• The KIPS Transactions:PartA
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• v.12A no.6 s.96
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• pp.531-538
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• 2005

In the high performance Analog Information Processing Systems(AIPS), gain boosting or additional gain stage is required when the gain is not sufficient with one stage amplification. This work shows that high gain is neatly obtained by enhancing the gain using the negative resistance element. Compared to the conventional techniques, the proposed scheme enjoys full output swing, small circuit area and power consumption, and the applications to various configurations of amplifiers. The negative resistance element is placed between the differential output nodes when used in the Op-Amp. The HSPICE simulation indicates that enhancement of more than 40 dB is readily obtained in this simple configuration when the negative resistance element is implemented in the form of cross-coupled CMOS inverters.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2763-2768
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• 2013

In this paper, a design method for a compact slot antenna for 5.8 GHz RFID band (5.725-5.875 GHz) is studied. The proposed slot antenna is size-reduced by bending both ends of the straight slot in "I"-shape, and a rectangular feed patch is located inside the slot. The effects of slot length, location of feed patch, and width and length of feed patch on the antenna performance are examined. A prototype antenna with optimized parameters for 5.8 GHz band is fabricated on an FR4 substrate and tested experimentally to verify the results of this study. The experimental results show that the frequency band for a VSWR < 3 ranges 5.72-6.13 GHz (bandwidth 410 MHz), and it corresponds fairly well with the simulated band 5.64-5.97 GHz (bandwidth 330 MHz). The fabricated antenna shows good radiation performance such as maximum power density in both directions normal to the slot plane, low cross-polarization level of < -20 dB, and realized gain > 0 dBi within the frequency band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.525-527
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• 2019

Cardiac arrest is a series of conditions occur when the heart is stopped, regardless of the cause. one of the only ways to save a patient's life in the event of cardiac arrest is cardiopulmonary resuscitation, which is very important beacause it can maintain circulation through this technique, and high-quality CPR affects the survival rate and neurological prognosis of the patient. For infant cardiopulmonary resuscitation, use two finger to compress the chest. Hower, this method can be diffcult to reach the chest commpressions recommended by the American Heart Association because of the anatomically increased fatigue of the fingers and diffculty of vertical pressure. The study aims to verify the effects of new chest compressions in the implementation of chest compressions during infant cardiopulmonary resuscitation. The study also showed singnificant differences in chest depth and average rate of pressure(p<0.001). Based on the results of this study, we can see that the accuracy of the new chest compressions during infant cardiopulmonary resuscitation is increased, and the depth of chest compressions is improved, improving the quality index of chest compressions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.768-777
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• 2020

In this paper, we describe recent research results on AODV routing protocol, which is widely deployed at mobile ad hoc networks, and AODV related routing protocols with multi-path routing schemes. We suggest the critical problems which minimum hop routing schemes have, such as AODV routing protocol, and then, propose a new C-AODV routing protocol with two routing metrics: the primary metric is the hop count, the secondary metric is the sum of link delay times. We implemented C-AODV protocol by modifying AODV at the NS-3, and thus, elaborate on how we change the original AODV source code of NS-3 in order to implement the C-AODV scheme. We show numerical comparison of C-AODV scheme with the original AODV scheme and then, discuss how much the C-AODV enhances routing performance over AODV protocol. In conclusion, we present future research items.

• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.23-36
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• 2021

Purpose: The purpose of this study was to determine how the use of level D personal protective equipment (PPE) and cardiopulmonary resuscitation (CPR) feedback equipment affects chest compression (CC). Furthermore, this study provides basic data for developing Korean CPR guidelines that can be applied to patients with suspected or confirmed COVID-19. Methods: This randomized, single-blinded, crossover simulation trial included 26 student paramedics who performed 2-minute chest compressions using three different methods: Method A involved performing traditional CC for two minutes without donning level D PPE, Method B involved performing CC while donning level D PPE, and Method C involved performing CC with a CPR feedback device while donning level D PPE. Results: The use of a CPR feedback device during the 2-minute CC increased the exercise intensity of the subjects, but donning level D PPE didn't affect the quality of CC and the exercise intensity. The results of methods A and B showed changes in the quality of compression 80 seconds after the start of CC. No significant changes occurred in 2-minute CC when using the CPR feedback device. Conclusion: Using a CPR feedback device could prevent deterioration in the quality of CC while donning level D PPE.

