• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.584-592
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• 2018

Background/Aims There is uncertainty about how to measure outcomes reported by patients in gastroesophageal reflux disease (GERD). This study was conducted to develop an instrument and to determine of the definition of respondent for a patient reported outcomes to assess the efficacy of a treatment used for GERD treatment. Methods A structural process has developed a self-evaluation questionnaire for GERD (SEQ-GERD); health-related quality of life questionnaire for GERD (GERD-QOL) was translated through cross-cultural validation. Two-week reproducibility was evaluated and construct validity was assessed by correlating the SEQ-GERD with the Patient Assessment of Gastrointestinal Disorders (PAGI-SYM), the reflux disease questionnaire (RDQ), and GERD-QOL. Changes in SEQ-GERD scores were compared to assess the discriminative validity following 4 weeks of proton pump inhibitor administration. Results A total of 83 Korean patients were included (mean age $46{\pm}14$ years, females 61.4%). The internal consistency of the 19-item SEQ-GERD was good (alpha = 0.60-0.94) and the test-retest reliability was high (intra-class correlation coefficient = 0.67-0.95). The SEQ-GERD highly correlated with the GERD domain of the PAGI-SYM (correlation coefficient r = 0.894, P < 0.001), the RDQ-GERD (r = 0.877, P < 0.001), and GERD-QOL (r = -0.536, P < 0.05). SEQ-GERD scores significantly varied according to the overall treatment effectiveness scale of drug responsiveness and significantly decreased after drug treatment (mean differences according to the overall treatment effectiveness scale, P = 0.020). Conclusion This study supports that SEQ-GERD is reliable and valid, and can be used to evaluate the treatment response in patients with GERD.

• Biomedical Engineering Letters
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• v.8 no.4
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• pp.399-404
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• 2018

The purpose of this study was to evaluate the accuracy of a mobile wireless digital automatic blood pressure monitor for clinical use and mobile health (mHealth). In this study, a manual sphygmomanometer and a digital blood pressure monitor were tested in 100 participants in a repetitive and sequential manner to measure blood pressure. The guidelines for measurement used the Korea Food & Drug Administration protocol, which reflects international standards, such as the American National Standard Institution/Association for the Advancement of Medical Instrumentation SP 10: 1992 and the British Hypertension Society protocol. Measurements were generally consistent across observers according to the measured mean ${\pm}SD$, which ranged in $0.1{\pm}2.6mmHg$ for systolic blood pressure (SBP) and $0.5{\pm}2.2mmHg$ for diastolic blood pressure (DBP). For the device and the observer, the difference in average blood pressure (mean${\pm}$SD) was $2.3{\pm}4.7mmHg$ for SBP and $2.0{\pm}4.2mmHg$ for DBP. The SBP and DBP measured in this study showed accurate measurements that satisfied all criteria, including an average difference that did not exceed 5 mmHg and a standard deviation that did not exceed 8 mmHg. The mobile wireless digital blood pressure monitor has the potential for clinical use and managing one's own health.

• Smart Structures and Systems
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• v.30 no.6
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• pp.687-701
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• 2022

Inevitable response loss under complex operational conditions significantly affects the integrity and quality of measured data, leading the structural health monitoring (SHM) ineffective. To remedy the impact of data loss, a common way is to transfer the recorded response of available measure point to where the data loss occurred by establishing the response mapping from measured data. However, the current research has yet addressed the structural condition changes afterward and response mapping learning from a small sample. So, this paper proposes a novel data driven structural response reconstruction method based on a sophisticated designed generating adversarial network (UAGAN). Advanced deep learning techniques including U-shaped dense blocks, self-attention and a customized loss function are specialized and embedded in UAGAN to improve the universal and representative features extraction and generalized responses mapping establishment. In numerical validation, UAGAN efficiently and accurately captures the distinguished features of structural response from only 40 training samples of the intact structure. Besides, the established response mapping is universal, which effectively reconstructs responses of the structure suffered up to 10% random stiffness reduction or structural damage. In the experimental validation, UAGAN is trained with ambient response and applied to reconstruct response measured under earthquake. The reconstruction losses of response in the time and frequency domains reached 16% and 17%, that is better than the previous research, demonstrating the leading performance of the sophisticated designed network. In addition, the identified modal parameters from reconstructed and the corresponding true responses are highly consistent indicates that the proposed UAGAN is very potential to be applied to practical civil engineering.

• Journal of Korean Critical Care Nursing
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• v.12 no.2
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• pp.1-12
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• 2019

Purpose : The purpose of this study was to validate the Korean version of Partners In Health scale (PIH-K) which is used to measure the self-management of patients with chronic illnesses in Korea. Methods : Translation of the 12-item PIH-K was conducted according to the World Health Organization guidelines. Data from 306 participants who took medicines over 3 months by doctor's prescription were collected from October to November 2017. Validity such as content validity, construct validity, and concurrent validity were conducted using content validity index (CVI), exploratory and confirmatory factor analyses (CFA). To evaluate concurrent validity, the correlation coefficients between the PIH-K and concurrent scales (Self-As-Carer Inventory) were calculated. The reliability of the PIH-K was examined using the internal consistency and test-retest reliability tests. Results : The CVI of the PIH-K was 0.91. According to the CFA, factor loadings for four factors ranged from .64 to .97, which explained 67.5% of the total variance. The PIH-K was significantly correlated with concurrent variables such as those on the Self-As-Carer Inventory. The Cronbach's ${\alpha}$ was .86 and the intraclass correlation coefficient for the two-week test-retest reliability was .88. Conclusion : Findings show that the PIH-K is reliable and valid in measuring self-management of patients with chronic illnesses.

