• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1101-1107
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• 2010

DVR is widely used in the security monitoring system because it has excellent performance compared with VCR. In this paper, the new DVR interfaces and repeaters enhancing the performance of the existing DVR have been designed and implemented, which enables a large-scaled security monitoring system to be built economically. A repeater in this paper connects 8 monitoring terminals to 2 channels of DVR and a DVR interface manages 16 repeaters to be able to accommodate 128 monitoring terminals. Eventually, the implemented system has a quadruple scalability compared to the existing systems and can reduce the installation cost substantially by using cost-effective UTP cables instead of coaxial cables. And the system could be effectively used in various environments and conditions because various functions such as video transmission, audio communication, emergency call, and RFID card are integrated into the system.

• Korean Journal of Remote Sensing
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• v.35 no.5_2
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• pp.851-859
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• 2019

The COMS satellites take image of the Korean Peninsula every 15 minutes, but due to the limitations of the observational channels, they tend to underestimate when estimating rainfall. In this study, we developed satellite-based rainfall estimation technology using COMS and GPM that can be used in the heavy rain on the Korean Peninsula. The time resolution and spatial resolution of COMS satellites and GPM satellites were matched to improve accuracy using GPM IMERG data. As a result, it showed that the number of correlations with the ASOS observations was more than 0.7, enabling the estimation of rainfalls that are more accurate than the estimates of rainfall by COMS satellites. It is believed that the application of the subsequent satellite(GK-2A) will provide more accurate rainfall estimation information in the future. Therefore, we expect greater utilization in disaster management for the ungauged areas.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.69-75
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• 2021

In a contact-free society, online services are becoming more important than classic offline services. At the same time, the role of a contact center, which executes customer relation management (CRM), is increasingly essential. For supporting the CRM tasks and their effectiveness, techniques of process automation need to be applied. Quality assurance (QA) is one of the time and resource consuming, and typical processes that are suitable for automation. In this paper, a method of automatic quality evaluation for voice based consultations is proposed. Firstly, the speech in consultations is transformed into a text by speech recognition. Then quantitative evaluation based on the QA metrics, including checking the elements in opening and closing mention, the existence of asking the mandatory information, the attitude of listening and speaking, is executed. 92.7% of the automated evaluations are the same to the result done by human experts. It was found that the non matching cases of the automated evaluations were mainly caused from the mistranslated Speech-to-Text (STT) result. With the confidence of STT result, this proposed method can be employed for enhancing the efficiency of QA process in contact centers.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.3
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• pp.5-30
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• 2019

The purpose of this study is to suggest an improvement of digitization criteria for records that can faithfully reproduce the contents and properties of original records by complementing the problems and deficiencies of "NAK 26:2018(v2.0) Digitization Criteria for records". Thus, this study proposes a technical standard improvement that should be applied to the digitization process for records not produced in the form of digital files by comparing and analyzing the criteria for digitization of records in Korea with overseas digitization criteria, guidelines, recommendations, and so on. In addition, verifying the validity on this study by interviewing experts from the record-related institutions. As a result, suggested a final improvement of criteria for digitization of records such as applying non compression-Lossless codecs, proposing appropriate resolution values for each type of records, audio channels, frame rates, scan methods, and criteria for microform types.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.6
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• pp.69-78
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• 2004

During the last decade, security models have been defined for two- and three-parity key exchange protocols. Currently there is a growing research interest in security models for group key management schemes. While various security models and provably secure protocols have been proposed for distributed group key exchange schemes, no results are hewn for centralized group key distribution schemes in spite of their theoretical and practical importance. We describe security requirements and a formal security model for centralized group key distribution scheme: we define the model on the channel controlled by adversaries with the ability of strong user corruption. In the security model, we propose a conversion module which can transform centralized tree-based group key distribution schemes in the literature to provably secure centralized tree-based group key distribution schemes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.27-35
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• 2011

