• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.1
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• pp.8-13
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• 2022

This paper investigates the method to implement a RF (Radio Frequency) energy harvesting sensor node and to build a sensor network using a CATV network and a leaky coaxial cable. The power supply of a sensor node is designed with the WPTS (Wireless Power Transfer System) receiver operating at 915MHz. A sensor network has limited coverage by the loss of RF signal at a wireless transmission link. The paper proposes to build a sensor network that the BLE signal of a sensor and the signal of a WPTS power transmitter are transmitted through a coaxial cable of a CATV network by utilizing WOC (WiFi over Coax) technology and radiates at a leaky coaxial cable. The length of a leaky coaxial cable and the total loss of a wire link are allowed to the point that the RSSI of a sensor node is more than the minimum value (-78dBm) and lead to extend wireless coverage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.254-260
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• 1999

Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antenna beam width to cover entire hot-spot region in the space and, by compensating effective burst length through cutting down man-made noises introduced by antenna. Based on the analysis, we are developed a small-opening-cavity antenna, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antenna exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100 km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antenna under same testing condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.6
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• pp.788-801
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• 1998

Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed ; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antennal beam width to cover entire hot-spot region in the space and, by compensating effective burst length throughcutting down man-made noises introduced by antennal. Based on the analysis, we are developed a small-opening-cavity antennal, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antennal exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antennal under same testing condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.8
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• pp.845-854
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• 2003

In this paper, the characteristics of compensation for WDM channel signal distortion due to both chromatic dispersion and Ken effect in 1,000 km 200 Gbps(5${\times}$40 Gbps) WDM systems was investigated. The WDM system has a path-averaged intensity approximation(PAIA) mid-span spectral inversion(MSSI) as a compensation method. This system has a highly nonlinear dispersion shifted fiber(HNL-DSF) optical phase conjugator(OPC) in the mid-way of transmission line. In order to evaluate the degree of compensation, 1 dB eye opening penalty(EOP), bit error rate(BER) characteristics and power penalty of 10$\^$-9/ BER are used. It is confirmed that HNL-DSF is an useful nonlinear medium in OPC fur wideband WDM system with PAIA MSSI and that the optimal compensation for WDM channel distortion is achieved by the selection of pump light power of OPC, which equalize the conjugated light power into the second half fiber section with the input WDM signal light power depending on total transmission length, dispersion coefficient of fiber, OPC pump light wavelength, conversion efficiency of WDM channel in OPC.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1701-1707
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• 2005

This study deals with the characterization of porcine PIK3C3 and association tests with quantitative traits. PIK3C3 belongs to the class 3 PI3Ks that participate in the regulation of hepatic glucose output, glycogen synthase, and antilipolysis in typical insulin target cells such as those in the such as liver, muscle system, and fat. On the analysis of full-length mRNA sequence, the length of the PIK3C3 CDS was recorded as 2,664 bps. As well, nucleotide and amino acid identities between human and pig subjects were 92% and 99%, respectively. Five SNPs were detected over 5 exons. We performed genotyping by using a SNP C2604T on exon24 for 145 F$_2$ animals (from a cross between Korean native boars and Landrace sows) by PCR-RFLP analysis with Hpy8I used to investigate the relationship between growth and fat depot traits. In the total association analysis, which doesn' consider transmission disequilibrium, the SNP showed a significant effect (p<0.05) on body weight and carcass fat at 30 weeks of age as well as a highly significant effect (p<0.01) on back fat. In an additional sib-pair analysis, C allele still showed positive and significant effects (p<0.05) on back fat thickness and carcass fat. Moreover, the effects of C allele on the means of within-family components for carcass fat and back fat were estimated as 2.76 kg and 5.07 mm, respectively. As a result, the SNP of porcine PIK3C3 discovered in this study could be utilized as a possible genetic marker for the selection of pigs that possess low levels of back fat and carcass fat at the slaughter weight.

• Applied Microscopy
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• v.39 no.2
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• pp.89-99
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• 2009

To investigate the morphological characteristics of spermatozoa of the grey red-blacked vole (Clethrionomys rufocanus) belongings to the subfamily Cricetinae, subgenus Clethrionomys were examined by scanning and transmission electron microscopes. The sperm head of C. rufocanus was an ax or hatchet in shape with a curved single dorsal hook. The total length of C. regulus sperm was 95.8 ${\mu}m$. The length of sperm head was 7.8 ${\mu}m$, and the tail (88.0 ${\mu}m$) consisted of four major segments: the neck (1.0 ${\mu}m$), middle piece (22.0 ${\mu}m$), and principal piece plus end piece (65.0 ${\mu}m$), respectively. The segmented columns were about 10~12 in number. The number of gyres of mitochondria ranged from about 170 to 178. The post-nuclear cap occupied about a half of nucleus. The equatorial segment is located between the post-nuclear cap segment and acrosomal cap on the nuclear surface. Nos. 1, 5 and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were in evidence, but the fibrous sheath was not seen at the end piece. In conclusion, the morphological structures of sperm head and tail may be useful information to patterning of sperm evolution and classifying of species.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.434-438
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• 2008

