• 제목/요약/키워드: Background elimination

검색결과 91건 처리시간 0.034초

인지증 판별 성능 향상을 위한 스펙트럼 국부 영역 분석 방법 (Local Region Spectral Analysis for Performance Enhancement of Dementia Classification)

  • 박준규;백성준
    • 한국산학기술학회논문지
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    • 제12권11호
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    • pp.5150-5155
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    • 2011
  • 인지증을 유발하는 원인은 알츠하이머병(Alzheimer's Disease: AD)과 혈관성 인지증(vascular Dementia: VD)이 가장 높은 비율을 차지한다. 본 논문에서는 측정된 라만 스펙트럼에서 AD, VD, 정상(NOR: normal)을 분류하기 위해 변별력 있는 영역을 조사하고, 특징 변환을 이용한 분류 실험 결과를 제시하였다. 혈소판으로부터 측정한 라만 스펙트럼은 먼저 smoothing을 적용한 다음 배경 잡음을 제거하고 스펙트럼의 기준 피크를 중심으로 그 위치를 정렬하였고 minmax 방법을 사용하여 정규화 하였다. 전처리를 거친 스펙트럼은 AD와 VD, NOR를 변별하기 가장 용이한 영역을 결정하기 위해 조사되었으며, 그 결과 725-777, 1504-1592, 1632-1700 $cm^{-1}$ 영역에서 스펙트럼이 많은 차이를 보임을 확인하였다. 분류 실험은 선택한 각 영역에 대하여 PCA(principal component analysis)와 NMF(nonnegative matrix factorization) 방법을 적용하여 얻은 특징을 이용하여 행하였다. 총 327개의 라만 스펙트럼에 대한 MAP(maximum a posteriori probability) 분류 실험 결과에 따르면, 본 연구에서 제안된 국부 영역 변환 특징을 사용했을 때 평균 92.8 %의 분류율을 보임을 알 수 있었다.

영역정보를 이용한 교통 혼잡도 측정 시스템의 설계 및 구현 (Design and Implemtation of a Road Congestion Analysis System using Regional Information)

  • 최병걸;정성일;안철웅;김승호
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제5권6호
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    • pp.748-757
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    • 1999
  • 본 논문에서는 차량 영역의 추출을 이용한 효율적인 교통 혼잡도 측정 시스템을 설계하고 구현한다. 차량 영역 정보의 추출은 첫째 영역 분할, 둘째 작은 영역의 제거와 영역의 직사각형화, 셋째 영역의 병합 및 삭제의 단계로 나눌 수 있다. 영역 분할 단계에서는 획득한 도로 영상을 영역 기반 영역 분할에 의해 영역으로 분할한다. 그 다음 영역 분할 후의 영역 정보 중 차량 영역을 추출하는데 영향을 미치지 않는 작은 영역들을 제거하고, 남은 영역들을 직사각형화한다. 마지막으로 차선 별로 남은 영역들을 병합, 삭제함으로써 각 차선마다 차량 영역 정보를 추출할 수 있다. 이러한 방법은 배경 영상과 같은 부가적인 정보를 사용하지 않고 도로 자체 영상만으로 교통 혼잡도를 측정할 수 있으며, 그림자의 영향이 없을 경우 적용할 수 있는 기법이다.Abstract In this paper, we designed and implemented an efficient road congestion analysis system using regional information. To extract vehicle regions from a road image, the system process the image in five steps: segmentation, small region elimination, region rectangularization, region merging and region deletion. First, we segment road image by a threshold value. Then, we eliminate useless small regions to extract vehicle region, and perform region rectangularization. Finally, we extract vehicle region of each lane of the road by region merging and deletion. This method has the advantage of measuring road congestion without additional information such as background images. But this method must be applied to road images without shadow.

효과적인 문자 인식을 위한 저 품질 문자 영상의 이진화 및 획 재구성 방법 (Binarization and Stroke Reconstruction of Low Quality Character Image for Effective Character Recognition)

  • 김도현;차의영
    • 한국정보통신학회논문지
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    • 제11권3호
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    • pp.608-618
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    • 2007
  • 영상의 이진화는 영상을 물체와 배경으로 구분하는 전처리 과정으로써 처리해야 할 대상이 되는 물체를 규정짓기 위한 매우 중요한 처리 과정이다. 본 논문에서는 저 품질 문자 영상에서 효과적인 문자 인식을 위한 효율적인 이진화 방법 및 획 영상 재구성 방법을 제안하다. 먼저 전역적 이진화 방법의 장점과 지역적 이진화 방법의 장점을 반영하여 문자 영역에 대한 이진화를 수행한 다음 이진화된 획 영상에 대한 분석을 통해 획에 붙어 있는 획 잡영 제거와 획 부분에 파여진 공백 잡영에 대한 채움 과정을 수행하여 고 품질의 획 영상으로 재구성하였다. 제안하는 문자 영상을 위한 이진화 알고리즘은 적응적인 임계값 선택 방법에 의해 속도와 성능의 효율성을 추구할 수 있도록 하였으며 이진화 결과로 인한 획 표면 잡영에 대해 단계적인 제거 과정을 수행하여 획 영상을 재구성함으로써 고 품질의 이진 영상을 획득할 수 있었다.

