• 한국도로학회논문집
• /
• 제20권3호
• /
• pp.59-64
• /
• 2018

PURPOSES : We propose a parameter-setting-free harmony-search (PSF-HS) algorithm to determine the individual sound power levels of noise sources in the cases of industrial or road noise environment. METHODS :In terms of using methods, we use PSF-HS algorithm because the optimization parameters cannot be fixed through finding the global minimum. RESULTS:We found that the main advantage of the PSF-HS heuristic algorithm is its ability to find the best global solution of individual sound power levels through a nonlinear complex function, even though the parameters of the original harmony-search (HS) algorithm are not fixed. In an industrial and road environment, high noise exposure is harmful, and can cause nonauditory effects that endanger worker and passenger safety. This study proposes the PSF-HS algorithm for determining the PWL of an individual machine (or vehicle), which is a useful technique for industrial (or road) engineers to identify the dominant noise source in the workplace (or road field testing case). CONCLUSIONS : This study focuses on providing an efficient method to determine sound power levels (PWLs) and the dominant noise source while multiple machines (or vehicles) are operating, for comparison with the results of previous research. This paper can extend the state-of-the-art in a heuristic search algorithm to determine the individual PWLs of machines as well as loud machines (or vehicles), based on the parameter-setting-free harmony-search (PSF-HS) algorithm. This algorithm can be applied into determining the dominant noise sources of several vehicles in the cases of road cross sections and congested housing complex.

• 한국정보통신학회논문지
• /
• 제8권2호
• /
• pp.338-343
• /
• 2004

블록 정합 알고리즘 (Block Matching Algorithm: BMA)에서 탐색 패턴은 탐색 속도와 화질에 매우 중요한 요소로 작용한다. 본 논문이 제안하는 HDS(Half Diamond Search) 패턴은 대부분 영상들의 움직인 벡터가 탐색 영역의 중심과 상ㆍ하ㆍ좌 우 방향에 집중되어 있는 특성을 고려하여 먼저 탐색 원점을 중심으로 4 방향 탐색 점을 배치한 후 블록 정합을 실행한다. 이들 중 정합 오차가 가장 작은 지점을 기준점으로 상 방향으로 탐색 점을 확장하여 정합 오차를 측정하고 기준점보다 오차가 작으면 상 방향확장을 선택하고 그렇지 않으면 기준점을 중심으로 좌우 두 점 중 정합오차가 작은 점을 선택한다. 선택된 방향으로 이 과정을 반복하며 움직임을 추정한다. 탐색하면서 움직임이 낮은 부분을 탐색 대상에서 제외해가기 때문에 탐색이 비교적 빠르고 정확하게 이루어진다. 이 방법은 기존의 부분 최적 탐색 기법인 NTSS, DS, 그리고HEXBS등의 탐색법과 비교할 때 유사한 화질을 유지하면서도 탐색 점수에서는 평균 23%의 개선된 결과를 얻었다.

• Structural Engineering and Mechanics
• /
• 제43권6호
• /
• pp.771-794
• /
• 2012

This paper presents a multi-objective evolutionary algorithm for combinatorial optimisation and applied for design optimisation of fiber reinforced composite structures. The proposed algorithm closely follows the implementation of Pareto Archive Evolutionary strategy (PAES) proposed in the literature. The modifications suggested include a customized neighbourhood search algorithm in place of mutation operator to improve intensification mechanism and a cross over operator to improve diversification mechanism. Further, an external archive is maintained to collect the historical Pareto optimal solutions. The design constraints are handled in this paper by treating them as additional objectives. Numerical studies have been carried out by solving a hybrid fiber reinforced laminate composite cylindrical shell, stiffened composite cylindrical shell and pressure vessel with varied number of design objectives. The studies presented in this paper clearly indicate that well spread Pareto optimal solutions can be obtained employing the proposed algorithm.

• Advances in Computational Design
• /
• 제1권1호
• /
• pp.79-86
• /
• 2016

In this study, the three different meta-heuristics namely the Grey Wolf Optimizer (GWO), Stochastic Fractal Search (SFS), and Adaptive Differential Evolution with Optional External Archive (JADE) algorithms are examined. This study considers optimization of the planer frame to minimize its weight subjected to the strength and displacement constraints as per the American Institute of Steel and Construction - Load and Resistance Factor Design (AISC-LRFD). The GWO algorithm is associated with grey wolves' activities in the social hierarchy. The SFS algorithm works on the natural phenomenon of growth. JADE on the other hand is a powerful self-adaptive version of a differential evolution algorithm. A one-bay ten-story planar steel frame problem is examined in the present work to investigate the design ability of the proposed algorithms. The frame design is produced by optimizing the W-shaped cross sections of beam and column members as per AISC-LRFD standard steel sections. The results of the algorithms are compared. In addition, these results are also mapped with other state-of-art algorithms.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.791-796
• /
• 1987

In this paper, an efficient algorithm to estimate the volume and surface area from ultrasonic imaging and a reconstruction algorithm to generate three-dimensional graphics are presented. The computing efficiency is Improved by using the graph theory and the algorithm to determine proper contour points is performed by applying several tolerances. The search for contour points is limited by the change in curvature in order to provide an efficient search of the minimum cost path. These algorithms are applied to a selected mathematical model of ellipsoid. The results show that the measured value of the volume and surface area for the tolerances of 1.0005, 1.001 and 1.002 approximate to the measured values for the tolerance of 1.000 resulting in small errors. The reconstructed 3-dimensional Images are sparse and consist of larger triangular tiles between two cross sections as tolerance is increased.

