• Journal of the Korean Society of Radiology
• /
• v.15 no.1
• /
• pp.9-14
• /
• 2021

Recently, magnetic resonance imaging (MRI), which can acquire images with good contrast without exposure to radiation, has been widely used for diagnosis. However, noise that reduces the accuracy of diagnosis is essentially generated when acquiring the MR images, and by adjusting the parameters, the noise problem can be solved to obtain an image with excellent characteristics. Among the parameters, the number of excitation (NEX) can acquire images with excellent characteristics without additional degradation of image characteristics. In contrast, appropriate NEX setting is required since the scan time increases and motion artifacts may occur. Therefore, in this study, after fixing all MRI parameters through the MRiLab simulation program, we tried to evaluate the tendency of image characteristics according to changing NEX through quantitative evaluation of brain T2 weighted images acquired by adjusting only NEX. To evaluate the noise level and similarity of the acquired image, signal to noise ratio (SNR), contrast to noise ratio (CNR), root mean square error (RMSE) and peak signal to noise ratio (PSNR) were calculated. As a result, both noise level and similarity evaluation factors showed improved values as NEX increased, while the increasing width gradually decreased. In conclusion, we demonstrated that an appropriate NEX setting is important because an excessively large NEX does not affect image characteristics improvement and cause motion artifacts due to a long scan.

• 한국사회정책
• /
• v.23 no.3
• /
• pp.17-47
• /
• 2016

This paper aims to analysis working-time of Korea focusing on "the difference and the distribution" by a stratum. Classifying working-time into four categories including marginal part-time, part-time work, standard-time work and long-time working, it compares the relative distribution by income quintile. The outcome is as following : 20% of low-ranking income quintile are (marginal) part-time working, 60% from income quintile 2 to 4 are in long-time working and 20% of top-ranking income quintile are in the standard-time working in overall. Working-time classes can be divided up into three: short time-low income of type 1, long time-medium income of type 2 and standard time-high income of type 3. Analysing working time type, the low wage-short time, medium wage-long time and high wage-standard time by the wage per month and low wage-very long time, medium wage-long time and high wage-standard time by the wage per hours are confirmed. Also, stratification of working-time has been intensified in terms of age, jobs and work status. Policy implication from this study is that the increase of minimum wage to the lowest income class and creation of employment by the reduction of working-time to the medium income class could be effective policies.

• (The)Study of the Eastern Classic
• /
• no.41
• /
• pp.211-247
• /
• 2010

The purpose of this article is to consider the status and the value of a different book of Chunghyangjeon that Professor Park Sunho possesses. Chunghyangjeon that Professor Park Sunho possesses has the text in Chinese and in Korean. Compared with Chullidaebon, Chunghyangjeon that Professor Park Sunho possesses includes deletion, contraction and addition. Chullidaebon has many mistakes while Parkbon in Chinese shows that the mistakes were corrected. According to the standard, Parkbon in Chinese is similar to Mansongbon and Donambon rather than Chullidaebon and it is more similar to Mansongbon than Donambon. In Parkbon in Chinese, hypocrisy of Yangnyeongdaegun is weakened while his negative personality is magnified. And psychological description of Yangyeongdaegun is weakened and Chunghyang's beauty is magnified. Parkbon in Korean shows deletion, contraction, addition, and change. It doesn't show consciousness of lineage and deletes hypocrisy and negative personality of Yangnyeongdaegun. Also, the phrases are being deleted and contracted, which are difficult for those who do not master Chinese literature or Chinese poems. The professor Park Sunho's copy is more significant than other novels circulated at that times, for it is bound along with a copy in Korean. Compared with other editions of Chunghyangjeon and other classical novels circulated, that kind of edition, which included Korean copy, is very peculiar. The Korean-including edition shows that the Chinese literate tried to share the novel with persons who are Korean literate but cannot read Chinese characters.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.23 no.6
• /
• pp.371-384
• /
• 2021