• Journal of the Korea Society of Computer and Information
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• v.28 no.3
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• pp.101-110
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• 2023

This study was conducted to identify factors influencing weight loss efforts in hypertensive patients with obesity in Korea using data from the 2016-2019 National Health and Nutrition Examination Survey. Weight perception, weight loss efforts, and weight control methods were investigated for 1,910 subjects. Data were analyzed using descriptive analysis, cross-tabulation analysis and logistic regression. Among obese hypertensive patients, 12.6% perceived their weight as normal. Weight loss efforts were 2.03 times (95% CI: 1.48 to 2.78) higher in people with overweight perception than those with normal weight perception, and 1.74 times (95% CI: 1.33 to 2.26) higher in women than in men. In addition, those with class 1 obesity were 1.50 times (95% CI: 0.85 to 2.65) higher than those with class 3 obesity, and those with class 2 obesity were 2.16 times (95% CI: 1.16 to 4.00) higher than those with class 3 obesity. These results suggest that weight management approaches for hypertensive patients with obesity should be individually designed according to weight perception, gender, and obesity class.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1023-1030
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• 2021

Korea Maritime Safety Tribunal (KMST) statistics released in of 2019 indicated that most collision accidents involving small-size vessels with less than 20 gross-tonnage occur mainly due to operational carelessness, such as forward-looking negligence and unskilled vessel control. As an effective remedy, training and education for vessel operators are being strengthened to prevent accidents. However, collision accidents are increasing, and technical measures are continuously developed to reduce accidents caused by human factors. In this study, an avoidance algorithm and prototype of terminal-controller against collision between two nearby vessels was developed for implementation on relative navigation control by adopting WAVE telecommunication technology. Moreover, several sea trial tests were performed to verify the collision avoidance algorithm and control system using two fishing vessels for dif erent scenarios.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.16-29
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• 2009

This paper investigates the kinematic and dynamic analysis of a spherical three degree of freedom parallel joint module, which is used in the exercise equipment for balance and leg-strength improvement of aged people. The joint module has three dyads which consist of two links and three revolute joints, and their all joints intersect at the global point located at the module's center. The paper shows the explicit mathematical procedure for deriving the closed form solutions in the inverse and forward position analysis of this parallel joint module. In velocity and acceleration analysis, we derived relations for joint velocities and accelerations of dyads and rotational velocity and acceleration of the top plate. For applying this module to rehabilitation exercise, we determined the dynamic model of the Korean males in their 50s and examined the model's results by dynamic model simulation.

• The Journal of the Acoustical Society of Korea
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• v.41 no.2
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• pp.210-217
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• 2022

Passive source depth estimation has been studied for decades since the source depth can be used for target classification, target tracking, etc. The purpose of this paper is to solve the problem of ambiguity in the previous paper [S.-il. Cho et al. (in Korean), J. Acoust. Soc. Kr. 38, 120-127 (2019)] that source depth is estimated in two points. The patterns of phase shift of Channel Impulse Response(CIR) reflected in ocean surface and bottom is used for removing ambiguity of the source depth estimation, and after removing ambiguity, source depth is estimated at one point through the intersection of CIR. In order to extract CIR in case of unknown source signal and continuous signal or noise, Ray-based blind deconvolution is used. The proposed algorithm is demonstrated through numerical simulation in ocean waveguide.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.300-302
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• 2022

The purpose of this study is to compare the speed, confidence, and ease of endotracheal intubation in a transfer posture by using the SALT(Supraglottic Airway Laryngopharyngeal Tube), and a direct laryngoscope to improve the ability to implement professional airway management. The subject of the study was an experimental study by a randomized crossover design, targeting 28 first-class emergency medical technicians working in J-do fire station, and the SPSS 20.0 version was used for data analysis. The endotracheal intubation by using SALT showed a significant difference in speed compared to endotracheal intubation by using a direct laryngoscope(p<.001), and also showed a significant difference in confidence and ease(p<.001). If it is transfer to endotracheal intubation by direct laryngoscope, or in the case of transfer patients, if SALT is used, safe and rapid intubation will be possible.