FES applied to the Gm and TA can be an important component of a rehabilitation program for improving stair climbing ability in persons with stroke.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.625-638
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• 2014

In this study, the uncertainties in the critical flow functions (CFFs) calculated by the AGA8-dc equation of state were estimated. To this end, the formulas for enthalpy, entropy, and speed of sound, which are used in calculating the CFF, were expressed in the form of dimensionless Helmholtz free energy and its derivatives, and the uncertainty in Helmholtz free energy was inferred. To consider the variations in the compressibility-dependent variables induced by the variation (i.e., uncertainty) in compressibility, the form of the AGA8-dc equation was modified to have a deviation equal to the uncertainty under each flow condition. For each independent uncertainty component of the CFF, a model for uncertainty contribution was developed. All these changes were applied to GASSOLVER, which is KOGAS's thermodynamic database. As a result, the uncertainties in the CFF were estimated to be 0.025, 0.055, and 0.112 % at 10, 50, and 100 bar, respectively, and are seen to increase with the increase in pressure. Furthermore, these results could explain the deviations in the CFFs across the different labs in which the CFF international comparison test was conducted under the ISO management in 1999.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.5
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• pp.44-51
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• 2009

In this paper, an air conditioner peak power control system using electric power line communication has been developed. The air conditioner power control system using RS-485 communication method is hard to install on the existing buildings due to difficulty in cabling, and the system using wireless communication methods has a weak point of not being able to be used in close space, while the developed system has its own advantages of overcoming the above mentioned obstacles. In addition, the system is extended to support not only single-phase electricity system but also three-phase four-wire electricity system, and therefore can be installed anywhere in the domestic environment. The system also has enhanced the ease of deployment, operational stability and economical efficiency by compact circuit design. Considering the current state requiring the energy sayings, the system would greatly contribute to the widespread use of the air conditioner power control system. The superiority in the performance and stability of the system has been proved by the design verification of each component such as remote air conditioner controller, electric power line gateway and so on, and the field test of the whole system.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.101-107
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• 2018

We identified the main impacts, drivers, and restoration projects for Atlantic Forest in Northwest of the Rio Grande do Sul State, Brazil. The objective was to analyze the quantity, distribution, and causes of the environmental crimes in 2000-2014. To verify differences between degraded and restored areas, we performed a t-test; ANOVA for the municipalities with more quantity of crimes, simple linear regression analysis for the relationship between sizes of degraded areas and quantity of seedlings planted, and Principal Component Analysis (PCA) for environmental damages categories and population of the municipalities. The main environmental damages found were deforestation outside permanent preservation area (20%) and those related to Permanent Preservation Area (37%). Environmental crimes in these areas fall into two categories: native and exotic vegetation removal (17%), and impediment to natural regeneration (20%). The average size of the degraded areas was $5,359{\pm}526m^2$, while for restored areas was $3,337{\pm}255m^2$. The sizes of the degraded fragments were similar among the five municipalities with the higher number of environmental crimes (ANOVA: p>0.05, F=1.24; df=241). The number of seedlings planted was positively related to the sizes of the degraded fragments (p<0.001, $R^2=0.53$). Segregation between the less and the most populous municipalities was found with the PCA analysis along PC1 (51.7%), while PC2 represented 19.2% of the total variation. The most populous municipalities showed the highest number of environmental crimes, and the majority of degraded areas were recovered by planting native seedlings. Atlantic Forest fragments need to be recognized and preserved as an ecosystem with a unique ecological function by the population and public administration.

• Journal of IKEEE
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• v.19 no.3
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• pp.440-446
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• 2015

This study has examined susceptibility of LNA(Low Noise Amplifier) due to Front-Door Coupling under Narrow-Band high power electromagnetic wave. M/DFR(Malfunction/Destruction Failure Rate) was measured to investigate the diagnostic of IC test. In addition, decapsulation analysis was used to understand the inside of the chip state in LNA devices. The experiments is employed as an open-ended waveguide to study the destruction effects of LNA using a 2.45 GHz Magnetron as a high power electromagnetic wave. The susceptibility level of LNA was assessed by electric field strength, and its failure modes were observed. The malfunction of LNA device has showed as the type of self-reset and power-reset. The electric field strength of malfunction threshold is 524 V/m and 1150 V/m respectively. Also, he electric field of destruction threshold is 1530 V/m. Three types of damaged LNA were observed by decapsulation analysis: component, onchipwire, and bondwire destruction. Based on these results, the susceptibility of the LNA can be applied to a database to help elucidate the effects of microwaves on electronic equipment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.94-105
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• 2010

