In IEEE 802.16j standard document, two modes about usage of RS are proposed; one is transparent mode to enhance data throughput and the other is non-transparent mode to extend coverage. In this paper, we focus on non-transparent mode and find that the mode also affects data throughput. We analyze data throughput on various RS topology and their extended coverage area in non-transparent mode. From the analysis, we see that higher throughput can be obtained when MR-BS and RS are located distantly.

In this paper, we investigate maximum transmission capacity of wireless ad-hoc networks. In the investigation, we consider a network topology with regularly located nodes. For the topology, we investigate the maximum transmission capacity with RTS/CTS medium access protocol, and next, we study the maximum transmission capacity without the protocol. We see that the results of our study overall follows the result of Gupta and Kumar's research.

For emergency patients as heart disease, fast treatment is very important. This paper describes a smart phone software to detect emergency circumstance and request rescue. Detection of emergency condition of heart disease patients is based on physical motion and biological heart signals as electrocardiogram. Most smart phones have three axis acceleration sensor. On emergency condition, patients remain stationary. Thus the software detect stationary condition by using acceleration sensor data. For more precise detection, it combines electrocardiogram of patients. To request rescue, it sends help messages to designated persons. In addition, it generates emergency sound to surrounding people and plays a video of emergency measure that any person on the place can help the patient temporarily.

The characteristics of floc formation of the iron(Fe) ions contained in the acid mine drainage was studied for developing the process treating the acid mine drainage. The iron(Fe) ions were formed into flocs by the acid-base reaction with the added $Ca(OH)_2$. The molal ratio of iron(Fe) vs $Ca(OH)_2$ was one of major control variables in treatment; pH change, iron(Fe) ions concentration in treated drainage, DO (dissolved oxygen content). In addition, the air gave much effect on the color of the $iron(Fe)-Ca(OH)_2$ flocs and the attachment to magnet. The attaching to the magnet of the flocs formed in the air was much less than the case without air.

We demonstrated the viability of fully microfabricating SWCNT(single-wall carbon nanotube) film strain sensors for force and weight sensing. Our spray-deposited SWCNT film strain sensors showed good linearity over a range from 0 to 400 microstrain, and much higher sensitivity compared to commercial metal foil-type gauges. The number of grids and the thickness of the SWCNT film were found to have a significant effect on the strain sensing properties of the SWCNT film gauges. A strain sensing methode for the CNT-based strain gauges was also investigated using a binocular type beam load cells. Preliminary results indicate that the microfabrication method shown here is promising for developing a commercial strain gauge using a spray-coated SWCNT thin film. In the near future, various studies will be performed to further enhance the properties of the spray-coated SWCNT film strain sensors.

We present a novel non-dispersive infrared (NDIR) $CO_2$ gas sensor with a light source emitting collimated light. Using this thermopile, we also have successfully developed a small, sensitive NDIR $CO_2$ detector module for accurate air quality monitoring systems in energy-saving building and automotive applications. The novel sample cavity comprising specular reflectors around the light bulb is configured to uniformly emit collimated light into the entrance aperture of the cavity in order to enhance the sensitivity of NDIR $CO_2$ detector.

In this paper the digital control scheme of interleaved PFC for 3-phase modular UPS is presented. The interleaved PFC is composed of two identical PFC connected in parallel and each PFC is controlled by the interleaved switching signals which have the same switching frequency and the $180^{\circ}$ phase difference. As a consequence of the interleaving operation, the Interleaved PFC exhibits both lower current ripple at the input side and lower voltage ripple at the outside. Therefore, the switching and conduction losses as well as EMI levels can be significantly decreased. Simulation and experimental results verify the usefulness of the interleaved PFC.

Currently, we only estimate the average flood water level by the cross-sections of the river using one-dimensional numerical analysis when establishing the basic plans. However, the reliability decreases when it comes to the river bend. In river bend, the difference of water-level between the inside and the outside of the river arises by centrifugal force. And it is estimated less than what it could be estimated when establishing the plan with average estimate of flood level. It is apprehended that the exterior of the river will be under-constructed when establishing the scour depth only with the mean depth. In the case of local scour of the abutment, it is difficult to estimate its depth precisely, and it tends to be over-estimated in the case of the empirical formulas. Therefore, the modification considering the deviation of the water depth of the exterior of the river bend is needed. In observing the deviation of each formula in river bend, it is found: Andru's formula for 58%, followed by the Laursen's for 26%, and the C.S.U's for 17% in pier, while it is 44% for Froehlich's formula in abutment. Under the 500CMS of the flood discharge, the deviation of the scour depth between pier and abutment was about 10 %. However, in further flood discharge, it shows 24~58% the biggest in deviation of piers. It is concluded that the scour depth estimate should be done with 2-dimensional numerical analysis.

In order to examine the tailorability of advanced sewage treatment of a separated sewer pipe, we observed the quality of leaked water in a reactor. A2C affiliation and MBR affiliation decreased by over 78% in cases of BOD, COD, and SS. SBR affiliation decreased by 79.1% in a case of T-N. Overall, the efficiency of T-N on the above affiliations was low. SS had the high efficiency in MBR affiliation. In the end, examination of water quality improvement showed that the quality was improved from 20% to 90%; hence, it is expected that this treatment can protect the water resources of the Hongcheon River and makes it easier to use the water of the river.

