• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.901-908
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• 2010

A geometrical description method is proposed to represent the process of the forward selection and backward elimination methods among many variable selection methods for multiple regression models. This graphical method shows the process of the forward selection and backward elimination on the first and second quadrants, respectively, of half circle with a unit radius. At each step, the SSR is represented by the norm of vector and the extra SSR or partial determinant coefficient is represented by the angle between two vectors. Some lines are dotted when the partial F test results are statistically significant, so that statistical analysis could be explored. This geometrical description can be obtained the final regression models based on the forward selection and backward elimination methods. And the goodness-of-fit for the model could be explored.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.97-102
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• 2010

The purpose of medical data mining for efficient algorithms and techniques throughout the various diseases is to increase the reliability of estimates to classify. Previous studies, an algorithm based on a single model, and even the existence of the model to better predict the classification accuracy of multi-model ensemble-based research techniques are being applied. In this paper, the higher the medical data to predict the reliability of the existing scope of the ensemble technique applied to the I-ENSEMBLE offers. Data for the diagnosis of hypothyroidism is the result of applying the experimental technique, a representative ensemble Bagging, Boosting, Stacking technique significantly improved accuracy compared to all existing, respectively. In addition, compared to traditional single-model techniques and ensemble techniques Multi modeling when applied to represent the effects were more pronounced.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.20-26
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• 2003

This study proposes the construction of attractor quadrant method for high-precision cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, using diamond turning machine to Perform cutting Processing, by measuring cutting force and surface roughness and according to cutting conditions the aluminum about cutting properties. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics and attractor quadrant characteristics. In quantitative quadrant feature extraction, 1,309 point in the case of A17075 (one quadrant) and 1,406 point (one quadrant) in the case of brass were proposed on the basis of attractor reconstruction. Proposed attractor quadrant method can be used for high-precision cutting characteristics evaluation of non-ferrous metals.

• Journal of the Korea Computer Graphics Society
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• v.6 no.4
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• pp.23-28
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• 2000

We introduce a new method for constructing a dynamic Delaunay triangulation for a set S of n sites in the plane under the $L_{\infty}(L_1)$ metric. We find that the quadrant neighbor graph is contained in the Delaunay triangluation and that at least one edge of each triangle in the Delaunay triangulation is contained in the quadrant neighbor graph. By using these observations and employing a range tree scheme, we present a method that dynamically maintains the $L_{\infty}(L_1)$ Delaunay triangulation under insertions and deletions in $O(log^2n)$ amortized time and O(log n) expected time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.123-125
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• 2023

4차 산업혁명의 가속화에 따라 해운 항만 산업 분야 또한 정보적 측면에서 빅 데이터에 대한 업종별 통합과 공유를 통해 연계 산업 간 산업활동 효율화를 위한 노력이 요구된다. 현재 물류 분야에 다양한 플랫폼들이 도입되고 있지만 대부분 화물운송업 또는 창고 중개업 분야에 편중되어 있다. 항만산업의 경우 코로나 펜데믹 이후 발생한 컨테이너 반입 제한 및 장치율 증가 등에 따라 운송사와 컨테이너터미널 간 갈등이 지속적으로 유발되는 상황이 발생되었다. 이에 따라 본 연구는 플랫폼을 활용한 컨테이너터미널과 운송사 간 플랫폼 개발의 필요성을 인지하고 상호 기업 간 연계 효율성을 높일 수 있는 방안을 모색하였으며 산업 관계자인 컨테이너터미널 운영사, 운송사, 포워더 업종 종사자들을 대상으로 설문지 기반 실증 분석을 수행하였다. 결과적으로 EFA를 통해 추출된 14가지 요인으로 IPA 분석을 수행한 결과 1사분면(사용 용이성, 보안성, 정보 정확성, 정보 적시성, 차량 반출/반입정보, 공컨테이너 반입/반출 정보, 풀컨테이너 반입/반출정보)으로 품질에 대한 지속적인 개선이 수행되어야 하며 2사분면(APP 시스템 품질)에 대한 고려가 종합적으로 수행되어야 함이 도출되었다. 또한, 플랫폼 개발의 주체와 이용자의 참여 유도가 필요하며 상호 이해관계자 간 효율적인 연계와 효율화를 위한 인식 구조 개선이 필요하다고 나타났다. 연구결과는 향후 컨테이너터미널과 내륙운송의 효율적인 연계를 위한 플랫폼 구축에 중대한 시사점을 제공한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.21-30
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• 2008

