• Title/Summary/Keyword: knowledge bases

검색결과 180건 처리시간 0.023초

임펠러 5축 NC가공을 위한 가공전략수립 지원시스템 (A 5-Axis NC Machining Strategy Support System for an Impeller)

  • 조민호;김동원;허은영;이찬기
    • 산업공학
    • /
    • 제21권4호
    • /
    • pp.411-417
    • /
    • 2008
  • An impeller is a type of high-speed rotor that is used to compress or transfer fluid under high-speed and pressure at high temperatures. The impeller is composed of an axial hub and several blades attached along the hub. The weight and shape of an impeller must be balanced, because their imbalances can cause noise and vibration, which can lead to the breakage of the impeller blades during operation. Thus, the hub and blades of an impeller are commonly machined in a 5-axis NC machine to obtain qualified surfaces. The impeller machining strategy or process plan can not be easily obtained due to the complex, overlapped and twisted shapes of impeller blades. Skillful machining process planners may generate appropriate machining strategies based on their experiences and floor data. However, in practice most shop floor data for the impeller machining is not well-structured such that it does not effectively provide a process planner with information for machining strategies and/or process plans. This paper reports the development of a case-based machining strategy support system (CBMS) that employs case-based reasoning to obtain the machining strategy of an impeller by using the existing machining strategies of the shop floor. The CBMS generates impeller machining strategies through a stepwise reasoning process considering the similarity features between the blade shapes and machining regions. A case study is provided to demonstrate that CBMS can generate useful machining strategies facilitating process planners. The developed system can simulate the tool paths of impeller machining and runs on the web.

정맥기형 환자에 있어서의 유전자 발현 차이 (Difference of Gene Expression in Venous Malformation)

  • 김택균;오은정;조병채;정호윤
    • Archives of Plastic Surgery
    • /
    • 제34권6호
    • /
    • pp.671-678
    • /
    • 2007
  • Purpose: Venous malformation(VM) which often causes pain and discomfort is the most common type of vascular malformations. Although it is presented with disfigured appearance and associated soft tissue or skeletal hypertrophy, the molecular bases of VMs are poorly understood. Differentially expressed genes(DEGs) of VMs were investigated to illuminate the molecular mechanism of the disease entity. Methods: Gene expressions of VM patients' subcutaneous tissue were studied in comparison with normal persons' by $GeneFishing^{TM}$ technique using the annealing control primers (ACPs) to identify DEGs. Candidate genes were sequenced and screened by basic local alignment search tool (BLAST) afterwards. Results: Among seventy DEGs identified, forty DEGs which had shown significantly different expression pattern were sequenced. Twenty eight out of 40 were up-regulated while 12 were down-regulated. BLAST searches revealed that 37 were known genes and 3 were unknown genes. Many genes were involved in the differentiation and remodeling of smooth muscle cells, opposed to the previous hypothesis that a lot of angiogenetic genes would be involved. Furthermore, several transcription factors and related genes, as well as cell signaling and metabolism regulators, were up regulated. Conclusion: It suggests that analysis of DEGs in VMs provide basic knowledge about its pathophysiology. and new therapeutic approaches.

생약제제의 약물동태 연구 및 상호작용 (Pharmacokinetic Studies and Drug-drug Interactions of Herbal Medicine)

  • 정원필;노금한;임미선;이혜원;김은정;윤영란;강원구
    • 한국임상약학회지
    • /
    • 제20권2호
    • /
    • pp.99-106
    • /
    • 2010
  • Drugs mostly represent an efficacy or an adverse effect according to their dosage and/or plasma concentrations. Therefore, to investigate the pharmacokinetic behavior of drugs including herbal medicines is necessary both to maximize the drug action and to minimize the adverse effect. To date, pharmacokinetic studies of herbal medicines have been conducted by some experts in this field on the bases of science and knowledge in Korea. On the other hand, in advanced countries, a typical series of pharmacokinetic studies has been conducted by using a harmonized guidance established. Consequently, an administrative support on these studies has to be needed in Korea as well. This study aimed to establish a draft guidance on pharmacokinetic studies of herbal medicines in non-clinical and clinical studies. Literatures previously published as well as guidances in the US, Europe and Japan were summarized for the present guidance. Effect of herbal medicines was listed on the proteins in charge of drug metabolism and transportation, as well as on the pharmacokinetics of chemical drugs. The present suggestion might be helpful to proceed pharmacokinetic studies of herbal medicines efficiently, and further polish should be needed in terms of an administrative point of view.

