• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.162-162
• /
• 2010

InSb has received great attentions as a promising candidate for the active layer of infrared photodetectors due to the well matched band gap for the detection of $3{\sim}5\;{\mu}m$ infrared (IR) wavelength and high electron mobility (106 cm2/Vs at 77 K). In the fabrication of InSb photodetectors, passivation step to suppress dark currents is the key process and intensive studies were conducted to deposit the high quality passivation layers on InSb. Silicon dioxide (SiO2), silicon nitride (Si3N4) and anodic oxide have been investigated as passivation layers and SiO2 is generally used in recent InSb detector fabrication technology due to its better interface properties than other candidates. However, even in SiO2, indium oxide and antimony oxide formation at SiO2/InSb interface has been a critical problem and these oxides prevent the further improvement of interface properties. Also, the mechanisms for the formation of interface phases are still not fully understood. In this study, we report the quantitative analysis of indium and antimony oxide formation at SiO2/InSb interface during plasma enhanced chemical vapor deposition at various growth temperatures and subsequent heat treatments. 30 nm-thick SiO2 layers were deposited on InSb at 120, 160, 200, 240 and $300^{\circ}C$, and analyzed by X-ray photoelectron spectroscopy (XPS). With increasing deposition temperature, contents of indium and antimony oxides were also increased due to the enhanced diffusion. In addition, the sample deposited at $120^{\circ}C$ was annealed at $300^{\circ}C$ for 10 and 30 min and the contents of interfacial oxides were analyzed. Compared to as-grown samples, annealed sample showed lower contents of antimony oxide. This result implies that reduction process of antimony oxide to elemental antimony occurred at the interface more actively than as-grown samples.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3D
• /
• pp.445-450
• /
• 2008

Recently, environmental and ecological approaches is in progress in urban stream, especially the guarantee of instream flow becomes very important. In this paper, it is suggested that water volume estimation method utilizing the topographical shape data obtained by field investigation and satellite image to manage the urban stream efficiently. The data obtained at Gap River is the study area are analysed and those results are as belows. First, surveying to investigate topographic shape characteristics of urban stream is carried out. In details, the gradient characteristics from water surface to bottom in case of sand area and in case of grass area are 0.013 and 0.065 respectively. In conclusion, the gradient characteristic of grass area is five times bigger than that of sand area. Besides, IKONOS image is classified by spectrum analysis and Minimum Distance Method and the sand area extraction method by the generalization method as Median filter is suggested to calculate water volume. Finally, mapping process on the sand area extracted from the topographical shape field data in river and satellite images is carried out by the GIS spatial analysis. And on the assumption that the water level was 1m at that time when satellite image was taken, the water volume was $225,258m^3$. It is clarified that the effect of water volume improvement was about 10.5% in comparison with water volume that had no consideration on the gradient characteristics of sand-bar.

• International Journal of Highway Engineering
• /
• v.14 no.2
• /
• pp.63-72
• /
• 2012

Current analysis method drives an irrationality a road, signal operation and cause confusion of road such as weaving, bottleneck being not including main traffic flow in analysis subject. Therefore, this research develops analysis method of simple grade facilities to grasp target equipment relationship effect as virtue process to grasp effect of simple grade facilities in city and there is the purpose to apply optimum space of analysis intersection. In this paper, get at effect of simple grade facilities in urban area, as well as, develop new analysis method of simple grade facilities and adapt optimal interval of intersection point. New method of this paper reasonably estimated to optimal interval of the traffic flow(diverge area, merge area). As research result, analysis method to present in this research could clarify vague part of existing analysis method and presume reasonable result. Optimal interval of diverge and merge area with facilities was appeared more then 65m from the main line and more then 45m from the frontage road. Meaning of this paper as follow. First, the effect of simple grade facilities estimate. as consider optimal interval of simple grade facilities in urban can plan efficiently operation planning of road and signal in connection with nearby intersection. Second, new method then previous methods. planner of transportation easily access due to run parallel with existing method. Third, new method is contained through traffic volumes. the existing method did not reflect one. and this new method reduce error to the minimum. when analysis of intersection and link. Fourth, using the new method propose improvement plan with road operation and signal operation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.2 no.4
• /
• pp.103-133
• /
• 2007

