• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.5
• /
• pp.16-24
• /
• 2007

Wireless mesh network extends the limited coverage of conventional wireless service from one-hop access point to wider area. It is recognized as an important issue to provide seamless handoff in the wide coverage of wireless mesh network. A long handoff delay may cause high packet loss and disconnection of service, degrading the network performance. The handoff delay is mainly introduced from the channel scanning process obtaining information to make handoff decision and the unnecessary handoffs due to inaccurate handoff decision. In this paper, we propose the handoff algorithm based on one-way trip time (OTT) to expedite the handoff procedure. As compared to the handoff algorithm based on the receiving signal power, the proposed algorithm takes advantage of OTT to obtain the necessary handoff information in a relatively shorter time and reduce the unnecessary handoffs. The performance of proposed algorithm is evaluated through the simulations. It is verified that the proposed handoff algorithm can effectively enhance the handoff accuracy, and therefore reduce the handoff delay and unnecessary handoffs.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.1
• /
• pp.88-95
• /
• 2011

In this paper, a new standby-mode control method for multiple output switching-mode power-supply is suggested, which uses the control signal of the feedback compensator of the inner loop in the linear voltage regulator located at the transformer secondary side, as the load current information. Conventional method has a problem that standby mode occurs depending only on the load condition of the main controller output, which makes the other secondary side output very inaccurate by burst mode operation. The proposed method detects all the load current information and operates in burst mode only when the all of them are light load condition. Minimum of the additional components are required for the implementation of the proposed method because the load information is obtained from the existing feedback circuit of the post-stage linear regulator. In this paper, the operating principles of the proposed standby-mode circuit are presented with an numerical analysis, and are verified by 25W hardware prototype implementation.

• Korean Journal of Remote Sensing
• /
• v.22 no.2
• /
• pp.123-129
• /
• 2006

High-resolution aerial color image offers great possibilities for geometric and semantic information for spatial data generation. However, shadow casts by buildings and trees in high-density urban areas obscure much of the information in the image giving rise to potentially inaccurate classification and inexact feature extraction. Though many researches have been implemented for solving shadow casts, few studies have been carried out about the extraction of features hindered by shadows from aerial color images in urban areas. This paper presents a asphalt road boundary extraction technique that combines information from aerial color image and LIDAR (LIght Detection And Ranging) data. The following steps have been performed to remove shadow effects and to extract road boundary from the image. First, the shadow regions of the aerial color image are precisely located using LEAR DSM (Digital Surface Model) and solar positions. Second, shadow regions assumed as road are corrected by shadow path reconstruction algorithms. After that, asphalt road boundary extraction is implemented by segmentation and edge detection. Finally, asphalt road boundary lines are extracted as vector data by vectorization technique. The experimental results showed that this approach was effective and great potential advantages.

• The Journal of the Korea Contents Association
• /
• v.19 no.3
• /
• pp.72-79
• /
• 2019

Autonomous locomotion has two essential functionalities: mapping builds and updates maps by uncertain position information and measured sensor inputs, and localization is to find the positional information with the inaccurate map and the sensor information. In addition, obstacle detection, avoidance, and path designs are necessarily required for autonomous locomotion by combining the probabilistic methods based on uncertain locations. The sensory inputs, which are measured by a metric-based scanner, have difficulties of distinguishing moving obstacles like humans from static objects like walls in given environments. This paper proposes the low resolution grid map combined with reinforcement learning, which is compared with the conventional recognition method for detecting static and moving objects to generate obstacle avoiding path. Finally, the proposed method is verified with experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.341-343
• /
• 2019

As the generation of high concentration particulate matter increases, much attention is focused on the prediction of particulate matter. Particulate matter refers to particulate matter less than $10{\mu}m$ diameter in the atmosphere and is affected by weather changes such as temperature, relative humidity and wind speed. Therefore, various studies have been conducted to analyze the correlation with weather information for particulate matter prediction. However, the nonlinear time series distribution of particulate matter increases the complexity of the prediction model and can lead to inaccurate predictions. In this paper, we try to mitigate the nonlinear characteristics of particulate matter by using cluster algorithm and classification algorithm of machine learning. The machine learning algorithms used are agglomerative clustering, density-based spatial clustering of applications with noise(DBSCAN).

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.1
• /
• pp.79-86
• /
• 2022

In general, since the types and types of ships, so complex and various variables are included to measure the amount of construction work. In addition, it is mot easy to predict the schedule or the number of working hours before ship construction, and it is also mostly inaccurate. As a result, the master plan is manually drawn up by the expert's experience, but there are limitations due to various factors. Medium and large shipyards are operating APS(Advanced Planning and Scheduling) system that reflects industrial characteristics to improve productivity in the planning stage, and utilize information from systems such as ERP(Enterprise Resource Planning) system and MES (Manufacturing Execution System). On the other hand, small shipyards rely mostly on manual work such as Excel work based on the experience of the workers. Therefore, this study intends to develop a master plan management system that can efficiently manage the production process from the business planning stage in consideration of the characteristics of small shipyards.

