• Journal of Communications and Networks
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• v.11 no.1
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• pp.36-41
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• 2009

The IEEE 802.16 wireless metropolitan area network (WMAN) standard is designed to correct expensive communication costs in CDMA-based mobile communication systems and limited coverage problems in wireless LAN systems. Thus, the IEEE 802.16e standard can provide mobile high-speed packet access between mobile stations and the Internet service provider through the base station with cheap communication fees. To efficiently accommodate voice over IP (VoIP) services in IEEE 802.16 systems, an uplink quality of service packet-scheduling scheme is proposed, and its performance is evaluated with an NS-2 network simulator in this paper. Numerical results show that this proposed scheme can increase the system capacity by 100% more than in the unsolicited rand service (UGS) scheme and 30% more than the extended real-time polling service (ertPS) scheme, respectively.

• Journal of Information Technology Applications and Management
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• v.31 no.1
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• pp.163-175
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• 2024

This study conducts topic modeling analysis on four electric scooter sharing platforms: Alpaca, SingSing, Kickgoing, and Beam. Using user review data, the study aims to identify key topics and issues associated with each platform, as well as uncover common themes across platforms. The analysis reveals that users primarily express concerns and preferences related to application usability, service mobility, and parking/accessibility. Additionally, each platform exhibits unique characteristics and challenges. Alpaca users generally appreciate convenience and enjoyment but express concerns about safety and service areas. SingSing faces issues with application functionality, while Kickgoing users encounter connectivity problems and device usability issues. Beam receives overall positive feedback, but users express dissatisfaction with application usability and parking. Based on these findings, scooter sharing service providers should focus on enhancing application features, stability, and expanding service coverage to meet user expectations and improve customer satisfaction. Furthermore, highlighting platform-specific strengths and providing tailored services can enhance competitiveness and foster continuous service growth and development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8A
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• pp.868-878
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• 2004

In this paper, we analyse feasibility of Zone-based Power Control (ZPC) scheme introduced for CDMA forward link(1) in the reverse link. To operate ZPC scheme in the CDMA systems the maximum power level that can be allocated to each traffic channel should be determined. Because all the service channels share the whole power resource in the forward lint a specific mechanism that determines Maximum power resource to each traffic channel is required to operate ZPC scheme in the forward link. However, ZPC scheme can be easily adopted to the reverse link, because of the fact that the whole power resource of service terminal is only confined to its traffic channel. In other words, we need not to determine the maximum power resource to be allocated in the reverse traffic channel. Simulation results show that ZPC scheme adopted to the reverse link yields a significant performance improvement compared with the conventional TPC(IS-95 TPC) scheme in terms of the power consumption and the traffic capacity of Portables, especially with the increasing number of high-rate data traffics. With the proposed scheme, not only be extended the service coverage of high-rate data traffic to the entire cell service coverage, but also the QoS of low-rate traffic can keep going through the service time, especially, in the situation that the incoming interference is much larger.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.390-396
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• 2021

In this research, design and fabrication of marine repeater capable to extend communication coverage in monitoring system of fishing gear automatic identification, which is one of implementation method of the real-name electric fishing gear system declared by Ministry of Oceans and Fisheries in 2016, is reported. The proposed marine repeater is fabricated in a form of RF repeater with interference cancellation system (ICS), which can cancel the oscillation due to feedback signal between service antenna and link antenna. In design process, we secure the isolation of 30 dB between service antenna and link antenna. It is confirmed that when the level of feedback signal into repeater input be lower of 15 dB than repeater gain, error vector magnitude due to oscillation can be lower than the performance criterion of 6%, from the test verification. It is expected that the service coverage will be extended by applying the developed marine ICS RF repeater into marine IoT network including monitoring system of fishing gear automatic identification.

