• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.449-456
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• 1999

The concrete wall is the most useful of retaining structure which can obtain the engineering stability, but has problems that is not friendly with nature environment in a fine view, such as poor rear drainage, and shrinkage crack by temperature difference, etc. Because of this problems, the research for a segmental crib retaining wall has been performed. A segmental crib retaining wall is quickly and easily erected because is possible to be erected as the individual members, and is not sensitive to differential settlement and earthquakes. Also, it shows effective drainage and has a friendly advantage with nature environment because of being able to be planted with vines and shrubs in retaining walls The design of crib retaining walls has traditionally been based on classical soil mechanics theories. These theories, originally derived by Rankine(1857) and Coulomb(1776), assume that the wall acts as a rigid body. This assumption results in failure being predicted by either monolithic overturning or base sliding mechanisms. However, the wall consists of individual members which have been created a three dimensional grid. This grid confines an fill mass which becomes part of the wall. The filled wall resists the earth pressure with the same mechanism of classical gravity walls. Because of the flexibility of the individual segment, it allows relative movement between the individual members within the wall. The three dimensional flexible grid leads to stress redistribution when the wall is subjected to external or fill loads. Due to the flexibility and the stress redistribution, the failure of segmental crib wall consists of not only overturing and base sliding but the local deformation and the failure between the segmental members. It has been researched in the field that due to this flexibility and load redistribution, serviceability failure of segmental crib walls is unlikely to be due to overturning or base sliding. Therefore, in this study, the relative displacement appearance of retaining wall due to variation of inclination is measured to examine this behavior characteristics. Also, the behavior characteristics of retaining walls by surcharge load, and location of acting point of retaining wall rear, and the displacement characteristics and deflections are estimated about the existence and nonexistence of Rear Stretcher performing an role in transmitting earth pressure of Header and Stretcher organizing retaining walls. This research focuses on the characteristics due to the behavior of retaining walls. This research focuses on the characteristics due to the behavior of retaining walls.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.562-573
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• 2006

It is required to reduce the peak-to-average power ratio(PAPR) in an orthogonal frequency division multiplexing system or a multicarrier system. And it is needed to eliminate the transmission of the side information in the Partial Transmit Sequences. So, in this paper, a new technique is proposed, where the subcarriers used for the multiple signal representation are only utilized for the reduction of PAPR to eliminate the burden of transmitting the side information. That is, it is proposed by taking the modified minimization criteria of partial transmit sequences scheme instead of using the convex optimization or the fast algorithm of tone reservation(TR) technique As the result of simulation, the PAPR reduction capability of the proposed method is improved by 3.2 dB dB, 3.4 dB, 3.6 dB with M=2, 4, 8(M is the number of partition in the so-called partial transmit reduction sequences(PTRS)), when the iteration number of fast algorithm of TR is 10 and the data rate loss is 5 %. But it is degraded in the capability of PAPR reduction by 3.4 dB, 3.1 dB, 2.2 dB, comparing to the TR when the data rate loss is 20 %. Therefore, the proposed method is outperformed the TR technique with respect to the complexity and PAPR reduction capability when M=2.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.430-439
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• 2007

In this paper, we propose a broadband TEM horn antenna optimized using a genetic algorithm. The characteristics required for the TEM horn are the broad matching bandwidth from 2 GHz to 10 GHz and high gain in broadside with a small gain deviation within that bandwidth. In addition, a broadband balun is designed to improve the portability and to reduce the total size of the antenna. The measured return loss of the proposed TEM horn with the broadband balun is less than -10 dB(VSWR<2) from 2 GHz to 10 GHz. Compared to a conventional triangular type TEM horn, the proposed antenna shows about 80 % reduced volume and gives the broadside gain about 12 dBi with a gain deviation less than 6 dB from 2 GHz to 10 GHz. The time domain measurement shows less than 0.4 ns group delay and the pulse measurement using the transmitting signal with the rising time of 58.5 ps shows the received pulse with the rising time of 66.5 ps, which is less than 10 % rising time variation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.694-700
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• 2009