Underground space, especially very-deep tunnel development in urban area, is a good alternative to solve the problem of insufficient ground space, and the need for underground space development is steadily increasing. However, due to the complex and time-consuming nature of design and construction, public conflicts related to the deep tunnel project are getting aggravating and more complex. In addition, since the public budget is mainly invested, when civil complaints arise, they often respond passively, resulting in amplification of conflicts or prolonging the deadlock in many cases. In this study, by analyzing the progress of major conflicts related to the construction of very-deep tunnels in urban area, the causes of conflicts, factors prolonging conflicts, and solutions are reviewed. Through a survey targeting ordinary citizens and tunnel experts, thoughts about the deep tunnel construction and major conflict factors were analyzed, and suggestions for minimizing conflicts were presented. The results of this study can be used to prepare alternatives such as various public involvement measures and improvement of project procedures to form a civic consensus on the construction of very-deep tunnels, and to prepare measures to improve prejudice against very-deep tunnels.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.6
• /
• pp.555-562
• /
• 2021

Recently, in the field of geospatial information construction, unmanned aerial vehicles have been increasingly used because they enable rapid data acquisition and utilization. In this study, photogrammetry was performed using fixed-wing, rotary-wing, and VTOL (Vertical Take-Off and Landing) unmanned aerial vehicles, and geospatial information was constructed using two types of unmanned aerial vehicle LiDAR (Light Detection And Ranging) sensors. In addition, the accuracy was evaluated to present the utility of spatial information constructed through unmanned aerial photogrammetry and LiDAR. As a result of the accuracy evaluation, the orthographic image constructed through unmanned aerial photogrammetry showed accuracy within 2 cm. Considering that the GSD (Ground Sample Distance) of the constructed orthographic image is about 2 cm, the accuracy of the unmanned aerial photogrammetry results is judged to be within the GSD. The spatial information constructed through the unmanned aerial vehicle LiDAR showed accuracy within 6 cm in the height direction, and data on the ground was obtained in the vegetation area. DEM (Digital Elevation Model) using LiDAR data will be able to be used in various ways, such as construction work, urban planning, disaster prevention, and topographic analysis.

• 한국체육학회지인문사회과학편
• /
• v.54 no.5
• /
• pp.727-737
• /
• 2015

The study investigated the relationship between vitamin D status and lifestyle risk factors in office workers. A total of 515 office workers(336 men and 179 women) aged 30 years or older were voluntarily recruited from S-city. Along with serum vitamin D levels, lifestyle risk factors including obesity index, physical fitness, metabolic risk factors, lipids profile and sedentary behavior were measured using standardized protocols. Subjects were classified as deficiency (<20ng/mL), insufficiency (20-29ng/mL), and sufficiency (≥30ng/mL) based on serum vitamin D levels. Linear contrast analysis using one-way ANOVA showed significant linear decreases in mean body fat (p=.030) and sedentary behavior (p<.001) and significant linear increases in skeletal muscle (p=.037), cardiorespiratory fitness (p<.001) and HDL-C (p=.013) across incremental serum vitamin D levels. Compared with the low cardiorespiratory fitness group, the high cardiorespiratory fitness group had a significantly higher odds ratio (men OR=2.144, p=.042, women OR=1.971, p=.045) for having vitamin D insufficiency or deficiency even adjustment after age. Compared to the shortest sitting time group, the longest sitting time group had a significantly higher odds-ratio in a group of female office workers (OR=1.262, p=.043) for having vitamin D insufficiency or deficiency even adjustment after age. The current findings of the study showed that poor physical fitness and sedentary behavior were the risk factors of low serum vitamin D levels, implying the urgent need for a healthy lifestyle modification along with vitamin D supplementation.

