Earticle

이 연구는 유화에서 손상된 부위를 식별하고 추출하는 데 있어 SIFT, ORB, AKAZE, BRIST의 네 가지 특징 감지 알고리즘의 효능을 비교합니다. 다양한 열화 현상을 특징으로 하는 600개의 유화 이미지 데이터 세트를 컴파일하고 전처리했습 니다. 성능 평가 지표에는 감지된 특징의 수, 일치 능력, 일치 비율, 일관성 및 실행 시간이 포함되었습니다. 그 결과 BRIXE는 특징 감지량과 일치 수에서 우수하지만 처리 시간이 증가하는 대가를 치렀습니다. AKAZE와 SIFT는 각각 25.3%와 25%로 가장 높은 일치 비율을 보여 고품질 특징 감지를 시사했습니다. ORB는 이미지 전 반에서 가장 일관된 성능을 보였으며 절대 일치 수에서 2위를 차지했습니다. 이 연 구에 따르면 알고리즘 선택은 특정 작업 요구 사항을 기반으로 해야 합니다: 철저 한 특징 감지를 위한 BRIST, 고품질 일치를 위한 AKAZE 또는 SIFT, 일관되고 효율적인 성능을 위한 ORB. 이 연구는 유화의 손상 평가를 위한 객관적인 방법을 제공하고 잠재적으로 복원 프로세스를 간소화하며 보존 노력의 자원 할당을 최적화 함으로써 예술 보존에 기여합니다.

This study compares the efficacy of four feature detection algorithms: SIFT, ORB, AKAZE, and BRIST in identifying and extracting damaged areas in emulsions. A dataset of 600 emulsified images featuring various deterioration phenomena was compiled and preprocessed. Performance evaluation metrics included the number of detected features, matching ability, matching rate, consistency, and execution time. The results showed that BRIXE was excellent in feature detection and matching number, but at the cost of increasing processing time. AKAZE and SIFT showed the highest matching rates, 25.3% and 25%, respectively, suggesting high-quality feature detection. ORB performed most consistently across images and ranked second in absolute matching number. According to this study, algorithm selection should be based on specific task requirements: BRIST for thorough feature detection, AKAZE or SIFT for high-quality matching, and ORB for consistent and efficient performance. This study contributes to art conservation by providing an objective method for the evaluation of damage in emulsions, potentially simplifying the restoration process, and optimizing the resource allocation of conservation efforts.

In this letter a new detection scheme combining the conventional Sphere decoders and best detection algorithm is proposed. This algorithm leverages the Sphere decoder (SD) results to use smaller values of in best algorithm to achieve better performance. Post best detection algorithm Darlington pairs of SD- SD, SD- SD, and -1 SD are used to get the final detection results. The proposed best detection algorithm finds out smallest paths by counting and sorting the bits of every candidate, which is much simpler as used in conventional sphere decoders. The computational complexity has been calculated in terms of time taken to visit the average number of K paths taken by Conventional SDs -SDs and Darlington pair of SDs. Extensive Monte Carlo simulations are used to demonstrate that the proposed approach exhibits significant performance gain over conventional SD schemes in terms of bit error rate and computational time. Besides, a complete analytical approach is provided to validate the simulation results.

To enhance the utilization of the traffic channels of a network (instead of allocating radio channel to an individual user), a channel or a group of channels are allocated to a user group. The idea behind this is the statistical distribution of traffic arrival rates and the service time for an individual user or a group of users. In this paper, we derive the blocking probability and throughput of a subscriber station of Worldwide Interoperability for Microwave Access (WiMAX) by considering both the connection level and packet-level traffic under a complete partition scheme. The main contribution of the paper is to incorporate the traffic shaping scheme onto the incoming turbulent traffic. Hence, we have also analyzed the impact of the drain rate of the buffer on the blocking probability and throughput.

