• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.40.3-41
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• 2009

인류가 위성을 발사하기 시작하면서 수많은 우주파편이 발생하게 되었고 이로 인하여 우주파편 환경은 날이 갈수록 심각해지고 있다. 우주공간을 비행하는 우주물체는 분쇄된 파편, 임무 관련 파편, rocket body 그리고 운용위성으로 구분된다. U.S. Space Surveillance Network에 따르면 10cm 이상 크기를 갖는 물체는 현재 13,000개가 넘는다고 알려지고 있고 질량만 해도 6,000톤이 넘는다. 이런 우주파편 환경으로 인하여 우주파편 간의 충돌, 우주파편과 운용위성 간의 충돌 또는 운용위성 간의 충돌에 대한 우려가 꾸준히 제기되어왔고, 불행하게도 2009년 2월 10일 Iridium 33과 Cosmos 2251 위성이 고도 790km 부근에서 충돌하여 1,300여개의 우주파편이 발생했다. 또한 2007년에 중국이 고도 860km 부근에서 750kg에 해당하는 자국의 위성(FY-1C)을 미사일로 격추시킴에 따라 2500여개의 우주파편이 발생하여 저궤도의 우주파편 환경을 더욱 심각하게 만들고 있다. 운용위성과 우주파편과의 충돌 가능성을 분석하기 위해서는 우주파편 및 위성의 궤도정보를 알아야 한다. 이를 위해서 NORAD(North American Aerospace Defense Command)에서 제공하는 TLE(Two Line Element)가 주로 이용된다. 하지만 관측 및 궤도 결정 특성상 수 km의 오차를 포함하므로 궤도정보의 공분산이 크다는 단점이 있으므로 충돌 분석을 수행하는데 있어 한계가 있다. 이 논문은 충돌분석 수행에 있어 TLE 정보만을 이용한 경우뿐만 아니라 정밀궤도와 TLE를 동시에 이용한 경우를 비교함으로써 충돌 불확실성의 해소방안을 제시할 계획이다.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.2
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• pp.151-161
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• 2014

Purpose: The purpose of this study was to identify the risk factors that influence surgical site infections after surgery. Methods: This study was a retrospective research utilizing Electronic Medical Records. Data collection targeted 4,510 adult patients who had 8 different kinds of surgery (gastric surgery, colon surgery, laparoscopic cholecystectomy, hip & knee replacement, hysterectomy, cesarean section, cardiac surgery) in 4 medical care departments, at one general hospital between January 2006 and December 2011. Multivariate logistic regression analyses were used to identify the risk factors affecting surgical site infections after surgery. Results: Risk factors for increased surgical site infection following surgery were confirmed to be age (OR=1.59, p<.001), BMI (Body Mass Index)(OR=1.25, p=.034), year of operation (OR=2.45, p<.001), length of operation (OR=3.06, p<.001), ASA (American Society of Anesthesiology) score (OR=1.36, p=.025), classification of antibiotic used (OR=2.77, p<.001), duration of the prophylactic antibiotics use (OR=1.85, p<.001), and interaction between classification of antibiotic used and duration of the prophylactic antibiotics use (OR=1.90, p=.016). Conclusions: Results suggest that risk factors affecting surgical site infections should be monitored before surgery. The results of this study should contribute to establishing effective infection management measures and implementing surveillance systems for patients who have actual risk factors.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_1
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• pp.693-698
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• 2021

As technology advances, there is increasing need for research in different fields where this technology is applied. On of the most researched topic in computer vision is Human activity recognition (HAR), which has widely been implemented in various fields which include healthcare, video surveillance and education. We therefore present in this paper a human activity recognition system based on scale and rotation while employing the Kinect depth sensors to obtain the human skeleton joints. In contrast to previous approaches that use joint angles, in this paper we propose that each limb has an angle with the X, Y, Z axes which we employ as feature vectors. The use of the joint angles makes our system scale invariant. We further calculate the body relative direction in the egocentric coordinates in order to provide the rotation invariance. For the system parameters, we employ 8 limbs with their corresponding angles each having the X, Y, Z axes from the coordinate system as feature vectors. The extracted features are finally trained and tested with the Long short term memory (LSTM) Network which gives us an average accuracy of 98.3%.

