• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.11a
• /
• pp.167-171
• /
• 2004

최근 들어 위성영상은 자료 처리 방식에 따라 지구표면이나 또는 지하면에 대한 다양한 정보(물리적인 정보, 화학적인 정보)를 얻을 수 있고 실제 지구를 가상으로 구현하는 데 활용될 수 있기 때문에 여러 산업에서 활용하고 있다. 또한 분류는 영상에 포함된 여러 가지 대상물을 구별하기 위해서 화소와 비교적 성질이 같은 화소 그룹별 특징에 대응되는 레벨을 지정하는 기술이 요구되며, 최소거리 분류법, 평행사변형법, 마하나로비스거리법(Mahanalobis Distance Method), 최대우도법(Maximum Likelihood Method)등 비교하여 분류를 수행

• The Journal of the Korea Contents Association
• /
• v.11 no.3
• /
• pp.48-55
• /
• 2011

In this paper, we analyze the input-output characteristics of fuzzy inference systems according to the division of entire input spaces and the fuzzy reasoning methods to identify the fuzzy model for nonlinear process. And fuzzy model is expressed by identifying the structure and parameters of the system by means of input variables, fuzzy partition of input spaces, and consequence polynomial functions. In the premise part of the rules Min-Max method using the minimum and maximum values of input data set and C-Means clustering algorithm forming input data into the hard clusters are used for identification of fuzzy model and membership function is used as a series of triangular membership function. In the consequence part of the rules fuzzy reasoning is conducted by two types of inferences. The identification of the consequence parameters, namely polynomial coefficients, of the rules are carried out by the standard least square method. And lastly, we use gas furnace process which is widely used in nonlinear process and we evaluate the performance for this nonlinear process.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1948-1952
• /
• 2008

본 연구에서는 수문변화 지표법을 적용하여 광동댐 등 12개 용수 전용댐의 연 최소 최대유량 크기와 지속기간, 고 저맥파 빈도와 주기, 수문곡선 변화 비율과 빈도, 유량변화정도 등을 분석하여 댐이 하류하천에 미치는 영향을 수치로 제시 하였다. 광동댐 등 12개 댐의 월 유량변화를 산정한 결과, 갈수기에 해당하는 10월부터 다음해 6월까지 8개월간의 댐건설전 월평균 방류량은 $0.64\;m^3/sec{\sim}3.05\;m^3/sec$이었으나, 댐건설후 월평균 방류량은 $0.33\;m^3/sec{\sim}2.99\;m^3/sec$로 $-69.7%{\sim}167.8%$의 분포를 나타내고 있으며, 12월과 1월을 제외하면 댐건설 이후 오히려 $6.8%{\sim}69.7%$가 감소하였다. 우기철인 7월부터 9월까지 3개월간은 댐건설전 월평균 방류량이 $6.82\;m^3/sec{\sim}7.67\;m^3/sec$이었으나, 댐건설후 월평균 방류량은 $4.12\;m^3/sec{\sim}4.35\;m^3/sec$로 $51.0%{\sim}55.1%$가 감소하여 저수지 공용량을 이용한 저류효과가 다소 있었던 것으로 분석되었다. 연 최소 최대유량 크기와 지속기간 분석결과 1일, 3일, 7일, 30일, 90일 최소유량은 광동댐 등 10개 댐이 댐건설 전후 모두 $0.0\;m^3/sec$로 증감이 없었으며, 달방댐의 경우 30일 최소유량이 $0.026\;m^3/sec$에서 $0.000\;m^3/sec$로 99.11%가 감소하였다. 영천댐의 경우도 30일 최소유량이 $0.101\;m^3/sec$에서 $0.067\;m^3/sec$로 33.73%가 감소 하였으며, 90일 최소유량의 경우 달방댐은 $0.067\;m^3/sec$에서 $0.031\;m^3/sec$로 53.48%가 영천댐은 $0.219\;m^3/sec$에서 $0.150\;m^3/sec$로 31.29%가 감소하였다. 12개 용수 전용댐중 유지용수공급이 계획되어 있는 영천댐과 달방댐을 제외하고는 댐하류 방류량이 없이 건천화 되었다는 사실을 알 수 있다. 고 저맥파의 빈도와 주기 분석결과 댐건설 이후 수문곡선이 25% 이하로 떨어지는 저맥파는 $72.99%{\sim}98.52%$가 감소하였으며, 저맥파의 기간은 $-80.0%{\sim}4,423.3%$까지 분포하여 상당히 증가하였다. 수문곡선이 75%를 초과하는 고맥파의 발생 횟수는 댐건설 이후 $34.28%{\sim}91.67%$가 감소하였으며, 고맥파의 기간은 $-64.31%{\sim}135.62%$로 증가 또는 감소하였다.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.10
• /
• pp.155-165
• /
• 2012

This paper suggests traveling salesman problem algorithm that have been unsolved problem with NP-Hard. The proposed algorithm is a heuristic with edge-swap method. The classical method finds the initial solution starts with first node and visits to mostly adjacent nodes then decides the traveling path. This paper selects minimum weight edge for each nodes, then perform Min-Min method that start from minimum weight edge among the selected edges and Min-Max method that starts from maximum weight edges among it. Then we decide tie initial solution to minimum path length between Min-Min and Min-Max method. To get the final optimal solution, we apply previous two-opt to initial solution. Also, we suggest extended 3-opt and 4-opt additionally. For the 7 actual experimental data, this algorithm can be get the optimal solutions of state-of-the-art with fast and correct.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.10
• /
• pp.1176-1178
• /
• 2016

We propose some binary locally repairable codes with locality 2 uising a parity-check matrix. The minimum distance of the proposed codes is 6. The proposed codes are optimal in the sense of achieving the upper bound of dimension for given length, minimum distance, and locality.

