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A Study on Properites of PV Solar cell AZO thin films post-annealing by RTP technique (RTP 공정을 통한 태양전지용 AZO 박막의 후열처리 특성연구)

  • Yang, Hyeon-Hun;Kim, Han-Wool;Han, Chang-Jun;So, Soon-Youl;Park, Gye-Choon;Lee, Jin;Chung, Hea-Deok;Lee, Suk-Ho;Back, Su-Ung;Na, Kil-Ju;Jeong, Woon-Jo
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.127.1-127.1
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    • 2011
  • In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient($2.0{\times}10-3$Torr)at temperatures of 200, 300, 400 and $500^{\circ}C$ for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was $500^{\circ}C$ the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

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Interfacial Electrical Studios on Adhesion of Hematite Particles to Polyester Fabric and their Removal from the Fabric(Part 2) (Polyester 직물에의 Hematite 입자의 부착과 제거에 관한 계면 전기적고찰 (제2보))

  • 강인숙;김성련
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.5
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    • pp.765-773
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    • 1995
  • Effect of interfacial electrical conditions such as, the f potential of PET fiber and u-Fe203 particles, the stability parameter and potential energy of interaction on adhesion of a-Fe903 particles to PET fabric and their removal from the fabric, were investigated as functions of pH, electrolyte and ionic strength. The stability parameter, potential energy of interaction between a-Fe2O3 particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model The adhesion of a-Fe2O3 particles to PET fabric and their removal from PET fabric were carried out by using water bath shaker and Terg-O-Tometer under various solution conditions. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 particles from the PET fabric were biphasic and were maximum and minimum at pH 7~8, respectively. With high pH and polyanion electrolytes in solution, the adhesion of a-Fe2O3 particles to the PET fabric was low but effects of electrolytes on the removal of a-Fe2O3 particles from the PET fabric was small. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 Particles from the PET fabric were biphasic, and were lowest and highest at the ionic strength 1$\times$10-3, respectively. The adhesion of a-Fe2O3 particles to PET fabric was well related with the interfacial electrical conditions; it was negatively correlated with the f potentials of a-Fe2O3 Particles of its absolute value, the stability parameter and the maximum of total potential energy, while, the adhesion was not related with the t potentials of PET fiber itself. Therefore, the primary factor determining the adhesion of a-Fe203 particles to PET fabric may be the stability of dispersed particles caused by the electrical repulsion of particles. The removal of a-Fe203 particles from PET fabric was not related to such interfacial electrical conditions as the t potentials of PET fiber, the stability parameter and the maximum of total potential energy but removal was related to t potential of a-Fe203 particles.

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A study on Cheong-ju urban land use planning on the subject of Zoning (청주권 토지이용 체계에 관한 연구 (지역지구제 중심으로))

  • 권상준
    • Journal of the Korean Professional Engineers Association
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    • v.16 no.1
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    • pp.20-34
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    • 1983
  • A phenomenon in the unplanned urban sprawl of Cheong-ju city has to be rest-rained from disposing and to develop, though progress in urbanization inevitably decreases rural area. So, this thesis aims at reviewing, revising and guiding toward the more effective land use planning practice and zoning mechanism and system of Cheong-ju city. I proposed that land use planning should be had several factors and thereupon that Korean zoning mechanism and system including Building Code should be amended because of inducing human activities in buildings and facilities not to demarcate and plan every one of them. First, the factors of urban planning are a rather diversified approach to it than a unified, supplementation of the applicable difference in time between preparing and appling it, a solid controlling system, a micro and macro planning theory and giving serious consideration for the inertia from the existing land use. Second, the applicable amendments for our zoning mechanism including Eluding Code are as follows; a need of reorganization for Zoning Ordinance appricated to different regulation concerning a scale and peculiarity of a oily, a decision of the different earmarked confinement in area to different zone ana from Zoning Ordinance in City Planning Law, a demarcated facilities and the more detailed land use concerning human activies than the exsisting and entrusting decision on the ways and processes of it to every rural city planning committee, a settlement of zone ana area considering for block-unit and Planned Unit Development(P. U. D.), and a need of security jurisprudence in order to solve the zoning regulation rather in City Planning Law than in Building Code that our zoning regulation and controlling system are depended on. According to these applicable amendments to Cheong-ju city, I proposed the conceptions of Cheong-ju city land use planning are as follows; a reinforcement with one cored pattern of urban land use, a selection of gradual urban sprawl by way of city development and renewal, a strengthening accessibility to the core of the city with Plurizing the system of arterial roads, a choice of priority to conservation at the core of tile city and security of open spaces and parking area at the area of the city, a harmonization between development and conservation at the inner ring area that is situated between the core and periphery reserved area in order to develop in the future, a buffered open space situated at the congested area with heterogenous functions, and a completion of urban open space system. The proposal made here so far is for the hope of the better structure of Cheong-ju city that should be granted to the peculiarity developed with educational, cultural, conservative and self-sufficient city functions.

