• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.620-626
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• 2004

For general nonlinear processes, it is difficult to control with a linear model-based control method and nonlinear controls are considered. Among the numerous approaches suggested, the most rigorous approach is to use dynamic optimization. Many general engineering problems like control, scheduling, planning etc. are expressed by functional optimization problem and most of them can be changed into dynamic programming (DP) problems. However the DP problems are used in just few cases because as the size of the problem grows, the dynamic programming approach is suffered from the burden of calculation which is called as 'curse of dimensionality'. In order to avoid this problem, the Neuro-Dynamic Programming (NDP) approach is proposed by Bertsekas and Tsitsiklis (1996). To get the solution of seriously nonlinear process control, the interest in NDP approach is enlarged and NDP algorithm is applied to diverse areas such as retailing, finance, inventory management, communication networks, etc. and it has been extended to chemical engineering parts. In the NDP approach, we select the optimal control input policy to minimize the value of cost which is calculated by the sum of current stage cost and future stages cost starting from the next state. The cost value is related with a weight square sum of error and input movement. During the calculation of optimal input policy, if the approximate cost function by using simulation data is utilized with Bellman iteration, the burden of calculation can be relieved and the curse of dimensionality problem of DP can be overcome. It is very important issue how to construct the cost-to-go function which has a good approximate performance. The neural network is one of the eager learning methods and it works as a global approximator to cost-to-go function. In this algorithm, the training of neural network is important and difficult part, and it gives significant effect on the performance of control. To avoid the difficulty in neural network training, the lazy learning method like k-nearest neighbor method can be exploited. The training is unnecessary for this method but requires more computation time and greater data storage. The pH neutralization process has long been taken as a representative benchmark problem of nonlin ar chemical process control due to its nonlinearity and time-varying nature. In this study, the NDP algorithm was applied to pH neutralization process. At first, the pH neutralization process control to use NDP algorithm was performed through simulations with various approximators. The global and local approximators are used for NDP calculation. After that, the verification of NDP in real system was made by pH neutralization experiment. The control results by NDP algorithm was compared with those by the PI controller which is traditionally used, in both simulations and experiments. From the comparison of results, the control by NDP algorithm showed faster and better control performance than PI controller. In addition to that, the control by NDP algorithm showed the good results when it applied to the cases with disturbances and multiple set point changes.

• Korean Business Review
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• v.21 no.1
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• pp.91-117
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• 2008

Since the late 20th century, due to the globalization of markets and the rapid developments of information and communication technologies, the world has entered into the age of fierce competition. With their abundant low-cost labor, former communist countries such as China, Russia and East Europe and former low-developed countries such as India and Brazil have received foreign investments from major industrial companies. Thus, there are no other alternatives remained for Korea and OECD countries other than moving the industrial economies to the knowledge based innovation systems. In the knowledge based innovation systems, economic developments and employments of regions and nations depend solely on companies situated in their territories. In this article, after reviewing the current state of technological based innovation small firms in korea, we provide a theoretical framework to promote the level of technology based innovation and entrepreneurship. The theoretical framework for analysis and policy suggestions is based on the Schumpeter's value system model that consist of supply factors, demand factors, and supporting institutions. In order to create more innovative small businesses, we insist on the followings. First, more R&D and innovation activities related with promising new technologies should be performed. Second, more R&D funds for technological innovation small companies should be provided from governments. Third, more M&A transactions and technology transactions should be marketed freely and competitively. Fourth, more business incubating services and venture capital services should be provided. Fifth, entrepreneurship and innovation culture should be popular and institutionized among people.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.523-528
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• 2012

The recent appearance and evolution of cloud service including IaaS(Infrastructure as a Service), PaaS(Platform as a Service) and SaaS(Software as a Service) is potentially one of the major advances in information and communication technology. While a lot of studies are currently taking place in the technology itself, there is an equally urgent need for understanding and researching the business-related issues surrounding cloud service. As more and more individuals and companies use the cloud service, their concerns are beginning to grow about just how safe and reliable an environment it is. This paper focus on SaaS as an one of the important cloud service. For successful implementation of SaaS service, it is necessary to establish the certification systems to ensure safety and reliability of SaaS. This paper provides the safe and reliable framework for systematic SaaS certification systems. In order to develop it, the critical issues related to service quality and certification of SaaS service are identified and the systematic framework for certification systems of SaaS service and service provider domains are developed. An evaluation methodology for the developed certification systems is also proposed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.12 s.354
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• pp.15-22
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• 2006

In this paper, 1.8V 8-bit 500MSPS Low-power CMOS Digital-to-Analog Converter(DAC) for UWB(Ultra Wide Band) Communication Systeme is proposed. The architecture of the DAC is based on a current steering 6+2 full matrix type which has low glitch and high linearity. In order to achieve a high speed and good performance, a current cell with a high output impedance and wide swing output range is designed. Further a thermometer decoder with same delay time and low-power switching decoder for high efficiency performance are proposed. The proposed DAC was implemented with TSMC 0.18um 1-poly 6-metal N-well CMOS technology. The measured SFDR was 49dB when the output frequency was 50MHz at 500MS/s sampling frequency. The measured INL and DNL were 0.9LSB and 0.3LSB respectively. The DAC power dissipation was 20mW and the effective chip area was $0.63mm^2$.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.225-234
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• 2015

