• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.107-116
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• 2009

Quantum-dot Cellular Automata (QCA) is one of the most promising next generation nanoelectronic devices which will inherit the throne of CMOS which is the domineering implementation technology for large scale low power digital systems. In late 1990s, the basic operations of the QCA cell were already demonstrated on a hardware implementation. Also, design tools and simulators were developed. Nevertheless, its design technology is not quite ready for ultra large scale designs. This paper proposes a new approach which enables the QCA designs to inherit the verification methodologies and tools of CMOS designs, as well. First, a set of disciplinary rules strictly restrict the cell arrangement not to deviate from the predefined structures but to guarantee the deterministic digital behaviors is proposed. After the gate and interconnect structures of. the QCA design are identified, the signal integrity requirements including the input path balancing of majority gates, and the prevention of the noise amplification are checked. And then the digital logic is extracted and stored in the OpenAccess common engineering database which provides a connection to a large pool of CMOS design verification tools. Towards validating the proposed approach, we designed a 2-bit adder, a bit-serial adder, and an ALU bit-slice. For each design, the digital logic is extracted, translated into the Verilog net list, and then simulated using a commercial software.

• Journal of Animal Environmental Science
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• v.8 no.3
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• pp.199-208
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• 2002

This paper introduces the method to make management network about milking cow farm tasks. The object of this research was to design of biological measuring system and managing network system in a livestock farm. This auto-management system provides informations about individual cows' temperature, conductivity of milk and weight for efficient management of feeding, and milking works by a micro-processor and RS -485 type serial COM. ports. And measured bio-data which are basic informations for remote raising management are saved to user PC by serial communication between the PLC and user PC. Milking cow farm is divided into three working place to each measurement work and feed. The first working place is milking station which has two thermometers, a conduct meter and a scale set. The second working place is feeding station, and the third place is cattle cage. These are combined by network system and the PLC which is used to drive network and sub-modules. Sub-modules have a micro-process to control the sensor and to interface with network. The PLC which drive network and control sequence has two serial communication port to be linked with user PC for sending the measured data and for receiving data. Above all, in this study tells the sequence operating method by the driving scenario of breeding milk cow for livestock auto-management using the PLC and network system.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.271-278
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• 2017

Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants. Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain garden systems having different characteristics were developed and evaluated to determine the optimum design and arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover, the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research will help in the further development and optimization of rain garden systems.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.15-23
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• 2000

RC oscillation method was applied to study the condenser characteristics of two metal sticks insulated by vinyl tube and used in the dielectric constant determinations of most soils. Its capacitance as influenced by the contacted ambient materials was measured as relative capacitance of the sensor sticks compared with the standard one on the RC oscillation circuit. According to the equivalent circuit of the sensor stick set, the measured capacitance was composed of a basic capacitance connected in parallel with sensor stick capacitance, which was composed of lineally connected vinyl tube capacitances and the sensing part capacitance. The dielectric constant (U) of the contacted ambient moist soil located in the sensing part around the sticks interrelated with the other parameters as following equation. $$\frac{1}{C-B}=\frac{k}{U}+Z$$ where C is the output total relative capacitance, B is the hidden and fixed basic relative capacitance, k is a constant related with U, and Z is a constant for the insulating vinyl tube capacitances determined by its thickness and dielectric constant. The constant k is determined by the spacing and length of sensor sticks. The Z value is theoretically an invariable constant, but it may become considerably bigger than the determined in lab if air tube is formed on the surface of sensor sticks by some shocks on them after their installation in soil. Due to the unstability of lab Z value, it may be better to revise it after sensor stick's installation in soil and no shaking shocks should be applied on them.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.113-120
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• 2006

Wastewater generated through the food waste recycling process have known high concentration, BOD 20,000~150,000 mg/L, which has to treat to the proper level because of a ban on reclamation. But it is impossible to treat less than 10 days by existing water treatment plant. Ecodays Ltd. is to treat this wastewater during 2~4 days by ER-1, which can simultaneously induce the modified PFR(Plug Flow Reactor) of the oxygen transfer rate, MLVSS concentration, and influent concentration to top from bottom of reactor. We tested the pilot test about low concentration food wastewater(BOD 16,500 mg/L) and high concentration food wastewater(64,431 mg/L) at the food waste recycling plant of H-Gun(20t/d). Hydraulic retention time(HRT) of ER-1 for low concentration food wastewater is 2.5day. In low concentration conditions, ER-1 treatment efficiency is to appear BOD 99%, COD 98%, TN 97%, and TP 96%. While ER-1 process for high concentration food wastewater treatment is composed 2 stages, which are to be HRT 2.5day for law wastewater and HRT 1.5 day for secondary treatment. In high concentration conditions, ER-1 treatment efficiency is to appear BOD 97%, COD 84%, TN 66%, and TP 95%. It is treated without temperature control about high temperature($50^{\circ}C$) to appear low treatment efficiency in high concentration conditions.