• Clinics in Shoulder and Elbow
• /
• v.27 no.1
• /
• pp.59-71
• /
• 2024

Background: Restoration of external (ER) and internal rotation (IR) after Grammont-style reverse shoulder arthroplasty (RSA) is often unreliable. The purpose of this systematic review was to evaluate the influence of RSA medio-lateral offset and subscapularis repair on axial rotation after RSA. Methods: We conducted a systematic review of studies evaluating axial rotation (ER, IR, or both) after RSA with a defined implant design. Medio-lateral implant classification was adopted from Werthel et al. Meta-analysis was conducted using a random-effects model. Results: Thirty-two studies reporting 2,233 RSAs were included (mean patient age, 72.5 years; follow-up, 43 months; 64% female). The subscapularis was repaired in 91% (n=2,032) of shoulders and did not differ based on global implant lateralization (91% for both, P=0.602). On meta-analysis, globally lateralized implants achieved greater postoperative ER (40° [36°-44°] vs. 27° [22°-32°], P<0.001) and postoperative improvement in ER (20° [15°-26°] vs. 10° [5°-15°], P<0.001). Lateralized implants with subscapularis repair or medialized implants without subscapularis repair had significantly greater postoperative ER and postoperative improvement in ER compared to globally medialized implants with subscapularis repair (P<0.001 for both). Mean postoperative IR was reported in 56% (n=18) of studies and achieved the minimum necessary IR in 51% of lateralized (n=325, 5 cohorts) versus 36% (n=177, 5 cohorts) of medialized implants. Conclusions: Lateralized RSA produces superior axial rotation compared to medialized RSA. Lateralized RSA with subscapularis repair and medialized RSA without subscapularis repair provide greater axial rotation compared to medialized RSA with subscapularis repair. Level of evidence: 2A.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.19 no.3
• /
• pp.151-158
• /
• 2024

Although on-device artificial intelligence (AI) has gained attention to diagnosing machine faults in real time, most previous studies did not consider the model retraining and redeployment processes that must be performed in real-world industrial environments. Our study addresses this challenge by proposing an on-device AI-based real-time machine fault diagnosis system that utilizes continual learning. Our proposed system includes a lightweight convolutional neural network (CNN) model, a continual learning algorithm, and a real-time monitoring service. First, we developed a lightweight 1D CNN model to reduce the cost of model deployment and enable real-time inference on the target edge device with limited computing resources. We then compared the performance of five continual learning algorithms with three public bearing fault datasets and selected the most effective algorithm for our system. Finally, we implemented a real-time monitoring service using an open-source data visualization framework. In the performance comparison results between continual learning algorithms, we found that the replay-based algorithms outperformed the regularization-based algorithms, and the experience replay (ER) algorithm had the best diagnostic accuracy. We further tuned the number and length of data samples used for a memory buffer of the ER algorithm to maximize its performance. We confirmed that the performance of the ER algorithm becomes higher when a longer data length is used. Consequently, the proposed system showed an accuracy of 98.7%, while only 16.5% of the previous data was stored in memory buffer. Our lightweight CNN model was also able to diagnose a fault type of one data sample within 3.76 ms on the Raspberry Pi 4B device.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.11S
• /
• pp.3390-3398
• /
• 1999

To achieve high-speed communication and to improve QoS characteristics, ATM is now being used as underlying transfer mechanism of Internet protocols, or TCP/IP. When TCP uses the ABR service in ATM networks, the ABR service control is important to improve the performance of TCP/IP traffic as long as there is no interaction between ABR rate control and TCP flow control. In such environment, the interoperability of EFCI and ER switches becomes unavoidable in order to more effectively control ABR traffic in ATM network. In this paper, we use the model of mixed EFCI-ER environment and discuss the performance issues, e.g., the fairness of bandwidth allocation, drop rate, throughput by using various ER switch algorithms. Among various ERSwitch algorithms, we present one algorithm that have a less network topology and allocate the fair share of VC bandwidth by simulation results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.323-327
• /
• 2001

Electrorheological(ER) and magnetorheological(MR) fluids have a unique ability to increase the dynamic yield stress of the fluid substantially when electric or magnetic field is applied. Controllable fluids such as ER and MR fluids have received considerable attention as several components of engineering devices. One of them is a smart impact damper using ER/MR fluids. Impact damper system can be used in the joint mechanism of railroad vehicle, protection equipment of elevator's drop, and launch equipment of aircraft. This paper presents the results of an analytical study of the performance of a smart impact damper to suppress vibration during impact excitation. The damping capabilities of MR impact damper for variable applied current are analyzed using Bingham model under sudden impact load.

• BMB Reports
• /
• v.48 no.8
• /
• pp.445-453
• /
• 2015

Endoplasmic Reticulum (ER) is an organelle where most secretory and membrane proteins are synthesized, folded, and undergo further maturation. As numerous conditions can perturb such ER function, eukaryotic cells are equipped with responsive signaling pathways, widely referred to as the Unfolded Protein Response (UPR). Chronic conditions of ER stress that cannot be fully resolved by UPR, or conditions that impair UPR signaling itself, are associated with many metabolic and degenerative diseases. In recent years, Drosophila has been actively employed to study such connections between UPR and disease. Notably, the UPR pathways are largely conserved between Drosophila and humans, and the mediating genes are essential for development in both organisms, indicating their requirement to resolve inherent stress. By now, many Drosophila mutations are known to impose stress in the ER, and a number of these appear similar to those that underlie human diseases. In addition, studies have employed the strategy of overexpressing human mutations in Drosophila tissues to perform genetic modifier screens. The fact that the basic UPR pathways are conserved, together with the availability of many human disease models in this organism, makes Drosophila a powerful tool for studying human disease mechanisms. [BMB Reports 2015; 48(8): 445-453]

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.23 no.11 s.170
• /
• pp.1960-1969
• /
• 1999

This paper presents dynamic modeling and controller design of a tracked vehicle installed with the double rod type ERSU(electro-rheological suspension unit). A 16 degree-of-freedom model for the tracked vehicle is established by Lagrangian method followed by the formulation of a new sky-ground hook controller. This controller takes account for both the ride quality and the steering stability. The weighting parameter between the two performance requirements is adopted to adjust required performance characteristics with respect to the operation conditions such as road excitation. The parameter is appropriately determined by employing a fuzzy algorithm associated with the vehicle motion. Computer simulations are undertaken in order to demonstrate the effectiveness of the proposed control system. Acceleration values at the driver's seat are analyzed under bump road profile, while frequency responses of vertical acceleration are investigated under random road excitation.