치위생과 학생들의 입학전 학과 인지도와 만족도 및 취업의식에 관한 조사 (A study of dental hygiene students on school subject degree of recognition before admission and satisfaction)

  • 김화주;임근옥;김윤정
    • 한국치위생학회지
    • /
    • 제6권2호
    • /
    • pp.115-127
    • /
    • 2006
  • A purpose of this study is degree of recognition and consciousness investigation about a satisfaction duty before admission about a school subject of some academic dental hygiene students. From responses to individual written survey questionnaires answered by 608 students who are studying Dental Hygiene at colleges in Mokpo, Iksan, Gangneung. The following are the results regarding their satisfaction levels with their majors and their interest in working abroad: 1. Regarding the motivating factors to major in Dental Hygiene, most students(51.3%), particularly most freshmen(57.3%), have chosen this major because of more job opportunities than students with other majors. The most common source of information in choosing majors is the Internet(30.8%). 2. Most students do not want to change their majors even if they are provided with the chance to do so(65.5%). They are in general satisfied with their studies. The result shows that the Dental Hygiene majors are positive toward their major. 3. Most students will choose their jobs by their own choices(40.6%), and the most important factor in their choices is the opportunity of self-growth and development(33.1%). The survey results show that the Dental Hygiene students value their own decisions and self-realization. 4. Showed the difference that as a result of having seen a knowledge degree advance a school subject of major in Dental Hygiene by a school year and ash students, an admission motive, relevance of an information acquisition path, all noted. 5. And were able to see the difference that noted in an adviser, work selection bases in case of work selection whether or not there was a dissatisfaction reason about a major and a criminal record.

  • PDF

양식어류의 질병과 수산동물용 의약품의 잔류방지 대책 (Diseases of Aquaculture Animals and Prevention of Drug Residues)

  • 허강준;신광순;이문한
    • 한국식품위생안전성학회:학술대회논문집
    • /
    • 한국식품위생안전성학회 1992년도 학술강연회
    • /
    • pp.7-19
    • /
    • 1992
  • Fish pathology is one of the main scientific bases upon which this expansion in aquaculture has been dependent and requires a wide knowledge of the environmental constraints, the physiology and characteristics of the various pathogens, the responses of the host and the methods by which they may be controlled. The primary disease and parasite problems in aquaculture animals relate to viral, bacterial, fungal and protozoan epizootics. Parasitic nematodes, trematodes and cestodes are commonly found in aquaculture animals, but seldom are they present in concentrations sufficinet to cause significant problems. When an epizootic does occur and chemical treatment is indicated, the appropriate chemical must be selected and properly applied. We have antibiotics, sulfa, nitrofuran and other chemicals for treatment of fish diseases. Some may be mixed with the fred during formulation, added to the pellets of feed as a surface coating, given in the dorm of an injection or used as a bath. Even though a drug or chemical has been officially approved for use in aquaculture, the substance should never be used unless there is a clear need. Some of the reasions for this view are as follows: (1) the constant use of antibiotics can lead to the development of resistant strains of bacteria, (2) biofilter efficiency may be impaired or destroyed by chemicals added to closed recirculating water systems, and (3) the injudicious use of chemicals can have a damaging effect on the environment as well as on human.

