• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2004.11a
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• pp.106-106
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• 2004

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.414-420
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• 2005

The ShortStack Micro Server enables any product that contains a microcontroller or microprocessor to quickly and inexpensively become a networked, Internet-accessible device. The ShortStack Micro Server provides a simple way to add LonWorks networking to new or existing smart devices. . It implements the LonTalk protocol and provides the physical interface with the LonWorks communication. The ShortStack host processor can be an 8, 16, or 32-bit microprocessor or microcontrollers. The ShortStack API and driver typically require about 4kbytes of program memory on the host processor and less than 200 bytes of RAM. The interface between host processor and the ShortStack Micro Server may be a Serial Communication Interface (SCI). The LonWorks control module with a high performance is developed, which is composed of the 8 bit PIC Microprocessor for host processor and the smart neuron chip for the ShortStack Micro Server. This intelligent control board is verified as proceeding the various function tests from experimental system with an boost pump and inverter driving systems. It is also confirmed that the developed control module provides stably 0-10VDC linear signal to the input signal of inverter driving system for varying the induction motor speed. Thus, the experimental results show that the fabricating intelligent board carried out very well the various functions in the wide operating ranges of boost pump system. This developed control module expect to apply to industrial fields to require the comparatively exact control and monitoring such as multi-motor driving system with inverter, variable air volume system and the boost pump water supply systems.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.291-292
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• 2010

The main purpose of this study is to design and develop the grid connected 4kW photovoltatic PCS(Power Conditioning System) targeting for Japanese market. To make this task, the development of DC to DC converter, one phase inverter and EMI filters, and the research on connection between inverter and utility line are made. The developed 4kW PCS has fully carried out performance verifications and evaluation works and acquired the JET(Japan Electrical Safety & Environment Technology Laboratories) certification for safety and performance.

• Journal of information and communication convergence engineering
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• v.11 no.3
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• pp.167-172
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• 2013

Recently, mobile communication systems are suffering from exponentially increasing data traffic. As a promising solution to the increase in data traffic, a coordinated multi-point transmission and reception (CoMP) scheme has been proposed. Although a great deal of research has been done on this new technology, the performance of mobile communication systems with CoMP has not been evaluated properly in a typical indoor environment. To address this, we have developed a system-level simulator and evaluated the performance of mobile communication systems with CoMP. Unlike previous works, we have used an actual antenna pattern in our simulator and link-level results are properly taken into account through link-level abstraction. By using a system-level simulator, we have evaluated the performance of mobile communication systems with CoMP in an indoor environment and found that unlike an outdoor cellular environment, CoMP may not improve the performance of overall mobile communication systems in an indoor environment.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.25-28
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• 1996

Recently, AC variable-speed motors are used for many steel rolling mill drive systems, because of their low maintenance and enhanced control performance. We have been applied GTO inverters for these AC motor drive systems since 1993. We have developed world largest 6-inch diameter GTO and large capacity 3-level GTO inverter up to 20000(kVA). As an example, in this paper, we describe the main circuit, system arrangement and control features of the 6-inches GTO inverters to drive rougher mills for hot strip mill of Pohang Iron & Steel Co., Ltd. The motor capacity is 6000(kW), and it's overload is 250(%).

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1065-1070
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• 2008

The evaluation of dredging works of pump dredger considering soil conditions is a main idea in calculating construction costs in non-cohesive soil layers. For using pump dredger, on effects of pump dredger equipment, some data of overseas code for pump dredger are different to those of results and a pump dredging capability table in the field of costs. In this study, considerations of sandy soils are described for application of construction works.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.1
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• pp.114-119
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• 2016

The necessity of IoT(Internet of Things) and Multimedia CSCW is described, and error control for multimedia CSCW(Computer Supported Cooperated Works) based on CoAP stack is suggested. This paper describes an error synchronization running on gateway software stack based CoAP. This system consists of an CS_EDA, and CS_ESA. CS_EDA is an agent that detects an error for multimedia distance system based on gateway software stack based CoAP environment. CS_ESA is an agent that is an error synchronization system for multimedia distance control based on gateway software stack based CoAP environment. From the perspective of multimedia collaborative environment of gateway software stack based CoAP, an error application becomes another interactive presentation error is synchronized with participants engaged in a cooperative work.

• Resources Recycling
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• v.22 no.1
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• pp.36-41
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• 2013

LF slag is formed by EAF carryover slag and slag former(such as lime, dolomite) put into the ladle during the tapping molten metal. After LF process, continuous casting is started when molten steel is sent from ladle to tundish through bottom nozzle of ladle. Conventionally, remained molten slag and steel in ladle are poured into a slag port and they are transferred to a slag yard and then recycled. In this study, we investigated about recycling of molten LF slag residue(including Fe residue to reuse) which is made in steelmaking process. As a result, lime usage was decreased about 2.2~3.2 kg/steel-ton and also molten steel yield rate was increased about 0.3 ~ 0.5 percent point.

• Korean Journal of Optics and Photonics
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• v.32 no.5
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• pp.230-234
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• 2021

Relief of thermal stress has received great attention, to improve the beam quality and stability of high-power laser diodes. In this paper, we investigate a microtrench structure engraved around a laser-diode chip-on-submount (CoS) to relieve the thermal stress on a laser-diode bar (LD-bar), using the SolidWorks® software. First, we systematically analyze the thermal stress on the LD-bar CoS with a metal heat-sink holder, and then derive an optimal design for thermal stress relief according to the change in microtrench depth. The thermal stress of the front part of the LD-bar CoS, which is the main cause of the "smile effect", is reduced to about 1/5 of that without the microtrench structure, while maintaining the thermal resistance.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.471-478
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• 2012

A carbon capture and storage (CCS) plays a very important role to reduce $CO_2$ dramatically in $CO_2$ emission sources which are distributed throughout various areas. Numerous research works have been undertaken to analyze the techno-economic feasibility of planning the CCS infrastructure. However, uncertainties such as $CO_2$ emissions, $CO_2$ reduction costs, and carbon taxes may exist in various impact factors of the CCS infrastructure. However, few research works have adopted these uncertainties in designing the CCS infrastructure. In this study, a two-stage stochastic programming model is developed for planning the CCS infrastructure under uncertain operating costs and carbon taxes. It can help determine where and how much $CO_2$ to capture, store or transport for the purpose of minimizing the total annual $CO_2$ reduction cost in handling the uncertainties while meeting the $CO_2$ mitigation target. The capability of the proposed model to provide correct decisions despite changing the operating costs and carbon taxes is tested by applying it to a real case study based on Korea. The results will help to determine planning of a CCS infrastructure under uncertain environments.