• Title/Summary/Keyword: Reference Point

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Searching an Efficient frontier in the DEA Model based on the Reference Point Method (참조점 방법을 이용한 DEA모형의 프론티어 탐구)

  • 오동일
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.1 no.1
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    • pp.83-90
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    • 2000
  • DEA is a newly developed analyzing tool to measure efficiency evaluation of decision making units (DMU). It compares DMU by radial Projection on the efficient frontier. The purpose of this study is to show reference point approach used for searching solution in multiple objective linear Programming can be usefully used to determine flexible efficient frontier of each DMU In reference point approach, the minimization of ASF Produces an efficient points in frontier and enhances the usefulness of DEA by Providing flexibility in DEA and optimally allocating resources to DMU. Various DEA models can be supported by reference point method by changing the projection direction in order to choose the targets units, standards costs and management benching-marking.

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A Derivation of the Equilibrium Point for a Controller of a Wheeled Inverted Pendulum with Changing Its Center of Gravity (무게중심이 변동되는 차륜형 역진자의 평형점 상태에 관한 연구)

  • Lee, Se-Han
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.5
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    • pp.496-501
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    • 2012
  • An equilibrium point of a WIP (Wheeled Inverted Pendulum) with changing its center of gravity is derived and validated by various numerical simulations. Generally, the WIP has two equilibrium points which are unstable and stable one. The unstable one is interested in this study. To keep the WIP over the unstable equilibrium point, the WIP is consistently being adjusted. A state feedback controller for the WIP needs a control reference for the equilibrium point. The control reference can be obtained by studying an equilibrium point of the WIP based on statics. By using Lagrange method, this study is deriving dynamic equations of the WIP both with and without changing its center of gravity. Various numerical simulations are carried out to show the validation of the equilibrium point.

Image Scale Prediction Using Key-point Clusters on Multi-scale Image Space (다중 스케일 영상 공간에서 특징점 클러스터를 이용한 영상스케일 예측)

  • Ryu, kwon-Yeal
    • Journal of the Institute of Convergence Signal Processing
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    • v.19 no.1
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    • pp.1-6
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    • 2018
  • In this paper, we propose the method to eliminate repetitive processes for key-point detection on multi-scale image space. The proposed method detects key-points from the original image, and select a good key-points using the cluster filters, and create the key-point clusters. And it select reference objects by using direction angles of the key-point clusters, predict the scale of the original image by using the distributed distance ratio. It transform the scale of the reference image, and apply the detection of key-points to the transformed reference image. In the results of the experiment, the proposed method can be found to improve the key-points detection time by 75 % and 71 % compared to SIFT method and scaled ORB method using the multi-scale images.

Design of Geometric Adaptive Controller for the Shaft Straightening Machine (축교정기용 기하학적 적응제어기 설계)

  • 안중용;안동철;김승철;정성종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.623-627
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    • 1995
  • This paper deals with the process which automatically straightens the shaft whose straightness is over the tolerance. The developed straightening process is composed of the measuring module and the control module. In the measuring module, the deflection of each measuring point is automatically measured, and the press point and the reference press stroke is determined. In the control module, the springback is predicted by the observer using the calculated reference press stroke and on-line-measured force and deflection. Through a series of experiments, the validity of the proposed process was verified.

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진단검사의학 검체검사의 정상치와 참고치

  • Lee, Gap-No
    • Journal of Korea Association of Health Promotion
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    • v.1 no.1
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    • pp.19-20
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    • 2003
  • In Korea association of health promotion(KHAP) there are fourteen laboratories in branch offices and one laboratory in headquarter office. To standardize the reference ranges of all laboratories of KAHP, they have been newly calculated from the laboratory data perfomed during the previous yearsby statistical metod annually for the period of 2000 through2003 so far. The referance ranges of total 56 test items were assigned. Among these there were eight test items that needed referance ranges by age groups and nine test items that needed reference rages by gender. The age grouping was into six groups : baby (0-3y), children(4-12y), adolescent(13-18y), adult(19-64y), younger elderly(19-64y), older elderly(over 80y) with references of statics in Medical Informatics and WHO classification. All the data collected were statistically analyzed with SAS 6.04 for Gaussian distribution that had been repeated two or three times after trimming out the the tests showed Gaussian distribution. Subsequently, Thereference ranges were defined in the rage from the point of lower 2.5% to the point of higher 97.5%. And in case the lower range could be "0", the reference ranges were defined in the range of 0 to 95%. Fifteen laboratoried troughout Korea of KAHP currently have standarzed reference rages of the tests that they perform. This means the patient data and reference values an be exchangeable among laboratories of KHAP.Annual revise of such reference rages can eventually lead to the level of those representing a standard of the national reference ranges.

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A Study on the Status of Building Reference Shelf and Analysis of Types of Online Reference Sources in the University Library (대학도서관의 온라인 참고서가 구축현황과 온라인 참고정보원의 유형분석에 관한 연구)

  • Choi, Eun-Ju
    • Journal of Information Management
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    • v.38 no.1
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    • pp.21-36
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    • 2007
  • This study aimed to investigate present status of online reference shelf and analyze access point in the home page and types of online reference sources in the university library. Data were collected by accessing home pages of 41 university libraries in the region of Seoul and Kyonggi-Do. 30 libraries had prepared reference shelf out of 41 libraries, and "User Service", "Electronic Reference Sources", or "Reference & Information Sources" were mostly used as home page menu. Types of references sources varied among libraries, and "Directories", "Dictionaries", "Statistics" or "Encyclopedias" were mostly loaded types in the reference shelf. For the enhancement of reference services through reference shelf, establishing and applying standards for evaluation, ease of access, access by subject, and continuous updates and additions of reference sources were suggested.

