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Poly(p-phenylenevinylene)s Derivatives Containing a New Electron-Withdrawing CF3F4Phenyl Group for LEDs

  • Jin, Young-Eup;Kang, Jeung-Hee;Song, Su-Hee;Park, Sung-Heum;Moon, Ji-Hyun;Woo, Han-Young;Lee, Kwang-Hee;Suh, Hong-Suk
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.139-147
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    • 2008
  • New PPV derivatives which contain electron-withdrawing CF3F4phenyl group, poly[2-(2-ethylhexyloxy)-5-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-1,4-phenylenevinylene] (CF3F4P-PPV), and poly[2-(4-(2-etylhexyloxy)-phenyl)-5-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-1,4-phenylenevinylene] (P-CF3F4P-PPV), have been synthesized by GILCH polymerization. As the result of the introduction of the electron-withdrawing CF3F4phenyl group to the phenyl backbone, the LUMO and HOMO energy levels of CF3F4P-PPV (3.14, 5.50 eV) and P-CF3F4P-PPV (3.07, 5.60 eV) were reduced. The PL emission spectra in solid thin film are more red-shifted over 50 nm and increased fwhm (full width at half maximum) than solution conditions by raising aggregation among polymer backbone due to electron withdrawing effect of 2,3,5,6-tetrafluoro-4-trifluoromethylphenyl group. The EL emission maxima of CF3F4P-PPV and P-CF3F4P-PPV appear at around 530-543 nm. The current density-voltage-luminescence (J-V-L) characteristics of ITO/PEDOT/polymer/Al devices of CF3F4P-PPV and P-CF3F4P-PPV show that turn-on voltages are around 12.5 and 7.0 V, and the maximum brightness are about 82 and 598 cd/m2, respectively. The maximum EL efficiency of P-CF3F4P-PPV (0.51 cd/A) was higher than that of CF3F4P-PPV (0.025 cd/A).

Nurse Practitioner Roles and Curriculums in the United States (미국 전문간호사(NP)의 역할과 교육과정에 관한 고찰)

  • Lee Sun-Ock
    • The Journal of Korean Academic Society of Nursing Education
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    • v.5 no.1
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    • pp.97-105
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    • 1999
  • Based on literature, status and role of the NP in America was reviewed. The process of developing NP program in America suggests us many things. In America, nurse practitioners have sustained a mutually beneficial status with their patients for over thirty years. Excel fence in academic education and clinical training will enable nurse practitioners to continue to provide quality health care. The magnitude changes in the health care system of the United States, the challange of providing real access of health care continues. Lack of access to adequate primary care was the driving force in the initial 1965 Federal Involvement in developing the NP role. In 1993 President Bill Clinton's health care reform initiative provided policy support for NPs as primary care providers. The Institute of Medicine explicitly recognized NPs as an integral part of the primary care team. In addition, several national reports recognized NPs as affordable, accessible, high-quality care providers. The recent passage of direct Medicare reimbursement for NPs reflected public policy statements coincided with and likely contributed to a growth spurt in the NP workforce. From 1965 to 1977 NP programs offered traditional primary care clinical tracks(adult, family, woman's health, and pediatrics) for relatively small clusters of students in a variety of institutional settings. From 1978 to 1990 these educational programs were incorporated into graduate schools of nursing. By 1990 the majority of NPs received educational preparation in master's-level nursing programs. A new emphases was placed on postmaster's NP programs designed for master's prepared clinical nurse specialists and nurse managers. he the health care system shifted hospital nursing resources toward community-based care, these master's -level nurses sought additional NP preparation. NP educational programs are defined as the educational structure in which one or more NP clinical tracks are offered. NP clinical tracks, in turn, offer curriculum and supervised clinical experiences that match standards in specific practice areas such as family(FNP), adult(AUP), geriatrics(GNP), pediatrics(PNP), women's health (WHNP), neonatal (NNP), and acute care(ACNP). There were indications that NP practice was expanding into new clinical areas as evidenced by new types of tracks, particularly in acute care and psychiatry. The increase in acute care NP students likely reflects the increased demand from hospitals and other acute care settings. In Korea, change of nurse's role into nurse practitioner's role may have many difficulties. The need of health consumer, policy support of government, approval of medical care team are all essential component. Every nursing personnel make effort to planning the new health care delivery system.

