• Journal of Positioning, Navigation, and Timing
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• 제9권4호
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• pp.357-366
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• 2020

This paper addressed a relative navigation method for autonomous rendezvous and docking of cube-satellites using single frequency Differential GPS (DGPS) under the intermittent communication between satellites. Since the ionospheric error of GPS measurement is variable depending on the visible satellites, a few meters error of relative navigation is occurred in the Low-Earth Orbit (LEO) environment. Therefore, it is essential to remove the ionospheric error to perform relative navigation. Besides, an intermittent communication period for receiving GPS measurements of the target satellite is limited for getting information every sampling time. To solve this problem, a method combining range domain DGPS and orbit propagation is proposed in this paper. The proposed method improves the performance of DGPS by using Hatch filter and solves an intermittent communication problem by estimating the relative position and velocity using Hill-Clohessy-Wiltshire Equation. Through the simulation, it is verified that the suggested algorithm provides the relative position error within RMS 0.5 m and the relative velocity error within RMS 3 cm/s. Furthermore, it has the advantage that it is suitable for real-time implementation using single-frequency GPS measurements and is computationally efficient.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.181-186
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• 2003

As the approach close-range digital photogrammetry has a variety of merits, the application of precision requiting fields is in Increase for its scope expansion. In the meantime, in case of photographic surveying by use of films, a lot of studies on experiment analysis and theoretical forecast models about a change of the exactness as per photographing coordinates have been conducted, but experiments about approach close-range digital photogrammetry are not enough yet. In consequence, this study has made photographing respectively by changing the photographic distance, converging angle, picturing direction by use of Rollei d7 metric and d7 metric$\^$5/ that is a measurement digital camera. And also in order to minimize the errors happened at the relative orientation, we have sorted out the prototype target that the relative orientation is automatically on the programming and have calculated RMSE by carrying out the bundle adjustment. We think that such a study could be used as very important basic data necessary in deriving the optimal photographic conditions by the close-range digital photogrammetry and in judging such a degree.

• 한국군사과학기술학회지
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• 제20권2호
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• pp.300-305
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• 2017

In this paper, we performed a evaluation for angular and energy dependence of military radiation detector PDR-1K. Its measuring range is divided into two section, low and high, and each range has a GM tube separately owing to broad scale. We observed a change in relative angular reactivity within 0.928 ~ 1.188 in low range and within 0.743 ~ 1.000 in high range from $-90^{\circ}$ to $+90^{\circ}$. The evaluation for energy dependence appeared a relative reactivity within 0.892 ~ 1.000 above 83 keV. This means PDR-1K isn't possible to use below 83 keV of radiation energy. It is possible to provide response information to user and to increase reliability of radiation measurement through this paper.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.85-91
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• 2013

실내에서의 위치기반 서비스 및 상황인식 서비스를 위해서는 실내에서의 정밀한 위치인식 기술이 필수적이다. 신호원과 여러 개의 신호 수신기와의 거리 차이를 이용하여 신호원의 상대위치를 추정하는 TDOA(Time Difference of Arrival) 기술이 사용되고 있는데, 거리 차이 측정의 오차에 따른 위치 추정 오차가 발생하므로 이를 최소화하기 위한 연구가 많이 진행되어 왔다. 본 논문에서는 신호원과의 거리 차이값을 이용하여 계산된 여러 근중에서 실제의 근을 선별하고 이를 평균내어 신호원의 위치를 추정하는 알고리즘이 제안되었으며, 기존의 방법에 비해 오차가 개선되었다.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1731-1736
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• 2003

The reaction of ${\alpha}$-Benzilmonoxime with palladium(II) produces a green complex in triton X-100 micellar media. Palladium has been determined using zero and first derivative spectrophotometric methods. The absorbances of Pd(II)- ${\alpha}$--benzilmonoxime complex at 441.8 and 677.0 nm in 0.10 M perchloric acid solution were monitored and linear working ranges of 0.3-12.0 and 0.7-20 ${\mu}$g mL$^{-1}$ with detection limits of 0.07 and 0.10 ${\mu}$g $mL^-1$ were obtained, respectively. Also, recoveries in the range of 92.8 to 100.1% and relative standard deviations in the range of 0.4 to 7.1% were obtained. First derivative spectrophotometry has also been applied for palladium determination under the optimum condition. The linear dynamic range of 0.2-24.0 ${\mu}$g $mL^{-1}$ palladium with relative standard deviations of 0.6-6.9% and recoveries in the range of 94.9-102.5% has been obtained by first derivative spectrophotometry. The method shows high selectivity because of the high concentration of acid used, which prevents formation of complexes of ${\alpha}$--benzilmonoxime with the other cations. The palladium complex formed was stable at least one day. The method was successfully applied to the determination of palladium in some synthetic palladium alloys and palladium-charcoal powder.

• 생명과학회지
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• 제12권3호
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• pp.363-368
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• 2002

한국 민속주의 품질평가를 위해 민속주 31종을 대상으로 에탄을 함량, pH, 산도, 총당 및 환원당의 함량과 같은 특성을 조사하였다. 또한 민속주의 ATP함량은 lumitester로 측정하여 생균수와 비전하였다. 민속주의 물리.화학적 특성은 아래와 같이 확인되었다.; pH는 3.59~4.79 였고 총 산도는 4.23~16.21이였으며 총당과 환원당의 함량은 각각 0.04 ~1.13, 0.006 ~ 0.999 g/100 mL로 나타났고 ATP함량은 $10^1$~$10^{6}$ RLU범위에서 관찰되었다.

