• 대한기계학회논문집B
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• 제28권11호
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• pp.1459-1466
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• 2004

The purpose of this study is to investigate the effect of swirler angle and the aspect ratio of swirl chamber of nozzle on the characteristics of single and twin spray. The characteristics of sprays have been investigated by measuring the spray angle, droplet size and velocity. Visualization of spray was conducted to obtain the spray angle and breakup process. The spray characteristics such as droplet size and velocity were measured by Phase Doppler Anemometry(PDA). It was found that the spray angle was increased with increasing the swirler angle. For both sprays, the axial velocity and SMD were decreased with increasing the swirler angle. It was also shown that the axial velocity and SMD were decreased with increasing the aspect ratio of swirl chamber, but for the twin spray, the axial velocity and SMD were not influenced significantly by the changing the aspect ratio of swirl chamber. The effect of swirler angle on the spray characteristics was greater than the aspect ratio of swirl chamber for single spray. The nozzle pitch was one of the important factors affecting the spray characteristics of twin spray.

• 대한화학회지
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• 제40권6호
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• pp.415-419
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• 1996

수소결합, 유전효과 그리고 입체효과는 케톤의 카르보닐 신축진동을 결정하는 요인이 된다. 케톤의 카르보닐 신축진동은 다양한 용매에서 케톤의 농도변화에 영향을 받는다. 비극성용매에서 카르보닐 신축진동은 케톤의 부피%가 증가함에 따라 낮은 파수로 이동하고 극성용매에서는 높은 파수로 이동한다. 용매 아세토니트릴에서 카르보닐 신축진동은 dimethyl ketone을 제외하고 케톤의 부피%가 증가함에 따라 높은 파수로 이동한다. 용매의 극성이 증가할수록 카르보닐 신축진동은 낮은 파수로 이동하고 혼합용매 $CHCI_3CCI_4$에서 부피%가 증가할수록 낮은 파수로 이동한다.

• 한국게임학회 논문지
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• 제15권3호
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• pp.87-96
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• 2015

재미와 행복은 인간이 추구하는 본질적 가치이다. 게임은 그러한 본질적 가치를 만족시키는 매우 편리한 수단 중 하나이다. 그 수단을 교육에 접목하여, 재미있는 교육을 추구하는 시도들이 활성화되고 있다. 기업과 학교의 인력교육 현장에서 게임의 활용도가 증가하면서, 게임을 접목한 교육방식의 한계와 역효과에 대한 우려의 목소리도 생기고 있다. 역효과와 한계점을 명확히 이해하고, 이에 대한 극복방안을 모색하여 교육 게이미피케이션을 활성화하는 것이 본 논문의 목적이다. 본 논문에서는 인력교육 현장에서 게이미피케이션을 통해 교육에 게임을 접목할 경우에 발생하는 역효과와 한계점을 관찰연구를 통해 정리하고, 이에 대한 피교육자의 의견을 인터뷰 형식으로 추가하였다.

• 대한기계학회논문집B
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• 제20권3호
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• pp.1040-1049
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• 1996

The high loading combustion is accomplished by making the turbulent intensity strong and the scale small in the premixed combustor. The Da-mkoler number, which is decreased by short turbulent characteristic time or by long chemical reaction time, can make the distributed reaction flame. So we developed a doubled jet burner for high loading combustion. The doubled jet burner was designed to make the scale of the flame small by the effect of impingement and increasing shear stress with doubled jet. We investigated the turbulence characteristics of unburned mixture and visualized several flames with the typical schlieren photography. Then we studied the influence of several factors that related the scale of flame. Consequently, the doubled jet burner can make the eddy very small. And we can obtain the detail information of the flame scale through ADSF(the Average Distance between Successive Fringes) in the micro- schlieren photography. The ADSF is not a exact flame scale, but it has qualitative trend with increasing turbulent intensity. The ADSF is diminished remarkably with increasing turbulent intensity. The reason is that strong turbulent intensity makes the flame zone thick and flamelets numerous. We can confirm this fact by the signal analysis of ion currents.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.29-35
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• 2021

This study discusses the effect of human capital and technology on economic growth in Indonesia using annual time series data over the 35-year research period (1984-2019). This study uses an autoregressive distribution gap to the cointegration approach to understanding the relationship between human capital, technology, and economic growth. Human capital is inherent in humans and becomes capital in providing the best performance that has an impact on their own income. We use the human capital framework in this study where education is one mechanism to increase human capital. Based on the results of our estimation, we find that the increase in human capital using the education mechanism affects economic growth. This shows the role of human capital investment is very important in economic growth. Technology shows a significant positive effect on economic growth. Increasing human resources and technology are important factors in efforts to increase economic growth in Indonesia. Educational development is the key to the success of increasing human capital and technological development because education plays a role in improving the quality of human resources. Increasing human resources here is in the form of increased knowledge, mastery of technology, innovation, and the ability to develop technology to encourage technology development.

