• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.847-854
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• 2005

Many of scheduling algorithms that provide a pre-defined bandwidth to a traffic flow fall into a category of Latency-rate (LR) server, the delay of whose network can be simply calculated by adding up individual 'latencies' of each LR servers. Deficit Round Robin (DRR) is one of such LR servers and the simplest one to implement, so that it is adopted in many real systems. In this research we suggest an improved version of DRR, the DRR with Instant Service (DRR-IS), and analyze it. We have proved that the DRR-IS is still an LR sewer and have obtained its latency. The DRR-IS, compared with DRR, turns out to have the same complexity while provide about $30\%$ better latency.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.1-10
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• 2011

Proportional.Integral.Derivative control schemes continue to provide the simplest and effective solutions to most of the control engineering applications today. However PID controller is poorly tuned in practice with most of the tuning done manually which is difficult and time consuming. This research comes up with a soft computing approach involving Genetic Algorithm, Evolutionary Programming, and Particle Swarm Optimization and Ant colony optimization. The proposed algorithm is used to tune the PID parameters and its performance has been compared with the conventional methods like Ziegler Nichols and Lambda method. The results obtained reflect that use of heuristic algorithm based controller improves the performance of process in terms of time domain specifications, set point tracking, and regulatory changes and also provides an optimum stability. This research addresses comparison of tuning of the PID controller using soft computing techniques on Machine Direction of basics weight control in pulp and paper industry. Compared to other conventional PID tuning methods, the result shows that better performance can be achieved with the soft computing based tuning method. The ability of the designed controller, in terms of tracking set point, is also compared and simulation results are shown.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.48-48
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• 2009

Conventionally in pulsed gas metal arc welding (GMAW-P), drop transfer is analyzed with simplest square pulse waveform. While the pulse current is described by four parameters (peak current magnitude and time plus base current magnitude and time), it deviates the real pulse shape. Real pulse can be better idealized by the trapezoidal pulse waveform described by two additional parameters, i.e., current rise and fall rate (dI/dt). Power source response rate is described by these parameters. In this work, the effect of these parameters on drop transfer is predicted by the force displacement model (FDM). While peak current has significant effects on drop detachment, drop transfer is also influenced by the current rise rate. Predictions indicate that the current rise rate can have considerable effects on the size of the detached drop if other pulse parameters are kept constant. FDM is applied to determine peak time for one drop one pulse condition (ODOP) when rests of the pulse parameters are given. The predicted range of ODOP shows good agreement with experimental data.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.144-147
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• 2008

A glass bulb is the most reliable and simplest device for a fire sprinkler head system. We had developed an accurate glass bulb. The glass bulb is composed with a glass ampoule, liquid filled within the ampoule and an air bubble in the liquid. The first step of the development was to establish a stable mass production system for uniform glass ampoule. The second step is to optimize the composition of the liquid and the size of the bubble. It was also a difficult problem to devise manufacturing process to form uniform bubble size. The final step for the development is to control the mechanics for glass breaking by surface treatment for the glass bulb.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.139-146
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• 2013

A process diagnosis method for membrane water treatment plant was developed using a constant flux membrane fouling model. This diagnosis method can be applied to a real-field membrane-based water treatment plant as an early alarming system for membrane fouling. The constant flux membrane fouling model was based on the simplest equation form to describe change in trans-membrane pressure (TMP) during the filtration cycle from a literature. The model was verified using a pilot-scale microfiltraton (MF) plant with two commercial MF membrane modules (72 m2 of membrane area). The predicted TMP data were produced using the model, where the modeling parameters were obtained by the least square method using the early plant data and modeling equations. The diagnosis was carried out by comparing the predicted TMP data (as baseline) and real plant data. As a result of the case study, the diagnsis method worked pretty well to predict the early points where fouling started to occur.