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A Study on the Role and Transition of the Tapgu in Stone Pagoda (석탑 탑구(塔區)의 역할 및 변천에 관한 연구)

  • Chung, Hae-Doo;Jang, Suk-Ha
    • Journal of architectural history
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    • v.19 no.1
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    • pp.91-104
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    • 2010
  • Korea's stone buildings are varied in their types such as stone pagodas, stone lanterns, stone bridges, stoneworks, etc. These account for more than 30% over the entire cultural properties, but research achievements are lacking compared to wooden buildings. Accordingly, this study aims to identify the shape, role and transition of Tapgu, which had been used to set up boundary at a stone pagoda, one of the stone buildings. The 20th stone pagodas, which have relative accuracy in its forming year, have been studied around national treasure or treasure between 7th century and 9th century. There are a lot of different opinions about the role and meaning of Tapgu, and at this writer's option, Tapgu is defined as follows: First, each structure plays a different role. A structure to pass the load in the upper part to the ground can be seen as a stair or a pedestal, but a structure to form double foundations can be considered as Tapgu. Second, Tapgu can be used to divide areas with stones or stepping stones. As a result, the shape, role and transition of Tapgu is as follows: Firstly, when it comes to its shape, Tapgu includes flagstone type, belt type, double foundation type, compound type. Flagstone type had been used to set up boundary at stone pagodas by using foundation stone, belt type by keeping apart from stone pagodas, and double foundation stone by installing dual foundation stones. Secondly, Tapgu is considered to set up boundary in the case of flagstone and plate stone, and acts like a structure which can prevent surrounding area of stone pagoda from coming up while being stuck around stone pagodas. Belt type was installed only for the purpose of forming boundary. At the bottom, double foundation stone had been used to pass the load in the upper part to the ground in the same way as the foundation stone in the upper part, and the boundaries were set varying the size. Thirdly, when it comes to the transition of Tapgu, flagstone type of boundary stone had been installed in the 7th century, and belt type of boundary stone had been mainly installed in the 8th century. And double foundation stone had been installed in the 9th century. Comprehensively, flagstone type and belt type had been made around the 7th and 8th century when Tapgu was regarded important and stone pagoda started to be built. At the turn to the 9th century, the role of Tapgu had been increasingly losing in the construction of stone pagoda, and foundation stone started to appear.

Optimization of Dispatching Strategies for Stacking Cranes Including Remarshaling Jobs (재정돈을 포함한 장치장 크레인의 작업 할당 전략 최적화)

  • Kim, Taekwang;Yang, Youngjee;Bae, Aekyoung;Ryu, Kwang Ryul
    • Journal of Navigation and Port Research
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    • v.38 no.2
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    • pp.155-162
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    • 2014
  • In container terminals, stacking yard is the place where import and export containers are temporarily stored before being loaded onto or after being discharged from a ship. Since all the containers go through the stacking yard in their logistic flow, the productivity of the terminal critically depends on efficient operation of stacking yard, which again depends on how well the stacking locations of the incoming containers are determined. However, a good location for stacking an incoming container later can turn out to be a bad one when that container is to be fetched out of the stacking yard, especially if some rehandling is required. This means that good locations for the containers are changing over time. Therefore, in most container terminals, the so-called remarshaling is done to move the containers from bad location to good locations. Although there are many previous works on remarshaling, they all assume that the remarshaling can be done separately from the main jobs when the cranes are idle for rather a long period of time. However, in reality, cranes are hardly available for a period long enough for remarshaling. This paper proposes a crane dispatching strategy that allows remarshaling jobs to be mixed together with the main jobs whenever an opportunity is detected. Experimental results by simulation reveals that the proposed method effectively contributes to the improvement of terminal productivity.