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Level of physical activity and influencing factors of the first and second year nursing students (간호대학 저학년생의 신체활동정도와 영향요인)

  • Lee, Mi-Suk;Gu, Mee-Ock
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.53-67
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    • 2017
  • This study was conducted to investigate the level of physical activity and identify factors influencing physical activity of first and second year nursing students. The participants were 234 female first and second year nursing students at one nursing college located in U city. Data were collected from September 5 to 15 in 2016 and analyzed by descriptive statistics, t-test, ANOVA, $Scheff{\breve{e}}$ test, Pearson's correlation coefficient, and stepwise multiple regression using SPSS/WIN 22.0. The average level of physical activity measured by the Korean version of the Godin-Shephard Liesure-Time Exercise Questionnaire was 9.09(range 0-80). According to the physical activity group classified by leisure score index, there were 25 students(10.7%) in the active group, 31 students (13.2%) in the moderately active group, and 178 students(76.1%) in the insufficiently active group. Factors influencing the level of physical activity were intention to participate in physical activity and habit to physical activity, which together explained 21.2% of the total variance in physical activity. Therefore, this study suggests that it is necessary to develop and apply a physical activity program enhancing intention and habit to physical activity for first and second year nursing students.

Legislation Cases, Management Policies and Countermeasures on Scientific Data -Focusing Australia, the United States and China- (과학데이터에 관한 입법례와 관리정책 그리고 대응방안 -호주, 미국, 중국을 중심으로-)

  • Yoon, Chong-Min;Kim, Kyubin
    • Journal of Korea Technology Innovation Society
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    • v.16 no.1
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    • pp.63-100
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    • 2013
  • Research data means data in the form of facts, observations, images, computer program results, recordings, measurements or experiences on which an argument, theory, test or hypothesis, or another research output is based. Data may be numerical, descriptive, visual or tactile. Scientific research is changing because of the paradigm shift. It is all being affected by the data deluge, and a data-intensive science paradigm is emerging. Hence, paradigm shift in scientific research led to increase of value and importance of scientific data. Essential to the creative research and development for scientific data can be reused efficiently is the sharing and utilization of establishing management system. Establishing of management system for sharing and utilization of scientific data should be done at the national level, but compared with Europe, Australia, the United States, China, the management system of Korea doesn't have not linkage or efficiency or internal stability. Australia, the United States, China continues to expand a Mid- and Long-Term policy making, legislation, its investment in infrastructure, so as to promote the utilization of data, such as collection, management and maintenance of scientific data through the relevant agencies at the national level. This study consider legislation cases and management policies of the above countries to the end to that establish management system for the efficient and fair sharing and utilization of scientific data and the legal system, and that provide scientific data legislation and policies related to the future of our country.

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Influences of Viscous Losses and End Effects on Liquid Metal Flow in Electromagnetic Pumps

