• 제목/요약/키워드: Rare frequent patterns

검색결과 17건 처리시간 0.024초

다중 최소 임계치 기반 빈발 패턴 마이닝의 성능분석 (Performance Analysis of Frequent Pattern Mining with Multiple Minimum Supports)

  • 양흥모;윤은일
    • 인터넷정보학회논문지
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    • 제14권6호
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    • pp.1-8
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    • 2013
  • 거대한 데이터베이스로부터 중요하고 의미 있는 정보를 찾아내기 위해 데이터 마이닝 기법들이 사용되며, 패턴 마이닝은 이러한 데이터 마이닝을 위한 중요한 기법 중에 하나이다. 패턴 마이닝은 거대 데이터베이스로부터 유용한 패턴을 찾아내는 기법이며, 패턴 마이닝 분야 중에 하나인 빈발 패턴 마이닝은 데이터베이스에서 최소 임계치 이상의 빈도수를 가지는 빈발 패턴을 마이닝 한다. 전통적인 빈발 패턴 마이닝은 전체 데이터베이스에 대한 단일 최소 임계치를 기반으로 중요 빈발 패턴을 마이닝 한다. 단일 최소 임계치 모델은 데이터베이스 내 모든 아이템이 동일한 특성을 가진다고 암묵적으로 가정한다. 그러나 실제 응용에서는 각 아이템들이 개별적인 특성을 가지고 있을 수 있으며, 따라서 이를 반영한 패턴 마이닝 기법이 요구된다. 데이터베이스 내 아이템들의 이러한 특성이 반영되지 않은 빈발 패턴 마이닝 모델에서, 중요한 희귀 아이템이 포함된 패턴을 마이닝 하기 위해서는 낮은 최소 임계치를 설정해야 한다. 그러나 너무 낮은 최소 임계치는 의미 없는 아이템들을 포함하는 수많은 패턴을 야기한다. 반대로 높은 최소 임계치는 희귀 아이템이 포함된 패턴을 마이닝 하지 못하는 희귀 아이템 문제라 불리는 딜레마가 발생한다. 이러한 문제의 해결을 위한 초기 연구들은 아이템 빈도수에 따라 데이터를 몇 개의 블록으로 분할하거나 관련 희귀 아이템들을 하나의 그룹으로 만드는 방법을 사용한 근사적 접근법을 제안하였다. 그러나 이러한 기법들은 근사적 방법의 적용에 의해 모든 희귀 패턴을 포함한 빈발 패턴을 마이닝 하지 못한다. 다중 최소 임계치를 고려한 패턴 마이닝 모델은 아이템들의 개별적인 특성을 반영하여 희귀 아이템 문제를 해결하기 위해 제안되었다. 다중 최소 임계치 기반의 빈발 패턴 마이닝 모델에서 각 아이템은 MIS (Minimum Item Support)라고 불리는 개별 최소 임계치를 가지며, 아이템들의 데이터베이스 내 빈도수를 기반으로 계산된다. 다중 최소 임계치 모델은 MIS를 통해 수많은 의미 없는 패턴을 생성하지 않고도 손실 없이 모든 희귀 빈발 패턴을 찾아낸다. 한편, 빈발 패턴을 마이닝 하는 과정에서 후보 패턴들이 생성되며, 단일 최소 임계치 모델에서는 각 후보 패턴의 빈도수가 유일한 최소 임계치와 비교된다. 따라서, 희귀 아이템 문제가 발생할 뿐만 아니라 후보 패턴을 구성하는 아이템들의 특성이 고려되지 않는다. 다중 최소 임계치 모델에서는 이 문제를 다루기 위해 후보 패턴을 구성하는 아이템들의 MIS 값 중에서 가장 작은 MIS 값을 해당 후보 패턴의 최소 임계치로 설정하여 패턴 내 아이템들의 특성을 반영한다. 이를 적용하여 효율적으로 희귀 빈발 패턴을 마이닝 하기 위해 트리 구조 기반의 알고리즘은 빈도수 내림차순으로 트리 내 아이템들을 정렬하는 단일 최소 임계치 모델과는 달리 MIS 내림차순으로 아이템들을 정렬하여 마이닝을 수행한다. 본 논문에서는 다중 최소 임계치 기반의 빈발 패턴 마이닝 알고리즘에 대한 특성을 살펴보고, 일반 단일 임계치 기반 알고리즘과의 성능평가를 수행한다. 성능평가는 실행 속도, 메모리 사용량, 그리고 확장성의 관점에서 수행된다. 성능평가 결과, 다중 최소 임계치 기반의 빈발 패턴 마이닝 알고리즘은 희귀 빈발 패턴을 포함한 모든 빈발 패턴을 단일 임계치 기반의 빈발 패턴 마이닝 알고리즘보다 더 빠른 속도로 마이닝 하였으며, 각 아이템의 최소 임계치 정보를 위한 추가적인 메모리를 필요로 하였다. 또한, 비교 알고리즘들은 좋은 확장성 결과를 보였다.

