• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.112-121
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• 2007

In this paper, we propose a new checkpointing strategy for dual modular redundancy real-time systems. For every checkpoints the execution results from two processors, and the result saved in the previous checkpoint are compared to detect faults. We devised an operation algorithm in chectpoints to recover from transient faults as well as permanent faults. We also develop a Markov model for the optimization of the proposed checkpointing strategy. The probability of successful task execution within its deadline is derived from the Markov model. The optimal number of checkpoints is the checkpoints which makes the successful probability maximum.

• The KIPS Transactions:PartA
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• v.19A no.3
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• pp.113-120
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• 2012

The visibility for signals in designs is required for their analysis and debug during the verification process. It could be achieved through the signal dumping for designs during the execution of HDL simulation. However, such signal dumping, in general, degrades the speed of simulation significantly, or can result in the number of simulation runs. In this paper, we have proposed an efficient and fast simulation method for dumping based on the design checkpoint, and shown its effectiveness by applying it to industrial SOC designs.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2533-2539
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• 1999

Two scheme are widely used for fault-tolerant systems : one is the duplex system that has a physical redundancy, and the other one is the checkpointing scheme that rolls back to the last checkpoint at a failure. The average execution time and availability are important factors for measuring the performance of the fault-tolerant systems. However, in fault-tolerant real-time systems with a time constraint, meeting the time constrain instead of reducing the average execution time is the most important factor in the performance evaluation. We analyze and compare the performance of two fault-tolerant scheme (the duplex system and the checkpointing scheme) for real-time applications.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.5
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• pp.147-152
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• 2015

In general, there are two synchronization methods in parallel event-driven simulation, pessimistic approach and optimistic approach. In this paper, we propose a new approach, sporadic synchronization combining both for prediction-based parallel event-driven logic simulation. We claim this hybrid solution is pretty effective to minimize both checkpoint overhead and restart overhead, which are related problems with frequent false predictions for improving the performance of the prediction-based parallel event-driven logic simulation. The experiment has clearly shown the advantage of the proposed approach.

• Journal of Gastric Cancer
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• v.21 no.3
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• pp.319-324
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• 2021

The abscopal effect refers to the phenomenon in which local radiotherapy is associated with the regression of metastatic cancer that is distantly located from the irradiated site. Here, we present a case of a patient with advanced gastric cancer and brain metastases who was successfully treated with brain radiotherapy and anti-programmed death-1 (PD-1) therapy-induced abscopal effect. Although anti-PD-1 therapy alone could not prevent disease progression, the metastatic lesions in the brain and also in the abdominal lymph node showed a drastic response after brain radiotherapy and anti-PD-1 therapy. To our knowledge, this is the first reported case of successful treatment of advanced gastric cancer with multiple brain and abdominal lymph node metastases, possibly through anti-PD-1 therapy combined with brain radiotherapy-induced abscopal effect. We suggest that the combination of brain radiotherapy and anti-PD-1 therapy may be considered as a therapeutic option for advanced gastric cancer, especially when there is brain metastasis.

• Molecules and Cells
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• v.44 no.5
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• pp.363-373
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• 2021

Immune checkpoint inhibitors have changed the paradigm of treatment options for non-small cell lung cancer (NSCLC). Monoclonal antibodies targeting programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) have gained wide attention for their application, which has been shown to result in prolonged survival. Nevertheless, only a limited subset of patients show partial or complete response to PD-1 therapy, and patients who show a response eventually develop resistance to immunotherapy. This article aims to provide an overview of the mechanisms of acquired resistance to anti-PD-1/PD-L1 therapy from the perspective of tumor cells and the surrounding microenvironment. In addition, we address the potential therapeutic targets and ongoing clinical trials, focusing mainly on NSCLC.

• Journal of Digestive Cancer Reports
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• v.8 no.1
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• pp.65-70
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• 2020

Although being one of the major causes of malignancy related death globally, hepatocellular carcinoma (HCC) has not received much attention in respect of novel drug development. Fortunately, several new drugs were found to be effective and tolerable in patients with advanced HCC from a number of phase 3 studies during the recent several years. Novel multi-targeted kinase inhibitors and immune checkpoint inhibitors were approved for clinical use, and combination strategies to maximize the potent of drugs demonstrated promising antitumor activity and safety with high response rate and improved safety profile. The increased number of available agents for HCC will contribute to change of treatment strategies and prognosis of patients with advanced HCC. Still, there is a many critical questions remain unanswered. Currently ongoing trials and future studies will provide better understanding of tumor biology and optimized criteria for patient selection and combination therapies.

