• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.6
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• pp.435-445
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• 2013

One of the most challenging issues in radio frequency identification (RFID) and near field communications (NFC) is to correctly and quickly recognize a number of tag IDs in the reader's field. Unlike the probabilistic anti-collision schemes, a query tree based protocol guarantees to identify all the tags, where the distribution of tag IDs is assumed to be uniform. However, in real implements, the prefix of tag ID is uniquely assigned by the EPCglobal and the remaining part is sequentially given by a company or manufacturer. In this paper, we propose an enhanced M-ary query tree protocol (EMQT), which effectively reduces unnecessary query-response cycles between similar tag IDs using m-bit arbitration and tag expectation. The theoretical analysis and simulation results show that the EMQT significantly outperforms other schemes in terms of identification time, identification efficiency and communications overhead.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.6
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• pp.289-299
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• 2019

The tendency to use a probabilistic design method rather than a deterministic design method for the design of nuclear power plants (NPPs) will increase because their safety should be considered and strictly controlled in relation to various causes of damage. The distance between a seismically isolated NPP structure and a moat wall is called the clearance to stop. The clearance to stop is obtained from the 90th percentile displacement response of a seismically isolated NPP subject to a beyond design basis earthquake (BDBE) in the probabilistic design method. The purpose of this study is to analyze the effects of heating and buckling effects on the 90th percentile displacement response of a lead-rubber bearing (LRB) subject to a BDBE. The analysis results show that considering the heating and buckling effects to estimate the clearance to stop is conservative in the evaluation of the 90th percentile displacement response. If these two effects are not taken into account in the calculation of the clearance to stop, the underestimation of the clearance to stop causes unexpected damage because of an increase in the collision probability between the moat wall and the seismically isolated NPP.

• Journal of The Korea Institute of Healthcare Architecture
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• v.30 no.2
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• pp.35-46
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• 2024

Purpose: It is the responsibility of public healthcare to respond quickly to infectious disease outbreaks and disasters such as MERS, COVID-19, the Syrian earthquake, and the Miryang Sejong Hospital fire accident. It is very important to secure safe medical facilities and protect lives through emergency medical support and disaster response systems. The purpose of this study is to investigate the safety status of regional medical facilities that play a central role in the event of a disaster. Methods: The target was 41 local public hospitals, including 35 regional medical centers and 6 Red Cross hospitals nationwide. We delivered a questionnaire to 41 medical facilities and collected data from 32 regional public hospitals that received responses. Results: In order to respond to safety accidents, a survey was conducted on infections, falls, patient identification, and incorrect connections for medical accidents, and for in-hospital accidents, a survey was conducted on entrapment, collision, water leaks, falling objects, and crime prevention. For natural disasters, we investigated the response environment for typhoons, floods, and snow damage, and for social disasters, we investigated the response environment for fire, power outages, and radiation damage. Implications: We hope that it will be used as basic data for developing standards and creating hospital facilities and environments that are safe for everyone to respond to various disasters and prevent patient safety accidents in the future.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.42-54
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• 2017

Objectives: The present study was conducted to investigate farm work environments among farmers and examine the level of management of safety and health, and to subsequently produce study result to serve as foundational data for the development of guidelines on safety and health as part of the improvement of farming work environments among farmers raising Korean native cattle. Methods: The present study conducted a survey on farm work environments and the management of safety and health with 407 farmers engaged in Korean native cattle farming in selected regions in eight provinces. It also visited 10 farmers to verify the current status of farm work. Results: The survey results showed that 16.4% of the respondents experienced safety-related accidents due to farm work. The locations of the accidents were inside the cattle shed (71.4%) and facilities outside the cattle shed (19.6%). The types of accident showed collision with animals (35.7%), collision or contact with obstacles (27.1%), and musculoskeletal accidents due to heavy object handling (12.9%). The causes of the accidents were cattle (38.3%), cultivators and tractors (25.4%), facility tools in cattle sheds (9.0%), and slippery floors (6.0%). The damaged areas were hand (21.0%), spine (19.8%), lower limb (18.5%), and foot (17.3%). A self-diagnostic survey on respiratory diseases showed that 11.5% of the respondents experienced respiratory-related symptoms. The survey on safety and health during farm work showed that wearing personal protective equipment and response to emergency situations, which were needed to prevent safety-related accidents, were relatively low compared to the level of recognition of the need and awareness of safety issues. Furthermore, the field survey identified the current status of safety and health issues such as prevention management of collision accidents with cattle, how to handle heavy objects, and wearing of personal protective equipment. Conclusions: The present study identified safety-related accidents and problems in the management of safety and health among Korean native cattle farmers. In order to address the problem, it is necessary to not only provide guidelines on safety and health management which are appropriate to the characteristics of Korean native cattle farming work, but also to study the development of personal protective equipment.

