• 제어로봇시스템학회논문지
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• 제10권2호
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• pp.112-124
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• 2004

A neural network based adaptive reconfigurable flight controller is presented for a class of discrete-time nonlinear flight systems in the presence of variations of aerodynamic coefficients and control effectiveness decrease caused by control surface damage. The proposed adaptive nonlinear controller is developed making use of the backstepping technique for the angle of attack, sideslip angle, and bank angle command following without two time separation assumption. Feedforward multilayer neural networks are implemented to guarantee reconfigurability for control surface damage as well as robustness to the aerodynamic uncertainties. The main feature of the proposed controller is that the adaptive controller is developed under the assumption that all of the nonlinear functions of the discrete-time flight system are not known accurately, whereas most previous works on flight system applications even in continuous time assume that only the nonlinear functions of fast dynamics are unknown. Neural networks learn through the recursive weight update rules that are derived from the discrete-time version of Lyapunov control theory. The boundness of the error states and neural networks weight estimation errors is also investigated by the discrete-time Lyapunov derivatives analysis. To show the effectiveness of the proposed control law, the approach is i]lustrated by applying to the nonlinear dynamic model of the high performance aircraft.

• 디지털융복합연구
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• 제11권2호
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• pp.159-165
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• 2013

K-IFRS 도입과 함께 기업 환경에 변화가 발생하는 상황에 대한 사례연구는 회계기준이 나아가야 할 방향성을 제시한다는 의의를 갖는다. 회계처리기준 변경에 따라 기업의 성과수치에 큰 차이를 보일 수 있으며 이는 실제 비즈니스에 큰 영향을 미칠 수도 있다. K-IFRS는 원칙중심의(Principle-Based) 회계처리기준이기 때문에, 필요적 규정에 대한 명시적 언급이 없는 경우가 많다. 따라서, 예전에 비해 회사 내부적으로 K-IFRS에 대한 대비가 철저히 이루어지지 않는다면, 상당한 애로사항이 발생할 수 있다. 이에 따른 A은행의 회계정책 및 대손충당금 설정시스템을 통한 대응방안을 살펴봄으로써 향후 K-IFRS 도입에 대응하여 기업 스스로가 혁신할 수 있는 방향성을 제시할 수 있었다.

• 제어로봇시스템학회논문지
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• 제21권6호
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• pp.589-594
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• 2015

In this paper, we described the Cramer-Rao Lower Bound (CLRB) performances of Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) methods when there are multiple emitters. The TDOA and FDOA values between two receivers can be simultaneously estimated by using the so-called Complex Ambiguity Function (CAF). In the case of multiple emitters, there exist Inter Symbol Interferences (ISIs) in the measurement data. Therefore, it is required to reduce the effect of ISI and provide a performance evaluation method of TDOA and FDOA estimations. In order to eliminate the ISIs, using of a filter bank before calculating CAF is proposed when the carrier frequencies of the emitters are different to one another. Angle of Arrival (AOA) or Received Signal Strength (RSS) methods before calculating CAF were proposed to reduce the ISIs when the carrier frequencies are the same. In order to evaluate the CRLB of TDOA and FDOA estimations, we employed the conditional probability distribution method and described the numerical comparison results.

• The Journal of Asian Finance, Economics and Business
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• 제6권3호
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• pp.235-245
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• 2019

This research focuses on the relationships among customer satisfaction, delight, and loyalty. Although customer delight is one facet of an affective evaluation that can be predicted from customer satisfaction as cognitive component of the evaluation, there is no empirical examination on the casual relationship among customer satisfaction, delight, and loyalty. This study aims at addressing this gap in the service literature. The research questions are (1) How is customer satisfaction related to customer delight? and (2) Does customer delight matter in the relationship between customer satisfaction and loyalty? Data from a survey of consumers across upscale restaurant and retail bank in Korea were obtained. Our results show that customer satisfaction contributes positively to customer delight, and that customer delight plays a significant role in the relationship between customer satisfaction and loyalty. This chained relationship from customer satisfaction to customer delight to customer loyalty suggests that achieving customer delight represents one of the underlying pathways through which basic or core requirements expected by customers are satisfied. Our finding suggests that service firms need to monitor and manage their levels of customer delight as a performance metric, and delighting customers may be an important strategy to build competitive advantage through customer loyalty.

• 한국항해항만학회지
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• 제44권5호
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• pp.414-422
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• 2020

In this study, an empirical analysis of 55 ship finance cases executed by a specific ship finance bank from 2009 to 2016 during the recession period was conducted. The purpose of this study was to find the factors affecting changes in the debt performance of Korean shipping companies. The main factors were the loan nature (investment purpose, loan-to-value (LTV), syndicated loans, loan terms, put-option, balloon, and spread), financial nature (total assets turnover, net profit-to-sales ratio, debt ratio, quick ratio, total borrowing, bonds payable to total assets, interest expenses-to-sales ratio, debt service coverage ratio (DSCR), and total assets), and the company nature (company age, chief executive officer's (CEO's) shares, and listing status). In this study, the factors affecting the debt repayment capability of domestic shipping companies (loan nature, financial nature, and company nature) were verified. The credit rating was used to measure the dependent variable, debt repayment ability. The variables of investment purpose, put-option, balloon, and spread in the loan nature, debt ratio in the financial nature, and the CEO's shares and company age in the company nature were found to be significant.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.881-885
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• 2002

