• 제목/요약/키워드: Hybrid LED

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Conceptual Development of Workplace Bullying: Focusing on Hospital Nurses (직장 내 괴롭힘 개념 개발: 병원간호사를 중심으로)

  • Lee, Younju;Lee, Eun Jin
    • Korean Journal of Health Education and Promotion
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    • v.31 no.1
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    • pp.57-70
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    • 2014
  • Objectives: The purpose of this study was to build a conceptual framework of bullying in nursing workplace. Methods: A comprehensive literature review was conducted to identify concepts in relation to bullying in nursing workplace by searching research articles published between 1995 and 2013. In-depth interviews were performed with 14 nurses who experienced bullying at work. The Hybrid Model was applied for concept analysis which led to identify attributes of bullying in nursing workplace. Results: The antecedents of bullying in nursing workplace were offenders, victims, and administrators. They create negative effects on organizational culture and imbalance of power between authority and subordinate workers in the organization. Bullying in nursing workplace that occurred in the forms of inefficient organizational culture, imbalance of power, and the vulnerability of individual or individuals and groups of individuals formed an unstable dynamic. It is expressed as verbal and nonverbal bullying, work-related bullying, and external threats. Consequently, workplace bullying causes physical and psychological withdrawal and increased negative energy in an organization. Conclusions: Workplace bullying consisted of verbal abuse, alienation, unreasonable work processes, restriction on work-related rights, and external threat.

A Study on the Electrical Characteristics of Battery Capacitor Applied to Photovoltaic Power System (태양광 시스템에 적용한 배터리 커패시터의 전기적 특성에 관한 연구)

  • Mang, Ju-Cheul;Yoon, Jung-Rag
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.12
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    • pp.1740-1744
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    • 2017
  • This paper describes the preparation and characteristics of a battery capacitor and module for solar power system. A cylindrical 30,000F battery capacitor ($60{\times}138mm$) was assembled by using the $LTO(Li_4Ti_5O_{12})$ electrode as an anode and $NMC(LiNiMnCoO_2)-LCO(LiCoO_2)$ as a cathode. The battery capacitor has reduced energy density and power density under high CC(constant current) and CP(constant power) conditions. Battery capacitor module (16V, 11Ah) was fabricated using an asymmetric hybrid capacitor with a capacitance of 30,000F. In order to determine the characteristics of the battery capacitor Module for solar power system, battery capacitor cells were connected in series with active balancing circuit. As a result of measuring the 100w LED lamp, it was discharged at the voltage of 15V~10V, and the compensation time at discharge was measured to be about 4979s. Experimental results show that it can be applied to applications related to solar power system by applying battery capacitor module.

Exergetic design and analysis of a nuclear SMR reactor tetrageneration (combined water, heat, power, and chemicals) with designed PCM energy storage and a CO2 gas turbine inner cycle

  • Norouzi, Nima;Fani, Maryam;Talebi, Saeed
    • Nuclear Engineering and Technology
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    • v.53 no.2
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    • pp.677-687
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    • 2021
  • The tendency to renewables is one of the consequences of changing attitudes towards energy issues. As a result, solar energy, which is the leader among renewable energies based on availability and potential, plays a crucial role in full filing global needs. Significant problems with the solar thermal power plants (STPP) are the operation time, which is limited by daylight and is approximately half of the power plants with fossil fuels, and the capital cost. Exergy analysis survey of STPP hybrid with PCM storage carried out using Engineering Equation Solver (EES) program with genetic algorithm (GA) for three different scenarios, based on eight decision variables, which led us to decrease final product cost (electricity) in optimized scenario up to 30% compare to base case scenario from 28.99 $/kWh to 20.27 $/kWh for the case study. Also, in the optimal third scenario of this plant, the inner carbon dioxide gas cycle produces 1200 kW power with a thermal efficiency of 59% and also 1000 m3/h water with an exergy efficiency of 23.4% and 79.70 kg/h with an overall exergy efficiency of 34% is produced in the tetrageneration plant.

Experimental study on shear damage and lateral stiffness of transfer column in SRC-RC hybrid structure

  • Wu, Kai;Zhai, Jiangpeng;Xue, Jianyang;Xu, Fangyuan;Zhao, Hongtie
    • Computers and Concrete
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    • v.23 no.5
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    • pp.335-349
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    • 2019
  • A low-cycle loading experiment of 16 transfer column specimens was conducted to study the influence of parameters, likes the extension length of shape steel, the ratio of shape steel, the axial compression ratio and the volumetric ratio of stirrups, on the shear distribution between steel and concrete, the concrete damage state and the degradation of lateral stiffness. Shear force of shape steel reacted at the core area of concrete section and led to tension effect which accelerated the damage of concrete. At the same time, the damage of concrete diminished its shear capacity and resulted in the shear enlargement of shape steel. The interplay between concrete damage and shear force of shape steel ultimately made for the failures of transfer columns. With the increase of extension length, the lateral stiffness first increases and then decreases, but the stiffness degradation gets faster; With the increase of steel ratio, the lateral stiffness remains the same, but the degradation gets faster; With the increase of the axial compression ratio, the lateral stiffness increases, and the degradation is more significant. Using more stirrups can effectively restrain the development of cracks and increase the lateral stiffness at the yielding point. Also, a formula for calculating the yielding lateral stiffness is obtained by a regression analysis of the test data.