  • Kim, Hee-Reyoung;Seo, Joon-Ho;Hong, Sang-Hee;Suwon Cho;Nam, Ho-Yun;Man Cho
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.233-240
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    • 1996
  • Analyses of the viscous and end effects on electromagnetic (EM) pumps of annular linear induction type for the sodium coolant circulation in Liquid Metal Fast Breeder Reactors have been carried out based on the MHD laminar flow analysis and the electromagnetic field theory. A one-dimensional MHD analysis for the liquid metal flowing through an annular channel has been performed on the basis of a simplified model of equivalent current sheets instead of three-phase currents in the discrete primary windings. The calculations show that the developed pressure difference resulted from electromagnetic and viscous forces in the liquid metal is expressed in terms of the slip, and that the viscous loss effects are negligible compared with electromagnetic driving forces except in the low-slip region where the pumps operate with very high flow velocities comparable with the synchronous velocity of the electromagnetic fields, which is not applicable to the practical EM pumps. A two-dimensional electromagnetic field analysis based on an equivalent current sheet model has found the vector potentials in closed form by means of the Fourier transform method. The resultant magnetic fields and driving forces exerted on the liquid metal reveal that the end effects due to finiteness of the pump length are formidable. In addition, a two-dimensional numerical analysis for vector potentials has been performed by the SOR iterative method on a realistic EM pump model with discretely-distributed currents in the primary windings. The numerical computations for the distributions of magnetic fields and developed pressure differences along the pump axial length also show considerable end effects at both inlet and outlet ends, especially at high flow velocities. Calculations of each magnetic force contribution indicate that the end effects are originated from the magnetic force caused by the induced current ( u x B ) generated by the liquid metal movement across the magnetic field rather than the one (E) produced by externally applied magnetic fields by three-phase winding currents. It is concluded that since the influences of the end effects in addition to viscous losses are extensive particularly in high-velocity operations of the EM pumps, it is necessary to find ways to suppress them, such as proper selection of the pump parameters and compensation of the end effects.

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Characteristic Radial Pulse Properties of Elderly Females according to Sasang Constitution-based Health Level (고령자 여성의 체질건강수준에 따른 맥파 특성 연구)

  • Kim, Jae Uk;Bae, Jang Han;Ku, Bon Cho;Jeon, Young Ju;Kim, Keun Ho;Kim, Jong Yeol;Kim, Young Min
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.970-975
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    • 2012
  • In Sasang constitutional medicine, doctors diagnose and treat patients according to their Sasang consitutition (SC) type. In this work, by a clinical test with a radial pulse tonometer, we investigated radial pulse properties which were significant in distinguishing unhealthy subjects from healthy subjects for each SC type. We measured radial pulse properties on left and right Gwan locations with a pulse tonometer for 299 elderly female subjects of age of 50 years old or above. We used a newly developed SCAT system to determine subjects' SC types. Subjects' health levels of either healthy or unhealthy were determined independently by two Korean medical doctors. To investigate the statistical differences, we used either of Student's t-test or Mann-Whitney U test depending on the normality of distribution of test statistic. For TE type, unhealthy subjects were characterized with significant increases in heart rate, systolic to diastolic period, pulse depth, while they showed significant decreases in width of pulse in normal direction, pulse area in diastolic period, and high harmonic components (6th, 7th) of power spectral density. For SE type, unhealthy subjects were characterized with significant increases in pulse pressure and pulse depth, while no significant differences were found for SY type. We investigated the characteristic differences in radial pulse properties due to change in health levels on each SC type for elderly females. Pulse variables which were significantly different between healthy subjects and unhealthy subjects were found to vary between SC types. For TE type subjects, many variables were found significant at the left Gwan location, which is in support of the theory of hyperactive liver functioning for TE type. Irrespective of the constitution, the related changes in the pulse properties due to worsened health level were in support of elevated blood flow amount in compensation with weakened blood circulatory function.

A Study on The Law and System of The Private Body Guard in Korea (한국(韓國) 민간신변보호(民間身邊保護)의 발전(發展)을 위한 법규(法規) 및 제도(制度)에 관한 고찰(考察))

  • Lee, Han-Ick
    • Korean Security Journal
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    • no.1
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    • pp.283-319
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    • 1997
  • Our society witnesses the rapid progress in the areas of politics, economy, society and culture in the process of national modernization since 1960s, which in turn as a reverse function gets to contract a societic pathology, totally lowering the security level of citizens' lives owing to various violent crimes like hostage commotions and murders with rifles and deadly weapons. what is the main reason for that? That may be partly because the chief police force concentrates on the current situation resulting in the vacuum of the public peace. However, the main reason is that the police fall short of man-power and equipments even if the whole police power were put to use in preventing and quelling the crimes. That is true not only of Korea but also of the advanced countries like the U.S.A., England and Japan. We realize that these advanced countries have higher level of security in every individual's life and property than Korea because their progress of the private guard systems can fill in a vacuum of the shortage of the police power, Therefore, we should without delay internationalize our private guard systems expecting the widely opening of the guard service markets in the age of Uruguay Round. To do this, we need to change our ideas for fostering the policy of the private guard from passive defense ideas into positive aggressive ones. Our police should urgently set up a plan to pursue the orientation of vision that we should dispatch our private guards overseas before foreign guards rush into our markets. Accordingly it goes without saying that the private guard group should distinguish their services from the public services initiating their own theory and strategy of private guard services and also readjust themselves between the public duties and the private services with the study of minimizing the reverse function of the private guard systems. The history criminal justice has always shown that the criminal system progressed at the initiative of the civil factor in case its demand and supply do not make both ends meet. Nevertheless, in the process the power of the government never weakens, rather it is built up in general. In conclusion, the necessity of the build-up of the private guard services must duly be acknowledged by the police as well as by the business which has its unique sphere within the criminal justice instead of as the suplemtary services of the simple the police power on the long-term basis. The purpose of the private guard services can be largely classified into the two categories; first it means the function to prevent the crimes against the citizens and secondly to enhance the national interest as an increasing mammoth business with a worldly competition capacity. The police has an absolute responsibility that they should protect the modem public in general from feeling the crisis of the personal threat, tension, anxiety and nervousness. In short, if we develop the complete private guard system to guarantee the societic atmosphere for all citizens, keep the public peace, and protect all citizens' lives and properties, we will sure enjoy a beautiful land, a wholesome society and a happy life in goodharmony of law and order.

