The numerical study was conducted using the equation of Vanapalli et al.(1996) related shear strength of unsaturated soils. Angle of shearing resistance(${\Phi}^b$) and angle of internal friction(${\Phi}^{\prime}$) appear identically in lower suction range, but angle of shearing resistance(${\Phi}^b$) has non-linearity as suction increases. Nevertheless, the numerical study was conducted using angle of shearing resistance(${\Phi}^b$) in even lower suction range because of limit of program function. However, behavior of real ground on applying numerical study can be analysed wrong by it. Therefore in this paper numerical analysis on applying the equation of Vanapalli et al.(1996) and ${\Phi}^b$ has been compared about unsaturated slope considering continuous rainfall.

To provide a development strategy on the method which assesses a potential risk of nationwide emerging IT infrastructure in planning and design phase, and to classify the assessment result into 5 levels is the goal of this research. The development strategy provided in this paper could improve a benefit-cost-ratio of investments on emerging IT infrastructure. With a premature assessment of the potential risks of a nationwide emerging IT infrastructure which needs astronomical amount of public funds, it could show a way of systematic investments on security systems and improve a benefit-cost-ratio of investments on emerging IT infrastructure. Also, this approach might improve the safety of nationwide IT infrastructure. It could identify and provide an optimized solution for the potential risks of nationwide IT infrastructure.

Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the micro-structure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the "critical non-propagating crack length" It is found that the reduction of the endurance limit of their particular micro-structures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress ${\sigma}_{wo}$ and the critical non-propagating crack length $L_c$ can be written as ${\sigma}_{wo}{^m}{\cdot}L_c=C$ where m,C is constant. Further experiments were carried out on cyclic loading history on the length of critical non-propagating crack. It shown that the length of critical non-propagating crack is closely related to cyclic loading history.

In this paper stability about lateral soil movement of bridge abutment constructed on the soft ground, reinforced with the sand compaction pile (SCP) and the preconsolidaton methods, was evaluated by using the centrifuge testing facility which stress conditions in field could be reconstructed in the laboratory. The layouts of model such as ground condition, sand compaction piles and abutment was determined on the basis of similitude law with the reduced scale of 1/200. Construction sequences of installing SCP, preparing reclaimed ground, preconsolidating ground and building the piled bridge abutment were reconstructed during centrifuge modelling and measurements of movement were followed in each sequence. From analyzing the results of measuring movements of the model abutment and the ground, measured lateral movement of model abutment was found to be within the allowable value so that stability of abutment against lateral sliding was secured.

This paper is results of analyzing the characteristics of rainfall triggering landslides and geometry of slopes, caused by the heavy rainfall and antecedent precipitation by Typhoons Ewiniar and Bilis at Chuncheon area in Gangwondo around July in 2006. As results of analyzing the characteristics of rainfall, landslides in 131 sites were found to happen due to the heavy rainfall having the maximum intensity of rainfall in an hour during July 15 and antecedent precipitation during July 12 to 14 causing the ground to be weak by increasing the degree of saturation previously. From results of analyzing the geometrical characteristics of 131 slopes where landslides occurred, the slope width were in the range of 6~10m. The average slope length and angle were 46m and $51.8^{\circ}$, which was relatively steep slope, respectively. Landlises occurred in the elevation of 400 - 500 m with the most probable frequency.

Recently, the introduction of iPhone forced Korea to open its mobile market worldwide. The success of iPhone s open and cooperative code and the transition to the software-oriented paradigm also forces Korean mobile industry to greatly change according to the new trend for mobile market. Therefore, in this paper, to cope with such challenges, we investigate the effect of iPhone and then estimate its future prospect. Specifically, we focus on the effect on domestic mobile market, domestic software industry and individual's mobile life.