• Geotechnical Engineering
• /
• v.13 no.5
• /
• pp.5-18
• /
• 1997

Anisotropy in strength and deformation characteristics of isotropically consolidated sande prepared by pluviating through air was studied by plane strain compression tests. Seven types of sand of the world-wide origins were tested, which have been extensively used for research purposes. The strains for direction of bmazimum principal stress and direction of minimum principal strews were measured continuously from $10^{-6}\; to 10^{-2}$. The following results were obtained for all sands. The behaviour at strains leas than about 0.001% was elastic and isotropic regardless of the angle $\delta\; of\; the\;\sigma$ direction relative to the bedding plane. However, the sands became gradually more anisotropic as the strain increased to the extent exceeding the elastic limit. The peak strength was noticeably anisotropic with a similar trend. Thus, the angle of internal friction $\phi\; decreased \;as\;\delta$ decreased from $90^{\circ}$, and the ratio of the smallest to largest values of was between 0.82 and 0.90. The l has a minimum at $\delta=0^{\circ}~30^{\circ}$ depending on the hypes of sand. The residual strength became isotropic again.

• Journal of IKEEE
• /
• v.24 no.4
• /
• pp.1081-1085
• /
• 2020

Instantaneous frequencies (IF) of the AM-FM signal is estimated based on the inflection point detection (IPD) method. Local maxima/minima are detected using the IPD, and they are exploited to find the IF of AM and FM components, respectively. The envelope of the maxima/minima is obtained to estimate the IF of the AM part. And the distance between neighboring maxima (or minima) is used to estimate the IF of the FM component. Computer simulation shows that the proposed method properly estimates the IF of the AM and FM when the signal has fixed frequencies for both parts. In the case of the time-varying IF of the FM part, the estimated IF shows some deviation from the true IF due to the rough sampling effect of the maximum/minimum points. Thus, the post-processing such as the lowpass filtering of the estimated IF is required to refine the resulting IF estimation.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.3
• /
• pp.319-332
• /
• 2021

With the rapid development of aesthetic ceramic materials and resin adhesives, the transition from metal ceramic crown to all-ceramic restoration is being actively carried out. When making porcelain restorations, the advantages can be maximized only when appropriate forms and techniques are used. Recently, an esthetic partial-coverage restoration method with supra-gingival margins was introduced by applying a minimally invasive tooth removal method that preserves enamel as much as possible and enhances adhesion efficiency. Through this, various advantages such as minimization of tooth structure removal and ease of excess cement removal can be obtained. In addition, since this manufacturing method does not require cord packing, it is possible to save time for impression taking and reduce patient discomfort. Furthermore, the margins can be clearly obtained without the intervention of gingival fluid or blood, making it possible to manufacture more accurate restorations. In the following cases of patients with partial tooth defects, esthetic ceramic partial-coverage restorations with supra-gingival margin was applied using minimally invasive tooth preparation method according to the concept of adhesive dentistry. Therefore, unnecessary tooth abutment preparation was prevented and residual tooth structure could be preserved as much as possible. After delivery of the ceramic partial-coverage restorations, favorable outcome was obtained.

• Journal of the Korea Convergence Society
• /
• v.6 no.5
• /
• pp.227-232
• /
• 2015

The fuzzy linear programming(FLP) is the useful approach to many real world problems under uncertainty. This paper deals with a FLP whose objective value is fuzzy. And the right hand sides of convergent equality constraints are fuzzy numbers. We assume that the membership function of the objective value is piecewise linear and those of the right hand side are trapezoidal. Each of these trapezoidal functions can be algebraically replaced with three linear functions. Then the FLP problem is transformed into the Zimmermann's symmetric model. The fuzzy solution based on the max-min rule can be obtained by solving the crisp linear programming problem derived from the symmetric model. A numerical example has illustrated our approach. The application of our approach to the inconsistent linear system can enable generate us to get define the useful and flexible inexact solutions within acceptable tolerance. Further research is required to generalize the membership function.

• Journal of the Korea Convergence Society
• /
• v.8 no.4
• /
• pp.183-188
• /
• 2017

As the price of small UAVs is getting cheaper and its controllability is getting greatly increased, many aerial applications using both fixed-wing and hoverable UAVs have appeared in recent years. In this paper, a new aerial advertising method is proposed using four hoverable UAVs. Using the UAV swarm control method, four UAVs are maneuvered to carry a $7.07{\times}7.07m^2$ square banner along collision-free and predefined waypoints for aerial advertising. According to simulation results, it takes about 270 s for UAVs to perform aerial advertising in $669{\times}669m^2$ size area and the minimum distance among UAVs turns out to be 0.45 m which proves there is no any collision. Due to abrupt direction changes of UAVs along the predefined waypoints, UAVs cannot always maintain exact square formation and it results the maximum and minimum side lengths of square formation to be 10.35 m and 1.96 m, respectively. Also, the maximum and minimum diagonal lengths of square formation turn out to be 14.75 m and 2.78 m, respectively.