• Title/Summary/Keyword: Coercive

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Conducting Crack Growth Behavior in Ferroelectrics Subjected to Electric Fields (전기장을 받는 강유전체 내의 전도균열 성장거동)

  • 정경문;박재연;범현규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.820-823
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    • 2002
  • The asymptotic problem of a semi-infinite conducting crack parallel to the poling direction in ferroelectric ceramics subjected to electric fields is analyzed. The main mechanism for the conducting crack growth behavior is thought to be ferroelectric domain switching leading to the development of a process zone around the crack. The shape and size of the switching zone is shown to depend strongly on the relative magnitude on the ratio of the coercive electric field to the yield electric field. It is shown that the crack growth can be either enhanced or retarded depending on the ratio of the coercive electric field to yield electric field.

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Magnetic Properties of Anodic Oxidized Films Electrodeposited Cobalt-Iron (코발트-철(鐵)을 전해석출(電解析出)한 양극산화피막(陽極酸化皮膜)의 자기특성(磁氣特性))

  • Kang, Hee-Woo
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.1143-1146
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    • 1993
  • The magnetic properties of aluminium anodized film in which Co-Fe alloy electrodeposited are investigated with regard to the alloy composition of magnetic films. The electrodeposited Co-Fe particles are confirmed to be single phase Co-Fe alloys by X-ray diffractions. The coercive force as well as the magnetic anisotropy energy can be controlled by changing the composition of the alloy. Magneticfilms having high saturation magnetization and high coercive force were obtained.

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승용차유통경로에서 딜러의 협력, 갈등, 성과 간의 관계에 관한 연구

  • 계도원
    • Journal of Distribution Research
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    • v.1 no.1
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    • pp.109-127
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    • 1996
  • The purpose of this study was to represent hypotheses of the interrelationship of the level of cooperation, conflict, and performance and to report the findings testing the hypotheses in car channels. This study provides some general guidance toward better cooperation, conflict, and performance management. The results indicate that noncoercive bases of power and dependence hale a positive effect on cooperation, while the proposed inverse relationship between coercive bases of power and cooperation is not statistically significant. Coercive bases of power have a positive effect on conflict, while conflict is not statistically significant for noncoercive bases of power, dependence, and cooperation. Finally, cooperation has a positive effect on dealer performance, but conflict has a negative effect on dealer performance.

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On Interfirm Power in the Department Store and Its' Women's Apparel Tenants in a Channel Distribution (백화점 입점 여성의류업체간 상호권력에 관한 연구)

  • Jung, Hyun-Ju
    • Journal of Global Scholars of Marketing Science
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    • v.7
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    • pp.375-390
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    • 2001
  • Currently the super power of department stores over their tenants has mentioned in Korean apparel newspapers very often. It may be the one that the government in fashion industry has not delved into the relationship between department stores and their tenants. The aim in here is to look at the conceptual framework of power based on the retail power oriented and to explain current issues with its theoretical backgrounds. Due to the inherent of retailer power oriented, this study involves not only in French and Raven's power sources but also in positioning power source that is the ability of allocating the location and adjusting size of the store. 235 samples are tested through Lisrel. The results of statistical analysis show that: The power of department store over that perceived by the tenant has negatively influenced countervailing power of the tenant upon department store. The coercive power sources of department store have positively influenced the power of department store over that perceived by the tenant while the non-coercive power sources have not significantly influenced on it. The countervailing power of the tenant has positively influenced the non-coercive power sources of department store perceived by the tenant. On the other hand, the countervailing power of the tenant has not significantly influenced the coercive power sources of department store perceived by the tenant. The implication of these results is that the retailer oriented power sources and its implements differs from the manufacturer oriented ones in the framework of power. A great deal more research is required in order that the relationship between department store and its tenants can be better understood.

