• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.53-64
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• 2021

Wargame is a simulated military operation with certain rules, specifications, and procedures, in which soldiers can virtually and indirectly experience the war. The ROK Navy operates the Cheonghae model, a training wargame model for helping commanders and staff master the procedures for conducting the war. It is important for commanders, staff and analysts to know whether a warship can perform its missions and how long it can last during a war. In existing model, the Cheonghae, the probability of kill of a warship is calculated simply considering the number of tonnage without any stochastic elements, and the warship's mission availability is also determined based on predetermined values. With this model, it is difficult to get a value of the probability of kill that makes sense. In this dissertation, the author has developed a probabilistic model in which the warship vulnerability data of ROK-JMEM can be used. A conceptual model and methodology that can evaluate the mission performance of personnel, equipment, and supplies has been proposed. This can be expanded to a comprehensive assessment of wartime warship loss rates by integrating damage rates for personnel, equipment, and supplies in wartime.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1373-1391
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• 2022

We investigate mobile multiple-input multiple-output (MIMO) molecular communication via diffusion (MCvD) system which is consisted of two source nodes, two destination nodes and one relay node in the mobile three-dimensional channel. First, the combinations of decode-and-forward (DF) relaying protocol and network coding (NC) scheme are implemented at relay node. The adaptive thresholds at relay node and destination nodes can be obtained by maximum a posteriori (MAP) probability detection method. Then the mathematical expressions of the average bit error probability (BEP) of this mobile MIMO MCvD system based on DF and NC scheme are derived. Furthermore, in order to minimize the average BEP, we establish the optimization problem with optimization variables which include the ratio of the number of emitted molecules at two source nodes and the initial position of relay node. We put forward an iterative scheme based on block coordinate descent algorithm which can be used to solve the optimization problem and get optimal values of the optimization variables simultaneously. Finally, the numerical results reveal that the proposed iterative method has good convergence behavior. The average BEP performance of this system can be improved by performing the joint optimizations.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.6
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• pp.394-404
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• 2013

In the present study, the characteristics of spectral peakedness parameter $Q_p$, bandwidth parameter ${\varepsilon}$, and spectral width parameter ${\nu}$ were analyzed as a first step to define the swell waves quantitatively. For the analysis, the joint probability density function of significant wave heights and peak periods were newly developed. The MCMC(Markov Chain Monte Carlo) simulations have been performed to generate the significant wave heights and peak periods from the developed probability density functions. Applying the simulated significant wave heights and peak periods to the theoretical wave spectrum models, the spectral shapes parameters were obtained and analyzed. Among the spectral shape parameters, only the spectral peakedness parameter $Q_p$, is shown to be independent with the significant wave height and peak wave period. It also best represents the peakedness of the spectral shape, and henceforth $Q_p$ should be used to define the swell waves with a wave period. For the field verification of the results, wave data obtained from Hupo port and Ulleungdo were analyzed and results showed the same trend with the MCMC simulation results.

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.115-123
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• 2017

Dispite the fact that our military has outwardly made notable accomplishments such as the development of weapon systems like tanks, self-propelled artillery, and missiles, there has been a lack of attention to producing weapon effectiveness data that suggests a standard as to what effects the developed weapons will demonstrate on the battlefield. For such reasons, most of the weapon effectiveness data utilizes JMEM data introduced by the United States and as for the rest of the data that cannot be acquired, respective branches create and utilize their own data through research. This research aims to develop a reliable methodology that can meet the requirements of the requesting branches in a short span of time and at a low cost by studying the existing weapon effectiveness data production methodologies such as that of JMEM. As a result I have developed a method that calculates the vulnerable area and the probability of kill of the weapon system that one wants to calculate by applying statistical technique and simulation technique based on weapon effectiveness data of similar weapon systems in JMEM and live test data.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.209-218
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• 2013

Military surveillance systems with electro-optical sensors can be used to track a number of targets efficiently and reliably. In MTT (Multi-Target Tracking), joint events in which different tracks share the same measurements may occur. Measurement-to-track assignment are computationally challenging because of the number of operations increases exponentially with number of tracks and number of measurements. IHPDA (Integrated Highest Probability Data Association) based on a 2D-Assignment technique can find an optimal solution for measurement to track one-to-one assignments for complex environments. In this paper, LM-IHPDA (Linear Multi-Target IHPDA) which does not need to form all feasible joint events of association and thus the computational load is linear in the number of tracks and the number of measurements. Simulation studies illustrate the effectiveness of this approach in an infrared image environment.

