• 제목/요약/키워드: incomplete

검색결과 2,605건 처리시간 0.027초

불완전 데이터를 위한 효율적 Top-k(g) 스카이라인 그룹 질의 처리 기법 (An Efficient Processing Method of Top-k(g) Skyline Group Queries for Incomplete Data)

  • 박미라;민준기
    • 정보처리학회논문지D
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    • 제17D권1호
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    • pp.17-24
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    • 2010
  • 최근에 스카이라인 질의에 대한 관심이 점차 증가하고 있다. 대부분의 스카이라인 질의에 대한 연구는 데이터들이 널 값을 가지지 않는다는 가정에서 이루어진다. 그러나 우리가 웹이나 다른 도구로 데이터베이스에 자료를 입력할 때는 널 값을 가지는 불완전한 데이터가 존재한다. 따라서 불완전한 데이터를 위한 다양한 스카이라인 처리 기법들이 제안되었다. 그러나 기존의 불완전한 데이터를 위한 스카이라인 질의 처리 기법은 불완전한 데이터만을 고려함으로써 완전한 데이터와 불완전한 데이터가 공존하는 환경을 고려하지 않았다. 본 논문에서는 완전한 데이터를 위한 스카이라인 질의와 불완전한 데이터를 위한 스카이라인 질의를 모두 처리 하는 스카이라인 그룹 질의 처리 기법을 제안한다. 이를 위하여, 사용자 정의에 의한 차원의 선호도에 따라서 g개의 스카이라인 그룹을 검색하는 top-k(g) 스카이라인 그룹 질의를 도입하고, 이를 질의 처리하는 기법을 제안한다. 그리고 모의실험을 통하여 제안한 방식의 성능을 보인다.

Effect of cone-beam computed tomography metal artefact reduction on incomplete subtle vertical root fractures

  • Andrea Huey Tsu Wang;Francine Kuhl Panzarella;Carlos Eduardo Fontana;Jose Luiz Cintra Junqueira;Carlos Eduardo da Silveira Bueno
    • Imaging Science in Dentistry
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    • 제53권1호
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    • pp.11-19
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    • 2023
  • Purpose: This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm. Materials and Methods: Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance. Results: Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition. Conclusion: The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.

The Pseudo-Covariational Reasoning Thought Processes in Constructing Graph Function of Reversible Event Dynamics Based on Assimilation and Accommodation Frameworks

  • Subanji, Rajiden;Supratman, Ahman Maedi
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제19권1호
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    • pp.61-79
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    • 2015
  • This study discussed about how pseudo-thinking process actually occurs in the mind of the students, used Piaget's frame work of the assimilation and accommodation process. The data collection is conducted using Think-Out-Loud (TOL) method. The study reveals that pseudo thinking process of covariational reasoning occurs originally from incomplete assimilation, incomplete accommodation process or both. Based on this, three models of incomplete thinking structure constructions are established: (1) Deviated thinking structure, (2) Incomplete thinking structure on assimilation process, and (3) Incomplete thinking structure on accommodation process.

부분이면교배에서의 블록계획 (Block Designs for Partial Diallel Crosses)

  • 손영남;최규정
    • 응용통계연구
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    • 제15권2호
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    • pp.367-379
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    • 2002
  • 본 연구에서는 부분이면교배에서 p개의 근교계통의 일반조합능력을 비교하기 위한 불완비 블록계획을 구성하는 방법을 제시한다. 부분이면 블록계획은 블록의 크기가 2 이면서 m개의 동반분류를 갖는 부분 균형 불완비 블록계획과균형 불완비 블록계획을 이용하여 구성한다. 또한, p $\leq$ 24일 때 이러한 방법으로 구성되는 블록계획의 효율성을 표로 제시한다.

삼첨판균열과 다발성 심방중격결손을 합병한 Incomplete Atrioventricular Canal 의 치험 (Incomplete atrioventricular canal associated with tricuspid valve cleft and multiple ASD: report of one case)

  • 오상준;김삼현;김근호
    • Journal of Chest Surgery
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    • 제17권4호
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    • pp.614-619
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    • 1984
  • Atrioventricular canal is divided into incomplete, intermediate and complete types. In ostium primum ASD [incomplete type] mitral valve cleft is almost always present, but ostium primum ASD with tricuspid valve cleft is a rare congenital anomaly. The patient was a 7 year old female whose complains were palpitation, exertional dyspnea and growth retardation. The chest films showed moderate cardiomegaly [C-T ratio, 61%]. EKG, Echocardiography, cardiac catheterization and left ventriculography were performed. Open heart surgery was done under the impression of incomplete atrioventricular canal. At the time of operation, ostium primum ASD [2x2.5 cm in diameter], secundum type ASD [lxl.5 cm in diameter] and cleft in the septal leaflet of the tricuspid valve were noted. But mitral valve was normal without cleft and VSD was not noted. Each anomalous portion was repaired. The patient made an uneventful recovery and we report this case, review and discuss the literatures.

