• 제목/요약/키워드: AC energy

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사물 인터넷 기반의 1인 가구를 위한 스마트 콘센트 시스템 (Smart Outlet System for Single-person Household based on IoT (Internet of Things))

  • 김희숙;박병주;조영주
    • 디지털콘텐츠학회 논문지
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    • 제18권5호
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    • pp.895-904
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    • 2017
  • 본 논문에서는 1인 가구를 대상으로 전기 안전, 전기 에너지 소비 관리 그리고 비상시 네트워크를 연결하여 예약된 연락처에 메시지를 전송하는 사물인터넷 기반의 스마트 콘센트 시스템 구축 방식을 제안한다. 제안된 스마트 콘센트 시스템은 서버와 모듈, 어플리케이션, WiFi AP 수신기 사이에 패킷 데이터와 프로토콜을 파싱하여 구현된다. 통신을 위해 구축된 WiFi AP는 콘센트 뿐 만 아니라 가스 차단, 도어락 등에 연결하여 사용하는 것이 가능하다. 또한 제안된 방식은 AC 전류센서(SCT-013)를 통해 받아온 해당 콘센트의 전력량을 실시간으로 수신하여 원격 모니터링 기능을 제공할 수 있다. 스마트 콘센트 시스템은 대기전력 차단 기능과 더불어 전력 사용 자동 분석을 통해 비상시 전력 자동 차단 기능까지 할 수 있을 것으로 기대한다.

저학년 간호대학생의 우울 영향 요인 (Factors Affecting Depression in Junior Nursing Students)

  • 이에리쟈
    • 디지털융복합연구
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    • 제17권12호
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    • pp.413-425
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    • 2019
  • 본 연구는 저학년 간호대학생의 우울 영향 요인을 탐색하기 위한 서술적 조사연구이다. 본 연구를 위해 S와 G지역의 종합대학 저학년 간호대학생 144명에게 신체증상, 수면의 질, 스트레스, 대학생활 적응, 우울로 구성된 자가보고식 설문지로 자료를 수집하였다. 저학년 간호대학생의 우울은 평균 18.89점이며, 58.3%가 임상치료가 필요한 우울증상을 경험하고 있었다. 우울 영향 요인으로 대학생활 적응(β=-.503, p=.000), 신체증상(β=.263, p=.000)순으로 나타났고, 우울의 설명력은 58.9%로 나타났다. 이에 저학년 간호대학생의 우울을 조절하기 위해서 입학초기부터 기초학습 능력을 진단하고, 학습능력향상을 위한 수준별 맞춤형 프로그램 제공을 통해 학문적 적응을 돕는 지도관리 방안이 마련되어야 할 것이다. 또한 다빈도로 경험하는 피로감/기운없음과 같은 신체증상을 완화하기 위한 다양한 중재프로그램의 개발 및 적용이 필요하다.

여러 가지 탄소 전구체와 TNB를 이용하여 탄소-$TiO_2$ 복합체를 제조 및 그들의 광촉매 특성 (Preparation of Carbon-$TiO_2$ Composites by Using Different Carbon Sources with Titanium n-Butoxide and Their Photocatalytic Activity)

  • 진명량;장봉군;장간;맹칙달;오원춘
    • Elastomers and Composites
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    • 제45권1호
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    • pp.25-31
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    • 2010
  • 우리는 탄소 전구체로 활성탄 (AC), 활성탄 섬유 (ACF)와 탄소나노튜브 (MWCNT)와 티타늄 전구체로써 TNB를 사용하여 탄소-$TiO_2$ 복합체를 제조하였으며, 이들의 특성을 SEM, TEM, BET, XRD와 EDX를 이용하여 분석하였다. 그리고 이들의 광촉매 활성은 UV 램프 조사에서 일정한 농도의 MB 용액을 이용하여 측정하였다. UV 조사한 후에 MB의 농도는 UV-vis 분광광도기를 이용하여 측정하였다.

Si이 첨가된 $Al_{0.33}Ga_{0.67}As$에서의 Electroreflectance에 관한 연구 (A Study on Electroreflectance in Si-Doped $Al_{0.33}Ga_{0.67}As$)

  • 김근형;김동렬;김종수;김인수;배인호;한병국
    • E2M - 전기 전자와 첨단 소재
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    • 제10권7호
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    • pp.692-699
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    • 1997
  • The silicon doped $Al_{0.33}$G $a_{0.67}$As were grown by molecular beam epitaxy. The electroreflectance(ER) spectra of Schottky barrier Au/n-Al/suu x/G $a_{1-x}$ As have been measured at various modulation voltage( $V_{ac}$ ) and dc bias voltage( $V_{bias}$). From the observed Franz-Keldysh oscillations(FKO) peak, the band gap energy of the $Al_{x}$G $a_{1-x}$ As is 1.91 eV which corresponds to an Al composition of 33%. The internal electric field( $E_{i}$)of this sample is 2.96$\times$10$^{5}$ V/cm. As the modulation voltage( $V_{ac}$ ) is changed, the line shape of ER signal does not change but its amplitude varies linearly. The amplitude as a function of modulation voltage has saturated at 0.8 V. The internal electric field has decreased from 6.47$\times$10$^{5}$ V/cm to 2.00$\times$10$^{5}$ V/cm as the dc bias voltage( $V_{bias}$) increases from -3.5 V to +0.8 V. The values of built-in voltage( $V_{bi}$ ) and carrier concentration(N) determined from the plot of $V_{bias}$ from the plot of $V_{bias}$ versus $E_{i}$$^{2}$ are 0.855 V and 3.83$\times$10$^{17}$ c $m^{-3}$ , respectively.ively.y.y.y.