Ultraviolet LEDs using n-ZnO:Ga/i-ZnO/p-GaN:Mg heterojunction (n-ZnO/i-ZnO/p-GaN:Mg 이종접합을 이용한 UV 발광 다이오드)

  • Han, W.S.;Kim, Y.Y.;Kong, B.H.;Cho, H.K.;Lee, J.H.;Kim, H.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.50-50
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    • 2008
  • ZnO has been extensively studied for optoelectronic applications such as blue and ultraviolet (UV) light emitters and detectors, because it has a wide band gap (3.37 eV) anda large exciton binding energy of ~60 meV over GaN (~26 meV). However, the fabrication of the light emitting devices using ZnO homojunctions is suffered from the lack of reproducibility of the p-type ZnO with high hall concentration and mobility. Thus, the ZnO-based p-n heterojunction light emitting diode (LED) using p-Si and p-GaN would be expected to exhibit stable device performance compared to the homojunction LED. The n-ZnO/p-GaN heterostructure is a good candidate for ZnO-based heterojunction LEDs because of their similar physical properties and the reproducibleavailability of p-type GaN. Especially, the reduced lattice mismatch (~1.8 %) and similar crystal structure result in the advantage of acquiring high performance LED devices with low defect density. However, the electroluminescence (EL) of the device using n-ZnO/p-GaN heterojunctions shows the blue and greenish emissions, which are attributed to the emission from the p-GaN and deep-level defects. In this work, the n-ZnO:Ga/p-GaN:Mg heterojunction light emitting diodes (LEDs) were fabricated at different growth temperatures and carrier concentrations in the n-type region. The effects of the growth temperature and carrier concentration on the electrical and emission properties were investigated. The I-V and the EL results showed that the device performance of the heterostructure LEDs, such as turn-on voltage and true ultraviolet emission, developed through the insertion of a thin intrinsic layer between n-ZnO:Ga and p-GaN:Mg. This observation was attributed to a lowering of the energy barriers for the supply of electrons and holes into intrinsic ZnO, and recombination in the intrinsic ZnO with the absence of deep level emission.

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Clinical evaluation of Oriental Medicine treatment of Stable Compression Fracture by D.I.T.I. (D.I.T.I로 본 Stable Compression Fracture의 한의학적 치료효과)

  • Lee, Geon-Mok;Moon, Sung-Jae;Lee, Byung-Chul
    • Journal of Oriental Medical Thermology
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    • v.1 no.1
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    • pp.28-37
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    • 2002
  • Stable Compression Fractures(SCF hereafter) are most often caused by trauma such as traffic accidents. These SCFs usually occur in the thoracic and lumbar regions of the spinal cord. Human life spans have increased as a result of medical advances, which in turn has led to an increase in the elderly population. SCFs are divided into the categories of stable and unstable. The categories are determined through X-rays and P/Ex tests. The D.I.T.I. is then used to diagnose the severity and prognosis of the fracture injuries, and it allows an objective evaluation of the symptoms. This author researched 40 patients who were treated at Wonkwang University Oriental Medical Center from October 1995 to December 1996. The patients were diagnosed by X-ray as having SCFs and treated primarily with acupuncture. Both the changes in D.I.T.I. and patients' self-diagnoses of their conditions before and after treatment yielded the meaningful results which have been presented here. 1. 75% of those who suffer from Stable Compression Fractures are 60 years of older. Of those, the ratio of male to female is 1 to 4. This is due in part to the fact that many elderly women seek Oriental medicine treatment for conditions associated with advanced age. 2. 53.3% of these injuries occurred between T11 and L2. 3. 65% of patients were hospitalized for 10 to 29 days, and then able to be treated on an outpatiens basis. 4. The D.I.T.I. results showed 50% below $0.2^{\circ}C$, 30% between 0.3 and $0.5^{\circ}C$, 10% between 0.5 and $0.7^{\circ}C$, 10% between 0.7 and $0.9^{\circ}C$, and 0% over $0.9^{\circ}C$. 5. The results of treatment using Modified Evaluation System in Thoracolumbar Vertebral Fractures Method showed that 55% of patients achieved excellent recovery and 40% achived good recovery. After comparing the D.I.T.I. results before and after treatment, we found 50% of patients showed excellent recovery $({\Delta}T{\leq}0.2)$ and 40% showed good recovery$(0.2<{\Delta}T{\leq}0.5)$.

