• 한국음향학회지
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• 제19권4호
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• pp.93-100
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• 2000

수중 능동소나에 의해 표적을 분류하는데 있어 표적신호의 특징파라미터는 매우 중요하다. 광대역이고 상관성이 높은 두 개의 펄스가 시간 T의 간격으로 분리되어 있을 때, 스펙트럼에서 리플간의 1/T Hz에 해당하는 TSP, 즉 피치 성분을 가진다. 음향산란 실험에 사용된 축소표적신호 또한 이러한 TSP 특징을 잘 반영하고 있다. 본 논문에서는 각 표적신호의 특징에 해당하는 TSP 정보를 FFT를 이용하여 효과적으로 추출하였다. 네 개의 표적과 각 표적의 자세각에 따라 추출된 TSP 특징파라미터를 패턴인식 기법에 적용하여 표적을 분류하고 각 표적의 특징을 분석하였다.

• 한국가정과교육학회지
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• 제29권3호
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• pp.77-88
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• 2017

2015 한국인 영양소 섭취기준에 제시된 18개의 연령군별 권장식사패턴을 대상으로 영양 적정성을 분석하였다. 권장식사패턴의 식품군별 배정 횟수와 대표영양가표를 활용하여 에너지 함량과 에너지분율의 적정성 여부를 조사하였고, 단백질, 식이섬유, 무기질(Ca, P, Fe, Na, K), 비타민(비타민 A, 티아민, 리보플라빈, 니아신, 비타민 C)의 12가지 영양소에 대하여 영양소 섭취기준 충족 여부를 확인하였다. 조사 대상 12가지 영양소 모두 영양소 섭취기준을 충족시키는 권장식사패턴(MAR=1.0)은 5개뿐으로, 모든 권장식사패턴이 식사구성안의 영양 기대 목표를 만족시키지는 못하는 것으로 나타났다. 권장식사패턴 18개 모두에서 영양소 섭취기준을 충족시켰던 영양소로 단백질과 나트륨이 있었으며, 식이섬유, 칼슘, 칼륨은 미 충족 권장식사패턴이 각각 15개, 10개, 9개나 되었다. 비타민 A의 경우 영양소 섭취기준의 단위는 RAE이고 대표영양가표의 단위는 RE로 되어 있다. 단위의 차이를 무시한 채 비교하였을 때는 18개 권장식사패턴 모두가 비타민 A 권장섭취량을 충족시키는 것으로 조사되었으나, 권장식사패턴의 RE 단위 함량을 RAE 단위 함량으로 환산하여 비교하는 경우 3개 권장식사패턴만이 권장섭취량을 충족시키는 것으로 나타났다. 그리고 여성 노인의 권장식사패턴은 MAR이 0.90으로 가장 낮았으며, 영양소 섭취기준을 충족시키지 못하는 영양소가 7가지나 있는 것으로 확인되어 조정이 필요하다. 단백질, 지방, 탄수화물의 에너지분율은 각각 16.04%, 24.35%, 60.91%로 에너지적정비율을 충족시키고 있었다. 권장식사패턴의 에너지 증감을 최소한으로 하면서 영양소 섭취기준에 미달하는 식이섬유, 칼슘, 칼륨, 비타민 A 함량을 증가시킬 수 있는 방안으로 채소군의 배정 횟수 증가가 바람직할 것으로 나타났고, 단백질의 과잉 섭취를 억제하는 방안으로 고기 생선 달걀 콩류군의 배정 횟수 감소도 일부 권장식사패턴의 경우 고려해 볼 필요성이 있다. 그리고 양념의 사용은 식단 구성 시 배제하고 있는데, 권장식사패턴에서 양념의 사용에 따른 에너지 배정이 적정 수준으로 확보될 수 있도록 고려하여야겠다.

• 전력전자학회논문지
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• 제4권6호
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• pp.616-623
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• 1999

엘리베이터의 속도패턴은 출발시부터 목표 위치 근처에 다다를 때까지의 시간기준 속도패턴과 정밀한 정위치 정지를 위한 거리기준 속도패턴등로 이루어진다. 시간기준 속도패턴에서 거리기준 속도패턴으로 절환시 속도와 가속도의 급격한 변화가 없도록 하여야 패턴 절환시의 충격을 최소화하여 안락한 승차감을 얻을 수 있다. 본 논문에서는 속도패턴 절환 시 항상 속도와 가속도가 연속이 되도록 하고, 또한 목표 위치로의 수렴 속도를 개선한 새로운 엘리베이터 속도패턴 발생 방법을 제시한다.

• Current Optics and Photonics
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• 제2권2호
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• pp.172-178
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• 2018

We propose a precise 3D endoscopic technique for medical and industrial applications. As the 3D measuring principle, the continuously scanning structured illumination microscopy (CSSIM), which enables to obtain 3D sectional images by the synchronous axial scanning of the target with the lateral scanning of the sinusoidal pattern, is adopted. In order to reduce the size of the probe end, the illumination and detection paths of light are designed as coaxial and a coherent imaging fiber bundle is used for transferring the illumination pattern to the target and vice versa. We constructed and experimentally verified the proposed system with a gauge block specimen. As the result, it was confirmed that the 3D surface profile was successfully measured with $16.1{\mu}m$ repeatability for a gauge block specimen. In order to improve the contrast of the sinusoidal illumination pattern reflected off on the target, we used polarizing optical components and confirmed that the visibility of the pattern was suitable in CSSIM.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.840-845
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• 2001