• Journal of Korean Academy of Dental Administration
• /
• v.10 no.1
• /
• pp.66-75
• /
• 2022

This study aimed to compare the perception of dental role-play or dental ASMR videos between the general public and dental personnel, to determine whether they are suitable for mass media or educational media, and to identify guidelines for video production. The survey consent form was agreed on using SNS for the general public and dental personnel, 236 ordinary people and 232 dental officers who said that they watched dental ASMR videos were analyzed. The questionnaire consisted of 27 questions for the general public and 31 for dental personnel. Data were analyzed using the chi-square test and the Independent T-test using SPSS 25.0 ver. The viewing experience of 'dental ASMR videos' was significantly higher among dentists (84.7%) than among the general population (71.5%) (p<0.001). Overall, 53.8% of the general public were interested in watching dental ASMR videos, and 47.8% of dental personnel acquired clinical information from them.. Overall, 64.8% of the general public and 65.5% of the dental workforce felt that such technical videos should be produced under the guidance of experts in the field to provide accurate technical information. It is necessary to avoid indiscriminate video production with inaccurate information produced by non-experts and to continuously monitor dental ASMR videos dental institutions for better quality of the videos.

• Journal of Korean Academy of Nursing
• /
• v.54 no.3
• /
• pp.418-431
• /
• 2024

Purpose: This study aimed to identify factors influencing oncofertility and to explore the oncofertility experiences of patients with gynecological cancer using quantitative and qualitative methods, respectively. Methods: An explanatory sequential mixed-methods study was conducted. The quantitative study involved 222 patients with gynecological cancer recruited from online cafes and hospitals. Data were analyzed using IBM SPSS Statistics 28. For qualitative research, eight patients with gynecological cancer were interviewed. Data were analyzed using theme analysis method. Results: Oncofertility performance was quantitatively assessed in 40 patients (18.0%). Factors that significantly affected oncofertility were fertility preservation awareness (odds ratio [OR] = 14.97, 95% confidence interval [CI]: 4.22~53.08), number of children planned before cancer diagnosis (OR = 6.08, 95% CI: 1.89~19.62; OR = 5.04, 95% CI: 1.56~16.29), monthly income (OR = 3.29, 95% CI: 1.23~8.86), social support (OR = 1.08, 95% CI: 1.01~1.17), and anxiety (OR = 0.79, 95% CI: 0.66~0.95). Qualitative results showed three theme clusters and eight themes: (1) themes for determinant factors affecting oncofertility selection: 'desire to have children' and 'special meaning of the uterus and ovaries;' (2) themes for obstructive factors affecting oncofertility selection: 'fertility preservation fall behind priorities,' 'confusion caused by inaccurate information,' and 'my choice was not supported;' (3) themes for support factors affecting oncofertility selection: 'provide accurate and reasonable information about oncofertility,' 'addressing the healthcare gap,' and 'need financial support for oncofertility.' Conclusion: Financial support, sufficient information, social support, and anxiety-relief interventions are required for oncofertility in patients with gynecological cancer.

• The Transactions of the Korea Information Processing Society
• /
• v.13 no.9
• /
• pp.421-428
• /
• 2024

Recently, services utilizing large-scale language models (LLMs) such as GPT-4 and LLaMA have been released, garnering significant attention. These models can respond fluently to various user queries, but their insufficient training on Korean data raises concerns about the potential to provide inaccurate information regarding Korean culture and language. In this study, we selected eight major publicly available models that have been trained on Korean data and evaluated their understanding of Korean culture using a dataset composed of five domains (Korean language comprehension and cultural aspects). The results showed that the commercial model HyperClovaX exhibited the best performance across all domains. Among the publicly available models, Bookworm demonstrated superior Korean language proficiency. Additionally, the LDCC-SOLAR model excelled in areas related to understanding Korean culture and language.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.427-433
• /
• 2004

Information is increasing continuously in on-line, it is real condition that inaccurate informations are mass-produced but effort to keep accuracy of these informations is lacking. Already, research about government official of information in World Wide Web is consisting of various method and viewpoint, but problem for the importance of correct information offer and offer of mistake information in World Wide Web about specification target and administration way presentation are no research reward yet and system that can keep accuracy of information is not equiped properly. ss and accuracy whether mistake information in harbor and bay connection web site's administration influences how in authoritativeness security of site and present condition information of harbor and bay and operation information. In this study, we wish to present administration way about mistake informations that is required that recognize problem of mistake information and the administration's importance in on-line in this research, and supply phenomenon information in Web site. We made the right definition about mistake of information through priority literature investigation and virtued research for this, and sorted mistake information in type. And we investigated Pusan port connection information and offered present condition in on-line and research on actual state of mistake information offer and analysis. Reflecting type and special quality of examined mistake informations, We want to make people recognize the importance af freshness and accuracy whether mistake information in harbor and bay connection web site's administration influences how in authoritativeness security of site and present condition information of harbor and bay and operation information.