Nowadays a Virtual Power Plant (VPP) represents an aggregation of distributed energy resource such as Distributed Generation (DG), Combined Heat and Power generation (CHP), Energy Storage Systems (ESS) and load in order to operate as a single power plant by using Information and Communication Technologies, ICT. The VPP has been developed and verified based on a single virtual plant platform which is connected with a number of various distributed energy resources. As the VPP's distributed energy resources increase, so does the number of data from distributed energy. Moreover, it is obviously inefficient in the aspects of technique and cost that a virtual plant platform operates in a centralized manner over widespread region. In this paper the concept of the large-scale VPP which can reduce a error probability of system's load and increase the robustness of data exchange among distributed energy resources will be proposed. In addition, it can directly control and supervise energy resource by making small size's virtual platform which can make a optimal resource scheduling to consider of variable and sensitive load in the large-scale VPP. It makes certain the result is verified by simulation.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.104-112
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• 2012

Recently, the HDR imaging technique that mimics human eye is incorporated with LCD/LED display devices to deal with mismatch between the real world scene and the displayed image. However, HDR image has a veiling glare limit as well as a scale of the local contrast problem. In order to overcome these problems, several color correction methods, CSR(center/surround Retinex), MSR (Multi-Scale Retinex), tone-mapping method, iCAM06 and so on, are proposed. However, these methods have a dominated color throughout the entire resulting image after performing color correction. Accordingly, this paper presents a new color correction method using dynamic cone response function. The proposed color correction method consists of tone-mapping and dynamic cone response. The tone-mapping is obtained by using a linear interpolation between chromatic and achromatic. Thereafter, the resulting image is processed through the dynamic cone response function, which estimates the dynamic responses of human visual system as well as deals with mismatch between the real scene image and the rendered image. The experiment results show that the proposed method yields better performance of color correction over the conventional methods.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.75-81
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• 2018

Recently, sedation is routinely used in children who lacked cooperation in pediatric dental clinics. The purpose of this study is to analyze dental treatment cases in department of pediatric dentistry at Dankook University Dental Hospital associating with sedation during 5 years. From January 2011 to December 2015, information about dental treatment cases in department of pediatric dentistry was collected and reviewed. The information gathered included patient gender, age, sedation type, sedative agents, date of operation, and type of procedure. The proportion of treatment cases with conscious sedation for total treatment cases continued to decline until 2014. On the other hand, the incidence of general anesthesia increased gradually. The frequency of midazolam administration and nitrous oxide inhalation sedation increased recently. The use of conscious sedation was significantly decreased when the age of patient was 3 years or older. The frequency of general anesthesia was similar in all age groups. There was a tendency to perform treatment with deeper sedation when the patient was male than female, and when the pulp treatment was performed together with the restorative treatment than not performed. The frequency of re-treatment within 90 days after restoration treatment decreased as the depth of sedation increased.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.35-39
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• 2018

In order to improve the coupling efficiency, a collimator lens that collects the light emitted from the laser diode at a wide angle to the core of the optical fiber is essential. Glass mold method using a mold is widely used as a collimator lens currently used. Although this method is inexpensive to produce, it is difficult to form precisely and quality problems such as spherical aberration. In this study, the precision of surface processing was improved by replacing the existing glass mold method with the semiconductor process, and the material of the lens was changed to silicon suitable for the semiconductor process. The semiconductor process consists of a photolithography process using PR and a dry etching process using plasma. The optical coupling efficiency was measured using an ultra-precision alignment system for the evaluation of the optical characteristics of the silicon lens. As a result, the optical coupling efficiency was 50% when the lens diameter was $220{\mu}m$, and the optical coupling property was 5% or less with respect to the maximum optical coupling efficiency in the lens diameter range of $210-240{\mu}m$.

• Journal of Technology Innovation
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• v.26 no.2
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• pp.95-128
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• 2018

Since mid and late 2000s, the smartphones has been widely diffused and Korea ranked first in global smartphone market in 2011 thanks to its rapid adoption of Android operating system, technology capability accumulated in featurephone development, vertical integration on smartphone production and premium positioning. However, Korea fell behind because of the rise of another latecomer, China, in four years (2015) after it recorded the top position globally. How did the leadership change occurred in the smartphone industry so rapidly? In order to answer the question, we investigated three favorable windows of opportunity for the rise of China, which are technological, demand, and institutional, and the strategic responses of Chinese firms as well as the rigidity and complacency with the past success of Korean firms. Our findings contribute to the extension of 'catch-up cycle' theory as well as provide in-depth insights for strategies and policies settings to overcome the recent rise of China in information and communication technology sector for Korea.

• Journal of Ginseng Culture
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• v.2
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• pp.27-38
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• 2020

Gaesung was the Mecca of Korean ginseng. Factors that Gaesung has been a leading brand of Korean ginseng were multiplicative. Those were natural conditions and huge commercial capital, red ginseng factory, creative business systems and etc. We can quote BongSang Son, SungHak Kong and JeongHo Kim as a famous Gaesung' ginseng merchants. They, as leaders modern ginseng industry had supplied the method of cultivation, prevention of phyto-diseases, excellent ginseng seed, and prepayment system of farming capital. The Gaesung merchants also adopted modern marketing techniques : commercial advertisement, made-order sales, changing package of the ginseng products. The book 'The Dictionary of Korean Companies and Stores' which was published in 1927 introduces BongSang Son as a great businessman in Gaesung. He was not only merchants but also educator and social worker. He practiced the spirit of entrepreneurship. BongSang Son's role of pioneer contributed to the development of Korean ginseng and Gaesung. Due to such efforts of Gaesung merchants, Korean ginseng industry were took a great step forward. This article considered the development of Korean ginseng industry through the life and achievement of the ginseng magnate BongSang Son who was a representative one of Gaesung merchants.