• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.85-96
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• 2006

This paper deal with a method for efficient placing 2 dimensional virtual labels on the view plane. The proposed method has suitable computational costs for realtime processing and it overcomes the local minima problem which is not solved in previous automatic label placement algorithms, and also it enhances readability by placing labels in less congestion area on the view plane. Background analysis must be considered for label placement. However previous works do not concern with this problem seriously. And furthermore, automatic label placement algorithm and background analysis algorithm have been studied separately in their own field. This paper proposed the background analysis method using background color and texture component to enhance readability, and it is the first research about analyzing the background of color image and applying it in automatic label placement field. This paper shown improved placement performance through combining automatic label placement algorithm and background analysis algorithm organically, and various experiments verified it.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.973-980
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• 2009

Many studies which have been done for efficient installation and management of wireless sensor networks (WSN) include energy savings, key managements and sensor deployments. Sensor deployment problem is one of the most important and fundamental issues among them in that the topic is directly related with the system cost and performance. In this paper, we suggest a sensor deployment scheme that reduces the system cost of WSN while satisfying the fundamental system requirements of connectivity between sensor nodes and sensing coverage. Using graphical information system(GIS) which contains region-dependent information related with connectivity condition, the initial positions of sensors in the procedure simulated annealing (SA) are determined. The GIS information helps in reducing system cost reduction not only at the initial deployment of SA but also at the final deployment of SA which is shown by computer simulations.

• Magazine of the Korea Concrete Institute
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• v.14 no.4
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• pp.82-85
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• 2002

매스 콘크리트 타설전 배합 및 적용 실험을 실시함으로써 현장의 여건에 알맞은 최적의 배합비를 도출하며 실내 배합 실험을 실시하고 배치 플랜트에 적용하여 실제 현장에 실용시킬 수 있다.(중략)

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.33-42
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• 2000

Adsorption onto the surfaces of solid particles is a well known phenomenon that causes the retardation effect of heavy metals in soils. For adequate remediation of soil and groundwater contamination, it is important to investigate the mobility of heavy metals that largely depends on pH conditions in the soil water since adsorption of heavy metals is pH-dependent. In this study, we investigated the transport of Zn ion under various pH conditions in a sandy soil by conducting batch and column tests. The batch test was performed using the standard procedure of equilibrating fine fractions collected from the soil with eleven different initial $ZnCl_2$ concentrations, and analysis of Zn ion in the equilibrated solutions using ICP-AES. The column test consisted of monitoring the concentrations of soil solutions exiting the soil column with time known as a breakthrough curve (BTC). We injected respectively $ZnCl_2$ and KCl solutions with the concentration of 10 g/L as a tracer in a square pulse type under three different pH conditions (7.7, 5.8, 4.1) and monitored the flux concentration at the exit boundary using an EC meter and ICP-AES. The resident concentration was also monitored at the 10cm-depth by Time Domain Reflectometry (TDR). The results of batch test showed that ion exchange process between Zn and other cations (Ca, Mg) was predominant. The retardation coefficients obtained from adsorption isotherms (Linear, Freundlich, Langmuir) resulted in the various values ranging from 1.2 to 614.1. No retardation effect but ion exchange was found for the BTCs under all pH conditions. This can be explained by the absence of other cations to desorb Zn ion from soil exchange sites under the conditions of ETC experiment imposing blank water as leachate in steady-state flow. As pH decreased, the peak concentration of Zn increased due to the competition of Zn with hydrogen ions ($H^+$) and the concentrations of other cations decreased. The peak concentration of Zn was increased by 12.7 times as pH decreased from 7.7 to 4.1.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.615-625
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• 2009

In this paper we describe Wilcoxon test and T-test that are well-known in two-sample location problem for detecting edges under different window configurations. The choice of window configurations is an important factor in determining the performance and the expense of edge detectors. Our edge detectors are based on testing the mean values of local neighborhoods obtained under the edge model using an edge-height parameter. We compare three window configurations based on statistical tests in terms of qualitative measures with the edge maps and objective, quantitative measures as well as CPU time for detecting edge.

• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.214-224
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• 2024

Sonobuoys are disposable devices that utilize sound waves for information gathering, detecting engine noises, and capturing various acoustic characteristics. They play a crucial role in accurately detecting underwater targets, making them effective detection systems in anti-submarine warfare. Existing sonobuoy deployment methods in multistatic systems often rely on fixed patterns or heuristic-based rules, lacking efficiency in terms of the number of sonobuoys deployed and operational time due to the unpredictable mobility of the underwater targets. Thus, this paper proposes an optimal sonobuoy placement strategy for Unmanned Aerial Vehicles (UAVs) to overcome the limitations of conventional sonobuoy deployment methods. The proposed approach utilizes reinforcement learning in a simulation-based experimental environment that considers the movements of the underwater targets. The Unity ML-Agents framework is employed, and the Proximal Policy Optimization (PPO) algorithm is utilized for UAV learning in a virtual operational environment with real-time interactions. The reward function is designed to consider the number of sonobuoys deployed and the cost associated with sound sources and receivers, enabling effective learning. The proposed reinforcement learning-based deployment strategy compared to the conventional sonobuoy deployment methods in the same experimental environment demonstrates superior performance in terms of detection success rate, deployed sonobuoy count, and operational time.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.598-603
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• 2008

Sequence-Pair(SP)는 플로어플랜을 표현하는 모델 중 하나로써, 일반적으로 SP 모델을 사용하는 플로 어프래너 (floorplanner)는 Simulated-Annealing (SA) 알고리즙을 통해 해 탐색 과정을 수행한다. SP 모델을 이용한 다양한 논문에서 플로어플랜 성능 향상을 위해 평가함수의 개선과 스케줄링 기법 향상을 모색하였으며, 평가함수의 경우 O(nlogn) 시간 알고리즘이 존재한다. 본 논문에서는 SP 모델을 이용한 SA 기법에서 SA의 해 탐색 과정 중 초기 해 탐색 시점에서 좋은 해를 빠르게 찾을 수 있는 방법을 제안한다. 제안 기법은 기존의 SA 프레임펙을 수정한 2단계 SA 알고리즘으로써 SP에 대응하는 배치를 압축하고 압축한 배치를 역변환하는 과정으로 구성된다. 실험과 결과를 통해 제안기법의 효과를 보이며, 평균적으로 동일한 SA 환경 하에서 제안기법이 최종결과 면에서 우수함을 보인다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.6
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• pp.85-93
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• 1984

In the paper, a new constructive initial placement algorithm is proposed in computer aided layout design in LSI. An useful object function are proposed to place the modules in logic design diagram laid down by manual to the fixed chip, reflecting the relative positions between modules and cells, and then an initial placement are determined by the function. In order to show the usefulness of the proposed method, it was compared with clustering development method in maximum cut numbers and total routing lengths by program experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.8 no.1
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• pp.30-37
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• 1983

In this paper I have proposed a heuristic layout algorism which is important in the CAD system of VLSI. I have designed a placement algorism to be used the method which depends upon the synthetic judgment of human. The placement algorism can reflect the position of a module in a logical design circuit diagram drawn up by human beings. Also, in order to show the usefulness of the new method I have compared through a program experiment it with the former method of cluster development placement. Moreover, a routing algorism is proposed in order to reduce the excessive problem of memory capacity. Of course this new algorism compensates for the former Maze's defects.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.225-232
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• 2005

The paper presented results of the strength distributions and tension failure behaviors of splices subjected to tension forces. The bolting patterns in the tension splices are regular and staggered patterns in the research. The finite element analyses were carried out to examine the experimental results and evaluated the stress distribution patterns. The yield stresses, maximum tension stresses, stress distribution ratios, and effective net areas were analyzed through the tension experiments.