• The korean journal of orthodontics
• /
• v.50 no.4
• /
• pp.229-237
• /
• 2020

Objective: To evaluate the construction reproducibility of a composite tooth model (CTM) composed of an intraoral-scanned crown and a cone-beam computed tomography (CBCT)-scanned root. Methods: The study assessed 240 teeth (30 central incisors, 30 canines, 30 second premolars, and 30 first molars in the maxillary and mandibular arches) from 15 young adult patients whose pre-treatment intraoral scan and CBCT were available. Examiner-Reference (3 years' experience in CTM construction) and Examiners-A and Examiner-B (no experience) constructed the individual CTMs independently by performing the following steps: image acquisition and processing into a three-dimensional model, integration of intraoral-scanned crowns and CBCT-scanned teeth, and replacement of the CBCT-scanned crown with the intraoral-scanned crown. The tooth axis angle in terms of mesiodistal angulation and buccolingual inclination of the CTMs constructed by the three examiners were measured. To assess the construction reproducibility of CTMs, intraclass correlation coefficient (ICC) assessments were performed. Results: The ICC values of mesiodistal angulation and buccolingual inclination among the 3 examiners showed excellent agreement (0.950-0.992 and 0.965-0.993; 0.976-0.994 and 0.973-0.995 in the maxillary and mandibular arches, respectively). Conclusions: The CTM showed excellent construction reproducibility in mesiodistal angulation and buccolingual inclination regardless of the construction skill and experience levels of the examiners.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.1
• /
• pp.9-13
• /
• 2002

Recently, Organic electroluminescent devices (OELDs) have been demonstrated the medium sized full color display with effective multi-layer thin films. In this study, the multi-layer OELDs were prepared on the patterened ITO (indium tin oxide)/glass substrates by the vacuum thermal evaporation method. The low molecule compounds such as $Alq_3$(trim-(8-hydroxyquinoline)aluminum) and CTM (carrier transfer material) as the electron transport and injection layers as well as TPD (triphenyl-diamine) and CuPc (copper phthalocyanine) as the hole transport and injection layers were used. The luminance was rapidly increased above the threshold voltage of 10 V. The luminance and emission spectrum for the OELDs samples with $A1/CTM/Alq_3$/TPD/1TO structures were found to be 430 cd/$m^2$and 512 nm at 17 V showing green color emission. In contrast, the samples with $Li-A1/Alq_3$/TPD/CuPC/1TO multi-structures showed 508 nm in emission spectrum and 650 cd/$m^2$at 17 V in the luminance. The increment of luminance may be ascribed to the improved efficiency of recombination in the region of the emission layers by the deposition of CuPc as hole injection layer and the low work function of the Li-Al electrode compared to the Al electrode.

• Biomolecules & Therapeutics
• /
• v.20 no.3
• /
• pp.286-292
• /
• 2012

All-trans retinoic acid (ATRA) is currently used in adjuvant differentiation-based treatment of residual or relapsed neuroblastoma (NB). It has been reported that short-term ATRA treatment induces migration and invasion of SH-SY5Y via transglutaminase-2 (Tgase-2). However, the detailed mechanism of Tgase-2's involvement in NB cell invasion remains unclear. Therefore we investigated the role of Tgase-2 in invasion of NB cells using SH-SY5Y cells. ATRA dose-dependently induced the invasion of SH-SY5Y cells. Cystamine (CTM), a well known tgase inhibitor suppressed the ATRA-induced invasion of SH-SY5Y cells in a dose-dependent manner. Matrix metalloproteinase -9 (MMP-9) and MMP-2, well known genes involved in invasion of cancer cells were induced in the ATRA-induced invasion of the SH-SH5Y cells. Treatment of CTM suppressed the MMP-9 and MMP-2 enzyme activities in the ATRA-induced invasion of the SH-SY5Y cells. To confirm the involvement of Tgase-2, gene silencing of Tgase-2 was performed in the ATRA-induced invasion of the SH-SH5Y cells. The siRNA of Tgase-2 suppressed the MMP-9 and MMP-2 activity of the SH-SY5Y cells. MMP-2 and MMP-9 are well known target genes of NF-${\kappa}B$. Therefore the relationship of Tgase-2 and NF-${\kappa}B$ in the ATRA-induced invasion of the SH-SY5Y cells was examined using siRNA and CTM. ATRA induced the activation of NF-${\kappa}B$ in the SH-SY5Y cells and CTM suppressed the activation of NF-${\kappa}B$. Gene silencing of Tgase-2 suppressed the MMP expression by ATRA. These results suggested that Tgase-2 might be a new target for controlling the ATRA-induced invasion of NBs.

