• Title/Summary/Keyword: High-Power-Factor

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제조공정에 따른 n형 Bi2Te2.85Se0.15합금의 열전성능 평가 (Effects of Various Fabrication Routes on Thermoelectric Properties of n-type Bi2Te2.85Se0.15 Alloys)

  • ;신동원;이명원;이상현;홍순직
    • 열처리공학회지
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    • 제31권3호
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    • pp.135-142
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    • 2018
  • In this study, we have fabricated n-type $Bi_2Te_{2.85}Se_{0.15}$ compounds by different processing routes such as crushing, milling and mixing respectively. Subsequently, the obtained powders were consolidated by spark plasma sintering (SPS). The phase crystallinity of bulk samples were identified using X-ray diffraction technique. Powder morphology and fracture surface of bulk samples were observed using the scanning electron microscopy (SEM). The Seebeck coefficient and electrical conductivity values were significantly increased for the milling sample than crushing and mixing samples. As a result, the maximum power factor was obtained $2.4mW/mK^2$, which is thrice than that of crushing process. The maximum figure of merit (ZT) of 0.77 was achieved at 400 K for the milling sample. Furthermore, relatively high hardness and density values were noticed for the different processed samples.

기업 내부노동시장 변화와 인적자원개발 투자 유인 (Changes of Internal Labor Market in Firms and Incentives for Investment in Human Resource Developments)

  • 배진한
    • 노동경제논집
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    • 제41권1호
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    • pp.83-124
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    • 2018
  • 최근까지 우리나라 기업들 내부노동시장에서 임금연공성의 약화, 경력직 채용의 증가, 그리고 교육 훈련의 감소 등 상당히 유의한 변화들이 일어나고 있다는 사실이 통계자료로 확인되고 있다. 이번 연구에서 한국직업능력개발원 "인적자본기업패널" 자료로 기업 내부의 근로자들에 대한 교육 훈련 투자 축소 주요 원인으로 내부노동시장의 약화를 의미하는 정규직 경력직 신규채용비율의 상승 변수의 설명력이 통계적으로 매우 유의하고 강력하다는 점을 발견하고 있다. 전직의 임금손실 가능성도 상당 정도 축소되어온 것으로 나타났다. 내부노동시장의 약화 또는 이완, 그리고 이에 따른 기업 내 교육 훈련의 감소에 대한 대안은 결국 기업외부에 청년층과 중소기업을 위한 현실성 있는 고품질의 인재육성의 사회적 장치들을 구축해나가는 방향이어야 할 것이다.

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Organic photovoltaic cells using low sheet resistance of ITO for large-area applications

  • 김도근;강재욱;김종국
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2009년도 추계학술발표대회
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    • pp.5.1-5.1
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    • 2009
  • Organic photovoltaic (OPV)cells have attracted considerable attention due to their potential for flexible, lightweight, and low-cost application of solar energy conversion. Since a 1% power conversion efficiency (PCE) OPV based on a single donor-acceptor heterojunction was reported by Tang, the PCE has steadily improved around 5%. It is well known that a high parallel (shunt)resistance and a low series resistance are required simultaneously to achieve ideal photovoltaic devices. The device should be free of leakage current through the device to maximize the parallel resistance. The series resistance is attributed to the ohmic loss in the whole device, which includes the bulk resistance and the contact resistance. The bulk resistance originated from the bulk resistance of the organic layer and the electrodes; the contact resistance comes from the interface between the electrodes and the active layer. Furthermore, it has been reported that the bulk resistance of the indium tin oxide (ITO) of the devices dominates the series resistance of OPVs for a large area more than $0.01\;cm^2$. Therefore, in practical application, the large area of ITO may significantly reduce the device performance. In this work, we investigated the effect of sheet resistance ($R_{sh}$) of deposited ITO on the performance of OPVs. It was found that the device performance of polythiophene-fullerene (P3HT:PCBM) bulk heterojunction OPVs was critically dependent on Rsh of the ITO electrode. With decreasing $R_{sh}$ of the ITO from 39 to $8.5\;{\Omega}/{\square}$, the fill factor (FF) of OPVs was dramatically improved from 0.407 to 0.580, resulting in improvement of PCE from $1.63{\pm}0.2$ to $2.5{\pm}0.1%$ underan AM1.5 simulated solar intensity of $100\;mW/cm^2$.