Development of a small gas-turbine combustor for 100kW class APU(Auxiliary Power Unit) has been performed. This combustor is a reverse-annular type and has a tangential swirler in the liner head to improve the fuel/air mixing and flame stability. Three main and three pilot fuel injectors of the simplex pressure-swirl type are used. The performance target at the design condition includes a turbine inlet temperature of 1170K, a combustion efficiency of 99%, a pattern factor of 30%, and an engine durability of 3000 hours. Under developing the combustor, we conducted performance test of our first prototype(TS1) with some variants. As a result of the test, the performance targets of the combustor are satisfied except that the pattern factor is about 4% higher than target value. So, we redesigned the second prototype(TS2) and conduct performance test with the critical focus on pattern factor and exit mean temperature. We adopted TS2 four variant to check the improvement of pattern factor. As the result, the pattern factors of several variants were satisfied with the performance target. Finally, We chose the TS2A variant as a final combustor for our APU model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.212-217
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• 1993

In this paper, characteristics of the motions of a human arm are investigated experimentally. When the conditions of the target point are restricted, human adjusts its trajectory and velocity pattern of the arm to fit the conditions skillfully. The purpose of this work is to examine the characteristics of the trajectory, velocity pattern, and the size of the duration in the following cases. First, we examine the case of point-to-point motion. The results are consistent with the minimum jerk theory. However, individual differences in the length of the duration can be observed in the experiment. Second, we examine the case which requires accuracy of positioning at the target point. It is found that the velocity pattern differs from the bell shaped pattern explained by the minimum jerk theory, and has its peak in the first half of the duration. When higher accuracy of the positioning is required, learning effects can be observed. Finally, to examine the case which requires constraint of the arm posture at the target point, we conduct experiments of a human trying to grasp a cup. It is considered that this motion consists of two steps : one is the positioning motion of the person in order to start the grasping motion, the other is the grasping motion of the human's hand approaching toward the cup and grasping it. In addition, two representative velocity patterns are observed : one is the similar velocity pattern explained in the above experiment, the other is the velocity pattern which has its relative maximum in the latter half of the duration.

• 대한기계학회논문집A
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• 제28권4호
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• pp.362-369
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• 2004

LGP(Light-Guide Panel) of LCD backlight is one of the major componets which affect on the product quality of LCD. The optical relation between brightness and pattern has been investigated for LGP with the uniform distribution of brightness. When given the brightness distribution as target, the solutions of pattern distribution is not unique. Each solution of pattern designs shows the different brightness intensity even though they have the same brightness distribution with target's one. The manufacturing condition of pattern has an influence on the possibly-maximum-brightness intensity among the solutions of pattern design. The present study has examined the effects of LGP thickness, pattern shape errors, and reflection film on the optical characteristics of LGP.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1067-1071
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• 2013

A 3D visual sensing method using a laser structured beam is presented for robotic tracking applications in a simple and reliable manner. A cylindrical shaped laser structured beam is proposed to measure the pose and position of the target surface. When the proposed laser beam intersects on the surface along the target trajectory, an elliptic pattern is generated. Its ellipse parameters can be induced mathematically by the geometrical relationship of the sensor coordinate and target coordinate. The depth and orientation of the target surface are directly determined by the ellipse parameters. In particular, two discontinuous points on the ellipse pattern, induced by seam trajectory, indicate mathematically the 3D direction for robotic tracking. To investigate the performance of this method, experiments with a 6 axis robot system are conducted on two different types of seam trajectories. The results show that this method is very suitable for robot seam tracking applications due to its excellence in accuracy and efficiency.

• Steel and Composite Structures
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• 제27권5호
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• pp.623-632
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• 2018

Performance-Based Plastic Design (PBPD) method has been recently developed to evaluate the behavior of structures in different performance levels. The PBPD method utilizes a base shear force and a lateral load pattern that are estimated based on energy and yielding mechanism concepts. Using of current lateral force pattern results in weak structural members in upper stories of a structure so that the values of the story drift in these stories are larger than the target drift, particularly in high-rise buildings. Therefore, such distribution requires modifications to overcome this drawback. This paper proposes a modified lateral load pattern for steel Eccentrically Braced Frames (EBFs) based on parametric study. In order to achieve the modified load pattern, a group of 26 EBFs has been analyzed under a set of 20 earthquake ground motions. Additionally, results of nonlinear dynamic analyses of EBFs have been post-processed by nonlinear regression analysis in order to derive the new load pattern. To prove the efficiency of present study, three EBFs as examples were designed by modified pattern and current PBPD distribution. Inelastic dynamic analyses results showed that the story drifts using modified lateral load pattern were well within the target values in comparison with current pattern in PBPD, particularly where the effect of the height is significant. The modified load pattern reduces the possibility of underdesigning in upper levels and overdesigning in lower levels of the frames.

• 한국국방경영분석학회지
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• 제3권1호
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• pp.97-107
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• 1977

This report examines several models, such as random or area bombardment, salvo fire and pattern fire, for the computation of target coverage when multiple rounds are fired at a target. Fractional kill of a fragment sensitive target by a fragmenting projectile as a function of the number of rounds fired is compared for two salvo fire models. The first is a standard salvo fire model in which N rounds are fired at the same aim point, in the second model single kill probability is computed for a fragment sensitive target and then fractional kill from the firing of N rounds is computed according to the assumption that the effects of each round are independent. Because the method of solution becomes very laborious for large patterns, this report gives a method only for the case of evaluating the effectiveness of stick and trianglar pattern fire. The need for the sophisticated and complicated target coverage models is demonstrated by the results of computations performed in this report.