  • PDF

다중 에이전트 시스템 환경에서 분산된 온톨로지 저장소의 사용 (Utilizing Distributed Ontology Repository in Multi-Agent System Environment)

  • 김성태;지경환;양정진
    • 지능정보연구
    • /
    • 제11권3호
    • /
    • pp.129-139
    • /
    • 2005
  • 급속한 정보통신의 발달은 인간의 삶에 직접적인 영향을 끼치는 단계에 접어들게 되었다. 기존의 컴퓨팅은 사용자의 요청에 근거하여 동작하지만 유비쿼터스 컴퓨팅은 사용자의 의향과 상황을 인지해 능동적으로 목표를 설정하고 협력을 통하여 업무를 수행하게 된다. 앞으로 다가올 새로운 컴퓨팅 환경에서 주된 역할을 하게 될 개체인 에이전트와 이들이 상호 협력하는 기반구조인 다중 에이전트 시스템에 관하여 활발히 연구가 진행 중이다. 본고에선 다중 에이전트 시스템에서의 의미적 상호 운용성을 보장하고 지적활동의 중심적 자료구조가 될 온톨로지와 온톨로지를 효율적으로 관리하는 저장소에 관한 요구사항과 구조를 제시한다. 또한 분산적으로 관리 되는 온톨로지 저장소와 다중 에이전트 환경에서 일반적인 온톨로지 저장소 사용을 위한 온톨로지 에이전트를 제시한다.

  • PDF

국제상사계약에 관한 일반원칙(PICC)하에서 현저한 불균형에 관한 법적 기준 (A Study on the Legal Bases for the Gross Disparity under PICC)

  • 윤상윤;심종석
    • 무역상무연구
    • /
    • 제69권
    • /
    • pp.127-151
    • /
    • 2016
  • UNIDROIT Principles of International Commercial Contracts(PICC) was published in 1994. PICC has been functioned as a guideline of international commercial contracts, an applicable law to govern a contract by the agreement of the parties to a contract, general principles of law and lex mercatoria. In addition, PICC has a role of interpreting or supplementing international uniform law instruments as well as domestic laws, and also has served as a model for national and international legislations. PICC has been accepted as a authoritative source of knowledge of international trade usages of international commercial contracts to the arbitral tribunal rather than domestic court because it excluded the characteristics of hard law at the drafting stage. This article dealt with the rule on gross disparity of validity which fall outside the scope of UN Convention on Contract for the International Sale of Goods(CISG), which has obtained a leading legal position of uniform law in international sales of good. In other words, PICC suggests a series of meaningful solutions to the issue of gross disparity of contract which is the most complicated among legal disputes occurring during the process of conclusion of contact and also extremely different and diverse between legal systems. This article covered the issue of gross disparity of contract at the conclusion of contact and suggested the legal basis of several rules related to the gross disparity by analysing gross disparity rule of PICC. Furthermore, this article suggested legal check points or implication as well as interpretation and evaluation on doctrine of laesio enormis and undue influence or unconscionability. This article also dealt with a comparative analysis with Principles of European Contract Law(PECL) and Common European Sales Law(CESL) which have important legal positions in the area of international commercial contract as well as in terms of close relationship to PICC by linking with recent court or arbitral tribunal rulings.

  • PDF

Association between Single Nucleotide Polymorphisms of Fatty Acid Synthase and Fat Deposition in the Liver of the Overfed Goose

  • Wu, Wei;Guo, Xuan;Zhang, Lei;Hu, Dan
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제27권9호
    • /
    • pp.1244-1249
    • /
    • 2014
  • Goose fatty liver is one of the most delicious and popular foods in the world, but there is no reliable genetic marker for the early selection and breeding of geese with good liver-producing potential. In our study, one hundred and twenty-four 78-day-old Landes geese bred in Shunda Landes goose breeding farm, Jiutai, Jilin, China were selected randomly. The fatty livers were sampled each week after overfeeding during a three week period. Polymerase chain reaction-single strand conformation polymorphism and DNA sequencing were used to identify single nucleotide polymorphisms (SNPs) of fatty acid synthase (FAS), which is an important enzyme involved in the synthesis of fat under both physiological and pathological conditions. Least-squares correlation was established between these SNPs and fatty liver weight, abdominal fat weight, and intestinal fat weight of the overfed Landes geese, respectively. The results showed that fatty liver weight of geese with EF and FF genotypes (amplified by primer P1) was significantly higher than that of the EE genotype (p<0.05), and liver weight of CD and DD genotypes (amplified by primer P2) was significantly higher than that of the CC genotype (p<0.05). Different genotype combinations showed different liver weights, and from highest to lowest were ABDD, DDEF, DDFF, DDEE, ABEF, ABFF, AADD, and CDEF. Further analysis of DNA sequencing showed that there were two SNPs within the 5' promoter region the FAS gene. The geese of EF and FF genotypes carried a change of T to C, and the geese of CD and DD genotypes carried a change of A to G. The changes of the bases could potentially influence the binding of some transcription factors to this region as to regulate FAS gene. To our knowledge, this is the first report of SNPs found within the 5' promoter region of the Landes goose FAS gene, and our data will provide an insight for early selection of geese for liver production.

