• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제11권12호
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• pp.445-452
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• 2022

디지털 세상에서 불균형 데이터에 대한 클래스 분포는 중요한 부분이며 사이버 보안에 큰 의미를 차지한다. 불균형 데이터의 비정상적인 활동을 찾고 문제를 해결해야 한다. 모든 트랜잭션의 패턴을 추적할 수 있는 시스템이 필요하지만, 일반적으로 패턴이 비정상인 불균형 데이터로 기계학습을 하면 소수 계층에 대한 성능은 무시되고 저하되며 예측 모델은 부정확하게 편향될 수 있다. 본 논문에서는 불균형 데이터 세트를 해결하기 위한 접근 방식으로 Synthetic Minority Oversampling Technique(SMOTE)와 Light GBM 알고리즘을 이용하여 추정치를 결합하여 대상 변수를 예측하고 정확도를 향상시켰다. 실험 결과는 Logistic Regression, Decision Tree, KNN, Random Forest, XGBoost 알고리즘과 비교하였다. 정확도, 재현율에서는 성능이 모두 비슷했으나 정밀도에서는 2개의 알고리즘 Random Forest 80.76%, Light GBM 97.16% 성능이 나왔고, F1-score에서는 Random Forest 84.67%, Light GBM 91.96% 성능이 나왔다. 이 실험 결과로 Light GBM은 성능이 5개의 알고리즘과 비교하여 편차없이 비슷하거나 최대 16% 향상됨을 접근 방식으로 확인할 수 있었다.

• Molecules and Cells
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• 제39권8호
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• pp.619-624
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• 2016

Glioblastoma stem cells (GBM-SCs) are believed to be a subpopulation within all glioblastoma (GBM) cells that are in large part responsible for tumor growth and the high grade of therapeutic resistance that is so characteristic of GBM. MicroRNAs (miR) have been implicated in regulating the expression of oncogenes and tumor suppressor genes in cancer stem cells, including GBM-SCs, and they are a potential target for cancer therapy. In the current study, miR-203 expression was reduced in $CD133^+$ GBM-SCs derived from six human GBM biopsies. MicroRNA-203 transfected GBM-SCs had reduced capacity for self-renewal in the cell sphere assay and increased expression of glial and neuronal differentiation markers. In addition, a reduced proliferation rate and an increased rate of apoptosis were observed. Therefore, miR-203 has the potential to reduce features of stemness, specifically in GBM-SCs, and is a logical target for GBM gene therapy.

• Journal of Korean Neurosurgical Society
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• 제52권5호
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• pp.484-487
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• 2012

Glioblastoma multiforme (GBM) is the most common primary brain tumor and the most malignant astrocytoma in adults, with rare extra-cranial metastases, especially for subcutaneous metastases. It could be easily misdiagnosed as primary subcutaneous tumor. In this report, we describe a patient with pontine GBM who developed a subcutaneous swelling at the ipsilateral posterior cervical region 8 months after operation, and the pathological and immunocytochemical examination carry the same characteristics as the primary intracranial GBM cells, which defined it as subcutaneous metastasis. GBM with subcutaneous metastasis is extremely rare, and knowledge of a prior intracranial GBM, pathological examinations and immunocytochemical tests with markers typically expressed by GBM are of vital importance for the diagnosis of GBM metastasis. Surgical resection of subcutaneous swelling, followed by chemotherapy and radiotherapy, could be the best strategy of treatment for the patients with GBM subcutaneous metastasis.

• 한국융합학회논문지
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• 제8권10호
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• pp.215-223
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• 2017

본 논문은 법인의 전기 사내유보가 당기 배당률에 미치는 영향을 분석함으로써 미환류 소득세제가 어느 정도 효과를 거두고 있는지 실증분석 하고자 하였으며 추가로 부채비율을 조절변수로 사용하여 정부정책의 유효성도 알아보고자 하였다. 또한 DRF와 GBM 모델을 이용하여 그 효과를 한 번 더 살펴보았다. 실증분석 결과 모형1, 모형2, 모형3에서 모두 현금흐름비율, 자기자본순이익률, 외국인보유비중 변수가 99% 수준에서 유의미함을 확인할 수 있었던 반면 광고선전비 비율, 대주주지분율 변수는 모든 모형에서 유의미하지 않은 결과를 보여주었다. 융합 차원에서 실시한 DRF와 GBM 모형의 분석 결과를 보면 DRF가 depth와 leaves에서 GBM 보다 더 높게 나타났으나 모형의 설명력에 있어서는 GBM이 DRF보다 더 높았다. 앞으로의 과제는 미환류 소득세제의 시행기간인 3년간(2015~2017)의 시계열 분석을 통하여 정부정책의 효과를 살펴볼 필요가 있다.

