• Smart Structures and Systems
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• v.26 no.1
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• pp.35-47
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• 2020

This paper proposes the use of transmissibility functions combined with a machine learning algorithm, Artificial Neural Networks (ANNs), to assess damage in a truss bridge. A new approach method, which makes use of the input parameters calculated from the transmissibility function, is proposed. The network not only can predict the existence of damage, but also can classify the damage types and identity the location of the damage. Sensors are installed in the truss joints in order to measure the bridge vibration responses under train and ambient excitations. A finite element (FE) model is constructed for the bridge and updated using FE software and experimental data. Both single damage and multiple damage cases are simulated in the bridge model with different scenarios. In each scenario, the vibration responses at the considered nodes are recorded and then used to calculate the transmissibility functions. The transmissibility damage indicators are calculated and stored as ANNs inputs. The outputs of the ANNs are the damage type, location and severity. Two machine learning algorithms are used; one for classifying the type and location of damage, whereas the other for finding the severity of damage. The measurements of the Nam O bridge, a truss railway bridge in Vietnam, is used to illustrate the method. The proposed method not only can distinguish the damage type, but also it can accurately identify damage level.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1255-1259
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• 2016

Background: Oral physiotherapy or mouth exercise is considered to be an adjunct but mandatory treatment modality for oral submucous fibrosis (OSMF). This study planned to evaluate the clinical efficacy of a newly designed mouth exercising device (MED) in OSMF patients receiving local ointment, intra-lesional drugs and surgical treatment. Materials and Methods: A total of 231 OSMF patients were selected and treated with basic regime including topical corticosteroids, oral antioxidants and the icecream-stick exercise regime and allotted randomly to two equal groups A and B. Group-A patients were additionally given MED. Subgroups A1 and B1 patients with an inter-incisal distance (IID) 20-35mm were not given any additional therapy; subgroup A2 and B2 patients (IID 20-35mm) were treated additionally with intra-lesional injections. Subgroups A3 and B3 with IID<20mm were managed surgically. IID was measured at baseline and at 6 months recall. The change in IID measurements was calculated and statistically analyzed using 2-way ANOVA and Tukeys multiple post hoc analysis. Results: Average improvement in IID after six months of recall visits was observed to be 8.4 mm in subgroup-A1 (n-53) compared to 5.5 mm in B1(n-50) (p<0.01). The IID improvement in subgroup-A2 was found to be 9.3mm (n-46) compared to 5.1 mm in B2 (n-48) (p<0.01). In the surgery group, mouth opening improvement was observed to be 9.6 mm in subgroup A3 (n-18) compared to 4.8 mm for B3 (n-16) (p<0.01). Conclusions: Use of the MED appears to be effective for increasing oral opening in OMSF patients in conjunction with local, injection and/or surgical treatment.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.10-14
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• 2017

A reverberation chamber is widely used in mobile handset measurements due to its faster and simpler measurement process compared to traditional anechoic chambers. We propose an ultra-wideband inverse conical antenna design suitable as a reference antenna in a reverberation chamber. Traditionally, multiple discone antennas are needed to cover more than 10:1 operation bandwidth of a reverberation chamber. The proposed inverse conical antenna offers wideband impedance matching bandwidth by virtue of the linear impedance transition along its oblique side. The antenna is feasible to mount on the conductive walls which can be utilized as a ground to improve the matching bandwidth, antenna gain and radiation patterns. The antenna geometry is optimized using a 3D electromagnetic simulation tool and fabricated using a 3D printer. The measured results show that the antenna reflection coefficient lower than -10dB and radiation efficiency more than 70% at the frequency range of 0.65~7 GHz.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.1
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• pp.33-41
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• 2015

Compact Network Real-Time Kinematic (RTK) is a method that combines compact RTK and network RTK, and it can effectively reduce the time and spatial de-correlation errors. A network RTK user receives multiple correction information generated from reference stations that constitute a network, calculates correction information that is appropriate for one's own position through a proper combination method, and uses the information for the estimation of the position. This combination method is classified depending on the method for modeling the GPS error elements included in correction information, and the user position accuracy is affected by the accuracy of this modeling. Among the GPS error elements included in correction information, tropospheric delay is generally eliminated using a tropospheric model, and a combination method is then applied. In the case of a tropospheric model, the estimation accuracy varies depending on the meteorological condition, and thus eliminating the tropospheric delay of correction information using a tropospheric model is limited to a certain extent. In this study, correction information modeling accuracy performances were compared focusing on the Low-Order Surface Model (LSM), which models the GPS error elements included in correction information using a low-order surface, and a modified LSM method that considers tropospheric delay characteristics depending on altitude. Both of the two methods model GPS error elements in relation to altitude, but the second method reflects the characteristics of actual tropospheric delay depending on altitude. In this study, the final residual errors of user measurements were compared and analyzed using the correction information generated by the various methods mentioned above. For the performance comparison and analysis, various GPS actual measurement data were collected. The results indicated that the modified LSM method that considers actual tropospheric characteristics showed improved performance in terms of user measurement residual error and position domain residual error.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.8
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• pp.933-945
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• 2011