E-learning has the potentials to provide educational publicity and equality, and has been deployed rapidly in many areas of our society. Growth of e-learning market is also rapid and sustained. However, for e-learning to be a good solution, enough contents should be provided, for which sharing limited contents in the early deployment stage should be necessary. In this paper, we survey some activities about contents sharing. On the other hand, there have been many complaint from e-learning about its effectiveness. Therefore, in this paper, based on the poll results on concentration and satisfaction of e-learning, we also study practical ways to improve studying efficiency of e-learners.

The number of elderly people living alone increases with the trend of nuclear family in recent aging society and advances of health and medical technologies, where the safety of the elderly people becomes a big social issue. One of the safety system for them these days is that security guards regularly visit homes of the elderly living alone to check their safety. However, it is an inefficient system since it costs a great deal. So, a new efficient system with low cost using modern advanced technologies needs to be developed. In this paper, we implement a monitoring system for elderly living alone using ubiquitous sensor and zigbeX. The system can remotely determine the health status of elderly people and report to their hospitals. Since the system can be implemented with low cost and do the same job as security guards do, we expect that it should replace the existing expensive monitoring system.

Three chitinase genes (chiA, chiB, and chiC) were cloned into E. coli by PCR amplification from Serratia marcescens KFRI314. The sizes of cloned chitinase genes were 1692 bp, 1500 bp, and 1443 bp which correspond to 563, 499, and 480 amino acids, respectively. Recombinant chitinases were overexpressed using pHCEIA expression vector and purified to homogenity. The molecular weights of chitinases were about 60kDa, 50 kDa, 52 kDa, respectively. Optimum pHs were around pH 5~6 and optimum temperatures were $45{\sim}50^{\circ}C$ while 90% of enzyme activities were stable up to $50^{\circ}C$. The specific activities of ChiA, ChiB, and ChiC were 233.1, 278.8, $111.3{\mu}mol\;(min)^{-1}\;mg^{-1}$ against colloidal chitin. From experiments using TLC and fluorescent substrate analogues, it was demonstrated that ChiA was endo-chitinase while ChiB and ChiC were chitobiosidase.

Chitinolytic activity was enhanced by coexpression of endo-chitinase gene (chiA) and chitobiosidase gene (chiB) from Serratia marcescens KFRI314 using constitutive expression vector, pHCEIA, in E. coli. Coexpression vector was constructed by inserting ribosome binding site (RBS) into junction between two chitinase genes. SDS-PAGE analyses showed that two chitinase were constitutively expressed while E. coli clones expressing two chitinases simultaneously increased halo size on colloidal chitin plate. Furthermore, the chitinolytic activities were much enhanced in coexpressed clones when degradation patterns of substrate analogues such as 4-MU-(NAG), $4-MU-(NAG)_2$,$4-MU-(NAG)_3$ were used. Consequently, the combined use of endochitinase and chitobiosidase greatly increased overall chitinolytic activities on recombinant E. coli clones.

This paper presents the development of LED street light lamp which is controled by central command system. This system includes a lamp unit controller, data repeater and command repeater as well as the LED lamps. These devices enable the individual power control and partial on/off control of the LED lamps by the control repeater through full duplex communication line. Also, they have the ability to control the brightness and period of on/off timing by detecting the car's existence. As a result of this development, it is founded that the performances of the system have been satisfied to apply for the actual road test.

Generally, the accuracy of the prediction of flood elevation is difficult to identify due to the sedimentation on a river bed, earth and sand being moved by flow, and localized torrential downpours caused by climate change. It is also because of natural and artificial influences on rivers. To predict river floodings successfully, more precise and reliable flood elevation prediction system is needed, in which the concentration time of downstream is numerically interpreted through analyzing and utilizing the watermark of the upper region. Therefore, this research analyzed the prediction methods of the changes in water levels, which use the watermarks of the upper region. The watermarks which impacts the spot being predicted of flood was selected through floodgate analysis and correlation analysis. With the selected watermarks, a statistically reliable regression equation was yielded.

