• Title/Summary/Keyword: Difference-In-Difference

Search Result 72,435, Processing Time 0.08 seconds

Characteristics of Ultrasonic Motor using Voltage Control and Phase Difference Control (초음파 모터의 전압 및 위상차 제어 특성)

  • Shin, Duk;Kim, Dong-Ok;Ko, Nak-Yong;Choi, Han-Soo;Kim, Young-Dong
    • Proceedings of the KIEE Conference
    • /
    • 1996.07b
    • /
    • pp.949-952
    • /
    • 1996
  • The ultrasonic motor(USM) has good characteristics such as compact size, silent motion, low speed, high torque and high speed response. The USM is driven by 2-phase AC electricity. The control parameters of USM are voltage, phase difference, frequency of input power, etc. In this paper, we propose voltage difference control. And we designed USM controller to adjust voltage and phase using pLSI(programmable Large Scale Integration). Voltage difference control has many advantages that are lower current, lower power than phase difference control. Especially there is nearly zero ampere at the zero point of speed and torque. we can apply this voltage difference control to the compliance control of DD manipulator.

  • PDF

A Study about Direction Estimate Device of the Sound Source using Input Time Difference by Microphones′ Arrangement (마이크로폰 배열로 발생되는 입력 시간차를 이용한 음원의 방향 추정 장치에 관한 연구)

  • 윤준호;최기훈;유재명
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.5
    • /
    • pp.91-98
    • /
    • 2004
  • Human uses level difference and time difference to get space information. Therefore this paper shows that method to presume direction of sound source by time difference and to mark presumed position. The position means direction from geometrical center of sensors to the sound source. To get the time difference of microphones input level, we will be explained about arrangement of microphones which used for the sensor to take the sound signal. It is included distance among the 3 microphones and distance between microphones and sound source. Secondly, input signals are transmitted to CPU througth digital process. CPU is used to DSP(Digital Signal Processor) for manage the signal by real time. Finally, the position of sound source is perceived by an explained algorithm in this paper.

New approach method of finite difference formulas for control algorithm (제어 알고리즘 구현을 위한 새로운 미분값 유도 방법)

  • Kim, Tae-Yeop
    • Journal of IKEEE
    • /
    • v.23 no.3
    • /
    • pp.817-825
    • /
    • 2019
  • Difference equation is useful for control algorithm in the microprocessor. To approximate a derivative values from sampled data, it is used the methods of forward, backward and central differences. The key of computing discrete derivative values is the finite difference coefficient. The focus of this paper is a new approach method of finite difference formula. And we apply the proposed method to the recursive least squares(RLS) algorithm.

UNIQUENESS OF A MEROMORPHIC FUNCTION WITH DIFFERENCE POLYNOMIAL OF DIFFERENCE OPERATOR SHARING TWO VALUES CM

  • H. R. Jayarama;H. Harish;S. H. Naveenkumar;C. N. Chaithra
    • Honam Mathematical Journal
    • /
    • v.46 no.2
    • /
    • pp.267-278
    • /
    • 2024
  • In this paper, we investigate the uniqueness of a meromorphic function f(z) and its difference polynomial of difference operator with two sharing values counting multiplicities. Our two results improve and generalize the recent results of Barki Mahesh, Dyavanal Renukadevi S and Bhoosnurmath Subhas S [4] and for the case q ≥ 2, this allows for a highly unique generalization. To further demonstrate the validity of our main result, we provide an example.

