• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.109-119
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• 2004

The home network environment can be defined as a network environment, connecting digital home devices such as computer systems, digital appliances, and mobile devices. In this kind of home network environments, there will be numerous local/remote interactions to monitor and control the home network devices and the home gateway. Such an environment may result in communication bottleneck. By applying the mobile agents that can migrate among the computing devices autonomously and work on behalf of the user, remote interactions and network traffics can be reduced enormously. The mobile agent authentication is necessary to apply mobile agent concept to the home network environments, as a prerequisite technology for authorization or access control to the home network devices and resources. The existing mobile agent systems have mainly used the public key based authentication scheme, which is not suitable to the home network environments, composed of digital devices of limited computation capability. In this paper, we propose a shared key based mobile agent authentication scheme for single home domain and expand the scheme to multiple domain environments with the public key based authentication scheme. Application of the shared key encryption scheme to the single domain mobile agent authentication enables to authenticate the mobile agent with less overhead than the public key based authentication scheme.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.2
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• pp.122-133
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• 2021

Cultivar parameter calibration can be affected by the reliability of the input data to a crop growth model. In South Korea, two sets of weather stations, which are included in the automated synoptic observing system (ASOS) or the automatic weather system (AWS), are available for preparation of the weather input data. The objectives of this study were to estimate the cultivar parameter using those sets of weather data and to compare the uncertainty of these parameters. The cultivar parameters of CERES-Rice model for Shindongjin cultivar was calibrated using the weather data measured at the weather stations included in either ASO S or AWS. The observation data of crop growth and management at the experiment farms were retrieved from the report of new cultivar development and research published by Rural Development Administration. The weather stations were chosen to be the nearest neighbor to the experiment farms where crop data were collected. The Generalized Likelihood Uncertainty Estimation (GLUE) method was used to calibrate the cultivar parameters for 100 times, which resulted in the distribution of parameter values. O n average, the errors of the heading date decreased by one day when the weather input data were obtained from the weather stations included in AWS compared with ASO S. In particular, reduction of the estimation error was observed even when the distance between the experiment farm and the ASOS stations was about 15 km. These results suggest that the use of the AWS stations would improve the reliability and applicability of the crop growth models for decision support as well as parameter calibration.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.154-162
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• 2021

The naturally opened Han river estuary is a place where the flows of the Han river, Imjin river, Yaesung river meet with West Sea of Korea, so the hydrodynamic mechanism(Impact-Response) structure of Han river estuary is complex. Continuous observation and measurement due to the morphological characteristics at the estuary are required to maintain the estuary environment and river management facilities. However, the Sannam wetland(the study area) is in the military operation area. Therefore, Sannam wetland has the limited access under the control from military office. In 2020, there had a natural disaster due to flooding in August and COVID-19, and it made a survey hard. The noncontact survey technique, the analysis of LANDSAT images at Sannam wetland, was applied to analyze riverbed fluctuation and morphological transformation around Sannam wetland. LANDSAT images obtained from EarthExplorer, USGS and analyzed by QGIS. The analysis was performed based on the area and the distance near Sannam wetland. As a result, an erosion was happened on the downstream of the study area, and the upstream of the study area did not have any serious sediment transport. Considering the resolution of LANDSAT images, this noncontect survey technique is applicable to manage the study area. From the analysis of LANDSAT images, it is assumed that the tidal effect is greater than the inflow from the upstream. The pattern change of tidal response causes the damage of the river facilities near the Hangang river estuary.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.23-29
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• 2022

