• International journal of advanced smart convergence
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• v.9 no.2
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• pp.76-83
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• 2020

The fourth industrial revolution (Industry 4.0) will generate great benefits and big challenges in equal measure. Industry 4.0 has an impact on context, technology and business as long as it transforms design, production systems and products themselves. Industry 4.0 has also created many opportunities and challenges for startups to improve their business efficiency. The reality has shown that the industry 4.0 has begun to strong impacts of various levels on many areas of Vietnam's economy. In such context, it is necessary to implement sufficient and thorough research and evaluation of many issues of startups and innovation and to consider suitable solutions and effective ways to take advantages of opportunities that the Industry 4.0 brings to Vietnam. This paper proposes the solution for supporting and promoting to develope of innovative start-up enterprise in accordance with the conditions and circumstances of Vietnam in the context of Industry 4.0.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.33-38
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• 2011

The introduction of alternative fuels is beneficial to overcome the fuel shortage and reduce engine exhaust emissions. LPG and CNG are relatively clean fuel and considered as most promising alternative automotive fuels worldwide because of its emission reduction potential and lower fuel price compared to gasoline. Now a day’s adaptation of dual fuel approach is the growing as common trend. The two fuels can be successfully implemented with existing gasoline engine with little modification. The present study was done to analyze the performance and emissions analysis of a multi cylinder spark ignition engine fuelled with the benefits of CNG and LPG aseffective alternate automotive fuels by simply using them in an unmodified petrol engine. The test results indicate, the energy content of CNG and LPG is the most limiting factor in acceptance for fuel economy and performance reasons. Thermal efficiency was high for CNG lowest for gasoline and LPG between the two. BSFC, CO and HC were low and NOx was high for CNG and low for gasoline, LPG lies between the two.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.1
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• pp.39-48
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• 2017

In a digital economy, users actively express their needs in many ways. Thus, many researchers analyze what users need and whether they are satisfied or not through opinion mining. In addition, they begin to find technology opportunities in heterogeneous technology fields. But they did not connect users' opinion to technology development process, only focused on natural language processing or marketing or manufacturing area. Also, heterogeneous technology fields are focused on fusion technology. Thus, this study suggests a novel approach that is based on sentimental value and can be applied to exploring technology opportunities in heterogeneous fields. Sentimental value is calculated from users' opinion through sLDA. The heterogeneous technology opportunity is explored by patent analysis. This research contributes to suggesting a hybrid methodology through patent and users' opinion. In addition, it can provide managerial efficiency by suggesting base data onto decision making.

• Journal of the Korean Home Economics Association
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• v.39 no.10
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• pp.55-67
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• 2001

The purpose of this study were 1) to find out the benefits sought factors and segment the customers of internet shopping mall, 2) to find out the store image factors of internet shopping mall, and 3) to analyze the internet shopping mall market using perceptual map of segmented groups. The questionnaires dealing with attribute dimension of internet shopping mall image, benefits sought, and demographic variables were selected from the previous studies or were developed for this study. The data from 319 respondents which were collected through the internet survey site was analyzed by factor analysis, cluster analysis, one-way ANOVA, and $X^2$-test. The results of this study were as follows: 1. Benefit sought by consumer in internet shopping malls was found to include six different factors: assortments of products, search efficiency, brand/fashionability, delivery convenience, promotion service and informativeness. 2. As a result of subdividing the consumers, four distinctive groups were formed on the basis of benefit factors: multi-benefit oriented group, convenience oriented group, brand oriented group and low-benefit oriented group. Demographic traits such as education and income level were proven to significantly differentiate the benefit segments. 3. In the structural components of internet shopping-malls image, product/information, service/convenience and economy were drawn from attribute dimensions. 4. 12 perceptual maps of internet shopping mall image were constructed and each ideal vector were drawn.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1326-1330
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• 2001

This study analyzed the lowest production cost and the greatest profit to be obtained from marketing hogs to determine the optimal operation scale for family-owned farrow-to-finish farms. Data were collected from 39 farrow-to-finish farms with 500 to 5,000 inventories for two consecutive years, and treated with GLM and quadratic regression models using the REG procedure. Analysis results indicated that farms capable of marketing 2,933 and 3,286 hogs annually had the lowest production cost and the greatest profit, respectively. Further analysis attributed the lowest production cost or the highest return in farms with an optimal scale of 3,000 to a higher survival rate of the herd, as well as lower expenses in veterinary medicine, labor, utilities and fuel, transportation, and depreciation. A similar feed conversion efficiency was observed for all the farms studied. Obviously, the cost efficiencies were associated with the economy of the operation scale of hog production until it reached 3,000 hogs marketed annually for a family-run unit. Beyond the optimal scale of 3,000 hogs, good stockmanship was more difficult to maintain and the herd management deteriorated as increasing mortality confirms. It is conclude that, unless advanced management is applied, the operation scale should not expand beyond 3,000 hogs.

