• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.5
• /
• pp.416-426
• /
• 2005

A B2Bi system needs a message storage subsystem that efficiently logs and searches XML messages which have been sent from orreceived by it. XML database systems and XML enabled relational databases systems are not adequate as a message storage system because of their expensiveness and excessiveness in functionality. Storage schemes that split XML messages into database records are also unacceptable because of either low performance or implementation hardness. In this paper, we propose a storage scheme that can be applied to implement a message storage system based on a relational database system. In this scheme, messages are examined only through the index fields that have been registered for each message types. Therefore, the proposed storage scheme cannot support such a powerful search facility like XQL, but it provides high performance message legging and restricted search facility. There are three alternative database schemas to store the index fields. This paper compares the advantages and disadvantages of the three schemas through experimental tests.

• Communications of the Korean Institute of Information Scientists and Engineers
• /
• v.1 no.1
• /
• pp.23-35
• /
• 1983

In its global meaning language translation refers to the process whereby a program which is executable in one computer can be executed in another computer directly to obtain the same result. There are four different ways of approaching translation. The first way is translation by a Translator or a Compier, the second way is Interpretation, the third way is Simulation, the last way is Emulation. This paper introduces the M-C Translator which was designed as the first way of translation. The MUSS 80 language (the subsystem of the UNIVAC Solid State 80 S-4 assembly language system) was chosen as the source language which includes forty-three instructions, using the CYBER COMPASS as the object language. The M-C translator is a two pass translator and is a two pas translator and es written in Fortran Extended language. For this M-C Translation, seven COMPASS subroutines and a set of thirty-five macros were prepared. Each executable source instruction corresponds to a macro, so it will be a macro instruction within the object profram. Subroutines are used to retain and handle the source data representation the same way in the object program as in the source system, and are used to convert the decimal source data into the equivalent binary result into the equivalent USS-80digits before and after arithmetic operations. The source instructions can be classified into three categories. First, therd are some instructions which are meaningless in the object system and are therefore unnecessary to translate, and the remaining instructions should be translated. Second, There are some instructions are required to indicate dual address portions. Third, there are Three instructions which have overflow conditions, which are lacking in the remaining instructions. The construction and functions of the M-C Translator, are explained including some of the subroutines, and macros. The problems, difficulties and the method of solving them, and easier features on this translation are analysed. The study of how to save memory and time will be continued.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.4
• /
• pp.25-35
• /
• 2008

Variable Message Sign(VMS) is one of the subsystem of Intelligent Transportation Systems (ITS), which is useful for providing real-time information on weather, traffic and highway conditions. However, there are various situations such as incidents/accidents, constructions, special events, etc., which would be occurred on segments, it is unable to control traffic with only the VMS. Thus, it is essential to use of PVMS(Portable Variable Message Signs), which can move to the location needed traffic control and provide more active traffic information than VMS. This study developed a legibility distance model for PVMS messages using in-vehicle Differential Global Positioning Data(DGPS). Traffic conditions, drivers' characteristics, weather conditions and characteristics of PVMS message were investigated for establishing the legibility model based on multiple linear regression analysis. The factors such as height of PVMS characters, spot speed, age, gender and day and night were identified as dominants affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing PVMS messages for providing more effective real-time traffic information.

• Aerospace Engineering and Technology
• /
• v.7 no.1
• /
• pp.229-235
• /
• 2008

The ground flight termination system(GFTS) could be used for the termination of launch vehicle in flight motion when the launch vehicle deviates from the designated route due to the system malfunction or failure as well as the launch vehicle can't be tracked by the ground tracking system. This paper introduces the basic concept and design of the ground flight termination system to be used for KSLV launch mission in NARO space center. In order to design the optimal ground flight termination system for KSLV launch application, the operational concept reflected on the flight trajectory and system characteristics of KSLV launch vehicle should be considered. Moreover the RF link budget analysis, and the analysis for system availability and reliability are done. Based on the analysis above, the each subsystem of ground flight termination to transmit the termination signal in stable is designed for KSLV launch mission.

• Korean Journal of Remote Sensing
• /
• v.4 no.1
• /
• pp.31-40
• /
• 1988

Low-cost microcomputer systems can be assembled which possess computing power, color display, memory, and storage capacity approximately equal to graphic workstactions. A low-cost, flexible, and user-friendly IBM/PC/XT/AT based image processing system has been developed and named as KMIPS(KAIST (Korea Advanced Institute of Science & Technology) Map and Image Processing Station). It can be easily utilized by the resource managers who are not computer specialists. This system can: * directly access Landsat MSS and TM, SPOT, NOAA AVHRR, MOS-1 satellite imagery and other imagery from different sources via magnetic tape drive connected with IBM/PC; * extract image up to 1024 line by 1024 column and display it up to 480 line by 672 column with 512 colors simultaneously available; * digitize photographs using a frame grabber subsystem(512 by 512 picture elements); * perform a variety of image analyses, GIS and terrain analyses, and display functions; and * generate map and hard copies to the various scales. All raster data input to the microcomputer system is geographically referenced to the topographic map series in any rater cell size selected by the user. This map oriented, georeferenced approach of this system enables user to create a very accurately registered(.+-.1 picture element), multivariable, multitemporal data sets which can be subsequently subsequently subjected to various analyses and display functions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.330-339
• /
• 2008