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Relationship between Magnetic and Mechanical Properties of Cermet Tools (절삭공구용 서멧의 자기적 특성과 기계적 성질의 관계)

  • Ahn, Dong-Gil;Lee, Jeong-Hee
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.3
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    • pp.231-237
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    • 2000
  • The commercial cermet cutting tools consist of multi-carbide and a binder metal of iron group, such as cobalt and nickel which are ferromagnetic. In this paper, a new approach to evaluate the mechanical properties of TiCN based cermet by magnetic properties were studied in relation to binder content and sintering conditions. The experimental cermet was prepared using commercial composition with the other binder contents by PM process. It was found that the magnetic properties of the sintered cermets remarkably depended on the microstructure and the total carbon content. The magnetic saturation was proportional to increment of coercive force. At high carbon content in sintered cermet, the magnetic saturation was increased by decreasing the concentration of solutes such as W, Mo, Ti in Co-Ni binder. As the coercive force increases, the hardness usually increases. The strength and toughness of the cermet also increased with increasing the magnetic saturation. The measurement of magnetic properties made it possible to evaluate the mechanical properties in the cermet cutting tools.

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Frequency Characteristics of Coercive Field in Ferroelectric Poly(Vinylidene Fluoride-Trifluoroethylene) Thin Film (강유전성 폴리(비닐리덴 플로라이드-트리플로로에틸렌) 박막의 항전계의 주파수 특성 분석)

  • Zhang, Ting;Rahman, Sheik Abdur;Khan, Shenawar Ali;Lee, Kwang-Man;Kim, Woo Young
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1206-1212
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    • 2018
  • In this study, the polarization reversal characteristics of thin film capacitors with a thickness of 100 nm or less fabricated with ferroelectric polymer were measured and analyzed. For the fixed film thickness, polarization reversal occurred at higher coercive fields as the applied maximum electric field increased. For the fixed maximum electric field, polarization reversal occurred at the same coercive field irrespective of the thickness of the thin film. The proportional constant values between the logarithmic electric field and the logarithmic scale frequency were $0.12{\pm}0.01$ for all measurements. As a result, the ferroelectric polymer capacitors consistently exhibited polarization reversal characteristics without any size effects up to a thickness of 40 nm. This study shows the possibility of a polymer memory device that can operate at low voltage, which is useful for predicting the behavior of a low-voltage operating polymer memory device.

Magnetic Characteristics of CoNbZr amorphous Films with Pd addition

  • Song, J.S.;Wee, S.B.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.90-95
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    • 2003
  • The present paper is to investigate the phase stability and soft magnetic properties of amorphous CoNbZr films when Pd is added as a substitution for CoNbZr alloys. The films were prepared by a RF magnetron sputtering method. The CoNbZrPd films deposited on Si wafers exhibited amorphous structures being independent upon the amount of Pd added in the films. On the addition of 4.34% Pd, the excellent soft magnetic characteristics of the films were observed with a coercive force of 0.54 Oe and an anisotropy field of 11 Oe, whereas a coercive force of 1 Oe and an anisotropy field of 3.5 Oe were shown in the film without the addition of Pd. The increased anisotropy field and low coercive force of the films may be attributed to the occupancy of Pd in the preferred sites parallel to the external magnetic field applied on the deposition process. A permeability of about 1100 was kept constant in the operation frequency ranging up to 100 MHz, which can be explained by the Landau-Lifshitz formula.

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The Effect of Power Sources of Department Store and Fashion Company, and Salesperson's Job Consciousness on Job Satisfaction in the Middle Management System of Department Store (백화점 중간관리 형태에서 백화점 및 패션업체의 권력원천과 판매원의 직업의식이 직무만족에 미치는 영향)