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A study on the transitional process of clothes in modern Korean women (한국현대여성복식제도(韓國現代女性服飾制度)의 변천과정연구(變遷過程硏究))

  • Nam, Yun-Suk
    • Journal of the Korean Society of Costume
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    • v.14
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    • pp.99-117
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    • 1990
  • The purpose of this study was to investigate the change of clothes in modem Korean women in terms of a socioeconomical background, the introduction to western clothes, and the improvement of clothes between the opening period of ports in the early 1900's and 1960's. In addition, the study investigated how western clothes became popular in a Korean society along with the traditional' Korean clothes, Hanbok. The radical social change since the opening of ports motivated the change in the way of Korean women's thinking, and consequenty the improvement of Hanbok which developed into the clothes-improvement-movement. It was not until 1905 that the improvement of clothes was hotly debated particularly in the matter of abolishing Jangeui and the extreme length of Jeogori and Chima. The Tongchima-Jeogori style which lengthened Jeogori and shortened Chima was widely accepted as everyday wear until the western clothes substituted them after the Independence from Japanese Conquest. As the length of Chima shortened, there occurred a change in Boson and Jipsin as well. There appeared shoes and Gomoosin in place of Jipsin, socks in stead of Boson and were popularized until after the Liberation in 1945. The popularity of Gomoosin diminished markedly with the diversification of shoes styles, due to the improvement of the standard of living with economic development in the 1960's. The traditional Hanbok was gradually differentiated according to the social status, for instance student, teachers, ordinary women, girls and Kisaeng. Especially since the white clothes caused much trouble in washing and sewing, there came into being the movement of wearing colorful clothes. The Movement of abolishing white clothes and promoting of wearing colorful clothes was enforced during the period of Japaness conquest from the 1920's to the Liberation, which consequently stimulated an interest for colors of clothes. The period under the war between 1937 and 1945 was especially noted for the extreme regulation over the clothes. The Japanese government forced each group of women, e.g., girl students, a young women's association, school teachers, and ordinary women and girls, to wear their own uniforms. Also, It recommended the use of Tongchima in stead of long skirts, and buttons in place of Coreum so as to conserve textile encouraging the use of other substitutes to save resources. The western clothes, a model of clothe's improvement was deemed as a symbol of modernization and enjoyed general popularity. The supply of relief clothes after the Korean war accelerated the expansion of western clothes even further and the trend of westernization along with economic progress in the 1960's resulted in wearing of western clothes as everyday dress. The expansion of western clothes as casual wear rapidly diminished wearing of Hanbok which in turn took the position of ceremonial dress worn in special cases only. Hence the Korean women's clothes were dualized into traditional Hanbok and western clothes and the western clothes that stems on its convenience was settled as everyday wear where as the Hanbok appeared as ceremonial dress stressing on ornamental features. As mentioned aboved, we are able to discovered an orientation in the course of transitional process of modern Korean women's clothes admist diversified changes, which is a consistent pursuit of convenience and practicality based upon progmatism. The trend such as this carne into a finale' as women's dress became dualistic in forms of Hanbok and western clothes, and the change since then is supposed to proceed in two forms of dress featuring its own style.