The purpose of this study is to investigate whether customer satisfaction is affected by the expenditure for the customer satisfaction such as advertising, promotion, and training. This study also investigate whether the financial performance of the firm is affected by the customer satisfaction. The major findings are summarized as following. First, the customer satisfaction is affected by the expenditure for the customer satisfaction such as promotion, training. But customer satisfaction is not affected by advertising cost. Second, considering the time-lag and incremental valiables, the relationship between customer satisfaction and expenditure for the customer satisfaction is not founded. Third, the customer satisfaction affects positively on the corporate financial performance, such as ratio of operating income to sales, ratio of net income to sales, return on total assets, and return on equity. Finally, considering the time-lag the relationship between customer satisfaction and financial performance is not founded. Considering the incremental valiables, the relationship between customer satisfaction and financial performance is founded when ratio of operating income to sales and return on total assets are used financial performance. These findings imply that the expenditure for promotiom and training is needed to increase the customer satisfaction. Also improvement customer satisfaction is needed to increase the financial performance. The limitations of this study are as following. First, this study could not consider the other variables that would affect on the relationship among expenditure for customer satisfaction, level of customer satisfaction, and financial performance. Second, the results of this study are difficult to generalize because this study is focused on the service industry.

• Hwankyungkyoyuk
• /
• v.22 no.2
• /
• pp.43-55
• /
• 2009

The objective of this study is to find out the professionalism of secondary school teachers in teaching environmental subjects. This research was conducted using a questionnaire survey of 431 secondary school teachers from 34 schools in Seoul and Gyeonggi Province, Korea. A 5-point Likert scale self-evaluation questionnaire on their professionalism in environmental education was developed based on Hungerford et al.'s (1994) evaluation criteria. Two middle school teachers' classes were observed, and video taping and interviewing were also conducted. The survey analysis revealed that teachers evaluated their professionalism on environmental subjects to be a little above the middle of the scale. The mean values were 2.80 for the foundation level; 2.86 for the conceptual awareness level; 2.84 for the investigation level; 2.94 for the environmental action skills level; and 2.84 for the educational application level. However, class observations revealed that there was some gap between their self-evaluation of professionalism and their actual classroom application. Both classes were not that satisfactory with regard to 'the abilities to communicate and apply ecological concepts', 'the ability to clarify the roles of different value systems for environmental issues and personal values in decision making', 'the ability to clarify their own value system regarding solutions to environmental issues', and 'the ability to apply citizen action skills for solving environmental issues and for sustainable development'. The results provide a basic reference for the improvement of environmental-related education.

• Journal of Korean Society of Transportation
• /
• v.29 no.2
• /
• pp.111-121
• /
• 2011

This paper discusses a method for optimizing the semi-actuated traffic signal control system by adjusting the initial interval according to the number of vehicles waiting for the green light in the actuated phase. We also present a Left-Turn actuated traffic signal control strategy that examines the vehicular noise in the detection area and determines the phase extension and the gap-out. In order to detect the vehicles in real-time, an image detector's Video Image Tracking technology was adopted. A 'Zone in Zone'method was implemented, and the image detection area is segmented into three zones: 1) Zone1 for verifying a vehicles obligatory presence, 2) Zone2 for counting the standby vehicles, and 3) Zone3 for examining the number of vehicles that have passed. The on-site assessment of the Left Turn Actuated Control is carried out using CORSIM, and the results show that the Control Delay decreased by 23.10%, 15.06%, and 4.34% compared to the delays resulted from pre-timed control, semi-actuated control-1 and semi-actuated control-2 traffic signal control systems respectively. The Queue Time also decreased by 36.24%, 20.10% and the Total Time by 14.36%, 7.02% for the same scenario. Which clearly demonstrates the operational efficiency. A sensitivity analysis reveals that the improvement from the propose traffic control strategy tends to increase as the through traffic volume reaches a saturated condition and the left-turn traffic volume decreases.

