• Title/Summary/Keyword: Frequency Adjustment

Search Result 387, Processing Time 0.022 seconds

Post-Divorce Adjustment: The Experience of the School Children and Adolescents (부모의 이혼에 따른 자녀들의 적응)

  • Chung, Hyun Sook
    • Korean Journal of Child Studies
    • /
    • v.14 no.1
    • /
    • pp.59-75
    • /
    • 1993
  • Based upon the ABC-X model and family systems theory, this study examined (1) problem-solving and behavioral strategies utilized by children in divorced families, and (2) factors related to children's post-divorce adjustment. Date were collected from 158 elementary school aged children and adolescents of divorced families in an urban area (56 male and 102 female). Results of this study indicated that there were significant age differences in problem-solving and behavioral strategies utilized by difficult family situations. Factors that are useful in predicting adjustment of divorced children are the following variables: sex, visitation frequency of noncustodial parent, quality of custodial parent-child communication, and length of divorce. Implications for knowledge as well as recommendations for future research are discussed.

  • PDF

The High-frequency Induction-heating application for 2700kW power (2700kW급 고주파 유도 가열 장치의 시작)

  • 이영호;김용환;이광수;이현우
    • Proceedings of the KIPE Conference
    • /
    • 1998.07a
    • /
    • pp.171-174
    • /
    • 1998
  • The development of the high-frequency induction-heating for 2700kW power range intend to make localization at forging and rolling mill part by technical innovation. And, the development makes to increase our's competitive power at technique, quality and cost. This paper describes the heart of high-frequency induction-heating technique, switching technique, a few problem in common using as an unsatisfied technique, load adjustment technique, system control, diagnostic system, and auto-interface etc.

  • PDF

Structural Modification of Crossed Planar Monopole Antenna for ISM 2.45GHz/5.8GHz Dual Band Characteristics (ISM 2.45GHz/5.8GHz 이중대역 특성을 위한 십자형 평판 모노폴 안테나의 구조 변경)

  • Shim, Jaeruen;Chun, Joong-Chang
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.1
    • /
    • pp.13-18
    • /
    • 2015
  • This study presents the structure design of antenna to have the dual band characteristics in a desired frequency band through the structural modification of an antenna structure. For the experiment, a wideband crossed planar monopole antenna was used. The target frequency band was set to ISM 2.45GHz/5.8GHz. To give the properties, an additional antenna element was added to the crossed planar monopole antenna, which is a main body of the antenna. And then structural adjustment parameter was set to change the length(shape) of the antenna. Various simulations were conducted to find the dual band characteristics in the desired frequency band. The simulations brought forth the antenna bandwidth above the normal values for ISM 2.45GHz/5.8GHz. The structural adjustment parameter introduced in this study for structural modification of an antenna can be useful in developing an antenna featured with dual band(multiband) characteristics.

A Study on the Audio Compensation System (음향 보상 시스템에 관한 연구)

  • Jeoung, Byung-Chul;Won, Chung-Sang
    • The Journal of the Acoustical Society of Korea
    • /
    • v.32 no.6
    • /
    • pp.509-517
    • /
    • 2013
  • In this paper, we researched a method that makes a good acoustic-speech system using a digital signal processing technique with dynamic microphone as a transducer. Good acoustic-speech system should deliver the original sound input to electric signal without distortion. By measuring the frequency response of the microphone, adjustment factors are obtained by comparing measured data and standard frequency response of microphone for each frequency band. The final sound levels are obtained using the developed adjustment factors of frequency responses from the microphone and speaker to match the original sound levels using the digital signal processing technique. Then, we minimize the changes in the frequency response and level due to the variation of the distance from source to microphone, where the frequency responses were measured according to the distance changes.

The Correlation between School-life Stress, Depression and College Adjustment Residing in the Dormitory (기숙사 거주 대학생의 학교생활 스트레스, 우울 및 대학생활적응 간의 관계)

  • Lee, Oi-Sun;Hong, Min-Joo;Gu, Hye-Ja
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.9
    • /
    • pp.483-492
    • /
    • 2016
  • This study was conducted to identify the correlation between the school-life stress, depression and college adjustment of dormitory residents, in order to provide the basic data needed to establish a strategy to improve the adjustment of college students. The subjects were 210 students in Korea. The data were collected using a self-report questionnaire from September 13 to 19, 2014, and analyzed by frequency, t-test, ANOVA and Pearson's correlation using the SPSS Win 21 program. The school-life stress, depression and college adjustment of the students residing in the dormitory on a 5-point scale were 2.43, 1.88 and 3.81, respectively. School-life stress had a significant positive correlation with depression (r=.639, p<.001) and significant negative correlation with college adjustment (r=-.709, p<.001). Depression had a significant negative correlation with college adjustment (r=-.788, p<.001). Those students with a higher school-life stress showed higher levels of depression and lower levels of college adjustment. Those students with a higher level of depression showed a lower level of college adjustment. Therefore, it is necessary to develop and test a suitable program in order to understand the differences between psychological adjustment based on gender, and to decrease school-life stress and depression and increase college adjustment.

