• The Journal of Information Systems
• /
• v.11 no.1
• /
• pp.175-198
• /
• 2002

This paper is to develop a security module for electronic approval systems. Electronic documents are created, transmitted and saved in the company's intranet computer network. Transmitting electronic documents, however, brings us a security problem. Communications among various computer systems are exposed to many security threats. Those threats are eavesdropping, repudiation, replay back etc. The main purpose of this paper is to develop a module which provides the security of electronic documents while they are passed from one place to another This paper applies Multi-Level security to the electronic approval system that guarantees security of electronic documents from many threats. Multi-Level security controls the access to the documents by granting security level to subject users and object electronic documents. To prevent possible replay back attacks, this paper also uses one time password to the system. The security module is composed of client program and server one. The module was developed using Microsoft Visual Basic 6.0 and Microsoft SQL Server 7.0. The code uses Richard Bondi's WCCO(Wiley CryptoAPI COM Objects) library functions which enables Visual Basic to access Microsoft CryptoAPI.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.5
• /
• pp.25-29
• /
• 2018

As society advances and consumers' perception of food safety changes, the demand for the safety of refrigerated and distributed foods is spreading. In this paper, we build an ICT system that can collect the TTH data from the NFC tag, store it, analyze the food safety level using it. This service platform consists of the temperature monitoring NFC tag attached to individual packaged food, the smartphone with NFC sensor, and the monitoring server with a big data system. Consumers and administrators in this system can easily identify and predict the safety level of individual packaged foods in real time using the provided app on smartphones. In the field of food safety, the use of new technologies such as ICT can create new value by combining with existing food industry in addition to creating new market by new service.

• Journal of The Korean Association For Science Education
• /
• v.12 no.1
• /
• pp.47-60
• /
• 1992

The purpose of this study was to investigate studesnts' attitudes toward computers and science subject using CAI(Computer-Assisted Instruction) as an instructional strategy in the elementary school level of science and computer literacy course. The influence of CAI programs on learner's attitudes toward computers and science varied according to the variables of,(l)sex (2)experience by computer learning, (3)learner's attitudes toward computers and science. Eighty nine samples were divided into the two groups.One group(48 studesnts)which is in the experimental group took a science instruction using CAI programs and computer literacy course, another group which is in the control group took only a science instruction using CAI programs. Data were collected and compared the experimental group with the control group. The results indicate as follows:(l) studesnts took science instruction using the CAI programs appeared a positive attitudes toward science. (2) the science attitudes of science instruction using the CAI programs was more effective in the lower group than in the upper group. (3) computer literacy course produced the positive attitude toward computers regardless of the experience by computer learning. (4) students using CAI programs with computer literacy course were more effective than students using CAI program only. (5) science instruction using the CAI programs was not found a meaningful difference by sex.

• The Journal of Information Systems
• /
• v.18 no.1
• /
• pp.25-46
• /
• 2009

According to adaptive structuration theory, faithfulness of appropriation(FOA), and consensus on appropriation(COA) are variables for measuring appropriation in use of IT. FOA is the level of interpreting and using the intentions of the IT designers objectively and COA is the level of agreement on ways of using IT among or with user group independently of designers' intention. In traditional theories of IT adoption, computer self-efficacy(CSE), self evaluation on abilities of using computer, has been considered as one of the important individual differences. which would influence on beliefs of using IT. Therefore, considering the relationship among CSE, FOA, COA and attitude, we can hypothesize that CSE would play a moderation varaible among appropriation related variables relationships, FOA-attitude and COA-attitude. The objective of this study is an analysis of CSE's moderation effects in causality relationship among appropriation measuring variables. For this purpose, we propose a research model where there are four hypotheses for moderation effects of CSE on the relationships between appropriation variables. We test these hypotheses by sampling ERP and groupware users. In result, our proposed hypotheses except moderation effect of COA-usefulness are accepted. Main contribution of this study is to identify the relationship between CSE and AST. This study implies that very careful consideration of users' CSE is necessary in order to perform managerial activities based on FOA and COA in IT management department.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.86.5-86
• /
• 2001

This work describes a design and implementation of the level & flow rate control system by using a single-chip microcontroller. The proposed model system is designed based on the use of the single-chip microcontroller 8031 with the EPROM emulator for programming the computer software. The microcontroller reaches the input level and flow signals from the level sensor and the turbine flowmeter, respectively, via the signal conditioning circuits and A/D converters in order to calculate the control signal. Moreover, the status of the process variable can easily be set up and controlled by program monitoring through the emulator, and can be graphically displayed on the computer screen. Experiment results were carried out which can be ...

