• Title/Summary/Keyword: 큐리점

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Simulataneous X-ray Diffraction Measurements of the Antiferroelectric-ferroelectric Phase Transition of PLZT under Electric Field (전장하에서 PLZTd의 반강유전-강유전 상전이의 동시적 X-선 회절 측정)

  • 고태경;조동수;강현구
    • Journal of the Korean Ceramic Society
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    • v.33 no.11
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    • pp.1292-1300
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    • 1996
  • In-site X-ray diffraction measurements under electric field up to 20kV/ cm were carried out on PLZT (x/70/30) with x=7.5, 8.0, 8.5, and 10.5 All of PLZT belonged to cubic phases. At x=7.5, 8.0 and 8.5 PLZT behaved as an antiferroelectric under low electric fields up to 4-8 kV/cm. PLZT became ferroelectric at the higher electric fields. The high-temperature measurements on the dielectric constants of PLZT with x=7.5, 8.0 and 8.5 showed that they were similar to relaxor ferroelectrics and underwent a diffuse phase transition from antiferroelectrics to paraelectrics at 50-7$0^{\circ}C$. Their P-E hysteresis curves confirmed that they were antifer-roelectrics. The broad distribution of Curie points suggests that there is a significant disorder of cations and vacances in the crystal structure of those PLZT due to La-substitution. The variation of the lattice strain of PLZT(10.5/70/30) with electic field was very small and did not show any hysteresis confirming that it was paraelectric. The degree of the electric-induced strain variation decreased as La doping increased. In PLZT(7.5/70/30) the intensity of 110 reflection changes sensitively by applying electric field. Some domains with polarization parallel to [110] appeared to be developed in the field-induced ferroelectric phase of the PLZT.

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Preparation of BaTiO3 Powder in $BaO2-TiO2-Reduction Agent-PSCA (Particle Size Control Agent) System by SHS and Its Dielectric Properties (B3O2-TiO2-환원제-입자제어제계에서 자전연소합성법에 의한 BaTiO3분말의 제조 및 유전특성)

  • Yun, Ki-Seok;Lim, Sung-Jae;Nersisyan, Hayk;Won, Chang-Whan
    • Journal of the Korean Ceramic Society
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    • v.41 no.11
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    • pp.842-850
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    • 2004
  • We have investigated on the preparation of BaTiO$_3$ powder at the system of BaO$_2$-TiO$_2$-Reduction ag.-PSCA by SHS. C and Mg were used as reduction agent, and NaCl was used as PSCA (Particle Size Control Agent). The effects of the various reduction agent and its concentration, particle size control agent, reaction mixture mass on the product in the preparation of BaTiO$_3$ powder at the optimum system by SHS were investigated. The optimum conditions for reaction system and composition were BaO$_2$+TiO$_2$+0.11 Mg +0.2C+0.75NaCl in the As atmosphere. NaCl as PSCA showed the effect of controlling the particle size of product as well as the combustion temperature. The particle size of BaTiO$_3$ synthesized at the optimum condition was about 0.5 ${\mu}{\textrm}{m}$. And as the mixture mass for the reaction was increased, the more stable combustion wave appeared. We have conducted the sintering experiment at the temperature of 130$0^{\circ}C$, the time of 2 h and the atmosphere of air to measure the dielectric properties of BaTiO$_3$ synthesised in this work, and the sample sintered in this condition showed 2,290 of dielectric constant at 10$0^{\circ}C$ and 13,890 at curie point (129$^{\circ}C$).

The threats and responses of cyber-terrorism in a new security environment: Issues and propositions on strategic frameworks (새로운 안보환경을 둘러싼 사이버 테러의 위협과 대응방안: 쟁점들과 전략적 접근 틀에 대한 논의)

  • Yun, Min-Woo
    • Korean Security Journal
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    • no.40
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    • pp.109-145
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    • 2014
  • Despite much discussions on cyber-terrorism in South Korea, several missing issues could be addressed. This paper attempts to deal with such missing but important issues. In South Korea, there has been little attentions on cyber-terrorism with the respects of national security strategy development under macro framework responding to future security environment. This article focuses on such issues. In other words, the purpose of this paper evaluates the meaning of national security threats raised from cyber-terrorism as a mode of security threats and proposes the matter of cyber-terrorism within the development of national security strategy in the future security environment. several issues in this discussion pass some important messages for the construction of national security strategic approach framework within the future security environment adding cyber-space. in the future environment, a new space called cyber is added as an important external condition which might determine the security of individuals, societies, and nations. Therefore, the fundamental strategic framework should be prepared. After that, the trend and direction of future technological advancement should be understood and the identity, nature, and types of threat should be analyzed. Also, after that, various responses and countermeasures are together constituted in the aspect of function and system regarding various anticipated threats of the future human society including cyber-terrorism.