Acquired noncaustic esophageal strictures in children

  • Sag, Elif;Bahadir, Aysenur;Imamoglu, Mustafa;Sag, Sefa;Reis, Gokce Pinar;Erduran, Erol;Cakir, Murat
    • Clinical and Experimental Pediatrics
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    • 제63권11호
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    • pp.447-450
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    • 2020
  • Background: Esophageal stricture (ES) is an uncommon clinic entity in pediatrics that may be congenital or acquired in childhood. Acquired noncaustic ES is very rare, and clinical features of affected patients are unknown. Purpose: We aimed to evaluate the clinical findings, and outcomes of patients with acquired noncaustic ES to aid physicians in the early referral of patients to gastroenterologists. Methods: The medical data of patients with acquired noncaustic ES who were followed in our gastroenterology clinic between January 2009 and December 2019 were reviewed. Results: Acquired noncaustic ES was found in 12 of the 4,950 patients (0.24%) who underwent endoscopy during the study period. The main symptoms were dysphagia (58.3%), vomiting (33.3%), and chronic anemia (8.3%). Chronic malnutrition and underweight were found in 66.6% of the patients. The most common etiological factors were radiotherapy, peptic reflux, and achalasia (16.6%, each), while chemotherapy, squamous-cell carcinoma (SC) of the esophagus, eosinophilic esophagitis (EoE), esophageal web, epidermolysis bullosa, and esophageal diverticulum (8.2%, each) were the other etiological factors. Patients with EoE underwent endoscopic bougie dilation in addition to steroid use and elimination diet. Patients with epidermolysis bullosa and esophageal web underwent bougie dilation. Patients with peptic reflux-related ES were initially put on antireflux therapy, but during follow-up, one patient required esophageal replacement with colonic interposition. Patients with radiotherapy-related ES recovered with medical therapy. The patient with initially underwent surgical gastrostomy and tumoral mass excision. The patient then received chemotherapy and radiotherapy and underwent jejunal interposition. Patients with achalasia underwent surgical esophagomyotomy. Conclusion: The presence of solid dysphagia, malnutrition, and an associated disease may alert physicians to the presence of ES.

Feasibility of the AtriClip Pro Left Atrium Appendage Elimination Device via the Transverse Sinus in Minimally Invasive Mitral Valve Surgery

  • Shirasaka, Tomonori;Kunioka, Shingo;Narita, Masahiko;Ushioda, Ryohei;Shibagaki, Keisuke;Kikuchi, Yuta;Wakabayashi, Naohiro;Ishikawa, Natsuya;Kamiya, Hiroyuki
    • Journal of Chest Surgery
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    • 제54권5호
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    • pp.383-388
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    • 2021
  • Background: Achieving external access to and manual occlusion of the left atrial appendage (LAA) during minimally invasive mitral valve surgery (MIMVS) through a small right thoracotomy is difficult. Occlusion of the LAA using an epicardial closure device seems quite useful compared to other surgical techniques. Methods: Fourteen patients with atrial fibrillation underwent MIMVS with concomitant surgical occlusion of the LAA using double-layered endocardial closure stitches (n=6, endocardial suture group) or the AtriClip Pro closure device (n=8, AtriClip group) at our institution. The primary safety endpoint was any device-related adverse event, and the primary efficacy endpoint was successful complete occlusion of blood flow into the LAA as assessed by transthoracic echocardiography at hospital discharge. The primary efficacy endpoint for stroke reduction was the occurrence of ischemic or hemorrhagic neurologic events. Results: All patients underwent LAA occlusion as scheduled. The cardiopulmonary bypass and aortic cross-clamp times in the endocardial suture group and the AtriClip group were 202±39 and 128±41 minutes, and 213±53 and 136±44 minutes, respectively (p=0.68, p=0.73). No patients in either group experienced any device-related serious adverse events, incomplete LAA occlusion, early postoperative stroke, or neurologic complication. Conclusion: Epicardial LAA occlusion using the AtriClip Pro during MIMVS in patients with mitral valve disease and atrial fibrillation is a simple, safe, and effective adjunctive procedure.

