• Journal of the Korean Ceramic Society
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• v.35 no.5
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• pp.472-478
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• 1998

Ferroelectric SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si substrates at 50$0^{\circ}C$ using a sintered SBT target Bi and Ta targets by modified rf magnetron sputtering and then were annealed at 80$0^{\circ}C$ for 10min in oxygen ambinet(760 torr) The composition of the SBT films could be easily controlled using the mul-ti-targets. The film composition of {{{{ {Sr }_{0.8 } {Bi }_{2.9 } {Ta}_{2.0 } {O }_{9 } }} was obtained with SBTd sputtering power of 100 W Bi of 25W and Ta of 10 W. A 250nm thick SBT films exhibited a dense and uniform microstructure and showed the remanent polarization(Pr) of 14.4 $\mu$C/cm2 and the coercive field({{{{ {E }_{c } }})of 60 kV/cm at applied voltage of 5 V. The SBT films show practically no polarization fatigue up to {{{{ {10 }_{10 } }} cycles under 5V bipolar pulse. The retention characteristics of the SBT films looked very promising and the leakage current density of the SBT films was about 1.23$\times${{{{ {10 }^{-7 } }}A/c{{{{ {m }^{2 } }} at 120kV/cm.

• Transactions on Electrical and Electronic Materials
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• v.6 no.3
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• pp.110-114
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• 2005

We present a micro fluxgate magnetic sensor having solenoid coils and racetrack shaped magnetic core, which was designed to decrease the .operating power and magnetic flux leakage. Electroplated copper coils of $6\;{\mu}m$ thickness and the core of $3\;{\mu}m$ thickness were separated by benzocyclobutane (BCB) having a high insulation and good planarization characters. Permalloy $(Ni_{0.8}Fe_{0.2})$ as a magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The core had the high DC effective permeability of $\~1,300$ and coercive field of $\~0.1$ Oe. The fabricated fluxgate sensor had the very small actual size of $3.0\times1.7\;mm^2$. The fluxgate sensor with a racetrack shaped core had the high sensitivity .of $\~350$ V/T at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.

• Asian Journal for Public Opinion Research
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• v.9 no.2
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• pp.161-187
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• 2021

To address threats to the natural environment, the government in Pakistan has banned the use of plastic bags for shopping. The concept of governmentality presented by Michel Foucault explores the techniques of governance and defines law not just as the manifestation of sovereign power but also as a technique of governance involving a range of organized practices designed to shape mentalities to achieve certain desired ends in subjects which claim to be for the welfare of the population. The present study explores the perceptions of the consumers regarding the rationality of the government behind the ban and also highlights the effectiveness of the use of law as a technique of governance. A qualitative approach was used by conducting fifteen interviews with young consumers selected through convenience sampling. The findings suggest that the rationality of the government behind the ban was received well by the consumers and the ban was viewed as a positive and pro-environmental step. The use of law as a technique of governance also proved to be effective in the said case because the people did not perceive the law as coercive despite the radical change it brought to their shopping practices. The present study contributes to the development of the theoretical understanding of governmentality and its sub-concept of the use of law as a technique of governance.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.194-194
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• 2003

As a result of the recent miniaturization an enhancement in the performance of thin film inductors and thin film transformers, there are increased demands for the thin films with high magnetic permeability in the high frequency range, high saturation magnetization, in high electrical resistivity, and low coercive force. In order to improve high frequency properties, we will investigate anisotropy field by shape and size of pattern. The Fe-Al-O thin films of 16mm and 1 $\mu\textrm{m}$ thickness were deposited on Si wafer, using RF magnetron reactive sputtering technique with the mixture of argon and oxygen gases. The fabricating conditions are obtained in the working partial pressure of 2mTorr, O$_2$ partial pressure of 5%, input power of 400W, and Al pellets on an Fe disk with purity of 99,9%. Magnetic properties of the continuous films as followed: the 4$\pi$M$\_$s/ of 19.4kG, H$\_$c/ of 0.6Oe, H$\_$k/ of 6.0Oe and effective permeability of 2500 up to 100㎒ were obtained. In this work, we expect to enhance effect of magnetic anisotropy on patterned of Fe-Al-O thin films.