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Trend of standardization in the field of Industrial Security through ISO/TC 292 (ISO/TC 292에 의한 산업보안 분야 국제표준화의 동향)

  • Park, Hyeon-Ho
    • Korean Security Journal
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    • no.48
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    • pp.79-111
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    • 2016
  • This study aims at analyzing the global trend of standardization in the field of Industrial Security through ISO/TC 292. It covers broad areas from risk management for industrial property protection and loss prevention through supply chain security, product and document fraud and counterfeiting countermeasures and control and community resilience. It also explores the historical background of the standardization in the security field, how ISO TC 292 came out as a leading group in order to standardize relevant security management systems. TC 292 deals with terminology, general security-related standards and supply chain security management. One of the major findings from this analysis is that security targets and threats are diversified and so organizations like enterprises should have proper flexibility to adapt themselves to new security environment and take appropriate resilience system to cope with the threats and incidents. Also the ISO standardization requires public or private entities to take holistic approaches in security management. Finally, it was found that South Korea has to prepare for this global trend of standardization in this field so that ISO certification market demand and the requirements for transnational trades can be well met.

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A Study on the Effect of Organizational Culture on Security Performance (조직문화가 보안성과에 미치는 영향 연구 - 군인 가치관의 매개효과를 중심으로 -)

  • Park, Jaegon
    • Korean Security Journal
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    • no.58
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    • pp.215-241
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    • 2019
  • This study approached the military security problem from the viewpoint of social psychology in view of the fact that the military security problem has been focused on the technical field such as cyber security along with the development of defense science and technology. In this background, we examined the causal relationship between variables after extracting variables affecting the security problem of the military through previous research. The significance of the study results is as follows. First, the military culture has a direct and indirect influence on improving the willingness to adhere to security and the security level of military organizations, as well as contributing to the establishment of military values. This indicates that the overall organizational culture of the current military is influencing the security consciousness of the soldiers and the achievement of organizational security, while at the same time showing the need for effort to create the right organizational culture. Second, the values of soldiers had a positive effect on the willingness of the individual to obey the security and the security performance. Values begin with an understanding of organizational culture and indicate that efforts can be made to establish an organizational security posture when the right values are formed. Third, we have improved the completeness of the study by verifying the causal relationship by extracting variables that correspond to the context of the ROK military.

Implications from Analysis on the U. K. Household Division (영국 왕실근위대 분석을 통한 국내 시사점 연구)

  • Bang, Whan-Bog
    • Korean Security Journal
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    • no.39
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    • pp.7-35
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    • 2014
  • The objective of this research is to find out what the Korean traditional changing of SooMunJang and the United Kingdom's ceremony of changing the guard suggests us by performing comparative analysis as well as research of the United Kingdom Household Division's history of transition, organization, and their missions since 1660. The Royal Household is a constitutional monarchy and served by the Household Division for 350 years as a symbol of the United Kingdom. The Household Division is a regular army that is affiliated to British Army. The Guards Division consists of two cavalry regiments and five infantry regiments along with the King's Troop, Royal Horse Artillery. The Household Division not only escorts the king, guards royal palace, and attends a official function, but also dispatched to a combat area as the most elite troops. Similarities in aspect of king escort, palace guard, and succession of tradition were found from the comparison between Korean and the United Kingdom's changing of the guard. On the other hand, fundamental purpose and objective, process of forming a tourist attraction, organization were distinctive. While the Household Division and the Royal Household became a worldwide symbol of the United Kingdom, Korean changing of SooMunJang is insufficient to represent Korean traditional royal guard custom and just reenacting historical tradition to emphasize the succession of tradition and to develop tourism. Therefore, this research is suggesting methods to improve the cultural contents of distinctive Korean traditional royal guard and escort of royal family.

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A Study on Developmental Plan of In-Flight Security Officer in Korea - Focused on U.S. Federal Air Marshal Service - (항공기내보안요원제도의 발전 방안에 관한 연구 - 미국 연방 Air Marshal 제도를 중심으로-)

  • Park, Hee-Kyun;Moon, Jun-Seob
    • Korean Security Journal
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    • no.53
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    • pp.83-105
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    • 2017
  • The purpose of this study is to identify the problems of In-Flight Security Officer responsible for the security of the aircraft in the situation where Acts of Unlawful Interference in Aircraft shows an increasing tendency and the aircraft security is threatened by the terror threat of IS(Daesh) and to suggests its policy implications. Based on the problems of In-Flight Security Officer system found in the media reports and laws, the US Air Marshal system and the domestic similar system were presented to the In-Flight Security Officer developmental implications. First, it is necessary to revise the "Operational Guidelines for Airline Operators' In-Flight security officer" and the related qualifications to the "National Technical Qualifications" system. Second, the plan to change the national civil servants of In-Flight Security Officer in the aircraft, Third, it is a plan to use the registered security guard system in the aircraft. Although this study has limitations the accessibility of information related to aviation security. But, contributions of this study is that the government's efforts to create the public sector jobs, the "strengthening of public services in the country", "the establishment of national accountability for safety accident prevention and disaster safety management" in the "A five-year plan for Government Operation" that it has a timeliness in that it is together. In addition, since there are not many researches related to In-Flight Security Officer, this study also has another contribution as a basic study of the researchers in the aviation security aircraft in the future.

