• Korean Journal of Child Education & Care
• /
• v.19 no.1
• /
• pp.87-99
• /
• 2019

Objective: The purpose of this study is to investigate the influence of mothers' parenting belief on the types of discipline methods. Methods: For this study, questionnaires were distributed to 219 mothers of 3~5 year old children who live in Seoul and Gyeonggido. Frequency analysis, descriptive statistic, correlation analysis and multiple regression analysis were conducted by using the SPSS 23.0 program. Results: Firstly, the highest parenting belief of young children's mothers was found to be problem-solving ability. And they used mostly the discipline of logical explanation. Secondly, there were positive correlations between parenting beliefs of problem-solving ability and creativity ability and the discipline of logical explanations. Thirdly, the parenting beliefs of problem-solving ability and creative ability were found to positively influence on logical explanations whereas it negatively influenced on the discipline of neglect and the forced punishment. Conclusion/Implications: The results of this study imply that the parenting belief affect on the types of discipline method and the mothers need education for the parenting belief of problem-solving ability and creative ability.

• Advances in aircraft and spacecraft science
• /
• v.5 no.2
• /
• pp.225-237
• /
• 2018

The difficulties of satellite vibration testing are due to the commonly expressed qualification requirements being incompatible with the limited performance of the entire controlled system (satellite + interface + shaker + controller). Two features cause the problem: firstly, the main satellite modes (i.e., the first structural mode and the high and low tank modes) are very weakly damped; secondly, the controller is just too basic to achieve the expected performance in such cases. The combination of these two issues results in oscillations around the notching levels and high amplitude beating immediately after the mode. The beating overshoots are a major risk source because they can result in the test being aborted if the qualification upper limit is exceeded. Although the abort is, in itself, a safety measure protecting the tested satellite, it increases the risk of structural fatigue, firstly because the abort threshold has been already reached, and secondly, because the test must restart at the same close-resonance frequency and remain there until the qualification level is reached and the sweep frequency can continue. The beat minimum relates only to small successive frequency ranges in which the qualification level is not reached. Although they are less problematic because they do not cause an inadvertent test shutdown, such situations inevitably result in waiver requests from the client. A controlled-system analysis indicates an operating principle that cannot provide sufficient stability: the drive calculation (which controls the process) simply multiplies the frequency reference (usually called cola) and a function of the following setpoint, the ratio between the amplitude already reached and the previous setpoint, and the compression factor. This function value changes at each cola interval, but it never takes into account the sensor signal phase. Because of these limitations, we firstly examined whether it was possible to empirically determine, using a series of tests with a very simple dummy, a controller setting process that significantly improves the results. As the attempt failed, we have performed simulations seeking an optimum adjustment by finding the Least Mean Square of the difference between the reference and response signal. The simulations showed a significant improvement during the notch beat and a small reduction in the beat amplitude. However, the small improvement in this process was not useful because it highlighted the need to change the reference at each cola interval, sometimes with instructions almost twice the qualification level. Another uncertainty regarding the consequences of such an approach involves the impact of differences between the estimated model (used in the simulation) and the actual system. As limitations in the current controller were identified in different approaches, we considered the feasibility of a new controller that takes into account an estimated single-input multi-output (SIMO) model. Its parameters were estimated from a very low-level throughput. Against this backdrop, we analyzed the feasibility of an LQG control in cancelling beating, and this article highlights the relevance of such an approach.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.7 s.110
• /
• pp.648-658
• /
• 2006

We propose a thin frequency selective surface(FSS) superstrate etched on a substrate for dual-band directivity enhancement, and present a design method of the superstrate. In the proposed new design, two FSS arrays with the same periodicity, but with different alignments are placed above and below a thin dielectric layer to overcome the problem of conventional superstrates for dual band directivity enhancements. Based on the unit-cell simulation, several important parameters that characterize the thin FSS superstrate are investigated, and the procedure for designing such a superstrate is described. We compare the resonant frequencies and the qualify factors of the unit cell with those of three FSS antenna composites with different quality factors, and identify the quality factors which support similar directivity enhancement at the dual-band directivity enhancement. It was found that there is an optimum FSS array size of a superstrate to enhance the directivity most efficiently. Measured results for a fabricated superstrate show a good agreement with the simulated ones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.6
• /
• pp.591-600
• /
• 2010

