• Resources Recycling
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• v.28 no.1
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• pp.23-31
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• 2019

Cementation is one of economical and efficient recycling method precipitating the metal ion in solution by adding another active metal. In this study for optimizing cadmium recovery efficiency, it was performed as a function of the effect of pH, temperature, particle size, and input amount of zinc in 0.1 M $CdSO_4$ solution and Ni-Cd battery leaching solutions, respectively. The particle size of zinc and temperature were key factors for Cd cementation and it was confirmed that the input amount of 2.6 of Zn/Cd ratio using granular-type zinc was optimal condition for selective Cd recovery efficiency at $25^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.2
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• pp.61-67
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• 2022

A metal salt solution was prepared from valuable metals (Ni, Co, Mn) recovered from a scrap of waste lithium secondary batteries, and an NCM811 precursor was synthesized from the solution. The effect on precursor formation according to reaction time was confirmed by SEM, PSA, and ICP analysis. Based on the analysis results, the electrochemical properties of the synthesized NCM811 precursor and the commercial NCM811 precursor were investigated. The Galvano charge-discharge cycle, rate performance, and Cycle performance were compared, and as a result, there was no significant difference from commercial precursors.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.443-448
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• 1997

The intelligent software system for nuclear power plants (NPPs) has been conceptually designed in this study. Its design goals are to operate NPPs in n improved manner and to support operators' cognitive tasks. It consists of six major modules such as "Information Processing," "Alarm Processing," "Procedure Tracking," "Performance Diagnosis," and "Event Diagnosis" modules for operators and "Malfunction Diagnosis" module for maintenance personnel. Most of the modules have been developed for several years and the others are under development. After the completion of development, they will be combined into one system that would be main parts of advanced control rooms in NPPs. that would be main parts of advanced control rooms in NPPs.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.79-82
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• 1995

The problem of temperature control for rapid thermal processing (RTP) in semiconductor manufacturing is discussed in this paper. Among sub=micron technologies for VLSI devices, reducing the junction depth of doped region is of great importance. This paper investigates existing methods for manufacturing wafers, focusing on the RPT which is considered to be good for formation of shallow junctions and performs the wafer fabrication operation in a single chamber of annealing, oxidation, chemical vapor deposition, etc., within a few minutes. In RTP for semiconductor manufacturing, accurate and uniform control of the wafer temperature is essential. In this paper, a robustr controller is designed using a recently developed optimization technique. The controller designed is then tested via computer simulation and compared with the other results.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.6
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• pp.391-402
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• 2015

In this paper, we present implementation of backward movement control of truck-trailer vehicles using a fuzzy mode-based control scheme considering practical constraints and computational overhead. We propose a fuzzy feedback controller where output is predicted with the delay of a unit sampling period. Analysis and design of the proposed controller is very easy, because it is synchronized with sampling time. Stability analysis is also possible when quantization exists in the implementation of fuzzy control architectures, and we show that if the trivial solution of the fuzzy control system without quantization is asymptotically stable, then the solutions of the fuzzy control system with quantization are uniformly ultimately bounded. Experimental results using a toy truck show that the proposed control system outperforms a conventional system.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.3
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• pp.128-134
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• 2014

A real-time, continuous-scale image interpolation method is proposed based on a bilinear interpolation with directionally adaptive low-pass filtering. The proposed algorithm was optimized for hardware implementation. The ordinary bi-linear interpolation method has blocking artifacts. The proposed algorithm solves this problem using directionally adaptive low-pass filtering. The algorithm can also solve the severe blurring problem by selectively choosing low-pass filter coefficients. Therefore, the proposed interpolation algorithm can realize a high-quality image scaler for a range of imaging systems, such as digital cameras, CCTV and digital flat panel displays.

• Annual Conference of KIPS
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• 2009.04a
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• pp.50-52
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• 2009

Ontology maintenance is a time consuming and costly process which requires special skill and knowledge. It requires joint effort of both ontology engineer and domain specialist to properly maintain ontology and update knowledge in it. This is specially true for medical domain which is highly specialized domain. This paper proposes a novel approach for maintenance and update of existing ontologies in a medical domain. The proposed approach is based on modified Ontology Maturing Process which was originally developed for web domain. The proposed approach provides way to populate medical ontology with new knowledge obtained from medical documents. This is achieved through use of natural language processing techniques and highly specialized medical knowledge bases such as Unified Medical Language System.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.10
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• pp.477-482
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• 2016

As being the advanced analytics indispensable on big data for agile decision-making and tactical planning in enterprises, distributed processing platforms, such as Hadoop and Spark which distribute and handle the large volume of data on multiple nodes, receive great attention in the field. In Spark platform stack, Spark SQL unveiled recently to make Spark able to support distributed processing framework based on SQL. However, Spark SQL cannot effectively handle advanced analytics that involves machine learning and graph processing in terms of iterative tasks and task allocations. Motivated by these issues, this paper proposes the design of SQL-based big data optimal processing engine and processing framework to support advanced analytics in Spark environments. Big data optimal processing engines copes with complex SQL queries that involves multiple parameters and join, aggregation and sorting operations in distributed/parallel manner and the proposing framework optimizes machine learning process in terms of relational operations.

• Journal of Powder Materials
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• v.21 no.4
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• pp.294-300
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• 2014

The connecting rod is one of the most important parts in automotive engines, transforming the reciprocal motion of a piston generated by internal combustion into the rotational motion of a crankshaft. Recent advances in high performance automobile engines demand corresponding technological breakthroughs in the materials for engine parts. In the present research, the powder metallurgy (P/M) process was used to replace conventional quenching and/or tempering processes for mass production and ultimately for more cost-efficient manufacturing of high strength connecting rods. The development of P/M alloy powder was undertaken not only to achieve the improvement in mechanical properties, but also to enhance the machinability of the P/M processed connecting rods. Specifically $MoS_2$ powders were added as lubricants to non-normalizing Fe-Cr-Mn-V-C alloy powder to improve the post-sintering machinability. The effects of $MoS_2$ addition on the microstructure, mechanical properties, and machining characteristics were investigated.

• Journal of Powder Materials
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• v.19 no.6
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• pp.405-411
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• 2012

Recovery of copper powder from copper chloride solution used in $MoO_3$ leaching process was carried out using a cementation method. Cementation is a simple and economical process, necessitating less energy compared with other recovery methods. Cementation utilizes significant difference in standard reduction potential between copper and iron under standard condition. In the present research, Cementation process variables of temperature, time, and added amount of iron scraps were optimized by using design of experiment method and individual effects on yield and efficiency of copper powder recovery were investigated using bench-scale cementation reaction system. Copper powders thus obtained from cementation process were further characterized using various analytical tools such as XRF, SEM-EDS and laser diffraction and scattering methods. Cementation process necessitated further purification of recovered copper powders and centrifugal separation method was employed, which successfully yielded copper powders of more than 99.65% purity and average $1{\mu}m$ in size.