Due to the advancement of IPTV technologies, Mobile IPTV service is needed to be supported for service and content protection. CAS is generally used in the IPTV service to protect service and content. However, the CAS is not efficient in the Mobile IPTV. The CAS needs too much bandwidth for Service Key update to the each subscriber. Moreover, the CAS is increasing computation burden for the service key refreshment in the key management server when the subscriber frequently changes of the IPTV service group. To solve the problems, we used hierarchical key structure based on pre-shared key that is securely stored into smart card or USIM and do not use the EMM for Service Key update. As a result, the proposed scheme decreases computation burden at the key management server and wireless bandwidth burden in the Mobile IPTV service.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.203-208
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• 2023

In this study, we propose a method to improve the precision of contact resistance measurement circuits using constant current method and voltage drop method, and implement a dashboard that monitors the measured data of contact resistance measurement systems through MQTT broker server. The contact resistance measurement system measures the resistance value and transmits the measured value to the MQTT broker server using wireless communications. This developed dashboard uses Node-RED and Node-RED-Dashboard to receive the resistance values of up to four contact resistance measurement systems and show them to user's monitor screen. Users can manage multiple measurement data using a single dashboard and easily interface with other devices through the MQTT broker server. Through the experimental results from real data measurements, the relative standard deviation about precision is improved to average 40.37% and maximum 64.73% respectively.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.1-7
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• 2023

The advent of deep learning technologies has led to the development of various medical applications, making healthcare services more convenient and effective. Among these applications, heart rate estimation is considered a vital method for assessing an individual's health. Traditional methods, such as photoplethysmography through smart watches, have been widely used but are invasive and require additional hardware. Recent advancements allow for contactless heart rate estimation through facial image analysis, providing a more hygienic and convenient approach. In this paper, we propose a lightweight methodology capable of accurately estimating heart rate in mobile environments, using a specialized 2-channel network structure based on 2D convolution. Our method considers both subtle facial movements and color changes resulting from blood flow and muscle contractions. The approach comprises two major components: an Encoder for analyzing image features and a regression layer for evaluating Blood Volume Pulse. By incorporating both features simultaneously our methodology delivers more accurate results even in computing environments with limited resources. The proposed approach is expected to offer a more efficient way to monitor heart rate without invasive technology, particularly well-suited for mobile devices.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.91-98
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• 2023

This study is an exploratory research on smart healthcare services, specifically focusing on a multi-channel CCR based healthcare service system. The study examines the overview and operational principles of the service system, highlighting the significance of user communication and its role in the system's functionality. Furthermore, the study investigates the impact of service quality on user satisfaction and intention to continue using the service. To achieve this, a structural equation modeling(SEM) analysis was conducted with a sample of 188 users who owned and utilized healthcare devices and apps. The results indicate that service quality dimensions (reliability, responsiveness, empathy, assurance, and tangibility) all had a positive influence on user satisfaction. Additionally, user satisfaction was found to have a significant impact on intention to continue using the service. The findings of this study contribute to exploring the effectiveness and potential value of CCR-based smart healthcare services. It was also provided insights for the future development of smart healthcare systems that offer accurate health information and personalized services for individual health management and prevention.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.23-31
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• 2016

The domestic market of CM at Risk has not been activated yet. It was analyzed duo to the fact that construction owners didn't have confidence in CM at Risk, because of the concerns regarding CM firms reliability, service, specialty, system and feasibility. Therefore, this study analyzed the problems to find the reason for declines in orders through a business diagnosis based on the Business Model Canvas(BMC) and set up the direction of business model improvement with one on one expert interviews. Additionally, we suggested the sub-activities for the business model improvements of CM at Risk service that are divided into 9 building blocks. Through this method, we determined that we would need preceding innovation activities such as good communication with customers, reinforcement of subcontract and excellence in project operations to convert the successful practice and settlement of the CM business model based in BMC. It is expected that the business model suggested from this study would contribute to improvement of CM at Risk competition and the differentiation strategy when compared with other firms. Also, it would be used a basis data to develop CM at Risk business model in the future.