청주지역 일부 대학생의 편의점 편의식 섭취 빈도에 따른 식습관 및 식품첨가물 관련 인식 (Dietary Habits and Perception Toward Food Additives according to the Frequency of Consumption of Convenience Food at Convenience Stores among University Students in Cheongju)

  • 배문경
    • 대한지역사회영양학회지
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    • 제21권2호
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    • pp.140-151
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    • 2016
  • Objectives: This study was performed to examine the consumption patterns of convenience food at convenience stores, dietary habits, and perception as well as knowledge of food additives among university students. Methods: Subjects were 352 university students in Cheongju, Korea, and data was collected by a self-administered questionnaire. They were divided into three groups according to the frequency of consumption of convenience food at convenience stores: 79 rare (${\leq}1$ time/month), 89 moderate (2-4 times/month) and 184 frequent (${\geq}2$ times/week). Results: More subjects from the frequent consumption group lived apart from parents (p<0.001) and possessed more pocket money (p<0.01). Frequent consumption group consumed noodles, Kimbab, and sandwich & burger significantly more often (p<0.001, respectively) than others. In addition, frequent consumption of convenience foods at convenience stores was associated with frequent breakfast skipping (p<0.05), irregular meal time (p<0.01), snacking (p<0.05), and eating late night meal (p<0.001). More from the rare consumption group had heard about food additives previously compared to the frequent consumption group (79.7% vs. 63.6%, p<0.01). Frequent consumption group showed significantly higher score than did the rare consumption group for the following questions: monosodium glutamate is harmful to your health (p<0.05), food additives are necessary for food manufacturing (p<0.005), food additives need to be labeled on products (p<0.05), there is no food additive at all if labeled as no preservatives, no coloring, and no added sugar (p<0.05). There was a significant difference in degrees of choosing products with less food additives depending on the consumption pattern. Conclusions: Our results provided a better understanding of the factors associated with frequent consumption of convenience foods at convenience stores among university students and will be useful to develop a nutrition education program for those who are more prone to consume convenience foods.

Lifestyle, dietary habits and consumption pattern of male university students according to the frequency of commercial beverage consumptions

  • Kim, Hye-Min;Han, Sung-Nim;Song, Kyung-Hee;Lee, Hong-Mie
    • Nutrition Research and Practice
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    • 제5권2호
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    • pp.124-131
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    • 2011
  • Because excessive consumption of sugar-sweetened beverages may reduce the quality of nutritional intake, this study examined the consumption patterns of commercial beverages, lifestyle, dietary habits, and perception of sweet taste. Participants were 407 male university students in Kyeooggido, Korea, and information was collected by self-administered questionnaire. Among them, 58 nonsmokers volunteered to participate in the taste test. Participants were divided into three groups according to the frequency of commercial beverage consumptions: 120 rare (< 1 serving/week), 227 moderate (1-3 servings/week) and 133 frequent (> 3 servings/week) consumption groups. More subjects from the rare consumption group chose water, tea, and soy milk, and more from the frequent consumption group chose carbonated soft drinks and coffee (P=0.031) as their favorite drinks. Frequent consumption group consumed fruit juice, coffee, and sports and carbonated soft drinks significantly more often (P=0.002, P=0.000, P=0.000, respectively), but not milk and tea. Frequent consumption group consumed beverages casually without a specific occasion (P=0.000) than rare consumption group. Frequent drinking of commercial beverages was associated with frequent snacking (P=0.002), meal skipping (P=0.006), eating out (P=0.003), eating delivered foods (P=0.000), processed foods (P=0.001), and sweets (P=0.002), and drinking alcoholic beverages (P=0.029). Frequent consumption group tended to have a higher threshold of sweet taste without reaching statistical significance. The results provide information for developing strategies for evidence-based nutrition education program focusing on reducing consumption of unnecessary sugar-sweetened commercial beverages.