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Shear stiffness of headed studs on structural behaviors of steel-concrete composite girders

  • He, Jun;Lin, Zhaofei;Liu, Yuqing;Xu, Xiaoqing;Xin, Haohui;Wang, Sihao
    • Steel and Composite Structures
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    • v.36 no.5
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    • pp.553-568
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    • 2020
  • Steel-concrete composite structures have been extensively used in building, bridges, and other civil engineering infrastructure. Shear stud connectors between steel and concrete are essential in composite members to guarantee the effectiveness of their behavior in terms of strength and deformability. This study focuses on investigating the shear stiffness of headed studs embedded in several types of concrete with wide range of compressive strength, and their effects on the elastic behavior of steel-concrete composite girders were evaluated. Firstly, totally 206 monotonic push-out tests from the literature were reviewed to investigate the shear stiffness of headed studs embedded in various types of concrete (NC, HPC, UHPC etc.). Shear stiffness of studs is defined as the secant stiffness of the load-slip curve at 0.5Vu, and a formulation for predicting defined shear stiffness in elastic state was proposed, indicating that the stud diameter and the elastic modulus of steel and concrete are the main factors. And the shear stiffness predicted by the new formula agree well with test results for studs with a diameter ranging from 10 to 30 mm in the concrete with compressive strength ranging from 22.0 to 200.0MPa. Then, the effects of shear stiffness on the elastic behaviors of composite girders with different sizes and under different loading conditions were analyzed, the equations for calculating the stress and deformation of simply supported composite girders considering the influence of connection's shear stiffness were derived under different loading conditions using classical linear partial-interaction theory. As the increasing of shear stiffness, the stress and deflection at the most unfavorable section under partial connected condition tend to be those under full connected condition, but the approaching speed decreases gradually. Finally, the connector's shear stiffness was recommended for fully connection in composite girders with different dimensions under different loading conditions. The findings from present study may provide a reference for the prediction of shear stiffness for headed studs and the elastic design of steel-concrete composite girder.

Effects of Price Discount on the Demand and Revenue of Oriental Medical Clinic (한방의료의 가격인하전략이 한방의료에 대한 수요와 경영수지에 미치는 영향)

  • Kim, Jin-Hyeon;;Park, Yeong-U
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.34-47
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    • 1996
  • We have seen a sharp increase in the utilization rate of medical services since the launch of Nation Health Insurance system in 1989. However, the market share of oriental medicine in the Korean health sector has been gradually diminished mainly due to low insurance coverage and high price. Especially high price as an entry barrier to oriental medical services has played a major role in decreasing market share. This paper investigated the effects of price discount on the financial condition and market share of oriental medical institutions. Microeconomic theory and multiple regression analysis were used as a methodology in testing the alternative hypothesis: price discount of enveloped herb drug will result in increases in both the revenue and market share of oriental medical institutions. Data was collected from the statistical yearbook and sample survey. The price elasticity of demand for enveloped herb drug was estimated at 5.8 during 1987-1995 period, which means that a 1% decrease in price will bring about a 5.8% increase in the utilization of oriental medical services. The empirical result shows that a drastic price discount for the enveloped herb drug will eventually improve the financial status of the oriental medical institutions and enlarge the market share of oriental medicine in the Korean health care sector.

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