잡음환경이 열악하고 대역폭이 부족한 HFC 망 상향채널에서 보다 나은 대칭형 멀티미디어 서비스를 제공할 수 있는 S-DMT 방식의 상향 채널 케이블모뎀을 위한 심볼 타이밍 복원 알고리즘을 제안하고 그에 대한 성능을 평가하였다. 타이밍 복원 알고리즘은 시간 영역에 PN 시퀀스를 삽입하는 방식을 제안하였으며 AWGN, ISI, 및 임펄스 잡음 환경에서 시뮬레이션을 통해 성능을 평가 하였다. 성능 평가 결과, PN 시퀀스 삽입 알고리즘에 의한 타이밍 복원방식은 잡음 환경에 따라 타이밍 추정 성능이 매우 달라지며, 동일한 샘플링 클럭 오프셋에서 AWGN, ISI, 및 임펄스 잡음이 함께 존재하는 채널일 경우가 임펄스 잡음 채널 경우보다 타이밍 실패 확률이 $10^3$일 때의 Eb/No가 10dB 이상 열화되나 초기부터 샘플링 클럭 오프셋을 보정하여 최적화한 경우 잡음환경에 의한 성능차이가 있으나 비교적 양호한 타이밍 추정 성능을 보임을 확인 하였다.

In this paper, we propose and evaluate symbol timing recovery algorithm for S-DMT cable modern, which supports more channels and better quality symmetric mutimedia service over HFC network. We adopt timing recovery algorithm of PN sequence insertion in time domain and evaluate the performance of it in various noise channel such as AWGN, ISI, impulse. We verified that performance of this algorithm is depends on the channel noise environment and sampling clock offset and that over 10 dB degradation of Eb/No is occurred at the timing failure probability of $10^3$ in the composite noise channel of AWGN, ISI, and impulse in comparison with impulse noise-alone channel. finally, we verified that this algorithm showed good timing failure probability in case of sampling clock optimization was performed in advance.

본 연구는 과학 학술정보 서비스 플랫폼 이용자의 정보 검색 편의성을 확보하고 적합한 정보의 획득에 소요되는 시간을 절약하기 위하여, 운영 중인 서비스 메뉴와 각 서비스 별 콘텐츠 정보를 제공하는 알고리즘 중 콘텐츠 추천 알고리즘을 최적화하고 그 결과를 비교평가 하는 것이다. 추천 정확도를 높이기 위해 이용자의 '전공' 항목을 기존 알고리즘에 추가하였으며, 기존 알고리즘과 최적화된 알고리즘을 통한 추천 결과의 성능평가를 수행하였다. 성능평가 결과 최적화된 알고리즘을 통해 이용자에게 제공되는 콘텐츠의 적합도가 21.2% 증가함을 파악하였다. 이용자에게 적합한 콘텐츠를 시스템에서 자동 도출하여 각 서비스 메뉴 별로 제공함으로써 정보 획득 시간을 단축하고, 연구정보로서 가치 있는 연구결과물의 생명주기를 연장할 수 있는 방안이라는 데 본 연구의 의의가 있다.

In order to secure the convenience of information retrieval by users of scientific information service platforms and to reduce the time required to acquire the proper information, this study proposes an optimized content recommendation algorithm among the algorithms that currently provide service menus and content information for each service, and conducts comparative evaluation on the results. To enhance the recommendation accuracy, users' major items were added to the original algorithm, and performance evaluations on the recommendation results from the original and optimized algorithms were performed. As a result of this evaluation, we found that the relevance of the content provided to the users through the optimized algorithm was increased by 21.2%. This study proposes a method to shorten the information acquisition time and extend the life cycle of the results as valuable information by automatically computing and providing content suitable for users in the system for each service menu.

This paper presents an optimal design and the performance evaluation of two-axis nano positioning stage with round notched flexure hinges. A flexure hinge mechanism with round notched flexure hinges is to guide the linear motions of a moving plate in the nano positioning stage. A Min-Max algorithm is applied to the design of the flexure hinge mechanism for nano positioning stage. In the design process, the structure of the flexure hinge mechanism is fixed, then the radius of a round hole and the width of two round holes are chosen as design variables, and finally the do sign variables are calculated by the Min-Max algorithm. The machined flexure hinge mechanism, stack type PZTs for actuation and capacitance type displacement sensors for position measurement are assembled into the nano positioning stage. The experimental results of the manufactured nano positioning stage show the first modal resonance frequency of 197 Hz, the operating range of 40 um, and the resolution of 3 nm.

