• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.379-382
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• 2013

In conventional solar energy harvesting systems, continuous perturbation techniques of the duty cycle or switching frequency of a power converter have been used to implement MPPT(Maximum Power Point Tracking) control. In this paper, we propose a new MPPT technique to control the duty cycle of a power switch powering a power converter. The proposed circuit is designed in 0.35um CMOS process, and the designed chip area including pads is $770um{\times}800um$.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2479-2481
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• 2000

It is the time-varying dissolved oxygen(DO) dynamics that requires controlling for maintaining the DO concentration in the aeration tank. Many linear controllers have thus been applied. Because of the nonlinearity of the oxygen transfer function together with the time-varying respiration rate, however, the linear controllers are found to poorly perform in many cases. To overcome this limitation, a number of advanced controlling techniques have been developed and applied. In this study, designed GA-PI Controller using genetic algorithm(GA). Genetic algorithms(GAs) are search algorithms based on the mechanics of natural selection and natural genetics. As result of computer simulation, GA-PI controller shows the better control performance especially under the condition of the continuously changing DO set-point. This result represents that GA-PI controller can be a good measure to control the DO concentration in the SBR process which requires the sequential DO set-point change to accomplish the nitrification and denitrification in a single reactor.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.3
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• pp.318-322
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• 1997

A prototype of combustion zone monitoring system as been developed and installed into tuyeres of the blast furnace. The system consists of CCD(charge coupled device) cameras, sonic flow meters, an image processor and a personal computer. The personal computer collects raceway luminance data and operational data from the image processor that is connected to the color CCD camera from the blast furnace process computer, respectively. In addition, the sonic flow meters supply coal injection rate data to the personal computer. Then, the personal computer evaluates the combustion conditions with the raceway inspection algorithm. This integrated monitoring system allows us to detect abnormal raceway conditions and the clogging status of coal injection pipe. The image processing techniques of the system enable us to effectively monitor unburnt coal sticking to tuyere tip and injection lance wear conditions. Such a developed system ensures rapid and precise raceway inspection. The image processing capability of the system has helped operator to early detect both the unburnt coal sticking problem and the errosion problem of injection lance. Furthermore, the system could control the abnormal raceway condition based the the analysis results obtained from combustion monitoring.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.139-143
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• 2015

A push-push voltage controlled dielectric resonator oscillator (VCDRO) with a modified frequency tuning structure using broadside couplers is investigated. The push-push VCDRO designed at 16 GHz is manufactured using a low temperature co-fired ceramic (LTCC) technology to reduce the circuit size. The frequency tuning structure using a broadside coupler is embedded in a layer of the A6 substrate by using the LTCC process. Experimental results show that the fundamental and third harmonics are suppressed above 15 dBc and 30 dBc, respectively, and the phase noise of push-push VCDRO is -97.5 dBc/Hz at an offset frequency of 100 kHz from the carrier. The proposed frequency tuning structure has a tuning range of 4.46 MHz over a control voltage of 1-11 V. This push-push VCDRO has a miniature size of 15 mm×15 mm. The proposed design and fabrication techniques for a push-push oscillator seem to be applicable in many space and commercial VCDRO products.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1444-1445
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• 2006

Carbon nanotubes (CNTs) are grown on TiN-Coated silicon substrates at $700^{\circ}C$ using an ICP-CVD method. Ni catalysts for CNT growth are formed using an RF magnetron sputtering system. Post-treatment using hydrogen ions has been performed in the ICP reactor by varying the treatment period. The characterization using various techniques, such as FESEM, HRTEM, and Raman spectroscopy, show that the physical dimension as well as the crystal quality of CNTs are changed by the post-treatment process. It is also seen that the hydrogen ion-bombardment may change the surface structure of CNTs, which may lead to produce better electron emission properties. The physical reason for all the measured data obtained are discussed to establish the relationship between the structural property and the electron emission characteristic of CNTs.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1862-1864
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• 2005