• Quality Improvement in Health Care
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• v.28 no.1
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• pp.2-13
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• 2022

Purpose: This study assessed the status of the Development and Utilization of critical pathways (CP) in South Korea. Methods: We surveyed 195 hospitals obtained on the Korean Hospital Association website. Data were collected using structured questionnaires for staff members in charge of CP management personnel in these hospitals. The questionnaire included CP developed by the institutions, the coverage rates and completion rates of CP in the current year, and management indicators related to CP. The questionnaire also included CP support systems and content within the institutions and questions regarding the advantages of CP utilization and obstacles associated with the CP development process. Results: Analysis of the responses from 70 hospitals (35.9% response rate) showed that a total of 1,370 CP sets were developed. The number of CP related to surgery departments was 365 (26.6%), and CP related to surgery and procedure was 1,093 (79.8%), respectively. The CP coverage rate was the most frequently used indicator to monitor the effect of CP (97.1%), followed by the completion rate (90.0%) and the length of stay in hospital (61.4%). CP managers reported that CP were highly useful for communication (3.39±0.493) and accurate information provision (3.39±0.491). The perception that CP violated doctors' autonomy in treatment was relatively low (2.87±0.645). Conclusion: It is necessary to establish an infrastructure in hospitals for CP. CP can facilitate communication and provide accurate information.

• Information Systems Review
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• v.25 no.2
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• pp.145-162
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• 2023

Asset management is a complex and difficult field that requires insight into numerous variables and even human psychology. Thus, it has traditionally been the domain of professionals, and these services have been expensive to obtain. Changes are taking place in these markets, and the driving force is the digital revolution, so-called the fourth industrial revolution. Among them, the Robo-Advisor service using artificial intelligence technology is the highlight. The reason is that it is possible to popularize investment advisory services with convenient accessibility and low cost. This study aims to clarify what factors are critically important when selecting robo-advisors for service users and providers in Korea, and what perception differences exist in the selection factors between user and provider groups. The framework of the study was based on the marketing mix 4C model, and the design and analysis of the model used Delphi survey and AHP. Through the study design, 4 main criteria and 15 sub-criteria were derived, and the findings of the study are as follows. First, the importance of the four main criteria was in the order of customer needs > customer convenience > customer cost > customer communication for both groups. Second, looking at the 15 sub-criteria, it was found that investment purpose coverage, investment propensity coverage, fee level and accessibility factors were the most important. Third, when comparing between groups, the user group found that the fee level and accessibility factors were the most important, and the provider group recognized the investment purpose coverage and investment propensity coverage factors as important. This study derived useful implications in practice. First, when designing for the spread of the robo-advisor service, the basis for constructing a user-oriented system was prepared by considering the priority of importance according to the weight difference between the four main criteria and the 15 sub-criteria. In addition, the difference in priority of each sub-criteria shown in the group comparison and the cause of the sub-criteria with large weight differences were identified. In addition, it was suggested that it is very important to form a consensus to resolve the difference in perception of factors between those in charge of strategy and marketing and system development within the provider group. Academically, it is meaningful in that it is an early study that presented various perspectives and perspectives by deriving a number of robo-advisor selection factors. Through the findings of this study, it is expected that a successful user-oriented robo-advisor system can be built and spread in Korea to help users.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.29-35
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• 2015

The heterogeneous LTE (Long Term Evolution)-Advanced networks comprising a macrocell and femtocells can provide an efficient solution not only to extend macrocell coverage but also to deal with packet traffics increasing explosively within macrocells. An efficient resource management scheme is necessary to maintain the QoS (Quality of Service) of mobile multimedia services because the LTE-Advanced system should support not only voice but also mobile applications such as data, image and video. This paper proposes a resource management scheme to guarantee QoS continuity of multimedia services and to maximize the resource utilization in OFDMA (Orthogonal Frequency Division Multiple Access) based LTE-Advanced systems. This scheme divides the resources into several service blocks and allocates those resources based on the competition between macrocell and femtocell. Simulation results show that it provides better performances than the conventional one in respect of handover failure rate and blocking rate.