Elimination of Lancet-Related Needlestick Injuries Using a Safety-Engineered Lancet: Experience in a Hospital

  • An, Hye-sun;Ko, Suhui;Bang, Ji Hwan;Park, Sang-Won
    • Infection and chemotherapy
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    • 제50권4호
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    • pp.319-327
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    • 2018
  • Background: Lancet-related needlestick injuries (NSIs) occur steadily in clinical practices. Safety-engineered devices (SEDs) can systematically reduce NSIs. However, the use of SEDs is not active and no study to guide the implementation of SEDs was known in South Korea. The lancet-related NSIs may be eliminated to zero incidence using a SED lancet with effective sharp injury protection and reuse prevention features. Materials and Methods: We implemented a SED lancet by replacing a conventional prick lancet in a tertiary hospital in a sequential approach. A spot test of the new SED was conducted for 1 month to check the acceptability in practice and a questionnaire survey was obtained from the healthcare workers (HCWs). A pilot implementation of the SED lancet in 2 wards was made for 1 year. Based on these preliminary interventions, a hospital-wide full implementation of the SED lancet was launched. The incidence of NSIs and cost expenditure before and after the intervention were compared. Results: There were 29 cases of conventional prick lancet-related NSIs for 3 years before the full implementation of SED lancet. The proportion of prick lancet-related NSIs among yearly all kinds of NSIs during two years before the pilot study was average 11.7% (22/188). Pre-interventional baseline incidence of all kinds of NSIs was 7.01 per 100 HCW-years. After the full implementation of SED lancet, the lancet-related NSIs became zero in the 2nd year (P = 0.001). The average direct cost of 18,393 US dollars (USD) per year from device and post-exposure medical care before the intervention rose to 20,701 USD in the 2nd year of the intervention. The incremental cost-effectiveness ratio was 210 USD per injury avoided. Conclusion: The implementation of a SED lancet could eliminate the lancet-related NSIs to zero incidence. The cost increase incurred by the use of SED lancet was tolerable.

Quantitative aspects of the hydrolysis of ginseng saponins: Application in HPLC-MS analysis of herbal products

  • Abashev, Mikhail;Stekolshchikova, Elena;Stavrianidi, Andrey
    • Journal of Ginseng Research
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    • 제45권2호
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    • pp.246-253
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    • 2021
  • Background: Ginseng is one of the most valuable herbal supplements. It is challenging to perform quality control of ginseng products due to the diversity of bioactive saponins in their composition. Acid or alkaline hydrolysis is often used for the structural elucidation of these saponins and sugars in their side chains. Complete transformation of the original ginsenosides into their aglycones during the hydrolysis is one of the ways to determine a total saponin group content. The main hurdle of this approach is the formation of various by-products that was reported by many authors. Methods: Separate HPLC assessment of the total protopanaxadiol, protopanaxatriol and ocotillol ginsenoside contents is a viable alternative to the determination of characteristic biomarkers of these saponin groups, such as ginsenoside Rf and pseudoginsenoside F11, which are commonly used for authentication of P. ginseng Meyer and P. quinquefolius L. samples respectively. Moreover, total ginsenoside content is an ideal aggregated parameter for standardization and quality control of ginseng-based medicines, because it can be directly applied for saponin dosage calculation. Results: Different hydrolysis conditions were tested to develop accurate quantification method for the elucidation of total ginsenoside contents in herbal products. Linearity, limits of quantification, limits of detection, accuracy and precision were evaluated for the developed HPLC-MS method. Conclusion: Alkaline hydrolysis results in fewer by-products than sugar elimination in acidic conditions. An equimolar response, as a key parameter for quantification, was established for several major ginsenosides. The developed approach has shown acceptable results in the analysis of several different herbal products.

Assessment of Household Catastrophic Total Cost of Tuberculosis and Its Determinants in Cairo: Prospective Cohort Study

