• Journal of IKEEE
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• v.26 no.3
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• pp.389-395
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• 2022

With the evolution of technology, cyber physical systems (CPSs) are being upgraded, and new types of cyber attacks are being discovered accordingly. There are many forms of cyber attack, and all cyber attacks are made to manipulate the target systems. A representative system among cyber physical systems is a cyber physical power system (CPPS), that is, a smart grid. Smart grid is a new type of power system that provides reliable, safe, and efficient energy transmission and distribution. In this paper, specific types of cyber attacks well known as false data injection attacks targeting state estimation and energy distribution of smart grid, and protection strategies for defense of these attacks and dynamic monitoring for detection are described.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.893-903
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• 2022

Recently, computer vision (CV)-based safety monitoring (i.e., object detection) system has been widely researched in the construction industry. Sufficient and high-quality data collection is required to detect objects accurately. Such data collection is significant for detecting small objects or images from different camera angles. Although several previous studies proposed novel data augmentation and synthetic data generation approaches, it is still not thoroughly addressed (i.e., limited accuracy) in the dynamic construction work environment. In this study, we proposed a game engine-driven synthetic data generation model to enhance the accuracy of the CV-based object detection model, mainly targeting small objects. In the virtual 3D environment, we generated synthetic data to complement training images by altering the virtual camera angles. The main contribution of this paper is to confirm whether synthetic data generated in the game engine can improve the accuracy of the CV-based object detection model.

• Ocean Systems Engineering
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• v.13 no.3
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• pp.287-312
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• 2023

The global performance of a 15 MW floating offshore wind turbine, a newly designed semisubmersible floating foundation with multiple heave plates by CNOOC, is investigated with two independent turbine-floater-mooring coupled dynamic analysis programs CHARM3D-FAST and OrcaFlex. The semisubmersible platform hosts IEA 15 MW reference wind turbine modulated for VolturnUS-S and hybrid type (chain-wire-chain with clumps) 3×2 mooring lines targeting the water depth of 100 m. The numerical free-decay simulation results are compared with physical experiments with 1:64 scaled model in 3D wave basin, from which appropriate drag coefficients for heave plates were estimated. The tuned numerical simulation tools were then used for the feasibility and global performance analysis of the FOWT considering the 50-yr-storm condition and maximum operational condition. The effect of tower flexibility was investigated by comparing tower-base fore-aft bending moment and nacelle translational accelerations. It is found that the tower-base bending moment and nacelle accelerations can be appreciably increased due to the tower flexibility.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.181-193
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• 2019

The regional economy growth of Jeju has seen higher than national growth since 2011 by the establishment of Jeju Special Self-Governing Province and the increase of incoming population, but its economic growth has slowed after 2016. This study conducted the dynamic shift-share analysis using the production and employees of each industry from 2010 to 2016, targeting Jeju with many factors of regional economic change. In the results of empirical analysis, the regional economy of Jeju was not the industrial structure depending on the national growth, but the industrial structure by the competitiveness and industrial structure of Jeju region. The industries having positive(+) effects of industrial mix effect and competitive effect on the production and the number of employees were the electricity/gas/heavy equipments & waterworks, construction, accommodation & restaurants, and service industry. These industries have positive effects on the regional industry of Jeju. The above-mentioned industries are not only more likely to grow than other regions, but also to drive the local economy of Jeju. In order for these industries to continuously contribute to the regional economy of Jeju, it would be necessary to have the policy/institutional support in the long-term perspective.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.65-68
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• 2004

CyberKnife is a stereotactic radiosurgery system which could be used to treat many tumors and lesions. It provides the surgeon unparalleled flexibility in targeting using a compact light linear accelerator mounted on a robotic arm. Advanced image guidance technology tracks patient and target position during treatment, ensuring accuracy without the use of an invasive head frame. CyberKnife with Dynamic Tracking Software is cleared to provide radiosurgery for lesions anywhere in the body when radiation treatment is indicated. It has often been used to radiosurgically treat otherwise untreatable tumors and malformations. Moreover, this instrument treats tumors at body sites, most of which are unreachable by other stereotactic systems. Compared with conventional radiotherapy, it is fundamentally different that using non-invasive, frameless, no excessive radiation exposure to normal tissue. In oral malignant neoplasm, surgical excision and radiation therapy should be tried first, additionally chemotherapy could be considered. However, after failure of conventional therapies, patients had poor systemic condition and surgical limitation. So, CyberKnife could be a suitable therapy. A 49 years man was referred in recurred mandibular cancer treated by radiotherapy. The tumor was considered inoperable, because of extensive invasion and was not expected to good response to conventional therapies. We experienced a case of CyberKnife after 4 cycle chemotherapies, so we report it with review of literature.

