• Korean Journal of Materials Research
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• v.32 no.3
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• pp.146-152
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• 2022

One disadvantage of deep cycle flooded lead-acid batteries is increasing water loss caused by use of (+) Pb-Sb / (-) Pb-Sb alloy grid. Water loss is generated by the emission of hydrogen gas from the (-) electrode during battery charging. In this paper, we maintain cycle life aspect through the development of hybrid flooded lead-acid batteries to which a (+) Pb-Sb / (-) Pb-Ca grid is applied and deal with the improvement of water loss. The amount of water loss compared to that of the (-) Pb-Sb grid decreased when Ca was added to the (-) Pb grid. For the (-) Pb-Ca grid, it was confirmed that the time to reach 0.0 V, at which water decomposition occurs, was increased compared to that of the (-) Pb-Sb grid at the NPV (Negative Potential Voltage). In the cycle life test conducted with the BCI (Battery Council International) standard, compared to the (+) Pb-Ca grid, the (+) Pb-Sb grid increased the life cycle of the batteries and the (+) Pb-Ca grid showed an early end of life due to PbO corrosion layer generation, as determined through SEM / EDS and Tear Down analysis. In conclusion, by addition of Sb to (+) Pb grid and Ca to (-) Pb grid, we developed a hybrid flooded lead-acid battery that meets user requirements to improve water loss characteristics and preserve cycle life characteristics.

• Korean Circulation Journal
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• v.54 no.3
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• pp.140-153
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• 2024

Background and Objectives: Although a single-lead electrocardiogram (ECG) patch may provide advantages for detecting arrhythmias in outpatient settings owing to user convenience, its comparative effectiveness for real-time telemonitoring in inpatient settings remains unclear. We aimed to compare a novel telemonitoring system using a single-lead ECG patch with a conventional telemonitoring system in an inpatient setting. Methods: This was a single-center, prospective cohort study. Patients admitted to the cardiology unit for arrhythmia treatment who required a wireless ECG telemonitoring system were enrolled. A single-lead ECG patch and conventional telemetry were applied simultaneously in hospitalized patients for over 24 hours for real-time telemonitoring. The basic ECG parameters, arrhythmia episodes, and signal loss or noise were compared between the 2 systems. Results: Eighty participants (mean age 62±10 years, 76.3% male) were enrolled. The three most common indications for ECG telemonitoring were atrial fibrillation (66.3%), sick sinus syndrome (12.5%), and atrioventricular block (10.0%). The intra-class correlation coefficients for detecting the number of total beats, atrial and ventricular premature complexes, maximal, average, and minimal heart rates, and pauses were all over 0.9 with p values for reliability <0.001. Compared to a conventional system, a novel system demonstrated significantly lower signal noise (median 0.3% [0.1-1.6%] vs. 2.4% [1.4-3.7%], p<0.001) and fewer episodes of signal loss (median 22 [2-53] vs. 64 [22-112] episodes, p=0.002). Conclusions: The novel telemonitoring system using a single-lead ECG patch offers performance comparable to that of a conventional system while significantly reducing signal loss and noise.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.957-961
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• 1997

In this paper, an assessment has been proceeded about component technology that stamping car panel can be designed and manufactured efficiently. Also this study investigated srandard model of CAD/CAM system in production process of automobile dies. Recently, motor companies are doing their best to increase productivity and to reduce production time. So to develop user-friendly and effective standard model of CAD/CAM system is very important. The obtained results will lead to the reductions in lead time and man-hour required for the design and manufacture of the automobile dies.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.56-68
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• 1997

The object of multiresponse optimization is to determine conditions on hte independent variables that lead to optimal or nearly optimal values of the response variables. Derringer and Suich (1980) extended Harrington's (1965) procedure by introducing more general transformations of the response into desirability functions. The core of the desirability a, pp.oach condenses a multivariate optimization into a univariate one. But because of the subjective nature of this a, pp.oach, inexperience on the part of the user in assessing a product's desirability value may lead to inaccurate results. To compensate for this defect, a weighted desirability function is introduced which takes into consideration the vriances of the responses.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.85-91
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• 1998

In this paper an assessment has been proceeded about component technology that stamping car panel can be designed and manufactured efficiently. Also this study investigate standard model of CAD/CAM system in production process of automobile dies, Recently, motor companies are doing their best to increase productivity and to reduce production time. So to develop user-friendly and effective standard model of CAD/CAM system is very important. The cbtained results will lead to the reductions in lead time and man-hour required for the design and manufacture of the automobile dies.

