• 대한기계학회논문집A
• /
• 제24권8호
• /
• pp.1978-1990
• /
• 2000

In this study, the free vibrations of the cantilever plate, which is one of the most frequently used elements in various machine structures, are analyzed and further the results are utilized to develop the methodology to predict and control the natural frequencies for designing stabilized systems. The proposed method has three major steps. The first step is the frequency response test to investigate the natural frequencies of some plates, then the database is constituted from experiments and the FEM, and finally the natural frequencies are predicted using the database to be cross-checked by the identification test. The result of this study will help design many different stable structures without any complicated calculations.

• 산업기술연구
• /
• 제18권
• /
• pp.343-353
• /
• 1998

Effective design of a database is essential for operating application systems efficiently. This paper discusses database design for a geographic information system. This goals of database design are multiple: to satisfy the information content requirements of the specified users and applications; to provide a natural and easy-to-understand structuring of the information; and to support processing requirements and any performance objectives such as response time, processing time, and storage space. Database design is a very complex process and is decomposed in three phases: conceptual, logical, and physical design. In this paper, we first collect and analyze the requirements for a geographic information system. We also perform database design for these requirements through the three design phases systematically. Our results would contribute to the effective construction of a database for a geographic information system.

• 한국경영과학회지
• /
• 제24권1호
• /
• pp.99-117
• /
• 1999

Since query language is used as a handy tool to obtain information from a database, a more intelligent query answering system is needed to provide user-friendly and fault-tolerant human-machine Interface. Frequently, database users prefer less rigid querying structure, one which allows for vagueness in composing queries, and want the system to understand the intent behind a query. When there is no matching data available, users would rather receive approximate answers than a null information response. This paper presents a knowledge abstraction database that facilitates the development of such a fault-tolerant and intelligent database system. The proposed knowledge abstraction database adepts a multilevel knowledge representation scheme called the knowledge abstraction hierarchy(KAH), extracts semantic data relationships from the underlying database, and provides query transformation mechanisms using query generalization and specialization steps. In cooperation with the underlying database, the knowledge abstraction database accepts vague queries and allows users to pose approximate queries as well as conceptually abstract queries. Specifically. four types of vague queries are discussed, including approximate selection, approximate join, conceptual selection, and conceptual Join. A prototype system has been implemented at KAIST and is being tested with a personnel database system to demonstrate the usefulness and practicality of the knowledge abstraction database in ordinary database application systems.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권3호
• /
• pp.465-479
• /
• 2020

Objective: This study performed a meta-analysis of published trials to determine the effects of zinc on the immune response and production performance of broilers. Methods: A database was built from published literature regarding the addition of zinc forms or doses and their relation to the immune response and production performance of broilers. Different doses or forms of zinc were identified in the database. The recorded parameters were related to the immune response and production performance. The database contained a total of 323 data points from 41 studies that met the criteria. Then, the data were processed for a meta-analysis using a mixed model methodology. The doses or different forms of zinc were considered fixed effects, different studies were treated as random effects, and p-values were used as the model statistics. Results: An increase in zinc dose increased (p<0.05) pancreas metallothionein (MT) and zinc concentrations in the plasma, tibia and meat, all in quadratic patterns, but linearly decreased (p<0.05) the heterophil/lymphocyte (H/L) ratio. Regarding the different zinc forms, both inorganic and organic zinc increased (p<0.05) the zinc concentrations in the plasma and tibia, the calcium and phosphorus contents in the tibia, and the antioxidant activity of superoxide dismutase in meat as compared to control. An increase in zinc dose increased average daily gain (ADG) and decreased feed conversion ratio (FCR) following a quadratic pattern (p<0.05). Inorganic and organic zinc decreased (p<0.05) FCR and H/L ratio than that of control, but these two forms were similar for these parameters. Conclusion: Zinc addition has a positive impact on immunity and broiler production. Zinc can suppress stress and inhibit the occurrence of lipid peroxidation in broilers, and it can also improve ADG, FCR, and the quality of broiler carcasses.

• 컴퓨터교육학회논문지
• /
• 제15권6호
• /
• pp.33-41
• /
• 2012

본 논문은 온라인 평가 문항 관리 시스템 및 방법에 관한 것이다. 제안하는 시스템은 학습자 정보 데이터베이스, 영역별, 난이도별로 분류된 문항을 저장하는 문제 은행 데이터베이스로 구성된다. 문제은행 데이터베이스는 특정 학습자 또는 특정 학습에 대한 문항을 선택하는 문항 선제부, 특정 학습자 또는 특정 학습에 대한 문제지를 제작하는 문제지 제작부, 문제지를 저장하였다가 온라인 테스트를 수행할 때 출력하는 문제지 은행 데이터베이스를 포함한다. 학습자가 온라인 테스트에 제출된 문항들에 대한 문항 선택순서, 보기 선택순서, 클릭회수, 반응시간에 대한 평가 데이터를 수집하는 온라인 테스트부, 및 온라인 테스트부로부터 수집된 학습자의 온라인 테스트 평가 데이터를 분석하여 학습자의 학습수준과 학습능력, 성향을 평가하고 진단하여 보고하는 반응패턴 분석부를 포함한다. 제안하는 시스템은 보기 선택순서, 클릭회수, 반응시간을 학습자의 평가결과에 반영하여 효율적으로 학습자의 학습수준과 학습능력, 성향을 평가하고 진단할 수 있다.