Carboxy-guns are used for rapid and precise injection of $CO_2$ gas to the target skin area using external power source. In the design of carboxy-gun, the most important thing is how to precisely control injection volume of $CO_2$ gas. This paper deals with the control scheme of injection volume of carboxy-gun using solenoid valve. First the amount of volume that passes through the solenoid valve under on-off time ratio control is estimated based on the assumption of compressible gas flow. The flow rate of gas is experimentally measured under the varying pressure of the gas reservoir. Two results showed good correlation to each other, thus demonstrating the validity of the volume control strategy.

In this paper, reviews and analyses of literatures related to characteristics and status of disaster occurrence in steep slopes in Korea, its maintenance and regulations and laws about maintenance of slopes in abroad were carried out to propose the measures of regulation reform for disaster reduction in steep slopes. The regulation on disaster prevention in steep slopes (National Emergency Management Agency, 2007), the most effective and systematically arranged regulation out of the currently practicing regulations, was introduced to understand the overall and contents of this regulation. Therefore, problems related to disaster reduction in steep slopes from institutional, technical and financial points of view respectively were raised and their improving measures were proposed to treat the problems effectively and actively.

In this paper, centrifuge model tests and numerical analysis on the breakwater structure were performed to investigate the stability and behavior of breakwater in field. In centrifuge model tests, construction sequence of breakwater structure such as preparation of weathered rock and sand deposit, construction of D.C.M, rubble mound with crushed stones and installment of breakwater structure was reconstructed like field condition and the behavior of ground settlement and breakwater displacement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of breakwater due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge model tests with respect to the behavior of structure as well as ground.

For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation(CRS) test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. As results of numerical method, the volumetric ratio and reclamation velocity were obtained for the reclamation condition.

To advance luminance efficiency of Titania at visible range, N-doped $TiO_2$ was prepared by using ammonium hydroxide as a source of nitrogen. The photoactivities of the synthesized $TiO_2$ were evaluated on the basis of degradation of humic acid in aqueous solutions with different light sources, UV-C, UV-A and fluorescent lamp. As a result, at UV-C is high efficiency $UV_{254}$ decrease and TOC removal. In this study, the best synthetic conditions of N-doped $TiO_2$ were 5.0 M of ammonium hydroxide concentration and calcination temperature of $550^{\circ}C$. The degradation rate of humic acid as an evaluation of photoactivities of the catalysts were conducted with pH variation, decrease rate of molecular absorption, removal rate of total organic carbon and fluorescece evolution for humic acid solution. XRD and SEM were applied for analysis of surface analysis of the catalysts.

Due to improvement of the semiconductor technology, the LED replaces the conventional lighting source and LED drivers have been studied and developed. The LED is driven by the constant current control method according to its characteristics. For the constant current control method, the linear regulator and the switching regulator is used. The switching regulator is usually used to LED drivers because it has specific characteristics as the wide input dynamic range and the high efficiency. In this paper, we have described the principle and the implement of the switching regulator, using the drive IC and the low cost DSP chip. Also, both methods have been implemented and its electrical characteristics had almost same experimental results in the steady state and the transient state.

In this paper, We studied LED(Light Emitted Diode) sensor lights system using PIR(Pyroelectric Infrared Ray) sensor, CdS and MCU(Micro Controller Unit). And applied the valley fill circuit to improve the power factor. We designed the amplifier for each sensor and the LED driver for constant current which is the buck converter. Also, we proposed the algorithm of LED control by each sensors using MCU. Experimental results showed that power factor is 92% with valley fill circuit.

Recently, there are a lot of papers in order to replace the electrolytic capacitor into the film capacitor in output of PFC(Power Factor Correction). However, the film capacitor, which has capacitance of low values, causes a large ripple voltage in output of PFC. The LED drivers are connected series in the output of PFC and affected by the magnitude of voltage ripple. In this paper, we have compared the fixed frequency method with the variable frequency for the constant-current control and propose the control method to avoid the sub-harmonic oscillation in the variable input voltage. An 80W PFC, using film capacitors instead of electrolytic capacitors, and LED driver has been built and compared the fixed frequency control method with the variable frequency control method.

Diamond-like carbon(DLC) thin films with interlayer were deposited on silicon substrate using a reactive sputtering method. The thermal stability of the films was investigated by annealing the films for 1hr in air in the range of 100 to $500^{\circ}C$. The $I_D/I_G$ ratio increased with increasing temperature as related to the $sp^3-to-sp^2$transition. Accordingly, G-position shifting started from $150^{\circ}C$ in the DLC films and from $270^{\circ}C$ in the a-Si/DLC films. Moreover, in the case of the a-Si/DLC films the film still observed even after annealing at $500^{\circ}C$. The thermal stability of the reactive sputtered DLC films appeared to be improved by the a-Si interlayer.

In this paper, we proposed a prioritization method of test cases using a value estimation model of test sets, that are key elements for highly effective software testings as well as involve a large cost factor in software developments and maintenances. Based on previous studies, our idea includes introducing some practical factors of the test case prioritization which critically influence the value of a test case: Relative values of test sets before and after the test running, Average value of these two relative values, Severity of the defect, Risks that are covered, Frequency of use, Change related values, Systematic elicitations, etc. Finally we discussed the usefulness and the expected effects of the proposed scheme.