In this paper, we propose a RFID tag antenna with low performance degradation due to nearby dielectric materials. The proposed antenna is designed to be appropriate for ink printing fabrication. The antenna is designed to operate in UHF band of $860{\sim}960$ MHz. The antenna uses a T-matching network in the middle of the main body and two parasitic patches in vicinity for complex conjugate matching with a commercial tag chip. In addition, the two parasitic patches induce currents at different dielectric constants of nearby dielectric materials. This can minimize the performance degradation due to nearby dielectric materials. The measured results show the half power matching bandwidth from 844 MHT to 1,268 MHz. It exhibits the reading distance of about 3.5 m in free space when the tag antenna is used with the commercial reader antenna (transmitting power of 20 dBm and the reader antenna gain of 6 dBi). When the tag is attached on dielectric materials of wood and FR4, the resulting reading distances are 2.61 m and 2.51 m, respectively.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.113-121
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• 1983

In an effort to understand epizootiological aspects of infectious laryngotracheitis (ILT), a total of 56 chicken flocks in six farms comprised of 35 broiler breeder, 13 commercial layer and 6 layer breeder flocks. were investigated. The farms experienced ILT during the period of one year from June, 1982. In most farms the birds were vaccinated against ILT just before or after the disease outbreak. In two of the farms in which ILT broke out in winter, it was possible to contain the disease in only one or two fleets without transmitting it to the remaining 5 to 7 flocks in the farms by adopting strict isolation procedures for the affected flocks. In regarding inter- flock spreading speed, it took an average of 6 days for flocks rearing on floor and 11 days for those in cages. Among the flecks in rearing cages. transmission among laying flocks was much faster. taking an average of 8 days, compared to non-laying flocks of 17 days, suggesting spreading of the disease by means of egg trays or egg collection process. Peak mortality was observed between 5 and 10 days after from the time of appearance of first dead birds from the disease and the period of mortality, with an average of 18 days, was not influenced by rearing systems, breeds and age of birds. Mortalities in the affected flocks ranged from lo/e to 19.8%, with an average of 6.5 %, and was also not influenced by the above variables except significantly lower mortality in immature broiler breeder flocks (2.9%) compared to immature layer (11.8%) and mature broiler breeder flocks (6.9%). In one breeder farm in which all the birds were kept on floor and ILT broke out in summer, mortality in male birds in all seven flocks of 37 weeks of age or older was as high as twice of that in female birds in the same flocks. This trend was not observed in one 31 weeks old flock and was reversed in another 14 weeks old flock in the farm.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.1-21
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• 2005

Pullorum disease and Fowl typhoid are kind of poultry specific disease for poultry. The peculiar character of these poultry specific diseases is that it can be infected by transmitting vertically and horizontally, also it is hard to be discovered by clinical sign, and pathology or immunology. So, to develop the PCR method which distinguishes these two genetically similar diseases of separated the specific DNA fragment from each strain and use it for differential diagnosis by subtraction PCR method. Standard strain of S gallinarum and S pullorum, and field isolation strain were verified by biochemistry, It confirmed existence of plasmid by using the PFGE. Then, Isolated DNA from it and used it as materials for the experiment. After cutting genomic DNA of two strains by using Sau 3Al, It ligated primer to tester DNA for PCR amplification and separated specific DNA fragment bacteria with method of subtraction PCR. And, It confirmed that it is a piece of unique DNA in every bacteria using base sequence of separated DNA fragment. 1. The six specific DNA fragment were separated from the DNA of S gallinarum and S pullorum by the subtraction PCR method. 2. In the result of comparison after setting base sequence of each fragment, each separated base sequence of DNA fragment they did not correspond to each other 3. As the result of each DNA fragment is derived from the each strain of DNA, and there was no homology of genomic DNA level in mutual. 4. The fragment originated in plasmid and includes S pullorum did not separate. 5. In the result of searching base sequence in Genebank, it partially shows homology in Salmonella enterica, S typhimurium, S dublin, Escherichia coli, Shigella flexneri, Yersinia pestis, Klebsiella pneumoniae. 6. Primer design by S gallinarum DNA 2, 3 fragment used PCR, They are positive reaction in only S gallinarum at 276, 367 bp position.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.381-387
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• 1992

