• International Journal of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.330-338
• /
• 2024

In this paper, a Ka-band high-output active phased array antenna device applicable to small radars and seekers was designed, and the improved performance was studied. The radiation device assembly consists of 1x8 arrangements, and the step flared notch antenna type. It shows low active reflection loss characteristics in broadband, and low loss characteristics by applying the air-strip feeding structure, and is designed to enable beam steering up to 45 degrees. The TRM(transmit receive module) output power is more than 2.0W per channel using GaN HPA in the transmitting path, and satisfies more than 25.0 dB gain and less than 6.0 dB noise figure in the receiving path. Accordingly, the Effective Isotropically Radiated Power(EIRP) of the antenna unit shows the performance of 0.00 dB or more and the receive gain-to-noise temperature ratio(G/T) of 0.00 dB/k or more. For demonstration, we have designed aforementioned planar array antenna which consists of 64 radiating elements having a size within 130 mm x 130 mm x 300 mm and weight of less than 4.9 kg..

• KIEAE Journal
• /
• v.11 no.4
• /
• pp.63-70
• /
• 2011

In respond to the global energy crisis and climate change, there have been many ongoing national efforts to develop a sustainable housing prototype followed by "2 million Green Home Project" in Korea. More than 50% of nation's population are currently living in apartment housing thus the country is seriously in need of developing green apartment prototype. In this research, we focused on energy-conservative green apartment design prototype that have both passive components and active systems explored in a systemic design approach. After selecting an existing basic apartment unit, we analyzed and compared statistical data with the simulated annual energy consumption to match these two data sets for validating simulation accuracy performed with TRNSYS package. We performed energy simulations with different passive design factors such as varied insulation thickness, window types and infiltration rates as well as the active design factors including boilers and lighting fixtures to analyze their impacts on the energy performance of the housing unit using TRNSYS software. As a result, we acquired significant energy reduction effect with explored design strategies but the life cycle cost analysis for the final design guidline would need to be performed. In this study, we focused on a systematic comparative energy analysis based on TRNSYS that can improve the design of a green apartment housing.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.55 no.8
• /
• pp.375-377
• /
• 2006

An adaptive IIR filter in ANC(Active Noise Control) systems is more effective than an adaptive FIR filter when acoustic feedback exists, in which cause an order of an adaptive FIR filter must be very large if some of poles of the ideal control filter are near the unit circle. But the IIR filters may have stability problems especially when the adaptive algorithm for adaptive filters is not yet converged. In this paper, a stabilized multi-channel recursive LMS (MCRLMS) algorithm for an adaptive multi-channel IIR filter is presented. RLMS algorithms usually diverge before the algorithm is not yet converged. So, in the beginning of the ANC system, the stability of the RLMS algorithms could be improved by pulling the poles of the IIR filter to the center of the unit circle, and returning the poles to their original positions after the filter converges. Computer simulations and experiments for dipole ducts using a TMS320C32 digital signal processor have performed to show the effectiveness of a proposed algorithm.

• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.30-32
• /
• 2006

An adaptive IIR filter in ANC(Active Noise Control) systems is more effective than an adaptive FIR filter when acoustic feedback exists, in which cause an order of an adaptive FIR filter must be very large if some of poles of the ideal control filter are near the unit circle. But the IIR filters may have stability problems especially when the adaptive algorithm for adaptive filters is not yet converged. In this paper, a stabilized multi-channel recursive LMS (MCRLMS) algorithm for an adaptive multi-channel IIR filter is presented. RLMS algorithms usually diverge before the algorithm is not yet converged. So, in the beginning of the ANC system, the stability of the RLMS algorithms could be Improved by pulling the poles of the IIR filter to the center of the unit circle, and returning the poles to their original positions after the filter converges. Computer simulations and experiments for dipole ducts using a TMS320C32 digital signal processor have performed to show the effectiveness of a proposed algorithm.