• BMB Reports
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• v.56 no.3
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• pp.166-171
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• 2023

Monocytes are peripheral leukocytes that function in innate immunity. Excessive triglyceride (TG) accumulation causes monocyte death and thus can compromise innate immunity. However, the mechanisms by which TG mediates monocyte death remain unclear to date. Thus, this study aimed to elucidate the mechanisms by which TG induces monocyte death. Results showed that TG induced monocyte death by activating caspase-3/7 and promoting poly (ADP-ribose) polymerase (PARP) cleavage. In addition, TG induced DNA damage and activated the ataxia telangiectasia mutated (ATM)/checkpoint kinase 2 and ATM-and Rad3-related (ATR)/checkpoint kinase 1 pathways, leading to the cell death. Furthermore, TG-induced DNA damage and monocyte death were mediated by caspase-2 and -8, and caspase-8 acted as an upstream molecule of caspase-2. Taken together, these results suggest that TG-induced monocyte death is mediated via the caspase-8/caspase-2/DNA damage/executioner caspase/PARP pathways.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.67-74
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• 2023

Perioperative treatment with conventional cytotoxic chemotherapy for resectable non-small cell lung cancer (NSCLC) has proven clinical benefits in terms of achieving a higher overall survival (OS) rate. With its success in the palliative treatment of NSCLC, immune checkpoint blockade (ICB) has now become an essential component of treatment, even as neoadjuvant or adjuvant therapy in patients with operable NSCLC. Both pre- and post-surgery ICB applications have proven clinical efficacy in preventing disease recurrence. In addition, neoadjuvant ICB combined with cytotoxic chemotherapy has shown a significantly higher rate of pathologic regression of viable tumors compared with cytotoxic chemotherapy alone. To confirm this, an early signal of OS benefit has been shown in a selected population, with programmed death ligand 1 expression ≥50%. Furthermore, applying ICB both pre- and post-surgery enhances its clinical benefits, as is currently under evaluation in ongoing phase III trials. Simultaneously, as the number of available perioperative treatment options increases, the variables to be considered for making treatment decisions become more complex. Thus, the role of a multidisciplinary team-based treatment approach has not been fully emphasized. This review presents up-to-date pivotal data that lead to practical changes in managing resectable NSCLC. From the medical oncologist's perspective, it is time to dance with surgeons to decide on the sequence of systemic treatment, particularly the ICB-based approach, accompanying surgery for operable NSCLC.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.162-172
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• 2002

Schizosaccharomyces pombe is suited for the study of cytokinesis as it divides by forming a septum in the middle of the cell at the end of mitosis. To enhance our understanding of the cytokinesis, we have carried out a genetic screen for temperature-sensitive S. pombe mutants that show defects in septum formation and cell division. Here we present the isolation and characterization of a new temperature-sensitive mutant, sun1(septum uncontrolled), which undergoes uncontrolled septation during cell division cycle at restrictive temperature $(37^{\circ}C)$. In sun1 mutant, actin ring and septum are positioned at random locations and angles, and nuclear division cycle continues. These observations suggest that the sun] gene product is required for the proper placement of the actin ring as well as precise septation. The sun] mutant is monogenic recessive mutation unlinked to previously known various cdc genes of S. pombe. In a screen for $sunl^+$ gene to complement the sun] mutant, we have cloned a gene, $susl^+$(suppressor of sun1 mutant), that encodes a protein of 689 amino acids. The predicted amino acid sequence of $susl^+$ gene is similar to the human hMadlp and Saccharomyces cerevisiae Mad1p, a component of the spindle checkpoint in eukaryotic cells. The null mutant of $susl^+$ gene grows normally at various temperatures and has the increased sensitivity to anti-microtubule drug, while $susl^+$ mutant shows no sensitivity to microtubule destabilizing drugs. The putative S. pombe Sus1p directly interacts with S. pombe Mad2p in yeast two-hybrid assays. These data suggest that the newly isolated susr gene encodes S. pombe Mad1p and suppresses sun] mutant defective in controlled septation in a cell division cycle.