• The Magazine of the IEIE
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• v.18 no.6
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• pp.51-54
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• 1991

• Explosives and Blasting
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• v.25 no.1
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• pp.31-43
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• 2007

In most tunnel constructions in South Korea, blasting has been widely used as an excavation method. In tunnel blasting, the center-cut to induce first free surface is very important for enhancing excavation efficiency and reducing vibration caused by exploding. This paper introduces new center-cut method named SAV-cut (Stage Advance V-cut) developed on the concept of V-cut. Significant features of SAV-cut are the center hole and stepwise ignition. Many field tests and numerical analysis were carried out to analyze the mechanical behavior and blasting vibration. From the results, the newly developed SAV-cut was proved as an effective center-cut method for both increasing blasting efficiency and decreasing blasting vibration.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.47-52
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• 2024

Through the coronavirus pandemic, research on the use and advancement of blockchain-based decentralized identity authentication (Decentralized ID) technology is being actively conducted in various fields, centered on the central government, local governments, and private businesses. In this paper, we introduce the results of development based on Hyperledger Fabric to change the existing central server-based identity authentication to a decentralized one. These development results can strengthen the security and transparency of identity authentication systems for commercial purposes and provide stable services for user ID issuance, inquiry, and disposal. In addition, the decentralized identity authentication system verified performance results of DID creation of 262,000 rps and DID inquiry of 1,850 rps, DID VP creation of 200 rps, and DID VP inquiry of 220 rps or less through public authentication.

• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.5-14
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• 2007

In this study, Matsuda formula used to evaluate the loads acting on the pillar was investigated and load reduction factor(${\alpha}$) was evaluated by numerical analysis to better apply for the design. From the results, normal stress was concentrated to one side due to excavation of preceding tunnel after construction of pillar. And 86.5% of maximum normal stress was revealed partly unequally when the ground was poor. By numerical analysis, $14{\sim}83%$ of total loads calculated by Matsuda formula decreased and then, from these results, load reduction factor(${\alpha}$) was estimated. From now on, stability and economic aspects could be guaranteed by applying the load reduction factor(${\alpha}$).

• Food Engineering Progress
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• v.13 no.4
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• pp.314-319
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• 2009

Metallothioneins (MTs) are low molecular weight, cysteine-rich, and heavy metal binding proteins, which could be induced with heavy metals such as Cd, Hg, Zn and Cu in liver, kidney, and in cultured cells. By using ion exchange chromatography on DE-52, MT was purified from the serum of carp induced with cadmium in order to produce antibody against MT. Polyclonal antibody produced against purified carp MT reacted well with MT in the serum of carp induced with cadmium, whereas control serum did not. This may indicate that the polyclonal antibody against the carp MT could be used for the preparation of biosensors to detect MT in fishes like carp.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.10a
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• pp.209-219
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• 2008

• Construction Engineering and Management
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• v.21 no.4
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• pp.11-15
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• 2020

• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.70-75
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• 2023

This study was conducted from October 2021 to October 2022 at Gulup island, Incheon, South Korea, to identify activity patterns of Formosan sika deer (Cervus nippon taiouanus) introduced in island areas, using camera trapping. We described the daily activity patterns of Formosan sika deer in each season by analyzing kernel density estimates of capture frequency and checked seasonal differences in daily activity patterns by analyzing the overlap coefficient between seasons. Formosan sika deers introduced to Gulup island showed a crepuscular behavior pattern only in winter and no distinct pattern from spring to fall. The crepuscular behavior pattern is typical for deers to reduce the risk of predation, and it is determined that Formosan sika deers introduced to Gulup island were affected by population control of the species by the local government in the winter. It was in contrast to the fact that human activities, such as backpacking, frequently carried out from spring to fall, did not affect the behavior of Formosan sika deers. Moreover, low winter temperatures have been shown to affect the nocturnal activities of Formosan sika deers in winter. The behavior patterns of Formosan sika deers overlapped least between summer and winter due to cold winter weather and population control. The relationship between the temporal status of Formosan sika deers and seasonal temperature confirmed in this study can be important basic ecological data for establishing control measures of Formosan sika deers introduced not only in islands but also in inland.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.377-382
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• 2004

In the present study, thirteen healthy volunteers performed lumbar extension exercises at 48$^{\circ}$/s, loaded by 40, 50, 60kg(about 44, 55, 66％ of maximum voluntary contraction). During the whole period of exercises, electromyographic(EMG) signal was measured in the erector spinae muscle in order to determine muscle fatigue. Using the wavelet transform, EMG signal was separated by various frequency ranges in the time-frequency domain, and muscle fatigue was analyzed, comparing with the results based on the median frequency(MDF). MDF shifted toward the lower frequency ranges with the muscle fatigue, showing a single characteristic frequency. On the other hand, wavelet transform of EMG signals resulted in increased power amplitude in lower frequency ranges(0-125Hz), and decreased power amplitude in higher frequency ranges(375-468Hz). This study reveals that the muscle fatigue during dynamic movement is explained better by wavelet analysis.

• Plant Journal
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• v.18 no.2
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• pp.46-51
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• 2022

As GHG reduction becomes a major global issue, the importance and interest of ETS is increasing. Korea experienced positive effects of the system since the introduction of ETS in 2015, but also faced various problems. The focus of this study is on the issue of applying the ETS system to the group energy of industrial complexes. The group energy of industrial complexes is a unique industrial form of Korea that cannot be found in the world. Therefore, if the system is implemented in the same way as the preceding countries, it will inevitably cause problems. In particular, the group energy of industrial complexes has the characteristic that the conditions and amount of heat supplied are dtermined according to the demands of customers and the amount of power generation is determined accordingly. We investigated how differenct temperatures of heat produced in cogeneration affect carbon credit calculations.