• Journal of Species Research
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• v.5 no.3
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• pp.459-462
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• 2016

The branchiobdellidan species Holtodrilus truncatus (Liang, 1963) is reported for the first time in Korea. The genus Holtodrilus Gelder and Brinkhurst, 1990 is monotypic within the family Xironodrilidae, and the genus and family of this species are also new to the Korean fauna. The branchiobdellidan specimens were collected from the exoskeletons of the freshwater atyid shrimp, Neocaridina sp., sampled from the 'Andeok Valley', Jeju-do Province, South Korea. Holtodrilus truncatus is characterized by its terete body form, 7/7 dental formula (with a large medial tooth and three pairs of smaller lateral teeth), and no trunk appendages. In addition, we determined a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene as a DNA barcode marker for H. truncatus. The present study is the first record of the branchiobdellidan occurrence on a non-crayfish host (shrimp) in Korea. To date, seven species (four genera in three families) of branchiobdellidans have been reported in the Korean fauna.

• Animal Systematics, Evolution and Diversity
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• v.30 no.1
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• pp.26-32
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• 2014

Cleantioides planicauda (Benedict, 1899) has previously been recorded in China and Japan. In the present study, to our knowledge, we report for the first time the occurrence of this species in South Korea. Here, we provide detailed descriptions and illustrations of the diagnostic characteristics of C. planicauda. Further, for the first time, we determined the partial sequence of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene of C. planicauda for molecular characteristic. Additionally, we provide a key to the Korean species and distribution of the genus Cleantioides. As a result of this study, four species of the genus Cleantioides, including C. planicauda, have now been recorded in South Korea.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.563-568
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• 1999

Generally the control method of wire feeding motor in welding machine has been used full-wave phase control method. The fire-angle control generates low frequency speed ripple, and it causes the output current ripple. So it results in the variation of welding condition and low welding performances such as spatter generation and bead state. For the purpose of welding performances improvement by speed controller in wire feeding motor, in this paper the constant speed control method for welding machine is proposed. The proposed system is composed of speed control loop and current control loop. As a result of experiment by using proposed constant wire feed experiment by using proposed constant wire feed speed controller, the output voltage and current waveform and metal transfer are maintained stably. And moreover the number of instantaneous short circuit occurrence is reduced remarkably.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.109-115
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• 2006

Although the clays were one of the major materials of building constructions, presently, its functions are lesser and the cements take its place as building materials. however, the IAQ problems such as $CO_2$ increase, Rn gas and VOCs occurrence should be imperative from production and construction processes of the cements. This study aims to develop the alternate clay compounds to cements and analyze its properties by experimental tests. For the study, the claymineral of Chungchong-bukdo 10 areas are used. The chemical and structural properties are experimentally analyzed and the pozzolan reaction possibilities of clays are executed.

• ALGAE
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• v.21 no.1
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• pp.11-13
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• 2006

In this work we report the occurrence of Scytosiphon gracilis Kogame (Scytosiphonaceae, Phaeophyceae) on the Pacific coast of Mexico. This is the first report of S. gracilis outside its previously known distribution in the western North Pacific (Korea and Japan). The identification was based on a morphological revision and a comparison of the plastid-encoded RuBisCO spacer sequences determined for Korean and Mexican algal material. Thalli were collected from the intertidal zone of Saldamando Beach, Baja California, in January 2003. The vegetative structure, as well as habitat and geographic distribution of the species are described. Reproductive structures were not found in our specimens. The poor presence/absence of S. gracilis in previous floristic studies of the area could be due to its small size and low frequency.

• Laser Solutions
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• v.3 no.2
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• pp.53-61
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• 2000

On the laser weld production line, a slight alteration of the welding condition produces many defects. The defects are monitored in real time, in order to prevent continuous occurrence of defects, reduce the loss of material, and guarantee good quality. The measurement system is produced by using three photo-diodes for detection of the plasma and spatter signal in CO$_2$ laser welding. For high speed CO$_2$ laser welding, laser tailored welded blanks for example, on-line weld quality monitoring system was developed by using fuzzy multi-feature pattern recognition. Weld qualities were classified optimal heat input, a little low heat input, low heat input, and focus misalignment, and final weld quality were classified good and bad.

• Wind and Structures
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• v.4 no.2
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• pp.147-162
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• 2001

This paper presents an analytical method which takes into account the non-linearity of individual members, and discusses some case study results. It also discusses the relationship between member non-elastic behavior and excitation duration, and the relationship between member fracture and overall structure behavior. It is clearly demonstrated that the frame already shows almost unstable behavior due to long-columnization just before the occurrence of a column fracture. Then, a column fracture immediately induces a structural collapse mechanism.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.373-382
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• 1999

Nucleation and growth process of sticking particle in ferritic stainless steels was investigated using a two disk type hot rolling simulator. The sticking behavior was strongly dependent on the surface roughness of a high speed steel roll(HSS) and the oxidation resistance of the ferritic stainless steels. A hot rolling condition with the lower oxidation resistance of the stainless steel and the higher surface roughness of HSS roll was more sensitive to sticking occurrence. It was also illucidated that the initial sticking particles were nucleated at the scratches formed on the roll surface and were served as the sticking growth sites. As rolling proceeded, the sticking particles grew sites. As rolling proceeded, the sticking particles grew by the process that the previous sticking particles provided the sticking growth sites.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.543-545
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• 2019

Recently, the demand for smart farms is increasing due to the increase in the cultivation area such as horticulture, fruit trees and special crops. However, due to the irregular weather changes and the cultivation method of the crops due to the different cultivation environment, there are frequent occurrence of diseases and insect pests and infectious diseases due to system error or carelessness, and the cycle is also very short. In addition, the Smart Farm business has been built by combining various sensors (temperature, humidity, CO2, illumination) and LED lighting, but it is costly in terms of frequent errors, lack of power supply, And thus the management can not be efficiently managed. Therefore, this paper combines real time sensing technology based on IoT Platform and high performance control technology to control pests and equipment errors and monitor the growth status of crops in real time based on big data analysis and Artificial Intelligence System.

• Journal of IKEEE
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• v.24 no.2
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• pp.426-434
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• 2020

FMI is being researched as a standard for linking large-scale simulation of CPS. In order to guarantee the reliability of the results in large-scale simulations using FMI, event handling through time management techniques is required. This paper aims to guarantee real-time performance and accuracy in large-scale co-simulation environments such as CPS. Synchronize the wallclock time and simulation time to ensure real time. Also, to ensure the accuracy, before the simulation, the event is checked and the simulation is performed with the smallest step size while maintaining the real time until the event occurrence time. As a result, the events occurring in the co-simulation environment are processed immediately and sequentially, ensuring the real-time performance and minimizing the numerical integration error by maximizing the simulation resolution. In the experiment, the proposed method was processed immediately, and it was confirmed that the numerical integration error is reduced by about 1/5 unlike the existing time management method which does not guarantee the resolution.