• Korean Journal of Head & Neck Oncology
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• v.24 no.2
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• pp.194-196
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• 2008

Dermoid cysts are developmental anomalies that represent the simplest form of teratoma. They are the result of the sequestration of the skin along the lines of embryonic closure. These cysts of the head and neck are uncommon and account for 7% of all dermoid cysts. They are predominantly found in the orbit, floor of mouth, and nose. As a dermoid cyst of the parotid gland is extremely rare, it is often misdiagnosed preoperatively. By way of imaging modalities such as computed tomography, MRI and ultrasongraphy along with FNAB, it can be differentiated from many other cystic lesions of the parotid gland. We report a case of dermoid cyst of the parotid gland which masqueraded as lipoma before complete surgical excision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5256-5262
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• 2014

Recently, Distributed Denial of Service (DDoS) attacks, such as spreading malicious code, cyber-terrorism, have occurred in government agencies, the press and the financial sector. DDoS attacks are the simplest Internet-based infringement attacks techniques that have fatal consequences. DDoS attacks have caused bandwidth consumption at the network layer. These attacks are difficult to detect defend against because the attack packets are not significantly different from normal traffic. Abnormal traffic is threatening the stability of the network. Therefore, the abnormal traffic by generating indications will need to be detected in advance. This study examined the abnormal traffic detection technique using a forecasting model-based trend model.

• Journal of Fashion Business
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• v.7 no.3
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• pp.60-70
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• 2003

Textile scientists have regarded the material appearance of natural fibers, especially that of silk or wool fibers, as the benchmark for reinventing the look and feel of the long term, friendly companion of mankind. The appearances or textures of the materials surrounding us in everyday life have long been interesting topics to many people.from scholars to painters. Even the simplest questions may require careful pondering. Why is the silk fabric so lustrous with subtlety? Recently, appearance models have become increasingly important in textile products. They are needed to model and simulate different models. In this study, the optical characteristics of filament yarns and knitted fabrics were investigated using images taken at various angles and illumination conditions. Then the images were analyzed using some image analysis techniques, such as thresholding and measuring luster blobs. The anisotropic nature of the filamentous specimens was studied based on the images acquired at different incident illumination and observing angles with several alignment positions of the fabric specimens. A few cylindrical models were generated using commercially available software, Rhinoceros, and then on the models, a ray-tracing algorithm based on a software, POV-Ray, was applied to simulate the appearance or lustrous images of the monofilament models.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.2
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• pp.113-123
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• 2001

The success of complete denture prosthesis is to satisfy three basic requirements for the edentulous patient : maximum comfort, efficiency, and esthetic appearance. This can be achieved only if the dentures are both stable and retentive. When the residual alveolar ridge has resorbed significantly, stability and retention are more dependent on the correct position of the teeth and external surfaces of the denture. The stability and retention of the denture can be improved by locating the denture in the neutral zone and reproducing exact mandibular border movement for balanced occlusion. The neutral zone philosophy is based upon the concept that there exists a specific area where the musculature function will not unseat the denture in the mouth. In here, forces generated by the tongue are neutralized by the forces generated by the lips and cheeks. One of the simplest methods for recording border movements in three dimensions is to make stereographic record of condylar movement. Stereographs are made in the mouth during mandibular movement with intraoral clutches and central bearing point, and used in dictating the condylar movement on the articulator later by generating the condylar paths in doughy acrylic resin. Its procedure is simpler and more convenient than that of Pantograph. In this clinical report, we introduce the concept of neutral zone and stereograph in complete denture fabrication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2197-2210
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• 1998

In the grand alliance (GA) HDTV receiver, a coherent detection is empolyed for coherent demodulation of vestigial side-band (VSB) signal by using frequency and phaselocked loop(FPLL) operating on the pilot carrier. Additional phase tracking loop (PTL) employed to track out phase noise that has not been removed by the FPLL in theGA system. In this paper, we propose an algorithm for phase detection which utilizes a weighting function. The simplest implementation of the proposed algorithm using te sign of the Q channel component can be tractable by imposing a phase detection gain to the loop gain. It is obserbed that the propsoed algorithm has a robust characteristic against the performance of the digital filters used for Q channel estimation. A second goal of this paper is to introduce a gain control algorithm for the PTL in order to provide an effective implementation of the proposed phase detection algorithm. And we design the PTL through the realization of the simplified digital filter for H/W reduction. The proposed algorithms and the designed PTL are evaluated by computer simulation. In spite of using the simplified H/W structure, simulation results show that the proposed algorithms outperform the coventional PTL algorithms in the phase detection and tracking performance.