• 대한기계학회논문집A
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• 제25권2호
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• pp.323-329
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• 2001

In this paper, we present a collaborative method for material delivery using a distributed vehicle agents system. Generally used AGV(Autonomous Guided Vehicle) systems in FA require extraordinary facilities like guidepaths and landmarks and have numerous limitations for application in different environments. Moreover in the case of controlling multi vehicles, the necessity for developing corporation abilities like loading and unloading materials between vehicles including different types is increasing nowadays for automation of material flow. Thus to compensate and improve the functions of AGV, it is important to endow vehicles with the intelligence to recognize environments and goods and to determine the goal point to approach. In this study we propose an interaction method between hetero-type vehicles and adaptive fuzzy logic controllers for sensor-based path planning methods and material identifying methods which recognizes color. For the purpose of carrying materials to the goal, simple color sensor is used instead vision system to search for material and recognize its color in order to determine the goal point to transfer it to. The proposed method reaveals a great deal of improvement on its performance.

• 한국정밀공학회지
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• 제18권5호
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• pp.42-49
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• 2001

In This paper, we present a collaborative method for material delivery using a distributed vehicle agents system. Generally used AGV(Autonomous Guided Vehicle) systems in FA(Factory Automation) require extraordinary facilities like guidepaths and landmarks and have numerous limitations for application in different environments. Moreover in the case of controlling multi vehicles, the necessity for developing corporation abilities like loading and unloading materials between vehicles including different types is increasing nowadays for automation of material flow. Thus to compensate and improve the functions of AGV, it is important to endow vehicles with the intelligence to recognize environments and goods and to determine the goal point to approach. In this study we propose an interaction method between hetero-type vehicles and adaptive fuzzy logic controllers for sensor-based path planning methods and material identifying methods which recognizes color. For the purpose of carrying materials to the goal, simple color sensor is used instead of intricate vision system to search for material and recognize its color in order to determine the goal point to transfer it to. The technique for the proposed method will be demonstrated by experiment.

• ETRI Journal
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• 제34권3호
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• pp.369-378
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• 2012

In this paper, we propose new adaptive search range motion estimation methods where the search ranges are constrained by the probabilities of motion vector differences and a search point sampling technique is applied to the constrained search ranges. Our new methods are based on our previous work, in which the search ranges were analytically determined by the probabilities. Since the proposed adaptive search range motion estimation methods effectively restrict the search ranges instead of search point sampling patterns, they provide a very flexible and hardware-friendly approach in motion estimation. The proposed methods were evaluated and tested with JM16.2 of the H.264/AVC video coding standard. Experiment results exhibit that with negligible degradation in PSNR, the proposed methods considerably reduce the computational complexity in comparison with the conventional methods. In particular, the combined method provides performance similar to that of the hybrid unsymmetrical-cross multi-hexagon-grid search method and outstanding merits in hardware implementation.

• Journal of Power Electronics
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• 제18권2호
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• pp.332-342
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• 2018

This paper proposes a parameter design method for multi-element resonant converters (MERCs) with a unique resonant zero point (RZP). This method is mainly composed of four steps. These steps include program filtration, loss comparison, 3D figure fine-tuning and priority compromise. It features easy implementation, effectiveness and universal applicability for almost all of the existing RZP-MERCs. Meanwhile, other design methods are always exclusive for a specific topology. In addition, a novel dual-CTL converter is also proposed here. It belongs to the RZP-MERC family and is designed in detail to explain the process of parameter selection. The performance of the proposed method is verified experimentally on a 500W prototype. The obtained results indicate that with the selected parameters, an extensive dc voltage gain is obtained. It also possesses over-current protection and minimal switching loss. The designed converter achieves high efficiencies among wide load ranges, and the peak efficiency reaches 96.9%.

• Korean Journal of Acupuncture
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• 제28권4호
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• pp.41-48
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• 2011

Objectives : This study aimed to explore the passive multi-channel time series analysis method by measuring bio-potentials of acupuncture point and the peripheral region Methods : Bio-potential was measured at ST36 and the peripherical region of ST36 of 5 healthy volunteers at three times. The diagram of the potential changes over time were smoothed by moving average method and similarities of ST36 and the other points were calculated. Results : In the normal weight group, bio-potential similarity tended to decrease in proportion to the distance from the acupuncture point. In the obesity group, bio-potential similarity appeared in a very wide area. Bio-potential similarity had positive correlation with BMI value. Conclusions : The passive multi-channel time series analysis method showed the possibility be appropriate for the electrical characteristics study of meridians.

