• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.6
• /
• pp.119-124
• /
• 2023

This paper proposes a new reference model that can represent data access with temporal locality and popularity bias. Among existing reference models, the LRU-stack model can express temporal locality, which is a characteristic that the more recently referenced data has, the higher the probability of being referenced again. However, it cannot take into account differences in popularity of the data. Conversely, the independent reference model can reflect the different popularity of data, but has the limitation of not being able to model changes in data reference trends over time. The reference model presented in this paper overcomes the limitations of these two models and has the feature of reflecting both the popularity bias of data and their changes over time. This paper also examines the relationship between the cache replacement algorithm and the reference model, and shows the optimality of the proposed model.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.6
• /
• pp.33-39
• /
• 2023

Recently, reinforcement learning has been used to improve the communication performance of flying ad-hoc networks (FANETs) and to design mobility models. Mobility model is a key factor for predicting and controlling the movement of unmmaned aerial vehicle (UAVs). In this paper, we designed and analyzed the performance of Q-learning with fourier basis function approximation and Deep-Q Network (DQN) models for optimal path finding in a three-dimensional virtual environment where UAVs operate. The experimental results show that the DQN model is more suitable for optimal path finding than the Q-learning model in a three-dimensional virtual environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.5
• /
• pp.177-182
• /
• 2023

When determining a meeting place, it is always a cumbersome problem to select an appropriate store with a short travel time for all participants. In this paper, to solve this problem, we propose an algorithm that recommends the best place and store based on the subway station and develop the system. This system provides a web-based store information registration function that allows self-employed people to register and promote their store, and provides an app-based function to recommend a meeting place to participants. The proposed algorithm reduces the travel time of all participants based on the subway map and improves fairness by using the standard deviation of the required time. In addition, this system presents a new way for self-employed people who have recently relied only on publicity through delivery apps.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.4
• /
• pp.57-64
• /
• 2024

The introduction of Smart Factories has transformed manufacturing towards more objective and efficient line management. However, most companies are not effectively utilizing the vast amount of sensor data collected every second. This study aims to use this data to predict product quality and manage production processes efficiently. Due to security issues, specific sensor data could not be verified, so semiconductor process-related training data from the "SAMSUNG SDS Brightics AI" site was used. Data preprocessing, including removing missing values, outliers, scaling, and feature elimination, was crucial for optimal sensor data. Oversampling was used to balance the imbalanced training dataset. The SVM (rbf) model achieved high performance (Accuracy: 97.07%, GM: 96.61%), surpassing the MLP model implemented by "SAMSUNG SDS Brightics AI". This research can be applied to various topics, such as predicting component lifecycles and process conditions.

• The KIPS Transactions:PartC
• /
• v.8C no.1
• /
• pp.75-87
• /
• 2001

The Conditional Access System is the complete system for ensuring that broadcasting services are only accessible to those who are entitled to receive them. Four major parts to this system are scrambling, descrambling, authentication and encryption. For the proper operation, which means hard-to- break and uninterrupted service, secure key management and efficient delivery mechanism are very important design factors to this system. Performance analysis is another important factor to this system that is used in massive subscriber environment. In this thesis, one of the secure and efficient key management mechanisms is proposed. For the secrecy of this mechanism, hierarchical stacking of keys and key generation matrix are proposed. For the proof of efficient delivery of those keys, simulation results and performance analysis. which is based on queuing analysis, are presented. Lastly, optimal key generation and delivery period, maximal and minimal key deliver time, and communication capacity for data collection are presented for various subscriber volume.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.1
• /
• pp.1-8
• /
• 2004