• 한국정보과학회논문지:데이타베이스
• /
• 제31권4호
• /
• pp.373-383
• /
• 2004

대량의 데이타를 관리하는 현대 데이타베이스 시스템 환경에서는 데이타베이스 시스템 튜닝에 대한 중요성이 증가하고 있다. 특히, 데이타베이스 시스템 성능 인자(performance parameters)를 시스템부하에 따라 적절하게 튜닝하여야 한다. 본 논문에서는 TPC-W 환경에서 데이타베이스 시스템의 단일 성능 인자 튜닝 전략 2가지(처리량 평가 방법, 응답시간 평가 방법)를 제시한다. 효과성을 입증하기 위하여 제시한 튜닝 전략은 두 개의 상용 데이타베이스 시스템에 적용하였다. 실험 결과는 제시된 튜닝 전략이 성능 향상에 기여함을 보인다.

• Journal of Information Processing Systems
• /
• 제11권3호
• /
• pp.389-405
• /
• 2015

Most traditional database systems exploit a record-oriented model where the attributes of a record are placed contiguously in a hard disk to achieve high performance writes. However, for read-mostly data warehouse systems, the column-oriented database has become a proper model because of its superior read performance. Today, flash memory is largely recognized as the preferred storage media for high-speed database systems. In this paper, we introduce a column-oriented database model based on flash memory and then propose a new column-aware flash indexing scheme for the high-speed column-oriented data warehouse systems. Our index management scheme, which uses an enhanced $B^+$-Tree, achieves superior search performance by indexing an embedded segment and packing an unused space in internal and leaf nodes. Based on the performance results of two test databases, we concluded that the column-aware flash index management outperforms the traditional scheme in the respect of the mixed operation throughput and its response time.

• Journal of Gastric Cancer
• /
• 제4권1호
• /
• pp.15-26
• /
• 2004

This nationwide survey was conducted to evaluate the current status of the database system on gastric cancer patients in Korea. The Information Committee of Korean Gastric Cancer Association (KGCA) sent questionnaires about the database management to all 402 KGCA members in 110 institutes. In addition, we asked them to send the gastric cancer sheet and the pathologic report of gastric cancer used in their institutes. Response rates were $18.9\%$ (76/402) for individuals and $51.8\%$ (57/110) for institutes, respectively. Most of the university hospitals responded to the questionnaire (response rate of university hospital: $74.6\%$, 44/59). A regular conference of gastric cancer and a digitalization of the database on gastric cancer patients were performed in 29 ($50.9\%$) and 43 ($75.4\%$) out of 57 institutes, respectively. MS excel was most commonly used for the digitalization of the database, followed by MS access and SPSS. A regularly formed gastric cancer sheet and pathologic report were used in 38 ($66.7\%$) and 49 ($86.0\%$) institutes, respectively. Hospital computerization, such as an Order Communicating System, an Electric Medical Record, and a Picture Archiving/Communicating System had been set up previously or would be set up in the near future in most institutes. In 25 gastric cancer sheets collected, the mean number of total items was 72.9 ($15\∼177$). Identification datafor the patients, surgical data, and pathologic data were included on most of the sheets, but preoperative status, preoperative diagnostic data, and postoperative hospital course were not.

• 전자공학회논문지CI
• /
• 제40권3호
• /
• pp.171-180
• /
• 2003

내용기반 이미지검색이란 색상, 형태 및 질감 등의 저-수준 특징정보를 이용하여 이미지 데이터베이스를 구축하고, 이미지에 대한 검색요구가 발생했을 때 사용자가 찾고자 하는 이미지와 유사한 이미지를 제공하는 시스템으로 정의된다. 데이터베이스의 구축시간과 사용자가 질의를 입력한 후 결과를 얻을 때까지의 반응시간을 나누어 고려할 때, 사용자는 반응시간에 보다 관심을 갖는 것이 일반적이다. 내용기반 이미지검색 시스템에서 질의이미지와 데이터베이스 내의 이미지와의 유사도 비교시간이 전체 반응시간 중에서 가장 큰 비중을 차지한다. 본 논문에서는 이러한 유사도 비교시간을 최소화하기 위해 특징벡터의 클러스터링 기법을 적용한 2단계 탐색방법을 제안한다. 실험 결과를 통해 제안하는 2단계 탐색방법으로 대용량의 이미지 데이터베이스 내의 전체 이미지에 대한 원 특징정보와 비교하는 전체검색에 비해, 동일한 적합성을 보장하면서 평균적으로 2배 이상의 검색속도 향상을 확인하였으며, 이미지의 수가 더욱 커질수록 효과적임을 입증하였다.

• 대한산업공학회지
• /
• 제41권2호
• /
• pp.162-172
• /
• 2015

This paper proposes a Product Data Management (PDM) system architecture that supports end-user computing for small and medium businesses (SMBs) in Korea to build and maintain efficient and sustainable information systems for their product development. Its open database with relational tables enables existing common application programs such as Microsoft office suites to access product data in PDM systems. In addition, the interactive query processor provided by database management systems helps design engineers to build ad hoc queries in standard SQL database language to response different data requirements during their product development. The PDM architecture with the open database allows design engineers or technical staffs in SMBs to build and maintain their application programs for product development by themselves. To show the feasibility of the proposed architecture, this study implemented a prototype PDM system based on the architecture and database, and represents real-world product data with the implemented PDM system.