• Journal of Preventive Medicine and Public Health
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• v.55 no.6
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• pp.559-567
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• 2022

Objectives: This study aimed to assess the effect of complete coverage and content of available antenatal care (ANC) on the incidence of low birth weight (LBW) in 4 countries belonging to the Association of Southeast Asian Nations (ASEAN). Methods: Measures of complete coverage and content of ANC services included the frequency of ANC visits and the seven service components (blood pressure measurement, iron supplementation, tetanus toxoid immunization, explanations of pregnancy complications, urine sample test, blood sample test, and weight measurement). The complete coverage and content of ANC services were assessed as high if more than 4 ANC visits and all seven components were delivered. Multivariable logistic regression with complex survey designs was conducted using Demographic Health Survey data from the 4 ASEAN countries in question from 2014 to 2017. Results: The proportion of LBW infants was higher in the Philippines (13.8%) than in Indonesia (6.7%), Cambodia (6.7%), or Myanmar (7.5%). Poor ANC services were associated with a 1.30 times higher incidence of LBW than a high level of complete coverage and content of ANC services (adjusted odds ratio [aOR], 1.30; 95% confidence interval [CI], 1.11 to 1.52). In addition, the risk of LBW was higher in the Philippines than in other countries (aOR, 2.25; 95% CI, 2.01 to 2.51) after adjusting for mothers' demographic/socioeconomic factors, health behaviors, and other factors. Conclusions: In sum, complete coverage and content of ANC services were significantly associated with the incidence of LBW in Indonesia, Cambodia, and Myanmar. The Philippines did not show statistically significant results for this relationship, but had a higher risk of LBW with poor ANC.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.141-148
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• 2013

This paper proposes an EMS algorithm designed to determine the optimal locations for Emergency Medical Service centers that both satisfy the maximum ambulance response time T in case of emergency and cover the largest possible number of residents given a limited number of emergency medical services p in a city divided into different zones. This methodology generally applies integer programming whereby cases are categorized into 1 if the distance between two zones is within the response time and 0 if not and subsequently employs linear programming to obtain the optimal solution. In this paper, where p=1, the algorithm determines a node with maximum coverage. In cases where $p{\geq}2$, the algorithm selects top 5 nodes with maximum coverage. Based on inclusion-exclusion method, this selection entails repeatedly selecting a node with the maximum coverage when nodes with lower numbers are deleted. Among these 5 selected nodes, the algorithm selects a single node set with the greatest coverage and thereby as the optimal EMS location. The proposed algorithm has proven to accurately and expeditiously obtain the optimal solutions for 12-node network, 21-node network, and Swain's 55-node network.

• Health Policy and Management
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• v.30 no.4
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• pp.460-466
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• 2020

Background: The purpose of this study is to analyze whether there is a change in patterns of medical use among those likely to be converted their health insurance qualifications when the family support rule is alleviated. There is no empirical analysis that converting health insurance qualification will affect the increase in medical use. Methods: For analysis, data were extracted from the national health insurance eligibility and medical care database. To identify analysis targets similar to that of medical aids' characteristics among health insurance coverage, we compared income, property level, and medical use patterns through basic statistical analysis and used a difference-in-difference (DID) analysis to estimate the net effect of changes in medical use following the change of qualifications. Results: The main results are as follows. The results show that those who are under the 5% income group (1st income group) of health insurance coverage are the most similar to the medical aids group. DID analysis shows that changes in the medical use of people who maintain their national insurance qualification and who are not. As a results, the number of hospitalized days of converting group was reduced by 3.5 days while outpatient days were increased by 1.8 days. Conclusion: As a result, there was not much difference in the patterns of medical use for the under 5% income group who are likely to be eligible for expanded medical aids when the family support rule is alleviated. In addition, more than 30% of them are in arrears with their health insurance premiums, causing inconvenience in using medical services. These findings suggest the need of abolishing the criteria obligated to support family, and great efforts should be made to contribute to non-paid poor and remove their medical blind spot.