• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.37
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• pp.361-389
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• 2008

The purpose of this study is to detect the factors which have an effect on transformation level and performance and to provide the ways of successful transformation and vitalization from OEM to ODM. This study was proceeded by an empirical analysis. A model and hypotheses were set up and they were verified through the empirical analysis. Those factors were divided into four, inner company factors, strategic factors, core competence factors and purchase determining factors. In the result of the model suitability analysis on the study model of relationship among 'influencing factors of ODM transformation - ODM transformation level-export performance', every factors, $X^2=912.067$, DF=261, p value=0.000, GFI=0.737, AGFI=0.620, NFI=0.786, IFI=0.837, CFI=0.834, Q value=3.495 were rather insufficient to be a good model, but they were good enough for the general analysis. Taking these accounts into consideration, this study suggests the following implications. First, making a plan and setting up strategies in advance are required. Second, financial plan has to be prepared. Third, trends in global markets have to be analyzed. Fourth, companies have to focus on developing new materials and products through R&D. Fifth, quality competitiveness and quality control systems are required.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.3
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• pp.264-273
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• 2012

In this paper, two types of integrated gasification combined cycle (IGCC) plants using either an air separation unit (ASU) or an ion transport membrane (ITM), which provide the oxygen required in the gasification process, were simulated and their thermodynamic performance was compared. Also, the influence of adopting a pre-combustion $CO_2$ capture in the downstream of the gasification process on the performance of the two systems was examined. The system using the ITM exhibits greater net power output than the system using the ASU. However, its net plant efficiency is slightly lower because of the additional fuel consumption required to operate the ITM at an appropriate operating temperature. This efficiency comparison is based on the assumption of a moderately high purity (95%) of the oxygen generated from the ASU. However, if the oxygen purity of the ASU is to be comparable to that of the ITM, which is over 99%, the ASU based IGCC system would exhibit a lower net efficiency than the ITM based system.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3026-3031
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• 2008

In conventional closed-loop crankcase ventilation systems, the lubrication oil had to be re-circulated to the intake manifold, in the form of oil mist mixed with the blow-by gas. This blow-by gas containing the engine lubricant oil affects on the engine problems and the exhaust emissions. A high-efficient oil separator is required to minimize consumption of engine oil and reduce harmful emissions. In the conventional oil separator of CI engines, it has good oil separation performance even though separator design is simple, due to lots of the blow-by gas. As the emission regulation becomes severe, the oil separator for SI engines is also required. But in SI engines, separator design should be optimized, due to small size of oil particles and little amount of blow-by gas. In this study, oil separation performance classified by diameter of oil mist in cylinder head cover internal model which has three cyclones and two baffle plates for SI engine is calculated with CFD methodology.

• Wind and Structures
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• v.4 no.3
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• pp.213-226
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• 2001

Wind uplift rating of roofing systems is based on standardised test methods. Roof specimens are placed in an apparatus with specified table size (length and width) then subjected to the required wind load cycle. Currently, there is no consensus on the table size to be used by these testing protocols in spite of the fact that a table size plays a significant role in evaluating the performance. This paper presents a study with the objective to investigate the impact of table size on the performance of roofing systems. To achieve this purpose, extensive numerical experiments using the finite element method have been conducted to investigate the performance of roofing systems subjected to wind uplift pressures. Numerical results were compared with results obtained from experimental work to benchmark the numerical modeling. Required table size and curves for the determinations of appropriate correction factors are suggested. This has been completed for various test configurations with thermoplastic waterproofing membranes. Development of correction factors for assemblies with thermoset and modified bituminous membranes are in progress. Generalization of the correction factors and its usage for wind uplift rating of roofs will be the focus of a future paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.740-745
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• 2013

This paper presents BER, FER performance comparison, especially on PHY mode of IEEE 802.15.4g and IEEE 802.11 under AWGN channel through a simulation, which is communication method using identical frequency bandwidth in M2M environment. This considers suitable communication method of required parameter. It is advantageous that FSK method is used in situations where the system require low complexity and inexpensive structure. And OFDM method is considered for system performance. Further, when the high throughput and various traffic characteristics of the system are required, it can be considered that the method of IEEE 802.11 OFDM PHY mode is used.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.162-168
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• 2009

This paper describes a study that is to redesign insulation of transmission lines and determine required the numbers of insulators in order to enhance the insulation performance of existing transmission lines which were constructed with standard insulation design, considering overvoltage analysis results, probabilities and characteristics of faults. To ensure proper insulation distance without deteriorating the required performance, EMTP model is established to calculate maximum overvoltage in the line. The fault records and predicted outage rates due to lightning and contamination in the line were investigated and analyzed respectively. It presents a method to determine the numbers of insulators considering the probability and the characteristic of fault.

• Journal of Mechanical Science and Technology
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• v.20 no.6
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• pp.864-873
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• 2006

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• Journal of Ocean Engineering and Technology
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• v.33 no.1
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• pp.85-91
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• 2019

In a cryogenic storage structure, the insulation system is in an environment in which fluid impact loads occur throughout the lifetime of the structure. In this study, we investigated the effect of repetitive impact loading on the mechanical performance of glass fiber-reinforced polyurethane foam. The repeated impact loading test was conducted in accordance with the required impact energy and the required number of repetitive impacts. The impact behavior of glass fiber-reinforced polyurethane foam was analyzed in terms of stress and displacement. After the impact test, the specimen was subjected to a compression test to evaluate its mechanical performance. We analyzed the critical impact energy that affected mechanical performance. For the impact conditions that were tested, the compressive strength and elastic modulus of the polyurethane foam can be degraded significantly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.10-11
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• 2020

This research is part of the research for unifying the mass concrete and utilizing the rate of super retarding agent. We analyzed the performance of super retarding agent under low temperature conditions. It was found that there was no deterioration in fluidity and air quality due to the change in the super retarding agent mixing rate. It was found that when super retarding agent was mixed up to 0.5 %, it was delayed for 22.3 hours at 20℃, 48.2 hours at 10℃, and 48.5 hours at 5℃. Therefore in order to ensure the performance required at the site, the super retarding agent mixing rate must be determined by fully considering the situation at the site. In addition it will be analyzed that super retarding agent performance analysis at high temperature will be required in subsequent studies.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.647-652
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• 2011

Developments in the teaching of the National Diploma in Building students should be geared towards meeting the needs of the construction industry in South Africa. These needs are usually in the form of skills and knowledge required to resolve thorny issues encountered in practice. The lack of capacity in the construction industry needs to be addressed from the basis of ensuring that the education system caters for both mature entry and matriculation entry students. The paper looks at a comparison in performance between mature entry and matriculation (just finish High School) entry students focusing on the National Diploma in Building students at the University of Johannesburg. The paper will make a comparison between those students who work first before enrolling for their first year National Diploma in Building and those who are directly from high school. Cooperative education involves training and systematically developing students through the acquisition of the requisite skills, attitudes, values and knowledge required to adequately perform in their chosen careers. The paper describes the problems and experiences that have been encountered by both mature and matriculation entry students in their three years of study which affects their performance. The paper will then look at the value of prior experience in enabling students to finish their National Diploma in Building within a three year period. The paper closes with some recommendations for the future.