• Journal of KIISE:Databases
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• v.37 no.6
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• pp.315-323
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• 2010

In Wireless Sensor Networks (WSNs), various Data-Centric Storages (DCS) schemes have been proposed to store the collected data and to efficiently process a query. A DCS scheme assigns distributed data regions to sensor nodes and stores the collected data to the sensor which is responsible for the data region to process the query efficiently. However, since the whole data stored in a node will be lost when a fault of the node occurs, the accuracy of the query processing becomes low, In this paper, we propose an in-network aggregation query processing method that assures the high accuracy of query result in the case of data loss due to the faults of the nodes in the DCS scheme. When a data loss occurs, the proposed method creates a compensation model for an area of data loss using the linear regression technique and returns the result of the query including the virtual data. It guarantees the query result with high accuracy in spite of the faults of the nodes, To show the superiority of our proposed method, we compare E-KDDCS (KDDCS with the proposed method) with existing DCS schemes without the data-loss correction method. In the result, our proposed method increases accuracy and reduces query processing costs over the existing schemes.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.35-44
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• 2016

Two primary tools to study park use are surveys and direct observation. Existing methods, however, are limited in terms of considerable costs in both time and money and the personal bias of respondents or observers. These limitations result in a lack of efficient, reliable, and affordable tools to investigate park use. This study explores the reliability and usability of unmanned aerial vehicles(UAVs) to explore park use in urban parks in Busan metropolitan city. By comparing with a systematic observation tool, SOPARC(System for Observing Play and Recreation in Communities), this study finds that the number of park users observed by two different techniques are highly correlated and not significantly different with each other. In addition, both methods show a high level of test-retest reliability. Comparing to existing methods, the UAV-using observation tool could cover larger target areas and is suitable to count park users in a more reliable and efficient way and map their use patterns, although it is weak in collecting detailed user information and surveying under poor conditions such as rain. Thus, the UAV method could complement direct observation. This study suggests practical implications of a UAV method to study park use.

• Journal of KIISE:Databases
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• v.33 no.6
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• pp.620-630
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• 2006

Event-detection is an important application of sensor networks. Join operations can facilitate event-detection with a condition table predefined by a user. When join operations are used for event-detection, it is desirable, if possible, to do in-network join processing to reduce communication costs. In this paper, we propose an energy-efficient in-network join algorithm, called PBA. In PBA, each partition of a condition table is stored along the path from each node to the base station, and then in-network joins are performed on the path. Since each node can identify the parts to store in its storage by its level, PBA reduces the cost of disseminating a condition table considerably Moreover, while the existing method does not work well when the ratio of the size of the condition table to the density of the network is a little bit large, our proposed method PBA does not have such a restriction and works efficiently in most cases. The results of experiments show that PBA is efficient usually and especially provides significant cost reduction over existing one when a condition table is relatively large in comparison with the density of the network, or the routing tree of the network is high.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.609-623
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• 2004

Various metadata registries have been built in many countries of the world. Although the metadata registry is an international standard, it does not provide a consistent access interface for handling the metadata registries. Therefore, all systems for managing them were developed by using different operations and access interfaces. It requires duplicate efforts on the same operations whenever metadata registry systems are developed. As a result, it causes unnecessary costs and efforts for building metadata registries, and also incurs inconsistency between the metadata registries because the previous developed systems use the different interfaces for the metadata registry elements This paper analyzes and defines operation patterns that are commonly used for the metadata registries. We defined and designed SQL/MDR extended from SQL using the analyzed operation patterns. SQL/MDR provides a standardized access interface for developing metadata registry systems. This paper shows the implementation of SQL/MDR and the result that we actually applied it to the bibliographical databases. By developing the metadata registry systems using SQL/MDR, we can reduce much time and efforts owing to its standard interface. It allows metadata registries to be accessed consistently. Additionally, it makes all metadata registries follow the international standard, ISO/IEC ll179.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.464-469
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• 2013