• 한국물환경학회지
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• 제27권1호
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• pp.120-128
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• 2011

Korea Groundwater Quality Monitoring Network is a database of annual groundwater quality survey results to prevent groundwater pollution. We estimated contamination index (CI) values for each type of land use, and analyzed temporal trends of pollutant concentration data in the Groundwater Quality Monitoring Network from 2001 to 2009. Among the pollutants considered in the database, the concentrations of nitrate and chloride were higher than their standards. In the case of nitrate, recreation parks, golf courses and general waste dumping regions showed increasing trends according to linear regression analysis, whereas industrial complexes and residential regions of urgan and recreation parks showed increasing trends in the chloride concentration data. According to multiple variable linear regression analysis, EC, pH and topography were major factors influencing CI values. These results suggest that groundwater with a high CI value and increasing trend is vulnerable for potential contamination, which requires more careful groundwater pollution control.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.353-357
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• 1996

Second-order rate constants have been measured spectrophotometrically for the reaction of 2,4-dinitrophenyl X-substituted benzenesulfonates with Z-substituted phenoxides in absolute ethanol at 25.0±0.1 ℃. The nucleophilic substitution reaction gives both S-O bond and C-O bond cleavage products. The extent of S-O bond cleavage increases significantly with increasing electron withdrawing ability of the sulfonyl substitutent X, while that of the C-O bond cleavage is independent on the electronic effect of the substituent. On the contratry, the effect of the substituent Z in the nucleophilic phenoxide is more significant for the C-O bond cleavage than for the S-O bond cleavage. Aminolyses of 2,4-dinitrophenyl benzenesulfonate (1) with various 1°, 2° and 3°amines have revealed that steric effect is little important. The extent of S-O bond cleavage increases with increasing the basicity of the amines, but decreases with increasing the basicity of the nucleophilic aryloxides, indicating that the HSAB principle is not always operative. Besides, reactant and solvent polarizability effect has also been found to be an important factor in some cases but not always to influence the reaction site.

• Structural Engineering and Mechanics
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• 제88권1호
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• pp.25-42
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• 2023

This paper presents a finite element (FE) simulation of eccentrically loaded lightweight aggregate concrete-encased steel (LACES) columns with H-shaped steel sections, analytical equations are also established to estimate the columns' axial and bending moment interaction capacities. The validity of the proposed models is checked by comparing the results with experimental data. Good agreements between the test and proposed models' results are found with acceptable agreements. Moreover, design parameters, including the lightweight aggregate concrete (LWAC) strength, eccentricity, column slenderness ratio, and confinement, are studied using the FE analysis, and their efficiency factors are discussed. The results show that the ultimate axial capacity of the LACES composite columns subjected to eccentric loading is negatively affected by the increase in the columns' height, but it is positively affected by the increase of the confinement. Increasing the eccentricity and columns' height reduced the columns'stiffness. In addition, the ultimate capacity of the LACES column is significantly influenced by the LWAC strength and eccentricity, where the ultimate capacity of the LACES column is significantly increased by increasing LWAC strength, and it is remarkably decreased by increasing the eccentricity. When the eccentricity changed from zero to 70 mm, the ultimate axial capacity and stiffness decreased by 67.97% and 63.56%, respectively.

• International Journal of Contents
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• 제8권2호
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• pp.43-51
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• 2012

This study identifies the determinants of increasing privacy concerns in the mobile apps. The privacy affecting factors will be divided into the 3 categories on the basis of both users' and developers' perspective. First, this study explores whether the users' seeking value affects concern of the mobile apps privacy. Second, gender gap on the mobile privacy sensitivity will be tested. Third, this study identifies the meaning of apps developers' providing toolkit in the users' sensitivity on the privacy. The result showed that innovation among the customer's characteristics was identified the most significant factor to affect the mobile app privacy sensitivity. Ethical norm related variables (ethical identity, subjective norm and utilitarian value) were also identified as the meaningful variables in the mobile app privacy. Toolkits provided by app developers are also appeared a significant variable to affect the customer's app privacy sensitivity negatively. Finally gender also appears the meaningful factor in the mobile app privacy sensitivity.

• 한국항만경제학회지
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• 제20권2호
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• pp.53-71
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• 2004

The container throughput of China, after the joining in the WTO, has begun to increase notably. As a result, China is busy building new ports continuously. In accordance with China's situation Korea promote the development plans of ports and marketing strategy to attract the increasing cargo traffics with China, including transhipment cargoes. To build the competition strategy and the panning port for trading cargoes with China, an analysis on origin/destination is necessary. The cargo volume from/to the particular port(Korea/China) and origin/destination of traffic are important factors in the requirement for the port development. Therefore, in the era that trading with China is rapidly increasing, this study is performed to analyze the port's usage of transporting the cargos and the origin/destination of trading cargoes with china. Also this paper suggests to the competitive strategies of Pyungtaek Port to attract cargoes particularly from/to China.