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The Effect Analysis of NEV(Neighborhood Electric Vehicle) Driving - with VISSIM Simulation - (저속형 전기자동차 주행시 시스템 영향분석 - VISSIM 시뮬레이션을 이용하여 -)

  • Yoon, Tae-Kwan;Baik, Nam-Cheol;Jung, In-Taek
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.2
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    • pp.77-82
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    • 2012
  • To share the lanes with conventional vehicles, traffic operation strategy is needed for NEV (Neighborhood Electric Vehicle). Because NEV cannot accelerate sharply as fast as common car include gasoline, diesel and LPG cars, they may interrupt traffic conditions and make traffic delay. After green lights turn on, all vehicles run through the street including NEV, but NEV have a maximum speed which is 50km/h. It can be an obstacle for following vehicles and will make traffic delay of the intersection. In this reason, we need to organize traffic systems like queue jump with priority traffic signal. To analyze the necessity for NEV road operations, we simulate three scenarios in congested and non-congested conditions. First is that we examine the condition which is mixed NEV and cars on the road, the second one is that we set up lane only NEV can accepted in simulation and last one is making queue jump lane and providing priority signal for NEV. In conclusion, we can conclude that making lane only for NEV is effective to improve travel speed when rate of NEVs is over 20%. Also queue jump lane and priority signal cannot make good effect to intersection delay and average speed.

The Relationship between Stress and Suicidal Ideation for Old Adult Living Alone -Multiple Mediator Effects of Self-criticism and Feelings of Loneliness, and the Moderating Effects of Social Support- (독거노인의 스트레스와 자살생각 간의 관계 -자기비판, 고독감의 다중매개효과와 사회적 지지의 조절효과-)

  • Park, Bonggil;Song, Inseok
    • Korean Journal of Social Welfare
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    • v.66 no.2
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    • pp.51-74
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    • 2014
  • This study aimed to examine a multiple mediator model in which stresses affect self-criticism. The self-criticism, in turn seemed to affect the feelings of loneliness, and this had an effect on over 65 years living alone. Furthermore, whether social support had any moderating effects in the pathway from the loneliness to suicidal ideation on our pass model were also investigated. Data were collected from 572 samples of persons 65 years of age and older living alone in Seoul. For the analyses of the mediating effects and moderating effects, structural equation modeling was used. The results were as follows. First, the pass model was identified to fit the observed data. This mean that self-criticism increased as stress rises, the increased levels of self-criticism increased loneliness, and the increased levels of loneliness increased the levels of suicidal ideation. Second, social support moderated the relation between loneliness and suicidal ideation on our model. These results suggested that interventions which deal with loneliness and suicidal ideation were needed, in order to reduce suicidal ideation caused by the stress. These imply, additionally, that when social workers try to reduce the suicidal ideation, they should consider the levels of social support at work as influences.

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Quay Crane Scheduling Considering the Workload of Yard Blocks in an Automated Container Terminal (장치장 블록의 작업부하를 고려한 안벽크레인 작업계획)

  • Lee, Seung-Hwan;Choe, Ri;Park, Tae-Jin;Kim, Kap-Hwan;Ryu, Kwang-Ryel
    • Journal of Intelligence and Information Systems
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    • v.14 no.4
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    • pp.103-116
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    • 2008
  • This paper proposes quay crane (QC) scheduling algorithms that determine the working sequence of QCs over ship bays in a container vessel in automated container terminals. We propose two scheduling algorithms that examine the distribution of export containers in the stacking yard and determine the sequence of ship bays to balance the workload distribution among the yard blocks. One of the algorithms is a simple heuristic algorithm which dynamically selects the next ship bay based on the entropy of workloads among yard blocks whenever a QC finishes loading containers at a ship bay and the other uses genetic algorithm to search the optimal sequence of ship bays. To evaluate the fitness of each chromosome in the genetic algorithm, we have devised a method that is able to calculate an approximation of loading time of container vessels considering the workloads among yard blocks. Simulation experiments have been carried out to compare the efficiency of the proposed algorithms. The results show that our QC scheduling algorithms are efficient in reducing the turn-around time of container vessels.

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