• 제목/요약/키워드: Well-ordered set

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Helicobacter pylori Strain 51 (Korean Isolate): Ordered Overlapping BAC Library, Combined Physical and Genetic Map, and Comparative Analysis with H. pylori Strain 26695 and Strain J99

  • KANG HYUNG-LYUN;LEE WOO-KON;SONG JAE-YOUNG;CHOI SANG-HAENG;PARK SEONG-GYU;RYU BOK-DEOK;LEE EUN-JOO;KIM JI-SUN;PARK JEONG-UCK;BAIK SEUNG-CHUL;CHOI MYOUNG-BUM;YOUN HEE-SHANG;KO GYUNG-HYUCK
    • Journal of Microbiology and Biotechnology
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    • 제15권4호
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    • pp.844-854
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    • 2005
  • We constructed a defined physical and genetic map of H. pylori strain 51, previously isolated from a Korean patient with a duodenal ulcer, by combining a restriction analysis by pulse-field gel electrophoresis with the construction of a BAC library. A Notl-digest of H. pylori strain 51 genome yielded seven fragments, from which the genomic size was estimated to be 1,698$\pm$24 kb. The BAC library was constructed from 50 to 200 kb fragments of HindIII-digested genomic DNA. From 700 BAC clones, an ordered overlapping maxi-set of 82 BAC clones was assembled that covered the entire genome. The positions of 15 genes were localized in the strain 51 genome with 4-22 kb of resolution and were compared with their orthologues in strain 26695 and strain J99. The arrangement of the 15 genes was identical in strain 51 and strain J99, except for flaA and hpaA. The plasticity zone of strain 51, like that of strain J99, was located in the single region, and was shorter than those of strain 26695 and strain J99. The strain 51 plasticity zone consisted of ORFs common only to strain 51 and J99 or to strain 51 and 26695, as well as strain 51-specific ORFs. Three genetic translocations and/or inversions were found between orthologue ORFs in strain 51 and strain J99. These results show that the chromosomal organization of strain 51 differs from Western strains such as strain 26695 and strain J99.

학교 주변 커뮤니티 CPTED에 관한 지역 주민의 인식 연구 (Analyzing Community CPTED Perception of Local Residents in the School Areas)

  • 고은비;이재송;정승윤;최열
    • 대한토목학회논문집
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    • 제37권5호
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    • pp.891-903
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    • 2017
  • 본 연구는 중요한 사회적 문제로 주목받고 있는 학교폭력을 예방하고 감소시키기 위해 범죄예방환경설계에 대한 지역 주민의 인식을 분석하여 적절한 커뮤니티 CPTED 적용 방안을 찾아보는데 그 목적이 있다. 먼저, 학교 외부의 학교 폭력 발생 가능 장소를 유형화하기 위하여 계층적 군집분석을 사용하고 지역 주민의 인식을 지도화했다. 다음으로 학교폭력 예방에 대한 커뮤니티 CPTED 적용의 중요성과 그것을 적용했을 때의 효과성에 대한 지역 주민의 인식을 분석하기 위하여 IPA를 사용하였다. 그리고 학교폭력으로부터 학교 외부가 안전하다고 생각하는지에 대한 지역 주민들의 인식을 분석하기 위하여 순서형로짓모형을 이용한 실증분석을 하였다. 세 분석의 결과를 통합하여 학교 외부 공간에서 학교폭력 예방을 위한 커뮤니티 CPTED 적용의 우선순위를 도출할 수 있었다. 학교폭력을 학교 주변에서 효과적으로 근절시키기 위한 커뮤니티 CPTED 적용에 있어서 지역주민의 인식을 반영한다면, 속해 있는 커뮤니티가 학생들에게 안전한 환경을 제공한다는 것으로부터의 커뮤니티 구성원의 만족도가 증가할 수 있다.

배달 애플리케이션 품질이 애플리케이션 신뢰, 라이더 신뢰 그리고 사용의도에 미치는 영향 : 온라인 플랫폼 물류에서의 신뢰 이전을 중심으로 (Effect of Delivery Application Quality on Application Trust, Delivery Rider Trust, and Intention to Use: Focused on Trust Transfer in Online Platform Logistics)