A Research on TF-IDF-based Patent Recommendation Algorithm using Technology Transfer Data (기술이전 데이터를 활용한 TF-IDF기반 특허추천 알고리즘 연구)

  • Junki Kim;Joonsoo Bae;Yeongheon Song;Byungho Jeong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.3
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    • pp.78-88
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    • 2023
  • The increasing number of technology transfers from public research institutes in Korea has led to a growing demand for patent recommendation platforms for SMEs. This is because selecting the right technology for commercialization is a critical factor in business success. This study developed a patent recommendation system that uses technology transfer data from the past 10 years to recommend patents that are suitable for SMEs. The system was developed in three stages. First, an item-based collaborative filtering system was developed to recommend patents based on the similarities between the patents that SMEs have previously transferred. Next, a content-based recommendation system based on TF-IDF was developed to analyze patent names and recommend patents with high similarity. Finally, a hybrid system was developed that combines the strengths of both recommendation systems. The experimental results showed that the hybrid system was able to recommend patents that were both similar and relevant to the SMEs' interests. This suggests that the system can be a valuable tool for SMEs that are looking to acquire new technologies.

Carrier Transport of Quantum Dot LED with Low-Work Function PEIE Polymer

  • Lee, Kyu Seung;Son, Dong Ick;Son, Suyeon;Shin, Dong Heon;Bae, Sukang;Choi, Won Kook
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.432.2-432.2
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    • 2014
  • Recently, colloidal core/shell type quantum dots lighting-emitting diodes (QDLEDs) have been extensively studied and developed for the future of optoelectronic applications. In the work, we fabricate an inverted CdSe/ZnS quantum dot (QD) based light-emitting diodes (QDLED)[1]. In order to reduce work function of indium tin oxide (ITO) electrode for inverted structure, a very thin (<10 nm) polyethylenimine ethoxylated (PEIE) is used as surface modifier[2] instead of conventional metal oxide electron injection layer. The PEIE layer substantially reduces the work function of ITO electrodes which is estimated to be 3.08 eV by ultraviolet photoemission spectroscopy (UPS). From transmission electron microscopy (TEM) study, CdSe/ZnS QDs are uniformly distributed and formed by a monolayer on PEIE layer. In this inverted QD LED, two kinds of hybrid organic materials, [poly (9,9-di-n-octyl-fluorene-alt-benzothiadiazolo)(F8BT) + poly(N,N'-bis (4-butylphenyl)-N,N'-bis(phenyl)benzidine (poly-TPD)] and [4,4'-N,N'-dicarbazole-biphenyl (CBP) + poly-TPD], were adopted as hole transport layer having high highest occupied molecular orbital (HOMO) level for improving hole transport ability. At a low-operating voltage of 8 V, the device emits orange and red spectral radiation with high brightness up to 2450 and 1420 cd/m2, and luminance efficacy of 1.4 cd/A and 0.89 cd/A, respectively, at 7 V applied bias. Also, the carrier transport mechanisms for the QD LEDs are described by using several models to fit the experimental I-V data.

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Chlorosis of Ogura-CMS Brassica rapa is due to down-regulation of genes for chloroplast proteins

  • Jeong, Seok-Won;Yi, Hankuil;Song, Hayoung;Lee, Soo-Seong;Park, Youn-Il;Hur, Yoonkang
    • Journal of Plant Biotechnology
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    • v.44 no.2
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    • pp.115-124
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    • 2017
  • Cytoplasmic male sterility (CMS) is a maternally inherited trait leading to loss of the ability to produce fertile pollen and is extensively used in hybrid crop breeding. Ogura-CMS was originally generated by insertion of orf138 upstream of atp8 in the radish mitochondrial genome and transferred to Brassica crops for hybrid breeding. Gene expression changes by dysfunctional mitochondria in Ogura-CMS result in pollen developmental defects, but little is known about gene expression patterns in vegetative tissue. To examine the interaction between nuclear and organellar regulation of gene expression, microarray and subsequent gene expression experiments were conducted with leaves of $F_1$ hybrid Chinese cabbage derived from self-incompatible (SI) or Ogura-CMS parents (Brassica rapa ssp. pekinensis). Out of 24,000 genes deposited on a KBGP24K microarray, 66 genes were up-regulated and 26 genes were down-regulated by over 2.5 fold in the CMS leaves. Up-regulated genes included stress-response genes and mitochondrial protein genes, while genes for ascorbic acid biosynthesis and thylakoid proteins were down-regulated. Most of the major component genes for light reactions of photosynthesis were highly expressed in leaves of both SI and CMS plants, but most of the corresponding proteins were found to be greatly reduced in leaves of CMS plants, indicating posttranscriptional regulation. Reduction in thylakoid proteins and chlorophylls led to reduction in photosynthetic efficiency and chlorosis of Ogura-CMS at low temperatures. This research provides a foundation for studying chloroplast function regulated by mitochondrial signal and for using organelle genome introgression in molecular breeding.

