• Journal of Surface Science and Engineering
• /
• v.32 no.6
• /
• pp.703-708
• /
• 1999

Silicides have been used extensively in ULSI logic device fabrication as contact materials for the active areas as well as the poly- Si gates. NiSi is a promising candidate for submicron device application due to less volume expansion, low formation temperature, little silicon consumption, and large stable processing temperature window. In this report, the microstructure of nickel silicides fabricated with a thermal evaporator has been investigated. We observed systematic transformation of Ni silicides of $Ni_2$Si, NiSi, $NiSi_2$, as annealing temperature increases. All the silicides have been identified by a X-ray diffractometer (XRD). The cross-sectional microstructure of silicides was examined by a transmission electron microscope (TEM) equipped with a energy dispersive spectrometer(EDS). The surface roughness of silicides was measured by scanning probe microscope(SPM). Although we observed thin oxide layer existed at the $Ni/NiSi_{x}$ interface, we fabricated successfully $550\AA$-thick planar Ni-monosilicide at the temperature range of$ 400~700^{\circ}C$.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.28A no.9
• /
• pp.752-760
• /
• 1991

The computer aided analysis is performed to investigate the influence of physical parameters (thickness and doping concentration, etc.) in the window, emitter, base on the efficiency characteristics of a uniformly doped hetroface cell. A field aided heteroface cell is newly designed on a basis of optimum data obtained from the theoretical analysis. The field aided heteroface cell fabricated using MOCVD exhibits a total/active area conversion efficiency of EFF. (tot) = 18.9% /EFF. (act.) = 21.4% under the natural incident light of 56.2 mW/cm\ulcorner having a low series resistance of Rs = 0.94 \ulcornercm\ulcornerand a high spectral response of S.R. (ext) > 90% in a range of $7700{\AA}$ < $8500{\AA}$.

• Annual Conference of KIPS
• /
• 2002.04a
• /
• pp.167-170
• /
• 2002

인터넷의 발달과 함께 웹 기반의 멀티미디어 컨텐츠들도 많은 발전을 하게 되었다. 기존의 텍스트 형식만을 지원하던 많은 시스템들이 멀티미디어 기능을 추가하게 됨으로 보고, 듣고, 말하는 복합기능이 요구되었다. 또한 컴퓨터와 전화를 연결하여 데이터베이스 응용의 부가가치를 향상시키는 CTI 기술의 마른 성장은 다양한 분야로 확산되어 가고 있다. 본 논문에서 이러한 기술의 통합을 시도하여, Oracle8i DB를 공유한 Linux기반의 CTI프로그램과 Window기반의 ActiveX 모듈을 연동한 전화 음성게시판(Voice-BBS)을 설계 및 구현하였다. 제안한 시스템은 PSTN 상에서 뿐만이 아니라 웹상에서도 음성 데이터를 저장하고 재생할 수 있도록 설계되었다.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.317-320
• /
• 2004

The exponential back-off algorithm doubles the back-off size after each collision without considering network traffic status, which causes degradation of system performance. In this paper, we propose a linear random back-off mechanism which dynamically selects the back-off window size based on the channel status which includes the number of active stations and collisions to significantly increase the protocol capacity. We present an analytical model for the saturated throughput of our linear random back-off algorithm. Simulation results show that performance can be substantially enhanced if binary exponential back-off algorithm is replaced by a linear back- off algorithm.

• Journal of Biomedical Engineering Research
• /
• v.16 no.1
• /
• pp.77-84
• /
• 1995

Nl and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. Nl -N2 audiograms were made by means of regulating stimulant intensities in order to produce constant Nl -N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip 15 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both nonlinear and active functions of the Cochlea can be monitored by Nl -N2 audiograms. Key words : Guinea Pig, Cochlea, Wl and N2 Gross Neural Action Potential, Nl -N2 audiogram.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.1
• /
• pp.34-39
• /
• 2007

According to the active use of internet the need for security in various environment is being emphasized. Moreover with the broad use of Messenger on PC and P2P applications. the security and management of individual hosts on internet became very important issues. Therefore in this paper we propose the design and implementation of a host based access control system for the hosts on internet including window based PC which provides access control, information on packets, and record and monitoring of log files.