• 한국융합학회논문지
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• 제13권2호
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• pp.249-255
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• 2022

본 연구는 최근 가공 불량 예측 방법으로 주목받고 있는 머신러닝 기반의 모델을 이용하여 CNC 가공 불량 발생의 실시간 예측을 위한 분석 프레임워크를 제안하고, 해당 프레임워크에 기반하여 XGBoost, CatBoost, LightGBM, 랜덤 포레스트, Extra Trees, SVM, k-최근접 이웃, 로지스틱 회귀 모델을 CNC 설비에 기본 내장된 센서들로부터 추출된 데이터에 적용 및 분석하였다. 분석 결과 XGBoost, CatBoost, LightGBM 모델이 동일하게 가장 우수한 정확도, 정밀도, 재현율, F1 점수, AUC 값을 보였으며, 이 중 LightGBM 모델이 소요 실행 시간이 가장 짧은 것으로 나타났다. 이러한 짧은 소요 실행 시간은 실 시스템 구축 비용 절감, 빠른 불량 예측에 따른 CNC 장비 파손 확률 감소, 전체적인 CNC 활용률 증가 등의 실무적 장점을 가지므로 LightGBM 모델이 기본 센서들만 설치된 CNC 설비에 적용 시 가공 불량 예측에 가장 효과적으로 판단된다. 또한 소요 실행 시간 및 컴퓨팅 파워의 제약이 없는 상황에서는 LightGBM, Extra Trees, k-최근접 이웃, 로지스틱 회귀 모형으로 구성된 앙상블 모델을 적용할 경우 분류 성능이 최대화됨을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3629-3633
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• 2014

Background: Glioblastoma (GBM) is an immunosuppressive tumor whose median survival time is only 12-15 months, and patients with GBM have a uniformly poor prognosis. It is known that heredity contributes to formation of glioma, but there are few genetic studies concerning GBM. Materials and Methods: We genotyped six tagging SNPs (tSNP) in Han Chinese GBM and control patients. We used Microsoft Excel and SPSS 16.0 statistical package for statistical analysis and SNP Stats to test for associations between certain tSNPs and risk of GBM in five different models. ORs and 95%CIs were calculated for unconditional logistic-regression analysis with adjustment for age and gender. The SHEsis software platform was applied for analysis of linkage disequilibrium, haplotype construction, and genetic associations at polymorphism loci. Results: We found rs891835 in CCDC26 to be associated with GBM susceptibility at a level of p=0.009. The following genotypes of rs891835 were found to be associated with GBM risk in four different models of gene action: i) genotype GT (OR=2.26; 95%CI, 1.29-3.97; p=0.019) or GG (OR=1.33; 95%CI, 0.23-7.81; p=0.019) in the codominant model; ii) genotypes GT and GG (OR=2.18; 95%CI, 1.26-3.78; p=0.0061) in the dominant model; iii) GT (OR=2.24; 95%CI, 1.28-3.92; p=0.0053) in the overdominant model; iv) the allele G of rs891835 (OR=1.85; 95%CI, 1.14-3.00; p=0.015) in the additive model. In addition, "CG" and "CGGAG" were found by haplotype analysis to be associated with increased GBM risk. In contrast, genotype GG of CCDC26 rs6470745 was associated with decreased GBM risk (OR=0.34; 95%CI, 0.12-1.01; p=0.029) in the recessive model. Conclusions: Our results, combined with those from previous studies, suggest a potential genetic contribution of CCDC26 to GBM progression among Han Chinese.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.463-466
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• 2016

Glioblastoma (GBM) is the most common and aggressive type of primary brain neoplasm. The current standard therapy for GBM consists of maximal surgical resection within safe limits, followed by radiation therapy (RT) and chemotherapy with temozolomide. Despite advances in treatment, the prognosis of GBM remains poor. Epileptic seizure is one of the most common symptoms in patients with GBM. Valproic acid (VPA), a histone deacetylase inhibitor, is often used as an anti-epileptic drug in patients with brain neoplasms due to its effectiveness and low toxicity profile. Several in vivo and in vitro studies have indicated that VPA has radiosensitizing effects for gliomas and radioprotective influence on normal brain tissue or hippocampal neurons. The results of several retrospective studies have also indicated potential benefit to improve survival of patients with GBM. Moreover, the promising treatment results of a phase 2 trial of concurrent radiation therapy, temozolomide, and VPA for patients with GBM have been recently reported. The use of VPA in patients with GBM has thus recently receiving more attention. In this article, we review the role of VPA in radiation therapy for GBM, focusing on the clinical evidence.