우간다 성인의 외식과 식이패턴의 관련성: 온라인 기반 설문조사 (Away-from-Home Eating and Dietary Patterns of Ugandan Adults: a Web-based- Survey)

  • 안토니 키됴;박필숙
    • 대한지역사회영양학회지
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    • 제27권1호
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    • pp.1-11
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    • 2022
  • Objectives: Away-from-home (AFH) eating has been associated with poor diet quality and health outcomes like obesity in developed countries. AFH eating is also emerging in low-income countries, but its influence on overall diet quality is under-researched. We examined the prevalence of AFH eating and its influence on the dietary patterns of Ugandan adults. Methods: This cross-sectional study employed a web-based survey to interview Ugandan adults aged 18 ~ 65 years. A qualitative food frequency questionnaire was used to assess the food group intake, which was then converted into daily intake frequencies. Principal component analysis was used to derive dietary patterns. The participants were then classified based on the tertiles (T) of dietary pattern scores. Results: About 75% of the 375 participants reported eating AFH. The young men, food insecure, and urban dwellers were more likely to eat AFH ≥ 5 times/week. Three dietary patterns emerged; the animal-based, beverage pattern; the high fat, sweet pattern; and the traditional, plant-based pattern. Participants who frequently ate AFH were 2.85 times and 5.64 times more likely to be in the second and third tertiles, respectively, of the animal-based, beverage pattern compared to the rare eaters (OR = 2.85, 95% CI: 1.35-6.06 for T2 vs T1; and OR = 5.64, 95% CI: 2.50-12.73 for T3 vs T1). The odds of being in the second tertile of the high fat, sweet pattern was significantly higher for frequent AFH eaters compared to the rare eaters (OR = 2.61, 95% CI:1.23-5.52). Conclusions: The prevalence of AFH eating was high. Frequent AFH eating was common among the young, male, food insecure, and urban dwellers, and was associated with unhealthy dietary patterns.

한강하류의 환경학적 연구 -VII. 식물플랑크톤군집의 장기간 변화와 전망- (Environmental Studies in the Lower Part of the Han River -VII. Long Term Variations and Prospect of the Phytoplankton Community-)

  • 이진환;정승원
    • ALGAE
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    • 제19권4호
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    • pp.321-327
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    • 2004
  • The literature review on the dynamics of the phytoplankton communities in terms of species composition, standing crops, abundant species and dominant species in the lower part of the Han River from 1940s to 2000s was conducted for the prospective prediction of their succession patterns. Total of 326 taxa were identified and they belonged to 47 blue-green algae, 139 green algae, 12 euglenoids, 126 diatoms, 6 din flagellates and 2 silicoflagellates. Composition of phytoplankton communities were 83.6% diatoms, 10.5% blue-green algae and 5.3% green algae in the middle of 1960s, whereas those were 43.2% diatoms, 40.7% green algae and 13.6% blue-green algae in the 1990s. Before 1990s, Synedra ulna, Melosira varians, Cymbella tumida, Synedra acus, Cymbella ventricosa, Navicula cryptocephala, Nitzschia palea, Aulacoseira granulata, Gomphonema parvulum and Cymbella affinis were most frequent, while those after 1990 were Asterionella formosa, Asterionella gracillima, Aulacoseira granulate, Aulacoseira granulata var. angustissima, Chlorella vulgare, Fragilaria crotonensis and Synedra ulna. Phytoplankton blooms were frequent from winter to the late spring and rare in summer due to heavy rain and discharge. Seasonal variations of the dominant species were fairly obvious; Asterionella gracillima and Aulacoseira granulata in spring, Aulacoseira granulate and Aulacoseira granulate var. angustissima in summer and autumn, Asterionella gracillima and Stephan discus hantzschii in winter. Recently blue-green algae, Microcystis, Aphanocapsa, Dactylococcopsis have been more abundant than those of the previous reports. Based on the current situations, Stephan discus hantzschii f. tennis, Asterionella gracillima, Aulacoseira granulate and blue-green algae will be more abundant and blooms of those species will be more frequent.

