• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.6 s.360
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• pp.31-39
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• 2007

In this paper, a system for real-time or periodic measurement and analysis of RF parameters such as forward transmit power and pilot power in CDMA base station systems is proposed. Such RF characteristic parameter measurement can be prevented from system fault and used to achieve optimal service quality and maximum investment return through cell coverage expansion, subscriber capacity increase and so on. For forward power measurement, the local oscillator frequency for the detector is varied so that the transmit power for all channels can be measured. The channel power measurement can be used to analyze the variation in transmit power for changes in voice traffic. By comparing to forward $E_c/I_o$, the pilot channel power can be deducted, which can be used to determine uy degradation in transmit section modules such as the high dover amplifier. Since an accurate analysis of carefully measured data using the CDMA level detector must be made, the system is designed so that measurement errors due to changes in crest factor with modulation method can be overcome.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8A
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• pp.829-837
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• 2008

A cellular system with fixed relays is considered to be a technology that can support high data transmission service to wide areas. However, either inter-cell interference or inter-sector interference that can be produced by adding relays to the cellular system with fixed relays does not guarantee high link performance to deteriorate function, so that resource allocation for avoidance of interference is very much important. In the paper, the cellular system performance with repeater relay has been compared with the cellular system performance with relay, and cell coverage expansion at the use of relay repeater has been compared. To compare, this paper has suggested resource allocation method to avoid inter-cell interference and inter-sector interference at installation of fixed relay on the cellular system. The proposed method can allocate different frequency resources on adjacent base stations and relays to reduce interference and to expand high data transmission area, and all of frequency bands are used at each sector to elevate efficiency of the frequency when base stations and relays operate simultaneously.

• Journal of Information Management
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• v.40 no.1
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• pp.133-156
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• 2009

In this study, we link informal Web resources to KISTI NDSL's collections using automatic semantic indexing and tagging to examine the possibility of the service which recommends related documents using the similarity between KISTI's formal information resources and informal web resources. We collect and index Web resources and make automatic semantic linking through STEAK with KISTI's collections for NDSL retrieval. The macro precision which shows retrieval precision per a subject category is 62.6% and the micro precision which shows retrieval precision per a query is 66.9%. The experts' evaluation score is 76.7. This study shows the possibility of semantic linking NDSL retrieval results with Web information resources and expanding information services' coverage to informal information resources.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.453-458
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• 2018

The analysis of maritime traffic refers to the processes that are used to analyze the environmental characteristics of the target area and, based on this analysis, predict the traffic pattern of the vessels. In recent years, maritime traffic analysis has become significant with increase maritime traffic volume and expansion of VTS coverage area. In addition, maritime traffic analysis is also applicable in the safety assessment of port facilities and the VTS (Vessel Traffic Service). In this paper, we propose a method to analyze the vessels' traffic pattern by using the heat map and the centroid method. This method is efficient for the analysis of the vessel trajectory data where spatial characteristics change with time. In the experiments, the traffic density and centroid by time have were analyzed. Trajectory data collected at Mokpo harbor was adopted. Finally, we reviewed the experimental results to verify the feasibility of the proposed method as a maritime traffic analysis method.

• Ocean and Polar Research
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• v.41 no.3
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• pp.159-168
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• 2019

Understanding the interaction between climate and the water cycle is critical especially in a drought sensitive region such as California. This study explored hydrologic changes in central and southern California in relation to the glacial-interglacial climate cycles over the last 30 thousand years. To do this, we reconstructed paleovegetation using plant wax carbon isotopic compositions (${\delta}^{13}C$) preserved in marine sediment cores retrieved from the central California continental shelf (ODP Site 1018) and Santa Barbara Basin (ODP Site 893A). The results were then compared to the existing sea surface temperature (SST) and pollen records from the same cores to understand terrestrial hydrology in relation to oceanographic processes. The Last Glacial was generally dry both in central and southern California, indicated by grassland expansion, confirming the previously suggested notion that the westerly storm track that supplies the majority of the precipitation in California may not have moved southward during the glacial period. Southern California was drier than central California during the Last Glacial Maximum (LGM). This drying trend may have been associated with the weakening of the California Current and northerly winds leading to the early increase in SST in southern California and decline in both offshore and coastal upwelling. The climate was wetter during the Holocene in both regions compared to the glacial period and forest coverage increased accordingly. We attribute this wetter condition to the precipitation contribution increase from the tropics. Overall, we found a clear synchronicity between the terrestrial and marine environment which showed that the terrestrial vegetation composition in California is greatly affected by not only the global climate states but also regional oceanographic and atmospheric conditions that regulate the timing and amount of precipitation over California.