• Toxicological Research
• /
• v.31 no.4
• /
• pp.331-337
• /
• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.4
• /
• pp.134-139
• /
• 2008

A spirally arrayed nano-pattern is designed as a model pattern for the next generation optical storage media. The pattern consists off types of embossed rectangular dot, which are 50nm, 100nm, 150nm and 200nm in length and 50nm in width. The height of the dot is designed to be 50nm. The pitch of the spiral track of the pattern is 100nm. A ER(Electron resist) master for this pattern is fabricated by e-beam lithography process. The ER is first spin-coated to be 50nm thick on a Si wafer and then the model pattern is written on the coated ER layer by e-beam. After developing this pattern written wafer in the solution, a ER pattern master is fabricated. The most conventional e-beam machine can write patterns in orthogonal way, so we made our own pattern generator which can write the pattern in circular or spiral way. This program generates the patterns to be compatible with the e-beam machine from Raith(Raith 150). To fabricate 50nm pattern master precisely, a series of experiments were done including the design compensation for the pattern size, optimization of the dose, acceleration voltage, aperture size and developing. Through these experiments, we conclude that the higher accelerating voltages and smaller aperture size are better for mastering the nano pattern which is in order of 50nm. With the optimized e-beam lithography process, a spiral arrayed 50nm pattern master adopting PMMA resist was fabricated to have dimensional accuracy over 95% compared to the designed. Using this pattern master, a metal pattern stamp will be fabricated by Ni electro plating for injection molding of the patterned plastic substrate.

• Journal of Preventive Medicine and Public Health
• /
• v.52 no.2
• /
• pp.82-91
• /
• 2019

Objectives: Many studies have explored the relationship between short-term weather and its health effects (including pneumonia) based on mortality, although both morbidity and mortality pose a substantial burden. In this study, the authors aimed to describe the influence of meteorological factors on the number of emergency room (ER) visits due to pneumonia in Seoul, Korea. Methods: Daily records of ER visits for pneumonia over a 6-year period (2009-2014) were collected from the National Emergency Department Information System. Corresponding meteorological data were obtained from the National Climate Data Service System. A generalized additive model was used to analyze the effects. The percent change in the relative risk of certain meteorological variables, including pneumonia temperature (defined as the change in average temperature from one day to the next), were estimated for specific age groups. Results: A total of 217 776 ER visits for pneumonia were identified. The additional risk associated with a $1^{\circ}C$ increase in pneumonia temperature above the threshold of $6^{\circ}C$ was 1.89 (95% confidence interval [CI], 1.37 to 2.61). Average temperature and diurnal temperature range, representing within-day temperature variance, showed protective effects of 0.07 (95% CI, 0.92 to 0.93) and 0.04 (95% CI, 0.94 to 0.98), respectively. However, in the elderly (65+ years), the effect of pneumonia temperature was inconclusive, and the directionality of the effects of average temperature and diurnal temperature range differed. Conclusions: The term 'pneumonia temperature' is valid. Pneumonia temperature was associated with an increased risk of ER visits for pneumonia, while warm average temperatures and large diurnal temperature ranges showed protective effects.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.20 no.2
• /
• pp.45-50
• /
• 2022

Purpose: This study utilizes the NEDIS (National Emergency Department Information System) database to suggest a predictive model for snakebite and envenomation in Korea by analyzing the geographical distribution and seasonal variation of snakebite patients visiting the ER. Methods: This was a retrospective study on snakebite patients visiting the ER using the NEDIS database from January 2014 to December 2019. The subjects include patients with the KCD (Korea Standard Classification of Disease) disease code T63.0 (Toxic effect of contact with snake venom). Geographical location, patient gender, patient age, date of ER visit, treatment during the ER stay, and disposition were recorded to analyze the geographical distribution and seasonal variation of snakebite patients in Korea. Results: A total of 12,521 patients were evaluated in this study (7,170 males, 54.9%; 5,351 females, 40.9%). The average age was 58.5±17.5 years. In all, 7,644 patients were admitted with an average admission time of 5.04±4.7 days, and 2 patients expired while admitted. The geographical distribution was Gyeongsang 3,370 (26.9%), Cheonra 2,692 (21.5%), Chungcheong 2,667 (21.3%), Seoul Capital area 1,999 (16.0%), Kangwon 1,457 (11.6%), and Jeju 336 (2.7%). The seasonal variation showed insignificant incidences in winter and higher severity in spring and summer than in fall: winter 27 (0.2%), spring 2,268 (18.1%), summer 6,847 (54.7%), and fall 3,380 (27.0%). Conclusion: Patients presenting with snakebites and envenomation in the emergency room were most common in the Gyeongsang area and during summer. The simple seasonal model predicted that 436 snakebites and 438 envenomation cases occurred in July and August. The results of this study can be applied to suitably distribute and stock antivenom. Appropriate policies can be formed to care for snakebite patients in Korea.