• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.432-445
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• 2021

Background: The European Centre for Ecotoxicology and Toxicology of Chemicals' Targeted Risk Assessment (ECETOC TRA) tool has been recognized by EU REACH as a preferred approach for calculating worker health risks from chemicals. Objectives: The applicability of the ECETOC TRA to occupational exposure estimation from industrial uses of methanol was studied by inputting surveyed and varied parameters for TRA estimation as well as through comparison with measured data. Methods: Information on uses of methanol was collected from seven working environment monitoring reports along with the measured exposure data. Input parameters for TRA estimation such as operating conditions (OCs), risk management measures (RMMs) and process categories (PROCs) were surveyed. To compare with measured exposures, parameters from the surveyed conditions of ventilation but no use of respiratory protection were applied. Results: PROCs 4, 5, 8a, 10, and 15 were assigned to ten uses of methanol. The uses include as a solvent for manufacturing sun cream, surfactants, dyestuffs, films and adhesives. Methanol was also used as a component in a release agent, hardening media and mold wash for cast products as well as a component of hard-coating solution and a viscosity-controlling agent for manufacturing glass lenses. PROC 8a and PROC 10 of a cast product manufacturer without LEV (local exhaust ventilation) and general ventilation as well as no respiratory protection resulted in the highest exposure to methanol. Assuming the identical worst OCs and RMMs for all uses, exposures from PROC 5, 8a, and 10 were the same and the highest followed by PROC 4 and 15. The estimation resulted in higher exposures in nine uses except one use where measured exposure approximated exposures without RMMs. Conclusions: The role of ECETOC TRA as a conservative exposure assessment tool was confirmed by comparison with measured data. Moreover, it can guide which RMMs should be applied for the safe use of methanol.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.89-103
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• 2009

This study investigates the applicability of the time reversal concept in modem acoustics to the Lamb waves, which have been widely studied for defect detection in plate-like structures. According to conventional time reversal acoustics, an input signal can be reconstructed at an excitation point if an output signal recorded at another point is reversed in the time domain and emitted back to the original source point. However, the application of a time reversal process(TRP) to Lamb wave propagations is complicated due to velocity and amplitude dispersion characteristics of Lamb waves and reflections from the boundaries of a structure. In this study, theoretical investigations are presented to better understand the time reversibility of Lamb waves. In particular, the effects of within-mode dispersion, multimode dispersion, amplitude dispersion, and reflections from boundaries on the TRP are theoretically formulated. Simple numerical case studies are conducted to validate the theoretical findings of this study.

• Journal of Korean Academy of Nursing Administration
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• v.6 no.1
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• pp.123-134
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• 2000

This study intended to analyze the effectiveness to obtain by developing the critical pathway presented as the method to improve the quality-betterment and cost effectiveness the through the continuous and consistent patient management for the hysterectomy patient and applying it to the real practice. This study was designed to develop and effect the critical pathway for hysterectomy patients in the way to be possible the intergrated in patient management. It was adopted the process of seven phase to develop a critical pathway. To analyze the application effect of the developed critical pathway, this author offered health care service applying the critical pathway to the hysterectomy patient from July. 20 to Oct. 19. 1999. The study method had been done by investigating the experimental group and control group through the questionnaire on 40 patients who had been inpatient hysterectomy. Dependent variables were measured by modified from satisfaction, and cost and length of hospital stay. The data anlyzed by frequency, x2-test, t-test. The results of this study was as follows; 1. It was decided that the vertical line of the critical pathway was made up of eight items such as monitoring/assessment, treatment, activity, medication, consult. Lab test, diet, patient teaching and horizontal line was 7days from admission to discharge. 2. After the verifying the validity of the expert group about the critical pathway, the horizontal line was amended from hospitalization to five postoperative days and taking their consensus, some contents of the horizontal line was amended and deleted. 3. There was no significant differences in the experimental group and control group in the satisfaction, and significant differences in the cost, the length of hospital stay.