• Health Policy and Management
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• v.31 no.3
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• pp.261-271
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• 2021

Background: In 2018, the government increased the fee for the magnetic resonance imaging (MRI) image deciphering services of the external hospital to discourage the redundant MRI scan and to induce appropriate use of the MRI services. It is important to evaluate the effect of the policy to provide the basis for establishing other MRI-related policies. Methods: The healthcare data of the patients who had brain MRI scans were organized by episode and analyzed using the panel study in order to find out the effect of the MRI-related policy on the substitution effect and the medical expenses. Results: As a result of the increase in the fee of deciphering the MRI image, there has been an uplift in deciphering the MRI scan of the external hospital. It implies that more hospitals chose to use the MRI scan taken by other clinics or hospitals, rather than the MRI scan taken at their own facilities. Conclusion: The research results imply that a policy that facilitates the exchange of the medical image data between the hospitals is needed in order to establish an efficient management system of the healthcare resources. Such improvement is expected to reduce the social cost and contribute to the stability in the finance of national health insurance.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.86-98
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• 2022

This study explored the agenda of conservative and liberal media in reporting COVID-19, and observed the effects of each media's partisan agenda-setting on the public with the same political orientation. To this end, researchers collected 5,286 articles on COVID-19 from five newspapers, and analyzed the survey data of 1,067 respondents. Next, the researchers extracted main agenda using LDA topic modeling and analyzed the correlation between newspapers' agenda and survey respondents' agenda. As results, 15 topics such as infection, vaccine, and economic crisis appeared as the media agenda, and the difference in major agenda between conservative and liberal media was found. On the other hand, the conservative media exerted an agenda-setting influence not only on the conservatives but also on the liberals, but the liberal media did not have a significant influence on the liberals. This study contributes to the methodological expansion of agenda-setting research by introducing a new way to confirm the effectiveness of agenda-setting by combining topic modeling and survey.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.17-23
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• 2009

Objectives : This study aimed to provide basic data for future policies regarding the expansion of health insurance, through investigating the current status of Oriental herbal medicine insurance as perceived by the public. Methods : Questionnaire was developed through literature searches, in-depth interviews, item generation and item reduction. The questionnaires were further refined by a focus group. 221 surveys were retrieved from the general public. Results : The in-depth interviews, reveal that the public is aware of the various forms of Oriental herbal medicine formulas, except for the use of mixture of which are soluble granules covered by insurance. The public awareness of the soluble granules turned out to be so low that enhanced awareness of it is required. The public identified decoctions as the most preferred formula as well as the most effective formulas out of all Oriental herbal medical formulas. They also suggested that it should be the first to be included when the insurance policy expands in the future. The public had frequent experienced not choosing Oriental herbal prescription due to the high cost. Insurance coverage of Oriental herbal prescription is much needed. The public indicated that they will make frequent visits to the KMD if the insurance covers Oriental herbal prescriptions. Conclusions : The current status quo of Oriental herbal medicine insurance showed that the public identified decoctions as the most preferred, most effective and the top priority to be covered by insurance.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1083-1095
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• 2020

Since 2019, ultrasound and magnetic resonance imaging for evaluation of urogenital disorders have been covered by the National Health Insurance (NHI) in Korea. Patients with urogenital malignancies were already insured by NHI for ultrasound and MRI. With the expansion of NHI coverage, patients with suspected prostate or gynecologic cancer, uterine fibroids before myomectomy and some other benign disease such as congenital anomaly can receive benefits of NHI. In consideration of these changes, radiologists and other clinicians should be aware of the indications and standard images of each examination and the required reporting forms. Clinical application based upon thorough understanding of the NHI guidelines will aid in improving the standard care of patients.

• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.99-128
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• 2008

Nearly all Koreans are insured through National Health Insurance(NHI). While NHI coverage is nearly universal, it is not complete. Coverage is largely limited to minimal level of hospital and physician expenses, and copayments are required in each case. As a result, Korea's public insurance system covers roughly 50% of overall individual health expenditures, and the remaining 50% consists of copayments for basic services, spending on services that are either not covered or poorly covered by the public system. In response to these gaps in the public system, 64% of the Korean population has supplemental private health insurance. Expansion of private health insurance raises negative externality issue. Like public financing schemes in other countries, the Korean system imposes cost-sharing on patients as a strategy for controlling utilization. Because most insurance policies reimburse patients for their out-of-pocket payments, supplemental insurance is likely to negate the impact of the policy, raising both total and public sector health spending. So far, most empirical analysis of supplemental health insurance to date has focused on the US Medigap programme. It is found that those with supplements apparently consume more health care. Two reasons for higher health care consumption by those with supplements suggest themselves. One is the moral hazard effect: by eliminating copayments and deductibles, supplements reduce the marginal price of care and induce additional consumption. The other explanation is that supplements are purchased by those who anticipate high health expenditures - adverse effect. The main issue addressed has been the separation of the moral hazard effect from the adverse selection one. The general conclusion is that the evidence on adverse selection based on observable variables is mixed. This article investigates the extent to which private supplementary insurance affect use of health care services by public health insurance enrollees, using Korean administrative data and private supplements related data collected through all relevant private insurance companies. I applied a multivariate two-part model to analyze the effects of various types of supplements on the likelihood and level of public health insurance spending and estimated marginal effects of supplements. Separate models were estimated for inpatients and outpatients in public insurance spending. The first part of the model estimated the likelihood of positive spending using probit regression, and the second part estimated the log of spending for those with positive spending. Use of a detailed information of individuals' public health insurance from administration data and of private insurance status from insurance companies made it possible to control for health status, the types of supplemental insurance owned by theses individuals, and other factors that explain spending variations across supplemental insurance categories in isolating the effects of supplemental insurance. Data from 2004 to 2006 were used, and this study found that private insurance increased the probability of a physician visit by less than 1 percent and a hospital admission by about 1 percent. However, supplemental insurance was not found to be associated with a bigger health care service utilization. Two-part models of health care utilization and expenditures showed that those without supplemental insurance had higher inpatient and outpatient expenditures than those with supplements, even after controlling for observable differences.