• Nuclear Engineering and Technology
• /
• v.31 no.3
• /
• pp.344-363
• /
• 1999

A multi-dimensional thermal-hydraulic system analysis code, MARS 1.3.1, has been developed in order to have the realistic analysis capability of two-phase thermal-hydraulic transients for pressurized water reactor (PWR) plants. As the backbones for the MARS code, the RELAP5/MOD3.2.1.2 and COBRA-TF codes were adopted in order to take advantages of the very general, versatile features of RELAP5 and the realistic three-dimensional hydrodynamic module of COBRA-TF. In the MARS code, all the functional modules of the two codes were unified into a single code first. Then, the source codes were converted into the standard Fortran 90, and then they were restructured using a modular data structure based on "derived type variables" and a new "dynamic memory allocation" scheme. In addition, the Windows features were implemented to improve user friendliness. This paper presents the developmental work of the MARS version 1.3.1 including the hydrodynamic model unification, the heat structure coupling, the code restructuring and modernization, and their verifications.their verifications.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.3
• /
• pp.348-354
• /
• 1993

In this research, a multi-tree coder at 9.6Kbits/sec using a novel scheme for adaptation of the short-term coefficients is developed. The overall delay of the tree coder is maintained at 2.5 msec(16 samples at the 6.4KHz sampling frequency). This coder produces good quality speech over ideal channels, and it is very robust to channel errors up to a bit error rate (BER) of $10^{-3}$. This robustness is achieved by using a parallel adaptation scheme in combination with the use of a smoothed version of the received excitation sequence for adaptation of the short-term prediction coefficients. For the multi-tree coder, reconstructed output speech is evaluated using signal-to-quantization noise ratios (SNR), segmental SNRs, and informal listening tests.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.2
• /
• pp.670-686
• /
• 2017

MapReduce (MRV1), a popular programming model, proposed by Google, has been well used to process large datasets in Hadoop, an open source cloud platform. Its new version MapReduce 2.0 (MRV2) developed along with the emerging of Yarn has achieved obvious improvement over MRV1. However, MRV2 suffers from long finishing time on certain types of jobs. Speculative Execution (SE) has been presented as an approach to the problem above by backing up those delayed jobs from low-performance machines to higher ones. In this paper, an adaptive SE strategy (ASE) is presented in Hadoop-2.6.0. Experiment results have depicted that the ASE duplicates tasks according to real-time resources usage among work nodes in a cloud. In addition, the performance of MRV2 is largely improved using the ASE strategy on job execution time and resource consumption, whether in a multi-job environment.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.6
• /
• pp.1493-1505
• /
• 1996

As Internet and its users grow dramatically multi-media data are getting common, many types of electronic mail applications are showing up. Internet s/w developers and users would like to electronic mail system for commercial purposes. They also would like to protect their electronic mail somehow. For these purpose, the security feature using cryptography is one of the essential functions. In this paper, we describe the library function development for handing MOSS(MIME Object Security Service), the security version of MINE(Multi -Purpose Internet Mail Extension). For these purpose, we explain the security features and structures of MOSS and defined the necessary function and we also discussed design issues for the MOSS implementation.

• 한국경영정보학회:학술대회논문집
• /
• 2008.06a
• /
• pp.383-393
• /
• 2008

Online games are the popular topic due to the increased total online game market volume nowadays. And many studies on online games are released. But most studies used the questionnaire method that reveals only section of the situation like a snapshot. For this reason, previous studies have a little limitation that does not show dynamical changing issues like a product life cycle and changes in customer's mind Because of this, we studied on online games with the system dynamic model which can show dynamic simulations to analysis time series data. We chose MMORPG (Massively Multi-play Online) RPG (Role Playing Game) in sort of online games because it has many absorbing factors and enthusiastic users. We designed the simulation model which analyzes the influences of update and CRM strategy on users. We put the game developer who is ready for updated version game and released that periodically and focused on dormant users who used to be enthusiastic about MMORPG. The simulation results showed that the update has positive influences on new users gathering and hold established users. And CRM strategies help to prevent dormant users from transferring to rivals by offering them re-absorbing factors. Through this study, we confirmed the importance of update on online games and the necessity of introducing CRM strategy in the online game market.

• Journal of Information Processing Systems
• /
• v.5 no.2
• /
• pp.105-116
• /
• 2009

To solve the general problems surrounding the application of genetic algorithms in stereo matching, two measures are proposed. Firstly, the strategy of simplified population-based incremental learning (PBIL) is adopted to reduce the problems with memory consumption and search inefficiency, and a scheme for controlling the distance of neighbors for disparity smoothness is inserted to obtain a wide-area consistency of disparities. In addition, an alternative version of the proposed algorithm, without the use of a probability vector, is also presented for simpler set-ups. Secondly, programmable graphics-hardware (GPU) consists of multiple multi-processors and has a powerful parallelism which can perform operations in parallel at low cost. Therefore, in order to decrease the running time further, a model of the proposed algorithm, which can be run on programmable graphics-hardware (GPU), is presented for the first time. The algorithms are implemented on the CPU as well as on the GPU and are evaluated by experiments. The experimental results show that the proposed algorithm offers better performance than traditional BMA methods with a deliberate relaxation and its modified version in terms of both running speed and stability. The comparison of computation times for the algorithm both on the GPU and the CPU shows that the former has more speed-up than the latter, the bigger the image size is.