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.3
• /
• pp.558-575
• /
• 2013

The purpose of a data leakage prevention system is to protect corporate information assets. The system monitors the packet exchanges between internal systems and the Internet, filters packets according to the data security policy defined by each company, or discretionarily deletes important data included in packets in order to prevent leakage of corporate information. However, the problem arises that the system may monitor employees' personal information, thus allowing their privacy to be violated. Therefore, it is necessary to find not only a solution for detecting leakage of significant information, but also a way to minimize the leakage of internal users' personal information. In this paper, we propose two models for representing the level of personal information disclosure during data leakage detection. One model measures only the disclosure frequencies of keywords that are defined as personal data. These frequencies are used to indicate the privacy violation level. The other model represents the context of privacy violation using a private data matrix. Each row of the matrix represents the disclosure counts for personal data keywords in a given time period, and each column represents the disclosure count of a certain keyword during the entire observation interval. Using the suggested matrix model, we can represent an abstracted context of the privacy violation situation. Experiments on the privacy violation situation to demonstrate the usability of the suggested models are also presented.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1039-1043
• /
• 2005

Despite the many significant advances made in robot architecture, the basic approaches are deliberative and reactive methods. They are quite different in recognizing outer environment and inner operating mechanism. For this reason, they have almost opposite characteristics. Later, researchers integrate these two approaches into hybrid architecture. In such architecture, Reactive module also called low-level motion control module have advantage in real-time reacting and sensing outer environment; Deliberative module also called high-level task planning module is good at planning task using world knowledge, reasoning and intelligent computing. This paper presents a framework of the integrated planning and control for mobile robot navigation. Unlike the existing hybrid architecture, it learns topological map from the world map by using MST (Minimum Spanning Tree)-based SOFM (Self-Organizing Feature Map) algorithm. High-level planning module plans simple tasks to low-level control module and low-level control module feedbacks the environment information to high-level planning module. This method allows for a tight integration between high-level and low-level modules, which provide real-time performance and strong adaptability and reactivity to outer environment and its unforeseen changes. This proposed framework is verified by simulation.

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.2
• /
• pp.19-33
• /
• 2002

In this Paper, we described the Parwan CPU using a VHDL at the behavioral level and then described by connecting CPU components at the dataflow level. Finally, we simulated to verify of execution of a CPU processor using a test-bench method. A presented design method was to enable information exchange of design and representation of operation were very exact and simple. Also. a documentation of design was available and it was easy that verify a operation of designed processor. The behavioral description of VHDL aids designer as we verify our understanding of the designed system, while the dataflow description can be used to verify the bussing and register structure of the design.

• Journal of Power Electronics
• /
• v.19 no.1
• /
• pp.108-118
• /
• 2019

This paper proposes a DC-link voltage balance controller using the fourth-phase of a three-level neutral-point clamped (NPC) PWM converter with medium vector selection (MVS) PWM for common-mode voltage reduction. MVS PWM makes the voltage reference by synthesizing the voltage vectors that cannot generate common-mode voltage. This PWM method is effective for reducing the EMI noise emitted from converter systems. However, the DC-link voltage imbalance problem is caused by the use of limited voltage vectors. Therefore, in this paper, the effect of MVS PWM on the DC-link voltage of a three-level NPC converter is analyzed. Then a proportional-derivative (PD) controller for the DC-link voltage balance is designed from the DC-link modeling. In addition, feedforward compensation of the neutral point current is included in the proposed PD controller. The effectiveness of the proposed controller is verified by experimental results.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2005.04a
• /
• pp.221-224
• /
• 2005

This paper proposes the system model that is more efficient and active than formal home automation system and it can conquer the limits of formal one using intelligent mobile robot. This system uses specialized intelligent mobile robot for home environment and the robot moves around home instead of human. We call the system model to HAuPIRS (Home Automation system using PDA based Intelligent Robot System). HAuPIRS control architecture is composed three parts and each part is User Level, Cognitive Level, Executive Level. It is easy to use system and possible to extend the home apparatusfrom new technology. We made the PBMoRo System (PDA Based Mobile Robot System) based on HAuPIRS architecture and verified the efficiency of the system model.