• 한국정보통신학회논문지
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• 제18권12호
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• pp.2953-2960
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• 2014

영상인식 분야에서 원형 검출은 가장 많이 사용되는 기술 중의 하나이다. 기존에 제안된 많은 원형 검출방법들은 허프변환에 기초하고 있고, 충분히 강인한 알고리즘을 제공한다. 그러나 허프변환은 해석적 곡선의 각점을 원의 중심 좌표와 반지름으로 대응시키는 과정을 도입함으로써 매우 많은 메모리와 실행시간을 필요로 하고, 또한 가끔씩 부정확한 원을 검출하는 경우가 발생하게 된다. 본 논문에서는 광섬유 연결 종단면 검사에 적합한 최적의 원형 검출방법과 근사화 방법을 제안한다. 제안한 방법은 에지 검출에 기초하여 초기 중심좌표와 반지름을 바탕으로 간단화된 K-means알고리즘을 도입함으로써 차 영역의 넓이가 최소가 되도록 하는 방법으로 원을 근사화 한다. 모의실험을 통하여 제안한 방식은 기존의 오픈라이브러리로 제공되는 OpenCV의 허프변환에 비해 원 검출 및 근사화에 있어 약 67% 정도의 성능 개선이 이루어졌고, 또한, 실행 시간에 있어 약 80% 정도 개선됨을 보인다.

• 수산해양기술연구
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• 제30권4호
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• pp.299-311
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• 1994

The new course distances of a ship are one of the important factors of the safety handling as the indices to indicate directly her abilities of course alteration. Recently, International Maritime Organization (IMO) exhorts that all vessels should use maneuvering booklets in which are drawn the curves of new course distances obtained from the test of measuring them and noted other maneuvering performance standard in various navigation conditions. This paper describes the method to calculate many new course distances for many rudder angles by turning circle test without observation or using other calculating methods. The main results are as follows: 1) The mean difference of the distances between two new course distances by the turning circle test and heading test of the experimental ship was about 7.7% vaules of the ones by the heading test. when her altering angles were $48^{\circ}$, $63^{\circ}$and $70^{\circ}$, using the rudder angle of $35^{\circ}$ . These new course distances were therefore found to be small in difference of those. 2) The mean difference of the distance between two new course distances by the turning circle test and the maneuvering indices of the experimental ship was about 4.5% values of the ones by the maneuvering indices, when her altering angles were $48^{\circ}$, $63^{\circ}$and $70^{\circ}$, using the rudder angle of $35^{\circ}$, these new course distances were therefore found to be small in difference of those. 3) The mean difference of the distance between two new course distances by the turning circle test and the observation of the experimental ship was about 6.1% values of the ones by the observation, when her altering angles were $48^{\circ}$, $63^{\circ}$and $70^{\circ}$, using the rudder angle of $35^{\circ}$. These new course distances were therefore found to be small in difference of those. 4) It is confirmed that many new course distances for many angles can be calculated easily by using the method of ship's simple turning circle test, without observation or using the maneuvering indices and heading test method. 5) It is considered to be helpful for the safety of ship handling to draw curves of new course distances by turning circle test and $\phi_4$ - $\phi_2 by heading test, and utilize them at sea.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 추계학술대회
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• pp.130-132
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• 2013

This paper presents an improvement for calculating method of astronomical vessel position with circle of equal altitude equation based on using a virtual object in sun and two stars observation. In addition, to enhance the accuracy of ship position achieved from solving linear matrix system, and surmount the disadvantages on rank deficient matrices situation, the authors used singular value decomposition (SVD) in least square method instead of normal equation and QR decomposition, so, the solution of matrix system will be available in all situation. As proposal algorithm, astronomical ship position will give more accuracy than previous methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.897-899
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• 2004

There is scientific work containing the recurrence method of synthesis the new class of orthogonal circle m-invariant signals: designed effective algorithms of fast-direct computing m-convolution in time domain: engineer methods of design economic scheme of decoders for optimal receiving in aggregate of suggested signal.