• Journal of Engineering Education Research
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• v.18 no.4
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• pp.26-33
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• 2015

The purpose of this study is to microscopically analyze the problem solving activities in creative robotics making and programming activity in order to investigate the characteristics of team interaction in accordance with MBTI disposition of team members in the creative robotics making activity in which the engineering education has a lot interest in the recent years. For the prosecution of this study, teams composed of 2 students targeting 30 students who were at the related department of engineering education in the college of eduction, A university located in Daejeon were organized. In addition, individual propensities of team members, in other words, team dynamic structure and team interaction were analyzed through microscopical analysis of the problem solving activities in creative robotics making and programming activity. The results of this study showed that there was a static correlation between the organization of MBTI Heterogeneity team and the interaction of team members, and also there was a positive interaction of team members in organizing MBTI Homogeneity team in area of Thought (T) - Feeling (F). In addition, mutual complement to solve the problems was carried out and the problem-solving capability was shown in the course of the communication along with the organization of MBTI team of extreme heterogeneity.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.173-179
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• 2011

This study aims to analyse difference in biomechanical factors between dominant legs and recessive ones according to muscular imbalance during drop landing targeting talented children in sports. The subjects of the study were ten primary students who are attending to Sports Program for Talented Children organized by C university (age: $12.28{\pm}0.70$ year, height: $1.52{\pm}0.11$ m, and weight: $45.2{\pm}4.9$ kg). Strength legs were classified into dominant side and strengthless legs were classified into non-dominant legs. For three-dimensional analyses of the data collected, 6 video cameras(MotionMaster200, Visol, Korea) were used. To analyse ground reaction force, two force platforms(AMTI ORG-6, MA) were used and to analyse electromyograghy a 8-channeled wireless Noraxon Myoresearch made in USA was used at 1000 Hz for sampling. As a result, it was discovered that the dominants legs controlled knee bending motions more stably than strengthless legs as the maximum vertical ground reaction force was significantly high in dominant legs(p<.05), and joint moment of knee joints of the dominant legs was high(p<.05). Therefore, this study suggested that injury prevention program focusing on muscular balance as well as the existing sports programs for talented children should be developed based on results of the study and it is expected that the results will be useful for improvement of sports programs for talented children.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.653-658
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• 2008

The demand of international intermodal transportation is continuously increasing in accordance with a changing environment on international logistics, Under this circumstance, the Sea&Air intermodal transportation, combined by sea-based and air-based transport, has a potential growth in the future. After analyzing routes for Origin/Destination and implementing portfolio analysis, finally, this research aims to propose alternatives to create additional customers(or cargoes) for the Sea&Air transport. As a result of the analyses, China appeared to be a major customer of the Sea&Air transport in Korea because some of the Chinese areas - i.e. Qingdao, Shanghai, Weihai and Yantai - account for 88.1% of the total throughput. In general, this indicates that it would be more efficient to establish specific strategies targeting those major areas. Excluding the four areas, most of the other area, have much less demands and are relatively unstable. The demands, growth rates and market shares especially in Vladivostok, Dandong and Tianjinxingang are on the decrease, and therefore, stable strategies seems to be appropriate than aggressive strategies for these areas.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1369-1376
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• 2006

Self-organized nanogels were prepared from pullulan/biotin conjugates (PU/Bio) for the development of an effective anticancer drug delivery system. The degree of biotin substitution was 11, 19, and 24 biotin groups per 100 anhydroglucose units of pullulan. The physicochemical properties of the nanogels (PU/Bio1, 2 and 3) in aqueous media were characterized by dynamic light scattering, transmission electron microscopy, and fluorescence spectroscopy. The mean diameter of all the samples was less than 300 nm with a unimodal size distribution. The critical aggregation concentrations (CACs) of the nanoparticles in distilled water were $2.8{\times}10^{-2},\;1.6{\times}10^{-2}$, and $0.7{\times}10^{-2}mg/ml$ for the PU/Bio1, 2, and 3, respectively. The aggregation behavior of the nanogels indicated that biotin can perform as a hydrophobic moiety. To observe the specific interaction with a hepatic carcinoma cell line (HepG2), the conjugates were labeled with rhodamine B isothiocyanate (RITC) and their intensities measured using a fluorescence microplate reader. The HepG2 cells treated with the fluorescence-labeled PU/Bio nanoparticles were strongly luminated compared with the control (pullulan). Confocal laser microscopy also confirmed internalization of the PU/Bio nanogels into the cancer cells. Such results demonstrated that the biotin in the conjugate acted as both a hydrophobic moiety for self-assembly and a tumor-targeting moiety for specific interaction with tumor cells. Consequently, PU/Bio nanogels would appear to be a useful drug carrier for the treatment of liver cancer.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.341-352
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• 2005

This study tries to analyze the dynamic market mechanism adopting relationship marketing techniques targeting between the shipping companies and shippers. Shipping companies rely on sales operation. so that analyzing the relation of structure of shipping companies and shippers needs to focus on the sales person's characteristic relationship and shipping company characteristic relationship. Therefore this study tries to focused on shipping companies to make a long term relationship with shippers affect matters which are, main of relationship quality and antecedent factor of characteristics of the shipping company and characteristics of the salesperson. It can be proffered available informations for construction of long term relationship between shipping companies and shippers.