• KIPS Transactions on Computer and Communication Systems
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• v.4 no.3
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• pp.85-90
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• 2015

In this paper, anew parallel event-driven logic simulation is proposed. As the proposed prediction-based parallel event-driven simulation method uses both prediction data and actual data for the input and output values of local simulations executed in parallel, the synchronization overhead and the communication overhead, the major bottleneck of the performance improvement, are greatly reduced. Through the experimentation with multiple designs, we have observed the effectiveness of the proposed approach.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.3
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• pp.73-80
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• 2014

In this paper, we propose an incremental simulation method in event-driven HDL simulation to reduce the simulation execution time. In general, the simulation is repeated with a series of design changes. Incremental simulation is an efficient simulation method that shortens the simulation execution time for the following simulation by using the result of previous simulation. We have observed the effectiveness of the proposed approach through the experimentation with multiple real designs.

• Journal of the Korea Society for Simulation
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• v.5 no.2
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• pp.73-84
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• 1996

As circuits are larger and more complicated, logic simulation is playing a very important role in design verification. A good simulator should be fast and accurate, but unknown values in 3 value simulator may generate X-propagation problem which makes inaccurate output values. In this paper, a new partitioning method is devised to deal with X-propagation problem efficiently and an efficient algorithm is developed which is able to optimize time and accuracy by controlling partition depths. The results prove the effectiveness of the new simulation algorithm using some benchmark circuits.

• Land and Housing Review
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• v.7 no.3
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• pp.137-145
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• 2016

This study aims to empirically verify the positive impacts of PB(performance-based) HRM on the organizational effectiveness in a public corporation. The independent variables are 'PB staffing', 'PB appraisal', 'PB compensation'. The dependent variables are 'JS(job satisfaction)', 'OC(organizational commitment)'. The results are as follows. 'PB staffing' shows positive impact on both 'JS' and 'OC', but 'PB compensation' doesn't show positive impact on both 'JS' and 'OC'. Also, it is found that both 'PB appraisal' and 'PB compensation' do not show positive impact on 'OC'. 'PB appraisal' shows positive impact on 'JS', though. From the empirical analysis, the positive effects of the PB-HRM on the organizational effectiveness are partially verified. It is thought that these mixed results are originated from the particular situation in which the surveyed corporation is placed. After the merger of the corporation in 2009, even though it has introduced various PB-HRM systems, it has been through a harsh time such as wage freeze and return as measures of business normalization. This organizational situation may influence the verification of effectiveness of the normal PB-HRM.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.150-153
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• 2002

High dose rate (HDR) brachytherapy in the treatment of cervix carcinoma has become popular, because it eliminated many of the problems with conventional brachytherapy. In order to improve clinical effectiveness with HDR brachytherapy, dose calculation algorithm, optimization procedures, and image registrations should be verified by comparing the dose distributions from a planning computer and those from a humanoid phantom irradiated. Therefore, the humanoid phantom should be designed such that the dose distributions could be quantitatively evaluated by utilizing the dosimeters with high spatial resolution. Therefore, the small size of thermoluminescent dosimeter (TLD) chips with the dimension of 1/8" and film dosimetry with spatial resolution of <1mm used to measure the radiation dosages in the phantom. The humanoid phantom called a pelvic phantom is made of water and tissue-equivalent acrylic plates. In order to firmly hold the HDR applicators in the water phantom, the applicators are inserted into the grooves of the applicator supporters. The dose distributions around the applicators, such as Point A and B, can be measured by placing a series of TLD chips (TLD-to- TLD distance: 5mm) in three TLD holders, and placing three verification films in orthogonal planes.

• Journal of Mechanical Science and Technology
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• v.17 no.9
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• pp.1349-1357
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• 2003

This paper deals with verification of the theoretical model for dynamic behavior of Pipeline Inspection Gauge (PIG) traveling through high pressure natural gas pipeline. The dynamic behavior of the PIG depends on the differential pressure across its body. This differential pressure is generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. To analyze the dynamic behavior characteristics such as gas flow in pipeline, and the PIG position and velocity, not only the mathematical models are derived, but also the theoretical models must be certified by actual pigging experiment. But there is not any found results of research on the experimental certification for dynamic behavior of the PIG. The reason is why the fabrication of the PIG as well as, a field application are very difficult. In this research, the effectiveness of the introduced solution using the method of characteristics (MOC) was certified through field application. In-line inspection tool, 30" geometry PIG, was fabricated and actual pigging was carried out at the pipeline segment in Korea Gas Corporation (KOGAS) high pressure system, Incheon LT (LNG Terminal) -Namdong GS (Governor Station) line. Pigging is fulfilled successfully. Comparison of simulation results with experimental results show that the derived mathematical models and the proposed computational schemes are effective for predicting the position and velocity of the PIG with a given operational conditions of pipeline.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.47-54
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• 2018