Recently, there has been enormous damage due to river floodings caused by localized heavy rains. The direct discharge triggered by those torrential rains inflicts severe property damage on the residents of nearby areas. To minimize the possibility of river floodings in case of heavy rains and to predict the possible damage, the management of existing rainfall and water level observatories should be checked and prediction methods based on the characteristics of water usage and floodgate of nearby rivers must be further analyzed. Therefore, this research analyzed the water level change predictions on different spots with a regression equation of rainfall and water levels, using the observation data of the water level observatory in Jeongseon-gun, Gangwon Province and the rainfall observatory which are located on the upper region of the Han river.

This study was intended to estimate the soil runoff at the basin of Mandaechun where the measure needs to be taken to deal with the increasing muddy water resulting from soil runoff during wet season and torrential rain at the high reaches of the Soyang lake where highland vegetables are cultivated and soil replacement for improvement is carried out every two to three years. The study was carried out in such a way of identifying the topographic factors using geographical spatial data from Water Management Information System (WAMIS) and ARC-VIEW program and estimating the soil runoff by rainfall frequency using Revised Universal Soil Loss Equation (RUSLE), and furthermore, evaluating the soil runoff contribution at the basin of Mandaechun based on estimate of the soil runoff by section.

Unlike the general lighting systems, stage lighting system requires accurate dimming control and reduction of flicker phenomenon. In this paper, we studied PWM dimming control and linear voltage level control methods. PWM Dimming is easy control and flicker phenomenon of linear voltage level dimming does not happen by experiment result. We concluded that stage lighting dimming system required to combine two techniques of the PWM and linear voltage level dimming control method.

In this paper, We proposed remote dimming control system for Light Emitting Diode(LED) street light using Power Line Communication(PLC). LED will be used widly by indoor or outdoor lighting because of semi-permanent life and environment restriction. For energy saving of street light, the dimming control system is very necessary and the PLC is a very efficient technique. Thus, in this paper we proposed the remote dimming control system for LED street light using PLC. A performance of the proposed system was validated by experimental results.

LC-3 is an educational microprocessor for processor logic design, instruction execution fundamentals, and assembly language programming. This paper presents an IDE software, LIDE (LC-3 Integrated Development Environment), which integrates assembly program editor, LC-3 assembler, and LC-3 simulator.

The influences on water quality of each river by effluents from environmental facilities $located^{*}$ in 14 unit watersheds of North- and South-Han River, and Gyungan-cheon were analyzed. Also, the water quality modeling for study area was carried out to analyze the improvement effect of water quality by the strengthening of T-P effluent standard of environmental facilities. For the calibration and verification of model, water quality data and effluent loading calculated for 2006 were used. Data of low water period were used for calibration, and normal water period for verification. The results of calibration and verification were well matched with the real water quality dataset of revers. Also, the validity of the results were estimated using RI (Reliability Index) method. When the T-P effluent standards for environmental facilities were strengthened, T-P concentrations were predicted to improve from $0.025mg/{\ell}$ to $0.023mg/{\ell}$ in the outlet location of North-Han River, from $0.056mg/{\ell}$ to $0.040mg/{\ell}$ for South-Han River,and from $0.233mg/{\ell}$ to $0.146mg/{\ell}$ for Gyungan-cheon. Also, the T-P concentrations of tributaries including Jojong-cheon, Dal-cheong, Sumgang, Chungmi-cheon, Bokha-cheon, Heuk-cheon, and Wonju-cheon were predicted to improve from $0.063mg/{\ell}$ to $0.010mg/{\ell}$, from $0.091mg/{\ell}$ to $0.053mg/{\ell}$, from $0.199mg/{\ell}$ to $0.100mg/{\ell}$, from $0.168mg/{\ell}$ to $0.148mg/{\ell}$, from $0.186mg/{\ell}$ to $0.105mg/{\ell}$, from $0.019mg/{\ell}$ to $0.013mg/{\ell}$, and from $0.822mg/{\ell}$ to $0.236mg/{\ell}$, respectively.