This paper presents the performance and the algorithm of a 1/3-octave band spectrum control system. The system is developed to provide various spectrums in a high intensity acoustic chamber. The required spectrum, which usually comes from launch vehicle company, starts from 25Hz band and ends 10kHz band. Automatic spectrum control system is preferred since the system requires short settling time to guarantee the safety of test objects and to reduce the amount of operating gas. The developed system adapted a PCI data-acquisition/signal-generation board installed in a personal computer to implement whole control logic. The control software used three cascade digital Butterworth filters using software. The filers are designed following ANSI S1.11 standard to implement 1/3 octave band filter bank. The graphical user interface of the system guides the user to follow standard operation procedure. The averaged control spectrum showed less than 0.05 dB in every running 1/3-octave band.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.560-565
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• 1997

DNA fragment assembly is a major concem in shot-gun DNA sequencing project. It is to reconstruct a consensus DNA sequence from a collection of random oritented fragments. We developed a computer program that is useful for DNA fragment assembly. Inputs to the program are DNA fragment sequences including IUB-IUPAC bases. The program produces the most probable reconstruction ot the original DNA sequence as a text format or a PostScript format. The program consists of four phases: the first phase quickly eliminates fragment pairs that can not possibly overlap. In the second phase, the quality of overlap between each pair is calculated to a score. In the third phase, overlap pairs are sorted by their scores and consistency of the overlaps is checked. The last phase determines consensus sequences and displays them. The performance of fragment assembly program was tested on a set of DNA fragment sequences which were generated from long DNA sequences of GenBank by a fragmentation program.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1511-1518
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• 2017

Renewable energy hybrid systems look into the process of choosing the finest arrangement of components and their sizing with suitable operation approach to deliver effective, consistent and cost effective energy source. This paper presents hybrid renewable energy system (HRES) solar photovoltaic, downdraft biomass gasifier, and fuel cell based generation system. HRES electrical power to supply the electrical load demand of academic research building sited in $23^{\circ}12^{\prime}N$ latitude and $77^{\circ}24^{\prime}E$ longitude, India. Fuzzy logic programming discover the most effective capital and replacement value on components of HRES. The cause regarding fuzzy logic rule usage on HOMER pro (Hybrid optimization model for multiple energy resources) software program finds the optimum performance of HRES. HRES is designed as well as simulated to average energy demand 56.52 kWh/day with a peak energy demand 4.4 kW. The results shows the fuel cell and battery bank are the most significant modules of the HRES to meet load demand at late night and early morning hours. The total power generation of HRES is 23,794 kWh/year to the supply of the load demand is 20,631 kWh/year with 0% capacity shortage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.551-553
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• 2002

The cubicle type GIS rated at 25.8kV has been designed and manufactured by Jinkwang E&C eacently with their own technologies and KERI's assistances. The C-GIS has been tested to check the design capability for reference before conducting the type test. The operating characteristics test, short time withstand current and peak withstand current test, basic short circuit test duty T60 for preconditioning test, cable charging current switching test, capacitor bank current switching test, basic short circuit test duty T100s and T100a, single phase earth fault test, double earth fault test has been conducted. The test results show that the design and the manufacturing of the C-GIS has an enough capability to pass through the type test except the occurrence of 2 NSDDs in the cable charging current switching test and the instability of opening time at the minimum operating voltage. The problems shown in the tests will be improved soon and the successful pass will be expected in the following type test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.361-363
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• 2005

본 논문에서는 MPEG-4 Version2 Audio 표준에 근거하여 낮은 연산부담을 갖는 독자적인 엘고리즘을 적용한 MPEG-4 BSAC Audio 디코더를 개발하였다. 개발된 BSAC 디코더는 32bit RISC 구조를 갖는 Intel Xscale Processor 기반 시스템에 최적화하여 구현 및 평가를 수행하였다. 수행속도 증가 및 연산 정밀도 향상을 위해 각 기능 블록별 기능 및 구현 원리 연구와 32 bit 연산 구조를 파악하여, 이를 고정소수점 연산 구조로 구현함으로써 성능을 향상시켰다. 유한비트에 따른 오차 영향을 최소화하기 위해 데이터의 표현 범위에 대한 연구를 통해 근사한 오차를 최소화 하여 연산 정밀도를 향상 시키고자 하였다. 비선형 양자화기 및 filter bank 등 상대적으로 높은 연산 부담을 갖는 기능 블록은 Table look-up, 보간법, 지수연산 제거, pre/post scrambling 기법 등을 적용하여 최적화 하였다. 최종적으로 개발된 BSAC 디코더는 32 bit 연산 구조의 X-scale 프로세서를 탑재한 Development Board와 WindowsCE OS로 구성된 타겟 system에 이식하여 performance 평가하였으며, 높은 연산 정밀도 및 다른 수행속도를 확인할 수 있었다. 주관적인 청각 평가에서도 MPEG-4 reference 디코더와의 음원의 차이가 거의 없음을 확인하였다.