• 제목/요약/키워드: Negative shift

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신호감지회로를 가진 극소형 위상고정루프 (An Ultra Small Size Phase Locked Loop with a Signal Sensing Circuit)

  • 박경석;최영식
    • 한국정보전자통신기술학회논문지
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    • 제14권6호
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    • pp.479-486
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    • 2021
  • 본 논문에서는 신호감지회로(Signal Sensing Circuit : SSC)를 추가하여 2개의 루프로 구성된 단일 커패시터 루프필터를 가진 극소형 위상고정루프(Phase Locked Loop : PLL)를 제안하였다. 위상고정루프 크기를 극단적으로 줄이기 위하여 가장 많은 면적을 차지하는 수동소자 루프필터를 극소형 단일 커패시터(2pF)로 설계하였다. 신호감지회로가 포함된 내부 부궤환 루프 출력이 외부 부궤환 루프의 단일 커패시터 루프필터 출력에 부궤환 역할을 하여 제안한 극소형 위상고정루프가 안정적으로 동작하도록 설계하였다. 위상고정루프 출력 신호 변화를 감지하는 신호 감지 회로는 루프필터의 커패시턴스 전하량을 조절하여 위상고정루프 출력 주파수의 초과 위상변이를 줄였다. 제안된 구조는 기존 구조에 비해 1/78 정도의 작은 커패시터를 가짐에도 불구하고 지터 크기는 10% 정도 차이가 난다. 본 논문의 위상고정루프는 1.8V 180nm 공정을 사용하였고, Spice를 통해 안정하게 동작하는 시뮬레이션 결과를 보여주었다.

노인간호에 대한 간호원의 태도조사연구 (A Study of the Attitudes of Nurses toward the Geriatric Nursing Care)

  • 최경옥
    • 대한간호학회지
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    • 제6권2호
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    • pp.1-9
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    • 1976
  • Presently, there is increasing demand for geriatric nursing care because of increasing preparation of elderly population due to extended age. Of particular importance in determining the effectiveness of nursing care given to the elderly is the attitude of the nurse toward the elderly patient. Knowledge of the various changes that usually occur with aging will enable the nurse to help an aged Person maximize his potential in illness and in health. The objectives of this study were : 1. To delineate the attitudes of nurses toward the geriatric nursing care. 2. To learn the influencing factors affecting the attitudes of nurses toward the geriatric nursing care. The study population defined and randomly selected is 225 nurses at one general hospital, one private hospital, two national hospitals in Seoul during the period of October l0th -20th, 1975. The questionnaire method was used. Respondents were 140 nurses. X$^2$- test and t- test were employed in analyzing the data. The questionnaire form included 54 statements which concerned the attitudes of nurses to-ward geriatric nursing care. It was divided into five areas : 1) General characteristics of study population. 2) The nurse's concepts of elderly. 3) Care of the geriatric patient. 4) Interpersonal relationship with geriatric patient. 5) Teaching of the geriatric patient. Each of the 54 statements of the questionnaire was considered to be either Positive or Negative. A Positive response was assigned the value of+1 , and a Negative response or no response was assigned the value of O. The results of the study were as follows : 1. The Investigation of attitudes of nurses toward geriatric nursing care. a. Data indicated , respondents have negative attitudes in their. concepts of elderly (74.3%) b. Data indicated respondents have positive attitudes in care of geriatric patient (64.3%). c. Data indicated respondents have positive attitudes in interpersonal relationship with geriatric patient (85% ). 4. Data indicated respondents have positive attitudes in teaching of geriatric patient (89.3%). 2. The results of study regarding the five hypothesis were as follows : a There was significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and level of education of the nurse. b. There was no significant difference between the attitudes of nurses toward the geriatric nursing care and clinical experience, but there was significant difference between care of the geriatric patient and clinical experience. c. There was no significant difference between the attitudes of nurses toward the geriatric nursing care and shift most frequently worked, but there was significant difference between care of the geriatric patient and shift most frequently worked. d. There was no significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and marital status, but there was significant difference in the mean scores between interpersonal relationship, teaching of geriatric patient and marital status. e, There was no significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and experience with elderly, but there was significant difference in the mean scores between care of geriatric patient and experience with elderly.

