• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.1-8
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• 2016

In small embedded systems including IoT devices, memory size is very small and it is important to reduce memory amount for execution of application programs. For multi-threaded applications, stack may consume a large amount of memory because each thread has its own stack of sufficiently large size for worst case. This paper presents an implementation of single stack multi-threading, called SSThread (Single Stack Thread), by sharing a stack for all threads to reduce stack memory size. By using SSThread, multi-threaded applications can be programmed based on normal C language environment and there is no requirement of transporting multi-threading operating systems. It consists of several library functions and various C macro definitions. Even though some functional restrictions in comparison to operating systems supporting complete multi-thread functionalities, it is very useful for small embedded systems with tiny memory size and it is simple to setup programming environment for multi-thread applications.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.228-233
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• 1997

An efficient corner matching algorithm is developed to minimize the amount of calculation. To reduce the amount of calculation, all available information from a corner detector is used to make model. This information has uncertainties due to discretization noise and geometric distortion, and this is represented by fuzzy rule base which can represent and handle the uncertainties. Form fuzzy inference procedure, a matched segment list is extracted, and resulted segment list is used to calculate the transformation between object of model and scene. To reduce the false hypotheses, a vote and re-vote method is developed. Also an auto tuning scheme of the fuzzy rule base is developed to find out the uncertainties of features from recognized results automatically. To show the effectiveness of the developed algorithm, experiments are conducted for images of real electronic components.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.265-274
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• 2016

In this paper, we consider a diffusion risk process, in which, its surplus process behaves like a Brownian motion in-between adjacent epochs of claims. We assume that the claims occur following a Poisson process and their sizes are independent and exponentially distributed with the same intensity. Our main goal is to derive the exact formula of the joint moment generating function of the ruin time and the total amount of aggregated claim sizes until ruin in the diffusion risk process. We also provide a method for computing the related first and second moments using the joint moment generating function and the augmented matrix exponential function.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.375-378
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• 2011

This study is intended to realize an intelligent controller using fuzzy control algorithms in order to recycle energy by recycling the waste water heat discharged by waste water heat collection boilers. Using waste water inflow temperature changes and waste water inflow amount changes as parameters, we present characteristic curves of the number of compressors being operated at fixed speeds and the temperature of hot water being discharged. We propose an intelligent controller that determines the optimum number of compressors being operated at fixed speeds in real time by measuring changes in the temperature and amount of waste water inflows in order to minimize the number of compressors being operated at fixed speeds relative to the waste water load flowing into the waste water heat collection boiler.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.5
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• pp.37-54
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• 2021

In this study, a customized model (CM) for the efficient operation of cold chain logistics considering the hypergeometric distribution is proposed. The CM focuses on the segmentation market of ready-to-eat foods and juices made from fresh materials. Companies should determine the amount of production by predicting consumer preferences and quantity to ensure high-efficiency production. The CM is represented as a mathematical formulation and implemented using the genetic algorithm (GA). Addition, the relative weights of CM are calculated. Further, the calculated weights are applied to the GA. In the numerical experiment, hypergeometric distribution is used to calculate the relative weights between the range of production quantities and the customized amount. Experiment results are the values of relative weights and the comparison results by average values of handling cost, total cost and CPU time. Finally, the significance of this study is summarized and a future research direction is remarked in conclusion.

• The Journal of Information Systems
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• v.27 no.4
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• pp.229-249
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• 2018

Purpose The purpose of this paper is to conduct exploratory comparative research on the determinants of successful crowdfunding projects, focusing on multiple crowdfunding platforms in Korea, U.S., and Japan. Design/methodology/approach This study collected data from three representative crowdfunding platforms: Wadiz (Korea), Kickstarter (U.S.), and Readyfor (Japan). Based on 1,906 crowdfunding projects from Wadiz, 3,864 projects from Kickstarter, and 3,060 projects from Readyfor, multiple regression models were applied. Findings Focusing on the crowdfunding projects which have overly achieved goal amount, the analysis results show that the number of comments, the number of Facebook likes and the number of backers have an positive impact on the performance of crowdfunding projects, while target amount has a negative impact. Comparatively, word counts of project description have an impact on funding performance in U.S. and Japan, while the number of images in project description affects funding performance in Korea and U.S. Meanwhile, video clips in project description has little impact on crowdfunding performance in all of the three funding platforms.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.282-287
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• 2013

A real-time digital holographic display is the core technology for the next-generation 3DTV. Holographic display requires a considerably large amount of calculation. If generating a large number of digital holograms is intended, the amount of calculation and the time required increase exponentially. This is a significant obstacle in a real-time hologram service. This paper proposes an algorithm that increases the speed of generating a Fresnel hologram by using a recursive addition operation covering the entire coordinate array of a digital hologram. The 3D object designed to calculate the digital hologram uses a depth-map image produced by computer graphics. The proposed algorithm is a technique that performs the computer-generated holography (CGH) operation with only recursive addition of all of the hologram's coordinates by analyzing the regularity between the 3D object and the digital hologram coordinates. The experimental results show that the proposed algorithm increases the operation speed by 70% over the technique using the conventional CGH equation and by more than 30% over the previously proposed recursive technique.

• Journal of Information Technology Applications and Management
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• v.20 no.3
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• pp.31-42
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• 2013

With a focus on Facebook, the most popular social network service (SNS), this research tried to find out which type of motivation makes users to spend more time on the SNS and in the same vein, which type of motivation makes users to believe that they will continue to use the SNS. The result shows that the need for play (entertaining) and image as social reputation affect the current amount of use, while the needs for information search, building relationship, and entertainment would make them continue to use.

• International Journal of Contents
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• v.9 no.1
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• pp.6-10
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• 2013

Foreground estimation in object segmentation has been an important issue for last few decades. In this paper we propose a GrabCut based automatic foreground estimation method using block clustering. GrabCut is one of popular algorithms for image segmentation in 2D image. However GrabCut is semi-automatic algorithm. So it requires the user input a rough boundary for foreground and background. Typically, the user draws a rectangle around the object of interest manually. The goal of proposed method is to generate an initial rectangle automatically. In order to create initial rectangle, we use Gabor filter and Saliency map and then we use 4 features (amount of area, variance, amount of class with boundary area, amount of class with saliency map) to categorize foreground and background. From the experimental results, our proposed algorithm can achieve satisfactory accuracy in object segmentation without any prior information by the user.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.163-168
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• 2002

The road sign in dynamic traffic system is an important element which affects on human cognitive performance on driving. Web-based vision system simulator was developed to examine the cognition time of the road sign in dynamic environment. This experiment was designed in within-subject design with two factors; vehicle speed and the amount of information of the traffic sign. It measured the cognition time of the road sign through two evaluation methods; the subjective test with vision system simulator and computational cognitive model. In these two evaluations of human cognitive performance under the dynamic traffic environment, it demonstrated that subject's cognition time was affected by both the amount of information of traffic sign and driving speed.