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어선원의 직업만족과 이직의도에 영향을 미치는 제요인에 관한 연구 (A Study on the Determinants of Fishermen's Work Satisfaction and Turnover Intention)

  • 황순철;최정윤
    • 수산경영론집
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    • 제27권1호
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    • pp.15-45
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    • 1996
  • The sustained economic growth cannot be expected without the balanced development in all the realms of industries. Korea has recorded the continuous high growth rate of economy, but it is now facing some difficulties in keeping the normal economic growth, because industrial workers do not like to work in some fields, the typical one of which is the fishery works. This thesis aims at studying the determinants of fishermen's job satisfaction(FJS) and the determinants of affecting the fishermen's trunover intention(FTI) to obtain and maintain the man power for fishing boats. This study assumes that the determinants which affact FJS are fishermen's work values, job characteristics, the attitude of accepting their fishery work, and that the determinants which affect FTI are FJS and their perceptions of labor market. This study concerns two kinds of Job satisfaction : one is an intrinsic satisfaction which comes directly from the work itself, and the other is an extrinsic satisfaction comes from the compensation for the work, but in this study “Pollnac's work satisfaction factor” is added as an additional determinant of FJS. There is a difference in job satisfactions between the individuals who have different work values. Some feel more satisfacttion than the others, which can be explained by the internal work values which assume the work is only a means for another objective of life. This study applies Hackman and 014ham's studies to the job characteristics that a worker's job satisfaction is positively related to the core job characteristis of the job. In addition, this study transformed their studies into variables. A job enrichment to reduce the simplicity of a work and make it more valueable can increase a job satisfaction, but an existing organization has limitation in redesigning the job for its enrichment. A reasonable answer about this matter can be obtained from the workers' subjective perceptins to highly regard the objective job characteristics. Worker's previews of fishery work also affect their job satisfaction because they are already informed of the details and charcteristics of the job that they have to carry out. A Job dissatisfaction causes their intention to leave jobs owing to general perceptions prevailing in labor markets.

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알루미나 기판상에 구현된 0.6mAh급 전고상 박막전지 (0.6 mAh All-Solid-State Thin Fim Battery Fabricated on Alumina Substrate)

  • 박호영;남상철;임영창;최규길;이기창;박기백;조성백
    • 전기화학회지
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    • 제8권4호
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    • pp.181-185
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    • 2005
  • 알루미나 기판을 사용하여 백금 박막 전류 집전체상에 $2.9{\mu}m$ 두께 및 $4cm^2$의 전극면적을 갖는 $LiCoO_2$ 박막을 R.F. 마그네트론 스퍼터링법에 의해 증착하였으며, 아르곤 공정 압력 및 인가된 R.F. 전력량에 따른 Li/Co 몰 비 의존성에 대해 고찰하였다. 비정질계 고체전해질인 Lipon 및 Li 음극이 순차적으로 증착된 박막전지를 제조하여 정전류충, 방전 시험하였으며, 고율방전 특성 및 충, 방전 횟수에 따른 전지 용량 변화를 측정하였다. 교류임피던스를 통해 전지내부의 저항성분을 측정하였으며, 이에 대한 등가회로를 구성하여 시뮬레이션한 결과와 비교하였다.

Complimentary Bifilar Archimedean Spiral Resonator(CBASR)를 이용한 저위상 잡음 전압 제어 발진기 (Low Phase Noise VCO Using Complimentary Bifilar Archimedean Spiral Resonator(CBASR))

  • 이훈성;윤원상;이경주;한상민;표성민;김영식
    • 한국전자파학회논문지
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    • 제21권6호
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    • pp.627-634
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    • 2010
  • 본 논문에서는 complimentary bifilar archimedean spiral resonator(CBASR)를 이용하여 저위상 잡음 특성을 갖는 새로운 구조의 전압 제어 발진기를 제안하였다. CBASR은 작은 면적, 저지대역에서 날카로운 스커트 특성과 통과대역에서 낮은 삽입 손실, 큰 결합 계수 값을 나타내며, 이로 인해 높은 Q값을 구현할 수 있는 장점이 있다. 따라서, 본 논문에서는 CBASR을 공진 회로로 사용하여 전압 제어 발진기의 위상 잡음을 개선시켰다. 제안된 전압 제어 발진기의 주파수 조절 범위는 제어 전압 0~5 V에서 2.396~2.502 GHz이며, 출력은 7.5 dBm, 그리고 위상 잡음 특성은 100 kHz offset에서 -119.16~-120.2 dBc/Hz이다.

SD 기법을 활용한 주거단지의 시지각적 평가 (SD Methodological Evaluation of the Visual Cognition to the Urban Landscape)

  • 황지욱;채병선;권대규;홍철운
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1918-1920
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    • 2005
  • The color and structure of urban constructions is a factor of urban landscape and shows their characteristics. Hence the modern buildings with their materials and external appearance makes up the urban image. But still yet, it was not easy to evaluate the value of visual landscape of buildings with objective measuring method. Most of all, it depends on the subjective estimation of a few talented or high educated experts with a sense of beauty. In relation to this kind of problems, it was tried here in this study to analyse the human response of brain wave pattern (EEG) with use of SD method, while the tested persons watched the urban landscape constructed in a visual reality. The tested persons were 10 adult males and females with no color blindness and intact cognitive function. Light source with color filter was used for color environment in chamber room. The signal of EEG is analysed digitally and grouped into the $\alpha$ and $\beta$ waves. The result showed that relative power of $\alpha$ wave ratio increased in natural landscape scenary clearly. From these results it was possible to evaluate the human response, which was affected by urban color and structure stimulation and it might be useful as an indicator of visual cognition amenity toward the design of urban construction environment.