• Journal of Internet Computing and Services
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• v.15 no.1
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• pp.179-191
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• 2014

In this paper, a frame transmission method to make IEEE 802.15.4 nodes run at a new channel and its characteristics are studied when they experience difficulties in transmission of frames due to WiFi traffic. The researches on evaluating the interference from WiFi traffic, searching for a new channel with little interference or not, and changing the operating channel are analyzed. In an wireless channel overlapped with IEEE 802.11 network, the transmission delay of IEEE 802.15.4 frames, the collision of frames in sending IEEE 802.15.4 frames without applying CSMA-CA algorithm, and the operation of IEEE 802.11 nodes are explained. A transmission method of frames including frame-formated code blocks in order to use the rest part of collided IEEE 802.15.4 frame is proposed. In the experiments of the proposed method, it is observed that frame-formated code blocks are synchronized and received by receivers in case of collision, and then the collided positions in IEEE 802.15.4 frame and the characteristics of frame reception rate are analyzed. The experimental results show that the performance of the proposed method is improved in comparison to an existing method when we measure the time taken to send a channel change command and get the response in order to avoid the interference from WiFi traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.141-146
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• 2017

New infectious diseases such as MERS have been in need of many measures such as initial discovery, isolation, and crisis response. In addition, the culture of hospitals is changing, such as the general public 's visiting and Nursing Care Integration Services. However, as the qualifications and regulations of medical personnel in hospitals become rigid, overseas such as linens, wastes movements are replacing possible works with robots. we have developed a hospital logistics robot that can carry out various goods delivery within a hospital, and can move various kinds of objects safely to a desired location. In this thesis, we have studied a hospital logistics robot that can carry out various kinds of goods delivery within the hospital, and can move various kinds of objects such as waste, and linen safely to a desired location. The movement of a robot in a hospital may cause a collision between a person and an object, so that the collision must be prevented. In order to prevent collision, it is necessary to recognize whether or not an object exists in the movement path of the robot. And if there is an object, it should recognize whether it moves or not. In order to recognize human beings and objects, we recognize the person with face/body recognition technology and generate the context awareness of the object using 3D Vision image segmentation technology. We use the generated information to create a map that considers objects and person in the robot moving range. Thus, the robot can be operated safely and efficiently.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.458-463
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• 2009

To establish and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and accurate quantitation of diarrhetic shellfish poisoning (DSP) toxins, we compared the results from different mobile phases and columns used for their analysis and collision energies for MS/MS experiments. Clear peaks of okadaic acid (OA) and dinophysistoxin-1 (DTX1) were obtained by using a mobile phase comprising aqueous acetonitrile containing 2 mM ammonium formate and 50 mM formic acid. The collision energies were optimized to facilitate the most sensitive detection for each toxin, namely, OA, DTX1, pectenotoxin-2 (PTX2), or yessotoxin (YTX). Further, the maximum ion response was obtained at a collision energy of 48 V for OA and DTX1. We compared the analytical performance of $C_8$ and $C_{18}$ columns. A wide range of toxins namely, OA, DTX1, PTX2, and YTX, except DTX3, were detected by both the columns. Although DTX3 was only detected by the $C_8$ column, we found that the $C_{18}$ column was also suitable for the quantitation of OA and DTX1 the toxins responsible for inducing diarrhea. The limit of detection of OA and DTX1 by the established LC-MS/MS conditions was 1 ng/g, and the limit of quantitation of the toxins under the same conditions was 3 ng/g. The process efficiencies were 91-118% for oysters (Crassostrea gigas) and 96-117% for mussels (Mytilus galloprovincialis) further, we observed no significant effect of matrix during the ionization process in LC-MS/MS. The comparison between mouse bioassay (MBA) and LC-MS/MS yielded varying results because low concentrations of OA and DTX1 were detected by LC-MS/MS in some shellfish samples, which provided positive results on MBA for DSP. The analysis time required by MBA for DSP analysis can be reduced by LC-MS/MS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.677-684
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• 2014

In response to possible HNS (Hazardous and Noxious Substance) spill accident, HNS spill accident scenario and response scenario were developed. The accident area listed in scenarios is the coastal area of Busan, and scenario for possible accident in the designated area and strategies to respond the accident were developed, respectively. The scenario for accident was developed by designating HNS spill according to risk evaluation of HNS and analysis of HNS spill probability along the coastal area of Busan, and then estimating possible and potential impact from the accident. The scenario for response has been suggested as a systematical responding operations in order to effectively reduce the estimated impact from the accident. The possible HNS spill accident on the seas around Busan, has been designated by the spillage of 1,000ton of xylene due to collision accident in Gamcheon Port, and the possible impacts occurred by the accident has been simulated with the help of the atmospheric and oceanic dispersion model of xylene. In the responding scenario for the accident, a phased strategies regarding emergency rescue of peoples, protection and recovery of xylene, protective measures for the responders, and post management of the accident have been suggested.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.1
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• pp.33-39
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• 2009

The 21st century is often referred to as maritime age. The sea is a rich repository of natural resources, comfort shelters and the hopes and dreams of human being. But there is always possibility of disaster as well as hopes and dreams. Although there have been many advances in the ship building technology, the risk of accidents is on the increase due to the increase of maritime traffic and the revitalization of marine leisure. I like to refer to the systematic search and rescue system for the rapid response by analyzing recent marine accidents. For the safe navigation, it is necessary to establish institutional systems such as ship technology, navigation equipments, excellent human resources, traffic control, etc. and navigation components also have to be well organized each other. It is also necessary to build a prompt accident management system. The search and rescue system for the rapid response and the way of reducing the incidence of marine accidents were reviewed through the analysis of recent marine accidents.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.8
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• pp.849-855
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• 2012

The effect of electric fields on the response of diffusion flames in a counterflow has been investigated experimentally by varying the AC voltage and frequency. The result showed that the flame was stationary with high AC frequency above the threshold frequency, and it increased with the applied voltage and then leveled off at 35 Hz. Below the threshold frequency, however, the flame oscillated with a frequency that was synchronized with the applied AC frequency. This oscillation can be attributed to the ionic wind effect due to the generation of bulk flow, which arises from the momentum transfer by molecular collisions between neutral molecules and ions, where the ions in the reaction zone were accelerated by the Lorentz force.