  • Lee, Hyun-Jin;Choo, Tae-Gue
    • Fashion & Textile Research Journal
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    • v.14 no.2
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    • pp.230-241
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    • 2012
  • The purpose of this study was to examine the effect of power sources of department store and fashion company, and salesperson's job consciousness on job satisfaction in the middle management system of department store. Questionnaire data from 193 salespeople in the middle management of department store were analyzed by reliability analysis, factor analysis, correlation analysis, multiple regression analysis, hierarchical regression analysis. The results of this study were as follows: First, coercive power, informational and expert power, and referent power of department store had significant effects on job satisfaction. The coercive power of department store had a negative influence on job satisfaction, while informational and expert power, and referent power of department store had a positive influence on job satisfaction. Second, referent power, expert power, reward power, coercive power of fashion company had a positive influence on job satisfaction. Third, referent power of department store had a greater influence on job satisfaction than other power sources. Fourth, job commitment and pride, prospect awareness had a positive influence on job satisfaction, while professional self-awareness had no effect on job satisfaction.

Piezoelectric and Electric Field Induced Strain Properties of PMW-PNN-PZT Ceramics with the Substitution of Ba (Ba 치환에 따른 PMW-PNN-PZT 세라믹스의 압전 및 전계유기왜형 특성)

  • 윤광희;김규수;최병수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.1
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    • pp.20-25
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    • 2001
  • To develop the piezoelectric actuator, the structural, dielectric and piezoelectric properties and electric fieldinduced strain of the ceramics(Pb$\_$1-2/Ba$\_$x/)[Mg$\_$1/2/W$\_$1/2/)$\_$0.03/-Ni$\_$1/3/Nb$\_$2/3/)$\_$0.12/-(Zr$\_$0.5/Ti$\_$0.5/)$\_$0.85/]O$_3$(x=0, 0.01, 0.03, 0.05, 0.07, 0.1) were investigated with the substitution of Ba. The tetragonality of crystal structure and grain size decreased by the substitution of Ba. Curie temperature decreased due to the decrease of the tetragonality, and dielectric constants increased with the substitution of Ba. The coercive field, remnant polarization and electromechanical coupling factor also decreased, whereas the piezoelectric constatns d$\_$33/ and d$\_$31/ were showed the highest value of 430 and 209(x10$\^$-12/C/N), respectively, because of the increase of dielectric constant. The strain induced by 60Hz AC electric field had the maximum value of 204x10$\^$-6/Δℓ/ℓ at the substitution of Ba 3mol%. As the applied electric field approaches to the coercive field, the piezoelectric element is depolarized and the electric field induced strain revealed non-linearity.

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Variations of ferroelectric properties with the addition of Yttrium acetate in the $Pb(Zr_{0.65}Ti_{0.35})O_3$ thin films prepared by Sol-Gel processing (Sol-Ge법에 의한 $Pb(Zr_{0.65}Ti_{0.35})O_3$박막의 Yttrium acetate 첨가에 따른 강유전 특성의 변화)

  • 김준한;이규선;이두희;박창엽
    • Electrical & Electronic Materials
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    • v.8 no.3
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    • pp.261-266
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    • 1995
  • In this study, PZT solutions added impurities of Yttrium acetate were prepared by sol-gel processing and were deposited on Pt/ $SiO_{2}$/Si substrates at 5000 rpm for 20 sec. using spin-coating method. Coated films were annealed at 700-750.deg. C for 30 min. using conventional furnace method. Variations of the crystallographic structure and microstructure of PZT thin films with adding impurities were observed using XRD and SEM, and the electrical properties, such as relative permittivity, tan .delta., hysteresis curves and leakage currents, were measured. As the yttrium contents were increased, the remanent polarization and coercive field were decreased. Variations of remanent polarizations and coercive fields of pure and yttrium doped specimens according to polarization reversal cycles were observed using hysteresis measurement. PZT thin films added $Y^{3+}$ ions were completely crystallized at 750.deg. C. $Y^{3+}$ ions, as donor impurity, substituted Pb.sup 2+/ ions located at A-site of perovskite structure. By substitution of $Y^{3+}$ ions, leakage currents became less by decreasing the space charges. Degradation of remanent polarizations of Yttrium added specimens after fatigue was not observed and coercive fields increased more than those of pure PZT thin films.

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