본 연구는 자율협력주행자동차의 도입 환경에서 도로교통 운영 효율성 향상을 목적으로, 기존에 제안된 칼만필터 기반 개별 차량 누적통행시간 예측 기반의 실시간 신호제어 알고리즘 을 국내 독립 교차로 운영 여건에 맞게 개선하였다. 개선된 알고리즘은 게이트 순환 유닛을 활용하여 개별 차량의 누적통행시간을 예측하고, 누적통행시간이 상대적으로 큰 접근로에 녹 색신호를 연장함으로써 실시간 신호제어를 수행한다. 알고리즘 개선 효과를 검증하기 위해 다 양한 교통상황을 반영한 시나리오를 구성하고, 평균지체 및 대기행렬 길이를 평가지표로 설정 하여 time of day(TOD) 신호제어 및 Synchro 기반 신호최적화 결과와 비교·분석하였다. 그 결 과, 제안한 실시간 신호제어 알고리즘은 기존 TOD 방식과 Synchro 기반 신호최적화, 칼만필터 기반 누적통행시간 예측 기반 결과 대비 평균지체를 약 40~50% 감소시키는 것으로 나타났다.

This study enhances a previously developed Kalman filter–based cumulative travel time(CTT) real-time signal control algorithm(CTR) for application to isolated intersections under a cooperative automated vehicle(CAV) environment. The improved method adopts a Gated Recurrent Unit(GRU) model to predict individual vehicle CTT and extends green time for the approach with higher CTT. Performance was evaluated under various traffic scenarios using average delay and queue length as measures of effectiveness. Compared with time-of-day(TOD) control, Synchro-based optimization, and the original Kalman filter–based CTR algorithm, the proposed GRU-based approach reduced average delay by approximately 40–50%.

세계 각국에서 연구개발 중인 ITS 기술은 기존 도로 인프라의 효율성 극대화, 복잡한 교통문제 해결 그리고 운전자 편의 서비스 제공 등을 해결하기 위한 방안으로 기대되고 있다. 이러한 ITS 기술의 핵 심은 서버가 교통정보를 수집하고 수집된 정보를 빠르고 정확하게 필요한 사용자에게 제공하는데 있다. 실제 주행환경 에서는 차량과 기지국 주변에 수많 은 통신장애요소들이 혼재함으로 ITS관련 서비스를 끊김없이 보장하기 위해서는 정확 하고 잡음신호에 강인한 핸드오버 기술이 필요하다. 본 논문에서는 실제 차량용 통신장치에 구현된 WAVE 핸드오버 알 고리즘을 소개하고 성능에 영향을 미치는 5가지 주요 파라미터를 도출하였다. 본 논문에서는 고속주행 시험도로에서 도 출된 파라미터들에 대해 여러 값을 대응하여 각각의 조건에서 핸드오버 성능 변화를 분석하였다. 본 논문의 시험결과는 빈번하게 발생하는 핸드오버 핑퐁 문제 해결을 위해 핸드오버 알고리즘에 사용되는 파라미터 값을 얼마나 잘 설정해야 하는지를 설명해준다.

ITS technologies are in the research and development around the world as a solution for maximizing the efficiency of the existing road infrastructure, solving the complex traffic problems and providing the convenient driving services. The core of these ITS technologies is to provide the information for the requesting users in fast and accurate way from the server. In real driving conditions, there are many communication barriers around the vehicles and the base stations so that an accurate and robust handover technology is needed in order to ensure seamless ITS services. This paper introduced an WAVE handover algorithm implemented in a real communication device and five parameters mainly affecting the handover performance are evaluated. The handover performance is measured by changing the parameter values at a highway testbed. The test results show that the handover algorithm parameter values should be configured carefully to remove the handover ping-pong problems.