A Study on the Characteristics of Lower Extremity Weight Bearing in Patients with Low Back Pain (요통환자의 기립시 하지체중 지지특성에 관한 연구)

  • Yoon, Hong-Il;Bae, Soo-Chan
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.5 no.1
    • /
    • pp.59-74
    • /
    • 1999
  • 66 patients with low back pain were evaluated to determine if any differences of weight bearing were existed between the same side leg that feel pain(pain side leg) and that without pain (non-pain side leg) of lower extremities while weight bearing. 66 patients were divided into 3 groups according to pain pattern such as low back pain only(26), radiating pain only(21) and low back pain with radiating pain (19). Control group were 28 normal persons. The weight bearing was rated by Limloader(Model LLD-2000, Ver 1.2) and analyzed by paired and independent t-test, one-way ANOVA, Dunan's analaysis and Pearson's correlation analysis. The results of this study were as follows : 1. In patient group, significant difference of weight bearing rating between pain side leg and non-pain side leg was found. There was borne significantly less weight bearing rating(14.68%) on the pain side leg(P<.001). 2. In normal group, there was no significant difference between left and right leg(P>.05). But there was significant difference(3.21%) in absolute difference of both leg(p<.001). 3. The difference of 1 and 2 was 11.47% : more difference of weight bearing rating between both legs in patient group than that of the control group(p<.001). 4. There were significant differences of weight bearing rating in those 3 groups : low back pain group(10.30%), radiating pain group (17.90%) and low back pain with radiating pain group (17.10%) (p<.001). 5. There was significant correlation between pain intensity and difference of weight bearing rating(p<.05). The severer pain intensity. the more difference of weight bearing rating was found. 6. There was no significant correlation between the age, height and duration of symptom, etc(p>.05).

  • PDF

A Study on the Transition of Clothing Behavior & Clothing Consumption Pattern of College Students - In Choong Nam Province - (대학생의 의생활 및 의복소비 태도의 변화에 관한 연구 - 충남지역을 중심으로 -)

  • Kim, Hee-Sook;Choi, Jong-Myoung
    • Korean Journal of Human Ecology
    • /
    • v.10 no.3
    • /
    • pp.275-290
    • /
    • 2001
  • The purpose of this study was to investigate the transition of clothing behavior and clothing consumption pattern of college students in Choong Nam province. 75 subjects were surveyed in 1995 and 2000. For statistical analysis, $X^2$-test were used by SPSSWIN program. The results of this study were as follows. 1. Number of clothing showed significant difference according to year and the number of coat and formal wear increased in 2000 compared with 1995. 2. Clothing consumption pattern showed significant difference according to year. College students purchased on sale more frequently and preferred more expensive clothes in the year 2000 compared with 1995. 3. Contentment for clothing behavior showed significant difference according to year and the extent of contentment decreased as years go by. 4. Number of clothing showed significant difference according to sex and female students had more clothes than male students, but the difference between male and female decreased as years go by from 1995 to 2000. 5. Clothing consumption pattern showed significant difference according to sex and female students purchased ell sale more frequently than male students, but the difference between male and female decreased as years go by. 6. Contentment for clothing behavior showed significant difference according to sex, but female students described to not adequate the quantity of feminine style wear and the interest in fashion of male students was increased as years go by.

  • PDF

THE PANORAMIC RADIOGRAPHIC STUDY OF THE VERTICAL MANDIBULAR ASYMMETRY OF IN THE TMJ DISORDER PATIENTS (파노라마 X-선사진을 이용한 측두하악관절 장애환자의 수직적 하악비대칭에 관한 연구)

  • Yoon Gui-Hyeon;Choi Soon-Chul
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.23 no.2
    • /
    • pp.315-322
    • /
    • 1993
  • To evaluate of the relationship between the TMJ disorder and the vertical mandibular asymmetry, the author analyzed the differences between condylar heights, ramus heights and mandibular heights of both sides. All measurements were performed with a digital micrometer on the panoramic radiographs of 36 TMJ disorder patients and 30 normal control group. The differences were expressed in millimeters and percentage using the following formula; |(R-L)/(R+L)|×100% The results were as follows : 1. The condylar height difference was greater of in patient group (1.86±1.66㎜) than that of in control group (1.22±0.85㎜)(p<0.05). But there was no significant difference in the condylar height ratio difference between patient group (11.67㎜11.44%) and control group (7.64±621%) (p>0.05). 2. The ramus height difference and ramus height ratio difference of patient group (4.52±3.70㎜, 4.39±3.49%) were greater than those of control group (2.64±2.13㎜, 2.46±2.02%)(p<0.05, p<0.01). 3. The mandibular height difference and mandibular height ratio difference of patient group (4.32±3.52㎜, 3.59±2.81%) were greater than those of control group (2.57±2.46㎜, 2.01±1.95%) (p<0.05). 4. The ratio difference in condylar height to ramus height and condylar height to mandibular height of patient group (5.01±4.13%, 3.36±2.88%) were greater than those of control group (2.33±1.78%, 1.90±1.40%) (p<0.01).