• Journal of Korea Multimedia Society
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• v.16 no.8
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• pp.962-971
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• 2013

In this paper, we propose a method to infer the user's behavior and situation through collected data from multi-sensor equipped with a smart clothing and it was implemented as a smart-phone App. This smart-clothes is able to monitor wearer users' health condition and activity levels through the gyro, temp and acceleration sensor. Sensed vital signs are transmitted to a bluetooth-enabled smart-phone in the smart-clothes. Thus, users are able to have real time information about their user condition, including activities level on the smart-application. User context reasoning and behavior determine is very difficult using multi-sensor depending on the measured value of the sensor varies from environmental noise. So, the reasoning and the digital filter algorithms to determine user behavior reducing noise and are required. In this paper, we used Multi-black Filter and SVM processing behavior for 3-axis value as a representative value of one.

• Smart Structures and Systems
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• v.20 no.3
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• pp.385-396
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• 2017

The recent advancements in sensing technologies allow us to record measurements from target structures at multiple locations and with relatively high spatial resolution. Such measurements can be used to develop data-driven methodologies for condition assessment, control, and health monitoring of target structures. One of the state-of-the-art technologies, Fiber Optic Strain Sensors (FOSS), is developed at NASA Armstrong Flight Research Center, and is based on Fiber Bragg Grating (FBG) sensors. These strain sensors are accurate, lightweight, and can provide almost continuous strain-field measurements along the length of the fiber. The strain measurements can then be used for real-time shape-sensing and operational load-estimation of complex structural systems. While several works have demonstrated the successful implementation of FOSS on large-scale real-life aerospace structures (i.e., airplane wings), there is paucity of studies in the literature that have investigated the potential of extending the application of FOSS into civil structures (e.g., tall buildings, bridges, etc.). This work assesses the feasibility of using FOSS to predict operational loads (e.g., wind loads) on chain-like structures. A thorough investigation is performed using analytical, computational, and experimental models of a 4-story steel building test specimen, developed at the University of Southern California. This study provides guidelines on the implementation of the FOSS technology on building-like structures, addresses the associated technical challenges, and suggests potential modifications to a load-estimation algorithm, to achieve a robust methodology for predicting operational loads using strain-field measurements.

• Smart Structures and Systems
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• v.15 no.2
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• pp.355-373
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• 2015

An optimal sensor placement (OSP) method based on structural subsection technique (SST) and model reduction technique was proposed for modal identification of truss structures, which was conducted using genetic algorithm (GA). The constraints of GA variables were determined by SST in advance. Subsequently, according to model reduction technique, the optimal group of master degrees of freedom and the optimal objective function value were obtained using GA in a case of the given number of sensors. Correspondingly, the optimal number of sensors was determined according to optimal objective function values in cases of the different number of sensors. The proposed method was applied on a scaled jacket offshore platform to get its optimal number of sensors and the corresponding optimal sensor layout. Then modal kinetic energy and modal assurance criterion were adopted to evaluate vibration energy and mode independence property. The experiment was also conducted to verify the effectiveness of the selected optimal sensor layout. The results showed that experimental modes agreed reasonably well with numerical results. Moreover the influence of the proposed method using different optimal algorithms and model reduction technique on optimal results was also compared. The results showed that the influence was very little.

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.17-23
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• 2016

Wireless sensor-actuator networks (WSANs) enhance the existing wireless sensor networks (WSNs) by equipping sensor nodes with an actuator. The actuators work with the sensor nodes and perform application-specific operations. The WSAN systems have several applications such as disaster relief, intelligent building, military surveillance, health monitoring, and infrastructure security. These applications require capability of reliable data transfer to act responsively and accurately. Biologically inspired modeling techniques have received considerable attention for achieving robustness, scalability, and adaptability, while retaining individual simplicity. In this paper, an epidemic-inspired algorithm for data dissemination with delay constraints while minimizing energy consumption in WSAN is proposed. The steady states and system stability are analyzed using control theory. Also, simulation results indicate that the proposed scheme provides desirable dissemination delay and energy saving.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.213-222
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• 2002