In this paper, three kinds of 24 GHz low-power CMOS cross-coupled voltage controlled oscillators are designed and fabricated for a short-range radar applications using TSMC 0.13 ${\mu}m$ CMOS process. The basic CMOS crosscoupled voltage controlled oscillator is designed for oscillating around a center frequency of 24.1 GHz and subthreshold oscillators are developed for low power operation from it. A double resonant circuit is newly applied to the subthreshold oscillator to improve the problem that parasitic capacitance of large transistors in a subthreshold oscillator can push the oscillation frequency toward lower frequencies. The fabricated chips show the phase noise of -101~-103.5 dBc/Hz at 1 MHz offset, the output power of -11.85~-15.33 dBm and the frequency tuning range of 475~852 MHz. In terms of power consumption, the basic oscillator consumes 5.6 mW, while the subthreshold oscillator does 3.3 mW. The subthreshold oscillator with the double resonant circuit shows relatively lower power consumption and improved phase noise performance while maintaining a comparable frequency tuning range. The subthreshold oscillator with double resonances has FOM of -185.2 dBc based on 1 mW DC power reference, which is an about 3 dB improved result compared with the basic oscillator.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.510-519
• /
• 2019

The aim of this study was to set a defect classification framework and evaluate the defect risks in apartment buildings For this, approximately 15,056 defect items for 133 apartment buildings were examined. As a result of the analysis, the major defect of the RC work was cracks, which were found mainly in public locations. Moreover, the RC work was found to exhibit a high defect risk of water problem and surface appearance, which are highly connected with cracks. Second, the finish work has a high defect risk because it is composed of various work types, and there are many kinds of materials and construction parts involved. Third, the major defects of the waterproof work were incorrect installation and missing tasks, which have high defect risks in the garage. This is because defects that require rework occur mainly in the underground garage. Based on these results, this study proposed countermeasures for defect risk management to be considered in the construction, handover, post-handover, and occupancy phases. These have been set in detail based on the three zones: low frequency high severity (LFHS), low frequency low severity (LFLS), and high frequency low severity (HFLS).

• Journal of Korean Society of Steel Construction
• /
• v.18 no.4
• /
• pp.437-446
• /
• 2006

Open-steel-plate-girder(OSPG) bridges are one of the most prevalent bridge types among Korean railway bridges. They account for about 40% of all Korean railway bridges. However, the line-type bearings used for OSPG bridges generate several problems with respect to the bridges' dynamic behavior and maintenance. The replacement of the existing bearings with polyurethane disk bearings could be a possible solution to this problem. This type of disk bearing is an elastic bearing using a polyurethane disk. This study estimated the variations in the natural frequency of a bridge when disk bearings were installed and the bridge's dynamic behavior with a running locomotive and running trains. The first natural frequency of the bridge was 3% lower than that of the as-built bridge after the installation of the disk lower, respectively. Also, the second and third frequencies were 7 and 15% lower, respectively. The disk bearings increased the vertical displacement of the bridge, but the pure displacement, excluding the disk deformation, did not vary. The vertical acceleration did not increase when the disk bearing was installed, with trains running. The shear pin in the disk bearing reduced the lateral displacement and the acceleration of the bridge.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.25-31
• /
• 2020

In an optical system that serves as the backbone of an information transmission system, it is essential to evaluate the statistical characteristics of the signal and noise for a performance evaluation and optimization of the system. The optical receiver system improves the reception sensitivity by adopting an optical amplifier in front of the optical detector to improve the reception sensitivity, but some problems change the bandwidth of the electronic signal to the optical signal in the optical receiver due to the ASE noise added to the output of the optical detector. The problem of changing the ratio of the bandwidth of these signals varies according to the passband characteristics of the filter present at the output stage. The frequency response effect can be solved by constructing an infinite order filter, but it is almost impossible to implement it. In this paper, the Butterworth filter was implemented to evaluate the frequency response characteristics of an optical receiver system according to the filter order. The simulation results showed that the receiver sensitivity increases as the order of Butter-Worth filters increases. In addition, as a result of simulation of the change of various values, it was confirmed that the reception sensitivity increased with increasing. That is, the average photocurrent increases, and the dispersion decreases with increasing.

