• Journal of Advanced Navigation Technology
• /
• v.23 no.4
• /
• pp.302-308
• /
• 2019

Aircraft data network (ADN) is a data networking for signal transmission among avionic systems in aircraft, and it mostly has been applied MIL-STD-1553B that guarantees high reliability considering its application environments. However, commercial Ethernet has been widely applied for ADN recently, and its range of applications have increased. Ethernet provides high speed of data transmission, however, it could not guarantee quality of service (QoS) so high as MIL-STD-1553B. In this paper, we propose dynamic routing and priority based data transmission schemes in order to improve the QoS of legacy Ethernet. Our propose schemes can be applied to Ethernet switch, and it is able to manage network traffic efficiently, and reduce the time for data transmission. We analyze the packet transmission time for both legacy and proposed schemes in Ethernet environments using simulation, and we show that our proposed scheme can reduce the time for data transmission compare to legacy spanning tree protocol.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.5
• /
• pp.49-57
• /
• 2008

User authentication and key agreement are very important components to provide secure home network service. Although the TTA adopted the EEAP-PW protocol as a user authentication and key transmission standard, it has some problems including not to provide forward secrecy. This paper first provides an analysis of the problems in EEAP-PW and then proposes a new attribute-based authenticated key agreement protocol, denoted by EEAP-AK. to solve the problems. The proposed protocol supports the different level of security by diversifying network accessibility for the user attribute after the user attribute-based authentication and key agreement protocol steps. It efficiently solves the security problems in the EEAP-PW and we could support more secure home network service than the EEAP-AK.

• Korean Journal of Remote Sensing
• /
• v.36 no.6_2
• /
• pp.1485-1492
• /
• 2020

It has been more than 20 years since the launch of KOMPSAT-1, and so far, a total of 5 satellites have been successfully launched. Until now, KOMPSAT has been used in various fields, including the production of various thematic maps, land change, environmental analysis, and marine monitoring. Many researchers have conducted research to process, analyze, and utilize KOMPSAT images. According to the national space development plan, the KOMPSAT series will be continuously developed to meet the demand for satellite images at the national level. If the ultimate purpose of satellite development is to utilize acquired images, systematic research to effectively utilize the developed satellites should be followed. This special issue introduces the recently conducted research on the use of KOMPSAT images.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_2
• /
• pp.1677-1689
• /
• 2022

Air pollution is social issue that has long-term and short-term harmful effect on the health of animals, plants, and environments. Chimneys are the primary source of air pollutants that pollute the atmosphere, so their location and type must be detected and monitored. Power plants and industrial complexes where chimneys emit air pollutants, are much less accessible and have a large site, making direct monitoring cost-inefficient and time-inefficient. As a result, research on detecting chimneys using remote sensing data has recently been conducted. In this study, YOLOv5-based chimney detection model was generated using BUAA-FFPP60 open dataset create for power plants in Hebei Province, Tianjin, and Beijing, China. To improve the detection model's performance, data split and data augmentation techniques were used, and a training strategy was developed for optimal model generation. The model's performance was confirmed using various indicators such as precision and recall, and the model's performance was finally evaluated by comparing it to existing studies using the same dataset.

• Journal of Korean Clinical Nursing Research
• /
• v.15 no.1
• /
• pp.43-53
• /
• 2009

Purpose: This study aimed to compare the moisturizing effect of cold water gargling, wet gauze application and humidification in reducing thirst and mouth dryness after nasal surgery. Method: Patients were randomly assigned into three groups of 19 subjects each. In the two intervention groups, each group was received hourly cold water gargling or wet gauze application for 4 hours postoperatively. In the control group, the subjects were received only humidification continuously on a bedside. We compared the thirst and oral condition at 0, 2, 4hours. after operation. Thirst was measured using VAS questionnaire, and oral condition(mouth dryness) by Oral Assessment Guide. Results: There was a significant difference among three groups in the level of thirst and mouth dryness. In the cold water gargling group, there was a significant decrease in thirst at 2, 4hours. In the wet gauze group, there was a significant decrease in thirst at 4hours. In the intervention group, there was a significant decrease in mouth dryness at 2, 4hours. In the control group, there was a significant decrease in mouth dryness at 4hours. Conclusion: The findings of this study suggest that the cold water gargling would be an effective nursing intervention to reduce thirst and mouth dryness postoperatively.