Nowadays the soccer becomes one of the best spot lighting sports in the world Especially the 2002 Korea-Japan World Cup was deeply impressed on all the korean. One goal of illuminating engineering should be the design of lighting system that can provide consistently high task visibility regardless of where a task might be located within a working space. The television broadcasting on the soccer has been an important role in the media. The standard of FIFA(The Federation Internationale do Football Association) requires recommended illuminance levels for artificial lighting for a player, an audience, TV broadcasting, as well as everybody in the stadium. This paper has proposed an algerian to select the suboptimal lighting tower position for watching and TV broadcasting a soccer game within a pleasant environment and an optimum illuminance distribution. The position using the software Philip's Calculux was chosen based an the calculations of a horizontal illuminance, vertical illuminance, uniformity, glare, and so on by changing lighting tower positions.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.9
• /
• pp.1147-1154
• /
• 2001

In this paper, we make plans for facilities, the 8-VSB DTV transmission system, installed in the near future, based on presently NTSC TV operating it. First of all we estimate transmission power for analog NTSC, digital 8-VSB terrestrial broadcasting and the effective condition of optimal receiving power result from it. It's also to estimate optimal receiving condition by using Longley-Rice's Field Strength calculating method that is to guess a profile between transmitting station and many receiving points. The 8-VSB DTV Propagation aims to high-speed transmission rates of 19.39Mbps datum to enable HDTV(High Definition Television) at NTSC 6MHz bandwidth. First of all, an optimization of field strength between transmission station and receiver must deal with considerable. Because of these reasons, 8-VSB DTV transmission needs effective extension for NTSC TV service coverage. Finally we present the transmitting output that is expected in changing NTSC VHF to DTV UHF for maintaining the transmitting output of NTSC TV that is equal to 8-VSB DTV in service coverage.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.2
• /
• pp.79-88
• /
• 2015

This paper introduces surveillance equipment "ADS-B", the core subject of traffic control system and study of ADS-B 1090ES ground receiver. The standard is set not only for functional but also its reliability by analyzing international standard documents and existing products. The Bias circuit is designed for less power consumption, low noise and high gain for RF module. The signal processing is capable of overcoming its bad conditions. MCU part is configured with the latest CPU for high speed communication with external parts and SNMP is selected for remote control communication. The performance of developed receiver satisfies national and international standards and its functions are more advanced compared to foreign receivers.

• Journal of Navigation and Port Research
• /
• v.27 no.4
• /
• pp.359-366
• /
• 2003

The paper describes on the construction and analysis of marine casualty numerical D/B (N-D/B) to implement Korean MArine Casualty Forecasting System (K-MACFOS). The main target of K-MACFOS is to broadcast the prediction number and risk level of marine casualties as like daily weather forecasting. The data relating to a total of 724 ship casualties in the west-southern sea area (33oN∼35oN, 124oE∼127oE) of Korean peninsula for 11 years (1990∼2000) have been compiled and converted into quantitative data with 14 numeric conversion scales. Through the statistical analysis using contour-map visualization, the usability of N-D/B and the casualty features of the target sea areas are discussed. In addition, the optimum year-band selection method is also proposed to provide correct N-D/B analysis and precise prediction of the number of marine casualties.

• Journal of Broadcast Engineering
• /
• v.11 no.1 s.30
• /
• pp.3-14
• /
• 2006

Music summarization means a technique which automatically generates the most importantand representative a part or parts ill music content. The techniques of music summarization have been studied with two categories according to summary characteristics. The first one is that the repeated part is provided as music summary and the second provides the combined segments which consist of segments with different characteristics as music summary in music content In this paper, we propose and evaluate two kinds of music summarization techniques. The algorithm using multi-level vector quantization which provides a repeated part as music summary gives fixed-length music summary is evaluated by overlapping ration between hand-made repeated parts and automatically generated summary. As results, the overlapping ratios of conventional methods are 42.2% and 47.4%, but that of proposed method with fixed-length summary is 67.1%. Optimal length music summary is evaluated by the portion of overlapping between summary and repeated part which is different length according to music content and the result shows that automatically-generated summary expresses more effective part than fixed-length summary with optimal length. The cluster-based algorithm using 2-D similarity matrix and k-means algorithm provides the combined segments as music summary. In order to evaluate this algorithm, we use MOS test consisting of two questions(How many similar segments are in summarized music? How many segments are included in same structure?) and the results show good performance.