• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.65-71
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• 2016

Cooperative relaying systems have been studied actively to improve the system performance effectively in wireless fading channels. Most of the cooperative relay studies are assumed fixed relay, recently the performance analysis of the cooperative relaying systems with spatially random relays considering the practical mobile environment are introduced. However the comparative studies for relay selection methods of incremental cooperative relay systems, the performance of which is influenced by the selection methods, have not been studied. Therefore we derive the performance of the system which has MRC(Maximal-ratio combining) with Max SNR(signal-to-noise ratio) selection or Max-min SNR selection, respectively. And the outage performances of the system with Max or Max-min selection method are compared for different transmit power allocation to the source and to the relays. The analytical results serve as useful tools for relay selection and power allocation to transmit nodes for opportunistic incremental relaying systems.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1370-1376
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• 2000

Consider the problem to updata breadth-First Spanning Tree in response to topology change of the network. The paper proposes an efficient distributed algorithm that solves such a problem after several processors and links are added and deleted. Its message complexity and its ideal-time complexity are O(p√q+q+a+n') respectively, where n' is the number fo processors in the network after the topology change, a is the number of added links, p is the total number of links in the biconnected component (of the network before the topology change) including the detected links or added links, and q is the total number of processors in the biconnected component (of the network before the topology change) including the deleted links or added links, and q is the total number of processors in the biconnected component including the deleted links or added links.

• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.516-518
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• 2013

A new leaf variegated cultvar 'White Edge' was developed by ethyle methane sulfonate(EMS) treatment on seed of Hosta minor. Among induced leaf variegated plant, some with white color on the edge of the leaves was selected. They were cultivated via vegetative propagation. 'White Edge' was finally selected through the test of characteristics from 2003 to 2005. Assessment of botanical characteristics was conducted for three years. The major characteristic of these cultivar is that they maintain uniformly all year round. 'White Edge'(Grant No.1880) was registered to the Korea Seed and Variety Service(KSVS) for commercialization in 2007. These cultivar are useful as materials for pot or as ground cover plants.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.4
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• pp.63-73
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• 2002

This paper presents the results of a ten-day long survey for assessing the possibility of further oil spillage from the sunken tanker, Kyung-Shin(995 G/T), which had sunken in the East Sea, off Pohang City, in February 1988. The survey was conducted using remotely operated vehicle(ROV), manned submersible and ultrasonic thickness gauge in September 2001. The external inspection by the optical camera shows that small scale oil spill has been continued from the sunken ship. It's hull thickness was also measured at several points of the ship, using an ultrasonic sensor for assessing the current corrosion status of the sunken ship. Taking into account the results of this survey and the existing salvage report, it is estimated that the remaining oil in the tanker is approximately 600 ㎘, and this oil could be leaked into marine environment due to continuous severe corrosion if no preventive is taken.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.20-29
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• 2014

As construction projects increase their complexity, variety, and scale, various recognition applications (such as RFID, bar-code etc.) have been tried for managing material effectively in construction projects. However, existing recognition applications for construction material management have some limitations that cause additional works (such as attaching RFID tag), additional cost (labor cost, recognition device cost, etc.), and cognitive impairment of workers. Therefore, this study proposed a character recognition technology as an alternative of previous recognition technologies such as RFID, bar-code, etc. The technical feasibility of proposed technology was validated by three recognition tests. Additionally, this study proposed code the structure to manage materials using the character recognition technology. The effects of character recognition technology are presented by comparing with existing RFID-based logistics processes.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1117-1124
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• 2018

Contrast enhancement plays an important role in various computer vision systems, since their usability can be improved with visibility enhancement of the images affected by weather and lighting conditions. This paper introduces a histogram modification algorithm that reflects the properties of original images in order to eliminate the saturation effect and washed-out of image details due to the over-enhancement. Our method modifies the original histogram so that an additive term fill histogram pits and the gamma correction suppresses histogram spikes. The parameters for the additive term and gamma correction are adjusted automatically according to statistical properties of the images. Experimental results for various low contrast and hazy images demonstrate that the proposed contrast enhancement improves visibility and reduces haze components effectively, while preserving the characteristics of original images, than the conventional methods.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.5-13
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• 2008

To identify the reclamation history formed by top dredged soil reclamation layer over the original ground, various field tests and laboratory tests were conducted. Especially when the original ground was not completely consolidated, CPTu test was carried out to calculate rational settlement due to the banking load. CPTu test results showed that the degree of consolidation of weak clay ground by dredged reclamation was on average 80%. As the research area was not completely consolidated by dredged reclamation in the past, the consolidation settlement should account for the residual settlement (20%) in the case of additional banking load. When the degree of consolidation of the original ground was not taken into account, the residual consolidation was expected in excessive settlement (up to 20%) and in such case PBD (Plastic Board Drain) was not effective in obtaining desired degree of consolidation.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.255-261
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• 2008

RFID(Radio Frequency IDentification) is a technology that automatically identifies objects containing the electronic tags by using radio frequency. In RFID system, the reader needs the anti collision algorithm for fast identifring all of the tags in the interrogation zone. This Paper proposes the tree based TPAE(Tag Prediction Algorithm using Extra bit) algorithm to arbitrate the tag collision. The proposed algorithm can identify tags without identifring all the bits in the tag ID. The reader uses the extra bit which is added to the tag ID and if there are two collided bits or multiple collided bits, it checks the extra bit and grasps the tag IDs concurrently. In the experiment, the proposed algorithm had about 50% less query iterations than query tree algorithm and binary search algorithm regardless of the number of tags and tag ID lengths.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.25-35
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• 1972

This investigation was carried out to find the effects of silkworm rearing technique on the harvesting amounts. In spring and autumn of 1971, 14 silkworm rearing farmers at Botong Ri and Youngsoo Ri, Chongnam Myun, Hwaseung Kun, Kyunggi Do in Korea were selected as sample farmers. They were devided into two groups, high productivity group and low productivity group according to their harvesting amounts per box of silkworm eggs in 1970. The high productivity group represents the farmer who produced above average harvesting amounts per box, and the low group represents below average group. In this investigation, all farmers were adjusted to share uniform rearing condition with even mulberry leaves. Under this uniform condition, the effects of rearing techniques on the harvesting amounts per box of silkworm eggs and the effects of rearing condition on the harvesting amounts were inferred. Results obtained are as fellows; (1) Measuring from the 14 sample farmers, the effect of rearing technique on the harvesting amounts per box covers 15% of farmers in spring rearing season but 33% in autumn season. (2) Measuring from these sample farmers, the effects of the nutrition condition is less than 56% in spring rearing season but less than 69% in autumn, and it can be concluded that these effects include the effect of climate factor. (3) In the low productivity group. the most important facto. affecting the low productivity is non-disinfection of rearing environment.

• Journal of the Korean GEO-environmental Society
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• v.20 no.3
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• pp.15-20
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• 2019

A large amount of site investigation data is essential to obtain reliable design value. However, site investigations are generally insufficient due to economic problems. It is important to estimate the ground profile information in unboring region for accurate earthwork-volume prediction, and such ground profile information can be estimated by using the geo-statistical approach. Furthermore, the ground profile information in unboring region can be estimated by training a model via machine learning technique such as artificial neural network. In this paper, artificial neural network-based model estimated the ground profile information in unboring region, and this results were compared with that of ordinary kriging technique, which is referred to the geo-statistical approach. Accordingly, a total of 84 ground profile information in an actual bridge environment was split into 75 training and 9 test databases. The observed ground profile information of the test database was compared with those of the ordinary kriging technique and artificial neural network.