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하지 부분마비 장애인을 위한 착용형 로봇의 보행 보조 방법 (Gait Assist Method by Wearable Robot for Incomplete Paraplegic Patients)

  • 우한승;이장목;공경철
    • 로봇학회논문지
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    • 제12권2호
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    • pp.144-151
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    • 2017
  • An important characteristic of people with partially impaired walking ability, such as incomplete paraplegics, is that they are able to generate voluntary motion of lower-limbs. Therefore, wearable robots for the incomplete paraplegic patients require a different assistance method compared to those of complete paraplegics. First, the wearable robot should be controlled to not resist wearer's motion. Second, it should be able to generate assistive torque accurately when needed. In this paper, a wearable robot, called EROWA, for the incomplete paraplegic patients is introduced. EROWA utilizes compact rotary series elastic actuators (cRSEAs) and a control method called the zero impedance control to reduce the mechanical resistance. An assistive torque trajectory is proposed to assist gait in this paper. The proposed method is verified by simulation and experimental studies.

불완비정보게임의 전력시장 적용 사례연구 (The Case Studies on the application of incomplete information game in Deregulated Power Pools)

  • 장세환;김진호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.361-362
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    • 2006
  • This paper presents the result of survey and analysis on a theoretical approach to the application of incomplete information game in deregulated Power Pools. The deregulation power market arc modeled by the incomplete information game. The case where participants have incomplete information about the operation costs of other participants are highlighted. Pool participants define transactions to maximize their benefit in non-cooperative situation, the ISO defines transactions among participants by looking for minimum price that satisfies the demand in the Pool. The incomplete information game determines Nash equilibrium satisfied Pool participants and the ISO.

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불완전분해법을 전처리로 하는 공액구배법의 안정화에 대한 연구 (Study on Robustness of Incomplete Cholesky Factorization using Preconditioning for Conjugate Gradient Method)

  • 고진환;이병채
    • 대한기계학회논문집A
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    • 제27권2호
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    • pp.276-284
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    • 2003
  • The preconditioned conjugate gradient method is an efficient iterative solution scheme for large size finite element problems. As preconditioning method, we choose an incomplete Cholesky factorization which has efficiency and easiness in implementation in this paper. The incomplete Cholesky factorization mettled sometimes leads to breakdown of the computational procedure that means pivots in the matrix become minus during factorization. So, it is inevitable that a reduction process fur stabilizing and this process will guarantee robustness of the algorithm at the cost of a little computation. Recently incomplete factorization that enhances robustness through increasing diagonal dominancy instead of reduction process has been developed. This method has better efficiency for the problem that has rotational degree of freedom but is sensitive to parameters and the breakdown can be occurred occasionally. Therefore, this paper presents new method that guarantees robustness for this method. Numerical experiment shows that the present method guarantees robustness without further efficiency loss.

불완전시장 하에서의 옵션가격의 결정 (Valuation of Options in Incomplete Markets)

  • Park, Byungwook
    • 한국경영과학회지
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    • 제29권2호
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    • pp.45-57
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    • 2004
  • The purpose of this paper is studying the valuation of option prices in Incomplete markets. A market is said to be incomplete if the given traded assets are insufficient to hedge a contingent claim. This situation occurs, for example, when the underlying stock process follows jump-diffusion processes. Due to the jump part, it is impossible to construct a hedging portfolio with stocks and riskless assets. Contrary to the case of a complete market in which only one equivalent martingale measure exists, there are infinite numbers of equivalent martingale measures in an incomplete market. Our research here is focusing on risk minimizing hedging strategy and its associated minimal martingale measure under the jump-diffusion processes. Based on this risk minimizing hedging strategy, we characterize the dynamics of a risky asset and derive the valuation formula for an option price. The main contribution of this paper is to obtain an analytical formula for a European option price under the jump-diffusion processes using the minimal martingale measure.

게임이론을 이용한 전력시장 정보의 불완비성 해석 (Analysis on Incomplete Information in an Electricity Market using Game Theory)

  • 이광호;신재홍
    • 대한전기학회논문지:전력기술부문A
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    • 제55권5호
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    • pp.214-219
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    • 2006
  • Oligopoly differs from perfect competition and monopoly in that a firm must consider rival firms' behavior to determine its own best policy. This interrelationship among firms is the issue examined in this paper. In the oligopoly market, the complete information market means that each producer has full information about itself, the market, and its rivals. That is, each producer knows the market demand function, its own cost function and the cost functions of rivals. On the other hand, the incomplete information market means that in general each producer lacks full information about the market or its rivals. Here, we assume that each firm doesn't know the cost functions and the strategic biddings of its rivals. The main purpose of this paper is to analyze firm' strategic behaviors and equilibrium in an electricity market with incomplete information. In the case study, the complete information market and the incomplete market are compared at the Nash Equilibrium from the viewpoints of market price, transaction quantities, consumer benefits, and Social Welfare.