Sagittal Reference Plane for Soft Tissue Analysis in Facial Asymmetry Patients (안면 비대칭 환자에서의 연조직분석을 위한 시상기준선)

  • Chung, Dong-Hwa
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.1
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    • pp.63-71
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    • 2011
  • Major type of facial asymmetry results from facial deformity and needs surgical correction. To diagnose facial asymmetry and set a treatment plane for patients, setting a sagittal reference plane is crucial. The purpose of this study is comparison of measurements of sagittal soft tissue reference point to three different sagittal planes. The subjects are 25 of asymmetry patients (M:15, F:10) and 19 of normal people. There are differences in point Gnathion and Stomion. Most of measurement of sagittal reference points showed within 1 mm difference from sagittal reference plane. Deviation of point Pronasale in Sa1 plane revealed significant difference among 3 reference planes. The deviation of Gnathion was proportional to the deviation of Stomion in all 3 reference planes.

Accuracy Analysis of Code-based PPP-RTK Positioning Utilizing K-SSR Correction Messages Outside the Reference Network

  • Yoon, Woong-Jun;Park, Kwan-Dong;Kim, Hye-In;Woo., Seung;Park, Junpyo
    • Journal of Positioning, Navigation, and Timing
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    • v.6 no.2
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    • pp.79-86
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    • 2017
  • Precise Point Positioning-Real Time Kinematic (PPP-RTK) refers to a technology that combines PPP with network-RTK in which a user does not directly receive observed data from a reference station but receives State-Space Representation (SSR) messages corrected for error components from a central processing station through Networked Transport of RTCM via Internet Protocol (NTRIP) or Digital Multimedia Broadcasting (DMB) for purposes of positioning. SSR messages, which refer to corrections used in PPP-RTK, are generated by a central processing station using real-time observed data collected from reference stations and account for corrections needed due to the ionosphere, troposphere, satellite orbital errors, satellite time offsets, and satellite biases. This study used a type of SSR message provided in South Korea, known as Korea-SSR (K-SSR), to implement a PPP-RTK algorithm based on code-pseudorange measurements and validated its accuracy within the reference station network. In order to validate the accuracy of the implemented algorithm outside of the network, the K-SSR was extrapolated and applied to positioning in reference stations in Changchun, China (CHAN) and Japan (AIRA). This also entailed a quantitative evaluation that measured improvements in accuracy in comparison with point positioning. The results of the study showed that positioning applied with extrapolated K-SSR correction data was more accurate in both AIRA and CHAN than point positioning with improvements of approximately 20~50%.

A Method to Construct a Cut-off Fingerprint Map to Improve Accuracy in Indoor Positioning Scheme (실내 위치 추정 방식에서 정확도를 향상시키기 위해 컷-오프 핑거프린트 지도를 구성하는 방식)

  • Kim, Dongjun;Son, Jooyoung
    • Journal of Korea Multimedia Society
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    • v.20 no.8
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    • pp.1330-1337
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    • 2017
  • In off-line phase of the preliminary Cut-off indoor positioning scheme, which is one of the indoor positioning scheme using the fingerprint, relative ranks of peak RSSIs received from beacons at each reference point are stored in the fingerprint map. In some reference points, signals of multiple beacons may be received. In this case, the relative ranks may be different when constructing fingerprint and when receiving signals in real-time. To solve this problem, we propose a method to utilize only up to five beacons with high ranking when constructing a fingerprint and when receiving signals in real-time and comparing them with stored information of a fingerprint. Experiments were conducted on the estimation probabilities and the average error when using this method. Those are compared with the previous methods. Experimental results show that the estimation probabilities and the average error are improved by removing only the remaining five beacons at each reference point of the fingerprint.

A Weighted Preliminary Cut-off Indoor Positioning Scheme Based on Similarity between Peaks of RSSI (최대 RSSI 간의 유사도를 기반으로 한 가중치 부여 사전 컷-오프 실내 위치 추정 방식)

  • Kim, Dongjun;Son, Jooyoung
    • Journal of Korea Multimedia Society
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    • v.21 no.7
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    • pp.772-778
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    • 2018
  • We have previously proposed a preliminary cut-off indoor positioning scheme considering the reference point with the same signal similarity. This scheme estimates the position using the relative rank of the peak of received signal strength from the beacons around user. However, this scheme has a weak point with lower accuracy when there are more than one nearest reference points having the same signal similarity. In order to tackle this, we propose a weighted preliminary cut-off indoor positioning scheme. Firstly, if the above problem occurs, the similarity to the peak of signal strength is considered as well as the relative rank. Next, weights are assigned to the nearest reference points using the similarity to the peak of the received signal strength. Finally, the user's position is estimated by applying the weights. As a result, the weighted preliminary cut-off scheme improves the positioning accuracy by about 7.9% compared to the previous scheme.