• The Journal of Bigdata
• /
• v.6 no.2
• /
• pp.151-159
• /
• 2021

Construction of a blockchain network needs a cumbersome and time consuming activity. To overcome these limitations, global IT companies such as Microsoft are providing cloud-based blockchain services. In this paper, we propose a blockchain-based construction and management tool that enables blockchain developers, blockchain operators, and enterprises to deploy blockchain more comfortably in their infrastructure. This tool is implemented using Hyperledger Fabric, one of the famous private blockchain platforms, and Ansible, an open-source IT automation engine that supports network-wide deployment. Instead of complex and repetitive text commands, the tool provides a user-friendly web dashboard interface that allows users to seamlessly set up, deploy and interact with a blockchain network. With this proposed solution, blockchain developers, operators, and blockchain researchers can more easily build blockchain infrastructure, saving time and cost. To verify the usefulness and convenience of the proposed tool, a blockchain network that conducts electronic voting was built and tested. The construction of a blockchain network, which consists of writing more than 10 setting files and executing commands over hundreds of lines, can be replaced with simple input and click operations in the graphical user interface, saving user convenience and time. The proposed blockchain tool will be used to build trust data infrastructure in various fields such as food safety supply chain construction in the future.

• Journal of Korea Entertainment Industry Association
• /
• v.6 no.4
• /
• pp.82-92
• /
• 2012

Recently people who enjoy social game via mobile devices significantly are increasing depending on the rapid adoption of smart phones and the development of the network such as LTE. Most of them are enjoying the casual gaming mobile social games that you are able to play easily, but social issues like health problems due to long play time are emerging. The users, however, do not last long because of the simplicity of the game, and there are few people who actually buy game items even though they play it long time. This study has been conducted aiming to overcome such difficulties. This study suggests ways to generate constantly revenue avoiding short-term box-office after the release of mobile social games based on the analysis for market trend and profitability of the mobile social game. In addition, by applying profitability model analyzed to Japan's most successful game practices, this paper suggests the concrete methods about the commitment of the users. For summarizing the main achievements of this paper, providing the latest market information about mobile social games, analysis of profitability, practical implications for the commitment of the users are presented.

• Journal of Advanced Navigation Technology
• /
• v.25 no.6
• /
• pp.510-516
• /
• 2021

Recently, the range of utilization and demand for unmanned aerial vehicle (UAV) has been continuously increasing, and research on the construction of a separate operating system for low-altitude UAV is underway through the development of a management system separate from manned aircraft. Since low-altitude UAVs also fly in the airspace, it is essential to establish technical standards and certification systems necessary for the operation of the aircraft, and research on this is also in progress. If the operating standards and certification requirements of the aircraft are presented, a test method to confirm this should also be presented. In particular, the accuracy of small UAV's navigation required during flight is required to be more precise than that of a manned aircraft or a large UAV. It was necessary to calculate a separate navigation error. In this study, we presented a test method for deriving navigation errors that can be applied to UAVs that have difficulty in acquiring long-term operational data, which is different from existing manned aircraft, and conducted verification tests.

• Journal of Industrial Convergence
• /
• v.22 no.6
• /
• pp.107-120
• /
• 2024

This study aimed to identify factors associated with metabolic abnormalities in non-obese and obese postmenopausal women based on biopsychosocial model. Secondary data analysis was conducted using data from 5,335 postmenopausal women who participated in the Korean National Health and Nutrition Examination Survey (2015-2021). According to logistic analysis with applying a complex simple analysis in SPSS 26.0, biomedical (increased age; a family history of hypertension, type 2 diabetes, dyslipidemia, and cardiovascular diseases) and biosocial factors (low educational level) were associated with 1-2 metabolic abnormalities and metabolic syndrome, regardless of adiposity. Additionally, low familial socioeconomic status and prolonged sedentary behaviors were the biosocial and psychosocial factors associated with metabolic syndrome regardless of adiposity. Finally, insufficient physical activity was associated with metabolic syndrome in obese postmenopausal women. Based on these results, tailored strategies should be developed considering the significant factors associated with metabolic abnormalities and adiposity in postmenopausal women.