The alkaline comet assay has been used with increasing popularity to investigate the level of DNA damage in biomonitoring studies within the last decade in Western countries. The purpose of this study was to evaluate the usefulness of the alkaline comet assay as a biomarker of oxidative DNA damage for monitoring in the Korean population, and also to evaluate the effect of nutritional status and lifestyle factors on H2O2 induced oxidative DNA damage measured by the alkaline comet assay in human lymphocytes. The study population consisted of 61 healthy Korean male volunteers, aged 20-28. Epidemiological background data including dietary habits, smoking habits and anthropometrical measurements were collected through personal interviews. After blood collection, the comet assay in peripheral lymphocytes and plasma lipids analysis was carried out and the results analyzed. Tail moment (TM) and tail length (TL) of the comet assay were use\ulcorner to measure DNA damage in the lymphocytes of the subjects. Statistically significant (p < 0.05) positive correlations were observed between DNA damage (TM or TL) and smoking habits expressed as cigarettes smoked per day and pack years (r = 0.311 and 0.382 for TM, r = 0.294 and 0.350 for TL, respectively). There were also significant positive correlations between DNA damage parameter and waist-hip ratio. Higher plasma triglyceride levels were associated with increased damage to DNA. There were no correlations between the consumption frequencies of vegetables and DNA damage to the subjects. However, consumption frequencies of fruit and fruit juice intake were inversely associated with the TM and TL. The results indicate that die comet assay is a simple, rapid and sensitive method for detecting lymphocyte DNA damage induced by cigarette smoking. Consumption of fruit or fruit juices could potentiall modify the damaged DNA in the human peripheral lymphocytes of young Korean men.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.241-248
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• 2012

Recently healthcare industry such as pharmaceutical, medical device and healthcare service technology is growing significantly. Mobile healthcare has attracted big attention due to IT convergence technology. Paradigm of healthcare has been changed from the 1st generation(communicable disease prevention) and the 2nd generation(treatment of disease due to extended life expectancy) to the 3rd generation(extended life expectancy due to prevention and control). In our study, we suggest the 3rd generation mobile healthcare system using Bluetooth based wearable ECG monitoring system and smart phone technology. The mobile healthcare system consists of wearable shirts with Bluetooth communication module, ECG sensor, battery, and mobile phone. The ECG data is obtained by a miniaturized sensor and the data is transferred to a mobile phone using Bluetooth communication. Then, user can monitor his/her own ECG signal on an application using Android in mobile phone. The Bluetooth communication device is used due to highly reliable data transmission property and the Bluetooth chip is embedded in every mobile phone. The wearable shirts with chest belt of Bluetooth ECG module is designed with a focus on convenience in the daily life of a wearer. The ECG signal evaluation software in Android based mobile phone is developed for the health check and the ECG signal variation is tested according to the activities of the wearer such as walking, climbing stairs, stand up and sit down, and so on.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.105-119
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• 2011

In order to develop the indicators which evaluate the management effectiveness for the protected forest areas in Korea, candidate indicators were listed based on literature and experts interviews, then questionnaire survey on the experts were conducted. 5 elements of context, planning, input, process, output and outcome and 32 indicators were selected. Context element includes 6 indicators of 1) documentation and assessment of values; 2) documentation and assessment of threats, 3) influence of government policy, 4) related regulations, 5) community cooperation and 6) the structure of management organization. 6 indicators of Planning element were 1) the management objective, 2) protected area design, 3) protected area size and number, 4) representation, 5) standards and categories and 6) management planning. Input element of 3 indicators were 1) management staff, 2) funding, 3) establishment and application of information. Process element were consisted of 1) governance, 2) management guidelines, 3) human resource management, 4) law enforcement, 5) eco-management, 6) disaster management, 7) education program and 8) research and monitoring. The element of outputs and outcomes were 1) accomplishment of plan, 2) accomplishment of program, 3) private land management, 4) threats change, 5) biodiversity change, 6) ecosystem health and vitality, 7) impact on community, 8) international management level and 9) visitors' satisfaction and variation in civil compliant. It is recommended to have further research on evaluation methods development by applying those above developed indicators for the protected forest areas to ensure the practicality of the indicators.