• Journal of Drive and Control
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• v.9 no.1
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• pp.1-9
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• 2012

Nowadays, various researches about eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. Since most of these green cars have electric motors, the regenerative energy technology can be used to improve the fuel economy and the energy efficiency of vehicles. The regenerative brake is an energy recovery mechanism which slows a vehicle by converting its kinetic energy into electric energy, which can be either used immediately or stored until needed. This technology plays a significant role in achieving the high energy usage. However, there are some technical problems for controlling the regenerative braking and the electro-hydraulic brake during switching at transient region. In this paper, the performance simulator for fuel-cell vehicle is developed and transient response characteristics of the regenerative braking system are analyzed in the various driving situations. And the hardware-in-the-loop simulation of electro-hydraulic brake is performed to validate the transient characteristics of the regenerative braking system for fuel-cell electric vehicle.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.1020-1027
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• 2007

As a national enterprise has been expanded over and over, the worldwide energy consumption has been growing necessarily. Moreover, as recently energy spendings are on the increase in countries such as BRICs, it has resulted that a rise in the price of both oil and mineral resources and instability between supply and demand become serious issue in the world resources market. The recent high price of oil and mineral resources have a deep influence on economy and threaten energy security and even national prosperity of Korea. In addition to these, exhaustion of fossil fuels and the enhanced greenhouse effect which results from gases emitted as a result of fossil fuels has been in serious questions which occur a great deal of effort to secure clean energy resources all around the world. As it is considerably possible for Korea that the Kyoto protocol may come into effect on and after 2013, it is essential to require the technological development to promote energy efficiency as well as to develope safe and renewable energy resources. The wind energy technology which converts kinetic energy into electrical energy has been in the focus of the world's attention. In this study, two-dimensional numerical analyses were conducted to observe subsidence aspects of the sea bottom on differently applied loads and various ground conditions.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.257-262
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• 2002

Water-Electrolyzed gas is a mixed gas has the constant volume ratio 2 1 Hydrogen and Oxygen gained from electrolyzed water, and it has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for existing gas welding equipment. So nowdays many studies of Water-Electrolyzed gas are progressed, and commercially used as a source of thermal energy for gas welding in the industry. For Water-Electrolyzed Source, it was used diode rectifier or SCR rectifier for get DC source. This method which is not looking to improve a source for impossible current control or voltage and limited control intervals. In this paper, it was relized and designed In source of pulse type for complementing existing - DC source type, also by experiment it was acquired producting characteristics of Hydrogen -Oxygen Gas through feature of source

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1710-1713
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• 2002

Recently, the pulsed power system has been used to many applications. Such as remediation of environmental hazards, food sterilization, air pollution control E/P (Electrostatic Precipitator), DeNOx/DeSOx power system, ozone generator, high energy physics, and other power source applications. A pulse energy efficiency for load depends on the rising time, peak value. Pulse duration and impedance matching etc. The pulsed power system generally required for short pulse duration and high peak value was forced to consider its volume and economy. In this paper, we investigated operating characteristics of the CO2 laser using an inductively pulsed power system.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.9-18
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• 2007

Phase separation and low cetane number are the main barriers to the large-scale use of ethanol-diesel blend fuel on small diesel engines. In this paper, an additive package is designed on the basis of the blended fuel properties to overcome these limitations. The experiments show that the solubility of ethanol in diesel is evidently increased by adding $1{\sim}2%$ (in volume) of the additive package and the flammability of ethanol-diesel blend fuel with the additive has reached the neat diesel level under the cold start conditions. Effects of the ethanol content in diesel on fuel economy, combustion characteristics, and emission characteristics are also investigated with the ethanol blend ratios of 10%, 20% and 30%. The increase in ethanol content shows that the specific fuel consumption and the brake thermal efficiency are both gradually increased compared to neat diesel. The soot concentrations of the three blended fuels are all greatly lower than that of neat diesel. $NO_x$ emission is increased with an increase in the engine load and is reduced with the increase in the ethanol blend ratio under a high load.