• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.16-25
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• 2014

The system analysis and design program of the liquid rocket engine has been developed for preliminary conceptual design process. The program consists of modular programs analyzing the main thruster, the gas-generator, turbo-pumps, the turbine, pipes, valves and so on. Each module has been developed in order to estimate performance, weight, and shape parameters of the components. The results of them have been verified with experimental data or other programs.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.299-307
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• 2023

In the midst of accelerating wars around the world, unmanned robot technology that can guarantee the safety of human life is emerging. ERP-42 is a modular platform that can be used according to the application. In the field of defense, it can be used for transporting supplies, reconnaissance and surveillance, and medical evacuation in conflict areas. Due to the nature of the military environment, atypical environments are predominant, and in such environments, the platform's path followability is an important part of mission performance. This paper focuses on reducing the minimum turning radius in terms of improving path followability. The minimum turning radius of the existing 2WS/2WD in-wheel platform was reduced by increasing the torque of the independent driving in-wheel motor on the rear wheel to generate oversteer. To determine the degree of oversteer, two GPS were attached to the center of the front and rear wheelbases and measured. A closed-loop speed control method was used to maintain a constant rotational speed of each wheel despite changes in load or torque.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.219-223
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• 2012

For an off-site consequence analysis at nuclear power plant, MELCOR Accident Consequence Code System(MACCS) II code is widely used as a software tool. In this study, the algorithm of web-based off-site consequence analysis program(OSCAP) using the MACCS II code was developed for an Integrated Leak Rate Test (ILRT) interval extension and Level 3 probabilistic safety assessment(PSA), and verification and validation(V&V) of the program was performed. The main input data for the MACCS II code are meteorological, population distribution and source term information. However, it requires lots of time and efforts to generate the main input data for an off-site consequence analysis using the MACCS II code. For example, the meteorological data are collected from each nuclear power site in real time, but the formats of the raw data collected are different from each site. To reduce the efforts and time for risk assessments, the web-based OSCAP has an automatic processing module which converts the format of the raw data collected from each site to the input data format of the MACCS II code. The program also provides an automatic function of converting the latest population data from Statistics Korea, the National Statistical Office, to the population distribution input data format of the MACCS II code. For the source term data, the program includes the release fraction of each source term category resulting from modular accident analysis program(MAAP) code analysis and the core inventory data from ORIGEN. These analysis results of each plant in Korea are stored in a database module of the web-based OSCAP, so the user can select the defaulted source term data of each plant without handling source term input data.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.107-117
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• 2001

The characteristics of groundwater movement under the heavy rainfall at Nan-ji waste landfill site are studied using HELP(Hydraulic Evaluation of Landfill Performance) program, which calculates the daily leachate in the Nan-ji waste landfill site. In this study, instead of the average recharge value, which is used in the past study, the real reacharge value is used to calculate the daily leachater. It is found about 70 times greater than thor average recharge value under the condition of heavy rainfall in the rainy season. The flow characteristics of groundwater for water level fluctuation is simulated using the ground water flow model MODFLOW(A Modular 3-D Finite Different Groundwater Flow Model) program, and the slurry layer is newly added. The result of the study is different from that of the ordinary simulation, which shows much higher ground water level than from the ordinary simulation.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.993-1001
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• 2024

The TANDEM project is a European initiative funded under the EURATOM program. The project started on September 2022 and has a duration of 36 months. TANDEM stands for Small Modular ReacTor for a European sAfe aNd Decarbonized Energy Mix. Small Modular Reactors (SMRs) can be hybridized with other energy sources, storage systems and energy conversion applications to provide electricity, heat and hydrogen. Hybrid energy systems have the potential to strongly contribute to the energy decarbonization targeting carbon-neutrality in Europe by 2050. However, the integration of nuclear reactors, particularly SMRs, in hybrid energy systems, is a new R&D topic to be investigated. In this context, the TANDEM project aims to develop assessments and tools to facilitate the safe and efficient integration of SMRs into low-carbon hybrid energy systems. An open-source "TANDEM" model library of hybrid system components will be developed in Modelica language which, by coupling, will extend the capabilities of existing tools implemented in the project. The project proposes to specifically address the safety issues of SMRs related to their integration into hybrid energy systems, involving specific interactions between SMRs and the rest of the hybrid systems; new initiating events may have to be considered in the safety approach. TANDEM will study two hybrid systems covering the main trends of the European energy policy and market evolution at 2035's horizon: a district heating network and power supply in a large urban area, and an energy hub serving energy conversion systems, including hydrogen production; the energy hub is inspired from a harbor-like infrastructure. TANDEM will provide assessments on SMR safety, hybrid system operationality and techno-economics. Societal considerations will also be encased by analyzing European citizen engagement in SMR technology safety.