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전북지역 위암환자의 위절제술 전.후 영양상태 평가 (A Study on Nutritional Status after Gastrectomy of Gastric Cancer Patients in Jeonbuk Province)

  • 정미진;김찬영;김숙배
    • 대한지역사회영양학회지
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    • 제11권6호
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    • pp.785-792
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    • 2006
  • The purpose of this study was to investigate the nutritional status before and after gastrectomy of gastric cancer patients in Jeonbuk Province. The subjects were 136 patients with gastrectomy of gastric cancer. We assessed the nutritional status before and after an operation by general characteristics (age, clinicopathological stage, type of operation, method of reconstruction), anthropometric characteristics (height, weight, skeletal muscle mass, body fat mass, body mass index (BMI), percent body fat, arm muscle circumference AMC, arm circumference AC) and biochemical characteristics (hemoglobin Hb, hematocrit Hct, mein corpuscular volume MCV, mean corpuscular hemoglobin MCH, total lymphocyte count TLC, serum albumin, serum transferrin). Mean ages were 60.0 yrs in males and 58.8 yrs in females. Age, clinicopathological stage, types of operation and reconstruction methods were not significantly different between males and females. Weight, skeletal muscle mass, body fat mass, BMI, percent body fat, AMC and AC significantly deteriorated by gastrectomy. There were severe weight losses in males and females after gastrectomy. Hemoglobin, Hct, MCV, MCH, TLC, albumin and transferrin significantly deteriorated by gastrectomy. After gastrectomy, subjects who were assessed as malnounrished in Hb and Hct were increased in male and those who were assessed as malnounrished in Hb were increased in females. These results suggest that a nutrition intervention, specially for energy, protein and iron, is necessary to improve the nutritional status of gastric cancer patients with gastrectomy.

Fabrication and Physicochemical Properties of Carbon/Titania/Bentonite Monolith for Architecture

  • Oh, Won-Chun;Choi, Jong-Geun;Song, Da-Ye;Kim, Ha-Rry;Chen, Ming-Liang;Zhang, Feng-Jun;Park, Tong-So
    • 한국재료학회지
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    • 제20권3호
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    • pp.167-173
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    • 2010
  • In this study, we used activated carbon (AC) and titanium oxysulfate as a titanium precursor to prepare carbon/titania composites. We then mixed it with bentonite in different ratios to make a carbon/titania/bentonite monolith for use in architecture bricks by using Phenolic rosin (PR) as a bonding agent. The physicochemical properties of the prepared composites were analyzed by BET surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), self-cleaning effect and bactericidal tests. The BET surface areas increased as the ratio of carbon/titania composites increased. The SEM microscopy showed that the $TiO_2$ and bentonite were coated on the surface of the AC. The XRD patterns showed a mixture structure of anatase and rutile of $TiO_2$ with a clear $SiO_2$ structure. The EDX spectra of the carbon/titania/bentonite monolith confirmed the presence of various elements, namely C, O, Ti and Si, as well as other, impure elements. Moreover, to determine the self-cleaning effect of the carbon/titania/bentonite monolith, we used methylene blue (MB, $C_{16}H_{18}N_3S{\cdot}Cl{\cdot}3H_2O$) in an aqueous solution under the irradiation of visible light. Accordingly, all of the samples had excellent degradation of the MB solution. Furthermore, it was observed that the composites with sunlight irradiation had a greater effect on E. coli than any other experimental conditions.

나노영가철/활성탄 입자전극과 과황산을 이용한 3차원 전기화학적 산화공정 (Three-dimensional Electrochemical Oxidation process using Nanosized Zero-valent Iron/Activated carbon as Particle electrode and Persulfate)

  • 민동준;김철용;안준영;조수빈;황인성
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제23권6호
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    • pp.104-113
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    • 2018
  • A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.

상용전원 주파수(60Hz)를 사용한 중전력 무선전력전송 연구 (Research on Medium-power Wireless Power Transmission using Commercial Power Frequency (60Hz))

  • 이기범
    • 한국전자통신학회논문지
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    • 제19권3호
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    • pp.497-506
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    • 2024
  • 본 논문에서는 상용전원 주파수(60 Hz)를 사용하여 중전력 무선전력전송을 구현한 것이다. 일반적인 자기유도 무선전력전송 장치는 수십 kHz 이상 사용하기 때문에 상용전원 주파수(60 Hz)를 그대로 사용할 수 없고, 교류/직류 변환기를 사용하여 60 Hz 전원주파수를 DC로 만들고, 고주파 파워앰프를 사용하여 DC를 수십 KHz로 만들어서 사용한다. 자기유도 무선전력전송에서 교류/직류 변환기와 고주파 파워앰프를 제거하고, 송전 공진탱크, 송전코일, 수전 공진탱크, 수전코일 만으로 구성한 상용전원 주파수를 사용하는 극저주파 무선전력전송 시스템을 구현하고, 무선전력전송 실험으로 검증하였다.