Gill epithelia of normal rainbow trout fingerlings and abnormal ones suffering bacterial gill disease by experimental infection were examined by transmitting electron microscopy (TEM) and scanning electron microscopy (SEM). TEM observations revealed that Flavobacterium branchiophila consisted of slender rods measuring 0.5 by 5 to $8{\mu}m$, and they had which were long, thin, flexible filaments measuring approximately 4 nm by $1{\mu}m$, and packed together to organize into bundles. Morphological alterations of the diseased epithelia started at hypertrophy of the lamellar epithelium. F branchiophila attached to the gill surface of infected fish through pili with a regular distance, and did not invade into gill tissue. In SEM observations, normal surface ultrastructure of epithelial cell in the outermost layer were characterized by a typical labyrinth-like structure branching and anastomosing microridges on the cell surface. Hyperplastic lesions in experimentally infected gill were most serious at near the tips. Each filament exhibited a club-like, and fusion between the filaments was sometimes observed at their tips. On the surface of gill filaments, thread-like bacterial cells attached and were entangled. The bacterial cells almost covered the surface. After immersion in 5 % NaCl, the cell of F branchiophila, however, appeared to be indeterminate shape.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.383-390
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• 2008

The mobile sink is most suitable to guarantee the real time processing to events in ubiquitous environment. However it brings many challenges to wireless sensor networks. In particular, the question of how to transfer the collected data to the mobile sink is an important topic in the aspect of effective management of wireless sensor nodes. In this paper, a new data dissemination model is proposed. Since this method uses the home agent and the access node concepts, it provides reliable and efficient data delivery to mobile sink with minimum overhead. In this proposed method, the information of the mobile sink which is constantly moving is informed only to the home agent node and the access node, instead of all sensor nodes. Thus, the collected data from sensor nodes are transferred to the fixed home agent and it sends these data to the mobile sink. Since the confliction phenomenon between data packets in wireless networks could be reduced, the success ratio of data arriving in the mobile sink is highly enhanced. In our experiments, the proposed method reduces the number of broadcast packets so that it saves the amount of energy consumed for transmitting and receiving the data packets. This effect contributes to prolong the lifetime of the wireless sensor networks operated by batteries.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.545-551
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• 1998

The Radio communication by existing SSB, VHF, etc. in a coast station and a base station for military affairs is still used to a very important the device of information delivery or transmitting and receiving by the remote controller to using to the exclusive cable for a equipment established at a long distance. When a number of consumer to connected and operated by a number of transceiver is essential for a circuit controller of ICS, in KOREA, is devoted by import to considerable quantity because of to be delayed development of this field. This Paper has been realized to optimal algorithm and designing of a circuit connection controller by multi-processor to pre-stage for the development of ICS. The H/W is composed able to remote control to circuit connector with the several slave processor and a processor for master, and this has taken possible through without any obstacle to communication circuits of a control signal by FSK system. The S/W make possible monitoring for communication condition of other circuits by means of a serial communication system by the multi-processing. This paper has been studied for connecting to a circuits wished to rapidly and precisely by the full application to a interrupt technique. A technique to control by remote to a number of transceiver is a way increasing to application for a frequency resource of the limited MF/SF, VHF and the existing radio communication technique. According to, this paper will achieve to be the reduction of energy & equipment and multiplicity of information delivery in the general communication and disposal to rapid and exact for the important communication as distress, urgency and safety on the sea.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.981-986
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• 2020

The Internet of Things refers to a space-of-things connection network configured to allow things with built-in sensors and communication functions to interact with people and other things, regardless of the restriction of place or time.IoT is a network developed for the purpose of services for human convenience, but the scope of its use is expanding across industries such as power transmission, energy management, and factory automation. However, the communication protocol of IoT, MQTT, is a lightweight message transmission protocol based on the push technology and has a security vulnerability, and this suggests that there are risks such as personal information infringement or industrial information leakage. To solve this problem, we designed a synchronous MQTT security channel that creates a secure channel by using the characteristic that different chaotic dynamical systems are synchronized with arbitrary values in the lightweight message transmission MQTT protocol. The communication channel we designed is a method of transmitting information to the noise channel by using characteristics such as random number similarity of chaotic signals, sensitivity to initial value, and reproducibility of signals. The encryption method synchronized with the proposed key value is a method optimized for the lightweight message transmission protocol, and if applied to the MQTT of IoT, it is believed to be effective in creating a secure channel.