• 대기
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• 제34권1호
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• pp.23-34
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• 2024

The Korea Meteorological Administration has improved medium-range weather forecasts by implementing post-processing methods to minimize numerical model errors. In this study, we employ a statistical correction technique known as the minimum continuous ranked probability score (CRPS) to refine medium-range forecast guidance. This technique quantifies the similarity between the predicted values and the observed cumulative distribution function of the Unified Model Ensemble Prediction System for Global (UM EPSG). We evaluated the performance of the medium-range forecast guidance for surface air temperature and relative humidity, noting significant enhancements in seasonal bias and root mean squared error compared to observations. Notably, compared to the existing the medium-range forecast guidance, temperature forecasts exhibit 17.5% improvement in summer and 21.5% improvement in winter. Humidity forecasts also show 12% improvement in summer and 23% improvement in winter. The results indicate that utilizing the minimum CRPS for medium-range forecast guidance provide more reliable and improved performance than UM EPSG.

• 대한교통학회지
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• 제26권2호
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• pp.121-133
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• 2008

기존의 첨단차량 추종거동 모형은 선행차량과의 상대거리와 관계없이 동일한 속도이면 추종상태를 유지하는 비현실적 제약성을 내포하고 있다. 따라서 본 연구에서는 추종상황에서 차량간 적정 상대거리를 유지함과 동시에 추종차량 운전자의 안전성과 안락함을 고려하기 위해 인간공학요소를 반영한 보다 현실적인 추종거동모형을 개발하고자 하였다. 인간공학요소의 반영을 위하여 운전자의 개별특성, 환경적 요소, 속도 및 거리관계에 의해 나타나는 운전자의 불안감도(MOA, Measurement of Alarm)를 퍼지모형 구축을 통해 측정하였으며, 측정된 불안감도를 경감시키고 적정 안전거리를 확보하도록 모형을 개발하였다. 개발된 모형의 성능을 검증하기 위하여 기 개발된 GGM(General GM)모형과 동일한 시나리오에 따라 시뮬레이션을 수행하였다. 수행 결과, 선행차량과의 상대거리에 관계없이 속도가 동일하면 추종을 그대로 유지하는 GGM모형과 달리, 제안된 모형은 선행차량과의 상대거리가 안전거리 이하 또는 이상이면 상대거리를 안전거리만큼 넓히거나 좁힌 후 추종상태를 유지하였다. 이는 제안된 모형이 기존의 모형에 비해 더욱 안전한 거동을 하는 것을 나타낸다. 또한 GGM모형이 상대거리와 속도 관계에 의해 높은 불안감도를 유지하는 반면, 제안된 모형은 불안감도를 허용 불안감도까지 경감시켜 추종거동을 유지하여 운전자의 안락함을 잘 반영하는 것으로 나타났다. 따라서 운전자 불안감도의 경감 측면과 도로이용의 효율성 측면에서 제안된 모형이 기존의 GGM모형을 대폭 현실화시킨 것으로 판단되었다.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권4호
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• pp.173-180
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• 2006

A key component of autonomous navigation of intelligent home robot is localization and map building with recognized features from the environment. To validate this, accurate measurement of relative location between robot and features is essential. In this paper, we proposed relative localization algorithm based on 3D reconstruction of scale invariant features of two images which are captured from two parallel cameras. We captured two images from parallel cameras which are attached in front of robot and detect scale invariant features in each image using SIFT(scale invariant feature transform). Then, we performed matching for the two image's feature points and got the relative location using 3D reconstruction for the matched points. Stereo camera needs high precision of two camera's extrinsic and matching pixels in two camera image. Because we used two cameras which are different from stereo camera and scale invariant feature point and it's easy to setup the extrinsic parameter. Furthermore, 3D reconstruction does not need any other sensor. And the results can be simultaneously used by obstacle avoidance, map building and localization. We set 20cm the distance between two camera and capture the 3frames per second. The experimental results show :t6cm maximum error in the range of less than 2m and ${\pm}15cm$ maximum error in the range of between 2m and 4m.

• 대한한의학방제학회지
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• 제12권2호
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• pp.1-17
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• 2004

This study was investigated to make sure the range of the Morus Cortex's treatment, the nature of disease, the chief virtue of medicine, the pathology and the usage quantity of it in Donguibogam The results were as follows; 1. The frequency of being used the Morus Cortex in the consumption or cough-relative chapter is as high as a ratio of 40.6%. 2. The Morus Cortex is used in a realm of the consumption or cough-relative disease, an otorhinolalyngology, an edema, a skin-relative disease, a bleeding trouble, a thirsty and diabetes melitus, etc. 3. The Morus Cortex is used in a realm of the pathology of the pulmonary heat, the pulmonary noxious vigor, the damage from external winds and colds, fatigue, etc. 4. The Morus Cortex is used in a range of $1g{\sim}12g$ in herbal-prescription. The main using dosage is 4g(about 42%). 5. The Morus Cortex is used with various crude herbs in accordance with the pathogeny. The Morus Cortex has been used to reduce heat from the lungs and soothe asthma, to promote urination and reduce edema from shinnongboncho era. According to the results, I suggest that we use the Morus Cortex in a various pathogenic fields. The Morus Cortex is able to remove not only pathogenic heat from the consumption or cough-relative disease, but also pathogenic otorhinolalyngology, an edema, a skin-relative disease, a bleeding trouble, a thirsty and diabetes melitus, etc.