• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.65-72
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• 2002

The closed cycle diesel system is operated in closed circuit system where there is non air breathing with working fluid consists of combination of oxygen, argon and recycled exhaust gas far obtaining underwater or underground power sources. Experimental apparatus using the MTU8V183SE92 high pressurized engine adapted for closed cycle running, capable of operating at the system pressure of maximum 5 bar is constructed with ACAP as data acquisition system in order to operate equally in the open cycle in surface or the closed cycle in submerged conditions. The general features and the characteristics of combustion of HP(high pressure) diesel engine, specially designed and manufactured only for CCDE, are investigated. The test results of performance of HP diesel engine in closed cycle system are presented with respect to power and boost pressure and compared with those of low pressure diesel engine. The oxygen concentration and specific heat ratio are investigated with its deviation

• Journal of the Korean Society for information Management
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• v.4 no.2
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• pp.62-83
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• 1987

This paper reports investigation of informal communication among Korean biological scientists. Scientists at the research front communicate informally each other and social organization based upon this communication relation is identified. Seventy-four percent of the scientists are joined together in a large communication network which includes all of the most productive and communicative scientists. Central scientists are the nodal points for dissemination of information as well as important information sources.

• The Journal of Asian Finance, Economics and Business
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• v.1 no.2
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• pp.5-13
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• 2014

The purpose of this paper is to carry out an empirical analysis of the link that exists between microfinance and poverty alleviation. The analysis is driven by literature searches on empirical works done by different researchers in different contexts. Qualitative research methodology was adopted, following a desktop approach. An empirical literature review took a centre stage in this investigation. An analysis of empirical works shows that microfinance enhances poverty alleviation despite the challenges such as the Indian Andhra Pradesh crisis. The paper is limited to a review of empirical sources of literature. A field survey, supported by an econometric analysis would have helped to generate robust results. This paper attempts to bring together the empirical works that were done in different contexts to shed light on the important relationship between microfinance and poverty. Many research works on microfinance depend upon personal anecdotes, thus this present paper attempts to compile the scattered empirical findings on microfinance and poverty alleviation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.85-93
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• 1985

An experimental investigation on condensing heat transfer for the Refrigerant-11 superheated vapor during condensation on the 40 mm O.D by 75 mm long horizontal tube is carried out under the various conditions of air contents as noncondensable gas, condensing pressure, and coolant temperature. The data span a refrigerant flow range from 23 to 63 kg/h and weight fractions of noncondensable gas range from 0 to $15\%$. The comparisons are made using data obtained by the authors and further data obtained from other sources. The characteristics of the condensing heat transfer of refrigerant superheated vapor with and without noncondensable gas flowing horizontally are revealed experimentally, and on the basis of the data obtained, correlations for predicting heat transfer coefficient during condensation on the tube are proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.1-4
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• 2008

Prediction models currently being used for road traffic noise in apartment are equation of NIER, HW-NOISE of Korea Expressway Corporation, FHWA of United States, CRTN of United Kingdom, NMPB of France, ASJ RTN-Model 2003 of Japan and ISO 9613-1, 2 as a international standard. ISO 9613 species an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. This study, prior to investigation of every prediction methods listed above, aims to examine the model internationally standardized and to establish a reference for the prediction of road traffic noise in apartment.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.197-202
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• 2018

This paper reveals the impact of the insertion of electromagnetic band gap (EBG) structures on the performance of circularly polarized (CP) patch-slot antenna with offset slot. Several optimizations are necessary to precise physical parameters in the aim to fix the resonance frequency at 3.2 GHz. The proposed antenna possesses lightweight, simplicity, low cost, and circular polarization ensured by two feeding sources to permit right-hand and left-hand circular polarization process (RHCP and LHCP). The measured results compared with simulation results of the proposed circularly polarized EBG antenna with offset slot show good band operations with –10 dB impedance bandwidths of 9.1% and 36.2% centered at 3.2 GHz, which cover weather radar, surface ship radar, and some communications satellites bands. Our investigation will confirm the simulation and experimental results of the EBG antenna involving new EBG structures.

• Asia pacific journal of information systems
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• v.26 no.1
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• pp.124-142
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• 2016

Companies operating in social network platforms continue to improve and expand their marketing techniques. This study examines the practice of "gating", which involves virtual barriers between social network users and company content. Gates demand mandatory user endorsements, in the form of a Facebook "Likes", Twitter "retweets" etc., to gain access to company content, such as coupons and rewards,. Gating practices demand a mandatory endorsement before any content consumption takes place. Thus, while user endorsements are assumed to arise voluntarily from trusted known sources, gating practices would appear to violate this assumption. However, whether this violation lessens the effectiveness of gating practices still requires empirical validation. We investigate this question through the use of a unique panel data set that includes data on "like" endorsements obtained from a number of real-world Facebook business pages. Results of the study show that gating practices are effective for endorsement solicitation; however, gates may interfere with more traditional marketing activities.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1645-1650
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• 2003

A numerical and experimental study is made of thermal behavior of a hot chuck which is specially designed for flip-chip bonders. The hot chuck consists of radiant heat sources and a heated plate of very high conductivity, which is for achievement of high-speed heat-up. A simplified numerical model is developed to simulate unsteady thermal behavior of the heated plate. Parallel experimental work is also conducted for a prototype of the hot chuck. Based on the experimental data, the numerical model is tuned to improve the reliability and accuracy. Design analysis using the numerical model is conducted. The results of numerical computations illustrate that the radiant heater system adopted in this study satisfies the key design requirements for a high-performance hot chuck.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.122-128
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• 2007

The electric part of thermal SEM(Scanning Electron Microscopy) consists of high voltage generation, lens control, and image processing. Several methodologies for enhancing SEM image are addressed and those results are verified through analyses and experiments. The controller employes a DSP(Digital Signal Processing), making the system more flexible and convenient than the classical analogue based controller. In some parts based the analog circuit, there are inevitable sources of noise and image distortion. The experimental investigation is provided along with analytical proof to enhance the SEM image.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.445-448
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• 2001

Noise radiated from pile driving operation is one of major sources of community noise pollution and thus its operation method is strictly restricted by regulations. Although the drilling method is now used been commonly used in urban areas because of its activity, the benefit of low noise decreases due to high working cost. In the present work, noise characteristics of pile driving operation are carried out. Based on the study result, a low-noise pile cap for driven piles is developed in order to satisfy both the noise level restriction and the economical efficiency. Effects of pile cap are investigated by a scale model experiment, which is focused on the variation of impact force and sound pressure level. The results show a good possibility of noise reduction by an appropriately designed pile cap.