• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.38 no.4
• /
• pp.45-53
• /
• 2001

We have proposed a new driving method of AC PDP for both high resolution over HDTV and high luminance. The new driving method can reduce data and scan pulse width to 0.85${\mu}s$ by utilizing both rising and falling edges of sustain pulse and can provide high resolution AC PDP with high luminance by increasing the number of addressing discharge using sustain pulses with phase shifts. As a result, the proposed driving scheme makes it possible to drive 2080 horizontal resolution panel with high luminance. The experimental results using 4-inch color AC PDP with $30{\times}58$ pixels indicate that the luminance can achieved up to 850 $cd/m^2$ without image noise when we employ the four phase shifted sustain pulses with the amplitude of 140V and the frequency of 125KHz.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.6
• /
• pp.83-91
• /
• 2006

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in longitudinal axis to achieve performance enhancements and improve stability. The flight control law of T-50 advanced trainer employs RSS concept in order to improve the aerodynamic performance and guarantee aircraft stability. The longitudinal center of gravity(X-c.g) varies as a function of external stores, fuel state and gear position. Shifts in X-c.g relate directly to longitudinal static margin in aircraft stability. This paper deals the maximum aft X-c.g for critical aircraft loadings and checks static margin limits using sensitivity such as damping, natural frequency, gain and phase margin. And nonlinear analysis was conducted for such as short period input. And also, this paper shows the T-50 aircraft stability based on the result of high angle of attack flight such as upright and inverted departure.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.27 no.3
• /
• pp.221-230
• /
• 2017

Objectives: This study was conducted to investigate general characteristics, job characteristics, characteristics of hospitals, and hospital coordinators, and to investigate the factors affecting the job satisfaction of medical workers. Methods: The data was collected through a self-reported questionnaire among 435 workers in plastic surgery and dermatology clinics in metropolitan city G. We investigated general characteristics, job-related characteristics, characteristics of medical institutions and hospital coordinators, job performance of hospital coordinators, and job satisfaction of medical workers. T-tests, ANOVA, correlation, and multiple regression analyses were conducted to investigate the factors related with job satisfaction. Results: The job satisfaction of the medical workers and the perceived job performance of hospital coordinators were $3.55{\pm}0.40$ and $3.74{\pm}0.43$, respectively. In multiple regression analysis, drinking frequency, number of night shifts, number of work days, and hospital coordinator introduction years were associated with the job satisfaction of medical workers. The more the overall job performance of hospital coordinators increased, the higher was job satisfaction(B=0.458, p<0.001). In detail, the more job roles(B=0.218, p<0.001), core competency(B=0.145, p=0.005), and leadership(B=0.099, p=0.037) increased, the higher was the job satisfaction of medical workers. Conclusions: The job satisfaction of the medical institution workers was associated with the perceived job performance of the hospital coordinator. In order to increase the job satisfaction of medical institution workers, a hospital coordinator with specialized job performance will be able to improve job satisfaction by carrying out efficient work in the medical institution.

• Smart Structures and Systems
• /
• v.17 no.1
• /
• pp.91-105
• /
• 2016

One of the most commonly used techniques to strengthen steel reinforced concrete structures is the application of externally bonded patches in the form of carbon fiber reinforced polymers (CFRP) or recently, textile reinforced cements (TRC). These external patches undertake the tensile stress of bending constraining concrete cracking. Development of full-field inspection methodologies for fracture monitoring are important since the reinforcing layers are not transparent, hindering visual observation of the material condition underneath. In the present study acoustic emission (AE) and digital image correlation (DIC) are applied during four-point bending tests of large beams to follow the damage accumulation. AE helps to determine the onset of fracture as well as the different damage mechanisms through the registered shifts in AE rate, location of active sources and change in waveform parameters. The effect of wave propagation distance, which in large components and in-situ can well mask the original information as emitted by the fracture incidents is also discussed. Simultaneously, crucial information is supplied by DIC concerning the moments of stress release of the patches due to debonding, benchmarking the trends monitored by AE. From the point of view of mechanics, conclusions on the reinforcing contribution of the different repair methodologies are also drawn.

• Safety and Health at Work
• /
• v.7 no.1
• /
• pp.72-77
• /
• 2016

Background: This study aimed to determine the prevalence and factors related to needle stick injuries (NSIs) and to assess related safety measures among a sample of Iranian nurses. Methods: In this cross-sectional study, a random sample of 168 registered active nurses was selected from different wards of one of the hospitals of Shiraz University of Medical Sciences (SUMS). Data were collected by an anonymous questionnaire and a checklist based observational method among the 168 registered active nurses. Results: The prevalence of NSIs in the total of work experience and the last year was 76% and 54%, respectively. Hollow-bore needles were the most common devices involved in the injuries (85.5%). The majority of NSIs occurred in the morning shift (57.8%) and the most common activity leading to NSIs was recapping needles (41.4%). The rate of underreporting NSIs was 60.2% and the major reasons for not reporting the NSIs were heavy clinical schedule (46.7%) and perception of low risk of infection (37.7%). A statistically significant relationship was found between the occurrence of NSIs and sex, hours worked/week, and frequency of shifts/month. Conclusion: The study showed a high prevalence of NSIs among nurses. Supportive measures such as improving injection practices, modification of working schedule, planning training programs targeted at using personal protective equipment, and providing an adequate number of safety facilities such as puncture resistant disposal containers and engineered safe devices are essential for the effective prevention of NSI incidents among the studied nurses.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.7
• /
• pp.1173-1179
• /
• 2008

