• Journal of Korea Port Economic Association
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• v.26 no.3
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• pp.18-41
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• 2010

The purpose of this paper is to show the empirical measurement way for predicting the seaport efficiency by using Super SBM(Slack-based Measure) with Wilcoxson signed-rank test under CRS(constant returns to scale) condition for 20 Korean ports during 11 years(1997-2007) for 3 inputs(port investment amount, birthing capacity, and cargo handling capacity) and 5 outputs(Export and Import Quantity, Number of Ship Calls, Port Revenue, Customer Satisfaction Point for Port Service and Container Cargo Throughput). The main empirical results of this paper are as follows. First, Super SBM model has well reflected the real data according to the Wilcoxon signed rank test, because p values have exceeded the significance level. Second,Super-SBM has shown about 87% of predicting ratio for the ports efficiency and the optimal size of investment in domestic seaport. The policy implication to the Korean seaports and planner is that Korean seaports should introduce the new methods like Super-SBM method with Wilcoxon signed rank test for predicting the efficiency of port performance and the optimal size of investment as indicated by Panayides et al.(2009, pp.203-204).

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.1-14
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• 1998

In this paper, Antenna, LNA, Mixer, VCO, and Modulation/Demodulation in Baseband processor which are the RF main components in Wireless LAN system for ultra high-speed communications network are studied. Antenna bandwidth and selective fading due to multipath can be major obstacles in high speed digital communications. To solve this problem, wide band MSA which has loop-structure magnetic antenna characteristics is designed. Distributed mixer using dual-gate GaAs MESFET can achieve over 10dB LO/RF isolation without hybrid, and minimize circuit size. As linear mixing signal is produced, distortions can be decreased at baseband signals. Conversion gain is achieved by mixing and amplification simultaneously. Mixer is designed to have wide band characteristics using distributed amplifier. In VCO design, Oscillator design method by large signal analysis is used to produce stable signal. Modulation/Demodulation system in baseband processor, DS/SS technique which is robust against noise and interference is used to eliminate the effect of multipath propagation. DQPSK modulation technique with M-sequences for wideband PN spreading signals is adopted because of BER characteristic and high speed digital signal transmission.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.447-453
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• 2007

In this letter, we derive the Gallager random coding bound for discrete memoryless channels purely by simple manipulations of algebraic inequalities rather than invoking conceptually difficult random coding arguments. Gallager random coding bound is a very useful tool in information and coding theory due to its applicability to situations in which it is difficult to determine the decision regions and due to the fact that it can be used to derive the channel coding theorem. The readers will find it relatively easy to apply to many practical problems of interest the step-by-step algebraic derivations of the Gallager random coding bound with appropriate modifications.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.1
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• pp.1-5
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• 2011

In this paper, firstly we have derived and presented the specific heat jump as a function of the critical temperature. Secondly, we have analyzed the sign and magnitude of the derived specific heat jump and predicted the expected experimental results. And lastly, we have compared the expected experimental results with the real experimental results. Theoretically derived specific heat jump is considerably compatible with the specific heat jump up and down phenomena of the $YNi_2B_2C$ crystal. Especially, the remarkable theoretical prediction-hat the specific heat would jump down during the normal state-to-superconducting state transition at extremely low temperatures-have been confirmed by the experimental results.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.388-393
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• 2007

In designing transform coders bit allocation is one of the important issues. In this paper we propose two optimal algorithms for integer bit allocation in transform coding. Based on high-resolution formulas for bit allocation, the most and least greedy algorithms are developed to optimally adjust non-integer bit rates of coefficient quantizers to integer values. In particular, a duality property is observed between the two greedy algorithms.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.197-203
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• 2009