  • Ellaban, Manar M.;Basyoni, Nashwa I.;Boulos, Dina N.K.;Rady, Mervat;Gadallah, Mohsen
    • Tuberculosis and Respiratory Diseases
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    • 제85권2호
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    • pp.165-174
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    • 2022
  • Background: One goal of the End tuberculosis (TB) Strategy is to see no TB-affected households experiencing catastrophic costs. Therefore, it is crucial for TB-elimination programs to identify catastrophic costs and their main drivers in order to establish appropriate health and social measures. This study aimed to measure the percent of catastrophic costs experienced by Egyptian TB patients and to identify its determinants. Methods: We conducted a prospective cohort study with 151 Egyptian TB patients recruited from two chest dispensaries from the Cairo governate from May 2019 to May 2020. We used a validated World Health Organization TB patient-cost tool to collect data on patients' demographic information, household income, and direct and indirect expense of seeking TB treatment. We considered catastrophic TB costs to be total costs exceeding 20% of the household's annual income. Results: Of the patients, 33% experienced catastrophic costs. The highest proportion of the total came in the pre-treatment stage. Being the main breadwinner, experiencing job loss, selling property, and the occurrence of early coronavirus disease 2019 lockdown were independent determinants of the incidence of catastrophic costs. Borrowing money and selling property were the most-often reported coping strategies adopted. Conclusion: Despite the availability of free TB care under the Egyptian National TB Program, nearly a third of the TB patients incurred catastrophic costs. Job loss and being the main breadwinner were among the significant predictors of catastrophic costs. Social protection mechanisms, including cash assistance and insurance coverage, are necessary to achieve the goal of the End TB Strategy.

Pharmacokinetics of thalidomide in dogs: can feeding affect it? A preliminary study

  • Pierini, Alessio;Sartini, Irene;Giorgi, Mario;Lebkowska-Wieruszewska, Beata;Lisowski, Andrzej;Poapolathep, Amnart;Marchetti, Veronica
    • Journal of Veterinary Science
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    • 제21권5호
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    • pp.60.1-60.11
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    • 2020
  • Background: Tumor-associated neoangiogenesis is a crucial target for antitumor therapies. Thalidomide (TAL) is a promising anti-neoangiogenetic drug that has recently been used in the treatment of several malignancies in dogs. Objectives: The aim of the study was to assess the pharmacokinetics of TAL after single oral administration in dogs. Additionally, the influence of feeding on the pharmacokinetic profile of TAL in dogs has been preliminarily investigated. Methods: Six healthy adult female Labradors were enrolled according to a randomized single-dose, 2-treatment, 2-phase, paired 2 × 2 cross-over study design. The dogs were administered a single 400 mg capsule of TAL in fasted and fed conditions. Blood was collected from 15 min to 48 h after dosing, and TAL quantified in plasma by a validated high-performance liquid chromatography method. The pharmacokinetics of TAL were analyzed using a non-compartmental approach. Results: TAL concentration was quantifiable up to 10 h and 24 h after fasted and fed conditions, respectively. Cmax (fasted, 1.34 ± 0.12 ㎍/mL; fed, 2.47 ± 0.19 ㎍/mL) and Tmax (fasted, 3 h; fed, 10 h) differed substantially between the 2 groups. AUC and t1/2λz were significantly higher in fed (42.46 ± 6.64 mg × h/L; 17.14 ± 4.68 h) compared to fasted (12.38 ± 1.13 mg × h/L; 6.55 ± 1.25 h) dogs. The relative oral bioavailability of TAL for the fasted group was low (36.92% ± 3.28%). Conclusions: Feeding affects the pharmacokinetics of oral TAL in dogs, showing a delayed, but higher absorption with different rate of elimination. These findings are of importance in clinical veterinary settings, and represent a starting point for further related studies.

공공데이터 융합역량 수준에 따른 데이터 기반 조직 역량의 연구 (A Study on the Data-Based Organizational Capabilities by Convergence Capabilities Level of Public Data)

  • 정병호;주형근
    • 디지털산업정보학회논문지
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    • 제18권4호
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    • pp.97-110
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    • 2022
  • The purpose of this study is to analyze the level of public data convergence capabilities of administrative organizations and to explore important variables in data-based organizational capabilities. The theoretical background was summarized on public data and use activation, joint use, convergence, administrative organization, and convergence constraints. These contents were explained Public Data Act, the Electronic Government Act, and the Data-Based Administrative Act. The research model was set as the data-based organizational capabilities effect by a data-based administrative capability, public data operation capabilities, and public data operation constraints. It was also set whether there is a capabilities difference data-based on an organizational operation by the level of data convergence capabilities. This study analysis was conducted with hierarchical cluster analysis and multiple regression analysis. As the research result, First, hierarchical cluster analysis was classified into three groups. It was classified into a group that uses only public data and structured data, a group that uses public data on both structured and unstructured data, and a group that uses both public and private data. Second, the critical variables of data-based organizational operation capabilities were found in the data-based administrative planning and administrative technology, the supervisory organizations and technical systems by public data convergence, and the data sharing and market transaction constraints. Finally, the essential independent variables on data-based organizational competencies differ by group. This study contributed. As a theoretical implication, this research is updated on management information systems by explaining the Public Data Act, the Electronic Government Act, and the Data-Based Administrative Act. As a practical implication, the activity reinforcement of public data should be promoting the establishment of data standardization and search convenience and elimination of the lukewarm attitudes and Selfishness behavior for data sharing.