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선팽창 온도특성에 의한 저밀도 폴리에틸렌의 유리 천이온도에 대한 고찰 (Investigation on glass transition temperature of low density polyethylene by the characteristics of temperature dependent linear expansion)

  • 김봉흡;강도열;김재환
    • 전기의세계
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    • 제30권7호
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    • pp.441-447
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    • 1981
  • As a preceeding work for the study on dielectric characterstics of a kind of low density polyethylene introduced morphological change by mechanical method, glass transition temperature which is regarded as a macroscopic aspect for relaxation of molecular chain segments has been observed by means of temperature dependent dilatometric measurement. The origina specimen clearly shows two knees which correspond to two peaks (.gamma. and .betha. peak) in the intenal friction measurement, suggesting the existence of separated glass transition temperatures at 150.deg.k and 260.deg.k respectively. On the specimen irradiated to 100 Mrad both glass transition temperatures tend to shift towards high temperature sides because of crosslinking by irradiation. furthemore an evidence can be seen that radiation effect, even in amorphous phase, is also slelctive depending on slight morphological differences. The specimen extended to four times in length shows a peculiar nature such as negative linear thermal expansion coefficient increasing with temperature between 220.deg.k and ambient temperature and that this fact is interpreted by considering that c axis of the lattice aligns along the extended direction by drawing, further c axis inherently possesses the characteristics of negative linear thermal expansion coefficient. For the observations that the relatively small positive linear expansion on the specimen extended to ca. two times as well as the part below 220.deg.k of the specimen extended to four times, it is considered for the reason of the facts that the incompletely oriented region indicated as the middle part of Peterlin's model tends to restore partially to orginal arrangement-a kind of phase transition-as increasing with temperature.

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외환위기 이후 한국경제의 서비스화와 구조변화의 특징 - 생산성 분해를 통한 제조업과 서비스업 업종별 분석과 국제비교를 중심으로 - (The Shift to the Service Economy and the Characteristic of the Structural Change since Financial Crisis in Korea -Focused on the Analysis of Manufacturing and Service Industry using Productivity Decomposition Methodology and International Comparison-)

  • 반가운
    • 노동경제논집
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    • 제33권1호
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    • pp.85-107
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    • 2010
  • 외환위기 이후 한국은 비교 대상국 가운데 가장 빠른 고용의 서비스화와 가장 큰 제조업과 서비스업 간의 생산성 격차가 나타났다. 생산성 분해를 통해 확인해 본 결과 이는 외환위기 전에 비해 생산성과 고용의 변동이 반대로 일어나는 부정적 구조변화의 경향이 심화되었기 때문이다. 그리고 제조업의 경우 고용 비중은 줄면서 자체의 생산성 향상 중심으로, 서비스업은 반대로 자체의 생산성 향상은 지지부진한 체 고용의 흡수를 통한 성장을 주로 해왔기 때문이기도 하다. 국제비교에서도 이러한 경향은 뚜렷이 드러난다. 그리고 한국의 서비스업은 제조업에 비해 부정적 구조변화의 경향이 외환위기 후 더 심해졌다.

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사건관련전위의 임상적 적용 (Clinical Applications of Event-related Potentials)

  • 권준수
    • 수면정신생리
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    • 제1권1호
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    • pp.36-46
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    • 1994
  • The event-related potentials are difined as the changes in voltage that occur at paticular time before, during and after something that happens in the physical world or some psychological processes. The possibilities of clinical applications of ERP are considered because the endogenous potentials such as P3 and contingent negative variation(CNV) are determined by the psychological significance of the stimulus. The P3 is a positive wave that occurs when a subject detects an informative task-relevant stimulus. The P3 amplitude and latency are affected by the various factors as subjective probabilites, stimulus meaning and information transmission. It is suggested that P3 wave is associated with the decision making, cognitive or perceptual closure, memory updating and transfer of information to consciousness etc. Although the intracerebral origin of the P3 wave is not known, the P3 may have multiple intracerebral generators. The CNV is a slow potential shift occuring during the foreperiod, between warning and response signals, in a reaction time experiment. It is related to expectancy, preparation etc. The abnormal findings of P3 wave and CNV in various psychiatric disorders are also discussed.

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Hysteresis Behavior in Pentacene Organic Thin-film Transistors

  • So, Myeong-Seob;Suh, Min-Chul;Koo, Jae-Bon;Choi, Byoung-Deog;Choi, Dae-Chul;Lee, Hun-Jung;Mo, Yeon-Gon;Chung, Ho-Kyoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1364-1369
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    • 2005
  • In this paper, we have identified the mechanism of C-V hysteresis behavior often observed in pentacene organic thin-film transistors (OTFTs). The capacitance-voltage (C-V) characteristics were measured for pentacene OTFTs fabricated on glass substrates with MoW as gate/source/drain electrode and TEOS $SiO_2$ as gate insulator. The measurements were made at room temperature and elevated temperatures. From the room temperature measurements, we found that the hysteresis behavior was caused by hole injection into the gate insulator from the pentacene semiconductor for large negative gate voltages, resulting in the negative flat-band voltage shift. However electron injection was observed only at elevated temperatures

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앙각을 가진 타원형 실린더 후류와 평판 경계층의 상호작용에 대한 연구 (Interaction between Turbulent Boundary Layer and Wake behind an Elliptic Cylinder at Incidence)