A Novel Virtual Space Vector Modulation Strategy for the Neutral-Point Potential Comprehensive Balance of Neutral-Point-Clamped Converters

  • Zhang, Chuan-Jin;Tang, Yi;Han, Dong;Zhang, Hui;Zhang, Xiao;Wang, Ke
    • Journal of Power Electronics
    • /
    • v.16 no.3
    • /
    • pp.946-959
    • /
    • 2016
  • A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.

Suppression of the High Frequency Distortion by Adjustment of Transconductance of the Diode-Connected Transistor in the Current Mode Max Circuit for Multiple Inputs (다수 입력용 전류모드 Max 회로에서 다이오드결선 트랜지스터의 트랜스컨덕턴스 조정에 의한 고주파 왜곡 억제)

  • 이준수;손홍락;김형석
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.40 no.11
    • /
    • pp.37-44
    • /
    • 2003
  • A distortion suppression technology for employing multiple inputs in 3n+1 type current mode Max circuit is proposed using the adjustment of transconductance. If the number of input blocks of the current mode Max circuit increases, the high frequency distortion in the output signal grows. In this paper, it has been disclosed that the distortion in the multiple input Max circuit is proportional to such accumulated parasitic capacitance, to the derivative of the output signal and also to tile inverse of transconductance of the common diode-connected transistor. The proposed idea is by employing as larger transconductance of the common diode-connected transistor as possible. The effectiveness of the proposed idea has been proved through the HSPICE simulation for the current mode Max circuits with various numbers of input signals.

Effects from the Interaction of Ego-Resilience, Social Supports in the School Adjustment of Elementary School Children (초등학생의 학교적응에 대한 자아탄력성과 사회적 지지의 상호작용효과)

  • Song, Young-Kyoung;Kim, Yeong-Hee;Hwang, Seong-Sil
    • Korean Journal of Human Ecology
    • /
    • v.20 no.1
    • /
    • pp.1-19
    • /
    • 2011
  • The purpose of this study was to investigate the interactions of ego-resilience and social supports in the school adjustment in children. The subjects of this study were 479 children drawn from the fourth and sixth grades of three elementary schools in Cheongju city. The pilot study was done to examine the applicability of survey instruments. Data was analyzed by frequency, percentage, Cronbach's t-test, ANOVA with Tukey post-hoc test, correlation, and hierarchial analysis using the SPSSWIN program. The results of this research were as follows: First, the results showed that the effects of the interaction of ego-resilience and social supports on school adjustment were different according to the children's gender and age. Second, teacher supports had influence on school life satisfaction, interest in the subject, attitude in class, and observance of school rules according to the children's gender and age. Finally, overall, the influence of school life satisfaction, interest in subjects, attitude in class, and observance of school rules was greater for girls than boys.

A Study on Self-Efficacy and Academic Adjustment Among the Aviation-related College Students (항공계열 대학생의 자기효능감 및 학업적 적응에 관한 연구)

  • Bae, Shin-Young
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.23 no.3
    • /
    • pp.94-104
    • /
    • 2015
  • Recently the departments of aviation-related in the college are increased as the aviation industry is rapidly expanded. To enhance their competitiveness and have differentiation, it is emphasized for each department to manage and teach their students well. Therefore this study aims to examine self-efficacy and academic adjustment of aviation-related college students and investigate the relationship between self-efficacy and academic adjustment. To achieve the objectives, it conducted a survey of aviation-related college students in C university from Apr. 27th. 2015 to May. 22th. 2015. A total of 225 questionnaires were analyzed using SPSS 18.0 statistical package program and frequency analysis, factor analysis, reliability analysis, multiple regression analysis, correlation analysis and one-way ANOVA were conducted. The result released that general self-efficacy was recognized higher at the department of aviation operation than aviation maintenance and aviation service and social self-efficacy was recognized higher at the department of aviation service than aviation maintenance and aviation operation. Also general self-efficacy had an influence on the motivation, application and performance and social self-efficacy affected motivation, performance and academic environment. The implication of these findings would help to manage aviation-related college students, develop their departments and provide the directions for future research.

Pulse-width Adjustment Strategy for Improving the Dynamic Inductor Current Response Performance of a Novel Bidirectional DC-DC Boost Converter

  • Li, Mingyue;Yan, Peimin
    • Journal of Power Electronics
    • /
    • v.18 no.1
    • /
    • pp.34-44
    • /
    • 2018
  • This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC-DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.