• Journal of Acupuncture Research
• /
• v.22 no.6
• /
• pp.51-60
• /
• 2005

Objectives : This study was designed to evaluate the effect of inbalance of autonomic nerve system on peripheral facial palsy patients in comparison of Heart Rate Variability results of healthy control group with that of peripheral facial palsy group. Methods : The peripheral facial palsy patiens who visited the Dongguk university Bundang oriental medicine hospital from April to June in 2005 were tested Heart Rate Variability items which are Mean Heart Rate(MHRT), Standard Deviation of all the Normal RR intervals (SDNN), Root Mean Square of Successive Differences Between The Normal Heart Beats(RMSSD), Total Power(TP), Low Frequency, High Frequency, ratio between the Low Frequency and High Frequency power(LF/HF ratio). The Heart Rate Variability test results of peripheral facial palsy group were compared with the HRV test results of healthy control group who didn't have nervous disease, musculoskeletal disease, heart problem and pain for the past 6 months. Results : 1. MHRT was not significantly different between peripheral facial palsy group and healthy control group(P=0.18). 2. SDNN was not significantly different between peripheral facial palsy group and healthy control group(P=0.41). 3. RMSSD was not significantly different between peripheral facial palsy group and healthy control group(P=0.93). 4. TP was not significantly different between peripheral facial palsy group and healthy control group(P=094). 5. LF and HF were not significantly different between peripheral facial palsy group and healthy control group((P=0.34, 0.30). 6. LF/HF ratio was significantly different between peripheral facial palsy group and healthy control group(P=0.04). Conclusion : LF/HF ratio is generally used as autonomic nerve system evaluation and there was significantly statistical difference between peripheral facial palsy group and healthy control group.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.5
• /
• pp.26-35
• /
• 2009

OFDM (Orthogonal Frequency Division Multiplexing) system is robust to frequency selective fading and narrowband interference in high-speed data communications. However, an OFDM signal consists of a number of independently modulated subcarriers and the superposition of these subcarriers causes a problem that can give a large PAPR(Peak-to-Average Power Ratio). Phase rotation method can reduce the PAPR without nonlinear distortion by multiplying phase weighting factors. But computational complexity of searching phase weighting factors is increased exponentially with the number of subblocks and considered phase factor. Therefore, a new method, which can reduce computational complexity and detect phase weighting factors efficiently, should be developed. In this paper, a modeling process is introduced, which apply metaheuristic algerian in phase rotation method and optimize in PTS (Particle Swarm Optimization) scheme. Proposed algorithm can solve the computational complexity and guarantee to reduce PAPR We analyzed the efficiency of the PAPR reduction through a simulation when we applied the proposed method to telecommunication systems.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.1
• /
• pp.133-137
• /
• 2015

Background: Cancer is a major public health problem and the leading cause of mortality in both males and females in developed and developing countries. The incidence of cancer is gender dependent. Among Iranians, it is the third cause of death. Materials and Methods: The information recorded in the files of all patients (7,695 individuals) pathologically diagnosed with cancer in Imam Reza referral hospital of Kermanshah University of Medical Sciences during the four year period of 2006-2009 were reviewed and analyzed using SPSS statistical software package version 16.0. Results: Around 61.6% of reported cancer cases were males and 38.4% were females. The most prevalent reported malignant tumors occurred at the age group of 70-79 years in males and in females these tumors were presented in the ages of 60-69 years. The most prevalent cancers among studied patients were gastrointestinal (GI) cancers with a frequency of 22.9% [gastric 10.7%, colorectal 6.9%, and esophageal 6%]. The second, third and forth prevalent cancers were blood at 16.4%, lung 13.5% and bladder 12.8%, respectively. In males the cancers of GI (25.6%) were the most prevalent followed in order of frequency by bladder (18%), blood (17.6%), lung (17.4%) and prostate (6.8%). In females the most frequent recorded cancer was breast (24.1%) followed in order of frequency by GI (20.5%), blood (14.4%), lung (7.3%), uterus (6.2%) and ovary (5.1%). Breast cancer was the most prevalent cancer (27%) in the age group of 40-49 years. Conclusions: The present study provides frequency data for various types of cancers in both males and females from a referral hospital of Kermanshah that are comparable with some reports from other areas of the country.