This research proposes a pattern design method for 24 pleated skirts in order to develop an automatic draft program for pleated skirts that will enhance fit and enable mass production. The research method and results are outlined as follow. 1. Three-dimensional body measurements were conducted on 30 randomly selected women in their 20s. By using 34 body measurement items and 6 types of calculations among the items, the items required in the designing of an original pleated skirt were extracted. They were then interpreted through correlation analysis, variance analysis, a t-test, linear regression analysis and multiple regression analysis. 2. An extra amount was added to the waist measurement and external capsule measurement according to the number of times the pleats coincided and the thickness of the fabric by the degree of polymerization of the horizontal cross section (the test of this research: 0.518mm). The extra amount of waist measurement was 3.6cm while the hip measurement was 4.3cm larger than the hip measurement combined with the external capsule measurement and the extra amount. 3. Based on the ${\pm}$standard deviation/2 as the average of the difference between the external capsule measurement and waist measurement, the subjects were classified into 3 somatotypes. Somatotype 1 presented an average total length of waist darts of 23.6cm while that of somatotype 2 was 26.2cm and that of somatotype 3 was 30.2cm. It has been confirmed that there is a significant difference among somatotypes in the total length of waist darts from the front center to the front side and the total length of waist darts from the side to the back center in terms of the average amount of waist darts for every 12 parts on the WL.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.542-548
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• 2001

A robust, accurate, broad-band, alternating current sensor using fiber-optics is being developed as a part of optical over current protection relay system. The sensor uses the Faraday effect in optical fiber and polarimetric measurements tc sense electrical current. The current sensing coil consists of a length of twisted optical fiber and Faraday rotator mirror to suppress the linear birefringence effect. Due to its single-ended closed path structure, it can not only be easily installed to the target with great isolation from other fields in the vicinity, but the sensitivity can be increased by using multiple turns. This paper reports on the theoretical backgrounds of the sensor design and the preliminary experimental results.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.3
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• pp.278-288
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• 2013

Purpose: The purpose of this study was to investigate the influence of communication competence and burnout on nursing performance in intensive care units (ICU). Method: The participants were 209 nurses from four university hospitals. Measurements included a socio-demographic and job related survey, communication competence inventory, the Maslach burnout inventory and a nursing performance scale. Data were collected from February 6 to 24, 2012, with a self-report questionnaire. The statistical analyses were performed with SPSS 18.0 software. Results: The mean scores for communication competence, burnout and nursing performance were 50.49, 84.72, and 62.18, respectively. Communication competence (r=.44, p<.001) and burn out (r=-.32, p<.001) were significantly correlated with nursing performance. In the multiple linear regression, factors influencing nursing performance were communication competence, age and burnout. These variables explained about 46% of the total variance of nursing performance. Communication competence (${\beta}$=.34, p<.001) was the most influential factor. Conclusion: Nurses' poor communication skills and burnout can influence the occurrences of medical errors in ICU nursing performance. The results suggest that good communication and burnout resolution skills programs should be implemented to improve nursing performance efficiency.

• 전자공학회논문지 IE
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• v.43 no.3
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• pp.13-21
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• 2006

Ryu et al. proposed a multiple target angle tracking algorithm using the angular measurement obtained from the signal subspace estimated by the output of sensor array. Ryu's algorithm has good features that it has no data association problem and simple structure. But its performance is seriously degraded in the low signal-to-noise ratio, and it uses the angular measurement obtained from the signal subspace of sampling time, even though the signal subspace is continuously updated by the output of sensor array. For improving the tracking performance of Ryu's algorithm, a measurement fusion method is derived based on ML(Maximum Likelihood) in this paper, and it admits us to use the angular measurements obtained form the adjacent signal subspaces as well as the signal subspace of sampling time. The new target angle tracking algorithm is proposed using the derived measurement fusion method. The proposed algorithm has a better tracking performance than that of Ryu's algorithm and it sustains the good features of Ryu's algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.675-682
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• 2011

This paper presents two ground plane effects due to the size of two rectangular apertures for two-wire transmission line with equal line length crossing the changeable rectangular apertures in infinite ground planes. The CST MWS is used to determine the characteristics of the insertion loss of the transmission line from the load section in accordance with the ground plane aperture size. The results show that the insertion gain and the insertion loss are periodically observed for the multiple frequency of the half wavelength resonance by the wire length when the transmission line is nearby to horizontal side or vertical side of the aperture. The measurements of the insertion loss are performed to verify the theoretical analysis.

• Child Health Nursing Research
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• v.23 no.4
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• pp.429-439
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• 2017

Purpose: The aim of this study was to identify the status of psychological health among boys in high school and to examine the mediating effects of social support on the relationship between anger and entrapment on psychological health. Methods: The participants in this study were 193 high school boys from Jeju. Measurements included state-trait anger expression inventory, entrapment scale, student social support scale, and questionnaires to assess mental and physical health. Data were analyzed using independent t-test, one-way ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, simple and multiple regression techniques with the SPSS 21.0. Mediation analysis was performed with the Baron and Kenny's method, and Sobel test. Results: Mean scores for anger experience, entrapment, social support, and psychological health were $29.81{\pm}7.34$, $34.09{\pm}16.33$, $45.75{\pm}7.02$, $22.51{\pm}9.91$, respectively. There was a significant correlation between anger experience and psychological health. Entrapment was significantly correlated with psychological health. Social support showed partial mediating effects in the relationship between anger experience and psychological health (Sobel test: Z=54.18. p<.001). Social support showed partial mediating effects in the relationship between entrapment and psychological health (Sobel test: Z=2.24. p=.025). Conclusion: The results indicate a need to develop social support programs for boys in high school.