The purpose of this study is to verify the long - range measurement performance for practical field application of VDMS. The reliability of the VDMS was verified by comparison with the existing monitoring sensor, GPS, Accelerometer and LDS. It showed the ability to accurately measure the dynamic displacement by tracking a motion of free vibration of target. And using the PSD function of measured data, the results in the frequency domain were also analyzed. We judged that VDMS is able to identify the higher system mode and has sufficient reliability. Based on the reliability verification, we conducted tests for long-distance applicability for actual application of VDMS. The distance from the stationary target model structure was increased by 50m interval, and the maximum distance was set to 400m. From the distance of 150m, the image obtained by the commercial camcorder has an error in the analysis, so the measured displacement comparison was performed between the LDS and the refractor telescope measurement results. In the measurement results of the displacement area of VDMS, the data validity was deteriorated due to the data shift by the external force and the quality degradation of the enlarged image. However, even under the condition that the effectiveness of the displacement measurement data of VDMS is low, the first mode characteristic included in the free vibration of the object is clearly measured. If the influence from the external environment is controlled and stable data is collected, It is judged that reliability of long-distance VDMS can be secured.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.181-192
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• 2014

This study aims to analyze in relation to the influence and variable that their job instability and job stress attribute turnover intention to 134 employees of Midium and Small Firm less than 50 employees of a company being legal management at metropolitan area(Seoul, Kyeonggi-do, Incheon). To analyze a data, I took advantage of SPSS V.21, to analyze correlativity as each variable & causability, utilized bivariate correlation analysis & simple, multiple regression analysis, used sobel test as parameter effectiveness verification and post verification. This research result drew an conclusion to influence to turnover intention and stress perception from employment instability and job role stress of employees of Midium and Small Firm less than 50 employees being legal management, make of effect to the relation to stress perception and turnover intention indirectly. This result suggested the importance of stress management and human resource administration of employee of a Midium and Small Firm being legal management, drew an conclusion to attempt the research at first on employment instability and job stress of employees of Midium and Small Firm being legal management.

• Journal of Digital Contents Society
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• v.10 no.2
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• pp.309-318
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• 2009

The youth of this research using the Internet, navigate to the factors and relationships with Internet addiction, and the sense of seeking and want to verify the effectiveness of the regulation of interpersonal relationships. Who was studied 347 high school students in the Gyeonggi Province. SPSS win 13.0 program to study the reliability coefficient was calculated and analysis of care. Regression analysis, control theory verification (MMR) was conducted. Factor analysis using the Internet when the Internet addiction affect, interpersonal relationships and the pursuit of a sense of interaction was confirmed by the positive control the effects. Verification results of this research using the Internet to the fact that Internet addiction Static (+) gave. Pursuit of interpersonal relationships and a sense of control and the interaction effects were different.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.27-37
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• 2020

The Fukushima Daiichi accident in 2011 revealed some vulnerabilities of existing Nuclear Power Plants (NPPs) under extended Station Blackout (SBO) accident conditions. One of the key Severe Accident Management (SAM) strategies developed post Fukushima accident is the In-Vessel Retention (IVR) Strategy which aims to retain the structural integrity of the Reactor Pressure Vessel (RPV). RELAP/SCDAPSIM/MOD3.4 is selected to predict the thermal-hydraulic response of APR1400 undergoing an extended SBO. To assess the effectiveness of the IVR strategy, it is essential to quantify the underlying uncertainties. In this work, both the epistemic and aleatory uncertainties are considered to identify the success window of the IVR strategy. A set of in-vessel relevant phenomena were identified based on Phenomena Identification and Ranking Tables (PIRT) developed for severe accidents and propagated through the thermal-hydraulic model using Wilk's sampling method. For this work, a Systems Engineering (SE) approach is applied to facilitate the development process of assessing the reliability and robustness of the APR1400 IVR strategy. Specifically, the Kossiakoff SE method is used to identify the requirements, functions and physical architecture, and to develop a design verification and validation plan. Using the SE approach provides a systematic tool to successfully achieve the research goal by linking each requirement to a verification or validation test with predefined success criteria at each stage of the model development. The developed model identified the conditions necessary for successful implementation of the IVR strategy which maintains the vessel integrity and prevents a melt-through.