Carbon nanotubes [CNTs] are grown on TiN-coated Si substrates at $700^{\circ}C$ by inductively coupled plasma-chemical vapor deposition (ICP-CVD). Pre-treatment of Ni catalysts has been performed using an RF magnetron sputtering system. Structural properties and field-emission characteristics of the CNTs grown are analyzed in terms of the RF power applied and the treatment time used in the pre-treatment process. The characterization using various techniques, such as FE-SEM, AFM, and Raman spectroscopy, show that the physical dimension as well as the crystal quality of CNTs are changed by pre-treatment of Ni catalysts. It is also seen that Ni catalysts with proper grain size and uniform surface roughness may produce much better electron emission. The physical reason for all the measured data obtained are discussed to establish the relationship between the structural property and the electron emission characteristic of CNTs.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2130-2133
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• 2003

For real-time recognizing of the load vehicles a new Neural Network algorithm is proposed. The proposed neural network technique is the real time computation method through the inter-node diffusion. In the network, a node corresponds to a state in the quantized input space. Each node is composed of a Processing unit and fixed weights from its neighbor nodes as well as its input terminal. The most reliable algorithm derived for real time recognition of vehicles, is a dynamic programming based algorithm based on sequence matching techniques that would process the data as it arrives and could therefore provide continuously updated neighbor information estimates. Through severa simulation experiments, real time reconstruction nonlinear image information is Processed. 1-D hardware has been composed and various experi with static and dynamic signals have implemented.

• Korean Journal of Childcare and Education
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• v.15 no.4
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• pp.37-57
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• 2019

Objective: The purpose of this study was to examine the sequential mediating effects of self-esteem and positive peer play interaction between warmth parenting and the social competence of preschoolers. Methods: The 7th wave of the Panel Study on Korean Children(2014) was used to analyze 1,113 preschoolers. Sequential mediation effects were analyzed using SPSS Process Macro(Hayes, 2013). Results: Warmth parenting indirectly affected preschooler's social competence (cooperation, assertion, self-control) by yielding sequential mediation effects on self-esteem and peer play interaction. Namely, warmth parenting does not directly affect social competence but does have a significant effect on preschooler self-esteem, which positively affected peer play interaction. This path increases the social competence(cooperation, assertion, self-control) of preschool children. Conclusion/Implications: In order to increase the social competence (cooperation, assertion, self-control) of preschool children, it is important for the preschooler to consider themselves a worthy person and to learn positive interaction techniques through warmth parenting.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1095-1100
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• 2021

This study aims to analyze the factors that influence people's behavioral intentions to recycle waste and focus on people's perceptions of informal waste recycling. The low level of participation in the e-waste recycling process makes research on the factors that encourage household interactions in sorting waste or recycling waste a priority. The purpose of this study is to build a comprehensive model and examine the relationship between perceptions of informal recycling, implementation e-waste management, behavioral intention, convenience of recycling and perceived behavioral control. The framework is the Theory of Planned Behavior (TPB). The implementation variable e-waste management is used to mediate the relationship between the two constructs. Respondents in this study were cellular phone users who had changed their phones. The number of respondents in this study totaled 165, using the purposive sampling technique. Data analysis techniques in this study used PLS-SEM with WarpPLS version 6.0. The findings show that: (1) perception of informal recycling, e-waste management, and behavioral intention have a significant positive effect; (2) management of e-waste, perception behavioral control and behavioral intention have a positive effect; and (3) the implementation of e-waste management, which causes the convenience of recycling, will increase the intensity of behavior, indicating the results are rejected.

• The Journal of Society for e-Business Studies
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• v.10 no.1
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• pp.61-80
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• 2005

Business Process Management (BPM) System is a software system to support an efficient execution, control and management of business processes. The system automates complex business processes and manages them effectively to raise productivity. Traditional commercial systems mainly focus on automating processes and do not have methods for enhancing process performances and task performer's efficiency. Therefore, there is room for enhancement of task performers' productivities and efficiency of business processes. In this paper, we propose a new method of executing business processes more efficiently in that a whole process is scheduled considering the degree of participants' workload. The method allows managing the largest constraints among constituent resources of the process. This method is based on the DBR (Drum-Buffer-Rope) in TOC (Theory of Constraints) concepts. We first consider the differences between business process models and DBR application models, and then develop the modified drum, buffer and rope. This leads us to develop BP-DBR (Business Process-DBR) that can control the proper size of task performers' work list and arrival rate of process instances. Use of BP-DBR improves the efficiency of the whole process as well as participants' working condition. We then carry out a set of simulation experiments and compare the effectiveness of our approach with that of the scheduling techniques used in existing systems.