• Journal of Korea Society of Industrial Information Systems
• /
• v.14 no.5
• /
• pp.61-73
• /
• 2009

Many software reliability growth models(SRGM) have been proposed since the software reliability issue was raised in 1972. The technology to estimate and grow the reliability of developing S/W to target value during testing phase were developed using them. Most of these propositions assumed the S/W debugging testing efforts be constant or even did not consider them. A few papers were presented as the software reliability evaluation considering the testing effort was important afterwards. The testing effort forms which have been presented by this kind of papers were exponential, Rayleigh, Weibull, or Logistic functions, and one of these 4 types was used as a testing effort function depending on the S/W developing circumstances. I propose the methology to evaluate the SRGM using least square estimater and maximum likelihood estimater for those 4 functions, and then examine parameters applying actual data adopted from real field test of developing S/W.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.11
• /
• pp.2569-2574
• /
• 2013

In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. In STAC protocol, the reader uses the tag number estimation scheme to determine the number of slots for the next reply round. If errors occur in the estimated number of tags, the identification performances will be degraded due to a lot of collision or idle slots. Therefore, in this paper, we propose an ERPB algorithm that the reader cancels the reply round when it experiences a series of collision or idle slots during the current round. The transmission probability control for the tag is also applied to the proposed algorithm. Through simulations, it is demonstrated that the collision rate for the proposed scheme is about 39% lower than STAC protocol. Therefore, the proposed scheme can achieve faster tag identification time compared with STAC protocol due to the low collision rate.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.6
• /
• pp.521-530
• /
• 2013

This paper proposes a task parallelism system (BioMP) to improve applications' execution time of multicore based mobile device. When application developers append the functions of parallel specification into the existing software, our proposed system supports the parallel processing of threads as well as a compatibility. BioMP improves the software in order that an existing large-scale source can recognize the multicore architecture. From our experiment, our idea improved the execution time of application until about 64% against the existing system in multicore environment based on quad core. In addition, BioMP does not require any additional modification of a mobile platform because BioMP is independent component. Consequently, when application developers release multicore-aware applications into the application store, users can immediately run without any modification of the mobile device.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.5
• /
• pp.933-940
• /
• 2024

In this study, an exponential family life distribution suitable for reliability analysis of system failures was applied to the NHPP-based software development model, and then the performance of models were newly evaluated by substituting the failure time data requested by the developer. First, as a result of analyzing the m(t) function that determines the model performance, all models showed the property of overestimating the ability to predict the true value. However, the Burr-Hatke-Exponential model, which showed the smallest error, was efficient. Second, the Lindley model was found to be the best when total evaluating the properties of the model performance (m(t), development cost, release time). Therefore, through this study, the performance of the exponential family life distribution was newly explored, and by utilizing related data, developers can identify required properties at an early stage and use them as basic reference data during the development testing phase.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1195-1201
• /
• 2011

Since the release of safety standard IEC 61508 which defines functional safety of electronic safety-related systems, SIL(Safety Integrity Level) certification for railway systems has gained lots of attention lately. In this paper, we propose a new design technique of the computer board for train control systems with high reliability and safety. The board is designed with TMR(Triple Modular Redundancy) using a certified SIL3 Texas Instrument(TI)'s TMS570 MCU(Micro-Controller Unit) to guarantee safety and reliability. TMR for the control device is implemented on FPGA(Field Programmable Gate Array) which integrates a comparator, a CAN(Controller Area Network) communication module, built-in self-error checking, error discriminant function to improve the reliability of the board. Even if a malfunction of a processing module occurs, the safety control function based on the proposed technique lets the system operate properly by detecting and masking the malfunction. An RTOS (Real Time Operation System) called FreeRTOS is ported on the board so that reliable and stable operation and convenient software development can be provided.

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

• Research in Community and Public Health Nursing
• /
• v.12 no.1
• /
• pp.150-167
• /
• 2001