• BMB Reports
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• 제51권10호
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• pp.481-483
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• 2018

Glioblastoma (GBM) is the most common and aggressive form of human adult brain malignancy. The identification of the cell of origin harboring cancer-driver mutations is the fundamental issue for understanding the nature of GBM and developing the effective therapeutic target. It has been a long-term hypothesis that neural stem cells in the subventricular zone (SVZ) might be the origin-of-cells in human glioblastoma since they are known to have life-long proliferative activity and acquire somatic mutations. However, the cell of origin for GBM remains controversial due to lack of direct evidence thereof in human GBM. Our recent study using various sequencing techniques in triple matched samples such as tumor-free SVZ, tumor, and normal tissues from human patients identified the clonal relationship of driver mutations between GBM and tumor-free SVZ harboring neural stem cells (NSCs). Tumor-free SVZ tissue away from the tumor contained low-level GBM driver mutations (as low as 1% allelic frequency) that were found in the dominant clones in its matching tumors. Moreover, via single-cell sequencing and microdissection, it was discovered that astrocyte-like NSCs accumulating driver mutations evolved into GBM with clonal expansion. Furthermore, mutagenesis of cancer-driving genes of NSCs in mice leads to migration of mutant cells from SVZ to distant brain and development of high-grade glioma through the aberrant growth of oligodendrocyte precursor lineage. Altogether, the present study provides the first direct evidence that NSCs in human SVZ is the cell of origin that develops the driver mutations of GBM.

• 생명과학회지
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• 제17권8호통권88호
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• pp.1039-1045
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• 2007

다형성 교모세포종은 뇌종양 가운데 가장 빈번하게 발병하는 악성종양이다. 다형성 교모세포종에 종양 줄기세포가 존재한다는 보고가 있음에도 불구하고, 항암제 내성과 종양 줄기세포 사이의 상호 연관성에 관한 연구는 아직 미비한 실정이다. 본 연구에서 다형성 교모세포종 세포주 A172 및 뇌종양 환자로부터 확립한 GBM2에 1,3-bis(2 -chloroethyl)-1-nitrosourea (BiCNU)를 처리시 극소량의 세포군만이 생존하며, 이들 생존 세포군은 BiCNU 재처리에 내성을 나타내는 것으로 조사되었다. 또한 이 다형성 교모세포종 유래 BiCNU-내성세포군의 Erk 및 Akt 인산화 활성이 증가되었으며, CD133 줄기세포 표지인자를 발현하는 세포가 다량 존재하였다. 이와 아울러, 다형성 교모세포종 유래 BiCNU-내성세포를 severe combined immuno-deficient (SCID) mouse brain에 이식하였을 때 암이 형성되는 것을 관찰할 수 있었다. 이와 같은 결과는 다형성 교모세포종 유래 BiCNU-내성세포가 종양줄기세포의 능력을 가지는 것으로 생각된다. 따라서 이상의 결과는 다형성 교모세포종에 존재하는 종양줄기세포가 항암제 내성에 관여 한다는 중요한 단서를 제공해줄 수 있을 것으로 사료된다.

• Journal of Korean Neurosurgical Society
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• 제38권6호
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• pp.475-477
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• 2005

The tendency of glioblastoma multiforme[GBM] to metastasize to the cerebrospinal fluidis well documented. However, symptomatic intradural extramedullary metastasis of GBM in the spinal cord are rarely reported. A 31-year-old female with a previously treated supratentorial GBM presented with back pain and lower extremities weakness. Magnetic resonance imaging of the thoracic spine demonstrated an intradural extramedullary mass at levels of T2-T4 and arachnoid membrane enhancement. The patient underwent an operation. Pathologic diagnosis was confirmed as spinal metastases of GBM. We present a case of spinal metastases from supratentorial GBM presented with paraparesis.