시맨틱 RDF 데이터에 대한 효과적인 키워드 검색 (Effective Keyword Search on Semantic RDF Data)

  • 박창섭
    • 한국콘텐츠학회논문지
    • /
    • 제17권11호
    • /
    • pp.209-220
    • /
    • 2017
  • 최근 지식 베이스, 시맨틱 웹 등 여러 응용 분야에서 시맨틱 데이터의 활용이 증가함에 따라 대규모 RDF 데이터에 대한 효과적인 검색 방법의 필요성이 커지고 있다. 기존의 개별 루트 시맨틱에 기반한 키워드 검색 방법들은 서로 다른 루트 노드를 갖는 결과 트리들의 집합만을 검색함에 따라, 의미적으로 유사하거나 연관성이 낮은 결과 트리들이 함께 검색되고, 동일한 루트 노드를 공유하되 의미적으로 다르고 질의 연관도가 높은 결과들은 함께 검색될 수 없는 문제점이 있다. 이를 개선하기 위해 본 논문에서는 결과 트리들의 루트 노드의 중복을 제한적으로 허용하여 질의 연관도가 높으면서 다양한 결과들을 함께 검색하는 방법을 제안한다. 이를 위해 결과 트리 집합의 루트 중복도 척도를 정의하고, 주어진 키워드 질의와 최대 루트 중복도에 따라 제한적인 루트 중복성을 가지면서 연관도가 높은 top-k 결과 트리들을 효율적으로 구하기 위한 검색 알고리즘을 제시한다. 실 데이터를 이용한 성능 실험 결과, 제안한 방법이 기존 방법보다 콘텐트 노드들의 중복이 적은 다양한 결과 트리들을 검색할 뿐만 아니라 결과 트리들의 루트 노드의 중복을 허용함으로써 질의 연관도가 더 높은 결과들을 생성할 수 있음을 보였다.

시맨틱웹 기술과 활용방안 (The SemanticWeb Technology and its Applications)

  • 오삼균
    • 정보관리학회지
    • /
    • 제19권4호
    • /
    • pp.298-319
    • /
    • 2002
  • 시맨틱웹은 기계가독형 정의에 기반한 정보의 연계를 통해 웹 자원을 지식화함으로써 정보의 효율적 검색, 통합, 재사용을 도모하는 새로운 기술이다. 시맨틱웹의 구축은 자원에 불변 고유식별자를 부과하는 URI 체제, 각 정보기관에서 생성되는 요소와 속성의 의미 충돌을 방지하는 XML 네임스페이스, 메타데이터 스키마를 활용한 호환적 자원기술을 가능하게 하는 RDF, 메타 데이터 요소 및 이와 연관된 클래스와 속성 관계 정의의 기반이 되는 RDF 스키마, 그리고 RDF 스키마 위에 논리적 추론과 표현력을 강화한 웹 온톨로지 언어 DAML+OIL 및 그 건조자 (constructors)를 삭제 또는 수정 보완한 OWL (Web Ontology Language) 등의 여러 핵심 개념과 기술을 필요로 하는 작업이다. 이 논문은 이러한 개념과 기술의 점진적 발전 양상을 개괄 설명하고, XML/RDF 스키마를 기반으로 메타데이터 요소들을 정의할 경우 도출할 수 있는 상호운용성과 온톨로지의 다양한 활용 방안 등을 고찰한다.