• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1305-1309
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• 2002

Subsurface radar characterize a broadband frequency to collect a information, such as a crack of building, because of using narrow pulse. In this paper, we design a broadband bowtie antenna, using a microstrip, with a FR-4 substrate of ${\varepsilon}_r=4.0$, t=1.6mm. It has a 9.31% bandwidth at s11<-10 dB and s11=-27.45 dB, VSWR=1.089 at 5.78GHz.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.11-15
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• 2014

Congenital central hypoventilation syndrome (CCHS) is a disorder of the autonomic nervous system characterized by a decreased response to hypercarbia. CCHS is frequently associated with congenital megacolon; the combination is called Haddad syndrome. CCHS is associated with dysfunction in respiratory features of the autonomic nervous system and with other disorders, including facial deformities, cardiovascular symptoms, and tumors. Patients with CCHS frequently have a mutation in the homeobox protein 2b (PHOX2B) gene. Most mutations involve heterozygous expansion of alanine repeats (GCN). Interestingly, a higher polyalanine repeat number is associated with a more severe clinical phenotype. To clarify the role of PHOX2B in disease pathogenesis, we introduce and review the clinical and molecular features of CCHS and Haddad syndrome.

• Information and Communications Magazine
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• v.19 no.8
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• pp.114-127
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• 2002

무선랜 기술은 사설망 내에서의 무선랜 기술을 기반으로 발전해 왔다. 최근 공중망을 기반으로 무선랜 기술이 발전하면서, IEEE 802.11b(1)에서 이루어지던 인증 및 보안 기술로는 안전성을 만족할 수 없게 되었고, 여기에 사용자의 이동성 보장은 필수사항으로 요구되고 있다. 본 논문에서는 지금까지 이루어지던 무선랜 인증 및 보안기술을 사용자의 이동성 보장을 위한 framework으로 발전시키기 위하여 필요한 인증 및 보안기술과, IEEE 802.11b 기반의 무선랜 망에서 필요한 향상된 인증 및 보안기술에 대하여 다양한 관점에서 기술한다. 802.11b 기반으로 이루어지는 보안 및 인증 기술을 보다 향상된 사용자 인증, 데이터 기밀성 향상을 위하여 802.1x(2)기반으로 실현하는 인증기술에 대하여 기술한다. 본 논문의 전개는 이동성을 요구하지 않는 경우의 기본적인 인증 메커니즘인 EAP-MD5(3)기반의 challenge/response 메커니즘과, 이동성을 필요로 하는 경우의 인증을 위한 MIP 인증 메커니즘(4-7)에 대하여 기술한다. 마지막으로 사용자의 증가 및 서비스 영역의 확대로 요구되는 새로운 framework에 대하여 기술한다.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.85-91
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• 2005

Coexistence of different wireless systems that share the 2.4 GHz ISM frequency band is becoming one of the most important issue. This paper presents a model of the interference that IEEE 802.11b may experience because of IEEE 802.15.4. The packet error rate (PER) of IEEE 802.11b under the interference of IEEE 802.15.4 is analyzed. The PER is obtained by using the bit error rate (BER) and the collision time. The analytical results are validated using simulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.161-168
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• 2011

This paper provides the performance measurement and analysis of Wireless LAN IEEE 802.11 in a mobile environment. The performances of IEEE802.11b/g and IEEE802.11p designed for Vehicle-to-Vehicle(V2V) communication are measured and analyzed. Diameter of communication and link access time are compared under variation of speed of the vehicle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.490-496
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• 2007

This paper describes the design and implementation of an integrated LTCC front-end module for the IEEE802.11a WLAN applications by performing the behavioral-level simulation using measurement-based behavioral model. To meet the IEEE802.11a WLAN standard, a system transmitting 1024 symbols through 64-QAM process at the rate of 54Mbps should be implemented and nonlinear properties are confirmed by simulations of ACPR and EVM in this circumstance. The right offsets of ACPR which are 30MHz, 20MHz, and 11MHz distant from the center frequency of 5.8GHz are 49.36dBc, 36.90dBc, and 24.58dBc, respectively. The left offsets are 50.14dBc, 30.04dBc, and 28.85dBc, respectively and EVM is 2.94%. The size of the module implemented with LTCC five-layer substrates is $13.4mm{\times}14.2mm$. The measured characteristics of the transmitter show P1dB of 16.2dBm and power gain of 16.73dB. Those of the receiver exhibit the small signal gain of 16.24dB and noise figure of 7.83dB.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.23-28
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• 2007

Auxin-producing antagonistic bacterium K11, which can inhibit Phytophtora capsici, was isolated from a local red-pepper field soil in Gyeong-buk. In order to check for additional PGPR(plant growth promoting rhizobacterium) functions of the strain K11, we confirmed siderophore and cellulase productions by CAS (chrome azurol S) blue agar and CMC plate with congo red, respectively. The strain K11 was identified as Bacillus licheniformis with 98% similarity on 16s rDNA comparison and Biolog analyses. B. licheniformis K11 promoted mung bean adventitious root induction and enhanced root growth of mung bean (160%), pea (150%), and Chinese cabbage (130%), Also, B. licheniformis K11 was able to effectively suppress (63%) P. capsici causing red-pepper blight in the pot in vivo test. Therefore, we could select a triple-functional PGPR which has auxin, siderophore, and cellulase producing ability for effective crops production in organic farming.

• Journal of the Korean Chemical Society
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• v.43 no.3
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• pp.302-306
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• 1999

The 1,3-dipolar cycloaddition reaction of the quinoxaline 4-oxide 10 with 2-chloroacrylonitrile gave the 2,3-dihydro-lH-1,2-diazepino[3,4-blquinoxalines lla, b, respectively, which were converted into the 2,3,4,6-tetrahydro-lH-l,2-diazepino[3,4-b]quinoxaline 12. The reaction of compound lla with selenium dioxide in acetic acid/water resulted in ring transformation to give the 1,4-dihydro-4-oxopyridazino[3,4-blquinoxaline 13.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.453-460
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• 2017

This study proposes effective quality control and maintenance method by developing a new qualitative evaluation method of apron for medical radiation protection. As an experimental material, one of 0.45 mm lead and 100 of 0.45 mm Pb aprons were used and irradiated under the conditions of a tube voltage of 75 kVp and a tube current of 12.5 mAs to obtain an image. and using the Image J program, PSNR values were compared and analyzed. The results showed that there were 40 aprons (less than 11dB), 55 aprons (less than 11dB, less than 30dB), and 5 aprons (30dB or more). In addition, the dose showed a normal distribution for the apron, and 5 aprons with PSNR less than 11dB and 30dB or more were selected and divided into 8 zones, and these groups were statistically significant.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.472-474
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• 1984

Gel filtration of water soluble protein of soybean and cotyledon of sprout at various growth stages by using Sephadex G-200 showed 5 fractions (A,B,C,D and E). According to gel filteration and disc gel electrophoresis, fraction B,C and D were identified as 11S,7S and 2S, respectively. Fraction A was turbid substance and fraction E showed 1 peak. During growth of sprout 7S decreased firstly, 2S secondly and 11S lastly in cotyledon. Fraction A increased until 6th day and decreased thereafter while E increased throughout the growth. In axis only two fractions (11S+7S and E) were showed, and 11S+7S fraction was little changed and fraction E increased slightly with the growth.