Although tropical cyclones with wind speeds weaker than 17 ms^-1 (weak tropical cyclones: WTCs) can cause significant damage, particularly over the Seoul metropolitan area, only a few studies have focused on WTC activity over South Korea. In this study, we found that WTC activity is likely associated with the Pacific Decadal Oscillation (PDO). During the negative phases of the PDO, landfall frequency of WTCs increased significantly compared to the positive phases at 95% confidence level. When related to the negative phases of the PDO, a positive relative vorticity anomaly is found in the northern sector of the western North Pacific while a negative relative vorticity anomaly and enhanced vertical wind shear prevail in the southern sector of the WNP. These factors are favorable for the northward shift of the genesis location of tropical cyclones on average, thereby reducing the total lifetime of WTCs. Moreover, a high-pressure anomaly over the Japanese islands would shift a tropical cyclone track westward in addition to the landfall location. Consequently, the effects of the topographical friction and the Yellow Sea Bottom Cold Water on a tropical cyclone may increase. These conditions could result in a weaker lifetime maximum intensity and landfall intensity, ultimately resulting in WTCs becoming more frequent over South Korea during the negative phases of the PDO.

• Therapeutic Science for Rehabilitation
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• v.10 no.4
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• pp.65-80
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• 2021

Objective : This study aimed to develop a Korean version of the HLS-EU-Q47 that deals with the concept of health literacy based on the understanding, apply/use, process/appraisal, and access/obtain to health information. The purpose of this study is to confirm the level of comprehensive health literacy of the elderly in Korea using this tool. Methods : After going through the Korean interpretation process of HLS-EU-Q47, the items were confirmed through content validity verification by experts. The completed Korean-HLS-EU-Q47 (K-HLS-EU-Q47) was applied to 254 elderly people in the local community to analyze the degree of internal consistency and reliability. Furthermore, a comparative analysis based on the general variables was conducted. Results : The internal consistency of this tool for the elderly yielded Cronbach's 𝛼 of .81~.91, indicating a high level of reliability. There was a difference in health literacy according to sex and age based on general characteristics. Men had higher health literacy than women, and with increasing age, health literacy decreased. Conclusion : In this study, the K-HLS-EU-Q47 was developed to assess the comprehensive health literacy level of the elderly in Korea. It is expected that the search for ways to maintain a healthier life for the elderly through understanding the health literacy levels of the elderly using the results of this study will become more active.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.309-317
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• 2022

It is reported that social distancing caused by the corona pandemic has resulted in a decrease in physical activity, and a decrease in muscle mass due to this increases the risk of vascular disease. Therefore, in this study, the risk of carotid intima media thickness was evaluated by measuring the thickness of CIMT, and the differences in variables according to gender were analyzed. From January 2022 to May 2022, a total of 220 people (121 males, 99 females) who performed blood tests, carotid ultrasound, and body composition analysis among those who visited the health check-up center of Busan H Hospital were included in this study. Significant differences in risk factors according to gender were analyzed using the chi-square test. The cut-off values of variables that can predict the risk of carotid intima media thickness were calculated, and the accuracy was evaluated by calculating the area under the curve, sensitivity, and specificity. As a result of the difference analysis, the higher the total cholesterol in men and the appendicular skeletal muscle index in women, the higher the risk of carotid intima media thickness. The cut-off value for predicting the risk of carotid intima media thickness was calculated to be greater than 199 mg/dL of total cholesterol in the male group and less than 5.9 kg/m² of the appendicular skeletal muscle index in the female group. As a result of this study, the higher the total cholesterol in men and the lower the appendicular skeletal muscle index in women, the higher the risk of increased CIMT. Therefore, in women, the appendicular skeletal muscle index is expected to serve as an indicator to predict and prevent vascular changes at an early stage.

• Korean Journal of Remote Sensing
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• v.38 no.6_4
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• pp.1925-1934
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• 2022

Monitoring nuclear activity for inaccessible areas using remote sensing technology is essential for nuclear non-proliferation. In recent years, deep learning has been actively used to detect nuclear-activity-related small objects. However, high-resolution satellite imagery containing small objects can result in class imbalance. As a result, there is a performance degradation problem in detecting small objects. Therefore, this study aims to improve detection accuracy by analyzing the effect of the ratio of small objects related to nuclear activity in the input data for the performance of the deep learning model. To this end, six case datasets with different ratios of small object pixels were generated and a U-Net model was trained for each case. Following that, each trained model was evaluated quantitatively and qualitatively using a test dataset containing various types of small object classes. The results of this study confirm that when the ratio of object pixels in the input image is adjusted, small objects related to nuclear activity can be detected efficiently. This study suggests that the performance of deep learning can be improved by adjusting the object pixel ratio of input data in the training dataset.