• The Journal of Information Systems
• /
• v.17 no.4
• /
• pp.281-299
• /
• 2008

An online game is popular topic due to the increased total online game market volume nowadays. Even though many studies on an online game are released, most studies have used survey method that reveal only section of the situation like a snapshot. For this reason, previous studies have a little limitation that does not show dynamically changing issues like a product life cycle and change in customer's satisfaction. Because of this, we researched on an online game with the system dynamic model which can show dynamic simulation to analysis time series data. We chose MMORPG (Massively Multi-play Online Role Playing Game) in sort of an online game because it has many absorbing factors and enthusiastic users. We assumed that the game developer is ready for updated version game and release that periodically and focused on dormant users who used to be enthusiastic about MMORPG and designed simulation model which analyze how to influence of update and CRM strategy on users. The simulation results showed that the update has positive influences to gather new users and hold established users and CRM strategies help to prevent dormant users from transferring to rivals to offer them re-absorbing factors. Through this study, we confirmed importance of update on a online game and suggested the necessity to introduce CRM strategy in an online game market.

• Journal of the Korean Society of Food Culture
• /
• v.30 no.5
• /
• pp.629-643
• /
• 2015

The goal of the current study was to analyze major factors for improvement of quality of life in contract foodservice customers. This study investigated how characteristics of customers, foodservice management, and competitors differ in different contract foodservice business environments in order to understand increasing concerns over health, in-house working, and the environment, which are directly connected to work and life satisfaction and company profits. For the foodservice business environment, this study classified environmental factors reported by Duncan (1972) into three factors: customer environment, foodservice management environment, and competitor environment. Multi-regression analysis was conducted on quality of life using the Korean version of the WHO Quality of Life Scale Abbreviated Version (WHOQOL-BREF). Sub-factors of the contract foodservice business environment included foodservice management environment, customer environment, and competitor environment in the order of importance. The results indicate that the foodservice management environment of the company or organization where the customer is employed has the most substantial influence on quality of customer life.

• Korean Journal of Occupational Health Nursing
• /
• v.25 no.3
• /
• pp.227-237
• /
• 2016

Purpose: The purpose of this study was to identify the effects of nursing work environment and job stress on health problems of hospital nurses. Methods: The subjects were 200 nurses working in S general hospital in Gyeongnam, and the data were collected using organized questionnaire from Jan 10 to 25, 2015. The Korean version of the practice environment scale of nursing work index, the instrument for job stress, and the Korean version of Todie Health Index for health problem were used for measurement. The collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation, and multiple regression. Results: The nursing work environment was found to be slightly negative, and the job stress was found to be high. There were significant correlation among nursing work environment, job stress, and health problems. In addition, it showed that the nursing work environment and job stress of nurses were factors affecting their health problems. Conclusion: The nursing work environment and job stress are influencing factors on the health problems of hospital nurses. Multi-faceted efforts to create a positive nursing work environment are required. Further researches related to association between the nursing work environment and health problem of nurses are needed.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.1
• /
• pp.255-259
• /
• 2016

Background: Reliable and validated instruments are needed in order to study the quality of life in myeloma patients. This study aimed to translate and explore the psychometric properties of the European Organisation for Research and Treatment of Cancer (EORTC) myeloma module (QLQ-MY20) in Iranian patients. Materials and Methods: Two hundred and fifteen patients with multiple myeloma (MM) were recruited from Imam Khomeini Hospital, Tehran. A standard forward-backward translation procedure was implemented. Participating patients were asked to complete the EORTC QLQ-C30 and the QLQ-MY20 three times, at study entry, after two weeks, and again after three months. Data were tested for the range of measurement, internal consistency, test-retest reliability, known group comparison, responsiveness and factor structure. Results: Mean age of the patients was 60.7 years. No floor and ceiling effects were seen for the QLQ-MY20. Cronbach's ${\alpha}$ was greater than 0.80 for all three multi-item scales (ranging from 0.82 to 0.93). All four scales had test-retest reliability of 0.85 or greater. Results of the confirmatory factor analysis that the hypothesized 3-scale measurement model of the QLQ-MY20. Moreover, the Persian version for the QLQ-MY20 differentiated between subgroups of the patients in terms of beta-2 microglobulin, fracture and performance status. The responsiveness of the QLQ-MY20 to change over time was confirmed within 3 months. Conclusions: the results of our study indicate that our Iranian version of the QLQ-MY20 is a feasible, reliable and valid questionnaire for assessing the condition-specific quality of life of patients with MM.