블록체인은 중앙 집중 시스템 형태에서 벗어난 탈중앙화 형태의 데이터 관리를 통하여 데이터 투명성과 보안성을 높일 수 있다. 블록체인 플랫폼 중 허가형 블록체인은 신뢰기반의 허가된 노드만이 분산 네트워크에 참여할 수 있다. 허가형 블록체인 의 특징을 고려하였을 때 합의 알고리즘 선정을 위한 조건으로 네트워크 통신 속도 및 거래내역의 최종성 합의, 안정성 등의 고려가 필요하다. 허가형 블록체인 환경의 합의 알고리즘은 PoA, PBFT, Raft 등 다양하지만 합의 알고리즘 선정을 위한 다 양한 평가요소가 존재하지 않는다. 본 논문에서는 허가형 블록체인의 각 합의 알고리즘의 특징을 분석하고 네트워크를 구성하 는 사용자 환경의 특징을 고려한 효율적 합의 알고리즘 선정을 위하여 다양한 성능평가항목을 제안하였다. 제안한 성능평가항 목은 신뢰를 전제로 한 노드 간 네트워크 속도, 안정성, 최종성 합의의 적합성 등을 고려할 수 있으며 이를 통하여 보다 효율 적인 블록체인 네트워크 환경을 구성할 수 있다.

Blockchain can enhance data transparency and security through decentralized data management that is out of the centralized system. permissioned blockchain of the blockchain platform, only trust-based authorized nodes can participate in the distributed network. Considering the characteristics of the permissioned blockchain, it is necessary to consider the network communication speed, transaction finality agreement, and stability as a condition for selecting the consensus algorithm. The consensus algorithms of the permissioned blockchain environment are diverse such as PoA, PBFT, Raft, etc., but there are no various evaluation factors for selecting consensus algorithms. In this paper, various performance evaluation factors are proposed to analyze the characteristics of each consensus algorithm of the permissioned blockchain and to select an efficient consensus algorithm considering the characteristics of the user environment that composes the network. The proposed performance evaluation factor can consider the network speed, stability, and consensus of the finality agreement between nodes under the premise of trust. Through this, a more efficient blockchain network environment can be constructed.

블록체인은 연결된 노드 간 합의를 통하여 동일한 데이터를 공유하며 사용자의 범위에 따라 퍼블릭 블록체인과 프라 이빗 블록체인으로 구분된다. 퍼블릭 블록체인은 임의의 불특정 다수가 노드로 참여할 수 있기 때문에 악의를 가진 노드의 보안 위협을 차단하기 위하여 과도한 컴퓨팅 파워와 지분을 요구하는 반면 프라이빗 블록체인은 신뢰 기반의 허가된 노드만이 네트워크에 참여할 수 있기 때문에 합의를 위한 과도한 컴퓨팅 파워 등이 필요치 않아 네트워크 통 신속도를 증가시킬 수 있고 트랜잭션의 최종성 합의가 가능하다. 프라이빗 블록체인 환경에서 적용 가능한 합의 알 고리즘은 다양하다. 하지만 합의알고리즘 선정을 위한 성능평가요소가 다양하지 않아 사용자의 환경을 고려한 최적 의 합의알고리즘 선택이 힘들 수 있다. 본 논문에서는 프라이빗 환경의 합의 알고리즘의 특징을 분석하고 사용자 환 경의 특징을 고려한 효율적 합의 알고리즘 선정을 위한 성능평가 요소를 제안하였으며 제안 내용의 적합성을 증명하 기 위하여 다수의 사례에 수식을 적용하여 적합한 합의 알고리즘을 제안하였다. 본 논문의 제안 내용을 통하여 사용 자의 목적에 부합하는 합의 알고리즘 선정을 위한 다양한 성능평가요소 확인 및 해당 요소를 통한 효율적 합의알고 리즘 선정이 가능하다.

