• Journal of dental hygiene science
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• v.21 no.4
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• pp.227-232
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• 2021

Background: Cancer-associated fibroblasts (CAFs) are abundant in tumor microenvironments and interact with cancer cells to promote tumor proliferation in oral squamous cell carcinoma (OSCC). Cathepsin D (CTSD) is a soluble lysosomal aspartic endopeptidase involved in tumor proliferation and angiogenesis. In this preliminary study, we observed CTSD expression in OSCC and CAFs, postulating that CTSD might act as a bridge between OSCC and CAFs. Methods: Human epidermal keratinocytes (HEKs), OSCC, and immortalized human normal oral fibroblasts (hTERT-hNOFs) were used in this study. Additionally, we used hTERT-hNOFs transfected with an empty vector, WT (wild-type)-YAP (Yes-associated protein), and YAPS127A (YAP serine 127 to alanine). YAP127A hTERT-hNOFs activated fibroblasts similar to CAFs. To identify CTSD expression between OSCC and CAFs, conditioned medium (CM) was collected from each cell. Protein expression of CTSD was identified by western blotting. Results: To identify the expression of CTSD in fibroblasts stimulated by OSCC, we treated fibroblasts with CM from HEK and OSCC. Results indicated that hTERT-hNOFs with OSCC CM showed a weakly increased expression of CTSD compared to stimulation by HEK CM. This indicates that CAFs, YAPS127 hTRET-hNOFs, overexpress CTSD protein. HEK cells showed no CTSD expression, regardless of treatment with fibroblast CM, whereas OSCC highly expressed CTSD proteins compared with the CTSD expression in HEK cells. We also found that CTSD expression was unaffected by changes in transforming growth factor-β levels. Conclusion: This study proposes that CTSD might have potential as an interacting executor between OSCC and CAFs. Further studies are needed to investigate the role of CTSD in tumor and stromal cells.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.773-782
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• 2022

Estimation of cable tension through proper measurements is one of the essential tasks in evaluating the safety of cable structures. In this paper, a study on cable tension estimation using the built-in accelerometer and camera in a smartphone was conducted. For the experimental study, visual displacement measurement using a smartphone camera and acceleration measurement using a built-in accelerometer were performed in the cable-stayed bridge model. The estimated natural frequencies and transformed tensions from these measurements were compared with the theoretical values and results from the normal visual displacement method. Through comparison, it can be seen that the error between the method using the smartphone and the normal visual displacement is sufficiently small to be acceptable. It has also been shown that those errors are much smaller than the difference between the values calculated by the theoretical model. These results show that the deviation according to the type of measurement method is not large and it is rather important to use an appropriate mathematical model. In conclusion, in the case of cable tension estimation, it can be said that the visual displacement measurement and acceleration using a smartphone can be a sufficiently applicable method, just like the normal visual displacement method. It is also noteworthy that the smartphone accelerometer has a larger magnitude error and has more limitations such as high-frequency sampling instability compared to the visual displacement method, but shows almost the same performance as the visual displacement method in this cable tension estimation.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.171-176
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• 2021

Die-to-wafer (D2W) hybrid bonding in the multilayer semiconductor manufacturing process is one of wafer direct bonding, and various studies are being conducted around the world. A noteworthy point in the current die-to-wafer process is that a lot of voids occur on the bonding surface of the die during bonding. In this study, as a suggested method for removing voids generated during the D2W hybrid bonding process, a flexible mechanism for implementing convex for die bonding to be applied to the bond head is proposed. In addition, modeling of flexible mechanisms, analysis/design/control/evaluation of static/dynamics properties are performed. The proposed system was controlled by capacitive sensor (lion precision, CPL 290), piezo actuator (P-888,91), and dSpace. This flexure mechanism implemented a working range of 200 ㎛, resolution(3σ) of 7.276nm, Inposition(3σ) of 3.503nm, settling time(2%) of 500.133ms by applying a reverse bridge type mechanism and leaf spring guide, and at the same time realized a maximum step difference of 6 ㎛ between die edge and center. The results of this study are applied to the D2W hybrid bonding process and are expected to bring about an effect of increasing semiconductor yield through void removal. In addition, it is expected that it can be utilized as a system that meets the convex variable amount required for each device by adjusting the elongation amount of the piezo actuator coupled to the flexible mechanism in a precise unit.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.3950-3969
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• 2021

