• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.729-737
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• 2012

In case that multiple jammers are transmitting the signals which are the same type a general algorithm based on TDOA method cannot estimate the positions of multiple jammers because there are many TDOA measurements including true and false values. This paper, therefore, designs a new algorithm based on TDOA method to localize multiple jammers. In this algorithm, TDOA measurements are obtained by rotating the reference sensor, and then the positions of multiple jammers can be estimated by detecting congregated point among the multiple estimated positions from TDOA measurements. Through computer simulations, it is verified that this algorithm localizes the multiple jammers well. The performance of the algorithm are also analysed by changing the distance between sensors and jammer, and sampling frequency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.34-40
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• 2012

Flux linkage of phase windings or phase inductance is an important parameter in determining the behavior of a switched reluctance motor (SRM) [1-8]. Therefore, the accurate prediction of inductance at aligned and unaligned rotor positions makes a significant contribution to the design of an SRM and its analytical approach is not straightforward due to nonlinear flux distribution. Although several different approaches using a finite element analysis (FEA) or curve-fitting tool have been employed to compute phase inductance [2-5], they are not suitable for a simple design procedure because the FEA necessitates a large amount of time in both modeling and solving with complexity for every motor design, and the curve-fitting requires the data of flux linkage from either an experimental test or an FEA simulation. In this paper, phase inductance at aligned and unaligned rotor positions is estimated by means of numerical method and magnetic equivalent circuit as well, and the proposed approach is analytically verified in terms of the accuracy of estimated inductance compared to inductance computed by an FEA simulation.

• Journal of KSNVE
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• v.9 no.2
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• pp.363-370
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• 1999

In this study, we establish a theory for dynamic behaviors of an automatic ball balancer, analyze its dynamic characteristics, and provide its design guide line. Equations of motion are derived by using the polar coordinate system instead of the rectangular coordinate system which was previously used in other researches. After nondimensionalization of the equations, the perturbation method is applied to locate the equilibrium positions and to obtain the linearized equations of motion around the equilibrium positions. The Eigenvalue problem is used to verify the dynamic stability around the equilibrium positions. On the other hand, the time responses are computed from the nonlinear equations of motion by using a time integration method.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.13-18
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• 2019

According to the development of autonomous vehicles worldwide, the driver's posture may not be a normal posture but the various seating positions. Recently, a numbers of research activities has been focused to protect of driver and passengers in various seating positions as well as seating postures. In this paper, the occupant injury severity was evaluated with different seat positions, seatback angles and TTF times.

• Forest Science and Technology
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• v.14 no.4
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• pp.169-180
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• 2018

The Republic of Korea (ROK) has had a successful experience in greening its land because of strong state policy and public participation. This paper aims to analyze the interest positions, participation, and accountability of multiple actors in the process of greening movements in the ROK. These movements were divided into two phases: forest rehabilitation (1973-1997) and urban greening (1998-2017). During the first phase, farmers caused deforestation by slash-and-burn farming and illegal logging, and governmental agencies acted as helpers controlled the farmers' deforestation activities. During the second phase, government agencies and enterprises caused deforestation with urban development projects, including construction of housings and roads. Multiple actors including citizens, NGOs, and enterprises helped urban greening through campaigns, donations, and monitoring. As a result, managing interest positions is significant to motivate multiple actors to participate in the greening movement. Participation with clear accountability is meaningful for successful greening. Therefore interest-based participation requiring accountability contributes to greening. This phenomenon indicates interconnection for interest positions, participation and accountability should be considered in designing greening policies.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.85-91
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• 1999

The purpose of this study is to investigate phonetic realization of flap [r], one of the allophones of Korean /l/. Phonetic realization of a segment is affected by not only its neighboring segments but also its prosodic position in an utterance. This study examined how various prosodic positions affect the phonetic realization of [r]. Effects of the four prosodic positions on the phonetic realization of [r] were examined: utterance initial, Intonation Phrase initial, Accentual Phrase initial, and Accentual Medial positions. Word positional effect was also examined: word initial, medial, and final positions. Acoustic and statistical analyses showed that flap [r] was realized in a variety of phonetic forms: from sonorant(the most reduced form) to short stop(the least reduced form). It was shown that generally. word-initial position is stronger than word-medial position. It was also shown that in many cases, utterance-initial position and intonation-phrase-initial position are stronger than accentual-phrase-initial and accentual-phrase-medial positions. Sonorants were observed more often in the prosodically weaker portions. VOT duration was also shorter in accentual-phrase-initial and accentual-phrase-medial positions.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.89-101
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• 2015

This paper proposes a statistical model of 3-D positions when tracking moving targets using the uncooled infrared (IR) stereo camera system. The proposed model is derived from two errors. One is the position error which is caused by the sampling pixels in the digital image. The other is the timing jitter which results from the irregular capture-timing in the infrared cameras. The capture-timing in the IR camera is measured using the jitter meter designed in this paper, and the observed jitters are statistically modeled as Gaussian distribution. This paper derives an integrated probability distribution by combining jitter error with pixel position error. The combined error is modeled as the convolution of two error distributions. To verify the proposed statistical position error model, this paper has some experiments in tracking moving objects with IR stereo camera. The 3-D positions of object are accurately measured by the trajectory scanner, and 3-D positions are also estimated by stereo matching from IR stereo camera system. According to the experiments, the positions of moving object are estimated within the statistically reliable range which is derived by convolution of two probability models of pixel position error and timing jitter respectively. It is expected that the proposed statistical model can be applied to estimate the uncertain 3-D positions of moving objects in the diverse fields.