• Journal of Information Processing Systems
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• v.19 no.6
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• pp.730-744
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• 2023

The topic of this paper is the recognition of human activities using egocentric vision, particularly captured by body-worn cameras, which could be helpful for video surveillance, automatic search and video indexing. This being the case, it could also be helpful in assistance to elderly and frail persons for revolutionizing and improving their lives. The process throws up the task of human activities recognition remaining problematic, because of the important variations, where it is realized through the use of an external device, similar to a robot, as a personal assistant. The inferred information is used both online to assist the person, and offline to support the personal assistant. With our proposed method being robust against the various factors of variability problem in action executions, the major purpose of this paper is to perform an efficient and simple recognition method from egocentric camera data only using convolutional neural network and deep learning. In terms of accuracy improvement, simulation results outperform the current state of the art by a significant margin of 61% when using egocentric camera data only, more than 44% when using egocentric camera and several stationary cameras data and more than 12% when using both inertial measurement unit (IMU) and egocentric camera data.

• IMMUNE NETWORK
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• v.16 no.5
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• pp.281-285
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• 2016

CD4⁺ regulatory T cells (Tregs) are essential for normal immune surveillance, and their dysfunction can lead to the development of autoimmune diseases, such as type-1 diabetes (T1D). T1D is a T cell-mediated autoimmune disease characterized by islet b cell destruction, hypoinsulinemia, and severely altered glucose homeostasis. Tregs play a critical role in the development of T1D and participate in peripheral tolerance. Pluripotent stem cells (PSCs) can be utilized to obtain a renewable source of healthy Tregs to treat T1D as they have the ability to produce almost all cell types in the body, including Tregs. However, the right conditions for the development of antigen (Ag)-specific Tregs from PSCs (i.e., PSC-Tregs) remain undefined, especially molecular mechanisms that direct differentiation of such Tregs. Auto Ag-specific PSC-Tregs can be programmed to be tissue-associated and infiltrate to local inflamed tissue (e.g., islets) to suppress autoimmune responses after adoptive transfer, thereby avoiding potential overall immunosuppression from non-specific Tregs. Developing auto Ag-specific PSC-Tregs can reduce overall immunosuppression after adoptive transfer by accumulating inflamed islets, which drives forward the use of therapeutic PSC-Tregs for cell-based therapies in T1D.

• Journal of Life Science
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• v.30 no.9
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• pp.749-762
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• 2020

Influenza A viruses are circulating in a variety of hosts, including humans, pigs, and poultry. Swine influenza virus is a zoonotic pathogen that can be readily transmitted to humans. The influenza viruses of the 2009 H1N1 pandemic were derived from swine influenza viruses, and it has been suggested that the 1957 H2N2 pandemic and the 1968 H3N2 pandemic both originated in pigs. Pigs are regarded as a mixing vessel in the creation of novel influenza viruses since they are readily infected with human and avian influenza viruses. We isolated three novel H1N2 influenza viruses from pigs showing respiratory symptoms on a Korean farm in 2019. These viruses were reassortants, containing PA and NP genes from those of the 2009 H1N1 influenza virus in addition to PB2, PB1, HA, NA, M, and NS genes from those of triple-reassortant swine H3N2 and classical swine H1N2 influenza viruses circulating in Korean pigs. Mice infected with the isolated H1N2 influenza virus lost up to 17% body weight and exhibited interstitial pneumonia involving infiltration of many inflammatory cells. Results suggest that close surveillance to detect emerging influenza viruses in pigs is necessary for the health of both pigs and humans.