• Educational Technology International
• /
• v.20 no.1
• /
• pp.1-24
• /
• 2019

The purpose of this study is to determine priorities for designing digital citizenship education based on the key indicators of importance-performance. Survey data were collected from 283 university students in South Korea and analyzed with Importance-Performance Analysis to diagnose the current level of digital citizenship and draw their needs for educational treatment. The results showed that for all the factors except the Technical Skills (TS), the level of importance was significantly higher than that of performance. Another finding indicated that in the Importance-Performance matrix all the factors were located in the first quadrant (i.e. maintaining the current state) and the third quadrant (i.e. low demands for improvement). Specifically, two items located in the second quadrant where urgent treatment is required could have to do with the increasingly active participation in socio-political issues raised in South Korea. This study offered a window into what to focus on when designing digital citizenship education based on the systematic analysis of the needs for digital citizenship education in South Korea.

• Journal of Korean Society of Water and Wastewater
• /
• v.29 no.4
• /
• pp.469-479
• /
• 2015

This study have been conducted to analyze the feasibility of establishing Contamination Warning System(CWS) that is capable of monitoring early natural or intentional water quality accidents, and providing active and quick responses for domestic C_water supply system. In order to evaluate the water quality data set, pH, turbidity and free residual chlorine concentration data were collected and each statistical value(mean, variation, range) was calculated, then the seasonal variability of those were analyzed using the independent t-test. From the results of analyzing the distribution of outliers in the measurement data using a high-pass filter, it could be confirmed that a lot of lower outliers appeared due to data missing. In addition, linear filter model based on autoregressive model(AR(1) and AR(2)) was applied for the state estimation of each water quality data set. From the results of analyzing the variability of the autocorrelation coefficient structure according to the change of window size(6hours~48hours), at least the window size longer than 12hours should be necessary for estimating the state of water quality data satisfactorily.

• Journal of Communications and Networks
• /
• v.11 no.5
• /
• pp.518-528
• /
• 2009

IEEE 802.11 wireless local area network (WLAN) has become the prevailing solution for wireless Internet access while transport control protocol (TCP) is the dominant transport-layer protocol in the Internet. It is known that, in an infrastructure-based WLAN with multiple stations carrying long-lived TCP flows, the number of TCP stations that are actively contending to access the wireless channel remains very small. Hence, the aggregate TCP throughput is basically independent of the total number of TCP stations. This phenomenon is due to the closed-loop nature of TCP flow control and the bottleneck downlink (i.e., access point-to-station) transmissions in infrastructure-based WLANs. In this paper, we develop a comprehensive analytical model to study TCP dynamics in infrastructure-based 802.11 WLANs. We calculate the average number of active TCP stations and the aggregate TCP throughput using our model for given total number of TCP stations and the maximum TCP receive window size. We find out that the default minimum contention window sizes specified in the standards (i.e., 31 and 15 for 802.11b and 802.11a, respectively) are not optimal in terms of TCP throughput maximization. Via ns-2 simulation, we verify the correctness of our analytical model and study the effects of some of the simplifying assumptions employed in the model. Simulation results show that our model is reasonably accurate, particularly when the wireline delay is small and/or the packet loss rate is low.

• Journal of Digital Convergence
• /
• v.15 no.12
• /
• pp.359-367
• /
• 2017

This study aims to identify the factors that have effects on career preparation behaviors in college students studying Emergency Medical Technology and provide basic data for career guidance, career counselling and development of employment guidance programs. The subjects of the study were 450 who were randomly selected and conveniently sampled from the Departments of Emergency Medical Technology located in J Province, G Province, B and G Metropolitan Cities. The survey lasted from August 7th, 2017 to 9th of the same month after agreement on the survey was obtained from the targets and they were interviewed with the use of an organized questionnaire. 420 copies of the data collected were analysed with the use of SPSS ver. 14.0 for Window. As a result, it was discovered that career identity had a statistically significant positive effect on career preparation behaviors. Therefore, to facilitate preparation behaviors, they should be taught to have career identity, be motivated and supported to do more active career preparation behaviors.