• Korean Journal of Occupational Health Nursing
• /
• v.28 no.1
• /
• pp.64-74
• /
• 2019

Purpose: The purpose of this study was to identify the influencing factors on burnout after analyzing the relationship among clinical nurses' various perfectionism and coping styles. Methods: A descriptive, cross-sectional study was conducted with 200 clinical nurses who had six months or more years of clinical experiences from two general hospitals located in D city. The data were analyzed by t-test, one-way ANOVA, Pearson's correlation coefficients, and stepwise regression analysis using IBM SPSS statistics 23.0 program. Results: The burnout of clinical nurses was positively correlated with socially prescribed perfectionism and negatively correlated with active coping style. Socially prescribed perfectionism was positively correlated with active coping style and passive coping style. Influencing factors on the burnout of clinical nurses were socially prescribed perfectionism (${\beta}=.37$), satisfied work unit (${\beta}=-.64$) and neutral satisfaction of work unit (${\beta}=-.27$), over 40 years of age (${\beta}=-.21$), and active coping style (${\beta}=-.14$). The model consisting of these variables explained 42% of variance of burnout in clinical nurses. Conclusion: Based on the findings of this study developing intervention programs that consider influencing factors such as perfectionism and coping styles is needed to reduce the level of burnout of clinical nurses.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.10a
• /
• pp.277-277
• /
• 2003

• Journal of the Korean Home Economics Association
• /
• v.48 no.8
• /
• pp.51-65
• /
• 2010

This research explored the importance of conflict resolution in communication between adolescents and their parents. A teaching and learning plan on communication using the Active listening, I-message method and no-lose conflict resolution method was developed and applied to teaching the 'Communication among Family Members' unit in the middle school home economics and technology textbook. The experimental class of 203 students using the active listening, I message and no-lose conflict resolution method in communication was compared with a comparative class of 163 students using only the active listening and I message method, investigating the amounts of communication, conflicts, functional communication and degree of satisfaction the students perceived regarding relationships with their parents via pre and post tests. Both groups showed significant increases in their amounts of communication and functional communication. However, only the experimental class showed an increase in their degree of relationship satisfaction with their parents. Both groups evaluated the lesson positively.

• The KIPS Transactions:PartA
• /
• v.10A no.4
• /
• pp.295-304
• /
• 2003

Active object is an Independent runnable unit which is scheduled by CPU in creation time. In this paper, we define the active object and suggest ART(Active object RunTime support systems) which controls creation and execution of the active object. ART can Provide users locational transparency and support easy method call mechanism. We also designed a communication model among active objects and implemented a communication method to make the distributed programing possible. The implementation target platform of ART is an embedded system which has only limited resources and runs in the distributed computing environment.

• Physical Therapy Korea
• /
• v.24 no.3
• /
• pp.40-46
• /
• 2017

Background: The active knee extension (AKE) test commonly used to assess the flexibility of the hamstring muscles. Many researchers have tested the reliability of the AKE test; however, no published studies have examined the intrarater and interrater reliability of the AKE test using a PBU. Objects: The purpose of this study was to determine the intrarater and interrater reliability of the AKE test performed with a pressure biofeedback unit (PBU) on healthy subjects. Methods: Sixteen healthy male participants volunteered and gave informed consent to participate in this study. Two raters conducted AKE tests independently with a PBU. Each knee was measured twice, and the AKE testing was repeated one week after the first round of testing. Results: The interrater reliability's intraclass correlation coefficients ($ICC_{2,1}$) were .887~.986 for the right knees and .915~.988 for the left knees. In addition, the intrarater (test-retest) reliability ($ICC_{3,1}$) values ranged between .820~.915 and .820~.884 for Raters 1 and 2, respectively. The values for the standard error of mesurement were low for all tests ($.81{\sim}2.97^{\circ}$); the calculated minimum detectable change was $2.24{\sim}8.21^{\circ}$. Conclusion: These findings suggest that the AKE test performed with a PBU had excellent interrater and intrarater reliability for assessing hamstring flexibility in healthy young males.

• Journal of Korean Physical Therapy Science
• /
• v.19 no.2
• /
• pp.63-71
• /
• 2012

Purpose : This study aimed to acquire a basic knowledge about lumbar stability and inquire into exercise approach of pressure biofeedback unit for lumbar stability. Methods : This study was composed with reviewed theory of lumbar stability and several books and articles for exercise using pressure biofeedback unit. Results : The stability of lumbar should work symmetrical with passive, active, control subsystem in neutral zone, and local muscles should be using for stability. Especially, selective using of transverse abdominis work for lumbar stability importantly. The control of using pressure biofeedback unit may important not only examination but treatment. Conclusion : The stability of lumbar need co-contraction of specific local muscle and training for timing as well as using pressure biofeedback unit for accurate control may use for examination and therapedic approach.