changsoo ok

Dr. changsoo ok

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 December 2022 in Electronics
Verified
Journal Article
Open access
PDF file
JOJeongRim Oh
JeongRim Oh
JPJongJin Park
JongJin Park
COchangsoo ok
changsoo ok
CHChunghun Ha
Chunghun Ha
HJHong-Bae Jun
Hong-Bae Jun
Recently, wind power plants that generate wind energy with electricity are attracting a lot of attention thanks to their smaller installation area and cheaper power generation costs. In wind power generation, it is important to predict the amount of generated electricity because the power system would be unstable due to uncertainty in supply. However, it is difficult to accurately predict the amount of wind power generation because the power varies due to several causes, such as wind speed, wind direction, temperature, etc. In this study, we deal with a mid-term (one day ahead) wind power forecasting problem with a data-driven approach. In particular, it is intended to solve the problem of a newly completed wind power generator that makes it very difficult to predict the amount of electricity generated due to the lack of data on past power generation. To this end, a deep learning based transfer learning model was proposed and compared with other models, such as a deep learning model without transfer learning and Light Gradient Boosting Machine (LGBM). As per the experimental results, when the proposed transfer learning model was applied to a similar wind power complex in the same region, it was confirmed that the low predictive performance of the newly constructed generator could be supplemented.

1 January 2016 in Journal of Advanced Mechanical Design, Systems, and Manufacturing
Verified
Journal Article
Open access
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JPJaeil Park
Jaeil Park
SPSeJoon Park
SeJoon Park
COchangsoo ok
changsoo ok
The summer season witnesses a tremendous rise in electrical power consumption. To meet this electric demand, the reduction of electrical power demand in summer by improving the efficient utilization of facilities is critical. Currently, power management and power-saving efforts in the manufacturing industry are focused on improving efficiency through replacement and improvement of equipment that consumes large amounts of energy. However, recent advances in demand response have significantly increased awareness that can lead factory managers to schedule their energy consumption efficiently by shifting electrical loads. This paper presents an optimization model for managing facility operations with shifting electrical loads in an effort to deal with the most expensive hours of the day. An integer programming (IP) model is used as a formal presentation of the problem. The results from a performance analysis of the formulation in solving problems with different characteristics are prepared, along with illustrative examples. They demonstrate how a factory manager can shift electrical loads in response to electricity prices.

31 December 2018 in Journal of Society of Korea Industrial and Systems Engineering
Verified
Journal Article
Closed access
JJJung-Heum Jo
Jung-Heum Jo
YCYong-Taek Chung
Yong-Taek Chung
SCSeong-Wook Choi
Seong-Wook Choi
COchangsoo ok
changsoo ok

30 December 2014 in Journal of Society of Korea Industrial and Systems Engineering
Verified
Journal Article
Closed access
IKInho Kim
Inho Kim
COchangsoo ok
changsoo ok

25 October 2015 in International Journal of Distributed Sensor Networks
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Journal Article
Open access
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KKKyungdoh Kim
Kyungdoh Kim
CHChunghun Ha
Chunghun Ha
COchangsoo ok
changsoo ok
Routing algorithms for large-scale sensor networks should be capable of finding energy efficient paths to prolong the lifetime of the networks in a decentralized manner. With this respect, Ant System has several proper characteristics for routing algorithm in large-scale wireless sensor networks. First, its distributed mechanism enables routing algorithm to find a solution with only local information and be robust for uncertainties in wireless sensor networks. Second, the framework of the Ant System is proper to solve dynamic problems such as routing problem. Transition probability in Ant System can be used to estimate how good a given routing path is. Capturing these features, this work proposes two Ant Systems based routing algorithms, which are AS-RWSNs (Ant System for Routing in Wireless Sensor Networks) and SAAS-RWSN (Structure-Aware AS-RWSN). The AS-RWSN applies the original Ant System to routing algorithm for wireless sensor network and SAAS-RSN upgrades AS-RWSN with considering properties of network structure such as degree of node. In SAAS-RSN, sensors with high node degree have high data traffic since they have more routing paths. Consequently, SAAS-RSN achieves an energy balance over sensor network through this routing scheme. We demonstrate the effectiveness of the proposed algorithms by comparing three existing routing algorithms.

28 March 2022 in Journal of Electrical Engineering & Technology
Verified
Journal Article
Closed access
PDF file
SKSehwan Kim
Sehwan Kim
COchangsoo ok
changsoo ok
HSHyesung Seok
Hyesung Seok