• Journal of Korean Library and Information Science Society
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• v.54 no.2
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• pp.43-65
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• 2023

The purpose of all public libraries is to provide knowledge and information services for the intellectual and reading activities of local residents, program services that provide opportunities for cultural enjoyment and lifelong learning, and third-party spaces and facilities that contribute to the development of the community. To this end, social needs must be reflected in a timely manner with the establishment of a sound infrastructure as a prerequisite. This study analyzed the current status centered on key indicators of the public libraries in Daegu City and presented policy issues that need to be improved through a survey. The key indicators in Daegu City, compared to the national average, were not only significantly weak for the 3rd largest city but also showed considerable variation among local governments. While Daegu citizens valued public libraries in their daily lives, the dissatisfaction rate was high in the order of transportation inconvenience, lack of necessary materials and desired programs, and various regulations. Therefore, Daegu City should focus on increasing the acquisition budget, strengthening the development of new book collections, expanding the number of librarians, expanding the construction of public libraries to address service disparities among local governments, improving accessibility, and addressing factors that hinder usage. In addition, with the establishment and operation of the Daegu Library in 2024, efforts should be made to establish an operational system for public libraries, expand the scope through collaborative partnerships with other knowledge and cultural institutions, and enhance knowledge and cultural services for the Daegu citizen.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.477-483
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• 2008

If designed properly, street transit systems can provide many useful functions with the flexibility of serving an unlimited range of locations throughout an urban area. Over the last decades urban regions of Korea cities have seen rapidly changing travel patterns and urban conditions. Under this circumstance transit planners need frequent evaluations of its street transit routes so as to restructure or modify them rationally. It should be noted that the changing network influences passengers, operators, as well as the city itself. However, there is no proper framework with which to evaluate the street transit network comprehensively. This paper develops and provides a framework including criteria and indicators for evaluating street transit networks. Five criteria, such as network size, network structure, service requirements, efficiency of operation and the relationship to the city are presented. A number of indicators and measures representing each criteria are then suggested. As a practical example, an analysis and comparison of three minibus networks in Busan are presented, utilizing the developed measures and indicators. The results of this study will be of great use for planners responsible for transit route planning, particularly for planning of new or analysis of existing routes; their comparison with routes/networks of various cities.

• Korean Journal of Social Welfare Studies
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• v.42 no.2
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• pp.123-153
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• 2011

This study tries to categorize innovation types for social welfare organizations and investigate the level of innovation in each type in practical field. Firstly, this study scrutinizes the concept and classification's criterias of innovation. Secondly, this study reviews not only classification of innovation in profit organization but also several researches of innovation in service industry and public sectors, and finally, this study makes a suggestion of innovations' classification that is applicable for social welfare organizations. Based on this suggestion, fifteen questions are designed to ask the innovative activities in the organizations. And total 496 respondents from 116 organizations answered these questionnaire. The outcomes of this survey were substantiated by second data through converted procedures to mean value of organizations. Consquently, service innovation, administrative innovation and human resource innovation, proposed based on theoretical review, were subdivided into six categories such as service innovation, structural innovation, internal and efficiency innovation, marketing and communication innovation, external and employment innovation and evalution and mission innovation. The mean value of service(mean=14.7) and marketing innovation(mean=13.3) are higher than other type of innovations, which shows the aspect of innovative activities in social welfare organizations. Based on this result, we can get the directions of following study in investigating innovation of social welfare organization.