Since there are very strong clutter returns in airborne and ground weather radars used for the detection of low altitude weather hazards, the reliable weather data cannot be extracted from the weak Doppler weather signal without cancellation of these strong clutter returns. However, the clutter cancellation in Doppler frequency domain is not an easy task since even the fixed clutter returns not to mention the moving clutter can have Doppler shifts due to the antenna rotation and operational environment. Therefore, it was shown in this paper a simple array antenna system can be used for the efficient clutter cancellation in the spatial domain. The weather signal, various moving and fixed clutters were modelled and simulated to prove the performance of this adaptive array system. Also, the degree of accuracy in pulse-pair estimates of a weather radar was compared and analyzed from the simulated weather data.

• The Journal of the Acoustical Society of Korea
• /
• v.40 no.2
• /
• pp.161-168
• /
• 2021

In this paper, a Silent Speech Interface (SSI) technology was proposed in which Doppler frequency shifts of the reflected signal were used to synthesize the speech signals when 40kHz ultrasonic signal was incident to speaker's mouth region. In SSI, the mapping rules from the features derived from non-speech signals to those from audible speech signals was constructed, the speech signals are synthesized from non-speech signals using the constructed mapping rules. The mapping rules were built by minimizing the overall errors between the estimated and true speech parameters in the conventional SSI methods. In the present study, the mapping rules were constructed so that the distribution of the estimated parameters is similar to that of the true parameters by using Generative Adversarial Networks (GAN). The experimental result using 60 Korean words showed that, both objectively and subjectively, the performance of the proposed method was superior to that of the conventional neural networks-based methods.

• International Journal of Computer Science & Network Security
• /
• v.23 no.7
• /
• pp.1-8
• /
• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.6
• /
• pp.797-807
• /
• 2023

This research aims to investigate the alterations in typhoon patterns attributable to climate change and to quantitatively assess the risk of damage to residential structures. The increasing prevalence of climate anomalies and severe weather events, a consequence of global warming, is causing escalating damage globally. Notably, numerous countries are facing substantial devastation due to shifts in typhoon trajectories. Despite this, there exists a gap in empirical research quantifying the impact of these changes on building integrity and the associated risk alterations driven by climate change. In addressing this gap, our study analyzes the frequency and intensity of typhoons impacting Korea, examining the evolution of these meteorological phenomena. Furthermore, we employ the Korean Typhoon Vulnerability Function for residential facilities to quantify the altered risk posed by these changing patterns. The outcomes of this study provide the private sector with essential data to formulate diverse scenarios and business strategies in response to the escalating risks of typhoon-related damage. Additionally, it equips governmental bodies with the necessary insights to develop comprehensive risk management strategies to mitigate the effects of future typhoons.

• Journal of Korean Academy of Nursing Administration
• /
• v.12 no.1
• /
• pp.63-75
• /
• 2006

Purpose: This study was aimed to specify roles of nurses from the anesthesia and recovery room by analyzing nursing activities as well as anesthesia nursing during surgery. Method: The objects were 12 RNs working in the recovery room of a university hospital located in Incheon. Self-report was performed by measuring stop-watch for five days from May 17th to May 21st in 2004. Research method was designed to record the time and frequency of the nursing activity from anesthesia and recovery room based on nurses' statement and other references for five days. The data were analyzed with descriptive statistics, ANOVA, and t-test via SPSS Win 10.0 program. Result: Nursing activities in anesthesia recovery room were classified into two different characteristics such as direct and indirect nursing activity. The activities consisted of 11 direct nursing areas and 39 nursing activities in anesthesia preparation room. The indirect nursing was classified into 8 nursing areas and 32 nursing activities. The direct nursing was classified into 12 nursing areas and 55 nursing activity. Also, the indirect nursing was classified into 7 nursing areas and 21 nursing activities in recovery room. In terms of prevalence of nursing activities in the anesthesia preparation room, observation and cooperation of anesthesia was the most prevalent activity, drug and eqipment management the second prevalent, and drug administration the third. On the other hand, in the recovery room, the most prevalent activity was vital sign checking and observation, the second most prevalent activity informative activity, and the third body temperature control. Nursing activity time was recorded according to the nursing characteristics. In the anesthesia preparation room, the direct nursing spent for 8092.20 minutes was larger than the indirect nursing spent for 7198.50 minutes. Also, in the recovery room, the direct nursing spent for 2361.16 minutes was larger than the indirect nursing spent for 1134.13 minutes. 4. Nursing activity time was compared to duty shifts. In the anesthesia preparation room, the direct nursing was more prevalent on day shift and the indirect nursing was prevalent on evening shift. However, in the recovery room, both direct and indirect nursing activities were prevalent on day shift. Conclusion: The role of anesthesia and recovery room nurses was analysed according to the time, frequency, and its characteristics.