Radio Frequency (RF)-based indoor localization technologies play significant roles in various Internet of Things (IoT) services (e.g., location-based service). Most such technologies require that all the devices comply with a specified technology (e.g., WiFi, ZigBee, and Bluetooth). However, this requirement limits its application scenarios in today's IoT context where multiple devices complied with different standards coexist in a shared environment. To bridge the gap, in this paper, we propose a cross-technology localization approach, which is able to localize target nodes using a different type of devices. Specifically, the proposed framework reuses the existing WiFi infrastructure without introducing additional cost to localize Non-WiFi device (i.e., ZigBee). The key idea is to leverage the interference between devices that share the same operating frequency (e.g., 2.4GHz). Such interference exhibits unique patterns that depend on the target device's location, thus it can be leveraged for cross-technology localization. The proposed framework uses Principal Components Analysis (PCA) to extract salient features of the received WiFi signals, and leverages Dynamic Time Warping (DTW), Gradient Boosting Regression Tree (GBRT) to improve the robustness of our system. We conduct experiments in real scenario and investigate the impact of different factors. Experimental results show that the average localization accuracy of our prototype can reach 1.54m, which demonstrates a promising direction of building cross-technology technologies to fulfill the needs of modern IoT context.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.243-246
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• 1982

A proposal of gene transfer scheme from diploid to hexaploid in oats was described. The main idea of this scheme are (1) use Avena magna which has two genomes partially in common with two genomes of the hexaploid Avena sativa or a common genome and the rest genomes partially commonn, and which lead to more regular pairing between them rather than AABB genome type to get 6x-amphiploid as a bridge between ploidy level. Cross between Avena strigosa and Avena magna is compatible and further give 42% seed set, (2) extract tetraploid derivatives which have in corporated desired genes from Avena strigasa to Avena magna, (3) Synthetic petaploid provide 2n=21 chromosome number in female gametes, which lead to complete pairing or nearly so in progenies with Avena sativa, (4) eventually homozygous lines will be produced by selfing the heterozygous (regarding to$A^{As}$ genome) at final step.

• Smart Structures and Systems
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• v.31 no.4
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• pp.393-407
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• 2023

To assess structural condition in a non-destructive manner, computer vision-based structural health monitoring (SHM) has become a focus. Compared to traditional contact-type sensors, the advantages of computer vision-based measurement systems include lower installation costs and broader measurement areas. In this study, we propose a novel computer vision-based vibration measurement and coarse-to-fine damage assessment method for truss bridges. First, a deep learning model FairMOT is introduced to track the regions of interest (ROIs) that include joints to enhance the automation performance compared with traditional target tracking algorithms. To calculate the displacement of the tracked ROIs accurately, a normalized cross-correlation method is adopted to fine-tune the offset, while the Harris corner matching is utilized to correct the vibration displacement errors caused by the non-parallel between the truss plane and the image plane. Then, based on the advantages of the stochastic damage locating vector (SDLV) and Bayesian inference-based stochastic model updating (BI-SMU), they are combined to achieve the coarse-to-fine localization of the truss bridge's damaged elements. Finally, the severity quantification of the damaged components is performed by the BI-SMU. The experiment results show that the proposed method can accurately recognize the vibration displacement and evaluate the structural damage.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.819-826
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• 2000