  • 서원태
    • 한국프랜차이즈경영연구
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    • 제12권4호
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    • pp.41-54
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    • 2021
  • Purpose: Delivery food orders are on the rise due to the COVID 19 pandemic. Many customers are ordering food through delivery apps rather than visiting restaurants to eat out. Delivery application platforms are growing due to the development of O2O. Most of the people who provide gig worker for delivery applications are rider. Rider provides labor on their own terms and have more work flexibility and autonomy than ordinary workers. Trust can be transferred from a well-known entity to an unknown entity. From the customer's point of view of using the delivery application, trust can be seen through the third-party trust of the delivery application platform-rider-customer. Therefore, this study intends to investigate the effect on delivery application trust and rider trust through the well-known characteristics of delivery applications. Research design, data, and methodology: This study was conducted on Korean consumers over 20 years of age who have ordered food through a delivery application for the past month. After educating 5 investigators about the purpose of this study, 60 copies of the survey were conducted per person. During the investigation period, from September 2 to September 26, 2021, 322 copies were collected over 25 days. Among the collected questionnaires, 37 were excluded from insincere or partially unanswered, and 285 were used for analysis. In addition, the collected data were analyzed using SPSS 25.0 and AMOS 25.0. Result: As a result of the study, convenience, price, and variety of restaurants were found to have a significant positive (+) effect on app trust, but design did not have a significant effect on app trust. Also, it was found that convenience had a significant positive (+) effect on trust in rider, but design, price, and variety of restaurants did not have a significant effect. App trust was found to have a significant positive (+) effect on rider trust and intention to use, and it was found to have a significant positive (+) effect on rider trust and intention to use. Conclusions: First, this study established a structural framework between delivery application characteristics-delivery-app trust-rider trust-intention to use. Second, in this study, it was found that customer trust in well-known delivery applications was transferred to less-known rider trust. Third, the delivery application should increase the convenience of use. Fourth, delivery application should set the delivery fee appropriately. Fifth, delivery application must continuously train the rider.

Genomic Diversity of Helicobacter pylori

  • Lee, Woo-Kon;Choi, Sang-Haeng;Park, Seong-Gyu;Choi, Yeo-Jeong;Choe, Mi-Young;Park, Jeong-Won;Jung, Sun-Ae;Byun, Eun-Young;Song, Jae-Young;Jung, Tae-Sung;Lee, Byung-Sang;Baik, Seung-Chul;Cho, Myung-Je
    • 대한미생물학회지
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    • 제34권6호
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    • pp.519-532
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    • 1999
  • Helicobacter pylori is a causative agent of type B gastritis and plays a central role in the pathogenesis of gastroduodenal ulcer and gastric cancer. To elucidate the host-parasite relationship of the H. pylori infection on the basis of molecular biology, we tried to evaluate the genomic diversity of H. pylori. An ordered overlapping bacterial artificial chromosome (BAC) library of a Korean isolate, H. pylori 51 was constructed to set up a genomic map. A circular physical map was constructed by aligning ApaI, NotI and SfiI-digested chromosomal DNA. When the physical map of H. pylori 51 was compared to that of unrelated strain, H. pylori 26695, completely different restriction patterns were shown. Fifteen known genes were mapped on the chromosome of H. pylori 51 and the genetic map was compared with those of strain 26695 and J99, of which the entire genomic sequences were reported. There were some variability in the gene location as well as gene order among three strains. For further analysis on the genomic diversity of H. pylori, when comparing the genomic structure of 150 H. pylori Korean isolates with one another, genomic macrodiversity of H. pylori was characterized by several features: whether or not susceptible to restriction digestion of the chromsome, variation in chromosomal restriction fingerprint and/or high frequency of gene rearrangement. We also examined the extent of allelic variation in nucleotide or deduced amino acid sequences at the individual gene level. fucT, cagA and vacA were confirmed to carry regions of high variation in nucleotide sequence among strains. The plasticity zone and strain-specific genes of H. pylori 51 were analyzed and compared with the former two genomic sequences. It should be noted that the H. pylori 51-specific sequences were dispersed on the chromosome, not congregated in the plasticity zone unlike J99- or 26695-specific genes, suggesting the high frequency of gene rearrangement in H. pylori genome. The genome of H. pylori 51 shows differences in the overall genomic organization, gene order, and even in the nucleotide sequences among the H. pylori strains, which are far greater than the differences reported on the genomic diversity of H. pylori.

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주파수대역 직접확산 통신시스템에서 다중경로 페이딩 보상을 위한 최적 레이크 신호처리에 관한 연구 (Optimum Rake Processing for Multipath Fading in Direct-Sequence Spread-Spectrum Communication Systems)

