• 제목/요약/키워드: Hold-back

검색결과 78건 처리시간 0.021초

평균전류모드 플라이백 토폴로지를 이용한 PDP용 고효율 AC-DC 컨버터 및 Hold-up 특성 개선 (High Efficiency AC-DC Converter Using Average-Current Mode Flyback Topology for PDP and Improvement of Hold-up Characteristic)

  • 이경인;임승범;정용민;오은태;이준영
    • 반도체디스플레이기술학회지
    • /
    • 제7권2호
    • /
    • pp.23-27
    • /
    • 2008
  • Recently, regulation for THD (Total Harmonic Distortion) such as IEC 61000-3-2, IEEE 519 is being reinforced about a product which directly connects to AC line in order to prevent distortion of common power source in electronic equipment and electrical machinery. In order to satisfy these regulations, conventional circuits were used two-stage structure attached power factor correction circuit at ahead of converter but this method complicate the circuit and then a number of element increases thereupon the cost of production rises. in this paper, we propose a high efficiency single-stage 300W PFC fly-back converter that improved power factor and efficiency than conventional two-stage power module.

  • PDF

Comparison of the effects of joint mobilization, gym ball exercises, and breathing exercises on breathing pattern disorders and joint position sense in persons with chronic low back pain

  • Lim, Chae-Gil
    • Physical Therapy Rehabilitation Science
    • /
    • 제9권1호
    • /
    • pp.25-35
    • /
    • 2020
  • Objective: To compare the effects of joint mobilization, gym ball exercises, and breathing exercises on breathing pattern disorders and joint position sense in persons with chronic lower back pain. Design: Three-group pretest-posttest design. Methods: Thirty-six individuals with chronic low back pain who were undergoing a postural correction and vertebral movement at a rehabilitation center participated in this study. The subjects were randomly divided into the joint mobilization group (n=12), gym ball exercises group (n=12), and the breathing exercises group (n=12). The exercises were applied for 40 minutes a day, twice a week for a total of 12 weeks. Measurement tools included the end-tidal CO2 (ETCO2), respiration rate (RR), breath hold time, Nijmegen Questionnaire (NQ), excursion, and joint position error (JPE). Results: The groups showed significant differences in the ETCO2, RR, NQ, Excursion and JPE test before and after the intervention (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in ETCO2 and RR (p<0.05). The differences between the groups were most significant in the group that received breathing exercises in NQ and excursion (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in JPE Lt. and Rt. (p<0.05). Conclusions: All three interventions had a significant impact on the biomechanical changes, respiratory variables, and joint position sense in participants with chronic lower back pain. Breathing exercises were found to be particularly effective in improving respiratory parameters.

성인여성의 의복 원형 개발에 관한 연구 -성인여성의 체형 분류에 관한 연구의 후속 연구- (The Study of Classification Body Types of Adults Women and Drawing of Prototype of Clothing)

  • 손혜순;손혜정
    • 복식문화연구
    • /
    • 제5권4호
    • /
    • pp.130-158
    • /
    • 1997
  • This study outputs calculation of regression of each items for production of torso basic pattern according to 6 body types as the result of another study and intends to present drawing method of torso model by short measure method modified and supplied and supplied by experiments of wearing clothing. SAS(Statistical Analysis System) is used for figures management and methods for analysis used are Frequency Analysis, Means Analysis, Regression Analysis, Correlation Analysis, etc. Results are as follows. 1. Correlation analysis is used to output the size necessary for torso prototype drawing by sort measure method and waist front length, back length, crotch length, shoulder point-cerricale-shoulder point, bust circumference, waist circumference, weight, etc, are set up as representative items calculation of regression of each type is suggested. 2. In the result of experiment of the first wearing clothing intended for 5 in each type and the whole 30, to develop torso prototype drawing method by short measure method, as we find some problems of the shape and propriety of neck root circumference line, the position of shoulder point, pulling or hold armpit parts, waist circumference line, the degree of dissatisfaction is high, so the second experiment of wearing clothing is propriety of each part is improved, all items except the length and quantity of shoulder dart, waist in back bodice, clearance quantity of hip circumference, and the place of shoulder line in side bodice. So, it was modifed and supplied and then the third torso prototyped drawing method by shout measure method was suggested. The third prototype drawing method was suggested, by modifying and supplying.