Shigella R Plasmid의 분자적 특성 (Molecular Characteristics of R Plasmids in Shigella)

  • 이유철;설성용;조동택;전도기
    • 대한미생물학회지
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    • 제22권1호
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    • pp.35-53
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    • 1987
  • Multiply resistant Shigella strains isolated in Taegu area were subjected for the characterization of R plasmids. All strains isolated in 1984 and 1985 were susceptible to gentamicin, amikacin, and cephalothin, and most strains were susceptible to kanamycin (Km) and rifampin by agar dilution antimicrobial susceptibility test. The resistance frequency of S. flexneri against ampicillin (Ap) was higher than that of S. sonnei. The strains resistant to sulfisomidine (Su) and trimethoprim (Tp) were found at higher frequency in S. sonnei than in S. flexneri. The most prevalent resistance pattern of S. flexneri was chloramphenicol (Cm) tetracycline (Tc) streptomycin (Sm) Ap, followed by the pattern of CmTcSmSuApTp, CmTcSmSuApTp nalidixic acid, and CmTcSmSuAp in the decreasing order. The antibiogram of CmTcSmSuTp was found to be the most frequent pattern in S. sonnei. The ratio of conjugal transfer of S. flexneri was 47% and 75% of S. sonnei. The average number of plasmid harboring in Shigella was 4 and the size of plasmid ranged 1.3 to 134 megadalton (Mdal). Most S. flexneri carried plasmids of 2 to 3 Mdal and S. sonnei carried those of 3 to 4 Mdal size. The sizes of conjugative plasmids ranged 40-90 Mdal. The incompatibility group (Inc) F II plasmids (54-59 Mdal) were most frequent and rare Inc B plasmids (60 Mdal) of isolates in 1979 and 1980 and Inc FI (87 Mdal) of 1983 isolates were able to be classified by the colony test with standard reference plasmids. The R plasmids of known Inc group were tested for the restriction endonuclease analysis. The pattern of plasmids digested by EcoRl were apparently different by the Inc group but there was no significant difference between species or by the resistance patterns. Nonconjugative plasmids and their phenotypes were identified by transformation test. The transformants were resistant to less than two drugs. Colicin producing transformants carried the Col plasmid of 3.7 or 3.9 Mdal size. $Ap^r$ plasmids derived from S. sonnei were found to be mobilized by transfer factor RT641 to E. coli #CS100. $Ap^r$ plasm ids of same size shared by S. flexneri, S. sonnei, and E. coli were digested with Pstl. All of them showed two restriction fragments of 2.8 kilobase(kb) and 0.7kb. Other plasmids ($Sm^r\;Su^r$) derived from S. flexneri, S. boydii, and S. sonnei were digested with Pstl and they showed same restriction fragment patterns of 3.1kb and 2.9kb. The plasmid profiles of three strains of S. sonnei producing colicin and showing same resistance pattern of CmTcSmSuApTpKm appeared to be similar. Restriction patterns by EcoRl and the behavior of plasmids in conjugation or transformation process were also similar between those plasmids. The restriction patterns were significantly different between the plasmids of Inc FI group and those of unclassified Inc group.

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점액세포가 관찰되는 침샘 관암종 -세침흡인 세포검사에서 점액표피모양암종으로 오인했던 1예 보고- (Salivary Duct Carcinoma with Mucin Containing Cells -Report of a Case Misdiagnosed as Mucoepidermoid Carcinoma on Fine Needle Aspiration Cytology-)

  • 김혜령;김현기;김호근;김진;홍순원;김세훈
    • 대한세포병리학회지
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    • 제17권1호
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    • pp.56-62
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    • 2006
  • Salivary duct carcinoma (SDC) is a rare primary salivary gland malignancy characterized by histological features similar to those of ductal carcinomas of the breast. It is regarded as a high-grade malignancy associated with frequent local recurrences and early distant metastases that require aggressive treatment. The typical fine needle aspiration cytology (FNAC) findings in SDC include cellular smears showing tumor cells with eccentric pleomorphic nuclei and a granular cytoplasm arranged in flat sheets or cribriform patterns against a necrotic background. However, the presence of mucin-containing cells in SDC has been rarely described. We report the FNAC findings in a patient with histologically confirmed SDC that demonstrated numerous mucin-containing cells and was subsequently misdiagnosed as a high-grade mucoepidermoid carcinoma. Here we discuss the problems involved in distinguishing SDC from high-grade mucoepidermoid carcinoma on the basis of cytologic findings alone.