• 정보관리연구
• /
• 제23권3호
• /
• pp.45-73
• /
• 1992

특이하게 운영(運營)되는 STN International은 세계 최대의 과학기술(科學技術) 온라인 정보검색(情報檢索) 시스템으로서 세 비영리기관인 미국(美國)의 Chemical Abstracts Service, 독일(獨逸)의 FIZ Karlsruhe, 일본(日本)의 과학기술정보(科學技術情報)센터가 공동으로 운영하고 있다. 본고에서는 STN에서 빠르고 효율적인 정보검색(情報檢索)을 위해서 설계(設計)한 Messenger 검색(檢索) 소프트웨어 기능, 검색시간(檢索時間)과 노력을 줄이는 진보된 소프트웨어인 SYN Express, 그리고 STN에 수록된 데이터베이스에 관해서 기술(記述)하였다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.138-148
• /
• 1998

The aim of the work described in this paper is to develop a complex underground acoustic system which detects and localizes the origin of an underground hammering sound using an array of hydrophones located about loom underground. Three different methods for the sound localization will be presented, a time-delay method, a power-attenuation method and a hybrid method. In the time-delay method, the cross correlation of the signals received from the way of sensors is used to calculate the time delays between those signals. In the power-attenuation method, the powers of the received signals provide a measure of the distances of the source from the sensors. A new hybrid method has been developed for estimating the origin of the underground acoustic source by coupling both methods. The Nelder-Meade simplex search algorithm is then used to numerically estimate the position of the source in those methods. For each method the sound localization is carried out in three dimensions underground. The distance between the true and estimated origins of the source is in some cases less than 6m for a search area of radius 250m.

• International journal of advanced smart convergence
• /
• 제10권3호
• /
• pp.72-80
• /
• 2021

Metaverse is an immersive 3D virtual environment, a true virtual artificial community in which avatars act as the user's alter ego and interact with each other. If we do not manage the hype for the metaverse, which has recently been receiving a surge in interest, the metaverse will fail to cross the chasm. In this study, to provide stakeholders with insights for the successful introduction and growth of the 3D immersive next-generation virtual world, metaverse, we analyzed user-side interest, media-side interest, and research-side interest. For this purpose, in this study, search traffic, news frequency and topic, and research article frequency and topic were analyzed. The methodology and results of this study are expected to provide insight for the stable success of metaverse transformation and the coexistence of the real world and the virtual world through hyper-connection and hyper-convergence.

• 경영정보학연구
• /
• 제19권3호
• /
• pp.179-199
• /
• 2017

멀티채널 소비자들의 크로스오버 쇼핑행동이 두드러지는 시점에서 최근 사용자 행동 메커니즘에 대한 관심이 높아지고 있다. 단순한 멀티채널 사용자행동에 대한 이해 차원을 넘어 면밀한 관찰을 통해 기존 연구방식에서 발견할 수 없었던 크로스 오버 쇼핑행동에 대한 연구 축적이 필요한 시점이라 할 수 있다. 본 연구는 근거이론(grounded theory)를 활용하여 멀티채널 사용자들이 왜, 어떻게 크로스오버 쇼핑행동을 하는지를 살펴보는데 그 목적이 있다. 본 연구에서는 총 25명의 응답자를 대상으로 인터뷰를 진행하였으며, 근거자료의 분석을 통해 118개의 개념을 추출하였고, 유사 개념간의 통합과정을 통해 28개의 범주를 제시하였다. 본 연구는 근거이론을 적용하여 기존 설문연구에서는 파악하기 어려웠던 사용자들의 동적인 탐색과 구매행동의 메커니즘을 포착함으로써 멀티채널 환경에서 설명 가능한 행동연구 방안을 제안하고 있다는 점에서 의의가 있다.

• 산업과 과학
• /
• 제3권2호
• /
• pp.8-16
• /
• 2024

본 논문에서는 인구통계학적, 생리학적 특성을 기반으로 환자에게 가장 적합한 약물을 예측하는 것을 목표로 하는 약물 분류 시스템을 제시한다. 데이터 세트에는 적절한 약물을 결정하기 위한 목적으로 연령, 성별, 혈압(BP), 콜레스테롤 수치, 나트륨 대 칼륨 비율(Na_to_K)과 같은 속성들이 포함된다. 본 연구에 사용된 모델은 KNN(K-Nearest Neighbors), 로지스틱 회귀 분석 및 Random Forest이다. 하이퍼파라미터를 최적화하기 위해 5겹 교차 검증을 갖춘 GridSearchCV를 활용하였으며, 각 모델은 데이터 세트에서 훈련 및 테스트 되었다. 초매개변수 조정 유무에 관계없이 각 모델의 성능은 정확도, 혼동 행렬, 분류 보고서와 같은 지표를 사용하여 평가되었다. GridSearchCV를 적용하지 않은 모델의 정확도는 0.7, 0.875, 0.975인 반면, GridSearchCV를 적용한 모델의 정확도는 0.75, 1.0, 0.975로 나타났다. GridSearchCV는 로지스틱 회귀 분석을 세 가지 모델 중 약물 분류에 가장 효과적인 모델로 식별했으며, K-Nearest Neighbors가 그 뒤를 이었고 Na_to_K 비율은 결과를 예측하는 데 중요한 특징인 것으로 밝혀졌다.