• Journal of Korean Academy of Nursing
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• v.39 no.3
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• pp.401-408
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• 2009

Purpose: The purpose of this study was to identify the relationship of peer relationships, self-reported attachment security, perceived parental rearing attitudes, and loneliness in upper elementary school-age children. Methods: The data were collected from 207 students in grades 5 or 6, and descriptive statistics, t-test, Pearson correlation coefficients and Stepwise multiple regression were used with the SPSS/PC 12.0 program to analyze the data. Results: There was a significant difference in loneliness between the upper 25% and lower 25% groups of peer relationships, perceived parental rearing attitudes, and self-reported attachment security. Stepwise multiple regression analysis showed affection-hostility in parental rearing attitudes, validation and conflict in peer relationships, and attachment security explained 39.6% of the total variance in loneliness. Conclusion: These results may contribute to a better understanding of loneliness in upper elementary school-age children. The results of the present study indicate a need to develop nursing interventions to prevent and manage children‘s loneliness.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.128-134
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• 2014

A Experimental study on frequency characteristics of the microphone array covered with Kevlar in closed test section wind tunnel. Microphones that are flush mounted in a closed test section wall of wind tunnel are subject to very high flow noise resulting from the turbulence in the wall boundary layer. At this time the microphones measure the strong hydrodynamic fluctuations generated by the flow. The phenomena are referred to a microphone self-noise and a method for reducing this has studied. In this paper the array that covered with acoustically transparent Kevlar sheet was designed and made to reduce the flow-induced self-noise. For the validation frequency characteristics of the Kevlar, the microphone array was installed on the wall and test was performed for white noise and sine wave of several frequencies using loudspeaker. In addition, the paper compared the signals as a tension of Kevlar. The results were presented that tend to decrease the sound pressure level at high frequency above 3500Hz according to existence of Kevlar.

• Smart Structures and Systems
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• v.4 no.3
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• pp.305-318
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• 2008

The development of a digital signal processor based prototype is described in relation to continuing efforts for realizing a fully self-contained active sensor system utilizing impedance-based structural health monitoring. The impedance method utilizes a piezoelectric material bonded to the structure under observation to act as both an actuator and sensor. By monitoring the electrical impedance of the piezoelectric material, insights into the health of the structured can be inferred. The active sensing system detailed in this paper interrogates a structure utilizing a self-sensing actuator and a low cost impedance method. Here, all the data processing, storage, and analysis is performed at the sensor location. A wireless transmitter is used to communicate the current status of the structure. With this new low cost, field deployable impedance analyzer, reliance on traditional expensive, bulky, and power consuming impedance analyzers is no longer necessary. A complete power analysis of the prototype is performed to determine the validity of power harvesting being utilized for self-containment of the hardware. Experimental validation of the prototype on a representative structure is also performed and compared to traditional methods of damage detection.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.45-52
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• 2016

This paper suggests a new method of finding regularization parameter for image restoration problems. Wiener filter requires priori information such that power spectrums of original image and noise. Constrained least squares restoration also requires knowledge of the noise level. If the prior information is not available, separate optimization functions for Tikhonov regularization parameter are suggested in the literature such as generalized cross validation and L-curve criterion. In this paper, self-regularization method that connects bias term of augmented linear system and smoothing term of Tikhonov regularization is introduced in the frequency domain and applied to the image restoration problems. Experimental results show the effectiveness of the proposed method.

• The Journal of Information Systems
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• v.30 no.2
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• pp.79-103
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• 2021

Purpose Based on consumers' economic, psychological, self-development and conversion costs, this study discusses the relationship between consumers' negative attitude to their shadow work during the course of using self-service in unmanned supermarkets and their behavior. Design/methodology/approach Along with the Hirschman(1970)'s EVLN(Exit, Voice, Loyalty, and Neglect) reviewed, the proposed model of this study is based on the S-O-R model(Mehrabian and Russel, 1974) and mental accounting theory(Thaler, 1999), having empirical validation. Findings In the process of visits and consumption in unmanned supermarkets, increasing economic and psychological benefits can effectively reduce consumers' negative attitudes towards shadow work. In addition, the increase in switching costs will also effectively reduce consumers' negative attitudes towards shadow work. When shadow work holds a negative attitude, all the three kinds of actions will occur. Unmanned supermarket operators use consumers to create value while giving a certain return to them, which is conducive to the sustainable development of unmanned supermarket enterprises.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.3
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• pp.47-58
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• 2020

In this study, a thrust modulation through oxidizer mass flow rate control and internal ballistic analysis based on Whitmore and Chandlers' models was conducted on a blow-down hybrid rocket using nitrous oxide. The tank pressure prediction considering mass flow rate control of the self-pressuring oxidizer was conducted, and the results showed good agreements with experimental results. In order to verify the internal ballistic analysis, a ground combustion test using a 500 N class hybrid rocket was conducted, and it was confirmed that the experimental results and the analytical results were quite consistent in the chamber pressure and thrust, thereby, a modeling technique capable of predicting the thrust modulation performance is proposed.