This cross sectional study was done to find out the situation of computer online pornography access by 4th to 6th grade elementary school students. The subjects of this study were three elementary schools in Andong, which were selected randomly and 120 students randomly selected from 4th to 6th grade for a total of 360 students. The questionnaire was composed with the help of a community health nursing professor and through the reference review. The collected data were analysed by a PC SPSS 10.0 according to school grade and sex, an 12-test was implemented to learn what percent of students have computers and software which prohibit the viewing of online pornography, access motivation and time, content viewed, attitude after accessing the contents, and opinions about computer online pornography. The results of this study were as follows. 1. A total of 86.1% of students had computers at home. Most students placed computers in their own room, 78.9% of students had computer online communication experience. Higher grade students tended to have more experience of communications on the internet (P<0.001). Most students chatted on the internet once or twice a week and higher grade students tended to communicate online more frequently. (P<0.001). Most students used computers more than one hour a day (P<0.05). They used computers according to the following priorities: game, studying, listening to music, communications, chatting. 2. Regarding the frequency of going computer online more than seven times per week, male students showed a higher frequency than female students (P<0.05). Male students used computers more than one hour a day and female students less than half an hour (P<0.001). Male students mostly used computers to play computer games. On the other hand. female students used the computer to study, listen to music, and chat (P<0.001). 3. Regarding software installation to prevent access of computer online pornography, a total of 19.4% of students responded they installed one. but 80.6% didn't have any, 20.3% of students had accessed pornography, 46.6% of students responded. they first get to know to the computer online pornography through friends. 4. The reasons for accessing computer online pornography were ranked as follows: curiosity, interest, to release stress, and sex drive (P<0.05). Obscene contents were found in computer games, pictures, and video. Among these, pictures were the most common. 5. Regarding students' attitude toward online pornography, most students responded that they took much pleasure in the contents (P<0.05). 6. Regarding the question 'Does online pornography degrade morals and cause a sex crime', most students responded as 'no'. They also responded positively to the suggestion that the contents would be effective in preventing sex crimes and to release stress. 74.7% of students responded that males' access of the contents as proper but females' access as immoral. Regarding social efforts to protect students from this harmful environment. most replied that those efforts were unnecessary (P<0.001).

• Computers and Concrete
• /
• v.19 no.1
• /
• pp.1-6
• /
• 2017

Prestressed concrete I-girders are subject to different load types at their construction stages. At the time of strand release, i.e., detensioning, prestressed concrete girders are under the effect of dead and prestressing loads. At this stage, the camber, total net upward deflection, of prestressed girder is summation of the upward deflection due to the prestressing force and the downward deflection due to dead loads. For the calculation of the upward deflection, it is generally considered that prestressed concrete I-girder behaves linear-elastic. However, the field measurements on total net upward deflection of prestressed I-girder after detensioning show contradictory results. In this paper, camber calculations with the linear-elastic beam and elastic-stability theories are presented. One of a typical precast I-girder with 120 cm height and 31.5 m effective span length is selected as a case study. 3D finite element model (FEM) of the girder is developed by SAP2000 software, and the deflections of girder are obtained from linear and nonlinear-static analyses. Only geometric nonlinearity is taken into account. The material test and field measurement of this study are performed at prestressing girder plant. The results of the linear-elastic beam and elastic-stability theories are compared with FEM results and field measurements. It is seen that the camber predicted by elastic-stability theory gives acceptable results than the linear-elastic beam theory while strand releasing.

• Proceedings of the Safety Management and Science Conference
• /
• 2006.11a
• /
• pp.499-507
• /
• 2006

The tower cranes are widely used in very useful construction machine the sites of constructing high-structure and have a structural sensitiveness. Therefore, the accidents have often happened due to the deficiency of laborer's understanding md lack of safety of structure. Till now, as we have research and studied above, we can properly protect accidents by construction equipments particularly crane as well as most disasters which occur frequently in construction site. The goal of this study is the safety inspection model of the tower crane a construction site, which preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower nine using the correcting data. This study will be proposed a build-up solutions about operating and release of safety constructions and researched about software safety estimation. Also, preventing safety problems of Tower Crane Construction site as applying safety estimation program and laws and regulations. As a result, The real time control of tower crane inspection system is implemented by to illustrate the application of the adopted optimal design model.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.1
• /
• pp.37-49
• /
• 2007

The tower cranes are widely used in very useful construction machine the sites of constructing high-structure and have a structural sensitiveness. Therefore, the accidents have often happened due to the deficiency of laborer's understanding and lack of safety of structure. Till now, as we have research and studied above, we can properly protect accidents by construction equipments particularly crane as well as most disasters which occur frequently in construction site. The goal of this study is the safety inspection model of the tower crane a construction site, which preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower crane using the correcting data. This study will be proposed a build-up solutions about operating and release of safety constructions and researched about software safety estimation. Also, preventing safety problems of Tower Crane Construction site as applying safety estimation program and laws and regulations. As a result, The real time control of tower crane inspection system is implemented by to illustrate the application of the adopted optimal design model.