• Journal of IKEEE
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• v.17 no.3
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• pp.385-392
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• 2013

In this paper, microstrip antenna to enhance the isolation between transmitting port and receiving port under the proximity objects is proposed, and applied to the Doppler radar sensor working at 5.8GHz ISM band which detects vital signals of a human body. Two 3dB quadrature hybrids are placed around radiation patch to form a balanced structure between transmitting port and receiving port, such that it consistently provides enhanced Tx/Rx isolation and excellent return loss over nearby objects. It is theoretically analyzed and simulated to verify the validity of the proposed application. The fabricated antenna that is 2mm away from the human body, has more than 16 dB return loss and at least 30dB isolation over ISM frequency band of 5.8GHz.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.105-109
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• 2020

The Future Army in 2050 should prepare for various future threats and effectively utilize its superintelligence and hyper-connected weapons systems to develop ways of fighting new concepts to dominate multi-regional battlefields and achieve victory. First, the establishment of active and offensive military strategies based on ability. Second, the battle of central strike for enemy combat will paralysis. Third, the battle of simultaneous integrated mosaic using multidisciplinary areas. Fourth, cyber warfare based on artificial intelligence that transcends time and space. Fifth, Combined Platform War. After all, future wars will be won or lost by invisible wars on cyber space.

• The Journal of Korean Association of Computer Education
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• v.8 no.4
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• pp.1-13
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• 2005

In this paper, to solve the imbalance between the skill factors demanded by the industry and the curriculum of the universities, demand-oriented educational contents are developed in the computer-software field. In the field, five tracks are selected: Software Development, System Integration, Embedded System Software, Multimedia and Game Software, and Business Information Technology. In each track, a curriculum with four demand-oriented courses is developed to reflect the demands of the IT industry. Detailed syllabuses and course materials are developed as well. Applying these artifacts, lectures have been performed at universities since 2004.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.148-155
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• 2007

The routing optimization mode, which Mobile IPv6 provides for the direct communication between a mobile node and its correspond node, introduces various security threats, thus causing several protocols to be proposed for the secure binding update procedure. In particular, the Kang-Park protocol, which Kang and Park presented in 2005, achieves the optimized cryptographic operations and the strong security, while based on its unique security proxy structure. In spite of such advantages, it has some drawbacks in terms of security and efficiency. This paper improves the Kang-Park protocol through the strong CoA validation and early binding update methods. Also, we show that the improved protocol is better than others.

• Korean Journal of Optics and Photonics
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• v.7 no.1
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• pp.37-43
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• 1996

Two type interference air refractometers have been developed by using a frequency stabilized He-Ne laser in a transverse magnetic field. The refractometers were based on symmetric multiple pass interferometer. In this system, One part of the beams passed through air whose refractivity is to be measured and the other part of the beams passed through a vacuum champer to be used as a reference. Several measurements were performed under normal air condition. Maximum difference between two interference refractometers was ${\pm}2{\times}10^{-8}$.

• Journal of Engineering Education Research
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• v.15 no.3
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• pp.3-11
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• 2012

This paper discusses the effect that classroom demonstrations have on students' conceptual understanding in concepts in introductory physics. We used the same conceptual survey to probe the students' understanding on certain concepts before and after taking the course. We introduce Hake's , which is used to evaluate the effect of various kind of teaching methods, suggested by physics education research groups, on conceptual understanding of students who took the class. The effect of physics class using demonstration turned to be better than the traditional lecture, higher for students who graduated from science schools with higher prior knowledge and demonstration experience. Authors suggest to use to probe concepts which need more attention.

• Journal of Educational Research in Mathematics
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• v.22 no.4
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• pp.459-475
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• 2012

Epistemology in which only subject and object of cognition exist can't play a role well in the society. In this paper we analyze structuralism which discusses linguistic and social conditions that make subject of cognition possible and semiologic epistemology's philosophical base with three keywords: subject, structure and discourse. Signification by the signs' relation not object of cognition and construct of subject make meaning of sign in network of signs. The construct exists before subject and subject can exist in the structural order. In understanding and analyzing learning of mathematics, this point of view makes you consider the other problems besides construction by subject.

• Journal of Agricultural Extension & Community Development
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• v.13 no.2
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• pp.375-384
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• 2006

농업－공동체 임업은 토지－나무－인간 사이의 관계를 폭넓게 포함하고 있으나 이 논문에서는 농업－공동체 임업활동이 베트남의 산지의 지속가능한 이용에 초점을 두고 있다. 농업－공동체 임업(AF와 CF)은 베트남에서 시급한 국가우선사항이 된 개발과 보전을 함께 고려할 수 있는 기능을 지닌 것으로 받아드려지고 있다. 베트남에서 AF와 CF를 동시에 지원할 수 있는 자원은 한정되어 있으며, 제약 사항은 위협적이고 시급한 상황이고, 황폐화가 진행될수록 복원은 어려워지는데, 농업의 생산성 감소에 따른 산촌주민들의 가족 부양을 위한 생태계 파괴도 가속화되고 있는 것으로 조사되었다. 이 연구는 농업－공동체 임업활동이 베트남의 산지 자원의 지속가능한 이용에 있어서의 연관된 문제들, 발전에의 제한요인, 특히 정책 제한요인을 분석하고 베트남 농업－공동체 임업 개발의 방향을 제시하고자 하였다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.6
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• pp.1-6
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• 1976

In this paper, the methode of calculating conversion loss is proposed by considering the thickness of bonding medium between electrode and delay material in the vibrator of Elastic delay lines. As the result of computations using digital computer, it is shown that the thickness of bonding medium must be less than about 1/100 of the thickness of vibrator and when the thickness of electrode is about 1110 of vibrator, the center fnequency is shifted. When the thickness of bonding medium is equal to or more than the thickness of vibrator, the 리uctuations in frequency Bandwidth become larger and larger.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.541-546
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• 2008

A novel, simple and broadband $90^{\circ}$ phase shifter was proposed and fabricated by the LTCC process. It is composed of a $180^{\circ}$ transmission line between two $90^{\circ}$ shorted transmission lines. Design equations for the proposed $90^{\circ}$ phase shifter are derived by the method of admittance parameter analysis. Based on design equations, $90^{\circ}$ phase shifter was designed and fabricated to operate in the C-band with ${\pm}2^{\circ}$ of phase deviation.