Finite field arithmetic is very important in the area of cryptographic applications and coding theory, and it is efficient to use normal bases in hardware implementation. Using the fact that $GF(2^{mk})$ having a type-I optimal normal basis becomes the extension field of $GF(2^m)$, we, in this paper, propose a new serial multiplier which reduce the critical XOR path delay of the best known Reyhani-Masoleh and Hasan's serial multiplier by 25% and the number of XOR gates of Kwon et al.'s multiplier by 2 based on the Reyhani-Masoleh and Hasan's serial multiplier for type-I optimal normal basis.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.63-66
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• 2004

본 논문에서는 채널간간섭 자기소거를 위한 부대역 부호화기법에 따른 직교 주파수분할다중화의 첨두전력대 평균전력비가 분석된다. 인접부대역에 대척신호를 할당하는 기존 상관부호화의 경우 전송신호열에서 형상성분이 발생되며, 이로 인하여 직교 주파수분할다중화 시스템의 첨두전력 대 평균전력비가 최대 3dB 가량 증가됨을 이론적$\cdot$실험적으로 검증한다. 그리고 이와 같은 형상성분을 제거할 수 있는 새로운 부대역 부호화기법이 제시된다. 여기서는 인접부대역에 할당되는 신호쌍의 위상차가 신호사상기의 출력에 따라 변화된다. 그 결과, 새로운 부대역 부호화기법이 적용된 시스템은 기존의 시스템보다 $2\~3dB$ 적은 첨두전력 대 평균전력비를 가지는 것을 확인할 수 있다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.821-826
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• 2012

p-ary sequences of period $N=2^k-1$ are widely used in many areas of engineering and sciences. Some well-known applications include coding theory, code-division multiple-access (CDMA) communications, and stream cipher systems. The analysis of cross-correlations of these sequences is a very important problem in p-ary sequences research. In this paper, we analyze cross-correlations of p-ary sequences which is associated with the equation $(x+1)^d=x^d+1$ over finite fields.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.438-441
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• 2000

In this paper, Turbo rode is describing a performance near the Shannon's channel capacity limit. So, basic theory of turbo code and MAP,Log-MAP decoding algorithm was arranged. The foundation of this using VHDL, Log-MAP turbodecoder was implemented by Altera´s FLEX10K CPLD.

• Proceedings of the Korea Society of Mathematical Education Conference
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• 2010.04a
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• pp.219-219
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• 2010

교육학의 질적 연구는 문헌 연구, 면담 연구, 비참여 관찰 연구, 참여 관찰 연구로 분류한다. 문헌연구에는 내용분석, 철학적 연구, 역사학적 연구, 문학적 비평이 들어가고, 면담연구에는 구술사, 전기, 탐문(探問) 저널리즘 등이 포함되고, 비참여 관찰연구에는 전문적 감정(鑑定), 인간의 종적 특성 연구, 관찰자 연구, 비개입적 행동 연구 등이 포함된다. 마지막으로 참여 관찰연구는 일반적 현장연구, 문화 기술적 연구가 포함된다. 질적 연구는 사람, 사물, 현상의 범주화나 수량화가 가해지기 이전의 상태, 즉 '있는 그대로'의 상태에 최대한 접근하는 방법으로써, 고정관념을 깨고 기존의 이론을 최대한 유보한 채 연구에 임하는 것으로 최근에 발달한 인문사회과학적 연구방법이다. 질적 인식이 자연언어에 주로 의존하는 데 비해 양적 인식은 인공언어에 많이 의존한다. 수식과 도형, 부호등은 대표적인 인공언어이다. 모든 사물이 질과 양의 속성을 다 가지고 있듯이 모든 연구는 질적 과정과 양적 과정을 다 포함하고 있다. 질적이냐, 양적이냐 하는 구분은 연구방법론의 문제인데 연구방법론은 연구논리와 연구기법을 포함한다. 본 연구는 인공언어인 수와 식에만 익숙한 수학교육에서, 질적 연구가 왜 필요한지, 어떤 특성이 있는지 논의함으로써 수학교육의 새로운 방법론을 제시하고자 한다.