  • 최재호;이상준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.465-471
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    • 2000
  • The flow characteristics around an elliptic cylinder with axis ratio of AR=2 located near a flat plate were investigated experimentally to study the interaction between the cylinder wake and the turbulent boundary layer. The pressure distributions on the cylinder surface and on the flat plate were measured with varying the angle of attack of the cylinder. In addition, the velocity profiles of wake behind the cylinder were measured using a hot-wire anemometry As the angle of attack increases, the location of peak pressure on the windward and leeward surfaces of the cylinder moves toward the rear and front of the cylinder, respectively. At positive angles of attack, the position of the minimum pressure on the flat plate surface is moved downstream, but it is moved upstream at negative angles of attack. With increasing the angle of attack, the vortex shedding frequency is gradually decreased and the critical angel of attack exists in terms of the gap ratio. By installing the elliptic cylinder at negative angle of attack, the turbulent boundary layer over the flat plate is disturbed more than that at positive incidence. This may be attributed to the shift of separation point on the lower surface of the cylinder according to the direction of the angle of attack.

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앙각을 가진 타원형 실린더 후류와 평판경계층의 상호작용에 대한 연구 (Interaction between Turbulent Boundary Layer and Wake Behind an Elliptic Cylinder at Incidence)

  • 최재호;이상준
    • 대한기계학회논문집B
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    • 제24권7호
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    • pp.976-983
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    • 2000
  • The flow characteristics around an elliptic cylinder with axis ratio of AR=2 located near a flat plate were investigated experimentally to study the interaction between the cylinder wake and the turbulent boundary layer. The pressure distributions on the cylinder surface and on the flat plate were measured with varying the angle of attack of the cylinder. In addition, the velocity profiles of wake behind the cylinder were measured using a hot-wire anemometry As the angle of attack increases, the location of peak pressure on the windward and leeward surfaces of the cylinder moves toward the rear and front of the cylinder, respectively. At positive angles of attack, the position of the minimum pressure on the flat plate surface is moved downstream, but it is moved upstream at negative angles of attack. With increasing the angle of attack, the vortex shedding frequency is gradually decreased and the critical angle of attack exists in terms of the gap ratio. By installing the elliptic cylinder at negative angle of attack, the turbulent boundary layer over the flat plate is disturbed more than that at positive incidence. This may be attributed to the shift of separation point on the lower surface of the cylinder due to the presence of a ground plate nearby.

비정질 하프늄인듐징크옥사이드 산화물 반도체의 공정 파워에 따른 트랜지스터의 전기적 특성 연구 (Study on the Electrical Properties of Amorphous HfInZnO TFTs Depending on Sputtering Power)

  • 유동윤;정유진;김도형;주병권;이상렬
    • 한국전기전자재료학회논문지
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    • 제24권8호
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    • pp.674-677
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    • 2011
  • The dependency of sputtering power on the electrical performances in amorphous HIZO-TFT (hafnium-indium-zinc-oxide thin film transistors) has been investigated. The HIZO channel layers were prepared by using radio frequency (RF) magnetron sputtering method with different sputtering power at room temperature. TOF-SIMS (time of flight secondary ion mass spectrometry) was performed to confirm doping of hafnium atom in IZO film. The field effect mobility (${\mu}FE$) increased and threshold voltage ($V_{th}$) shifted to negative direction with increasing sputtering power. This result can be attributed to the high energy particles knocking-out oxygen atoms. As a result, oxygen vacancies generated in HIZO channel layer with increasing sputtering power resulted in negative shift in Vth and increase in on-current.

Private Brand 제품구매에 미치는 영향 연구 (A Study on the Consumer Factors Affecting Private Brand Proneness)

  • 윤차영;권영상
    • 산업융합연구
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    • 제2권1호
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    • pp.159-186
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    • 2004
  • One of the biggest change in the distributive market recently is that the development of private brand is progress actively since consumers purchasing behavior is tend to shift to resonable and practical planned purchase from brand image or brand name. Once the development of private brands is done successfully, the independent merchandising distinguished from other distribution companies is established, store image through customer satisfaction is strengthen and volume of sales and profit are increased. However, the existing studies in this field have not dealt with this matter systematically. Therefore, the purpose of this study is to propose an integrated framework within which to view private brand proneness. Factors found to influence private brand proneness included perceived cost, with private brand, perceived value for money, store fame, perceived risk, perceived quality variation between national and private brand products. Foe empirical analysis, the data were collected from 211 consumers who purchased the private brands in discount store and department store. With the collected survey data, reliability test, factor analysis for validity test and regression analysis for hypotheses test were conducted. Most hypotheses were accepted but on hypotheses were rejected negative relation of perceived cost and private brand proneness. Research results indicate that private brand proneness is affected by perceived value, perceived fame and there are negative relation between private brand proneness and perceived quality variation.

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