The travel speed collected by the prove-car equipped with the GPS has the problems, which are the data's stability and finding out the representative travel speed, by the influence of the traffic signal and etc. at the interrupted traffic. This study was conducted to develop the method of filtering the outlier data from the data collected by the prove-car. The method to remove the outlier data from the serial data which were collected by the prove-car was adapted to each of the quartile deviation statistics model and the management graphic statistics model. The rate of removing the outlier data by the quartile deviation method was $0{\sim}3.7%$ while the rate by the management graphic statistic methods was $0.3{\sim}7.2%$. Both methods show the low removal rate at the dawn time when the traffic is inactivity, on the other hand the remove rate is high during the daytime. However, both methods have the problem such that the threshold level for removing the outlier data was established at the low bound in the case as good as the statistics model. Therefore, it is required for the experience calibration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1754-1766
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• 2015

Packet classification carried out in Internet routers is one of the challenging tasks, because it has to be performed at wire-speed using five header fields at the same time. In this paper, we propose a leaf-pushed AQT bitmap trie. The proposed architecture applies the leaf-pushing to an area-based quad-trie (AQT) to reduce unnecessary off-chip memory accesses. The proposed architecture also applies a bitmap trie, which is a kind of multi-bit tries, to improve search performance and scalability. For performance evaluation, simulations are conducted by using rule sets ACL, FW, and IPC, with the sizes of 1k, 5k, and 10k. Simulation results show that the number of off-chip memory accesses is less than one regardless of set types or set sizes. Additionally, since the proposed architecture applies a bitmap trie, the required number of on-chip memory accesses is the 50% of the leaf-pushed AQT trie. In addition, our proposed architecture shows good scalability in the required on-chip memory size, where the scalability is identified by the stable change in the required memory sizes, as the size of rule sets increases.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1181-1196
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• 2011

Image fusion is the process of combining information from two or more source images of a scene into a single composite image with application to many fields, such as remote sensing, computer vision, robotics, medical imaging and defense. The most common wavelet-based fusion is discrete wavelet transform fusion in which the high frequency sub-bands and low frequency sub-bands are combined on activity measures of local windows such standard deviation and mean, respectively. However, discrete wavelet transform is not translation-invariant and it often yields block artifacts in a fused image. In this paper, we propose a robust image fusion based on the stationary wavelet transform to overcome the drawback of discrete wavelet transform. We use the activity measure of interquartile range as the robust estimator of variance in high frequency sub-bands and combine the low frequency sub-band based on the interquartile range information present in the high frequency sub-bands. We evaluate our proposed method quantitatively and qualitatively for image fusion, and compare it to some existing fusion methods. Experimental results indicate that the proposed method is more effective and can provide satisfactory fusion results.

• Resources Recycling
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• v.15 no.3 s.71
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• pp.46-57
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• 2006

This study was carried out for the purpose of recovering the refined gypsum from waste phosphogypsum. The refined gypsum was recovered as a under product of 325 mesh wet screening followed by dehydration and hydration stage. The influence of dehydration temperature and time, dehydration rate, aging time, slurry density of hydration and sonication time on the yield and grade of gypsum were investigated. The refined gypsum of $94{\sim}96%$ grade is recovered in 95% yield by wet screening after selective dehydration and hydration process, from the phosphogypsum. For the better separation efficiency of gypsum, it is recommended to treat the phosphogypsum at the conditions of as follows; 6hr's dehydration at $140^{\circ}C$, hydration slury density of $3{\sim}10%$, hydration temperature of $20{\sim}30^{\circ}C$, hydration time of 2hr. In additions, addition of sodium citrate 0.005M and sonication of $5{\sim}10min.$ are effective for increase the recovery of gypsum. On the other hand, aging the dehydrated gypsum 16 hours or longer make decrease the recovery of gypsum remarkably.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.556-563
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• 2017

The purpose of this study is to verify the difference of importance-performance about human right of social worker who works in housing facilities of the disabled. Based on our result, we suggest strategies to implement human rights for the disabled. We collected data from 344 social workers in Busan. We analyzed descriptive statistics, and employed T-Test and Importance-Performance Analysis. Results found the importance level was higher than the performance level of human rights for the disabled. Second, agreement of residential space open and vote right guarantees, the importance level was higher than performance level. Items, excluding ensuring religious activities, prohibiting corporal punishment, strengthening the facility monitoring system and improve facility environment and strengthen program, featured a higher performance level than the importance level. Third, based on the IPA analysis, we derived action strategies for each IPA analysis matrix. We examined 10 items, including free communication included in the first quadrant, improvement of facilities management policy in the second quadrant, prohibition of corporal punishment and strengthening of facility monitoring system in the fourth quadrants.