To detect faults in an inverter-fed permanent magnet synchronous motor (PMSM) drive under the circumstance having faults in a stator winding and inverter switch, an on-line basis fault detecting scheme during operation is presented. The proposed scheme is achieved by monitoring the second-order harmonic component in q-axis current and the fault is detected by comparing these components with those in normal conditions. The linear interpolation method is employed to determine the harmonic data in normal operating conditions. As soon as the fault is detected, the operating mode is changed to identify a fault type using the phase current waveform. To verify the effectiveness of the proposed fault detecting scheme, a test motor to allow inter-turn short in the stator winding has been built. The entire control algorithm is implemented using DSP TMS320F28335. Without requiring an additional hardware, the fault can be effectively detected by the proposed scheme during operation so long as the steady-state condition is satisfied.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.180-191
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• 2015

This study attempted to identify the relationships among perceived value (hedonic and utilitarian values), consumption emotions, and satisfaction. In addition, this study also tested the relationships of measurement items of these variables. The data were collected from American restaurant diners who have experienced any Asian restaurants within the last 30 days. A total of 435 responses was used for data analysis. Descriptive statistics, principal component analysis, reliability test, and regression analysis were utilized to analyze the data. The results found that hedonic value influenced positive emotions and satisfaction. Utilitarian value increased positive emotions and satisfaction while decreases negative emotions. In addition, positive emotions increased customer satisfaction; negative emotions decreased customer satisfaction. In the measurement level, traditional music, traditional aspects of food, and restaurant layout of hedonic value influenced positive emotions and interior design had an impact on customer satisfaction. On the other hand, food taste and healthy food option of utilitarian value influenced positive emotions and satisfaction; only food taste was negatively related to negative emotions. Managerial implications were provided.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.91-96
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• 2012

The retract actuator makes the landing gear retract or extend during take-off and landing of an aircraft. To prevent folding of landing gear that has remained in the extended state because of an unexpected external disturbance, an internal locking device is applied to the retract actuator. The locking device is restrained with another internal component by oil pressure supplied to the retract actuator, and this restraint makes the locking of the actuator possible. Because locking and unlocking are repeated during retraction and extension of the landing gear, the locking device takes repeated identical loads, and the possibility of fatigue failure exists. In this study, the process and results of fatigue analysis for the locking device are presented, and the appropriateness of the analysis result is verified using a fatigue test.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.367-374
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• 2014

In this study, skin permeation enhancement was confirmed by designing it to have a structure and composition similarity to the intercellular lipids that improve miscibility with skin by cross-linked lipids poloxamer. The cross-linked lipids poloxamer was synthesized and analyzed by 1H NMR that structure dose had conjugated pluronic with ceramide3. Active component is released by modification of liquid crystal structure because PPO part, large-scale molecule block of pluronic, has hydrophobic nature at skin temperature of $35^{\circ}C$. Conjugated pluronic with ceramide3 was synthesized using Pluronic F127 and p-NPC (4-nitrophenyl chloroformate) at room temperature yielded 89%. Pluronic(Ceramide 3-conjugated Pluronic) was synthesized by reaction of p-NP-Pluronic with Ceramide3 and DMAP. The yield was 51%. This cross-linked lipids poloxamer was blended and dissolved at isotropic state with skin surface lipids, phospholipid, ceramide, cholesterol and anhydrous additive solvent. Next step was preceded by ${\alpha}$-Transition at low temperature for making the structure of Meso-Phase Lamella, and non-hydrous skin analogue liquid crystal using thermo-sensitivity smart sensor, lamellar liquid crystal structure through aging time. For confirmation of conjugation thermo-sensitivity smart sensor and non-hydrous skin analogue liquid crystal, structural observation and stability test were performed using XRD(Xray Diffraction), DSC(Differential Scanning Calorimetry), PM (Polarized Microscope) And C-SEM (Cryo-Scanning Electron Microscope). Thermo-sensitivity observation by Franz cell revealed that synthesized smart sensor shown skin permeation effect over 75% than normal liquid crystal. Furthermore, normal non-hydrous skin analogue liquid crystal that not applied smart sensor shown similar results below $35^{\circ}C$ of skin temperature, but its effects has increased more than 30% above $35^{\circ}C$.