• Journal of Navigation and Port Research
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• v.48 no.4
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• pp.327-334
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• 2024

Amidst the burgeoning research on autonomous ships, there has been a marked increase in the development of new systems and equipment for these vessels. This study identifies specific assets and functional requirements essential for managing autonomous ships, and presents a system architecture applicable to conventional and autonomous vessels alike. The recommended fleet asset management system encompasses ship information, maintenance, crew, and operational management. Assets specific to autonomous ships include the MASS rating within ship information, advanced software and hardware for maintenance, and remote operators in the crew management. These asset functions are managed through separate, modular systems that permit easy attachment and detachment, hence ensuring compatibility with both traditional and autonomous ships. Moreover, the system is web-based which facilitates access through an internet environment without necessitating the installation of any program.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.4
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• pp.293-313
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• 2021

The aim of this study is to classify the structure levels and types of the reading program in the secondary school library. The object of analysis is the practice case of the reading program included in 'Occupying School Library by 1318 Bookworms' for recently 10 years. There are 375 cases. According to the analysis result, most of the reading programs have three layers made up of 'blend title- reading activities- educational activities'. And there are classified into eight types (lecture, viewing, presentation, exhibition, making sth, debating, answering a quiz, experience) of the reading activities. The type of reading program depend on how to combine to the educational activities(reading, writing, listening, watching, speaking, making). This attribute of educational activities match up with modularity, completeness itself and organizing system. Through modular process of educational activities, it's possible to design their own reading programs based on the reading activity by adding, compensating other educational activities.

• Journal of information and communication convergence engineering
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• v.4 no.4
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• pp.166-169
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• 2006

Almost all network systems provide an authentication mechanism based on user ID and password. In such system, it is easy to obtain the user password using a sniffer program with illegal eavesdropping. The one-time password and challenge-response method are useful authentication schemes that protect the user passwords against eavesdropping. In client/server environments, the one-time password scheme using time is especially useful because it solves the synchronization problem. In this paper, we present a new identification scheme: OPI(One Pass Identification). The security of OPI is based on the square root problem, and OPI is secure: against the well known attacks including pre-play attack, off-line dictionary attack and server comprise. A number of pass of OPI is one, and OPI processes the password and does not need the key. We think that OPI is excellent for the consuming time to verify the prover.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.69-72
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• 2003

This paper presents a current-mode multiple-input minimum circuit. The proposed circuit can be implemented by applying De Morgan’s law. The circuit diagram is simple and modular. It operates using a single 2.5V supply and has very low dissipation. The realization method is suitable for fabrication using CMOS technology and all transistors are operated in their saturation region. The performances of this proposed circuit were studied using the PSPICE analog simulation program. The simulation results show the approval of this circuit that it has adequate basic performances for a real-time fuzzy controller and a fuzzy computer.

• Publications of The Korean Astronomical Society
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• v.10 no.1
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• pp.67-78
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• 1995

An introduction to the first CCD camera system in Bohyunsan Optica1 Astronomy Observatory(CCD#l) is presented. The CCD camera adopts modular dewar design of IfA(Institute for Astronomy at Hawaii University) and SDSU(San Diego State University) general purpose CCD controller. The user interface is based on IfA design of easy-to-use QUI program running on the NeXT workstation. The characteristics of the CCD#l including Gain, Charge Transfer Efficiency, rms Read-Out Noise, Linearity and Dynamic range is tested and discussed. The CCD#l shows 6.4 electrons RON and gain of 3.49 electrons per ADU, and the optimization resulted in about 27 seconds readout time guaranteeing charge transfer efficiency of 0.99999 for both direction. Linearity test shows that non-linear coefficient is $6{\times}10^{-7}$ in the range of 0 to 30,000 ADU.