• Journal of Korea Water Resources Association
• /
• v.54 no.7
• /
• pp.495-507
• /
• 2021

With the recent industrial development, accidental pollution in riverine environments has frequently occurred. It is thus necessary to simulate pollutant transport and dispersion using water quality models for predicting pollutant residence times. In this study, we conducted a field experiment in a meandering reach of the Sum River, South Korea, to validate the field applicability and prediction accuracy of RAMS+ (River Analysis and Modeling System+), which is a two-dimensional (2D) stream flow/water quality analysis program. As a result of the simulation, the flow analysis model HDM-2Di and the water quality analysis model CTM-2D-TX accurately simulated the 2D flow characteristics, and transport and mixing behaviors of the pollutant tracer, respectively. In particular, CTM-2D-TX adequately reproduced the elongation of the pollutant cloud, caused by the storage effect associated with local low-velocity zones. Furthermore, the transport model effectively simulated the secondary flow-driven lateral mixing at the meander bend via 2D dispersion coefficients. We calculated the residence time for the critical concentration, and it was elucidated that the calculated residence times are spatially heterogeneous, even in the channel-width direction. The findings of this study suggest that the 2D water quality model could be the accidental pollution analysis tool more efficient and accurate than one-dimensional models, which cannot produce the 2D information such as the 2D residence time distribution.

• Informatization Policy
• /
• v.31 no.1
• /
• pp.3-31
• /
• 2024

This study aimed to examine public concerns in South Korea considering the country's unique context, triggered by the advent of generative artificial intelligence such as ChatGPT. To achieve this, comments from 102 YouTube video news related to ethical issues were collected using a Python scraper, and morphological analysis and preprocessing were carried out using Textom on 15,735 comments. These comments were then analyzed using a Correlated Topic Model (CTM). The analysis identified six primary topics within the comments: "Legal and Ethical Considerations"; "Intellectual Property and Technology"; "Technological Advancement and the Future of Humanity"; "Potential of AI in Information Processing"; "Emotional Intelligence and Ethical Regulations in AI"; and "Human Imitation."Structuring these topics based on a correlation coefficient value of over 10% revealed 3 main categories: "Legal and Ethical Considerations"; "Issues Related to Data Generation by ChatGPT (Intellectual Property and Technology, Potential of AI in Information Processing, and Human Imitation)"; and "Fear for the Future of Humanity (Technological Advancement and the Future of Humanity, Emotional Intelligence, and Ethical Regulations in AI)."The study confirmed the coexistence of various concerns along with the growing interest in generative AI like ChatGPT, including worries specific to the historical and social context of South Korea. These findings suggest the need for national-level efforts to ensure data fairness.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.18 no.1
• /
• pp.39-43
• /
• 1981

The auther presents two simplified methods of stability analysis for small vessels. The paper includes a brief review of some excellent papers recently published. The righting arm and moment of inertia of trimmed waterplane resulted from two methods are compared with. The conclusion is reached that CTTM is more adequate than CTM to ensure statical stability for vessels.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2010.04a
• /
• pp.566-567
• /
• 2010

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.7
• /
• pp.414-420
• /
• 2003

The domestic needs for larger capability of power sources are increasing to cope with the expanding power load which results from the industrial developments & the progressed life style. In summer, the peak load is mainly due to the non-industrial reasons such as air-conditioners and other cooling equipments. To cover the concentrated peak load in stable, the power transmission lines should be more constructed and efficiently operated. The ampacity design of the underground cable system is generally following international standards such as IEC287, IEC60853 and JCS168 which regards the shape of 100% daily full power loads. It is not so efficient to neglect the real shapes of load curves generally below 60~70% of full load. The dynamic (real time) rating system tends to be used with the measured thermal parameters which make it possible to calculate the maximum ampacity within required periods. In this paper, the CTM(Conductor Temperature Monitoring) which is the base of dynamic rating systems for tunnel environment is proposed by a design of lumped thermal network ($\pi$-type thermal model) and distribution temperature sensor attached configuration, including the estimation results of its performances by load cycle test on 345kV single phase XLPE cable.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1972-1977
• /
• 2005

In this work, an inverse dynamic control method is developed to enhance tracking performance of industrial robots, which effectively deal with the nonlinear dynamic interferential forces. In general, the DFF (Dynamic Feed-Forward) controller and the CTM (Computed-Torque Method) controller are used for dynamic control for industrial robots. We study on the practical issues for implementing these inverse dynamic controllers via simulations and experiments. We develop the dynamic models in two different ways. One is a model designed through Newton-Euler method for real time computation and the other is a model designed through SimMechanics for evaluating the developed controller via simulations. We evaluate the nominal performance and robustness of the controller via simulations and experiments using serial 4-DOF HyRoHILS (Hyundai Robot Hardware-In-the-Loop Simulation) system. The results show that the inverse dynamic controller is effective and practically useful for a real control structure.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.1
• /
• pp.151-159
• /
• 2015

This article analyzes English abstracts of the articles published in Journal of the Korean Data & Information Science Society using text mining techniques. At first, term-document matrices are formed by various methods and then visualized by social network analysis. LDA (latent Dirichlet allocation) and CTM (correlated topic model) are also employed in order to extract topics from the abstracts. Performances of the topic models are compared via entropy for several numbers of topics and weighting methods to form term-document matrices.