After city of Busan has been entered to the aging society in 2000, the city has the highest aging rate among 7 representative cities in 2011. Moreover, while entire population and number of average household are decreasing, over 65 years old of elderly population is rapidly increasing. So, it is possible to enter the super-aged society, where aging rate would be about 20% after 2020. The purpose of this study is that older housing-related analysis is consisted of dong-unit, and this led microscopic analysis has become necessary. Surveys from 2000 through 2010, census aggregate (output area) unit of spatial analysis was conducted. Take advantages of this, aging population and area, soaring area, high-density areas, such as the region of interest were primary extracted, and microscopic location and spatial distribution patterns were analyzed. Upon analysis, aging population is concentrated in the city and adjacent area, the highlands, and 10 years of increasing rate was more than 30 times in certain aggregate. Regarding the characteristic of these areas, the original city center, Busan, especially concentrated and intensified in aging population. Also, 2000 to 2010, the overall distribution pattern of Busan has identified aging population that is increasingly being distributed. This is the result, which is confronted with previous research result. Entering a super aged-society for the future is accordance with migration of social costs and improve the quality of life of elderly. And this could be the basic information to use the spatial dimension for the corresponding.

• Journal of Oriental Neuropsychiatry
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• v.25 no.4
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• pp.389-400
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• 2014

Objectives: Though there are many studies about sleep disorder, no research has been performed on the utilization of oriental medicine as a treatment. Therefore, the oriental medical treatment pattern of Korean patients with sleep disorders was examined herein using the Health Insurance Review and Assessment Service (HIRAS). Methods: The medical records of patients with sleep disorders (G47) or nonorganic sleep disorders (F51) as a main diagnosis were adopted from the HIRAS database from 2011 to 2013. Analysis was performed on the number of patients and cost per patient, with comparison between oriental and western medicine in terms of gender, age, patient care service type, and hospital type. Results: 1) Regarding sleep disorders, the medical visits and insurance charges have been increasing. Western medicine was utilized 8 times more often than oriental medicine during 3 years. 2) There were 2.5 times more women than men. 3) Among all ages, the 50~59 year group had the highest representation. 4) In comparison of average portions of patient care type over 3 years, outpatients were the majority, while the number of visits of outpatients and hospitalization has been increasing. 5) Comparison of average portion of oriental hospital type over 3 years revealed oriental clinics to be used most. The use of general hospitals was higher in western medicine treatment, while public health centers used oriental medicine more. 6) Regarding average oriental medical cost per patient over 3 years, the total was 88,000 won, with 353,000 won for hospitalization and 85,000 won for outpatients. The outpatient cost has been increasing. 7) In line with 6, oriental medical hospitals cost 126,000 won, local clinics were 85,000 won, and etc. was 95,000 won. Average costs of all types have increased during 3 years, except oriental medical hospitals in 2013. Conclusions: This study provided objective information about the epidemiologic characteristic of oriental medicine used for treatment of sleep disorder. For expansion of oriental medical demand for sleep disorder, this study would be helpful in understanding the recent status.

• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.99-106
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• 2002

Objective : Until now, there have been no evidence-based guidelines produced for the mass screening of hyperlipidemia cases in Korea. This study was done to find the most efficient strategy for a hyperlipidemia-screening program among Korean adults, Method : Seven alternative strategies for hyperlipidemia screening were formulated and compared ir terms of cost-effectiveness. Cost and effectiveness were estimated from social perspectives and using a two-stage screening process (initial testing and additional testing for positives from the first test). A computerized database (based on persons who had visited a health promotion center in one teaching hospital for a routine health check-up) was used to determine the cost and the outcome of various strategies. Official data was used in calculating direct and indirect costs. Effectiveness was measured according to the number of persons who needed clinical intervention for hyperlipidemia. A stratified analysis, considering age group and sex, was then done. Sensitivity analyses, focusing on several uncertain parameters, were also done. Results : Of the seven test alternatives available, the most cost-effective strategy was a screening program, which consisted of an initial test of total cholesterol, high-density lipoprotein cholesterol and triglyceride. There was some variation in the rank of the cost-effectiveness ratios for the seven alternatives dependent on age group or gender. Conclusions : Current hyperlipidemia screening practice, for National Health Insurance beneficiaries, tests only the total cholesterol level with a cut-off value of 260mg/dl as an initial screening test. It is not the best strategy for cost-effectiveness, and should be modified. Different screening strategies taking age group and sex into account should be developed and used for the efficient mass screening of hyperlipidemia cases among Korean adults.