• Journal of Smart Tourism
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• v.2 no.4
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• pp.35-43
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• 2022

Tourism businesses use chat services to provide immediate customer support and to help users navigate within a website, but there are more outcomes of this interaction that should be examined. The current study aimed to discover if the online travel chat service quality and information value of the online travel chat service lead to user satisfaction with the service and visit intention to a recommended destination by Korea Tourism Organization's 1330 Live Chat. The results indicate that information value (functional and innovation) and online travel chat service quality (reliability, assurance, and security) lead to satisfaction with the live chat service and visit intention to a recommended destination. The results can benefit practitioners who want to expand and improve their customer service interaction and recommendations, and to scholars who study the relationship between customer services in tourism recommendation and sales context.

• Journal of The Korean Association of Information Education
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• v.17 no.2
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• pp.211-224
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• 2013

The purpose of this study was to find the effective way of composition in terms of UX(user experience) when configuring UI(user interface) of educational game by utilizing ET(eye-tracking). Experimental material was a game related to the middle school 'force and motion'. SMI (SensoMotoric Instruments)' iView X TM RED was used in order to collect eye movement data. The results of this study was as follows. First, the lead element for fast visual attention should be placed in the center when the educational game UI is configured. Second, burton that changes character's features and the information about them should be placed close to each other. Third, learning quiz caught visual attention faster when it was placed on the left side of UI. Fourth, when one UI was overlapped by another, parts that were not overlapped was fixated, too.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.121-128
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• 2015

In this paper, we introduce our smart phone application for hearing impaired people. Unlike previous hearing aids application, our application has both functions of self hearing tests and sound amplification. We provide user with two types of self hearing test, those are standard hearing test and detail hearing test. Each test has different advantages like short test time and accurate test result, however both tests provide reliable result. Our hearing test allows that user can measure their hearing loss level according to the frequency. Sound amplification function provide proper fitting formula by using NAL-NL1, and it guarantees high speech intelligibility. Our application can also memorize user's fitting data at specific test condition. Therefore those who using our hearing aids application can easily reset their hearing aids / earphone properties periodically. Our application is advanced at the aspect of self fitting function that no other previous application did. So we are expecting these comfortable processes about fitting lead the number of hearing aids user to be increased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.10
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• pp.527-536
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• 2015

Studies for the reduction of lighting energy have been done using technologies such as user and location awareness. However, the focus of current research on location-based lighting control has been on energy reduction, which can lead to other issues including an imbalance in indoor illumination. This study proposes a lighting control system applying general illumination and technology for user and location awareness. The proposed lighting control system reduced lighting energy by 72.1%, 66.5% and 62.3% for 1, 2 and 3 users, respectively, compared to the On/Off lighting control system. This lighting control system causes an increase in lighting energy of 35.8% and 10.9% for 1 and 2 users compared to the lighting control system with user and location awareness, while a reduction of 9.4% was seen for 3 users. This means that the proposed system provides more effective energy reduction for a room with multiple occupants as it is based on the general lighting control scheme. The lighting control system applying general illumination and technology of user and location awareness improved the uniformity factor by 32.0%, 39.4% and 33.4% for 1, 2 and 3 users, respectively.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.379-384
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• 2019

This study is an online survey user experience study. The purpose of this research is user experience research to make use and development of online surveys. In-depth interviews were conducted with 8 native Koreans who were not experienced with Naver and Google, and were surveyed using Peter Morville's Honeycomb model. In addition, we performed evaluation through tasks and think-aloud. Naver is highly useful, usable, desirable and findable, and Google can confirm its superior accessible and flexible. Research has shown that improvements in usability and ease of functioning are needed by reclassifying and moving menu categories. Online survey user experience that has not been studied previously can predict the direction of usability improvement and can help the user side. We hope that this research will improve the usability of online surveys, and will lead to various related research.