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제주도민의 119화를 위한 소방의 발전방안 (A Study on Development way of Fire fighting 119 angers of Jeju Islander)

  • 고재문;김태민
    • 한국응급구조학회지
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    • 제7권1호
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    • pp.147-178
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    • 2003
  • In terms of reinforcing the functions and services of rescue 119 and emergency corps, we must review the following considerations : Building up security system along with operational expansion, building up a system for emergency medical treatment, buliding up a comprehensive information management system for rescue and emergency, constructing a provincial safety museum and so forth. For the ways to better the works of rescue 119, we can review the following considerations : Improving the education for fire fighting trainging corps under Jeju Provicial Fire and disaster management department, providing rescue members with more opportunity for clinical practices, enhancing the morale of rescue members, installing a comprehensive briefing room for emergency rescue members, building up medical networks along with reasonable policies for information service, operating the consulting system for rescue 119 and so on. Provide little more superior quality high fire fighting service to jeju islander, and need long-term and elaborate research to correspond in rising fire fighting man-power demand newly and investment. Construction of well-matched disaster administration system is assignment that must hurry in international free city. That jejudo receives time factor about that is received for another thing area's number of persons or equipment when regional special quality large scale or disaster happens is that of course the support receives limitation immediately. Jeju fire fighting services is one story reform, specialization taking into account particular situation of jeju area to grow as sightseeing and center of culture intending international free city, should be upgraded. So, it may do big contribution naturally in jeju international free city phase that coincide jeju islander's social welfare promotion and safety desire.

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Blueberry, blackberry, and blackcurrant differentially affect plasma lipids and pro-inflammatory markers in diet-induced obesity mice

  • Kim, Bohkyung;Lee, Sang Gil;Park, Young-Ki;Ku, Chai Siah;Pham, Tho X.;Wegner, Casey J.;Yang, Yue;Koo, Sung I.;Chun, Ock K.;Lee, Ji-Young
    • Nutrition Research and Practice
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    • 제10권5호
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    • pp.494-500
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    • 2016
  • BACKGROUND/OBJECTIVES: Evidence indicates that berry anthocyanins are anti-atherogenic, antioxidant, and anti-inflammatory. However, berries differ vastly in their anthocyanin composition and thus potentially in their biological and metabolic effects. The present study compared hypolipidemic, antioxidant, and anti-inflammatory properties of blueberry (BB), blackberry (BK), and blackcurrant (BC) in a diet-induced obesity (DIO) mouse model. MATERIALS/METHODS: Male C57BL/6J mice were fed a high fat (HF; 35% fat, w/w) control diet or a HF diet supplemented with freeze-dried 5% BB, 6.3% BK or 5.7% BC for 12 weeks (10 mice/group) to achieve the same total anthocyanin content in each diet. Plasma lipids, antioxidant status and pro-inflammatory cytokines were measured. The expression of genes involved in antioxidant defense, inflammation, and lipid metabolism was determined in the liver, epididymal adipose tissue, proximal intestine, and skeletal muscle. Histological analysis was performed to identify crown-like structure (CLS) in epididymal fat pads to determine macrophage infiltration. RESULTS: No differences were noted between the control and any berry-fed groups in plasma levels of liver enzymes, insulin, glucose, ferric reducing antioxidant power, superoxide dismutase, and tumor necrosis factor ${\alpha}$. However, BK significantly lowered plasma triglyceride compared with the HF control and other berries, whereas BC significantly reduced F4/80 mRNA and the number of CLS in the epididymal fat pad, indicative of less macrophage infiltration. CONCLUSIONS: The present study provides evidence that BB, BK and BC with varying anthocyanin composition differentially affect plasma lipids and adipose macrophage infiltration in DIO mice, but with no differences in their antioxidant capacity and anti-inflammatory potential.

자동차의 블랙박스 와이어링 화재 위험성에 관한 연구 (A Study on the Fire Risk of Black Box Wiring in Motor Vehicle)

  • 강신동;김주희;최준표;김재호
    • 한국안전학회지
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    • 제32권6호
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    • pp.22-28
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    • 2017
  • According to the National Fire Data System (NFDS), more than 5,000 vehicle fires have occurred every year for the last 10 years. Vehicle fires are primarily caused by mechanical (breaking system and engine), electrical (wiring and battery), and chemical (oil and fuel gas leakage) problems. The electrical factor has increased with the installation of driver convenience equipment. For example, today, the black box is widely used to provide video data recording of motor vehicle accidents. The black box consists of a front camera, rear camera, and wires. The black box wires are directly connected to the junction box or fuse box from the start battery that operates to provide normal on power supplying for engine stop. It is extremely dangerous when the wires short circuit due to insulation aging, mechanical and electrical stress, etc. In this study, the black box wiring fire risk have been analyzed and investigated when the steady state and abnormal operations, and under the following conditions: wiring arrangements with a high temperature condition, insulation aging, poor contact, and short circuits. The results showed that black box wiring short circuits had a higher fire risk than the other fire hazard elements. To prevent fire hazards caused by black box wiring, the black boxes must be installed by qualified service personnel. Do not modify the wiring, remove the fuse and secure the wiring using cable ties or insulation tape.