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A Study on the Prediction Method of Voice Phishing Damage Using Big Data and FDS (빅데이터와 FDS를 활용한 보이스피싱 피해 예측 방법 연구)

  • Lee, Seoungyong;Lee, Julak
    • Korean Security Journal
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    • no.62
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    • pp.185-203
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    • 2020
  • While overall crime has been on the decline since 2009, voice phishing has rather been on the rise. The government and academia have presented various measures and conducted research to eradicate it, but it is not enough to catch up with evolving voice phishing. In the study, researchers focused on catching criminals and preventing damage from voice phishing, which is difficult to recover from. In particular, a voice phishing prediction method using the Fraud Detection System (FDS), which is being used to detect financial fraud, was studied based on the fact that the victim engaged in financial transaction activities (such as account transfers). As a result, it was conceptually derived to combine big data such as call details, messenger details, abnormal accounts, voice phishing type and 112 report related to voice phishing in machine learning-based Fraud Detection System(FDS). In this study, the research focused mainly on government measures and literature research on the use of big data. However, limitations in data collection and security concerns in FDS have not provided a specific model. However, it is meaningful that the concept of voice phishing responses that converge FDS with the types of data needed for machine learning was presented for the first time in the absence of prior research. Based on this research, it is hoped that 'Voice Phishing Damage Prediction System' will be developed to prevent damage from voice phishing.

A Study on the Authority of Private Security Personnel (민간경비원의 권한에 대한 연구)

  • Choi, Sun-Woo
    • Korean Security Journal
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    • no.21
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    • pp.177-199
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    • 2009
  • In this study, I would try to observe the scopes and related matters of the authority of private security personnel based on the basic discussion about the identity of private security. Everybody knows, the problems of private personnel have been mainly discussed in the relations of the public police. Because the roles of private personnel are similar to the police, and in the perspective of the law, private security are regulated by the police. When we compared with the police, the scopes of authorities of private personnel are considered in several points. First, most private personnel are just only 'citizen', so they can exercise the authority as citizen. It can include self-defense, self-help. flagrante delicto arrest. But when discuss the authority in the scopes of a possessionary right or managemental right, the authority of private personnel can be extended somewhat. Moreover, when private personnel are delegated by the special laws, their authority are extended much more. Finally, when the whole authority are delegated by such as the privatization, private personnel authority can be nearly same to the police. But, it can be considered that the degrees of the delegated authority are flexible. And the exercise of the authority must be performed in the limit that not infringe the individual freedom and rights. It seems to me that the degrees of fairness in use of authorities and it's a permitted limit are set forth a premise not only the legitimate base but also judicial judgement. Therefore, the attitudes of the courts related the exercise of authority are very important. And the growth of private security and the extension of authority followed are inevitably accompany the various problems of responsibility, so it must be considered about that in many perspectives.

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Development and Application in Measurement of Security Need Satisfaction From Users of Electronic Security System (기계경비시스템 이용자의 안전욕구충족 척도 개발과 적용)

  • Kim, Chan-Sun
    • Korean Security Journal
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    • no.16
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    • pp.47-64
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    • 2008
  • The purpose of this study is to develop the measurement of security needs satisfaction from users of electronic security system, to verify its validity and reliability, and by applying them, to examine the effects between the communities using this system. In 2008, the users of electronic security system in big cities in Seoul(Yong-San, Jong-Lo) and Gyung-Gi Do(Su-Won) for their convenience stores, jewelry shops, communication services, banks, government and public offices, etc. were arranged for a population and 262 of them were used for the final analysis by purposive sampling. This study yields following results. First, the validity of security need satisfaction from users of electronic security system is very high, which means the explanatory adequacy of environmental security need is the highest. Second, the reliability of security need satisfaction from users of electronic security system is very high, in which the reliability value(Cronbach's $\alpha$) of internal consistency is over .765. Third, the security need of electronic security system has the most effects on the group of bank workers. That is, through a close cooperative system between the bank and the service of electronic security system, the more keeping satisfied the environmental, bodily, physical security needs are, the less the in security of this group has. Informational security need has the most effects on convenient store group. It means the service companies of electronic security system offer more services at dawn time and make or supply all sorts of visual information system, which reduces insecurity of the convenient store group.

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