Traditional Living Habits of the Taz Tundra Population: A Paleoparasitological Study

  • Slepchenko, Sergey Mikhailovich;Ivanov, Sergey Nikolaevich;Nikolaevich, Bagashev Anatoly;Alekseevich, Tsybankov Alexander;Sergeyevich, Slavinsky Vyacheslav
    • Parasites, Hosts and Diseases
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    • 제54권5호
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    • pp.617-623
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    • 2016
  • An excavation of the Vesakoyakha II-IV and Nyamboyto I burial grounds was conducted during the 2014 field season, and soil samples from intact burials dating from the 19th and 20th centuries, respectively, were analyzed to determine interactions between parasites and host/vectors. Considering the discovery of Diphyllobothrium sp. and Taenia sp. eggs in soil samples from the pelvic region, diphyllobothriasis was the most frequent helminthic infection among the Taz Nenets. The Nyamboyto Nenets mainly consumed uncooked fish, while the Vesakoyakha Nenets had a bigger variety in food choices, including reindeer meat. Nenets children were given raw fish from early childhood. The paleoparasitological results corroborate rare ethnographic records about the consumption of uncooked reindeer cerebrum which led to beef tapeworm helminthiases. This is the first parasitological report of helminthic diseases among the Taz Nenets, and, as such, it provides insight into their subsistence activities and food patterns and broadens our understanding of their health condition.

소집단 토론 과정에서의 언어적 상호작용 분석 (Analysis of Verbal Interaction in Small Group Discussion)

  • 강석진;김창민;노태희
    • 한국과학교육학회지
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    • 제20권3호
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    • pp.353-363
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    • 2000
  • 본 연구에서는 4개 소집단의 학생간 토론 양상을 조사하였다. 소집단 토론 과정에서 나타나는 언어적 상호작용을 녹음 및 녹화한 후, 기록 원고를 작성하고, 분석하였다. 개별 진술, 상호작용 단위, 에피소드 수준의 분류들을 개발하였다. 개별 진술 분석에서 학생들의 이전 성취도와 지식 구성 과정 기여도 사이에는 뚜렷한 관계가 없었다. 상호작용 단위 분석에서는 부분 참여형 상호작용과 대칭적 상호작용이 상대적으로 많이 발견되어 학생간의 상호작용이 부분적이고 피상적인 것으로 나타났다. 또한, 에피소드 분석에서는 제시된 의견의 수용이나 부분적인 정교화 유형이 가장 흔히 나타났고, 변증법적인 대화는 드물었다.

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성문상부암과 하인두암의 경부전이 양상과 양측 경부청소술의 의의 (Patterns of Neck Node Metastasis and Bilateral Neck Dissections in Supraglottic and Hypopharyngeal Cancers)

  • 이형석;태경;김주묵;박준수;김선곤
    • 대한두경부종양학회지
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    • 제13권1호
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    • pp.24-29
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    • 1997
  • Background: Supraglottic and hypopharyngeal regions drain into the upper deep cervical lymph nodes. And bilateral neck node metastasis is frequently occured especially, in the early stage. It influences on the prognosis of above diseases. The prognosis for patients wih supraglottic and hypopharyngeal cancers, although usually poor, has improved by modern imaging technique, better application of treatment modalities, increasing assortment of reconstructive procedures and improved application of radiation therapy. Objectives: This study was designed to obtain objective data about the patterns of neck node metastasis and to identify the necessity of elective bilateral neck dissection. Material and Methods: Twenty four patients with supraglottic cancer and twenty six patients with hypopharyngeal cancer were investigated from the chart review. Results: In supraglottic cancer, the most frequent sites of neck metastasis is level II (52.9%) and level III (52.9%) in ipsilateral side, level II (29.4%) in contralateral side, in hypopharyngeal cancer, level II (73.7%) and III (52.6%) in ipsilateral side, level II (10.5%) in contralateral side. In elective neck dissection, the occult metastasis is about 50% in supraglottic cancer, but there is no occult metastasis in hypopharyngeal cancer. Conclusion: In supraglottic cancer, elective bilateral neck dissection is necessary because of early contralateral neck metastasis, but in hypopharyngeal cancer, elective contralateral neck dissection may not be always necessary because of rare occult metastasis and contralateral neck metastasis.

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