• Journal of Preventive Medicine and Public Health
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• v.42 no.6
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• pp.403-407
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• 2009

Objectives : The amount of medical utilization by Medical Aid recipients was 3.7 times that of patients with Korean Medical Insurance. This study aims to describe the surplus medicine and the medication-related utilization, and to determine factors contributing to surplus medicine. Methods : Among those who used copayment-free Class I Medical Aid in 2005, 146,880 subjects who were $\geq19$ year-old and received >365 days medical treatment per year were studied with their case managers by conducting face-to-face interviews. The analytic methods were description, chi-square, t-tests, ANCOVA and multiple logistic regressions. Results : Most subjects were female (68.6%), the elderly (62.5%), and the separated (61.6%), had an elementary graduation or less (74.8%), and had disabilities (33.2%). The percentage of subjects with surplus medicine was 18.5%. However, the percentage of females, the elderly, those with non-disabilities, the separated, the uneducated, those with a very poor perceived health status and those with an economical burden for medical treatment was 19.3%, 18.9%, 19.0%, 19.3%, 19.0%, 20.2% and 24.3%, respectively. For subjects with surplus medicine, averages for the number of used pharmacies, the pharmacy-visit days and the medication costs were 4.6 drugstores, 34.9 days and approximately 1,124 thousand Won(￦). These values were higher than those without surplus medicine (4.4 drugstores, 33.8 days, and ￦1,110 thousand, respectively). The odds ratios of the contributing factors to surplus medicine were female 1.11 (95% CI=1.07-1.14), the elderly 1.06 (95% CI=1.02-1.10), those with non-disabilities 1.08 (95% CI=1.05-1.12), the separated 1.14 (95% CI=1.10-1.18), the unmarried 1.12 (95% CI=1.07-1.18), the uneducated 1.03 (95% CI=1.01-1.08), those with a very poor perceived health status 1.04 (95% CI=1.01-1.08) and experiencing an economical burden for medical treatment 2.33 (95% CI=2.26-2.40). Conclusions : 18.5% of subjects had surplus medicine with a higher mean of medication cost. Therefore, health education and health promotion programs to prevent surplus medicine and to improve the appropriate usage of medication are necessary.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.794-799
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• 2005

With the quantitative growth of the petroleum industry, the pipe facilities that connect each process increased significantly and the corresponding maintenance and repair costs of the pipe facilities increased as well. The diagnosis techniques to check a pipe efficiency while in operation are few in Korea, but in the advanced countries the pipe diagnosis using gramma-ray source was on-going research since 1960's. In this study, field experiments were performed to analyze the reasons for abnormal operation of the pipe connected to a distillation tower, and the degree of abnormality was estimated using a sealed gamma-ray source ($^{137}Cs$). Gamma radiation counts were measured by a detector (NaI) positioned outside the pipe-wall diametrically opposite to the gamma source. The results showed that a gas zone section's distribution pattern was different from the pattern of nearby fluid in a pipe. Th diagnosis technique using a gamma radiation source was proved to be an effective and reliable method, offering the information on the fluid distribution in pipe.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.3
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• pp.175-186
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• 2017

In this study was to survey method of national/public land actual condition survey to utilization of UAV, in order to evaluate the economic and accuracy. we carried out the comparative evaluation of the cadastral status surveying in terms of accuracy of parcel checkpoint, economical costs. The results are summarized as follows. First, average position error of the orthoimage was 0.033m in X error, 0.023m in Y error when the RMSE average calculated 0.046m from the intersection of plane distance connections. Secondly, it was appeared the accuracy of the orthophotograph is 0.076m at the maximum RMSE of the UAV orthoimage check point and 0.042m at the minimum RMSE compared with the VRS-GNSS survey results. Thirdly, when the allowable error specified in the implementing regulation of the current cadastral survey is applied, all of the checkpoint of 0.360m tolerance corresponding to the scale of 1/1,200 is satisfied. Finally, UAV utilization method in national/public land actual condition survey is 26,497,436(KRW) cheaper than cadastral survey method for In the economic evaluation of national/public land actual condition survey. Therefore, as a result of this study shows that the method of utilizing UAV in the national/public land actual condition survey satisfies legal standards in terms of accuracy and economical aspect is a way to further reduce the local government budget.