This study was performed to develop a measurement system of tractor field performance for plow and rotary operations. Measurement system for tractor consisted of torque sensors to measure torque of drive axles and PTO axle, speed sensors to measure rotational speed of drive axles and engine, microcomputer to control data logger, and data logger as I/O interface system. The measurement system was installed on four-wheel-drive tractor. Four-element full-bridge type strain gages were used for torque measurement of drive axles and optical encoders were used to measure speeds of drive axles and engine. Slip rings were mounted on the rotational axles. Signals from sensors were inputted to data logger that was controlled by microcomputer with parallel communication. Sensors were calibrated before the field tests. Regression equations were found on completion of the calibrations. The field experiment was performed at paddy fields and uplands. Rotary and plow were used when the tractor was operated in the field. Travelling speeds of the tractor were 1.9 km/h, 2.7 km/h, 3.7 km/h, 5.5 km/h, 8.2 km/h, and 11.8 km/h. Operating depths of implements were maintained approximately 20cm during the tests. Torque data of drive axles were different at each location during plow and rotary operations. Results showed that torque of rear axles were greater than those of front axles. Total torque were 6860 - 11064 Nm at the upland and 7360 - 14190 Nm at the paddy field for plow operations. It was found that torque at the paddy field were about 20% greater than those at the upland for plow operations. Torque data showed that rotary operations required less power than plow operation at the paddy field and the upland. Torque measurements at each axle for rotary operations were only 8 - 16% of plow operations in the upland and 15 - 20% in the paddy field.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.287-295
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• 2023

The collapse of bridges due to earthquakes results in many casualties and property damages. Thus, accurate prediction and preparation are required for the behavior of bridges during earthquakes. In particular, columns play an important role in the seismic behavior of bridges. The risk of collapse due to an earthquake increases when there is a problem of the insufficient lap splice in the column. In this study, to analyze the characteristics of the lap splice in the column, a numerical model was defined for the insufficient lap-spliced columns and verified using experimental data. The developed column model was applied to a commonly used RC slab bridge. Nonlinear static analysis for the column was performed to evaluate the change in the performance of the column according to the lap-spliced length. In addition, this study assessed the effect of the lap-spliced length on the seismic fragility analysis.

• The Journal of Bigdata
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• v.7 no.1
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• pp.37-47
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• 2022

Autonomous delivery operation data is the key to driving a paradigm shift for last-mile delivery in the Corona era. To bridge the technological gap between domestic autonomous delivery robots and overseas technology-leading countries, large-scale data collection and verification that can be used for artificial intelligence training is required as the top priority. Therefore, overseas technology-leading countries are contributing to verification and technological development by opening AI training data in public data that anyone can use. In this paper, 326 objects were collected to trainn autonomous delivery robots, and artificial intelligence models such as Mask r-CNN and Yolo v3 were trained and verified. In addition, the two models were compared based on comparison and the elements required for future autonomous delivery robot research were considered.

• Journal of Korean Medical Ki-Gong Academy
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• v.22 no.1
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• pp.28-71
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• 2023

Objective : From March 2018 to July 2022, H Korean Medicine Hospital conducted a guidance on Gigong training using the Moosim Gigong Doinbeop and Moosim Gigong Walking. This report intends to report the results and share the specific methods of a guidance on Gigong training used in the process of implementation, thereby helping the research of a guidance on Gigong training later. Methods : The methods and results of the implementation of Moosim Gigong Doinbeop and Moosim Gigong Walking implemented by H Korean Medicine Hospital were reported. For the movements of Doinbeop, the posture and movements, the precautions to be taken when guiding, the alternative movements, and the meaning of the movements were summarized. For Moosim Gigong Walking, the method of progress, the method of motion, precautions to be taken, and replaceable movements were summarized. The method of implementing the guidance on Gigong training for severely ill and elderly patients was introduced. The application cases that were applied to some diseases and effective were recorded. Results : At H Korean Medicine Hospital, Moosim Gigong Doinbeop and Moosim Gigong Walking were conducted in the form of an open lecture, and 4,682 patients attended the Doinbeop class and 3,373 patients attended the Walking class. There is no restriction on the type of disease of the participating patients. The attending physician recommends and the patient wishes, the patient participates in the course. Conclusions : Curing technology is a long-standing treatment method of Korean Medicine, but it has not yet been activated in the modern Korean Medicine system. Research on the guidance on Gigong training can be conducted to establish itself as a new treatment method for Korean Medicine.