• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.1
• /
• pp.39-49
• /
• 2018

In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.4
• /
• pp.692-698
• /
• 2001

The radio communications by SSB and VHF transceivers are still used very efficiently in coast stations and military base stations. The communication system by the conventional SSB and VHF transceivers between a coast station and a terminal is an one-to-one system. In this dissertation, however, the conventional one-to-one system is expanded to one-to-multiple systems. Then, frequencies can be used effectively for distress, urgency, safety traffic, and military communications. An ICS has been proposed and added, in this dissertation, to the conventional SSB and VHF communication systems, which can realize one-to- several terminal communications. The line switching system by the ICS is to be remote-controlled by ASK modulated PTT signals and audio signals. An ICS can change a connection between terminal and transceiver through a circuit switching system at any time. For this purpose, the author has researched and developed a ASK transmission system, ICS system, control algorithm, multiprocessor system, and moni-toring system. As a conclusion, the developed line switching control systems and equipments can be used effectively for maritime communication, military communication, fishery communication, etc.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.5
• /
• pp.338-343
• /
• 2020

In this paper, it was shown that the decoding method of Hamming codes using soft values can be applied to molecular communication channels. A soft value criterion that can be used for decoding of Hamming codes for a molecular communication channel was proposed, and it has been shown through simulation that the decoding method using these values can improve reliability even in the molecular communication channel. A diffusion-based molecular communication channel was assumed, and information symbols were transmitted using BCSK modulation. After demodulating the number of molecules absorbed by the receiver at each symbol interval with an appropriate threshold, the number of molecules is no longer used. In this paper, the BER performance of the decoder was improved by utilizing information on the number of molecules that are no longer used as soft values in the decoding process. Simulation was performed to confirm the improvement in BER performance. When the number of molecules per bit is 600, the error rate of the Hamming code (15,11) was improved about 5.0×10^-3 to the error rate of the BCSK system without the Hamming code. It can be seen that the error rate of (15,11) Hamming code with the soft values was improved to the same extent. In the case of (7,4) Hamming code, the result is similar to that of (15,11) Hamming code. Therefore, it can be seen that the BER performance of the Hamming code can be greatly improved even in the molecular communication channel by using the difference between the number of molecules absorbed by the receiver and the threshold value as a soft value.

• Archives of design research
• /
• v.14 no.4
• /
• pp.179-188
• /
• 2001

Exhibit space is result that various kinds works of architecture design, interior design, plan and control of exhibit program, embodiment to display space, operation and administration etc. are formed accomplishing creation. Because exhibit space must consider interaction of value that is in dwelled along with the external form about human and exhibits. Therefore, display space of exhibition must achieve functional role that can accomplish communication with spectator as well as function as place that possess products of accumulative value. Therefore, we must establish effective communication plan by position and form of display space as well as properly of exhibits, display contents, exhibit program to achieve purpose of trade fair display. Display space of trade fair can be classed by wall style, corner style, head style, island style, two entrance style 5 according to the position. And we must plan communication plan by these position dividing the function to passive communication area, active communication area, intensive communication area, function achievement area. We will can grope contents and method for successful exhibit through communication plan that is connected form and position of exhibit between exhibit space of such trade fair and we may achieve purpose of trade fair display.

• Journal of Distribution Science
• /
• v.20 no.1
• /
• pp.1-11
• /
• 2022

Purpose: Increasing advancements in the technology industry are forcing people to become more accustomed to digital financial transaction activities. The need for fast and secure payment mechanisms has birthing new idea to digital financial transaction services. Along with increasing access to technology in digital payments, new service is developed in the form of digital wallets as the successor for electronic money. Research design, data and methodology: This research aims to find out whether using QR code as digital payment tool can build customer loyalty in consumers, especially to measure the factors of satisfaction, trust and commitment of customers to do payments with QR Codes. The QR code in this study is refer to the Quick Response Code Indonesian Standard (QRIS) which was officially implemented by Bank Indonesia starting on January 1, 2020 as a means of payment for digital transactions nationally. The research method uses a quantitative approach by way of surveying questionnaires using Likert scale of 100 samples. Results: The hypothesis analysis proved that the variables of satisfaction, trust and commitment together have positive and significant influences on customer loyalty. Conclusion: This research found that there are high interest in Millennials to do transaction using QRIS because it is deemed to be more easy, quick and safe. If a customer achieves a level of loyalty in the usage of digital transaction using QRIS then cashless society lifestyle can be considered successful and can be used in the future.