Private blockchain can be applied to various consensus algorithms. Since the performance evaluation factors for selecting the consensus algorithm of the private blockchain environment are not diverse, it may be difficult to select the optimal consensus algorithm considering the user's environment. In this paper, propose a performance evaluation element for analyzing the characteristics of the consensus algorithm in the private environment and selecting an efficient consensus algorithm considering the characteristics of the user environment. The process of selecting is presented. Through the research contents of this paper, it is possible to identify various performance evaluation factors for selecting a consensus algorithm that meets the user's purpose and to select an efficient consensus algorithm through those factors.

In this study, a response model of a beam structure was established through finite element analysis by analyzing the vibration response to external excitation. The vibration control performance of the beam was then evaluated by applying the narrow-band Fx-LMS algorithm for active structural control. The transfer function was obtained at the error sensor location when the structure was excited and the three-axis actuator was operated. The performance of the active control was investigated with 18 channels for error input and actuator output. When the equipment is exciting, the response of the error sensor is the primary path, and when the inertial 3-axis actuator operates, the response of the error sensor position is the secondary path, and the Fx-LMS algorithm is applied. The simulation was performed by changing the control parameters so that the response of the error sensor can satisfy the target performance. From the results of this study, the acceleration results over time showed about 70% vibration reduction after active control, and the average error value of the error sensor also decreased by about 68%. In addition, it was confirmed that real-time control of a system with 18 sensors and 18 actuators is possible even if the secondary path is configured in two orders.

Fingerprint Identification System performance largely depends on the quality of input fingerprint images. High quality input fingerprint images are prerequisite for high performance systems. In this paper, we have proposed an algorithm of fingerprint image enhancement by using Iterative Fast Fourier Transform (IFFT). Iterative image reconstruction algorithms play an important role in fingerprint identification systems in order to achieve higher degree of efficiency. With the fast increase of the sizes of the fingerprint data, design of the reconstruction algorithms is of great importance in order to improve the performance. Fourier-based frequency orientation methods have the potential to considerably reduce the computation time in iterative reconstruction. We also have designed an approach for removing the false minutia generated during the fingerprint processing and a method to reduce the false minutia to increase the efficacy of identification system. We have used fingerprint Verification Competition 2006 (FVC 2006) as a database for implementation of proposed algorithm to verify the degree of efficiency of proposed algorithm. Experimental result shows that the proposed enhancement algorithm is better than existing Fast Fourier Transform algorithm.

At present the hash algorithm analysis is mostly confined to the randomness of the hash values. Researchers have not analyzed the effect of hash algorithm in the network equipment. We propose three evaluation measures of hash algorithm from the perspective of theory analysis and experimental evaluation: the output stream integrity by combining with the dictionary sorting and binary search method to verify, the flow distribution uniformity of hash algorithm, load balancing effect according to the group packet number variance and the max-min packet number ratio. In the experiments, we evaluate the hash algorithm of the current domestic well-known network equipment manufacturers with the backboneflow. The results show that the evaluation measure can effectively measure hash algorithm. It network is helpful for network equipment manufacturers to choose proper hash algorithm.

The defects of BP neural network, such as low convergence speed, falling into local minimum easily, bad generalization ability, can depress the calculation accuracy of BP neural network and damage its practical effect. So the research of improving BP neural network has great theoretical and practical significance. The paper advances a new fuzzy neural network algorithm to overcome the defects of original BP neural network algorithm and evaluate rural public service performance. First, the paper designs a new calculation structure based on fuzzy and BP neural network theory, and selects new self-training methods for the improved fuzzy neural network algorithm; Second, the performance of the advanced algorithm is also analyzed form four aspects in theory; Finally, based on analyzing and constructing the evaluation indicator system, the improved fuzzy neural network algorithm is applied to evaluate rural public service performance and the experimental results show that the superiorities of the improved algorithm include high evaluation accuracy, fast convergence speed, small oscillation, simple algorithm process.