  • PDF

여과지가 장착된 3단 카세트를 이용한 입자상물질 채취용 펌프의 유량성능 평가방법 (Development of an Evaluation Method for Flow Rate Performance of Particulate Sampling Pump using Three-pieces Cassette Holder Containing Filters)

  • 송호준;김남희;김기연;마혜란;이광용;정지연
    • 한국산업보건학회지
    • /
    • 제23권4호
    • /
    • pp.348-355
    • /
    • 2013
  • Objectives: In working environment measurement, sampling is an important stage for obtaining reliable result as analysis. A personal air sampling pump is one of the most fundamental and important element in the work environment measurement, but it remains at the level of calibrating the flow rate of the pump before and after sampling. There is no checking whether the flow rate set at the initial stage would be hold during sampling. The purpose of this study was to develop a method to evaluate the flow rate performance of particulate sampling pump with three-pieces cassette holder containing filters commonly used to sample particulate. Materials and methods: We tested back pressure of particulate sampling pumps commonly used in Korea with three-pieces cassette holder containing various filters, and tried to find out the combination conditions of filters in accordance with back pressure required by ISO standard 13137. Results: We found out the matrix of sampling media such as three-pieces cassette holder containing filters applicable to the pressure drop required by the ISO standard for evaluating the flow rate stability under increasing pressure drop and long term(8 hour) performance. Conclusions: This evaluation method using sampling media matrix for checking flow rate stability proposed by this study could be very useful tool to find out good performance pumps before sampling.

상하의 의류 영상을 이용한 가상 의류 착의 시스템 (A Virtual Fitting System Using The Top and Bottom Image of Garment)

  • 최란;조창석
    • 한국멀티미디어학회논문지
    • /
    • 제15권7호
    • /
    • pp.941-950
    • /
    • 2012
  • 본 연구에서는 PC상에서 인체 3차원 데이터에 상하의 의류를 중첩 착의하는 가상 착의 시스템을 소개한다. 이를 위하여, 레이저 스캔 방식으로 얻은 인체 3차원 데이터와 의류 앞뒷면의 모습을 촬영하여 얻은 의류 디지털 데이터를 이용한다. 2차원의 앞뒷면 의류 디지털 데이터에는 의류 소재 내 질점 간의 장력이 반영되었고, 인체 데이터에의 착의 과정에는 마찰력과 중력을 적용해 주었다. 하의 착용 시에는 마찰력과 중력에 추가적으로 혁대 개념을 도입하여 흘러내리는 의류를 고정하였고, 하의를 착의한 인체데이터위에 상의를 착의하는 중첩 착의 방법을 제시하였다. 본 시스템이 지닌 장점은 복잡한 패턴을 이용하여 착의하는 다른 연구와 달리, 의류의 앞뒷면만을 이용하여 착의하면서도 현실감은 뒤지지 않는다는 것에 있다. 현재 의류전자상거래 시 의류의 앞뒷면만을 전시하여 판매하는 방법과 유사한 방식으로 온라인 판매가 이루어지나, 착의 모습을 제공할 수 없는 기존 방식과 달리 3차원의 착의 모습까지 제공하게 되어, 의류 판매의 방식을 바꾸게 할 것으로 기대한다.

배낭 가방의 끈 길이 차이가 머리척추각도에 미치는 영향 (Effect of craniovertebral angle on length difference of backpack strap)

  • 이지은;강대한;박소현;이유진;윤슬기
    • 대한물리치료과학회지
    • /
    • 제22권2호
    • /
    • pp.29-36
    • /
    • 2015
  • Purpose : the purpose of the study was to investigate the effect of craniovertebral angle on bag strap length change method : this study is aimed at twenties healthy adult for 30 persons (male-8, female-22) research participant attach marks on tragus and cervical7 participant did not carry bag in First test. thereafter we take a picture mark point and measure the angle. immediately the second experiment was designed to carry back on participant's iliac crest and to walk freely for five minutes. afterward, we take a picture mark point and measure the angle. last experiment was performed after five minutes break. participants carried back on 10cm below participant's iliac crest and third experiment was performed the same way. results : Increase the length of the bag, craniovertebral angle is reduced and there is a significant difference between the three experiments.(p=.000) conclusion : when hold the back too long, Cervical spine cause temporary head forward posture. so carry on bag short.