• Strategy21
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• s.37
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• pp.65-103
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• 2015

This study is an attempt to look into the future role of the ROKN and to provide a strategic way forward with a special focus on naval strategic concept and force planning. To accomplish this goal, this research takes four sequential steps for analysis: 1) assessing the role and utility of naval power of ROKN since its foundation back in 1945; 2) forecasting features of various maritime threats to influence the security of Korea in the future directly or indirectly; 3) identifying the roles to be undertaken by future ROKN; and 4) recommending Korean way of naval force planning and the operational concept of naval power. This study seeks to show that ROKN needs comprehensive role to better serve the nation with respect to national security, national prosperity and development, and future battle-space management. To safeguard the national security of Korea, it suggests three roles: 1) national guard for the peaceful unification; 2) protector of the maritime sovereignty; and 3) suppressor to maritime threats. Three more roles are highlighted for national prosperity: 1) escort of the national economy; 2) guardian for national maritime activities; and 3) contributor to the world peace. These roles need to be closely connected with the role for the battle-space management. This paper addresses the need for a dramatic shift of the central operational domain from land to maritime in the future. This will eventually offer future ROKN a leading role for developing strategic concept and force planning rather than merely a supporting one. This study finally suggests 'balanced' strategy both in concept development and force planning. A balanced force planning is a 'must' rather than an 'option' when considering a division of function between Task Fleets and Area Fleets, constructing cutting-edge conventional forces such as Aegis destroyer, CVs, or submarines, and the mix of high-profile platform and low-profile when composing future fleets. A 'balance' is also needed in operational concept. The fleet should be prepared to fulfill its missions based on two different types of force operation i.e., coercive or cooperative application of the utility of naval force. The findings and recommendations of the study are relevant today, and will be increasingly important in the future to achieve various political goals required by enhancing the utility of naval power.

• Journal of National Security and Military Science
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• s.8
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• pp.239-270
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• 2010

This thesis is to make an appropriate national defense policy of Republic of Korea through studying the Hegemony Strategy of United States. I searched the theory of hegemony. The hegemony was differently defined by the point of time and region. The strong power nations with the hegemony have been making efforts to maintain their hegemony everytime. I have conclusion that the presence of hegemony once emerged, it brought regional stability in place whether it is coercive or beneficial. The stability and instability of international order IS not exclusively dependent on hegemony. Even if the safety of hegemony cannot guarantee absolute stability of international order, there IS on doubt that the hegemony has enormous impact on that. According to the hegemonic theory, the history of mankind equals to the history of rising and falling hegemony. The international order was changed as the hegemony changes. The United States has been making efforts to maintain her global hegemony during the post cold-war era as well. Taking all these into consideration, relevant military strategy direction able to pursue national interest is that to make up for the relative weakness in the strategic environment. South Korea have to prepare security policy response as following. First, South Korea should build the military force equipped with advanced weapons in military technology sector and solidify military diplomatic relation able to form cooperative relation in wartime. Second, South Korea should make solid Alliance of Korea and U.S. Third, develop and maintain multilateral security cooperation of East Asia. Forth, we could realize that there are means that can neutralize opponent's strong point by seeking one or two and more asymmetry in the aspect of strategy, tactics, and means through asymmetric strategy. Than the military force of South Korea should develop into a force that is able to overcome to the traditional North Korea's threat and new type of conflicts. And the force should have sufficient strength and be deployed to effectively defend the Korean Peninsula. So, we need to establish a denial and defense system against any hostile neighboring country. Therefore, ROK military forces preparing for the future should try to construct a future military power to gradually establish enough strength for self-defense to prepare for a uncertain security environment and when the Korean Peninsula is unified in a future.

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.37-41
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• 1991

Amorphous $Fe_{68.5}Co_5M_3Cu_1Si_{13.5}B_9(M=Nb, Mo, Mn, Cr)$ alloys were prepared by using rapidly quenching techinque and were annealed above their crystallization temperatures. Coercive force, initial permeability and AC power loss of the annealed $Fe_{68.5}Co_5M_3Cu_1Si_{13.5}B_9(M=Nb, Mo, Mn, Cr)$ alloys have been studied systematically. Nanocrystallines are formed in the annealed alloys which include Mo and Nb. Remarkably improved soft magnetic properties are obtained in the alloys whose average grain size is around 10 nm. However, soft magnetic properties of the alloys are degraded when grain size is less than IOnm or larger than 15nm. It is considered that the degradation of soft magnetic properties in the alloys whose average grain size is less than 10 nm is due to the Fe-rich amorphous phase retained at grain boundary during the initial crystallization process.

• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.245-267
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• 2012

This paper analyzes the discrimination of private property right protection in urban regeneration projects that is implemented by eminent domain based on public use in the United States. In spite of urban regeneration projects which depends on property condemnation for public use as a coercive power, it is executed on the discrimination of property right and sacrifice of the social disadvantages that transfer property from these private party to another big capitals and private developers. At first this paper investigates research trends in urban regeneration within the framework of multidisciplinary approach and suggests legal geographical perspective as a new research field. Next I figure out current state, types and numbers of brownfields site with the EPA and GAO data, and define these sites as results of deindustrialization and suburbanization process. Finally this paper uncover that the discrimination process of private property right is due to complex actions of expansion of public use concept in the U.S. Supreme Court from public ownership to economic public use, privatization of eminent domain, growth coalition regime and business friendly policy focused on economic development, class and racial bias, neoliberal movements of property right reform.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.508-514
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• 2004

A fluxgate magnetic sensor consists of a solenoid excitation coil, pick-up coil, and magnetic core. We presents the effect of magnetic core shape in a micromachined fluxgate sensor. To observe the performance of fluxgate sensor with magnetic core side width and gap, side width of 125 ${\mu}{\textrm}{m}$, 250 ${\mu}{\textrm}{m}$, and 500 ${\mu}{\textrm}{m}$ were designed in a rectangular-ring shaped core and the gaps of 0 ${\mu}{\textrm}{m}$, 50 ${\mu}{\textrm}{m}$, and 100 ${\mu}{\textrm}{m}$ were also fabricated in a racetrack shaped core. The solenoid coils and magnetic core were separated by benzocyclobutane(BCB) which had high insulation and good planarization characters. Copper coil patterns of 10 ${\mu}{\textrm}{m}$ width and 6${\mu}{\textrm}{m}$ thickness were electroplated on Ti(300 $\AA$) / Cu(1500 $\AA$) seed layers. 3 ${\mu}{\textrm}{m}$ thick N $i_{0.8}$F $e_{0.2.}$(permalloy) film for the magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The magnetic core had the high DC effective permeability of ∼1,300 and coercive field of ∼0.1 Oe. Because the magnetic cores of 500 ${\mu}{\textrm}{m}$ side width and 0 gap had a low magnetic flux leakage, high sensitivity of ∼350 V/T were measured at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. The power consumption of ∼14 ㎽ was measured. The fabricated fluxgate sensor had the very small actual size of 3.0${\times}$1.7 $\textrm{mm}^2$. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.m.m.m.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.266-269
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• 2009

Iron-based soft magnetic materials are widely used as cores, such as transformer transformers, motors, and generators. Reducing losses generated from soft magnetic materials of these applications results in improving energy conversion efficiency. Recently, the new P/M soft magnetic material realized an energy loss of 68 W/kg with a drive magnetic flux of 1 T, at a frequency of 1 kHz, rivaling general-purpose electromagnetic steel sheet in the low frequency range of 200 Hz to 1 kHz. In this research, the effect of rolling parameters on soft magnetic properties of Fe-based powder cores was investigated. The Fe-based soft magnetic plates were produced by the hot powder rolling process after both pure Fe and Fe-4%Si powders were canned, evacuated, and sealed in Cu can. The soft magnetic properties such as energy loss and coercive power were measured by B-H curve analyzer. The soft magnetic properties of rolled sheets were measured under conditions of a magnetic flux density of 1 T at a frequency of 200 kHz. It was found that rolling reduction ratio is the most effective parameter on reducing both energy loss and coercivity because of increasing aspect ratio with reduction ratio. By increasing aspect ratio from 1 to 9 through hot rolling of pure Fe powder, a significant loss reduction of one-third that of SPS sample was achieved.