• The Journal of Korean Physical Therapy
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• 제6권1호
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• pp.171-183
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• 1994

Purphose. This present study examines the effect of brief, intense transcutaneous electrical nerve stimulation(BTENS) on sensory nerve conduction, electrical pain threshold, and two-point discrimination measured at the superficial radial nevre distribution in 20 healthy subjects. Subjects. Twenty volunteercs, (10 females and 10 males(age range : 20-38 years : $mean{\pm}SD\;:\;27.00{\pm}5.12$), only subjects without prior traumatological and pathological were eligible to participated in this study. Methods. Nerve conduction were determined for the right superficial radial nerve. Electrical pain threshold were determined for the right wrist ipsilateral to the site of BTENS. Small disc electrodes were attached to the surface of the skin stradding the end of the radius. Square wave electrical pulses were delivered from an isolated stimulator through a constant current device at a frequency of 2 Hz(5 ms pulse width). Two-point discrimination, measured on the sensory distribution of superficial radial nerve. BTENS was delivered using a Max-SD( Medical design co.) portable battery powered stimulator. A cicular Ag/AgCl electrode in contact with hypertonic saline gel was attached to the lateral(radial side) surface of the forearm. Results. No significant effects were observed between stimulation methods in the prestimulation cycle(multi-way ANOVA repeated measures : distal latency ; F1.14=0.332. amplitude ; F 0.80=0.445, pain threshold ; F0.06=0.940.2 point discrimination ; F1.50=0.236). Highly significant effects were observed time with the pretreatment and 6 posttreatment cycles(p<0.01). Mighty significants differences in nerve conduction and pain threshold were found using un multi-way ANOVA repeated measures among stimulation methods for each cycles(p<0.01). Conclusion and Discussion The authors concludes that both nerve conduction and pain threshold changes are associated with therapy (stimulation) level of BTENS.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1125-1135
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• 2010

A fundamental characteristic of PMHT (Probabilistic Multi-Hypothesis Tracker) is that the number of targets and initial states of targets in the surveillance area must be a priori known. This requirement is impossible to fulfil in almost every realistic scenario. In the paper, we present two track initiation methods to solve the problem. The proposed track initiation methods are 2-point track initiation and Hough transform track initiation, and they are used to evaluate track initial states and weights for FTD (False Track Discrimination) of the PMHT algorithm. Also suggested as automatic target detection for tracking systems that combines track initiation for target detection with the PMHT algorithm for target tracking in a cluttered environment. A series of Monte-Carlo simulation runs is employed to evaluate the overall system performance with the two track initiation methods and the results are compared and analyzed.

• Journal of Communications and Networks
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• 제13권6호
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• pp.655-663
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• 2011

Diffuse optical wireless (DOW) systems have the advantage that they do not require point-to-point siting so one transmitter can communicate with several receivers. In this paper, we investigate multiple access scheduling methods for downlink orthogonal frequency division multiplexing (OFDM) in diffuse optical wireless networks. Unlike the radio frequency (RF) channel, the DOW channel has low-pass filter characteristics and so requires different scheduling methods than those developed for the RF channel. Multi-user diversity orthogonal frequency division multiple access (OFDMA) systems nominate a cluster of subcarriers with the largest signal-to-noise-ratio for transmission. However, in a DOW channel, most users would choose the lowest frequency clusters of subcarriers. To remedy this problem, we make two proposals. The first is to use a variable cluster size across the subcarriers; the lower frequency clusters will have fewer subcarriers while the higher frequency clusters will have more subcarriers. This will equalize the capacity of the clusters. The second proposal is to randomize a user's cluster selection from a group of clusters satisfying a minimum threshold. Through simulation it is shown that combining these strategies can increase the throughput while ensuring a fair distribution of the available spectrum.

• 대한토목학회논문집
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• 제41권2호
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• pp.133-141
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• 2021

프로브 차량 데이터로부터 전수화 된 교통량, 밀도, 대기행렬 길이를 추정하기 위해 프로브 차량 비율이 필요하다. 이를 위해 기존 연구는 프로브차량과 일반 차량의 위치에 대한 확률구조를 활용하여 지점 검지기 없이 프로브 차량 비율을 추정하는 방법을 제시하였으나, 기존 연구의 방법론은 다차로 도로에 적용할 수 없다는 한계가 있었다. 따라서 본 연구는 각 차로의 대기행렬 길이에 확률분포를 도입함으로써 다차로 접근로에서 프로브 차량 비율을 추정하고자 하였다. 사례연구 결과, 추정치와 관측치 간 이격이 있었으나, 추정치가 관측치의 경향을 따라가는 것으로 나타났으며, 향후 보정계수 도입 등을 통하여 추정치를 개선할 여지가 있었다. 본 연구는 지점 검지기가 없는 다차로 접근로에서 전수화 된 교통량, 밀도, 대기행렬 길이를 추정하기 위한 기초연구로서 활용될 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권12호
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• pp.2374-2391
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• 2011

A variety of reconstruction methods has been developed to convert a set of scattered points generated from real models into explicit forms, such as polygonal meshes, parametric or implicit surfaces. In this paper, we present a method to construct multi-scale implicit surfaces from scattered points using multiscale kernels based on kernel and multi-resolution analysis theories. Our approach differs from other methods in that multi-scale reconstruction can be done without additional manipulation on input data, calculated functions support level of detail representation, and it can be naturally expanded for n-dimensional data. The method also works well with point-sets that are noisy or not uniformly distributed. We show features and performances of the proposed method via experimental results for various data sets.