• Journal of Broadcast Engineering
• /
• v.22 no.2
• /
• pp.214-233
• /
• 2017

For people with physical or sensory limitations, broadcasting is the main means of information acquisition and leisure. Recently, changes in the media environment, such as convergence of broadcasting and communication, digital mobile conversion of broadcasting, and active media usage behavior of users, make broadcasting accessibility of the disabled difficult, and as a result, the information gap between the disabled and the non-disabled is increasing. A notice on broadcasting rights for the disabled was enacted in consequence of the amendment of the Broadcasting Law in July 2011 and the web accessibility guideline became more effective with the amendment of the National Informatization Act in 2013 so that legal basis for the right of media access for the disabled was established. However, media services for them are still lacking quantitatively and qualitatively. In this study, we describe the present status of the audio description service for the visually impaired, and analyze the results of the questionnaire survey on the usage status, satisfaction and improvement requirements of the audio description service for 100 visually impaired people.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.3
• /
• pp.134-144
• /
• 2010

In China, the enhancement of water services has become the most crucial issue confronted with the rapid urbanization and industrialization process. A huge financial gap to meet the demand for water infrastructure and need for adopting advanced operation technology precipitated the rapid growth of PPP over the last 10 years. Diverse schemes of PPP such as TOT, Divestiture, and Management Contract and Lease have been practiced. Local governments and private investors/operator have adjusted their objectives and strategies to avoid potential pitfalls behind BOT projects in China. However, current academic research outcomes do not properly reflect important issues of BOT projects or related case studies in China. This limitation has brought in the lack of assessment of important risks and success factors required for the improvement of the body of risk management. In this regard, this study uses the market analysis method to identify major schemes of PPP water projects and conducts case studies on five PPP projects to identify key risk and success factors in association with each different scheme. It is expected that the risk and success factors identified from the cases will be used as reference to Korean companies which plan to enter the Chinese water market.

• Atmosphere
• /
• v.21 no.1
• /
• pp.1-16
• /
• 2011

Numerical prediction capability has been improved over the decades, but progress of prediction for high-impact weather (HIW) was unsatisfactory. One reason of low predictability for HIW is lack of observation data. The National Institute of Meteorological Research (NIMR) has been performed observation program for improvement of predictability, and reduction in social and economical cost for HIW. As part of this observation program, summer intensive observation program (ProbeX-2009) was performed at the observation-gap areas from 25 August to 6 September 2009. Sounding observations using radiosonde were conducted in the Gisang2000 research vessel (R/V) from the Korea Meteorological Administration (KMA) over the West Sea and the Eardo R/V from the Korea Ocean Research and Development Institute (KORDI) over the South Sea. Observation System Experiment (OSE) is carried out to examine the effect of ProbeX-2009 data. OSEs using Korea Local Analysis and Prediction System (KLAPS) and Weather Research and Forecasting (WRF) Model are conducted to investigate the predictability for a short time forecast. And, OSEs using WRF/3DVAR system and WRF forecast model are conducted to study the predictability for an extended time. Control experiment (K_CTL and CNTL) used only GTS observation and experiment (K_EXP and SWEXP) used ProbeX-2009 data from two system are performed. ETS for 3hr accumulated rainfall simulated by KLAPS-WRF shows that K_EXP is higher than K_CTL. Also, ETS for 12hr accumulated rainfall of SWEXP from 3DVAR-WRF is higher than CNTL. The results indicate that observation over the ocean has positive impact on HIW prediction.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.4
• /
• pp.326-332
• /
• 2011

Carbon, Aramid, Boron and Glass fibers are used as fibrous materials to promote structural bearing strength. Of these fiber types, carbon fiber is the most commonly used material, and is characterized by having a one-way direction, which is strengthened by tensile strength due to the attached direction only, while other types of fibers are two-way. Therefore, when applied in the field, the attachment direction of fiber is a very important factor. However, when fiber direction is not mentioned in the design drawing, there sometimes is no improvement in structural strength, as the fiber is being installed by a site engineer or workers who lack structural knowledge. The purpose of this study was to propose an optimal direction of carbon fiber through a comparison & analysis of reinforcing efficiency with reinforced experimental columns that used carbon fibers in each of the inclined, horizontal and vertical directions. According to the results, horizontal direction in the reinforced column was improved by 153.43%, but vertical direction was 104.61% only, and it was understood this was due to increased tensile strength along the fiber direction. For this reason, it is necessary to include information regarding fiber direction in design and site management.