• Korean Journal of Oriental Medicine
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• v.14 no.2
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• pp.107-112
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• 2008

Although the pulse diagnosis position, Guan is apart from Cun or Chi by only $10{\sim}20$ mm at most, traditional medical doctors applies different indent pressures and even they states different pulse images are felt at Cun, Guan and Chi, To support their clinical behaviors, in this study, we tested statistically whether there are differences in pulse waveform measured at these three positions with SphygmoCor system used world widely, A 30 years old female subject without any evidence of cardiovascular diseases was involved in this experiment. Radial pulse waves were recorded at three different positions on left lower arm 10 times at three positions-Cun, Guan and Chi. With ANOVA, we tested whether, among three different positions. there are any differences in 12 parameters of radial pulse waveform and in estimated AIx(Augmentation Index) as an arterial stiffness index extracted from radial pulse waveform. As results, differences in optimal indent pressure h0 were observed at different measuring positions(P<0.001) but not significantly different. And pulse pressure his were found to be different(Chi$22.60{\pm}3.06%,\;18.60{\pm}3.37%\;and\;26.4{\pm}5.02%$ respectively. Consequently. AIx at Gwan seems to be lowest and that at Chi seems to be highest. So. we assert the AIx at Chi is likely to be overestimated. In further studies. we want to examine what make differences in these parameters between measuring positions. And it also seems to be worthy to investigate the relationship between the depth of radial artery and AIx. And, ultimately, we need to determine the best measuring process including measuring position, hold-down pressure, signal quality validation and so on. so to achieve the optimal waveform which represents subject's health condition for both western medicine and traditional medicine.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.341-348
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• 2019

In order to reduce the safety risk of forestry operations, this research was conducted to examine the suitability of chainsaw protective pants after repeated laundering, testing four different products that are currently used in hand-held chainsaw operations. Laundering was repeated 10, 20, 30, 40, and 50 times. After washing, we measured the shrinkage ratio of 17 measurement positions mostly affecting the safety of forest operations and suggested the expected safety life cycle of chainsaw protective clothes. The results showed that most of the products have only one measurement position where the standard shrinkage ratio (<6%) was exceeded after 20 washings, and that the lateral direction of measurement positions shrank more than the vertical one. The numbers of repeated launderings and measurement positions were found to be significant factors influencing the shrinkage ratio (p<0.05). In the shrinkage rates for 17 measurement positions, there were significant correlations between five of the measurement positions (a, b, g, j, and n) and the number of repeated launderings (p<0.05). Therefore, the results suggest that about 10 months would be suitable for an adequate safety lifetime for chainsaw protective pants. The relationship between the number of repeated launderings and the measurement positions will be further analyzed in detail to examine the durability of chainsaw protective pants.

• Journal of Korean Medical classics
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• v.37 no.2
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• pp.31-48
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• 2024

Objectives : The purpose of this paper is to find the corresponding pathological situation of the Renmai(任脈), Dumai(督脈), and Chongmai(衝脈) at the Cun(寸), Guan(關), Chi(尺) pulse positions using the Qikoujiudaomai diagnostic method in order to find the pathological pattern of the Eight Extra Meridians. The pulse positions are divided into nine parts, using a three dimensional surface-middle-bottom concept. Methods : Relevant contents in classical texts such as the Maijing, Qijingbamaikao, Zabingyuanliuxizhu, Maiyijianmo were examined, along with previous studies on the topic. The findings were that the Renmai, Dumai, Chongmai examination of the Qikoujiudaomai manifested as floating, tight, firm patterns in the Cun, Guan, Chi positions. Results & Conclusions : n terms of the Renmai, the converging and fast Qi manifested in the three positions as a tight pattern; in the Dumai, the extended and scattering Qi manifested in the three positions as a floating pattern; in the Chongmai, the excessive, solid and full Qi manifested in the three positions as a firm pattern. Once the pathological qi overflows in the 12 meridians, disease happens in the Eight Extra Meridians. As such, disease in the Renmai, Dumai, Chongmai were connected to the main meridians as three branches from one root. Through this study, it could be concluded that diagnosis and acupuncture treatment through the Qikoujiudaomai method is possible.