To selection of optimal shading material, two-year-old ginseng (Panax ginseng C. A. Meyer) of new cultivar, 'Cheonpoong' (CP), and native species 'Hwangsookjong' (HS) were cultured under three kinds of shading materials such as three-layered blue and a one-layered black PE (polyethylene) net (TBSB), blue PE sheet (BS), and aluminium coated PE sheet (AS) in imperfectly drained paddy soil. Growth characteristics, yield and ginsenoside contents were investigated under three shading materials. Yield and ginsenoside contents of ginseng were distinctly affected by intensity and quality of sunlight penetrated through shading materials. Light transmission ratio, air and soil temperature according to shading materials were higher in order of BS, AS, and TBSB. However, ratio of aerial phase and porosity of the soil were higher in order of AS, BS, and TBSB, respectively. There was no significantly difference in the ratio of rusty colored root by shading materials. CP showed higher stem length, leaf area, and root weight than that of HS, while the former showed distinctly lower discolored leaf ratio than that the other. Eight kinds of ginsenosides content of CP were higher than that of HS in $Rg_1$, Re, Rf, $Rb_1$ and Rc except $Rg_2$, $Rb_2$, and $Rb_3$. Total ginsenoside contents of CP was distinctly higher than that of HS. Total ginsenoside contents as affected by shading materials was higher in order of BS, TBSB, and AS in CP, while TBSB, BS, and AS in HS.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.230-237
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• 2003

This study was conducted to investigate the occurrence and characterization of tobacco mosaic virus(TMV) in Chinese foxglove isolated from the field of the Chonbuk province(Jinan, Jangsu, Jeongeup). TMV was detected in all three regions and confirmed positive reaction by ELISA test. In the host range test, Chenopodium amaranticola, Nicotiana glutinosa, N. tabacum cv. 'Bright yellow', N. tabacum cv. 'KY­57, Datura stramonium were locally infected with the virus. The virus produced mosaic symptom on inoculated leaves of N. tabacum cv. 'Samson'. However, Chenopodium quinoa, Glycine max, Raphanus sativus, Cucumis sativus, Cucurbita moschata, Brassica rape and Lycopersion esculentum did not show any symptoms. TMV particles were revealed as a stiff rod shape by transmission electron microscopic(TEM) and measured as 300 nm in length with 18 nm in diameter. Total RNA was extracted from showing symptom loaves infected with TMV and the reverse transcription­polymerase chain reaction (RT­PCR) obtained 531 bp DNA product of RNA with specific primer used. The capsid protein of TMV­RE showed higher amino acid sequence homology(97.7％) with TMV­To than with TMV­P(72.2％). The capsid protein of TMV­152 showed same amino acid sequence homology with TMV­F. The result of comparison of nucleotides sequence homology between TMV­RE strain and other TMV strain showed 94％ homology with others except TMV­P(67.3％) and TMV ­ C(68.6％).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.77-82
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• 2010

Our study aims to understand the flow of liquid in an open-top rectangular microchannel that can be used in micro total analysis systems ($\mu$-TAS) because it has advantages in terms of light transmission and energy efficiency. We measured the liquid velocity using particle tracking technique and conducted a simulation with computational fluid dynamics by altering the area of channel cross section and channel length for the capillary-driven flow in the open-top rectangular microchannel. When liquid water drops to an entrance of the fabricated microchannel with a height of 20 μm and a width of 20 ${\mu}m$, it flows along the microchannel by only capillary force. In the wetting behavior of the liquid, important parameters of this flow are channel size, contact angle and liquid properties such as surface tension and viscosity, which are used to control the flow of liquid in the microchannel.

• 한국문화재보존과학회:학술대회논문집
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• 2001.11a
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• pp.27-34
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• 2001

Following the recommendations made by the cultural authorities the wooden cultural properties (WCP) had been treated with fire-retardants for fire protection. However, visual inspections of some of the WCPs treated with fire-retardants showed microbial decay. The work was extended to examine the micromorphological characteristics of the WCPs in a Buddhist temple which had been treated with fire-retardant. Microscopic examination showed the presence of typical soft rot cavities along the length of microfibrils in the secondary wall. Bacterial attack was also observed by scanning and transmission electron microscopy. It is interesting that the decay patterns observed in the Buddhist temple were very similar to those observed in the waterlogged woods. Presumably chemicals in the fire-retardants used rendered the wood susceptible to attack by soft-rot and bacterial decay by causing an increase in the moisture content of wood. Further studies are needed to investigate the effect of fire-retardants used currently on the hygroscopicity and the strength of wood materials in the WCPs. Microbial attacks caused degradation of the secondary cell walls and in some cases also of the middle lamella. In addition, the cell walls in the outer parts of wood were also degraded due to weathering, and cell separation occurred from total disintegration of the middle lamella.