  • PDF

A Study of an Independent Evaluation of Prosody and Segmentals: with Reference to the Difference in the Foreign Accent of Korean, Chinese, and Japanese Learners of English (운율 및 분절음의 독립적 발음 평가 연구: 한국인, 중국인, 일본인 영어 학습자의 액센트 차이를 중심으로)

  • Park, Hansang
    • Phonetics and Speech Sciences
    • /
    • v.4 no.4
    • /
    • pp.37-43
    • /
    • 2012
  • This study investigates an independent evaluation of prosody and segmentals with reference to the difference in the foreign accent of Korean, Chinese, and Japanese learners of English. For this study, a set of stimuli were made of English sentences read by male and female Korean, Chinese, and Japanese learners of English by prosody swapping technique. Two groups of American and Korean subjects evaluated the difference in the prosody and segmentals of the stimuli by pairwise difference rating. The results showed that there was no significant difference in the evaluation scores of prosody and segmentals across accents for either subject group. The results also showed that both subject groups indicated a greater score with segmentals than with prosody. The results of the present study are significant in that they are opposite to the claim of some previous studies that prosodic factors could have a greater influence on the foreign accent and intelligibility than segmentals.

Physical Properties of Wood Treated with the Essential Oil Penetration (정유 침투처리를 한 목재의 물리적 성질)

  • Chong, Song-Ho;Chun, Su-Kyoung;Park, Byung-Su;Jung, Doo-Jin
    • Journal of the Korea Furniture Society
    • /
    • v.16 no.2 s.30
    • /
    • pp.77-83
    • /
    • 2005
  • The specific gravity of wood treated with the essential oil penetration was higher than that of untreated wood. However, in case of oven-dried wood the difference of treated and untreated products decreased, compared with air-dried wood. The shrinkage of treated wood showed no consistent trend and the difference was trivial. In addition, similar trend was shown in each direction. Compression strength parallel to grain of treated wood was somewhat higher than that of untreated wood and the difference was trivial. The difference in static bending strength was slight and showed no consistent trend. The stage of check for Pinus koraiensis and Populus tomentiglandulosa and Alnus hirsuta was 2 stage and 3 stage, respectively. Deformation stage with no relation to the essential oil treatment was 1 stage for Pinus koraiensis, 2 stage Populus tomentiglandulosa and 3 stage for Ainus hirsuta, respectively, and there was no difference in essential oil penetration.

  • PDF

A Study on the Pitch and Formants of Vowels Produced by Monolingual and Bilingual Children (이중언어 환경 아동의 모음 포먼트 특성에 관한 연구)

  • Kwon, Mi-Ji;Ko, Young-Ok;Kim, Hye-Kyung;Lee, Eun-Jeong;Jeong, Ok-Ran
    • Speech Sciences
    • /
    • v.14 no.3
    • /
    • pp.47-57
    • /
    • 2007
  • The aim of this study was to investigate the pitch and formant characteristics of vowels produced by monolingual and bilingual children. We collected sustained phonation of single vowels, /a/, /i/, /u/, from children aged 6 through 10 and compared their acoustic characteristics, fo, F1, F2. Results showed a significant difference between the groups in fo and F1 in the sustained phonation /a/, but not in F2. In the sustained phonation /i/, F2 revealed a significant difference but fo and F1 showed no significant difference. The F2 showed a significant difference in the sustained phonation /u/, but fo and F1 revealed no significant difference between the groups. It is needed to study further on the acoustic characteristics of bilingual children so that we can make a proper language intervention strategy for them.

  • PDF