• Journal of information and communication convergence engineering
• /
• v.8 no.5
• /
• pp.586-590
• /
• 2010

Medical technology is gradually being developed by applying information technologies. Especially, RFID technology is being used for precise disease history information of patients [4]. And in case the patient is far away, the patient can be treated using network communication of the internet [5][6]. The internet makes us to treat or operate the patient without being restricted to time or space. If the above technologies are made as a system, the patient can be treated or operated without being restricted to time or space. In this paper, we present a patient treatment system has been implemented with a system using RFID and network communication of the internet [1][2][3][4]. The system is driven as follows. First, the information of patient can be checked from a remote PC, if the tag that a patient has been read through a reader. And a remote treatment is performed by controlling robot's arm with a joystick using internet network [19][20][21]. The RFID system was implemented in frequency of 125 KHz [1]. The information of patient can be checked with PDA, PC and C-LCD using Bluetooth and WLAN [7][8][9][10]. For the treatment and operation of the patient, the robot's arm has been formed using AX-12 motor, joystick and two buttons [11][12][13][14][15] [17][18].

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.4
• /
• pp.103-109
• /
• 2012

In this paper, We suggest electricity power management system which makes a good efficient and minimize wasteness of electricity power. We made electricity power management system based USN(Ubiquitous Sensor Network) for industries, factories, public offices and so on, with optimized system. Simply, we can measure and control electricity power as we plug it outlets. This system can monitor and control electricity power, organizing network of PLC(Power Line Communication) and TCP/IP with the sensor for electricity power. Through the acquisition data, this proposed system can manage and save the electricity power efficiently and also we can connect this system to server, anytime, anywhere with Android phone.

• Journal of Information Management
• /
• v.26 no.2
• /
• pp.111-130
• /
• 1995

New technologies will soon bring fundamental changes to the process of scientific communication. To understand the path that these changes may take in the future, we need to take a careful look at the past. By examining the history of scientific communication, we can see how new technologies can interact with changes in communication forms. By looking at the complex roles that journals have traditionally played, we can better understand how and when journals may incorporate these new technologies. From these models we can project that electronic journals must meet the basic needs that print journals do, that they will initially maintain many of the features of traditional print journals, that their transformation may be driven by external forces, and that they will be slow in reaching their full potential.

• Journal of Internet Computing and Services
• /
• v.19 no.3
• /
• pp.1-6
• /
• 2018

Widely used around the world, smartphones contain many features and can store content such as contacts, photos, and videos. Information that can be leaked in proportion to the information that the smartphone can store has also been increased. In recent years, accidents such as personal information leakage have occurred frequently. Personal information leakage is happening in the Android environment, which accounts for more than half of the smartphone operating system market share. Analyzing malicious apps that leak information can tell you how to prevent information leakage. Malicious apps that leak information will send importantinformation to the hacker's (C & C) server, which will use network communication. Malicious apps that are emerging nowadays encrypt and transmit important information through SSL communication. In this case, it is difficult to knowwhat kind of information is exposed to network. Therefore, we suggest a method to analyze malicious apps when leak important information through SSL communication. In this paper, we identify the way malicious apps leak information. And we propose a method for analyzing information leaked by SSL communication. Data before encryption was confirmed in the device through SSL hooking and SSL Strip method.

• Journal of Communications and Networks
• /
• v.17 no.5
• /
• pp.517-524
• /
• 2015

The fast and accurate spectrum sensing over an ultra-wide bandwidth is a big challenge for the radio environment cognition. Considering sparse signal feature, two novel compressed sensing schemes are proposed, which can reduce compressed sampling rate in contrast to the traditional scheme. One algorithm is dynamically adjusting compression ratio based on modulation recognition and identification of symbol rate, which can reduce compression ratio. Furthermore, without priori information of the modulation and symbol rate, another improved algorithm is proposed with the application potential in practice, which does not need to reconstruct the signals. The improved algorithm is divided into two stages, which are the approaching stage and the monitoring stage. The overall sampling rate can be dramatically reduced without the performance deterioration of the spectrum detection compared to the conventional static compressed sampling rate algorithm. Numerous results show that the proposed compressed sensing technique can reduce sampling rate by 35%, with an acceptable detection probability over 0.9.