An XG-PON (10-Gbps-capable passive optical network) system is comprised of an OLT (optical line termination) and multiple ONUs (optical network units). In general, ONUs report their requests to the OLT and then the OLT performs a dynamic bandwidth allocation operation to allocate non-overlapping transmission slots to ONUs. In this paper, we consider an XG-PON system that ONUs do not report their requests to. The OLT estimates the ONU status by monitoring the upstream bandwidth usage of the ONU. We propose a dynamic bandwidth allocation method for the XG-PON system in which ONUs do not report their reports. The proposed method allocates a bandwidth to an ONU only if the ONU has fully used its upstream slot. Also, the proposed method periodically allocates a probe bandwidth to an ONU to prevent service starvation. Using simulation, we evaluate the performance of the proposed method under balanced and unbalanced traffic.

This paper applies WiMedia UWB network into a wireless ship area network (WSAN) so as to support high-quality multimedia services on board and reliable instrument control information as well, since the need for mixed high-quality video traffic and shipboard control data traffic is essential for a high-cost valued digital ship. Thus, in this paper, prioritized contention access (PCA) and distributed reservation protocol (DRP) based on WiMedia UWB (ECMA-368) MAC protocols are combined and proposed to such mixed traffic environment, by varying the portions of superframe according to traffic type. It is shown that the proposed WiMedia UWB MAC protocol can provide reliable mixed video and shipboard control data traffic as well.

In recent years, wireless sensor network is becoming the hottest research fields, which opens up a wealth of opportunities for many application domains. Comprehensive performance of WSNs is important for planning and management of a construction network. In order to deal with the deficiency of existing evaluation methods for WSNs performance, an intelligent evaluation model based on fuzzy optimization neural network model is proposed, which introduces genetic algorithm to optimize the connection weight of the neural network model to achieve approximate optimal solution. The weights are to be regarded as initial values for the next step that a neural network is tuned finely further. Fuzzy optimization model is as activation function of the neural network, therefore the model has explicit physical meanings. This model is applied to evaluate WSNs performance of some samples, and the comparative analysis with other models shows that the model improves evaluation precision and efficiency and is practical. The first part is the research status and related problems. The second part is the establishment of evaluation model. The last part is the experimental analysis and conclusion.

기업 내 과업 활동이 디지털화됨에 따라 조직에서는 알고리즘을 활용하여 직원의 태도와 성과를 측정하고 평 가하려는 시도가 관찰되고 있다. 알고리즘 평가 제도에 관한 기존 연구는 알고리즘 평가 제도 도입이 직원과 조 직의 성과에 미치는 영향에 초점을 두었지만, 알고리즘 평가 제도의 대상이 되는 직원들의 수용성 및 공정성에 관한 이해는 부족하였다. 누가, 언제 알고리즘 평가 제도를 공정하다고 인식할까? 이 질문에 답하기 위해 본 연구 는 공정성 이론에 기반하여 알고리즘 평가 제도에 대한 직원의 공정성 인식을 예측하는 이론적 모델을 제시하였 다. 연구 모델을 검증하기 위해 먼저 직장인들의 알고리즘 평가 제도에 대한 장단점 인식 조사를 파일럿 연구를 통해 수행하였고, 이를 바탕으로 알고리즘 평가 제도에 대한 실험 시나리오를 만들어 국내 정규직 직원 300명을 대상으로 설문을 진행하였다. 분석 결과 개인의 업무 목표가 조직 내 다른 구성원들과 상호 의존적인 경우 알고 리즘 HRM의 결정에 상사가 적절하게 개입해야 더욱 공정하다고 인식하였다. 또한, 자기 효능감이 높아 스스로 업무를 충분히 완수하여 성과를 달성할 수 있다고 믿는 직원들은 상사가 개입할 경우 알고리즘 평가 제도에 대한 공정성 인식이 저해될 수 있음을 보였다. 이러한 결과를 바탕으로 이론적 기여와 실무적 시사점을 논의하였다.

