• 품질경영학회지
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• 제31권2호
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• pp.194-204
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• 2003

It is very important to understand and interpret the meaning of the sigma level correctly through the Six Sigma project. Especially, the confusion over the relation between sigma level from the short-term point of view and defective proportion or DPMO from the long-term point of view may make a big gap between expected results of the Six Sigma project and real results in the field. The one-tail approximation is commonly used to calculate the sigma level both in most literatures introducing Six Sigma and actual cases of the Six Sigma project. Since the one-tail approximation undervalues the sigma level of the fields such as business and service of which the sigma level is generally low, however. there can be misleading results of the explanation of the sigma level and inappropriate project evaluation. This paper describes the relation between sigma level and defective proportion in detail and clears the difference between the one-tail and two-tail approximation.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2010년도 추계학술대회
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• pp.35-39
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• 2010

The research classifies three types of asymptotic tail distributions such as long(heavy, thick) tailed distribution, medium tailed distribution and short(light, thin) tailed distribution. The extreme value distributions(EVD) classified in this paper can be used in SPC(Statistical Process Control) control chart and reliability engineering.

• 대한수학회논문집
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• 제28권4호
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• pp.751-766
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• 2013

We study the existence and long-time behavior of solutions to the following semilinear degenerate parabolic equation on $\mathbb{R}^N$: $$\frac{{\partial}u}{{\partial}t}-div({\sigma}(x){\nabla}u+{\lambda}u+f(u)=g(x)$$, under a new condition concerning a variable non-negative diffusivity ${\sigma}({\cdot})$. Some essential difficulty caused by the lack of compactness of Sobolev embeddings is overcome here by exploiting the tail-estimates method.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2022년도 추계학술대회
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• pp.164-166
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• 2022

Long-tail problem은 class 별로 sample의 개수에 차이가 있어 성능에 안 좋은 영향을 미치는 것을 말한다. 본 논문에서는 cost-sensitive learning 중 Class-Balanced Loss를 이용해 성능을 개선하여 Long-tail problem을 해결하려고 한다. 먼저, balanced data set과 imbalanced data set의 성능 차이를 살펴보도록 할 것이다. 그 후, Class-Balanced Loss를 3가지 버전으로 이용해 그 성능을 측정하고 분석해 볼 것이다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제16권2호
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• pp.127-130
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• 2013

Rapunzel syndrome refers to a very rare condition in which swallowed hair forms a gastric trichobezoar that has a long tail extending into the small bowel. We describe a case of Rapunzel syndrome in an 8-year-old girl who presented with abdominal mass, epigastric pain and vomiting. Abdominal computed tomography scan showed a markedly dilated stomach filled with coarse heterogeneous materials. Upper gastrointestinal endoscopy revealed a huge hairy ball with a tail extending through the pylorus. We performed a surgical laparotomy and successfully removed a huge trichobezoar with a long tail extending into the middle portion of jejunum. Psychiatric consultation with review showed her past history of trichotillomania and trichophagia 4 years ago. But her parents denied further psychiatric therapy and she was lost to the follow-up. Rapunzel syndrome should be included in the differential diagnosis in children with chronic abdominal pain and trichophagia.

• 대한수학회지
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• 제54권6호
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• pp.1879-1903
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• 2017

In this paper we study the closure property and probability tail asymptotics for randomly weighted sums $S^{\Theta}_n={\Theta}_1X_1+{\cdots}+{\Theta}_nX_n$ for long-tailed random variables $X_1,{\ldots},X_n$ and positive bounded random weights ${\Theta}_1,{\ldots},{\Theta}_n$ under similar dependence structure as in [26]. In particular, we study the case where the distribution of random vector ($X_1,{\ldots},X_n$) is generated by an absolutely continuous copula.

• 디지털콘텐츠
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• 7호통권158호
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• pp.13-13
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• 2006

• 정보관리학회지
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• 제35권1호
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• pp.157-182
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• 2018

빅 데이터 시대에 접어들면서 저장 기술과 처리 기술이 급속도로 발전함에 따라, 과거에는 간과되었던 롱테일(long tail) 데이터가 많은 기업과 연구자들에게 관심의 대상이 되고 있다. 본 연구는 롱테일 법칙의 영역에 존재하는 데이터의 활용률을 높이기 위해 텍스트 마이닝 기반의 기술 용어 네트워크 생성 및 통제 기법을 제안한다. 특히 텍스트 마이닝의 편집 거리(edit distance) 기법을 이용해 학문분야에서 사용되는 기술 용어의 상호 네트워크를 자동으로 생성하는 효과적인 방안을 제시하였다. 데이터의 활용률 향상 실험을 위한 데이터 수집을 위해 LOD(linked open data) 환경을 이용하였으며, 이 과정에서 효과적으로 LOD 시스템의 데이터를 활용하는 기법과 용어의 패턴 처리 알고리즘을 제안하였다. 마지막으로, 생성된 기술 용어 네트워크의 성능 측정을 통해 제안한 기법이 롱테일 데이터의 활용률 제고에 효과적이었음을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2643-2657
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• 2023

Scene graphs are structured representations that can clearly convey objects and the relationships between them, but are often heavily biased due to the highly skewed, long-tailed relational labeling in the dataset. Indeed, the visual world itself and its descriptions are biased. Therefore, Unbiased Scene Graph Generation (USGG) prefers to train models to eliminate long-tail effects as much as possible, rather than altering the dataset directly. To this end, we propose Geometric and Semantic Improvement (GSI) for USGG to mitigate this issue. First, to fully exploit the feature information in the images, geometric dimension and semantic dimension enhancement modules are designed. The geometric module is designed from the perspective that the position information between neighboring object pairs will affect each other, which can improve the recall rate of the overall relationship in the dataset. The semantic module further processes the embedded word vector, which can enhance the acquisition of semantic information. Then, to improve the recall rate of the tail data, the Class Balanced Seesaw Loss (CBSLoss) is designed for the tail data. The recall rate of the prediction is improved by penalizing the body or tail relations that are judged incorrectly in the dataset. The experimental findings demonstrate that the GSI method performs better than mainstream models in terms of the mean Recall@K (mR@K) metric in three tasks. The long-tailed imbalance in the Visual Genome 150 (VG150) dataset is addressed better using the GSI method than by most of the existing methods.

• BMB Reports
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• 제50권4호
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• pp.226-231
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• 2017

At the post-transcriptional and translational levels, microRNA (miRNA) represses protein-coding genes via seed pairing to the 3' untranslated regions (UTRs) of mRNA. Although working models of miRNA-mediated gene silencing are successfully established using miRNA transfections and knockouts, the regulatory interaction between miRNA and long non-coding RNA (lncRNA) remain unknown. In particular, how the mRNA-resembling lncRNAs with 5' cap, 3' poly(A)-tail, or coding features, are regulated by miRNA is yet to be examined. We therefore investigated the functional interaction between miRNAs and lncRNAs with/without those features, in miRNA-transfected early zebrafish embryos. We observed that the greatest determinants of the miRNA-mediated silencing of lncRNAs were the 5' cap and 3' poly(A)-tails in lncRNAs, at both the post-transcriptional and translational levels. The lncRNAs confirmed to contain 5' cap, 3' poly(A)-tail, and the canonical miRNA target sites, were observed to be repressed in the level of both RNA and ribosome-protected fragment, while those with the miRNA target sites and without 5' cap and 3' poly(A)-tail, were not robustly repressed by miRNA introduction, thus suggesting a role as a miRNA-decoy.