Ground-based interceptors(GBI) comprise a major element of the strategic defense against hostile targets like Intercontinental Ballistic Missiles(ICBM) and reentry vehicles(RV) dispersed from them. An optimum design of the subsystems is required to increase the performance and reliability of these GBI. Propulsion subsystem design and optimization is the motivation for this effort. This paper describes an effort in which an entire GBI missile system, including a multi-stage solid rocket booster, is considered simultaneously in a Genetic Algorithm(GA) performance optimization process. Single goal, constrained optimization is performed. For specified payload and miss distance, time of flight, the most important component in the optimization process is the booster, for its takeoff weight, time of flight, or a combination of the two. The GBI is assumed to be a multistage missile that uses target location data provided by two ground based RF radar sensors and two low earth orbit(LEO) IR sensors. 3Dimensional model is developed for a multistage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The monostatic radar cross section (RCS) data of a three stage ICBM is used. For preliminary design, GBI is assumed to have a fixed initial position from the target launch point and zero launch delay. GBI carries the Kill Vehicle(KV) to an optimal position in space to allow it to complete the intercept. The objective is to design and optimize the propulsion system for the GBI that will fulfill mission requirements and objectives. The KV weight and volume requirements are specified in the problem definition before the optimization is computed. We have considered only continuous design variables, while considering discrete variables as input. Though the number of stages should also be one of the design variables, however, in this paper it is fixed as three. The elite solution from GA is passed on to(Sequential Quadratic Programming) SQP as near optimal guess. The SQP then performs local convergence to identify the minimum mass of the GBI. The performance of the three staged GBI is validated using a ballistic missile intercept scenario modeled in Matlab/SIMULINK.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.11a
• /
• pp.359-365
• /
• 2008

Turbopump test for a 30-ton-thrust liquid rocket engine was carried out using real-propellant. Liquid oxygen, kerosene, cold hydrogen gas were used for the oxidizer pump, the fuel pump, the turbine, respectively. The turbopump was run stably at the design and off-design conditions and the performance requirements were satisfied, which implies that the turbopump development at the engine subsystem level is successfully accomplished in the point of performance validation. This paper presents the results of a test where the turbopump was run for 75 seconds at three operating modes. In terms of performance characteristics of pumps and turbine, the results from turbopump assembly test using real-propellant showed a good agreement with those from the turbopump component tests using simulant working fluid.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.4
• /
• pp.22-33
• /
• 2018

Recently domestic manufacturing companies have been experiencing worsening profitability and stunted growth due to the long-term economic recession and the rapid rise of developing countries such as China and Southeast Asia. These difficulties force many companies to concentrate their core competencies on new value creation and innovation in order to gain momentum for new growth. Enterprise Resource Planning (ERP) has been considered as one of viable solutions. Among the various modules in ERP, shop floor control function in the production management module is rather limited. In order to overcome this problem, Manufacturing Execution System (MES) has been used as a subsystem which has a strong information gathering power and flexibility. Both systems interact closely with each other. In particular, ERP requires fast, accurate shop floor information at MES. This paper describes how to synchronize relevant information between ERP and MES with theory of constraints (TOC). The processing time information transmitted from the MES workplace is received at the ERP workplace. In the process, the received processing time is causing information distortion in ERP, when the information gathering standard of MES is different from the ERP information interpretation standard. The Drum-Buffer-Rope theory of TOC was applied to resolve this problem, therefore, information synchronization between both systems was made. As a precondition, the standard time of the upper ERP system was rearranged according to the capacity constraints resource. As a result, standard time restructuring has affected changes in labor costs. Standard labor costs have come close to actual ones, and information synchronization of MES transmission data has improved the reliability of standard product costs, such that it enabled various company-wide restructuring actions to be much more effective.

• Knowledge Management Research
• /
• v.22 no.1
• /
• pp.1-19
• /
• 2021

Large-scaled hospital information system projects are often delayed than originally planned. Regarding project management, it is necessary to examine main factors triggering the schedule delay and to analyze the causality of such delay. This study tries to find the delay factors and causal relationship between them based on the case of the hospital information system development project by using the grounded theory method. It turned out that 'unrealistic scheduling' affects overall schedule delays like domino phenomenon, and 'poor analysis of existing systems' leads to poor quality of work analysis while 'poor subsystem integrated interface' triggers poor design quality. This study found out the factors affecting the delay of a project, analyzing cause-and-effect relationships between them in the academic side. From the practical view, it shows a solution to minimize delays in the project schedule for each of SI companies, hospitals and project managers.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.3
• /
• pp.175-182
• /
• 2022

In many engineering problems, the dynamic substructuring can be useful to analyze complex structures which made with many substructures, such as aircrafts and automotive vehicles. It was originally intended as a method to simplify the engineering problem. The powerful advantage to this is that computational efficiency dramatically increases with eliminating unnecessary degrees-of-freedom of the system and the system targets are concurrently satisfied. Craig-Bampton method has been widely used for the linear system reduction. Recently, multi-level optimization (such as target cascading), which propagates the system-level targets to the subsystem-level targets, has been widely utilized. To this concept, the genetic algorithm which one of the global optimization technique has been utilized to the substructure optimization. The number of internal modes for each substructure can be obtained by the genetic algorithm. Simultaneously, the reduced system meets the top-level targets. In this paper, various numerical examples are tested to verify this concept.