• Progress in Superconductivity
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• 제9권2호
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• pp.146-151
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• 2008

Measurements of surface resistance ($R_s$) of high temperature superconductor (HTS) films with accuracy are essential for microwave applications of HTS materials. In using the dielectric resonator method, uncertainties in the unloaded quality factor of the resonator cause significant errors in the measured $R_s$ of HTS films. We compare the Rs values of $YBa_2Cu_3O_{7-{\delta}}$ films calculated from the $Q_0$ as determined from the Lorentzian fit with that from the $Q_0$ as determined from the S-parameter circle-fit at temperatures between 15 K and 77 K. The two sets of values appeared to differ by 5%, 7%, 6%, and 11% at temperatures of 15, 60, 70, and 77 K, respectively, from each other, implying that careful error analysis needs to be performed in obtaining the $R_s$ of HTS films by using the Lorentzian-fit method, with the ones determined from the S-parameter circle-fit used as the reference.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1057-1062
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• 2014

This paper proposes a tip-over detection method for a mobile robot using a support inscribed circle defined as an inscribed circle of a support polygon. A support polygon defined by the contact points between the robot and the terrain is often used to analyze the tip-over. For a robot moving on uneven terrain, if the intersection between the extended line of gravity from the robot's COG and the terrain is inside the support polygon, tip-over will not occur. On the contrary, if the intersection is outside, tip-over will occur. The terrain is detected by using an RGB-D sensor. The terrain is locally modeled as a plane, and thus the normal vector can be obtained at each point on the terrain. The support polygon and the terrain's normal vector are used to detect tip-over. However, tip-over cannot be detected in advance since the support polygon is determined depending on the orientation of the robot. Thus, the support polygon is approximated as its inscribed circle to detect the tip-over regardless of the robot's orientation. To verify the effectiveness of the proposed method, the experiments are carried out using a 4-wheeled robot, ERP-42, with the Xtion RGB-D sensor.

• 품질경영학회지
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• 제6권1호
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• pp.23-26
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• 1978

The purpose of this study is to find the problems, which occurs in the course of the acceptance and the propulsion of the Q. C. circle, the accomodational attitude, and the desirable circumstances for the Q. C. circles, to be of help to settle firmly the "Sae-ma-eul" (New-Community) Movement in the industrial fields, and Q. C. circle and to fix the Q. C. of Korean style through the investigation of the 310 Q. C. circles, which was selected at random from entered circles to the Q. C. Propulsion Headquarters until July, 1977, through the questionaire and interviews.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.338-341
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• 2013

눈동자 검출은 운전 부주의 검출, 졸음 검출, 시선 검출 등 다양한 상황 인지에 이용되고 있다. 이러한 상황 인지를 위해 본 논문에서는 원 허프 변환(Hough Circle Transform)을 이용한 눈동자 검출방법을 제안한다. 이것은 영상 내 원을 검출하는 방법으로 연산량이 많아 실시간 처리에 문제가 된다. 이러한 문제를 해결하기 위해 눈 검출 후 눈 영역의 크기를 일정한 눈 크기로 정규화 하고 눈의 양쪽 끝점간 거리에 따른 대략적인 눈동자의 반지름 값 범위를 추정한다. 그 추정된 반지름 값 범위 내에서 Hough Circle Transform을 수행하면 연산량의 축소가 가능하며 그 결과 초당 21frames 정도의 눈동자 검출이 가능하였다.

• 대한조선학회논문집
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• 제52권2호
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• pp.110-118
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• 2015

Weather routing method is one of the best practices of SEEMP (Ship Energy Efficiency Management Plan) for fuel-efficient operation of ship. KR is carrying out a basic research for development of the weather routing algorithm and making a monitoring system by FOC (Fuel Oil Consumption) analysis compared to the reference, which is the great circle route. The added resistances applied global sea/weather data can be calculated using ship data, and the results can be corrected to ship motions. The global sea/weather data such as significant wave height, ocean current and wind data can be used to calculate the added resistances. The reference route in a usual navigation is the great circle route, which is the shortest distance route. The global sea/weather data can be divided into grids, and the nearest grid data from a ship's position can be used to apply a ocean going vessel's sea conditions. Powell method is used as an optimized routing technique to minimize FOC considered sea/weather conditions, and FOC result can be compared with the great circle route result.

• Journal of Power Electronics
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• 제3권1호
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• pp.55-61
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• 2003

This paper presents parameter measurement for permanent magnet synchronous motors based on the P-Q circle diagram. Three electrical parameters of permanent magnet synchronous motors, i.e., the equivalent iron loss resistance, armature inductance, and electrical motive force (emf) coefficient are simultaneously measured. The advantages of this method are that it can be implemented under constant excitation and it dispenses with the generating test for the emf coefficient. The proposed method is applied to a 160w permanent magnet synchronous motor, and then the measurement results are analyzed.