  • PDF

Comparisons for the Abnormality of Breathing Pattern, Kinesiophobia and Flexion Relaxation Phenomenon in Patients with Chronic Low Back Pain and Healthy Person during Flexion and Extension of the Trunk

  • Yoon, Junggyu
    • 국제물리치료학회지
    • /
    • 제10권2호
    • /
    • pp.1750-1755
    • /
    • 2019
  • Background: Most of the previous researches on the abnormality of breathing pattern have focused on the silence of functional movements owing to such abnormality, however, have not been clearly identified the relationship between the abnormal breathing pattern on one hand and kinesiophobia and flexion relaxation phenomenon (FRP) on the other hand. Objective: To compare patients with chronic low back pain (CLBP) and healthy person in the abnormality of breathing pattern, kinesiophobia, and FRP during flexion and extension of the trunk. Design: Case-control study. Methods: The research subjects consisted of a group of 15 healthy adults and another group of 15 patients with CLBP. Capnography was used to measure the endtidal $CO_2$ ($EtCO_2$) and respiratory quotient (RQ). The muscle activity of multifidus and erector spinae of the subjects was measured during flexion and extension of the trunk to identify their FRP. The Nijmegen Questionnaire (NQ) and Tampa Scale of Kinesiophobia (TSK) were utilized to measure their breathing patterns and kinesiophobia, respectively. The Kolmogorov-Smirnov (K-S) test was conducted in order to analyze the normal distribution of the measured data. Their general characteristics were identified by the descriptive statistics and the independent t-test was performed to identify the differences between the two groups in terms of abnormality of breathing pattern, kinesiophobia, and FRP. The level of significance was set at ${\alpha}=.05$. Results: The patients with CLBP had significantly less $EtCO_2$ and shorter breathing hold time (BHT) than normal healthy person (p<.05). The patient with CLBP also had significantly greater kinesiophobia than healthy person (p<.05), and had less FRP than the healthy person (p<.01). Conclusions: These results suggest that the CLBP had greater abnormality of breathing pattern and kinesiophobia with less FRP than healthy person.

A Historical Account of Some Alternating Patterns and Anomalies in Modem English

  • Moon, An-Nah
    • 영어어문교육
    • /
    • 제6호
    • /
    • pp.75-88
    • /
    • 2000
  • There are many reasons why foreigners have difficulties learning English. In addition to the difference between English and the learner's grammar, the large number of irregularities found in English become another obstacle to learning English. Understanding the difference and the irregularities will help us not only have a good command of English but also teach English more effectively. Many irregular or alternating patterns, or even anomalies in Modern English are the results of historical changes. In this paper, I would like to focus on some of the irregular or alternating patterns found in different components of the grammar of English and to show how they can be accounted for historically. Through this study, I would like to show that the irregular patterns and anomalies in English were once regular and systematic, they have deviated from the regular patterns of the grammar as time has gone by, and they have survived in Modern English as irregular and alternating patterns. Many of the irregular or alternating patterns can be traced back by phonological, morphological and/or semantic changes in the history of English. Finally, by looking at language history, we can hold a more tolerant view on many anomalies present in English.

  • PDF

Security-Based Intranet Structure

  • Lee, S. M.;Lee, P. J.
    • 한국정보보호학회:학술대회논문집
    • /
    • 한국정보보호학회 1997년도 종합학술발표회논문집
    • /
    • pp.265-273
    • /
    • 1997
  • Intranet is an enterprise network using Internet protocols as communication standard and HTML as content standard. The Internet is like a house built on information water. It has a lot of strong points as a future enterprise network. However, companies wish to have confidence in its functional and economic effectiveness and security before adopting it. The security issue especially is a problem to solve inevitably. Enterprises will hold back to adopt Intranet unless there are enough security counter plans and countermeasures against vulnerabilities of Intranet(it is the wise decision !). Nevertheless the researches related to Intranet has been concentrated on techniques for building it. In this paper, we focus the security aspect of Intranet. Intranet security must be considered on the whole from structure design to users' services. We propose a security-based Intranet structure and security management system.

  • PDF

한국의 조기유학 (South Korean Early Study Abroad)

  • 이순형;권미경
    • 아동학회지
    • /
    • 제30권6호
    • /
    • pp.297-308
    • /
    • 2009
  • The study abroad phenomenon at an early age in Korea is increasing steadily. Increasing social demand for global leaders, disappointment in Korean educational system and economic growth are motivating more students to study abroad. The study abroad is a social phenomenon that is widespread across all social status in Korea. This study tries to examine the phenomenon in respect to social, psychological, educational and economical perspectives and seek future research questions. The findings suggest ways to improve Korean educational system, support students currently or planning to study abroad and to re-adjust in Korea after they come back. A balanced perspective is necessary in viewing study abroad phenomenon, rather than preventing, implementing stronger pulling factors in Korean educational system. It is necessary to hold the study abroad as another educational opportunity.

  • PDF