As employee work activities become digitized, organizations are trying to utilize data and algorithms to measure and evaluate employees' attitudes and performance. Previous studies have predominantly focused on leveraging algorithm-based performance evaluation to accurately predict employee behaviors and enhance performance. However, there has been a lack of understanding from the employee perspective regarding the acceptability and fairness of algorithm-based performance evaluation. Who perceives algorithm-based performance evaluation as fair, and under what circumstances? To address this question, we draw from organizational justice theory to develop a theoretical model predicting employee perception of fairness for algorithm-based performance evaluation. We argue that goal interdependence is positively related to perceived fairness in algorithm-based performance evaluation when supervisors intervene in decisions made by the algorithm. We also argue that self-efficacy is positively related to perceived fairness in algorithm-based performance evaluation when supervisors are unable to intervene. To test our theoretical model, we conducted a pilot study using topic modeling to identify perceived strengths and weaknesses of algorithm-based performance evaluation. Building on the insights from the pilot study, we tested our theoretical model with a sample of 300 full-time employees. Lastly, we discussed the theoretical contributions and practical implications of our findings.

본 논문은 SMMA (Sliced Multi Modulus Algorithm) 등화 알고리즘에서 등화기의 출력 전력에 비례하는 adaptive modulus와 adaptive stepsize를 적용하므로서 등화 성능을 개선할 수 있는 Hybrid-SMMA 알고리즘에 관한 것이다. 기존 SMMA 알고리즘에서는 등화기의 탭 계수 갱신을 위한 오차 신호를 발생할 때 송신측 신호의 통계 특성치인 modulus를 고정적으로 사용하지만, 제안 Hybrid-SMMA에서는 등화기 출력 신호의 전력에 비례토록 modulus와 오차 신호의 비선형성을 이용하여 stepsize를 적응적으로 변화시킨다. 제안 알고리즘의 개선된 등화 성능을 컴퓨터 시뮬레이션을 통해 확인하였으며, 시뮬레이션 결과 제안 방식이 기존 SMMA보다 모든 성능에서 우월함을 확인하였다.

This paper relates with the Hybrid-SMMA adaptive equalization algorithm that is possible to improve the equalization performance based on adaptive modulus and adaptive stepsize which is propotional to the output power of equalizer in the current SMMA (Sliced Multi Modulus Algorithm). The fixed statistic modulus of transmitted signal is used in current SMMA algorithm in order to generate the error signal for updating the tap coefficient of equalizer. The proposed Hybrid-SMMA based on the adaptive modulus which is propotion to the equalizer output signal power and adaptive stepsize which is fuction of the nonlinearties of error signal. The computer simulation was performed in order to confirm the improved equalization performance of proposed algorithm. As a result of computer simulation, the proposed Hybrid-SMMA has fairly good in every performance than the current SMMA.

본 논문은 16-QAM 신호 전송시 시분산 채널에서 발생되는 진폭과 위상 찌그러짐에 의한 부호간 간섭을 경 감시키기 위한 적응 등화 알고리즘인 VSDA (Variable stepsize Square contour Decision directed Algorithm)의 성능에 관한 것이다. 기존 SCA 에서는 송신 신호의 2차 통계치인 Constellation Dependent Constant를 이용하여 수신 신호의 진폭과 위상을 보상하지만, VSDA에서는 constellation matching을 위한 distance adjusted approach 개념과 decision directed 비용 함수를 부가하여 수렴 성능을 더욱 개선시킨 것이다. 논문에서는 컴퓨터 시뮬레이션을 통하여 VSDA와 SCA의 등화 성능을 비교하였으며, 이를 위한 성능 지수로는 등화기 출력 신호 성상도, 잔류 isi양, 최대 찌그러짐 및 MSE를 사용하였다. 성능의 비교 결과 수렴 속도에서는 VSDA 알고리즘이 SCA보다 훨씬 개선되었지만, 모든 성능 지수는 유사함을 알 수 있었다.

This paper relates with the VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference due to the distortion which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the conventional SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSDA, it is possible to the increasing the equalization performance by adding the concept of distance adjusted approach for constellation matching and the cost function of decision directed. We compare the performance of VSDA and SCA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSDA algorithm has better than the SCA in convergence speed, but it gives nearly same equalization performance in other index.