• Journal of Korea Multimedia Society
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• v.19 no.5
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• pp.890-900
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• 2016

This paper presents a multiple target tracking system using target feature information. In the proposed system, the state of target is defined as its kinematic as well as feature : the kinematic includes a location and a velocity; the feature contains the image correlation between a prior target and a current measurement. The feature information is used for generating the validation matrix and association probability of joint probabilistic data association (JPDA) algorithm. Through the Kalman filter, the target kinematic is updated. Then the tracking information is cycled by the track management algorithm. The system has been evaluated using the images obtained from Electro-Optics/ InfraRed (EO/IR) sensor. It is verified that the proposed system can reduce the complexity burden of JPDA process and can enhance the track maintenance rate.

• Geotechnical Engineering
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• v.4 no.2
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• pp.5-14
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• 1988

A probabilistic model for the progressive failure in a homogeneous soil slope consisting of strain-softening material is presented. The local safety margin of any slice above failure surface is assumed to follow a normal distribution. Uncertainties of the shear strength along potential failure surface are expressed by one-dimensional random field models. In this paper, only the case where failure initiates at toe and propagates up to the crest is considerd. The joint distribution of the safety margin of any two adjacent slices above the failure surface is assumed to be bivariate normal. The overall probability of the sliding failure is expressed as a product of probabilities of a series of conditional el.eats. Finally, the developed procedure has been applied in a case study to yield the reliability of a cut slope.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.241-247
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• 2015

Cognitive radio has been attracting increased attention as an effective approach to improving spectrum efficiency. One component of cognitive radio, spectrum sensing, has an important relationship with the performance of cognitive radio. In this paper, after a summary and analysis of the existing spectrum-sensing algorithms, we report that the existing eigenvalue-based semi-blind detection algorithm and blind detection algorithm have not made full use of the eigenvalues of the received signals. Applying multi-antenna systems to cognitive users, we design a variety of spectrum-sensing algorithms based on the joint distribution of the eigenvalues of the received signal. Simulation results validate that the proposed algorithms in this paper are able to detect whether the signal of the primary user exists or not with high probability of detection in an environment with a low signal-to-noise ratio. Compared with traditional algorithms, the new algorithms have the advantages of high detection performance and strong robustness

• Journal of Mechanical Science and Technology
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• v.15 no.1
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• pp.44-51
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• 2001

One of the recent issues in design of the spot-welded structure such as the automobile body is to develop an economical prediction method of the fatigue design criterion without additional fatigue test. In this paper, as one of basic investigation for developing such methods, fracture mechanical approach was investigated. First, the Model I, Mode II and Mode III, stress intensity factors were analyzed. Second, strain energy density factor (S) synthetically including them was calculated. And finally, in order to decide the systematic fatigue design criterion by using this strain energy density factor, fatigue data of the ΔP-N(sub)f obtained on the various in-plane bending type spot-welded lap joints were systematically re-arranged in the ΔS-N(sub)f relation. And its utility and reliability were verified by the theory of Weibull probability distribution function. The reliability of the proposed fatigue life prediction value at 10(sup)7 cycles by the strain energy density factor was estimated by 85%. Therefore, it is possible to decide the fatigue design criterion of spot-welded lap joint instead of the ΔP-N(sub)f relation.

• Journal of muscle and joint health
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• v.2 no.2
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• pp.168-184
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• 1995

This deductive-survey study was undertaken in order to examine if there were relationship between causal perceptions, expectation for the cure and compliance. The sampling method was a non-probability, purposive sampling technique. The participants of this study was 195 volunteers 1) who have been diagnosed as having chronic arthritis and 2) who were at the rheumatis center of one university hospital in Seoul between September 18th to September 25th 1989. This instruments used for this study were the compliance scale developed by Choi and causal perception scale developed by the researcher. Analysis of data was done using pass analysis, Pearson correlation coefficient. The result of study were as follow : Hypothesis 1 : "It's correlated that causal perception, expectation for cure and compliance" was accepted. (F=4.85, p< .05) Hypothesis 2 : "It's correlated that causal perception, expectation for cure and with depression" was partially accepted. Total age group-worry and anxiety (r=.1580, p<.001) After 40-function of immunity (r=.1731, p<.05) warry and anxiety (r=.1730, p<.001). In the relationship between general characteristics and the variables, age group correlated with compliance and causal perception.