온도보상회로를 부착한 개방형 전류측정기의 특성 (Characteristics of Open-Loop Current Sensor with Temperature Compensation Circuit)

  • 구명환;박주경;차귀수;김동희;최종식
    • 한국산학기술학회논문지
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    • 제16권12호
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    • pp.8306-8313
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    • 2015
  • 개방형 전류측정기는 DC 모터 콘트롤러, AC 가변 콘트롤러, UPS(Uninterruptible Power System)에 주로 사용되며 최근 신재생 에너지의 성장과 전력망의 스마트 그리드화로 인하여 활용성이 점차 확대되고 있다. 이러한 신재생 에너지의 성장으로 관련 핵심기술의 보유여부가 중요해지고 있으며 대부분 수입에 의존하고 있는 개방형 전류측정기의 국산화 및 관련 기술의 확보를 필요로 한다. 본 논문에서는 일반 산업용 개방형 전류측정기의 제작과정과 특성을 측정한 결과를 기술하였다. 개방형 전류측정기를 구성하는 C형 철심의 공극자장분포 해석 및 형상 설계, 홀센서의 선정 및 특성시험, 정전류 전원공급회로와 신호처리회로의 회로설계 과정을 기술하며 DIP(Dual In-line Package) type과 SMD (Surface Mount Device) type의 100A급 개방형 전류측정기를 제작하고 특성을 측정했다. 제작된 전류측정기로 0~100A 범위에서 통전 실험을 실시한 했고 직류전류와 60Hz의 교류전류에서 특성을 측정한 결과 정밀도 오차 2% 이내, 선형도 오차 2% 이내의 성능을 만족하였다. 또한 부 특성 온도계수를 갖는 NTC(Negative Temperature Coefficient) 서미스터를 이용한 온도보상회로를 사용하여 $-35{\sim}100^{\circ}C$의 범위에서 온도보상 효과를 확인하였다.

간호대학생의 자아상태와 대응양상과의 관계 연구 (Study on the Ego states and Coping Style of Nursing Students)

  • 원정숙
    • 여성건강간호학회지
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    • 제8권4호
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    • pp.608-618
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    • 2002
  • The purpose of this study is to analyze the type of ego states and stress coping style on female college students who are in the course of nursing study. This study is performed in the view of Transactional Analysis and designed to scrutinize descriptive correlations between the type of ego states and stress coping style. The subject is consists of 144 freshmen and sophomore, 138 junior and senior students group, who are students of K nursing college located in Seoul. The sampling investigation period is on Sept. 14, 2002 to Oct. 26, 2002. The measuring instrument used for Transactional Analysis ego state is 50 items Ego-gram research paper devised by Dusay(1997). For studying coping style, Folkman & Lazarus's measurement(1984) was adopted, which is translated and modified by Han, and Oh,(1990). Statistic average and standard deviation were generated by using SPSS PC+, t-test and Pearson correlation. The results were as follows: 1) In the type of ego states on both groups(lower group : freshmen, sophomore upper group : junior, senior) indicated the arithmetic apex NP(maximum value), then the point A was high and the data made a down slope to point AC. In the comparison to type of ego states between two groups, only at point CP, the data value of upper year students represented higher than that of lower year ones by C(t=2.28, p=.023). In the psychological energy level of ego states, both groups indicated average level.2) Stress coping style of whole students were highly and affirmatively dedicated to research. Consecutive consequences follow like this(high to low) : the central point of problem, search for social support, hopeful aspect and indifference. Especially hopeful aspect(t=.67, p=.05), relaxation of tension(t=-2.16, p=.03) made significant difference each other in the view of arithmetic calculation 3) While verifying coping style in terms of ego states level between lower and upper students group, In type CP, high level ego states group indicated significant difference on stress coping style area than low leveled group and made such sequences as the central point of problem, hopeful aspect, search for social support, positive interest and relaxation of tension. In type NP, sequences such as the central point of problem, search for social support, positive interest and relaxation of tension were emerged with little differences. In type A, the central point of problem, positive interest and relaxation of tension. In type FC, hopeful aspect, search for social support, positive interest and relaxation of tension. In type AC, hopeful aspect and indifference were derived significantly different(p<.05). 4) In the aspect of relation between ego states and coping style, type CP presented the central point of problem and relaxation of tension, type NP presented positive interest, search for social support and the central point of problem, type A showed the central point of problem, positive interest and relaxation of tension, type FC showed relaxation of tension, positive interest, search for social support, indifference and the central point of problem, type AC showed hopeful aspect, indifference and the central point of problem. All the sequence shown above had high-to-low procedure and represented static relations each other(p<.05).

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