• KSBB Journal
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• v.5 no.3
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• pp.279-291
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• 1990

Partial hydrolysed and deacetylated chitin, CHITA and CHITB as supports of immobilized enzyme were obtained by treatment of acid and base respectively. Glutaraldehyde, bifunctional reagent, was employed for crosslinking between $\beta$-glucosidase and support. Immobilized enzyme activities of CHITA-Gase and CHITB-Gase were determined with the reaction of p-nitrophenol-$\beta$-D-glucopyranoside(PNG) in batch reactor, CSTR and PFR. Their optimum temperature, pH and enzymatic characteristics including Km and Vmax values were observed with variation of the flow rates. Mass transfer coefficient(h), effectiveness factor(η), deactivation rate(kd ) of two immobilized enzymes were also examined to compare efficiency of reactors.

• Food Science and Preservation
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• v.11 no.2
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• pp.269-275
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• 2004

This study was conducted to develop an optimization model using Box's Complex Algorithm, and to determine optimum operating conditions to minimize costs for the drying and storage system using the grain cooler. To minimize the system operation cost, the optimum moisture contents after the first drying were found to be from 17.2 to 19.8 %. And optimum drying and cooling capacities were obtained. The combination of the dryer and grain cooler was found to be economical, showing enhancement of the drying capacity over 50%, and decrease of drying cost over 10%. When the circulating grain dryers of 6 and 20 ton/batch were used in conjunction with the grain cooler, the cost required for drying and storage system for paddy were 28,464∼33,317won/ton and 20,588∼26,511 won/ton, respectively, which was from 2.6 to 27.3% lower than that of conventional drying and storage system.

• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.91-98
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• 2010

Advances in communications and control technology, the strengthening of the Internet, and the growing recognition of the urgency to reduce the risk and production cost are motivating the development of improvements in the traditional manufacturing industry. In this paper, we developed a remote dust collector bag control system which is a combination of advanced IT and traditional dust collector based on the event. At first, we made the A/D(Analog/Digital) converter using a micro processor because the differential pressure transmission, which is a sensor of the dust collector, produces analog volt data. A/D converter can provide RS-232 communication to connect with Power Line Communication(PLC) modem. And, n-bytes message format was defined for the efficient dust collector bag information transmission from a dust collector to a user. Also, we designed the data types to model the dust collector and the dust collector bag, and they were logically modeled using XML and object-oriented modeling method. In addition to that, we implemented the system for showing the dust collector bag exchange time exactly to users at real-time using various visual user interfaces.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.3
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• pp.186-192
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• 2009

PID controllers are simple in structure and easy for implementation. However, they may produce large overshoots and over-oscillatory responses. Combining PID control with other control techniques often results in advanced hybrid schemes that are able to improve pure PID controllers. This paper proposes hybrid controller for position control system of servo motor. The proposed controller is composed of a subcontroller and a parallel PID controller. The subcontroller improves the transient system performance while the PID controller is mainly responsible for the steady-state system performance. A very promising advantage of this hybrid scheme, in terms of controller synthesis, is that the subcontrollers and controller components can be designed separately. Systematic design methods for various controller components are developed. The proposed hybrid scheme is applied to a DC motor position servo system. The effectiveness of the proposed controller is verified through the computer simulation results.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.102-109
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• 2014

In this paper, an algorithm to design fuzzy PID controllers is proposed. The proposed controllers are composed of fuzzy rules of which consequences are linear PID controllers and are designed with help of TSK fuzzy controllers. TSK fuzzy controllers are designed from TSK fuzzy model using pole assignment and have outstanding ability making the output response of nonlinear systems similar to the desired one. However, because of its structure complexity the TSK fuzzy controller is difficult to be used in industry. The proposed controllers have PID controller structure which can be easily realized, and are designed by using the data obtained from control simulations with TSK fuzzy controllers. To verify the proposed algorithm, two example simulations are performed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1188-1193
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• 2004

So far, there have been grossly 3 types of studies on GF(2m) multiplier architecture, such as serial multiplication, array multiplication, and hybrid multiplication. Serial multiplication method was first suggested by Mastrovito (1), to be known as the basic CF(2m) multiplication architecture, and this method was adopted in the array multiplier (2), consuming m times as much resource in parallel to extract m times of speed. In 1999, Paar studied further to get the benefit of both architecture, presenting the hybrid multiplication architecture (3). However, the hybrid architecture has defect that only complex ordo. of finite field should be used. In this paper, we propose a novel approach on developing serial multiplier architecture based on Mastrovito's, by modifying the numerical formula of the polynomial-basis serial multiplication. The proposed multiplier architecture was described and implemented in HDL so that the novel architecture was simulated and verified in the level of hardware as well as software. The implemented GF(2m) multiplier shows t times as fast as the traditional one, if we modularized the numerical expression by t number of parts.

• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.1-13
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• 2017

This study aims to identify the warm and cold periods(WP, CP) of November appeared in the daily normals of daily minimum temperature of Seoul for 1941~1970 and 1971~2000 and to investigate synoptic characteristics of the temperature changes of WP and CP. The WP temperatures are increased clearly(p value 0.000), the CP temperatures are also warming but not significant statistically. In WP, there are not apparent trends corresponding the warming of WP temperature, in the Siberian High, Sea Level Pressure(SLP), 925hPa surface wind(U925, V925) around the Korean peninsula. In high period(1972~1979) of WP temperature, there are positive SLP anomaly and anomalous anticyclonic circulation pattern of 925hPa wind field over the Korean peninsula then the winter monsoon is weakened and the WP temperature is ascending. In CP, the Siberian high are weakening, the Hokkaido eastern low are strengthening and the westerlies(U925) over the Korean Peninsula are enlarging. So CP temperature are suppressed in rising trend or shows weak descent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.620-625
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• 2003

The coplanar waveguide bandpass filter using folded-line stepped-impedance resonators(SIRs) is proposed. The folded-line SIR has about λ/8 length using the short-circuited end on coplanar waveguide. It make that the bandpass filter has the half size in comparison with general λ/4 SIR filter. In this paper, we derive the equivalent circuit and design the bandpass filter by using that. We design and fabricate the bandpass filter which has 5 GHz center frequency and 3 % fractional bandwidth. The measurement results fur 4-pole folded SIR bandpass filter agreed well with full-wave simulation and equivalent circuit results. The fabricated bandpass filter has a good spurious characteristic, which the harmonic frequency appeared at 2.5f$\_$0/). The proposed folded-line SIR bandpass filter are applicable for MMIC and High-Tc superconducting filters. bandwidth.

• Journal of the Korean School Mathematics Society
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• v.21 no.3
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• pp.227-245
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• 2018

Debates of calculators in mathematics lessons sometimes have happened in both countries that students rarely use calculators in math lessons including Republic of Korea and countries that students usually use calculators in math lessons. Korea has tried to activate usage of calculators in math lessons as the revision of national math curriculums and the development the strategies to support schools and math teachers. On the other hand, Singapore has the different educational strategies to use calculators in math lessons, but students have higher math achievements in TIMSS and interests in math lessons than Korea. This study intended to study the difference between Korea and Singapore on the usage of calculators in math lessons. To accomplish this, the study compared math curriculums of two countries on the usage of calculators and analysed TIMSS 2015 related with the survey items about calculators in math lessons. This study results in some suggestions that we should do in oder to use calculators in math lessons effectively.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.75-75
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• 2017

3륜 승용관리기는 4륜 승용관리기에 비하여 작업기를 복부에 장착함으로 작업의 정밀도, 편이성, 관측의 용이성 향상과 함께 지상고 제고, 차폭 조절, 조향 등의 성능 개선을 기할 수 있다. 국내에서는 3륜 승용관리기용 복부 장착 부속작업기가 거의 개발되어 있지 않으며, 특히 두류 재배에 있어서 일관기계화 작업을 위한 관리작업기의 개발이 매우 필요한 실정이다. 콩의 순 지르기 작업은 콩이 지나친 생육을 한 경우 미리 줄기의 윗부분을 제거하는 저심처리를 해주면 곁가지들의 왕성한 생육을 유도하여 많은 꼬투리를 얻고 쓰러짐도 줄어들어 수량을 높일 수 있다. 순 지르기 작업은 보통 낫이나 배부식 예취기를 이용하여 작업함으로 노동력이 많이 들고 작업부담이 심하여 개선이 필요한 실정이다. 따라서 본 연구는 3륜 승용관리기에 적합한 복부장착형의 순 지르기 작업기를 설계 제작하였다. 3륜 승용관리기용 순 지르기 작업기는 승용관리기의 복부 PTO에서의 구동력 전달을 위한 연결 조인트, 중간축, 기어 전동기구, 구동축으로 구성된 동력전달부, 2 조의 원판형 작업 날, 다양한 조간거리에 적응을 위한 조간조정 나사부, 3륜 승용관리기에의 부착을 위한 프레임 및 부착보조 작업기 이동용 바퀴장치 등으로 구성 설계 제작하였다. 원판형 칼날은 시판 중인 예취기의 외경 305 mm, 칼날 톱니 수 90개의 초경 비트 부착 날을 사용하였다. 작업 날의 승강높이는 150~540 mm 범위로 조절하도록 하였다. 조간거리의 조절범위는 수동나사에 의하여 660~860 mm 범위로 무단조절 할 수 있도록 하였다. 순 지르기 작업기는 3륜 승용 관리기 복부의 평행링크에 부착되므로 작업기의 이동 및 부착 편이를 위하여 이동용 바퀴를 설치하였다. 제작된 순 지르기 작업기의 크기는 길이${\times}$폭${\times}$높이가 $514{\times}1138{\times}810mm$, 중량은 약 100 kg으로 제작되었다.