  • 장원석;이재천
    • 한국통신학회논문지
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    • 제28권10C호
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    • pp.995-1006
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    • 2003
  • 무선 통신 시스템은 전자파 신호의 전파 특성과 주위 환경/장애물에 의해 다중 경로 페이딩을 겪게 되어 수신 신호의 급격한 전력 감쇄가 생길 수 있음은 잘 알려져 있는 사실이다. 한편으로 송신기에서 생성된 하나의 동일한 송신 신호가 여러 경로를 통해서 해당 수신기에 도달하므로 이점을 적극적으로 활용하면 데이터 수신 성능을 향상 시킬 수 있는데 이것의 한가지 방법이 레이크 신호처리 기법이다. 본 연구는 PN (pseudo noise) 수열을 사용하여 주파수대역 확산을 구현하는 무선통신 수신기에서 레이크 신호처리 기법에 대해서 연구하였다. 기존의 고정 PN 레이크 복조기는 다중 경로 페이딩 채널의 임펄스 응답 계수의 공액 복소수 값을 계수로 하는 유한 길이 디지털 필터에 의해 수신 신호론 처리한 후, PN 복조 과정을 거쳐 데이터 신호를 재생하게 된다. 본 연구에서는 기존의 PN 복조 과정을 대체하는 최적 복조기의 개념 및 적응 설계 기법을 제안하였다. 제안된 최적 레이크 복조기에 대해 이론적인 성능 분석을 수행하였으며, 컴퓨터 모의 실험을 통해 유도된 결과들의 타당성을 검증하였다. 결과로 새로운 최적 레이크 신호처리기법을 통해 기존의 고정 PN 레이크 복조기에 비해 심볼평균제곱오차가 10dB 이상의 월등한 성능 향상이 가능함을 보였다. 또한 다중 경로 신호의 결합과 PN 복조를 동시에 한 복조 심볼 구간 안에서 수행하는 통합 복조기에 비해서도 약 10 dB 정도의 성능 향상이 있었다. 그리고 최적 레이크 복조기의 심볼평균제곱오차가 이론적인 한계치인 백색잡음 채널에서 QPSK 복조기의 심볼평균제곱오차에 매우 근접함을 보였다.

다양한 다분류 SVM을 적용한 기업채권평가 (Corporate Bond Rating Using Various Multiclass Support Vector Machines)

  • 안현철;김경재
    • Asia pacific journal of information systems
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    • 제19권2호
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    • pp.157-178
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    • 2009
  • Corporate credit rating is a very important factor in the market for corporate debt. Information concerning corporate operations is often disseminated to market participants through the changes in credit ratings that are published by professional rating agencies, such as Standard and Poor's (S&P) and Moody's Investor Service. Since these agencies generally require a large fee for the service, and the periodically provided ratings sometimes do not reflect the default risk of the company at the time, it may be advantageous for bond-market participants to be able to classify credit ratings before the agencies actually publish them. As a result, it is very important for companies (especially, financial companies) to develop a proper model of credit rating. From a technical perspective, the credit rating constitutes a typical, multiclass, classification problem because rating agencies generally have ten or more categories of ratings. For example, S&P's ratings range from AAA for the highest-quality bonds to D for the lowest-quality bonds. The professional rating agencies emphasize the importance of analysts' subjective judgments in the determination of credit ratings. However, in practice, a mathematical model that uses the financial variables of companies plays an important role in determining credit ratings, since it is convenient to apply and cost efficient. These financial variables include the ratios that represent a company's leverage status, liquidity status, and profitability status. Several statistical and artificial intelligence (AI) techniques have been applied as tools for predicting credit ratings. Among them, artificial neural networks are most prevalent in the area of finance because of their broad applicability to many business problems and their preeminent ability to adapt. However, artificial neural networks also have many defects, including the difficulty in determining the values of the control parameters and the number of processing elements in the layer as well as the risk of over-fitting. Of late, because of their robustness and high accuracy, support vector machines (SVMs) have become popular as a solution for problems with generating accurate prediction. An SVM's solution may be globally optimal because SVMs seek to minimize structural risk. On the other hand, artificial neural network models may tend to find locally optimal solutions because they seek to minimize empirical risk. In addition, no parameters need to be tuned in SVMs, barring the upper bound for non-separable cases in linear SVMs. Since SVMs were originally devised for binary classification, however they are not intrinsically geared for multiclass classifications as in credit ratings. Thus, researchers have tried to extend the original SVM to multiclass classification. Hitherto, a variety of techniques to extend standard SVMs to multiclass SVMs (MSVMs) has been proposed in the literature Only a few types of MSVM are, however, tested using prior studies that apply MSVMs to credit ratings studies. In this study, we examined six different techniques of MSVMs: (1) One-Against-One, (2) One-Against-AIL (3) DAGSVM, (4) ECOC, (5) Method of Weston and Watkins, and (6) Method of Crammer and Singer. In addition, we examined the prediction accuracy of some modified version of conventional MSVM techniques. To find the most appropriate technique of MSVMs for corporate bond rating, we applied all the techniques of MSVMs to a real-world case of credit rating in Korea. The best application is in corporate bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. For our study the research data were collected from National Information and Credit Evaluation, Inc., a major bond-rating company in Korea. The data set is comprised of the bond-ratings for the year 2002 and various financial variables for 1,295 companies from the manufacturing industry in Korea. We compared the results of these techniques with one another, and with those of traditional methods for credit ratings, such as multiple discriminant analysis (MDA), multinomial logistic regression (MLOGIT), and artificial neural networks (ANNs). As a result, we found that DAGSVM with an ordered list was the best approach for the prediction of bond rating. In addition, we found that the modified version of ECOC approach can yield higher prediction accuracy for the cases showing clear patterns.