Studies on the Improvement of Developmental Capadty of the Nucleocytoplasmic Hybrid by (계대핵치환에 의한 무미 양서류 종간핵치환개체의 발생수행능력 증진에 관한 연구)

  • 이자경;정해문
    • The Korean Journal of Zoology
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    • v.32 no.3
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    • pp.258-263
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    • 1989
  • Nuclear Transplantation between Rana pipiens and Rana dybowskii When diploid blastula nuclei of Rana pipiens are traraplanted into enucleated eggs of Rana dybowskii the resulting nucleocytoplasmic hybrids are lethal-those development were arrested around the stage of the dorsal lip formation For the improvement of developmental capacity, serial nuclear transplantation was carried out. Even though serial transplantation of 15 generations showed normal development in each generation until gastrula stage, there was no sign of fundamental improvement in development afterward. This results implied that up to gastrulation normal DNA replication and cell division can take place in foreign cytoplasm. Since chromosomal aberrations both in shape and number were usually observed, the nuclei must have been modifted while resided in the foreign cytoplasm. Those nuclei didn't participate in normal development and led the embryos to early death. Tissue graft experiment indicated that the abnormal behavior of this lethal nucleocytoplasmic hybrid is an inherent property which is not corrected by the contact with its own tissue.

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Physicochemical Effect on Permeate Flux in a Hybrid Ozone-Ceramic Ultrafiltration Membrane Treating Natural Organic Matter (자연유기물을 처리하는 혼합 오존-세라믹 한외여과 시스템에서 물리화학적 특성이 투과플럭스에 미치는 영향)

  • Kim, Jeong-Hwan
    • Membrane Journal
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    • v.18 no.4
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    • pp.354-361
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    • 2008
  • Effects of operational conditions and solution chemistry on permeate flux in a hybrid ozone-ceramic ultra-filtration (UF) membrane system treating natural organic matter (NOM) were investigated. Results showed that the extent of permeate flux decline was higher at higher cross-flow velocity and ozone dosage, but it was higher at lower transmembrane pressure (TMP). The mechanism of fouling mitigation was found to be more dependent upon reaction between ozone and natural organic matter at/near catalytic membrane surface than scouring effect due to ozone gas bubbles. Addition of calcium into model NOM solution at high pH led to significant decline in permeate flux while the calcium effect on permeate flux decline was less pronounced at lower pH. After permeate flux decline during the early stage of filtration, the flux started recovering and approached fully to the initial value of it due to degradation of NOM by catalytic ozonation at ceramic membrane surface in the hybrid ozone-ceramic membrane system.

Oscillating Boundary Layer Flow and Low Frequency Instability in Hybrid Rocket Combustion (하이브리드 로켓 연소에서의 경계층 진동 변화와 저주파수 연소불안정)

  • Kim, Jina;Lee, Changjin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.10
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    • pp.720-727
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    • 2019
  • Resonating thermal lags of solid fuel with heat transfer oscillations generated by boundary layer oscillation is the primary mechanism of the occurrence of the LFI (Low Frequency Combustion Instability) in hybrid rocket combustion. This study was experimentally attempted to confirm that how the boundary layer was perturbed and led to the LFI. Special attention was also made on oxidizer swirl injection to investigate the contribution to combustion stabilization. Also the overall behavior of fluctuating boundary layer flow and the occurrence of the LFI was monitored as swirl intensity increased. Fluctuating boundary layer was successfully monitored by the captured image and POD (Proper Orthogonal Decomposition) analysis. In the results, oscillating boundary layer became stabilized as the swirl intensity increases. And the coupling strength between high frequency p', q' diminished and periodical amplification of RI (Rayleigh Index) with similar frequency band of thermal lag was also decreased. Thus, results confirmed that oscillating axial boundary layer triggered by periodic coupling of high frequency p', q' is the primary mechanism to excite thermal resonance with thermal lag characteristics of solid fuel.