• Journal of the Korean association of regional geographers
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• v.16 no.5
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• pp.610-622
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• 2010

The proportion of overweight and obese individuals in the United States has been continuously increasing up to recently. Many studies related to obesity have concentrated on jurisdictional levels of aggregation, making it very difficult to dearly illustrate at risk regions. In other words, little research has been conducted in relation to spatial patterns considering spatial dependency and heterogeneity by spatial autocorrelation models over space. In response, this research analyzes spatial patterns between overweight/obesity and risk factors, such as high blood pressure and diabetes, over space. Specifically, the Moran''s I and Geary''s C will be conducted for global and local measures. What is more, the Ordinary Least Square (OLS) linear regression and Geographically Weighted Regression methods will be applied to identify spatial dependency and spatial heterogeneity. Data provided by the Behavioral Risk Factor Surveillance System (BRFSS) have Body-Mass Index (BMI) rates, containing 4 rates of under, healthy, overweight, and obesity. In addition, high blood pressure and diabetes rates in the United States will be used as independent variables. Lastly, we are confident that this research will be beneficial for a decision maker to make a prevention plan for obesity.

• Journal of Broadcast Engineering
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• v.23 no.5
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• pp.598-605
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• 2018

Behavior awareness is a technology that recognizes human behavior through data and can be used in applications such as risk behavior through video surveillance systems. Conventional behavior recognition algorithms have been performed using the 2D camera image device or multi-mode sensor or multi-view or 3D equipment. When two-dimensional data was used, the recognition rate was low in the behavior recognition of the three-dimensional space, and other methods were difficult due to the complicated equipment configuration and the expensive additional equipment. In this paper, we propose a method of recognizing human behavior using only CCTV images without additional equipment using only RGB and depth information. First, the skeleton extraction algorithm is applied to extract points of joints and body parts. We apply the equations to transform the vector including the displacement vector and the relational vector, and study the continuous vector data through the RNN model. As a result of applying the learned model to various data sets and confirming the accuracy of the behavior recognition, the performance similar to that of the existing algorithm using the 3D information can be verified only by the 2D information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.461-466
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• 2016

In this paper, a capsule body shaped surveillance/monitoring device is developed. The device includes a camera and GPS module to transmit live video data and real time GPS coordinates respectively using the Intel Edison module. A control application is developed for the smart phones and tablets to wirelessly view the live video stream and location of the capsule device and also to switch between the multiple capsule devices installed at different locations. The coordination between the developed device and the smart phone / tablet is done using the wireless function of the Intel Edison module.

• Journal of Korean Public Health Nursing
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• v.17 no.1
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• pp.96-112
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• 2003

The purpose of this study was to determine how often toddlers and preschoolers in kindergartens have accidents and what factors affect the accident rate. The study population consisted of 150 children who were attending at nursery schools and 150 children who were attending at kindergartens. The data was collected from ten nursery schools and five kindergartens from five districts in Daegu. The questionnaires were distributed to teachers of participating nursery schools and kindergartens to be completed using nursing care records in the institutions and by interviewing children's parents about all of the accidents happened in a previous year. Data were collected during the period of August 1 through 31, 2002. The results of the study are as follow: 1. Among 300 children, 282 had 506 accidental injuries during the study period. 2. The month, the day and the time with the highest accident rate were April. Monday, and between 2 and 4 o'clock in the afternoon, respectively. 3. Locations where the injury took place most included nursery schools or kindergartens, around the homes of the children, and inside the home. 4. Most accidents were occurred due to lack of carefulness of the children, and the most prevalent forms of injury was abrasions. 5. Most frequently injured part of the body was legs of the children. 6. Most injuries were healed within three days and required first aid measures to disinfect the wound. Mostly, these were performed by family members at home. Some children go to the hospital to suture the open wound. Most frequent type of complication was scar formation and the cost of the treatment ranged from 9,000 to 30,000 won. 7. Children's age. sex, birth order. personality. type of family composition. type of residency. father's occupation, father's age, and mother's age were significantly related to the frequency of injury among children. Children who were in nursery schools and kindergartens need their assessment for accident involving condition according to seasons, time. place. This study provided a very useful and important data to prepare accident prevention education program and accident prevention strategies, and to develop Injury Surveillance System.