• Journal of Advanced Navigation Technology
• /
• v.28 no.2
• /
• pp.178-184
• /
• 2024

The radar installed on an aircraft has various operating modes depending on tactical purposes, allowing for the configuration of search areas according to each mode's operational objectives. active electronically scanned array (AESA) radar emits search beams sequentially according to a predefined search beam grid within the designated search area specified by the pilot to detect targets within it. It is crucial that the radar can stably search the area designated by the pilot for target detection, even as the aircraft's attitude changes. This paper focuses on stabilizing the search pattern in the air-to-air operational mode of aircraft-mounted radar to ensure stable target detection during roll and pitch maneuvers of the aircraft. The paper demonstrates its performance by simulating aircraft maneuvers and targets in a system integration laboratory (SIL) test environment.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.5
• /
• pp.384-391
• /
• 2023

In modern electronic warfare, a number of radar emitters are in operation, causing radar receivers to receive high-density signal pulses that occur simultaneously. To analyze the radar signals more accurately and identify enemies, the sorting process of high-density radar signals is very important before analysis. Recently, machine learning algorithms, specifically K-means clustering, are the subject of research aimed at improving the accuracy of radar signal sorting. One of the challenges faced by these studies is that the clustering results can vary depending on how the initial points are selected and how many clusters number are set. This paper introduces a repeated K-means clustering algorithm that aims to accurately cluster all data by identifying and addressing false clusters in the radar sorting problem. To verify the performance of the proposed algorithm, experiments are conducted by applying it to simulated signals that are generated by a signal generator.

• Journal of Chest Surgery
• /
• v.34 no.10
• /
• pp.769-774
• /
• 2001

Background: Descending necrotizing mediastinitis(DNM) is a serious complication originating in odontogenic or oropharyngeal infection with previously reported mortality rates of 25% to 40%. We retrospectively reviewed the 4 years of our surgical drainage and debridement in DNM. Material and Method: We studied 7 cases diagnosed as DNM from 1997 through 2000. Primary oropharyngeal infection lead to DNM in four cases(57%) and odontogenic abscess in three cases(43%). All patients were received emergent cervicotomy and thoracotomy or sternotomy for debridement of necrotic tissue and mediastinal or pleural drainage. Result: Five cases were evolved well and were discharged after a mean of 42 days. Two patients(28.6%) died. Three patients required reoperation due to local surgical complication; empyema(two) and impending cardiac tamponade. One of these patients died on 12 post-reoperative day due to great vessel erosion, renal and respiratory insufficiency. The other patient died of broncho- esophageal fistula and asphyxia on 10 postoperative day without reoperation. Conclusion: On the basis of experience accrued in treating these patients, early diagnosis by cervicothoracic computed tomographic scan of neck and thorax aids in rapid indication of a surgical approach of DNM. We emphasize that performing early surgical drainage and debridement of necrotic tissues with intensive postoperative care can significantly reduce the mortality rate.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_3
• /
• pp.1679-1692
• /
• 2023

South Korea is a country that emits a large amount of pollutants as a result of population growth and industrial development and is also severely affected by transboundary air pollution due to its geographical location. As pollutants from both domestic and foreign sources contribute to air pollution in Korea, the location of air pollutant emission sources is crucial for understanding the movement and distribution of pollutants in the atmosphere and establishing national-level air pollution management and response strategies. Based on this background, this study aims to effectively acquire spatial information on domestic and international air pollutant emission sources, which is essential for analyzing air pollution status, by utilizing high-resolution optical satellite images and deep learning-based image segmentation models. In particular, industrial parks and quarries, which have been evaluated as contributing significantly to transboundary air pollution, were selected as the main research subjects, and images of these areas from multi-purpose satellites 3 and 3A were collected, preprocessed, and converted into input and label data for model training. As a result of training the U-Net model using this data, the overall accuracy of 0.8484 and mean Intersection over Union (mIoU) of 0.6490 were achieved, and the predicted maps showed significant results in extracting object boundaries more accurately than the label data created by course annotations.

• The Journal of the Korea Contents Association
• /
• v.13 no.12
• /
• pp.771-785
• /
• 2013

The purposes of this study were 1) to explore the differences in career competency and career preparation behavior in accordance with high school students' work experience types and 2) to examine the interaction effects between work experience type and sex or work experience type and grades. Three work experience types were classified as no work experience, positive work experience, and negative work experience. The study used the data from "2009 Youth Career? Occupation Survey" conducted in the National Youth Policy Institute. For the statistical analysis, two-way MANOVA was employed. The results indicated that female students had higher levels of career competency and career preparation than male students. Also, female students showed higher negative effects of negative work experience compared to male students. The analysis confirmed the interaction effects between work experience types and sex. Female students showed the higher negative effects of negative work experience than no work experience, whereas work experience, whether or not it is negative, was helpful for male students in career competency and career preparation behavior.